Abortion The Deliberate Termination of a Human Pregnancy...

What is Abortion? Abortion is the deliberate termination of a human pregnancy. Or a more political way of describing abortion is, the intentional termination of a pregnancy after conception. Giving women the right to conscientiously put an end to their pregnancies, in essence, is allowing them to kill the undeveloped embryo (fetus), which makes it a very controversial subject in American politics. I disagree with abortion. I think that no matter when you terminate, it is still killing a possible life; a life that is not theirs to give. Pro-life advocates, as well as many scientists, feel life starts at conception. If this is the case, abortion is akin to murder, which is the act of taking a human life. In our country, the rights of all†¦show more content†¦If the future mother thinks she is not old enough or can’t handle the new baby, then she has the option to give it up for adoption. In that situation, everyone wins. There are 1.5 million families wanting to adopt a child. So, there is no argument that abortion solves the problem of an â€Å"unwanted† child. Finally, an abortion can also result in medical conditions later in life and make it more likely to have a miscarriage in a woman’s subsequent â€Å"wanted† pregnancies. This becomes heartbreaking to women who have to live with the consequences of their youth. Whether you are for abortion or against it, there is one thing we all can agree upon; when a woman is pregnant there IS something in her in existence. If there wasn’t anything in the womb, there would be no point of the abortion. It is also fact, all humans come from that â€Å"something.† The controversial subject we cannot agree upon is when does that something become â€Å"us?† More importantly, when does this â€Å"something† actually become a human with civil rights under the constitution? I believe it is from the beginning. When the changes are being set in a women’s body, this is when a little human life is beginning to be created. Birth is only an environmental change. Yo u take the baby out of the womb, â€Å"changing the environment.† Cutting the umbilical cord only changes the way the baby breathes. Many people have a strongShow MoreRelatedAbortion : The Deliberate Termination Of A Human Pregnancy937 Words   |  4 PagesAccording to the Oxford dictionary, abortion is â€Å"the deliberate termination of a human pregnancy, most often performed during the first 28 weeks.† In 1973, Roe v. Wade, a major court case, made abortion legal after it was illegal. Justice Harry Blackmun ruled that abortion was supported under the United States Constitution and it violated the first, fourth, ninth, and fourteenth amendments, which all discuss privacy (pbs.org). No country should recognize abortion as a legal act because it is murderRead MoreAbortion, â€Å"The Deliberate Termination Of A Human Pregnancy,1379 Words   |  6 PagesAbortion, â€Å"the deliberate termination of a human pregnancy, most often performed during the first 28 weeks of a pregnancy†. Abortion may be one of the most personal decision one has to make; however, it is widely talked about. While, there are two sides to this agreement. The first, being that a fetus is a human; therefore, abortion is murder. On the other hand, it is the women’s body, so what she wants to do is her choice. However, no matter what your personal opinion is, nobody should have a sayRead MoreAbortion Is The Deliberate Termination Of A Human Pregnancy2966 Words   |  12 PagesAbortion is the deliberate termination of a human pregnancy, most commonly performed during the first seven months of pregnancy (Merriam-Webster.) It is often regarded as a taboo subject because of its political and religious inclination. Though it is considered distasteful to talk about, abortions are still an ongoing event in the world around us. Many people choose to believe that this is a new subject of interest, but really abortions have taken place for thousands of years. As of late, they haveRead MoreAbortion : The Deliberate Termination Of A Human Pregnancy1454 Words   |  6 PagesAbortion: the deliberate termination of a human pregnancy, most often performed during the first 28 weeks of pregnancy. An abortion that occurs spontaneously is also known as a miscarriage. If a abortion is cause purposely it is known as induced abortion or less frequently called induced miscarriage. It can be very dangerous and cause very severe pain. The parent can choose between a surgical or medical abortion in the first couple weeks of the pregnancy. Many people do not know but a baby’s lifeRead MoreAbortion Is The Deliberate Termination Of A Human Pregnancy874 Words   |  4 Pages â€Å"God would not approve of abortions!† â€Å"If a woman has an abortion, she is a MURDERER.† â€Å"Why get pregnant if you do not plan to keep the baby?† â€Å"Abortions are dangerous. You are killing a child!† In our society, abortion is one the most controversial debated topics today. What is abortion? Abortion is the deliberate termination of a human pregnancy. Pro-life activists believe in a woman should not have an abortion due to reasons such as religion, in the eyes of God, or â€Å"the killing† of a fetus.Read MoreAbortion Is The Deliberate Termination Of A Human Pregnancy Essay1041 Words   |  5 PagesWhat is Abortion? Well abortion is the deliberate termination of a human pregnancy, most often performed during the first 28 weeks of pregnancy, although it may be done in the third trimester. Third trimester abortion is illegal in many countries. Many things come along with this procedure Psychologically and physically. This is a big choice to make in life. Many people are against abortion, and many are all for it. Personally I am against it, but we are not here to discuss my personal beliefs. EveryRead MoreThe Right And Life Of Abortion1246 Words   |  5 PagesSender. Abo rtion is defined in the Merriam-Webster dictionary as â€Å"the deliberate termination of a pregnancy and is most often preformed during the first 28 weeks of pregnancy.† Beginning early on in history, abortions were viable solutions for immigrants, as their pregnancy rates were higher than the natives of an area or region. As timed passed, laws on abortion began to create a war on the separation of Church and State. These issues have yet to suppress. The Catholic Church defines abortions as â€Å"theRead MoreUnder What Circumstances is Abortion Acceptable? Essay541 Words   |  3 PagesAbortion by google definition is a deliberate termination of ta human pregnancy. This, in fact, is a termination of a human life and should be deemed as murder. Abortion is a severely understated reality of the disregard and disrespect of human life. I believe that every human life should be treasured and respected, I feel abortion diminishes the meaning of life. There is a clear indication in science that like begins at conception. The fusion of the zygote is where human life beings, each zygoteRead MoreAbortion Is Not Forbidden Within The Bible1393 Words   |  6 PagesIt is estimated almost half of pregnancies in Australia are unplanned . Unexpected pregnancies happen for various individual, social, economic and political reasons . The World Health Organisation (WHO) approximates one in three women in Australia will an abortion procedure in their life . Abortion data is only gathered by South Australia, Western Australia and the Northern Territory. However, South Australia is the only state to publish data and report findings annually. Religion vs EthnicityRead MoreThe Termination Of A Life845 Words   |  4 PagesTermination of a life is a very disputable issue that one could stimulate an enormous amount of emotions on both sides of the fence. Many that are against women having an abortion would call it murder, and condemn the woman for playing God. The fact of someone taking life in their own hands, of judging who lives and who dies is unacceptable is one side of the disagreement. The other side is the pregnancy dangerous for the mother or the child to come to full term, this constitutes a medical emergency

Child Abuse - 3642 Words

Child Abuse Abstract Thousands of children are abused every year and most of the time by members of their own families. A recent study carried out by the WHO estimated 1,273,000 children in America had been victims of some form of abuse in the year 1984. This report was based on projected or actual figures which were supplied by the official state liaisons for child abuse and neglect. It suggested a noticeable increase in the number of cases, up from an estimated 1,007,000 in 1981. The figures are frightening, however, they do point to a new found awareness about the tragedy of child abuse. A problem that has long been kept secret is now being uncovered. In this paper; types of child abuse, legal mandates, its risk factors and causes, effects, diagnosis, treatment and prevention are discussed. Child Abuse Introduction Child abuse is one of the most increasing social problems nowadays all over the world. Few issues generate the concern, anger, and frustration as the abuse or neglect of children. According to data from the US Department of Health and Human Services, six million children have been abused and neglected in the year 2009 and majority of these children needed action right away (US Department of Health and Human Services 2010). Legal Mandates A relatively new concept, child abuse has been recently designated as a serious public health concern (Barriere, 2005). Both federal and state agencies have created definitions for child abuse. TheShow MoreRelatedChild Abuse1247 Words   |  5 PagesDiscipline, Child Abuse? Many people have noticed that parents are starting to get more frustrated with with their lives and are taking it out on their children. Parents start to under think their actions and instead of disciplining their children, they are abusing their children. There are many precautions that should be taken when dealing with situations like these. Many experiments can be done in order to determine if abuse is taking place in the home. In order to determine child abuse, authoritiesRead MoreChild Abuse1545 Words   |  7 PagesRunning head: CHILD ABUSE Title- Child Abuse SENTENCE OUTLINE TOPIC: Child Abuse TOPIC SENTENCE: Child abuse is any act or inaction on the part of a parent or caregiver on a child 18 years and under. THESIS STATEMENT: The UK Guidance working together to safeguard children 2010, says that, child abuse constitutes of neglect, emotional, physical, and sexual abuse. SUB TOPICRead Morechild abuse1271 Words   |  6 Pages Child Abuse Research Paper Most parents and other caregivers do not intend to hurt their children, but abuse is defined by the effect on the child, not the motivation of the parents or caregiver.Tens of thousands of children each year are traumatized by physical, sexual, and emotional abusers or by caregivers who neglect them.Child abuse as common as it is shocking. Most of us can’t imagine what would make an adult use violence against a child, and the worse the behaviorRead MoreChild Abuse1921 Words   |  8 Pagesor Outside: How Safe is my Child? 23/1/13, ICG A very good morning to all of you and a warm welcome to this seminar on ‘At Home or Outside: How Safe is my Child?† Thank you for sparing your valuable time to be here to discuss and deliberate on an issue that is slowly making our society hollow and will cause a major collapse of all value systems if timely action is not taken. It can be very difficult to talk about child abuse or more specifically child sexual abuse, which we are discussing todayRead MoreChild Abuse And Domestic Abuse1636 Words   |  7 Pagesin life that while not yet adults they are not quite children either. A factor that creates violent and aggressive adolescents includes being exposed to child abuse and domestic abuse. Moylan, T. Herrenkohl, Sousa, Tajima, R. Herrenkohl, and Russo (2010) look at the relationship between those who were exposed to either child abuse, domestic abuse, or both and the outcome of aggressive adolescents. Families were first assessed when children were in preschool, eighteen months to six years old. The secondRead MoreChild Abuse And Child Maltreatment918 Words   |  4 PagesThere are many types and faces of child abuse and child maltreatment in the world today that go unknown. This leaves many of our children unprotected to physical, sexual or emotional abuse, and neglect by parents. The problem is how are dealing with the violence against children inside and outside the home and with their f amily. Physical, sexual, emotional abuse and neglect are types of abuse, which I and have a deep concern. Too many of our children today are been abused, neglected, and killedRead MoreThe Effects Of Abuse And Child Abuse2622 Words   |  11 PagesNassau, New York, homicide squad, after finding three young children dead in their bed after their mother had killed them. (Qtd. In Juettner 12). Abuse doesn’t just affect children, it affects adults too. While many cases of abuse are reported, there are still many that go unreported. Abuse and child abuse is not something to be taken lightly, even after the abuse has been stopped there are long lasting effects. Could you imagine being abused by someone you thought loved or cared about you? According toRead MoreHistory of Child Abuse1113 Words   |  5 PagesHistory of child abuse BSHS/408 February 15 2016 Chiffone N Shelton Abstract In order to discuss child abuse and neglect it is important to have a clear understanding of what child abuse and neglect is and the different form of child abuse. How the various types of child abuse and neglect are different from one another, ill-treatment of children comes in many forms, physical abuse, sexual abuse, emotional ill-treatment, and child neglect. Child neglect comes in many forms and occurs whenRead MoreThe Problem Of Child Abuse1055 Words   |  5 Pagesyounger ones is child abuse. â€Å"In 2009, the child protective services across the country received 3.3 million reports of child abuse. The farther the child protective services would investigate they discovered more than 700,000 children that had been abused or mistreated.† (Kauchak and Eggen 51) The U.S Congress in the Family Services Act of 1988 came up with a definition of all types of abuse. (Mufson and Kranz 26) There is neglect, emotional, sexua, and physical abuse. â€Å"Over than 78% of abuse vict ims sufferRead MoreChild Abuse Essay1749 Words   |  7 PagesLauren Arnold 3rd hour Mrs. Williams Effects of Abuse on Babies, Infants, and Toddlers Later in Life The causes of child abuse on infants, babies, and toddlers are catastrophic. There are several people who get abused from infancy to adultance. Each person who gets abused and survives the trauma is left with devastating memories. Many abused children come from homes that are disturbed, chaotic, and violent. (Markham). A child who has been abused is more likely to grow up into an angry teenager

Logical and Physical Data Models Free Essays

The Physical Data Model (PDM) describes how the information represented in the Logical Data Model is actually implemented, how the information-exchange requirements are implemented, and how the data entities and their relationships are maintained. There should be a mapping from a given Logical Data Model to the Physical Data Model if both models are used. The form of the Physical Data Model can vary greatly, as shown in Figure 31. We will write a custom essay sample on Logical and Physical Data Models or any similar topic only for you Order Now For some purposes, an additional entity-relationship style diagram will be sufficient. The Data Definition Language (DDL) may also be used. References to message format standards (which identify message types and options to be used) may suffice for message-oriented implementations. (Getting information from the LDM in form of file) Descriptions of file formats may be used when file passing is the mode used to exchange information. Interoperating systems may use a variety of techniques to exchange data, and thus have several distinct partitions in their Physical Data Model with each partition using a different form. The figure illustrates some options for expressing the Physical Data Model and an other table (in the original document) provides a listing of the types of information to be captured. A physical data model (or database design) is a representation of a data design which takes into account the facilities and constraints of a given database management system. In the lifecycle of a project it typically derives from a logical data model, though it may be reverse-engineered from a given database implementation. A complete physical data model will include all the database artifacts required to create relationships between tables or to achieve performance goals, such as indexes, constraint definitions, linking tables, partitioned tables or clusters. Analysts can usually use a physical data model to calculate storage estimates; it may include specific storage allocation details for a given database system. As of 2012 seven main databases dominate the commercial marketplace: Informix, Oracle, Postgres, SQL Server, Sybase, DB2 and MySQL. Other RDBMS systems tend either to be legacy databases or used within academia such as universities or further education colleges. Physical data models for each implementation would differ significantly, not least due to underlying operating-system requirements that may sit underneath them. For example: SQL Server runs only on Microsoft Windows operating-systems, while Oracle and MySQL can run on Solaris, Linux and other UNIX-based operating-systems as well as on Windows. This means that the disk requirements, security requirements and many other aspects of a physical data model will be influenced by the RDBMS that a database administrator (or an organization) chooses to use. Overview Logical data models represent the abstract structure of a domain of information. They are often diagrammatic in nature and are most typically used in business processes that seek to capture things of importance to an organization and how they relate to one another. Once validated and approved, the logical data model can become the basis of a physical data model and inform the design of a database. Logical data models should be based on the structures identified in a preceding conceptual data model, since this describes the semantics of the information context, which the logical model should also reflect. Even so, since the logical data model anticipates implementation on a specific computing system, the content of the logical data model is adjusted to achieve certain efficiencies. The term ‘Logical Data Model’ is sometimes used as a synonym of ‘Domain Model’ or as an alternative to the domain model. While the two concepts are closely related, and have overlapping goals, a domain model is more focused on capturing the concepts in the problem domain rather than the structure of the data associated with that domain. History The ANSI/SPARC three level architecture, which â€Å"shows that a data model can be an external model (or view), a conceptual model, or a physical model. This is not the only way to look at data models, but it is a useful way, particularly when comparing models†. [1] When ANSI first laid out the idea of a logical schema in 1975,[2] the choices were hierarchical and network. The relational model – where data is described in terms of tables and columns – had just been recognized as a data organization theory but no software existed to support that approach. Since that time, an object-oriented approach to data modelling – where data is described in terms of classes, attributes, and associations – has also been introduced. Logical data model topics Reasons for building a logical data model * Helps common understanding of business data elements and requirements * Provides foundation for designing a database Facilitates avoidance of data redundancy and thus prevent data business transaction inconsistency * Facilitates data re-use and sharing * Decreases development and maintenance time and cost * Confirms a logical process model and helps impact analysis. Modeling benefits * Facilitates business process improvement * Focuses on requirements independent of technology * Facilitates data re-use and sharing * Increases return on inves tment * Centralizes metadata * Fosters seamless communication between applications * Focuses communication for data analysis and project team members * Establishes a consistent naming scheme Logical Physical Data Model A logical data model is sometimes incorrectly called a physical data model, which is not what the ANSI people had in mind. The physical design of a database involves deep use of particular database management technology. For example, a table/column design could be implemented on a collection of computers, located in different parts of the world. That is the domain of the physical model. Logical and physical data models are very different in their objectives, goals and content. Key differences noted below. Logical Data Model| Physical Data Model| Includes entities (tables), attributes (columns/fields) and relationships (keys)| Includes tables, columns, keys, data types, validation rules, database triggers, stored procedures, domains, and access constraints| Uses business names for entities attributes| Uses more defined and less generic specific names for tables and columns, such as abbreviated column names, limited by the database management system (DBMS) and any company defined standards| Is independent of technology (platform, DBMS)| Includes primary keys and indices for fast data access. Is normalized to fourth normal form(4NF)| May be de-normalized to meet performance requirements based on the nature of the database. If the nature of the database is Online Transaction Processing(OLTP) or Operational Data Store (ODS) it is usually not de-normalized. De-normalization is common in Datawarehouses. | A logical data model describes the data in as much detail as possible, without regard to how they will be physical implemented in the database. Features of a logical data model include: * Includes all entities and relationships among them. All attributes for each entity are specified. * The primary key for each entity is specified. * Foreign keys (keys identifying the relationship between different entities) are specified. * Normalization occurs at this level. The steps for designing the logical data model are as follows: 1. Specify primary keys for all entities. 2. Find the relationships between different entities. 3. Find all attributes for each entity. 4. Resolve many-to-many relationships. 5. Normalization. The figure below is an example of a logical data model. Logical Data Model Comparing the logical data model shown above with the conceptual data model diagram, we see the main differences between the two: * In a logical data model, primary keys are present, whereas in a conceptual data model, no primary key is present. * In a logical data model, all attributes are specified within an entity. No attributes are specified in a conceptual data model. * Relationships between entities are specified using primary keys and foreign keys in a logical data model. In a conceptual data model, the relationships are simply stated, not specified, so we simply know that two entities are related, but we do not specify what attributes are used for this relationship. Logical Model Design Physical Model Design Figure 5. A logical data model (Information Engineering notation). You also need to identify the cardinality and optionality of a relationship (the UML combines the concepts of optionality and cardinality into the single concept of multiplicity). Cardinality represents the concept of â€Å"how many† whereas optionality represents the concept of â€Å"whether you must have something. For example, it is not enough to know that customers place orders. How many orders can a customer place? None, one, or several? Furthermore, relationships are two-way streets: not only do customers place orders, but orders are placed by customers. This leads to questions like: how many customers can be enrolled in any given order and is it possible to have an order with no customer involved? Figure 5 shows that customers place zero or more orders and that any given order is placed by one customer and one customer only. It also shows that a customer lives at one or more addresses and that any given address has zero or more customers living at it. Although the UML distinguishes between different types of relationships – associations, inheritance, aggregation, composition, and dependency – data modelers often aren’t as concerned with this issue as much as object modelers are. Subtyping, one application of inheritance, is often found in data models, an example of which is the is a relationship between Item and it’s two â€Å"sub entities† Service and Product. Aggregation and composition are much less common and typically must be implied from the data model, as you see with the part of role that Line Item takes with Order. UML dependencies are typically a software construct and therefore wouldn’t appear on a data model, unless of course it was a very highly detailed physical model that showed how views, triggers, or stored procedures depended on Logical Data Models (LDMs) represent data table (Entity Type) relationships. Logical Data Model Notations Entity Type Entity Type refers to a group of related data placed in an RDBMS (Relational Database Management Systems) table. An entity is an instance of an entity type represented as a single row in a data table. Relationships and Multiplicity Relationships illustrate how two entity types are related. Cardinality specifies how many instances of an entity relate to one instance of another entity. Physical data model represents how the model will be built in the database. A physical database model shows all table structures, including column name, column data type, column constraints, primary key, foreign key, and relationships between tables. Features of a physical data model include: * Specification all tables and columns. Foreign keys are used to identify relationships between tables. * Denormalization may occur based on user requirements. * Physical considerations may cause the physical data model to be quite different from the logical data model. * Physical data model will be different for different RDBMS. For example, data type for a column may be different between MySQL and SQL Server. Steps For Physi cal Data Model * Convert entities into tables. * Convert relationships into foreign keys. * Convert attributes into columns. * Modify the physical data model based on physical constraints / requirements. Physical v/s logical Entity names are now table names. * Attributes are now column names. * Data type for each column is specified. Data types can be different depending on the actual database being used. Data modeling is the act of exploring data-oriented structures. Like other modeling artifacts data models can be used for a variety of purposes, from high-level conceptual models to physical data models (PDMs). Physical data modeling is conceptually similar to design class modeling, the goal being to design the internal schema of a database, depicting the data tables, the data columns of those tables, and the relationships between the tables.      | presents a partial PDM for the university – you know that it isn’t complete by the fact that the Seminar table inclu des foreign keys to tables that aren’t shown, and quite frankly it’s obvious that many domain concepts such as course and professor are clearly not modeled. All but one of the boxes represent tables, the one exception is UniversityDB which lists the stored procedures implemented within the database. Because the diagram is given the stereotype Physical Data Model you know that the class boxes represent tables, without the diagram stereotype I would have needed to use the stereotype Table on each table. Relationships between tables are modeled using standard UML notation, although not shown in the example it would be reasonable to model composition and inheritance relationships between tables. Relationships are implemented via the use of keys (more on this below). Figure 1. A partial PDM for the university. When you are physical data modeling the following tasks are performed in an iterative manner: * Identify tables. Tables are the database equivalent of classes; data is stored in physical tables. As you can see in Figure 1 the university has a Student table to store student data, a Course table to store course data, and so on. Figure 1 uses a UML-based notation (this is a publicly defined profile which anyone can provide input into). If you have a class model in place a good start is to do a one-to-one mapping of your classes to data tables, an approach that works well in â€Å"greenfield† environments where you have the luxury of designing your database schema from scratch. Because this rarely happens in practice you need to be prepared to be constrained by one or more legacy database schemas which you will then need to map your classes to. In these situations it is unlikely that you will need to do much data modeling, you will simply need to learn to live with the existing data sources, but you will need to be able to read and understand existing models. In some cases you may need to perform legacy data analysis and model the existing schema before you can start working with it. * Normalize tables. Data normalization is a process in which data attributes within a data model are organized to increase the cohesion of tables and to reduce the coupling between tables. The fundamental goal is to ensure that data is stored in one and only one place. This is an important consideration for application developers because it is incredibly difficult to stores objects in a relational database if a data attribute is stored in several places. The tables in Figure 1 are in third normal form (3NF). * Identify columns. A column is the database equivalent of an attribute, and each table will have one or more columns. For example, the Student table has attributes such as FirstName and StudentNumber. Unlike attributes in classes, which can either be primitive types or other objects, a column may only be a primitive type such as a char (a string), an int (integer), or a float. Identify stored procedures. A stored procedure is conceptually similar to a global method implemented by the database. In Figure 1 you see that stored procedures such as averageMark() and studentsEnrolled() are modeled as operations of the class UniversityDB. These stored procedures implement code that work with data stored in the database, in this case they calculate th e average mark of a student and count the number of students enrolled in a given seminar respectively. Although some of these stored procedures clearly act on data contained in a single table they are not modeled as part of the table (along the lines of methods being part of classes). Instead, because stored procedures are a part of the overall database and not a single table, they are modeled as part of a class with the name of the database. * Apply naming conventions. Your organization should have standards and guidelines applicable to data modeling, and if not you should lobby to have some put in place. As always, you should follow AM’s practice of Apply Modeling Standards. * Identify relationships. There are relationships between tables just like there are relationships between classes. The advice presented relationships in UML class diagrams applies. * Apply data model patterns. Some data modelers will apply common data model patterns, David Hay’s (1996) book Data Model Patterns is the best reference on the subject. Data model patterns are conceptually closest to analysis patterns because they describe solutions to common domain issues. Hay’s book is a very good reference for anyone involved in analysis-level modeling, even when you’re taking an object approach instead of a data approach because his patterns model business structures from a wide variety of business domains. * Assign keys. A key is one or more data attributes that uniquely identify a row in a table. A key that is two or more attributes is called a composite key. A primary key is the preferred key for an entity type whereas an alternate key (also known as a secondary key) is an alternative way to access rows within a table. In a physical database a key would be formed of one or more table columns whose value(s) uniquely identifies a row within a relational table. Primary keys are indicated using the stereotype and foreign keys via . Read here for more about keys. Although similar notation is used it is interesting to note the differences between the PDM of Figure 21 and the UML class diagram from which is ti based: 1. Keys. Where it is common practice to not model scaffolding properties on class models it is common to model keys (the data equivalent of scaffolding). 2. Visibility. Visibility isn’t modeled for columns because they’re all public. However, because most databases support access control rights you may want to model them using UML constraints, UML notes, or as business rules. Similarly stored procedures are also public so they aren’t modeled either. 3. No many-to-many associations. Relational databases are unable to natively support many-to-many associations, unlike objects, and as a result you need to resolve them via the addition of an associative table. The closest thing to an associative table in is WaitList which was introduced to resolve the on waiting list many-to-many association depicted in the class diagram. A pure associative table is comprised of the primary key columns of the two tables which it maintains the relationship between, in this case StudentNumber from Student and SeminarOID from Seminar. Notice how in WaitList these columns have both a PK and an FK stereotype because they make up the primary key of WaitList while at the same time are foreign keys to the other two tables. WaitList isn’t truly an associative table because it contains non-key columns, in this case the Added column which is used to ensure that the first people on the waiting list are the ones that are given the opportunity to enroll if a seat becomes available. Had WaitList been a pure associative table I would have applied the associative table stereotype to it. Logical Versus Physical Database Modeling * March 14, 2001 * By Developer. com Staff * Bio  » * Send Email  » * More Articles  » After all business requirements have been gathered for a proposed database, they must be modeled. Models are created to visually represent the proposed database so that business requirements can easily be associated with database objects to ensure that all requirements have been completely and accurately gathered. Different types of diagrams are typically produced to illustrate the business processes, rules, entities, and organizational units that have been identified. These diagrams often include entity relationship diagrams, process flow diagrams, and server model diagrams. An entity relationship diagram (ERD) represents the entities, or groups of information, and their relationships maintained for a business. Process flow diagrams represent business processes and the flow of data between different processes and entities that have been defined. Server model diagrams represent a detailed picture of the database as being transformed from the business model into a relational database with tables, columns, and constraints. Basically, data modeling serves as a link between business needs and system requirements. Two types of data modeling are as follows: * Logical modeling * Physical modeling If you are going to be working with databases, then it is important to understand the difference between logical and physical modeling, and how they relate to one another. Logical and physical modeling are described in more detail in the following subsections. * Post a comment * Email Article * Print Article * Share Articles Logical Modeling Logical modeling deals with gathering business requirements and converting those requirements into a model. The logical model revolves around the needs of the business, not the database, although the needs of the business are used to establish the needs of the database. Logical modeling involves gathering information about business processes, business entities (categories of data), and organizational units. After this information is gathered, diagrams and reports are produced including entity relationship diagrams, business process diagrams, and eventually process flow diagrams. The diagrams produced should show the processes and data that exists, as well as the relationships between business processes and data. Logical modeling should accurately render a visual representation of the activities and data relevant to a particular business. Note| Logical modeling affects not only the direction of database design, but also indirectly affects the performance and administration of an implemented database. When time is invested performing logical modeling, more options become available for planning the design of the physical database. | The diagrams and documentation generated during logical modeling is used to determine whether the requirements of the business have been completely gathered. Management, developers, and end users alike review these diagrams and documentation to determine if more work is required before physical modeling commences. Typical deliverables of logical modeling include * Entity relationship diagrams An Entity Relationship Diagram is also referred to as an analysis ERD. The point of the initial ERD is to provide the development team with a picture of the different categories of data for the business, as well as how these categories of data are related to one another. * Business process diagrams The process model illustrates all the parent and child processes that are performed by individuals within a company. The process model gives the development team an idea of how data moves within the organization. Because process models illustrate the activities of individuals in the company, the process model can be used to determine how a database application interface is design. * User feedback documentation Physical Modeling Physical modeling involves the actual design of a database according to the requirements that were established during logical modeling. Logical modeling mainly involves gathering the requirements of the business, with the latter part of logical modeling directed toward the goals and requirements of the database. Physical modeling deals with the conversion of the logical, or business model, into a relational database model. When physical modeling occurs, objects are being defined at the schema level. A schema is a group of related objects in a database. A database design effort is normally associated with one schema. During physical modeling, objects such as tables and columns are created based on entities and attributes that were defined during logical modeling. Constraints are also defined, including primary keys, foreign keys, other unique keys, and check constraints. Views can be created from database tables to summarize data or to simply provide the user with another perspective of certain data. Other objects such as indexes and snapshots can also be defined during physical modeling. Physical modeling is when all the pieces come together to complete the process of defining a database for a business. Physical modeling is database software specific, meaning that the objects defined during physical modeling can vary depending on the relational database software being used. For example, most relational database systems have variations with the way data types are represented and the way data is stored, although basic data types are conceptually the same among different implementations. Additionally, some database systems have objects that are not available in other database systems. Implementation of the Physical Model| The implementation of the physical model is dependent on the hardware and software being used by the company. The hardware can determine what type of software can be used because software is normally developed according to common hardware and operating system platforms. Some database software might only be available for Windows NT systems, whereas other software products such as Oracle are available on a wider range of operating system platforms, such as UNIX. The available hardware is also important during the implementation of the physical model because data is physically distributed onto one or more physical disk drives. Normally, the more physical drives available, the better the performance of the database after the implementation. Some software products now are Java-based and can run on virtually any platform. Typically, the decisions to use particular hardware, operating system platforms, and database software are made in conjunction with one another. | A logical data model describes your model entities and how they relate to each other. A physical data model describes each entity in detail, including information about how you would implement the model using a particular (database) product. In a logical model describing a person in a family tree, each person node would have attributes such as name(s), date of birth, place of birth, etc. The logical diagram would also show some kind of unique attribute or combination of attributes called a primary key that describes exactly one entry (a row in SQL) within this entity. The physical model for the person would contain implementation details. These details are things like data types, indexes, constraints, etc. The logical and physical model serve two different, but related purposes. A logical model is a way to draw your mental roadmap from a problem specification to an entity-based storage system. The user (problem owner) must understand and approve the logical model. A physical model is the roadmap from the logical model to the hardware. The developer (software owner) must understand and use the physical model. ERD Consider a hospital: Patients are treated in a single ward by the doctors assigned to them. Usually each patient will be assigned a single doctor, but in rare cases they will have two. Heathcare assistants also attend to the patients, a number of these are associated with each ward. Initially the system will be concerned solely with drug treatment. Each patient is required to take a variety of drugs a certain number of times per day and for varying lengths of time. The system must record details concerning patient treatment and staff payment. Some staff are paid part time and doctors and care assistants work varying amounts of overtime at varying rates (subject to grade). The system will also need to track what treatments are required for which patients and when and it should be capable of calculating the cost of treatment per week for each patient (though it is currently unclear to what use this information will be put). How to cite Logical and Physical Data Models, Essay examples

Parasitic wasps Essay Example For Students

Parasitic wasps Essay Malaria is one of the most prevalent and dangerous diseases known to man. It has existed for centuries and affects a myriad of people in the tropical region. Even today, with our newly discovered treatments for many of the tropical diseases, over 10% of the people that are infected with malaria each year and do not receive proper treatment die. In Africa alone, over 1 million children die each year because of malaria and new cases are reported frequently. Malaria is very dangerous and harmful to man. However, the protozoan that causes malaria has existed since man came into being. Fossils of mosquitoes that are 30 million years old contain the vector for malaria. After written history, many civilisations have known about malaria. The Greek physician Hippocrates described the symptoms of malaria in the 5th Century BC The name malaria is derived from the Italian words, mal and aria, meaning bad air, because people of earlier times believed that the disease was caused by polluted air near swaps and wetlands in Europe. The scientific identification of malaria was not found until 1880. The French army physician, Charles Laveran, while stationed in Algeria, noticed strange shapes of red blood cells in certain patients and identified the disease scientifically and linked to a certain protozoan. Although the disease had been identified, it was not until 1897, when British army physician, Ronald Ross studied birds and discovered that the malarial protozoan was transmitted through mosquito es. Soon after, two Italian scientists noted that mosquitoes spread malaria to humans as well. Many attempts have been made to try to eradicate the disease. As early as 7 AD, in Rome, swamps were drained to try to prevent the bad air from reaching nearby cities. Recently, in the 1950s and 1960s, about 25 years after the development of DDT, the United Nations World Health Organisation tried to wipe out the disease through the use of DDT. Although, the number of cases was reduces in many areas, they started again. Scientists today believe that malaria can never be eradicated due to the fact that the protozoan can manipulate easily and become resistant to a drug that is overused. The mosquitoes that spread malaria are also becoming resistant to insecticides. Malaria can be treated on an individual basis and treatments and medicines can be used. To understand these treatments however, one must understand what happens to a malarial protozoan. The disease, malaria, is cause by the protozo an, Plasmodium, which lives in tropical regions all around the world. There are only four species of this protozoan that cause malaria in humans, Plasmodium ovale, Plasmodium vivax, Plasmodium malariae, and Plasmodium falciparum. These protozoans are spread from infected to healthy people through the bite of the Anopheles mosquito, blood transfusions, or through hypodermic injections. This makes malaria one of the most easily communicable diseases in the world. These enter red cells where both sexual and asexual cycles continue. Malaria is spread only through the females of the 60 different types of the Anopheles mosquito, as the males do not feed on blood. The symptoms of this disease are many, however a physician must be consulted to avoid risk to a person. To treat malaria, many drugs are used today. Forms of these drugs date back to the 1500s and 1600s. Physicians diagnose malaria by identifying Plasmodia in a patients body. Once identified, malaria can be treated with chloroquine and primaquine. Since some forms of Plasmodia falciparum have become resistant to these, quinine, mefloquine, or halofautrine are used. Almost all of the cases of malaria can be treated if done in the proper way. However, to suffer the pain and illness of malaria, people can use many preventive measures. All swampy areas must be avoided as well as tropical water that may be contaminated or local food. People should just protect themselves from mosquitoes and risk of infection will be tremendously lowered. This can be done by im pregnated bednets. These involve surrounding the bed with a curtain that is sprayed with certain compounds. These are normally pyrethroids or organophosphates, which create an effective barrier between the mosquito and its blood meal. Alternative barrier methods are insect repellents. These are certain chemicals that that when applied to the skin as a spray or lotion is quite effective at deterring the mosquito from landing on a person in order to feed. Other methods of controlling malaria are the use of insecticides and vaccines. Insecticides are chemicals such as pyrethrum, which are sprayed within persons living quarters. This was thought to kill the female mosquito preventing it from spreading malaria and laying further eggs as long as it had no means from escaping the room before spraying. Vaccines work by stimulating antibody production to destroy a foreign organism in the body. As the foreign organism has the same surface antigens as the pathogenic organism, the antibody that the body produces to destroy the antigenic material in the vaccination will be equally as effective against the pathogenic organism. The lymphocytes that produce the antibody will remain in the blood stream. When the pathogenic organism enters the body the lymphocytes will be triggered to produce the antibody in order to destroy the invading organism. At the moment this is where a lot of malaria research is centred in trying to produce a malaria vaccine. Man evolved as a hunter-gatherer, with populations of low densities compared with other primates. At these low densities man would not have been the preferred host of many parasites, but would have experienced malaria as a zoonosis. It is postulated that the development of agriculture around 10,000 to 7000 years ago resulted in man made changes in nutrition, the environment and population density. These changes are so recent in genetic terms that the species has not adapted. The success of our species, expressed as population expansion, has been at the cost of widespread disease, of which malaria related diseases are common manifestations. The burden is heaviest on pregnant women and children under five years old. Over 8 million of the 13 million under-five deaths in the world each year can be put down to diarrhoea, pneumonia, malaria, and vaccine-preventable diseases. But this simple way of classifying hides the fact that death is not usually an event with one cause but a process with many causes. In particular, it is the conspiracy between malnutrition and infection, which pulls many people into the downward spiral of an early death and poor growth in children. Now, a new study has attempted to quantify the role of malnutrition in child deaths. Using data from 53 developing countries, researchers from Cornell University have concluded that over half of those 13 million child deaths each year are associated with malnutrition. Further, they show that more than three-quarters of all these malnutrition-assisted deaths are linked not to severe malnutrition but to mild and moderate forms. This suggests that nutrition programmes focusing only on the severely malnourished will have far less impact than programmes to improve nutrition among the much larger number of mildly and moderately malnourished children. As discussed in the 1994 edition of The Progress of Nations, low-cost methods of reducing all forms of malnutrition are available and have been shown to work. And action on both fronts to improve nutrition and to protect against disease could save many more lives (and be far more cost-effective) than action on either front alone. Malnutrition receives few banner headlines, like the AIDS crisis does. There is no excuse for starvation, with technology and science making food as plentiful as it is. Yet famine and malnutrition are not the same thing. Many of these children may be getting food. But what are missing are the nutrients they need to grow into healthy and productive adults. A report by UNICEF indicates that at least 100 million young children and several million pregnant women have damaged immune systems not because of HIV or AIDS, but because of malnutrition It is thought that malaria can be prevented and risk of infection lowered with varies nutritional aspects. These include minerals such as Iron, zinc and Vitamins A, C, D, E, antioxidants, fatty acids and carbohydrates. Over the years, as the control of diseases such as malaria has improved, the significance of malnutrition has emerged more clearly. There is a need to understand its cause to ensure secure foundations for schemes of prevention, and thus preventing disease. Nutrition and many tropical infections such as malaria interact, not just because of extensive geographical overlap between areas where malaria occur or nutrient deficiencies are common. The clinical and public health implications and the range of such interactions are becoming increasingly appreciated. It is evident that in many countries malnutrition is responsible for the high mortality in children along with disease. It is with children and pregnant women particularly that most of the research with nutrition and malaria has been done. Malaria is truly a grave problem and could affect any ignorant person. However, if a person takes certain precautions and does not get involved with insects, they might just be safe from being one of the 300,000,000 people who are infected each year, or even worse, one of the 1,500,000 people that die of malaria annually. Most people are familiar with the Recommended Daily Allowances (RDA) for vitamins and minerals that have been established by the Food and Nutrition Board of the National Research Council. The RDA is defined as the level of intake of an essential nutrient that is judged to be adequate to meet the known needs of healthy people. At these levels, in other words, people should not develop the deficiency illness associated with a lack of that nutrient. The RDA does not apply to people with special nutritional needs, nor does it suggest that these are the optimal dietary levels for these nutrients for normal people. We now know that mild to moderate deficiency of basic nutrients, while not causing the classic deficiency illnesses, may contribute to a host of other illnesses, especially in todays world, where stress and poor lifestyle habits may tax the bodys nutritional resources. Scientific data suggest that the consumption of many nutrients above the RDAs may prevent or combat many common illnesses. Vitamin C60 mgcitrus fruits, strawberries, tomatoes, cantaloupe, broccoli, asparagus, peppers, spinach, potatoesVitamin E30 IUvegetable oils (soy, corn, olive, cottonseed, safflower, and sunflower), nuts, sunflower seeds, wheat germ. Beta Carotene15-50 mgdark green, yellow, and orange vegetables including spinach, collard greens, broccoli, carrots, peppers, and sweet potatoes; yellow fruits such as apricots and peaches. (IU = international units; mg = milligrams)Investigations into interactions between nutrient status and infectious disease are seriously complicated by the difficulties of assessing status of many nutrients during the acute phase response to infection. Many nutrients are acute phase reactants for example, plasma retinol, zinc and iron and the degree of transferrin saturation all decrease, and plasma copper and ferritin and erythrocyte protoporphyrin increase, in response to infection or trauma (Filteau, S M, and Tomkins, A M, 1994). There is an urgent need for research into nutritional assessment of infected individuals and populations since these are frequently the people whose nutritional status is of most concern. The consistent alterations of micronutrient metabolism suggests that these may have advantages in the fight against infection, the alterations in iron metabolism have been suggested as a means of pathogen replication (Thurnham, 1990). The redistribution of zinc to liver and bone marrow after infection of inflammatory cytokines may serve to support acute phase protein synthesis and haematopoesis. Patients with chronic inflammatory conditions have increased concentrations of zinc in mononuclear leukocytes, which may indicate that cells of the immune system are also favoured for zinc during inflammatory responses. The potential benefits of retinol fluxes during infection have not been explored. Although it is clear that a decreased plasma concentration of a nutrient during infection may be a beneficial adaptation rather than a harmful deficiency (Filteau, S M, and Tomkins, A M, 1994). The problems of assessing nutrient status during infection have made it difficult to determine whether infections decrease status itself over the long term. Several factors could contribute to impaired status, including decreased appetite, decreased absorption due to diarrhoea, or increased requirement for nutrients for immune functions or tissue repair. Internet Hackers EssayErythrocytic malaria parasites live in the blood which is rich in haemoglobin, a ready source of nutrients, but also a potential source of toxic forms of iron. In acquiring nutrients the parasites take up large quantities of haemoglobin. In this process, globin is hydrolysed to free amino acids and haem is converted to haemozoin. Globin hydrolysis is presumed to provide the bulk of amino acids for parasite protein synthesis, and haem processing is thought to both detoxify haem molecules and provide necessary parasite iron. The processes of haemoglobin catabolism and iron utilisation are targets for a number of compounds with antimalarial activity. Erythrocytic parasites require iron for the synthesis of iron containing proteins such as ribonucleotide reductase, superoxide dismutase and cytochromes and for de novo haem biosynthesis. The source of free iron for malaria parasites is not known. Three possible sources are serum iron, free erythrocytic iron and haemoglobin. There are some reports of iron uptake from serum by parasitised erythrocytes, supporting a serum source for parasite iron. This backs-up the observations that iron deficient individuals are partially protected against malaria infection. Although studies showing a lack of transferin receptors on parasitised erythrocytes, argues against a serum source for parasite iron (Peto, T E A, Thompson, J L, 1986). Observations show that cell-impermeant, serum depleting, iron chelators have no antimalarial activity in culture. A report showed that the antimalarial effects of iron chelators in mice are independent of host iron status and a study showed that the course of malar ia in children is unaffected by iron supplementation (Peto, T E A, Thompson, J L, 1986). Arguing against free erythrocytic iron as the source of parasite iron are observations that iron chelators inserted into the erythrocyte cytoplasm are non toxic to cultured parasites. Considering this, the large amount of haemoglobin that is degraded by erythrocytic parasites, and the observation that small amounts of iron are released from haem after incubation at the pH of the food vacuole, it is logical that haemoglobin is the principal source of parasite iron (Rosenthal P J and Meshnick, S R, 1996). Although this has never been tested. The best studied antimalarial iron chelator is deferoxamine (desferrioxamine B, DFO). Its antimalarial activity has been demonstrated in vitro, in animals and patients with both moderate and severe P. falciparum infections. The entry of DFO into the parasite is essential for antimalarial activity. DFO treatment of patients with cerebral malaria had a much greater effect on coma recovery time than on parasite clearance time, suggesting that iron chelation may have an effect on the disease process beyond its anti parasitic effect (Rosenthal, P J, 1996). This suggests that it may be possible that iron deposition in tissue may be partially responsible for severe malaria. Indeed, haemozoin deposition in the brain was significantly higher in mice with cerebral malaria like illness than in mice with ordinary malaria. Although DFO has shown promising activity, it is unlikely to be of practical use as it is expensive and must be administrated by continuous infusion. A number of other iron che lators have shown antimalarial activity in vitro and in vivo. One of these may prove to be more clinically useful than DFO. Anaemia is said to be one of the malaria related diseases, it affects 30% of the worlds population. It is an important health problem because it may increase maternal morbidity and decrease physical work capacity owing to reduction in O2 delivery to tissues (World Health Organisation 1975). DiaBibliography:Internethttp://www.malaria.org/whatismalaria.htmlhttp://www.cdc.gov/travel/malinfo.htmhttp://www.who.int/ctd/html/malaria.htmlhttp://sites.huji.ac.il/malaria/maps/hemoglobinpolpath.htmlJournalsBerclaz, P Y, Benedek C, Jequier, E, Schutz, Y, Changes in protein turnover and resting energy expenditure after treatment of malaria in Gambian children. Black. R E, Therapeutic and preventive effects of zinc on serious childhood infectious diseases in developing countries. American Journal of clinical Nutrition, 1998, 68, No.2 ss, pp.S476-S479Davidson, L, Walczyk, T, Morris, A, Hurell, R F, Influence of ascorbic acid on iron absorption from an iron-fortified chocolate-flavoured milk drink in Jamaican children. American /journal of Clinical Nutrition, 1998, 67, 873-7. Fairweather-Tait, S, Hurrel, R F, Bioavailability of minerals and trace elements. Nutr. Res Rev, 1996, 9, 295-324. Fevang, P, Bjorkman, A, Hostmark, A, Suppression of Plasmodium Falciparum in vitro by polyunsaturated fatty acids. XIII International Congress for Tropical Medicine and Malaria, 1992, 29, Jomtien, Thailand Abstracts, p. 268. Filteau, S M, Tomkins, A M, Micronutrients and tropical infections. Transactions of the royal society of tropical medicine and Hygiene, 1994, 88, No.1, p.1 et seq. Fleming, A F, Agriculture-related aneamias, British Journal of Biomedical Sciences, 1994, 51, 345-357. Foster, L H, Sumar, S, Selenium in health and disease: a review. Critical Reviews in Food Science and Nutrition, 1997, 37(3), 211-228. Gibson, R S, Huddle J M, Suboptimalzinc status in pregnant Malawian women: its association with low intakes of poorly available zinc, frequent reproductive cycling, and malaria, American Journal of Clinical Nutrition, 1998, 67, 702-9. Ginsburg, H, Gorodetsky, R, Krugliak, M, The status of Zinc in malaria (Plasmodium falciparum) infected human red blood cells: stage dependant accumulation, commpartmentation and effect of dipicolinate. Biochimica et Biophysica Acta, 1986, 886, 337-344. Halliwell, B, and Chirco, S, Lipid peroxidation: its mechanisms, measurement and significance, American Journal of Clinical Nutrition, 1993, 57, 715S-725S. Hendrickse, R G, Lamplugh, S M, Maegraith, B G, Influence of aflatoxin on nutrition and malaria in mice. Transactions of the Royal Soceity of Tropical Medicine and Hygiene, 1986, 80, No.5, pp.846-847. Hongo, T, Ohtsuka, R, Nakazawa, Inaoka, T, Suzuki, T, Nutritional status of trace elements in traditional populations inhabiting tropical lowland, Papua New Guinea. Proceedings of the Ninth Internationalm Symposium on Trace Elements in Man and Animals, 1997, 9, pp. 120-122. Huddle, J M, Gibson, R S, Cullinan, T R, 1998, Is zinc a limiting nutrient in the diets of rural pregnant Malawian women? British Journal of Nutrition, 1998, 79, 257-265. Krugliak, M, Deharo, E, Shalmiev, G, Sauvain, M, Moretti, C, Ginsburg, H, Antimalarial effects of C18 fatty acids on Plasmodium falciparum in culture and on Plasmodium vinckei and Plasmodium yoelii nigeriensis in vivo. Experimental Parasitology, 1995, 81, 97-105Lehmann, D, Howard, P, Heywood, P, Nutrition and Morbidity acute lower respiratory-tract infections, diarrhea and malaria. Papua New Guinea Medical Journal, 1988, 31, No. 2, pp. 109-116. Levander, O A, Selenium and sulphur in antioxidant protective systems: relationships with vitamin E and malaria. Soceity for Experimental Biology and Medicine, 1992, 200, 255-259. Levander, O A, Ager, A L, Malaria parasites and antioxidant nutrients. Parasitology, 1993, 107, S95-S106Phillips, M, Sanghvi T, Suarez, R, Mc Kigney, J, Fielder, J, The cost and effectiveness of three vitamin A interventions in Guatemala. Social Science Medicine, 1996, 42, No. 12, 1661-1668. Nakazawa, M, Ohtsuka, R, Kawabe, Hongo, T, Inaoka, T, Akimichi, T, Suzuki, T, Iron nutrition and anaemia in a malaria-endemic enviroment: haematological investigation of the Gidra-speaking population in lowland Papua New Guinea. British Journal of Nutrition, 1996, 76, 333-346. Northrop-Clewes, C A, Paracha, P I, McLoone, U J, Thurnham, D I, Effect of improved vitamin A status on response to iron supplementation in Pakistani infants, American Journal of Nutrition, 1996, 64, 694-9. Pelletier,D L, et al, The effects of malnutrition on child mortality in developing countries, Bulletin of the World Health Organization, vol. 73, no. 4, 1995 (in press). Peto, T E A, Thompson, J L, A reappraisal of the effects of iron and desferrioxamine on the growth of Plasmodium falciparum in vitro: the unimportance of serum iron. British Journal of Haematology, 1986, 63, 273-280. Rosenthal P J, Meshnick S R, Hemoglobin catabolism and iron utilization by malaria parasites, Molecular and Biochemical Parasitology, 1996, 83, 131-139. Shankur, A H, Genton, B, Semba, R D, Baiser, M, Paino, J, Tamja, S, Adiguma, T, Wu, L, Rare, L, Tielsch, J M, Alpers, M P, West, K P, Effect of vitamin A supplementation on morbidty due to Plasmodium falciparum in young children in Papua New Guinea: a randomised trial, The Lancet, 1999, 354, 203-09. Smith, T M, Jukes, D, J, Food control systems in Canada. Critical Reviews in Food science and Nutrition, 1997, 37(3), 229-251. Steketee, R W, Wirima, J J, Campbell, C C, Developing effective strategies for malaria prevention programs for pregnant african women. American Journal of Tropical Medicine and Hygiene, 1996, 55, No. 1 ss, pp.95-100. Thurnham, D I, Antioxidants and prooxidants in malnourished populations. Proceedings of the Nutrition Society, 1990, 49, 247-249. Turner, R J, Finch, J M, Selenium and the immune response. Proceedings of the Nutrition Soceity, 1991, 50, 275-285. West, K P, and Sommer, A, Periodic large oral doses of vitamin A for the prevention of vitamin A deficiency and xerophthalmia a summary of experiences. IVACG. Washington DC 1984. BooksAdriane Fugh-Berman, M.D., Alternative Medicine: What Works (Tucson, AZ: Odonian Press, 1996). George Lewith, Julian Kenyon and Peter Lewis, Complementary Medicine: An Integrated Approach (Oxford: Oxford University Press, 1996), p. 108-9. Griffith, H W, (1988) The Complete Guide to Vitamins, Minerals ; Supplements, Fisher Books. Harinder S, Garewal, (1997) Antioxidants and disease prevention, CRC Press. Harrison, G A, Waterlow, J C, (1990) Diet and disease in traditional and developing societies, Cambridge University Press. Michael T. Murray, N.D., Encyclopedia of Nutritional Supplements (Rocklin, CA: Prima Publishing, 1996). Melvyn Werbach, M.D., Healing Through Nutrition: A Natural Approach to Treating 50 Common Illnesses With Diet and Nutrients (New York: Harper Collins Publishers, 1993). Smith, K T, (1988) Trace minerals in foods, Marcel Dekker, Inc./New York and Basel