9.3 Health The leader must be informed of any problems of mental or physical health that may affect safety during field-work. This may include, for instance, information on diabetes, asthma or epilepsy; students should also inform the leader if they require extra assistance. All work handling living organisms, soil or water may give some risk of infection, and protection in the form of gloves, masks, etc., may need to be carried. Supervisors should give advice concerning particular health hazards that m
7.2 Information sources The best source of information is the material safety data sheet (MSDS). By law (CHIP3) this should accompany any chemical that is purchased. However, if this is not available, or the chemical is old, then copies can be obtained from the manufacturer's website or information can sometimes be found in t 5.1 Basic do's and don'ts and lone working Some basic ‘do's and don'ts’ are: Laboratory coats must be worn at all times. When handling chemicals or sharps (any sharp object that can cause injury, particularly to the hands), observe good laboratory practice by wearing gloves. Latex or nitrile gloves are best, depending on the application. There should be no eating, chewing gum, drinking, smoking or applying cosmetics in any laboratory. No p 4.2 Why do I need to know about first aid? It takes only 3 to 4 minutes for a blocked airway to kill someone, but it can take more than 8 minutes for an ambulance to arrive on the scene. A simple procedure like opening an airway can save someone's life while you are waiting for professional help to arrive. If you are working with harmful substances (chemicals, biological agents and dusts) you must know the first aid treatment if you are exposed. Do not expect a nurse or a doctor to know everything about every harmful substance. 1 History of health and safety The discipline of health and safety is relatively modern, only developing in the last century. However, throughout the ages people have voiced their concerns about people being exposed to harmful substances. Hippocrates mentions in the 4th century BC that lead miners and workers tended to suffer from diseases. The phrase ‘mad as a hatter’ was coined because mercury used in the hat industry caused mental illness. In 1775 Pott reported that chimney s Learning outcomes By the end of this unit you should be able to: understand the legal framework of the Health and Safety at Work etc. Act 1974 and Regulations associated with it; understand the employers’, employees’ and visitors’ duties; evaluate hazards and risks in order to carry out a risk assessment; understand the legal requirement to report any accident or dangerous occurrence; develop risk assessments for scientific laborat Introduction Ths unit is an adapted extract from the course Postgraduate research skills in science (STM895) This unit is designed to introduce you to the concepts of health and safety within a science laboratory or in the field. There are a number of legal requirements that must be adhered to before carrying out work in a laboratory. One of these is the necessity to carry out risk assessments on the chemical and biological agents that are to be used as part of your practical work activities. As par References 3.2 Herbicide tolerance As you discovered from Activity 1, herbicide tolerance is the trait most commonly incorporated into commercial GM plants. A crop can be made tolerant to herbicide by inserting a gene that causes plants to become unresponsive to the toxic chemical. Before considering how the genetic manipulation can be achieved, it is useful to understand a little about how herbicides act. Many herbicides work by inhibiting a key plant enzyme necessary for growth (if you're not exactly sure what this mea 3.1 Insect resistance We will now look briefly at the science underlying the traits introduced into commercial crops, which you explored in Activity 1; a useful place to start is by considering how the property of resistance to insects is acquired by crops. Insect damage causes huge losses of agricultural crops each year. For example, without co 2.2 Using A. tumefaciens to genetically modify plant cells Genetic engineers have capitalised on the fact that part of the DNA from the Ti plasmid of A. tumefaciens is integrated into the plant genome during the infection process. Ti plasmids can be isolated and a foreign gene spliced in at an appropriate point, making it possible to transfer the novel gene into the plant. Acknowledgements Grateful acknowledgement is made to the following sources for permission to reproduce material in this unit: The content acknowledged below is Proprietary and used under licence (not subject to Creative Commons licence). See Terms and Conditions. Figure 4 BP (2 4.1 Introduction As bacteria secrete such powerful chelators into the environment, iron in other organisms must be kept under very close control. Any free iron within an organism is likely to be chelated by a siderophore, which may lead to bacterial infection within the organism In this Section we shall examine the biochemical systems that handle iron within the human body. The two areas we shall study are iron transport and iron storage. 3.3 Summary of Section 3
E. coli has a remarkable method of obtaining iron from its environment, which involves the use of very powerful iron chelators, called siderophores. One siderophore in particular, enterobactin, forms an extremely stable complex with iron(III). The high stability of this complex is due partly to the rigid, preorganised structure of the ligand, and partly to the iron(III) being the correct size and charge to be chelat 3.1 How do organisms take up iron? Nearly all organisms are able to take up iron. However, only a handful of organisms have had their iron-uptake chemistry studied. The organism that has received most attention (other than human) is a single-cell, prokaryotic bacterium (found in the human large intestine and elsewhere), called Escherichia coli (abbreviated to E.coli), a high-resolution image of which is shown in Author(s): Introduction In this unit we will see that, despite having a high natural abundance, iron is in very short supply because of the insolubility of its oxides and hydroxides. A result of this is that organisms have developed methods for the uptake, transport and storage of iron. For example, iron storage in mammals, including humans, is achieved by ferritin, which stores iron as a hydrated iron(III) oxide – an example of biomineralisation. This unit is from our archive and is an adapted extract from 3.6.2 Experiencing the pregnancy If a woman does find herself pregnant, what can she expect? Pregnancy is a time of enormous physical and emotional changes, and these are often difficult to cope with. To begin with, the physical effects of early pregnancy can be extremely unpleasant. The nausea and vomiting of morning sickness can be very severe, and although in many women the symptoms abate after a while, in others they persist right through the pregnancy. Sickness is thought to be due to the high levels of progestogen circ 3.4.2 Compaction and adhesion Around the time of the 8- to 16-cell division, the conceptus undergoes a morphological (shape) change, called compaction, in which the cells fatten on each other, and the outlines of individual cells become hard to distinguish. This stage, sometimes referred to as a morula, from the Greek word for mulberry, is shown in Figure 17i. At this stage it is hard to see individual cells; in fact, unless the cells are separated by various laboratory treatments, it is not possible to see the two 4.4 Hormonal control of sperm production The most important hormone involved in controlling sperm production is a steroid called testosterone. This is produced in the testis itself, by the Leydig cells (see Figure 12a). The testosterone is released from the Leydig cells between the tubules, and taken up by the neighbouring Sertoli cells. The Leydig cells are stimulated to make testosterone by two other hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are both produced by the pituitary gland and 1.3.4 Surgical methods of contraception Surgical methods are by and large the most drastic and irreversible ones, ranging from castration to relatively untraumatic tube-tying. Because of the psychological and physiological side-effects, surgical removal of the testes or ovaries is not generally carried out for contraceptive reasons alone, although these operations may be carried out for other reasons, such as the presence of malignant tumours. Any kind of surgical sterilization can be physiologically traumatic for a woman, as it in
7.2.1 How do I find the information required to carry out COSHH risk assessments?
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