By J. Marlo. Aurora University. 2018.
Both the behaviour of the cells in isolation and all of the interactions between them must be considered buy zithromax 250mg amex virus killing kids. A ﬁnite-element computer model that represents an organ at the level of the cell allows us to observe the individ- ual interactions between tens of thousands of cells simultaneously purchase zithromax 100mg free shipping treatment for dogs ear infection yeast. Finite-element modelling of biological systems has already begun in a number of areas, including bone, skin and brain mechanics, intercellular communication within tissues, and heart contraction. One important factor in the design of a car is protecting its occupants during collisions, known as crashworthiness. One aim is to minimise the deceleration forces that act upon the occupants, which is achieved by making the car body absorb impact energy by deforming in a particular way. But large deformations will result in physical intrusions into the passenger compartment, which are also undesirable. The trick is to balance these two opposing factors, rigidity and deformability, in an efﬁcient way. The most cost-effective way of doing this is to use use ﬁnite-element modelling on a computer. The intact car is ﬁrst divided into a large number of small elements (discretisation). The relatively simple equations that describe the physical interactions between adjacent elements are then formulated, taking into account the material properties of the elements. This set of equations is then solved whilst an appropriate stimulus is applied. In this example, the stimulus is an obstacle at the front of the vehicle (simulation). The resulting deformations and deceleration forces are then investigated in detail, in order to predict how best to modify the design in order to improve its performance (reconstruction). The system of interest may be continuous, as in a ﬂuid, or it may comprise separate, discrete components, such as the pieces of metal in this example. The basic principle of ﬁnite-element modelling, to simulate the operation of a system by deriving equations only on a local scale, mimics the physical reality by which interactions within most systems are the result of a large number of localised interactions between adjacent elements. These interactions are often bi-directional, in that the behaviour of each element is also affected by the system of which it forms a part. The ﬁnite-element method is particularly powerful because with the appropriate choice of elements it is easy to accurately model complex interactions in very large systems because the physical behaviour of each element has a simple mathematical description. Assemblies of carbon, hydrogen and oxygen atoms combine to form molecules that, when linked together, form proteins, carbohydrates and fats. These three fundamental types of biological molecule combine to form cells that are typically 0. Cells can be independent organisms, as in a bacterium, or, by co-operating with other cells, form tissues. By acquiring specialised functions, assemblies of tissues form the next distinct structural and functional unit, the organ. At the highest level, a human comprises 75 000 000 000 000 cells divided into ten major organ systems. It is natural to describe the function at each level in the biological hierarcy in terms of the components at the next level down. Sometimes it is necessary to consider processes occurring two levels down, but further subdivision is seldom beneﬁcial. Schrödinger’s equation, for example, is useful when modelling the behaviour of atoms in a molecule, but it would be absurd to model car crashworthiness using this level of detail. When we are interested in the operation of a complete organ, a description at the level of the cell is the natural choice. The model must incorporate both the operation of the cell in isolation and the interactions between cells since, by analogy, we could not predict the load-bearing capacity of the Forth Rail Bridge by considering only the strength of the individual cantilevers in isolation. The structural properties of bone are determined by non- cellular organic and inorganic components. The potential exists to assess quantita- tively an individual patient’s risk of bone fracture, which has signiﬁcant clinical implications in an ageing population. Currently, estimates of this risk are limited by the inability to allow for complex structural features within the bone.
Doctors have become increasingly involved in the regulation of the more intimate and personal aspects of their patients’ lives order 500mg zithromax with mastercard infection and immunity, seeking to influence their conduct of intimate relationships zithromax 100 mg mastercard virus 71. Thus GPs are now exhorted to take an active interest in patients’ sexual behaviour, to be alert to all possible manifestations of domestic violence and to promote parenting skills. Different influences have pushed these concerns into the GP’s surgery, moving with different dynamics over the past decade. The new discipline of ‘sexual health’ indicated the creation of a link between ‘sex’ and ‘health’, two formerly autonomous, if not antagonistic, spheres of human endeavour. A series of public controversies around issues of child protection in the 1980s led to the formulation of policies requiring closer involvement of GPs in issues of child protection. The growing influence of feminism in public life, catalysed by the election of the New Labour government in Britain in 1997, brought the crusade against domestic violence into the surgery, with a plethora of guidelines and recommendations in the late 1990s. The new government also gave a priority to public health and to issues of ‘inequalities’ in health and welfare and ‘social exclusion’. These policies did not involve any redistribution of resources to the poor (the anathematised tradition of Old Labour); in practice, they meant more intensive measures to push people into the labour market and schemes to foster healthy lifestyles and parenting skills— which is where GPs come in. Any suggestion that this extension of professional inter-vention into the personal sphere, and the implicit shifting of the boundary between the public and the private, might have adverse consequences for the autonomy of the individual and the stability of the family, is dismissed as yet another voice of the forces of conservatism trying to hold back the tide of progress. Let’s look more closely at the role of the GP in the bedroom, the living room and the nursery. Sex in the surgery Shortly before the millennium, we were bombarded at the health centre with invitations to attend a ‘sexuality training day’ on the subject of ‘sex in primary care’. I requested details of the agenda which promised ‘an opportunity to discuss [my] experience of sexual history taking, explore associated issues and develop and enhance [my] skills and confidence to discuss sex with a diverse range of patients’. Highlights of a day featuring games and role play included an ‘orgasm exercise’: ‘pairs to practice communications skills to talk about experience of or understanding of an orgasm’. Another exercise tackled ‘sexual language’: ‘small groups to brainstorm words for Male and Female sexual organs and homosexual/homosexuality’. My first response was to regard this course as rather silly and self- indulgent, as yet another example of the ‘dumbing down’ of postgraduate education. But, if we ask the question—how is a sexuality training day for GPs supposed to relate to their work with patients? It is clear that the aim of the course is to overcome doctors’ own inhibitions in talking about sex so that they can in turn break through their patients’ reserve in these matters. Challenging doctors’ personal reticence is the key to opening up the intimate areas of ordinary people’s lives to professional scrutiny and interference. The ‘Sex and the GP’ conference, one of many such training initiatives, is part of a wider campaign to encourage GPs to play a more interventionist role in their patients’ sexual health. In 1995, for example, the BMA Foundation for Aids sent a complimentary copy 119 THE PERSONAL IS THE MEDICAL of Sexual health promotion in general practice (retail price £15) to every GP in London (Curtis et al. It is the only book on sexual health promotion which has been written and presented in an attractive, readable format specifically for busy doctors, nurses and other staff working in general practice. The main justification offered for this well-resourced drive to recruit GPs to the safe sex crusade was that it was part of the campaign to reduce the incidence of HIV and other sexually transmitted diseases. This did not make much sense as both HIV and STDs are fairly uncommon in general practice and also because there is a flourishing network of clinics already dealing with these problems. The free sexual health handbook provides a long list of the ‘advantages’ of general practice as ‘a setting for promoting sexual health’, of which the first three are: • Reaches large numbers of people on a one-to-one basis • Relationship with patient already exists • Opportunities to discuss sexual health arise during relevant consultations, for example, for smears or contraception. The importance of general practice is that it provides access to the mass of the population through an individual who has a relationship with people that reaches deep into their personal, private space. The central concern of sexual health promotion is not to prevent disease but to preach a new form of sexual morality. The distinctive feature of this moral code is that it explicitly disclaims being a moral code. Yet the new framework simply replaces ‘good’ with ‘safe’ and ‘evil’ with ‘unsafe’ and proceeds to construct a code as dogmatic and authoritarian as any to be found in the Bible or the Koran.
He undertook with great zeal Paul was one of those unusual persons with the position of caring for the post-poliomyelitic boundless energy 500mg zithromax with amex virus alive. Initially when most of his time was consumed by the there were very few patients effective 250 mg zithromax antibiotic injection for uti, but in the late 1940s development of the Harrington instruments and the patient load increased dramatically as a result his theories concerning the treatment of the scol- of the poliomyelitis epidemics. During the same period he also National Infantile Paralysis Association was became an expert on photography and high- established, the ﬁrst such organization in the ﬁdelity systems. Harrington became well recognized for his ested in scoliosis, having realized that the current accomplishments as recipient of the Most Distin- methods for treating scoliosis were inappropriate guished Alumnus Award in 1975 from the for the patient who was severely paralyzed after Medical Alumni Association at the University of poliomyelitis. He also received the Cora and Webb resulting from poliomyelitis was manual correc- Mading Medal from the Institute for Rehabilita- tion of the scoliotic deformity at the time of tion and Research and Baylor College of Medi- surgery, and internal ﬁxation of each facet. This cine in 1973, and the Nicolas Andry Award from worked well initially, but the ﬁxation did not hold. In the Paul Randall Harrington died on November 29, beginning, he would fashion the instruments the 1980, ending a life of accomplishment that began night before surgery. After surgery the next day, in Kansas City, Kansas, on September 27, 1911. Once the basic design was devel- for his straightforward frankness, his bow ties, his oped, he had it tested extensively by the Engi- par golf, his smile, his trumpet, and above all for neering Department at Rice University in being a nice person. Houston, Texas, and at a commercial testing company in Chicago, Illinois. He then allowed the instruments to be sold, but initially only to those who personally had seen his technique performed. Harrington belonged to many medical asso- ciations, and was one of the founding members of the Scoliosis Research Society. Harrington was orthopedic consultant to the United States Air Force and to the United States Army in San 125 Who’s Who in Orthopedics Hospital in Weston for the treatment of this disease in civilians. His interest in tuberculosis never left him and he held weekly clinics for 35 years—his last clinic being held just before he left for Banff. Gallie was extremely anxious, when he was appointed Professor of Surgery at the University of Toronto, to have a surgeon of Dr. Harris left the Hospital for Sick Chil- dren to join the staff of the Toronto General Hospital. Though at ﬁrst continuing to be a general surgeon, his interest continued to lie in the ﬁeld of orthopedics and he increasingly conﬁned himself to its practice. When, in 1940, a Division of Orthopedic Surgery was established in the Toronto General Hospital, Dr. Harris that, on Robert Inkerman HARRIS the advent of the Second World War, he should 1889–1966 enlist in the Royal Canadian Army Medical Corps. With the rank of colonel, he served at Robert Inkerman Harris was born in Toronto on home and overseas as a surgical consultant to the July 1, 1889. His brilliance as a student soon became manifold commitments, he found time during his apparent at the University of Toronto, where he service to compile his classic work The Canadian was elected a member of the honorary medical Army Foot Survey. He was mentioned in dent of both the American and Canadian Ortho- despatches, and awarded the Military Cross pedic Associations on the occasion of the ﬁrst twice, before being wounded and invalided home combined meeting of the Orthopedic surgeons of in 1917. It was at this meeting After the war, he was appointed to the staff of that he established one of the greatest advances in the Sick Children’s Hospital where he remained the teaching of orthopedics—the Exchange Trav- for the next 10 years, during which time his inter- eling Fellowship Program. After the war, he estab- sometimes been abandoned by others, such as lished a unit for the treatment of veterans with Syme’s amputation; his thoroughness and bold- skeletal tuberculosis. A great believer in helio- ness and keen personal interest in his patient therapy, he supervized the treatment of these vet- never let him abandon any patient, no matter how erans thought to be suffering from an incurable insuperable the problem appeared to be; and his disease on the “Roof Ward” of Christie Street inventiveness led to the development of new Hospital. Most of them lived to take part in a 1934 instruments and appliances, such as the incompa- “Re-union of the Sun Worshippers. His astuteness as an At the request of the National Sanatorium observer led him to describe the pathological Association, he established a unit at the Toronto basis of ill-understood clinical syndromes, such 126 Who’s Who in Orthopedics as peroneal spastic ﬂat foot and discogenic back pain; his inexhaustible supply of energy led him not only to complete his memorable work on The Canadian Army Foot Survey, but also to rewrite the whole thesis when the original hand-written draft was stolen; and his unquenchable thirst for knowledge stimulated all the people he trained to search for better solutions to common orthopedic problems and to seek more deeply into their cause. In 1949, he was appointed Hunterian Lecturer by the Royal College of Sur- geons of England. In 1955, he became the ﬁrst Canadian to be appointed Sims Commonwealth Professor. He was made an Honorary Fellow of the Royal College of Surgeons of England, of the Royal College of Surgeons of Edinburgh, and of the Royal Australasian College of Surgeons. In Julius HASS January 1966, he gave the ﬁrst Gallie Lecture to the Royal College of Physicians and Surgeons of 1885–1959 Canada. The following month he was presented with the Distinguished Service Award of the The death of Julius Hass brought to a close a life Ontario Society for Crippled Children.
With carbon dioxide 500mg zithromax for sale antibiotics for acne what to expect, water zithromax 500mg otc antibiotic used to treat strep throat, and the help of Giardia form dormant structures called cysts that are resistant specialized enzymes, the light energy absorbed creates chem- to chlorination. The prevalence of these protozoans in world- ical energy in a form the cell can use to carry on its processes. Thus, the effec- In addition to chlorophyll, there are other pigments tiveness of chlorination may be compromised in some water known as accessory pigments that are able to absorb light systems. As well, adherent bacterial populations of bacteria where the chlorophyll is unable to. Carotenoids, like B- such as Escherichia coli that form in distribution pipelines are carotenoid, are also located in the thylakoid membrane. A third concern with chlorination is the reaction between algae, bacteria, and diatoms, coloring them varying shades of chlorine and methane gas, which produces one or more chlo- red, orange, blue, and violet. The best known are trichloromethane (chloroform) and tetrachloromethane (carbon tetrachloride). See also Autotrophic bacteria; Blue-green algae These chlorinated hydrocarbons have been shown to have adverse health effects in humans when ingested in sufficient quantity for a long time. CChlorophytaHLOROPHYTA Furthermore, from an engineering point of view, excess chlorine can be corrosive to pipelines. In older water treatment Chlorophyta are microorganisms that are grouped in the king- systems in the United States, for example, the deterioration of dom called Protista. The microbes are plant-like, in that they the water distribution pipelines is a significant problem to are able to manufacture energy from sunlight. Terrestrial habitats include tree CChlorophyllHLOROPHYLL trunks, moist rocks, snowbanks, and creatures including turtles, sloths and mollusks. There are some 8,000 species of chloro- Chlorophyll is a green pigment contained in the foliage of phytes, ranging in size from microscopic to visibly large. The first class, responsible for absorbing sunlight required for the production of which contains the greatest number of organisms, is called sugar molecules, and ultimately of all biochemicals, in the plant. A notable example of an organism from this Chlorophyll is found in the thylakoid sacs of the chloro- class is Chlorella, which is economically important as a dietary plast. The chloroplast is a specialized part of the cell that func- supplement. Another member of the class is Volvox, a spherical tions as an organelle. Once the appropriate wavelengths of organized community containing upwards of 60,000 cells. In this class have existed since prehistoric times, as evidenced by photosynthesis, the chloroplast absorbs light energy, and con- verts it into the chemical energy of simple sugars. An example of this class is Spirogyra, which form Vascular plants, which can absorb and conduct moisture slimy filaments on the surface of freshwater. Some become associated with sea slugs where they as chlorophyll a and b, differ slightly in chemical makeup and provide the slug with oxygen and are in turn provided with in color. These chlorophyll molecules are associated with spe- protection and nutrients. Species of a calcium-rich green algae cialized proteins that are able to penetrate into or span the called Halimeda form the blinding white sand beaches of the membrane of the thylakoid sac. Caribbean when they wash up onshore and become bleached When a chlorophyll molecule absorbs light energy, it by the sun. Another example from this class is Ulva that grows becomes an excited state, which allows the initial chain reac- on rocks and wharves as green, leafy-appearing clusters. The pigment molecules clus- Chlorophyta contain structures that are called chloro- ter together in what is called a photosynthetic unit. Within the chloroplasts two pigments (chlorophyll a hundred chlorophyll a and chlorophyll b molecules are found and chlorophyll b) are responsible for the conversion of sun- in one photosynthetic unit. The energy is typically stored as A photosynthetic unit absorbs light energy. Red and starch, and in their cell walls, which are composed of a mate- blue wavelengths of light are absorbed. The stored material can be used for absorbed by the chlorophyll and the light is reflected, making energy as needed.
9 of 10 - Review by J. Marlo
Votes: 292 votes
Total customer reviews: 292