The organization and implementation of control activities 139 in countries should be strengthened; research institutes should be encouraged to jamie arteries order propranolol on line amex fund and implement research on medicines heart disease icd 9 buy propranolol 40mg online, diagnosis and prevention; information management and dissemination should be harmonized and exchange of technical information facilitated capillaries of the liver best purchase propranolol. Furthermore coronary artery narrowing symptoms order propranolol paypal, training should be provided for people involved in leishmaniasis activities. Eventually, international technical collaboration should lead to definition of a common approach to control. Greater international and national technical collaboration is necessary for obtaining knowledge about the burden of the disease, including economic aspects; implementation of research at field level; vector control issues; the availability and accessibility of medicines; pharmacovigilance and monitoring drug resistance; and the coordination and implementation of drug development and clinical trials. Factors that restrict the control of leishmaniasis should be addressed as a priority. Recognizing that the operational capacities of national programmes vary greatly according to the financial resources and political stability of a country, it is important to retain good emergency preparedness capacity at international level, so that aid to national programmes in difficulty can be provided rapidly and in order to establish a coordinating body at national level. As the tools for control of leishmaniasis are relatively sophisticated, sufficient numbers of trained technicians must be available. Cross-border collaboration for coordination and periodic exchange of information will support control efforts. In order to address the distinctively regional characteristics of leishmaniasis, regional or subregional programmes should be strengthened for harmonization and centralization of epidemiological surveillance, exchange of information between national programmes, research institutes and nongovernmental organizations and standardization of control methods and techniques. Strong advocacy and awareness-raising programmes to increase the visibility of leishmaniasis control efforts must be seen as a priority. Advocacy is particularly important to ensure adequate continuing commitment from donors and national governments, without which worldwide control cannot succeed. Regional or subregional control programmes are more likely to attract funds than a single country. This applies particularly to the international code for labelling parasite isolates (see section 2. Quality assurance of tests can be promoted by exchange of reference sera and standard antigens. The target group for health education might include public health managers, health staff, community health workers and leaders, people living in endemic areas and patients. The main objectives of health education in leishmaniasis control include: fi achieving strong political commitment for control; fi enabling the community to obtain clear, correct information (preferably in their own language) and develop their capacity to make the right decisions; educating local communities, especially women, about control measures and educating and involving medical institutions in educational plans; fi enabling the community to understand problems objectively and to analyse them; fi positively changing behaviour and practice, motivating and leading the community in the right direction to effect the desired change; and fi establishing links and collaboration with people concerned with health promotion and disease control. Decision-makers should be sensitized about the importance of leishmaniasis as a public health problem so that they will support and defend control programmes. In endemic areas, training courses for health authorities and health personnel should be organized before they begin work. Medical doctors and laboratory technicians should take part in health education programmes, as they are usually unfamiliar with the disease. Primary health education programmes should be organized for community health workers and leaders, schoolteachers and communities in endemic areas so that thay are able to recognize the disease and guide patients on what to do, to be proactive and to participate in prevention and control campaigns. Health education applies equally to personnel in nonendemic areas where infections are seen in people who have travelled to endemic areas. Countries should develop appropriate health education and behavioural change communication strategies and plans on the basis of the local context. It should be completed according the characteristics of the disease and the control programme in each country. Health authorities and decision-makers should receive training in recognizing leishmaniasis as a public health problem, focusing on risk factors, preventive methods and treatment in order to support the development of multidisciplinary and interinstitutional research activities, the design of national control guidelines and issues of drug access and prevention. Health staff, including physicians, entomologists, parasitologists, veterinarians and biologists, assigned to collaborate with the leishmaniasis control programme need special training to become familiar with the general objectives of the multidisciplinary approach to determining the epidemiological and biological characteristics of the disease, risk factors, prevention and control measures, treatment and pharmacovigilance. Laboratory technicians require training on use of the different diagnostic methods available in the country. If a comprehensive programme is envisaged, parasite isolation by culture and molecular biology tools for diagnosis should also be included in their training. Social scientists must be trained in the basic epidemiological and clinical characteristics of the disease. Community health workers should be trained to suspect cases and to refer them to a health centre for diagnosis and treatment. They should also be trained to support treatment administration and reporting of clinical evolution and drug-related adverse effects. A control manual for field personnel, describing current control techniques and methods, should be prepared in a language appropriate to the potential users and distributed. They should have clear information on the mechanism of referral of suspected cases of leishmaniasis. It is important to emphasize the need for confirming the diagnosis and providing adequate treatment. Discussions about potential risk factors associated with the disease and preventive measures should also be part of health education and training. Local training sessions are particularly recommended, as local circumstances are best known by the participants, teachers and community leaders, and large groups of people can be reached. A concerted research effort should be made to define the population at risk and the global burden of the disease accurately. It is therefore important to identify and develop effective surveillance tools and methods for use in endemic countries. Research on risk factors for infection and transmission are necessary, including social economic and nutritional aspects. Steps should be taken to incriminate vectors in foci where they are unknown and in new foci as they arise. Studies on the basic biology of proven vectors are needed to judge whether control by attacking the vector is feasible, including areas where elimination or control programmes are under way. The minimum biological information should include population dynamics, with times of transmission, the range of hosts on which the vector feeds, the resting sites of adults and breeding sites. Field studies on new foci and outbreaks of leishmaniasis should be launched without delay to determine the structure of the focus and the feasibility of control. Long-term monitoring should be conducted of annual fluctuations in important vector populations in representative transmission sites of leishmaniasis. Research and development of innovative tools for vector and reservoir control are needed, including evaluations of the cost, feasibility, acceptability and sustainability of control strategies. In particular, insecticide-based vectorcontrol tools (indoor residual spraying and insecticide-treated nets) and nonchemical ecological interventions should be evaluated, especially for anthroponotic transmission conditions. Clinical research to evaluate new drugs and combinations of drugs to reduce the duration of treatment for all clinical forms of leishmaniasis remains a high priority. Operational research to improve the collection of information about 149 treatment compliance and implementation of a pharmacovigilance system is important to better define algorithms for new treatment regimens. Social–behavioural research to identify social determinants of the use of health-care services and health care-seeking behaviour is important. Identification of behavioural blocks in completing treatment and of ways to overcome these problems is important. Studies to determine the economic and social consequences of leishmaniasis are necessary for advocacy and for designing better control measures. Development of a leishmaniasis vaccine must be a priority, as immunization would be the method of choice for future control. Existing knowledge and molecular tools for the identification and characterization of Leishmania parasites and sandflies should be improved and harmonized. Standardization and adoption of more sensitive, definitive molecular techniques for the diagnosis and characterization of Leishmania parasites is critical, as, in many instances, the treatment choice depends on the infecting Leishmania species. In addition, methods for determining drug resistance are needed, which are standardized and usable in endemic countries. Research and development of rapid tests for the diagnosis of visceral leishmaniasis and tests for cure based on antigen and nucleic acid detection should be undertaken. Research on more effective medicines that meet the current standards of safety remains a high priority. International support and collaboration in terms of finance and technical expertise should be mobilized. The development of new medicines and vaccines for the different forms of leishmaniasis is challenging because of the variety of parasite species, 150 pathology and immune responses (in particular immunosuppression). The requirements of patients and control programmes define the target product profile and the specifications of the final product. Improved in-vivo models are needed to help in the selection of compounds, to confirm their activity against a panel of species and to optimize pharmaceutical formulations. Translational research to transform lead molecules into candidate drugs must take into account the ‘drug likeness’ or ‘druggability’ of these molecules.
M3 Acute promyelocytic Leukemic cells show translocation 10% leukemia between chromosomes 15 and 17 coronary heart calcium score purchase propranolol 40mg visa. M4 Acute myelomonocytic Leukemic cells often have 20% leukemia inversion of chromosome 16 zig zag arteries propranolol 80 mg without a prescription. M6 Acute erythroid Leukemic cells have features of 5% leukemia developing red blood cells capillaries puncture cheap 40 mg propranolol mastercard. M7 Acute megakaryocytic Leukemic cells have features of 5% leukemia developing platelets heart disease 26 years old discount propranolol 40 mg with visa. Huge numbers of abnormal cells expand the bone marrow and spread into the peripheral circulation and eventually infiltrate the liver and spleen, where more cells are formed in a process referred to as extramedullary hematopoiesis, causing the organs to enlarge. The two genes fuse and produce an abnormal protein that increases the rate that leukocytes divide. Sometimes patients develop dyspnea or mild confusion because the increased number of malignant cells in the blood inhibits blood flow. Over time, the disease becomes more severe and people begin to develop other symptoms. The disease goes through different phases: • Chronic: this phase is fairly stable and may persist for 2 to 5 years without treatment. During this phase, the white blood count rises but most cells are mature and function normally. Typical symptoms include fatigue, headache, and pain or fullness in the left abdomen from splenomegaly. This stage usually lasts 1 to 6 months if the leukemia is untreated but may last >1 year with treatment. In addition to the symptoms experienced during the chronic phase, the patient may experience fever, night sweats, weight loss, anemia, and dyspnea. The mature granulocytes exhibit a delay in normal apoptosis (programmed cell death), so they live longer and begin to accumulate. These cells have no or low levels of alkaline phosphatase, so stains show a low score. Bone marrow biopsy with cytogenic studies provides definitive diagnosis, especially with a finding of the Philadelphia (Ph1) chromosome. Remission rates are 70% and survival of 94% at 3 years for those treated in the chronic phase. Complete remission rates drop to 28% if treatment is given during acceleration phase and 4% if during blast crisis. Two newer generation drugs, nilotinib and dasatinib, shower higher rates of remission but are associated with more side effects and are more expensive. In up to 30% of patients, imatinib is not effective in bringing about complete remission. The cell of origin is the precursor to B lymphocytes in 75% and to T lymphocytes in 25%. This is the most common type of childhood leukemia (85%), peaking between ages 2 to 5 and rare after age 15 with incidence in males higher than females. Despite positive survival rates, long-term morbidity and mortality related to treatment are high, including cardiac disease, pulmonary disease, and secondary cancers. Diagnostic findings Because production of normal blood cells is inhibited, laboratory testing usually shows decreased numbers of leukocytes, erythrocytes, and platelets. In some cases the leukocyte count is low but with a high proportion of immature cells. Treatment considerations Because only about 20% of adults are cured with standard chemotherapy, many are entered into clinical trials. The standard adult treatment protocol comprises 4 phases: • Induction: A 4-drug regimen of vincristine, prednisone, anthracycline, and cyclophosphamide or L -asparaginase or a 5drug regimen of vincristine, prednisone, anthracycline, cyclophosphamide, and L -asparaginase is given over the course of 4-6 weeks. Regimens using a standard 4to 5-drug induction usually include Ara-C in combination with an anthracycline or epipodophyllotoxin. The pediatric treatment protocol comprises 5 phases: • Induction: 3-4 drugs, which may include a glucocorticoid, vincristine, asparaginase, and possibly an anthracycline. B-cell acute lymphoblastic leukemia is usually treated with two months to 8 months of intensive therapy. However, those with Bprecursor and T-cell acute lymphoblastic leukemia require approximately 2 to 2. In current acute lymphoblastic leukemia clinical trials, the total duration of therapy for girls is 2 years from the start of interim maintenance and for boys is 3 years from the start of interim maintenance. L2 65% of Large and heterogeneous cells, adult cases heterogeneous chromatin, irregular nuclear shape, and nucleolus often 14% of large. L3 5% of adult Large and homogeneous cells with cases multiple nucleoli, moderate deep blue 1% of cytoplasm, and cytoplasmic pediatric vacuolization that often overlies the nucleus (most prominent feature). About 5% have a translocation between chromosomes 4 and 11, also predicting a poor prognosis. Those who go into remission within 4 to 5 weeks have a better prognosis than those who take longer. Approximately 17,000 new cases are reported yearly in the United States, but researchers believe the actual figure may be up to 38% higher as many cases are not reported to the tumor registry. These patients have median survival of 13 months with minimal responses to chemotherapy. Thrombocytopenia and anemia are important negative variables, suggesting a more aggressive course of the disease. I Absolute lymphocytosis with B No anemia or lymphadenopathy without thrombocytopenia with hepatosplenomegaly, anemia, or three or more areas of thrombocytopenia. Symptoms Patients are often asymptomatic at the time of diagnosis, especially in the early stages of the disease, but they are progressively more at risk for infection because of defects in humor and cell-mediated immune systems. Lymph nodes typically are enlarged and painful as lymphocytes become trapped in the nodes. Patients may complain of abdominal fullness and discomfort and early satiety because of splenomegaly. Frequent infections occur, including herpes zoster, Pneumocystis jiroveci, and Candid albicans. Typically, patients with low risk or Binet A classification are simply monitored because early chemotherapy has not been associated with increased survival. Corticosteroids are commonly used to treat autoimmune hemolytic anemia and thrombocytopenia. The first line agent is fludarabine, which is either given alone or in combination with cyclophosphamide and/or rituximab (a monoclonal antibody). Summary Leukemia is a group of malignant disorders affecting the blood and blood-forming tissues in the bone marrow, lymphatic system, and spleen. Leukemias are classified as lymphoid or myeloid, depending on the affected stem cell type, and may be acute or chronic. Two primary concerns with leukemia are neutropenia, which increases risk of infection, and thrombocytopenia, which increases risk of bleeding. Nomenclature and identification of the streptococci the classification of streptococcal species is complex and sometimes confusing. Many new species have recently been added to the genus Streptococcus and strains from some species have been reclassified. In the 1980s, some species of Streptococcus were moved to the new genera Lactococcus and Enterococcus. Recently, six more new genera — Abiotrophia, Granulicatella, Dolosicoccus, Facklamia, Globicatella and Ignavigranum — were established; these genera mainly contain organisms that previously belonged to the genus Streptococcus. Clinical identification of the streptococci is based partly on their hemolytic reactions on blood agar and Lancefield grouping. Beta-hemolytic streptococci are those that completely lyse the red cells surrounding the colony. Alpha-hemolytic streptococci cause a partial or “greening” hemolysis around the colony, associated with the reduction of red cell hemoglobin. In many cases, it is of limited value to distinguish alphafrom gammahemolysis; many species can be described simply as “non-beta-hemolytic. The species and age of the red cells, other properties of the medium, and the culture conditions affect hemolysis.
It is considered acute when it lasts for less than 4 weeks (typically associated with a bacterial or viral infection) and chronic when it persists for more than four weeks blood vessels popping in eye buy propranolol 80 mg with visa. Exudative diarrhea is characterized by the presence of blood and/or pus in the stool blood vessels cover approximately propranolol 80 mg for sale. Double-Dummy A research testing method in which patients in all treatment groups receive medication of the same appearance cardiovascular system development buy discount propranolol 80 mg line, one of which is inactive (placebo) and the other active capillaries tight junctions purchase propranolol master card. See also Efficacy Efficacy the therapeutic effect of an intervention as demonstrated or observed in a controlled setting, such as a clinical trial. See also Effectiveness Emesis Emesis is the complex reflex consisting of ejecting the contents of the stomach through the mouth. Also known as vomiting, this reflex can be triggered by various endogenous or exogenous factors. Epithelium the cellular avascular tissue layer that covers all free cutaneous, mucous and serous surfaces. G G-Protein One of several mediators of activated cell surface receptors and their enzymes and ion channels. They are responsible for the signal transduction pathways which alter the concentration of intracellular second messengers. G-Protein-Coupled Receptor Cell surface receptors that are coupled to G proteins. They have seven membrane spanning domains and have been divided into two subclasses: those in which the binding site is in the extracellular domain. Activation can result in potent anti-inflammatory activity as well as regulation of several cardiovascular, metabolic, immunologic and homeostatic responses. It regulates several cardiovascular, metabolic, immunologic and homeostatic responses. Headache Diffuse pain experienced in various regions of the head, not limited to the area of distribution of any single nerve. Hemagglutinin A membrane glycoprotein (550 amino acids) of the influenza virus type A involved in receptor binding and fusion. Hepatitis A A form of viral hepatitis that is known as infectious hepatitis because it can spread through contact with oral secretions or stool or through sexual contact. Symptoms of hepatitis C may not manifest until the chronic stage and include jaundice, fatigue, abdominal pain, loss of appetite, intermittent nausea and vomiting. Cirrhosis from hepatitis C is the major condition responsible for the majority of orthotopic liver transplants in the U. The virion consists of a nucleocapsid core and two envelope proteins within the lipid bilayer. Hepatitis, Fulminant A rare syndrome usually associated with hepatitis B and, in rare cases, with hepatitis A or E. It is characterized by rapid clinical deterioration and the onset of hepatic encephalopathy. The liver parenchyma undergoes massive necrosis and the organ size decreases significantly. Functional renal failure sometimes occurs; in some cases, coma may develop within hours of onset. The virus is spread via sexual contact with an infected individual, exposure to contaminated blood. Immunization, Active the means by which antibody production or cell-mediated immunity is stimulated by giving the antigen in the form of a vaccine or through exposure to naturally occurring antigens such as bacteria, viruses or fungi. Immunocompromised Used to describe persons with an underdeveloped (as in the very young) or impaired immune system. Immunoglobulin A (IgA) Major class of immunoglobulins found in mammalian serum, body fluids. Of the five types of Igs (IgM, IgG, IgA, IgE and IgD) in the body, only IgE has been shown to be involved in allergic reactions. IgG2 differs from the rest in that it cannot be transferred across the placenta and IgG4 does not fix complement. Inflammation the response of the immune system to an injury caused by irritation, infection, physical damage or chemically-induced cell stress. The five symptoms of inflammation are redness, heat, swelling, pain and dysfunction of the affected area, although not all five need be present at any one time. It is characterized by inflammation of the nasal mucosa, the pharynx and conjunctiva and by headache, generalized myalgia, fever and chills. The incubation period is one to three days and the disease can persist for three to ten days. Influenza Virus Serologically different viruses (A, B and C) from the orthomyxovirus family that cause influenza. Inoculum Cells or viruses added to start a culture or infect a culture of cells, respectively. Interferons have been classified into three main subtypes (alpha, beta and gamma) based on interaction with antibodies, chemical properties and cellular origin. Both isotypes are secreted by monocytes, macrophages and/or accessory cells early during an immune response and they activate T and B cells, stimulate T cell proliferation and enhance T and B cell responses to antigens. It inhibits the synthesis and release of proinflammatory cytokines produced by stimulated monocytes and macrophages and is under development for rheumatoid arthritis. This cytokine has been implicated as playing a role in rheumatoid arthritis and is overexpressed in psoriasis and pulmonary inflammatory diseases. It is currently under investigation as an immunotherapeutic cancer agent and as an angiogenic factor. In particular, this cytokine is suspected to be involved in the activation and maintenance of the Th17 subset of inflammatory T cells. Leukocyte A member of a heterogeneous cell population, also known as white blood cells, found in various tissues and circulating blood that is formed in myelopoietic, lymphoid and reticular portions of the reticuloendothelial system. Pathologic lymphocytosis occurs in chronic inflammation, recovery from acute infection, lymphocytic leukemia and hypoadrenocorticism and indicates a strong immune stimulus of chronic duration from a bacterial infection, viremia or immune-mediated disease. Missense Mutation A mutation that converts a codon coding for one amino acid to a codon coding for another amino acid. An example is Mycoplasma pneumoniae is responsible for pneumonia in humans and some domestic animals. Some common causes include motion, early pregnancy, intense pain, emotional stress, gallbladder disease, food poisoning, enteroviruses among others. Paramyxovirus is a genus of this family of which human parainfluenza virus type 1 is a member. This stage of drug development is intended to facilitate the transition from animal to human studies. The trials evaluate doses determined in animal studies that are only 1/100th of those expected to be required for therapeutic effect. These studies usually involve large patient populations randomized to receive a new or standard therapy and/or placebo. Pneumonia is a form of acute respiratory infection that inflames the alveoli in the lungs which in healthy individuals fill with air during inhalation. Pneumonia may be caused by a variety of organisms, including bacteria, viruses and fungi. The mixture is cooled to 60fiC, allowing the artificial primers to wind to the ends of the template chains. Multiple identical or nearly identical subunits called monomers are linked together in a chain to form a polymer. For example, monosaccharides polymerize into polysaccharides, amino acid monomers into proteins and nucleotide monomers into nucleic acid polymers. Polymorphonuclear Leukocytes White blood cells with multilobed nuclei and cytoplasmic granules. They include neutrophils (granules stain with neutral dyes), eosinophils (granules stain with eosin) and basophils (granules stain with basic dyes). Preclinical Studies Experimental in vitro and/or in vivo testing in animals performed prior to clinical studies to determine the biological activity and safety of an agent. Prognosis An assessment of the likely outcome of the disease judged from general experience of the disease and the age and condition of the individual patient.
For example heart disease handout buy propranolol 40 mg visa, if the object or body can is horizontal (x) cardiovascular disease ppt discount propranolol express, although they may be oriented in any be seen to heart disease and stroke statistics purchase propranolol american express move up or down (vertically) and to capillaries of the brain are surrounded by 80 mg propranolol with mastercard the right manner. It should be emphasized that the designations of or to the left (horizontally) as viewed from one direction, these axes as x or y is arbitrary. What is important is to be consistent in four quadrants in which movements to the left of the in naming the axes. These two axes (x and y) form a plane origin result in negative x-values and movements below that is referred to as the x–y plane. It is an In certain circumstances, the axes may be reoriented advantage to place the reference system such that all of such that one axis (y) runs along the long axis of a segment the points are within the first quadrant, where both xand and the other axis (x) is perpendicular to the y-axis. All coordinate values are positive in the first quadrant of the reference system, where the movements are horizontal and to the right (x), vertical and upward (y), and horizontal and forward (z). Correspondingly, negative movements are to the left (x), downward (y), and backward (z). In this system, the coordinates can designate any point on a surface, not just a plane, as in the 2D system. A 3D kinematic analysis of human motion is much more complicated than a 2D analysis and thus will not be addressed in this book. Figure 8-5 shows a 2D coordinate system and how a point is referenced in this system. It is important to remember that the number designated as the x-coordinate determines the distance from the y-axis and the y-coordinate determines the distance from the x-axis. This reference system has three axes, each of which is Before recording the movement, the biomechanist perpendicular or orthogonal to the others, to describe a usually places markers on the end points of the body segposition relative to the horizontal or x-axis, to the vertiments to be analyzed, allowing for later identification of cal or y-axis, and to the mediolateral or z-axis. For example, if physical space, three pieces of information are required to the biomechanist is interested in a sagittal (2D) view of accurately locate parts of the body or any point of interest the lower extremity during walking or running, a typical because the concept of depth (z-axis; medial and lateral) placement of markers might be the toe, the fifth metamust be added to the 2D components of height (y-axis; up tarsal, and the calcaneus of the foot; the lateral malleolus and down) and width (x-axis; forward and backward). The intersection single frame of a recording illustrating a sagittal view of a runner using these specific markers. Appendix C presents 2D coordinates for one complete walking cycle using a whole-body set of markers. In a kinematic analysis, the time interval between each frame is determined by the sampling or frame rate of the camera or sensor. Video cameras purchased in electronic stores generally operate at 24 to 30 fields or frames per second (fps). High-speed video cameras or motion capture units typically used in biomechanics can operate at 60, 120, 180, or 200 fps. Usually, a key event at the start of the movement is designated as the beginning frame for digitization. For example, in a gait analysis, the first event may be considered to be the ground contact of the heel of the camera-side foot. With camera-side foot contact occurring at time zero, all subsequent events in the movement are timed from this event. The data collected for the walking trial in Appendix C are set up in this fashion, with data presented from time zero with the right-foot heel strike through to 1. If a quantitative analysis is conducted, it is necessary to report the findings in the correct units of measurement. For either a 2D or a 3D analysis, a global or stationIn biomechanics, the metric system is used exclusively in ary coordinate system is imposed on each frame of data, scientific research literature. Every quantity of way, each segment end point location can be referenced a measurement system has a dimension associated with it. Each dimension has a unit associfirst frame, plot the ordered pairs of x, y coordinates for ated with it. For example, when one runs a the analysis of the temporal or timing factors in human race that is 5 km long, the distance or the magnitude of movement is an initial approach to a biomechanical analythe race is 5 km. In human locomotion, factors such as cadence, stride described with a single number include mass, volume, and duration, duration of the stance or support phase (when speed. Other quantities, however, cannot be completely the body is supported by a limb), duration of swing phase described by their magnitude. These quantities are called (when the limb is swinging through to prepare for the vectors and are described by both magnitude and direcnext ground contact), and the period of nonsupport may tion. The knowledge of the temporal patterns ment, the distance and the direction are important. Many 288 Section iii Mechanical Analysis of Human Motion Vectors may also undergo forms of multiplication that are used mainly in a 3D analysis and, therefore, are not described in this book. Multiplying a vector by a scalar changes the magnitude of a vector but not its direction. Therefore, multiplying 3 (a scalar) times the vector A is the same as adding A + A + A. A vector may also be resolved or broken down into its horizontal and vertical components. In Figure 8-9A, the vector A is illustrated with its horizontal and vertical components. A right triangle can consist of the two because they are equivalent in magnitude and direction. Consider a right triangle with sides x, y, and a, in which a is the hypotenuse of the right triangle. The sine of the angle theta (u) of the quantities calculated in kinematic analysis are vecis defined as: tors, so a thorough understanding of vectors is necessary. Vectors are represented by an arrow, with the magnilength of side opposite u sin u fi tude represented by the length of the line and the arrow hypotenuse pointing in the appropriate direction. Vectors or are equal if their magnitudes are equal and they are y pointed in the same direction. Graphically, vectors r may be added by placing the tail of one vector at the head of the other vector. In Figure 8-8B, the vectors are not in the same direction, but the tail of B can still be placed at the head of A. Joining the tail of B to the head of A produces the vector C, which is the sum of A + B, or the resultant of the two vectors. These two valx = a sin u2 ues identify the point relative to the origin of the coordinate system. Resolution of this vector into x = a cos 25° horizontal and vertical components can be computed in a x = 12 fi 0. The vertical component of the vector can be It is common to work with multiple vectors that must computed using: be combined to evaluate the resultant vector. Vectors can be graphically combined by connecting the vectors head y = a sin u1 to tail and joining the tail of the first one with the head of = a sin 155° the last one to obtain the resultant vector. This composition of multiple vectors can To illustrate, the two vectors shown in Figure 8-8B will be applied to any number of vectors. Units of length are used to x = 10 cos 45° measure the position of an object from a reference axis. The reference is the y = 5 sin 0° water surface, and the diver’s position is 10 m above the y = 5 fi 0. The position of the diver may be determined = 0 throughout the dive with a height measured from the x = 5 cos 0° water surface. As previously mentioned, the analysis of video or sensor frames determines the position of a body x = 5 fi 1. The walking To find the magnitude of the resultant vector, the horiexample in Appendix C has the 2D reference frame origizontal and vertical components of each vector are added nating on the ground in the middle of the experimental and resolved using the Pythagorean theorem: area. This makes all y values positive because they are relative to the ground and all x values positive or negative depending on whether the body segment is behind (2) or in front (1) of the origin in the middle of the walking area. Motion, therefore, may be defined as a progressive change of posiC fi 2x 2 fi y 2 tion over time. In this example, the diver undergoes a 2 2 10-m displacement from the diving board to the water. In Figure 8-11, a runner starts the race, runs to point A, turns right to point B, turns left to point C, To find the angle of resultant vector, the trigonometric turns right to point D, and then turns left to the finish. Displacement, on the other hand, is a straight line can be used to calculate the angle between the vectors: between the start and the finish of the race.
Public anxiety had been mounting steadily since the end of March when government ofcials descended on Amoy Gardens clogged arteries 100 propranolol 80 mg with mastercard. The following day cardiovascular disease or disorder generic 80mg propranolol mastercard, 1 April 113 blood vessels answers order propranolol 80mg without a prescription, a 14-year-old boy decided to cardiovascular consultants generic propranolol 80mg line play an April Fool’s prank by posting a bogus message on the website of a local newspaper. The message stated that Hong Kong was about to be declared an “infected port,” that the Hang Seng Index had collapsed, and that its chief executive had resigned. Terrifed, people rushed to grocery stores to stock up on rice and other essential commodities, then bolted the doors of their apartments and telephoned and texted those who had not yet heard the “news. Prior to 2 April, Hong Kong’s airport had been one of the busiest in the world, processing nearly 100,000 inbound passengers a day. Within weeks passenger numbers had fallen by two-thirds, and by the end of the month Hong Kong was seeing just 15,000 arrivals a day. In Britain, Hong Kong children attending a boarding school on the Isle of Wight were informed that they would be quarantined on the island following the Easter vacation. At the University of California, Berkeley, Hong Kong students and their families were asked to stay away from graduation ceremonies. Meanwhile, in Switzerland, health ofcials issued a decree banning anyone who had been in Hong Kong, Singapore, China or Vietnam since 1 March from attending the World Jewellery andWatch Fair in Basel and Zurich. Hong Kong, which usually mustered the second biggest delegation after the Swiss, threatened to sue, but the Swiss refused to budge, prompting one Hong Kong company to erect a sign over an empty booth that read: “Due to our fear of Swiss Aggravated Respiratory Syndrome we are going home. As a lawyer and flmmaker recently arrived in Hong Kong recalled, “It was no longer an animal fu, but ‘Severe Acute Respiratory Syndrome’—an altogether more urban-sounding virus. And why, if the disease was so infectious, had none of the hotel staf at the Metropole contracted itfi Until Peiris identifed the coronavirus and diagnostic tests became available, investigators had no way of checking these intuitions. Now, they were in a position to gather samples from diferent locations of the Metropole and at Amoy Gardens and send them to Peiris’s laboratory to be analyzed. In late April a team of environmental health experts from Health Canada arrived in Hong Kong to assist the Department of Health with its investigation, and on 16 May they reported their fndings. The investigators had concentrated their eforts on the ninth foor of the Metropole as this was where most of those who had fallen ill had been staying. However, four positive samples had been collected from the carpet and door sills outside his room and the rooms on either side, suggesting that he may have thrown up when he stepped out of his room or else spread the virus when he coughed in the corridor. In addition, four positive samples were collected from the air inlet fan of the elevator that served the ninth foor. That suggested that Liu’s body fuids had been aerosolized when he entered the elevator, meaning that anyone who stepped out of the ninthfoor lift shortly afterward would have been exposed. However, the investigators dismissed the theory that the virus was transmitted through contact with elevator buttons, door handles, or handrails, pointing out that, if that had been the case, then other guests in the hotel, as well as staf, would also have been infected. As the virus had been found in stools for at least two days and the investigators suspected the man had had a high viral load, they speculated that his faeces could have been the cause of the outbreak. Noting that many of the drain taps in the bathrooms had dried out or been removed, and that many residents had bought exhaust fans that were six to ten times more powerful than were needed for such a small space, the investigators suggested that contaminated faecal matter could have been sucked into the bathrooms via the sewerage system when people showered. Alternatively, contaminated air from nearby bathroom vents could have carried droplets from adjoining bathrooms via the light well, releasing contaminants through the open windows of apartments above and below. Another factor that may have contributed to the spread of the virus was a sixteen-hour water shutdown that occurred in Block E on the evening of 21 March in order to allow a broken pipe to be fxed. During that period, many residents fushed their toilets with buckets of water, a practice that may have resulted in splashing, increasing the risk of contamination. Nor, despite the fears generated by the reports of hospital super spreaders, was it an efcient aerosol, meaning it was unlikely to recommend itself to terrorists. Having said that, at the point when patients develop symptoms—typically two to seven days after infection—they are highly infectious and one person can infect as many as three other people, possibly more if infection controls are inadequate and there is frequent contact between patients and nurses, as occurred in hospitals. As several of those cases had been traced to chefs and seafood merchants, the obvious places to look were the markets where restaurants bought exotic animals for their clientele. In May 2003 Peiris’s colleagueYi Guan packed a satchel with syringes, swabs and sample vials and set of by train for Shenzhen’s Dongmen Market. There, working with the Shenzhen Centers for Disease Control, Guan approached animal traders and asked to take nasal samples and faecal swabs. Those who demurred were reassured that if any animal died they would be compensated up to the sum of 10,000 Hong Kong dollars (about $6), but more often than not Guan was able to anaesthetize the animals and take samples on the spot. As you might expect, there was a wide array of animals on sale: raccoon dogs, Chinese ferret badgers, beavers, Chinese hares and Himalayan palm civets. They showed that four out of six of the palm civets carried a coronavirus that was 99. In addition, one of the raccoon dogs carried the same virus as the civet cats, while one ferret badger had antibodies to the virus. When the animal viruses were sequenced, they were found to have a short section of twenty-eight nucleotides that were missing in the human virus, leading Guan and his colleagues to conclude that it was the absence of this sequence, or perhaps a random mutation, that had enabled the virus to transmit easily between humans. Moreover, 40 per cent of the animal traders whose blood was tested and 20 per cent of those involved in slaughtering the animals had antibodies to the virus carried by the civet cats, indicating that the virus had probably been circulating between animals and market traders for some time without causing disease. Even though other researchers were not immediately able to replicate Guan’s fndings, the Chinese halted sales of ffty-four species of wild animals while further tests were conducted in other markets. However, it did not resolve the question of where the virus normally resided in nature. One explanation was that the civets had been infected by some other animal in the wild, or on the farms where they bred. In other words, civet cats and other animals popular in Chinese markets might be “intermediate hosts that increase the opportunity for transmission of infection to humans. However, those viruses were missing a crucial protein that binds to a receptor on the surface of human cells, meaning that the bat viruses could not infect humans directly—they would have to pass through an intermediary animal host frst. Then, in 2013, scientists from China, Australia and the United States announced another discovery: after visiting a cave inhabited by horseshoe bats in Kunming, in southern China, they identifed two new strains of coronavirus. Unlike previous strains isolated from bats, these did contain the crucial protein enabling them to infect mammalian cells, including cells lining the human lung. However, it seems that nothing could sate the Chinese appetite for the exotic mammals, and soon customer demand had driven up the price for civets to $200, making it likely they would fnd their way onto restaurant menus whatever action the authorities took. Roasted whole, braised or added to soups, civets are considered a delicacy by the Chinese. They are also said to be full of yang, a heat-giving energy source that, according to traditional beliefs, helps people stay warm in cold weather. That it found these human vessels at the Metropole Hotel was bad luck for the hotel’s owners, but it could just as easily have been any Hong Kong hotel catering to international business travellers and package tourists. Once it was airborne, the virus ensnared the globe in a web of interconnecting lines, like a Lufthansa map iterated to the power of ten. This was something new and scary, serving as a reminder that unlike the physical borders between countries, international airspace is highly porous and vulnerable to interfows of people and pathogens. Coming in the wake of 9/11 and the anthrax letter mailings, it was also a reminder that, in the words of Peiris and Guan, “‘nature’ remains the greatest bioterrorist threat of all. Previously, the Communist Party had insisted there were just thirty-seven cases in the Chinese capital. Thanks to the institution of mass quarantines and the construction of new treatment facilities—a feat the Chinese accomplished virtually overnight—disaster was averted, but it was a close call. However, had the virus become seeded in poorer, rural areas lacking sophisticated medical facilities, it could have been a diferent story. As airports shut and pictures of nervous Hong Kong commuters fashed around the globe, the tourism, aviation and service sectors took a massive fnancial hit, resulting in an estimated $50 billion in losses to the global economy. He predicted such measures would have met greater resistance in North America, where people tended to be more litigious, and to a lesser extent in western Europe. The tree was a wellknown roosting spot for lolibelo—a species of insectivorous, long-tailed bats—and the children liked nothing better than coaxing the tiny grey mammals from their hiding places. In a region where chimpanzees and other sources of bushmeat are scarce, the Angolan free-tailed bat Mops condylurus was an important source of protein. Indeed, for the children of Meliandou the tree stump en route to the village watering hole was the nearest thing to a hamburger stand and Mops condylurus was the equivalent of a Big Mac. In recent years, as more and more forested areas around Meliandou were cleared for palm oil cultivation, the lolibelo had taken to nesting under the roofs of the villagers’ simple mud-and-wattle dwellings and had become a familiar sight. What is known is that shortly after visiting the tree stump, one of the children, a two-year-old boy named Emile Ouamouno, developed a high fever, with vomiting and bloody stools. His father gave him soup in the hope of calming his stomach, but nothing would halt the progress of his illness and on 6 December Emile died.
Cheap propranolol online. Program Spotlight - Diagnostic Medical Sonography.