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Some test media are designed to provide multiple test results. These include Kligler's iron agar, which determines fermentation reactions for glucose and lactose and the production of hydrogen sulfide. Hydrogen sulfide is produced as a result of the breakdown of the amino acid cysteine. It contains .1% glucose, 1% lactose, peptone, ferrous salts, and phenol red as a pH indicator. This media is prepared as a slant and is inoculated by streaking the slant and stabbing the butt of the tube. This medium is useful in the differentiation of the gram-negative enteric bacteria. When only glucose is utilized the slant turns red and the butt of the test tube is yellow. The slant is red because glucose was degraded aerobically and the ammonia released from peptone utilization caused the aerobic slant to become alkaline. The butt of the tube is yellow because glucose was fermented anaerobically. Kligler's iron agar is a good example of how one type of media can be used to test multiple characteristics in a given species of bacteria.

Microscope eyepieces are the third basic optical component of compound microscopes. The other basic components are the objectives and substage condensers. Eyepieces derive from two basic designs, Ramsden and Huygenian. No matter the design, the important issue is the contribution that the eyepiece(s) make to the optical system that we call the microscope. The eyepiece, also referred to as the microscope ocular, takes the real primary image that is formed at the intermediate image plane and magnifies it so that the eye can view the resulting virtual image at the desired magnification. The total magnification is equal to the product of the objective and the ocular. Thus, a 4X objective combined with a 10X eyepiece produces a final magnification of 40X. Eyepieces come in varying powers with 10X being the most common. Other available powers include 5X and 20X. While the eyepiece does not contribute to the resolution of the primary image, it is important that it be of the same optical quality as the objective since an inferior quality eyepiece can degrade the image produced by the objective. Some objectives can also support accessory components such as pointers and measuring reticles. When purchasing a microscope be sure that the eyepiece(s) will support the ultimate purpose of the system.

Bacteria use a variety of degradative and hydrolytic enzymes to degrade large macromolecules into smaller units that can be imported into the cell. Because of the presence of the cell wall, bacteria lack the ability to surround and engulf their food by phagocytosis. Amylases and cellulases degrade starch and cellulose into simple sugars that are then transported into the cell where they are metabolized. Proteases such as casein and gelatin degrade proteins and peptides into amino acids. Lipases convert triglycerides into fatty acids and glycerol. Bacteria also hydrolyze small molecules because they can then acquire carbon compounds. Tryptophane is split into pyruvate and indole by the enzyme trytophanase. The pyruvate is then metabolized however the indole accumulates in the growth medium. The accumulation of indole is the basis for a test that differentiates bacteria that produce tryptophanase from those that do not. The presence or absence of various hydrolytic and and degradative enzymes can be used to identify bacteria.

Osteoporosis literally means porous bone. It is described as the thinning of bone tissue and loss of bone density over time. There are several reasons a bone can become porous. As well as it can affect a certain demographics over another. Osteoporosis is more common in women than men and is generally caused when the body doesn't create enough new bone and/or too much old bone is reabsorbed by the body. This lost of bone causes the bone to become weak and brittle, making the body more susceptible to fractures and breaks. In fact, the bones can become so weak that an innocent sneeze can cause a bone to break. The lost of bone density does not happen over night and in most cases by the time this disease surfaces with blatant symptoms, the patient is in advance stages of the disease. Homeostasis also plays a role in osteoporosis. A link to this disease is a drop in the hormones estrogen, in women over 50, and testosterone, in men over 70. Caucasian women with a history of osteoporosis in there family have a greater than average risk of developing the disease. Please see list below regarding other risk and symptom information. Risk Factors: Chronic Rheumatoid Arthritis; Chronic Kidney Disease; Eating Disorders; Corticosteriod medications every day; Hyperpathyroidsim; Amenorrhea; Binge and Surplus amounts of Alcohol; Hormone treatments for prostate or breast cancer; Low Body Weight; Smoking; Too Little Calcium in Diet; Family History of the Disease Symptoms: Bone pain or tenderness; Fractures and breaking of bone easily; Loss of height over time; Kyphosis

*** For more information regarding this disease please go to http://www.nof.org/

In 1846 and 1847 Ignaz Semmelweis discovered the importance of hand scrubbing at the Lying-In Hospital in Vienna. He was the head of obstetrics and noticed that the death rate due to childbirth fever was approaching 20%. He observed that medical students and doctors were delivering babies after being in dissection and autopsy rooms. These doctors were not washing their hands after being in these rooms. At the same time, babies delivered by midwives and nurses had a lower death rate. Semmelweis instituted a policy that required doctors to disinfect their hands with bleach prior to examining obstetric patients or delivering babies. As a result, the death rate was lowered to 1%. Today it is routine practice to wash one's hands prior to the examination of a patient and to do a complete surgical scrub before surgery. The human skin contains a wide range of microorganisms. Some protect us from harmful bacteria by outcompeting them for space. Diptheroids are gram-positive bacteria that break down the oily substance in our hair. Staphylococcus epidermidis is non-pathogenic and lives on our skin. It survives by secreting substances that kill other species of bacteria.

Microscope objectives are the heart and soul of the compound microscope. They are responsible for formation of the intermediate image that the eyepiece(s) then further magnify to produce the image that is ultimately observed, analyzed and/or photographed. Common microscope objectives are usually identified as achromats, plan-achromats and plan-apochromats. The criteria for these categories are well defined and well recognized. Achromatic objectives may account for as much as 90% of the objectives seen in everyday use. They are corrected for chromatic aberration (color anomalies) for two wavelengths of light, usually red and blue and one wavelength of light, usually yellow for spherical aberration. Achromats are readily available, inexpensive and quite useful for much of routine microscopy. They, can however, exhibit a lack of sharp focus at the edges of the field of view that we recognize as spherical aberration, but color rendition is acceptable. Plan-achromatic objectives address this lack of peripheral sharpness by incorporating additional optical elements that cause the entire visible field of view to be in sharp focus. They are somewhat more expensive than achromats, but the image improvement is worth the additional cost. Plan-apochromatic objectives offer the highest level of correction for normal brightfield microscopy. These objectives have a third color correction in the green wavelength where color vision is most sensitive and an additional wavelength of spherical correction. These additional design enhancements provide the most highly corrected brightfield images. While these objectives are the most expensive, they also provide the highest levels of sharpness, contrast and resolution for the most demanding microscopists. Microscope objectives usually have engraving on their barrels to indicate the level of correction as well as other useful information. Unmarked objectives can be assumed to be achromats. When shopping for a microscope, pay special attention to the description of the objectives to help evaluate the overall quality of the instrument you are considering and the tasks you want to accomplish with it.

Sonography or ultrasound scanning is a procedure that uses high-frequency sound waves to produce internal pictures of the human body. Unlike radiology, which uses x-rays by ionizing radition to produce a still image, sonography utilizes sound waves to create real time imaging of internal organs and processes. An ultrasound is ideal because it is non-evasive and can be use to diagnose and treat medical conditions. Ultrasounds are most commonly know in the obstetrics field to monitor growth and development of human embryos/fetuses during the prenatal period of pregnancy. However, ultrasounds are used in a variety of different medical fields including but not limited to: cardiology, gastroenterology, neurology, urology and musculosektal diagnostics. An ultrasound unit consists of several items including a console, computer, video display screen and transducer. The transducer's function is to send out sound waves throughout the tissues of the body and listen for return echoes to create an image. The image is produced from the amplitude frequency and the time it takes for the echo to return from the patients body/tissue to the transducer. In order for the transducer to work effectively a water-based gel is applied to the part of the body being examined to eliminate air pockets between the skin and transducer.

Everyday, a variety of antiseptics are used to control and/or kill microorganisms. Hospitals disinfect areas using strong chemicals such as sodium hypochlorite, which is identical to houshold bleach. Doctors and nurses use alcohol to swab areas where a needle will be injected. Betadine is used on skin prior to surgeries to ensure that bacteria does not cause infection. Municipalities use chlorine to prevent the spread of bacteria in drinking water and chemical agents are added to food to prevent spoilage. Antiseptics are agents that inhibit or kill microorganisms on living tissue while disinfectants are more harsh and used on non living objects. Some disinfectants are referred to as sterilants or sporocides, which mean they destroy all microbial life including endospores. Ethylene oxide is an example of a sterilizer that is used to sterilize objects that can't be exposed to high heat. Sanitizers, such as those used in the food industry, reduce microbial numbers to safe levels but do not eliminate all microbes. Agents that are bacteriostatic inhibit the growth of bacterial cells but do not kill them.

the rendition of the colors may be less than accurate. One way to correct for this anomaly is to use appriopriate filters in the light path. The general categories that these filters fall into include neutral density, absorptive and interference. Neutral density filters attenuate the strength of the illumination without changing the color of the light. This is important when a specific "color temperature" must be maintained in order for the specimen to exhibit correct color properties. Absorptive and interference filters work by either retarding or enhancing specific colors or color ranges in order to enhance the effect of the stain on the sample. Though they use somewhat different means to accomplish this, the end result is effectively the same. A good way to learn what filter is needed and in what strength is to experiment with familiar samples to gain an understanding of how different filters work. Brightfield microscopes apply filters to such techniques as phase contrast and fluorescence and use other filters to enhance specimen colors in cytological and histological sample preparations.