Shigella flexneri Shigella flexneri, a facultative anaerobe belonging to the family Enterobacteriaceae, is a Gram-negative rod that is the causative agent of diarrhea and dysentery in humans. Potentially life-threatening, S. flexneri's effects include bacteremia, hemolytic uremic syndrome (HUS) and toxic megacolon (4). The principle disease of diarrhea and dysentery caused by this pathogen is known as shigellosis. 10-100 organisms are sufficient to cause disease, and transmission is generally from person-to-person by way of fecal-oral (2). Shigellosis can be characterized as a disease with over 60% incidence in children ages 1-5 (6). Life cycle: S. flexneri causes infection via bacterial penetration of the mucous membrane in the human colon. Humans are the only known reservoir to this pathogen (7). Following invasion of M cells and upon contact with the epithelial cells of the colon, S. flexneri releases Ipa proteins through a type three secretion system. Once inside the host cell, Ipa proteins activate small GTPases in the Rho family as well as c-src, a protooncogene, leading to cytoskeletal rearrangements. This alteration to the cytoskeleton allows the bacteria to be macropinocytosed by the host cell. Once inside the host, the pathogen colonizes the cytoplasm. IcsA, a bacterial surface protein, activates the host protein N-WASP and, in turn, stimulates actin assembly by host Arp 2/3. Thus, S. flexneri develops actin-based motility enabling the pathogen to become efficient at cell-to-cell spread and host cell cytoplasmic colonization. Infected cells become highly proinflammatory and secrete IL-8. IL-8 attracts neutrophils to the site of infection. The influx of neutrophils, chemokines and cytokines to the area damages the epithelial layer permeability and, in turn, advocates further S. flexneri invasion (6). Once initial invasion of S. flexneri occurs, the targeted epithelial cells require 45 minutes to 4 hours to mount an inflammatory response (8). A diagram outlining S. flexneri's type three secretion system can be viewed at: http://www.grad.ucl.ac.uk/comp/2003/jointposter/gallery/index.pht?entryID=29 Virulence: A 214-kb virulence plasmid encodes for S. flexneri's entry into human epithelial cells and intra-intercellular movement (6). Once in contact with the target cell, Ipa proteins (IpaB, IpaC and Ipa D) encode for a specific type III secretion system, thus, enabling entry of the pathogen into the target cell and characterizing S. flexneri with an invasive phenotype (1). One 30-kb block of the plasmid contains genes at the ipa/mxi-spa locus.
Many scientists often find themselves wondering if the tri-state tornado was really a single massive tornado or if it was part of a family of tornadoes that continuously evolve from one supercell to another. Only one factor stands in the way of this theory and that is a cyclical supercell usually has breaks in its destructive path. The tri-state tornado's path of damage appeared to be continuous despite two slight decreases in the destruction. One of which was near the onset of the storm, and one near the demise. No matter which is believed, one thing is for certain, and that is a storm like the tri-state tornado could very well happen again, but there is no telling when or where it may occur.
Her final love isn’t intended to appease another person, values respect, and pushes past trials while exemplifying kindness (1 Corinthians 13:4). This outward expression of Janie’s maturity and faith allows her to lessen her dependence on a husband. On the final page of the novel Janie finally finds peace, without a man standing by her side (193). She recognizes that in her first two marriages, abuse, conformity, and pride were rampant and that these characteristics strongly oppose the marriage she viewed in nature. However, Janie finds a love with Tea Cake that “never gives up, never loses faith, is always hopeful, and endures through every circumstance,” which she remembers and refuses to let die (1 Corinthians
The novel is not a story of Janie’s quest for love but rather than her quest for sense of security and independence. Janie’s improvement has been charted along the way as she studies the use of language and discovering her relationship to her own voice. At the end of her journey, Janie is stronger and more confident then she was when returns to Eatonville. As a young girl, Janie has some romantic bones in her body (Shmoop Editorial Team). Her magical experience underneath a blossoming pear tree has a profound effect on her; she associates the pollination of pear tree blossoms with the epitome of a romantic experience (Shmoop Editorial Team). When we first see Janie, she is unsure of herself or how she wants to live. Janie’s revelation under the blossoming pear tree initiates her quest when shares her story with Pheoby. After seeing the pear tree, Janie is immediately inspired to seek love, which leads to her first kiss and lifetime searching for true love (Shmoop Editorial Team).
According to Webster’s Dictionary, a tornado is a rotating column of air accompanied by a funnel shaped downward extension of a cumulonimbus cloud and having a vortex several hundred yards in diameter whirling destructively at speeds of up to three hundred miles per hour. There are six classifications of tornadoes, which are measured on what is known as the Fujita Scale. These tornadoes range from an F0 to an F5, which is the most devastating of all. Abnormal warm, humid, and oppressive weather usually precede the formation of a tornado. Records of American tornadoes date back to 1804 and have been known to occur in every state of the United States.
On May 20th, 2013 a EF 5 tornado hit Moore, Oklahoma and surrounding towns, with a path as wide as 1.3 miles wide (2.1 km) and had a wind speed, estimated at its peak, of 210 miles per hour (340 km/h). Killing 24 people, and injuring 377, this was one of the United States worst tornadoes in the past few years, along side the Joplin, Missouri tornado, in 2011. One of Mother Nature’s most dangerous and still very mysterious phenomenons averages about 1,200 reported each year, resulting in 80 deaths and injuring 1500. With very little known about them, especially whether or not they will form is one of the questions that plague meteorologist to this very day. What causes tornadoes, how does the tilt and gravity of the earth affect the winds to produce a tornado, and what will the future hold about our understanding of tornadoes?
... and quickly grow. Secondly, invasins help the bacteria spread in the host’s tissues. An invasion is a protein that acts locally to damage host cells to facilitate the growth and spread of the pathogen. More simply, Staphylococcus aureus and Streptococcus pyogens have a small army of invasins that basically attack the host very quickly and spread the bacteria out far – into the blood and organs. Another virulence factor of both Staphylococcus aureus and Streptococcus pyogens is their cellular secretions. The secretions include antigens, enzymes, and toxins that assist with various functions needed to feed the bacteria and fend off the host’s immune defences.
Tornadoes are devastating atmospheric events that affect the ecology and the lives of people in their paths. Tornadoes are defined as “a violently rotating column of air, in contact with the ground, either pendant from a cumuliform cloud or underneath a cumuliform cloud, and often (but not always) visible as a funnel cloud” (Glossary of Meterology, 2011). The Tri-state tornado was the most deadly tornado in the United States. It stayed on the ground for a total of 219 miles through areas of Missouri, Illinois, and Indiana, killed a total of 695 people, and an estimated $16.5 million in damages (National Weather Service, 2011). Luckily, the tornado’s path was largely rural farmland with scattered small towns between them.
...ld last for up to 1 week but vary from client to client and depending on what the clients desired outcome is. Clients with oily, acne prone skin types should maintain regular treatments of 1 to 2 times weekly and eventually once a week to maintain and prevent further acne and for sanitizing the skin. Other clients with mature skin should maintain a regular treatment of once weekly to maintain plumpness in the skin and to help with the appearance with fine lines and wrinkles. Anyone can have this treatment as desired as it is known for its relaxing properties as well.
A tornado requires some basic ingredients to come together. First, energy in the form of warm, moist air must exist to feed thunder storms. Second, there must be a top layer of hot, dry air called a cap. This air acts like a lid on a simmering pot, holding in the warm air that’s accumulating in the atmosphere below until the storm’s ready to burst. Last, there has to be rotating winds speeding in oppositedirections at two different levels in the atmosphere, a phenomenon called wind shear, can cause the storms to rotate. Tornado alley is perfectly situated to meet these requirements. (1)
Although much is unknown on the causes of R.A. there are many things we see in correlation with the onset of disease. These include Bacterial, viral, and fungal infections. The mycoplasma bacteria, Epstein-Barr virus, cytomegalovirus, parvovirus and rubella (German measles) virus have all been considered as possible causative factors but conclusive evidence is still lacking (Zeliadt, 2010). Many times there have only been considerations for infectious bacteria causing this disease but now that idea is being questioned. A study involving mice in bacteria free cages showed that the friendly gut dwelling segmented filamentous bacteria (SFB) can cause onset of R.A. in greater numbers than those without. The mice that did no...
1. According to the USA Today Tornado Information website, a tornado is a "violently rotating column of air in contact with the ground and pendant from a thunderstorm." Therefore, thunderstorms are the first step in the creation of a tornado.
Bacterial Adhesions:(39,47) :Target specific drug delivery can be achieved by adherence of pathogenic bacteria to the mucosal membrane. K-99 fimbriae , an attachment protein derived from E.coli can be attached covalently to the polyacrylic networks.
A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm (or sometimes as a result of a hurricane) and produced when cool air overrides a layer of warm air, forcing the warm air to rise rapidly. Tornadoes can cause a lot of damage and even deaths. The damage from a tornado is a result of the high wind velocity and wind-blown debris. Tornado season is generally March through August, although tornadoes can occur at any time of year. They tend to occur in the afternoons and evenings: over 80 percent of all tornadoes strike between noon and midnight. From 1950-1995 the total number of tornadoes in Michigan was 722, with an average of 5 deaths and 3,217 injuries (70 a year average) resulting from the storm a year.
Exposing students to the power of social media in the classroom is an important part of preparing them to be active and positive digital citizens in a 21st century world. In the last two years, my own students have rapidly been drawn to Twitter, Instagram, Tumblr, and many other social networking platforms. They upload, share, and connect with others often without any regard to how their digital footprints may reflect them as individuals. Having continuous conversations with students about the choices that they make can lead to positive results. Students don't realize how powerful social media platforms can be in terms of networking, researching, and engaging in academic conversations. It makes me laugh every time I hear them whisper about my colleague Heather's or my Twitter feed. First of all kids, I can hear you. Second of all, yes, social media can be an amazing way to give and exchanged knowledge.
All thunderstorms are characterized by updrafts, rising air currents which supply the warm, humid air that fuels thunderstorms; sometimes, however, the column of rising air becomes a vortex—a funnel cloud, or if it reaches the ground, a tornado. A tornado is often located at the edge of an updraft, next to air coming down from the thunderstorm with falling rain or hail. This explains why a burst of heavy rain or hail sometimes announces a tornado’s arrival. As air rises from the ground in the tornado’s vortex, a low-pressure area is created near the ground. Air rushes to fill this area, causing additional damaging to areas not directly hit by the tornado. As air rushes into the vortex, its pressure lowers, cooling the air. T...