In the united States we do not need to plan for retirement Social Essay

In the united States we do not need to plan for retirement Social Security will cover our needs when we retired - Essay Example They think they are entitled to their monetary contributions which they had earned by virtue of their retirement. However, the American government indicated clearly even from the start when the law was signed that social security is not intended to be the sole income source of retired people. What the government had in mind when creating social security was to provide an alternative for people who are down and out financially but never to support them entirely for the rest of their lives. The intention was to supplement whatever incomes the retired people may have. It is also unrealistic to expect the United States government to provide for the financial, medical and other basic needs of retirees when the economics of doing so dictates otherwise. Social security became a law as America’s response to the Great Depression in which millions of workers were thrown out of work. The economy was in a shambles and it was the government only which had the means to help these millions o f poor workers who are able to work but cannot find work. Capitalism and free markets had collapsed but once the economy recovers, people are expected to find gainful employment again and set aside some money for their retirement by saving and investing part of their wages and salaries for retirement aims. Discussion Social security benefits are projected based on so many external factors just like any insurance program. Put simply, making projections even with the most powerful computer models cannot ensure any accurate outcomes. Additionally, many people have the wrong perceptions and concepts of the social security program. This safety-net law was to provide benefits for working people on their retirement, any disability, survivorship (for dependents) and death. Over the years, many other benefits were added such as those amendments for a â€Å"Supplemental Security Income† program for the aged, the blind and the disabled persons (although this is managed separately) even though they had not worked a single day before and did not contribute any social security taxes. The social security system of the United States of America works just as an insurance program would. This means it works on the assumption that everyone will be covered and all workers who are gainfully employed will contribute to the program to make it viable. Social security works on the idea that risk is spread over a big proportion of the working population. Additionally, the ideal should be more workers paying contributions to support the retired or elderly people who will now draw down on their contributions to support themselves. The social security fund comes from contributions made by people of working age. It means demographic shifts such as the graying of the population has a big impact on the future financial viability of the program. Actuarial calculations are just best estimates or assumptions about fertility, life expectancy, quality of health care and state of the economy ; these factors determine the fund’s financial viability. The ideal set-up for social security would be workers supporting fellow retired workers. When it began in 1935, the contributions of 17 workers had paid for the benefits of one retiree. By 2035, the ratio is estimated to be only 2.1 workers per beneficiary. This situation clearly is financially not sustainable to continue giving benefits. The reduced ratio of contributing workers

Using SEI Strategies in a SIOP Essay Example for Free

Using SEI Strategies in a SIOP Essay Instruction will begin by discussing the differences between fictional and non-fictional books; Students will read the non-fiction book â€Å"What If You Had Animal Teeth† by Sandra Markle. This book is filled with fun and interesting facts on animal’s different teeth. The book will be read in its entirety engaging students and creating interest. Learning objectives will be introduced using chart paper. 1. I can gather important information related to my topic. 2. I can teach my partner how to find facts related to the chosen topic. 3. I can write my own informative book Teacher will display a premade chart that describes what nonfiction is. Read the definition aloud as students track with their eyes. Create a new chart and list nonfiction characteristics that can be found in a book and discuss their purpose. Look through nonfiction books to see specific examples of the nonfiction characteristics. Inform students that we will now go back and review the book â€Å"What If You Had Animal Teeth† and we will consider what facts we are given. Go to the first page, read the sentence and ask students  to do a think/pair/share. Think: What facts are given? Discuss with your group. Prompt students to share out with the whole class. Continue with each page. Tell students that they get to practice finding more facts by reading other nonfiction animal books. Give students a list of nonfiction books to choose from. Generate a discussion of what nonfiction means. Guide student discussion to the idea that we will research facts and create our own nonfiction booklet to help readers understand important information of our chosen topic. Give students the option of choosing 1 out of 4 animals to research and write about. Point out how when writing nonfiction material, you can use headings to help break up important information that you want readers to understand about the topic. Using ELMO (document camera), display worksheet â€Å"The Working Tools of Insects†. â€Å"We are going to look at the top of page. Does anyone remember what we call this?† Check for student understanding. â€Å"It is the heading.† Read aloud the heading found at the top of the page while students track with their eyes. Ask students to consider what the material is going to be based on the heading. â€Å"What do you think this story is going to be about based on what the heading is? I know that Insects don’t use tools like hammers or screwdrivers, so what else can tools mean?† Illicit responses such as â€Å"their antenna, their stingers, etc.† Relay to students that animals have tools too. â€Å"Birds can use their beaks to gather food. Porcupines can use their quills to protect them against predators.† Tell students that they will now have the opportunity to create their own fact booklet. Show students a premade example of the â€Å"fact booklet† that they will be creating. Explain to students what the purpose of nonfiction writing is. â€Å"Nonfiction writing is used to teach people information about something. When writing nonfiction we need to decide on what the most important information is that we should include in the writing.† Tell students that before writing nonfiction, they should ask themselves â€Å"What information will help the reader to understand the topic?† Ask students to brainstorm and share with their group by reviewing the reading materials of the chosen topic to find important information that they want to include. Show the students an example of how their first page in their fact booklet might look like. â€Å"I will choose to write facts about dogs. What important information  about dogs do I want my readers to know? I want my readers to know about the physical features of dogs for those readers who might not be familiar with them.† Write down a fact on the first page. Tell students that it is also important to have illustrations to help readers connect the pictures to the words, and understand what they are reading. Draw a picture above the facts on the first page. Students will now create their own fact booklet. Pass out construction paper. Have students fold paper in half, creating 12 pages altogether. Have them staple the pages to create a book. On the first page, have students write down their information on the bottom half of the page. On the top half of the page, have students draw a picture illustrating the facts that they have written. Have students include headings for each new fact that they are including. Reflection: Gather students in whole group to debrief. Ask students to explain what nonfiction means. Ask them to explain the difference between fiction and nonfiction. (Guide students to understand that nonfiction is used to give readers an understanding of a topic). Call on several students to share one fact that they have created in their fact booklet. This will give the teacher a good idea of how well students understand nonfiction. The influx of English Language Learners in U.S. educational school systems is on the rise. With this increase, our educators are feeling the pressure of finding a proper balance to support our linguistically diverse students through language and content instruction, allowing them to integrate within school and their community with ease. Educators can meet the immense and distinct needs of all students by integrating different educational instruction methods in their lesson planning. This paper will discuss five important components that should be included in educational instructional strategies for ELL learners and classrooms: comprehensible input, ongoing, specific, and immediate feedback, grouping structures and techniques, building background and vocabulary development, and student engagement. The SIOP lesson plan that can be found above is a detailed summary of a conceivable fourth grade lesson that can be directed in an ELL comprehensive classroom. This lesson encompasses instructional strategies used to  accommodate ELLs throughout class instruction. The Arizona State Standards used to support the components of the SIOP model can also be recognized in this lesson. Addressed in the SIOP lesson is the students’ ability to show awareness and understanding of non-fictional works, their ability to recognize the relationship between fiction and non-fiction, and their ability to recognize differences in the structure and components of non-fiction work by clarifying what nonfiction works are, as well as them capably using specific actions, emotions, or conditions that are basic to specific content (Center for Applied Linguistics, 2013). This lesson includes different instructional practices used with the students including partnering up and whole group discussion. These strategies were utilized to gain a clear and confident understanding of non-fictional structures of writing. The goal of the SIOP lesson plan is to engage students in collaboration with each other so that they can identify why nonfiction is an important part of reading and writing. While using the think/pair/share method, learners will acquire the ability to recognize nonfiction writing and compare it to fictional works. Both language and content objectives have been aligned with state standards, influencing the lesson plan. The language objectives used in this lesson include collaboration with partners and as a class, recognize significant information to a topic, create a structured informational book, and use nonfictional structures of writing. The content objectives include effective collaboration, convey clear ideas and information through informative writing, using appropriate writing format, develop work with facts, definitions, concrete details, quotations, or other information and examples related to the topic, and use appropriate words that demonstrate an understanding of the lesson in its entirety. The instructional strategies that were used in this lesson could be applied to all learners. Learners were given the chance to hold whole group discussion, think/pair/share, have paired peer discussion, and make comparisons. ELLs were able to build background by the inclusion of meaningful activities, collaboration, tactics, repetition, and response used in this lesson. This lesson also provided a scaffolding effect which can endorse high levels of success for second language acquisition. It is critical to an Ell’s growth and development that comprehensible input be integrated within each lesson. Comprehensible input can be described as the ability for students to  understand what is being said and presented to them (Campbell Mailman, 2013). With the use of oral demonstration and context or visual cues being incorporated into numerous methods in instructional teachings, comprehensible input can be attained. It is also important for educators to challenge their students by requesting that they explain what is expected of them. These practices can help heighten a learner’s familiarity and understanding of English. Another important element used in ELL instruction and which can be applied to all learners is feedback. Feedback is given to students to provide them with an awareness of their strengths and what improvements are needed to improve their performance. An educator can deliver feedback orally or through non-verbal communication. It is important to note that feedback is not a one-way communication, but rather an interaction between an educator and learner (McKimm). An attentive teacher recognizes the importance in instantaneous, detailed, and continuous feedback to help build student’s assurance in their own capabilities. This self-confidence can help students extend it to their communicative skills, evaluate their achievements and continue to improve on their work. Educators must ensure that all feedback is remedial, appropriate and applies to the benchmarks given. Educators must also remember that is it not important in the amount of mistakes a student makes. The true value is in the amount of instructional information that a student learns and understands. Grouping structures and methods are also used by educators to endorse collaboration and learning. By grouping students who have strong, developed English language skills with students whose English language skills are still emerging, students have had higher success rates while learning the English language (Albertazzi, Azofeifa, Serrani, 2013). Integrating ELL and non-ELL students gives all students the opportunity to develop and continue to build vocabulary, as well as expand their skills in understanding, listening and speaking. Collaborating with one another can be an equally powerful teaching strategy as any other method of teaching done by educators. Building background and vocabulary development is another instructional strategy used in ELL classrooms to help develop innovative approaches that familiarize ELLs to new language(Campbell Mailman, 2013). This strategy also reinforces language meanings, a crucial step to English language development. By making use of key ideas that emphasize reading,  writing, and vocabulary as well as articulation and word enunciation strategies, teachers can support ELLs in developing their vocabulary so that they learn English proficiently. Lastly, student engagement is an equally important task in ELL instruction. Keeping students active and engaged while teaching a subject that is complex can be difficult. By using various strategies such as acknowledging students interests, providing additional materials, and requesting students to bring in personal motivators to learning English, such as letters from pen pals or applications for sports sign ups, teachers can help keep students actively engaged and participating in educational instruction. Acquiring a second language can be a challenging task for ELL students. Educators are responsible for considering the dynamics of English language acquisition and must take strategic steps in engaging and instructing ELL students. If educators implemented each of the components mentioned throughout this paper by integrating them into their teaching, all students will have the opportunity to receive exceptional learning experiences. References Albertazzi, S., Azofeifa, M., Serrani, G. (2013) Second Language Acquisition. Retrieved on November 14, 2013 from http://www.slideshare.net/milaazofeifa/krashens-theory-on-second-language-acquisition Campbell, A. Mailman, L. (2013). Theories of Language Development. Retrieved on November 15, 2013 from http://languagedevelopment.tripod.com/id15.html The Arizona K-12 Academic Standards. English Language Learners. (n.d.). The Arizona Department of Education. Retrieved November 14, 2013 from http://www.azed.gov/english-language-learners/elps/forms/ CAL SIOP. (2013). What is the SIOP Model. Center for Applied Linguistics. Retrieved on November 15, 2013 from http://www.cal.org/siop/about/index.html McKimm, J. (n.d.). What is Feedback. Retrieved from http://www.faculty.londondeanery.ac.uk/e-learning/feedback/what-is-feedback

Viable But Non Culturable Bacteria Biology Essay

Viable But Non Culturable Bacteria Biology Essay Viable but Non-Culturable state is a unique survival strategy of many bacteria in environment in response to adverse environmental conditions. VBNC bacteria cant be cultured on routine microbiological media but they remain viable and retain their virulent capacity too. VBNC bacteria can be resuscitated when provided with appropriate conditions. A good number of bacteria including many human pathogens have been reported to enter VBNC state. Though, there was disputes on the existence of VBNC in past, extensive molecular studies have resolved most of them and VBNC has been accepted as distinct survival state by all. VBNC bacteria are considered as threats to public health and food safety due to their non-detectability and virulence as food and water have been reported to be contaminated with pathogens at VBNC state though conventional methods declared them as safe and clean. A number of outbreaks have also been reported where VBNC bacteria has been implicated as causative agent. Furthe r molecular and combinatorial research in conjunction with predictive modeling are needed to elucidate the mechanisms and to identify the critical points to tackle the threat posed by VBNC bacteria with regard to public health and food safety. Key words: VBNC, Pathogen, public health, Food safety, Detection Introduction The cells that form colony in specific media are the culturable cells. Viable means metabolically or physiologically active. So the cells those are metabolically or physiologically active but cant be cultured on specific media are the viable but non-culturable cells (VBNC) (Bogosian Bourneuf, 2001). Most microorganisms growing in nature have yet to be cultured in the laboratory. In fact less than 1% of the microorganisms in natural water and soil samples are cultured in viable count procedures (Barcian Arana, 2009). In 1982, Prof. Rita Colwell and co-workers introduced the term Viable But Non-Culturable Bacterial Cells (VBNC) to distinguish particular cells that could not form colonies on solid media but obtained metabolic activity and the ability to elongate after the administration of nutrients (Xu et al., 1982). According to Oliver (1995), VBNC can be defined as a metabolically active bacterial cell that crossed a threshold in this way, for known or unknown reasons and become unable to multiply in or on a medium normally supporting its growth. Most of the bacteria that enter VBNC state are gram negative species belonging to the gamma subclass of the Proteobacteria branch, except for Rhizobium, Agrobacterium and Helicobacter-Campylobacter species (Oliver, 2000). History Debra Bashford and colleagues announced that they had recovered Vibrio cholerae from streams and drainage ditches, including sites with negligible chance of sewage contamination. Around the same lime, Rita Colwell was also finding Vibrio cholerae in Maryland. She and her coworkers showed that both this bacterium and E. coli, incubated in artificial sea water remained viable but lost the capacity to form colonies on culture media (Colwell Grimes, 2000). Soon Salmonella enteritidis, Shigella sonnie and Legionella pneumophila joined the list of organisms known to be capable of entering a state in which they failed to show up on nutrient agar yet took up substrates and signaled in other ways that they were certainly not dead. The use of laboratory media to recover and enumerate bacteria and lo link them with or absolve them from pathological and other activities became obsolete by the new discoveries and a term VBNC (viable but non-culturable) came (McDougald et al., 1998). VBNC Microorganisms that do not grow in culture methods, but which are still metabolically active and capable of causing infections in animals and plants are said to be in VBNC state. The conditions for these organisms to resume growth are not being met using the normal laboratory culture conditions (Yamamoto, 2000). Bacteria that have been semi-starved will immediately resume growth when provided with the appropriate nutrients and conditions. Viable but non-culturable cells will not resume growth even when nutrients are provided (NystrÃÆ'-m, 2001). VBNC cells exhibit active metabolism in the form of respiration or fermentation, incorporate radioactive substrates, and have active protein synthesis but cannot be cultured or grown on conventional laboratory media. They have been detected by observing discrepancies between plate count enumeration of bacterial population and direct staining and microscopic counts (Sachidanandham Gin, 2009). These cells may be of particular problems in the e nvironment if they are pathogens, for example, viable but non-culturable cells of Vibrio cholerae, Enteropathogenic E. coli, Legionella pneumophila and various other bacteria have been shown to regain culturability after they have entered the intestinal tracts of animals (Colwell et al., 1996). The VBNC state is defined as a state of dormancy triggered by environmental harsh conditions, such as nutrient starvation (Cook Bolster, 2007), temperature (Besnard et al., 2002), osmotic stress (Asakura et al., 2008), oxygen availability (Kana et al., 2008), several food preservatives (Quirà ³s et al., 2009), heavy metals (Ghezzi Steck, 1999), exposure to white light (Gourmelon et al., 1994) and decontaminating processes, as pasteurization of milk (Gunasekera et al., 2002) and chlorination of wastewater (Oliver, 2005). VBNC state is believed to be a unique survival strategy of bacteria in response to environmental stresses (Oliver, 2010). It is also considered as an important reservoir of many human pathogens in the environment (Lleo et al., 2007). VBNC state has been a matter of dispute for ling since its inception, due to the difficulty of differentiation of VBNC cells dormant cells through resuscitation phenotypic studies, recent molecular studies, data of which supported the existence of VBNC state, the dispute has mostly been put to rest (Barer and Harwood, 1999). VBNC Pathogens Following list includes but not limited to pathogenic bacteria that can enter VBNC state (Oliver, 2010)- Aeromonas hydrophila, Agrobacterium tumefaciens, Burkholderia cepacia, Campylobacter jejuni, Enterobacter aerogenes, Enterobacter cloacae, Enterococcus faecalis, Escherichia coli (including EHEC), Helicobacter pylori, Klebsiella pneumoniae, Legionella pneumophila, Listeria monocytogenes, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Salmonella typhi, Salmonella typhimurium, Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Streptococcus faecalis, Vibrio alginolyticus, Vibrio cholerae, Vibrio harveyi, Vibrio parahaemolyticus, Vibrio vulnificus (types 1 and 2) Characteristics of Bacteria in VBNC state 1. Maintain apparent cell integrity; 2. possession of some form of measurable cellular activity (Lai et al., 2009); 3. possess apparent capacity to regain culturability (Anuchin et al., 2009); 4. respond to external stimulus by specific gene expression (kell et al., 1998); 5. low metabolic activity (oliver, 2005); 6. Exhibit dwarfing (Costa et al., 1999); 7. reduced nutrient transport; 8. High ATP level and high membrane potential (Signoretto et al., 2000); 9. extensive modifications in cytoplasmic membrane fatty acid compositions (Day Oliver, 2004); 10. Changes in cell wall peptidoglycan such as increasing cross linking, increasing muropeptides bearing covalently bound lipoprotein shortening of average length of glycan strands (signoretto et al., 2002); 11. Higher autolytic capability than exponentially growing cells; 12. Plasmids are retained; 13. changed antibiotic sensitivity as metabolic activity is lower, most bacteria at VBNC state demonstrate high antibiotic resistance (Ol iver, 2010); 14. Changes in outer-membrane protein profile (Muela et al., 2008); 15. Continuous gene expression (Maalej et al., 2004) etc. Conditions stimulating VBNC state In the environment, bacterial cells can enter VBNC state may be due to- 1. Lack of nutrients; 2. Lack of temperatures; 3. High pressure; 4. Sharp changes in pH or salinity (Cunningham et al., 2009); 5.damage to or lack of an essential cellular component; 6. DNA damage; 7. activation of lysogenic phages or suicide genes such as sok/hak or autolysins (Aizenman et al., 1996); 8. Nutrient starvation; 9. incubation outside the normal temperature range of growth; 10. elevated or lower osmotic concentrations; 11. oxygen concentrations (Mascher et al., 2000); 12. food preservatives; 13. Heavy metals (Del Campo et al., 2009); 14. exposure to white light; 15. pasteurization of milk (Gunasekara et al., 2002); 16. chlorination of wastewater (Oliver, 2005) etc. Public health significance of VBNC Though virulence of bacteria in VBNC state is still not very clear, many believed that pathogens in VBNC state are unable to induce infection/disease but still retain their virulent properties has potential to cause disease infection following resuscitation and resume of active metabolic state, which occurs when they pass through host animal (Baffone et al., 2003). The VBNC state appears to be the common to many bacteria especially those which have aquatic habitats, and may represent a mechanism to survive adverse environmental factors as temperature, salinity etc. or have a means of inducing cross protection against other adverse factors (Du et al., 2007). Among these bacteria entering this state are many significant human pathogens and indicator bacteria of these pathogens; such cells may represent a public health hazard and may be a factor in human health and/or disease (Rivers Steck, 2001). Even today, it is still not possible to cultivate most bacterial species directly from the environmental samples or after exposure of previously culturable cells to environmental conditions unfavorable for growth and multiplication in vitro. The passage of VBNC through an appropriate animal host will induce return of culturability. Even these VBNC bacteria retain their pathogenicity and may trigger life in vivo and thus cause severe disease (Sardessai, 2005). Under normal condition it is not possible to culture or detect VBNC. Many diagnostic laboratory set up does not have sufficient molecular facilities to detect VBNC. In case of food and water quality control test, such VBNC may not be detected. Even some indicator of some pathogenic bacteria undergoes VBNC state and may remain undetected (Signoretto et al., 2004). Upon consuming such food or after drinking such water, one may be infected by those VBNC that can trigger life as well as pathogenicity (Adams et al., 2003). Thus, environmental and clinical samples no longer can be considered free from pathogens if culturing yields negative results. For the general public, the presence of VBNC in water and food may be related to low-grade infections or so called aseptic infection. For example, Vibrio cholerae O1 in the surface water remain as non-culturable state. These water sources are used for domestic purpose regularly and posed a risk of infection (Edwards, 2000). When conditions are not favorable for growth then it transforms to the non-culturable state in association with crustacean copepods. Persistence of Vibrio cholerae in water in the VBNC state is an important public health factor, since detection will not be successful if only conventional cultural methods are used (Barer et al., 1993). Similarly, Shigella can undergo VBNC state in water but become a threat when enter in human body. Thus it is important to recognize that non-culturable bacteria are capable of producing diseases. The first evidence of pathogenicity of non-culturable cells was the demonstration of fluid accumulation in rabbit ileal loop assay (RICA) by VBNC Vibrio cholerae O1, followed by human volunteer experiments (Amel et al., 2008). VBNC E. coli non-culturable cells were re-isolated after passage through rabbit ileal loops 4 days post inoculation and chick embryos died when injected with non-culturable cells of Legionella pneumophila, led to the conclusion that VBNC pathogens remain potentially pathogenic. So, VBNC has a huge significance in public health care (Cappelier et al., 2007). Reports indicate that many potentially harmful bacteria survive treatment and persist in processed food, pasteurized milk, potable water and in the environment (Colwell et al., 2000). Many evidences suggested that recurrent urinary tract infections in many individuals are caused by uropathogenic E. coli cells which remain in VBNC state (Anderson et al., 2004) thus resistant to antibiotic treatment cause reinfection when resuscitate back to active metabolic state (Steck, 2001; Mulvey et al., 2001). Studies also showed that uropathogenic E. coli retain enteropathogenicity at VBNC state through continued production of enterotoxin (Pommepuy et al., 1996). Nilsson et al. (2002) showed that VBNC Helicobacter pylori cells can express virulence factors such as cagA, vacA and vreA. All these above evidence proved that many deathly pathogenic strains not only enter but also persist survive in VBNC state in environment most of them remain infectious as well. VBNC state of foodborne bacteria- a challenge in food safety Many evidences suggested presence of VBNC bacteria in food (Ordax et al., 2009). For example, in stored wine, acetic acid and lactic acid bacteria entered VBNC state as consequence of lack of oxygen and presence of sulphites, respectfully (Millet and Lonvaud-Funel, 2000). Food and its surrounding environment is a complex system, in which physic-chemical characterisitcs (pH, aw, chemical composition) and environmental factors (storage temperature and time, decontamination treatments, packaging under modified atmosphere) act simultaneously on contaminating bacteria (Sun et al., 2008). For example, it has been demonstrated that refrigerated pasteurized grapefruit juice induced VBNC state in E. coli O157:H7 and S. typhimurium within 24 hours of incubation (Nicolo et al., 2011). Again, Gunasekera et al. (2002) reported that in pasteurized milk which have undergone thermal treatment, contaminating bacteria such as E. coli and Pseudomonas putida enter into VBNC state but retained transcription and translation machineries. Several foodborne outbreaks has been reported in Japan, where pathogen such as Salmonella enterica subsp. enterica (Asakura et al., 2002) and E. coli O157 (Makino et al., 2000) in food in VBNC state were responsible for the outbreak. Therefore, the role of food and treatment for food preservation in induction of VBNC state has to be elucidated. Predicitve models offered by biomathematics and bioinformatics would be very helpful tools, in order to evaluate the possibility that, under certain conditions, pathogen bacteria contaminating a tipology of food may enter the VBNC state (Fakruddin et al., 2012). Methods of detection of VBNC bacteria 1. Bright Field Microscopy with Nalidixic acid For detection of Bright-field or light microscopic is usually used. Cell division inhibitor such as nalidixic acid (20-40 mg/L) is used to stop cell division. After such treatment the viable cells, which actively growing, will be appeared as lengthen and the non-viable/ metabolically inactive cell will remain as it is. The cells are then observed under microscope. Viable cells will be seen as elongated whereas VBNC/ dormant cells will be seen as oval and large. 2. Fluorescent Microscopy Various fluorescent staining procedures are used in combination with other procedure to determine VBNC organisms. Frequently used stains are Acridine orange, 4,6- Diamino-2-phenyl indole (DAPI), Fluorescein isothiocyanante (FITC), Indophenyl-nitrophenyl-phenyl tetrazolium chloride (INT), 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) etc (Villarino et al., 2000). Table: Fluorescent dyes used for detection of VBNC bacteria Dye Mechanism Reaction Acridine orange Acridine orange stain cells depending on the ratio of DNA to protein in the cells Actively reproducing cells appear green but slow-grower or non-reproducing cells at time of staining appear orange Di-amino-phenyl-indole (DAPI) Living cells look green under fluorescent microscope Indophenyl-nitrophenyl-phenyl tetrazolium chloride (INT) INT deposit red dye in cells that have active dehydrogenase and thus determine which of the observed cells are metabolically active INT react with dehydrogenase enzyme to produce formazone and red color, thus living cells appear red. Nalidixic acid (NA) Lengthen metabolically active cells, VBNC cells remain as it is Cells that are dividing appear to be longer in size than VBNC Fluorescein isothiocyanante (FITC) Enzyme activity in living cell FITC stain living cells violet or blue In recent years, a new differential staining assay, the BacLight ® Live/Dead assay, has been developed. The assay allows to simultaneously count total and viable (metabolically active) cells, by using two nucleic acid stains, that is green-fluorescent SYTO ® 9 stain and red-fluorescent propidium iodide stain. These stains differ in their ability to penetrate intact cell membranes. When used alone, SYTO ® 9 stain labels both live and dead bacteria. In contrast, propidium iodide penetrates only bacteria with damaged membranes, reducing SYTO ® 9 fluorescence when both dyes are present. Thus, live bacteria with intact membranes fluoresce green, while dead bacteria with damaged membranes fluoresce red (Rowan, 2011). 3. Gene probe / oligonucleotide probe / hybridization: Molecular analysis can also be used to study non-culturable microorganisms in nature. Oligonucleotide probes of l8-20 nucleotides are proving most useful because they hybridize rapidly to specific DNA sequences of target organisms. These gene probes can reveal closely related organisms or organisms with similar functional capabilities. Especially useful for the analyses of rRNA that demonstrate the presence of diverse microbial populations whose phylogenetic relationships can be ascertained by comparison with rRNA sequences from previously described microorganisms (Josephson et al., 1993). Blotting: There are different types of blotting such as colony blot, slot blot, dot blot and southern blot. The principle of blotting is the use of radio- or non-radioactive or fluorescence labeled probe (DNA/RNA/Antibody) to detect VBNC cells directly from the environmental samples. Fluorescent in situ Hybridization (FISH): In situ hybridization is an alternative format for hybridization probes in which fluorescence labeled DNA or RNA probes are hybridized with target nucleic acids in whole, permeabilized cells. The application of this method to the detection of single microbial cells by using rRNA-targeted probes in combination with epifluorescent microscopy has been developed. This is done through selective targeting of regions of rRNA, which consist of conserved and variable nucleotide regions. By choosing the appropriate rRNA probe sequence, FISH can be used to detect all bacterial cells (a universal probe) or a single population of cells (a strain specific probe) of VBNC. It has lower sensitivity and cannot distinguish live and dead cells. 4. Molecular techniques: Hybridization probes and DNA/RNA amplification: Hybridization probes are nucleic acids (DNA/RNA) which have been (a) chemically or radioactively labeled and are used to detect complementary target DNA/RNA. Hybridization assay DNA/ RNA probes form a stable double stranded structure with target nucleic acid via H-bonding between complementary bases. Amplification of targets: DNA Based methods: Specific amplification of DNA targets in bulk DNA extracts from environmental and clinical samples permits detection of specific organisms or groups of related organisms without the need to cultivate them. DNA recovery procedures do not discriminate between culturable and non-culturable forms of the target organisms- all cells with intact amplification targets will be detected. Confocal laser microscopy in combination with fluorescence-based hybridization assays, also provide a more sensitive method for detecting and identifying VBNC organisms. RNA based methods: Due to the failure of distinguishing between dead or live cells by DNA-based methods, the mRNA level may be a valuable estimate of gene expression and/or cell viability under different conditions (Lleo et al., 2000). RT-PCR: RT-PCR (Reverse Transcriptase PCR) can distinguish between Live and dead cell. This is possible because this is an mRNA based method and mRNA is short lived (half-life less than 1 minute), mRNA is only present in metabolically active cells, not found in nature after the cell death. By this method we can study community relationship and can also detect non-culturable but active or live cells. DNase enzyme is used during the isolation of RNA from environmental samples. Reverse transcriptase and random primers are added to the reaction mixture and the RNA in the sample (both RNA and rRNA) is transcribed into DNA. PCR is then use to amplify the specific sequence of interest (Pai et al., 2000). Is the concept of VBNC is a misnomer? By extending the concept of bacterial self-suicide scientists tried to explain what happens when cells are exposed to chemical and physical injury (Forsman et al., 2000). Thus VBNC organisms came alongside with those, which do not grow in ordinary media but which do grow when offered selective or enrichment media. They said, Such cells are not un-culturable they wrote We are simply failing to provide appropriate conditions to support culture (Sinton, 2006). The reasons, which made the term, VBNC a misnomer are as follow: 1. Bacteria that have been semi-starved will immediately resume growth when provided with the appropriate nutrients and conditions. But viable but non-culturable bacteria do not resume growth when nutrients are provided. Evidence suggests that these cells have become too starved to be able to grow on rich medium initially; this phenomenon was observed over three decades ago and was known then as substrate accelerated death (Heim et al., 2002). It was found that substrate that normally supported growth of certain Gram-negative bacteria hastened their death when introduced into starved populations of these bacteria. These substrates were considered lethal substrates. These starved cells require an adjustment period to allow phenotypic adaptation back to the normal growth state (Epstein, 2009). A sudden shift to nutrient rich agar creates a metabolic imbalance that results in the formation of super-oxide and free radicals, causing DNA damage that can result in cell death (Barer Harwood , 1997). 2. There is yet no complete and perfect media to isolate arid culture all the organisms from environment. 3. Cells are usually-injured or stressed or starved condition in natural environment. So complete system has been devised to enrich or resuscitated the VBNC cells. Culture condition that can be applied in laboratory is not sufficient to recover all microorganisms i.e. yet it is not possible to provide or stimulate exact environmental conditions in the laboratory. Conclusion Regardless of the role that the VBNC state plays, it is clear that a large number of non-spore-forming bacteria, most notably a large number of human pathogens, are capable of entering this state, maintaining cellular structure and biology and continuing significant gene expression while otherwise non-culturable by standard laboratory methods. That they can exit from this state, and become culturable again, is also undeniable. Finally, it can no longer be questioned that the VBNC state plays a critical role in the survival of important human (and other) pathogens, and possibly in their ability to produce disease.

Essay --

World War II had many events that changed the world we live in today. There were two major events which were the Holocaust and dropping two atomic drops on the Japanese civilians. They both were reasoning with mass killing and also, mass caulsitaites. Holocaust was Adolf Hitler way to eliminate the enemy. World War II saw new military technology such as the atomic bomb. As a result of creating the atomic bomb, many countries raced to be the first to have it. The United States wanted to end the war as quickly as possible and believed dropping the atomic bomb was the best way to accomplish this. The men involved in these outrageous events justified there actions. Henry L. Stimson was the U.S Secretary of War and help with the decision to drop the atomic bomb. Rudolf Hoss was a Nazi solider in a concentration camp during the Holocaust. â€Å"Memoirs† by Rudolf Hoss and â€Å"The Decision to Use the Atomic Bomb† by Henry L. Stimson give us some insight on what was going on at that time. Rudolf Hoss reconciled his role in the mass annihilation of Jews by racial superiority and anti-Semitism, while Henry L. Stimson reconciled his role in dropping the atomic bomb by claiming it was the best way to save as many American lives as possible. Henry L. Stimson result in dropping of the atomic bomb on Nagasaki and Hiroshima in 1945 is a very controversial issue. The Japanese were known to be determined soldiers, and why dropping the bombs was the right choice when saving American lives. Stimson reconcile this choice because defeating the japanese would require lots of time, the lives of thousands of soldiers and numerous resources. Stimson states â€Å"the allies would be faced with the enormous task of destroying an armed force of five million men and five ... ...how that he was not anti-semitic but that is not the case. He still treats them like every other prisoner because he feels empowered to do so. Hitler was this high ranking officer who gave Germany an enemy that everybody could hate. Atomic bombed getting dropped on Nagasaki and Hiroshima in 1945 and the Holocaust were both huge events that happened during World War II. They both had massive death tolls. â€Å"Memoirs† by Rudolf Hoss and â€Å"The Decision to Use the Atomic Bomb† by Henry L. Stimson give us some insight on what was going on at that time. Rudolf Hoss and Henry L. Stimson both justified their actin during these events. Stimson reconciled his role in dropping the atomic drop to end the war early and to save as many Americans as possible. Hoss rationalizes his action in killing the massive amount of Jewish people were racial superiority and German nationalism.

Education †Morality Essay

Education is not only cognitive and intellectual learning, and learning of skills and work-related competences. It is much broader to include moral and ethical issues, values, attitudes, religion, spiritualism, art and more. It is, indeed, important to focus on this when education in schools and universities has become a large â€Å"industry† and when the world, instead of becoming more peaceful, seems to be more confrontational than before. The main reason behind this scenario, that I see, is that students are being taught and not trained and also the fact that teachers do not have any target for teaching instead they teach for the pay they get and sincerity with the profession is waning very fast. EDUCATIONAL SYSTEM The educational system that I see should be one that suits all the citizens of the country. It should consider the cultural, ethical, moral, religious and economical norms of the society and should produce respectable and responsible citizens for the society as a whole and a dignified and confident person. |This point arises due to the fact that every country consists of multi-cultural and multi ethical societies with different religious and economic backgrounds. Thus the system should have contents that may not hurt the morals and values of any person and also produce effective results that can be calculated as per the prosperity of that particular society or country as a whole. PURPOSE OF EDUCATION The foundation of our work as educators is moral and ethical education. We must teach the right values and the right ways of analyzing issues. We must seek what is true and act accordingly. Part of that is to learn that we are all responsible for our own attitudes, decisions and actions. We must use education to foster equality between sexes, classes, people of different geographic areas, creeds, colors, cultures and religions. We must learn to understand the importance of solidarity among groups at home and across the borders in order to create peace, development and prosperity. Besides this we are also imparted with the responsibility of teaching science, commerce and arts subjects to the students using latest techniques, information and research to enable our students to prepare themselves to be a productive part of the society and compete with the world in the respective fields of their study. Major areas that a teacher may address are as follows: 1. To help students gain literacy: This is supposed to be the top most priority as if a student is literate he or she may mold in any society and get adapted to its culture and norms without losing its own. 2. To enable students to use and enjoy their learning experiences: Here a student gets in hand expertise to use what it learned during the schooling period to better their social and personal life in a given environment. 3. To teach students to believe and respect others, to contribute to the well-being of their community: A learned person better knows whom to respect and whom not too, who deserves to be valued and who does not, and gets bold enough to express its feelings in a dignified and respectful way in the society. He is able to distinguish between duties bestowed upon him by the community and tries to serve the community within available resources. 4. To give students the opportunity to learn how to inquire and discover new information: When a student learns through experimentation and reasoning he tries to use the same technique throughout his life and does not accepts all and sundry information without analyzing it. 5. To help students develop broader understandings of new information: This enables a student understand and characterize given information and then apply it in his daily life. 6. To help students develop the skills and values they will need to function in a free and just society: Last but not the least it makes sure that a student is made aware of the morals and values of religion and society and to act accordingly not hurting any ones feelings and making progress accordingly in the society individually and as a community as a whole. In the process of enabling the students to get all the above qualities they are supposed to be taught different subjects but should be encompassed under the umbrella of a just religion and that is Islam not because we live in the Islamic Republic Of Pakistan but due to the fact that Islam is the only religion that addresses to all the matters discussed with command and covers all the topics amicably, may it be the moral, cultural, and or ethical values or upbringing, or the contemporary studies of science, commerce and arts. Reference: 1. http://www. intime. uni. edu 2. www. nation. com. pk †º Columns.

Amazon Case study Essay

As seen from 2014, Amazon.com is a no brainer of a business proposition. Today you can buy most things from Amazon.com – books, movies, health and beauty products, appliances, sporting goods†¦..online and the company will ship these purchases to your home the same day and often at little or no cost to you. The typical 2014 university student has grown up with the World Wide Web and eCommerce and takes these services for granted. For its part Amazon recorded revenues of $17.09 billion dollars in 2013 but for all that activity, the company did not yield a profit. According to its founder and CEO Jeffrey P. Bezos, Amazon strives to be the retailer of choice for all things and for all people globally. To this end, Amazon’s profit margins on most products are razor thin and its business practices regarding free shipping and generous return policies erode earnings. Still there is no question that Amazon.com is one of the darlings of the new millennium’s Internet e conomy and a trend-setting retailer in the era of online retailing. In contrast, Amazon’s early history was marked by startling losses and lots of red ink. Why was this so? To understand Amazon’s origins, we must go back to 1994 when Bezos worked for the Shaw grocery store chain and read a study that predicted the Internet would explode in popularity. He figured that before long people would be making money selling over the Web. After considering any number of products to sell online, he settled on books, a standardized product already electronically cataloged, that could be easily managed through an automated supply chain system. Most notably, the typical book store typically managed an inventory of two to three thousand books whereas his imagined online service that would carry them all. In Bezo’s business model, he would disintermediate the retail process, eliminating stores and warehouses. Instead his customers would purchase their books from catalogs on his company’s Web site. Orders would be filled from a new kind of facility, a fulfillment center. In implementing this business model, Bezos quickly discovered that the only way to ensure a positive customer experience was for Amazon to operate their own fulfillment centers, controlling the transaction from start to finish. All of this may sound quite straightforward today but Bezo and his backers were treading in totally unchartered waters in 1995. To compete in this space, Amazon.com required a huge infusion of capital. Those fulfillment centers cost about $50 million apiece. The first of these in Fernley Nevada housed three  million books, CDs, toys, and housewares in a building a quarter-mile long by 200 yards wide. What distinguished this facility from the typical retail warehouse was that it was completely computerized. The associated business processes were largely automated and information intensive. Once customer orders were placed via Amazon.com’s Web site, the company’s information systems would send these orders to fulfillment center â€Å"pickers† who would in turn roam the shelves in a systematic manner assembling customer orders. Along the way, these information systems would capture detailed information on the time and steps involved in filling individual orders, w orker error rates, the flow and turnover of inventory and of course associated cost of operations data. Amazon managers employ this information to squeeze every last drop of productivity out of their processes. For example, as reported by Fred Vogelstein: †¦. by redesigning a bottleneck where workers transfer orders arriving in green plastic bins to a conveyor belt that automatically drops them into the appropriate chutes, Amazon has been able to increase the capacity of the Fernley warehouse by 40%. [In 2003], Amazon’s warehouses handle three times the volume they could in 1999, and in the past three years the cost of operating them has fallen from nearly 20% of Amazon’s revenues to less than 10% percent. The company doesn’t believe it will even have to think about building a new warehouse for another year. The warehouses are so efficient that Amazon turns over its inventory 20 times a year. Virtually every other retailer’s turnover rate is under 15. Indeed, one of the fastest-growing and most profitable parts of Amazon’s business today is its use of its supply chain management processes to service the eCommerce business needs of other retailers, suc h as Toys â€Å"R† Us and Target. All of this helps explain Bezos’s larger point, one he’s been making since he started Amazon but that people are only now starting to believe: â€Å"In the physical world it’s the old saw: location, location, location,† †¦.. â€Å"The three most important things for us are technology, technology, technology.† [But technology is actually the means by which Amazon manages its most valuable asset, its data. Data about products, data about customers, data about supply chain management, data about suppliers†¦Ã¢â‚¬ ¦.] â€Å"There just aren’t other companies that let a consumer order two out of what are millions of products in a warehouse and then quickly and efficiently, at low cost, get those two things into a single box.†. But success was not a  forgone conclusion. Amazon faced a lot of red ink in its first five years. Ultimately its devotion to data paid off. As its competitors disappeared from the scene, Amazon leveraged its data management capabilities to drive error out of operations, personalize the Web experience for its customers, and add value to its relations with suppliers by providing them with deep business intelligence concerning the public’s interest in their various products. To achieve these results, Amazon developed its own methods and built its own Web-enabled information systems from scratch. Fortunately, the company could take advantage of established supply-chain management (SCM) systems for the backend of the business. In the final analysis, it was Am azon’s dedication to collecting and using information to run its business, an effort spearheaded by the company’s Chief Technology Officer Werner Vogels and his MIS team that turned the enterprise profitable. Now that Amazon has mastered both the fulfillment side of eCommerce and the data and information management side of global business management, two major profit centers at Amazon that help feed its bottom line include: back-end fulfillment services for other global retailers and cloud computing services for the likes of iTunes and Netflix.