Computers And Biology Essays - Bacteriorhodopsin, Photosynthesis

Computers And Biology By Jack Brown Computers have enhance the study of Biology tremendously, as well discoveries have enhance the progression of computers. Without computers, Biology would be no where. We would not have the high tech microscopes. We would not be able to process information at lighting speeds. Finally, we would have no place to store all the information that we gathered. Can you imagine all the paper we would use to record all the information that we gather? Computers have not only helped us with experimenting; they have helped us to educate students. There has been tons of software developed to educate students about science and in particular Biology. They have allowed students to create experimental 3D models, collect research and now students can even use computers to dissect ?Virtual Creatures? Aimed at middle school and high school students, Virtual Creatures is the creation of a group called SUMMIT (Stanford University Medical Media and Information Technologies Group). SUMMIT was founded eight years ago to create computer-based teaching tools for the Stanford University School of Medicine and has expanded to provide educational multimedia for medical students and doctors. This program will allow students to dissect frogs without the scalpels, probes or formaldehyde. Without touching the frog, you can rotate it to view it from any angle and study its external anatomy. On command, the skin turns transparent. You can even zoom through it to view the muscles, or peel the muscles back to expose the internal organs and skeleton. The Virtual Creatures team used virtual reality technology to create a rich environment -- called Frog Island -- with many opportunities for interactive learning. After being greeted by a ranger who explains how to get around the island, students can visit, in any order, a series of huts, each focusing on a different aspect of frog biology: muscles, organ systems, bones, nerves, habitat and so on. With this virtual reality model students don't have to worry about real-life constraints. For instance, you can take a frog apart in any sequence. You could start with the digestive system and then put it back together. This as you would expect does require a lot of processing power and high-end graphics. But the speed of innovation in the computer industry should soon make the necessary technology affordable for many schools. The SUMMIT team is also looking at ways to transfer most of the processing work to a central computer, which students and teachers could access by logging on from a cheaper computer. This is where biology has actually helped computers develop. Biology and the study of proteins and molecular biology have helped scientists develop new ways of building computers. They have helped reduce the size and cost of creating components for a computer system. Imagine if we could create a storage medium the size of a sugar cube that stores a terabyte of information. Imagine if I said that it would not be based on silicon transistors, but would be based on protein molecules that change their shape when exposed to light. This enables them to store and transfer massive amounts of data. This technology is called Nanotechnology. It is leading to the development of electronic components at the molecular and atomic levels. Single bits are going to be represented by single atoms. Chip sizes have been shrinking at an incredible rate. If they continue at the current pace now, it will so be more expensive to shrink then it's worth. This new technology may provide the answer in protein-based computing. Researchers are currently studying several molecules to find a possible ?biology standard? for designing computers. The most popular molecule is a protein called bacteriorhodopsin. Although we are just hearing about it now, Soviet scientists have been interested in this protein since the early 70's. They recognized the potential of the molecule to act as a switch with on and off positions. This is basically how the silicon transistors work today. While silicon transistors alter its state when a current of electricity excites the electrons in it, a protein changes its shape when it absorbs light. A laser beam is used to control the switching in a matrix of memory cells. Bacteriorhodopsin is a complex protein found in most salt-marsh environments. It contains a light-absorbing component called a chromophore. When this chromosphore is exposed to light, such as a laser beam, it absorbs the rays and causes a series of internal processes to occur with in the bacteriorhodopsin. This changes the electrical character. Scientists can then translate these resulting electrical changes into the binary

The prevalence of dental caries in European Children (0-18 years) and Associated Risk Factors The WritePass Journal

The prevalence of dental caries in European Children (0-18 years) and Associated Risk Factors Introduction The prevalence of dental caries in European Children (0-18 years) and Associated Risk Factors IntroductionMethods Review Questions ObjectivesSource of Information Search StrategyInclusion Criteria Exclusion criteriaQuality Assessment SystemData Extraction SystemResultsDiscussionReferencesRelated Introduction Dental caries (also known as tooth decay or a cavity) is a disease where bacteria (in the presence of food) damage the hard tooth structure (Enamel, Dentin and Cementum). Acs et al. (1992) showed that three year-olds with nursing caries (caries caused due to prolonged breast and bottle feeding) with atleast one pulpally involved tooth were likely to weigh about 1 kg less than the children without nursing caries. They also reported that, when dental rehabilitation was carried out, the children’s growth rate increased. Therefore, it appears that the poor oral conditions were compromising nutritional intake. Poor oral health can have a profound effect on general health and quality of life (Peterson et al., 2005). The decline in the prevalence of dental caries in Western European countries was documented at the ‘Second International Conference of Declining Caries‘  Ã‚   held in London in April 1994 (Naylor, 1994). In Central and Eastern Europe, the prevalence of caries is still high and there are no signs of substantial improvements. In the recent years an increasing number of papers have shown that the prevalence of dental caries was highest in the lowest socioeconomic strata with the immigrants of Europe (Bratthall et al., 2000) showing the skewed nature. Dental caries is still a common disease among children and adolescents (Nithila et al., 1998; Marthaler, 2004) and affects 46% of 4-year-old children (Stecksà ©n-Blicks et al., 2004) and 80% of 15-year-olds (Hugoson et al., 2005). Furthermore, there is a trend in many developed countries for the prevalence of dental caries to increase again, especially among young children (Haugejorden and Birkeland, 2002; Stecksà ©n-Blicks et al., 2004), after a long period of caries decline (Marthaler, 2004). The purpose of this systematic literature review is to summarize the prevalence of dental caries in European children (0-18 years) since 1995 (end of decline) till March, 2011. Methods â€Å"A systematic literature review can be defined as the rigorous search, selection, appraisal, synthesis and summary of the findings of the primary research in   order to answer a specific question† (Parahoo, 2006:134) Review Questions    What is the available evidence regarding the prevalence of dental caries in European children (0-18 years) since 1995? What are the factors associated with such prevalence? Objectives    To investigate the prevalence of dental caries among children up to the age of 18 years. To study the risk factors associated with the prevalence. To analyze the data odds ratio and confidence interval were reported. Odds ratio is the ratio of the odds of an event occurring in one group to the odds of it occurring in another group. Source of Information PubMed and Science Direct were extensively searched to retrieve articles. An additional supplementary search was also done. The initially identified papers were carefully examined which provided the further relevant articles. Other UEL-databases (Medline, EBSCO, Project Muse) were also searched. An additional advanced search was done on British Dental Journals. Search Strategy The key words included in the search strategies in PubMed and Science Direct were (dental caries, prevalence, Europe, children, risk factors) related to the research questions. One of the search strategy is described in detail below: Search Strategy PubMed: (Epidemiology[Subheading] OR Epidemiology[All Fields] OR Prevalence[MeSH Terms]) AND (Dental Caries[MeSH Terms]) AND (Europe[MeSH Terms] OR Europe[All Fields])=3484 (Epidemiology[Subheading] OR Epidemiology[All Fields] OR Prevalence[MeSH Terms]) AND (Dental Caries[MeSH Terms]) AND (Europe[MeSH Terms] OR Europe[All Fields]) AND (Risk Factors[MeSH Terms])=387 ((Epidemiology[Subheading] OR Epidemiology[All Fields] OR Prevalence[MeSH Terms]) AND (Dental Caries[MeSH Terms]) AND (Europe[MeSH Terms] OR Europe[All Fields]) AND (Risk Factors[MeSH Terms]) AND (Infant[MeSH Terms] OR Child[MeSH Terms] OR Adolescent[MeSH Terms])=302 ((Epidemiology[Subheading] OR Epidemiology[All Fields] OR Prevalence[MeSH Terms]) AND (Dental Caries[MeSH Terms]) AND (Europe[MeSH Terms] OR Europe[All Fields]) AND (Risk Factors[MeSH Terms]) AND (Humans[MeSH Terms]) AND English[lang] AND (Infant[MeSH Terms] OR Child[MeSH Terms] OR Adolescent[MeSH Terms]) AND (1995[PDAT] : 2011[PDAT]))Limits: English, Humans=179 Total 179 articles were retrieved in this single search.   The titles of 179 journals were read and inclusion- exclusion criteria were applied and 50 papers were selected. (2,4,7,8,10,12,14,20,21,23,24,26,29,31,34,35,36,39,42,44,47,49,51,55,56,60,63,64,65,67,70,73,74,75,77,82,84,88,90,98,109,110,111,112,118,122,128,129,143,147). Abstracts of 50 papers were critically read and finally six papers were included in the study. Four papers were identified and included from the reference lists, three papers were added by the manual searching of local journals (to include papers from all geographical regions of Europe) and one journal was retrieved from British Dental Journals. Sixteen papers from different countries of Europe (England, Scotland, Wales, Northern Ireland, Norway, Kosovo, Germany, Lithuania, Spain, Latvia, Sweden, Portugal, Turkey and Greece) were included in this review. Inclusion Criteria Studies conducted in Europe. Studies reporting overall prevalence of dental caries in dmft/DMFT (The number of D=decayed; M=missing due to caries; F=filled T=teeth in a case or individual, one of the most reliable dental caries index). Studies that reported risk factors. Original papers published in English. Studies including children (0-18 years). This age group was chosen because this is the root foundation stage where good habits are developed and incorporated in the daily life. Preventive measures if used give the best outcomes. Studies conducted from 1995. There was constant decline in dental caries in Central and Western Europe till 1995 but after this period, there was a tendency towards an increase in dental caries (Mathaler et al., 1996) the reason to select the studies from 1995 till 2011. Exclusion criteria Studies without the overall prevalence of dental caries. Papers not published in English. Studies not using the World Health Organisation DMFT criteria. Studies with single person opinion. Studies on age group 18years. Studies involving cases with hospital and special dental care needs. Quality Assessment System Wong et al (2008) argued that quality assessing tools like QUOROM, CONSORT, STARD and STROBE were aimed at authors for reporting, not for reviewers and proposed QATSO guidelines for observational studies. As QATSO was used, the following parameters and scoring system were considered for this review, for methodological flaws (internal validity and generalisation (external validity). : Sample size:   ≠¥1000=1,   1000=0. Response Rate: ≠¥60%=1, 60%=0. Number of recruitment sites: ≠¥5=1, 5=0. Sampling strategies: Probabilistic=1, Non-probabilistic=0. Statistical analysis: Yes=1, No=0. Table 1 Each study was coded A to C (on the basis of above criterion) to measure its quality. High Quality (A) score ≠¥4. Fair quality (B) score 2 to 3. Poor Quality (C) – score 2. Data Extraction System Data extraction system comprised of the following sections and each section included a series of questions to extract data. Bibliographic information. Authors. Date of publication (year). Journal title. Focus of the study. Main focus of the study (prevalence of dental caries). Demographic details of participants (European children). Location (Country). Methodology Sampling strategy and sample size. Data collection methods. Data extraction methods. Clinical settings in which children were diagnosed. Strengths of study. Limitations of the study. Findings Results. Conclusions. Recommendations. Results The findings reported in the reviewed studies suggested the prevalence of dental caries ranged from 25% in Scotland (mean dmft1.1) to 86.31% in Kosovo (South Eastern Europe) (dmft-5.8). All the studies used WHO criteria to record the caries index (mean dmft/DMFT) indicating the prevalence of dental caries, this facilitates comparison between the studies of various regions. Three studies (Studies 1, 9 and 16) show very high DMFT in Kosovo (mean DMFT=5.8) and Lativia (mean DMFT=5.0). Sweden, Turkey, Germany, Norway, Portugal, Lithuania and Greece were reported to have mean DMFT index ranging from 2.05 to 3.19 (Studies 3,4,10,12,13,14 and 15). A low caries index (mean DMFT2) was found in the UK (England, Wales, Scotland and Northern Ireland) (Studies 2,6,7,8 and 11). Comparing the studies 2 and 11, it was found that the mean DMFT index tends to increase with increasing age (Scotland 2007/08; mean dmft 3 year-olds =1.0, mean dmft five year-olds= 1.87). Studies that reported risk factors mostly used logistic regression to quantify different independent variables (sugar consumption, preventive measures, socioeconomic factors and so on) with dental caries as the dependent variable. Most of the studies used the above mentioned variables. Eagle et al. (2003) (study 3) reported the form in which sugars are consumed as an important predictor for dental caries; consuming sweetened tea and milk increased the risk of caries by 225 times and 15 times (reference water =1) (p0.001) which is statistically significant. The risk of developing caries increased to 1.39, 1.44, 1.46 and 1.68 times when processed sugars were consumed once, twice, three times and four times respectively as opposed to never consuming processed sugars as reference (=1) (Gac Sanit;   Study 5) Socioeconomic factors (study 2,10,11,12,13,14 and 15) were also reported to be an important predictor for causing dental caries. Living in remote areas was reported to be a protective factor with cities as reference. The risk of having caries in remote and rural areas was reported to range between 0.29 times (CI 0.13-0.63; p=0.002) to 0.52 (CI 0.39-0.69) and this is statistically significant. People living in deprived areas (including immigrants) were reported to be more vulnerable. The odds of developing caries was 2.9 times (CI2.31-3.64; p0.001) (study 2), 5.32 times (p0.01) (Study 13) and 5.94 times (p0.01) with native/caries free population as reference. The risk of developing caries was reported to be 1.68 times higher in children with mothers having secondary education as opposed to the children whose mother had done higher studies (Constantine et al. (2011); Study 15). Eagle et al. (2003) (study 3) reported that 70% of the mothers having caries free children knew about caries and its prevention but only 22.5% of mothers having children   with caries were aware of this problem (p0.001). The results were statistically significant. With daily tooth brushing as reference, the risk of having dental caries for children who brushed on alternate days was 1.48 times (CI 1.22-111.78)higher; for children who brushed with two days gap was 1.57 times(CI 0.91-2.33) higher and for those who brushed with gap of three or more days was 1.60 times(CI 1.20-2.28) higher (Study 5). Applying excessive toothpaste while brushing was reported as a risk factor for caries. Risk of caries was 1.32 times (CI 1.10-2.16) and 1.52 times (CI1.20-1.61) higher if the amount of tooth paste used was 2/3 of the tooth brush head size and whole head size respectively with 1/3 of the toothbrush head size as reference(=1) (Study 5). Constantine et al. (2011) reported sealants (material used by dentists to fill the deep pits and fissures (where caries start), of teeth in young children) as a protective factor the risk of having caries in children with sealants was 0.76 times the children without sealant use (OR=0.76; CI=0.57-1.00; p0.05) which was sta tistically significant (Study 15). Discussion Based on sixteen papers, this review demonstrates variation in the prevalence of dental caries in different regions of Europe and it ranged from 1.0 (Scotland) to 5.8 (Kosovo) (dmft).   Although, the prevalence of dental caries has decreased in Western and Central Europe, Eastern Europe is still facing a high prevalence of dental caries. This is similar to the findings of Marthaler, 2004.   In this review lower socio-economic status, sweets consumption and inadequate oral hygiene were reported as major risk factors. Studies 3 and 5 reported sugar consumption as a cause of dental caries. Similar association was reported by Cottrell, 2005. Awareness of mothers and rurality were reported as a protective factor for dental caries in studies 10,11,12 and 13. These findings were similar to Marserijian, Tavres, Hayes, Soncini and Trachtenberg (2008), who showed that caries were higher in urban children of New England than rural children. Tooth brushing was also reported as protective fac tor in study 5. Limitations of the study included, limited exploration of other factors that could be significant due to limited number of papers (+15). Journals could not be retrieved from all the European countries hence the result was generalised more widely. In most of the studies dental mirrors, dental probes, cotton rolls and natural daylight were used and these conditions were sub-optimal. Radiographs, artificial light and compressed air were not available. Finally, no attempt was done to perform a meta-analysis in the review to give a pooled prevalence. Despite, above mentioned limitations, this review can serve as a starting point for more ambitious reviews. All the studies included in this review used WHO criteria for recording the prevalence of dental caries (DMFT). The higher prevalence of dental caries in Eastern Europe is attributed to their under developed health system. Hence, there is need to strengthen the health systems in Eastern European countries. Highest caries prevalence is in lowest economic strata (Bratthall et al., 2000). Hence, there is immediate need to target lower socio-economic strata in the public health policies. 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