The major players in adaptive immunity

Our immune system, by and large, does a fine job in protecting us from opportunistic and infectious microbes, potential carcinogens and allergens. It is therefore crucial to understand the organization of the immune network. This article focuses on some important features and key players involved in adaptive immune response. The first part of the article dealt with the humoral immune response mediated mainly by immunoglobulins produced by the B cells. The second part deals with T cells, the Major Histocompatibility Complex (MHC)-encoded molecules, and Recombination Activating Genes (RAG) responsible for generating diverse B-cell receptors (BCR) and T-cell receptors (TCR). With the advent of newer and smarter infectious agents, it is important to understand the working of the immune network as more research in this area may facilitate the development of better protective strategies.     

Using school scholarships to estimate the effect of private education on the academic achievement of low-income students in Chile

This paper estimates the impact of private education on the academic achievement of low-income students in Chile. To deal with selection bias, we use propensity score matching to compare the test scores of reduced-fee paying, low-income students in fee-charging private voucher schools to those of similar students in public schools and free private voucher schools. Our results reveal that students in fee-charging private voucher schools score slightly higher than students in public schools. The difference in standardized test scores is approximately 10 points, a test score gain of 0.2 standard deviations. We find no difference in the academic achievement of students in the fee-charging private voucher treatment group relative to their counterparts in free private voucher schools.     

Plasma Fatty Acid Composition and Estimated Desaturase Activities Reflect Dietary Patterns in Subjects with Metabolic Syndrome

Changes in plasma fatty acid (FA) composition and desaturase activities are observed in metabolic syndrome (MS). However, whether these changes are a reflection of dietary intakes of fats and FAs is not well established. The current study was aimed at assessing plasma FA composition and desaturase enzyme activities as biomarkers of dietary intakes in subjects with MS. Case control study was done on 41 MS patients and was compared with age matched 45 controls. Dietary intakes, anthropometric and clinical parameters were measured. FA composition was analysed using gas chromatography-flame ionisation detector and desaturase enzyme activities were estimated as ratios of product to precursor FAs. Higher levels of 14:0, 16:0, 16:1, 18:1, D9D-18 activity and lower levels of 18:0 and 18:2 n-6 were seen in MS group when compared to controls (p < 0.05). Strong positive correlations were seen between plasma triglyceride (TG) levels and 14:0, 16:0, 16:1, 18:1, total saturated fatty acid, total monounsaturated fatty acid, and D9D activities, while 18:0, 18:2 n-6 and total polyunsaturated fatty acid were negatively correlated with TG. Positive correlations were seen between plasma 14:0, 18:1 and D9D-18 activity with total energy intake and carbohydrate (CHO) intakes but not with fat intake. Plasma FA profile appears to be a better index of total energy intake and CHO intake than fat intake, suggesting it might be a good reflection of endogenous FA metabolism. Changes in FA composition may therefore serve as an early index of dysregulation of FA metabolism, resulting in increased risk of MS.     

Automatic testing and assessment of neuroanatomy using a digital brain atlas: Method and development of computer‐ and mobile‐based applications

Preparation of tests and student's assessment by the instructor are time consuming. We address these two tasks in neuroanatomy education by employing a digital media application with a three‐dimensional (3D), interactive, fully segmented, and labeled brain atlas. The anatomical and vascular models in the atlas are linked to Terminologia Anatomica. Because the cerebral models are fully segmented and labeled, our approach enables automatic and random atlas‐derived generation of questions to test location and naming of cerebral structures. This is done in four steps: test individualization by the instructor, test taking by the students at their convenience, automatic student assessment by the application, and communication of the individual assessment to the instructor. A computer‐based application with an interactive 3D atlas and a preliminary mobile‐based application were developed to realize this approach. The application works in two test modes: instructor and student. In the instructor mode, the instructor customizes the test by setting the scope of testing and student performance criteria, which takes a few seconds. In the student mode, the student is tested and automatically assessed. Self‐testing is also feasible at any time and pace. Our approach is automatic both with respect to test generation and student assessment. It is also objective, rapid, and customizable. We believe that this approach is novel from computer‐based, mobile‐based, and atlas‐assisted standpoints. Anat Sci Educ 2:244–252, 2009. © 2009 American Association of Anatomists.     

Mentoring and Argumentation in a Game-Infused Science Curriculum

Engaging in argumentation from evidence is challenging for most middle school students. We report the design of a media-based mentoring system to support middle school students in engaging in argumentation in the context of a game-infused science curriculum. Our design emphasizes learners apprenticing with college student mentors around the socio-scientific inquiry of a designed video game. We report the results of a mixed-methods study examining the use of this media-based mentoring system with students ages 11 through 14. We observed that the discourse of groups of students that engaged with the game-infused science curriculum while interacting with college student mentors via a social media platform demonstrated statistically significant higher ratings of cognitive, epistemic, and social aspects of argumentation than groups of students that engaged with the social media platform and game-infused science curriculum without mentors. We further explored the differences between the Discourses of the mentored and non-mentored groups. This analysis showed that students in the mentored groups were invited, guided, and socialized into roles of greater agency than students in the non-mentored groups. This increased agency might explain why mentored groups demonstrated higher levels of scientific argumentation than non-mentored groups. Based on our analyses, we argue that media-based mentoring may be designed around a video game to support middle school students in engaging in argumentation from evidence.     

Serum Vitamin D Levels in Indian Patients with Multiple Sclerosis

Low serum vitamin D level has an increased association with risk of multiple sclerosis (MS).There has been no published data on the levels of this vitamin in Indian population with MS. Hence we decided to undertake this study to document if there is evidence of vitamin D deficiency in patients with MS in our population. 26 patients with diagnosis of MS by modified Mc Donald’s criteria were enrolled in this study. Serum vitamin D (1,25 hydroxy) levels were measured by electro-chemiluminescence in our biochemistry lab. An age-matched control group of 202 patients who did not have a diagnosis of MS were included. In our study group 76.9 % had vitamin D level less than 20 ng/ml compared to 65.5 % of control group (p value of 0.019). Our study revealed a trend towards low vitamin D values in Indian MS patients.     

Fate of nutrients in human dominated ecosystems

Jakkur Lake in the city of Bengaluru covers an approximate area of 55 hectares and primarily receives inflows from the Jakkur sewage treatment plant (STP) and an open storm drain. Jakkur STP discharges an average of 10 million litres of treated water daily (MLD) into the lake. The open drain discharges about 0.5 MLD of raw sewage into the lake. In the absence of environmental flows it becomes critical to assess the impact of nutrient flux on the quality of water, and design cost effective treatment solutions to address the issues of lake water quality. As part of this study, we have assessed the impact of these two primary inflows on the overall water quality of Jakkur Lake. The results have shown that nutrient inflows have led to the increase of chlorophyll-a levels, eventually causing hypereutrophication of Jakkur lake. We have also used simple mass balance approach to assess the contributions of in-lake activities (sedimentation and reaction) on removal of nutrients from the lake. We have concluded that the phosphorus load has to be reduced by approximately 96% from the current levels to prevent algal blooms within Jakkur Lake.     

Comparative genomics

An important hallmark of biological research is the aspect of ‘comparisons’. As the complete genome sequences of numerous organisms have become available, the emphasis in biology has shifted to comparisons at the genome level. Indeed, the last few years have witnessed an exponential rise in the number of organisms whose complete genome has been sequenced, and we are still climbing up the graph. The present article, a primer, explains how one can extract a great deal of information from such analyses that is of great value in our research. The subject of comparative genomics impinges on evolutionary biology and phylogenetic reconstructions of the tree of life, drug discovery programs, function predictions of hypothetical proteins and genes, regulatory motifs and other non-coding DNA motifs, and genome flux and dynamics. Finally the article describes how the information one can extract from a comparative analysis of genomes depends to a large extent, on the specific aspect of the genomes that is being compared and the phylogenetic distances of the organisms involved.