Coordination compounds in biology

Vitamin B₁₂ is an important coordination compound in biology. It is an interesting biomolecule in the sense that no other vitamin contains a metal ion. This is the only naturally occurring organometallic compound found in biology. An intriguing aspect of vitamin B₁₂ is the great stability of the metal-carbon bond. A great deal of new and interesting inorganic chemistry has been uncovered while studying systems pertinent to B₁₂. In this article some salient features of this unique molecule (B₁₂) and its model compounds are presented.     

SWOT Analysis of Veterinary and Animal Science Education in India: Implications for Policy and Future Directions

Abstract

Purpose: The purpose of this study was to identify and rank the SWOT issues of India's veterinary and animal science education.

Design: The data were collected at the Indian Veterinary Research Institute (IVRI) from 168 post-graduate students. The two surveys generated 72% (N=121) and 68% (N=114) response rates, respectively. In the first stage, the vital SWOT issues were listed by respondents and in the second stage, they ranked the top eight issues on a Likert scale.

Findings: Uniform curriculum; merit-based admissions; and huge demand and employment prospects were perceived as major strengths. Gaps in curriculum revision and inadequate faculty, colleges and hands-on experience were perceived as key weaknesses. Regular curriculum revisions; novel instructional methods; and single admission tests were important opportunities perceived. Out-dated education model; urban biased admissions; and regional barriers were the major threats perceived.

Practical implication: The SWOT issues identified are similar to those faced by veterinary education programmes in many countries with minor variations.

Originality/value: The findings are of interest for veterinary faculties in developing and under-developed countries to harmonize their veterinary education systems on par with global norms. The related implications for policy and future directions are discussed.     

Academic Self‐Perceptions,Effort, and Strategy Use in Students with Learning Disabilities: Changes Over Time

This study investigated changes in teachers' and students' perceptions of students' effort, strategy use, and academic difficulties when strategy instruction was infused into the classroom curriculum. The sample consisted of 201 students with learning disabilities, 210 average achievers, and 57 teachers from Grades 4–9 in two urban and suburban communities. After six months of classroom‐based strategy instruction, students with learning disabilities reported more consistent use of strategies with their schoolwork and perceived themselves as struggling less in reading, writing, and spelling. Teachers perceived the students with learning disabilities as more strategic and as applying more effort to their schoolwork. Teachers also perceived their students as showing significant improvements in spelling, regardless of whether they had learning disabilities. These findings extended the results of previous investigations and indicated the small, positive impact of classroom‐based strategy instruction. Further investigations are critical to evaluate the generalizability of these findings.     

Computational investigations of the mixing performance inside liquid slugs generated by a microfluidic T-junction

Droplet-based microfluidics has gained extensive research interest as it overcomes several challenges confronted by conventional single-phase microfluidics. The mixing performance inside droplets/slugs is critical in many applications such as advanced material syntheses and in situ kinetic measurements. In order to understand the effects of operating conditions on the mixing performance inside liquid slugs generated by a microfluidic T-junction, we have adopted the volume of fluid method coupled with the species transport model to study and quantify the mixing efficiencies inside slugs. Our simulation results demonstrate that an efficient mixing process is achieved by the intimate collaboration of the twirling effect and the recirculating flow. Only if the reagents are distributed transversely by the twirling effect, the recirculating flow can bring in convection mechanism thus facilitating mixing. By comparing the mixing performance inside slugs at various operating conditions, we find that slug size plays the key role in influencing the mixing performance as it determines the amount of fluid to be distributed by the twirling effect. For the cases where short slugs are generated, the mixing process is governed by the fast convection mechanism because the twirling effect can distribute the fluid to the flow path of the recirculating flow effectively. For cases with long slugs, the mixing process is dominated by the slow diffusion mechanism since the twirling effect is insufficient to distribute the large amount of fluid. In addition, our results show that increasing the operating velocity has limited effects on improving the mixing performance. This study provides the insight of the mixing process and may benefit the design and operations of droplet-based microfluidics.     

Assessment of oxidative stress and antioxidant status in age related cataract in a rural population

Oxidative stress was assesed by estimating lipid peroxidation product (LPO) in the form of thiobarbituric acid reactive substances (TBARS), enzymatic antioxidants in the form of superoxide dismutase (SOD), catalase and nonenzymatic antioxidant vitamins e.g. vitamin C, β carotene and vitamin E in either serum or plasma or erythrocytes in 190 cases of age related cataract in the age group of 50–80 years. 190 cases were grouped into three morphological types namely, 73 cases of cortical, 77 cases of posterior subcapsular and 40 cases of nuclear cataract and values of LPO and antioxidants were compared with 78 cases of age matched healthy control groups. Plasma TBARS levels were cataract cases when compared with control groups. There were no significant differences in the erythrocyte levels of catalase and plasma levels of Vit E between cataract cases and control groups. No significant changes of parameters were seen among three different morphological types of age related cataract. The present study shows that the oxidative stress may play an important role in the age related cataract.     

Examining Teachers’ Attitudes and Experiences with Coaching to Inform Research-Based Practice: An Iterative Developmental Design Study

The purpose of this qualitative study was to examine teachers’ attitudes and experiences with coaching. This study was conducted in advance of a planned randomized controlled trial of a coaching intervention to better align the model with teachers’ needs and goals. Thirty-four K–5 general (n = 26), special education (n = 6), and educational support staff (n = 2) working in two high-poverty schools participated in focus groups. Interrater reliability between independent coders was high (К = 0.92; range: 0.76–1.0). Thematic analyses identified facilitators and barriers to teacher participation in the planned intervention and were used to improve upon the existing coaching model. Themes focused on advantages and disadvantages to coaching and characteristics of effective coaches and coaching models. Implications of findings for research and practice are discussed.     

Host protective immunity and vaccine development studies in lymphatic filariasis

Lymphatic filariasis caused mainly by infection fromWuchereria bancrofti andBrugia malayi remains as the major cause of clinical morbidity in tropical and subtropical countries. Development of vaccine against filarial infection can act as additional measure to the existing therapeutic and vector control methods in the control of this disease. The main hurdles in the development of anti-filarial vaccine are the strict primate specificity ofWuchereria bancrofti, the paucity of parasite material, the diversity of clinical manifestations and their associated complex immune responses, lack of clear understanding on host-parasite interactions and the mechanisms involved in protective immunity. However in the past few years, the information generated in immuno-epidemiological studies, correlated with observations in experimental animals suggests that a filarial vaccine is feasible. Initially live irradiated infective larvae have been successfully used to induce high level of protective immunity in several animal models. Applying diverse strategies, variety of purified or recombinant filarial antigens have been explored for their ability to induce protection in different host-parasite systems. Some of these targeted filarial antigens induced high level of resistance in experimental animals against challenge infections. More focussed studies on thorough characterization of parasitological and immunological changes associated with resistance induced by such candidate protective antigens and on delivery mechanisms and safety aspects will be crucial in their selection for possible use in humans.     

Circulating Cell-Free DNA Level in Prediction of COVID-19 Severity and Mortality: Correlation of with Haematology and Serum Biochemical Parameters

Lymphocyte dysregulation in coronavirus disease-19 (COVID-19) is a major contributing factor linked to disease severity and mortality. Apoptosis results in the accumulation of cell-free DNA (cfDNA) in circulation. COVID-19 has a heterogeneous clinical course. The role of cfDNA levels was studied to assess the severity and outcome of COVID-19 patients and correlated with other laboratory parameters. The current case series included 100 patients with mild COVID-19 (MCOV-19) and 106 patients with severe COVID-19 (SCOV-19). Plasma cfDNA levels were quantified using SYBR green quantitative real-time PCR through amplification of the β-actin gene. CfDNA level was significantly higher in SCOV-19 at 706.7 ng/ml (522.6–1258) as compared to MCOV-19 at 219.8 ng/ml (167.7–299.6). The cfDNA levels were significantly higher in non-survivor than in survivors (p = 0.0001). CfDNA showed a significant correlation with NLR, ferritin, LDH, procalcitonin, and IL-6. The diagnostic sensitivity and specificity of cfDNA in the discrimination of SCOV-19 from MCOV-19 were 90.57% & 80%, respectively. CfDNA showed a sensitivity of 94.74% in the differentiation of non-survivors from survivors. CfDNA levels showed a significant positive correlation with other laboratory and inflammatory markers of COVID-19. CfDNA levels, NLR, and other parameters may be used to stratify and monitor COVID-19 patients and predict mortality. CfDNA may be used to predict COVID-19 severity with higher diagnostic sensitivity.     

Relationships Among Measures as Empirical Evidence of Validity: Incorporating Multiple Indicators of Achievement and School Context

In this article we examine empirical evidence on the criterion, predictive, transfer, and fairness aspects of validity of a large-scale language arts performance assessment, referred to as the Performance Assignment (PA). We use multilevel models to avoid biased inferences that might result from the naturally nested data. Specifically, we examine the relationships of the assessment with the Stanford Achievement Test, 9th Edition and the California High School Exit Examination. The results indicate that the measures are related, that students demonstrate a degree of transfer, and that the language arts PA is relatively more fair than comparison assessments. The results are robust to various model specifications and demonstrate that benefits do not accrue to all students equally.