Demonstration of a new biosensing concept for immunodiagnostic applications based on change in surface conductance of antibodies after biomolecular interactions

We report an important observation that the surface conductivity of antibody layer immobilized on polylysine-coated glass substrate decreases upon the formation of complex with their specific antigens. This change in conductivity has been observed for both monoclonal and polyclonal antibodies. The conductance of monoclonal mouse IgG immobilized on polylysine-coated glass substrate changed from 1.02×10⁻⁸ Ω⁻¹ to 1.41×10⁻¹¹ Ω⁻¹ at 10 V when complex is formed due to the specific biomolecular interactions with rabbit anti-mouse IgG F(ab′)₂. Similar behavior was observed when the same set up was tested in two clinical assays: (1) anti-Leishmania antigen polyclonal antibodies taken from Kala Azar positive patient serum interacting with Leishmania promastigote antigen, and (2) anti-p21 polyclonal antibodies interacting with p21 antigen. The proposed concept can represent a new immunodiagnostic technique and may have wide ranging applications in biosensors and nanobiotechnology too.     

Stable individual differences on developmental tasks in young yellow-crowned parakeets,<Emphasis Type="Italic">Cyanoramphus auriceps</Emphasis>

We report on stable individual differences in young yellow-crowned parakeets across 38 tasks of cognitive development on three scales involving object permanence, means-end relations, and spatial relations. Stable performance ranks on blocks of tasks emerged after 13 weeks in two groups of sibling parakeets, one hand-reared and the other parent-reared. Examination of subject characteristics, such as hatch order, sex, general activity level, avoidances, latencies, social status, and errors, showed no significant correlations with these performance ranks. Characteristic individual approaches to unstructured play activities (from a fourth scale) were consistent with individual behavioral differences seen on the structured cognitive tasks.     

Academics' attitudes towards use of electronic journals: A case study of Punjab and Chandigarh

The article examines academics attitude towards e-journal use. A well structured questionnaire was designed to elicit the opinions of the users. Responses were gathered from 542 faculty members of five universities. The results of the study showed that the characteristics that affect the choice of e-format over print in order of preference are ‘faster access’, ‘available from desktop’, ‘convenience’, ‘remote access’, ‘timeliness’, ‘available at all times’, ‘hyperlinks’, ‘multi-user access’, ‘currency of information’, ‘inclusion of audio–video material’, ‘interactivity’ and ‘animation of graphics’. The characteristics that affect the choice of print format over electronic in order of priority are ‘physical comfort’, ‘portability’, ‘ability to underline’, ‘familiarity with format’ and ‘ability to browse’. A majority of the teachers use e-journals for ‘research’, ‘teaching’, ‘writing reports’, ‘current awareness’, ‘background research’ and ‘internal/external presentations’. The problems faced in accessing e-journals are ‘access difficulties’, ‘discomfort of reading from computer screen’, ‘lack of IT knowledge/skill’, ‘information overload’ etc. A majority of the teachers want future e-journals to have features such as ‘full text index of every article’, ‘searching capability across a wide range of journal articles’, ‘searching capability within an article, display relationship between a wide range of works’ and ‘links to multimedia files’, etc. On the basis of the findings, some suggestions are made for maximizing the use of e-journals.     

Molecular Basis of Cystic Fibrosis Disease: An Indian Perspective

Cystic fibrosis is a common autosomal recessive disorder usually found in population of white Caucasian descent. Now it is well documented the presence of CF disease in India with the advancement of laboratory testing. As once it was thought non existence of this disease in our population. Most of the phenotype of CF disease was in accordance of western population. Genetic analysis of CFTR gene in Indian CF patients revealed that most common mutation was delta F508 mutation. However, it was less than Caucasian population. CFTR mutations are also a causative factor in the pathogenesis of male infertility due to obstructive azoospermia. There are two most common mutation viz. IVS8-T5 and delta F508 which are responsible for congenital absence of vas deferens in male infertility patients. Elevated levels of sweat chloride at two occasions along with the presence of two mutations in CFTR gene was gold standard method for diagnosis of CF disease. It is noteworthy here that due to magnitude of Indian population, the total CF disease load would be more than many European countries. Clinical data demonstrate the prevalence of both classical and genetic form of CF in India.     

On-chip recalcification of citrated whole blood using a microfluidic herringbone mixer

In vitro assays of platelet function and coagulation are typically performed in the presence of an anticoagulant. The divalent cation chelator sodium citrate is among the most common because its effect on coagulation is reversible upon reintroduction of divalent cations. Adding divalent cations into citrated blood by batch mixing leads to platelet activation and initiation of coagulation after several minutes, thus limiting the time blood can be used before spontaneously clotting. In this work, we describe a herringbone microfluidic mixer to continuously introduce divalent cations into citrated blood. The mixing ratio, defined as the ratio of the volumetric flow rates of citrated blood and recalcification buffer, can be adjusted by changing the relative inlet pressures of these two solutions. This feature is useful in whole blood assays in order to account for differences in hematocrit, and thus viscosity. The recalcification process in the herringbone mixer does not activate platelets. The advantage of this continuous mixing approach is demonstrated in microfluidic vascular injury model in which platelets and fibrin accumulate on a collagen-tissue factor surface under flow. Continuous recalcification with the herringbone mixer allowed for flow assay times of up to 30 min, more than three times longer than the time achieved by batch recalcification. This continuous mixer allows for measurements of thrombus formation, remodeling, and fibrinolysis in vitro over time scales that are relevant to these physiological processes.     

Information empowerment: predeparture resource training for students in global health

The Taubman Health Sciences Library (THL) collaborates with health sciences schools to provide information skills instruction for students preparing for international experiences. THL enhances students'' global health learning through predeparture instruction for students who are involved in global health research, clinical internships, and international collaborations. This includes teaching international literature searching skills, providing country-specific data sources, building awareness of relevant mobile resources, and encouraging investigation of international news. Information skills empower creation of stronger global partnerships. Use of information resources has enhanced international research and training experiences, built lifelong learning foundations, and contributed to the university''s global engagement. THL continues to assess predeparture instruction.