Glial cells: The other cells of the nervous system

Carl Ludwig Schleich (1859–1922) was an anaesthetist and a surgeon who for the first time emphasized the role of neuroglia in brain function. In an era that was dominated by the idea that neurons alone were functional units of the nervous system and that glial cells were a mere glue holding neurons in place, Schleich insisted that glia had a prominent functional role to play. He suggested that interactions between neurons and glia were so strong that it is necessary to consider brain as a neuron-glia system whose performance is dependent on both the cell types. Today Carl Ludwig Schleich is considered the forgotten ancestor to a new breed of neurobiologists, the gliologists, who specialize in working on these neglected cells of the nervous system. Though outnumbering the neurons and occupying almost half the volume of the brain, glial cells have been given little importance in textbooks of neurobiology and are very often cursorily mentioned in discussions related to brain function. Glial cells deserve a better deal, for over the years a lot of evidence has accumulated to prove that they perform a wide spectrum of functions. This is the first of a series of articles that aims to update students on what is known about glia today. It provides an overview of the various types of glia and their origins. The following articles will deal with each of the glial sub-types and their functions.     

Religiosity as a moderator of the links between parental psychological control and children's prosociality

Three studies examined the links between psychological control and prosociality in middle childhood, and the role of religiosity as a moderator. Study 1 (101 Israeli Jewish families, ages 6–9, 50% girls) found a significant interaction, with a negative association between maternal psychological control and children's prosociality in secular but not in religious families. Study 2 (161 Israeli Jewish families, ages 6–12, 48% girls) replicated this interaction for mothers using a continuous religiosity measure. Study 3 (64 Arab Muslim Israeli families, ages 6–8.5, 50% girls) also found a significant interaction, with a positive link between psychological control and prosociality seen at higher, but not at lower, religiosity levels. The findings suggest that religiosity may alter the meaning and consequences of parenting practices.     

Phytochemical composition,biological potential and enzyme inhibition activity of <Emphasis Type="Italic">Scandix pecten-veneris</Emphasis> L.

Objective

Scandix pecten-veneris L. is a less studied wild edible herb and is considered an extinct plant species in many parts of the world. This study was designed to evaluate its phytochemical composition and biological potential of S. pecten-veneris L.

Methods

Phytochemicals including alkaloids, flavonoids, polyphenols, and tannins were determined in extracts of S. pecten-veneris. Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), while reducing power was tested by ferric reducing/antioxidant power (FRAP) assay. Antimicrobial activity against seven bacterial and four fungal strains was evaluated using agar well diffusion assay. Enzymes inhibition study was performed for urease, phosphodiesterase-I, and catalase-II.

Results

S. pecten-veneris showed moderate antiradical activity and reducing potential of hydroxyl radicals to about 20% of the initial value. The antioxidant activity of various extracts of S. pecten-veneris showed a linear correlation with total phenolic contents in the order of water>n-butanol>chloroform>ethyl acetate>methanol extracts. S. pecten-veneris leaves showed the highest inhibitory activity against Staphylococcus aureus while the highest antifungal activity was observed against Candida albicans. The plant extract was most potent against urease enzymes but showed moderate activity against phosphodiestrase-I and carbonic anhydrase-II.

Conclusions

Our data demonstrate that in addition to its culinary uses, S. pecten-veneris has good medicinal potential and hence could be used for treating some specific health ailments.

     

Delinquency and reputational orientations of adolescent at‐risk and not‐at‐risk males and females

This research investigated differences in delinquent activities and the reputational orientations of at‐risk and not‐at‐risk male and female adolescents. Initially, we sought to establish that adolescent males and females differed in these respects. This was found to be the case: males (n = 722) scored significantly higher than females (n = 738) on seven self‐reported delinquency variables and on eight reputation enhancement variables pertaining to social deviance, non‐conforming reputation, and power/evaluation private identity. When a sample of 31 at‐risk females was subsequently pair‐wise age matched with 31 not‐at‐risk females, at‐risk females scored significantly higher on all delinquency variables other than school misdemeanors. These at‐risk females also scored significantly higher on four reputation enhancement variables relating to social deviance and non‐conformity. Given that at‐risk females did not differ from their not‐at‐risk counterparts in level of involvement in school misdemeanors, we sought to determine whether this was also the case for at‐risk and not‐at‐risk males. An age‐matched sample of 91 pairs revealed that at‐risk males reported significantly higher involvement than not‐at‐risk males in all aspects of delinquency, including school misdemeanors. They also sought a more non‐conforming reputation. To explore the relationships between delinquency and reputation enhancement, a canonical correlation analysis was performed. All findings are discussed in the light of reputation enhancement theory.     

Characterization of lectins and their specificity in carcinomas—An appraisal

Lectins, a group of specific glycoproteins present in animal as well as plant cells, are used as differentiating markers to study cancers and metastatic cell lines. This property of lectins depends on the process of cellular glycosylation. Glycosylation of some of the extracellular membrane proteins and lipids maintains the cell/cell and cell/matrix interactions. Chemical alterations in glycosylation play an important role in the metastatic behavior of tumor cells. Carbohydrate residues of the membrane glycoproteins can be detected using lectins due to their binding specificity to carbohydrates. Lectins, therefore have gained an importance in the field of cancer research. Galectins, a specialized group of lectin like proteins that are Ca+ independent and galactoside binding, are also considered as differentiation markers in some specific cancers like the carcinomas of thyroid. Thus the use of lectins and galectins to identify specific carbohydrates present on cell surface help in invasion and metastasis processes.     

Investigation of a novel perforation technique in petroleum wells—perforation by drilling

The objective of perforating the petroleum wells is to maximize well productivity. A good connectivity between the wellbore and formation can lead up to achieve that goal. However, the conventional method of perforation, which basically involves the use of explosive charges, rarely meets the expected well productivity. It is mainly because of the formation of a region of reduced permeability around the perforation tunnel. To offset such and several other shortcomings of present practices, a new technique is required, the highlight of this paper. Described as the ‘perforation by drilling’ (PD), this new technique is examined and compared for its performance with that of another technique, ‘Perforation by Shooting’ (PS). For this, the experimental and numerical results of the PS technique on cylindrical sand samples of varying amounts of strength and porosity are studied. Moreover, in order to achieve a so-called ‘perfect perforation’, results are compared with the ‘Casting technique’. Three different samples were selected for the measurement of fluid flow rate and differential pressure across the perforation using a ‘geotechnical digital system’ (GDS), which is a triaxial testing device. Profiles such as fluid flow rate with a change in differential pressure and pressure build-up data with time, signify that the PD technique can achieve maximum wellbore productivity when compared to the PS technique. Results also indicate that at a 100 kPa differential pressure, the PS, PD and Casting techniques can achieve 0.20, 0.65 and 1.00 mL/s fluid flow rates respectively across a sample. The paper also implements a 1-D time dependent porous media flow model to simulate flow across the perforated cylindrical samples created by the PS, PD and Casting techniques. Results show a good consistency between the experimental and numerical approaches.     

Prioritizing natural-selection signals from the deep-sequencing genomic data suggests multi-variant adaptation in Tibetan highlanders

Human genetic adaptation to high altitudes (>2500 m) has been extensively studied over the last few years, but few functional adaptive genetic variants have been identified, largely owing to the lack of deep-genome sequencing data available to previous studies. Here, we build a list of putative adaptive variants, including 63 missense, 7 loss-of-function, 1,298 evolutionarily conserved variants and 509 expression quantitative traits loci. Notably, the top signal of selection is located in TMEM247, a transmembrane protein-coding gene. The Tibetan version of TMEM247 harbors one high-frequency (76.3%) missense variant, rs116983452 (c.248C > T; p.Ala83Val), with the T allele derived from archaic ancestry and carried by >94% of Tibetans but absent or in low frequencies (<3%) in non-Tibetan populations. The rs116983452-T is strongly and positively correlated with altitude and significantly associated with reduced hemoglobin concentration (p = 5.78 × 10⁻⁵), red blood cell count (p = 5.72 × 10⁻⁷) and hematocrit (p = 2.57 × 10⁻⁶). In particular, TMEM247-rs116983452 shows greater effect size and better predicts the phenotypic outcome than any EPAS1 variants in association with adaptive traits in Tibetans. Modeling the interaction between TMEM247-rs116983452 and EPAS1 variants indicates weak but statistically significant epistatic effects. Our results support that multiple variants may jointly deliver the fitness of the Tibetans on the plateau, where a complex model is needed to elucidate the adaptive evolution mechanism.     

Hypoglycemic, lipid lowering and antioxidant activities in root extract of Anthocephalus indicus in alloxan induced diabetic rats

The present study was carried out to evaluate the hypoglycemic, lipid lowering and antioxidant activities in root extract of Anthocephalus indicus (A indicus) in alloxan inducd diabetic rats. Oral administration of ethanol extract of root (500mg/ kg body weight) for 21 days resulted in significant decrease in the levels of blood glucose, triglycerides, total cholesterol, phospholipid and free fatty acids. Furthermore, the root extract (100–400μg) inhibited the generation of superoxide anions and hydroxyl radicals, in both enzymic and non-enzymic systems, in vitro. The result of the present study demonstrated hypoglycemic, lipid lowering and antioxidant activities in root extract of A indicus, which could help in prevention of diabetic dyslipidemia and related diseases.     

Things Fall Apart and Come Together: Using the Visual for Reflection in Alternative Teacher Education Programmes

In this article, we focus on the use of the visual for reflection in ‘alternative’ pre‐service teacher education and, in particular, we address the question: How and what can we learn about teacher education using the visual? By way of illustration, we focus on the use of pre‐service teachers’ photographs in a public exhibition, participatory video documentary production and pre‐service teachers’ use of photographs in their professional teaching portfolios. The article draws from research done in relation to three alternative pre‐service teacher education projects based at McGill University in Canada and the University of KwaZulu‐Natal in South Africa.