Enhanced efficiency in vector control of a Surface-mounted PMSM drive

In this paper, emphasis has been put on providing the result of a detailed simulation study on the dynamics and efficiency of a vector-controlled voltage source inverter (VSI)-fed surface-mounted permanent magnet synchronous motor (SPMSM) drive; which employs firstly a model-based loss-minimization algorithm (MLMA) and secondly a binary search-based online loss-minimization algorithm (BSOLMA), so as to reduce the total controllable electrical losses without much affecting the dynamic performance of the drive. The steady-state SPMSM model taking into account the core loss has been considered. The dynamic performances of the SPMSM drive employing individually the abovementioned loss minimization algorithms (LMAs) have been compared with that employing conventional zero d-axis current control (ZDCC) through extensive digital computer simulations. The simulation results show that efficiency of the drive enhances with the employment of the LMA.     

Role of oxidative stress in ethanol induced germ cell apoptosis — An experimental study in rats

The study was undertaken to evaluate the possible involvement of oxidative stress in the pathogenesis of ethanol induced testicular atrophy in rats. Adult male rats were orally administered ethanol at a dose of 1.6 g/kg body weight/day for four weeks. Twenty-four hours after the last treatment the rats were sacrificed using anesthetic ether. Testes were removed and weighed. Apoptosis was studied by using the Feulgen reaction on 5 μ thin paraffin sections of testis. Testicular homogenate was prepared and centrifuged. The supernatant was used for the estimation of extent of lipid peroxidation and antioxidant defense status. There was significant reduction in body weight: and in testicular weight and diameter in ethanol treated rats. Extent of germ cell apoptosis was significantly high in ethanol treated rats. Ethanol treated rats showed significantly high tissue TBARS level and glutathione S-transferase activity; and low tissue ascorbic acid, reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities. Chronic ethanol administration resulted in high oxidative stress in the testes either due to increased extent of lipid peroxidation or due to decreased antioxidant defenses, and thereby induces germ cell apoptosis leading to testicular atrophy.     

Study of serum lipid profile in pregnancy induced hypertension

Four groups of subjects: normal healthy normotensive nonpregnant women (Group A), normal normotensive pregnant women (Group B), women with preeclamptic toxaemia (Group C) and eclamptic women (Group D): with fifty subjects in each group, were investigated for serum lipid profile in the third trimester of pregnancy. There was significant increase in serum triglyceride and VLDL cholesterol leve as well as decrease in LDL cholesterol in normal pregnancy, while total cholesterol and HDL cholesterol levels did not show any statistically significant alteration. The preeclampsia (Group C) was associated with a significant rise in triglyceride and VLDL cholesterol and fall in HDL cholesterol concentration, while eclamptic women showed significant fall in HDL cholesterol and rise in LDL cholesterol as compared to normal pregnant women. However, interestingly, elevation of the ratios of total cholesterol: HDL cholesterol and triglyceride: HDL cholesterol as well as diminuition of the ratio of HDL cholesterol: VLDL cholesterol showed statistical significance in pregnancy induced hypertension in both Groups C and D, while eclamptic women showed significant elevation of LDL cholesterol: HDL cholesterol ratio in addition.     

Effect of Copper on <Emphasis Type="SmallCaps">l</Emphasis>-Cysteine/<Emphasis Type="SmallCaps">l</Emphasis>-Cystine Influx in Normal Human Erythrocytes and Erythrocytes of Wilson’s Disease

Wilson’s disease is a disease of abnormal copper metabolism in which free serum copper level is raised. The objective of the study was to determine, whether in Wilson disease, l-cysteine/l-cystine influx into RBC was decreased or not and the specific amino acid transporter affected by copper in normal human RBC. For l-cysteine/l-cystine influx, ten untreated cases, ten treated cases and ten age and sex matched healthy controls were recruited. To study the effect of copper on l-cysteine/l-cystine influx in RBC, 15 healthy subjects were selected. RBC GSH and l-cysteine/l-cystine influx were estimated by Beautler’s and Yildiz’s method respectively. In untreated cases, l-cysteine/l-cystine influx and erythrocyte GSH level were decreased showing that elevated level of free copper in serum or media decreased l-cysteine/l-cystine influx in human RBC. Copper treatment inhibited L amino acid transporter in normal RBC specifically.     

Escherichia coli lipopolysaccharide administration alters antioxidant profile during hypercholesterolemia

Pathogens, especially Gram-negative bacteria or bacterial endotoxin, along with other classical factors, may be involved in inflammatory response within the aortic endothelium during the progression of cardiovascular disease. Studies have shown that bacterial endotoxin activates various inflammatory processes in the body. Our study aims to establish a correlation between endotoxemia and vascular expression of antioxidant enzymes. Swiss albino mice (4 weeks old) were fed a high fat diet for 24 weeks and then were administered Escherichia coli endotoxin intraperitonealy, for 4 weeks. Tissue antioxidant enzymes, serum levels of IL-6 and TNF alpha were measured from the mice. We report that i.p. administration of endotoxin to hyperlipidemic mice resulted in elevation of superoxide dismutase and catalase enzymes, which was paralleled by a systemic reduction of serum cholesterol and LDL expression. Myeloperoxidase levels were also found to be elevated in aortic tissue, while an increase was also observed in the serum cytokine levels.     

Whiteness,internationalization, and erasure: decolonizing futures from the Global South

ABSTRACT

The essay explores the mobility of Whiteness in networks of Communication Studies that posture themselves as speaking from the Global South. Depoliticized languages of de-westernizing, internationalizing, and decolonizing are often articulated by elites in North-South networks pushing neoliberal governmentality, erasing claims to radical equality that emerge from within socialist struggles in the Global South. In resistance, a radical framework of knowledge from the Global South emerges from within subaltern struggles for hegemony, achieved through (a) delinking from the metropoles of the North and (b) explicitly crafting a socialist anticolonial politics that names and dismantles Whiteness as a capitalist project.     

A new fabrication technique to form complex polymethylmethacrylate microchannel for bioseparation

Recent studies show that reduction in cross-sectional area can be used to improve the concentration factor in microscale bioseparations. Due to simplicity in fabrication process, a step reduction in cross-sectional area is generally implemented in microchip to increase the concentration factor. But the sudden change in cross-sectional area can introduce significant band dispersion and distortion. This paper reports a new fabrication technique to form a gradual reduction in cross-sectional area in polymethylmethacrylate (PMMA) microchannel for both anionic and cationic isotachophoresis (ITP). The fabrication technique is based on hot embossing and surface modification assisted bonding method. Both one-dimensional and two-dimensional gradual reduction in cross-sectional area microchannels were formed on PMMA with high fidelity using proposed techniques. ITP experiments were conducted to separate and preconcentrate fluorescent proteins in these microchips. Thousand fold and ten thousand fold increase in concentrations were obtained when 10 × and 100 × gradual reduction in cross-sectional area microchannels were used for ITP.     

An initial preparation for human cadaveric dissection ameliorates the associated mental distress in students

It is universally recognized that cadaveric dissection is an essential part of anatomy training. However, it has been reported to induce mental distress in some students and impair their intrinsic motivation (IM) to study. One of the postulated reasons for this behavior is the lack of adequate information and preparation of students for cadaveric dissection. Therefore, it is hypothesized that providing relevant information prior to cadaveric dissection will ameliorate the mental distress, enhance the IM of students, and improve their academic performance. A cohort of occupational therapy students enrolled in an anatomy course were psychologically prepared for cadaveric dissection. Students were provided with a curated list of YouTube videos and peer-reviewed journal articles related to cadaveric dissection prior to the commencement of the anatomy course. All students were also required to attend an oral presentation immediately before commencing dissection. The control group included students who had not been provided with any resources in preparation for cadaveric dissection. Compared to the control group, students who had been prepared demonstrated better quality of cadaveric dissection, improved academic performance, reported less mental distress and greater IM. Moreover, students reported the oral presentation to be most relevant and journal articles to be least useful in their preparation. Therefore, this is an effective approach in the amelioration of mental distress and improvement of performance in anatomy students. Consequently, this study represents a paradigm shift in the pedagogy of anatomy, and could represent a vital element in the evolution of a revitalized anatomy curriculum.     

Singing Sand Dunes

One of the highly striking yet poorly understood natural phenomena is the song of dunes. Some sand dunes in deserts are capable of emitting a loud persistent sound with a characteristic audible low-frequency (≈ 75—105 Hz), that can sometimes be heard up to 10 km away. Scientific in-vestigations suggest that the sustained low fre-quency sound of sand dunes that resembles a pure note from a musical instrument, is due to the synchronized motion of well-sorted dry sand grains when they spontaneously avalanche under gravity. This article describes the underlying mechanism for sustained sound emission in singing sand dunes in light of recent physical ex-periments.