Global Epidemiology of Tuberculosis: Past, Present and Future

No9 abstract

ADVANCED RECEIVER ARCHITECTURES IN RADIO-FREQUENCY APPLICATIONS

The general principles of several types of receivers fall under the two main headings of TRF (tuned radiofrequency) receivers, where the received signal is processed at the incoming frequency right up to the detector stage, and thesuperhet (supersonic heterodyne) receiver, where the incoming signal is translated (sometimes after some amplification atthe incoming frequency) to an intermediate frequency for further processing. There are however, a number of variants ofeach of these two main types. Regeneration (‘reaction’ or ‘tickling’) may be applied in a TRF receiver, to increase both itssensitivity and selectivity. This may be carried to the stage where the RF amplifier actually oscillates – either continuously,so that the receiver operates as a synchrodyne or homodyne, or intermittently, so that the receiver operates as a superregenerativereceiver, both of which have been described previously. The synchrodyne or homodyne may be consideredalternatively as a superhet, where the IF (intermediate frequency) is 0 Hz. In this paper we present the new type of receiverarchitectures which work in radiofrequencies.Keywords: Supersonic Heterodyne, Tuned Radio Frequency

Structure and stability of glucoamylase II from Aspergillus niger: a circular dichroism study

Glucoamylase II (EC 3.2.1.3) from Aspergillus niger has 31 % α-helix, 36 % β-structure and rest aperiodic structure at pH 4.8 as analysed by the method of Provencher and Glockner (1981,Biochemistry, 20,33). In the near ultra-violet circular dichroism spectrum the enzyme exhibits peaks at 304, 289, 282 and 257 nm and troughs at 285, 277 and 265 nm respectively. The enzyme activity and structure showed greater stability at pH 4.8 than at pH 7.0, were highly sensitive to alkaline pH but less sensitive to acid pH values. The enzyme retained most of its catalytic activity and structure even on partial removal of carbohydrate moieties by periodate treatment but was less stable at higher temperatures and storage at 30‡C. Reduction of the periodate treated enzyme did not reverse the loss of stability. Binding of the synthetic substrate, p-nitrophenyl-α-D-glucoside, perturbed the environment around aromatic amino acids and caused a decrease in the ordered structure

Measurement of Differentially Methylated INS DNA Species in Human Serum Samples as a Biomarker of Islet β Cell Death

The death of islet β cells is thought to underlie the pathogenesis of virtually all forms of diabetes and to precede the development of frank hyperglycemia, especially in type 1 diabetes. The development of sensitive and reliable biomarkers of β cell death may allow for early therapeutic intervention to prevent or delay the development of diabetes. Recently, several groups including our own have reported that cell-free, differentially methylated DNA encoding preproinsulin (INS) in the circulation is correlated to β cell death in pre-type 1 diabetes and new-onset type 1 diabetes. Here, we present a step-by-step protocol using digital PCR for the measurement of cell-free INS DNA that is differentially methylated at cytosine at position -69 bp (relative to the transcriptional start site). We demonstrate that the assay can distinguish between methylated and unmethylated cytosine at position -69 bp, is linear across several orders of magnitude, provides absolute quantitation of DNA copy numbers, and can be applied to samples of human serum from individuals with new-onset type 1 diabetes and disease-free controls. The protocol described here can be adapted to any DNA species for which detection of differentially methylated cytosines is desired, whether from circulation or from isolated cells and tissues, and can provide absolute quantitation of DNA fragments

Floral biology studies in wild melon [Cucumis melo L. ssp. agrestis (Naudin) Pangalo var. agrestis Naudin]

Studies on floral morphology, phenology and biology of wild melon revealed that the ratio of staminate and pistillate flowers was 3.40:1. The longevity of the male flowers were between 5 and 6 days, whereas, female flowers between 6 and 7 days. Anthesis was observed from 4.00 am to 10.00 am, while, the anther dehiscence started from 5.00 am which was continued to 7.00 am. The peak anthesis was observed from 8.00 am to 9.00 am and anther dehiscence from 6.00 am to 6.30 am. Freshly opened flowers showed pollen viability up to 98.35%, decreased upon closure and crashed to 17.48% in 3 days. Pollen germination was occurred after 15 minutes of incubation and continued up to 24 h of incubation. The stigma receptivity lasts from one to two days of anthesis. Major pollinator of wild melons observed was honey bee, mostly visited between 9:00 am to 6:00 pm

Polyamine biosynthesis is critical for growth and differentiation of the pancreas

The pancreas, in most studied vertebrates, is a compound organ with both exocrine and endocrine functions. The exocrine compartment makes and secretes digestive enzymes, while the endocrine compartment, organized into islets of Langerhans, produces hormones that regulate blood glucose. High concentrations of polyamines, which are aliphatic amines, are reported in exocrine and endocrine cells, with insulin-producing β cells showing the highest concentrations. We utilized zebrafish as a model organism, together with pharmacological inhibition or genetic manipulation, to determine how polyamine biosynthesis functions in pancreatic organogenesis. We identified that inhibition of polyamine biosynthesis reduces exocrine pancreas and β cell mass, and that these reductions are at the level of differentiation. Moreover, we demonstrate that inhibition of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, phenocopies inhibition or knockdown of the enzyme deoxyhypusine synthase (DHS). These data identify that the pancreatic requirement for polyamine biosynthesis is largely mediated through a requirement for spermidine for the downstream posttranslational modification of eIF5A by its enzymatic activator DHS, which in turn impacts mRNA translation. Altogether, we have uncovered a role for polyamine biosynthesis in pancreatic organogenesis and identified that it may be possible to exploit polyamine biosynthesis to manipulate pancreatic cell differentiation

effect of porosity and cell topology on elastic plastic behavior of cellular structures

Abstract In this work we study the mechanical behavior of Ti6Al4V cellular structures by varying the randomness in the cell topology from regular cubic to completely random and the porosity of the structure. The porosity of the structure is altered by changing the strut thickness and the pore size to obtain a stiffness value between 0.5-12Gpa. The geometrical deviation in the structures from the as-designed values is studied by morphological characterization. The samples are subjected to compression and tensile loading to obtain the stiffness and the elastic-plastic behavior of the samples. Finite element modelling (FEM) is carried out on the as-designed structures for both tensile and compressive loading to study the effect of deviation between the as-designed and as-built structures. FEM is also carried out for as-built regular structures, by introducing the geometrical deviation to match the porosity of the as-built structures. Comparison of FEM and experimental results indicated that the effect of cell topology depends on the porosity values. Simulation results of as-built structures demonstrated the importance of defects in the structure

Proportion, Risk Factors and the Impact of Dysmenorrhea among Girls

Background: Dysmenorrhea is the leading cause of recurrent short-term school absence in adolescent girls and a common problem in women of reproductive age. There are many factors related to this disorder which include a younger age, low body mass index (BMI), smoking, early menarche, and prolonged menstrual flow. Objectives: (1) To find the proportion of dysmenorrhea among girls of a nursing college; (2) To find out the risk factors and impact of dysmenorrhea.Materials and Methods: A cross-sectional study was conducted from November 2011 to April 2012 at Nursing College, VIMS, Bellary, Karnataka. Data were collected by a pre-tested and pre-designed semi-structured pro forma. The study was performed on a total of 196 students who agreed to participate and present at the time of study. Analysis was done by using Epi-info version 3.4.3.Results: The average age of the study group was 19.3+1.8 years (range 17–30). Proportion of dysmenorrhea was found to be 77% and was significantly higher in females with positive family history of dysmenorrhea when compared to the others (P<0.05), who had early age of menarche, irregular cycle, increased amount of flow, gynecological problems and lack exercise had high rate of dysmenorrhea compared to others but statistically it was not significant. In this study, because of dysmenorrhea 20.5% had class absenteeism, 23.2% college absenteeism, 44.4% had poor concentration, 31.8% were depressed, 53% were irritable and 2.6% had suicidal tendencies.Conclusion and Recommendation: There was a high proportion of dysmenorrhea and also girls were very much worried about it. There is a need to educate them about causes, treatment and also to cope with stress at the time of menstrual cycle