On the dynamics of high-risk fertility in Bangladesh

Our aim in this study is to explore the dynamics of age-pattern of childbearing and risk fertility among Bangladeshi women. By using age-specific fertility rates of 21 age schedules from 1986 to 2006 contribution of early, on time and delayed childbearing on total fertility rates are studied and time trend behavior of risk fertility is observed. Our study explored that the level of early childbearing seems to be stagnant over the years. The decrement of the high-risk fertility is due to the decrease of total fertility rates, however, the contribution of early childbearing to the total fertility rates is unchanged and contribution of early childbearing to the high-risk fertility is more influential than the delayed childbearing. The ratio of risk-birth is plateau at the same level even after twenty years. Possible policies to reduce the risk-birth are also discussed in this paper

Far-Infrared Blocked Impurity Band Detector Development

DRS Sensors & Targeting Systems, supported by detector materials supplier Lawrence Semiconductor Research Laboratory, is developing far-infrared detectors jointly with NASA Langley under the Far-IR Detector Technology Advancement Partnership (FIDTAP). The detectors are intended for spectral characterization of the Earth's energy budget from space. During the first year of this effort we have designed, fabricated, and evaluated pilot Blocked Impurity Band (BIB) detectors in both silicon and germanium, utilizing pre-existing customized detector materials and photolithographic masks. A second-year effort has prepared improved silicon materials, fabricated custom photolithographic masks for detector process, and begun detector processing. We report the characterization results from the pilot detectors and other progress

Evaluation of two concepts of fertilization for wheat in a calcareous soil of Bangladesh

Two popular concepts of soil fertilization, basic cation saturation ratio (BCSR) and sufficiency level of available nutrients (SLAN), were tested on a calcareous soil (Aeric haplaquept) during 1995-1996 at the Bangladesh Rice Research Institute (BRRI) Regional Station Rajshahi using wheat as a test crop. According to BCSR concept the soil was deficient in potassium (K) and according to SLAN concept it was deficient in phosphorus (P), respectively. Potassium dose of 120 kg ha-1 [to attain 2% saturation of total cation exchange capacity (CEC) according to BCSR] along with other two doses (0 and 60 kg K ha-1) and P dose of 50 kg ha-1 (to attain available P at sufficiency level) along with other two doses (0 and 100 kg P ha-1) were compared in a randomized complete block design. The application of 50 kg P ha-1 significantly increased plant height, spikes m-2, grains per spike, grain and straw yields of wheat over 0 kg P ha-1 with or without K but increasing P dose from 50 to 100 kg P ha-1 did not give additional yields. The agronomic parameters and yields were not affected significantly by K application. Similar results were also observed in nutrient content and nutrient uptake. Thus, SLAN concept appeared as an effective tool for fertilizer recommendation for the calcareous soil while BCSR gave no apparent result there

Yield and phosphorus efficiency of some lowland rice varieties at different levels of soil‐available phosphorus

A field experiment was conducted on an Aeric Haplaquept soil to study the effect of phosphorus (P) deficiency in soil on the P nutrition and yield of five modern varieties of rice, viz., Purbachi, BR1, BR3, BR14, and BR29, popular with the rice farmers of Bangladesh. Soil-available P in the different plots of the experimental field varied widely, from 2.8 to 16.4 ppm. This plot to plot variation in soil-available P content resulted from differences in the total amounts (0 to 480 kg ha -1) of P the plots had received over a period of 8 years in a long-term P fertilizer trial conducted previously in the same field. Phosphorus deficiency in soil drastically reduced the grain yield of all the rice varieties. In severely P deficient plots, where soil-available P was around 3 ppm, the yield was less than 1 ton ha -1 while in plots containing an adequate P level, i.e., >6 ppm, the yield was more than 4 t ha -1. Rice yield increased linearly with an increase in soil P content up to 6 ppm, and the highest grain yield for any variety, obtained at 6-7 ppm of soil-available P leveled off at this point. Soil P deficiency not only decreased rice yield severely but also decreased P content in straw and grain drastically. However, differences among rice varieties were noted in P nutrition, particularly at low soil P levels. The rice varieties differed markedly also in respect of internal P efficiency. The BR29 showed the highest internal P efficiency both at low and high soil P levels. In all the rice varieties, internal P efficiency decreased with an increase in soil P levels

Premature Cell Senescence and T Cell Receptor‐Independent Activation of CD8+ T Cells in Juvenile Idiopathic Arthritis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99044/1/art38015.pd

A Comparison of Dry Plasma and Wet Chemical Etching of GaSb Photodiodes

We report on the performance of GaSb pn junction photodiodes fabricated using electron cyclotron resonance plasma etching using Cl 2 /Ar recipe, a mixed gas recipe consisting of Cl 2 /BCl 3 /CH 4 /Ar/H 2 and wet chemical etching. Diodes fabricated using Cl 2 /BCl 3 /CH 4 /Ar/H 2 recipe show an order of magnitude lower leakage current density and lower ideality factor. The highest value of the zero bias dynamic resistance-area product was obtained for Cl 1 GaSb is an attractive choice as a substrate material because its lattice parameter matches various ternary and quaternary III-V compound semiconductors whose band gaps cover a wide spectral range from ϳ0.3 to 1.58 eV, i.e., 0.8-4.3 m. High quantum efficiency photodetectors, 2,3 photovoltaic cells, 4,5 and laser diodes with low threshold current A common choice of plasma chemistries for dry etching of GaSb-based structures consists of chlorine based precursors, such as SiCl 4 , BCl 3 , or Cl 2 because the volatilities of the gallium and antimony chlorides are generally very high. 8 Also, high-density plasma sources, such as electron cyclotron resonance ͑ECR͒, are preferred because of the increased density of low energy ions in the plasma. Pearton et al. 10 Dry etching of GaSb using methane/hydrogen (CH 4 /H 2 ) and ethane/hydrogen (C 2 H 6 /H 2 ) chemistry has also been reported. 12,13 C 2 H 6 -based plasmas show 50% higher etching rates as compared to the CH 4 -based plasmas. 13 Addition of a polymer forming gas such as CH 4 results in the formation of a polymeric thin film on the sidewalls, which minimizes the undercutting and provides passivation. 14,15 Although mixed chlorine and methane etches have been reported for various III-V compound semiconductors, systematic studies of antimonide are very few. 17 The effect of etching conditions on the device performance of GaSb and related materials has not been well addressed in the literature. In this paper, we have compared the performance of pn junction photodiodes fabricated using a Cl 2 /Ar recipe roughly based on the results reported by Pearton et al. 10,18 a mixed gas recipe consisting of Cl 2 /BCl 3 /CH 4 /Ar/H 2 , 17 and wet chemical etching using a NaK tartrate based recipe. Experimental The substrates used in this study were ͑100͒ n-type GaSb ͑Te doped͒ obtained from Galaxy Compound Semiconductor Inc. The carrier concentration was 5 ϫ 10 17 cm Ϫ3 . The substrates were degreased with hot xylene followed by acetone and methanol rinse ͑XAM cleaning͒. Then the samples were etched in hydrochloric acid ͑HCl͒ to remove the native oxide layer. Zinc ͑Zn͒ acts as p-type impurity in GaSb. Zn diffusion was carried out at 500°C for 5 h using the leaky box technique. 19 Solid Zn pellets were used as the source. The samples were next subjected to backside etching using a 2% solution of bromine in methanol for 30 s. Back side contacts were formed by electron beam ͑E-beam͒ evaporation of 200 Å of tin and 1000 Å of gold; followed by rapid thermal annealing ͑RTA͒ at 350°C for 5 s. The front side metal contact consisted of 400 Å titanium followed by 800 Å gold evaporated using E-beam. The final step in the fabrication process was the mesa etching. The front metal contacts were protected using a photoresist and the mesa areas were patterned. The photoresist was cured by baking at 110°C for 10 min. A Plasmatherm Electron Cyclotron Resonance 357 system with a loadlocked chamber was used for the dry etching of GaSb. One sample set was etched using Cl 2 /Ar plasma. The gases were in the ratio of 1:6 at a pressure of 1.5 mTorr. 100 W rf power and 300 W plasma power was used and the temperature was maintained at Ϫ30°C. The etch rate obtained with this process was 135 nm/min. A Cl 2 /BCl 3 /CH 4 /Ar/H 2 gas mixture in the ratio 2:1:2:6:12 was used to etch the second set of samples. A chamber pressure of 1.3 mTorr, rf power of 150 W, and plasma power of 400 W was used. The etching was carried out at room temperature. This recipe gave an etch rate of about 560 nm/min. The details of the surface morphology after etching are presented elsewhere

Performance-based social comparisons in humans and long-tailed macaques

Social comparisons are a fundamental feature of human thinking and affect self-evaluations and task performance. Little is known about the evolutionary origins of social comparison processes, however. Previous studies that investigated performance-based social comparisons in nonhuman primates yielded mixed results. We report three experiments that aimed (a) to explore how the task type may contribute to performance in monkeys, and (b) how a competitive set-up affects monkeys compared to humans. In a co-action touchscreen task, monkeys were neither influenced by nor interested in the performance of the partner. This may indicate that the experimental set-up was not sufficiently relevant to trigger social comparisons. In a novel co-action foraging task, monkeys increased their feeding speed in competitive and co-active conditions, but not in relation to the degree of competition. In an analogue of the foraging task, human participants were affected by partner performance and experimental context, indicating that the task is suitable to elicit social comparisons in humans. Our studies indicate that specifics of task and experimental setting are relevant to draw the monkeys’ attention to a co-actor and that, in line with previous research, a competitive element was crucial. We highlight the need to explore what constitutes “relevant” social comparison situations for monkeys as well as nonhuman animals in general, and point out factors that we think are crucial in this respect (e.g. task type, physical closeness, and the species’ ecology). We discuss that early forms of social comparisons evolved in purely competitive environments with increasing social tolerance and cooperative motivations allowing for more fine-grained processing of social information. Competition driven effects on task performance might constitute the foundation for the more elaborate social comparison processes found in humans, which may involve context-dependent information processing and metacognitive monitoring

Agricultural livelihoods in coastal Bangladesh under climate and environmental change - A model framework

We describe a novel integrated modelling system aiming to approximate the impact of environmental change on farmers' livelihoods in Bangladesh.</p

Size-Controlled Synthesis of Colloidal Gold Nanoparticles at Room Temperature Under the Influence of Glow Discharge

Highly dispersed colloidal gold (Au) nanoparticles were synthesized at room temperature using glow discharge plasma within only 5 min. The prepared Au colloids were characterized with UV–visible absorption spectra (UV–vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) equipped with an energy dispersion X-ray spectrometer (EDX). UV–vis, XPS and EDX results confirmed that Au3+ ions in HAuCl4 solution could be effectively reduced into the metallic state at room temperature with the glow discharge plasma. TEM images showed that Au nanoparticles were highly dispersed. The size of colloidal Au nanoparticles could be easily tuned in the nanometer range by adjusting the initial concentration of HAuCl4 solution. Moreover, the as-synthesized Au colloids (dav = 3.64 nm) exhibited good catalytic activity for glucose oxidation. The nucleation and growth of colloidal Au particles under the influence of the plasma was closely related with the high-energy electrons generated by glow discharge plasma