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Ligand nanocalipers made using DNA nanotechnology are used to display ephrin-A5 at well-defined spatial intervals to study how nanoscale ligand spacing affects EphA2 receptor activation in breast cancer cells. The spatial organization of membrane-bound ligands is thought to regulate receptor-mediated signaling. However, direct regulation of receptor function by nanoscale distribution of ligands has not yet been demonstrated, to our knowledge. We developed rationally designed DNA origami nanostructures modified with ligands at well-defined positions. Using these 'nanocalipers' to present ephrin ligands, we showed that the nanoscale spacing of ephrin-A5 directs the levels of EphA2 receptor activation in human breast cancer cells. Furthermore, we found that the nanoscale distribution of ephrin-A5 regulates the invasive properties of breast cancer cells. Our ligand nanocaliper approach has the potential to provide insight into the roles of ligand nanoscale spatial distribution in membrane receptor–mediated signaling.

The agricultural sector is highly vulnerable to climate change, particularly in drought-prone environments. An understanding of perceptions, adaptation strategies, and their determinants including a gender analysis can benefit vulnerable farmers and policy makers. Using a survey of 360 farming household heads and their spouses, this study identified the intra-household perceptions and their determinants, the major strategies adopted by the farmers to adapt to climate change, and the factors that affect their adaptation decision and choice of strategies including the role of intra-household decision making in a drought prone environment of Bangladesh. The adaptation methods identified include short-duration and drought-tolerant rice varieties, supplementary irrigation for crop production, non-rice winter and horticultural crops, and improved channels for irrigation and water harvesting. Discrete choice model results indicate that age, household size, membership in any organization, access to credit, drought severity, amount of cultivated land, and agricultural subsidy significantly influence farmers’ adaptation decision and choices. Results reveal that climate change perceptions of husbands and spouses within the same households differ significantly and intra-household decision making plays a significant role in adaptation decision and selection of alternative adaptation strategies. The results would improve our understanding of farms and farming households and their climate change perceptions and adaptation choices by location and gender, thereby enabling us to outline better strategies to adapt to the changing climate.

In this report, we use first-principles calculations to study the methylammonium lead iodide (MAPI) perovskite interfaces with titanium dioxide (TiO2), zinc oxide (ZnO), and tin oxide (SnO2). Our study suggests that the binding energy of MAPI on SnO2 is weak compared to TiO2 and ZnO. However, we show that the strong binding to TiO2 and ZnO deprotonates CH3NH3 molecules which influences the decomposition process. Among the three interfaces studied in this report, TiO2-based interfaces showed the highest charge transfer followed by the interfaces formed on SnO2. We report a possible interfacial recombination mechanism inside MAPI/TiO2 and MAPI/SnO2 devices. Our study concludes that MAPI/SnO2 interfaces provide advantages due to their improved stability for perovskite solar cells.

Background: Since the first detection on 8th March 2020 in Bangladesh, the number of cases is rising alarmingly. The paediatric population is also getting infected in Bangladesh. So far there is no study of COVID in children in this country. Aim: This study reports on clinical profile, laboratory findings and outcomes of COVID-19 children admitted to Combined Military Hospital (CMH), Dhaka. Materials and Methods: In this prospective observational study, RT-PCR confirmed fifty COVID-19 patients aged below twelve years were included. Relevant investigations were done in the Armed Forces Institute of Pathology (AFIP). Data were collected from patients and/or their attendants by a structured questionnaire. Results: Mean age was 59.96±43.24 months, 48% were male and 52% were female. Predominant symptoms were fever (44%), cough (26%), anosmia (26%) and diarrhea (12%). There was neutropenia in 66% and lymphocytosis in 84% of cases. Mean neutrophil and lymphocyte counts were 38±13% and 52.5±13%, respectively. Significantly raised CRP observed in 14% and high serum procalcitonin was in10% of cases. Serum LDH, D-Dimer and ferritin were raised in 80%,34% and 6% of affected children, respectively. The majority (98%) of the children were improved and discharged from the hospital. One child died in this cohort. Conclusion: Fever and cough were the predominant symptoms of COVID-19 affected children in this study. Lymphocytosis and neutropenia were two important laboratory finding. Death in COVID-19 is also not uncommon. J Bangladesh Coll Phys Surg 2021; 39(3): 154-159

Challenge 3 of the 2022 NIST additive manufacturing benchmark (AM Bench) experiments asked modelers to submit predictions for solid cooling rate, liquid cooling rate, time above melt, and melt pool geometry for single and multiple track laser powder bed fusion process using moving lasers. An in-house developed A dditive M anufacturing C omputational F luid D ynamics code (AM-CFD) combined with a cylindrical heat source is implemented to accurately predict these experiments. Heuristic heat source calibration is proposed relating volumetric energy density (ψ) based on experiments available in the literature. The parameters of the heat source of the computational model are initially calibrated based on a Higher Order Proper Generalized Decomposition- (HOPGD) based surrogate model. The prediction using the calibrated heat source agrees quantitatively with NIST measurements for different process conditions (laser spot diameter, laser power, and scan speed). A scaling law based on keyhole formation is also utilized in calibrating the parameters of the cylindrical heat source and predicting the challenge experiments. In addition, an improvement on the heat source model is proposed to relate the Volumetric Energy Density (VED σ ) to the melt pool aspect ratio. The model shows further improvement in the prediction of the experimental measurements for the melt pool, including cases at higher VED σ . Overall, it is concluded that the appropriate selection of laser heat source parameterization scheme along with the heat source model is crucial in the accurate prediction of melt pool geometry and thermal measurements while bypassing the expensive computational simulations that consider increased physics equations.

Field size and shape constrain spatial and temporal management of agriculture with implications for farm profitability, field biodiversity and environmental performance. Large, conventional equipment struggles to farm small, irregularly shaped fields efficiently. The study hypothesized that autonomous crop machines would make it possible to farm small, non-rectangular fields profitably, thereby preserving field biodiversity and other environmental benefits. Using the experience of the Hands Free Hectare (HFH) demonstration project, this study developed algorithms to estimate field times (h/ha) and field efficiency (%) subject to field size and shape in grain-oil-seed farms of the United Kingdom using four different equipment sets. Results show that field size and shape had a substantial impact on technical and economic performance of all equipment sets, but autonomous machines were able to farm small 1 ha rectangular and non-rectangular fields profitably. Small fields with equipment of all sizes and types required more time, but for HFH equipment sets field size and shape had least impact. Solutions of HFH linear programming model show that autonomous machines decreased wheat production cost by €15/ton to €29/ton and €24/ton to €46/ton for small rectangular and non-rectangular fields respectively, but larger 112 kW and 221 kW equipment with human operators was not profitable for small fields. Sensitivity testing shows that the farms using autonomous machines adapted easily and profitably to scenarios with increasing wage rates and reduced labour availability, whilst farms with conventional equipment struggled. Technical and economic feasibility in small fields imply that autonomous machines could facilitate biodiversity and improve environmental performance.

Background: The use of disposable diaper is gradually increasing for the infants in our country. However, the major hazard of diaper is diaper dermatitis. The magnitude of diaper related hazards is unknown in Bangladesh. This study was conducted to assess the frequency of hazards of wearing diaper among infants.Objectives: The study was conducted (i) to observe diaper related hazards among infants and (ii) to assess the factors affecting diaper related hazards.Materials and Methods: This observational study was conducted at department of Pediatrics of Dhaka Medical College Hospital & Bangabandhu Sheikh Mujib Medical University during May to September 2012. Fifty children aged 7 days to 12 months wearing disposable diaper for at least 7 days were enrolled in this study. A face to face interview was taken and finding were recorded on a preset questionnaire. The infants were also examined for presence of diaper rash. Obtained data were analyzed thoroughly by SPSS 21. Results: Among 50 children, 24(48%) male and 26(52%) female infants. Of them 13(26%) infants developed diaper rash in their diaper wearing time. The age distribution of the cases was 3(23.1%) below 01 months; 2(15.3%) 1-6 months and 8(61.6%) 7-12 months. Six (24%) male infant and 7(27%) female infant developed rash in their diaper wearing time. Diapers are mostly used by solvent families as diapers are not cost effective. The frequency 84.6%, increases with increased duration of using a single diaper at a time for more than 4 hours without change whereas those who changed diaper more frequently every 3-4 hours and 1-2 hours have diaper rash 15.4% and 0% respectively.Conclusion: From the result of the present study it can be concluded that the frequency of diaper rash is increased with increasing age of infants and use of diaper for long duration.J Bangladesh Coll Phys Surg 2017; 35(4): 170-173

Autonomous machines have the potential to maintain food production and agroecological farming resilience. However, autonomous complex mixed cropping is proving to be an engineering challenge because of differences in plant height and growth pattern. Strip cropping is technically the simplest mixed cropping system, but widespread use is constrained by higher labor requirements in conventional mechanized farms. Researchers have long hypothesized that autonomous machines (i.e., crop robots) might make strip cropping profitable, thereby allowing farmers to gain additional agroecological benefits. To examine this hypothesis, this study modeled ex‐ante scenarios for the Corn Belt of central Indiana, using the experience of the Hands Free Hectare‐Linear Programming (HFH‐LP) optimization model. Results show that per annum return to operator labor, management, and risk‐taking (ROLMRT) was$568/ha and $ 163/ha higher for the autonomous corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] strip crop farm compared to the whole field sole crop and the conventional strip crop farms, respectively, that were operated by human drivers. The conventional strip cropping practice was found challenging as this cropping system required four times more temporary hired labor than autonomous strip cropping and three times more than whole field sole cropping. Even if autonomous machines need 100% human supervision, the ROLMRT was higher compared to whole field sole cropping. Profitable autonomous strip cropping could restore and improve in‐field biodiversity and ecosystem services through a sustainable techno‐economic and environmental approach that will address the demand for healthier food and promote environmental sustainability. Core Ideas Autonomous machines enable use of alternative mixed crop geometries. Autonomous strip cropping has higher economic payoffs than sole and conventional strip cropping. Even with lower grain prices and full‐time supervision, swarm robots have economic benefits. Autonomous machines could reconcile economic and agroecological goals.