Linear methods for regression with small sample sizes relative to the number of variables.

In data sets where there are a small number of observations but a large number of variables observed for each observation, ordinary least squares estimation cannot be used for regression models. There are many alternative including stepwise regression, penalized methods such as ridge regression and the LASSO, and methods based on derived inputs such as principal components regression and partial least squares regression. In this thesis, these five methods are described. K-fold cross validation is also discussed as a way for determining regularization parameters for each method. The performance of these methods in estimation and prediction is also examined through simulation studies under various interesting scenarios. Finally, the methods will be applied to a real data set in which each method is applied to build a model for the weights of mice based on microarray expression data for a large number of genes

Climate Change Impact and Agriculture of Bangladesh

Over the last period of years, it has been observed that climate change has become a major issue affecting the agriculture sector. Impacts of climate change in agriculture are global concern but for Bangladesh where lives and livelihoods depend on agriculture, it’s becoming a great threat for national food security. Considering crop agriculture as the predominant factor in the national economy, this paper tries to focus on the climate change impact and vulnerability in Bangladeshi Agriculture; it also highlights various strategies that can be taken in response to climate change, ways to adapt to the altered situation and Bangladesh’s saline tolerant, flood tolerant and shorter maturity varieties of rice and other crops. From this study it also found that these strategies will help in short run and to continue this extensive agricultural extension services need to make these varieties available to the farmers. One immediate need is to start multi-disciplinary human capability development planning and implementation for climate and environmental management. Keywords: Bangladesh, Climate Change, Agriculture, Food Security, Vulnerabilit

Urea Super Granule (USG) as Key Conductor in Agricultural Productivity Development in Bangladesh

The deep placement of large urea granules (known as Guti urea in Bangladesh) into puddle enhances the soil's nitrogen absorption capacity. It helps nitrogen to stay close to the roots of paddy plants, preventing urea from being washed away by rains or floods. Urea Super Granule (USG) technology is cost effective and environment friendly. Ministry of Agriculture (MoA) with technical assistance from the International Fertilizer Development Center (IFDC) has been implementing the Guti Urea Technology Extension Project in the country since November 2007. Study says, cultivated lands using Guti urea get three times better result than the lands cultivated by urea sprayed by hand in the traditional method and earn good amount of profit and normal fertility of the land may shrink faster with the use of Guti urea instead of using organic compost fertilizer. This technology is not new in Bangladesh now but due to some gaps i.e., lack of proper marketing and demonstration, subsidy in fertilizer (especially to promote USG), less availability of user friendly Urea Deep Placement (UDP) applicator and communication gap between farmers and officials became some major constraints. In this study, author tried to focus on total scenario of Bangladesh agriculture highlighting UDP technology as productive agricultural input. Comparing with field survey data and it has been found that the technology not yet been popular to the farmers due to some technical problems like high labor cost, time consuming and difficult application process. To solve these problems it is suggested that, necessity of active marketing to spread the technology to the farmers is very important, also create more demonstration project, available supply of USG, active co-operation from fertilizer dealers can be a major support to achieve this technology as successful. Keywords: Bangladesh, USG, FDP, UDP, Agricultural Policy, Agricultur

System and method for online end point detection for use in chemical mechanical planarization

The present invention is an online methodology for end point detection for use in a chemical mechanical planarization process which is both robust and inexpensive while overcoming some of the drawbacks of the existing end point detection approaches currently known in the art. The present invention provides a system and method for identifying a significant event in a chemical mechanical planarization process including the steps of decomposing coefficient of friction data acquired from a chemical mechanical planarization process using wavelet-based multiresolution analysis, and applying a sequential probability ratio test for variance on the decomposed data to identify a significant event in the chemical mechanical planarization process

System and method for the identification of chemical mechanical planarization defects

The present invention presents a novel application of a wavelet-based multiscale method in a nanomachining process chemical mechanical planarization (CMP) of wafer fabrication. The invention involves identification of delamination defects of low-k dielectric layers by analyzing the nonstationary acoustic emission (AE) signal collected during copper damascene (Cu-low k) CMP processes. An offline strategy and a moving window-based strategy for online implementation of the wavelet monitoring approach are developed

Studies on CL-20/HMX (2:1) Cocrystal: A New Preparation Method and Structural and Thermokinetic Analysis

A new preparation method for CL-20/HMX (2:1) cocrystal has been established at the laboratory level that is amenable for scale up. Solvent evaporation from a saturated solution of the stoichiometric mixture in the presence of a high boiling antisolvent, comparatively a very efficient and cheaper method, yielded pure cocrystals. Cocrystals were well characterized by spectroscopic, thermoanalytical tools, X-ray diffraction, and microscopic techniques. A correlation of percentage of cocrystal formation with evaporation rate has been obtained through quantitative analysis using Raman spectrometry. An evaporation rate of <1 mL/min consistently produced pure cocrystal confirmed by Raman and powder X-ray diffraction analysis. Thermokinetic analysis suggests the cocrystal to be more stable than CL-20 with an energy of activation of 65 kcal/mol, higher than CL-20 but inferior to HMX. Significant augmentation in the values of <i>k</i> and <i>A</i> over CL-20 justified a faster decomposition rate. Enhanced insensitivity toward friction and impact forces and higher measured velocity of detonation indicate improved performance on incorporation into high explosive formulations

Prevalence, years lived with disability, and trends in anaemia burden by severity and cause, 1990–2021: findings from the Global Burden of Disease Study 2021

Background: Anaemia is a major health problem worldwide. Global estimates of anaemia burden are crucial for developing appropriate interventions to meet current international targets for disease mitigation. We describe the prevalence, years lived with disability, and trends of anaemia and its underlying causes in 204 countries and territories. Methods: We estimated population-level distributions of haemoglobin concentration by age and sex for each location from 1990 to 2021. We then calculated anaemia burden by severity and associated years lived with disability (YLDs). With data on prevalence of the causes of anaemia and associated cause-specific shifts in haemoglobin concentrations, we modelled the proportion of anaemia attributed to 37 underlying causes for all locations, years, and demographics in the Global Burden of Disease Study 2021. Findings: In 2021, the global prevalence of anaemia across all ages was 24·3% (95% uncertainty interval [UI] 23·9–24·7), corresponding to 1·92 billion (1·89–1·95) prevalent cases, compared with a prevalence of 28·2% (27·8–28·5) and 1·50 billion (1·48–1·52) prevalent cases in 1990. Large variations were observed in anaemia burden by age, sex, and geography, with children younger than 5 years, women, and countries in sub-Saharan Africa and south Asia being particularly affected. Anaemia caused 52·0 million (35·1–75·1) YLDs in 2021, and the YLD rate due to anaemia declined with increasing Socio-demographic Index. The most common causes of anaemia YLDs in 2021 were dietary iron deficiency (cause-specific anaemia YLD rate per 100 000 population: 422·4 [95% UI 286·1–612·9]), haemoglobinopathies and haemolytic anaemias (89·0 [58·2–123·7]), and other neglected tropical diseases (36·3 [24·4–52·8]), collectively accounting for 84·7% (84·1–85·2) of anaemia YLDs. Interpretation: Anaemia remains a substantial global health challenge, with persistent disparities according to age, sex, and geography. Estimates of cause-specific anaemia burden can be used to design locally relevant health interventions aimed at improving anaemia management and prevention. Funding: Bill & Melinda Gates Foundation

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

Background Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications. Methods We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC). Findings In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683–0·717]). Interpretation In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required. Funding British Journal of Surgery Society