Estimation and detection techniques for doubly-selective channels in wireless communications

A fundamental problem in communications is the estimation of the channel. The signal transmitted through a communications channel undergoes distortions so that it is often received in an unrecognizable form at the receiver. The receiver must expend significant signal processing effort in order to be able to decode the transmit signal from this received signal. This signal processing requires knowledge of how the channel distorts the transmit signal, i.e. channel knowledge. To maintain a reliable link, the channel must be estimated and tracked by the receiver. The estimation of the channel at the receiver often proceeds by transmission of a signal called the 'pilot' which is known a priori to the receiver. The receiver forms its estimate of the transmitted signal based on how this known signal is distorted by the channel, i.e. it estimates the channel from the received signal and the pilot. This design of the pilot is a function of the modulation, the type of training and the channel. [Continues.

Improving performance of broilers fed lower digestible protein diets

Background and Problem Statement There is a great interest in recent years to replace soybean meal by cost effective protein sources such as rapeseed meal and maize gluten in animal feed. In poultry, this replacement, however, may result in a poorer performance due to among others its low ileal digestibility, which may lead to hindgut protein fermentation. This hindgut protein fermentation can result in the production of harmful compounds such as ammonia, branched chain fatty acids, biogenic amines and different sulfur containing compounds such as skatole, indole and phenolic compounds. This can negatively affect the cost of broiler meat production. When digestibility is low gut health may be compromised. Also feed to gain ratios will be high and overall performance will be low. Apart from the economic losses, good digestible protein sources may be preferably used for human consumption. Thus, the challenge is to provide the basis for the development of a new feeding strategy that meets the nutrient requirements of modern-day broilers, especially when they are fed a low ileal digestible protein source, i.e. rapeseed meal and maize gluten, thereby minimizing the interruption of their production performance. Objectives of the Study The aim of the study was to find ways to improve protein digestibility of poor ileal digestible resources, to reduce potential hindgut protein fermentation by developing appropriate dietary strategies such as an adequate diet structure, the supplementation of organic acids and/or fermentable energy that improve nutrient availability at ileal level and gut health in broilers. The specific objectives of the present study were to: Review various factors that influence hindgut protein fermentation in broilers and nutritional strategies that may reduce hindgut protein fermentation (Chapter 2). Determine the effects of protein source, differing in fermentation characteristics, and of digestible dietary protein content on performance, gut morphology and cecal fermentation characteristics in broiler (Chapter 3). Investigate the effects of diet structure combined with different levels of indigestible dietary protein source on performance and gut morphology in broilers (Chapter 4). Study the main and interactive effects of protein source, diet structure, butyric acid and fermentable energy supplementations on performance, gut morphology and cecal fermentation characteristics (Chapter 5). Analyze the effects of protein source, diet structure, butyric acid and fermentable energy supplementation on cecal microbiota population and composition (Chapter 6). Major Findings of the Thesis This thesis provides a literature review and describes the results of three experiments in which different nutritional strategies were tested. All experiments were carried out with Ross-308 broilers. Chapter 2 reviews the literature on hindgut fermentation in broilers with special attention to protein fermentation, its detrimental effects on performance, gut health and on gut microbiota population. A wide range of harmful products such as ammonia, branched chain fatty acids, biogenic amines and different sulfur containing compounds such as skatole, indole and phenols are produced as a result of protein fermentation. Greater concentrations of biogenic amines, branched chain fatty acids, hydrogen sulfide, ammonia, indole, phenols, cresol and skatole in the cecal indicate more proteolytic fermentation. Low concentrations of some of the protein fermentation products including biogenic amines are necessary for a normal gut development. This may result in distinct differences in protein digestibility when measured at the ileum and the total digestive tract. It was concluded that nutritional strategies, such as a reduction in dietary CP, supplementation of pre- and probiotics and organic acids, or feeding diets with coarse particles may increase ileal CP digestibility, thereby reducing the amount of substrate available for fermentation. These nutritional interventions can potentially enhance protein digestion in the upper gastrointestinal tract and, therefore, reduce the chances of protein fermentation in the hindgut. In Chapter 3, effects of three major protein sources, soybean meal, rapeseed meal and maize gluten at two different digestible CP levels (15.8 and 17.2%) were studied to test the hypothesis that broilers fed a diet with high levels of indigestible protein, will result in a reduced growth performance, lower villus heights, deeper crypts, and more protein fermentation products in cecal digesta. In total, 288 one-day-old male broilers were used for this study. Broilers fed soybean meal diet showed a better performance compared with those fed rapeseed meal and maize gluten diets due its greater ileal digestibility compared with the other two protein sources. High digestible CP (17.2%) diet fed broilers showed better performance compared with those on low digestible CP (15.8%) diet. No significant effects of protein source as well as digestible CP level were found on gastrointestinal tract development, cecal ammonia and volatile fatty acid concentrations. Broilers fed soybean meal had improved duodenal morphology compared with those fed the rapeseed meal and maize gluten diets. A lower cecal pH and greater branched chain fatty acids concentrations in the cecal digesta were observed in broilers fed the rapeseed meal diet compared with those fed the soybean meal and maize gluten diets, indicating more proteolytic fermentation. In conclusion, protein source as well as digestible CP level affected growth performance, gut morphology and protein fermentation characteristics in broilers. In Chapter 4, a hypothesis that a coarse diet improves performance of broilers fed a poorly digestible protein source was tested by using 210 one-day-old broilers. A highly digestible protein diet based on soybean meal was gradually replaced by a low digestible protein diet based on rapeseed meal (RSM) in five steps (RSM-0%, RSM-25%, RSM-50%, RSM-75% and RSM-100%) with two diet structures (fine vs. coarse). An increase in indigestible dietary protein decreased the performance of broilers. Total cecal volatile fatty acid concentrations decreased from 209 to 126 mmol/kg DM digesta in broilers with increasing rapeseed meal in diets. Increase in the indigestible protein level, from RSM-0% to RSM-100%, decreased villus heights (1782 vs. 1574 µm), whereas crypt depths increased (237 vs. 274 µm). A coarse diet improved the performance with a 15% heavier empty gizzard weight and changed gut morphology. Coarseness of the diet reduced the empty weights of the crop, proventriculus and jejunum, and reduced gizzard pH by 16%. Protein fermentation indices such as branched chain fatty acids and biogenic amines were reduced by 24 and 12%, respectively, in the cecal digesta of broilers fed coarse diets compared with those fed fine diets. In conclusion, feeding coarse particles improved the performance of broilers even with a poorly digestible protein source. Hindgut protein fermentation was reduced in broilers fed diets with a low CP digestibility by coarse grinding of the diet. In Chapter 5, the effects of protein source, diet structure and supplementation of butyric acid and fermentable energy on growth performance and cecal digesta characteristics were investigated to test the hypothesis that a coarse diet supplemented with butyric acid and fermentable energy improves growth performance of broilers fed a poorly digestible protein source. The interaction effects of diet structure (fine vs. coarse), fermentable energy (with vs. without) and butyric acid supplementation (with vs. without) in a poorly digestible diet based on rapeseed meal were evaluated. Coarseness of the diet positively affected performance and improved relative empty gizzard weights by on average 14%. The relative empty weights of the crop, duodenum, jejunum and ileum, were reduced in coarse diets fed broilers compared with those fed fine diets. Broilers fed coarse diet showed a 6% greater ileal protein digestibility, 20% lower gizzard pH, improved gut morphology, and 23% reduced cecal branched chain fatty acids compared with those fed the fine diets. Broilers fed butyric acid supplemented diets had improved performance and gut morphology compared with those fed the diets without butyric acid. Fermentable energy supplementation did not influence growth performance nor gut development and contents of total branched chain fatty acids and total biogenic amines in the cecal digesta. Supplementation with fermentable energy, however, decreased the concentration of spermine by approximately 31%. In conclusion, feeding a coarse diet supplemented with butyric acid improves growth performance of broilers even if they are fed a diet containing a poorly digestible protein source. The negative effects of a low digestible protein source can thus be partly counterbalanced by coarse grinding and butyric acid supplementation in the diet. In Chapter 6, the effects of protein source, diet structure, butyric acid and fermentable energy supplementations on cecal microbiota population and composition in broilers were evaluated. Cecal digesta samples collected in experiments 1, 2 and 3 were therefore, analysed for some microbiota. The results indicated that cecal microbial diversity was suppressed by dietary coarseness. Similarly, butyric acid and fermentable energy supplementation also resulted in a lower microbial diversity. Soybean meal promoted the average relative contribution of health beneficial L. paracasei and C. lactifermentans spp. compared with those fed rapeseed meal. Dietary coarseness reduced the average relative contribution of E. coli. Butyric acid supplementation promoted the average relative contribution of C. lactifermentans and R. bromii, and suppressed the pathogenic C. perfringens in the cecal digesta. Fermentable energy, in contrast, promoted C. perfringens. In conclusion, feeding a poorly digestible protein source, with coarse grinding and supplemented with butyric acid may be an effective strategy to promote health beneficial and suppress pathogenic microbiota in the cecal digesta. Conclusions The main conclusion of the study is that rapeseed meal diets reduce performance and gut health, but these negative effects can be partially counterbalanced by coarse grinding and butyric acid supplementation. Some specific conclusions based on the results of the studies described in this thesis are: Rapeseed meal is a poorly digestible protein source for broilers and results in reduced growth performance and gut morphology (Chapter 3). Coarse diet feeding enhances the development of the foregut, specially the gizzard, and it increases villus heights and reduces crypts depths in the duodenum (Chapters 4 and 5). The negative effects of moderate inclusion of indigestible protein can be counterbalanced to some extent by feeding a coarse diet (Chapters 4 and 5). The improved foregut development and villus height in the duodenum is associated with an enhanced ileal digestibility of protein, thereby allowing less protein available for fermentation in the hindgut (Chapter 5). Butyric acid supplementation improves growth performance and gut morphology (Chapter 5). Both soybean meal and dietary coarseness suppress cecal microbial diversity and promotes health beneficial microbiota (Chapter 6). Dietary coarseness suppresses pathogenic bacteria and promotes health beneficial microbiota in the ceca (Chapter 6). Coarsely ground diet with a moderate inclusion of poorly digestible protein source, supplements with butyric acid, is a good strategy to improve the ileal digestibility of protein and thus growth performance of broilers (Chapters 4 and 5). Practical Implementations This study might have some practical conclusions. Rapeseed meal can be used as a protein source in a broiler ration. Coarsely ground rapeseed meal, supplemented with butyric acid (approximately €2.1/100 broilers), can potentially replace soybean meal. It will not only provide a cheaper protein source but will also reduce the cost of feed production by reducing the steps in grinding the feed ingredients or using a roller mill instead of a hammer mill. These coarse particles will improve gut morphology and growth performance of broilers as well as increase the profitability of broiler feed producers and also broiler farmers (approximately €6/100 broilers). The most perspective feeding strategy to enhance the growth performance of broilers fed a poorly digestible protein source is the use of coarsely ground supplemented with butyric acid.</p

Soil Adhesion Preventing Mechanism of Bionic Bulldozing Plates and Mouldboard Ploughs

Soil adheres to the surfaces of soil engaging components of various tools. The adhesion of soil increases the draft and adversely affects the quality of work. For example, up to 50% of the gross energy required for tillage operations may be consumed by adhesion and friction between soil and tillage tools. Therefore, it is important to find out the ways to reduce adhesion of soil to the surfaces of various tools. Soil animals such as ground beetles stay in moist sticky soils for extended periods without soil sticking to their bodies. The soil adhesion preventing mechanisms of such animals can be used as guide for improving the scouring properties of various tools. Both the surface morphology and chemical composition of soil animal’s cuticle play important role in preventing adhesion of soil to their bodies. The surfaces of mouldboard ploughs and bulldozing plates were modified based on the surface morphology of ground beetle and tested in the laboratory. Two materials such as Steel-45 and Ultra High Molecular Weight – Polyethylene (UHMW-PE) were used for convexes. The modified ploughs and plates have better scouring properties and required less draft than conventional tools. The size of convexes, their arrangement and the material of these convexes played important role in reducing adhesion and scouring soil. UHMW-PE had better scouring properties and improved wear resistances than steel-45. This paper covers the modified ploughs and bulldozing plates where UHMW-PE convexes were used for modification. The distribution of these convexes on the surfaces of bulldozing plates and mouldboard ploughs resulted in changes in mechanical characteristics and the state of water film at soil-tool interface. The unsmoothed surface morphology broke down the continuity of water film, reduced the area of contact and increased pressure at soil tool interface. The higher pressure squeezed out more water and reduced the water tension. This process was helpful in reducing friction and adhesion of soil to the surfaces of modified tools. The drafts of modified plough by bionic using UHMW-PE convexes were reduced by 25% and 30% at 3.6 km/h and 4 km/h working speeds respectively. The draft reductions in bionically modified bulldozing plates were 27%, 27% and 29% less than the conventional plates operating at 0.01, 0.02 and 0.06 m/s speeds. Key words: adhesion; bionic; unsmoothed; mouldboard ploughs; bulldozing plates; draf

Exploring New Pathways to Gender Equality in Education: Does Information and Communication Technology Matter?

Through the use of the System Generalized Method of Moments Technique, this study aims to establish links between Information and Communication Technologies (ICTs), gender equality in education and economic growth, for segregated levels of education. The study focuses on the decade of 2000-2010 for the case of Lower Middle Income countries. Through simultaneous solution of the models, it is concluded that ICTs do have some potential to promote gender equality but the relationship is not strong enough, either due to lack of relevant statistical data or due to inefficient integration of ICTs into the society. It is, however, deduced that the strongest factor promoting gender equality is the average schooling of adult population. Furthermore, the study finds out that for lower middle income countries, gender equality at lower levels of education plays an important role in economic growth than gender equality in higher education

Role of Ultrasound for the Diagnosis of Uterine Prolapse in Women: A Systemic Review

Background: Uterine prolapse is the herniation of the uterus into or beyond the vagina as a result of failure of the ligamentous and fascia supports. It often coexists with prolapse of the vaginal walls, involving the bladder or rectum. Objective: The aim of this study is to evaluate the role of ultrasound for the diagnosis of uterine prolapse in young women. Methodology: In this systematic review data extracted by Medline, PubMed, science direct and Obs-gyne online library that were queried for studies published between 2000 to 2021 by using specific MeSH terms. In this systematic article we reviewed 10 retrospective style analytical studies for the collection of data. Results: 10 studies conducted between the years 2000 to 2021 were included in this systematic review. The total sample size was 2500 women aged between 10-60 years. All subjects were examined by trans-perineal three-dimensional ultrasound for the detection of uterine prolapse. Out of 2500 patient almost 1000 determine with uterine prolapse on ultrasound. Ultrasound findings had excellent predictive value for the diagnosis of clinical uterine prolapse. An eye‐ shaped vaginal canal with an antero-posterior diameter of greater than 10 mm in the rendered axial plane was a sign of uterine prolapse. This sign may be helpful for detecting concealed uterine prolapse in complex pelvic organ prolapse. In fact, uterine prolapse can often be more prominent on imaging than on clinical examination. This may be due to the fact that the functional anatomy of the levator hiatus seems to matter most for uterine descent. Conclusion: From this systematic reviewed study we concluded that Ultrasound is the most appropriate form of imaging in uro-gynecology for reasons of low cost, access and performance, and due to the fact that it provides information in real time. Trans-perineal three-dimensional 2 ultrasound can evaluate the morphological changes of levator hiatus in patients with uterine prolapse, and the area of levator hiatus has high diagnostic value for uterine prolapse. Keywords: Pelvic organ prolapse; Trans-perineal Ultrasound; Uterine Prolapse; levator ani muscles. DOI: 10.7176/JHMN/92-05 Publication date:August 31st 2021

A qualitative comparative analysis of women’s agency and adaptive capacity in climate change hotspots in Asia and Africa

There is growing concern about sustainable and equitable adaptation in climate change hotspots, commonly understood as locations that concentrate high climatic variability, societal vulnerability, and negative impacts on livelihood systems. Emphasizing gender within these debates highlights how demographic, socio-economic and agro-ecological contexts mediate the experiences and outcomes of climate change. Drawing on data from 25 qualitative case studies across three hotspots in Africa and Asia, analysed using Qualitative Comparative Analysis, we show how and in what ways women’s agency, or the ability to make meaningful choices and strategic decisions, contributes to adaptation responses. We find that environmental stress is a key depressor of women’s agency even when household structures and social norms are supportive, or legal entitlements available. These findings have implications for the effective implementation of multilateral agreements such as the United Nations Framework Convention on Climate Change, Sendai Framework on Disaster Risk Reduction, and the Sustainable Development Goals

Do natural disasters change savings and employment choices? Evidence from Pakistan

We investigate the economic response of rural households to natural disasters in Pakistan. In particular, we explore to what extent households adjust their savings, and income strategies in response to floods. Using a detailed panel dataset that was assembled concurrently with two major flood events, we find evidence of an economic response, although adjustments appear to be temporary: affected farmers move away from agriculture as an immediate response to floods, but they return within a year. Although flood exposure lowers savings, adjustments in income strategies help farmers to overcome immediate losses and initiate recovery: flood affected households allocate a significantly higher portion of their post-flood income than unaffected households to replenishing livestock and seeds. The findings have policy implications in terms of strategies to develop nonfarm employment opportunities and financing economic migration to reduce income vulnerability

Potential Assessment and Economic Analysis of Concentrated Solar Power against Solar Photovoltaic Technology

Competition between concentrated solar power and solar photovoltaic has been the subject of frequent debate in recent years based on their cost of fabrication, efficiency, storage, levelized cost of energy, reliability, and complexity of respective technologies. Taking Pakistan as a testbed, a study was conducted to determine which technology is economical in a particular location and climate. The study assesses the meteorological, orographic, and spatial factors that impact the performance and cost of both renewable energy systems. A SWOT analysis, followed by technoeconomic analyses, was conducted to determine suitable sites for setting up solar power plants in Pakistan. A detailed assessment of siting factors for solar power plants was conducted to shortlist the most suitable sites. Based on the results, economic analysis was performed to install 100 MW photovoltaic and parabolic trough power plants at selected locations. The levelized cost of energy for the 100 MW parabolic trough is 10.8 cents/kWh and 12 cents/kWh in best-case scenarios, i.e., for locations of Toba and Quetta, respectively, whereas the LCOEs of 100 MW photovoltaic systems stand comparatively low at 7.36 cents/kWh, 7.21 cents/kWh, 7.01 cents/kWh, 6.82 cents/kWh, 6.02 cents/kWh, and 5.95 cents/kWh in Multan, Bahawalpur, Rahim Yar Khan, Hyderabad, Quetta, and Toba, respectively. The results favor choosing solar PV plants over solar CSP plants in terms of finances in the selected regions. The findings will assist financiers and policymakers in creating better policies in terms of long-term goals.publishedVersio