HEXOSYS II - Towards realization of light mass robotics for the hand

This research presents a prototype of a direct-driven, optimized and light-mass hand exoskeleton that is designed to fit over the dorsal side of the hand, thus retaining palm free for interaction with real/virtual objects. The link lengths of the proposed Hand EXOskeleton SYStem (HEXOSYS) TT have been selected based on an optimization algorithm. In an attempt to make the design human hand compatible, the actuators of HEXOSYS II have been chosen as a result of series of experiments on human hands of various sizes. The system based on an optimum under-actuated mechanism provides 3 DOF/finger. The resultant motion of the exoskeleton allows the wearer to perform flexion/abduction as well as passive abduction/adduction. Simple and under-actuated mechanisms together with compact mechanical design lead to realize a light mass robotic system. The first prototype of HEXOSYS II has been fabricated. Comprising of four fingers, which are enough to accomplish most of our daily life activities, the system weighs 600 grams. © 2011 IEEE

Essays in Empirical Corporate Finance and Labor Economics

In the first chapter of this dissertation, I exploit the Covid-19 pandemic and associated government restrictions as a natural experiment in order to study the resilience of businesses in the United States. I use a border-county identification strategy with data on government restrictions, employment and open small businesses, in order to assess the resilience of small businesses in the United States. In my main results, I find negative impacts of stay-at-home orders on the number of open small merchants. In particular, shutdowns of businesses accelerated 8 weeks after imposition of a stay-at-home order, suggesting that many businesses were only resilient enough to handle adverse conditions for 8 weeks. On average, a county with a stay-at-home order experienced an additional 1.51 percentage points loss in the number of open small businesses, relative to January 2020, 8 weeks later compared to a neighboring county that did not have a stay-at-home order. Firms were quicker to resort to layoffs. On average a county with an active stay at home order in a month experienced an additional 1.19 percentage point loss in employment, relative to January 2020, the following month compared to a neighbor that did not have a stay-at-home order the previous month. My results suggest that in future scenarios where governments consider enacting similar restrictions further aid is needed for businesses in order to help them stay afloat. In particular, more assistance should be delivered to businesses within two months from the enacting of the order. In the second chapter of this dissertation, I study economic spillovers in the context of theCovid-19 associated government restrictions. I use a detailed geolocation dataset to construct data on the number of visitors per-capita between neighboring counties in the early stages of the pandemic, which I use as a proxy for economic spillovers. I employ a similar border-county identification strategy as in the first chapter to identify the causal effect of stay-at-home orders on inter-county movement. Additionally, I provide evidence for an assumption used in chapter one by examining if there are reduced spillovers in county-pairs that lie in the different commute zones. I find that stay-at-home orders caused reductions in inter-county visits in both directions in a county-pair. That is, I find a decrease in travel from the county without a stay-at-home order to the county with one, as well as a decrease in the opposite direction. On average, a county that does not have stay-at-home order will receive 408 fewer weekly visitors from their neighboring county that has a stay-at-home order. I also examine the effect of stay-at-home orders on the ratio of travel between the two directions in order to find evidence of a net spillover effect between the two counties and fail to find evidence of a net spillover effect. I also find that spillover effects are indeed reduced in neighbor county-pairs where the two counties are in different commute zones. The results of this paper imply that residents in counties with stay-at-home orders decreased travel to their neighboring counties even when those counties did not issue their own orders. In future situations where policy makers need to consider similar restrictions, they should focus on acting more quickly and not be concerned if neighboring counties are not cooperative. In the third chapter of this dissertation, I test the predictions of career concerns models by studying Major League Baseball umpires. Major League Baseball games can be dramatically shaped by minor lapses in judgement from the umpires officiating the game. Due to the indefinite length a game may have, this can include having the game shaped in a way that ends it faster. I study whether evidence for the career concerns model can be found in baseball umpires. A career concerns model would suggest that older umpires, whose careers and reputations are much more established than younger ones, would be more inclined to improperly make judgements that favor the end of the game in extra innings. I use data on MLB umpires and extra-innings games from the 2010-2018 seasons to conduct my empirical analysis and use a linear probability model to isolate the impact of the umpires’ tenure on the probability they make a “bad call.” I find evidence supporting the career concerns hypothesis and that the probability that an umpire makes a bad call that shortens the length of the game and allows them to go home increases with their tenure. I show that these results are likely driven by career concerns, rather than carelessness, by showing their error rate does not increase with tenure in situations where it would not reduce their workload

Comparison of QTC Interval Prolongation in Cirrhotic and Non-Cirrhotic Chronic Hepatitis C Patients

Objective: To determine frequency of QTc interval prolongation in hepatitis C infection. To compare QTc interval prolongation in patients with cirrhotic and non-cirrhotic chronic hepatitis c infectionStudy design: Descriptive Case SeriesSetting: Medical Unit-III, Fauji Foundation Hospital, RawalpindiDuration of study: 06 months duration of study i.e 10th May, 2017 to 10th Nov, 2017Methodology: Patients having chronic hepatitis c infection with cirrhosis was taken from medical ward and non-cirrhotic chronic hepatitis c infection was taken from general medical OPD. Consent was taken. For QTc interval calculation ECG was performed by ECG technician having 22 years of experience as ECG technician in Fauji Foundation Hospital Rawalpindi. Information was recorded on the form. The variable of interest was age, gender, cirrhosis, QTc interval and comparison of prolongation of QTc between hepatitis c positive cirrhotic and non-cirrhotic patients. Results: Total 110 patients were included according to the inclusion criteria of the study. Mean age (years) in the study was 56.84+11.05. There were 48 (43.6) male and 62 (56.4) female patients who were included in the study according to the inclusion criteria. Mean duration of QTc interval was 0.48+0.04. Out of 110 patients, there were 27 (24.5) patients who have prolonged QTc interval. The frequency of QTc interval prolongation in patients with cirrhotic and non-cirrhotic chronic hepatitis C infection was 22 (57.9) and 05 (6.9) respectively which was statistically significant (p-value 0.000).Conclusion: The study concludes that QTc interval prolongation in cirrhotic patients was high which showed that cirrhotic patients are at risk of developing ventricular arrhythmias due to cardiomyopathy, so a simple ECG test can be used to diagnose and prevent cardiac events in cirrhotic patients as it is simple as well as easily available.Keywords: Cirrhosis, Hepatitis C, Prolonged QT interval, non-cirrhotic Chronic Hepatitis C Infectio

Diabetes and Inflammation; Association Between C-Reactive Protein and Diabetic Nephropathy in Rawalpindi

Objective: To determine the frequency of elevated C-reactive protein in type 2 diabetics and to compare the levels of C-reactive protein between people with diabetes and non-diabetics nephropathy among the population of Rawalpindi, Pakistan. Methodology: This cross-sectional study Diabetic and Medical OPD of Fauji Foundation Hospital, Rawalpindi from January 2019 to July 2019. A total of 150 patients who had type 2 diabetes, aged between 35 to 60 years, irrespective of gender, were included. Blood samples were collected for blood sugar random, fasting, renal function test, WBC count, and C-reactive protein. Urine samples were collected for the measurement of 24-hour urinary proteins. The presence or absence of proteinuria was used to categorize patients into two groups. Group A consisted of 58 patients with type 2 diabetes who did not have nephropathy, and Group B consisted of 92 patients with type 2 diabetes who had nephropathy (proteinuria greater than 30 mg/dl in 24 hours). Results: The mean age in our study was 49.41+7.66. Ninety-two patients (61.3%) presented with diabetic nephropathy. CRP levels (> 8200 ng/ml) were raised in 50 (54.3%) patients of group B and 19 (32.8%) patients of group A. The difference was statistically significant (p-value 0.010). Conclusion: This study showed a higher prevalence of raised CRP in type 2 diabetics with nephropathy. This reinforces the idea that low-grade inflammation has an essential role in the inception and evolution of diabetic renal disease

Celiac Disease and Glycemic Control Among Patients with Type 1 Diabetes Mellitus

Objective: To determine the frequency of celiac disease among type 1 diabetic patients and to compare the frequency of adequate glycemic control in patients having T1DM plus CD and T1DM alone. Study Design: Cross-sectional study. Place and Duration: Unit-II, Department of Medicine, Foundation University Medical College, Islamabad. from 16th June 2016 to 16th December 2016 Methodology: Patients were recruited through medical and diabetes OPDs and medical wards. All the relevant information was recorded on a Proforma. In all type 1 diabetics a sample of blood was sent to AFIP for the determination of Anti-tTG (IgA) antibodies; using a commercially available ELISA technique (Pharmacia Upjohn, Sweden) based on recombinant human tTG as antigen. The measuring range of this test is 0.1 - 100 U/ml. We used the cut-offs: anti-tTG IgA ≤ 10 U/ml were considered negative, > 10 U/ml was considered positive. The assay was a quantitative assay. On the same visit, another blood sample was sent for HbA1C estimation.  Results: Total 160 patients were included according to the inclusion criteria of the study. Mean age (years) in the study was 26.58+9.13. There were 83 (51.9) male and 77 (48.1) female patients who were included in the study according to the inclusion criteria. The frequency of celiac disease among type 1 diabetic patients was 42 (26.3) in the study whereas the frequency of adequate glycemic control in patients having T1DM plus CD and T1DM alone was 26 (61.9) and 31 (26.3) respectively. Conclusion: The study concludes that the prevalence of celiac disease in type 1 diabetes mellitus in our own population is high. Furthermore, gluten-free diet effects on glycemic control of type 1 diabetic patients which in screening for celiac disease in type 1 diabetes mellitus patients and to decreased risk of complication of diabetes.&nbsp

Exploring the Relationship between Liquidity Ratios and Indicators of Financial Performance: An Analytical Study on Food Industrial Companies Listed in Amman Bursa

The study aims to examine the relationship between liquidity ratios and indicators of financial performance (profitability ratios) in the food industrial companies listed in Amman Bursa during the period (2012-2014). The study sample included (8) industrial companies which operate in the field of food listed in Amman bursa. The results showed no relationship between all liquidity ratios and the gross profit margin, while there is a weak positive relationship between the current ratio and each of the operating profit margins and the net profit margin, as the study pointed to the existence of a positive relationship between (quick ratios, defensive interval ratio) and operating cash flow margin.  There is a positive relationship between liquidity ratios (current ratio, quick ratio, cash ratio) and return on assets. Keywords: Liquidity, Financial Performance, Profitability, Food Industrial Companies, Amman Bursa, Jordan. JEL Classifications: G10, G1

Effects Of Doping Concentration And Annealing Temperature On Indium Doped Zinc Oxide Particles Prepared Via Sol-Gel Method

Doping of indium in zinc oxide (ZnO) is one of the means to increase its electrical conductivity. This study focuses on investigating the effects of indium doping concentration (In/Zn = 3%, 5% and 7%) and annealing temperature (200°C, 300°C and 450°C) on the electrical conductivity, structural, morphological and elemental properties of the indium doped zinc oxide (IZO) particles. The synthesis of IZO particles was carried out by a simple sol-gel method where sol-gel was evaporated to xerogel, heat treated and milled to form solid particles. The particles were characterized by four-point probe, X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). The results obtained demonstrate an impressive increase of electrical conductivity by one order of magnitude at 5% of indium doping compared to the pristine zinc oxide (ZnO) as a result of cumulative charge carriers. Besides, an increase of annealing temperature also shows a positive effect on the electrical conductivity. XRD results show distinctive changes on crystal structure of polycrystalline wurtzite structure and its crystallite size with the change in parameters. FTIR results indicate the effects of both parameters by the presence and elimination of peaks designated for IZO functional group. The SEM-EDX analysis reveals the microstructure morphology at different parameters and validates the existence of each element according to doping concentratio

Recognition of Ziziphus lotus through Aerial Imaging and Deep Transfer Learning Approach

Abstract: Please refer to full text to view abstrac

Prospective, multicentre study of screening, investigation and management of hyponatraemia after subarachnoid haemorrhage in the UK and Ireland

Background: Hyponatraemia often occurs after subarachnoid haemorrhage (SAH). However, its clinical significance and optimal management are uncertain. We audited the screening, investigation and management of hyponatraemia after SAH. Methods: We prospectively identified consecutive patients with spontaneous SAH admitted to neurosurgical units in the United Kingdom or Ireland. We reviewed medical records daily from admission to discharge, 21 days or death and extracted all measurements of serum sodium to identify hyponatraemia (<135 mmol/L). Main outcomes were death/dependency at discharge or 21 days and admission duration >10 days. Associations of hyponatraemia with outcome were assessed using logistic regression with adjustment for predictors of outcome after SAH and admission duration. We assessed hyponatraemia-free survival using multivariable Cox regression. Results: 175/407 (43%) patients admitted to 24 neurosurgical units developed hyponatraemia. 5976 serum sodium measurements were made. Serum osmolality, urine osmolality and urine sodium were measured in 30/166 (18%) hyponatraemic patients with complete data. The most frequently target daily fluid intake was >3 L and this did not differ during hyponatraemic or non-hyponatraemic episodes. 26% (n/N=42/164) patients with hyponatraemia received sodium supplementation. 133 (35%) patients were dead or dependent within the study period and 240 (68%) patients had hospital admission for over 10 days. In the multivariable analyses, hyponatraemia was associated with less dependency (adjusted OR (aOR)=0.35 (95% CI 0.17 to 0.69)) but longer admissions (aOR=3.2 (1.8 to 5.7)). World Federation of Neurosurgical Societies grade I–III, modified Fisher 2–4 and posterior circulation aneurysms were associated with greater hazards of hyponatraemia. Conclusions: In this comprehensive multicentre prospective-adjusted analysis of patients with SAH, hyponatraemia was investigated inconsistently and, for most patients, was not associated with changes in management or clinical outcome. This work establishes a basis for the development of evidence-based SAH-specific guidance for targeted screening, investigation and management of high-risk patients to minimise the impact of hyponatraemia on admission duration and to improve consistency of patient care

Security price reaction to dividend announcement: Evidence from Dhaka Stock Exchange Ltd

Appropriate information is always an important device for decision making process, especially in corporate finance. Managers possess inside information about their firms' future prospects. They use various signaling devices to convey these information to public. The investors take into account those information while making their investment decisions. This is the common perception about the management - investor relationship. For the past few decades, there had been many studies and research work about the signaling devices that management uses to convey information to the market. Out of several important issues, dividend got the most attention of researchers. It was under the spotlight from the very beginning, and those studies are both in favour of and against the effectiveness of dividend as a signaling device. In this paper, the effectiveness of dividend as a signaling device which conveys information to the market about the firm is studied. Here, a test is conducted on some selected securities traded in the Dhaka Stock Exchange Ltd. In Bangladesh, there is no recognized research work on the effect of dividend announcement on security prices. From this point of view, it is hoped that the study will explore the avenues for further study and draw attention of security analysis and portfolio investors