Miracle-dz/UniFAR-FTUs huggingface dataset:
The VIX Index: Forecasting Power and Perfomance in a Risk Management Framework

This paper explores the information content and forecasting power of the VIX Index computed by CBOE (Chicago Board Options Exchange) on two different levels. The analysis is organised around two research questions. The first question is aimed at understanding whether the Volatility Index (VIX), due to its forward-looking nature, forecasts the future realised volatility better than other estimation techniques that are based on historical data. This part of the analysis is in line with a rich stream of literature on the topic, and our contribution intends to test whether the empirical results obtained by other researchers hold true in the years of hightened volatility following the Lehman Brothers collapse. The second research question aims to evaluate the perfomance of the VIX within a risk management framework, exploring an aspect that has been scarcely analysed in the literature and that has produced relatively contradictory results. In particular, we use the VIX alongside other volality measures to compute the Value-at-Risk (VaR) metric for a hypothetical portfolio replicating the Standard & Poor's 500 Index. The various measures of maximum potential loss are then backtested against actual returns and compared in order to understand which one is more effective. Results show that the VIX index possesses a strong information content, even if it is an upward biased forecast of realised performance. When used to compute VaR however, the measures based on VIX are less effective than others using different volatility estimations, especially during periods of higher turbulence.
Altered microRNAs in bicuspid aortic valve: a comparison between stenotic and insufficient valves.

BACKGROUND AND AIM OF THE STUDY Bicuspid aortic valve (BAV), the most common form of congenital heart disease, is a leading cause of aortic stenosis (AS) and aortic insufficiency (AI). AS is typically caused by calcific valve disease. Recently, microRNAs (miRNAs) have been shown to modulate gene expression. The study aim was to examine the miRNAs that were altered in the aortic valve leaflets of patients with AS compared to those in patients with AI. In-vitro experiments were also carried out to determine if these miRNAs could modulate calcification-related genes. METHODS Aortic valve samples (fused and unfused leaflets) were collected from nine male patients (mean age 44.9 +/- 13.8 years) undergoing aortic valve replacement (AVR). PIQOR miRXplore Microarrays containing 1,421 miRNAs were used and hybridized to fused leaflet samples labeled with Cy5; unfused samples were used as controls and labeled with Cy3. A quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to validate the miRNA array results. Cultured human aortic valve interstitial cells (AVICs) were treated with miRNA mimics, and qRT-PCR was carried out to determine any changes in mRNAs. RESULTS By microarray analysis, seven miRNAs were shown to be statistically different between the AS and AI patients. In the stenotic samples, the MiR-26a and miR-195 levels were shown (by qRT-PCR) to be reduced by 65% and 59%, respectively (p < 0.05), and MiR-30b to be reduced by 62% (p < 0.06). Human AVICs treated with miR-26a or miR-30b mimics showed decreased mRNA levels of calcification-related genes. MiR-26a repressed BMP2 by 36%, alkaline phosphatase (ALPL) by 38%, and SMAD1 by 26%, while MiR-30b reduced the expression of SMAD1 by 18% and of SMAD3 by 12%. In contrast, miR-195-treated AVICs had increased mRNA levels of calcification-related genes, such as BMP2 by 68% and RUNX2 by 11%. CONCLUSION MiR-26a, miR-30b, and miR-195 were each decreased in the aortic valves of patients requiring AVR due to AS, compared to those requiring replacement due to AI. These miRNAs appear to modulate calcification-related genes in vitro.
Commercialisation of Agriculture in Kenya: Case Study of Urban Bias on Food Availability in Farm Households

This study investigates the effect of cash cropping on food availability and examines the determinants of the proportion of income allocated for food expenditures in the Nyeri district in Kenya. Using a Tobit model, the results suggest that in general food expenditure allocations suffer due to cash cropping in Kenya as the lump-sum income flows from this may be used for purchases other than food. Food expenditure also suffers when remittances are irregular. On the other hand, earnings from outside employment for married women living with husbands are positively associated with food expenditure allocations. Amounts of non-cash food output as well as ownership of livestock are negatively associated with food expenditure allocations. These findings indicate that lump sum income may not lead to improved welfare of women and children. Thus, there may be social reasons for increasing non-cash food production especially by women, instead of over emphasising cash cropping as now seems to be so in public policy.
Abdominal surgical emergency in the elderly Yafll › lardaki abdominal cerrahi aciller

Background/aims: Longer life expectancy has created an increasing demand for surgical care of the elderly. Abdominal surgical emergencies are potentially serious and life-threatening conditions for this group of patients. The aim of this study was to evaluate the records of elderly patients undergoing emergency surgical treatment. Methods: A total of 181 patients aged 60 years and above who had undergone emergency surgical interventions were retrospectively analysed according to demographic features, indications for emergency surgery, postoperative clinical course and outcome. Results: Sixty-one percent of the patients were male, with an average age of 70.3 (range 60-95) years. Octogenarians constituted 19% of our series. Causes of surgical emergency were acute cholecystitis (31.5%), strangulated hernia (18.2%), hollow viscus perforation (17.1%), bowel obstruction (10.5%), acute mesenteric ischaemia (9.4%), acute appendicitis (8.3%) and upper gastrointestinal haemorrhage (5%). Gallstones had been previously detected by ultrasound in 25 (45.5%) of 55 patients with acute calculous cholecystitis. Thirty (93.8%) of 32 patients were aware of their external hernias prior to incarceration. Twenty seven patients (14.4%) died in the early postoperative period, with acute mesenteric vascular occlusion being the leading cause of death: A higher mortality rate was noted in mesenteric ischaemia (76.5%), gastrointestinal bleeding (22.2%) and in perforation (19.4%) cases, being 36.8% (21/57) in patients with these three severe conditions and 4.8% (6/124) in the remaining patients. Conclusions: Acute calculous cholecystitis and external strangulated hernias, which are generally preventable, were the most common surgical emergencies. Surgical treatment of acute mesenteric ischaemia, gastrointestinal haemorrhage and peritonitis secondary to free perforation had a worse prognosis in older patients.
The neural basis of the osteopathic lesion.

FOUR of the main principles in osteopathy appear to be: 1. Joints and their supports are subject to anatomic and functional derangements. 2. These derangements have distant as well as local effects. 3. They are related, directly or indirectly, to other pathologic influences. 4. They may be recognized, and their local and distant effects influenced favorably by manipulation. Accepting the existence of joint derangements (osteopathic lesions), it is our purpose in this paper to examine not the mechanical and etiological factors involved, but rather the fundamental basis for principles 2 and 3 and to a small extend principle 4 and report progress in our understanding thereof. The osteopathic lesion has many aspects which are partly revealed in the local and distant effects referred to as principle 2. Included among these are: 1. Hyperesthesia, especially of the muscles and vertebrae 2. Hyperirritability, reflected in altered muscular activity and in altered states of muscular contraction. 3. Changes in the tissue texture of the muscle, connective tissue, and skin 4. Changes in local circulation and in the exchange between blood and tissues. 5. Altered visceral and other autonomic functions. How are these effects produced? What are the central factors responsible for these manifestations of structural and postural abnormalities? What in in the intrinsic nature of the osteopathic lesion is the basis for the peripheral, palpable, and clinical effects? What fundamental changes take place as a result of effective
The effect of two kinds of training ( oral lecture and e-mail ) on body postures of bank staffs : a comparative study

Musculoskeletal disorders (MSDs) are among the most common occupational diseases. Bankers are exposed to different ergonomic hazards. This study was conducted to assess work posture among bank workers and the effect of two training methods was compared. The 80 bank workers from eleven bank in Yazd, Iran participated in this crosssectional study. Cluster sampling was used to select the subjects. RULA method was used for posture analysis. Subjects were randomly allocated into two groups. The intervention included a training course presented by oral lecture and email and the efficacy of the methods was compared. Mean RULA score before intervention was 4.10±1.60 and 4.15±1.14 in e-mail and lecture groups, respectively and the difference was not statistically different (P = 0.86). RULA score was significantly reduced in both groups after interventions. The study showed that both training methods significantly affected the body posture of bank workers and this effect was larger using lecture for training.
Feasibility of Swept Synthetic Aperture Ultrasound Imaging

Ultrasound image quality is often inherently limited by the physical dimensions of the imaging transducer. We hypothesize that, by collecting synthetic aperture data sets over a range of aperture positions while precisely tracking the position and orientation of the transducer, we can synthesize large effective apertures to produce images with improved resolution and target detectability. We analyze the two largest limiting factors for coherent signal summation: aberration and mechanical uncertainty. Using an excised canine abdominal wall as a model phase screen, we experimentally observed an effective arrival time error ranging from 18.3 ns to 58 ns (root-mean-square error) across the swept positions. Through this clutter-generating tissue, we observed a 72.9% improvement in resolution with only a 3.75 dB increase in side lobe amplitude compared to the control case. We present a simulation model to study the effect of calibration and mechanical jitter errors on the synthesized point spread function. The relative effects of these errors in each imaging dimension are explored, showing the importance of orientation relative to the point spread function. We present a prototype device for performing swept synthetic aperture imaging using a conventional 1-D array transducer and ultrasound research scanner. Point target reconstruction error for a 44.2 degree sweep shows a reconstruction precision of 82.8 and 17.8 in the lateral and axial dimensions respectively, within the acceptable performance bounds of the simulation model. Improvements in resolution, contrast and contrast-to-noise ratio are demonstrated in vivo and in a fetal phantom.
Returns to Human Capital in Pakistan: A Gender Disaggregated Analysis

The impact of human capital variables on the earnings of regular wage employees is explored in this paper. Besides education and experience, literacy index, technical training, and school quality are included in the earning functions estimated for individuals. The credentialist view that education does not improve productivity—that it rather provides positive signals about productivity—is also tested. The results are based on the Pakistan Integrated Household Survey 1995-96 data, which provides information on many aspects of the individual’s characteristics missing in other surveys. The results of the study provide ample evidence in favour of human capital as a productivity-enhancing device for both male and female workers. All human capital variables are found to be statistically significant, having positive magnitude. The diploma effect is not very important for Pakistani workers, as only a few diploma dummies are statistically significant.
Electronic and structural properties of arsenopyrite bulk and its cleavage surfaces – A DFT study

Arsenopyrite is the most abundant arsenic containing mineral on earth and it is normally associated with many other minerals of economic importance. Therefore, it is involved in environmental impacts of mining activities. The bonding nature of arsenopyrite and its preferential cleavage surface are still controversial. In the present work we have investigated the structural and electronic properties of arsenopyrite and its surfaces formation using density functional/plane waves method. Quantum theory of atoms in molecules (QTAIM) and electron localization function (ELF) were applied for investigating the nature of the bonding in arsenopyrite. No evidence was found for Fe– Fe bonding in the bulk structure. The As-S bond has large covalent character and it is unexpected to be broken in the surface formation. The cleavage and surface energies have been calculated indicating that (001) surface is the most favored to be formed. Key-words: Arsenopyrite, DFT, Cleavage Surface, Plane Waves, QTAIM Page 2 of 27 RSC Advances R S C A dv an ce s A cc ep te d M an us cr ip t
Antidumping duties, undertakings, and foreign direct investment in the EU

We study the e/ects of EU antidumping policy when foreign 0rms can ‘jump’ antidumping duties through foreign direct investment (FDI) in the EU. We show that duty jumping or duty pre-empting FDI occurs if the EU administration has broader objectives than protecting EU industry’s pro0tability and if cost advantages of foreign 0rms are transferable abroad. The (expectation of) price undertakings reduces the incentives to engage in FDI and may even discourage FDI as long as products are not too di/erentiated. The results are consistent with recent empirical 0ndings on antidumping jumping FDI. c © 2003 Elsevier B.V. All rights reserved. JEL classi"cation: L13; F13
Information cascades in complex networks

Information cascades are important dynamical processes in complex networks. An information cascade can describe the spreading dynamics of rumour, disease, memes, or marketing campaigns, which initially start from a node or a set of nodes in the network. If conditions are right, information cascades rapidly encompass large parts of the network, thus leading to epidemics or epidemic spreading. Certain network topologies are particularly conducive to epidemics, while others decelerate and even prohibit rapid information spreading. Here we review models that describe information cascades in complex networks, with an emphasis on the role and consequences of node centrality. In particular, we present simulation results on sample networks that reveal just how relevant the centrality of initiator nodes is on the latter development of an information cascade, and we define the spreading influence of a node as the fraction of nodes that is activated as a result of the initial activation of that node. A systemic review of existing results shows that some centrality measures, such as the degree and betweenness, are positively correlated with the spreading influence, while other centrality measures, such as eccentricity and the information index, have negative correlation. A positive correlation implies that choosing a node with the highest centrality value will activate the largest number of nodes, while a negative correlation implies that the node with the lowest centrality value will have the same effect.We discuss possible applications of these results, and we emphasize how information cascades can help us identify nodes with the highest spreading capability in complex networks.
Technology: A Catalyst for Teaching and Learning in the Classroom

Literacy in these areas [mathematics and science] affects the ability to understand weather and stock reports, develop a personal financial plan, or understand a doctor's advice. Taking advantage of mathematical and scientific information does not generally require an expert's grasp of those disciplines. But it does require a distinctive approach to analyzing information. We all have to be able to make accurate observations, develop conjectures, and test hypotheses: In short, we have to be familiar with a scientific approach. (p. 14)
Mass-processing method for aging otoliths of walleye pollock Theragra chalcogramma using black resin

The reliability of a mass-processing aging method for walleye pollock Theragra chalcogramma was examined. The method is a half-otolith method, in which 10–20 otoliths are embedded simultaneously in black resin and the mass-processed half plane section is viewed under reflected light (black-resin method). Seasonal periodicity of otolith growth was confirmed by the monthly observations of the percent of translucent zone at the otolith edge, and interannual variation in age distribution detected the progression of dominant year-classes. These results support the assumption that the translucent zone is formed once a year. The black-resin method was compared to the break-burn method, which is the standard technique for this species. The estimated ages of these methods were not biased throughout the age range examined. The coefficient of variation in the black-resin method (4.9–5.7%) was similar to those of the break-burn method (3.5–5.5%). These results suggest that the black-resin method is reliable as an aging method for walleye pollock.
Institutional Ownership and Private Equity Placements: Evidence from Chinese Listed Firms

This paper examines the impact of institutional ownership on the performance of private equity placements (PEPs) for listed firms in China. We find that the presence of institutional investors can alleviate the information asymmetries between listed firms and the market. The market reaction to PEP announcements is significantly smaller if there is a higher portion of institutional shareholdings. Long‐term firm operational performance after PEPs is positively correlated with institutional shareholdings. Moreover, we find that the relationship between institutional shareholdings and PEP performance is mainly driven by nonlisted corporate investors and mutual funds. Finally, the relationship between PEP performance and institutional shareholdings is stronger in smaller PEP issuers.
Autonomy in face of school authority, bullying and school performance

Abstract In order to verify the relationship between autonomy in face of authority, bullying and academic performance, we developed three scales that were applied to 274 ninth-graders from public schools in Sao Paulo , of which 122 were girls with a mean age of 14.1 years ( SD = 0.8). It was found that the more students defended punishment for disobedience and respect for authority, the more frequently they were appointed as the best in class and vice versa; these students also considered being victims of violence, which indicates that even students with good performance do not necessarily develop autonomy in face of authority, as they may be following rules without thinking about them. Students who suffer violence tend not to be independent from authority. Further research including students from private schools could corroborate the results of this study. Keywords: Academic achievement; Authority; Bullying; Personal autonomy. Resumo Com o objetivo de verificar a relacao entre autonomia frente a autoridade, de um lado, com o bullying e o desempenho academico, de outro, foram construidas tres escalas aplicadas a 274 alunos do nono ano do ensino fundamental de escolas publicas paulistanas; 122 do sexo feminino, idade media de 14,1 anos (DP = 0,8). Verificou-se que quanto mais o aluno concordou com a necessidade da punicao a desobediencia e com o respeito a autoridade, mais foi indicado como melhor nas disciplinas e vice-versa e, mais se considerou como vitima da violencia. Isso indica que mesmo alunos com bom desempenho nao desenvolvem necessariamente autonomia frente a autoridade, pois podem estar seguindo normas sem refletir sobre elas, e que alunos que sofrem a violencia tendem a nao ser independentes dessa autoridade. Novos estudos considerando tambem alunos de escolas particulares poderiam, alem de corroborar os resultados desta pesquisa, ampliar seu alcance.Palavras-chave
Improving Face Verification and Person Re-Identification Accuracy Using Hyperplane Similarity

The standard framework for using a convolutional neural network (CNN) for face verification is to compare the feature vectors taken from the penultimate network layer of a CNN trained to classify the identity of an input face using a softmax loss over identities. Feature vectors are typically compared using the simple L2 distance. We demonstrate that the L2 distance is not the best distance to use in this scenario, and propose the hyperplane similarity as a more appropriate similarity function that is derived from the soft-max loss function used to train the network. We demonstrate that hyperplane similarity improves verification results especially for low false acceptance rates which are usually the most important operating regimes for real applications. We also propose a fast algorithm for finding the separating hyperplanes needed to compute hyperplane similarity.
ASSET PRICING WITH HIGHER COMOMENTS

Empirical and theoretical research has for some time argued that investors also expect rewards for bearing risk related to higher moments. This thesis examines if inclusion of coskewness and cokurtosis helps to explain the variation in asset returns. These factors are added to models that also account for market risk , Fama-French factors and momentum. We use methodology of realized moments to estimate our proxies for coskewness and cokurtosis. A simulation shows that the estimator work well under certain return characteristics. We find that cokurtosis often is significant and adds explaining power, but the evidence is not always consistent. Coskewness does not prove to be an important factor in our model.
Coarse Electrocorticographic Decoding of Ipsilateral Reach in Patients with Brain Lesions

In patients with unilateral upper limb paralysis from strokes and other brain lesions, strategies for functional recovery may eventually include brain-machine interfaces (BMIs) using control signals from residual sensorimotor systems in the damaged hemisphere. When voluntary movements of the contralateral limb are not possible due to brain pathology, initial training of such a BMI may require use of the unaffected ipsilateral limb. We conducted an offline investigation of the feasibility of decoding ipsilateral upper limb movements from electrocorticographic (ECoG) recordings in three patients with different lesions of sensorimotor systems associated with upper limb control. We found that the first principal component (PC) of unconstrained, naturalistic reaching movements of the upper limb could be decoded from ipsilateral ECoG using a linear model. ECoG signal features yielding the best decoding accuracy were different across subjects. Performance saturated with very few input features. Decoding performances of 0.77, 0.73, and 0.66 (median Pearson's r between the predicted and actual first PC of movement using nine signal features) were achieved in the three subjects. The performance achieved here with small numbers of electrodes and computationally simple decoding algorithms suggests that it may be possible to control a BMI using ECoG recorded from damaged sensorimotor brain systems.