Miracle-dz/UniFAR-FTUs huggingface dataset:
Expected stock returns and the conditional skewness

Motivated by the parsimonious jump-diﬀusion model of Zhang, Zhao and Chang (2010), we show that the aggregate market returns can be predicted by the conditional skewness of returns and the variance risk premium, a diﬀerence between the physical and risk-neutral variance of market returns, even though the variance is supposed to be constant only if jump exists. The magnitude of the predictability is particularly striking at the intermediate quarterly return horizon, even combing other predictor variables, like P/D ratio, the default spread and the consumption-wealth ratio (CAY). We also ﬁnd that the third central moments are signiﬁcant in explaining the variance risk premium, which further implies that the potential link between the variance risk premium and the excess market return is the third central moments, not the skewness. Abstract Motivated by the parsimonious jump-diﬀusion model of Zhang, Zhao and Chang (2010), we show that the aggregate market returns can be predicted by the conditional skewness of returns and the variance risk premium, a diﬀerence between the physical and risk-neutral variance of market returns, even though the variance is supposed to be constant only if jump exists. The magnitude of the predictability is particularly striking at the intermediate quarterly return horizon, even combing other predictor variables, like P/D ratio, the default spread and the consumption-wealth ratio (CAY). We also ﬁnd that the third central moments are signiﬁcant in explaining the variance risk premium, which further implies that the potential link between the variance risk premium and the excess market return is the third central moments, not the skewness.
Animal diets in the Waterberg based on stable isotopic composition of faeces

Faecal analysis of diet in free-ranging mammals can provide insight into local habitat conditions by reflecting the resources actually utilized. Here we used stable light isotope analysis of faeces to qualify, as well as quantify, certain aspects of mammal food selection in a recovering, nutrient-poor, savanna habitat in the Waterberg. Stable carbon isotope ratios in faeces reflect proportions of C3-foods (browse) to C4-foods (grass) consumed, whereas stable nitrogen isotope ratios reflect a combination of trophic behaviour, protein intake, and water and nutritional stress. Percentage nitrogen indicates the nutritional quality of the diet, at least in terms of crude protein intake. We used these data to reconstruct and compare the diets of various mammal species from two reserves in the Waterberg: the Welgevonden Private Game Reserve and Zoetfontein Private Game Farm.
Did the rise of CLOs lead to riskier lending

There is growing evidence that securitization adversely affected the screening incentives of mortgage lenders, contributing to a large increase in delinquencies in the U.S. subprime housing market during the crisis. In this paper we investigate whether the growth of securitization had also affected corporate lending. We find that during the boom years of the CLO business, loans sold to CLOs at the time of their origination underperform similar unsecuritized loans originated by the same bank. Banks account for this difference in performance because they charge higher interest rates on the loans they sell to CLOs than on their unsecuritized loans. The difference in performance between CLO credits and non-CLO credits appear to have resulted from banks’ use of laxer standards to underwrite the loans they sell to CLOs. Banks also retain lower “skin in the game” when they sell loans to CLOs, and it appears this too contributed for the underperformance of CLO credits.
Revisiting employee fraud: gender, investigation outcomes and offender motivation

Purpose – This paper aims to present the findings of a study examining fraud in the workplace setting, principally in the Australasian context. Although prior research into occupational fraud is conceptually rich, there is a lack of empirical evidence of this important but elusive problem. Design/methodology/approach – Based on investigative data from 14 participating firms, the paper provides insights into the gender breakdowns and stated motivations of offenders. The paper also provides evidence of the number of investigations, interviews and reports to law enforcement in these firms. Findings – The study finds that genders are evenly balanced for most firms, with females significantly outnumbering males in banking firms. Self-imposed financial hardship was the most popular motivator. Of the number of admissions to wrongdoing, only half were subsequently reported to law enforcement. Research limitations/implications – Particularly complex or advanced types of occupational fraud may go unreported or unde.
Unions, Work Practices, and Wages under Different Institutional Environments: The Case of Canada and England

Using data collected in 2003–2004 in national telephone surveys of 750 Canadian and 450 English workers, the author finds that alternative work practices (AWPs), such as autonomous teams, quality circles, and information sharing, provided meaningful pay gains for non-union workers but not union workers in both Canada and England. In Canada, non-union AWP payoffs approached union wage premia at even moderate levels of AWP adoption, suggesting that AWPs may serve as an alternative means to higher pay, one that is incompatible with unions and that could erode demand for union representation. In England, there was no meaningful union wage premium, suggesting that AWPs may have replaced pay bargaining as a means to higher pay; but an interaction term combining union representation and “best” HR practices bore a strong association with higher pay, consistent with a new economic role whereby unions achieve gains for their members through collaborative, performance-enhancing strategies.
Improving Performance and Applying Cascades in Visual Classification Master Thesis

Computer-based object classification has improved consistently over the last decade, but the performance of current computational schemes is still significantly lower than human classification performance. In addition, the errors made by current classifiers are often unreasonable by human standards. Since improvements to performance become increasingly difficult to achieve when absolute performance is already high, it is currently unclear which future directions will be useful for reaching truly human level performance. In this work I examined two general directions for future improvements in current classification scheme. One general direction assumes that current methods extract only a part of the available information for classification from the training set, and attempts to identify the main possible sources of additional information. I examined a number of plausible sources for possible improvements. Some of the methods under study, but we concluded that they are unlikely to be sufficient by themselves to reach human-level performance. The second general direction assumes that a major limitation comes from the size of the training set: training sets used in practice may be inherently insufficient to capture all the necessary variations needed to learn a truly high-performance classifier. Our experiments suggested that classification performance indeed increase monotonically and without clear saturation as the training set increases in size. We also found that the set of features used for classification needs to be increased to capture the additional information in the increased training set. These results have two implications to the classification scheme. First, they raise the advantage of constructing classifiers in an on-line manner, in which the classifier is continuously improved by new examples. Second, they raise the problem of increasing computational load as the number of features used for classification increases. To deal with these problems we developed and tested two classification schemes. Both are multi-stage, or 'cascade' methods in which all images are analyzed in the first stage, and, depending on the results, only some of them are analyzed further by subsequent stages. The first of these methods was a so-called 3-way cascade, which is an extension of previously used cascade methods. In this method, a first-level classifier is first applied to the new image to be classified. If the response is high or low enough a decision is made, otherwise, a second-level classifier, which uses more features, is applied to the image to allow a more confident response. The second multi-stage scheme we developed is the so-called …
Prenatal Cocaine Exposure Increases Sensitivity to the Attentional Effects of the Dopamine D1 Agonist SKF81297

Sensitivity to the attentional effects of SKF81297, a selective full agonist at dopamine D1 receptors, was assessed in adult rats exposed to cocaine prenatally (via intravenous injections) and controls. The task assessed the ability of the subjects to monitor an unpredictable light cue of either 300 or 700 msec duration and to maintain performance when presented with olfactory distractors. SKF81297 decreased nose pokes before cue presentation and increased latencies and response biases (the tendency to respond to the same port used on the previous trial), suggesting an effect of SKF81297 on the dopamine (DA) systems responsible for response initiation and selection. The cocaine-exposed (COC) and control animals did not differ in sensitivity to the effects of SKF81297 on these measures. In contrast, the COC animals were significantly more sensitive than were controls to the impairing effect of SKF81297 on omission errors, a measure of sustained attention. This pattern of results provides evidence that prenatal cocaine exposure produces lasting changes in the DA system(s) subserving sustained attention but does not alter the DA system(s) underlying response selection and initiation. These findings also provide support for the role of D1 receptor activation in attentional functioning.
A Hedonic Analysis of the Value of Rail Transport in the Greater Dublin Area. ESRI WP264. November 2008

We use a hedonic house price model to estimate the value of transport networks to homeowners in the Dublin area. Using a dataset of house sales between 2001 and 2006 and combining it with available geographical information system data on the train and tram lines in Dublin, it is possible to assess the values assigned to different transport links by homeowners. We find that the value of transport depends on how far from the property it is located and is also affected by the availability of alternative transport options in the area. There are differences in the values assigned to recently constructed tramlines compared to the traditional rapid transit train stations. The study also takes into account house characteristics and other environmental amenities.
Is it necessary to stop antiplatelet agents before a native renal biopsy?

BACKGROUND The practice of advising patients to stop antiplatelet agents before an elective renal biopsy is widespread. The aim of this study was to compare the rate of bleeding complications in two centres that have different policies regarding the ongoing use of antiplatelet agents in patients undergoing an elective renal biopsy. Neither centre routinely checks bleeding time before renal biopsy. A secondary aim, therefore, was to compare complication rates from this cohort with those reported in the literature where screening for prolonged bleeding time is standard practice. METHODS A retrospective study of 1120 biopsies performed by nephrologists under direct ultrasound guidance in the two renal units in Glasgow, Scotland (Jan 2000 to May 2007) was undertaken. Antiplatelet agents were stopped 5 days before biopsy in one centre but continued in the other. Bleeding time was not measured before biopsy and pro-coagulants were not routinely administered. Major bleeding was defined as the need for blood transfusion, surgical or radiological intervention. Minor bleeding was defined as an >or=1.0 g/dL fall in haemoglobin following biopsy without the need for transfusion or intervention. RESULTS Haemoglobin fell by >or=1.0 g/dL in 221 (19.7%) patients. There were 21 (1.9%) major bleeding complications. No patient died or required nephrectomy. Gender, advancing age or worse renal impairment was not associated with an increased likelihood of bleeding. Bleeding complications in 75 patients continuing antiplatelet agents were compared with those occurring in 60 patients whose antiplatelet agents were discontinued. Minor complications were commoner in the first group (31.0 versus 11.7%; P = 0.008), though there was no difference in the rate of major complications. CONCLUSIONS The risk of major bleeding following a native renal biopsy under ultrasound guidance is low. Stopping antiplatelet agents before biopsy was associated with a lower rate of minor complications but there was no difference in the rate of major complications. Complication rates compare favourably with other published series in which bleeding time was checked and corrected.
Optimal Network Security Strengthening Using Attack-Defense Game Model

For assessing the security and optimal strengthening of large enterprise networks, this paper proposes a new approach uses configuration information on firewalls and vulnerability information on all network devices to build defense graphs that show the attack and defense strategy. Some models including a defense graph model, attack-defense taxonomy and cost quantitative model, and Attack-Defense Game (ADG) model. We regard the interactions between an attacker and the defender as a two-player, non-cooperative, zero-sum, finite strategic game and formulate the ADG model for the game. An algorithm for optimal strengthening strategy selection based on those models is proposed. Optimal strengthening strategies with minimizing costs are used to defend the attack and strengthening the network in advance. And finally, we perform empirical experiments to verify the effectiveness of the model experiment results indicate that our models and methods are effective and efficient.
Monetary shocks and the nominal interest rate

This paper reconsiders the effects of monetary shocks on the nominal interest rate in a standard macroeconomic model. It is determined that, when the policy objective is controlling the money stock, money supply shocks generate a situation of excess demand for money. The positive relationship between nominal interest rates and monetary innovations in the United States following the 1979 change in regime is, thus, not puzzling but perfectly consistent with standard theory. Nominal interest rate decreases are possible only when "fine-tuning" rules are adopted. Copyright 1992 by The London School of Economics and Political Science.
Preoperative oral antibiotics in colorectal surgery increase the rate of Clostridium difficile colitis.

HYPOTHESIS Bowel preparation traditionally consists of cathartics, oral antibiotics, and intravenous antibiotics. We hypothesize that the use of oral antibiotics in bowel preparation results in a higher rate of postoperative Clostridium difficile colitis. DESIGN Retrospective case-controlled study of elective colon surgery patients; January 1997 to June 2003. SETTING Tertiary care veterans administration hospital. PATIENTS Records of patients who underwent elective colorectal surgery (n = 304) were reviewed. Patients with bowel obstruction or emergent operation were excluded. MAIN OUTCOME MEASURE Detection of C difficile toxin A/B by enzyme-linked immunosorbent assay in a stool specimen within 30 days of surgery. RESULTS All 304 patients received both cathartics and intravenous antibiotics. Of 304 patients, 107 (35.1%) received oral antibiotics. The rate of postoperative C difficile colitis was 4.2% in the entire study population. The rate of C difficile infection was higher in patients who received oral antibiotics (7.4%) compared with patients who did not receive oral antibiotics (2.6%; P = .03). There were no C difficile-related mortalities. CONCLUSION Oral nonabsorbable antibiotics in bowel preparation resulted in a higher rate of C difficile infection. This may be due to the additional effect of oral antibiotics on normal bowel flora. We recommend that oral nonabsorbable antibiotics not be used in preoperative bowel preparation regimens since postoperative C difficile infection can lead to additional morbidity, length of stay, and hospital costs.
Understanding Crude Oil Prices

This paper examines the factors responsible for changes in crude oil prices. The paper reviews the statistical behavior of oil prices, relates this to the predictions of theory, and looks in detail at key features of petroleum demand and supply. Topics discussed include the role of commodity speculation, OPEC, and resource depletion. The paper concludes that although scarcity rent made a negligible contribution to the price of oil in 1997, it could now begin to play a role.
GADD45β induction by S-adenosylmethionine inhibits hepatocellular carcinoma cell proliferation during acute ischemia-hypoxia

Growth arrest DNA damage-inducible gene 45β (GADD45β), which influences cell growth, apoptosis and cellular response to DNA damage, is downregulated in hepatocellular carcinoma (HCC). S-adenosylmethionine (SAMe) serves as an essential methyl donor in multiple metabolic pathways and is a polyamine and glutathione (GSH) precursor. In this study, we assessed the roles of GADD45β and SAMe in cell survival during acute ischemia-hypoxia (I/H). SAMe treatment induced growth of HL-7702 normal hepatic cells, but decreased the viability of HepG2 (p53 wild-type) and Hep3B (p53 null) HCC cells. Cells were exposed to I/H with or without SAMe pre-treatment. I/H exposure alone triggered HCC cell proliferation promoted by autophagy. SAMe pre-treatment restored GADD45β expression and activated HCC cell apoptosis and eliminated I/H-induced HCC cell proliferation. p53 loss blunted the response to SAMe and I/H exposure in Hep3B cells; thus, the inhibitory effect of SAMe on cell proliferation may be reduced in p53-null cells as compared to wild-type cells. These results indicate that GADD45β induction by SAMe inhibits HCC cell proliferation during I/H as a result of increased apoptosis, and that SAMe also protects normal hepatocytes from apoptotic cell death and promotes normal cell regeneration. SAMe should be considered a potential therapeutic agent for the management of HCC.
Neural correlates of feedback processing in decision-making under risk

Introduction: Event-related brain potentials (ERPs) provide important information about the sensitivity of the brain to process varying risks. The aim of the present study was to determine how different risk levels are reflected in decision-related ERPs, namely the feedback-related negativity (FRN) and the P300. Materials and Methods: Twenty participants conducted a probabilistic two-choice gambling task while an electroencephalogram (EEG) was recorded. Choices were provided between a low-risk option yielding low rewards and low losses and a high-risk option yielding high rewards and high losses. While options differed in expected risks, they were equal in expected values and in feedback probabilities. Results: At the behavioral level, participants were generally risk-averse but modulated their risk-taking behavior according to reward history. An early positivity (P200) was enhanced on negative feedbacks in high-risk compared to low-risk choices. With regard to the FRN, there were significant amplitude differences between positive and negative feedbacks on high-risk choices, but not on low-risk choices. While the FRN on negative feedbacks did not vary with decision riskiness, reduced amplitudes were found for positive feedbacks in high-risk relative to low-risk choices. P300 amplitudes were larger in high-risk decisions, and in an additive way, after negative compared to positive feedback. Discussion: The present study revealed significant influences of risk and valence processing on ERPs. FRN findings suggest that the reward prediction error signal is increased after high-risk decisions. The increased P200 on negative feedback in risky decisions suggests that large negative prediction errors are already processed in the P200 time range. The later P300 amplitude is sensitive to feedback valence as well as to the risk associated with a decision. Thus, the P300 carries additional information for reward processing, mainly the enhanced motivational significance of risky decisions.
Serving large-scale batch computed data with project Voldemort

Current serving systems lack the ability to bulk load massive immutable data sets without affecting serving performance. The performance degradation is largely due to index creation and modification as CPU and memory resources are shared with request serving. We have extended Project Voldemort, a general-purpose distributed storage and serving system inspired by Amazon's Dynamo, to support bulk loading terabytes of read-only data. This extension constructs the index offline, by leveraging the fault tolerance and parallelism of Hadoop. Compared to MySQL, our compact storage format and data deployment pipeline scales to twice the request throughput while maintaining sub 5 ms median latency. At LinkedIn, the largest professional social network, this system has been running in production for more than 2 years and serves many of the data-intensive social features on the site.
A Posteriori Error Estimates for Finite Volume Approximations

We present new a posteriori error estimates for the finite volume approximations of elliptic problems. They are obtained by applying functional a posteriori error estimates to natural extensions of the approximate solution and its flux computed by the finite volume method. The estimates give guaranteed upper bounds for the errors in terms of the primal (energy) norm, dual norm (for fluxes), and also in terms of the combined primal-dual norms. It is shown that the esti- mates provide sharp upper and lower bounds of the error and their practical computation requires solving only finite-dimensional problems.
A Critical Discourse Analysis of the Reports Issued by the International Atomic Energy Agency (IAEA) Director General on Iran"s Nuclear Program during the Last Decade

Regarding the importance of Critical Discourse Analysis (CDA) in discovering the way ideology is diffused through the prevalence of various discourses, the present paper is an attempt to illustrate how the ideological and political considerations are realized through textual features of Negation and Repetition as well as intertextual features of Argumentation and Persuasion. Reports about Iran’s nuclear program provided by IAEA’s Director General are examples of mediating role which such genres play to dictate the underlying contemplations of their producers. Using Fairclough three-dimensional framework for studying discourse at three levels of micro, meso and macro, it is shown how the language used in these 38 reports is not merely a vehicle of explicit transmission of knowledge but a means of implicit construction of ambiguity. An attempt has been made to demonstrate how an organization such as IAEA with a technical body through politicized linguistic elements directs the readers’ impression of the IAEA reports and consequently revises and constructs their ideologies.