Miracle-dz/UniFAR-FTUs huggingface dataset:
The Counting Process Approach to Default Modeling

Counting processes provide a very flexible framework for modeling discrete events occurring over time. Estimation and interpretation is easy, and links to more familiar approaches are at hand. The key is to think of data as "event histories," a record of times of switching between states in a discrete state space. In a simple case, the states could be default/non-default; in other models relevant for credit modeling the states could be credit scores or payment status (30 dpd, 60 dpd, etc.). We illustrate the approach with an application to mortgage default, using data on high LTV mortgages. Borrowers seeking to finance more than 80% of a house’s value with a mortgage usually either purchase mortgage insurance, allowing a first mortgage greater than 80% from many lenders, or use second mortgages. Are there differences in performance between loans financed by these different methods? We address this question in the counting process framework. In fact, MI is associated with lower default rates for both fixed rate and adjustable rate first mortgages The Counting Process Approach to Default Modeling Kiefer & Larson August 2013 Page 1 of 56
A Bayesian Procedure for File Linking to Analyze End-of-Life Medical Costs

End-of-life medical expenses are a significant proportion of all health care expenditures. These costs were studied using costs of services from Medicare claims and cause of death (CoD) from death certificates. In the absence of a unique identifier linking the two datasets, common variables identified unique matches for only 33% of deaths. The remaining cases formed cells with multiple cases (32% in cells with an equal number of cases from each file and 35% in cells with an unequal number). We sampled from the joint posterior distribution of model parameters and the permutations that link cases from the two files within each cell. The linking models included the regression of location of death on CoD and other parameters, and the regression of cost measures with a monotone missing data pattern on CoD and other demographic characteristics. Permutations were sampled by enumerating the exact distribution for small cells and by the Metropolis algorithm for large cells. Sparse matrix data structures enabled efficient calculations despite the large dataset (≈1.7 million cases). The procedure generates m datasets in which the matches between the two files are imputed. The m datasets can be analyzed independently and results can be combined using Rubin’s multiple imputation rules. Our approach can be applied in other file-linking applications. Supplementary materials for this article are available online.
Live-Wires Using Path-Graphs

Summary Objectives: This article discusses our new Path-Graph approach for the interactive Live-Wire segmentation method in 2D applied to pre-segmented data. Furthermore, we examine whether or not the Live-Lane extension provides advantages in combination with pre-segmentation. Methods: We automatically over-segment the image data in a preprocessing step, using region growing with an automatic seed point generation. The Live-Wire algorithm is applied on this mosaic data by using the outlines of the homogeneous regions as the basis for graph building. We present a new definition of this underlying graph where the edges of the standard graphs are turning into vertices and the vertices of the new graph are defined by the edge connectivity in the standard graph. For better differentiation we name our new graph Path-Graph and the original defined graph Node-Graph. Results: The quality evaluation is done by comparing our segmentation results with existing model data. We show that using the Path-Graph as basis for the Live-Wire algorithm instead of the Node-Graph allows for a finer segmentation. We achieve a reduction of incorrectly classified pixels by 20.66 per cent and a decrease of the mean boundary deviation by 11.61 per cent. Since savings on cost tree calculations are compensated by additional computation time required to compute the Live-Lanes, a performance loss of 2.41 per cent is measured. Conclusions: Our redefinition of the underlying graph increases the quality of the Live-Wire segmentation. The Live-Lane extension in combination with pre-segmentation is not justified for our data.
Sub-Wavelength Dual Capillaries-Assisted Chalcogenide Optical Fibers: Unusual Modal Properties in Mid-IR (2–5 μm) Spectral Range

In this study, we apply the concept of sub-wavelength light confinement to achieve flat effective mode area (Aeff) characteristics over a wide wavelength range of 1400 nm in nano-sized dual capillary assisted chalcogenide core optical fibers. An unusual spectral behavior of Aeff is observed where the effective mode area increases, remains constant for a wide bandwidth, decreases and again increases with the increase in wavelength. The spectral region, in which this behavior is observed, can be tuned by varying the structural parameters of the fiber. Additionally, we noticed that the fiber exhibits four zero dispersion wavelengths for a particular polarization which suggests that sub-wavelength light localization can be an alternative solution for the dispersion engineering in order to attain multiple zero dispersion wavelengths. The fabrication tolerance of the dispersion profile has been found to fall within the current fabrication accuracies achievable. We believe that our findings might be useful in different applications such as light-matter interaction and spatial soliton propagation.
Iron-Responsive Regulation of the Helicobacter pylori Iron-Cofactored Superoxide Dismutase SodB Is Mediated by Fur

ABSTRACT Maintaining iron homeostasis is a necessity for all living organisms, as free iron augments the generation of reactive oxygen species like superoxide anions, at the risk of subsequent lethal cellular damage. The iron-responsive regulator Fur controls iron metabolism in many bacteria, including the important human pathogen Helicobacter pylori, and thus is directly or indirectly involved in regulation of oxidative stress defense. Here we demonstrate that Fur is a direct regulator of the H. pylori iron-cofactored superoxide dismutase SodB, which is essential for the defense against toxic superoxide radicals. Transcription of the sodB gene was iron induced in H. pylori wild-type strain 26695, resulting in expression of the SodB protein in iron-replete conditions but an absence of expression in iron-restricted conditions. Mutation of the fur gene resulted in constitutive, iron-independent expression of SodB. Recombinant H. pylori Fur protein bound with low affinity to the sodB promoter region, but addition of the iron substitute Mn2+ abolished binding. The operator sequence of the iron-free form of Fur, as identified by DNase I footprinting, was located directly upstream of the sodB gene at positions −5 to −47 from the transcription start site. The direct role of Fur in regulation of the H. pylori sodB gene contrasts with the small-RNA-mediated sodB regulation observed in Escherichia coli. In conclusion, H. pylori Fur is a versatile regulator involved in many pathways essential for gastric colonization, including superoxide stress defense.
Exchange-traded funds in bullish and bearish markets

An Exchange-Traded Fund (ETF) aims to track the performance of market indices. This article examines the performances of 15 worldwide ETFs across bearish and bullish markets over the period 1999 to 2007. The results indicate that ETFs always provide higher returns in a bullish market than in a bearish market by the Sharpe ratio test that shows that ETF returns are not positive, proportional to the market volatility. Additionally, ETFs with the same underlying index do not perform exactly the same. It is believed that active portfolio management plays an important role in ETFs.
Elevation of Mitochondrial Calcium by Ryanodine-sensitive Calcium-induced Calcium Release*

Calcium is an important regulator of mitochondrial function. Since there can be tight coupling between inositol 1,4,5-trisphosphate-sensitive Ca2+ release and elevation of mitochondrial calcium concentration, we have investigated whether a similar relationship exists between the release of Ca2+ from the ryanodine receptor and the elevation of mitochondrial Ca2+. Perfusion of permeabilized A10 cells with inositol 1,4,5-trisphosphate resulted in a large transient elevation of mitochondrial Ca2+ to about 8 μm. The response was inhibited by heparin but not ryanodine. Perfusion of the cells with Ca2+ buffers in excess of 1 μm leads to large increases in mitochondrial Ca2+ that are much greater than the perfused Ca2+. These increases, which average around 10 μm, are enhanced by caffeine and inhibited by ryanodine and depletion of the intracellular stores with either orthovanadate or thapsigargin. We conclude that Ca2+-induced Ca2+ release at the ryanodine receptor generates microdomains of elevated Ca2+ that are sensed by adjacent mitochondria. In addition to ryanodine-sensitive stores acting as a source of Ca2+, Ca2+-induced Ca2+release is required to generate efficient elevation of mitochondrial Ca2+.
Internal displacement and the education of school-aged children in Colombia

Internal displacement and the education of school-aged children in Colombia Ximena Duenas Internal displacement in Colombia is a country-wide phenomenon that has affected almost five percent of the country’s population or 14% of the country’s rural population. Colombia’s violent conflict has not reached yet a post-conflict stage since no peace agreement has been reached between the State and violent actors. This makes an analysis of the effects of displacement and of the state-led initiatives relating to it, such as the Familias en Accion para la poblacion desplazada , highly relevant to the current status of this humanitarian crisis. Using a unique data set from Colombia, the National Survey of Displaced Households (ENHD) performed in 2004, this thesis examines the educational situation of displaced children and studies the impact of various forces, including government policy, on the schooling of displaced children. The dissertation investigates the following questions: 1) What are the main factors determining the enrollment of internally displaced children at the destination municipalities? 2) What is the effect associated with the participation in the Familias en Accion for IDPs Program on enrollment? 3) What is the prevalence of school overage among internally displaced children and what are its main determinants? With respect to the first research question, the results show that children who are members of a female-headed household have a lower probability of being enrolled in school. Conversely, children whose head of household is literate have a higher probability of enrollment. The research is also able to examine the impact of how long families have been displaced. The results show that after a year, children’s probability of enrollment increases significantly, bouncing upwards relative to the period immediately following displacement. Finally, the results show that higher household income is associated with greater enrollment, but in a nonlinear way: if a household belongs to the first three income quintiles the probability of enrollment does not increase significantly, but for the fourth and fifth income quintiles, the probability of enrollment increases by 10 and 12 percentage points evaluated at the mean. The second research question examines the effect of the Familias en Accion for IDPs Program on enrollment using a difference in differences (DID) model. The results obtained using the DID approach show that children whose families are aid beneficiaries are more likely to be enrolled in schools, holding other things constant. The third research question in the dissertation looks at the prevalence – and determinants – of school overage among internally displaced children. It is estimated that there are two years of overage after displacement which comes from the fact that this population is forced to leave their places of origin and resettle in other destinations, time during which children are not be able to enroll in school thus affecting their attainment.
Pendulating—A grounded theory explaining patients’ behavior shortly after having a leg amputated due to vascular disease

Introduction Although the group of vascular leg amputated patients constitutes some of the most vulnerable and frail on the orthopedic wards, previous research of amputated patients has focused on patients attending gait training in rehabilitation facilities leaving the patient experience shortly after surgery unexplored. Understanding patients’ behavior shortly after amputation could inform health professionals in regard to how these vulnerable patients’ needs at hospital can be met as well as how to plan for care post-discharge. Aim To construct a grounded theory (GT) explaining patients’ behavior shortly after having a leg amputated as a result of vascular disease. Method In line with constructivist GT methodology, data from ethnographic observations and interviews were simultaneously collected and analyzed using the constant comparative method covering the patients’ experiences during the first 4 weeks post-surgery. Data collection was guided by theoretical sampling and comprised 11 patients. A GT was constructed. Results Patients went through a three-phased process as they realized they were experiencing a life-changing event. The first phase was “Losing control” and comprised the sub-categories “Being overwhelmed” and “Facing dependency. ” The second phase was “Digesting the shock” and comprised the sub-categories “Swallowing the life-changing decision,” “Detecting the amputated body” and “Struggling dualism. ” The third phase was “Regaining control” and comprised the sub-categories “Managing consequences” and “Building-up hope and self-motivation. ” “Pendulating” was identified as the core category describing the general pattern of behavior and illustrated how patients were swinging both cognitively and emotionally throughout the process. Conclusion The theory of “Pendulating” offers a tool to understand the amputated patients’ behavior and underlying concerns and to recognize where they are in the process. Concepts from the theory could be used by health professionals who support patients coping with the situation by offering terms to express and recognize patients’ reactions.
Mitigating DDoS attacks towards Top Level Domain name service

As the largest country code Top Level Domain (ccTLD) name service, . CN receives billions of queries every day. Under the threat of Distributed Denial-of-Service (DDoS) attacks, effective mechanism for client classification is especially important for such busy ccTLD service. In this paper, by analyzing the query log of . CN name service, we propose a novel client classification method based on client query entropy and global recursive DNS service architecture. By checking with the query frequencies of the clients, we validate the effectiveness of the proposed method on both busy and long-tailed clients. We find that 2.32% clients can cover the most important web spiders, recursive servers, and well-known internet services, etc. The results indicate that, our method can bring significant benefits for creating the client whitelist, which is useful for mitigating DDoS attack towards Top Level Domain (TLD) name service.
Multi-product cost functions and the funding of tuition in UK universities

A quadratic multi-product cost function is estimated for UK universities prior to the abolition of the binary divide. The arguments of the function include linear and interaction terms in undergraduate tuition, postgraduate tuition and research, and in each case these are separately identified for the (broadly defined) arts and sciences. The preferred specification is used to evaluate ray economies of scale, product-specific economies of scale and economies of scope. Estimates of average incremental costs are also provided. Results from OLS and stochastic frontier methods are compared.
Game theoretic D2D content dissemination in 4G cellular networks

The widespread proliferation of mobile devices has motivated Device-to-Device (D2D) communications as a means of cell offloading toward better Quality of Service (QoS) and higher energy efficiency. Although Wi-Fi networks have the lion's share regarding the D2D communications in the unlicensed spectrum, it is uncertain whether they constitute the best option as technology evolves. In particular, the increasing transmission data rates, the novel interference cancelation techniques, as well as the potential of centralized network support, stress the need for new Medium Access Control (MAC) protocols, especially in content dissemination scenarios where all nodes share the same goal. In this article we study the suitability of Wi-Fi technology in content dissemination scenarios with multiple available source nodes, and we propose two energy-aware game theoretic MAC strategies (a distributed and a network-assisted) as possible alternatives. Our simulation results show the effectiveness and the flexibility of our proposed solutions, highlighting the necessity for new MAC designs.
GSE Debt and the Decline in the Treasury Debt Market

As a result of the economic expansion during the late 1990s, the size of the federal debt has declined significantly. Contemporaneous with this reduction in Treasury debt, growth in federal agency debt has been remarkable. Understanding the impact of the decline in federal debt outstanding on the GSE debt market is of critical importance to policymakers involved in the debate regarding the costs and benefits of the GSEs' Congressional charter. Thus, this paper separates the liquidity effect of GSE benchmark creation from the substitution effect resulting from the reduction in the Treasury debt market.
Enhanced Active Equity Strategies

Enhanced active equity investing relaxes the long-only constraint by permitting short sales, while maintaining full exposure to equity market return and risk. The enhanced active equity approach is facilitated by modern prime brokerage structures that allow investors to use the proceeds from short sales to purchase long positions. Freeing equity portfolios from the long-only constraint can enhance performance by permitting meaningful underweight positions that are simply not achievable in long-only portfolios. The investor can thus more fully exploit security valuation insights.
Assessing nanotechnology potentials: interplay between the paths of knowledge evolution and the patterns of competence building

This paper seeks to assess the potentials of countries to grasp value from nanoscience and nanotechnology (N&N) opportunities as reflected in the crucial, but mostly overlooked, field of micro and nanofabrication technologies. N&N potentials are assessed relative to the paths along which the nano knowledge structures are being channelled. Conceptually, this is visualised in terms of the interplay between the patterns of nano competence building for relevant countries and the paths of nano knowledge evolution. Hereby, higher N&N potentials are expected to ensue the closer both aspects follow each other. To analyse the case, this research makes use of intensive bibliometric and social network methods based on scientific publications. A series of implications for policy makers and researchers on the critical role of micro and nanofabrication technologies within the N&N field will be described in this paper.
Do fiduciary duties matter

Purpose – The purpose of this paper is to explore whether fiduciary duties impact the behavior of firm insiders. Trust law imposes stricter fiduciary obligations on insiders than corporate law does. This paper seeks to examine whether the difference in fiduciary duties impacts agency conflict, performance, and/or risk taking.Design/methodology/approach – The paper takes an empirical approach to answering the question by comparing mutual funds organized as trusts and as corporations. The existence of these two types of organizations within the same industry offers a unique laboratory for the study of the effects of fiduciary duties.Findings – Mutual funds organized in trust form charge significantly lower fees and take on less risk than equivalent mutual funds organized in corporate form. Evidence also suggests that the trusts tend to under‐perform their corporate counterparts, even after adjusting for differences in risk.Originality/value – Much of the existing literature on firm governance and investor p.
Synthesis and biochemical characteristics of nucleoproteins following a toxic dose of retinoic acid in cycling and differentiating HL-60 cells.

Exposure of HL-60 cells to 2 microM retinoic acid (RA), twice the dose necessary for differentiation, initiated rapid synthesis (2 h) of the nuclear stress proteins (SPs) e.g., 90, 70c, 70x, 22 (Mr x 10(-3)) during the G0 + G1 phase of the cell cycle as observed by polyacrylamide gel electrophoresis (PAGE). Synthesis of SPs was cell cycle correlated and not dependent on time-after-dosing, and all labeling disappeared from these proteins within 48 h of RA exposure. Stress proteins were not elicited with a 1 microM dose or less of retinoic acid. Non-stress nuclear proteins revealed changes in synthesis levels (e.g., actin, lamins, tubulins) which were cell cycle related and temporally associated with dosing. A major non-stress nuclear protein (Mr 120,000) which possessed an affinity for actin in binding assays, was cell cycle related in control cells, and was suppressed in synthesis in cells exposed to 2 microM retinoic acid. Two additional nuclear non-SPs 51 and 55 (Mr x 10(-3)) covalently bound the isotope [3H]retinoic acid, and their incorporation was cell cycle correlated during early periods of RA exposure. Except for the induction of SPs, the autoradiographs of nuclear proteins of RA dosed HL-60 cells, showed more quantitative than qualitative changes.
Threshold Events and Identification: A Study of Cash Shortfalls

Threshold events are discrete events triggered when an observable continuous variable passes a known threshold. We demonstrate how to use threshold events as identification strategies by revisiting the evidence in Rauh (2006) that mandatory pension contributions cause investment declines. Rauh's result stems from heavily underfunded firms that constitute a small fraction of the sample and that differ from the rest of the sample in important ways; that is, the control group differs from the treated group. To alleviate this issue, we use observations near funding thresholds and find causal effects of mandatory contributions on receivables, R&D, and hiring, but not on investment. We also provide useful suggestions and diagnostics for analyzing threshold events.