Miracle-dz/UniFAR-FTUs huggingface dataset:
Using Electoral Cycles in Police Hiring to Estimate the Effect of Police on Crime: Comment

Previous empirical studies have typically uncovered little evidence that police reduce crime. One problem with those studies is a failure to adequately deal with the simultaneity between police and crime: while police may or may not reduce crime, there is little doubt that expenditures on police forces are an increasing function of the crime rate. In this study, the timing of mayoral and gubernatorial elections is used to identify the effect of police on crime. This paper first demonstrates that increases in the size of police forces disproportionately occur in mayoral and gubernatorial election years, a relationship that had previously gone undocumented. After controlling for changes in government spending on other social programs, there is little reason to think that elections will be otherwise correlated with crime, making elections ideal instruments. Using a panel of large U.S. cities from 1970-1992, police are shown to reduce crime for six of the seven crime categories examined. Each additional police officer is estimated to eliminate eight to ten serious crimes. Existing estimates of the costs of crime suggest that the social benefit of reduced crime is approximately $100,000 per officer per year, implying that the current number of police is below the optimal level.
Effects of Mouse Recombinant Bone Morphogenetic Protein-7 Transfection on Cell Apoptosis, NF-κB, and Downstream Genes in Cultured Primary Cardiomyocytes After Simulated Ischemia and Reperfusion Injury

Aim: To evaluate the acting mechanism of bone morphogenetic protein-7 in anti-ischemic protective effect, we investigate the effects of BMP-7 transfection on cell apoptosis, NF-κB activity, and downstream genes in neonatal rat cardiomyocytes during simulated ischemia-reperfusion. Method: In vitro cultured neonatal rat cardiomyocytes were divided into four groups: normal control group (Group C), simulated ischemia-reperfusion group (Group IR: cultured cardiomyocytes were subjected to 2 hours hypoxia followed by 4 hours reoxygenation), transfected group (Group BT: after transfection with pcDNA3.1-BMP-7 plasmid, cardiomyocytes were subjected to 2 hours hypoxia/4 hours reoxygenation), and empty vector control group (Group ET: same as group BT except that cells were transfected with empty pcDNA3.1 vector). Malondialdehyde content, superoxide dismutase activity, and Ca2+ concentration were measured. Terminal deoxynucleotide transferase-mediated dUTP nick-end labeling staining and fluorescence activated cell sorting assay were applied to determine the apoptotic rate of cardiomyocytes and immunocytochemistry and Western blot were used to detect nuclear expression of NF-κB in cardiomyocytes. Reverse transcription-polymerase chain reaction was used to detect mRNA expression of monocyte chemoattractant protein-1 and intercellular cell adhesion molecule-1. Results: Compared with Group IR, malondialdehyde content of Group BT significantly decreased, whereas superoxide dismutase activity significantly elevated. In addition, intracellular Ca2+ concentration of Group BT significantly reduced and apoptotic cells were significantly less. Decreased optical density ratio of NF-κB in the nucleus and reduced monocyte chemoattractant protein-1 and intercellular cell adhesion molecule-1 mRNA expression were also detected. Conclusion: These results suggest that rat recombinant BMP-7 transfection provides sustained support for the repair of myocardium from ischemia injury through reducing cell apoptosis, inhibiting lipid peroxidation, antagonizing intracellular Ca2+ overload, and preventing the activation of downstream signaling factors in signal transduction pathway mediated by NF-κB.
A Nonlinear Modulator Using Delta Modulation Principles

A delta modulator in which the clock is replaced by voltage sources and the comparator is modified to have some controlled hysteresis is shown to behave like a relay-mode multivibrator whose "on" and " off" periods are functions of input voltages. Both approximate and exact analysis of the circuit are included. Under different input conditions, the circuit behaves as an A//D converter or square law or linear frequency modulator and a reconstruction filter.
Cervical disc deformation during flexion–extension in asymptomatic controls and single‐level arthrodesis patients

The aim of this study was to characterize cervical disc deformation in asymptomatic subjects and single‐level arthrodesis patients during in vivo functional motion. A validated model‐based tracking technique determined vertebral motion from biplane radiographs collected during dynamic flexion–extension. Level‐dependent differences in disc compression–distraction and shear deformation were identified within the anterior and posterior annulus (PA) and the nucleus of 20 asymptomatic subjects and 15 arthrodesis patients using a mixed‐model statistical analysis. In asymptomatic subjects, disc compression and shear deformation per degree of flexion–extension progressively decreased from C23 to C67. The anterior and PA experienced compression–distraction deformation of up to 20%, while the nucleus region was compressed between 0% (C67) and 12% (C23). Peak shear deformation ranged from 16% (at C67) to 33% (at C45). In the C5–C6 arthrodesis group, C45 discs were significantly less compressed than in the control group in all disc regions (all p ≤ 0.026). In the C6–C7 arthrodesis group, C56 discs were significantly less compressed than the control group in the nucleus (p = 0.023) and PA (p = 0.014), but not the anterior annulus (AA; p = 0.137). These results indicate in vivo disc deformation is level‐dependent, and single‐level anterior arthrodesis alters the compression–distraction deformation in the disc immediately superior to the arthrodesis. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1881–1889, 2013
Porphyromonas gingivalis lipopolysaccharide lipid A heterogeneity differentially modulates the expression of IL-6 and IL-8 in human gingival fibroblasts.

AIM Porphyromonas gingivalis lipopolysaccharide (LPS) displays a significant amount of structural heterogeneity, containing both tetra- (LPS(1435/1449) ) and penta-acylated (LPS(1690) ) lipid A structures. This study investigated the effects of the two isoforms of P. gingivalis LPS on the expression of IL-6, IL-8 and TNF-α in human gingival fibroblasts (HGFs). MATERIALS AND METHODS HGFs were stimulated with P. gingivalis LPS(1435/1449) and LPS(1690) in both dose- (1 ng-10 μg/ml) and time-dependent (2-48 h) experiments. Total RNA and protein were extracted and used for analysis of the IL-6, IL-8 and TNF-α transcripts as well as IL-6 and IL-8 proteins, by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. RESULTS P. gingivalis LPS(1690) significantly up-regulated the mRNA and protein expression of IL-6 and IL-8, whereas P. gingivalis LPS(1435/1449) did not induce significant host response. The expression levels of IL-6 and IL-8 up-regulated by P. gingivalis LPS(1690) continuously increased with time course. In contrast, TNF-α transcript expression was up-regulated promptly by P. gingivalis LPS(1690) after 2 h of stimulation and gradually declined afterwards. CONCLUSIONS This study suggests that P. gingivalis LPS heterogeneity may differentially modulate the pro-inflammatory cytokine expression in HGFs, which may contribute to periodontal pathogenesis.
SENSE and simultaneous multislice imaging

Simultaneous multislice (SMS) acquisitions play an important role in the challenge of increasing single‐shot imaging speed. We show that sensitivity encoding in two spatial dimensions (two‐dimensional sensitivity encoding [2D‐SENSE]) can be used to reconstruct SMS acquisitions with periodic but otherwise arbitrary undersampling patterns.
In Drosophila, don juan and don juan like encode proteins of the spermatid nucleus and the flagellum and both are regulated at the transcriptional level by the TAFII80 cannonball while translational repression is achieved by distinct elements

The genes don juan (dj) and don juan like (djl) encode basic proteins expressed in the male germline. Both proteins show a similar expression pattern being localized in the sperm heads during chromatin condensation and along the flagella. Prematurely expressed Don Juan–eGFP and Myc‐Don Juan Like localize to the cytoplasm of spermatocytes and in mitochondrial derivatives from the nebenkern stage onward suggesting that both proteins associate with the mitochondria along the flagella in elongated spermatids. Premature expression of Myc‐Don Juan Like does not impair spermatogenesis where‐as Don Juan‐eGFP when prematurely expressed causes male sterility as spermatids fail to individualize. In spite of the sequence identity of 72% on the nucleotide level and 42% on the protein level, the presumptive promoter regions and the untranslated regions of the mRNA are diverged. Our in vivo analysis revealed that don juan and don juan like are transcriptionally and translationally controlled by distinct short cis regulatory regions. Transcription of don juan and don juan like depends on the male germ line specific TAFII80, Cannonball (Can). Translational repression elements for both mRNAs are localized in the 5′ UTR and are capable to form distinct secondary structures in close proximity to the translational initiation codon. Developmental Dynamics 235:1053–1064, 2006. © 2006 Wiley‐Liss, Inc.
EVIDENCE FOR A SNOW LINE BEYOND THE TRANSITIONAL RADIUS IN THE TW Hya PROTOPLANETARY DISK

We present an observational reconstruction of the radial water vapor content near the surface of the TW Hya transitional protoplanetary disk, and report the first localization of the snow line during this phase of disk evolution. The observations are comprised of Spitzer-IRS, Herschel-PACS, and Herschel-HIFI archival spectra. The abundance structure is retrieved by fitting a two-dimensional disk model to the available star+disk photometry and all observed H2O lines, using a simple step-function parameterization of the water vapor content near the disk surface. We find that water vapor is abundant (∼10−4 per H2) in a narrow ring, located at the disk transition radius some 4 AU from the central star, but drops rapidly by several orders of magnitude beyond 4.2 AU over a scale length of no more than 0.5 AU. The inner disk (0.5–4 AU) is also dry, with an upper limit on the vertically averaged water abundance of 10−6 per H2. The water vapor peak occurs at a radius significantly more distant than that expected for a passive continuous disk around a 0.6 M☉ star, representing a volatile distribution in the TW Hya disk that bears strong similarities to that of the solar system. This is observational evidence for a snow line that moves outward with time in passive disks, with a dry inner disk that results either from gas giant formation or gas dissipation and a significant ice reservoir at large radii. The amount of water present near the snow line is sufficient to potentially catalyze the (further) formation of planetesimals and planets at distances beyond a few AU.
How Do Entrepreneurs Organize Firms Under Conditions of Uncertainty?

Entrepreneurs looking to exploit market opportunities and create economic value must concern themselves with both value creation and value appropriation. In this context, entrepreneurs face an unusual challenge; they must accomplish these two tasks before the economic value of the market opportunity is known, even probabilistically. The purpose of this article is to describe how entrepreneurs in these settings organize a firm to solve their resource coordination and profit appropriation problems. Three different ways of organizing firms in these settings are examined, and their implications for research in entrepreneurship and other fields are discussed.
Effect of the Delay Phenomenon in the Rat Single‐Perforator‐Based Abdominal Skin Flap Model

&NA; During the last decade, innovations in reconstructive surgery have presented a new type of flap called the “perforator‐based flap. ” Perforator‐based flaps became useful alternatives for solving difficult problems. In the authors' previous study, they created a single musculocutaneous perforator‐based abdominal skin flap. In their current study they evaluate the effect of various surgical delay procedures on this model. They divided 32 Sprague‐Dawley rats equally into four groups (one control group and three delay groups). Three different delay procedures were employed in the delay groups. In one group, only the flap boundaries were incised (delay group 1). In the other delay groups, flap boundaries were incised and the contralateral (opposite side of the pedicle, delay group 2) or ipsilateral (pedicle side, pedicle left intact; delay group 3) musculocutaneous perforators were ligated. The period of delay was 1 week in all groups. After 1 week, a single‐perforator‐based abdominal skin flap was elevated as in the control group. One week after the final procedure, surviving skin areas were calculated and microangiograms were acquired. The mean surviving skin area was 75% ± 3% (standard deviation) in the control group, 97% ± 3% in delay group 1, 81% ± 6% in delay group 2, and 96% ± 3% in delay group 3. Delay group 2 showed substantial necrosis 1 week after the delay procedure and was thus excluded from the study. Results were analyzed using one‐way analysis of variance, and post hoc analyses were performed using Tukey's multiple comparison test. The authors observed the advantages of the delay phenomenon in the two delay groups (p < 0.05). Microangiograms were examined grossly, and a marked difference between the two delay groups and the control group was observed. Many dilated choke vessels were seen in delay groups 1 and 3. Incising the flap boundaries with or without ligating the ipsilateral perforators (keeping the pedicle intact) 1 week before harvesting single‐perforator‐based abdominal skin flaps in the rat results in a delay effect. Conversely, incising the flap boundaries and ligating the contralateral perforators have no delay effect in this model. Coşkunfirat OK, Okşar HS, Özgentaş HE. Effect of the delay phenomenon in the rat single‐perforator‐based abdominal skin flap model. Ann Plast Surg 2000;45:42‐47
EVA and Traditional Accounting Measures: Which Metric is a Better Predictor of Market Value of Hospitality Companies?

This study tests the hypothesis that Economic Value Added (EVA) is more highly associated with hospitality firm values than with traditional performance measures. The purpose of this study is to provide empirical evidence on the relative and incremental information content of EVA and traditional performance measures, earnings, and cash flow. Regression analysis tests the information content of EVA and indicates that earnings are more useful than cash flow in explaining the market value of hospitality firms. EVA itself has very little explanatory power. Incremental information content tests show that EVA makes only a marginal contribution to information content beyond earnings and cash flow. Overall, the results do not support the hypothesis that EVA is superior to traditional accounting measures in association with equity market value.
Enlargement, reform and the European Commission. Weathering a perfect storm?

The European Commission may be the world's most powerful international administration. However, the notion that it has been in decline since the resignation of the Santer Commission in 1999 has become accepted wisdom. This analysis asks whether radical internal reforms and the European Union (EU) enlargements of 2004–07 add up to a sort of perfect storm, accelerating the Commission's decay. Recent changes have been dramatic and, in some ways, traumatic. Yet, in some respects, the internal reforms and enlargement are likely to yield a more modern Commission better able to add value to new forms of network governance. Ultimately, there is evidence to suggest that the Commission has become a more intergovernmental institution: less autonomous but more integrated into the EU system. Crucially, however, the very notion of ‘intergovernmental’ requires redefinition in the new EU.
Dividend Taxes and Stock Volatility

How do dividend taxes affect stock volatility? If a risk-averse executive faces price risk through his incentive contract, changes in stock volatility due to dividend taxes may increase agency costs and therefore decrease overall welfare. In this paper, I use a decrease in dividend taxes as a natural experiment to identify their effect on the firm’s idiosyncratic stock return volatility. Stock volatility decreased after the tax cut for firms at which executives have larger sensitivity to stock price in their incentive compensation package relative to firms at which executives have a smaller sensitivity. Therefore, with risk-averse executives and risk-neutral shareholders, dividend taxes may exacerbate agency costs. The increase in agency costs will decrease shareholder welfare, which can be partially offset by the use of options in the employment contract.
Use of BGP for Routing in Large-Scale Data Centers

Some network operators build and operate data centers that support over one hundred thousand servers. In this document, such data centers are referred to as "large-scale" to differentiate them from smaller infrastructures. Environments of this scale have a unique set of network requirements with an emphasis on operational simplicity and network stability. This document summarizes operational experience in designing and operating large-scale data centers using BGP as the only routing protocol. The intent is to report on a proven and stable routing design that could be leveraged by others in the industry.
Pollen sensitization and allergy in children depend on the pollen load

We investigated the influence of grass and birch pollen load on specific IgE response, skin prick test reactivity, and manifest allergic disorders of the eyes and respiratory tract. The study population was two groups of 200 children each, matched in sex and age, who were domiciled in areas with high and low pollen load, respectively. In the children from the area with high pollen load, the grass pollen load was 1.7 times higher than in the other and only specific IgE to grass pollen was found to be present more frequently (23.5 % as against 12.5%; P < 0.01), In the same area, the birch pollen load was 2.8 times higher, which caused specific IgE in 10.5% as against 3.5% of the other group (P < 0.01) as well as positive skin prick test in 9.0% as against 3.5% (P < 0.05), Reports of subjective complaints were rare among the group with high pollen load but the total number did not amount to a statistically significant increase. There was no difference between the two groups concerning sensitization and allergy to house dust mite. This suggests that the influence of the pollen load is strongest on the development of specific IgE, and less on skin test reactivity and manifest allergies.
Determinants of Store-Level Price Elasticity

Using weekly scanner data representing 18 product categories, the authors estimated store-specific price elasticities for a chain of 83 supermarkets. They related these price sensitivities to a comprehensive set of demographic and competitor variables that described the trading areas of each of the stores. Despite the inability of previous research to find much of a relationship between consumer characteristics and price sensitivity, 11 demographic and competitive variables explain on average 67% of the variation in price response. Moreover, the authors found that the consumer demographic variables are much more influential than competitive variables. Their findings open the possibility for more effective everyday and promotional pricing strategies that exploit store-level differences in price sensitivity.
Dynamic Competition in Technological Investments: An Empirical Examination of the LCD Panel Industry

When are technological laggards more likely to try to catch up with leaders? We offer empirical evidence on firm-level data of plant investments in the TFT-LCD panel industry, where technological competition has been intense and dynamic. We find that the followers' level of technology has a non-monotonic effect on technology-improving investments, with intermediate followers the most apt to invest in catch-ups. This result is a puzzle given the existing theory on technology race. We also find that followers' catch-up investments increase with the capacity of the leader that employs the state-of-the-art technology. These results are robust to variations in specification and alternative accounts of effects. We discuss our findings and contributions in light of the technology race literature.
Overreaction of Exchange-Traded Funds During the Bubble of 1998-2002

This study of overreaction is motivated by the unique characteristics of exchange-traded funds (ETFs), which should contribute to market efficiency. Since ETFs represent portfolios of stocks, they may not be as susceptible to short-term overreaction as individual stocks. In addition, they can be traded throughout the day and can be sold short, which might further limit potential overreaction. Yet, the tradability of ETFs may allow unusual pressure on ETF prices that is not initiated by price movements of all the component stocks. We find substantial overreaction of ETFs during normal trading hours (9:30 a.m. to 4 p.m.) and after hours, which presents opportunities for feedback traders. Extreme price movements of ETFs occur more frequently after hours. Yet, the after-hours correction of extreme price movements that occurred that day is more pronounced than the day correction of extreme stock price movements that occurred in the previous after-hours period, even after controlling for ETF type and other potential confounding effects. The degree of overreaction is also more pronounced for international ETFs.
Into thin air: using a quantile regression approach to explore the relationship between R&D and innovation

Applying quantile regression to 760 Finnish firms, we show that the relationship between R&D and firm performance is less straight forward than so far assumed. OLS regression analysis fails to capture the effect of R&D expenditure at different locations on the performance distribution. We reveal that R&D matters, especially on the medium quantiles, while regressing against the upper quantiles of the economic gains from innovation distribution exhibit decreasing returns scale in R&D. Our results confirm that Gaussian statistics fail to capture the most interesting part of the distribution – namely the extreme observations located in the tails.
Workers, Firms, or Institutions: What Determines Job Duration for Male Employees in Germany?

The authors examine job durations of German workers using the Linked Employer-Employee Data of the Institute of Employment Research (LIAB). Results indicate that exit rates are strongly influenced by firm characteristics, such as the existence of works councils and the opportunity for further training. The effects of these characteristics, however, are limited to jobs held by blue-collar workers or by those possessing vocation-educational skills. Changes in coefficients across specifications provide clear evidence for a sorting process whereby workers with long expected job durations are matched to firms offering stable employment and vice versa. An extension of the model to a competing-risks framework shows that both individual-and firm-level characteristics differ greatly in their effects on worker job exits to unemployment and to new jobs. Evidence suggests that works councils decrease exits to both states, but only for blue-collar workers.