Miracle-dz/UniFAR-FTUs huggingface dataset:
Comparing Biomarkers as Principal Surrogate Endpoints

Summary Recently a new definition of surrogate endpoint, the “principal surrogate,” was proposed based on causal associations between treatment effects on the biomarker and on the clinical endpoint. Despite its appealing interpretation, limited research has been conducted to evaluate principal surrogates, and existing methods focus on risk models that consider a single biomarker. How to compare principal surrogate value of biomarkers or general risk models that consider multiple biomarkers remains an open research question. We propose to characterize a marker or risk model’s principal surrogate value based on the distribution of risk difference between interventions. In addition, we propose a novel summary measure (the standardized total gain) that can be used to compare markers and to assess the incremental value of a new marker. We develop a semiparametric estimated‐likelihood method to estimate the joint surrogate value of multiple biomarkers. This method accommodates two‐phase sampling of biomarkers and is more widely applicable than existing nonparametric methods by incorporating continuous baseline covariates to predict the biomarker(s), and is more robust than existing parametric methods by leaving the error distribution of markers unspecified. The methodology is illustrated using a simulated example set and a real data set in the context of HIV vaccine trials.
Cooperative spectrum sensing for cognitive radios using jointly adaptive FRESH filters

In this paper, the problem of cooperative spectrum sensing of cyclostationary signals for cognitive radios is considered. It has been shown that the MMSE optimal filters for cyclostationary signals involve one or more frequency shift branches and are called FRESH (FREquency SHift) filters. Adaptive FRESH filters have been used in the past to enhance cyclostationary signals so as to ease their detection in AWGN channels. It has been observed that space time FRESH filtering leads to gains of up to 10 dB over a standard energy detector in a single user case. In this paper, it is proposed to extend this approach to a cooperative setting under fading channels resulting in gains of up to 3 dB over the standard energy detectors. Following this, the problem of joint adaptation of weights at different sensors is considered. It is seen via simulation that joint adaptation leads to additional gains of nearly 2 dB for a flat fading channel and 1 dB for a dispersive channel, in comparison to local adaptation schemes.
A model-based Bayesian framework for ECG beat segmentation

The study of electrocardiogram (ECG) waveform amplitudes, timings and patterns has been the subject of intense research, for it provides a deep insight into the diagnostic features of the heart's functionality. In some recent works, a Bayesian filtering paradigm has been proposed for denoising and compression of ECG signals. In this paper, it is shown that this framework may be effectively used for ECG beat segmentation and extraction of fiducial points. Analytic expressions for the determination of points and intervals are derived and evaluated on various real ECG signals. Simulation results show that the method can contribute to and enhance the clinical ECG beat segmentation performance.
The Impact of the Number and the Familiarity of Alliance Formations on a Firm's Performance: The Case of the Korean Telecommunications Industry

Most managers face a decision as to whether to increase the number of alliances they form or not and which type of partners they should select. This paper investigates the impact of the number of alliance formations and the degree of familiarity in alliances on a firm's economic performance in the Korean telecommunications industry. The empirical results show that grow in the overall number of alliance formations negatively influences the firm's performance. This result is mainly due to the fact that the Korean telecommunications industry has become saturated, and therefore the potential benefit from the alliance is limited. However, greater familiarity in emergent alliances has positive effects on performance. This implies that an alliance related to the reduction of transaction costs through the company's existing resources and governance capability tends to make a direct contribution to performance by generating effective synergies.
Field-induced interplanar magnetic correlations in the high-temperature superconductor La1.88Sr0.12CuO4

We present neutron scattering studies of the inter-planar correlations in the high-temperature superconductor La1.88Sr0. 12CuO4 (T_c=27 K). The correlations are studied both in a magnetic field applied perpendicular to the CuO2 planes, and in zero field under different cooling conditions. We find that the effect of the magnetic field is to increase the magnetic scattering signal at all values of the out-of-plane wave vector L, indicating an overall increase of the magnetic moments. In addition, weak correlations between the copper oxide planes develop in the presence of a magnetic field. This effect is not taken into account in previous reports on the field effect of magnetic scattering, since usually only L~0 is probed. Interestingly, the results of quench-cooling the sample are similar to those obtained by applying a magnetic field. Finally, a small variation of the incommensurate peak position as a function of L provides evidence that the incommensurate signal is twinned with the dominating and sub-dominant twin displaying peaks at even or odd L, respectively.
Corporate Social Responsibility, Corporate Governance, and Managerial Risk-Taking

This paper investigates the association between corporate social responsibility (CSR) and managerial risk-taking, as well as the differences in governance structure that affect this association. Using a sample of US public firms, we find that firms with strong CSR records engage in higher risk-taking. Furthermore, we find that accounting for differences in governance structure substantially accentuates this relationship. Prior literature establishes that high managerial risk-tolerance is necessary for the undertaking of risky yet profitable investment decisions. Thus, these findings suggest that CSR, rather than being a waste of scarce corporate resources, is instead an important aspect of shareholder value creation. They contribute to the debate on CSR by documenting that corporate risk-taking is one mechanism among others through which CSR maps into higher firm value.
Point-of-care ultrasonography for the diagnosis of acute cardiogenic pulmonary edema in patients presenting with acute dyspnea: a systematic review and meta-analysis.

OBJECTIVES Acute dyspnea is a common presenting complaint to the emergency department (ED), and point-of-care (POC) lung ultrasound (US) has shown promise as a diagnostic tool in this setting. The primary objective of this systematic review was to determine the sensitivity and specificity of US using B-lines in diagnosing acute cardiogenic pulmonary edema (ACPE) in patients presenting to the ED with acute dyspnea. METHODS A systematic review protocol adhering to Cochrane Handbook guidelines was created to guide the search and analysis, and we searched the following databases: PubMed, EMBASE, Ovid MEDLINE, Ovid MEDLINE In-Process & Other Non-Indexed Citations, and the Cochrane Database of Systematic Reviews. References of reviewed articles were hand-searched, and electronic searches of conference abstracts from major emergency medicine, cardiology, and critical care conferences were conducted. The authors included prospective cohort and prospective case-control studies that recruited patients presenting to hospital with symptomatic, acute dyspnea, or where there was a clinical suspicion of congestive heart failure, and reported the sensitivity and specificity of B-lines in diagnosing ACPE. Studies of asymptomatic individuals or in patients where there was no suspicion of ACPE were excluded. The outcome of interest was a diagnosis of ACPE using US B-lines. A final diagnosis from clinical follow-up was accepted as the reference standard. Two reviewers independently reviewed all citations to assess for inclusion, abstracted data, and assessed included studies for methodologic quality using the QUADAS-2 tool. Contingency tables were used to calculate sensitivity and specificity. Three subgroup analyses were planned a priori to examine the effects of the type of study, patient population, and lung US protocol employed. RESULTS Seven articles (n = 1,075) were identified that met inclusion criteria (two studies completed in the ED, two in the intensive care unit [ICU], two on inpatient wards, and one in the prehospital setting). The seven studies were rated as average to excellent methodologic quality. The sensitivity of US using B-lines to diagnosis ACPE is 94.1% (95% confidence interval [CI] = 81.3% to 98.3%) and the specificity is 92.4% (95% CI = 84.2% to 96.4%). Preplanned subgroup analyses did not reveal statistically significant changes in the overall summary estimates, nor did exclusion of three potential outlier studies. CONCLUSIONS This study suggests that in patients with a moderate to high pretest probability for ACPE, an US study showing B-lines can be used to strengthen an emergency physician's working diagnosis of ACPE. In patients with a low pretest probability for ACPE, a negative US study can almost exclude the possibility of ACPE. Further studies including large numbers of ED patients presenting with undifferentiated dyspnea are required to gain more valid and reliable estimates of test accuracy in ED patients.
Some benefits and limitations of binaural cochlear implants and our ability to measure them

We review new recognition and localization skills in patients using one or two cochlear implant(s). We observed one unilateral patient who showed localization performance above chance. We also provide evidence for binaural processing in bilateral cochlear implant patients, even when tested with speech from the front without noise. We unsuccessfully attempted to find correlations between localization and squelch, between these variables and pre-implant threshold differences, or these variables and post-implant recognition differences. We strongly believe that new tests are needed to examine the potential benefit of two implants. We describe three tests that we use to show a binaural advantage: cued recognition, movement direction, and recognition with multiple jammers.
Welfare reform, precarity and the re-commodification of labour

While welfare reform matters for workers and workplaces, it is peripheral in English-language sociology of work and industrial relations research. This article’s core proposition is that active labour market policies (ALMPs) are altering the institutional constitution of the labour market by intensifying market discipline within the workforce. This re-commodification effect is specified drawing on Marxism, comparative institutionalism, German-language sociology and English-language social policy analysis. Because of administrative failure and employer discrimination, however, ALMPs may worsen precarity without achieving the stated goal of increasing labour market participation.
Board Attributes and Performance of Non-Banking Financial Institutions in Bangladesh: An Empirical Study

This paper examines the relationship between board of directors, an important corporate governance instrument, and performance of non-bank financial institutions in Bangladesh. Based on the economic perspective of agency theory, this research develops hypotheses to explain the board-performance relationship. With the 40 firm-year observations, this study conducts regression analysis to investigate the relationship. Results show the positive but least significant impact of board independence on firm performance. However, the associations of other board attributes with performance measures are insignificant which indicates the lack of effectiveness of board as a corporate governance mechanism to protect shareholders’ interests. Empirical findings of the study contribute in the scarce literature related to corporate governance in financial institutions, and these have important policy implications to public and private policy makers to formulate appropriate corporate governance framework.
Case for active physician involvement in US practice.

PURPOSE To assess the benefit of active physician involvement in ultrasound (US) examinations. MATERIALS AND METHODS Concordance of findings by technologists and physicians was assessed prospectively for examinations of 1,510 consecutive patients who underwent US during regular working hours. RESULTS Overall concordance was generally good (74%). However, in cases in which a major or minor new diagnosis was made from the US scan, concordance rates were substantially lower (36% and 32%, respectively). Agreement varied with the type of examination. The discordance rate for obstetric examinations (17%) was only half that for abdominal and pelvic examinations (31%). Concordance improved with increasing years of experience of the technologist. CONCLUSION An active role of physicians in the overall conduct of US examinations is essential to optimize provision of a complete, accurate report.
Canadian market reaction to dividend omission and resumption announcements

This study examines share price reaction and changes in beta and trading activity surrounding announcements of dividend omissions and resumptions made by Canadian corporations. Significant negative abnormal returns are identified for a three-day announcement period. No significant shift in beta is found. The abnormal returns are not related to corporate size or to the size of the dividend changes. Dividend omission announcements generate changes in trading value. When the dividend omission sample is split into two subgroups according to the subsequent dividend policies of the corporations, the market model CAR are comparable and insignificantly different from each other. Dividend resumption announcements are not followed by significant changes in share price, beta or trading activity. All reported findings are robust to various estimation biases.
Association of cumulus–oocyte complexes with the intrafollicular levels of a blood proten in Bubalus bubalis

Summary The protein pattern of the follicular fluid (FF) and the ultrastructure of the inner cumulus–oocyte complex (COC) has been analysed in single antral follicles (n = 146) of buffalo B. Bubalis ovaries. The protein population of FF was fractionated by SDS-PAGE; the resulting pattern was Coomassie stained and processed for densitometry. Comparartive analysis of sera and autologous FFs showed a marked difference in the level (measured as the percentage of total proteins) of one 21 kDa polypeptide band, called ‘L’. Concentration of L, which was mainly higher in the serum (2.05 ± 1.5%) than in the surrounding FF(0.98 ± 0.94%), fluctuated widely in fluids from the in the same ovary. On gel filtration of FF and SDS-PAGE of ther factions collected, the L polypeptide was found and eluted together with a 36 kDa polypeptide, called ‘H’, with an exclusion volume lower than that of albumin. The levels of both polypeptides in the eluted fractions were measured by gel densitometry and the same ratio H/L was found (2:1). These data suggest that H and L are subunits of a complex high-molecular-weight protein. The presence of L levels in male sera comparable to those detected in females indicates that this putative protein does not originate in the ovary but is transported from the blood. Moreover, a correlation between the increase in the percentage of Lf (calculated as %L in FF/%L in serum) and atresia was observed. COCs (n = 86) obtained during the collection of the single FF samples were processed for transmission electron microscopy. The ultrastructure of each COC was compared with the SDS-PAGE data of the associated FF. Healthy COCs were found to be related to very low levels of Lf (between 0 and 14% of those measured in serum). COCs with an early atretic ultrastructure undetectable at the dissection microscope, were associated with FFs having Lf levels between 24% and 60%; advanced atresia was associated with Lf values up to 70%. Finally, the acrosome reaction of buffalo precapacitated spermatozoa in vitro was monitored by adding one volume of FF with high (FF +; Lf = 80%) or undetectable (FF - ) values of Lf to the sperm suspension. It was found that 96.2% of spermatozoa treated with FF - showed a normal acrosome reaction, without any change in their motility pattern; spermatozoa treated with FF +, in contrast, exhibited poor motility, and only 66.4% of them underwent the acrosome reaction. The ionophore A23187, in a control experiment, resulted in lower percentages of acrosome reactions (38%). In conclusion, our results suggest that enhanced influx of L from serum into the follicle antrum causes an increase in the polypeptide level in FF. This might be due to a loss of selectivity in the blood-follicle barrier of early atretic follicles. The use of the L polypeptide as a biochemical marker for identifying the earlier stage of follicular atresia is proposed.
INTRAVITREAL RANIBIZUMAB FOR POLYPOIDAL CHOROIDAL VASCULOPATHY IN NON-ASIAN PATIENTS

Purpose: To determine safety, tolerability, and efficacy of intravitreal ranibizumab in the treatment of polypoidal choroidal vasculopathy in a non-Asian population. Methods: Phase I/II, prospective, open-label, single-center, nonrandomized, uncontrolled, consecutive, interventional case series of 20 eyes in 19 patients with exudative active polypoidal choroidal vasculopathy. Eyes received 3 monthly intravitreal ranibizumab injections (0.3 or 0.5 mg), with additional ranibizumab injections, observation, or alternative treatments at investigators' discretion, through 24 months. Main outcome measures were ocular and systemic safety and mean change from baseline in best-corrected visual acuity and center point thickness. Results: Visually significant ocular adverse events included cataract progression (n = 3), mild vitreous hemorrhage (n = 2), and macular hole (n = 1). No systemic drug-related adverse events were observed. Mean baseline best-corrected visual acuity was 20/127 (range, 20/16–20/500) and center point thickness was 298 &mgr;m. Mean best-corrected visual acuity increased from baseline by 1.2 Snellen lines at 12 months and 24 months. Mean center point thickness decreased by 53 &mgr;m and 67 &mgr;m from baseline at 12 months and 24 months, respectively. Conclusion: Intravitreal ranibizumab was well tolerated in non-Asian patients with polypoidal choroidal vasculopathy; the majority of eyes experienced improvements in best-corrected visual acuity and center point thickness after ranibizumab treatment.
Demographic and clinical parameters of patients with high risk behavior in a general hospital: the use of constant observation.

BACKGROUND General hospital staff are often required to care for physically ill patients who arouse concern regarding risk of harm to themselves or others. Some of these patients,will be placed under one-to-one "constant observation. " This is the first Israeli study of general hospital patients with high risk behavior. OBJECTIVES To examine a population of general hospital patients whose behavioral management required the use of constant observation. Demographic and clinical parameters including physical diagnoses were examined, and risk factors for constant observation were identified. The findings of this study were compared to those of previous studies. METHODS This prospective observational study examined 714 inpatients referred for psychiatric consultation; 150 were found to require constant observation, and 156 who did not served as a control group. RESULTS In this study younger age, suicidal concerns and alcohol/substance abuse were identified as risk factors for ordering constant observation. Ischemic heart disease and chronic obstructive pulmonary disease were the only physical diagnoses found to be significantly correlated with a longer duration of observation, regardless of admission duration. Constant observation was less frequently used in the management of organic brain syndrome patients in this study compared to other studies. CONCLUSIONS Some of our results (predictive factors for constant observation) confirmed the findings of overseas studies. Our finding that a diagnosis of organic brain syndrome was not a predictive factor for constant observation was unexpected and requires further investigation. The correlation between a diagnosis of ischemic heart disease or COPD and duration of observation has not been reported previously and warrants further studies.
Inhibition of glycogenolysis in astrocytes interrupts memory consolidation in young chickens

Glycolysis and glycogenolysis are involved in memory processing in day‐old chickens and, aside from the provision of energy for neuronal and astrocytic energy metabolism these pathways enable astrocytes to supply neurones with precursor for transmitter glutamate by glucose‐based de novo synthesis. We have previously shown that memory processing for bead discrimination learning is dependent on glycolysis; however, the metabolic inhibitor used, iodoacetate, inhibits pyruvate formation from both glucose and glycogen. At specific time points after training transient reductions in brain glycogen content occur, mirrored by increases in glutamate/glutamine content. In the present study, we used intracerebral injection of a glycogen phosphorylase inhibitor, 1,4‐dideoxy‐1,4‐imino‐D‐arabinitol (DAB), which does not affect glucose breakdown, to evaluate the role of glycogen metabolism in memory consolidation. Dose‐dependent inhibition of learning occurred when DAB was administered at specific time periods in relation to training: (i) 5 min before training, (ii) around 30 min posttraining, and (iii) 55 min posttraining. After injection at either of the two earlier periods, memory disappeared after consolidation 30 min postlearning, and after injection 55 min after learning memory was absent at 70 min. The memory loss caused by early administration could be prevented after training by central injection of the glutamate precursor glutamine or the astrocyte‐specific substrate acetate together with aspartate, substituting for pyruvate carboxylation. Thus, glycogenolysis is essential for learning in this paradigm and, aside from energy supply considerations, we suggest that an important role for glycogenolysis is to provide neurones with glutamine as the precursor for neuronal glutamate and GABA. © 2006 Wiley‐Liss, Inc.
Do Institutional Investors Destabilize Stock Prices? Evidence on Herding and Feedback Trading

This paper uses a new data set of quarterly portfolio holdings of 769 all-equity pension funds between 1985 and 1989 to evaluate the potential effect of their trading on stock prices. We address two aspects of trading by money managers: herding, which refers to buying (selling) the same stocks as other managers buy (sell) at the same time; and positive-feedback trading, which refers to buying winners and selling losers. These two aspects of trading are commonly a part of the argument that institutions destabilize stock prices. At the level of individual stocks at quarterly frequencies, we find no evidence of substantial herding or positive-feedback trading by pension fund managers, except in small stocks. Also, there is no strong cross-sectional correlation between changes in pension funds' holdings of a stock and its abnormal return.
The Relevance of External Credit Ratings in the Capital Structure Decision-Making Process

This paper empirically examines the relevance of external credit ratings in the capital structure decision-making process with regard to an international firm sample. Using the rating outlook to measure the imminence of a rating change, allows us to test managers’ ex-ante capital structure behavior more concisely than prior studies have. The results show that companies near a rating change issue 1.8% less net debt relative to net equity as a percentage of total assets than firms not near a rating change. We find that the effect is economically larger for US firms and also if access to the commercial paper market is at risk.