214 research outputs found
On the Strategic Use of Debt and Capacity in Imperfectly Competitive Product Markets
In capital intensive industries, firms face complicated multi-stage financing, investment, and production decisions under the watchful eye of existing and potential industry rivals. We consider a two-stage simplification of this environment. In the first stage, an incumbent firm benefits from two first-mover advantages by precommiting to a debt financing policy and a capacity investment policy. In the second stage, the incumbent and a single-stage rival simultaneously choose production levels and realize stochastic profits. We characterize the incumbent's first-stage debt and capacity choices as factors in the production of an intermediate good we call "output deterrence." In our two-factor deterrence model, we show that the incumbent chooses a unique capacity policy and a threshold debt policy to achieve the optimal level of deterrence coinciding with full Stackelberg leadership. When we remove the incumbent's first-mover advantage in capacity, the full Stackelberg level of deterrence is still achievable, albeit with a higher level of debt than the threshold. In contrast, when we remove the incumbent's first-mover advantage in debt, the Stackelberg level of deterrence may no longer be achievable and the incumbent may suffer a dead-weight loss. Evidence on the telecommunications industry shows that firms have increased their leverage in a manner consistent with deterring potential rivals following the 1996 deregulation.Industrial organization; Deregulation; Deterrence; Capital structure; Capacity; Telecommunications
Crisis and Non-Crisis Short Selling and Bank Enforcement Actions
Employing standard informed trading intuition, we develop testable hypotheses regarding short selling before and after bank enforcement action (EA) initiations. For U.S.-listed bank firm data for 2007 to 2012, we find strong support for differentiated short seller activity and skill in crisis versus non-crisis periods. In financial crises, short sellers predominantly position prior to EAs. The EA initiations then act as information-homogenizing and profit-taking events reducing incentives to remain positioned. In contrast, EAs in non-crisis periods appear to serve as wake-up calls that attract additional short selling. Our findings offer potentially important insights for regulators considering short sellers’ reactions to EA announcements in general, during financial crises, and when not experiencing a broad financial crisis
Automated prediction of mastitis infection patterns in dairy herds using machine learning
© 2020, The Author(s). Mastitis in dairy cattle is extremely costly both in economic and welfare terms and is one of the most significant drivers of antimicrobial usage in dairy cattle. A critical step in the prevention of mastitis is the diagnosis of the predominant route of transmission of pathogens into either contagious (CONT) or environmental (ENV), with environmental being further subdivided as transmission during either the nonlactating “dry” period (EDP) or lactating period (EL). Using data from 1000 farms, random forest algorithms were able to replicate the complex herd level diagnoses made by specialist veterinary clinicians with a high degree of accuracy. An accuracy of 98%, positive predictive value (PPV) of 86% and negative predictive value (NPV) of 99% was achieved for the diagnosis of CONT vs ENV (with CONT as a “positive” diagnosis), and an accuracy of 78%, PPV of 76% and NPV of 81% for the diagnosis of EDP vs EL (with EDP as a “positive” diagnosis). An accurate, automated mastitis diagnosis tool has great potential to aid non-specialist veterinary clinicians to make a rapid herd level diagnosis and promptly implement appropriate control measures for an extremely damaging disease in terms of animal health, productivity, welfare and antimicrobial use
A mixed-method investigation of patient monitoring and enhanced feedback in routine practice: Barriers and facilitators
Objective: To investigate the barriers and facilitators of an effective implementation of an outcome monitoring and feedback system in a UK National Health Service psychological therapy service. Method: An outcome monitoring system was introduced in two services. Enhanced feedback was given to therapists after session 4. Qualitative and quantitative methods were used, including questionnaires for therapists and patients. Thematic analysis was carried out on written and verbal feedback from therapists. Analysis of patient outcomes for 202 episodes of therapy was compared with benchmark data of 136 episodes of therapy for which feedback was not given to therapists. Results: Themes influencing the feasibility and acceptability of the feedback system were the extent to which therapists integrated the measures and feedback into the therapy, availability of administrative support, information technology, and complexity of the service. There were low levels of therapist actions resulting from the feedback, including discussing the feedback in supervision and with patients. Conclusions: The findings support the feasibility and acceptability of setting up a routine system in a complex service, but a number of challenges and barriers have to be overcome and therapist differences are apparent. More research on implementation and effectiveness is needed in diverse clinical settings
Leukocyte telomere length and left ventricular function after acute ST-elevation myocardial infarction:data from the glycometabolic intervention as adjunct to primary coronary intervention in ST elevation myocardial infarction (GIPS-III) trial
Background Telomere length has been associated with coronary artery disease and heart failure. We studied whether leukocyte telomere length is associated with left ventricular ejection fraction (LVEF) after ST-elevation myocardial infarction (STEMI). Methods and results Leukocyte telomere length (LTL) was determined using the monochrome multiplex quantitative PCR method in 353 patients participating in the glycometabolic intervention as adjunct to primary percutaneous coronary intervention in STEMI III trial. LVEF was assessed by magnetic resonance imaging. The mean age of patients was 58.9 +/- A 11.6 years, 75 % were male. In age- and gender-adjusted models, LTL at baseline was significantly associated with age (beta +/- A standard error; -0.33 +/- A 0.01; P <0.01), gender (0.15 +/- A 0.03; P <0.01), TIMI flow pre-PCI (0.05 +/- A 0.03; P <0.01), TIMI flow post-PCI (0.03 +/- A 0.04; P <0.01), myocardial blush grade (-0.05 +/- A 0.07; P <0.01), serum glucose levels (-0.11 +/- A 0.01; P = 0.03), and total leukocyte count (-0.11 +/- A 0.01; P = 0.04). At 4 months after STEMI, LVEF was well preserved (54.1 +/- A 8.4 %) and was not associated with baseline LTL (P = 0.95). Baseline LTL was associated with n-terminal pro-brain natriuretic peptide (NT-proBNP) at 4 months (-0.14 +/- A 0.01; P = 0.02), albeit not independent for age and gender. Conclusion Our study does not support a role for LTL as a causal factor related to left ventricular ejection fraction after STEMI
Clinical, radiologic, pathologic, and molecular characteristics of long-term survivors of diffuse intrinsic pontine glioma (DIPG): a collaborative report from the International and European Society for Pediatric Oncology DIPG registries
Purpose Diffuse intrinsic pontine glioma (DIPG) is a brainstem malignancy with a median survival of < 1 year. The International and European Society for Pediatric Oncology DIPG Registries collaborated to compare clinical, radiologic, and histomolecular characteristics between short-term survivors (STSs) and long-term survivors (LTSs). Materials and Methods Data abstracted from registry databases included patients from North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the United Kingdom, and Croatia. Results Among 1,130 pediatric and young adults with radiographically confirmed DIPG, 122 (11%) were excluded. Of the 1,008 remaining patients, 101 (10%) were LTSs (survival ≥ 2 years). Median survival time was 11 months (interquartile range, 7.5 to 16 months), and 1-, 2-, 3-, 4-, and 5-year survival rates were 42.3% (95% CI, 38.1% to 44.1%), 9.6% (95% CI, 7.8% to 11.3%), 4.3% (95% CI, 3.2% to 5.8%), 3.2% (95% CI, 2.4% to 4.6%), and 2.2% (95% CI, 1.4% to 3.4%), respectively. LTSs, compared with STSs, more commonly presented at age < 3 or > 10 years (11% v 3% and 33% v 23%, respectively; P < .001) and with longer symptom duration ( P < .001). STSs, compared with LTSs, more commonly presented with cranial nerve palsy (83% v 73%, respectively; P = .008), ring enhancement (38% v 23%, respectively; P = .007), necrosis (42% v 26%, respectively; P = .009), and extrapontine extension (92% v 86%, respectively; P = .04). LTSs more commonly received systemic therapy at diagnosis (88% v 75% for STSs; P = .005). Biopsies and autopsies were performed in 299 patients (30%) and 77 patients (10%), respectively; 181 tumors (48%) were molecularly characterized. LTSs were more likely to harbor a HIST1H3B mutation (odds ratio, 1.28; 95% CI, 1.1 to 1.5; P = .002). Conclusion We report clinical, radiologic, and molecular factors that correlate with survival in children and young adults with DIPG, which are important for risk stratification in future clinical trials
Efficacy of RTS,S/AS01E vaccine against malaria in children 5 to 17 months of age.
BACKGROUND: Plasmodium falciparum malaria is a pressing global health problem. A previous study of the malaria vaccine RTS,S (which targets the circumsporozoite protein), given with an adjuvant system (AS02A), showed a 30% rate of protection against clinical malaria in children 1 to 4 years of age. We evaluated the efficacy of RTS,S given with a more immunogenic adjuvant system (AS01E) in children 5 to 17 months of age, a target population for vaccine licensure. METHODS: We conducted a double-blind, randomized trial of RTS,S/AS01E vaccine as compared with rabies vaccine in children in Kilifi, Kenya, and Korogwe, Tanzania. The primary end point was fever with a falciparum parasitemia density of more than 2500 parasites per microliter, and the mean duration of follow-up was 7.9 months (range, 4.5 to 10.5). RESULTS: A total of 894 children were randomly assigned to receive the RTS,S/AS01E vaccine or the control (rabies) vaccine. Among the 809 children who completed the study procedures according to the protocol, the cumulative number in whom clinical malaria developed was 32 of 402 assigned to receive RTS,S/AS01E and 66 of 407 assigned to receive the rabies vaccine; the adjusted efficacy rate for RTS,S/AS01E was 53% (95% confidence interval [CI], 28 to 69; P<0.001) on the basis of Cox regression. Overall, there were 38 episodes of clinical malaria among recipients of RTS,S/AS01E, as compared with 86 episodes among recipients of the rabies vaccine, with an adjusted rate of efficacy against all malarial episodes of 56% (95% CI, 31 to 72; P<0.001). All 894 children were included in the intention-to-treat analysis, which showed an unadjusted efficacy rate of 49% (95% CI, 26 to 65; P<0.001). There were fewer serious adverse events among recipients of RTS,S/AS01E, and this reduction was not only due to a difference in the number of admissions directly attributable to malaria. CONCLUSIONS: RTS,S/AS01E shows promise as a candidate malaria vaccine. (ClinicalTrials.gov number, NCT00380393.
The Australia Telescope 20GHz Survey: Hardware, Observing Strategy, and Scanning Survey Catalog
The Australia Telescope 20GHz (AT20G) survey is a large area (2{\pi} sr),
sensitive (40mJy), high frequency (20GHz) survey of the southern sky. The
survey was conducted in two parts: an initial fast scanning survey, and a
series of more accurate follow-up observations. The follow-up survey catalog
has been presented by Murphy et al. 2010. In this paper we discuss the hardware
setup and scanning survey strategy as well as the production of the scanning
survey catalog.Comment: 32 pages, 20 figures, accepted for publication in experimental
astronom
Developing a collaborative agenda for humanities and social scientific research on laboratory animal science and welfare.
Improving laboratory animal science and welfare requires both new scientific research and insights from enquiry in the humanities and social sciences. Whilst scientific research provides evidence to replace, reduce and refine procedures involving laboratory animals (the ‘3Rs’), work in the humanities and social sciences can help understand the social, economic and cultural processes that enhance or impede humane ways of knowing and working with laboratory animals. However, communication across these disciplinary perspectives is currently limited, and they frame questions, generate results, engage users, and seek to influence policy in different ways. To facilitate dialogue and future research at this interface, we convened an interdisciplinary group of 45 life scientists, social scientists, humanities scholars, non-governmental organisations and policy-makers to generate a collaborative research agenda. This drew on other agenda-setting exercises in science policy, using a collaborative and deliberative approach for the identification of research priorities. Participants were recruited from across the community, invited to submit research questions and vote on their priorities. They then met at an interactive workshop in the UK, discussed all 136 questions submitted, and collectively defined the 30 most important issues for the group. The output is a collaborative future agenda for research in the humanities and social sciences on laboratory animal science and welfare. The questions indicate a demand for new research in the humanities and social sciences to inform emerging discussions and priorities on the governance and practice of laboratory animal research, including around: international harmonisation, openness and public engagement, ‘cultures of care’, harm-benefit analysis and the future of the 3Rs. The process underlines the value of interdisciplinary exchange for improving mutual understanding of different research cultures and identifies ways of enhancing the effectiveness of future research at the interface between the humanities, social sciences, science and science policy
Safety of the Malaria Vaccine Candidate, RTS,S/AS01E in 5 to 17 Month Old Kenyan and Tanzanian Children
The malaria vaccine candidate, RTS,S/AS01E, showed promising protective efficacy in a trial of Kenyan and Tanzanian children aged 5 to 17 months. Here we report on the vaccine's safety and tolerability. The experimental design was a Phase 2b, two-centre, double-blind (observer- and participant-blind), randomised (1∶1 ratio) controlled trial. Three doses of study or control (rabies) vaccines were administered intramuscularly at 1 month intervals. Solicited adverse events (AEs) were collected for 7 days after each vaccination. There was surveillance and reporting for unsolicited adverse events for 30 days after each vaccination. Serious adverse events (SAEs) were recorded throughout the study period which lasted for 14 months after dose 1 in Korogwe, Tanzania and an average of 18 months post-dose 1 in Kilifi, Kenya. Blood samples for safety monitoring of haematological, renal and hepatic functions were taken at baseline, 3, 10 and 14 months after dose 1. A total of 894 children received RTS,S/AS01E or rabies vaccine between March and August 2007. Overall, children vaccinated with RTS,S/AS01E had fewer SAEs (51/447) than children in the control group (88/447). One SAE episode in a RTS,S/AS01E recipient and nine episodes among eight rabies vaccine recipients met the criteria for severe malaria. Unsolicited AEs were reported in 78% of subjects in the RTS,S/AS01E group and 74% of subjects in the rabies vaccine group. In both vaccine groups, gastroenteritis and pneumonia were the most frequently reported unsolicited AE. Fever was the most frequently observed solicited AE and was recorded after 11% of RTS,S/AS01E doses compared to 31% of doses of rabies vaccine. The candidate vaccine RTS,S/AS01E showed an acceptable safety profile in children living in a malaria-endemic area in East Africa. More data on the safety of RTS,S/AS01E will become available from the Phase 3 programme
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