Fisher-information condition for enhanced signal detection via stochastic resonance

Various situations where a signal is enhanced by noise through stochastic resonance are now known. This paper contributes to determining general conditions under which improvement by noise can be a priori decided as feasible or not. We focus on the detection of a known signal in additive white noise. Under the assumptions of a weak signal and a sufficiently large sample size, it is proved, with an inequality based on the Fisher information, that improvement by adding noise is never possible, generically, in these conditions. However, under less restrictive conditions, an example of signal detection is shown with favorable action of adding noise.Fabing Duan, François Chapeau-Blondeau, Derek Abbot

Endoscopic endonasal management of recurrent petrous apex cholesterol granuloma.

Petrous apex cholesterol granulomas (PACG) are uncommon lesions. Recurrence following transcranial or endonasal approaches to aerate the cyst occurs in up to 60% of cases. We describe the technical nuances pertinent to the endonasal endoscopic management of a recurrent symptomatic PACG and review the literature. A 19-year-old woman presented with a recurrent right abducens nerve paresis. Four months prior, she underwent an endonasal transsphenoidal surgery (TSS) for drainage of a symptomatic PACG. Current imaging documented recurrence of the right PACG. Transsphenoidal and infrapetrous approaches were performed to obtain a wider bony opening along the petrous apex and drain the cyst. A Doyle splint was inserted into the cyst's cavity and extended out into the sphenoid, maintaining patency during the healing process. Three months after surgery, the splint was removed endoscopically, allowing visualization of a patent cylindrical communication between both aerated cavities. The patient remains symptom- and recurrence-free. Endoscopic endonasal surgery must be adapted to manage recurrent PACG. A TSS may not be sufficient. An infrapetrous approach with wider bony opening, extensive removal of the cyst's anterior wall, and use of a stent are indicated for the treatment of recurrent PACG and to prevent recurrences

Sustainable development of smallholder crop-livestock farming in developing countries

Meeting the growing demand for animal-sourced food, prompted by population growth and increases in average per-capita income in low-income countries, is a major challenge. Yet, it also presents significant potential for agricultural growth, economic development, and reduction of poverty in rural areas. The main constraints to livestock producers taking advantage of growing markets include; lack of forage and feed gaps, communal land tenure, limited access to land and water resources, weak institutions, poor infrastructure and environmental degradation. To improve rural livelihood and food security in smallholder crop-livestock farming systems, concurrent work is required to address issues regarding efficiency of production, risk within systems and development of whole value chain systems. This paper provides a review of several forage basedstudies in tropical and non-tropical dry areas of the developing countries. A central tenet of this paper is that forages have an essential role in agricultural productivity, environmental sustainability and livestock nutrition in smallholder mixed farming systems

Endobronchial Tuberculosis: A Rare Presentation

Endobronchial tuberculosis (EBTB) is an infection of the tracheobronchial tree by Mycobacterium tuberculosis. It is common among young females. Patient can present with fever, cough, wheeze, with or without any constitutional symptoms. It presents as a diagnostic dilemma, as patient sputum smear can be false negative. CT scan may or may not show any abnormality, or any endobronchial lesion. Bronchoscopy with bronchoalveolar lavage and biopsy offers the diagnostic choice. We hereby report a case of a young immunocompetent Asian female who was found to have endobronchial pathology, leading to diagnosis and timely therapy

Determination Of Appropriate Clomipramine Dosage Among Depressed African Outpatients In Dar Es Salaam, Tanzania

A CAJM article on the appropriate clomipramine dosage among depressed African outpatients in Dar es Salaam, Tanzania.Ethnic and racial factors have been implicated as determinants to the outcome of psychotropic medication. Ethnic differences in response to such medication affects dosage requirements and risk of potential side effects. Looking specifically at antidepressant medication, significantly lower treatment and maintenance dosage requirements have been noted in Orientals when compared to Occidentals. Patients were noted to respond equally to antidepressants regardless of the dosage chosen in Asia and other developing countries as opposed to the Occident where higher doses were effective

Seriously Injured Urban Black Men’s Perceptions of Clinical Research Participation

Purpose: Black men are uniquely vulnerable in American society and our health care system: they bear a disproportionate burden of injury, yet are underrepresented in clinical research. This study aimed to explore the reasons why urban Black men with serious injuries chose to participate in clinical research and their concerns about research participation. Methods: This qualitative study was conducted within the context of a larger study focused on psychological effects of serious injury in urban Black men; 83 Black men with serious injuries were recruited while hospitalized in an urban trauma center. Informed consent was obtained. Semi-structured interviews were conducted in participants’ homes three months after discharge from the hospital and were audiotaped, transcribed, and de-identified. Thematic content analysis was used to identify themes about perceptions of participating in clinical research. Results: The mean age of our sample was 38.2 years, and the mean injury severity score was 10.7 (SD 9.6). The majority (53.2 %) of injuries was due to interpersonal violence, and 47 % were due to unintentional mechanisms. Eight reasons for research participation emerged from the data: human connection, altruism/community, self-improvement, compensation, gaining knowledge, curiosity/interest, low risk, and reciprocity. Conclusions: A major finding was that injured urban Black men participated in clinical research for the opportunity for human and therapeutic connection. Despite some expressions of mistrust, participants were willing to participate for altruistic reasons rooted in community priorities, and as part of their recovery process post-injury

Seriously Injured Urban Black Men’s Perceptions of Clinical Research Participation

Purpose: Black men are uniquely vulnerable in American society and our health care system: they bear a disproportionate burden of injury, yet are underrepresented in clinical research. This study aimed to explore the reasons why urban Black men with serious injuries chose to participate in clinical research and their concerns about research participation. Methods: This qualitative study was conducted within the context of a larger study focused on psychological effects of serious injury in urban Black men; 83 Black men with serious injuries were recruited while hospitalized in an urban trauma center. Informed consent was obtained. Semi-structured interviews were conducted in participants’ homes three months after discharge from the hospital and were audiotaped, transcribed, and de-identified. Thematic content analysis was used to identify themes about perceptions of participating in clinical research. Results: The mean age of our sample was 38.2 years, and the mean injury severity score was 10.7 (SD 9.6). The majority (53.2 %) of injuries was due to interpersonal violence, and 47 % were due to unintentional mechanisms. Eight reasons for research participation emerged from the data: human connection, altruism/community, self-improvement, compensation, gaining knowledge, curiosity/interest, low risk, and reciprocity. Conclusions: A major finding was that injured urban Black men participated in clinical research for the opportunity for human and therapeutic connection. Despite some expressions of mistrust, participants were willing to participate for altruistic reasons rooted in community priorities, and as part of their recovery process post-injury

Rethinking energy security and services in practice: national vulnerability and three energy pathways in Tajikistan

To help answer questions about availability, accessibility, sustainability and other dimensions of energy security, the vulnerability approach concentrates the attention of policymakers on the assessment of risks associated with natural, technical, political and economic factors. This understanding, combined with a focus on energy services (e.g. lighting, heating, telecommunications, mobility, etc.) helps to prioritize actions to achieve the goal of energy security. This paper conceptualizes energy security as low vulnerability of vital energy systems and sustained provision of modern energy services. Taking Tajikistan as a case, this paper highlights key vulnerabilities including neglect of environmental conditions, insufficient energy production capacity, unreliable and expensive energy imports, dwindling power infrastructure causing technical and economic losses, inadequate transparency in the power sector, lack of regional cooperation in energy and water resources sharing, and inadequate financial resources to address these challenges. Three major proposals presented by the World Bank, the United Nations Development Program, and the Government of Tajikistan to achieve energy security in Tajikistan are evaluated. Specifically, they lack a focus on energy services and therefore overlook people's socio-cultural context and appropriate energy needs. This paper highlights energy services as critical to people’s wellbeing and socio-economic development

Application of the Gaussian mixture model in pulsar astronomy -- pulsar classification and candidates ranking for {\it Fermi} 2FGL catalog

Machine learning, algorithms to extract empirical knowledge from data, can be used to classify data, which is one of the most common tasks in observational astronomy. In this paper, we focus on Bayesian data classification algorithms using the Gaussian mixture model and show two applications in pulsar astronomy. After reviewing the Gaussian mixture model and the related Expectation-Maximization algorithm, we present a data classification method using the Neyman-Pearson test. To demonstrate the method, we apply the algorithm to two classification problems. Firstly, it is applied to the well known period-period derivative diagram, where we find that the pulsar distribution can be modeled with six Gaussian clusters, with two clusters for millisecond pulsars (recycled pulsars) and the rest for normal pulsars. From this distribution, we derive an empirical definition for millisecond pulsars as $\frac{\dot{P}}{10^{-17}} \leq3.23(\frac{P}{100 \textrm{ms}})^{-2.34}$. The two millisecond pulsar clusters may have different evolutionary origins, since the companion stars to these pulsars in the two clusters show different chemical composition. Four clusters are found for normal pulsars. Possible implications for these clusters are also discussed. Our second example is to calculate the likelihood of unidentified \textit{Fermi} point sources being pulsars and rank them accordingly. In the ranked point source list, the top 5% sources contain 50% known pulsars, the top 50% contain 99% known pulsars, and no known active galaxy (the other major population) appears in the top 6%. Such a ranked list can be used to help the future follow-up observations for finding pulsars in unidentified \textit{Fermi} point sources.Comment: 9 pages, 4 figures, accepted by MNRA