404 research outputs found

    Quantum corrections in Higgs inflation: the real scalar case

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    We present a critical discussion of quantum corrections, renormalisation, and the computation of the beta functions and the effective potential in Higgs inflation. In contrast with claims in the literature, we find no evidence for a disagreement between the Jordan and Einstein frames, even at the quantum level. For clarity of discussion we concentrate on the case of a real scalar Higgs. We first review the classical calculation and then discuss the back reaction of gravity. We compute the beta functions for the Higgs quartic coupling and non-minimal coupling constant. Here, the mid-field regime is non-renormalisable, but we are able to give an upper bound on the 1-loop corrections to the effective potential. We show that, in computing the effective potential, the Jordan and Einstein frames are compatible if all mass scales are transformed between the two frames. As such, it is consistent to take a constant cutoff in either the Jordan or Einstein frame, and both prescriptions yield the same result for the effective potential. Our results are extended to the case of a complex scalar Higgs.Comment: 28 pages, 1 figure. v2: minor changes, updated references, published versio

    Nutrient and Microbial Movement from Seasonally-Used Septic Systems

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    Unanswered seasonal vacation communities present unique problems for on-site sewage disposal. Seasonal occupancy may promote the transmission of contaminants to groundwater due to incomplete formation of a biological clogging mat in the soil absorption system. Groundwater surrounding three seasonally-used septic systems was monitored to determine the movement and attenuation of nitrogen, phosphorus and two bacterial indicators of human fecal contamination, fecal coliforms and Clostridium perfringens. Nitrate-N concentrations were often three to four-fold greater than the drinking water standard at wells 6 m from the soil absorption systems. Minimal phosphorus migration occurred from these systems. Although more than 1.5 m of unsaturated soil separated the bottom of the soil absorption system from the groundwater, elevated numbers of both bacterial indicators were observed in groundwater at both 2 m and 6 m away from the absorption systems. Biological clogging mats, which are considered to be critical for even distribution of wastewater within a drainfield, were not ground when the systems were excavated at the end of summer occupancy. Siting seasonally-used shoreline septic systems may require improved effluent distribution to achieve wastewater renovation

    Economic analysis of pandemic influenza mitigation strategies for five pandemic severity categories

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    BACKGROUND: The threat of emergence of a human-to-human transmissible strain of highly pathogenic influenza A(H5N1) is very real, and is reinforced by recent results showing that genetically modified A(H5N1) may be readily transmitted between ferrets. Public health authorities are hesitant in introducing social distancing interventions due to societal disruption and productivity losses. This study estimates the effectiveness and total cost (from a societal perspective, with a lifespan time horizon) of a comprehensive range of social distancing and antiviral drug strategies, under a range of pandemic severity categories. METHODS: An economic analysis was conducted using a simulation model of a community of ~30,000 in Australia. Data from the 2009 pandemic was used to derive relationships between the Case Fatality Rate (CFR) and hospitalization rates for each of five pandemic severity categories, with CFR ranging from 0.1% to 2.5%. RESULTS: For a pandemic with basic reproduction number R(0) = 1.8, adopting no interventions resulted in total costs ranging from 441perpersonforapandemicatcategory1(CFR0.1441 per person for a pandemic at category 1 (CFR 0.1%) to 8,550 per person at category 5 (CFR 2.5%). For severe pandemics of category 3 (CFR 0.75%) and greater, a strategy combining antiviral treatment and prophylaxis, extended school closure and community contact reduction resulted in the lowest total cost of any strategy, costing $1,584 per person at category 5. This strategy was highly effective, reducing the attack rate to 5%. With low severity pandemics costs are dominated by productivity losses due to illness and social distancing interventions, whereas higher severity pandemic costs are dominated by healthcare costs and costs arising from productivity losses due to death. CONCLUSIONS: For pandemics in high severity categories the strategies with the lowest total cost to society involve rigorous, sustained social distancing, which are considered unacceptable for low severity pandemics due to societal disruption and cost

    A Case of Catecholaminergic Polymorphic Ventricular Tachycardia

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    Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial cardiac arrhythmia that is related to RYR2 or CASQ2 gene mutation. It occurs in patients with structurally normal heart and causes exercise-emotion-triggered syncope and sudden cardiac death. We experienced a case of CPVT in an 11 year-old female patient who was admitted for sudden cardiovascular collapse. The initial electrocardiogram (ECG) on emergency department revealed ventricular fibrillation. After multiple defibrillations, sinus rhythm was restored. However, recurrent ventricular fibrillation occurred during insertion of nasogastric tube without sedation in coronary care unit. On ECG monitoring, bidirectional ventricular tachycardia occurred with sinus tachycardia and then degenerated into ventricular fibrillation. To our knowledge, there has been no previous case report of CPVT triggered by sinus tachycardia in Korea. Therefore, we report the case as well as a review of the literature

    A no-go for no-go theorems prohibiting cosmic acceleration in extra dimensional models

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    A four-dimensional effective theory that arises as the low-energy limit of some extra-dimensional model is constrained by the higher dimensional Einstein equations. Steinhardt & Wesley use this to show that accelerated expansion in our four large dimensions can only be transient in a large class of Kaluza-Klein models that satisfy the (higher dimensional) null energy condition [1]. We point out that these no-go theorems are based on a rather ad-hoc assumption on the metric, without which no strong statements can be made.Comment: 20 page

    Population Genetics of Bowhead Whales (Baleana mysticetus) in the Western Arctic

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    Bowhead whales (Balaena mysticetus) in the Bering, Chukchi, and Beaufort seas experienced a severe reduction as a result of commercial whaling in the 19th century. Since the cessation of commercial whaling, the population has recovered to a size that is approaching pre-whaling estimates. Inupiat and Yupik communities in northern and western Alaska hunt these Western Arctic (WA) bowheads along their migratory path during spring and fall. This hunting is regulated by the International Whaling Commission. Recent but preliminary analysis of available genetic data (207 whales and 10 microsatellite markers) raised the question of the presence of multiple, genetically distinct populations within the WA bowheads. Here we re-examined this question on the basis of a study of 414 whales and 22 newly developed microsatellite loci. We identified widespread departures from Hardy-Weinberg equilibrium; however, we were unable to detect significant evidence of multiple genetic populations within the WA bowheads that could explain this Hardy-Weinberg disequilibrium, particularly when compared to the strength of evidence for differentiation between WA bowheads and other populations from distant regions such as the Okhotsk Sea and eastern Canada. There was conclusive evidence of genetic differentiation among the three regions. The statistical rejection of panmixia within the WA improves our understanding of bowhead whale biology, and the lack of evidence for multiple populations within the WA enables risk-averse management of aboriginal hunting of Western Arctic bowhead whales.La population de baleines borĂ©ales (Balaena mysticetus) des mers de BĂ©ring, de Tchoukotka et de Beaufort a enregistrĂ© un grave dĂ©clin en raison de la pĂȘche commerciale Ă  la baleine au XIXe siĂšcle. Depuis que la pĂȘche commerciale Ă  la baleine a cessĂ©, la population de baleines borĂ©ales a connu un certain essor au point oĂč elle approche maintenant les estimations de la taille qu’elle avait avant la pĂȘche commerciale Ă  la baleine. Les collectivitĂ©s Inupiat et Yupik du nord et de l’ouest de l’Alaska chassent les baleines borĂ©ales de l’ouest de l’Arctique le long de leur voie de migration au printemps et Ă  l’automne. La chasse est rĂ©glementĂ©e par l’International Whaling Commission. Des analyses rĂ©centes, bien que prĂ©liminaires, des donnĂ©es gĂ©nĂ©tiques disponibles (207 baleines et 10 marqueurs microsatellites) ont soulevĂ© la question de la prĂ©sence de multiples populations gĂ©nĂ©tiquement distinctes au sein de la population de baleines borĂ©ales de l’ouest de l’Alaska. Ici, nous avons rĂ©examinĂ© cette question en fonction de l’étude de 414 baleines et de 22 locis microsatellites nouvellement mis au point. Nous avons remarquĂ© d’importantes dĂ©viations de l’équilibre de Hardy-Weinberg; toutefois, nous n’avons pas pu trouver de preuve significative de populations gĂ©nĂ©tiques multiples au sein des baleines borĂ©ales de l’ouest de l’Alaska qui pourrait expliquer ce dĂ©sĂ©quilibre de Hardy-Weinberg, plus particuliĂšrement en comparaison avec la force de la preuve de diffĂ©renciation entre les baleines borĂ©ales de l’ouest de l’Arctique et d’autres populations de rĂ©gions distantes telles que la mer d’Okhotsk et l’est du Canada. Il y avait des preuves concluantes de diffĂ©renciation gĂ©nĂ©tique entre les trois rĂ©gions. Le rejet statistique de la panmixie au sein de l’ouest de l’Arctique amĂ©liore notre comprĂ©hension de la biologie des baleines borĂ©ales, et le manque de preuves de populations multiples dans l’ouest de l’Arctique donne lieu Ă  la gestion de l’aversion au risque de la chasse Ă  la baleine borĂ©ale de l’ouest de l’Arctique par les Autochtones
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