899 research outputs found

    A Biased Review of Tau Neutrino Mass Limits

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    After a quick review of astrophysically relevant limits, I present a summary of MeV scale tau neutrino mass limits derived from accelerator based experiments. I argue that the current published limits appear to be too consistent, and that we therefore cannot conclude that the tau neutrino mass limit is as low as usually claimed. I provide motivational arguments calling into question the assumed statistical properties of the usual maxumum likelihood estimators, and provide a prescription for deriving a more robust and understandable mass limit.Comment: 9 pages, 5 figures, 2 tables. To appear in the Proceedings of the Sixth International Workshop on Tau Lepton Physics, Sept 18-21 2000, Victoria (Canada

    Progress On The Paternal Brain: Theory, Animal Models, Human Brain Research, And Mental Health Implications

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    With a secure foundation in basic research across mammalian species in which fathers participate in the raising of young, novel brain‐imaging approaches are outlining a set of consistent brain circuits that regulate paternal thoughts and behaviors in humans. The newest experimental paradigms include increasingly realistic baby‐stimuli to provoke paternal cognitions and behaviors with coordinated hormone measures to outline brain networks that regulate motivation, reflexive caring, emotion regulation, and social brain networks with differences and similarities to those found in mothers. In this article, on the father brain, we review all brain‐imaging studies on PubMed to date on the human father brain and introduce the topic with a selection of theoretical models and foundational neurohormonal research on animal models in support of the human work. We discuss potentially translatable models for the identification and treatment of paternal mood and father–child relational problems, which could improve infant mental health and developmental trajectories with potentially broad public health importance. RESUMEN Con fundación segura en la investigación básica a través de las especies mamíferas en las que los padres participan en la crianza de sus pequeños, los novedosos acercamientos en el campo de imágenes cerebrales están definiendo un grupo de circuitos cerebrales consistentes que regulan los pensamientos y conductas paternas en los humanos. El más reciente paradigma experimental incluye cada vez más estímulos realistas al bebé para provocar percepciones y conductas paternas con medidas hormonales coordinadas para delinear las redes cerebrales que regulan la motivación, el cuidado reflexivo, la regulación de la emoción y las redes cerebrales sociales, con diferencias y similitudes a las que se presentan en las madres. En este artículo sobre el cerebro del padre, revisamos todos los estudios de imágenes cerebrales en PubMed hasta la fecha sobre el cerebro humano del padre e introducimos el tema con una selección de modelos teóricos y una básica investigación neuro‐hormonal en modelos animales como apoyo al trabajo humano. Discutimos modelos potencialmente transferibles para la identificación y tratamiento de problemas de estado de humor y de relación padre‐hijo, lo cual pudiera mejorar la salud mental infantil y las trayectorias de desarrollo con una potencial amplia importancia de salud pública. RÉSUMÉ Avec une fondation solide en recherches de base au travers des espèces de mammifères dans laquelle les pères participent à l’éducation des jeunes, des nouvelles approachs d’imagerie exposent un groupe de circuits du cerveau constants qui régulent les pensées paternelles et les comportements chez les humains. Les nouveaux paradigmes expérimentaux incluent des bébé‐stimulus de plus en plus réalistes pour provoquer des cognitions et des comportements paternels avec des mesures d’hormones coordonnées afin de souligner les réseaux qui régulent la motivation, le soin réfléchi, la régulation de l’émotion et les réseaux sociaux du cerveau avec les différences et les similarités que l’on trouve chez les mères. Dans cet article sur le cerveau du père, nous passons en revue toutes les études d’imagerie cérébrale trouvées par le moteur de recherche PubMed qui existent sur le cerveau humain du père et nous présentons le sujet au moyen d’une sélection de modèles théoriques et de recherches en matière neurohomormonale fondamentale chez des modèles animaux pour soutenir le travail sur l’humain. Nous discutons des modèles que l’on pourrait traduire pour l’identification et le traitement de l’humeur paternelle et les problèmes relationnels père‐enfant, qui pourraient améliorer la santé mentale du nourrisson et les trajectoires de développement cela pouvant avoir à la clé une grande importance pour la santé publique. ZUSAMMENFASSUNG Mit einem sicheren Fundament in der Grundlagenforschung über Säugetierarten, tragen Väter zu der Entwicklung von jungen, neuartigen bildgebenden Ansätzen bei, indem eine Reihe von konsistenten neuronalen Verschaltungen skizziert wird, die väterliche Gedanken und Verhaltensweisen beim Menschen regulieren. Die neuesten experimentellen Paradigmen nutzen realistische Säuglings‐Stimuli, um väterliche Kognitionen und Verhaltensweisen hervorzurufen, um mit abgestimmten Hormonerfassungen Netzwerke im Gehirn zu skizzieren, die Motivation, reflexive Fürsorge, Emotionsregulation und soziale Netzwerke im Gehirn regulieren. Diese sollen hinsichtlich Unterschieden und Ähnlichkeiten zu denen bei Müttern gefundenen Netzwerken betrachtet werden. In diesem Artikel zum Gehirn des Vaters, bieten wir einen Überblick über alle aktuellen bildgebenden Studien auf Pubmed über das menschliche Gehirn des Vaters und führen mit einer Auswahl von theoretischen Modellen und grundlegender neurohormonaler Forschung an Tiermodellen zur Unterstützung der menschlichen Arbeit in das Thema ein. Wir diskutieren potenziell übersetzbare Modelle für die Erkennung und Behandlung der väterlichen Stimmung und von Vater‐Kind‐Beziehungsproblemen, welche die psychische Gesundheit von Säuglingen und Entwicklungsverläufe mit potenziell großer Bedeutung für die öffentliche Gesundheit verbessern könnten. ABSTRACT 抄録:父親が幼い子育てに参加するほ乳類全体にわたる基礎研究での強固な基盤とともに、新しい脳画像アプローチによって、人類における父親の思考と行動を調節する一連の一貫した脳回路の輪郭が描かれつつある。母親に見られたものとの共通点と相違点とともに、動機、リフレクティブな養育、情緒調節を調節する脳のネットワーク、および社会脳のネットワークの輪郭を描くために、最新の実験パラダイムには、協調的なホルモンの測定とともに、父親の認知と行動を引き起こすための、ますます現実的な赤ちゃんの刺激が含まれる。父親の脳についてのこの論文では、私たちは今日までの人間の父親の脳についての pubmed にある全ての脳画像研究をレビューする。そして、人間の研究を支援して、選択した理論的モデルと、動物モデルについての基礎的神経内分泌研究のトピックを紹介する。私たちは、父親の気分と父子関係の問題を同定し治療するための、翻訳可能なモデルを考察する。それは、幅広い公衆衛生の重要性を持つ可能性のある、乳幼児精神保健と発達の軌跡を向上させるだろう。Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108662/1/imhj21471.pd

    Facilitating the analysis of a UK national blood service supply chain using distributed simulation

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    In an attempt to investigate blood unit ordering policies, researchers have created a discrete-event model of the UK National Blood Service (NBS) supply chain in the Southampton area of the UK. The model has been created using Simul8, a commercial-off-the-shelf discrete-event simulation package (CSP). However, as more hospitals were added to the model, it was discovered that the length of time needed to perform a single simulation severely increased. It has been claimed that distributed simulation, a technique that uses the resources of many computers to execute a simulation model, can reduce simulation runtime. Further, an emerging standardized approach exists that supports distributed simulation with CSPs. These CSP Interoperability (CSPI) standards are compatible with the IEEE 1516 standard The High Level Architecture, the defacto interoperability standard for distributed simulation. To investigate if distributed simulation can reduce the execution time of NBS supply chain simulation, this paper presents experiences of creating a distributed version of the CSP Simul8 according to the CSPI/HLA standards. It shows that the distributed version of the simulation does indeed run faster when the model reaches a certain size. Further, we argue that understanding the relationship of model features is key to performance. This is illustrated by experimentation with two different protocols implementations (using Time Advance Request (TAR) and Next Event Request (NER)). Our contribution is therefore the demonstration that distributed simulation is a useful technique in the timely execution of supply chains of this type and that careful analysis of model features can further increase performance

    Interference-induced gain in Autler-Townes doublet of a V-type atom in a cavity

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    We study the Autler-Townes spectrum of a V-type atom coupled to a single-mode, frequency-tunable cavity field at finite termperature, with a pre-selected polarization in the bad cavity limit, and show that, when the mean number of thermal photons N1N\gg 1 and the excited sublevel splitting is very large (the same order as the cavity linewidth), the probe gain may occur at either sideband of the doublet, depending on the cavity frequency, due to the cavity-induced interference.Comment: Minor changes are mad

    Transiting Exoplanets with JWST

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    The era of exoplanet characterization is upon us. For a subset of exoplanets -- the transiting planets -- physical properties can be measured, including mass, radius, and atmosphere characteristics. Indeed, measuring the atmospheres of a further subset of transiting planets, the hot Jupiters, is now routine with the Spitzer Space Telescope. The James Webb Space Telescope (JWST) will continue Spitzer's legacy with its large mirror size and precise thermal stability. JWST is poised for the significant achievement of identifying habitable planets around bright M through G stars--rocky planets lacking extensive gas envelopes, with water vapor and signs of chemical disequilibrium in their atmospheres. Favorable transiting planet systems, are, however, anticipated to be rare and their atmosphere observations will require tens to hundreds of hours of JWST time per planet. We review what is known about the physical characteristics of transiting planets, summarize lessons learned from Spitzer high-contrast exoplanet measurements, and give several examples of potential JWST observations.Comment: 22 pages, 11 figures. In press in "Astrophysics in the Next Decade: JWST and Concurrent Facilities, Astrophysics & Space Science Library, Thronson, H. A., Tielens, A., Stiavelli, M., eds., Springer: Dordrecht (2008)." The original publication will be available at http://www.springerlink.co

    Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

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    Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    Leptodora kindtii survival in the laboratory

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    Leptodora kindtii , a pelagic predatory cladoceran, suffers high mortality on transfer to laboratory, which makes the experimental work difficult. We investigated the causes of high mortality, using four variables: water volume, animal density, light intensity, and origin of water for culturing, i.e., water from native or a non-native lake. For the experiments we used Leptodora and water from Lake Loosdrecht and Lake Maarsseveen (The Netherlands). Water was found to be the most important factor; the animals did not necessarily do better in lake water from which they were collected. Water volume and animal density were of limited importance, and light intensity did not affect survival.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41752/1/10452_2004_Article_DO00000328.pd
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