Improved Constraints on Z' Bosons from Electroweak Precision Data

We analyze various models with an extra U(1) gauge symmetry in addition to the Standard Model (SM) gauge group at low energies, and impose limits on the mass of the neutral Z' boson, M_Z', predicted in all such models, and on the Z-Z' mixing angle, theta_ZZ'. The precision electroweak data strongly constrain theta_ZZ' to very small values and for most models we find lower limits on M_Z' of order 1 TeV. In one case we obtain a somewhat better fit than in the SM (although this is only marginally statistically significant) and here we find a weak upper limit at the 90% C.L.Comment: 18 pages, 10 figures, final version as it will appear in Journal (JHEP

Characterizing a single photon detector

I will present my work about constructing and characterizing a single photon detector. Using the 1550nm laser and second harmonic light generation, I am able to count single photons on a Multi‐Pixel Photon Counter (MPPC) silicon APD. My results show that upwards of 22% quantum efficiency is achievable with the MPPC. Future work will include coincidence detection of correlated photon‐pair

Optimizing Acoustic Activation of Phase Change Contrast Agents With the Activation Pressure Matching Method: A Review

Sub-micron phase-change contrast agents consist of a liquid perfluo ocarbon core that can be vaporized by ultrasound (acoustic droplet vaporization) to generate contrast with excellent spatial and temporal control. When these agents, commonly referred to as nanodroplets, are formulated with cores of low boiling-point perfluo ocarbons such as decaflu orobutane and octafluo opropane, they can be activated with low-mechanical index imaging pulses for diagnostic applications. Since the utilization of minimum mechanical index is often desirable to avoid unnecessary biological effects, enabling consistent activation of these agents in an acoustic fiel is a challenge because the energy that must be delivered to achieve the vaporization threshold increases with depth due to attenuation. A novel vaporization approach called Activation Pressure Matching has been developed to deliver the same pressure throughout a fiel of view in order to produce uniform nanodroplet vaporization and to limit the amount of energy that is delivered. In this manuscript, we discuss the application of this method with a Versasonics V1 Research Ultrasound System to modulate the output pressure from an ATL L11–5 transducer. Vaporization-pulse spacing optimization can be used in addition to matching the activation pressure through depth, and we demonstrate the feasibility of this approach both in vivo and in vitro. The use of optimized vaporization parameters increases the amount of time a single bolus of nanodroplets can generate useful contrast and provides consistent image enhancement in vivo. Therefore, APM is a useful technique for those wishing to maximize the efficac of phase change contrast agent while minimizing delivered acoustic energy

Barreiras de acesso a tratamento para mães com depressão pós-parto em centros de atenção primária: um modelo preditivo

Objective to develop a predictive model to evaluate the factors that modify the access to treatment for Postpartum Depression (PPD). Methods prospective study with mothers who participated in the monitoring of child health in primary care centers. For the initial assessment and during 3 months, it was considered: sociodemographic data, gyneco-obstetric data, data on the services provided, depressive symptoms according to the Edinburgh Postpartum Depression Scale (EPDS) and quality of life according to the Short Form-36 Health Status Questionnaire (SF-36). The diagnosis of depression was made based on MINI. Mothers diagnosed with PPD in the initial evaluation, were followed-up. Results a statistical model was constructed to determine the factors that prevented access to treatment, which consisted of: item 2 of EPDS (OR 0.43, 95%CI: 0.20-0.93) and item 5 (OR 0.48, 95%CI: 0.21-1.09), and previous history of depression treatment (OR 0.26, 95%CI: 0.61-1.06). Area under the ROC curve for the model=0.79; p-value for the Hosmer-Lemershow=0.73. Conclusion it was elaborated a simple, well standardized and accurate profile, which advises that nurses should pay attention to those mothers diagnosed with PPD, presenting low/no anhedonia (item 2 of EPDS), scarce/no panic/fear (item 5 of EPDS), and no history of depression, as it is likely that these women do not initiate treatment.Objetivo desarrollar un modelo predictivo para evaluar los factores que modifiquen el acceso a tratamiento para la DPP. Métodos estudio prospectivo de madres que asistieron a control de niño sano en centros de atención primaria. En evaluación basal y 3 meses, se registraron: datos sociodemográficos, gineco-obstétricos, variables de uso de servicios, síntomas depresivos con la Escala de Depresión Posparto de Edimburgo (EPDS) y calidad de vida con el Cuestionario de Salud SF-36. El diagnóstico de depresión se hizo con el MINI. Se siguió a madres que en evaluación basal tenían DPP. Resultados se construyó un modelo estadístico para determinar los factores que impidieron el acceso a tratamiento, compuesto por: ítems del EPDS 2 (OR 0,43, IC95%: 0,20-0,93) y 5 (OR 0,48, IC95%: 0,21-1,09), e historia previa de tratamiento de depresión (OR 0,26, IC95%: 0,61-1,06). Área bajo la curva ROC para el modelo=0,79; valor de p para la prueba de Hosmer-Lemershow=0,73. Conclusión se elaboró un perfil simple, bien calibrado y discriminante, que sugiere que los/las enfermeros/as estén atentos/as a aquellas madres con DPP que presenten baja/nula anhedonia (ítem 2 EPDS), escaso/nulo pánico/miedo (ítem 5 EPDS), y sin antecedentes de depresión, ya que es probable que estas mujeres no ingresen a tratamiento.Objetivo desenvolver um modelo preditivo para avaliar os fatores que modificam o acesso a tratamento para a DPP. Métodos estudo prospectivo com mães que participaram do acompanhamento da saúde da criança em centros de atenção primária. Na avaliação inicial e durante 3 meses, foram registrados: dados sociodemográficos, gineco-obstétricos, dados sobre o uso dos serviços, sintomas depressivos de acordo com a Escala de Depressão Pós-parto de Edimburgo (EPDS) e qualidade de vida de acordo com o Questionário de Saúde SF-36. O diagnóstico de depressão foi feito com o MINI. Foram acompanhadas as mães que tinham DPP na avaliação inicial. Resultados foi construído um modelo estatístico para determinar os fatores que impediram o acesso a tratamento, constituído por: item 2 da EPDS (OR 0,43, IC95%: 0,20-0,93) e 5 (OR 0,48, IC95%: 0,21-1,09), e história prévia de tratamento para depressão (OR 0,26, IC95%: 0,61-1,06). Área sob a curva ROC para o modelo=0,79; valor de p para o teste de Hosmer-Lemershow=0,73. Conclusão foi elaborado um perfil simples, bem padronizado e preciso, que recomenda que os/as enfermeiros/as estejam atentos/as àquelas mães com DPP que apresentem anedonia baixa/nula (item 2 da EPDS), pânico/medo escasso/nulo (item 5 da EPDS) e sem antecedentes de depressão, já que é provável que estas mulheres não entrem em tratamento

Coup-TFII expression defines two different septum transversum cell compartments crucial to cardiac septation and compact ventricular wall growth

COUP-TFII encodes for an orphan nuclear receptor expressed by multiple embryonic tissues. COUP-TFII functions include the regulation of mesodermal progenitor differentiation and cell fate specification, and is required for completion of cardiovascular development as shown by the early death (E9.5) of COUP-TFII-null mice. In this study, we show that COUP-TFII, which is strongly expressed in the atrial myocardium, is also expressed in two different compartments of the septum transversum (ST, E9.5), a mesodermal folding adjacent to cardiac inflow myocardium. The first ST compartment is COUP-TFII+/Isl1+; cells in this compartment concentrate in the posterior part of the ST, overlap with SHF, and are continuous with the dorsal mesenchymal protrusion (DMP, also known as spina vestibuli). The second compartment is characteristically COUP-TFII+/Isl1-, and comprises the majority of proepicardial cells. To dissect the role of COUP-TFII+ ST cells in cardiac development, we conditionally deleted COUP-TFII in the ST using two different Cre constructs (Wt1Cre; G2-Gata4Cre). We show that COUP-TFII deletion in the ST is most severe in G2-Gata4Cre;COUP-TFII-/- mice, containing various cardiovascular progenitor lineages. Mutant mice display atrial septation and atrioventricular septal defects as well as a severe disruption of compact ventricular myocardial growth and coronary vascularization. We conclude that COUP-TFII plays critical, pleiotropic, tissue-dependent roles during cardiac septation, growth and vascularization.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Centro Nacional de Investigaciones Cardiovasculares (CNIC-ISCIII

Non-lethal exposure to H2O2 boosts bacterial survival and evolvability against oxidative stress

Unicellular organisms have the prevalent challenge to survive under oxidative stress of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). ROS are present as by-products of photosynthesis and aerobic respiration. These reactive species are even employed by multicellular organisms as potent weapons against microbes. Although bacterial defences against lethal and sub-lethal oxidative stress have been studied in model bacteria, the role of fluctuating H2O2 concentrations remains unexplored. It is known that sub-lethal exposure of Escherichia coli to H2O2 results in enhanced survival upon subsequent exposure. Here we investigate the priming response to H2O2 at physiological concentrations. The basis and the duration of the response (memory) were also determined by time-lapse quantitative proteomics. We found that a low level of H2O2 induced several scavenging enzymes showing a long half-life, subsequently protecting cells from future exposure. We then asked if the phenotypic resistance against H2O2 alters the evolution of resistance against oxygen stress. Experimental evolution of H2O2 resistance revealed faster evolution and higher levels of resistance in primed cells. Several mutations were found to be associated with resistance in evolved populations affecting different loci but, counterintuitively, none of them was directly associated with scavenging systems. Our results have important implications for host colonisation and infections where microbes often encounter reactive oxygen species in gradients

Maschinelles Spielen im Klassiker Asteroids

Das Ende der 80er Jahre veröffentlichte, auf Reaktion und Planung basierende Spiel Asteroids, gilt inzwischen als eines der erfolgreichsten Computerspiele aller Zeiten. Es eignet sich hervorragend als Testplattform für die verschiedensten KI-Konzepte, die anhand erreichter Punktezahlen verglichen werden können. In der vorliegenden Arbeit wird ein adaptives physikalisches Weltmodell eingeführt, mit dessen Hilfe eine optimale Verhaltensstrategie gefunden werden kann. Mittels einer heuristischen Suche wird eine Aktionsfolge gefunden, die in minimaler Zeit versucht, die Punkte zu maximieren. Die hier vorgestellten Ideen wurden im Programm jAsteroidsAI realisiert, welches erfolgreich am Wettbewerb der Computerzeitschrift c’t 2008 teilnahm und in fünf Minuten eine Spitzenpunktezahl von 85:000 erreichte

Understanding transfer from a dynamic system approach:Two studies of children using problem-solving tasks

Transfer is not static but a dynamic process of learning. In this article, the concept of transfer and the implications of its study are reconsidered from the theoretical basis of the complex dynamic system approach. We describe “transfer” as an emergent process that implies not a copy of knowledge applied to a new situation, but a new configuration of knowledge to solve new situations. Therefore, we discussed the concept of transfer based on the following dynamic principles: soft-assembly, multi causality, variability, self-organization, and iteration. To reconsider the concept of transfer, we provide empirical evidence, illustrating these principles by discussing two studies of transfer carried out with preschoolers. The participants were 34 children of 4 years old (M = 4,6), and 8 children of 4 to 6 years old (M = 5,2). Using repeated measure designs (3 weeks and 6 months, respectively), participants worked on sets of problem-solving situations in the domain of physics (i.e. Archimedes’ principle and Air pressure). By using time-series graphs we identified the relevant elements of the tasks used by the children during the problem-solving process to analyze how this process changes over time. Results show transfer as a self-organized and context-related process in which the information is not static but in constant transformation