Three flavor neutrino oscillations in matter

We derive analytic expressions for three flavor neutrino oscillations in the presence of matter in the plane wave approximation using the Cayley-Hamilton formalism. Especially, we calculate the time evolution operator in both flavor and mass bases. Furthermore, we find the transition probabilities, matter mass squared differences, and matter mixing angles all expressed in terms of the vacuum mass squared differences, the vacuum mixing angles, and the matter density. The conditions for resonance in the presence of matter are also studied in some examples.Comment: 25 pages, 6 figures (PostScript), RevTe

Dynamics of Natural Killer cell receptor revealed by quantitative analysis of photoswitchable protein

Natural Killer (NK) cell activation is dynamically regulated by numerous activating and inhibitory surface receptors that accumulate at the immune synapse. Quantitative analysis of receptor dynamics has been limited by methodologies which rely on indirect measurements such as fluorescence recovery after photobleaching. Here, we report a novel approach to study how proteins traffic to and from the immune synapse using NK cell receptors tagged with the photoswitchable fluorescent protein tdEosFP, which can be irreversibly photoswitched from a green to red fluorescent state by ultraviolet light. Thus, following a localized switching event, the movement of the photoswitched molecules can be temporally and spatially resolved by monitoring fluorescence in two regions of interest. By comparing images with mathematical models, we evaluated the diffusion coefficient of the receptor KIR2DL1 (0.23 +- 0.06 micron^2/s) and assessed how synapse formation affects receptor dynamics. Our data conclude that the inhibitory NK cell receptor KIR2DL1 is continually trafficked into the synapse and remains surprisingly stable there. Unexpectedly however, in NK cells forming synapses with multiple target cells simultaneously, KIR2DL1 at one synapse can relocate to another synapse. Thus, our results reveal a previously undetected inter-synaptic exchange of protein.Comment: 25 pages, 5 figure

Women's views of continuity of information provided during and after pregnancy: A qualitative interview study

Straightforward transfer of care from pregnancy to the postpartum period is associated with health benefits and is desired by women worldwide. Underpinning this transfer of care is the sharing of information between healthcare professionals and the provision of consistent information to women. In this qualitative study, two aspects of continuity of information were examined; first the information passed on from midwife to health visitor regarding a woman and her baby before the health visitor meets the woman postnatally and second, the consistency of information received by women from these two healthcare professionals (the main healthcare providers during and after pregnancy in England). To be eligible for the study, women had to have had a baby in England within 12 months prior to the interview. Participants also needed to be able to read and speak English and be over 18 years old. Recruitment of participants was via word of mouth and social media. Twenty-nine mothers were interviewed of whom 19 were first time mothers. The interviews took place in the summer and autumn of 2016 and were transcribed verbatim and analysed using Framework Analysis. Two overarching themes were identified: not feeling listened to and information inconsistencies. Women reported little experience of midwives and health visitors sharing information about their care, forcing women to repeat information. This made women feel not listened to and participants recommended that healthcare professionals share information; prioritising information about labour, mental health, and chronic conditions. Women had mixed experiences regarding receiving information from midwives and health visitors, with examples of both consistent and inconsistent information received. To avoid inconsistent information, joint appointments were recommended. Findings from this study clearly suggest that better communication pathways need to be developed and effectively implemented for midwives and health visitors to improve the care that they provide to women

Effect of the 24 September 2011 solar radio burst on precise point positioning service

An intense solar radio burst occurred on 24 September 2011, which affected the tracking of Global Navigation Satellite Systems’ (GNSS) signals by receivers located in the sunlit hemisphere of the Earth. This manuscript presents for the first time the impacts of this radio burst on the availability of Fugro’s real-time precise point positioning service for GNSS receivers and on the quality of the L band data link used to broadcast this service. During the peak of the radio burst (12:50–13:20 UT), a reduction in the L band signal-to-noise ratio (SNR) is observed. For some receiver locations, a reset in the position filter is observed, which can be either due to the reduction in the L band SNR or the reduction in the number of tracked GNSS satellites. This reset in the position filter is accompanied by degradation in the positioning accuracy, which is also discussed herein

A massa dos neutrinos. Teoria versus experimento.

Nas últimas décadas, soluções ao problema do neutrino solar têm sido investigadas no contexto de teorias nas quais os neutrinos têm massa e podem oscilar entre os sabores eletrônico, muônico e tauônico. Os dados experimentais, hoje, parecem indicar que os neutrinos têm massa e que oscilações entre sabores realmente acontecem. No presente trabalho, efetuaremos uma revisão geral sobre a física de neutrinos desde a época da proposta de sua existência, apresentaremos suas propriedades e uma breve discussão das interações entre neutrinos e as outras partículas elementares no contexto do modelo padrão das interações fundamentais. Uma visão geral dos principais mecanismos de produção de neutrinos no interior solar, o espectro de energia destes neutrinos, os métodos de detecção de neutrinos e as características dos principais detectores existentes serão apresentados. No contexto de teorias envolvendo neutrinos massivos, mostraremos como o fluxo de neutrinos solares pode ser afetado devido a oscilações entre sabores de neutrinos. Alguns dados experimentais e as conclusões que podemos tirar do confronto entre estes dados e a hipótese de oscilações entre sabores serão também apresentados

The Heat Distribution of the Underdamped Langevin Equation

In the Stochastic Thermodynamics theory, heat is a random variable with a probability distribution associated. Studies in the distribution of heat are mostly in the overdamped regime. Here we solve the heat distribution in the underdamped regime for three different cases: the free particle, the linear potential, and the harmonic potential. The results are exact and generalize known results in the literature.Comment: 19 pages, 9 subfigure