520 research outputs found

    Cooling curves for neutron stars with hadronic matter and quark matter

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    The thermal evolution of isothermal neutron stars is studied with matter both in the hadronic phase as well as in the mixed phase of hadronic matter and strange quark matter. In our models, the dominant early-stage cooling process is neutrino emission via the direct Urca process. As a consequence, the cooling curves fall too fast compared to observations. However, when superfluidity is included, the cooling of the neutron stars is significantly slowed down. Furthermore, we find that the cooling curves are not very sensitive to the precise details of the mixing between the hadronic phase and the quark phase and also of the pairing that leads to superfluidity.Comment: 19 pages, 25 figure

    Identifying (subsurface) anthropogenic heat sources that influence temperature in the drinking water distribution system

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    The water temperature in the drinking water distribution system and at the customers’ taps approaches the surrounding soil temperature at ca. 1 meter depth. Water temperature is an important determinant of water quality, since it influences physical, chemical and biological processes, such as absorption of chemicals, microbial growth and chlorine decay. In the Netherlands drinking water is distributed without additional residual disinfectant and the temperature of drinking water at the customers’ tap is not allowed to exceed 25 ºC. Routine water quality samples at the tap in urban areas have shown locations with relatively high soil temperatures compared to the expected modelled soil temperatures, which indicate so called ‘underground hot-spots’. In the last decades, the urban sub-surface is getting more occupied with various types of sub-surface infrastructures and some of these can be heat sources. A few recent studies tackle the anthropogenic sources and their influence on the underground, at coarse spatial scales. Little is known about the urban shallow underground heat profile on small spatial scales, of the order of 10 m × 10 m. Our research focuses on developing a method to identify and to localise potential underground hot-spots at −1.0 m at a small spatial scale. In this article we describe a method to find anthropogenic heat sources that influence temperature in the drinking water distribution system through a combination of mapping urban anthropogenic heat sources, modelling the soil temperature and extensive measurements in Rotterdam

    Development of a radioimmunoassay for serum 21-deoxycortisol and its potential application in the diagnosis of congenital adrenal hyperplasia

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    Serum 21-deoxycortisol (21DF) has been considered a useful hormonal marker for the diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD). Although several radioimmunoassay (RIA) methods for 21DF have been reported, none are commercially available. We developed a RIA adapted for 21DF determination, preceded by ether-extraction and liquid chromatographic separation (HPLC) of samples. The assay was employed to evaluate children (15F/10M) with the classic form of 21OHD and a control group (5F/8M). The antibody obtained, in addition to efficient HPLC separation, permitted tritiated cortisol instead of 21DF to be used, since labeled ³H-21DF is expensive and difficult to obtain. Serum cortisol levels were reduced in patients with 21OHD (48h following therapy withdrawal) as compared to controls (2.1±2.1 vs. 16.2±7.0mug/dl), whereas serum levels of 21DF were significantly elevated (1,359±853ng/dl, ranging from 434 to 3,079) in the former, but consistently below the sensitivity limit of the assay (156ng/dl) in the latter group. The reported method, although devoid of sensitivity for its application in normal subjects, permits 21DF to be quantified in patients with 21OHD, with adequate sensitivity and specificity to diagnose and follow patients with this condition.O 21-deoxicortisol (21DF) sérico tem sido considerado um excelente marcador para o diagnóstico da hiperplasia adrenal congênita (HAC) por deficiência de 21-hidroxilase (D21OH). Embora vários métodos de radioimunoensaio (RIE) tenham sido descritos para 21DF, nenhum deles está disponível comercialmente. Desenvolvemos um RIE adaptado para a dosagem de 21DF, com extração prévia das amostras com éter e separação por cromatografia líquida (HPLC). O ensaio foi aplicado para a avaliação de crianças portadoras da forma clássica de D21OH (15F/10M) e um grupo controle (5F/8M). O anticorpo obtido, associado à eficiência da separação por HPLC, viabilizou o emprego do cortisol triciado neste RIE. Enquanto nos pacientes os níveis de cortisol estavam reduzidos (48h após suspensão do tratamento) em comparação com o grupo controle (2,1±2,1 vs. 16,2±7,0mig/dl), os valores do 21DF sérico estavam bastante elevados (1.359±853ng/dl, variando de 434 a 3.079), embora consistentemente abaixo do limite de sensibilidade (156ng/dl) no grupo controle. O presente método, mesmo destituído de sensibilidade para aplicação em indivíduos normais, permite a quantificação deste esteróide em portadores de D21OH, com a sensibilidade e a especificidade necessárias para o diagnóstico e acompanhamento desta condição clínica.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) EPM Departamento de MedicinaHospital Infantil Darcy Vargas Serviço de Endocrinologia PediátricaHôpital Saint Louis Service de Biologie HormonaleUNIFESP, EPM, Depto. de MedicinaSciEL

    REM34 and REM35 control female and male gametophyte development in Arabidopsis thaliana

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    The REproductive Meristem (REM) gene family encodes for transcription factors belonging to the B3 DNA binding domain superfamily. In Arabidopsis thaliana the REM gene family is composed of 45 members, preferentially expressed during flower, ovule and seed development. Only a few members of this family have been functionally characterized: VERNALIZATION1 (VRN1) and most recently TARGET OF FLC AND SVP1 (TFS1) regulate flowering time and VERDANDI (VDD), together with VALKYRIE (VAL) control the death of the receptive synergid cell in the female gametophyte. We investigated the role of REM34, REM35 and REM36, three closely related and linked genes similarly expressed in both female and male gametophytes. Simultaneous silencing by RNA interference (RNAi) caused about 50% of the ovules to remain unfertilized. Careful evaluation of both ovule and pollen development showed that this partial sterility of the transgenic RNAi lines was due to a post meiotic block in both female and male gametophytes. Furthermore, protein interaction assays revealed that REM34 and REM35 interact, which suggests that they work together during the first stages of gametogenesis

    Fabrication and heating rate study of microscopic surface electrode ion traps

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    We report heating rate measurements in a microfabricated gold-on-sapphire surface electrode ion trap with trapping height of approximately 240 micron. Using the Doppler recooling method, we characterize the trap heating rates over an extended region of the trap. The noise spectral density of the trap falls in the range of noise spectra reported in ion traps at room temperature. We find that during the first months of operation the heating rates increase by approximately one order of magnitude. The increase in heating rates is largest in the ion loading region of the trap, providing a strong hint that surface contamination plays a major role for excessive heating rates. We discuss data found in the literature and possible relation of anomalous heating to sources of noise and dissipation in other systems, namely impurity atoms adsorbed on metal surfaces and amorphous dielectrics.Comment: 17 pages, 5 figure

    Drinking water temperature around the globe: Understanding, policies, challenges and opportunities

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    Water temperature is often monitored at water sources and treatment works; however, there is limited monitoring of the water temperature in the drinking water distribution system (DWDS), despite a known impact on physical, chemical and microbial reactions which impact water quality. A key parameter influencing drinking water temperature is soil temperature, which is influenced by the urban heat island effects. This paper provides critique and comprehensive summary of the current knowledge, policies and challenges regarding drinking water temperature research and presents the findings from a survey of international stakeholders. Knowledge gaps as well as challenges and opportunities for monitoring and research are identified. The conclusion of the study is that temperature in the DWDS is an emerging concern in various countries regardless of the water source and treatment, climate conditions, or network characteristics such as topology, pipe material or diameter. More research is needed, especially to determine (i) the effect of higher temperatures, (ii) a legislative limit on temperature and (iii) measures to comply with this limit

    Rice MADS6 interacts with the floral homeotic genes SUPERWOMAN1, MADS3, MADS58, MADS13, and DROOPING LEAF in specifying floral organ identities and meristem fate

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    AGAMOUS-LIKE6 (AGL6) genes play essential roles in flower development, but whether and how they work with floral organ identity genes remain less understood. Here, we describe interactions of the rice (Oryza sativa) AGL6 gene MADS6 with other rice floral homeotic genes in flower development. Genetic analyses revealed that MADS6 specifies the identity of the three inner whorls and floral meristem determinacy redundantly with SUPERWOMAN1/MADS16 (B-gene) or MADS3 (C-gene). MADS6 was shown to define carpel/ovule development and floral determinacy by interacting with MADS13 (D-gene) and control the palea and floral meristem identities together with the YABBY gene DROOPING LEAF. Expression analyses revealed that the transcript levels of six B-, C-, and E-class genes were reduced in mads6-1 at the early flower developmental stage, suggesting that MADS6 is a key regulator of early flower development. Moreover, MADS6 can directly bind to a putative regulatory motif on MADS58 (C-gene), and mads6-1 mads58 displayed phenotypes similar to that of mads6-1. These results suggest that MADS6 is a key player in specifying flower development via interacting with other floral homeotic genes in rice, thus providing new insights into the mechanism by which flower development is controlled.Haifeng Li, Wanqi Liang, Yun Hu, Lu Zhu, Changsong Yin, Jie Xu, Ludovico Dreni, Martin M. Kater, and Dabing Zhan

    Psychiatry during the Nazi era: ethical lessons for the modern professional

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    For the first time in history, psychiatrists during the Nazi era sought to systematically exterminate their patients. However, little has been published from this dark period analyzing what may be learned for clinical and research psychiatry. At each stage in the murderous process lay a series of unethical and heinous practices, with many psychiatrists demonstrating a profound commitment to the atrocities, playing central, pivotal roles critical to the success of Nazi policy. Several misconceptions led to this misconduct, including allowing philosophical constructs to define clinical practice, focusing exclusively on preventative medicine, allowing political pressures to influence practice, blurring the roles of clinicians and researchers, and falsely believing that good science and good ethics always co-exist. Psychiatry during this period provides a most horrifying example of how science may be perverted by external forces. It thus becomes crucial to include the Nazi era psychiatry experience in ethics training as an example of proper practice gone awry
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