Thermal history of chondrules during shock-wave heating

Evaporation during chondrule melting may have resulted in depletion of volatile elements in chondrules. However, no evidence for a large degree of heavy-isotope enrichment has been reported in chondrules. In order to meet this observed constraint, the rapid heating rate at temperatures below the silicate solidus is required to form chondrules. We have developed a new shock-wave heating model with the radiative transfer among dust particles and calculated the thermal history of chondrules. We have found that optically-thin shock waves for the thermal continuum emission from dust particles can meet the high heating rate constraint, because the dust thermal emission does not keep the dust particles high temperature for a long time in the pre-shock region and dust particles are abruptly heated by the gas drag heating in the post-shock region. We have also found a trend that the optically-thick shock waves lead to rapid heating in the pre-shock region and rapid cooling in the post-shock region. On the contrary, the optically-thin shock waves have a tendency to cause slow heating in the pre-shock region and slow cooling in the post-shock region. Since these two tendencies seem to be inconsistent with observational constraints (rapid heating and slow cooling for chondrule formation), more careful quantitative studies are needed in the future to see if the shock-wave heating model can reproduce the observations

Mixed Lubrication Analysis of Vane Sliding Surface in Rotary Compressor Mechanisms

In the compression mechanisms of a rotary compressor for air conditioners, a vane and a rolling piston are provided to separate the suction chamber and the compression chamber. The rolling piston is driven by the crank, and revolves on the axis of the shaft eccentrically, and also rotates on its own axis. The vane undergoes reciprocating motion, and its top usually comes into contact with the rolling piston by the spring force and the discharge pressure. The lubricating condition between the vane top and the rolling piston is severe because the contact pressure is high owing to the line contact of the vane top. For the prevention of scuffing, abnormal wear and so on, it is important to clarify the lubricating characteristics between the vane top and the rolling piston. Because the normal force acting on piston at vane contact is greatly influenced by the friction of vane sliding surface between the vane and the vane-slot, a mixed lubrication analysis of the vane sliding surface between the vane and the vane-slot is required to obtain the normal force acting on piston at vane contact accurately. In order to investigate the lubricating characteristics between the vane top and the rolling piston, a numerical analysis of the motion of the rolling piston and the motion of the vane considering the mixed lubrication of the vane sliding surface has been performed. The cases of different friction coefficient of the vane sliding surface at solid contact were calculated, and the results were compared. As a result, the effects of the friction of the vane sliding surface on the lubricating characteristics between the vane top and the rolling piston have been made clear

Two mechanisms forming a comblike step pattern induced by a moving linear adatom source

We carry out phase field simulations to study properties of the comblike step patterns induced by an adatom source. When an adatom source advances right in front of a step, stepwandering is caused by the asymmetry of the surface diffusion field and small protrusions are formed. If the velocity of the source Vp is smaller than a critical value V c p , the protrusions follow the adatom source with coarsening of the step pattern, and a regular comblike pattern with finger-like protrusions is formed.With a sufficiently small Vp, the gap of the supersaturation is large at the adatom source. Since the period of protrusions, , decreases with increasing Vp, the coarsening of step pattern is irrelevant for the protrusions to catch up with the adatom source. Near V c p , the gap of the supersaturation at the adatom source is small. Taking account of the increase in with increasing Vp, the coarsening of the step pattern is essential for the protrusions to follow the adatom source

Gene expression changes during caste-specific neuronal development in the damp-wood termite Hodotermopsis sjostedti

<p>Abstract</p> <p>Background</p> <p>One of the key characters of social insects is the division of labor, in which different tasks are allocated to various castes. In termites, one of the representative groups of social insects, morphological differences as well as behavioral differences can be recognized among castes. However, very little is known about the neuronal and molecular bases of caste differentiation and caste-specific behavior. In almost all termite species, soldiers play defensive roles in their colonies, and their morphology and behavior are largely different from workers (or pseudergates). Therefore, we predicted that some genes linked to defensive behavior and/or those required for neuronal changes are differentially expressed between workers and soldiers, or during the soldier differentiation, respectively.</p> <p>Results</p> <p>Using the brain and suboesophageal ganglion (SOG) of the damp-wood termite <it>Hodotermopsis sjostedti</it>, we first screened genes specifically expressed in soldiers or during soldier differentiation by the differential display method, followed by quantitative real-time polymerase chain reaction. No distinctive differences in expression patterns were detected between pseudergates and soldiers. In the course of soldier differentiation, however, five genes were found to be up-regulated in brain and/or SOG: 14-3-3epsilon, fibrillin2, beta-tubulin, ciboulot, and a hypothetical protein containing a SAP motif. Some of these genes are thought to be associated with cytoskeletal structure or motor-associated proteins in neuronal tissues.</p> <p>Conclusion</p> <p>The identified five genes could be involved in soldier-specific neuronal modifications, resulting in defensive behaviors in termite soldiers. The temporal expression patterns of these genes were consistent with the neuronal changes during soldier differentiation, suggesting that molecular machineries, in which the identified factors would participate, play important roles in behavioral differentiation of termite soldiers.</p

Gamergate controls dopamine levels of workers in <i>Diacamma</i> sp.

Introdução: O climatério representa uma fase de mudança e de transição no ciclo de vida feminino, durante o qual as mulheres experimentam alterações físicas e psicológicas decorrentes do hipoestrogenismo e envelhecimento. O Médico de Família é habitualmente o primeiro profissional de saúde a quem a mulher recorre para esclarecer as suas dúvidas e solicitar o alívio da sintomatologia climatérica, ocupando uma posição privilegiada para promover a capacitação e empowerment das utentes. Métodos: Promoveu-se um estudo observacional transversal, aplicando um questionário de auto-preenchimento a 92 mulheres, com idades compreendidas entre os 40 e os 60 anos, que frequentam os Centros de Saúde Norton de Matos e S. Martinho do Bispo (USF Mondego), de forma a avaliar a abordagem da menopausa nos Cuidados de Saúde Primários. A recolha dos dados decorreu de abril a julho de 2014. O tratamento estatístico foi efetuado através da plataforma estatística IBM SPSS v21.0. Resultados: Mais de metade das mulheres (55,4%) referiu ter conversado com o Médico de Família sobre a menopausa e todos os assuntos relacionados, todavia 19,6% ainda manifestavam dúvidas. O médico foi considerado a principal fonte de informação para 50% das inquiridas. A maioria das mulheres (77,2%) descreveu a presença de sintomas climatéricos, sendo os mais frequentes as dores ósseas (73,2%) e a ansiedade (67,6%). 39,1% das inquiridas indicaram a interferência do climatério na sua vida diária, sendo a vida familiar (69,4%) e a sexual (58,3%) as mais afetadas. Verificou-se uma associação significativa entre a presença de sintomas e a interferência do climatério na vida diária e na qualidade de vida da mulher. As mulheres sintomáticas (OR=12,983 com IC95% [2,808;60,033]) e as que referiram a interferência do climatério no dia a dia (OR=5,965 com IC95% [2,364;15,048]) apresentaram uma probabilidade aumentada de recorrer a consultas de Medicina Geral e Familiar. As infeções urinárias de repetição (91,7%) foram as queixas que mais motivaram a ida ao Médico de Família. Das mulheres sintomáticas, 45,1% referiram ter cuidados adicionais ou fazer algum tratamento. A terapêutica hormonal revelou-se a mais eficaz no alívio das queixas, tendo como prescritor mais frequente o Ginecologista (58,3%). Conclusão: O Médico de Família assume um papel crucial na capacitação e acompanhamento da mulher climatérica. Constatou-se que ainda permanecem dúvidas que necessitam de ser esclarecidas e que são necessárias normas que uniformizem a abordagem da menopausa na prática clínica.Introduction: The climacteric represents a time of change and transition in the female life cycle, during which women experience physical and psychological changes resulting from hypoestrogenism and aging. The general practitioner is usually the first health professional to whom a woman appeals to clarify her doubts and request relief from climacteric symptoms, occupying a privileged position to promote capacity building and empowerment of patients. Methods: It was promoted a cross-sectional observational study, applying a self-completion questionnaire to 92 women, aged between 40 and 60 years, who attend the health centers of Norton de Matos and S. Martinho do Bispo (USF Mondego), in order to evaluate the approach of menopause in Primary Health Care. Data collection took place from April to July 2014. The statistical analysis was performed by the statistical platform IBM SPSS v21.0. Results: More than half of women (55.4%) said they had talked to the general practitioner about menopause and all the related subjects, however 19.6% still had doubts. The doctor was considered the main source of information for 50% of the surveyed women. Most women (77.2%) described the presence of menopausal symptoms, the most common being bone pain (73.2%) and anxiety (67.6%). 39.1% of the surveyed indicated the interference of the climacteric in their everyday life, being the family life (69.4%) and the sexual life (58.3%) the most affected. There was a significant association between the presence of symptoms of menopause and the interference of the climacteric in daily life and quality of life. Symptomatic women (OR = 12.983 with 95% CI [2.808, 60.033]) and those who mentioned the interference of the climacteric in daily life (OR = 5.965 95% CI [2.364, 15.048]) had an increased likelihood of appealing to a general practitioner. Recurrent urinary tract infections (91.7%) were complaints that most commonly lead going to the general practitioner. Of symptomatic women, 45.1% said having additional care or getting some treatment. Hormone therapy proved more effective in relieving complaints, having the gynecologist as the most frequent prescriber (58.3%). Conclusion: The general practitioner plays a key role in the capacity building and monitoring of the climacteric woman. It was found that there are still questions that need to be clarified and that standards are necessary to standardize the approach of menopause in clinical practice

Shock-Wave Heating Model for Chondrule Formation: Prevention of Isotopic Fractionation

Chondrules are considered to have much information on dust particles and processes in the solar nebula. It is naturally expected that protoplanetary disks observed in present star forming regions have similar dust particles and processes, so study of chondrule formation may provide us great information on the formation of the planetary systems. Evaporation during chondrule melting may have resulted in depletion of volatile elements in chondrules. However, no evidence for a large degree of heavy-isotope enrichment has been reported in chondrules. In order to meet this observed constraint, the rapid heating rate at temperatures below the silicate solidus is required to suppress the isotopic fractionation. We have developed a new shock-wave heating model taking into account the radiative transfer of the dust thermal continuum emission and the line emission of gas molecules and calculated the thermal history of chondrules. We have found that optically-thin shock waves for the thermal continuum emission from dust particles can meet the rapid heating constraint, because the dust thermal emission does not keep the dust particles high temperature for a long time in the pre-shock region and dust particles are abruptly heated by the gas drag heating in the post-shock region. We have also derived the upper limit of optical depth of the pre-shock region using the radiative diffusion approximation, above which the rapid heating constraint is not satisfied. It is about 1 - 10.Comment: 58 pages, including 5 tables and 15 figures, accepted for publication in The Astrophysical Journa