Diapycnal dissolved organic matter supply into the upper Peruvian oxycline

The eastern tropical South Pacific (ETSP) hosts the Peruvian upwelling system, which represents one of the most productive areas in the world ocean. High primary production followed by rapid heterotrophic utilization of organic matter supports the formation of one of the most intense oxygen minimum zones (OMZs) in the world ocean, where dissolved oxygen (O2) concentrations reach less than 1&thinsp;µmol&thinsp;kg−1. The high productivity leads to an accumulation of dissolved organic matter (DOM) in the surface layers that may serve as a substrate for heterotrophic respiration. However, the importance of DOM utilization for O2 respiration in the Peruvian upwelling system in general and for shaping the upper oxycline in particular remains unclear so far. This study reports the first estimates of diapycnal fluxes and supply of O2, dissolved organic carbon (DOC), dissolved organic nitrogen, dissolved hydrolysable amino acids (DHAA) and dissolved combined carbohydrates (DCCHO) for the ETSP off Peru. Diapycnal flux and supply estimates were obtained by combining measured vertical diffusivities and solute concentration gradients. They were analysed together with the molecular composition of DCCHO and DHAA to infer the transport of labile DOM into the upper OMZ and the potential role of DOM utilization for the attenuation of the diapycnal O2 flux that ventilates the OMZ. The observed diapycnal O2 flux (50&thinsp;mmol&thinsp;O2&thinsp;m−2&thinsp;d−1 at maximum) was limited to the upper 80&thinsp;m of the water column; the O2 supply of ∼1&thinsp;µmol&thinsp;kg−1&thinsp;d−1 was comparable to previously published O2 consumption rates for the North and South Pacific OMZs. The diapycnal DOM flux (31&thinsp;mmol&thinsp;C&thinsp;m−2&thinsp;d−1 at maximum) was limited to ∼30&thinsp;m water depth, suggesting that the labile DOM is extensively consumed within the upper part of the shallow oxycline off Peru. The analyses of DCCHO and DHAA composition support this finding, suggesting that DOM undergoes comprehensive remineralization within the upper part of the oxycline, as the DOM within the core of the OMZ was found to be largely altered. Estimated by a simple equation for carbon combustion, aerobic respiration of DCCHO and DHAA, supplied by diapycnal mixing (0.46&thinsp;µmol&thinsp;kg−1&thinsp;d−1 at maximum), could account for up to 38&thinsp;% of the diapycnal O2 supply in the upper oxycline, which suggests that DOM utilization plays a significant role for shaping the upper oxycline in the ETSP.</p

Calcium in Kenyon Cell Somata as a Substrate for an Olfactory Sensory Memory in Drosophila

Animals can form associations between temporally separated stimuli. To do so, the nervous system has to retain a neural representation of the first stimulus until the second stimulus appears. The neural substrate of such sensory stimulus memories is unknown. Here, we search for a sensory odor memory in the insect olfactory system and characterize odorant-evoked Ca2+ activity at three consecutive layers of the olfactory system in Drosophila: in olfactory receptor neurons (ORNs) and projection neurons (PNs) in the antennal lobe, and in Kenyon cells (KCs) in the mushroom body. We show that the post-stimulus responses in ORN axons, PN dendrites, PN somata, and KC dendrites are odor-specific, but they are not predictive of the chemical identity of past olfactory stimuli. However, the post-stimulus responses in KC somata carry information about the identity of previous olfactory stimuli. These findings show that the Ca2+ dynamics in KC somata could encode a sensory memory of odorant identity and thus might serve as a basis for associations between temporally separated stimuli

Escrevendo em aulas de Ciências

Neste artigo, apresentamos uma análise dos registros escritos dos alunos do 3° ano do Ensino Fundamental nas aulas de Ciências, em que a professora utilizou as atividades de conhecimento físico, criadas pelo Laboratório de Pesquisa e Ensino de Física da Faculdade de Educação da Universidade de São Paulo. Os registros analisados foram coletados na Escola de Aplicação da Feusp, no ano de 2001, durante o acompanhamento de três aulas de Ciências: o problema do submarino, o problema do barquinho e o problema da pressão. O artigo procura mostrar um panorama de como aparecem os registros realizados pelos alunos, após uma aula de Ciências em que eles são levados a resolver situações problemáticas por meio da experimentação, argumentar e escrever sobre os fenômenos físicos. Durante a análise, levou-se em consideração os tipos de textos que os alunos escrevem, o uso da primeira pessoa, o uso de verbos de ação, o respeito à ordem cronológica dos eventos e quais os tipos de explicações os alunos atribuem aos fenômenos trabalhados

The meaning of religious beliefs for a group of cancer patients during rehabilitation

Este estudo exploratório teve o objetivo de identificar como a religião influencia a sobrevivência de um grupo de pacientes oncológicos. Consistiu em estudo de caso etnográfico, com a participação de seis laringectomizados, de ambos os sexos, na faixa etária de 51 a 72 anos, operados de dois a cinco anos. Os dados foram coletados por entrevistas semi-estruturadas e analisados segundo os conceitos de cultura e religião. Sintetizou-se os resultados em três categorias descritivas: a representação moral do câncer, as crenças religiosas na trajetória do câncer e a negociação com a religião para a sobrevivência. O significado que emerge - "a expectativa por uma segunda chance" - enfatiza a importância da religião como parte das redes de apoio que se articulam com o enfrentamento do estigma do câncer, com a expectativa da cura e com as formas de organizar a vida cotidiana, na sobrevivência.La finalidad de este estudio exploratorio fue identificar cómo la religión influencia la supervivencia de un grupo de pacientes oncológicos. Consistió en un estudio de caso etnográfico con la participación de seis laringectomizados, de ambos sexos, con edad de 51 a 72 años, que habían sido operados de dos a cinco años antes. Los datos fueron recogidos por entrevistas semi-estructuradas y analizados según los conceptos de cultura y religión. Sintetizamos los resultados en tres categorias descriptivas: la representación moral del cáncer, las creencias religiosas en el trayecto del cáncer y la negociación con la religión por la supervivencia. El significado que resulta - "la expectativa por una segunda oportunidad" - enfatiza la importancia de la religión como parte de las redes de apoyo que se encadenan con la conciliación con el estigma del cáncer, con la expectativa de cura y con las formas de arreglar la vida cotidiana, en la supervivenvia.The objective of this exploratory study was to identify how religion influences the survival of a group of cancer patients. The study consisted of an ethnographic case with the participation of six laryngectomized male and female patients between 51 and 72 years old, who had been operated on two to five years earlier. Data were collected by semistructured interviews and analyzed on the basis of the concepts of culture and religion. The results were synthesized into three descriptive categories: the moral representation of cancer, religious beliefs about the cancer trajectory, and negotiation with religion for survival. These categories give rise to the meaning "the hope for a second chance", which emphasizes the importance of religion as part of the support networks that articulate with the patient's coping with the stigma of cancer, with the hope for cure, and with the ways of organizing everyday life, during survival

Detection of pneumonia associated pathogens using a prototype multiplexed pneumonia test in hospitalized patients with severe pneumonia

Severe pneumonia remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods--particularly in patients with prior antibiotic treatment--and therefore, may improve the accuracy of microbiological diagnosis for hospitalized patients with pneumonia. Conventional detection techniques and multiplex PCR for 14 typical bacterial pneumonia-associated pathogens were performed on respiratory samples collected from adult hospitalized patients enrolled in a prospective multi-center study. Patients were enrolled from March until September 2012. A total of 739 fresh, native samples were eligible for analysis, of which 75 were sputa, 421 aspirates, and 234 bronchial lavages. 276 pathogens were detected by microbiology for which a valid PCR result was generated (positive or negative detection result by Curetis prototype system). Among these, 120 were identified by the prototype assay, 50 pathogens were not detected. Overall performance of the prototype for pathogen identification was 70.6% sensitivity (95% confidence interval (CI) lower bound: 63.3%, upper bound: 76.9%) and 95.2% specificity (95% CI lower bound: 94.6%, upper bound: 95.7%). Based on the study results, device cut-off settings were adjusted for future series production. The overall performance with the settings of the CE series production devices was 78.7% sensitivity (95% CI lower bound: 72.1%) and 96.6% specificity (95% CI lower bound: 96.1%). Time to result was 5.2 hours (median) for the prototype test and 43.5 h for standard-of-care. The Pneumonia Application provides a rapid and moderately sensitive assay for the detection of pneumonia-causing pathogens with minimal hands-on time