300 research outputs found
Trophic flow within the microbial and mesozooplankton foodweb in the North Atlantic: processes indicated by analyses of stable isotopes and biovolume spectra.
The trophic flow from primary producers through the microbial and mesozooplankton food web
makes sun energy available in particulate form for higher trophic levels. Pathways through the
lower trophic levels are highly variable and determine productivity of the marine pelagic food webs.
We analysed spatial variability in food web structure across the North Atlantic by means of stable
isotope analyses (SIA) and biovolume spectrum theories (BST). At 7 stations in the Iceland Basin,
Reykjanes Ridge, Irminger Basin and Labrador Sea, respectively, chlorophyll a, zooplankton net
samples (55 μm and 150 μm) and laser optical plankton counter data were collected in the upper
200 to 500 m during a EURO-BASIN cruise with R/V M.S.Merian in spring (March/April) 2013.
Trophic indices were determined by both methods (SIA and BST) for different size groups of the
pelagic community. For the smallest fraction, both methods yielded trophic indices around 2 to 3
and agreed reasonable well. Large differences between both methods were observed in the mediumsized
fraction, which was dominated by more omnivorous species, with much higher trophic indices
estimated by BST. The largest fraction showed slightly higher value by BST, especially in the
Labrador Sea. Comparing differences between SIA and BST might allow to trace energy flow
through the microbial food web. A conceptual model is developed for the trophic flow through the
lower trophic levels and discussed with respect to phytoplankton bloom stage, water mass, and stratification.EUROBASIN (FP7-ENV-2010 Project no. 264933
Coprodução de hormônio do crescimento e prolactina em paciente com sela túrcica parcialmente vazia primária: relato de caso
Introduction: The empty sella syndrome is a neuroradiological diagnosis that shows pituitary gland reduction or flattening, with a prevalence of around 8% to 35% in general population. Objective: We report a case in which there is an association between partial primary empty sella syndrome and high levels of growth hormone and prolactin. Methods: A 67-year-old man, from Coronel Mota Hospital, Boa Vista / RR, with no specific complaints, was referred to the Endocrinology ambulatory to investigate a modification in sella area. After anamnesis and physical examination, acromegaly research began. Pituitary hormones and magnetic resonance imaging of the sella turcica with contrast were requested. Results: General physical examination revealed acromegalic face, nasal enlargement, macroglossia and frontal cutis verticis gyrata. Radiological examination showed partial empty sella. Laboratory evaluation confirmed the clinical suspicion of acromegaly and revealed hyperprolactinemia presence. It was decided to treat the patient with cabergoline 1.5 mg / week and to refer him to a center specialized in neuroendocrinology. Conclusion: This report shows a case of partial primary empty sella and co-production of growth hormone and prolactin, making this association interesting, since somatotropinomas are mostly (80%) macroadenomas. In addition, the underdiagnosis of acromegaly is highlighted, since the symptoms are nonspecific and insidious, leading to high morbidity and mortality and reduction of the affected patients life expectancy.Introdução: A síndrome da sela túrcica vazia é um diagnóstico neurorradiológico que evidencia a redução ou o achatamento da glândula pituitária, com prevalência em torno de 8 a 35% na população geral. Objetivo: Este estudo de caso relata a associação entre sela túrcica parcialmente vazia primária e elevados níveis de hormônio do crescimento e prolactina. Métodos: Homem de 67 anos, proveniente do hospital Coronel Mota, Boa Vista/RR, sem queixas específicas, encaminhado ao ambulatório de Endocrinologia para investigação de alteração em região selar. Após realização de anamnese e exame físico, iniciou-se investigação de acromegalia. Foram solicitados basais hipofisários e ressonância magnética de sela túrcica com contraste. Resultados: O exame físico geral evidenciou fácies acromegálica, alargamento nasal, macroglossia e cutis verticis gyrata frontal. O exame radiológico demonstrou sela túrcica parcialmente vazia. A avaliação laboratorial confirmou a suspeita clínica de acromegalia e revelou a presença de hiperprolactinemia. Optou-se por tratar o paciente com cabergolina 1.5mg/semana e encaminhá-lo para centro especializado em neuroendocrinologia. Conclusão: Este relato mostra um caso de sela parcialmente vazia primária e coprodução de hormônio do crescimento e prolactina, tornando esta associação interessante, uma vez que somatotropinomas são em sua maioria (80%) macroadenomas. Além disso, ressalta-se para o subdiagnóstico da acromegalia, uma vez que os sintomas são inespecíficos e insidiosos, acarretando elevada morbimortalidade e redução da expectativa de vida dos pacientes acometidos
Predictors of mortality in critically ill patients with COVID-19 and diabetes
The COVID-19 pandemic has challenged the entire world, and patients with diabetes mellitus (DM) have been particularly affected. We aimed to evaluate predictors of mortality during the first 30 days of hospitalization in critically ill patients with COVID-19 and comorbid DM. This prospective study included 110 critically ill patients admitted with COVID-19 infection. Thirty-two (29%) patients had a previous diagnosis of DM. Clinical variables, laboratory tests, and vascular biomarkers, such as VCAM-1, syndecan-1, ICAM-1, angiopoietin-1, and angiopoeitin-2, were evaluated after intensive care unit (ICU) admission. A comparison was made between patients with and without DM. No difference in mortality was observed between the groups (48.7 vs 46.9%, P=0.861). In the multivariate Cox regression analysis, VCAM-1 levels at ICU admission (HR: 1 [1-1.001], P<0.006) were associated with death in patients with DM. Among patients with DM, advanced age (HR 1.063 [1.031-1.096], P<0.001), increased Ang-2/Ang-1 ratio (HR: 4.515 [1.803-11.308] P=0.001), and need for dialysis (HR: 3.489 [1.409-8.642], P=0.007) were independent predictors of death. Higher levels of VCAM-1 in patients with DM was better at predicting death of patients with severe COVID-19 and comorbid DM, and their cut-off values were useful for stratifying patients with a worse prognosis. Vascular biomarkers VCAM-1 and Ang-2/Ang-1 ratio were predictors of death in patients with severe COVID-19 and comorbid DM and those without DM. Additionally, kidney injury was associated with an increased risk of death
Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
We review HB stars in a broad astrophysical context, including both variable
and non-variable stars. A reassessment of the Oosterhoff dichotomy is
presented, which provides unprecedented detail regarding its origin and
systematics. We show that the Oosterhoff dichotomy and the distribution of
globular clusters (GCs) in the HB morphology-metallicity plane both exclude,
with high statistical significance, the possibility that the Galactic halo may
have formed from the accretion of dwarf galaxies resembling present-day Milky
Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the
second-parameter problem is presented. A technique is proposed to estimate the
HB types of extragalactic GCs on the basis of integrated far-UV photometry. The
relationship between the absolute V magnitude of the HB at the RR Lyrae level
and metallicity, as obtained on the basis of trigonometric parallax
measurements for the star RR Lyrae, is also revisited, giving a distance
modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are
studied. Finally, the conductive opacities used in evolutionary calculations of
low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and
Space Scienc
Aspectos Estruturais e Fitoquímicos de partes vegetativas de Costus spicatus (Jacq.) Sw. (Costaceae)
Desempenho de macieiras 'Imperial Gala' e 'Mishima Fuji' em diferentes porta-enxertos
Resumo: O objetivo deste trabalho foi avaliar a influência de diferentes porta-enxertos no desempenho das cultivares de macieira (Malus domestica) Imperial Gala e Mishima Fuji. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições. Utilizaram-se os porta-enxertos CG.969, CG.874, CG.210, CG.56, CG.008, JM.2 e JM.7, além da combinação de Marubakaido com interenxerto de M.9 (Marubakaido/M.9). Avaliaram-se as variáveis: produção por planta, produtividade, número de frutos por planta, massa de fruto, área da seção transversal do tronco, sólidos solúveis, firmeza do fruto e índice iodo-amido. A produtividade de ambas as cultivares foi maior com os porta-enxertos Marubakaido/M.9, JM.2, CG.008, CG.874, CG.210 e CG.56. Além disso, os porta-enxertos CG.008, CG.874, CG.210 e CG.56 reduzem o vigor da cultivar-copa, mas sem reduzir a produtividade. O teor de sólidos solúveis dos frutos é maior quando se utilizam porta-enxertos menos vigorosos
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