1,147 research outputs found

    Extractability of P in major soils of Angola as affected by P fertilizers and lime application

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    Phosphorus (P) deficiency is the major constraint to crop production in most tropical soils (Sahrawat et al., 2001). In Angola, such constraint (i.e, low concentration and low P solubility) has also been reported to limit crop production in many agricultural soils (Ucuassapi, 2006). These soils may require application of inorganic P through soluble and relatively reactive phosphate rock sources, and lime (Dobermann et al., 2002; Murphy, 2007). However, appropriate P management strategies may require information on the fate of applied P and its interaction with the colloidal constituents. Therefore, information on the different P fractions (inorganic and organic) after the application of different rates of P fertilizers and lime, as fractionated sequentially by the Hedley modified procedure (Tiessen and Moir, 1993) is crucial for making appropriate fertilizer and lime rate recommendations for crops (Islam et al., 2010)

    Seasonal proteome variation in intertidal shrimps under a natural setting: connecting molecular networks with environmental fluctuations

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    The ability of intertidal organisms to maintain their performance via molecular and physiological adjustments under low tide, seasonal fluctuations and extreme events ultimately determines population viability. Analyzing this capacity in the wild is extremely relevant since intertidal communities are under increased climate variability owing to global changes. We addressed the seasonal proteome signatures of a key intertidal species, the shrimp Palaemon elegans, in a natural setting. Shrimps were collected during spring and summer seasons at low tides and were euthanized in situ. Environmental variability was also assessed using hand-held devices and data loggers. Muscle samples were taken for 2D gel electrophoresis and protein identification through mass spectrometry. Proteome data revealed that 55 proteins (10.6% of the proteome) significantly changed between spring and summer collected shrimps, 24 of which were identified. These proteins were mostly involved in cytoskeleton remodelling, energy metabolism and transcription regulation. Overall, shrimps modulate gene expression leading to metabolic and structural adjustments related to seasonal differences in the wild (i.e. abiotic variation and possibly intrinsic cycles of reproduction and growth). This potentially promotes performance and fitness as suggested by the higher condition index in summer-collected shrimps. However, inter-individual variation (% coefficient of variation) in protein levels was quite low (min-max ranges were 0.6-8.3% in spring and 1.2-4.8% in summer), possibly suggesting reduced genetic diversity or physiological canalization. Protein plasticity is relevant to cope with present and upcoming environmental variation related to anthropogenic forcing (e.g. global change, pollution) but low inter-individual variation may limit evolutionary potential of shrimp populations.publishe

    Death ideation in cancer patients: contributing factors

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    Advances in cancer research and therapy have improved prognosis and the quality of life of many patients. However, previous epidemiological studies in oncologic patients have shown an increased risk of suicide. Suicidal thoughts, relatively well known in those terminally ill, may be just as important for cancer patients who are survivors or are living with the disease. Nonetheless, there is a relative paucity of data about suicidality in this setting. The authors conducted a prospective observational study to identify death thoughts and to explore the factors associated with suicidal ideation in cancer patients. A sample of 130 patients referred for psychiatric consultation was obtained following informed consent and authorization from the local ethics committee. A semistructured interview assessed sociodemographic data, psychosocial support, and information regarding the cancer process and its treatment. Psychometric instruments were used to evaluate psychopathology, namely the Hospital Anxiety and Depression Scale, the Beck Hopelessness Scale, and the Beck Scale for Suicide Ideation. Psychiatric diagnoses were obtained through the application of the Mini International Neuropsychiatric Interview. Death ideation was identified in 34.6% of patients, yet only 10% had active suicidal thoughts. Risk of suicide was associated with female gender, a psychiatric diagnosis (major depressive disorder, panic disorder, or dysthymia), difficult interpersonal relationships, associated pain, high hopelessness, and depressive and anxiety symptoms. Although suicidal thoughts are frequent in cancer patients at different stages of disease, most are transitory. Risk factors for suicidal ideation have been identified, such as depression, hopelessness, uncontrolled pain, and difficult interpersonal relationships. Further assessment is necessary to identify those at higher risk of attempting suicide, and underlying psychiatric disorders should be vigorously treated

    Desempenho de cultivares de abóbora híbrida tetsukabuto em sistema plantio direto.

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    Suplemento. Edição dos Anais do 53 Congresso Brasileiro de Olericultura, jul. 2014

    Carbono orgânico total e suas frações físicas em latossolo vermelho cultivado com hortaliças em sistemas conservacionistas.

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    O presente trabalho teve como objetivo quantificar os teores de carbono orgânico total (COT) e suas frações físicas em um Latossolo Vermelho Distrófico cultivado com hortaliças em sistemas conservacionistas há seis anos

    Carbono das substancias húmicas em latossolo vermelho cultivado com hortaliças em sistemas conservacionistas.

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    O presente trabalho teve como objetivo quantificar os teores de carbono das substâncias húmicas em um Latossolo Vermelho Distrófico típico cultivado com hortaliças em sistemas conservacionistas há cinco anos

    What can genetics tell us about the history of a human-mediated introduction of the golden-striped salamander south of its native range?

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    The golden-striped salamander is a streamside species endemic to the northwestern corner of the Iberian Peninsula. In the first half of the twentieth century, an undisclosed number of individuals of this species were reportedly captured in Buçaco, Central Portugal, and deliberately introduced in Sintra Mountains, 170 km south of its native distribution range. The discovery of a breeding population of this salamander in Sintra during 2015 prompted this work: we used neutral genetic markers, the mitochondrial DNA cytochrome b (cytb), and seven microsatellite loci to elucidate on the relict/human-introduced nature of Sintra population, identify the potential source population, and infer the severity of founder effect. Our results support a human-mediated introduction. First, sequencing analysis of cytb showed the presence of a unique haplotype (h31) in Sintra, which was detected only in Buçaco and in two additional populations located close to Mondego river. Second, microsatellite analysis showed that Sintra is more closely related to populations in between Douro and Mondego rivers (Central Portugal), instead of its geographically closest populations (southernmost), as would be expected if Sintra was a relict population isolated in an interglacial refuge. Third, Sintra presents both reduced levels of genetic variability and effective population size when compared to native populations, particularly to those of Central Portugal. Consistent with an isolated population funded by a small number of individuals (inferred herein to be ca. 10–11 salamanders), Sintra forms a geographically coherent genetic unit that is significantly differentiated from the extant native C. lusitanica populations. Although our data provide supporting evidence for Buçaco as a likely source population, as documented in the literature, overall, we cannot unequivocally exclude other populations close to Mondego river as a potential source of the introduced individuals in Sintra.info:eu-repo/semantics/acceptedVersio
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