151 research outputs found

    Atmospheric deposition and precipitation are important predictors of inorganic nitrogen export to streams from forest and grassland watersheds: a large-scale data synthesis

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    Previous studies have evaluated how changes in atmospheric nitrogen (N) inputs and climate affect stream N concentrations and fluxes, but none have synthesized data from sites around the globe. We identified variables controlling stream inorganic N concentrations and fluxes, and how they have changed, by synthesizing 20 time series ranging from 5 to 51 years of data collected from forest and grassland dominated watersheds across Europe, North America, and East Asia and across four climate types (tropical, temperate, Mediterranean, and boreal) using the International Long-Term Ecological Research Network. We hypothesized that sites with greater atmospheric N deposition have greater stream N export rates, but that climate has taken a stronger role as atmospheric deposition declines in many regions of the globe. We found declining trends in bulk ammonium and nitrate deposition, especially in the longest time-series, with ammonium contributing relatively more to atmospheric N deposition over time. Among sites, there were statistically significant positive relationships between (1) annual rates of precipitation and stream ammonium and nitrate fluxes and (2) annual rates of atmospheric N inputs and stream nitrate concentrations and fluxes. There were no significant relationships between air temperature and stream N export. Our long-term data shows that although N deposition is declining over time, atmospheric N inputs and precipitation remain important predictors for inorganic N exported from forested and grassland watersheds. Overall, we also demonstrate that long-term monitoring provides understanding of ecosystems and biogeochemical cycling that would not be possible with short-term studies alone.publishedVersio

    Experimental studies on combustion characteristics of oil-palm biomass in fluidized-bed: a heat energy alternative

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    One of the technologies that can be used to meet energy needs is biomass combustion. In this study, the oil palm biomass fuels used were empty fruit bunches, oil palm fibers, oil palm midribs, and palm kernel shells. This research was carried out by a direct combustion method using a fluidized-bed combustor. The purpose of this experiment was to investigate the reaction of kinetics and the mechanism of combustion of oilpalm biomass in fluidized-bed combustor. The characteristics observed in this test were the combustion temperature profile, flue-gas composition, and the composition of the ash-deposit chemical compound. The results of the experiments conducted showed that the best biomass combustion temperature profile was recorded at 2 kg biomass with an air flow rate of 0.9375 m3/s at 90.1%. The maximum temperature of biomass combustion recorded at biomass 3 kg with an air flow rate of 1.25 m3/s are 950°C (95%). The higher conversion combustion of biomass was found at biomass condition of 3 kg with an air flow rate of 0.9375 m3/s. The value of O2 emissions from biomass combustion shows that it was very small 0.2%. While the highest CO2 value was recorded at 19.9%. The highest combustion efficiency on FBC found 1 kg of biomass fuel with an air flow rate of 0.0654 m3/s recorded 94.9%

    Usefulness of the Palliative Prognostic Index in patients with lung cancer.

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    The usefulness of the Palliative Prognostic Index (PPI) has been successfully validated in a variety of clinical settings. However, while lung cancer is the leading cause of death worldwide, patients with lung cancer accounted for only 6.9-25.8 % of the study populations in these previous studies. We conducted a retrospective study to evaluate the usefulness of the PPI for survival prediction in patients with lung cancer. Patients with lung cancer who were admitted to our hospital between 2009 and 2013 to receive palliative care were enrolled. The association between the Palliative Prognostic Index, determined based on the data recorded in the clinical charts at the last admission to our hospital, and survival was evaluated. The patient group with a PPI of >6 showed a significantly shorter survival time than the patient group with a PPI of ≤ 6 (P < 0.0001, log-rank test). The sensitivity and specificity of the PPI determined using the cutoff value of 6 for predicting less than 3 weeks of survival were 61.3 and 86.8 %, respectively. However, the sensitivity decreased to 50.0 % when the assessment was carried out in only patients with small cell lung carcinoma. Our findings suggest the existence of a close association between the PPI and survival in patients with lung cancer receiving palliative care. However, the sensitivity of the index for predicting less than 3 weeks of survival was relatively low in patients with small cell lung carcinoma

    Epigenetic Activation of a Subset of mRNAs by eIF4E Explains Its Effects on Cell Proliferation

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    BACKGROUND: Translation deregulation is an important mechanism that causes aberrant cell growth, proliferation and survival. eIF4E, the mRNA 5′ cap-binding protein, plays a major role in translational control. To understand how eIF4E affects cell proliferation and survival, we studied mRNA targets that are translationally responsive to eIF4E. METHODOLOGY/PRINCIPAL FINDINGS: Microarray analysis of polysomal mRNA from an eIF4E-inducible NIH 3T3 cell line was performed. Inducible expression of eIF4E resulted in increased translation of defined sets of mRNAs. Many of the mRNAs are novel targets, including those that encode large- and small-subunit ribosomal proteins and cell growth-related factors. In addition, there was augmented translation of mRNAs encoding anti-apoptotic proteins, which conferred resistance to endoplasmic reticulum-mediated apoptosis. CONCLUSIONS/SIGNIFICANCE: Our results shed new light on the mechanisms by which eIF4E prevents apoptosis and transforms cells. Downregulation of eIF4E and its downstream targets is a potential therapeutic option for the development of novel anti-cancer drugs

    Epigenetics and inheritance of phenotype variation in livestock

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