787 research outputs found
Recent disruptions in the timing and intensity of precipitation in Calakmul, Mexico
This study addresses changes in the timing and intensity of precipitation from 1982 to 2016 from three meteorological stations around Calakmul, Mexico, a landscape balancing biodiversity conservation and smallholder agricultural production. Five methods were used to assess changes in precipitation: the Mann-Kendall test of annual and wet season trends; a fuzzy-logic approach to determine the onset of the rainy season; the Gini Index and Precipitation Concentration Index (PCI) to evaluate the temporal distribution of precipitation; Simple Precipitation Intensity Index (SDII) to evaluate precipitation intensity; and the Rainfall Anomaly Index (RAI) to identify the deficit or surplus of rainfall compared to the long-term mean. Overall, rainfall trends in Calakmul over this period indicate a slight increase, though results of the indices (Gini, SDII, PCI) all indicate that rainfall has become more intense and more unevenly distributed throughout the year. There was no significant trend in the onset date of rainfall or the RAI overall, though there were more pronounced crests and troughs from 2004 to 2016. Higher interannual variability and more pronounced rainfall anomalies, both positive and negative, suggest that rainfall in the Calakmul region has become more extreme. This research informs for management and livelihood strategies in the local region and offers insights for analyses of regional patterns of seasonal precipitation events in tropical landscapes worldwide
Genetic variation in circadian regulation of nocturnal stomatal conductance enhances carbon assimilation and growth
Circadian resonance, whereby a plant's endogenous rhythms are tuned to match environmental cues, has been repeatedly shown to be adaptive, although the underlying mechanisms remain elusive. Concomitantly, the adaptive value of nocturnal transpiration in C3 plants remains unknown because it occurs without carbon assimilation. These seemingly unrelated processes are interconnected because circadian regulation drives temporal patterns in nocturnal stomatal conductance, with maximum values occurring immediately before dawn for many species. We grew individuals of six Eucalyptus camaldulensis genotypes in naturally lit glasshouses and measured sunset, predawn and midday leaf gas exchange and whole-plant biomass production. We tested whether sunrise anticipation by the circadian clock and subsequent increases in genotype predawn stomatal conductance led to rapid stomatal opening upon illumination, ultimately affecting genotype differences in carbon assimilation and growth. We observed faster stomatal responses to light inputs at sunrise in genotypes with higher predawn stomatal conductance. Moreover, early morning and midday stomatal conductance and carbon assimilation, leaf area and total plant biomass were all positively correlated with predawn stomatal conductance across genotypes. Our results lead to the novel hypothesis that genotypic variation in the circadian-regulated capacity to anticipate sunrise could be an important factor underlying intraspecific variation in tree growth
Current concepts on oxidative/carbonyl stress, inflammation and epigenetics in pathogenesis of chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) is a global health problem, and current therapy for COPD is poorly effective and the mainstays of pharmacotherapy are bronchodilators. A better understanding of the pathobiology of COPD is critical for the development of novel therapies. In the present review, we have discussed the roles of oxidative/aldehyde stress, inflammation/immunity, and chromatin remodeling in the pathogenesis of COPD. Imbalance of oxidant/antioxidant balance caused by cigarette smoke and other pollutants/biomass fuels plays an important role in the pathogenesis of COPD by regulating redox-sensitive transcription factors (e.g. NF-κB), autophagy and unfolded protein response leading to chronic lung inflammatory response. Cigarette smoke also activates canonical/alternative NF-κB pathways and their upstream kinases leading to sustained inflammatory response in lungs. Recently, epigenetic regulation has been shown to be critical for the development of COPD because the expression/activity of enzymes that regulate these epigenetic modifications have been reported to be abnormal in airways of COPD patients. Hence, the significant advances made in understanding the pathophysiology of COPD as described herein will identify novel therapeutic targets for intervening COPD
Antibiotic activities of peptides, hydrogen peroxide and peroxynitrite in plant defence
Genes encoding plant antibiotic peptides show expression patterns that are consistent with a defence role. Transgenic over-expression of defence peptide genes is potentially useful to engineer resistance of plants to relevant pathogens. Pathogen mutants that are sensitive to plant peptides in vitro have been obtained and a decrease of their virulence in planta has been observed, which is consistent with their hypothetical defence role. A similar approach has been followed to elucidate the potential direct anti-microbial role of hydrogen peroxide. Additionally, a scavenger of peroxynitrite has been used to investigate its involvement in plant defenc
Effects of Propofol on Endotoxin-Induced Acute Lung Injury in Rabbit
This study was undertaken to clarify the effects of propofol on endotoxin-induced acute lung injury. Rabbits were randomly assigned to one of four groups. Each group received intravenous infusion of saline only, saline and Escherichia coli endotoxin, propofol (1 mg/kg bolus, then 5 mg/kg/hr) and endotoxin, or propofol (4 mg/kg bolus, then 20 mg/kg/hr) and endotoxin respectively. Infusion of saline or propofol was started 0.5 hr before the infusion of saline or endotoxin, and continued for 6 hr thereafter. The lungs of rabbits were ventilated with 40% oxygen. Mean blood pressure, heart rate, arterial oxygen tension (PaO2), and peripheral blood leukocyte and platelet count were recorded. The wet/dry (W/D) weight ratio of lung and lung injury score were measured, and analysis of bronchoalveolar lavage fluid (BALF) was done. Endotoxin decreased PaO2, and peripheral blood leukocyte and platelet count. And it increased W/D ratio of lung, lung injury score and leukocyte count, percentage of PMN cells, concentration of albumin, thromboxane B2 and IL-8 in BALF. Propofol attenuated all these changes except the leukocyte count in peripheral blood. In conclusion, propofol attenuated endotoxin-induced acute lung injury in rabbits mainly by inhibiting neutrophil and IL-8 responses, which may play a central role in sepsis-related lung injury
Concepts of price fairness: Empirical research into the Dutch coffee market
This paper researches perceptions of the concept of price fairness in the Dutch coffee market. We distinguish four alternative standards of fair prices based on egalitarian, basic rights, capitalistic and libertarian approaches. We investigate which standards are guiding the perceptions of price fairness of citizens and coffee trade organizations. We find there is a divergence in views between citizens and key players in the coffee market. Whereas citizens support the concept of fairness derived from the basic rights approach, holding that the price should provide coffee farmers with a minimum level of subsistence, representatives of Dutch coffee traders hold the capitalistic view that the free world market price is fair
Second Workshop on Estimation with the RDBES data model (WKRDB-EST2; outputs from 2020 meeting)
This report shows how the new RDBES that is currently in development will be better able to support the recast EU Data Collection Framework (Regulation (EU) 2017/1004) than the existing RDB. The RDBES is an essential platform for MS and RCGs to fulfil their obligations towards documenting and improving data quality and designing and implementing regional sampling designs. The evaluation of data precision was performed using two complementary techniques. For relatively simple sampling designs it is possible to use analytical functions to calculate the precision (or a related statistical measure such as variance) of a statistical estimate. These calculations and implementations of them in R code are presented in this report. For more complicated sampling designs, the use of analytical functions is usually not feasible. In these cases, it is necessary to evaluate precision using numerical techniques, the main one of which is bootstrapping. This report discussed when bootstrapping is appropriate and gives several worked examples describing how bootstrapping can be applied in different cases. The evaluation of bias is a difficult subject and is hard to quantify. The approach followed in this report was to build on the previous work available in the ICES literature and identify and enumerate the main common sources of bias in catch sampling programs they describe. The information was collated and an evaluation performed as to whether data stored using the RDBES data format and reports issues from them can inform about the potential for bias in catch estimates. A set of example reports was coded that demonstrates the utility of the RDBES in relation to bias issues and can already help member states to identify how deviations in their sampling programmes and sampling variability may potentially lead to bias in their catch estimates
Demethylation of the Coding Region Triggers the Activation of the Human Testis-Specific PDHA2 Gene in Somatic Tissues
Human PDHA2 is a testis-specific gene that codes for the E1α subunit of Pyruvate Dehydrogenase Complex (PDC), a crucial enzyme system in cell energy metabolism. Since activation of the PDHA2 gene in somatic cells could be a new therapeutic approach for PDC deficiency, we aimed to identify the regulatory mechanisms underlying the human PDHA2 gene expression. Functional deletion studies revealed that the −122 to −6 promoter region is indispensable for basal expression of this TATA-less promoter, and suggested a role of an epigenetic program in the control of PDHA2 gene expression. Indeed, treatment of SH-SY5Y cells with the hypomethylating agent 5-Aza-2′-deoxycytidine (DAC) promoted the reactivation of the PDHA2 gene, by inducing the recruitment of the RNA polymerase II to the proximal promoter region and the consequent increase in PDHA2 mRNA levels. Bisulfite sequencing analysis revealed that DAC treatment induced a significant demethylation of the CpG island II (nucleotides +197 to +460) in PDHA2 coding region, while the promoter region remained highly methylated. Taken together with our previous results that show an in vivo correlation between PDHA2 expression and the demethylation of the CpG island II in testis germ cells, the present results show that internal methylation of the PDHA2 gene plays a part in its repression in somatic cells. In conclusion, our data support the novel finding that methylation of the PDHA2 coding region can inhibit gene transcription. This represents a key mechanism for absence of PDHA2 expression in somatic cells and a target for PDC therapy
Skeletal muscle metabolomics and blood biochemistry analysis reveal metabolic changes associated with dietary amino acid supplementation in dairy calves
The effects of different amino acid (AA) supplementations of milk protein-based milk replacers
in pre-ruminant calves from 3 days to 7 weeks of age were studied. Animals were divided into 4
groups: Ctrl) Control group fed with milk protein-based milk replacer without supplementation; GP)
supplementation with 0.1% glycine and 0.3% proline; FY) supplementation with 0.2% phenylalanine
and 0.2% tyrosine; MKT) supplementation with 0.62% lysine, 0.22% methionine and 0.61% threonine.
For statistical analysis, t-test was used to compare AA-supplemented animals to the Ctrl group. At week
7, body weight and average daily gain (ADG) were measured and blood samples and skeletal muscle
biopsies were taken. Blood biochemistry analytes related to energy metabolism were determined
and it was shown that MKT group had higher serum creatinine and higher plasma concentration
of three supplemented AAs as well as arginine compared with the Ctrl group. GP group had similar
glycine/proline plasma concentration compared with the other groups while in FY group only plasma
phenylalanine concentration was higher compared with Control. Although the AA supplementations
in the GP and FY groups did not affect average daily gain and metabolic health profile from serum, the
metabolome analysis from skeletal muscle biopsy revealed several differences between the GP-FY
groups and the Ctrl-MKT groups, suggesting a metabolic adaptation especially in GP and FY groupsinfo:eu-repo/semantics/publishedVersio
Developing agreement on never events in primary care dentistry:an international eDelphi study
Introduction:
Never events (NEs) are a subset of serious patient safety incidents that should not occur if appropriate preventive measures are implemented. Although there is a consensus in medicine, there is no agreement on NEs in dentistry.
Aim:
To identify NEs in primary care dentistry.
Method:
We undertook an electronic Delphi exercise to develop an international agreement on NEs for primary care dentistry.
Results:
We initially identified candidate NEs through a scoping review of the literature and then analysed dentistry-related reports in a national incident reporting system. Next, we invited an international panel of 41 experts to complete two rounds of questionnaires; 32 agreed to participate (78%) and completed the first round and 29/41 (71%) members completed the second round. We provided anonymised controlled feedback between rounds and used a cut-off of 80% agreement to define consensus. Consensus was achieved for 23 out of 42 candidate NEs. These related to routine assessment, and pre-operative, intra-operative and post-operative stages of dental procedures.
Discussion and conclusion:
To our knowledge, this is the first international expert consensus-based approach that has identified NEs for primary care dentistry. We suggest that dental regulators consider these to support quality assessment and governance activities
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