This investigation evaluates whether there is coherency in warm and cool season precipitation at the low-frequency scale that may be responsible for multi-year droughts in the US Southwest. This ...low-frequency climate variability at the decadal scale and longer is studied within the context of a twentieth-century reanalysis (20CR) and its dynamically-downscaled version (DD-20CR). A spectral domain matrix methods technique (Multiple-Taper-Method Singular Value Decomposition) is applied to these datasets to identify statistically significant spatiotemporal precipitation patterns for the cool (November–April) and warm (July–August) seasons. The low-frequency variability in the 20CR is evaluated by exploring global to continental-scale spatiotemporal variability in moisture flux convergence (MFC) to the occurrence of multiyear droughts and pluvials in Central America, as this region has a demonstrated anti-phase relationship in low-frequency climate variability with northern Mexico and the southwestern US By using the MFC in lieu of precipitation, this study reveals that the 20CR is able to resolve well the low-frequency, multiyear climate variability. In the context of the DD-20CR, multiyear droughts and pluvials in the southwestern US (in the early twentieth century) are significantly related to this low-frequency climate variability. The precipitation anomalies at these low-frequency timescales are in phase between the cool and warm seasons, consistent with the concept of dual-season drought as has been suggested in tree ring studies.
Mechanical failures are the most common defects in induction motors (IMs). They derive from the continuous starts and stops with high-load torque. They can cause interruptions in production lines ...with great economic losses. Therefore, online monitoring systems, allowing a continuous monitoring for fault diagnosis in early stages, have been intended for many researches in last years. Broken rotor bars (BRBs) are common failures, which are among the most difficult to detect since the induction motor works with apparent normality without giving any signal about the defect. Several methodologies have been proposed to detect BRBs in IMs. However, they require high-computational-complexity algorithms for parameterizing the current signal, making it difficult to achieve an online implementation of the corresponding monitoring system. Hence, aiming to overcome the limitations provoked by complex parameterizations of the current signal and to improve the fault classification accuracy, in this work, a novel methodology, based on a hardware processing system implemented on a field-programmable gate array (FPGA), for electric current signal analysis in the Walsh-Hadamard domain is proposed to achieve online intelligent BRB diagnosis. The <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula>-nearest neighbors (<inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula>-NN) algorithm is used for classifying different operational conditions from the Walsh-Hadamard transform (WHT) of the electric-current signal. Experimentally obtained results from applying the proposed method on acquired real data demonstrate that the introduced approach reaches a remarkable high efficiency on detecting and classifying BRBs.
Hemostasis is a defense mechanism that protects an organism from bleeding. Abnormal hemostasis results in bleeding disorders and thrombosis. Several factors are known to control hemostasis in ...mammals. Despite this progress, more factors remain to be identified. Classical genetic approaches have resolved physiological pathways. However, classical genetics could not be applied completely to hemostasis pathways a decade ago. We introduced zebrafish as a model system to study hemostasis and thrombosis using classical genetic methods. First, we established that zebrafish hemostasis is essentially similar to mammalian hemostasis. Secondly, we developed screening tools for isolating hemostatic mutants. These tools enabled us to identify hemostatic mutants, as well as providing a means to study hemostasis by knockdown methods. Continued characterization of the physiology of thrombus formation led to the novel finding of thrombocyte clustering. Recently, we have discovered that fish secrete proteases, which participate in hemostasis and may have direct relevance in humans. Future work to identify most of the players in thrombus formation is underway.
Military risk factors for Alzheimer's disease Weiner, Michael W; Friedl, Karl E; Pacifico, Anthony ...
Alzheimer's & dementia,
July 2013, Letnik:
9, Številka:
4
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Abstract Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are signature injuries of the wars in Iraq and Afghanistan and have been linked to an increased risk of Alzheimer's ...disease (AD) and other dementias. A meeting hosted by the Alzheimer's Association and the Veterans' Health Research Institute (NCIRE) in May 2012 brought together experts from the U.S. military and academic medical centers around the world to discuss current evidence and hypotheses regarding the pathophysiological mechanisms linking TBI, PTSD, and AD. Studies underway in civilian and military populations were highlighted, along with new research initiatives such as a study to extend the Alzheimer's Disease Neuroimaging Initiative (ADNI) to a population of veterans exposed to TBI and PTSD. Greater collaboration and data sharing among diverse research groups is needed to advance an understanding and appropriate interventions in this continuum of military injuries and neurodegenerative disease in the aging veteran.
Rasagiline N-propargyl-1(R)-aminoindan is a selective irreversible MAO-B inhibitor as is (−)deprenyl. The effect of the drug on antioxidant enzyme activities on dopaminergic tissue was examined in ...male F-344 rats (8.5-months-old). Two experi-mental groups were infused subcutaneously with rasagiline saline solutions by means of osmotic minipumpus implanted subcutaneously in the back of the rats. Control animals were also similarly implanted with saline filled mini-pumps. Three-and-one-half weeks later, animals were sacrificed and selected tissue samples removed from brain, kidney and heart. Two doses of rasagiline (0.5 mg/kg/day, 1.0 mg/kg/day, both for 3.5 weeks) significantly increased catalase activities about 2-fold in substantia nigra and striatum but not in hippocampus. Interestingly, in both renal cortex and medulla, catalase (CAT) activities were significantly increased. Both Mn- and Cu,Zn-superoxide dismutase (SOD) activities were increased 2 to 4 fold in substantia nigra, striatum and renal cortex and heart. Several groups, including our own have reported an extension of survival of deprenyl-treated animals of different species. Although the mechanism(s) of the life extension by deprenyl remains unresolved, it would be interesting to investigate the effect of rasagiline on the survival of animals, since deprenyl also was shown to increase antioxidant enzyme activities in brain dopaminergic regions.
The discovery of leptin has sparked a rapidly growing number of publications concerning the role of leptin in the regulation
of body adiposity, feeding, and reproductive system in mammals. To date, ...there have been no reports on the presence of leptin-related
peptide, and functional studies on the role of leptin remain limited in fishes. We investigated the effect of mouse recombinant
leptin on basal and sea bream (sb) GnRH-induced LH release from dispersed pituitary cells obtained from male European sea
bass ( Dicentrarchus labrax ) at different stages of sexual development. The potential interaction of leptin with the porcine neuropeptide Y (pNPY), known
to play a dual role in feeding and reproduction in vertebrates, was also investigated. High doses of leptin (10 â8 â10 â6 M) and/or pNPY (0.1 and 1 nM) had different effects on LH release at various stages of sexual development. Porcine NPY alone
was weakly effective on basal LH release, but it enhanced LH release induced by leptin (10 â6 M) in late prepuberty but not in early postpuberty. Additive or inhibitory effects of leptin were observed on sbGnRH-induced
LH release depending on sbGnRH dose and stage of sexual development. The direct action of leptin on LH release at the pituitary
level in sea bass suggests that leptin is a regulator of the reproductive system in fishes.
A core subset of Spanish durum wheat landraces was evaluated at two nitrogen levels (80 and 220 kg/ha) to identify landrace genotypes adapted to low N production. Yield differences were statistically ...significant between N levels and among genotypes at both levels. Fifty-one per cent of the landraces yielded significantly more at low than at high N (low-N varieties) while 26% had a positive (high-N varieties) and 23% an indifferent (indifferent-N varieties) response to N fertilizer. No significant agromorphological differences were found among low and high-N varieties at low N level that conferred some advantage to low-N varieties. In contrast, high-N varieties possessed longer grain-filling period under high N level. Phenological characters showed an important influence on yield and on the performance of the varieties within each subgroup. The traits affecting grain yield most positively, mainly the low-N varieties, were long filling period and earliness. Five entries were selected for prebreeding to low N adaptation.
Background. Sleep duration, either short or long, has been associated with diseases such as obesity, type-2 diabetes and cardiovascular diseases. Characterizing the prevalence and patterns of sleep ...duration at the population-level, especially in resource-constrained settings, will provide informative evidence on a potentially modifiable risk factor. The aim of this study was to explore the patterns of sleep duration in the Peruvian adult and adolescent population, together with its socio-demographic profile. Material and Methods. A total of 12,424 subjects, mean age 35.8 years (SD ±17.7), 50.6% males, were included in the analysis. This is a cross-sectional study, secondary analysis of the Use of Time National Survey conducted in 2010. We used weighted means and proportions to describe sleep duration according to socio-demographic variables (area and region; sex; age; education attainment; asset index; martial and job status). We used Poisson regressions, taking into account the multistage sampling design of the survey, to calculate crude and adjusted prevalence ratios (PR) and 95% confidence intervals (95% CI). Main outcomes were short- (<6 h) and long-sleep duration (≥ 9 h). Results. On average, Peruvians slept 7.7 h (95% CI 7.4-8.0) on weekdays and 8.0 h (95% CI 7.8-8.1) during weekends. The proportions of short- and long-sleep, during weekdays, were 4.3% (95% CI 2.9%-6.3%) and 22.4% (95% CI 14.9%-32.1%), respectively. Regarding urban and rural areas, a much higher proportion of short-sleep was observed in the former (92.0% vs. 8.0%); both for weekdays and weekends. On the multivariable analysis, compared to regular-sleepers (≥ 6 to <9 h), short-sleepers were twice more likely to be older and to have higher educational status, and 50% more likely to be currently employed. Similarly, relative to regular-sleep, long-sleepers were more likely to have a lower socioeconomic status as per educational attainment. Conclusions. In this nationally representative sample, the sociodemographic profile of short-sleep contrasts the long-sleep. These scenarios in Peru, as depicted by sleeping duration, differ from patterns reported in other high-income settings and could serve as the basis to inform and to improve sleep habits in the population. Moreover, it seems important to address the higher frequency of short-sleep duration found in urban versus rural settings.
Replacement of regular salt with potassium-enriched substitutes reduces blood pressure in controlled situations, mainly among people with hypertension. We report on a population-wide implementation ...of this strategy in a stepped-wedge cluster randomized trial (NCT01960972). The regular salt in enrolled households was retrieved and replaced, free of charge, with a combination of 75% NaCl and 25% KCl. A total of 2,376 participants were enrolled in 6 villages in Tumbes, Peru. The fully adjusted intention-to-treat analysis showed an average reduction of 1.29 mm Hg (95% confidence interval (95% CI) (-2.17, -0.41)) in systolic and 0.76 mm Hg (95% CI (-1.39, -0.13)) in diastolic blood pressure. Among participants without hypertension at baseline, in the time- and cluster-adjusted model, the use of the salt substitute was associated with a 51% (95% CI (29%, 66%)) reduced risk of developing hypertension compared with the control group. In 24-h urine samples, there was no evidence of differences in sodium levels (mean difference 0.01; 95% CI (0.25, -0.23)), but potassium levels were higher at the end of the study than at baseline (mean difference 0.63; 95% CI (0.78, 0.47)). Our results support a case for implementing a pragmatic, population-wide, salt-substitution strategy for reducing blood pressure and hypertension incidence.
PDF
