265 research outputs found
Earthquake source parameters and scaling relationships in Hungary (central Pannonian basin)
Abstract Fifty earthquakes that occurred in Hungary (central
part of the Pannonian basin) with local magnitude ML
ranging from 0.8 to 4.5 have been analyzed. The digital
seismograms used in this study were recorded by six permanent
broad-band stations and twenty short-period ones at
hypocentral distances between 10 and 327 km. The displacement
spectra for P- and SH-waves were analyzed according
to Brune’s source model. Observed spectra were corrected
for path-dependent attenuation effects using an independent
regional estimate of the quality factor QS. To correct spectra
for near-surface attenuation, the k parameterwas calculated,
obtaining it fromwaveforms recorded at short epicentral distances.
The values of the k parameter vary between 0.01 to
0.06 s with a mean of 0.03 s for P-waves and between 0.01
to 0.09 s with a mean of 0.04 s for SH-waves. After correction
for attenuation effects, spectral parameters (corner
frequency and low-frequency spectral level) were estimated
by a grid search algorithm. The obtained seismic moments
range from4.21×1011 to 3.41×1015 Nm (1.7≤Mw ≤4.3).
The source radii are between 125 and 1343 m. Stress drop
values vary between 0.14 and 32.4 bars with a logarithmic
mean of 2.59 bars (1 bar = 105 Pa). From the results, a linear
relationship between local andmomentmagnitudes has been
established. The obtained scaling relations show slight evidence
of self-similarity violation. However, due to the high
scatter of our data, the existence of self-similarity cannot be
excluded
Non union of scaphoid fracture in a cricketer – possibility of a stress fracture: a case report
Scaphoid stress fractures are rare and can be a cause of wrist pain in sportspersons. All the cases reported in the literature have been sportspersons. Missing a scaphoid stress fracture could lead to non-union of the scaphoid and early degenerative arthritis of the radio-carpal joint. This can cause chronic wrist pain and can reduce the career span of a sportsperson. We report a case of non union of a scaphoid fracture in a cricketer possibly secondary to a stress fracture
Understanding resilience of female adolescents towards teenage pregnancy: a cross-sectional survey in Dar es Salaam, Tanzania
Abstract Background In Tanzania, teenage pregnancy rates are still high despite the efforts being made to reduce them. Not enough is known about how adolescents experience and cope with sexuality and teenage pregnancy. Over the past few decades, most studies have focused on vulnerability and risk among youth. The concept of ‘reproductive resilience’ is a new way of looking at teenage pregnancy. It shifts the perspective from a deficit-based to a strength-based approach. The study presented here aimed to identify factors that could contribute to strengthening the reproductive resilience of girls in Dar es Salaam, Tanzania. Methods Using a cross-sectional cluster sampling approach, 750 female adolescents aged 15–19 years were interviewed about how they mobilize resources to avoid or deal with teenage pregnancy. The main focus of the study was to examine how social capital (relations with significant others), economic capital (command over economic resources), cultural capital (personal dispositions and habits), and symbolic capital (recognition and prestige) contribute to the development of adolescent competencies for avoiding or dealing with teenage pregnancy and childbirth. Results A cumulative competence scale was developed to assess reproductive resilience. The cumulative score was computed based on 10 competence indicators that refer to the re- and pro-active mobilization of resources. About half of the women who had never been pregnant fell into the category, ‘high competence’ (50.9%), meaning they could get the information and support needed to avoid pregnancies. Among pregnant women and young mothers, most were categorized as ‘high competence’ (70.5%) and stated that they know how to avoid or deal with health problems that might affect them or their babies, and could get the information and support required to do so. Cultural capital, in particular, contributed to the competence of never-pregnant girls [OR = 1.80, 95% CI = 1.06 to 3.07, p = 0.029], pregnant adolescents and young mothers [OR = 3.33, 95% CI = 1.15 to 9.60, p = 0.026]. Conclusions The reproductive resilience framework provides new insights into the reproductive health realities of adolescent girls from a strength-based perspective. While acknowledging that teenage pregnancy has serious negative implications for many female adolescents, the findings presented here highlight the importance of considering girls’ capacities to prevent or deal with teenage pregnancy
Tsunami hazards in the Catalan Coast, a low-intensity seismic activity area
The final publication is available at Springer via http://dx.doi.org/10.1007/s11069-017-2918-zThe potential impacts of tsunamis along the Catalan Coast (NW Mediterranean) are analysed using numerical modelling. The region is characterized by moderate to low seismic activity and by moderate- to low-magnitude earthquakes. However, the occurrence of historical strong earthquakes and the location of several active offshore faults in front of the coast suggest that the possibility of an earthquake-triggered tsunami is not negligible although of low probability. Up to five faults have been identified to generate tsunamis, being the highest associated possible seismic magnitudes of up to 7.6. Coastal flooding and port agitation are characterized using the Worst-case Credible Tsunami Scenario Analysis approach. The results show a multiple fault source contribution to tsunami hazard. The shelf dimensions and the existence of submerged canyons control the tsunami propagation. In wide shelves, waves travelling offshore may become trapped by refraction causing the wave energy to reach the coastline at some distance from the origin. The free surface water elevation increases at the head of the canyons due to the sharp depth gradients. The effects of potential tsunamis would be very harmful in low-lying coastal stretches, such as deltas, with a high population concentration, assets and infrastructures. The Ebro delta appears to be the most exposed coast, and about the 20% of the delta surface is prone to flooding due to its extremely low-lying nature. The activity at Barcelona port will be severely affected by inflow backflow current at the entrance of up to 2 m/s.Peer ReviewedPostprint (author's final draft
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis
Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen
Eukaryotic Protein Kinases (ePKs) of the Helminth Parasite Schistosoma mansoni
<p>Abstract</p> <p>Background</p> <p>Schistosomiasis remains an important parasitic disease and a major economic problem in many countries. The <it>Schistosoma mansoni </it>genome and predicted proteome sequences were recently published providing the opportunity to identify new drug candidates. Eukaryotic protein kinases (ePKs) play a central role in mediating signal transduction through complex networks and are considered druggable targets from the medical and chemical viewpoints. Our work aimed at analyzing the <it>S. mansoni </it>predicted proteome in order to identify and classify all ePKs of this parasite through combined computational approaches. Functional annotation was performed mainly to yield insights into the parasite signaling processes relevant to its complex lifestyle and to select some ePKs as potential drug targets.</p> <p>Results</p> <p>We have identified 252 ePKs, which corresponds to 1.9% of the <it>S. mansoni </it>predicted proteome, through sequence similarity searches using HMMs (Hidden Markov Models). Amino acid sequences corresponding to the conserved catalytic domain of ePKs were aligned by MAFFT and further used in distance-based phylogenetic analysis as implemented in PHYLIP. Our analysis also included the ePK homologs from six other eukaryotes. The results show that <it>S. mansoni </it>has proteins in all ePK groups. Most of them are clearly clustered with known ePKs in other eukaryotes according to the phylogenetic analysis. None of the ePKs are exclusively found in <it>S. mansoni </it>or belong to an expanded family in this parasite. Only 16 <it>S. mansoni </it>ePKs were experimentally studied, 12 proteins are predicted to be catalytically inactive and approximately 2% of the parasite ePKs remain unclassified. Some proteins were mentioned as good target for drug development since they have a predicted essential function for the parasite.</p> <p>Conclusions</p> <p>Our approach has improved the functional annotation of 40% of <it>S. mansoni </it>ePKs through combined similarity and phylogenetic-based approaches. As we continue this work, we will highlight the biochemical and physiological adaptations of <it>S. mansoni </it>in response to diverse environments during the parasite development, vector interaction, and host infection.</p
Of monkeys and men:Impatience in perceptual decision-making
For decades sequential sampling models have successfully accounted for human and monkey decision-making, relying on the standard assumption that decision makers maintain a pre-set decision standard throughout the decision process. Based on the theoretical argument of reward rate maximization, some authors have recently suggested that decision makers become increasingly impatient as time passes and therefore lower their decision standard. Indeed, a number of studies show that computational models with an impatience component provide a good fit to human and monkey decision behavior. However, many of these studies lack quantitative model comparisons and systematic manipulations of rewards. Moreover, the often-cited evidence from single-cell recordings is not unequivocal and complimentary data from human subjects is largely missing. We conclude that, despite some enthusiastic calls for the abandonment of the standard model, the idea of an impatience component has yet to be fully established; we suggest a number of recently developed tools that will help bring the debate to a conclusive settlement
Signal transduction-related responses to phytohormones and environmental challenges in sugarcane
BACKGROUND: Sugarcane is an increasingly economically and environmentally important C4 grass, used for the production of sugar and bioethanol, a low-carbon emission fuel. Sugarcane originated from crosses of Saccharum species and is noted for its unique capacity to accumulate high amounts of sucrose in its stems. Environmental stresses limit enormously sugarcane productivity worldwide. To investigate transcriptome changes in response to environmental inputs that alter yield we used cDNA microarrays to profile expression of 1,545 genes in plants submitted to drought, phosphate starvation, herbivory and N(2)-fixing endophytic bacteria. We also investigated the response to phytohormones (abscisic acid and methyl jasmonate). The arrayed elements correspond mostly to genes involved in signal transduction, hormone biosynthesis, transcription factors, novel genes and genes corresponding to unknown proteins. RESULTS: Adopting an outliers searching method 179 genes with strikingly different expression levels were identified as differentially expressed in at least one of the treatments analysed. Self Organizing Maps were used to cluster the expression profiles of 695 genes that showed a highly correlated expression pattern among replicates. The expression data for 22 genes was evaluated for 36 experimental data points by quantitative RT-PCR indicating a validation rate of 80.5% using three biological experimental replicates. The SUCAST Database was created that provides public access to the data described in this work, linked to tissue expression profiling and the SUCAST gene category and sequence analysis. The SUCAST database also includes a categorization of the sugarcane kinome based on a phylogenetic grouping that included 182 undefined kinases. CONCLUSION: An extensive study on the sugarcane transcriptome was performed. Sugarcane genes responsive to phytohormones and to challenges sugarcane commonly deals with in the field were identified. Additionally, the protein kinases were annotated based on a phylogenetic approach. The experimental design and statistical analysis applied proved robust to unravel genes associated with a diverse array of conditions attributing novel functions to previously unknown or undefined genes. The data consolidated in the SUCAST database resource can guide further studies and be useful for the development of improved sugarcane varieties
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