262 research outputs found
Determination of the Half-Value Layer by Using Filter Aluminum Sheets for Digital Mammography
A method of determining the half-value layers (HVL) with or without using an aluminum (Al) filter sheet for digital mammography has been developed. HVL measurements using a single exposure method are performed without the addition of an aluminium filter. This study was conducted to evaluate the accuracy of measurements of HVL values in a single exposure method using a RaySave ion space detector. a standard method with a variation in aluminium filter thickness from 0.110 to 0.980 mm. The HVL measurement values were performed with the distance between the focus of the detector 60.5 cm, and the current 80 mAs at a voltage of 23 kVp, 25 kVp, 27 kVp, 29 kVp and 32 kVp. The HVL value is determined by using the interpolation formula. The results showed that the HVL value using aluminium filter was 0.03 mm higher than the standard method by using multiple exposures for the same thickness of the aluminium filter
Numerical simulation of the 1996 Toli-Toli tsunami and the 2000 peleng tsunami central of Celebes with single fault model
Central of Celebes is a seismic active region caused close to the triple junction between the Eurasian, Indo-Australian, and Pacific/Philippine plates. This region has high seismicity which dominated by shallow earthquake. This condition can be a trigger to generate an earthquake with tsunami potentially. The purpose of this study are to make model of Toli-Toli and Peleng tsunami source, its tsunami propagation and identify its run up at some point. In this study, we use two study cases. There are the 1996 Toli-Toli tsunami which located in Celebes Sea caused by activity of Palu Koro active fault which intersect with convergent boundaries of two tectonic plates, Philiphina Plate and Eurasian Plate and the 2000 Peleng tsunami which occur because of Batui Thrust which activated by Sorong Fault in East Celebes. This study use earthquake source parameter from Global Centroid Moment Tensor (CMT) catalog. We use single fault model to describe the source. While to get tsunami propagation and run up we use bathymetry data from National Oceanic and Atmospheric Administration (NOAA) to see tsunami propagation and its run up at some point which may be get maximum height. All of data were treated by using tsunami simulation program from Mamoru Nakamura with finite difference method. The simulation run up of Toli-Toli tsunami get the highest in South Dampal with height about 4 m, while for Peleng tsunami simulation, Bangkalan Island get the highest with height about 2.67 m. The simulation result from run up Toli-Toli tsunami indicate similarity with visual estimate but for simulation of Peleng tsunami, there are different with visual estimate result. It is caused by the morphology of the Peleng island which going constriction relatively, so energy can be amplified, easily therefore visual estimate can be different with our simulation
Unbiased optical mapping of telomere-integrated endogenous human herpesvirus 6
Next-generation sequencing technologies allowed sequencing of thousands of genomes. However, there are genomic regions that remain difficult to characterize, including telomeres, centromeres, and other low-complexity regions, as well as transposable elements and endogenous viruses. Human herpesvirus 6A and 6B (HHV-6A and HHV-6B) are closely related viruses that infect most humans and can integrate their genomes into the telomeres of infected cells. Integration also occurs in germ cells, meaning that the virus can be inherited and result in individuals harboring the virus in every cell of their body. The integrated virus can reactivate and cause disease in humans. While it is well established that the virus resides in the telomere region, the integration locus is poorly defined due to the low sequence complexity (TTAGGG)n of telomeres that cannot be easily resolved through sequencing. We therefore employed genome imaging of the integrated HHV-6A and HHV-6B genomes using whole-genome optical site mapping technology. Using this technology, we identified which chromosome arm harbors the virus genome and obtained a high resolution map of the integration loci of multiple patients. Surprisingly, this revealed long telomere sequences at the virus-subtelomere junction that were previously missed using PCR-based approaches. Contrary to what was previously thought, our technique revealed that the telomere lengths of chromosomes harbor ing the integrated virus genome were comparable to the other chromosomes. Taken together, our data shed light on the genetic structure of the HHV-6A and HHV-6B integration locus, demonstrating the utility of optical mapping for the analysis of genomic regions that are difficult to sequence
Evolutionary History of Endogenous Human Herpesvirus 6 Reflects Human Migration out of Africa
Human herpesvirus 6A and 6B (HHV-6) can integrate into the germline, and as a result, similar to 70 million people harbor the genome of one of these viruses in every cell of their body. Until now, it has been largely unknown if 1) these integrations are ancient, 2) if they still occur, and 3) whether circulating virus strains differ from integrated ones. Here, we used next-generation sequencing and mining of public human genome data sets to generate the largest and most diverse collection of circulating and integrated HHV-6 genomes studied to date. In genomes of geographically dispersed, only distantly related people, we identified clades of integrated viruses that originated from a single ancestral event, confirming this with fluorescent in situ hybridization to directly observe the integration locus. In contrast to HHV-6B, circulating and integrated HHV-6A sequences form distinct clades, arguing against ongoing integration of circulating HHV-6A or "reactivation" of integrated HHV-6A. Taken together, our study provides the first comprehensive picture of the evolution of HHV-6, and reveals that integration of heritable HHV-6 has occurred since the time of, if not before, human migrations out of Africa
E-Mobility -- Advancements and Challenges
Mobile platforms cover a broad range of applications from small portable electric devices, drones, and robots to electric transportation, which influence the quality of modern life. The end-to-end energy systems of these platforms are moving toward more electrification. Despite their wide range of power ratings and diverse applications, the electrification of these systems shares several technical requirements. Electrified mobile energy systems have minimal or no access to the power grid, and thus, to achieve long operating time, ultrafast charging or charging during motion as well as advanced battery technologies are needed. Mobile platforms are space-, shape-, and weight-constrained, and therefore, their onboard energy technologies such as the power electronic converters and magnetic components must be compact and lightweight. These systems should also demonstrate improved efficiency and cost-effectiveness compared to traditional designs. This paper discusses some technical challenges that the industry currently faces moving toward more electrification of energy conversion systems in mobile platforms, herein referred to as E-Mobility, and reviews the recent advancements reported in literature
Evolutionary History of Endogenous Human Herpesvirus 6 Reflects Human Migration out of Africa.
Human herpesvirus 6A and 6B (HHV-6) can integrate into the germline, and as a result, ∼70 million people harbor the genome of one of these viruses in every cell of their body. Until now, it has been largely unknown if 1) these integrations are ancient, 2) if they still occur, and 3) whether circulating virus strains differ from integrated ones. Here, we used next-generation sequencing and mining of public human genome data sets to generate the largest and most diverse collection of circulating and integrated HHV-6 genomes studied to date. In genomes of geographically dispersed, only distantly related people, we identified clades of integrated viruses that originated from a single ancestral event, confirming this with fluorescent in situ hybridization to directly observe the integration locus. In contrast to HHV-6B, circulating and integrated HHV-6A sequences form distinct clades, arguing against ongoing integration of circulating HHV-6A or "reactivation" of integrated HHV-6A. Taken together, our study provides the first comprehensive picture of the evolution of HHV-6, and reveals that integration of heritable HHV-6 has occurred since the time of, if not before, human migrations out of Africa
Evolutionary paths to macrolide resistance in a Neisseria commensal converge on ribosomal genes through short sequence duplications
Neisseria commensals are an indisputable source of resistance for their pathogenic relatives. However, the evolutionary paths commensal species take to reduced susceptibility in this genus have been relatively underexplored. Here, we leverage in vitro selection as a powerful screen to identify the genetic adaptations that produce azithromycin resistance (� 2 μg/mL) in the Neisseria commensal, N. elongata. Across multiple lineages (n = 7/16), we find mutations that reduce susceptibility to azithromycin converge on the locus encoding the 50S ribosomal L34 protein (rpmH) and the intergenic region proximal to the 30S ribosomal S3 protein (rpsC) through short tandem duplication events. Interestingly, one of the laboratory evolved mutations in rpmH is identical (7LKRTYQ12), and two nearly identical, to those recently reported to contribute to high-level azithromycin resistance in N. gonorrhoeae. Transformations into the ancestral N. elongata lineage confirmed the causality of both rpmH and rpsC mutations. Though most lineages inheriting duplications suffered in vitro fitness costs, one variant showed no growth defect, suggesting the possibility that it may be sustained in natural populations. Ultimately, studies like this will be critical for predicting commensal alleles that could rapidly disseminate into pathogen populations via allelic exchange across recombinogenic microbial genera
Diasporic virginities: social representations of virginity and identity formation amongst British arab muslim women
This study compares how practising and non-practising British Arab Muslim women position themselves in relation to representations of virginity. Overall, in our qualitative study, we found that representations of culture and religion influenced social practices and social beliefs in different ways: non-practising Muslim women felt bound by culture to remain virgins, while practising Muslim women saw it as a religious obligation but were still governed by culture regarding the consequences of engaging in premarital sex. Interestingly, some practising Muslim participants used Mut’a (a form of temporary ‘marriage’) to justify premarital sex. This, however, did not diminish the importance of virginity in their understanding and identification as Arab women. In fact, this study found that virginity, for the British Arabs interviewed, embodied a sense of ‘Arabness’ in British society. Positioning themselves as virgins went beyond simply honour; it was a significant cultural symbol that secured their sense of cultural identity. In fact this cultural identity was often so powerful that it overrode their Islamic identities, prescribing their behaviour even if religion was seen as more ‘forgiving’
The Experience of Quality in Higher Education in the United Arab Emirates: In Times of Rapid Change and Complexities
In less than five decades, from offering formal education only in a few schools to a small tribal community to providing a selection of three public and approximately 100 private higher education institutions to the citizens of seven emirates creates a unique context in the United Arab Emirates (UAE). It is an evolution that corresponds with its remarkable economic growth. Quality assurance of diverse higher educational institutions requires complex schemes to ensure their fitness for purpose, while perhaps development and enhancement aspects need time to mature. The quality of the education is especially important because the UAE yearns for the diversified and knowledge-based economy; one that is led by its own citizens whose contribution to the workforce is currently less than 10%. This chapter highlights contextual complexities in the UAE that might have direct and/or indirect impacts on the quality experiences in the higher education sector, with proposed recommendations
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