310 research outputs found
Generating short-term observation schedules for space mission projects
In this paper, we propose a new dispatching rule and a set of local search algorithms based on the filtered beam search, GRASP and simulated annealing methodologies to construct short-term observation schedules of space mission projects, mainly for NASA's Hubble Space Telescope (HST). The main features of generating short-term observations of HST are state dependent set up times, user specified deadlines, visibility windows of the targets and the priorities assigned to the observations. The objective of HST scheduling is to maximize the scientific return. We have tested the relative performances of the proposed algorithms including the nearest neighbor rule both in objective function value and computational time aspects by utilizing a full-factorial experimental design
Identification of salivary mucin MUC7 binding proteins from Streptococcus gordonii
<p>Abstract</p> <p>Background</p> <p>The salivary mucin MUC7 (previously known as MG2) can adhere to various strains of streptococci that are primary colonizers and predominant microorganisms of the oral cavity. Although there is a growing interest in interaction between oral pathogens and salivary mucins, studies reporting the specific binding sites on the bacteria are rather limited. Identification and characterization of the specific interacting proteins on the bacterial cell surface, termed adhesins, are crucial to further understand host-pathogen interactions.</p> <p>Results</p> <p>We demonstrate here, using purified MUC7 to overlay blots of SDS-extracts of <it>Streptococcus gordonii </it>cell surface proteins, 4 MUC7-binding bands, with apparent molecular masses of 62, 78, 84 and 133 kDa from the <it>Streptococcus gordonii </it>strain, PK488. Putative adhesins were identified by in-gel digestion and subsequent nanoLC-tandem mass spectrometry analysis of resultant peptides. The 62 kDa and 84 kDa bands were identified as elongation factor (EF) Tu and EF-G respectively. The 78 kDa band was a <it>hppA </it>gene product; the 74 kDa oligopeptide-binding lipoprotein. The 133 kDa band contained two proteins; alpha enolase and DNA-directed RNA polymerase, beta' subunit. Some of these proteins, for example alpha enolase are expected to be intracellular, however, flow cytometric analysis confirmed its location on the bacterial surface.</p> <p>Conclusion</p> <p>Our data demonstrated that <it>S. gordonii </it>expressed a number of putative MUC7 recognizing proteins and these contribute to MUC7 mucin binding of this streptococcal strain.</p
Retinal haemangioblastomas in von Hippel–Lindau germline mutation carriers: progression, complications and treatment outcome
Purpose: Evaluation of phenotype and treatment outcome of retinal haemangioblastomas (RH) in von Hippel–Lindau (VHL) disease and correlation of these features with the genotype of VHL germline mutation carriers. Methods: Retrospective analysis of a longitudinal cohort of 21 VHL germline mutation carriers and RH. Clinical and genetic data were obtained to analyse the correlation of genotype with phenotype and treatment outcomes. Results: All patients were categorized in two genotypic categories: missense mutations (MM) and truncating mutations (TM). Mean follow-up duration was 16.3 years and did not differ significantly between mutation groups (p = 0.383). Missense mutations (MM) carriers (n = 6) developed more progression-related complications compared to TM carriers (n = 15) (p = 0.046). Vitreoretinal surgery was more often applied in MM carriers (p = 0.036). Moderate (visual acuity (VA)20/80 to 20/200) to severe (VA < 20/200) visual impairment was observed in 53.3% of the eyes of MM carriers and 28.1% of the eyes of TM carriers at last recorded visit. Conclusion: Missense mutations in VHL patients seem to have a higher prevalence of progression-related comp
Electrical anisotropy in high-Tc granular superconductors in a magnetic field
We propose an analytical model devoted to explain the anisotropy of the electrical resistance observed below the critical temperature in granular high-Tc superconductors submitted to a magnetic field H. Reported experimental results obtained on a YBCO sample show that the superconducting transition occurs in two stages, with a steep drop of the resistance at Tc and a subsequent, smoother decrease. In this second stage, the resistance versus temperature curve is strongly dependent not only on the field intensity, but also on the angle between H and the macroscopic current density j. We start from the assumption that the resistance below Tc is mainly due to the weak links between grains. In the model, weak links are thought of as flat surface elements separating adjacent grains. We calculate the probability for a weak link to undergo the transition to the resistive state as a function of the angle it makes with the external magnetic field H and the macroscopic current density j. In doing this, an important role is given to the strong nonuniformity of the local magnetic field within the specimen, due to the effect of the screening supercurrents flowing on the surface of the grains. Finally, we calculate the electrical resistance of the sample in the two cases H⊥j and H∥j. The predictions of this simple model turn out to be in reasonable agreement with reported experimental results obtained on a YBCO granular specimen
Genetic Background of Iris Melanomas and Iris Melanocytic Tumors of Uncertain Malignant Potential
PURPOSE: Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Iris melanoma comprises 4% to 10% of all UMs and has a lower mortality rate. The genetic changes in iris melanoma are not as well characterized as ciliary body or choroidal melanoma. The aim of this study was to gain more insight into the genetic background of iris melanoma and iris nevi. DESIGN: Multicenter, retrospective case series. PARTICIPANTS: Patients diagnosed with iris melanoma or iris nevi who underwent surgical intervention as primary or secondary treatment. METHODS: Next-generation sequencing of GNAQ, GNA11, EIF1AX, SF3B1, BAP1, NRAS, BRAF, PTEN, c-Kit, TP53, and TERT was performed on 30 iris melanomas and 7 iris nevi. Copy number status was detected using single nucleotide polymorphisms (SNPs) included in the next-generation sequencing (NGS) panel, SNP array, or fluorescent in situ hybridization. BAP1 immunohistochemistry was performed on all samples. MAIN OUTCOME MEASURES: Mutation and copy number status were analyzed. Results of BAP1 immunohistochemistry were used for survival analysis. RESULTS: In 26 of the 30 iris melanoma and all iris nevi, at least 1 mutation was identified. Multiple mutations were detected in 23 iris melanoma and 5 nevi, as well as mutations in GNAQ and GNA11. Furthermore, 13 of 30 BAP1, 5 of 30 EIF1AX, and 2 of 30 SF3B1 mutations were identified in iris melanoma. No correlation between BAP1 status and disease-free survival was found. The iris nevi showed 1 EIF1AX and 3 BAP1 mutations. Two of the nevi, with a BAP1 mutation, were histologically borderline malignant. Mutations in NRAS, BRAF, PTEN, c-KIT, and TP53 were detected in 6 iris melanomas and 4 iris nevi. CONCLUSIONS: Mutations that are often found in uveal and cutaneous melanoma were identified in this cohort of iris melanomas and iris nevi. Therefore, iris melanomas harbor a molecular profile comparable to both choroidal melanoma and cutaneous melanoma. These findings may offer adjuvant targeted therapies for iris melanoma. There was no prognostic significance of BAP1 expression as seen in choroidal melanoma. Consequently, iris melanoma is a distinct molecular subgroup of UM. Histologic borderline malignant iris nevi can harbor BAP1 mutations and may be designated iris melanocytic tumors of uncertain malignant potential
Relationship between articular eminence inclination and alterations of the mandibular condyle: a CBCT study
Resilience in the Face of Disaster: Prevalence and Longitudinal Course of Mental Disorders following Hurricane Ike
Objectives: Natural disasters may increase risk for a broad range of psychiatric disorders, both in the short- and in the medium-term. We sought to determine the prevalence and longitudinal course of posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), panic disorder (PD), depression, and suicidality in the first 18 months after Hurricane Ike.
Methods: Six hundred fifty-eight adults representative of Galveston and Chambers Counties, Texas participated in a random, population-based survey. The initial assessment was conducted 2 to 5 months after Hurricane Ike struck Galveston Bay on September 13, 2008. Follow-up assessments were conducted at 5 to 9 and 14 to 18 months after Hurricane Ike. Results: Past-month prevalence of any mental disorder (20.6% to 10.9%) and hurricane-related PTSD (6.9% to 2.5%) decreased over time. Past-month prevalence of PTSD related to a non-disaster traumatic event (5.8% to 7.1%), GAD (3.1% to 1.8%), PD (0.8% to 0.7%), depression (5.0% to 5.6%), and suicidality (2.6% to 4.2%) remained relatively stable over time.
Conclusions: PTSD, both due to the hurricane and due to other traumatic events, was the most prevalent psychiatric disorder 2 to 5 months after Hurricane Ike. Prevalence of psychiatric disorders declined rapidly over time, suggesting that the vast majority of individuals exposed to this natural disaster ‘bounced back’ and were resilient to long-term mental health consequences of this large-scale traumatic event
Understanding Communication of Sustainability Reporting: Application of Symbolic Convergence Theory (SCT)
The purpose of this paper is to investigate the nature of rhetoric and rhetorical strategies that are implicit in the standalone sustainability reporting of the top 24 companies of the Fortune 500 Global. We adopt Bormann’s (Q J Speech 58(4):396–407, 1972) SCT framework to study the rhetorical situation and how corporate sustainability reporting (CSR) messages can be communicated to the audience (public). The SCT concepts in the sustainability reporting’s communication are subject to different types of legitimacy strategies that are used by corporations as a validity and legitimacy claim in the reports. A content analysis has been conducted and structural coding schemes have been developed based on the literature. The schemes are applied to the SCT model which recognizes the symbolic convergent processes of fantasy among communicators in a Society. The study reveals that most of the sample companies communicate fantasy type and rhetorical vision in their corporate sustainability reporting. However, the disclosure or messages are different across locations and other taxonomies of the SCT framework. This study contributes to the current CSR literature about how symbolic or fantasy understandings can be interpreted by the users. It also discusses the persuasion styles that are adopted by the companies for communication purposes. This study is the theoretical extension of the SCT. Researchers may be interested in further investigating other online communication paths, such as human rights reports and director’s reports
Micronutrient fortification of food and its impact on woman and child health: A systematic review
Background: Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.Methods: A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.Results: Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.Conclusion: Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality
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