474 research outputs found

    Geomorphological mapping and geophysical profiling for the evaluation of natural hazards in an alpine catchment

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    International audienceLiechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geo-electrical profiling was used to assess hazards near Malbun, a village potentially endangered by landslides, and especially debris flows. The area is located on the tectonic contacts of four different nappe slices. The bedrock consists of anhydrite and gypsum, dolomite, shale, marl, and limestone. The spatial distribution and occurrence of debris flows and slides is evaluated through a combination of geomorphological expert knowledge, and detailed visualization in a geographical information system. In a geo-database a symbol-based 1:3000 scale geomorphological map has been digitized and rectified into polygons. The polygons include information on the main geomorphological environment, the Quaternary material distribution and of geomorphological processes, which are stored in attribute tables. The spatial distribution of these attributes is then combined with geophysical information and displacement rates interpolated from benchmark measurements. On one of the landslides two geo-electrical profiles show that the distance to a potential failure plane varies between 10-20 m and that the topography of the failure plane is influenced by subterranean gypsum karst features. The displacement measurements show that this landslide actively disintegrates into minor slides and is not, therefore, a risk to the village of Malbun. The hazard zonation indicates that debris flows can pose a risk if no countermeasures are taken. Gypsum karst may locally accelerate the landslide activity. In contrast, the impact of debris flows is diminished because collapse dolines may act as sediment traps for the debris flow materials. This research illustrates how geomorphological expert knowledge can be integrated in a GIS for the evaluation of natural hazards on a detailed scale

    Гарантоздатність як фундаментальний узагальнюючий та інтегруючий підхід

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    Представлені головні принципи та умови становлення і етапи розвитку фундаментальної теорії і практики узагальнюючих та інтегруючих концепцій гарантоздатності, починаючи з першої об’єднаної конференції двох наукових шкіл Дж. фон Неймана і Н. Вінера. Приведені основні положення розвитку теоретичних засад і результатів прикладних досліджень інтеграційних процесів безвідмовності (надійності), відмовостійкості та гарантоздатності інформаційно-управляючих комп’ютерних систем (ІУКС).Представлены главные принципы, условия становления и этапы развития фундаментальной теории и практики обобщающих и интегрирующих концепций гарантоспособности, начиная с первой объединённой конференции двух научных школ Дж. фон Неймана и Н. Винера. Приведены основные положения развития теоретических основ и результатов прикладных исследований интеграционных процессов безотказности (надёжности), отказоустойчивости и гарантоспособности информационно-управляющих компьютерных систем (ИУКС).The main principles and conditions of formation and stages of development of the fundamental theory and practice of the generalizing and integrating concepts of dependability were presented after the leadthrough the first joint conference of two scientific schools of J. von Neumann and N. Wiener. The basic aspects of development of theoretical principles and results of applied researches of integration processes of reliability (fail-safety)

    Formative peer assessment in a CSCL environment

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    In this case study our aim was to gain more insight in the possibilities of qualitative formative peer assessment in a computer supported collaborative learning (CSCL) environment. An approach was chosen in which peer assessment was operationalised in assessment assignments and assessment tools that were embedded in the course material. The course concerned a higher education case-based virtual seminar, in which students were asked to conduct research and write a report in small multidisciplinary teams. The assessment assignments contained the discussion of assessment criteria, the assessment of a group report of a fellow group, and writing an assessment report. A list of feedback rules was one of the assessment tools. A qualitative oriented study was conducted, focussing on the attitude of students towards peer assessment and practical use of peer assessment assignments and tools. Results showed that students’ attitude towards peer assessment was positive and that assessment assignments had added value. However, not all students fulfilled all assessment assignments. Recommendations for implementation of peer assessment in CSCL environments as well as suggestions for future research are discussed

    Central Adrenal Insufficiency Is Rare in Adults With Prader-Willi Syndrome

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    CONTEXT: Prader-Willi syndrome (PWS) is associated with several hypothalamic-pituitary hormone deficiencies. There is no agreement on the prevalence of central adrenal insufficiency (CAI) in adults with PWS. In some countries, it is general practice to prescribe stress-dose hydrocortisone during physical or psychological stress in patients with PWS. Side effects of frequent hydrocortisone use are weight gain, osteoporosis, diabetes mellitus, and hypertension-already major problems in adults with PWS. However, undertreatment of CAI can cause significant morbidity-or even mortality. OBJECTIVE: To prevent both over- and undertreatment with hydrocortisone, we assessed the prevalence of CAI in a large international cohort of adults with PWS. As the synacthen test shows variable results in PWS, we only use the metyrapone test (MTP) and insulin tolerance test (ITT). DESIGN: Metyrapone test or ITT in adults with PWS (N = 82) and review of medical files for symptoms of hypocortisolism related to surgery (N = 645). SETTING: Outpatient clinic. PATIENTS OR OTHER PARTICIPANTS: Eighty-two adults with genetically confirmed PWS. MAIN OUTCOME MEASURE: For MTP, 11-deoxycortisol > 230 nmol/L was considered sufficient. For ITT, cortisol > 500 nmol/L (Dutch, French, and Swedish patients) or > 450 nmol/L (British patients) was considered sufficient. RESULTS: Central adrenal insufficiency was excluded in 81 of 82 patients. Among the 645 patients whose medical files were reviewed, 200 had undergone surgery without perioperative hydrocortisone treatment. None of them had displayed any features of hypocortisolism. CONCLUSIONS: Central adrenal insufficiency is rare (1.2%) in adults with PWS. Based on these results, we recommend against routinely prescribing hydrocortisone stress-doses in adults with PWS

    Relationship between freight accessibility and logistics employment in US counties

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    This paper analyzes the relationship between freight accessibility and logistics employment in the US. It develops an accessibility measure relevant for logistics companies based on a gravity model. This allows for an analysis of the accessibility of US counties focusing on four different modes of transportation: road, rail, air, and maritime. Using a Partial Least Squares model, these four different freight accessibility measures are combined into two constructs, continental and intercontinental freight accessibility, and related to logistics employment. Results show that highly accessible counties attract more logistics employment than other counties. The analyses show that it is very important to control for the effect of the county population on both freight accessibility and logistics employment. While county population explains the most variation in the logistics employment per county, there is a significant relationship between freight accessibility and logistics employment, when controlling for this effect

    A haploid pseudo-chromosome genome assembly for a keystone sagebrush species of western North American rangelands

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    Increased ecological disturbances, species invasions, and climate change are creating severe conservation problems for several plant species that are widespread and foundational. Understanding the genetic diversity of these species and how it relates to adaptation to these stressors are necessary for guiding conservation and restoration efforts. This need is particularly acute for big sagebrush (Artemisia tridentata; Asteraceae), which was once the dominant shrub over 1,000,000 km2 in western North America but has since retracted by half and thus has become the target of one of the largest restoration seeding efforts globally. Here, we present the first reference-quality genome assembly for an ecologically important subspecies of big sagebrush (A. tridentata subsp. tridentata) based on short and long reads, as well as chromatin proximity ligation data analyzed using the HiRise pipeline. The final 4.2-Gb assembly consists of 5,492 scaffolds, with nine pseudo-chromosomal scaffolds (nine scaffolds comprising at least 90% of the assembled genome; n = 9). The assembly contains an estimated 43,377 genes based on ab initio gene discovery and transcriptional data analyzed using the MAKER pipeline, with 91.37% of BUSCOs being completely assembled. The final assembly was highly repetitive, with repeat elements comprising 77.99% of the genome, making the Artemisia tridentata subsp. tridentata genome one of the most highly repetitive plant genomes to be sequenced and assembled. This genome assembly advances studies on plant adaptation to drought and heat stress and provides a valuable tool for future genomic research.This research was made possible by 2 NSF Idaho EPSCoR grants (award numbers OIA-1757324 and OIA-1826801), as well as a Dovetail Genomics Tree of Life Award.Introduction Materials and methods Sample collection, in vitro tissue propagation, and biomass production Flow cytometry and genome complexity analysis PacBio and Omni-C sequence data generation PacBio long-read de novo assembly and validation Pseudomolecule construction with HiRise Genome annotation RNA sequencing Repeat identification Functional annotation Results and discussion Validation of genome assembly and annotation Genome complexity and evidence of past polyploidization Comparing the A. tridentata and A. annua genome assemblies Applications of the sagebrush reference genome Data availability Acknowledgments Literature cite

    Bone Health in Adults With Prader-Willi Syndrome : Clinical Recommendations Based on a Multicenter Cohort Study

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    Prader-Willi syndrome (PWS) is a rare complex genetic syndrome, characterized by delayed psychomotor development, hypotonia, and hyperphagia. Hormone deficiencies such as hypogonadism, hypothyroidism, and growth hormone deficiency are common. The combination of hypotonia, low physical activity, and hypogonadism might lead to a decrease in bone mass and increase in fracture risk. Moreover, one would expect an increased risk of scoliosis due to hypotonia and low physical activity. To study the prevalence and risk factors for skeletal problems (reduced bone mineral density, fractures, and scoliosis) in adults with PWS. We retrospectively collected patient characteristics, medical history, medication, biochemical measurements, dual-energy X-ray absorptiometry scans, and spinal X-rays and reviewed the current literature. We included 354 adults with PWS (median age 31 years; 43% males), of whom 51 (14%) had osteoporosis (T-score below −2.5) and 143 (54%) had osteopenia (T-score −1 to −2.5). The most prevalent modifiable risk factors for osteoporosis were hypogonadism, insufficient dairy intake, sedentary lifestyle, and corticosteroid use. Male sex was associated with osteoporosis (P =.005). Growth hormone treatment was not associated with osteoporosis. A history of vertebral fractures was present in 10 (3%) and nonvertebral fractures in 59 (17%). Scoliosis was present in 263 (80%), but no modifiable risk factors were identified. Besides scoliosis, osteoporosis is common in adults with PWS. Based on the literature and the risk factors for osteoporosis found in our cohort, we provide practical clinical recommendations to avoid skeletal complications in these vulnerable patients

    Kidney disease in adults with Prader-Willi syndrome:international cohort study and systematic literature review

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    BACKGROUND: Prader-Willi syndrome (PWS) is a rare, complex, genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass and hypothalamic dysfunction. Adults with PWS often have obesity, hypertension and type 2 diabetes mellitus (DM2), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Early symptoms of CVD and CKD may be masked by intellectual disability and inability to express physical complaints. Furthermore, kidney diseases are often asymptomatic. Therefore, renal and cardiovascular disease might be missed in patients with PWS. Microalbuminuria is an early sign of microvascular damage in the kidneys and other vascular beds. Therefore, we screened our adult PWS cohort for the presence of elevated urinary albumin and (micro)albuminuria.METHODS: We retrospectively collected anthropometric measurements, blood pressure, medical history, medication use, urine dipstick and biochemical measurements form electronic patient files. In addition, we performed a systematic literature review on kidney disease in PWS.RESULTS: We included 162 adults with genetically confirmed PWS (56% male, median age 28 years), of whom 44 (27%) had DM2. None had known CVD. All subjects had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals. Elevated urinary albumin or (micro)albuminuria was present in 28 (18%); 19 out of 75 (25%) had an increased urinary albumin-to-creatinine ratio (UACR) and 10 out of 57 (18%) had an increased urinary protein-to-creatinine ratio. Elevated urinary albumin was present at a young age (median age 26 (IQR 24-32) years) and was associated with an significantly higher BMI and LDL-cholesterol levels and higher prevalence of DM2, hypertension and dyslipidemia than those with normal UACR (p=0.027, p=0.019, p&lt;0.001, p&lt;0.001, p=0.011 and respectively).CONCLUSION: Upon screening, one in every five adults with PWS had increased urinary albumin or (micro)albuminuria, early signs of microvascular disease. All had normal eGFR, according to non-PWS reference intervals, and none had a formal diagnosis of CVD. As muscle mass is low in PWS, creatinine levels and eGFR may be spuriously normal. Urinalysis in this patient group can be used as a screening tool for microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS.</p

    Kidney disease in adults with Prader-Willi syndrome: international cohort study and systematic literature review

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    BackgroundPrader-Willi syndrome (PWS) is a rare, complex, genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass and hypothalamic dysfunction. Adults with PWS often have obesity, hypertension and type 2 diabetes mellitus (DM2), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Early symptoms of CVD and CKD may be masked by intellectual disability and inability to express physical complaints. Furthermore, kidney diseases are often asymptomatic. Therefore, renal and cardiovascular disease might be missed in patients with PWS. Microalbuminuria is an early sign of microvascular damage in the kidneys and other vascular beds. Therefore, we screened our adult PWS cohort for the presence of elevated urinary albumin and (micro)albuminuria.MethodsWe retrospectively collected anthropometric measurements, blood pressure, medical history, medication use, urine dipstick and biochemical measurements form electronic patient files. In addition, we performed a systematic literature review on kidney disease in PWS.ResultsWe included 162 adults with genetically confirmed PWS (56% male, median age 28 years), of whom 44 (27%) had DM2. None had known CVD. All subjects had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals. Elevated urinary albumin or (micro)albuminuria was present in 28 (18%); 19 out of 75 (25%) had an increased urinary albumin-to-creatinine ratio (UACR) and 10 out of 57 (18%) had an increased urinary protein-to-creatinine ratio. Elevated urinary albumin was present at a young age (median age 26 (IQR 24-32) years) and was associated with an significantly higher BMI and LDL-cholesterol levels and higher prevalence of DM2, hypertension and dyslipidemia than those with normal UACR (p=0.027, p=0.019, p&lt;0.001, p&lt;0.001, p=0.011 and respectively).ConclusionUpon screening, one in every five adults with PWS had increased urinary albumin or (micro)albuminuria, early signs of microvascular disease. All had normal eGFR, according to non-PWS reference intervals, and none had a formal diagnosis of CVD. As muscle mass is low in PWS, creatinine levels and eGFR may be spuriously normal. Urinalysis in this patient group can be used as a screening tool for microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS
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