(Un) Resolved contradictions in the Late Pleistocene glacial chronology of the Southern Carpathians - new samples and recalculated cosmogenic radionuclide age estimates

Application of cosmogenic nuclides in the study of Quaternary glaciations has increased rapidly during the last decade owing to the previous absence of direct dating methods of glacial landforms and sediments. Although several hundred publications have already been released on exposure age dating of glacial landforms worldwide, very few studies targeted the Carpathians so far (Kuhlemann et al, 2013a; Makos et al., 2014; Reuther et al, 2004, 2007; Rinterknecht et al. 2012).There are many unresolved or contradictory issues regarding the glacial chronology of the Romanian Carpathians. Recently, some attempts have been made to develop an improved temporal framework for the glaciations of the region using cosmogenic 10Be dating (Reuther et al. 2004, 2007, Kuhlemann et al. 2013a). However, these studies made the picture even more confusing because the local last glacial maximum, for instance, apparently occurred in asynchronous timing compared to each other and also to other dated glacial events in Europe (Hughes et al, 2013).This situation is even more interesting if we take into account that the local glacial maximum tends to agree with the global LGM derived from the Eastern Balkans (Kuhlemann et al. 2013b), while the penultimate glaciation seems to significantly overtake the LGM advance over the Western Balkans (Hughes et al. 2011).The primary candidate reasons to resolve these discrepancies are methodological, e.g. insufficient number of samples (one sample/landform) ignoring geological scatter of the data and the application of different half-lives, production rates and scaling schemes during the calculation of exposure ages. Systematic methodological uncertainties in computing exposure ages from measured nuclide concentrations have a significant impact on the conclusions concerning correlations of exposure-dated glacier chronologies with millennial scale climate changes (Balco, 2011). The changes in glacial timing generated by only using the most recent constants for the exposure age calculations has not been considered in the most recent review on the timing of the LGM (Hughes et al., 2013).Main objective of our study is to utilize the potential offered by the cosmogenic in situ produced 10Be dating to disentangle the contradictions in the available Southern Carpathian Late Pleistocene glacial chronology (Kuhlemann et al, 2013a; Reuther et al, 2004, 2007). We recalculate 10Be data published by Reuther et al. (2007) in accordance with the new half-life and production rate of 10Be. Besides, a new sample set has been collected to establish a precise chronological framework supported by in-situ exposure dating of several additional moraine generations

Development of a Type 2 Diabetes Risk Model From a Panel of Serum Biomarkers From the Inter99 Cohort

Udgivelsesdato: 2009-JulOBJECTIVE: The purpose of this study was to develop a model for assessing the 5-year risk of developing type 2 diabetes from a panel of 64 circulating candidate biomarkers. RESEARCH DESIGN AND METHODS: Subjects were selected from the Inter99 cohort, a longitudinal population-based study of approximately 6,600 Danes in a nested case-control design with the primary outcome of 5-year conversion to type 2 diabetes. Nondiabetic subjects, aged >or=39 years, with BMI >or=25 kg/m(2) at baseline were selected. Baseline fasting serum samples from 160 individuals who developed type 2 diabetes and from 472 who did not were tested. An ultrasensitive immunoassay was used to measure of 58 candidate biomarkers in multiple diabetes-associated pathways, along with six routine clinical variables. Statistical learning methods and permutation testing were used to select the most informative biomarkers. Risk model performance was estimated using a validated bootstrap bias-correction procedure. RESULTS: A model using six biomarkers (adiponectin, C-reactive protein, ferritin, interleukin-2 receptor A, glucose, and insulin) was developed for assessing an individual's 5-year risk of developing type 2 diabetes. This model has a bootstrap-estimated area under the curve of 0.76, which is greater than that for A1C, fasting plasma glucose, fasting serum insulin, BMI, sex-adjusted waist circumference, a model using fasting glucose and insulin, and a noninvasive clinical model. CONCLUSIONS: A model incorporating six circulating biomarkers provides an objective and quantitative estimate of the 5-year risk of developing type 2 diabetes, performs better than single risk indicators and a noninvasive clinical model, and provides better stratification than fasting plasma glucose alone

Permafrost conditions in the Mediterranean region since the Last Glaciation.

Cold-climate geomorphological processes today in the Mediterranean region are only distributed in the highest mountain environments. However, climate condition prevailing during the Late Pleistocene and Holocene have conditioned significant spatio-temporal variations of the glacial and periglacial domain in these mountains, including permafrost. In this communication we examine permafrost condition in the Mediterranean region taking into account five periods: Last Glaciation, deglaciation, Holocene, Little Ice Age (LIA) and present-day. The distribution of currently inactive permafrost-derived landforms and sedimentary records indicates that the permafrost elevation during the Last Glaciation was ca. 1000 m lower than present. Permafrost was also widespread in non-glaciated slopes above the snowline forming rock glaciers and block streams, as well as in relatively flat summit areas where meter-sized stone circles developed. As in most areas of the Northern Hemisphere, the deglaciation in the Mediterranean region started ca. 19-20 ka. The exposed terrain by retreating glaciers was affected by paraglacial dynamics and intense periglacial processes, mostly associated with permafrost condition. Many rock glaciers, protalus lobes and block streams formed in these recently deglaciated environments, becoming gradually inactive as temperatures rose during the Bølling-Allerød. Following the Younger Dryas glacial advance, the last massive deglaciation in Mediterranean mountains took place during the Early Holocene together with a progressive shift of the periglacial belt to higher elevations. It is unlikely that widespread permafrost have existed in Mediterranean mountains during the Holocene, except in the highest massifs exceeding 2500-3000 m. The colder climate prevailing during the LIA favoured a minor glacial advance and the spatial expansion of permafrost, with the development of new protalus lobes and rock glaciers in the highest massifs. Finally, the warming started during the second half of the 19th century has led to glacial retreat and/or complete melting, increased paraglacial activity, migration of periglacial processes to the highest lands and degradation of alpine permafrost along with geoecological changes

Classification of hepatitis C virus into six major genotypes and a series of subtypes by phylogenetic analysis of the NS-5 region

Hepatitis C virus (HCV) shows substantial nucleotide sequence diversity distributed throughout the viral genome, with many variants showing only 68 to 79 % overall sequence similarity to one another. Phylogenetic analysis ofnucleofide sequences derived from part of the gene encoding a non-structural protein (NS-5) has provided evidence for six major genotypes of HCV amongst a worldwide collection of 76 samples from HCV-infected blood donors and patients with chronic hepatitis. Many of these HCV types comprised a number of more closely related subtypes, leading to a current total of 11 genetically distinct viral populations. Phylo-genetic analysis of other regions of the viral genome produced relationships between published sequences equivalent to those found in NS-5, apart from the more highly conserved 5 ' non-coding region in which only the six major HCV types, but not subtypes, could be differentiated. A new nomenclature for HCV variants is proposed in this communication that reflects the twotiered nature of sequence differences between different viral isolates. The scheme classifies all known HCV variants to date, and describes criteria that would enable new variants to be assigned within the classification as they are discovered

A Simple, Inexpensive Device for Nucleic Acid Amplification without Electricity—Toward Instrument-Free Molecular Diagnostics in Low-Resource Settings

Molecular assays targeted to nucleic acid (NA) markers are becoming increasingly important to medical diagnostics. However, these are typically confined to wealthy, developed countries; or, to the national reference laboratories of developing-world countries. There are many infectious diseases that are endemic in low-resource settings (LRS) where the lack of simple, instrument-free, NA diagnostic tests is a critical barrier to timely treatment. One of the primary barriers to the practicality and availability of NA assays in LRS has been the complexity and power requirements of polymerase chain reaction (PCR) instrumentation (another is sample preparation).In this article, we investigate the hypothesis that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays. We assess the heater's equivalence to commercially available PCR instruments through the characterization of the temperature profiles produced, and a minimal method comparison. Versions of the prototype for several different isothermal techniques are presented.We demonstrate that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays, and that the results of those assays are not significantly different from ones incubated in parallel in commercially available PCR instruments. These results clearly suggest the potential of the non-instrumented nucleic acid amplification (NINA) heater for molecular diagnostics in LRS. When combined with other innovations in development that eliminate power requirements for sample preparation, cold reagent storage, and readout, the NINA heater will comprise part of a kit that should enable electricity-free NA testing for many important analytes

Dipstick Test for Rapid Diagnosis of Shigella dysenteriae 1 in Bacterial Cultures and Its Potential Use on Stool Samples

International audienceBACKGROUND: We describe a test for rapid detection of S. dysenteriae 1 in bacterial cultures and in stools, at the bedside of patients. METHODOLOGY/PRINCIPAL FINDINGS: The test is based on the detection of S. dysenteriae 1 lipopolysaccharide (LPS) using serotype 1-specific monoclonal antibodies coupled to gold particles and displayed on a one-step immunochromatographic dipstick. A concentration as low as 15 ng/ml of LPS was detected in distilled water and in reconstituted stools in 10 minutes. In distilled water and in reconstituted stools, an unequivocal positive reaction was obtained with 1.6×10⁶ CFU/ml and 4.9×10⁶ CFU/ml of S. dysenteriae 1, respectively. Optimal conditions to read the test have been determined to limit the risk of ambiguous results due to appearance of a faint yellow test band in some negative samples. The specificity was 100% when tested with a battery of Shigella and unrelated strains in culture. When tested on 328 clinical samples in India, Vietnam, Senegal and France by laboratory technicians and in Democratic Republic of Congo by a field technician, the specificity (312/316) was 98.7% (95% CI:96.6-99.6%) and the sensitivity (11/12) was 91.7% (95% CI:59.8-99.6%). Stool cultures and the immunochromatographic test showed concordant results in 98.4 % of cases (323/328) in comparative studies. Positive and negative predictive values were 73.3% (95% CI:44.8-91.1%) and 99.7% (95% CI:98-100%). CONCLUSION: The initial findings presented here for a simple dipstick-based test to diagnose S. dysenteriae 1 demonstrates its promising potential to become a powerful tool for case management and epidemiological surveys

Africa’s response to the COVID-19 pandemic : A review of the nature of the virus, impacts and implications for preparedness

Background: COVID-19 continues to wreak havoc in different countries across the world, claiming thousands of lives, increasing morbidity and disrupting lifestyles. The global scientific community is in urgent need of relevant evidence, to understand the challenges and knowledge gaps, as well as the opportunities to contain the spread of the virus. Considering the unique socio-economic, demographic, political, ecological and climatic contexts in Africa, the responses which may prove to be successful in other regions may not be appropriate on the continent. This paper aims to provide insight for scientists, policy makers and international agencies to contain the virus and to mitigate its impact at all levels. Methods: The Affiliates of the African Academy of Sciences (AAS), came together to synthesize the current evidence, identify the challenges and opportunities to enhance the understanding of the disease. We assess the potential impact of this pandemic and the unique challenges of the disease on African nations. We examine the state of Africa’s preparedness and make recommendations for steps needed to win the war against this pandemic and combat potential resurgence. Results: We identified gaps and opportunities among cross-cutting issueswhich must be addressed or harnessed in this pandemic. Factors such as the nature of the virus and the opportunities for drug targeting, point of care diagnostics, health surveillance systems, food security, mental health, xenophobia and gender-based violence, shelter for the homeless, water and sanitation, telecommunications challenges, domestic regional coordination and financing. Conclusion: Based on our synthesis of the current evidence, while there are plans for preparedness in several African countries, there are significant limitations. A multi-sectoral efforts from the science, education, medical, technology, communication, business, and industry sectors, as well as local communities, must work collaboratively to assist countries in order to win this fight