66 research outputs found

    Bacteroides Microbial Source Tracking Markers Perform Poorly in Predicting Enterobacteriaceae and Enteric Pathogen Contamination of Cow Milk Products and Milk-Containing Infant Food

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    Consumption of microbiologically contaminated food is one of the leading causes of diarrheal diseases. Understanding the source of enteric pathogens in food is important to guide effective interventions. Enterobacteriaceae bacterial assays typically used to assess food safety do not shed light on the source. Source-specific Bacteroides microbial source tracking (MST) markers have been proposed as alternative indicators for water fecal contamination assessment but have not been evaluated as an alternative fecal indicator in animal-derived foods. This study tested various milk products collected from vendors in urban Kenyan communities and infant foods made with the milk (n = 394 pairs) using conventional culture methods and TaqMan qPCR for enteric pathogens and human and bovine-sourced MST markers. Detection profiles of various enteric pathogens and Bacteroides MST markers in milk products differed from that of milk-containing infant foods. MST markers were more frequently detected in infant food prepared by caregivers, indicating recent contamination events were more likely to occur during food preparation at home. However, Bacteroides MST markers had lower sensitivity in detecting enteric pathogens in food than traditional Enterobacteriaceae indicators. Bacteroides MST markers tested in this study were not associated with the detection of culturable Salmonella enterica and Shigella sonnei in milk products or milk-containing infant food. The findings show that while Bacteroides MST markers could provide valuable information about how foods become contaminated, they may not be suitable for predicting the origin of the enteric pathogen contamination sources

    On Maximum Weight Clique Algorithms, and How They Are Evaluated

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    Maximum weight clique and maximum weight independent set solvers are often benchmarked using maximum clique problem instances, with weights allocated to vertices by taking the vertex number mod 200 plus 1. For constraint programming approaches, this rule has clear implications, favouring weight-based rather than degree-based heuristics. We show that similar implications hold for dedicated algorithms, and that additionally, weight distributions affect whether certain inference rules are cost-effective. We look at other families of benchmark instances for the maximum weight clique problem, coming from winner determination problems, graph colouring, and error-correcting codes, and introduce two new families of instances, based upon kidney exchange and the Research Excellence Framework. In each case the weights carry much more interesting structure, and do not in any way resemble the 200 rule. We make these instances available in the hopes of improving the quality of future experiments

    An expanding culture of control? The municipal administrative sanctions Act in Belgium

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    This article provides an in-depth study of the Act on Municipal Administrative Sanctions 1999 (MAS), which is the first major piece of legislation regulating antisocial behaviour in Belgium. MAS provides municipalities with an instrument to sanction antisocial behaviour and conduct perceived to disturb public order. The article uses Garland’s(2001) thesisonthecultureofcontroltoanalysewhetherMAShasledtoincreasedgovernmentcontrol and the exclusion of significant groups of the population. The research is based on a multiple case study in which the application of MAS was analysed over a 25-year period of security policies in Belgium (1985–2010). The Act’s implementation was studied in the two Belgian cities of Antwerp and Liège in order to consider the influence of the Flemish government and the Walloon government, respectively, in this policy area. The article uses insights from this comparison to revisit the culture of control thesis and its limitations in understanding the political competition that exists over the formulation of policies on antisocial behaviour. Effective Protection of Fundamental Rights in a pluralist worl

    Mobilise-D insights to estimate real-world walking speed in multiple conditions with a wearable device

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    This study aimed to validate a wearable device’s walking speed estimation pipeline, considering complexity, speed, and walking bout duration. The goal was to provide recommendations on the use of wearable devices for real-world mobility analysis. Participants with Parkinson’s Disease, Multiple Sclerosis, Proximal Femoral Fracture, Chronic Obstructive Pulmonary Disease, Congestive Heart Failure, and healthy older adults (n = 97) were monitored in the laboratory and the real-world (2.5 h), using a lower back wearable device. Two walking speed estimation pipelines were validated across 4408/1298 (2.5 h/laboratory) detected walking bouts, compared to 4620/1365 bouts detected by a multi-sensor reference system. In the laboratory, the mean absolute error (MAE) and mean relative error (MRE) for walking speed estimation ranged from 0.06 to 0.12 m/s and − 2.1 to 14.4%, with ICCs (Intraclass correlation coefficients) between good (0.79) and excellent (0.91). Real-world MAE ranged from 0.09 to 0.13, MARE from 1.3 to 22.7%, with ICCs indicating moderate (0.57) to good (0.88) agreement. Lower errors were observed for cohorts without major gait impairments, less complex tasks, and longer walking bouts. The analytical pipelines demonstrated moderate to good accuracy in estimating walking speed. Accuracy depended on confounding factors, emphasizing the need for robust technical validation before clinical application. Trial registration: ISRCTN – 12246987

    In-situ calcite U-Pb geochronology of hydrothermal veins in Thailand: new constraints on Indosinian and Cenozoic deformation

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    U-Pb dating of calcite veins allows direct dating of brittle deformation events. Here, we apply this method to hydrothermal calcite veins in a fold-and-thrust belt and a large scale strike-slip fault zone in central and western Thailand, in an attempt to shed new light on the regional upper crustal deformation history. Calcite U-Pb dates for the Khao Khwang Fold and Thrust Belt (KKFTB) of 221 ± 7 Ma and 216 ± 3 Ma demonstrate that calcite precipitated during tectonic activity associated with stage II of the Indosinian Orogeny (Late Triassic – Early Jurassic). One additional sample from the KKFTB suggests that the Indosinian calcite has locally been overprinted by a Cenozoic fluid event with a different chemistry. For the Three Pagodas Fault Zone (TPFZ), our calcite U-Pb results suggest a complex, protracted history of Cenozoic brittle deformation. Petrographic information combined with contrasting redox-sensitive trace elemental signatures suggest that the vein arrays in the TPFZ precipitated during two distinct events of brittle deformation at ~48 and ~23 Ma. These dates are interpreted in the context of far-field brittle deformation related to the India-Eurasia collision. The presented calcite U-Pb dates are in excellent agreement with published age constraints on the deformation history of Thailand, demonstrating the utility of the method to decipher complex brittle deformation histories. The paper further illustrates some of the complexities in relation to calcite U-Pb dating and provides suggestions for untangling complex datasets that could be applied to future studies on the deformation history of Thailand and other regions

    Lu-Hf, Sm-Nd, and U-Pb isotopic coupling and decoupling in apatite

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    Available online 12 October 2022Apatite is a useful geochronological tool due to its common occurrence and incorporation of a variety of radioactive parent isotopes during crystallisation. However, an understanding of the geological conditions recorded by each of these isotopic systems in apatite is necessary for their effective application to geological problems. In this study, U–Pb, Sm–Nd, and Lu–Hf dates for apatite grains from samples of 3.0 Ga TTG gneisses in the Akia terrane of the North Atlantic Craton (south-western Greenland) were obtained in order to better understand the conditions under which isotopic re-equilibration in apatite is achieved. This isotopic data records at least two thermotectonic events subsequent to the initial magmatic crystallisation of these rocks. Whereas the Lu–Hf and Sm–Nd isotopic systems in these apatites record a regional high temperature metamorphic event at ̃2.7 Ga, the U–Pb system records a milder thermal event at 1.7 Ga. This decoupling of the U–Pb from the Sm–Nd and Lu–Hf systems in apatite reflects a difference in closure temperature. The regional thermal effects of the 1.7 Ga Nagssugtoqidian orogeny in adjacent parts of the North Atlantic Craton resulted in partial to complete reequilibration of the U–Pb systems in apatite across the Akia terrane but were insufficient to cause open system behaviour of Sm–Nd or Lu–Hf. The indistinguishable apatite Sm–Nd and Lu–Hf ages produced in each analysed sample suggest that these systems are similarly susceptible to isotopic re-equilibration. The older ages produced by the Sm–Nd and Lu–Hf systems relative to U–Pb in apatite demonstrate that the former are more robust and thus more likely to faithfully record high temperature events than the U–Pb system.Jack Gillespie, Christopher L. Kirkland, Peter D. Kinny, Alexander Simpson, Stijn Glorie, and Kai Rankenbur

    Late Miocene (10.0~6.0 Ma) rapid exhumation of the Chinese South Tianshan: implications for the timing of aridification in the Tarim Basin

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    Cenozoic exhumation in the Tianshan is controlled by a complex interaction between tectonics and climate. However, the timing and magnitude of exhumation of the Tianshan and its contribution to climate change in Central Asia remains debated. In this study, we report new apatite fission track and (U-Th)/He ages for granite samples from the roof of the South Tianshan that are significantly younger than those published for other parts of the South Tianshan. Inverse and forward modeling reveals two phases of accelerated cooling at 10∼6∼Ma and since ∼3∼Ma, which can be linked to (1) the reactivation of strike-slip faults and hot asthenospheric upwelling during India- Eurasia convergence and (2) the interplay between tectonics and glaciation, respectively. The 10∼6∼Ma exhumation phase further corresponds to the timing of climate change, suggesting that this exhumation phase significantly contributed to the enhanced aridification of the Tarim BasinJian Chang, Stijn Glorie, Nansheng Qiu, Kyoungwon Min, Yao Xiao and Wei X
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