1,311 research outputs found
New bulk scalar field solutions in brane worlds
We use nonlinear perturbation theory to obtain new solutions for brane world
models that incorporate a massive bulk scalar field. We then consider tensor
perturbations and show that Newtonian gravity is recovered on the brane for
both a light scalar field and for a bulk field with large negative mass. This
latter result points to the viability of higher-derivative theories of gravity
in the context of bulk extra dimensions.Comment: 4+\epsilon pages, no figure
Safe food and feed through an integrated toolbox for mycotoxin management: the MyToolBox approach
There is a pressing need to mobilise the wealth of knowledge from the international mycotoxin research conductedover the past 25-30 years, and to perform cutting-edge research where knowledge gaps still exist. This knowledgeneeds to be integrated into affordable and practical tools for farmers and food processors along the chain inorder to reduce the risk of mycotoxin contamination of crops, feed and food. This is the mission of MyToolBox – a four-year project which has received funding from the European Commission. It mobilises a multi-actorpartnership (academia, farmers, technology small and medium sized enterprises, food industry and policystakeholders) to develop novel interventions aimed at achieving a significant reduction in crop losses due tomycotoxin contamination. Besides a field-to-fork approach, MyToolBox also considers safe use options ofcontaminated batches, such as the efficient production of biofuels. Compared to previous efforts of mycotoxin reduction strategies, the distinguishing feature of MyToolBox is to provide the recommended measures to theend users along the food and feed chain in a web-based MyToolBox platform (e-toolbox). The project focuseson small grain cereals, maize, peanuts and dried figs, applicable to agricultural conditions in the EU and China. Crop losses using existing practices are being compared with crop losses after novel pre-harvest interventionsincluding investigation of genetic resistance to fungal infection, cultural control (e.g. minimum tillage or cropdebris treatment), the use of novel biopesticides suitable for organic farming, competitive biocontrol treatment and development of novel modelling approaches to predict mycotoxin contamination. Research into post-harvestmeasures includes real-time monitoring during storage, innovative sorting of crops using vision-technology, novelmilling technology and studying the effects of baking on mycotoxins at an industrial scale
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Sublethal injury and Viable but Non-culturable (VBNC) state in microorganisms during preservation of food and biological materials by non-thermal processes
The viable but non-culturable (VBNC) state, as well as sublethal injury of microorganisms pose a distinct threat to food safety, as the use of traditional, culture-based microbiological analyses might lead to an underestimation or a misinterpretation of the product's microbial status and recovery phenomena of microorganisms may occur. For thermal treatments, a large amount of data and experience is available and processes are designed accordingly. In case of innovative inactivation treatments, however, there are still several open points with relevance for the investigation of inactivation mechanisms as well as for the application and validation of the preservation processes. Thus, this paper presents a comprehensive compilation of non-thermal preservation technologies, i.e., high hydrostatic pressure (HHP), pulsed electric fields (PEFs), pulsed light (PL), and ultraviolet (UV) radiation, as well as cold plasma (CP) treatments. The basic technological principles and the cellular and molecular mechanisms of action are described. Based on this, appropriate analytical methods are outlined, i.e., direct viable count, staining, and molecular biological methods, in order to enable the differentiation between viable and dead cells, as well as the possible occurrence of an intermediate state. Finally, further research needs are outlined
Enhancement of the formation of ultracold Rb molecules due to resonant coupling
We have studied the effect of resonant electronic state coupling on the
formation of ultracold ground-state Rb. Ultracold Rb molecules
are formed by photoassociation (PA) to a coupled pair of states,
and , in the region below the
limit. Subsequent radiative decay produces high vibrational levels of the
ground state, . The population distribution of these state
vibrational levels is monitored by resonance-enhanced two-photon ionization
through the state. We find that the populations of vibrational
levels =112116 are far larger than can be accounted for by the
Franck-Condon factors for transitions with
the state treated as a single channel. Further, the
ground-state molecule population exhibits oscillatory behavior as the PA laser
is tuned through a succession of state vibrational levels. Both of
these effects are explained by a new calculation of transition amplitudes that
includes the resonant character of the spin-orbit coupling of the two
states. The resulting enhancement of more deeply bound ground-state molecule
formation will be useful for future experiments on ultracold molecules.Comment: 6 pages, 5 figures; corrected author lis
Histopathological features of gastrointestinal mucosal biopsies in children with juvenile idiopathic arthritis
BACKGROUND: The association between inflammatory bowel disease and joint involvement is well established. There is a paucity of data describing histopathological features of the gut in relation to juvenile idiopathic arthritis (JIA). METHODS: We retrospectively identified 33 (21 male) children aged 3-16 y with JIA (11 with oligoarthritis, 5 with polyarthritis, 8 with systemic onset arthritis, 8 with enthesitis-related arthritis (ERA), and 1 with psoriatic arthritis) with significant gastrointestinal (GI) symptoms who underwent upper and/or lower endoscopy. The histopathological findings were reviewed in addition to presence of autoantibodies and concomitant treatment. RESULTS: The most common GI indications for endoscopy were persistent abdominal pain (14/33 (42%)) and diarrhea (10/33 (30%)). Of the 33 children, 28 (85%) had gut mucosal inflammation, mostly affecting the colon (80%). Active inflammation of the gut was found in 5 of 28 (17%) children, and 15 of 28 (53%) children showed mild nonspecific inflammation. Eight patients (27%) had predominantly an eosinophilic infiltrate. Twenty-six patients had previously received treatment for JIA. There was a negative association with the use of immunomodulators and the presence of eosinophil inflammation. CONCLUSION: The majority of children with JIA and GI symptoms have histological evidence of mild nonspecific inflammation, but some having active colitis and prominent eosinophil infiltrate
The correlations of glycated hemoglobin and carbohydrate metabolism parameters with heart rate variability in apparently healthy sedentary young male subjects
Introduction Sedentary lifestyle is a major risk factor for diabetes, cardiovascular and many other age-related diseases. Heart rate variability (HRV) reflects the function of regulatory systems of internal organs and may sensitively indicate early metabolic disturbances. We hypothesize that quantitative and qualitative changes of HRV in young subjects may reflect early metabolic derangements responsible for further development of clinically significant disease. Aim The aim of our study was to determine whether the parameters of carbohydrate metabolism (fasting blood glucose, HBA1c and surrogate insulin sensitivity/resistance indices) correlate with anthropometric data and HRV. Methods The study group consisted of 30 healthy sedentary male subjects aged 20–40, nonsmokers, mainly office and research employees, medical staff and students. Athletes, actively training more than one hour per week, severely obese and men of physical work were excluded from the study. HRV parameters were derived from short term ECG records (five minutes intervals) in supine position and during orthostatic test. Anthropometric data included height, weight, body mass index (BMI), age and body composition (estimation by bioelectric impedance method). The fasting blood glucose, insulin and C-peptide, homeostatic model assessment (HOMA-IR) index and glycated hemoglobin (HbA1c) were evaluated. Linear correlation coefficient (r) was calculated using Statistica 10.0 software. Results and discussion HOMA-IR index correlated positively with body weight, visceral fat and BMI (p=0.047, 0.027 and 0.017 respectively). In supine position pNN50 positively correlated with glucose/insulin ratio (p=0.011) and heart rate with HOMA-IR (p=0.006). In orthostatic test negative correlations of HBA1c with standard deviation, total and low frequency power were determined (p=0.034, 0.400 and 0.403 respectively), which indicates a gradual worsening of functional capacity of cardiovascular system with low-grade increase (under the conventional threshold) of HBA1c. Conclusions In apparently healthy sedentary subjects HRV reduction correlates with the age advancement, subclinical deteriorations of carbohydrate metabolism and excessive fat accumulation
Frenkel and charge transfer excitons in C60
We have studied the low energy electronic excitations of C60 using momentum
dependent electron energy-loss spectroscopy in transmission. The momentum
dependent intensity of the gap excitation allows the first direct experimental
determination of the energy of the 1Hg excitation and thus also of the total
width of the multiplet resulting from the gap transition. In addition, we could
elucidate the nature of the following excitations - as either Frenkel or charge
transfer excitons.Comment: RevTEX, 3 Figures, to appear in Phys. Rev.
High sensitivity tests of the Pauli Exclusion Principle with VIP2
The Pauli Exclusion Principle is one of the most fundamental rules of nature
and represents a pillar of modern physics. According to many observations the
Pauli Exclusion Principle must be extremely well fulfilled. Nevertheless,
numerous experimental investigations were performed to search for a small
violation of this principle. The VIP experiment at the Gran Sasso underground
laboratory searched for Pauli-forbidden X-ray transitions in copper atoms using
the Ramberg-Snow method and obtained the best limit so far. The follow-up
experiment VIP2 is designed to reach even higher sensitivity. It aims to
improve the limit by VIP by orders of magnitude. The experimental method,
comparison of different PEP tests based on different assumptions and the
developments for VIP2 are presented.Comment: 6 pages, 3 figures, Proceedings DISCRETE2014 Conferenc
Pre-clinical imaging of invasive candidiasis using ImmunoPET/MR
This is the final version of the article. Available from Frontiers Media via the DOI in this record.The human commensal yeast Candida is the 4th most common cause of hospital-acquired bloodstream infections, with C. albicans accounting for the majority of the >400,000 life-threatening infections annually. Diagnosis of invasive candidiasis (IC), a disease encompassing candidemia (blood-borne yeast infection) and deep-seated organ infections, is a major challenge since clinical manifestations of the disease are indistinguishable from viral, bacterial and other fungal diseases, and diagnostic tests for biomarkers in the bloodstream such as PCR, ELISA and pan-fungal β-D-glucan lack either standardisation, sensitivity or specificity. Blood culture remains the gold standard for diagnosis, but test sensitivity is poor and turn-around time slow. Furthermore, cultures can only be obtained when the yeast resides in the bloodstream, with samples recovered from hematogenous infections often yielding negative results. Consequently, there is a pressing need for a diagnostic test that allows the identification of metastatic foci in deep-seated Candida infections, without the need for invasive biopsy. Here, we report the development of a highly specific mouse IgG3 monoclonal antibody (MC3) that binds to a putative β-1,2-mannan epitope present in high molecular weight mannoproteins and phospholipomannans on the surface of yeast and hyphal morphotypes of C. albicans, and its use as a [64Cu]NODAGA-labeled tracer for whole-body pre-clinical imaging of deep-seated C. albicans infections using antibody-guided positron emission tomography and magnetic resonance imaging (immunoPET/MRI). When used in a mouse intravenous (i.v.) challenge model that faithfully mimics disseminated C. albicans infections in humans, the [64Cu]NODAGA-MC3 tracer accurately detects infections of the kidney, the principal site of blood-borne candidiasis. Using a strain of the emerging human pathogen Candida auris that reacts with MC3 in vitro, but which is non-infective in i.v. challenged mice, we demonstrate the accuracy of the tracer in diagnosing invasive infections in vivo. This pre-clinical study demonstrates the principle of antibody-guided molecular imaging for detection of deep organ infections in IC, without the need for invasive tissue biopsy.This work was supported, in part, by the European Union Seventh Framework Program FP7/2007-2013 under grant 602820
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