319 research outputs found
VARIETIES WHOSE TOLERANCES ARE HOMOMORPHIC IMAGES OF THEIR CONGRUENCES
The homomorphic image of a congruence is always a tolerance (relation) but, within a given variety, a tolerance is not necessarily obtained this way. By a Maltsev-like condition, we characterise varieties whose tolerances are homomorphic images of their congruences (TImC). As corollaries, we prove that the variety of semilattices, all varieties of lattices, and all varieties of unary algebras have TImC. We show that a congruence n-permutable variety has TImC if and only if it is congruence permutable, and construct an idempotent variety with a majority term that fails TImC
A large-scale study of a poultry trading network in Bangladesh: implications for control and surveillance of avian influenza viruses
Since its first report in 2007, avian influenza (AI) has been endemic in Bangladesh. While live poultry marketing is widespread throughout the country and known to influence AI dissemination and persistence, trading patterns have not been described. The aim of this study is to assess poultry trading practices and features of the poultry trading networks which could promote AI spread, and their potential implications for disease control and surveillance. Data on poultry trading practices was collected from 849 poultry traders during a cross-sectional survey in 138 live bird markets (LBMs) across 17 different districts of Bangladesh. The quantity and origins of traded poultry were assessed for each poultry type in surveyed LBMs. The network of contacts between farms and LBMs resulting from commercial movements of live poultry was constructed to assess its connectivity and to identify the key premises influencing it
Age-dependent parathormone levels and different CKD-MBD treatment practices of dialysis patients in Hungary - results from a nationwide clinical audit
BACKGROUND: Achieving target levels of laboratory parameters of
bone and mineral metabolism in chronic kidney disease (CKD)
patients is important but also difficult in those living with
end-stage kidney disease. This study aimed to determine if there
are age-related differences in chronic kidney disease-mineral
and bone disorder (CKD-MBD) characteristics, including treatment
practice in Hungarian dialysis patients. METHODS: Data were
collected retrospectively from a large cohort of dialysis
patients in Hungary. Patients on hemodialysis and peritoneal
dialysis were also included. The enrolled patients were
allocated into two groups based on their age (=65
years). Characteristics of the age groups and differences in
disease-related (epidemiology, laboratory, and treatment
practice) parameters between the groups were analyzed. RESULTS:
A total of 5008 patients were included in the analysis and the
mean age was 63.4+/-14.2 years. A total of 47.2% of patients
were women, 32.8% had diabetes, and 11.4% were on peritoneal
dialysis. Diabetes (37.9% vs 27.3%), bone disease (42.9% vs
34.1%), and soft tissue calcification (56.3% vs 44.7%) were more
prevalent in the older group than the younger group (p<0.001 for
all). We found an inverse relationship between age and
parathyroid hormone (PTH) levels (p<0.001). Serum PTH levels
were lower in patients with diabetes compared with those without
diabetes below 80 years (p<0.001). Diabetes and age were
independently associated with serum PTH levels (interaction:
diabetes x age groups, p=0.138). Older patients were more likely
than younger patients to achieve laboratory target ranges for
each parameter (Ca: 66.9% vs 62.1%, p<0.001; PO4: 52.6% vs
49.2%, p<0.05; and PTH: 50.6% vs 46.6%, p<0.01), and for
combined parameters (19.8% vs 15.8%, p<0.001). Older patients
were less likely to receive related medication than younger
patients (66.9% vs 79.7%, p<0.001). CONCLUSIONS: The achievement
of laboratory target ranges for bone and mineral metabolism and
clinical practice in CKD depends on the age of the patients. A
greater proportion of older patients met target criteria and
received less medication compared with younger patients
Phenotypic Variation and Bistable Switching in Bacteria
Microbial research generally focuses on clonal populations. However, bacterial cells with identical genotypes frequently display different phenotypes under identical conditions. This microbial cell individuality is receiving increasing attention in the literature because of its impact on cellular differentiation, survival under selective conditions, and the interaction of pathogens with their hosts. It is becoming clear that stochasticity in gene expression in conjunction with the architecture of the gene network that underlies the cellular processes can generate phenotypic variation. An important regulatory mechanism is the so-called positive feedback, in which a system reinforces its own response, for instance by stimulating the production of an activator. Bistability is an interesting and relevant phenomenon, in which two distinct subpopulations of cells showing discrete levels of gene expression coexist in a single culture. In this chapter, we address techniques and approaches used to establish phenotypic variation, and relate three well-characterized examples of bistability to the molecular mechanisms that govern these processes, with a focus on positive feedback.
Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at âs = 7 TeV with the ATLAS detector
This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of âs = 7 TeV;{\rm Te}{\rm V}4.6\;{\rm f}{{{\rm b}}^{-1}}{{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}|\eta |\lt 1.9{{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at sâ=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fbâ1 of protonâproton collision data at âs = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via tËâtÏË01 or tËâ bÏ˱1 âbW(â)ÏË01 , where ÏË01 (Ï˱1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of tË â tÏË01 . For a branching fraction of 100%, top squark masses in the range 270â645 GeV are excluded for ÏË01 masses below 30 GeV. For a branching fraction of 50% to either tË â tÏË01 or tË â bÏ˱1 , and assuming the Ï˱1 mass to be twice the ÏË01 mass, top squark masses in the range 250â550 GeV are excluded for ÏË01 masses below 60 GeV
Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at âs=8TeV
The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fbâ1of data collected in protonâproton collisions at âs=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV
Processing of spatial-frequency altered faces in schizophrenia: Effects of illness phase and duration
Low spatial frequency (SF) processing has been shown to be impaired in people with schizophrenia, but it is not clear how this varies with clinical state or illness chronicity. We compared schizophrenia patients (SCZ, n534), first episode psychosis patients (FEP, n522), and healthy controls (CON, n535) on a gender/facial discrimination task. Images were either unaltered (broadband spatial frequency, BSF), or had high or low SF information removed (LSF and HSF conditions, respectively). The task was performed at hospital admission and discharge for patients, and at corresponding time points for controls. Groups were matched on visual acuity. At admission, compared to their BSF performance, each group was significantly worse with low SF stimuli, and most impaired with high SF stimuli. The level of impairment at each SF did not depend on group. At discharge, the SCZ group performed more poorly in the LSF condition than the other groups, and showed the greatest degree of performance decline collapsed over HSF and LSF conditions, although the latter finding was not significant when controlling for visual acuity. Performance did not change significantly over time for any group. HSF processing was strongly related to visual acuity at both time points for all groups. We conclude the following: 1) SF processing abilities in schizophrenia are relatively stable across clinical state; 2) face processing abnormalities in SCZ are not secondary to problems processing specific SFs, but are due to other known difficulties constructing visual representations from degraded information; and 3) the relationship between HSF processing and visual acuity, along with known SCZ- and medication-related acuity reductions, and the elimination of a SCZ-related impairment after controlling for visual acuity in this study, all raise the possibility that some prior findings of impaired perception in SCZ may be secondary to acuity reductions
Dissimilar impact of type 2 diabetes on cardiovascular outcomes according to age categories: a nationwide population study from Hungary
BACKGROUND: The excess risks of mortality and cardiovascular morbidity among patients with type 2 diabetes mellitus (T2DM) is well known. In this nationwide study, we assessed risks of mortality and cardiovascular events comparing patients with T2DM and matched controls. METHODS: We identified patients with T2DM in a retrospective cohort study using the database of the National Health Insurance Fund between 1 January 2010 and 31 December, 2013. Controls were randomly included and matched according to age, gender, and zip code of residence. Patients were divided into subgroups according to age decades for outcome analyses. RESULTS: During the mean follow-up period of 2.3 years, 152,678 patients with T2DM and 305,356 matched controls were included. Patients with T2DM showed significantly higher risk for all-cause mortality (HR 1.26, 95% CI 1.22-1.29, p < 0.0001), myocardial infarction (HR 1.81, 95% CI 1.69-1.94, p < 0.0001) and stroke (HR 1.40, 95% CI 1.35-1.46, p < 0.0001) compared to matched controls. The higher risk associated with T2DM for mortality, myocardial infarction and stroke differed significantly between age groups (pinteraction < 0.05 for all outcomes) with significantly higher risk observed in younger patients. CONCLUSIONS: The risk of cardiovascular outcomes and all-cause mortality is significantly higher in patients with T2DM. Notably, the relative hazard increases with decreasing age suggesting that younger patients with T2DM should receive more attention for cardiovascular prevention
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