849 research outputs found
CP violation Beyond the MSSM: Baryogenesis and Electric Dipole Moments
We study electroweak baryogenesis and electric dipole moments in the presence
of the two leading-order, non-renormalizable operators in the Higgs sector of
the MSSM. Significant qualitative and quantitative differences from MSSM
baryogenesis arise due to the presence of new CP-violating phases and to the
relaxation of constraints on the supersymmetric spectrum (in particular, both
stops can be light). We find: (1) spontaneous baryogenesis, driven by a change
in the phase of the Higgs vevs across the bubble wall, becomes possible; (2)
the top and stop CP-violating sources can become effective; (3) baryogenesis is
viable in larger parts of parameter space, alleviating the well-known
fine-tuning associated with MSSM baryogenesis. Nevertheless, electric dipole
moments should be measured if experimental sensitivities are improved by about
one order of magnitude.Comment: 33 pages, 6 figure
The predictive and prognostic potential of plasma telomerase reverse transcriptase (TERT) RNA in rectal cancer patients
Background: Preoperative chemoradiotherapy (CRT) followed by surgery is the standard care for locally advanced rectal cancer,
but tumour response to CRT and disease outcome are variable. The current study aimed to investigate the effectiveness of plasma
telomerase reverse transcriptase (TERT) levels in predicting tumour response and clinical outcome.
Methods: 176 rectal cancer patients were included. Plasma samples were collected at baseline (before CRT\ubcT0), 2 weeks after
CRT was initiated (T1), post-CRT and before surgery (T2), and 4\u20138 months after surgery (T3) time points. Plasma TERT mRNA levels
and total cell-free RNA were determined using real-time PCR.
Results: Plasma levels of TERT were significantly lower at T2 (Po0.0001) in responders than in non-responders. Post-CRT TERT
levels and the differences between pre- and post-CRT TERT levels independently predicted tumour response, and the prediction
model had an area under curve of 0.80 (95% confidence interval (CI) 0.73\u20130.87). Multiple analysis demonstrated that patients with
detectable TERT levels at T2 and T3 time points had a risk of disease progression 2.13 (95% CI 1.10\u20134.11)-fold and 4.55 (95% CI
1.48\u201313.95)-fold higher, respectively, than those with undetectable plasma TERT levels.
Conclusions: Plasma TERT levels are independent markers of tumour response and are prognostic of disease progression in rectal
cancer patients who undergo neoadjuvant therapy
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Methane emission by Camelids
Methane emissions from ruminant livestock have been intensively studied in order to reduce contribution to the greenhouse effect. Ruminants were found to produce more enteric methane than other mammalian herbivores. As camelids share some features of their digestive anatomy and physiology with ruminants, it has been proposed that they produce similar amounts of methane per unit of body mass. This is of special relevance for countrywide greenhouse gas budgets of countries that harbor large populations of camelids like Australia. However, hardly any quantitative methane emission measurements have been performed in camelids. In order to fill this gap, we carried out respiration chamber measurements with three camelid species (Vicugna pacos, Lama glama, Camelus bactrianus; n = 16 in total), all kept on a diet consisting of food produced from alfalfa only. The camelids produced less methane expressed on the basis of body mass (0.3260.11 L kg21 d21) when compared to literature data on domestic ruminants fed on roughage diets (0.5860.16 L kg21 d21). However, there was no significant difference between the two suborders when methane emission was expressed on the basis of digestible neutral detergent fiber intake (92.7633.9 L kg21 in camelids vs. 86.2612.1 L kg21 in ruminants). This implies that the pathways of methanogenesis forming part of the microbial digestion of fiber in the foregut are similar between the groups, and that the lower methane emission of camelids can be explained by their generally lower relative food intake. Our results suggest that the methane emission of Australia’s feral camels corresponds only to 1 to 2% of the methane amount produced by the countries’ domestic ruminants and that calculations of greenhouse gas budgets of countries with large camelid populations based on equations developed for ruminants are generally overestimating the actual levels
Abatement of particulate-laden SO2 in tapered bubble column with internals
The performance of particulate-laden SO2 scrubbing in a modified tapered bubble column with internals is reported in this article. The presence of particles improved the particulate-laden SO2 removal efficiency to about 15% that was elucidated by the facilitated adsorptive mass transport. Experimentation revealed that nearly 100% removal efficiency of particulate-laden SO2 was achievable without any additives or pretreatment under certain operating condition of the scrubber. An empirical correlation was developed to predict the performance of the modified tapered scrubber. Experimental values fitted excellently well with the predicted values through the correlation (within ±5% deviation). The performance of the modified tapered bubble scrubber with column internals has been found to be better than a tapered bubble column without any internals
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.
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Relaxation of contact pressure and self-loosening in dynamic bolted joints
Bolted joints are widely used in a variety of engineering applications where they are dynamically loaded with frequencies of vibration spread over a wide spectrum with the same general effects. When under dynamic loading, bolted joints can become loose due to a loss in clamping pressure in the joints. This vibrational loosening sometimes can cause serious problems, and in some cases can lead to fatal consequences if it remains undetected. Non-intrusive ultrasonic and image processing techniques were simultaneously used to investigate the relaxation of contact pressure and loosening of bolted joints subjected to cyclic shear loading. Three critical areas, the contact interface of the bolted component, the bolt length and the rotation of the bolt head, were monitored during loosening of the joints. The results show that loosening of bolted joints can be grouped into three stages: very rapid, rapid, and gradual loosening. The earliest stage of the loosening of bolted joints is characterised by cyclic strain ratcheting–loosening of the bolted joint during vibration without rotation of the bolt head. The higher the rate of relaxation at this early stage, the lower is the resistance of the bolted joint to vibration-induced loosening. Both the dynamic shear load and an additional constant shear load in another direction were observed to affect the rate of loosening, and at this early stage, a rise in the magnitude of the additional constant shear load increases the rate of loosening. Furthermore, the contact pressure distribution affects the rate of loosening at the bolted joint interface, as loosening increases away from area of high contact pressure
Role of lipid-mobilising factor (LMF) in protecting tumour cells from oxidative damage
Lipid-mobilising factor (LMF) is produced by cachexia-inducing tumours and is involved in the degradation of adipose tissue, with increased oxidation of the released fatty acids through an induction of uncoupling protein (UCP) expression. Since UCP-2 is thought to be involved in the detoxification of free radicals if LMF induced UCP-2 expression in tumour cells, it might attenuate free radical toxicity. As a model system we have used MAC13 tumour cells, which do not produce LMF. Addition of LMF caused a concentration-dependent increase in UCP-2 expression, as determined by immunoblotting. This effect was attenuated by the β3 antagonist SR59230A, suggesting that it was mediated through a β3 adrenoreceptor. Co-incubation of LMF with MAC13 cells reduced the growth-inhibitory effects of bleomycin, paraquat and hydrogen peroxide, known to be free radical generators, but not chlorambucil, an alkylating agent. There was no effect of LMF alone on cellular proliferation. These results indicate that LMF antagonises the antiproliferative effect of agents working through a free radical mechanism, and may partly explain the unresponsiveness to the chemotherapy of cachexia-inducing tumours. © 2004 Cancer Research UK
Geographic Variation of Strontium and Hydrogen Isotopes in Avian Tissue: Implications for Tracking Migration and Dispersal
Background: Isotopes can provide unique solutions to fundamental problems related to the ecology and evolution of migration and dispersal because prior movements of individuals can theoretically be tracked from tissues collected from a single capture. However, there is still remarkably little information available about how and why isotopes vary in wild animal tissues, especially over large spatial scales. Methodology/Principal Findings: Here, we describe variation in both stable-hydrogen (dDF) and strontium ( 87Sr/86SrF) isotopic compositions in the feathers of a migratory songbird, the Tree Swallow (Tachycineta bicolor), across 18 sampling sites in North America and then examine potential mechanisms driving this variation. We found that dDF was correlated with latitude of the sampling site, whereas 87Sr/86SrF was correlated with longitude. dDF was related to dD of meteoric waters where molting occurred and 87Sr/86SrF was influenced primarily by the geology in the area where feathers were grown. Using simulation models, we then assessed the utility of combining both markers to estimate the origin of individuals. Using 13 geographic regions, we found that the number of individuals correctly assigned to their site of origin increased from less than 40 % using either dD or 87Sr/86Sr alone to 74 % using both isotopes. Conclusions/Significance: Our results suggest that these isotopes have the potential to provide predictable an
Duplication events downstream of IRX1 cause North Carolina macular dystrophy at the MCDR3 locus
Autosomal dominant North Carolina macular dystrophy (NCMD) is believed to represent a failure of macular development. The disorder has been linked to two loci, MCDR1 (chromosome 6q16) and MCDR3 (chromosome 5p15-p13). Recently, non-coding variants upstream of PRDM13 (MCDR1) and a duplication including IRX1 (MCDR3) have been identified. However, the underlying disease-causing mechanism remains uncertain. Through a combination of sequencing studies on eighteen NCMD families, we report two novel overlapping duplications at the MCDR3 locus, in a gene desert downstream of IRX1 and upstream of ADAMTS16. One duplication of 43 kb was identified in nine families (with evidence for a shared ancestral haplotype), and another one of 45 kb was found in a single family. Three families carry the previously reported V2 variant (MCDR1), while five remain unsolved. The MCDR3 locus is thus refined to a shared region of 39 kb that contains DNAse hypersensitive sites active at a restricted time window during retinal development. Publicly available data confirmed expression of IRX1 and ADAMTS16 in human fetal retina, with IRX1 preferentially expressed in fetal macula. These findings represent a major advance in our understanding of the molecular genetics of NCMD and provide insights into the genetic pathways involved in human macular development
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