14,448 research outputs found
B_s^0 - bar{B}_s^0 Mixing and the B_s -> J/psi phi Asymmetry in Supersymmetric Models
We analyse supersymmetric contributions to B_s mixing and their impact on
mixing-induced CP asymmetries, using the mass insertion approximation. We
discuss in particular the correlation of SUSY effects in the CP asymmetries of
B_s -> J/psi phi and B_d -> phi K_S and find that the mass insertions dominant
in B_s mixing and B_d -> phi K_S are (delta_{23}^d)_{LL, RR} and
(delta_{23}^d)_{LR, RL}, respectively. We show that models with dominant
(delta_{23}^d)_{LR, RL} can accomodate a negative value of S_{phi K_S}, in
agreement with the BELLE measurement of that observable, but yield a B_s mixing
phase too small to be observed. On the other hand, models with dominant
(delta_{23}^d)_{LL, RR} predict sizeable SUSY contributions to both Delta M_s
and the mixing phase, but do not allow the asymmetry in B_d -> phi K_S to
become negative, except for small values of the average down squark mass,
which, in turn, entail a value of Delta M_s too large to be observed at the
Tevatron and the LHC. We conclude that the observation of B_s mixing at hadron
machines, together with the confirmation of a negative value of S_{phi K_S},
disfavours models with a single dominant mass insertion.Comment: 17 pages, 5 figure
Targeting ATM pathway for therapeutic intervention in cancer
The Ataxia Telangiectasia Mutated gene encodes the ATM protein, a key element in the DNA damage response (DDR) signalling pathway responsible for maintaining genomic integrity within the cell. The ATM protein belongs to a family of large protein kinases containing the phosphatidylinositol-3 catalytic domain, including ATM, ATR and PI3K. ATM provides the crucial link between DNA damage, cell cycle progression and cell death by first sensing double stranded DNA breaks and subsequently phosphorylating and activating other downstream proteins functioning in DNA damage repair, cell cycle arrest and apoptotic pathways,. Mammalian cells are constantly challenged by genotoxic agents from a variety of sources and therefore require a robust sensing and repair mechanism to maintain DNA integrity or activate alternative cell fate pathways. This review covers the role of ATM in DDR signalling and describes the interaction of the ATM kinase with other proteins in order to fulfil its various functions. Special emphasis is given to how the growing knowledge of the DDR can help identify drug targets for cancer therapy, thus providing a rationale for exploiting the ATM pathway in anticancer drug development. Moreover, we discuss how a network modelling approach can be used to identify and characterise ATM inhibitors and predict their therapeutic potential
The Use of Local Mineral Formulas as a Feed Block Supplement for Beef Cattle Fed on Wild Forages
The present research was carried out to study the diversity of mineral contents of wild forages and to evaluate the beneficial effect of mineral feed supplement formulated by using locally available materials on the performances of beef cattle. The present research was initiated by analyzing mineral contents of wild forages grown around Limau Manis campus areas. Forage samples were collected at 9 sampling areas scattered at plantation, conservation and idle lands. Samples were then analyzed for macro minerals of Ca, P, Mg, K, Na, and S and micro minerals of Co, Cu, Fe, Mn, Se, and Zn. Feeding trial was then conducted to evaluate the beneficial effect of supplementation of local mineral formulas (LMF) produced by using locally available materials on the performances of cattle. Feeding trial was conducted for 6 weeks by using 9 Simmentals cross bred heifers. The trial consisted of 3 treatments, i.e., P1: only grass without supplementation, P2: grass + LMF and P3: grass + mineral premix enriched LMF. Variables measured were: body weight, feed intake, FCR, feed cost and net return. Results showed that the highest macro mineral content of wild forages was Na of about 13.05±2.22 g/kg, varied from 4.1 to 23.8 g/kg, followed by K (11.09±1.43 g/kg) and Ca (6.10±1.09 g/kg DM). Three minerals of Mg, P, and S were found in relatively small concentrations of 1.34±0.30, 0.83±0.23, and 0.17±0.01 g/kg, respectively. Fe, Mn, Cu and Zn were found in relatively high concentrations. The highest concentration of micro minerals was Fe of about 613.8±128.9 mg/kg, followed by Mn of 143.9±23.3 mg/kg, while Zn and Cu were found in relatively small amount of about 31.3±5.5 and 13.2±2.5 mg/kg, respectively. Heifers supplemented with LMF (P2) and mineral premix enriched LMF (P3) showed higher body weight gain, lower FCR and net return than those cattle fed only grass (P1). The most profitable feeding strategy was by supplementation of heifers with mineral premix enriched LMF.Key words: wild forage quality, local mineral formula, ruminant mineral nutritio
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Selective Fetal Growth Restriction in Dichorionic Twin Pregnancies: Diagnosis, Natural History, and Perinatal Outcome.
This study aims to evaluate the natural history, disease progression, and outcomes in dichorionic twins with selective fetal growth restriction (sFGR) according to different diagnostic criteria and time of onset. Dichorionic twins seen from the first trimester were included. sFGR was classified according to the Delphi consensus, and was compared to the outcomes of those classified by the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) diagnostic criteria. Early sFGR occurred before 32-weeks, and late sFGR after 32-weeks. Disease progression, neonatal outcomes such as gestation at delivery, birthweight, neonatal unit (NNU) admission, and morbidities were compared. One-hundred twenty-three of 1053 dichorionic twins had sFGR, where 8.4% were classified as early sFGR, and 3.3% were late sFGR. Disease progression was seen in 36%, with a longer progression time (5 vs. 1 week) and higher progression rate (40% vs. 26%) in early sFGR. Perinatal death was significantly higher in the sFGR than the non-sFGR group (24 vs. 16 per 1000 births, p = 0.018), and those with early sFGR had more NNU admissions than late sFGR (p = 0.005). The ISUOG diagnostic criteria yielded a higher number of sFGR than the Delphi criteria, but similar outcomes. sFGR have worse perinatal outcomes, with early onset being more prevalent. Use of the Delphi diagnostic criteria can reduce over-diagnosis of sFGR and avoid unnecessary intervention
Criticality of natural absorbing states
We study a recently introduced ladder model which undergoes a transition
between an active and an infinitely degenerate absorbing phase. In some cases
the critical behaviour of the model is the same as that of the branching
annihilating random walk with species both with and without hard-core
interaction. We show that certain static characteristics of the so-called
natural absorbing states develop power law singularities which signal the
approach of the critical point. These results are also explained using random
walk arguments. In addition to that we show that when dynamics of our model is
considered as a minimum finding procedure, it has the best efficiency very
close to the critical point.Comment: 6 page
Quantitative analysis of NRF2 pathway reveals key elements of the regulatory circuits underlying antioxidant response and proliferation of ovarian cancer cells
Cells are constantly exposed to Reactive Oxygen Species (ROS) produced both endogenously to meet physiological requirements and from exogenous sources. While endogenous ROS are considered as important signalling molecules, high uncontrollable ROS are detrimental. It is unclear how cells can achieve a balance between maintaining physiological redox homeostasis and robustly activate the antioxidant system to remove exogenous ROS. We have utilised a Systems Biology approach to understand how this robust adaptive system fulfils homeostatic requirements of maintaining steady-state ROS and growth rate, while undergoing rapid readjustment under challenged conditions. Using a panel of human ovarian and normal cell lines, we experimentally quantified and established interrelationships between key elements of ROS homeostasis. The basal levels of NRF2 and KEAP1 were cell line specific and maintained in tight correlation with their growth rates and ROS. Furthermore, perturbation of this balance triggered cell specific kinetics of NRF2 nuclear–cytoplasmic relocalisation and sequestration of exogenous ROS. Our experimental data were employed to parameterise a mathematical model of the NRF2 pathway that elucidated key response mechanisms of redox regulation and showed that the dynamics of NRF2-H2O2 regulation defines a relationship between half-life, total and nuclear NRF2 level and endogenous H2O2 that is cell line specific
Magnetic Response of Magnetospirillum Gryphiswaldense
In this study we modelled and measured the U-turn trajectories of individual
magnetotactic bacteria under the application of rotating magnetic fields,
ranging in ampitude from 1 to 12 mT. The model is based on the balance between
rotational drag and magnetic torque. For accurate verification of this model,
bacteria were observed inside 5 m tall microfluidic channels, so that they
remained in focus during the entire trajectory. From the analysis of hundreds
of trajectories and accurate measurements of bacteria and magnetosome chain
dimensions, we confirmed that the model is correct within measurement error.
The resulting average rate of rotation of Magnetospirillum Gryphiswaldense is
0.74 +- 0.03 rad/mTs.Comment: 17 pages, 12 figure
Muon Anomalous Magnetic Moment and mu -> e gamma in B-L Model with Inverse Seesaw
We study the anomalous magnetic moment of the muon, a_\mu, and lepton flavor
violating decay \mu -> e \gamma in TeV scale B-L extension of the Standard
Model (SM) with inverse seesaw mechanism. We show that the B-L contributions to
a_\mu are severely constrained, therefore the SM contribution remains intact.
We also emphasize that the current experimental limit of BR(\mu -> e \gamma)
can be satisfied for a wide range of parameter space and it can be within the
reach of MEG experiment.Comment: 10 pages, 4 Figure
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An International Support Programme for Sustainable Investment Facilitation
The global challenges of poverty, sustainable development, and climate change are being tackled with renewed vigour in international negotiations of sustainable development goals for 2016–2030. New commitments also mean increased demands for investment—quantitatively more and qualitatively more sustainable. The latter depends on unleashing the inherent package of benefits embedded in capital and on creating shared value for all stakeholders. Much evidence suggests that sustainability can be commercially viable under appropriate policy frameworks. Hence, the need to put such frameworks in place, globally and nationally, to ensure meeting the increased investment demands of the future. Actions at the national level will require international support. This note advances the case for an international support programme for sustainable investment facilitation. As it explains, potentially all investments are sustainable, but the appropriate policy frameworks need definition, often in novel ways and increasingly in partnership with multiple stakeholders, domestic and foreign. Facilitating investment for future needs, therefore, is not a matter of promotion-as-usual, but a process of discovery and diffusion of new approaches and applications, a process that needs nurturing and support by the international community. Ways in which such backing can be provided to an international support programme for sustainable investment facilitation are discussed in detail, including making use of the World Trade Organization- (WTO) led Aid-for-Trade Initiative and the recently adopted WTO Trade Facilitation Agreement. The issues mentioned for possible inclusion in the support programme, as well as the options outlined on how such a programme could be put in place, are illustrative. The key premise is the importance—and urgency—of creating more favourable conditions for sustainable FDI flows to meet the investment needs of the future. As governments and the private sector increasingly share this view, they will hopefully muster the political will and find the appropriate venue to put an international support programme for sustainable investment facilitation in place
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