4,735 research outputs found
Charm rescattering contribution in rare decay
Following the experimental results from LHCb on the rare decay , we investigate the possibility where this process is dominated by
a double charm rescattering. The decay to double charm channels have a
weak topology that is favoured in comparison with the direct production of
in the final state, suppressed by quark annihilation. The decay
amplitude for with decaying first to double charm
channels is described by a charm penguin diagram, represented by charm hadronic
triangle loops, which reach the final state of interest after or transitions. We show that these
processes give rise to non-resonant amplitudes with a clear signature in the
Dalitz plot. In a near future, the new data from LHCb run II will be able to
confirme if the main hypotheses of this work is correct and the dominant
mechanism to produce from the decay of is through charm
rescattering
Mapping the risk of anaemia in preschool-age children: the contribution of malnutrition, malaria, and helminth infections in West Africa
BACKGROUND Childhood anaemia is considered a severe public health problem in most countries of sub-Saharan Africa. We investigated the geographical distribution of prevalence of anaemia and mean haemoglobin concentration (Hb) in children aged 1-4 y (preschool children) in West Africa. The aim was to estimate the geographical risk profile of anaemia accounting for malnutrition, malaria, and helminth infections, the risk of anaemia attributable to these factors, and the number of anaemia cases in preschool children for 2011. METHODS AND FINDINGS National cross-sectional household-based demographic health surveys were conducted in 7,147 children aged 1-4 y in Burkina Faso, Ghana, and Mali in 2003-2006. Bayesian geostatistical models were developed to predict the geographical distribution of mean Hb and anaemia risk, adjusting for the nutritional status of preschool children, the location of their residence, predicted Plasmodium falciparum parasite rate in the 2- to 10-y age group (Pf PR(2-10)), and predicted prevalence of Schistosoma haematobium and hookworm infections. In the four countries, prevalence of mild, moderate, and severe anaemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The mean Hb was lowest in Burkina Faso (89 g/l), in males (93 g/l), and for children 1-2 y (88 g/l). In West Africa, severe malnutrition, Pf PR(2-10), and biological synergisms between S. haematobium and hookworm infections were significantly associated with anaemia risk; an estimated 36.8%, 14.9%, 3.7%, 4.2%, and 0.9% of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium infections, hookworm infections, and S. haematobium/hookworm coinfections, respectively. A large spatial cluster of low mean Hb (95%) was predicted for an area shared by Burkina Faso and Mali. We estimate that in 2011, approximately 6.7 million children aged 1-4 y are anaemic in the three study countries. CONCLUSIONS By mapping the distribution of anaemia risk in preschool children adjusted for malnutrition and parasitic infections, we provide a means to identify the geographical limits of anaemia burden and the contribution that malnutrition and parasites make to anaemia. Spatial targeting of ancillary micronutrient supplementation and control of other anaemia causes, such as malaria and helminth infection, can contribute to efficiently reducing the burden of anaemia in preschool children in Africa.Funded by the University of Queensland and National Health and Medical Research Council (NHMRC), Australia
Role of the transverse field in inverse freezing in the fermionic Ising spin-glass model
We investigate the inverse freezing in the fermionic Ising spin-glass (FISG)
model in a transverse field . The grand canonical potential is
calculated in the static approximation, replica symmetry and one-step replica
symmetry breaking Parisi scheme. It is argued that the average occupation per
site is strongly affected by . As consequence, the boundary phase
is modified and, therefore, the reentrance associated with the inverse freezing
is modified too.Comment: 6 pages, 3 figures, accepted for publication in PR
BIDs, Economic Recession and the Future of Stakeholder-led Public Realm Management
BIDs were introduced in the UK in 2003/2004 and their widespread adoption was linked to their ability to raise funds to invest in the locality, through a mandatory supplementary levy on business rates, voluntary contributions, sponsorship and public sector grants. However, the economic downturn has already restricted those sources of funding, and public sector spending cuts are likely to restrict them even further. This case-study research has investigated the impact recession and spending cuts have had and are still likely to have on the way BIDs operate, and has tried to identify the threats and opportunities to them as stakeholder-led instruments for the management of town centres and commercial and industrial areas
Effects of assimilate enhancement on grain filling and carbohydrate and nitrogen partitioning in maize.
Source-sink relationhips is a controversial topic. Some workers assert that grain yield in corn is limited by availability of assimilate during the grain filling period. Others have reported the sink size as the limiting factor. In this research, I studied the effects of assimilate availabilibty on kernel growth rate and final weight by investigating the effects of altered source/sink ratios on soluble sugars, starch and nitrogen content in plant parts of maize. Special attention was given to plant's compensatory response such as soluble carbohydrates and nitrogen redistribution to the grain. Two genotypes: M14 x W64A and Pionner-brand '3780', were grown in field plots at St. Paul, Mn in 1982. The treatment were arranged in a split plot manner in a randomized complete block design of four replicates. The alterations of source/sink ratio consisted of partial kernel removal (removing the tip half of the ear), and thinning by a 50% plant population reduction imposed before and after the onset of linear growth (6 days and 24 days after mid-silking, respectively). M14 x W64A responded to early thinning, as indicated by an extended grain filling period, increased starch content of the kernels and greater final kernel weight. However, kernel growth rate, number of kernels per ear and kernel soluble sugars content were not affected. Thinning and partial kernel removel on both dates increased internode dry weight and soluble sugar content. Kernels removal early enhanced the nitrogen content in the internodes and (...)Dissertação (Mestrado) - University of Minnesota, Minneapolis
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