Particle size segregation in granular flow in silos

Segregation and layering of alumina in storage silos are investigated, with a view to predicting output quality versus time, given known variations in input quality on emplacement. A variety of experiments were conducted, existing relevant publications were reviewed, and the basis for an algorithm for predicting the effect of withdrawing from a central flowing region, in combination with variations in quality due to geometric, layering and segregation effects, is described in this report

Microglia-derived TNFα induces apoptosis in neural precursor cells via transcriptional activation of the Bcl-2 family member Puma

Neuroinflammation is a common feature of acute neurological conditions such as stroke and spinal cord injury, as well as neurodegenerative conditions such as Parkinson’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis. Previous studies have demonstrated that acute neuroinflammation can adversely affect the survival of neural precursor cells (NPCs) and thereby limit the capacity for regeneration and repair. However, the mechanisms by which neuroinflammatory processes induce NPC death remain unclear. Microglia are key mediators of neuroinflammation and when activated to induce a pro-inflammatory state produce a number of factors that could affect NPC survival. Importantly, in the present study we demonstrate that tumor necrosis factor α (TNFα) produced by lipopolysaccharide-activated microglia is necessary and sufficient to trigger apoptosis in mouse NPCs in vitro. Furthermore, we demonstrate that microglia-derived TNFα induces NPC apoptosis via a mitochondrial pathway regulated by the Bcl-2 family protein Bax. BH3-only proteins are known to play a key role in regulating Bax activation and we demonstrate that microglia-derived TNFα induces the expression of the BH3-only family member Puma in NPCs via an NF-jB-dependent mechanism. Specifically, we show that NF-jB is activated in NPCs treated with conditioned media from activated microglia and that Puma induction and NPC apoptosis is blocked by the NF-jB inhibitor BAY-117082. Importantly, we have determined that NPC apoptosis induced by activated microglia-derived TNFα is attenuated in Puma-deficient NPCs, indicating that Puma induction is required for NPC death. Consistent with this, we demonstrate that Puma-deficient NPCs exhibit an B13-fold increase in survival as compared with wild-type NPCs following transplantation into the inflammatory environment of the injured spinal cord in vivo. In summary, we have identified a key signaling pathway that regulates neuroinflammation induced apoptosis in NPCs in vitro and in vivo that could be targeted to promote regeneration and repair in diverse neurological conditions

Nanomatemàtiques: modelització matemàtica a la nanoescala

En aquest article exposem tres problemes estudiats recentment al grup de Matemàtica Industrial del Centre de Recerca Matemàtica, en els quals l'aproximació del continu resulta vàlida per a descriure fenòmens a la nanoescala: 1. Transferència de calor en nanofluids: els resultats experimentals que confirmen l'increment de la capacitat de transferir calor dels nanofluids respecte dels fluids estàndard són sovint contradictoris. Mitjançant una anàlisi de capa límit mostrarem com el model matemàtic utilitzat en nombroses ocasions per justificar l'increment en la transferència de calor dels nanofluids preveu, de fet, una disminució d'aquesta propietat. 2. Fusió de nanopartícules: les nanopartícules mostren un increment abrupte de la velocitat de transició de fase a mesura que el seu radi decreix. Presentarem un model matemàtic que descriu aquest fenomen. El model preveu temps totals de transició sòlid-líquid que concorden amb les observacions experimentals. 3. Increment del flux d'un fluid en nanotubs de carboni (CNT): mostrarem que els resultats experimentals sobre l'increment de flux en nanotubs de carboni es poden explicar mitjançant les equacions estàndard de la dinàmica de fluids amb la incorporació d'una capa d'extinció (depletion layer) a la interfície entre el fluid i el sòlid.In this paper we discuss three problems recently studied within the Industrial Maths Research Group at the Centre de Recerca Matemàtica, where continuum theory may be applied to describe nanoscale phenomena: 1. Heat transfer with nanofluids: Experimental results concerning the remarkable heat transfer characteristics of nanofluids are at times contradictory. We apply a boundary layer analysis to show that a standard model which has been used by many authors to predict an improvement in heat transfer with increasing nanoparticle concentration in fact shows a decrease. 2. Nanoparticle melting: Nanoparticles often exhibit a sharp increase in melting rate as the size decreases. A mathematical model will be presented which predicts this phenomena and explains the experimentally observed abrupt melting of the smallest nanoparticles. 3. Enhanced flow in carbon nanotubes (CNTs): This model shows that the experimentally observed enhancement can be explained using standard flow equations but with a depletion layer between the liquid and solid interfaces. The results also provide one physical explanation for the Navierslip condition

Framework for better living with HIV in England

Duration: April 2007 - May 2009 Sigma Research was funded by Terrence Higgins Trust to co-ordinate the development of a framework to address the health, social care, support and information needs of people with diagnosed HIV in England. It has now been published as the Framework for better living with HIV in England. The over-arching goal of the framework is that all people with diagnosed HIV in England "are enabled to have the maximum level of health, well-being, quality of life and social integration". In its explanation of how this should occur the document presents a road map for social care, support and information provision to people with diagnosed HIV in England. By establishing and communicating aims and objectives, the framework should build consensus and provide a means to establish how interventions could be prioritised and coordinated. The key drivers for the framework were clearly articulated ethical principles, agreed by all those who sign up to it, and an inclusive social development / health promotion approach. Sigma Research worked on the framework with a range of other organisations who sent representatives to a Framework Development Group (see below for membership). The framework is evidence-based and seeks to: Promote and protect the rights and well-being of all people with HIV in England. Maximise the capacity of individuals and groups of people with HIV to care for, advocate and represent themselves effectively. Improve and protect access to appropriate information, social support, social care and clinical services. Minimise social, economic, governmental and judicial change detrimental to the health and well being of people with HIV. Alongside the development of the framework, Sigma Research undertook a national needs assessment among people with diagnosed HIV across the UK called What do you need?. These two projects informed and supported each other. Framework Development Group included: African HV Policy Network Black Health Agency George House Trust NAM NAT (National AIDS Trust) Positively Women Terrence Higgins Trus

SNP Assay Development for Linkage Map Construction, Anchoring Whole-Genome Sequence, and Other Genetic and Genomic Applications in Common Bean.

A total of 992,682 single-nucleotide polymorphisms (SNPs) was identified as ideal for Illumina Infinium II BeadChip design after sequencing a diverse set of 17 common bean (Phaseolus vulgaris L) varieties with the aid of next-generation sequencing technology. From these, two BeadChips each with >5000 SNPs were designed. The BARCBean6K_1 BeadChip was selected for the purpose of optimizing polymorphism among market classes and, when possible, SNPs were targeted to sequence scaffolds in the Phaseolus vulgaris 14× genome assembly with sequence lengths >10 kb. The BARCBean6K_2 BeadChip was designed with the objective of anchoring additional scaffolds and to facilitate orientation of large scaffolds. Analysis of 267 F2 plants from a cross of varieties Stampede × Red Hawk with the two BeadChips resulted in linkage maps with a total of 7040 markers including 7015 SNPs. With the linkage map, a total of 432.3 Mb of sequence from 2766 scaffolds was anchored to create the Phaseolus vulgaris v1.0 assembly, which accounted for approximately 89% of the 487 Mb of available sequence scaffolds of the Phaseolus vulgaris v0.9 assembly. A core set of 6000 SNPs (BARCBean6K_3 BeadChip) with high genotyping quality and polymorphism was selected based on the genotyping of 365 dry bean and 134 snap bean accessions with the BARCBean6K_1 and BARCBean6K_2 BeadChips. The BARCBean6K_3 BeadChip is a useful tool for genetics and genomics research and it is widely used by breeders and geneticists in the United States and abroad

Reviews

Reviews of International and comparative industrial relations, Tatau Tatau - one big union altogether, Remedy for present evils: a history of the New Zealand Public Service Association from 1890, Sexual harassment in the workplace, Employee selection, Legislating for workplace hazards in New Zealand: overseas experience and our present and future needs, People and enterprises - human behaviour in New Zealand organisations and From school to unemployment? The labour market for young peopl

Quantum sticking, scattering and transmission of 4He atoms from superfluid 4He surfaces

We develop a microscopic theory of the scattering, transmission, and sticking of 4He atoms impinging on a superfluid 4He slab at near normal incidence, and inelastic neutron scattering from the slab. The theory includes coupling between different modes and allows for inelastic processes. We find a number of essential aspects that must be observed in a physically meaningful and reliable theory of atom transmission and scattering; all are connected with multiparticle scattering, particularly the possibility of energy loss. These processes are (a) the coupling to low-lying (surface) excitations (ripplons/third sound) which is manifested in a finite imaginary part of the self energy, and (b) the reduction of the strength of the excitation in the maxon/roton region