2,286 research outputs found

    Extremal Values of the Interval Number of a Graph

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    The interval number i(G)i( G ) of a simple graph GG is the smallest number tt such that to each vertex in GG there can be assigned a collection of at most tt finite closed intervals on the real line so that there is an edge between vertices vv and ww in GG if and only if some interval for vv intersects some interval for ww. The well known interval graphs are precisely those graphs GG with i(G)1i ( G )\leqq 1. We prove here that for any graph GG with maximum degree d,i(G)12(d+1)d, i ( G )\leqq \lceil \frac{1}{2} ( d + 1 ) \rceil . This bound is attained by every regular graph of degree dd with no triangles, so is best possible. The degree bound is applied to show that i(G)13ni ( G )\leqq \lceil \frac{1}{3}n \rceil for graphs on nn vertices and i(G)ei ( G )\leqq \lfloor \sqrt{e} \rfloor for graphs with ee edges

    Study of air pollutant detection by remote sensors

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    Air pollution detection using satellite observatio

    Determination of aerosol content in the atmosphere from ERTS-1 data

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    The author has identified the following significant results. Significant results, relating the radiance over water surfaces to the atmospheric aerosol content, have been obtained. The results indicate that the MSS channels 4, 5, and 6 centered at 0.55, 0.65, and 0.75 microns have comparable sensitivity, and that the aerosol content can be determined within + or - 10% with the assumed measurement errors of the MSS. The fourth channel, MSS 7, is not useful for aerosol determination due to the water radiance values from this channel generally being less than the instrument noise. The accuracy of the aerosol content measurement could be increased by using an instrument specifically designed for this purpose. This radiance-aerosol content relationship can possibly provide a basis for monitoring the atmospheric aerosol content on a global basis, allowing a base-line value of aerosols to be established. The contrast-aerosol content investigation shows useful linear relationships in MSS channels 4 and 5, allowing the aerosol content to be determined within + or - 10%. MSS 7 is not useful due to the low accuracy in the water radiance, and MSS 6 is found to be too insensitive. These results rely on several assumptions due to the lack of ground truth data, but do serve to indicate which channels are most useful

    Placing the transfer of learning at the heart of HRD Practice

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    Training evaluation is a key area of Human Resource Development, however, measuring the effectiveness of training and the transfer of learning from a training programme to the workplace can be a challenging activity. This is even more problematic for a training provider who does not have the continuous relationship or access to performance measures of an in-house training department. This paper reports on the evaluation of a training model, assessing the impact from introduction to completion of the cycle. There are three partners in this research project: the training company, the client organisation and the university researchers. Synaptic Change Ltd is a training consultancy delivering bespoke training to organisations. Utilising a case study approach, this project reports on the evaluation of their training model through its introduction at Connect Housing, a charitable housing and support provider. This presents an interesting context for the study as researchers have suggested the distinctive value led culture of the Voluntary Sector can support a strong learning culture within the organisation. The project seeks to assess the value of learning to the organisation derived from the introduction of the model. The paper explores theoretical and empirical research concerning the evaluation of training and discusses the context of the case study organisation. It then positions the methodology employed and how data will be collected. As a working paper, the findings are not available at this time but will be presented and discussed at the UFHRD conference

    Determinants of anemia and hemoglobin concentration in haitian school-aged children

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    Anemia diminishes oxygen transport in the body, resulting in potentially irreversible growth and developmental consequences for children. Limited evidence for determinants of anemia exists for school-aged children. We conducted a cluster randomized controlled trial in Haiti from 2012 to 2013 to test the efficacy of a fortified school snack. Children (N = 1,047) aged 3–13 years were followed longitudinally at three time points for hemoglobin (Hb) concentrations, anthropometry, and bioelectrical impedance measures. Dietary intakes, infectious disease morbidities, and socioeconomic and demographic factors were collected at baseline and endline. Longitudinal regression modeling with generalized least squares and logit models with random effects identified anemia risk factors beyond the intervention effect. At baseline, 70.6% of children were anemic and 2.6% were severely anemic. Stunting increased the odds of developing anemia (adjusted odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.05–2.08) and severe anemia (adjusted OR: 2.47, 95% CI: 1.30–4.71). Parent-reported vitamin A supplementation and deworming were positively associated with Hb concentrations, whereas fever and poultry ownership showed a negative relationship with Hb concentration and increased odds of severe anemia, respectively. Further research should explore the full spectrum of anemia etiologies in school children, including genetic causes

    Q2Q_2-free families in the Boolean lattice

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    For a family F\mathcal{F} of subsets of [n]=\{1, 2, ..., n} ordered by inclusion, and a partially ordered set P, we say that F\mathcal{F} is P-free if it does not contain a subposet isomorphic to P. Let ex(n,P)ex(n, P) be the largest size of a P-free family of subsets of [n]. Let Q2Q_2 be the poset with distinct elements a, b, c, d, a<b, c<d; i.e., the 2-dimensional Boolean lattice. We show that 2No(N)ex(n,Q2)2.283261N+o(N),2N -o(N) \leq ex(n, Q_2)\leq 2.283261N +o(N), where N=(nn/2)N = \binom{n}{\lfloor n/2 \rfloor}. We also prove that the largest Q2Q_2-free family of subsets of [n] having at most three different sizes has at most 2.20711N members.Comment: 18 pages, 2 figure

    The perceived barriers to the inclusion of rainwater harvesting systems by UK house building companies

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    This work investigates the barriers that exist to deter the implementation of rainwater harvesting into new UK housing. A postal questionnaire was sent to a selection of large, medium and small house-builders distributed across the UK. Questions were asked concerning potential barriers to the inclusion of rainwater harvesting in homes separated into five sections; (1) institutional and regulatory gaps, (2) economic and financial constraints, (3) absence of incentives, (4) lack of information and technical knowledge, and (5) house-builder attitudes. The study concludes that although the knowledge of rainwater systems has increased these barriers are deterring house-builders from installing rainwater harvesting systems in new homes. It is further acknowledged that the implementation of rainwater harvesting will continue to be limited whilst these barriers remain and unless resolved, rainwater harvesting's potential to reduce the consumption of potable water in houses will continue to be limited

    Glial βii spectrin contributes to paranode formation and maintenance

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    Action potential conduction along myelinated axons depends on high densities of voltage-gated Na channels at the nodes of Ranvier. Flanking each node, paranodal junctions (paranodes) are formed between axons and Schwann cells in the peripheral nervous system (PNS) or oligodendrocytes intheCNS. Paranodal junctions contribute to both no deassembly and maintenance. Despitetheir importance, the molecular mechanisms responsible for paranode assembly and maintenance remain poorly understood. βII spectrin is expressed in diverse cells and is an essential part of the submembranous cytoskeleton. Here, we show that Schwann cell βII spectrin is highly enriched at paranodes. To elucidate the roles of glial βII spectrin, we generated mutant mice lacking βII spectrin in myelinating glial cells by crossing mice with a floxed allele of Sptbn1 with Cnp-Cre mice, and analyzed both male and female mice. Juvenile (4 weeks) and middle-aged (60 weeks) mutant mice showed reduced grip strength and sciatic nerve conduction slowing, whereas no phenotype was observed between 8 and 24 weeks of age. Consistent with these findings, immunofluorescence microscopy revealed disorganized paranodes in the PNS and CNS of both postnatal day 13 and middle-aged mutant mice, but not in young adult mutant mice. Electron microscopy confirmed partial loss of transverse bands at the paranodal axoglial junction in the middle-aged mutant mice in both the PNS and CNS. These findings demonstrate that a spectrin-based cytoskeleton in myelinating glia contributes to formation and maintenance of paranodal junctions.Fil: Susuki, Keiichiro. Baylor College of Medicine; Estados UnidosFil: Zollinger, Daniel R.. Baylor College of Medicine; Estados UnidosFil: Chang, Kae Jiun. Baylor College of Medicine; Estados UnidosFil: Zhang, Chuansheng. Baylor College of Medicine; Estados UnidosFil: Huang, Claire Yu Mei. Baylor College of Medicine; Estados UnidosFil: Tsai, Chang Ru. Baylor College of Medicine; Estados UnidosFil: Galiano, Mauricio Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina. Baylor College of Medicine; Estados UnidosFil: Liu, Yanhong. Baylor College of Medicine; Estados UnidosFil: Benusa, Savannah D.. Virginia Commonwealth University; Estados UnidosFil: Yermakov, Leonid M.. Wright State University; Estados UnidosFil: Griggs, Ryan B.. Wright State University; Estados UnidosFil: Dupree, Jeffrey L.. Virginia Commonwealth University; Estados UnidosFil: Rasband, Matthew N.. Baylor College of Medicine; Estados Unido

    TARGETING METHYLGLYOXAL AND PPAR GAMMA TO ALLEVIATE NEUROPATHIC PAIN ASSOCIATED WITH TYPE 2 DIABETES

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    Neuropathic pain affects up to 50% of the 29 million diabetic patients in the United States. Neuropathic pain in diabetes manifests as a disease of the peripheral and central nervous systems. The prevalence of type 2 diabetes is far greater than type 1 (90%), yet the overwhelming focus on type 1 models this has left the mechanisms of pain in type 2 diabetes largely unknown. Therefore I aimed to improve the current mechanistic understanding of pain associated with type 2 diabetes using two preclinical rodent models: Zucker Diabetic Fatty rats and db/db mice. In addition, I highlight the translational importance of simultaneous measurement of evoked/sensory and non-evoked/affective pain-related behaviors in preclinical models. This work is the first to show a measure of motivational-affective pain in a model of type 2 diabetes. I used methodological approaches including: (1) immunohistochemical and calcium imaging to assess stimulus-evoked sensitization; (2) measurement nociceptive behaviors and evoked sensory thresholds as well as pain affect using novel mechanical conflict avoidance and conditioned place preference/aversion assays; (3) pharmacological and genetic manipulation of methylglyoxal, TRPA1, AC1, and PPARγ. I hypothesized that the thiazolidinedione class of peroxisome proliferator-activated receptor gamma (PPARγ) agonists would reduce neuropathic pain-like behavior and spinal neuron sensitization in traumatic nerve injury and type 2 diabetes. As PPARγ is a nuclear receptor, and already targeted clinically to promote cellular insulin sensitization to reduce hyperglycemia, sustained changes in gene expression are widely believed to be the mechanism of pain reduction. In two separate research aims, I challenged this view and tested whether the PPARγ agonist pioglitazone would (1) rapidly alleviate neuropathic pain through a non-genomic mechanism and (2) reduce painful sensitization in nociceptive and neuropathic pain models independent from lowering blood glucose. I aimed to investigate the contribution of the glucose metabolite methylglyoxal to painful type 2 diabetes. I tested the hypothesis that methylglyoxal produces nociceptive, evoked, and affective pain that is dependent on activation of the sensory neuron cation channel TRPA1 and the secondary messenger enzyme AC1. I also tested whether pioglitazone or the novel methylglyoxal scavenging peptide GERP10 could alleviate painful type 2 diabetes
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