460 research outputs found
Machine-Part cell formation through visual decipherable clustering of Self Organizing Map
Machine-part cell formation is used in cellular manufacturing in order to
process a large variety, quality, lower work in process levels, reducing
manufacturing lead-time and customer response time while retaining flexibility
for new products. This paper presents a new and novel approach for obtaining
machine cells and part families. In the cellular manufacturing the fundamental
problem is the formation of part families and machine cells. The present paper
deals with the Self Organising Map (SOM) method an unsupervised learning
algorithm in Artificial Intelligence, and has been used as a visually
decipherable clustering tool of machine-part cell formation. The objective of
the paper is to cluster the binary machine-part matrix through visually
decipherable cluster of SOM color-coding and labelling via the SOM map nodes in
such a way that the part families are processed in that machine cells. The
Umatrix, component plane, principal component projection, scatter plot and
histogram of SOM have been reported in the present work for the successful
visualization of the machine-part cell formation. Computational result with the
proposed algorithm on a set of group technology problems available in the
literature is also presented. The proposed SOM approach produced solutions with
a grouping efficacy that is at least as good as any results earlier reported in
the literature and improved the grouping efficacy for 70% of the problems and
found immensely useful to both industry practitioners and researchers.Comment: 18 pages,3 table, 4 figure
Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.
The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
Can being gay provide a boost in the hiring process? Maybe if the boss is female
Purpose – The purpose of this study was to investigate whether men and women differentially prefer hiring gay and lesbian job applicants relative to equally qualified heterosexual job applicants.
Design/methodology/approach – Data were collected from two samples of non-student participants. Each participant evaluated the perceived hirability of an ostensibly real job applicant by reviewing the applicant’s resume. In reality, all participants were randomly assigned to evaluate the same fictitious resume that differed only in the gender and sexual orientation of the applicant.
Findings – We find that men perceived gay and lesbian job applicants as less hirable, while women perceived gay and lesbian job applicants as more hirable than heterosexual job applicants. Additionally, we show perceptions of hirability are mediated by perceptions of gay and lesbian job applicants’ competence.
Implications – These results show that bias against gays and lesbians is much more nuanced than previous work suggests. One implication is that placing more women in selection roles within organizations could be a catalyst for the inclusion of gay and lesbian employees. Additionally, these results could influence when and how gays and lesbians disclose their gay identities at work.
Originality/value –These studies are the first to identify a positive bias in favor of gay and lesbian job applicants. As attitudes toward gays and lesbians become more positive, results like these are important to document as they signal a shift in intergroup relations. These results will also help managers and organizations design selection processes to minimize bias towards applicants.
Keywords: gender, sexual orientation, selection, bia
Biomechanics and the thermotolerance of development
Successful completion of development requires coordination of patterning events with morphogenetic movements. Environmental variability challenges this coordination. For example, developing organisms encounter varying environmental temperatures that can strongly influence developmental rates. We hypothesized that the mechanics of morphogenesis would have to be finely adjusted to allow for normal morphogenesis across a wide range of developmental rates. We formulated our hypothesis as a simple model incorporating time-dependent application of force to a viscoelastic tissue. This model suggested that the capacity to maintain normal morphogenesis across a range of temperatures would depend on how both tissue viscoelasticity and the forces that drive deformation vary with temperature. To test this model we investigated how the mechanical behavior of embryonic tissue (Xenopus laevis) changed with temperature; we used a combination of micropipette aspiration to measure viscoelasticity, electrically induced contractions to measure cellular force generation, and confocal microscopy to measure endogenous contractility. Contrary to expectations, the viscoelasticity of the tissues and peak contractile tension proved invariant with temperature even as rates of force generation and gastrulation movements varied three-fold. Furthermore, the relative rates of different gastrulation movements varied with temperature: the speed of blastopore closure increased more slowly with temperature than the speed of the dorsal-to-ventral progression of involution. The changes in the relative rates of different tissue movements can be explained by the viscoelastic deformation model given observed viscoelastic properties, but only if morphogenetic forces increase slowly rather than all at once. © 2014 von Dassow et al
Investigation of the cerebral hemodynamic response function in single blood vessels by functional photoacoustic microscopy
The specificity of the hemodynamic response function (HRF) is determined spatially by the vascular architecture and temporally by the evolution of hemodynamic changes. Here, we used functional photoacoustic microscopy (fPAM) to investigate single cerebral blood vessels of rats after left forepaw stimulation. In this system, we analyzed the spatiotemporal evolution of the HRFs of the total hemoglobin concentration (HbT), cerebral blood volume (CBV), and hemoglobin oxygen saturation (SO2). Changes in specific cerebral vessels corresponding to various electrical stimulation intensities and durations were bilaterally imaged with 36 × 65-μm2 spatial resolution. Stimulation intensities of 1, 2, 6, and 10 mA were applied for periods of 5 or 15 s. Our results show that the relative functional changes in HbT, CBV, and SO2 are highly dependent not only on the intensity of the stimulation, but also on its duration. Additionally, the duration of the stimulation has a strong influence on the spatiotemporal characteristics of the HRF as shorter stimuli elicit responses only in the local vasculature (smaller arterioles), whereas longer stimuli lead to greater vascular supply and drainage. This study suggests that the current fPAM system is reliable for studying relative cerebral hemodynamic changes, as well as for offering new insights into the dynamics of functional cerebral hemodynamic changes in small animals. © 2012 Society of Photo-Optical Instrumentation Engineers (SPIE)
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.
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Genome-wide association and functional follow-up reveals new loci for kidney function
Chronic kidney disease (CKD) is an important public health problem with a genetic component. We performed genome-wide association studies in up to 130,600 European ancestry participants overall, and stratified for key CKD risk factors. We uncovered 6 new loci in association with estimated glomerular filtration rate (eGFR), the primary clinical measure of CKD, in or near MPPED2, DDX1, SLC47A1, CDK12, CASP9, and INO80. Morpholino knockdown of mpped2 and casp9 in zebrafish embryos revealed podocyte and tubular abnormalities with altered dextran clearance, suggesting a role for these genes in renal function. By providing new insights into genes that regulate renal function, these results could further our understanding of the pathogenesis of CKD
Community-acquired Klebsiella pneumoniae meningitis in an alcoholic patient with an infected pancreatic pseudocyst; a case report and review of literature
We report a case of a 49-year-old male with a history of chronic alcoholism and evidence of a pancreatic pseudocyst on CT scanning. He presented with a 3-days history of fever, loss of appetite and upper abdominal pain. Blood cultures grew Klebsiella pneumoniae and he improved clinically with a seven-day course of intravenous co-amoxiclav and metronidazole. Two weeks later he was readmitted to hospital with impaired consciousness and septic shock, and died three days later in intensive care. Post mortem examination revealed bacterial meningitis and an infected pancreatic pseudocyst. Klebsiella pneumoniae was isolated from the pancreas and meninges
A Common Origin for Neutrino Anarchy and Charged Hierarchies
The generation of exponential flavor hierarchies from extra-dimensional
wavefunction overlaps is re-examined. We find, surprisingly, that coexistence
of anarchic fermion mass matrices with such hierarchies is intrinsic and
natural to this setting. The salient features of charged fermion and neutrino
masses and mixings can thereby be captured within a single framework. Both
Dirac and Majorana neutrinos can be realized. The minimal phenomenological
consequences are discussed, including the need for a fundamental scale far
above the weak scale to adequately suppress flavor-changing neutral currents.
Two broad scenarios for stabilizing this electroweak hierarchy are studied,
warped compactification and supersymmetry. In warped compactifications and
"Flavorful Supersymmetry," where non-trivial flavor structure appears in the
new TeV physics, Dirac neutrinos are strongly favored over Majorana by lepton
flavor violation tests. We argue that this is part of a more general result for
flavor-sensitive TeV-scale physics. Our scenario strongly suggests that the
supersymmetric flavor problem is not solved locally in the extra dimension, but
rather at or below the compactification scale. In the supersymmetric Dirac
case, we discuss how the appearance of light right-handed sneutrinos
considerably alters the physics of dark matter.Comment: Comparison with the Froggatt-Nielsen mechanism omitted. Some
clarifications added. This is the version accepted by PRL with a longer
abstract
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