bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptually Based Appearance Modification for Compliant Appearance Editing
Authors: Law Alvin J. , Aliaga Daniel G. , Sajadi Behzad , Majumder Aditi , Pizlo Zygmunt
Published: October 2011

Projection‐based appearances are used in a variety of computer graphics applications to impart different appearances onto physical surfaces using digitally controlled projector light. To achieve a compliant appearance, all points on the physical surface must be altered to the colours of the desired target appearance; otherwise, an incompliant appearance results in a misleading visualization. Previous systems typically assume to operate with compliant appearances or restrict themselves to the simpler case of white surfaces. To achieve compliancy, one may change the physical surface's albedo, increase the amount of projector light radiance available or modify the target appearance's colours. This paper presents an approach to modify a target appearance to achieve compliant appearance editing without altering the physical surface or the projector setup. Our system minimally alters the target appearance's colours while maintaining cues important for perceptual similarity (e.g. colour constancy). First, we discuss how to measure colour compliancy. Next, we describe our approach to partition the physical surface into patches based on the surface's colours and the target appearance's colours. Finally, we describe our appearance optimization process, which computes a compliant appearance that is as perceptually similar as possible to the target appearance's colours. We perform several real‐world projection‐based appearances and compare our results to naïve approaches, which either ignore compliancy or simply reduce the appearance's overall brightness.
Uniform Asymptotic Expansions for the Discrete Chebyshev Polynomials
Authors: Pan J. H. , Wong R.
Published: October 2011

The discrete Chebyshev polynomials tn(x, N) are orthogonal with respect to a distribution function, which is a step function with jumps one unit at the points x = 0, 1, … , N − 1, N being a fixed positive integer. By using a double integral representation, we derive two asymptotic expansions for tn(aN, N + 1) in the double scaling limit, namely, N →∞ and n/N → b, where b ∈ (0, 1) and a ∈ (−∞, ∞). One expansion involves the confluent hypergeometric function and holds uniformly for , and the other involves the Gamma function and holds uniformly for a ∈ (−∞, 0). Both intervals of validity of these two expansions can be extended slightly to include a neighborhood of the origin. Asymptotic expansions for  can be obtained via a symmetry relation of tn(aN, N + 1) with respect to . Asymptotic formulas for small and large zeros of tn(x, N + 1) are also given.
Quantile Estimates of Counterfactual Distribution Shifts and the Effect of Minimum Wage Increases on the Wage Distribution
Authors: Stewart Mark B.
Published: October 2011

The paper presents a method for estimating the effects of a policy change on an outcome distribution that uses a comparator quantile rather than a control group and provides methods for estimating the variances of the estimators. The empirical analysis presents estimates of ‘spillover’ effects of increases in the UK minimum wage, i.e. effects on the wages of those who are already above the minimum, under various counterfactual distribution shift assumptions. Evidence is presented against a simple scaled counterfactual. On the basis of the proposed counterfactual estimated spillover effects are small and in most cases do not reach above the fifth percentile.
HISTORY/PHILOSOPHY/SCIENCE: SOME LESSONS FOR PHILOSOPHY OF HISTORY
Authors: Zammito John H.
Published: October 2011

Rheinberger's brief history brings into sharp profile the importance of history of science for a philosophical understanding of historical practice. Rheinberger presents thought about the nature of science by leading scientists and their interpreters over the course of the twentieth century as emphasizing increasingly the local and developmental character of their learning practices, thus making the conception of knowledge dependent upon historical experience, “historicizing epistemology.” Linking his account of thought about science to his own work on “experimental systems,” I draw extensive parallels with other work in the local history of science (the ideas of Latour, Pickering, Rouse, and others) and consider the epistemological implications both for the relation between history and philosophy of science and between history and theory more broadly. In doing so, I suggest that the long‐standing gap between the natural sciences and history as a “human science” has been significantly bridged by the insistence upon the local, mediated, indeed “historicized epistemology” of actual science.
ALL WRITTEN UP
Authors: Steedman Carolyn
Published: October 2011

This edited collection of conference papers moves historiographical debate beyond the cultural, linguistic, subjective, and archival “turns,” and beyond historiographical questions asked from the “postcolony,” to consider the historian's role as writer and in relationship to his or her (dead) subjects. Wider cultural appropriations of the Holocaust frame several contributions and underpin the ethics of historical reconstruction discussed. This review of Unsettling History considers “raising the dead” as a paradigmatic activity of Western social historians, first articulated in the European nineteenth century. Using the perspective of its editors and contributors, it argues for a yet more detailed attention to historians' acts and performances of writing.
Social security contribution collection and compliance: Improving governance to extend social protection
Authors: Enoff Louis D. , McKinnon Roddy
Published: October 2011

Using survey evidence collected from social security organizations and contribution collection agencies, a major aim of this article is to advance knowledge sharing and good practice on contribution collection and the enforcement of compliance. Although contribution collection and compliance have important social protection, political and fiscal dimensions, this article frames the pursuit of these objectives as an aspect of administrative good governance. The evidence suggests that seven core factors combine often to form the basis of success in contribution collection and compliance. In addition to improving benefit adequacy and the financial health and public standing of programmes, such success may support also national and international efforts to extend social protection coverage. Ultimately, the achievement and scale of any such success may be determined and delimited by the broader national policy environment, over which most social security organizations have little or no influence.
Environmental enrichment compensates for the effects of stress on disease progression in Tg2576 mice, an Alzheimer’s disease model
Authors: Jeong Yun Ha , Kim Joon Min , Yoo Jongman , Lee Sang Hyung , Kim Hye‐Sun , Suh Yoo‐Hun
Published: October 2011

J. Neurochem. (2011) 10.1111/j.1471‐4159.2011.07514.x

Various environmental factors are known to influence the onset and progression of Alzheimer’s disease (AD). Environmental enrichment was reported to improve cognitive performance in various Alzheimer’s transgenic mice via an amyloid‐related or unrelated mechanism. However, stress has been found to accelerate amyloid deposition and cognitive deficits in many AD models. The aim of this study was to determine whether environmental enrichment compensates for the effects of stress on disease progression in the Tg2576 mice, an established AD model. We housed Tg2576 mice under environmental enrichment, enrichment plus stress, stress, or control conditions at 3 months of age. In this study, we first report that environmental enrichment counteracts the effects of stress in terms of cognitive deficits, tau phosphorylation, neurogenesis, and neuronal proliferation during AD‐like disease progression. These results strongly implicate the importance of environmental factors as a major modulator for the disease progression of AD.
Biosynthesis of the biomarker okenone: χ‐ring formation
Authors: VOGL K. , BRYANT D. A.
Published: October 2011

Purple sulfur bacteria (PSB) mainly occur in anoxic aquatic and benthic environments, where they play important roles in cycling carbon and sulfur. Many PSB characteristically produce the unique keto‐carotenoid, okenone, which is important not only for its light absorption and photoprotection properties but also because of its diagenesis product, okenane, which is a biomarker for ancient sediments derived from anoxic environments. The specific methylation pattern of the χ‐ring of okenane is unlikely to be formed by diagenetic processes and should therefore reflect an enzymatic activity from okenone biosynthesis. This study describes two enzymes that produce the χ‐ring of okenone, the only structural element of okenone preserved in okenane. Genes encoding enzymes of carotenogenesis were identified in the draft genome sequence of an okenone‐producing PSB, Thiodictyon sp. strain CAD16. Two divergently transcribed genes encoded a CrtY‐type lycopene cyclase and a CrtU/CruE‐type γ‐carotene desaturase/methyltransferase. Expression of crtY in Escherichia coli showed that this gene encoded a lycopene cyclase that produced γ‐carotene as the only product. Although the sequence of the γ‐carotene desaturase/methyltransferase was more similar to CrtU sequences of green sulfur bacteria than to CruE sequences of cyanobacteria, expression of the crtU gene in Chlorobaculum tepidum showed that the enzyme produced carotenoids with χ‐rings rather than φ‐rings. Phylogenetic analysis of the carotene desaturase/methyltransferases revealed that enzymes capable of converting β‐rings to χ‐rings have independently evolved at least two times. These results indicate that it probably will not be possible to deduce the activity of carotene desaturase/methyltransferases solely from sequence data.
Post‐transcriptional regulation of IGF1R by key microRNAs in long–lived mutant mice
Authors: Liang Ruqiang , Khanna Amit , Muthusamy Senthilkumar , Li Na , Sarojini Harshini , Kopchick John J. , Masternak Michal M. , Bartke Andrzej , Wang Eugenia
Published: October 2011

Long‐lived mutant mice, both Ames dwarf and growth hormone receptor gene–disrupted or knockout strains, exhibit heightened cognitive robustness and altered IGF1 signaling in the brain. Here, we report, in both these long‐lived mice, that three up‐regulated lead microRNAs, miR‐470, miR‐669b, and miR‐681, are involved in posttranscriptional regulation of genes pertinent to growth hormone/IGF1 signaling. All three are most prominently localized in the hippocampus and correspond to reduced expression of key IGF1 signaling genes: IGF1, IGF1R, and PI3 kinase. The decline in these genes’ expression translates into decreased phosphorylation of downstream molecules AKT and FoxO3a. Cultures transfected with either miR‐470, miR‐669b, or miR‐681 show repressed endogenous expression of all three genes of the IGF1 signaling axis, most significantly IGF1R, while other similarly up‐regulated microRNAs, including let‐7g and miR‐509, do not induce the same levels of repression. Transduction study in IGF1‐responsive cell cultures shows significantly reduced IGF1R expression, and AKT to some extent, most notably by miR‐681. This is accompanied by decreased levels of downstream phosphorylated forms of AKT and FoxO3a upon IGF1 stimulation. Suppression of IGF1R by the three microRNAs is further validated by IGF1R 3′UTR reporter assays. Taken together, our results suggest that miR‐470, miR‐669b, and miR‐681 are all functionally able to suppress IGF1R and AKT, two upstream genes controlling FoxO3a phosphorylation status. Their up‐regulation in growth hormone signaling‐deficient mutant mouse brain suggests reduced IGF1 signaling at the posttranscriptional level, for numerous gains of neuronal function in these long‐lived mice.
Glycation‐altered proteolysis as a pathobiologic mechanism that links dietary glycemic index, aging, and age‐related disease (in nondiabetics)
Authors: Uchiki Tomoaki , Weikel Karen A. , Jiao Wangwang , Shang Fu , Caceres Andrea , Pawlak Dorota , Handa James T. , Brownlee Michael , Nagaraj Ram , Taylor Allen
Published: October 2011

Epidemiologic studies indicate that the risks for major age‐related debilities including coronary heart disease, diabetes, and age‐related macular degeneration (AMD) are diminished in people who consume lower glycemic index (GI) diets, but lack of a unifying physiobiochemical mechanism that explains the salutary effect is a barrier to implementing dietary practices that capture the benefits of consuming lower GI diets. We established a simple murine model of age‐related retinal lesions that precede AMD (hereafter called AMD‐like lesions). We found that consuming a higher GI diet promotes these AMD‐like lesions. However, mice that consumed the lower vs. higher GI diet had significantly reduced frequency (P < 0.02) and severity (P < 0.05) of hallmark age‐related retinal lesions such as basal deposits. Consuming higher GI diets was associated with > 3 fold higher accumulation of advanced glycation end products (AGEs) in retina, lens, liver, and brain in the age‐matched mice, suggesting that higher GI diets induce systemic glycative stress that is etiologic for lesions. Data from live cell and cell‐free systems show that the ubiquitin–proteasome system (UPS) and lysosome/autophagy pathway [lysosomal proteolytic system (LPS)] are involved in the degradation of AGEs. Glycatively modified substrates were degraded significantly slower than unmodified substrates by the UPS. Compounding the detriments of glycative stress, AGE modification of ubiquitin and ubiquitin‐conjugating enzymes impaired UPS activities. Furthermore, ubiquitin conjugates and AGEs accumulate and are found in lysosomes when cells are glycatively stressed or the UPS or LPS/autophagy are inhibited, indicating that the UPS and LPS interact with one another to degrade AGEs. Together, these data explain why AGEs accumulate as glycative stress increases.
Investigation into photocatalytic decolorisation of CI Reactive Black 5 using titanium dioxide nanopowder
Authors: Low Fiona Chai Foong , Wu Ta Yeong , Teh Chee Yang , Juan Joon Ching , Balasubramanian N
Published: October 2011

The photocatalytic decolorisation of CI Reactive Black 5 using titanium dioxide nanopowder as a catalyst was studied and the results obtained are discussed in terms of its decolorisation efficiency. All experiments were performed using a double‐walled quartz immersion well batch reactor in which the slurry form of the reactants was at its natural pH of 5.1. The performance of titanium dioxide nanopowder (size <25 nm; surface area 200–220 m2/g) was compared with that of reference titanium dioxide powder (size ca. 230 nm; surface area 11 m2/g); in both cases, the titanium dioxide samples were anatase. It was found that the photocatalytic decolorisation efficiencies obtained using titanium dioxide nanopowder were higher than those of the reference titanium dioxide powder, with the latter taking approximately 8 min longer to achieve almost complete decolorisation of 10 mg/l CI Reactive Black 5. The photocatalytic decolorisation rate of CI Reactive Black 5 using both titanium dioxide photocatalysts typically followed a first‐order reaction and the decolorisation kinetics were successfully fitted to a simplified Langmuir–Hinshelwood kinetic model. In addition, the effects of light type and intensity, catalyst loading and initial CI Reactive Black 5 concentration were investigated using titanium dioxide nanopowder as the photocatalyst in the decolorisation of the dye. This study shows that the recommended parameters for treating 10 mg/l CI Reactive Black 5 based on the experimental set‐up and operating conditions are an ultraviolet light power of 125 W (39.3 mW/cm2) and a 0.3‐g/l catalyst loading.
Mobile Outreach Strategies for Screening Hepatitis and HIV in High‐Risk Populations
Authors: Zucker Donna M. , Choi Jeungok , Gallagher Emily R.
Published: October 2011

ABSTRACT Objectives: To screen, counsel and offer hepatitis A and B vaccination for subjects at high risk for hepatitis C virus (HCV) and HIV, and determine any relationship between risk factors and HCV positivity.

Design and Sample: A descriptive correlational design. We correlated risk factors and HCV positivity and measured vaccination completion rates. Two hundred and two unduplicated subjects in 4 locations in Western Massachusetts: a walk in substance abuse clinic, a homeless shelter, a county jail, and a community corrections facility.

Measures: Demographic data and a standard HCV risk‐ screening survey were used.

Results: Significantly higher rates of HCV were found in subjects who were currently using injection drugs (83.3% HCV positive, χ2(1)=20.85, p<.001), who had a history of sharing needles for drug use (75% HCV positive χ2(1)=83.20, p<.001), or a history of receiving treatment for drug abuse/alcoholism (38.4% HCV positive χ2(1)=12.14, p<.001). Vaccination completion ranged by setting between 18% and 38%.

Conclusions: Targeted outreach to hard to reach groups is effective in providing access for those at high risk for HIV and HCV infection. A mobile outreach strategy can focus needed resources for a variety of groups in a community.
Blood–brain barrier dysfunction, status epilepticus, seizures, and epilepsy: A puzzle of a chicken and egg?
Authors: Friedman Alon
Published: October 2011

Status epilepticus is often associated with endothelial dysfunction and increased vessels permeability. We discuss here the direct role of blood–brain barrier (BBB) dysfunction in epileptogenesis and brain damage. On the cellular level, astrocytes respond early to the efflux of serum proteins in the presence of dysfunctional BBB, with activation of the innate immune system and disturbed homeostasis of extracellular potassium and glutamate. In turn, there is enhanced excitability of neurons and altered network connectivity. Transforming growth factor beta (TGF‐β) signaling appears to be a potential new target for the prevention of epileptogenesis and secondary damage following status epilepticus.
Complications of the management of status epilepticus in the intensive care unit
Authors: Schmutzhard Erich , Pfausler Bettina
Published: October 2011

Barbiturates and propofol are widely used to control status epilepticus. This review aims to discuss all possible adverse effects incurred by the administration of GABA‐mediated anesthetic agents. Further on unconventional therapies such as ketamine, lidocaine, or anesthetic agents are discussed both with respect to efficacy and complications. The aim of this review is to raise awareness of complications incurred by therapeutic approaches to patients with status epilepticus in the intensive care unit.
Super‐refractory status epilepticus: An approach to therapy in this difficult clinical situation
Authors: Shorvon Simon
Published: October 2011

Super‐refractory status epilepticus (SE) is a stage of refractory SE characterized by unresponsiveness to initial anesthetic therapy. It is a new concept that has been the focus of recent basic and therapeutic work, and is defined as “SE that continues or recurs 24 hours or more after the onset of anesthesia, including those cases in which SE recurs on the reduction or withdrawl of anesthesia.” It is encountered typically, but not exclusively, in two quite distinctive clinical situations: (1) in patients with severe acute brain injury, and (2) in patients with no history of epilepsy in whom status epilepticus develops out of the blue with no overt cause. There are a variety of treatments used, almost entirely based on open observational studies or case reports. Therapy includes anesthesia, antiepileptic drug therapy, hypothermia and ICU therapy, other medical, immunological, and physical therapies. In this review, the range of possible therapies is outlined and an approach to therapy is discussed.
Therapeutic potential of new antiinflammatory drugs
Authors: Vezzani Annamaria , Bartfai Tamas , Bianchi Marco , Rossetti Carlo , French Jacqueline
Published: October 2011

Experimental and clinical findings have shown in the past decade that specific proinflammatory mediators and their cognate receptors are upregulated in epileptic brain tissue. In particular, the IL‐1 receptor (R)/Toll‐like receptor (TLR) signaling pathways are activated in experimental models of seizures and in human epileptic tissue from drug‐resistant patients. Pharmacological targeting of these proinflammatory pathways using selective receptor antagonists, or the use of transgenic mice with perturbed cell signaling, demostrated that the activation of IL‐1R type 1 and TLR4 by their respective endogenous ligands, i.e., interleukin (IL)‐1b and High Mobility Group Box 1, is implicated in the precipitation and recurrence of experimentally induced seizures in rodents. This evidence highlights a new target system for pharmacological intervention to inhibit seizures by interfering with mechanisms involved in their genesis and recurrence.
Acellular dermal matrix allograft versus subepithelial connective tissue graft in treatment of gingival recessions: a 5‐year randomized clinical study
Authors: Moslemi Neda , Mousavi Jazi Mahvash , Haghighati Farideh , Morovati Seyyedeh Pouya , Jamali Raika
Published: October 2011

Aim

The present randomized clinical trial compared the long‐term results of subepithelial connective tissue graft (SCTG) versus acellular dermal matrix allograft (ADMA) in treatment of gingival recessions.

Materials and Methods

In 16 patients with bilateral Miller Class I/II gingival recessions, one side was treated with SCTG and the other side with ADMA. Clinical parameters were measured at baseline, 6 months, and at 5 years post‐surgery.

Results

Fifteen patients completed the study. At 6 months, all parameters showed significant improvement in ADMA and SCTG groups [complete root coverage (CRC): 73.3% versus 26.7%, p = 0.027; reduction of recession depth (RD): 2.6 ± 1.1 mm versus 2.2 ± 1.1 mm, p = 0.376; reduction of recession width (RW): 3.0 ± 1.4 mm versus 2.4 ± 1.4 mm, p = 0.207 respectively]. At 5 years, significant relapses were detected in CRC and reduction of RD and RW in both groups with no statistically significant difference (CRC: 20.0% versus 13.3%, p = 1.00; RD: 1.6 ± 1.2 mm versus 1.5 ± 1.4mm, p = 0.838; RW: 1.8 ± 1.4 mm versus 1.3 ± 1.5mm, p = 0.367). Patients practicing horizontal toothbrushing habit showed more relapse (OR = 11.2; p = 0.01). Compared with baseline, the gingival width (GW) did not increase in ADMA‐treated sites (p = 0.903).

Conclusion

Five‐year results of SCTG and ADMA were similar in terms of CRC and reduction of RD and RW. Both techniques showed a significant relapse associated with returning to horizontal toothbrushing habit. Increase of GW was stable in SCTG‐treated sites, but reached to pre‐surgical values in ADMA‐treated cases.
New technologies for studying the complexity of oral diseases
Authors: Burbelo PD , Bayat A , Lebovitz EE , Iadarola MJ
Published: October 2011

Oral Diseases (2012) 18, 121–126

Several new technologies are providing useful diagnostic tools and new information related to the pathogenesis of certain oral diseases. In this review, we describe several of these technologies including gene and microRNA arrays, proteomics, and antigen arrays as they relate to the study of Sjögren’s syndrome and head and neck cancer. A common theme is the systematic analysis of large‐scale inventories of RNAs, proteins, and autoantibody biomarkers revealing information not previously recognized. We also discuss metagenomic approaches that characterize the many different microorganisms present in the oral cavity that may impact oral and human health. Lastly, we describe applications of a new type of antibody‐profiling technology termed Luciferase Immunoprecipitation Systems (LIPS), which has a wide dynamic range of detection of both linear and conformational epitopes needed for optimum diagnostics and biomarker discovery. We propose that the information offered by these technologies will enhance our ability to diagnose, treat, and further understand the pathogenesis of multiple oral diseases.
Neurophysiology of Erection and Ejaculation
Authors: Giuliano François
Published: October 2011

Introduction

Penile erection and ejaculation are closely associated during sexual intercourse. Erection is a central psychoneuroendocrine and peripheral neuro-vasculo-tissular event, resulting in blood filling the sinusoidal spaces of the corpora cavernosa and corpus spongiosum. Ejaculation represents the climax of the sexual cycle and comprises emission (secretion of semen) and expulsion (propulsion of semen) phases.

Aim

This article provides an overview of the proposed neurophysiology of erection and ejaculation.

Methods

Review of the literature.

Main Outcome Measures

Current data on the neurophysiology of erection and ejaculation.

Results

In terms of peripheral innervation, the pelvic plexus represents a junction for efferent nerves to the structures involved in erection and ejaculation. At the spinal level, the spinal cord contains three sets of neurons (thoracolumbar sympathetic, sacral parasympathetic, and somatic) innervating the sexual organs involved in erection and ejaculation. The presence of cerebral descending pathways to spinal erection and ejaculation centers indicates that the brain has an excitatory or inhibitory effect on these processes. Brain structures that modulate spinal command of erection and ejaculation are part of a larger network that is dedicated to regulating sexual responses. Neurophysiological and pharmacological research has elucidated that dopamine and serotonin have central roles in modulating erection and ejaculation. Interestingly, erection is not a prerequisite for ejaculation, and each of these sexual responses can exist without the other.

Conclusion

Despite the association between erection and ejaculation during intercourse, these two processes can be considered distinct events from an anatomical, physiological, and pharmacological perspective.
An Overview of Pharmacotherapy in Premature Ejaculation
Authors: Porst Hartmut
Published: October 2011

Introduction

With increasing interest and clinical research in male sexual disorders, it has become clear that not only psychological but also organic, neurobiological, and genetic factors may play an important role in premature ejaculation (PE).

Aim

This article provides an overview of the different treatment options both for lifelong (primary, “congenital”) and acquired (secondary) PE.

Methods

Review of the literature.

Main Outcome Measures

Currently used treatment options for PE.

Results

Treatments reviewed include psychological/behavioral/sexual counseling therapy, topical anesthetics, dapoxetine, and other selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, and phosphodiesterase-5 (PDE-5) inhibitors.

Conclusions

Before starting any therapy for PE, correct diagnosis has to be made considering the patient's reported intravaginal ejaculatory latency time (IELT) and the duration and type of PE. Concomitant erectile dysfunction (ED) should be either ruled out or proven by appropriate means. In uncomplicated cases of PE with stable partnerships, medical treatment represents the first-choice option with a high likelihood of success. Dapoxetine, where available, or other SSRIs provide suitable therapeutic options with a good risk/benefit profile for patients. In complicated (“difficult-to-treat”) PE patients, a combination of medication and sexual counseling should be considered the first treatment option. Combination therapies of PDE-5 inhibitors and PE-related medications should be offered to patients suffering from comorbid PE and ED, with ED treatment starting first. In those patients with severe PE—IELTs of <30–60 seconds or anteportal ejaculation—combination therapy of topical and oral medications can be offered and may considerably increase IELT, compared with either monotherapy.
Evidence for Seed Dispersal by Rodents in Tropical Montane Forest in Africa
Authors: Nyiramana Aisha , Mendoza Irene , Kaplin Beth A. , Forget Pierre‐Michel
Published: October 2011

Seed dispersal by rodents has been understudied in Africa. Based on seed‐removal experiments, the presence of seeds in burrows and caches, cotyledon burial of seedlings, and images from camera traps, we provide evidence that rodents (Cricetomys kivuensis) remove and hoard large seeds ofCarapa grandiflorain Nyungwe National Park, Rwanda.
Short and long gamma-ray bursts: same emission mechanism?
Authors: Ghirlanda G. , Ghisellini G. , Nava L.
Published: October 2011

We study the spectral evolution on second and subsecond time-scales in 11 long and 12 short gamma-ray bursts (GRBs) with peak flux >8.5 × 10−6 erg cm−2 s (8 keV–35 MeV) detected by the Fermi satellite. The peak flux correlates with the time-averaged peak energy in both classes of bursts. The peak energy evolution, as a function of time, tracks the evolution of the flux on short time-scales in both short and long GRBs. We do not find evidence of a hard-to-soft spectral evolution. While short GRBs have observed peak energies larger than few MeV during most of their evolution, long GRBs can start with a softer peak energy (of few hundreds keV) and become as hard as short ones (i.e. with Eobspeak larger than few MeV) at the peak of their light curve. Six GRBs in our sample have a measured redshift. In these few cases we find that their correlations between the rest frame Epeak and the luminosity Liso are less scattered than their correlations in the observer frame between the peak energy Eobspeak and the flux P. We find that the rest frame Epeak of long bursts can be as high or even larger than that of short GRBs and that short and long GRBs follow the same Epeak(t)–Liso(t) correlation, despite the fact that they likely have different progenitors.
Neuromyotonia in a dachshund with clinical and electrophysiological signs of spinocerebellar ataxia
Authors: Vanhaesebrouck A. E. , Bhatti S. F. , Polis I. E. , Plessas I. N. , Van Ham L. M.
Published: October 2011

A 10‐month‐old dachshund was presented with a recent history of episodic muscle rippling and generalised stiffness. An uncoordinated gait was present since eight weeks of age. On presentation the dog showed cerebellar‐like ataxia and poor menace responses. Myokymic contractions were visible in the appendicular and truncal muscles and neuromyotonic discharges were detected by electromyography. Central components of the brain auditory evoked potentials were absent and the onset latencies of the tibial sensory‐evoked potentials recorded at the lumbar intervertebral level were delayed. Response to slow‐release phenytoin was temporary. The clinical picture together with the electrophysiological findings in this dachshund are identical to the findings in Jack Russell terriers with hereditary ataxia and neuromyotonia. This is the first description of neuromyotonia associated with clinical and electrophysiological signs of spinocerebellar ataxia in a breed other than the Jack Russell terrier. This case also strengthens the theory that spinocerebellar ataxia and neuromyotonia are related. An ion channel dysfunction is presumed to link both disorders.
Improved periodontal health and cardiovascular risk
Authors: Rose‐Hill S , Ford PJ , Leishman SJ , Do HL , Palmer JE , Heng NCK , West MJ , Seymour GJ , Cullinan MP
Published: October 2011

Background:  Previous studies have demonstrated variable effects on systemic inflammatory and immune responses following improved periodontal health. This study examined changes in serum levels of the inflammatory mediators IL‐1β, IL‐6, TNF‐α and sICAM‐1, and antibodies to Porphyromonas gingivalis, human heat shock protein (hHSP) 60 and P. gingivalis GroEL following improvement in periodontal health in high cardiovascular (CV) risk and low CV‐risk patients.

Methods:  Patients retrospectively selected from a longitudinal study, had undergone yearly periodontal examinations and peripheral blood collections. They had demonstrated a quantifiable improvement in periodontal health (>60% reduction in number of sites with probing depth ≥4 mm from the baseline visit) and could be classified as either high CV‐risk (≥6 classical risk factors, n = 13) or low CV‐risk (≤1 classical risk factor, n = 14). Serum levels of the cytokines and antibodies were measured using ELISA.

Results:  For sICAM‐1 and anti‐P. gingivalis GroEL and anti‐hHSP60 antibodies, most patients recorded decreased levels. Reductions in serum sICAM‐1 levels were more notable in low CV‐risk patients (p = 0.006); and reductions in levels of anti‐P. gingivalis GroEL and anti‐hHSP60 antibodies (p = 0.001 and 0.009 respectively) were more notable in high CV‐risk patients.

Conclusions:  This study found that subsequent to improved periodontal health, the anti‐HSP (HSP60 and GroEL) antibody response was reduced, particularly for high CV‐risk patients. sICAM‐1 levels were also lowered, more so for low CV‐risk patients.
Histopathological characteristics of non‐alcoholic fatty liver disease in children: Comparison with adult cases
Authors: Takahashi Yoshihisa , Inui Ayano , Fujisawa Tomoo , Takikawa Hajime , Fukusato Toshio
Published: October 2011

Aim:  Non‐alcoholic steatohepatitis (NASH) has been classified pathologically into type 1 (characterized by ballooning and perisinusoidal fibrosis) and type 2 (characterized by portal inflammation and portal fibrosis). Reportedly, type 2 NASH has been the most commonly observed histopathological feature in pediatric non‐alcoholic fatty liver disease (NAFLD). While only a few studies have documented the histopathology of pediatric NAFLD so far, appropriate histopathological classification or characteristics of pediatric NAFLD, and the disease incidence correlation with race or ethnicity are still controversial.

Methods:  In this study, we compared the clinical and histopathological characteristics of NAFLD in 34 pediatric and 23 adult cases.

Results:  We found that pediatric steatosis was more severe than adult steatosis. Perisinusoidal fibrosis was significantly milder in pediatric cases than in adult cases. Lobular inflammation and ballooning was found to be milder in pediatric cases than in adult cases. On the other hand, portal inflammation was more severe in pediatric cases than in adult cases. The so‐called borderline zone 1 NASH, similar to type 2 NASH, was observed in 21% of pediatric subjects; this rate was more than twice that in adult subjects. Fifty percent of pediatric cases showed overlapping features of types 1 and 2 NASH. Intralobular and portal changes showed positive and significant correlations with each other. Serum aminotransferase levels reflected the histopathological severity of NAFLD.

Conclusion:  We confirmed that pediatric NAFLD exhibits histopathological features that are different from adult NAFLD. The classification consisting of “type 1 NASH” and “type 2 NASH” may be impractical.
Non‐invasive predictive score of fibrosis stages in chronic hepatitis C patients based on epithelial membrane antigen in the blood in combination with routine laboratory markers
Authors: Attallah Abdelfattah M. , Abdallah Sanaa O. , El Sayed Amr S. , Omran Mohamed M. , El‐Bendary Mahmoud , Farid Khaled , Kadry Mohamed
Published: October 2011

Aim:  The epithelial membrane antigen (EMA) could detect small deposits of liver malignant cells. However, no information exists regarding the use of EMA in patients with chronic hepatitis C (CHC). Therefore, we attempted to evaluate the diagnostic performance of EMA to distinguish patients with different liver fibrosis stages.

Methods:  Epithelial membrane antigen was identified in sera of 154 CHC patients using Western blot and enzyme linked immunosorbent assay (ELISA). Multivariate discriminant analysis (MDA) and receiver operating characteristic (ROC) curve analyses were used to create a predictive model including EMA in addition to a panel of routine blood markers. A combination algorithm was developed and validated prospectively in 170 CHC additional patients.

Results:  Epithelial membrane antigen at 130 kDa was identified, purified and quantified in sera of CHC patients using ELISA. Based on these encouraging results, we purified and developed a direct ELISA for the quantitation of EMA in sera of CHC. MDA selected a score for the prediction of significant liver fibrosis patients based on measurements of EMA, aspartate aminotransferase to platelet ratio index and albumin. Areas under the ROC curves (AUC) of the score for the three biomarkers were 0.82 for patients with liver fibrosis (F1–F4), 0.86 for significant liver fibrosis (F2–F4), 0.87 for advanced liver fibrosis (F3–F4) and 0.86 for liver cirrhosis (F4). The results of the validation study demonstrated that (74%) of patients could have avoided liver biopsy.

Conclusion:  This score was validated for the prediction of liver fibrosis stages and may minimize the need for liver biopsy.
The effect of observational learning on students’ performance, processes, and motivation in two creative domains
Authors: Groenendijk Talita , Janssen Tanja , Rijlaarsdam Gert , van den Bergh Huub
Published: October 2011

Background.  Previous research has shown that observation can be effective for learning in various domains, for example, argumentative writing and mathematics. The question in this paper is whether observational learning can also be beneficial when learning to perform creative tasks in visual and verbal arts.

Aims.  We hypothesized that observation has a positive effect on performance, process, and motivation. We expected similarity in competence between the model and the observer to influence the effectiveness of observation.

Sample.  A total of 131 Dutch students (10th grade, 15 years old) participated.

Method.  Two experiments were carried out (one for visual and one for verbal arts). Participants were randomly assigned to one of three conditions; two observational learning conditions and a control condition (learning by practising). The observational learning conditions differed in instructional focus (on the weaker or the more competent model of a pair to be observed).

Results.  We found positive effects of observation on creative products, creative processes, and motivation in the visual domain. In the verbal domain, observation seemed to affect the creative process, but not the other variables. The model similarity hypothesis was not confirmed.

Conclusions.  Results suggest that observation may foster learning in creative domains, especially in the visual arts.
Finite Element Analysis of the Cyclic Stress Amplitude of Threaded Fasteners Using Helical Thread Models
Authors: Fukuoka Toshimichi , Nomura Masataka , Fuchikami Takashi
Published: October 2011

Fatigue failures of bolted joints frequently lead to serious accidents in machines and structures. It is well known that fatigue failure is likely to occur around the first thread root of the bolt adjacent to the nut loaded surface and the run-out of bolt thread. That is because high stress amplitudes are generated there due to alternating external forces. Accordingly, it is significantly important to evaluate the stress amplitudes along the thread root in order to rigorously examine the fatigue failure mechanism of bolted joints. In this study, stress amplitude distributions along the thread helix including the thread run-out are analyzed by three-dimensional finite element analysis. The numerical models of the bolted joints are constructed so as to accurately represent the effect of thread helical geometry, using the modeling scheme proposed in the previous study which analyzed the stress concentrations at the thread root. The analytical objectives are bolted joints with axisymmetric geometry except for the helical-shaped threaded portions that are subjected to axisymmetric external forces. It has been substantiated, based on the stress amplitude distributions along the thread helix, which the fatigue failures are likely to originate from the first bolt thread, as in the case of the maximum stress, and the run-out of threads. It has also been shown that a bolt with reduced diameter is effective for the purpose of lowering the stress amplitude at the first thread root of bolt.
Fluidelastic Instability in a Normal Triangular Tube Bundle Subjected to Air-Water Cross-Flow
Authors: Ricciardi G. , Pettigrew M. J. , Mureithi N. W.
Published: October 2011

This paper presents the results of tests on the vibration of a normal triangular tube bundle subjected to air–water cross-flow. The pitch-to-diameter ratio of the bundle is 1.5, and the tube diameter is 38 mm. The tubes were preferentially flexible in one direction. Both the lift and the drag direction were tested. A wide range of void fractions and fluid velocities was tested. Fluidelastic instabilities and tube resonances were observed. The resonances induced significant vibration amplitudes at high void fractions in the lift direction. The results are compared with those obtained with a rotated triangular tube bundle. They show that the normal triangular configuration is more stable than the rotated triangular configuration.
Experimental Evaluation of Separation Methods for a Riser Dilution Approach to Dual Density Drilling
Authors: Shelton John , Smith John Rogers , Gupta Anuj
Published: October 2011

A dual gradient, deepwater drilling system based on dilution of riser mud requires economically separating the riser mud into a low density dilution fluid and a higher density drilling fluid. This study investigated the practicality of accomplishing this separation using hydrocyclones and centrifuges and examined the possible benefits and efficiency of each. The separation experiments were conducted using a laboratory centrifuge and 2 in. hydrocyclones. The laboratory centrifuge was able to separate the riser mud into near ideal densities for dilution and drilling fluid. However, the dense slurry retained in the centrifuge had lower electrical stability than the feed stream. The hydrocyclones achieved much less contrast in density between the low and high density discharges, but their use consistently resulted in a beneficial increase in the stability of the mud emulsion in all of the flow streams and gave more desirable rheological properties. A qualitative comparison indicates that the hydrocyclone separation system may offer a feasible and desirable alternative to a centrifuge separation system.
Integration of moth-eye structures into a poly(dimethylsiloxane) stamp for the replication of functionalized microlenses using UV-nanoimprint lithography
Authors: Senn Tobias , Kutz Oliver , Weniger Christian , Li Junming , Schoengen Max , Löchel Heike , Wolf Johannes , Göttert Philipp , Löchel Bernd
Published: October 2011

The increasing demand for low cost camera modules for mobile devices requires technological solutions for the manufacturing process. One of the most promising fabrication processes for microlenses for camera modules is UV-nanoimprint lithography. In a typical fabrication process, an elastomer stamp is used to replicate microlenses. In this work, a method is presented to integrate moth-eye structures as an antireflective layer into a poly(dimethylsiloxane) (PDMS) stamp containing a microlens array. The integration of these structures is done by a thermoforming process. Due to the integration of the moth-eye structures into the PDMS stamp, the optical performance of the replicated microlenses can be improved and no additional processing steps are necessary after the replication process.
Two applications of time reversal mirrors: Seismic radio and seismic radar
Authors: Hanafy Sherif M. , Schuster Gerard T.
Published: October 2011

Two seismic applications of time reversal mirrors (TRMs) are introduced and tested with field experiments. The first one is sending, receiving, and decoding coded messages similar to a radio except seismic waves are used. The second one is, similar to radar surveillance, detecting and tracking a moving object(s) in a remote area, including the determination of the objects speed of movement. Both applications require the prior recording of calibration Green’s functions in the area of interest. This reference Green’s function will be used as a codebook to decrypt the coded message in the first application and as a moving sensor for the second application. Field tests show that seismic radar can detect the moving coordinates (x(t), y(t), z(t)) of a person running through a calibration site. This information also allows for a calculation of his velocity as a function of location. Results with the seismic radio are successful in seismically detecting and decoding coded pulses produced by a hammer. Both seismic radio and radar are highly robust to signals in high noise environments due to the super-stacking property of TRMs.
Baseline-free estimation of residual fatigue life using a third order acoustic nonlinear parameter
Authors: Amura Mikael , Meo Michele , Amerini F.
Published: October 2011

Prediction of crack growth and fatigue life estimation of metals using linear/nonlinear acousto-ultrasound methods is an ongoing issue. It is known that by measuring nonlinear parameters, the relative accumulated fatigue damage can be evaluated. However, there is still a need to measure two crack propagation states to assess the absolute residual fatigue life. A procedure based on the measurement of a third-order acoustic nonlinear parameter is presented to assess the residual fatigue life of a metallic component without the need of a baseline. The analytical evaluation of how the cubic nonlinear-parameter evolves during crack propagation is presented by combining the Paris law to the Nazarov–Sutin crack equation. Unlike other developed models, the proposed model assumes a crack surface topology with variable geometrical parameters. Measurements of the cubic nonlinearity parameter on AA2024-T351 specimens demonstrated high sensitivity to crack propagation and excellent agreement with the predicted theoretical behavior. The advantages of using the cubic nonlinearity parameter for fatigue cracks on metals are discussed by comparing the relevant results of a quadratic nonlinear parameter. Then the methodology to estimate crack size and residual fatigue life without the need of a baseline is presented, and advantages and limitations are discussed.
Acoustic-phonetic characteristics of speech produced with communicative intent to counter adverse listening conditions
Authors: Hazan Valerie , Baker Rachel
Published: October 2011

This study investigated whether speech produced in spontaneous interactions when addressing a talker experiencing actual challenging conditions differs in acoustic-phonetic characteristics from speech produced (a) with communicative intent under more ideal conditions and (b) without communicative intent under imaginary challenging conditions (read, clear speech). It also investigated whether acoustic-phonetic modifications made to counteract the effects of a challenging listening condition are tailored to the condition under which communication occurs. Forty talkers were recorded in pairs while engaged in “spot the difference” picture tasks in good and challenging conditions. In the challenging conditions, one talker heard the other (1) via a three-channel noise vocoder (VOC); (2) with simultaneous babble noise (BABBLE). Read, clear speech showed more extreme changes in median F0, F0 range, and speaking rate than speech produced to counter the effects of a challenging listening condition. In the VOC condition, where F0 and intensity enhancements are unlikely to aid intelligibility, talkers did not change their F0 median and range; mean energy and vowel F1 increased less than in the BABBLE condition. This suggests that speech production is listener-focused, and that talkers modulate their speech according to their interlocutors’ needs, even when not directly experiencing the challenging listening condition.