993 resultados para Gerald Cohen
Resumo:
We describe a new exact relation for large N(c) QCD for the long-distance behavior of baryon form factors in the chiral limit. This model-independent relation is used to test the consistency of the structure of several baryon models. All 4D semiclassical chiral soliton models satisfy the relation, as does the Pomarol-Wulzer holographic model of baryons as 5D Skyrmions. However, remarkably, we find that the holographic model treating baryons as instantons in the Sakai-Sugimoto model does not satisfy the relation.
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Background: Although meta-analyses have shown that placebo responses are large in Major Depressive Disorder (MDD) trials; the placebo response of devices such as repetitive transcranial magnetic stimulation (rTMS) has not been systematically assessed. We proposed to assess placebo responses in two categories of MDD trials: pharmacological (antidepressant drugs) and non-pharmacological (device-rTMS) trials. Methodology/Principal Findings: We performed a systematic review and meta-analysis of the literature from April 2002 to April 2008, searching MEDLINE, Cochrane, Scielo and CRISP electronic databases and reference lists from retrieved studies and conference abstracts. We used the keywords placebo and depression and escitalopram for pharmacological studies; and transcranial magnetic stimulation and depression and sham for non-pharmacological studies. All randomized, double-blinded, placebo-controlled, parallel articles on major depressive disorder were included. Forty-one studies met our inclusion criteria-29 in the rTMS arm and 12 in the escitalopram arm. We extracted the mean and standard values of depression scores in the placebo group of each study. Then, we calculated the pooled effect size for escitalopram and rTMS arm separately, using Cohen's d as the measure of effect size. We found that placebo response are large for both escitalopram (Cohen's d-random-effects model-1.48; 95% C.I. 1.26 to 1.6) and rTMS studies (0.82; 95% C.I. 0.63 to 1). Exploratory analyses show that sham response is associated with refractoriness and with the use of rTMS as an add-on therapy, but not with age, gender and sham method utilized. Conclusions/Significance: We confirmed that placebo response in MDD is large regardless of the intervention and is associated with depression refractoriness and treatment combination (add-on rTMS studies). The magnitude of the placebo response seems to be related with study population and study design rather than the intervention itself.
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We have systematically studied the magnetic properties of ferrite nanoparticles with 3, 7, and 11 nm of diameter with very narrow grain size distributions. Samples were prepared by the thermal decomposition of Fe (acac)(3) in the presence of surfactants giving nanoparticles covered by oleic acid. High resolution transmission electron microscopy (HRTEM) images and XRD diffraction patterns confirms that all samples are composed by crystalline nanoparticles with the spinel structure expected for the iron ferrite. ac and dc magnetization measurements, as well in-field Mossbauer spectroscopy, indicate that the magnetic properties of nanoparticles with 11 and 7 nm are close to those expected for a monodomain, presenting large M(S) (close to the magnetite bulk). Despite the crystalline structure observed in HRTEM images, the nanoparticles with 3 nm are composed by a magnetically ordered region (core) and a surface region that presents a different magnetic order and it contains about 66% of Fe atoms. The high saturation and irreversibility fields in the M(H) loops of the particles with 3 nm together with the misalignment at 120 kOe in the in-field Mossbauer spectrum of surface component indicate a high surface anisotropy for the surface atoms, which is not observed for the core. For T < 10 K, we observe an increase in the susceptibility and of the magnetization for former sample, indicating that surface moments tend to align with applied field increasing the magnetic core size. (C) 2010 American Institute of Physics. [doi:10.1063/1.3514585]
Resumo:
Although texts and wall paintings suggest that bees were kept in the Ancient Near East for the production of precious wax and honey, archaeological evidence for beekeeping has never been found. The Biblical term ""honey"" commonly was interpreted as the sweet product of fruits, such as dates and figs. The recent discovery of unfired clay cylinders similar to traditional hives still used in the Near East at the site of Tel Rehov in the Jordan valley in northern Israel suggests that a large-scale apiary was located inside the town, dating to the 10th-early 9th centuries B.C.E. This paper reports the discovery of remains of honeybee workers, drones, pupae, and larvae inside these hives. The exceptional preservation of these remains provides unequivocal identification of the clay cylinders as the most ancient beehives yet found. Morphometric analyses indicate that these bees differ from the local subspecies Apis mellifera syriaca and from all subspecies other than A. m. anatoliaca, which presently resides in parts of Turkey. This finding suggests either that the Western honeybee subspecies distribution has undergone rapid change during the last 3,000 years or that the ancient inhabitants of Tel Rehov imported bees superior to the local bees in terms of their milder temper and improved honey yield.
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We used environmental accounting to evaluate high-intensity clonal eucalyptus production in Sao Paolo, Brazil, converting inputs (environmental, material, and labor) to emergy units so ecological efficiency could be compared on a common basis. Input data were compiled under three pH management scenarios (lime, ash, and sludge). The dominant emergy input is environmental work (transpired water, similar to 58% of total emergy), followed by diesel (similar to 15%); most purchased emergy is invested during harvest (41.8% of 7-year production totals). Where recycled materials are used for pH amendment (ash or sludge instead of lime), we observe marked improvements in ecological efficiency; lime (raw) yielded the highest unit emergy value (UEV = emergy per unit energy in the product = 9.6E + 03 sej J(-1)), whereas using sludge and ash (recycled) reduced the UEV to 8.9E + 03 and 8.8E + 03 sej J(-1), respectively. The emergy yield ratio was similarly affected, suggesting better ecological return on energy invested. Sensitivity of resource use to other operational modifications (e.g., decreased diesel, labor, or agrochemicals) was small (<3% change). Emergy synthesis permits comparison of sustainability among forest production systems globally. This eucalyptus scheme shows the highest ecological efficiency of analyzed pulp production operations (UEV range = 1.1 to 3.6E + 04 sej J(-1)) despite high operational intensity.
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The identification and annotation of protein-coding genes is one of the primary goals of whole-genome sequencing projects, and the accuracy of predicting the primary protein products of gene expression is vital to the interpretation of the available data and the design of downstream functional applications. Nevertheless, the comprehensive annotation of eukaryotic genomes remains a considerable challenge. Many genomes submitted to public databases, including those of major model organisms, contain significant numbers of wrong and incomplete gene predictions. We present a community-based reannotation of the Aspergillus nidulans genome with the primary goal of increasing the number and quality of protein functional assignments through the careful review of experts in the field of fungal biology. (C) 2009 Elsevier Inc. All rights reserved.
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Time-averaged conformations of (+/-)-1-[3,4-(methylenedioxy)phenyl]-2-methylaminopropane hydrochloride (MDMA, ""ecstasy"") in D(2)O, and of its free base and trifluoroacetate in CDCl(3), were deduced from their (1)H NMR spectra and used to calculate their conformer distribution. Their rotational potential energy surface (PES) was calculated at the RHF/6-31G(d,p), 133LYP/6-31G(d,p), B3LYP/cc-pVDZ and AM1 levels. Solvent effects were evaluated using the polarizable continuum model. The NMR and theoretical studies showed that, in the free base, the N-methyl group and the ring are preferentially trans. This preference is stronger in the salts and corresponds to the X-ray structure of the hydrochloride. However, the energy barriers separating these forms are very low. The X-ray diffraction crystal structures of the anhydrous salt and its monohydrate differed mainly in the trans or cis relationship of the N-methyl group to the a-methyl, although these two forms interconvert freely in solution. (C) 2007 Elsevier Inc. All rights reserved.
Resumo:
There is now considerable evidence to suggest that non-demented people with Parkinson's disease (PD) experience difficulties using the morphosyntactic aspects of language. It remains unclear, however, at precisely which point in the processing of morphosyntax, these difficulties emerge. The major objective of the present study was to examine the impact of PD on the processes involved in accessing morphosyntactic information in the lexicon. Nineteen people with PD and 19 matched control subjects participated in the study which employed on-line word recognition tasks to examine morphosyntactic priming for local grammatical dependencies that occur both within (e.g. is going) and across (e.g. she gives) phrasal boundaries (Experiments 1 and 2, respectively). The control group evidenced robust morphosyntactic priming effects that were consistent with the involvement of both pre- (Experiment 1) and post-lexical (Experiment 2) processing routines. Whilst the participants with PD also recorded priming for dependencies within phrasal boundaries (Experiment 1), priming effects were observed over an abnormally brief time course. Further, in contrast to the controls, the PD group failed to record morphosyntactic priming for constructions that crossed phrasal boundaries (Experiment 2). The results demonstrate that attentionally mediated mechanisms operating at both the pre- and post-lexical stages of processing are able to contribute to morphosyntactic priming effects. In addition, the findings support the notion that, whilst people with PD are able to access morphosyntactic information in a normal manner, the time frame in which this information remains available for processing is altered. Deficits may also be experienced at the post-lexical integrational stage of processing.
Resumo:
Leon Battista Alberti, 'On the Art of Building in Ten Books' Translated by Joseph Rykwert, Neil Leach and Robert Tavemor L. A. Zhadova (ed.), 'Tatlin' (Budapest 1984). English translation Helen Ross, 'Just For Living, Aboriginal Perceptions of Housing in North West Australia' Tony Fry, 'Design History Australia: A Source Text in Methods and Resources' Phillip Cox and David Moore, 'The Australian Functional Tradition' Lenore Coltheart and Don Fraser (eds.), 'Lamdmarks in Public Works, Engineers and Their Works in New South Wales 1884-1914' Peter Bridges and Don MacDonald, 'James Barnet, Colonial Architect' Don Watson and Judith McKay, 'A Directory of Queensland Architects to 1940' Russell Walden, 'Voices of Silence: New Zealand's Chapel of Futuna' Jeremy Salmond, 'Old New Zealand Houses 1800-1940' Victoria Middleton, 'The Legend of Green Valley' Dyranda Prevost and Ann Rado, 'Living Places' Mark Jackson and Mark Stiles (directors), 'Universal Provider' Lars Lerup, 'Planned Assaults'
Resumo:
Enhancement of interdiffusion in GaAs/AlGaAs quantum wells due to anodic oxides was studied. Photoluminescence, transmission electron microscopy, and quantum well modeling were used to understand the effects of intermixing on the quantum well shape. Residual water in the oxide was found to increase the intermixing, though it was not the prime cause for intermixing. Injection of defects such as group III vacancies or interstitials was considered to be a driving force for the intermixing. Different current densities used in the experimental range to create anodic oxides had little effect on the intermixing. ©1998 American Institute of Physics.
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BACKGROUND. Prostate secretory granules (PSG) represent the basic secretory unit of the prostate gland, containing many of its exocrine proteases. Recent analysis of intraluminal corpora amylacea, a proposed by-product of PSG secretion, detected sulfated glycosaminoglycans (GAG) possibly keratan sulfate (KS),indicating a secretory mechanism for GAG in the human prostate surface epithelial cell. METHODS. Immunostains using anti-KS and anti-prostate-specific antigen (PSA) were evaluated on 10 sequential radical prostatectomy specimens, three of which had received neoadjuvant antiandrogen therapy. Extracts of normal secretory tissue as well as a sample composed almost entirely of prostatic stroma were subjected to Western blot analysis, using the same antibody panel. RESULTS. Keratan sulfate secretion from the normal prostate epithelial cell has been confirmed and correlates, as does PSA, with the presence of cytoplasmic PSG. No such correlation exists in most adenocarcinomas or in benign epithelium after androgen ablation. Western blot analyses confirmed tissue immunostains and demonstrated a secretory proteoglycan of 70-95 kDa. CONCLUSIONS. Recognition of PSG heralds a novel secretory mechanism within the human prostate gland that is linked to the secretion of KS. The role of KS in normal prostate secretion remains unknown, although it appears downregulated in neoplastic and androgen-ablated cells. (C) 2000 Wiley-Liss, Inc.
Resumo:
Screaming and other types of disruptive vocalization are commonly observed among nursing home residents. Depressive symptoms are also frequently seen in this group, although the relationship between disruptive vocalization and depressive symptoms is unclear. Accordingly, we sought to examine this relationship in older nursing home residents. We undertook a controlled comparison of 41 vocally disruptive nursing home residents and 43 non-vocally-disruptive nursing home residents. All participants were selected to have Mini-Mental State Examination (MMSE) scores of at least 10. Participants had a mean age of 81.0 years (range 63-97 years) and had a mean MMSE score of 17.8 (range 10-29). Nurse ratings of disruptive vocalization according to a semioperationalized definition were validated against the noisy behavior subscale of the Cohen-Mansfield Agitation Inventory. Subjects were independently rated for depressive symptoms by a psychiatrist using the Dementia Mood Assessment Scale, the Cornell Scale for Depression in Dementia, and the Depressive Signs Scale. Vocally disruptive nursing home residents scored significantly higher than controls on each of these three depression-in-dementia scales. These differences remained significant when the effects of possible confounding variables of cognitive impairment, age, and sex were removed. We conclude that depressive symptoms are associated with disruptive vocalization and may have an etiological role in the generation of disruptive vocalization behaviors in elderly nursing home residents.