4,493 research outputs found

    Exact Solution of a Jamming Transition: Closed Equations for a Bootstrap Percolation Problem

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    Jamming, or dynamical arrest, is a transition at which many particles stop moving in a collective manner. In nature it is brought about by, for example, increasing the packing density, changing the interactions between particles, or otherwise restricting the local motion of the elements of the system. The onset of collectivity occurs because, when one particle is blocked, it may lead to the blocking of a neighbor. That particle may then block one of its neighbors, these effects propagating across some typical domain of size named the dynamical correlation length. When this length diverges, the system becomes immobile. Even where it is finite but large the dynamics is dramatically slowed. Such phenomena lead to glasses, gels, and other very long-lived nonequilibrium solids. The bootstrap percolation models are the simplest examples describing these spatio-temporal correlations. We have been able to solve one such model in two dimensions exactly, exhibiting the precise evolution of the jamming correlations on approach to arrest. We believe that the nature of these correlations and the method we devise to solve the problem are quite general. Both should be of considerable help in further developing this field.Comment: 17 pages, 4 figure

    The association of maternal prenatal psychosocial stress with vascular function in the child at age 10-11 years: findings from the Avon longitudinal study of parents and children

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    Objective To investigate whether (1) maternal psychosocial stress (depression/anxiety) during pregnancy is associated with offspring vascular function and (2) whether any association differs depending on the gestational timing of exposure to stress. We also investigated whether any association is likely to be due to intrauterine mechanisms by (3) comparing with the association of paternal stress with offspring vascular function and (4) examining whether any prenatal association is explained by maternal postnatal stress. Methods and results Associations were examined in a UK birth cohort, with offspring outcomes (systolic and diastolic blood pressure, SBP and DBP, endothelial function assessed by brachial artery flow-mediated dilatation (FMD); arterial stiffness assessed by carotid to radial pulse wave velocity (PWV), brachial artery distensibility (DC), and brachial artery diameter (BD) assessed at age 10–11 years (n = 4318). Maternal depressive symptoms and anxiety were assessed at 18 and 32 weeks gestation and 8 months postnatally. Paternal symptoms were assessed at week 19. With the exception of DBP and BD, there were no associations of maternal depressive symptoms with any of the vascular outcomes. Maternal depressive and anxiety symptoms were associated with lower offspring DBP and wider BD, though the latter attenuated to the null with adjustment for confounding factors. Paternal symptoms were not associated with offspring outcomes. Maternal postnatal depressive symptoms were associated with lower offspring SBP. Conclusions We found no evidence to support the hypothesis that maternal stress during pregnancy adversely affects offspring vascular function at age 10–12 years via intrauterine mechanisms

    Coming Out of Crisis: Patient Experiences in Primary Care in New Orleans, Four Years Post-Katrina

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    Examines the network of neighborhood clinics funded with federal, state, and local money that emerged after Hurricane Katrina as a model for serving vulnerable populations. Looks at access, communication, chronic illnesses management, and preventive care

    Geometry of Empty Space is the Key to Near-Arrest Dynamics

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    We study several examples of kinetically constrained lattice models using dynamically accessible volume as an order parameter. Thereby we identify two distinct regimes exhibiting dynamical slowing, with a sharp threshold between them. These regimes are identified both by a new response function in dynamically available volume, as well as directly in the dynamics. Results for the selfdiffusion constant in terms of the connected hole density are presented, and some evidence is given for scaling in the limit of dynamical arrest.Comment: 11 page

    Application of Real-time AMDF Pitch Detection in a Voice Gender Normalisation System

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    Traditionally the interest in voice gender conversion was of a more theoretical nature rather than founded in real-life applications. However, with the increase in mobile communication and the resulting limitation in transmission bandwidth new approaches to minimising data rates have to be developed. Here voice gender normalisation (VGN) presents an efficient method of achieving higher compression rates by using the VGN algorithm to remove gender specific components of a speech signal and thus enhancing the information content to be transmitted. A second application for VGN is in the field of speech controlled systems, where current speech recognition algorithms have to deal with the voice characteristics of a speaker as well as the information content. Here again the use of VGN can remove the speaker's voice gender characteristics and thus enhance the message contents. Therefore, such a system would be capable of achieving higher recognition rates while being independent of the speaker. This paper presents the theory of a VGN system and furthermore, outlines an efficient real-time hardware implementation for the use in portable communications equipment

    Descending aortic calcification increases renal dysfunction and in-hospital mortality in cardiac surgery patients with intraaortic balloon pump counterpulsation placed perioperatively : a case control study

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    Introduction: Acute kidney injury (AKI) after cardiac surgery increases length of hospital stay and in-hospital mortality. A significant number of patients undergoing cardiac surgical procedures require perioperative intra-aortic balloon pump (IABP) support. Use of an IABP has been linked to an increased incidence of perioperative renal dysfunction and death. This might be due to dislodgement of atherosclerotic material in the descending thoracic aorta (DTA). Therefore, we retrospectively studied the correlation between DTA atheroma, AKI and in-hospital mortality. Methods: A total of 454 patients were retrospectively matched to one of four groups: -IABP/-DTA atheroma, +IABP/-DTA atheroma, -IABP/+DTA atheroma, +IABP/+DTA atheroma. Patients were then matched according to presence/absence of DTA atheroma, presence/absence of IABP, performed surgical procedure, age, gender and left ventricular ejection fraction (LVEF). DTA atheroma was assessed through standard transesophageal echocardiography (TEE) imaging studies of the descending thoracic aorta. Results: Basic patient characteristics, except for age and gender, did not differ between groups. Perioperative AKI in patients with -DTA atheroma/+IABP was 5.1% versus 1.7% in patients with -DTA atheroma/-IABP. In patients with +DTA atheroma/+IABP the incidence of AKI was 12.6% versus 5.1% in patients with +DTA atheroma/-IABP. In-hospital mortality in patients with +DTA atheroma/-IABP was 3.4% versus 8.4% with +DTA atheroma/+IABP. In patients with +DTA atheroma/+IABP in hospital mortality was 20.2% versus 6.4% with +DTA atheroma/-IABP. Multivariate logistic regression identified DTA atheroma > 1 mm (P = *0.002, odds ratio (OR) = 4.13, confidence interval (CI) = 1.66 to 10.30), as well as IABP support (P = *0.015, OR = 3.04, CI = 1.24 to 7.45) as independent predictors of perioperative AKI and increased in-hospital mortality. DTA atheroma in conjunction with IABP significantly increased the risk of developing acute kidney injury (P = 0.0016) and in-hospital mortality (P = 0.0001) when compared to control subjects without IABP and without DTA atheroma. Conclusions: Perioperative IABP and DTA atheroma are independent predictors of perioperative AKI and in-hospital mortality. Whether adding an IABP in patients with severe DTA calcification increases their risk of developing AKI and mortality postoperatively cannot be clearly answered in this study. Nevertheless, when IABP and DTA are combined, patients are more likely to develop AKI and to die postoperatively in comparison to patients without IABP and DTA atheroma

    Prikaz knjige: Zorislav Kaleb - Djelovanje kaznene presude na parnični postupak /Vizura, Zagreb, 2008./

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    Nedavno je u izdanju nakladničke kuće Vizura objavljena knjiga mr. sc. Zorislava Kaleba, suca Kaznenog odjela Općinskog suda u Zagrebu, Djelovanje kaznene presude na parnični postupak s podnaslovom Vezanost parničnog suda za pravomoćnu presudu kaznenog suda. Knjiga Djelovanje kaznene presude na parnični postupak predstavlja autorov izra¬đeni i obranjeni magistarski rad na poslijediplomskom znanstvenom studiju iz trgovačkog prava i prava društava na Pravnom fakultetu Sveučilišta u Zagrebu dana 4. travnja 2006. godine na temu Vezanost parničnog suda za pravomoćnu presudu kaznenog suda pred Povjerenstvom koje su činili akademik Jakša Barbić, predsjednik Povjerenstva, prof. dr. se. Mihajlo Dika kao mentor, te prof. dr. se. Davor Krapac i dr. se. Branko Vukmir kao članovi Povjerenstva. Isti rad je autor u međuvremenu dijelom prilagodio radi objave kao monografije, a također je unio i izmjene koje su se u međuvremenu dogodile našem pozitivnom zakonodavstvu. U knjizi se obrađuje odnos između parničnog i kaznenog postupka, vezanost par¬ničnog suda za pravomoćnu osuđujuću presudu kaznenog suda po tužbi iz istog događaja, prejudicijelno djelovanje presude kaznenog suda na parnični postupak, djelovanje kaznene presude kao pravno relevantne činjenice u parničnom postupku, prekid postupka po od¬luci suda u parničnom postupku, donošenje pravomoćne kaznene presude kao razlog za ponavljanje parničnog postupka, te neki zaključni prijedlozi de legeferenda. Rad dijelom komparativno obrađuje istu materiju i u nekim drugim zakonodavstvima u opsegu koliko je to zanimljivo za našeg praktičara. Knjiga je rezultat dvogodišnjeg istraživanja autora prvenstveno odluka Županijskog suda u Zagrebu i Vrhovnog suda Republike Hrvatske, te potom i dostupnih odluka drugih domaćih i stranih sudova

    Use of soil moisture information in yield models

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    There are no author-identified significant results in this report
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