Miracle-dz/UniFAR-FTUs huggingface dataset:
The Nature of generic cosmological singularities

The existence of a singularity by definition implies a preferred scale--the affine parameter distance from/to the singularity of a causal geodesic that is used to define it. However, this variable scale is also captured by the expansion along the geodesic, and this can be used to obtain a regularized state space picture by means of a conformal transformation that factors out the expansion. This leads to the conformal `Hubble-normalized' orthonormal frame approach which allows one to translate methods and results concerning spatially homogeneous models into the generic inhomogeneous context, which in turn enables one to derive the dynamical nature of generic cosmological singularities. Here we describe this approach and outline the derivation of the `cosmological billiard attractor,' which describes the generic dynamical asymptotic behavior towards a generic spacelike singularity. We also compare the `dynamical systems picture' resulting from this approach with other work on generic spacelike singularities: the metric approach of Belinskii, Lifschitz, and Khalatnikov, and the recent Iwasawa based Hamiltonian method used by Damour, Henneaux, and Nicolai; in particular we show that the cosmological billiards obtained by the latter and the cosmological billiard attractor form complementary `dual' descriptions of the generic asymptotic dynamics of generic spacelike singularities
Author ' s personal copy Smooth reverse Loop and Catmull – Clark subdivision

In this paper we present a new multiresolution technique for general topology surfaces based on reversing subdivision with energy minimization. We first introduce a general reverse subdivision approach that starts from a trial set of biorthogonal multiresolution filters and refines the resulting coarse points using local masks. The refinement step tries to find a good approximation of the fine points while minimizing the local energy of the coarse points in a least-squares sense. This approach is then used to find smooth reverse of the Loop and Catmull–Clark subdivisions. We discuss the advantages of using this technique in various surface editing and synthesis applications. 2011 Elsevier Inc. All rights reserved.
Coping and the course of mother's depressive symptoms during and after pediatric bone marrow transplantation.

OBJECTIVE To evaluate the role of maternal coping strategies in depressive symptoms experienced by mothers of children undergoing bone marrow transplantation (BMT). METHOD A total of 207 mothers completed measures of coping and depressive symptoms at the time of the child's BMT, 3 and 6 months post-BMT. The sample was collected between 1998 and 2002. The acceptance rate was 73%. The contribution of demographic, illness and treatment parameters, and mothers' concerns about the child were also evaluated. Growth curve modeling was used to evaluate the role of coping in the course of depressive symptoms. Both main effects and interactions of coping strategies with time of assessment were evaluated. RESULTS Acceptance and humor were associated with reductions in maternal depressive symptoms, and planning and alcohol/substance use were associated with increases in maternal depressive symptoms. Positive reframing, use of emotional support, and use of religion were associated with the course of depressive symptoms, but the magnitude of associations differed depending on the use of the coping strategies at the time of transplantation. Mothers' fears about the child also predicted depressive symptoms. CONCLUSIONS Acceptance and humor may be targets for behavioral interventions to reduce mothers' depressive symptoms during and after pediatric BMT hospitalization.
Refractive error, axial length, and relative peripheral refractive error before and after the onset of myopia.

PURPOSE To evaluate refractive error, axial length, and relative peripheral refractive error before, during the year of, and after the onset of myopia in children who became myopic compared with emmetropes. METHODS Subjects were 605 children 6 to 14 years of age who became myopic (at least -0.75 D in each meridian) and 374 emmetropic (between -0.25 D and +1.00 D in each meridian at all visits) children participating between 1995 and 2003 in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study. Axial length was measured annually by A-scan ultrasonography. Relative peripheral refractive error (the difference between the spherical equivalent cycloplegic autorefraction 30 degrees in the nasal visual field and in primary gaze) was measured using either of two autorefractors (R-1; Canon, Lake Success, NY [no longer manufactured] or WR 5100-K; Grand Seiko, Hiroshima, Japan). Refractive error was measured with the same autorefractor with the subjects under cycloplegia. Each variable in children who became myopic was compared to age-, gender-, and ethnicity-matched model estimates of emmetrope values for each annual visit from 5 years before through 5 years after the onset of myopia. RESULTS In the sample as a whole, children who became myopic had less hyperopia and longer axial lengths than did emmetropes before and after the onset of myopia (4 years before through 5 years after for refractive error and 3 years before through 5 years after for axial length; P < 0.0001 for each year). Children who became myopic had more hyperopic relative peripheral refractive errors than did emmetropes from 2 years before onset through 5 years after onset of myopia (P < 0.002 for each year). The fastest rate of change in refractive error, axial length, and relative peripheral refractive error occurred during the year before onset rather than in any year after onset. Relative peripheral refractive error remained at a consistent level of hyperopia each year after onset, whereas axial length and myopic refractive error continued to elongate and to progress, respectively, although at slower rates compared with the rate at onset. CONCLUSIONS A more negative refractive error, longer axial length, and more hyperopic relative peripheral refractive error in addition to faster rates of change in these variables may be useful for predicting the onset of myopia, but only within a span of 2 to 4 years before onset. Becoming myopic does not appear to be characterized by a consistent rate of increase in refractive error and expansion of the globe. Acceleration in myopia progression, axial elongation, and peripheral hyperopia in the year prior to onset followed by relatively slower, more stable rates of change after onset suggests that more than one factor may influence ocular expansion during myopia onset and progression.
Disruptive prefetching: impact on side-channel attacks and cache designs

Caches are integral parts in modern computers; they leverage the memory access patterns of a program to mitigate the gap between the fast processors and slow memory components. Unfortunately, the behavior of caches can be exploited by attackers to infer the program's memory access patterns, by carrying out cache-based side-channel attacks, which can leak critical information. Secure caches that were proposed employ cache partitioning or randomized memory-to-cache mapping techniques to prevent these attacks. Such techniques may add to the complexity of cache designs. In this work, we suggest the use of specialized prefetching algorithms for the purpose of protecting from cache-based side-channel attacks. Our prefetchers can be combined with conventional set associative cache designs, are simple to employ, and require low incremental hardware overhead costs, if the base prefetching scheme is already employed. We integrated our prefetching policies with commonly used GHB and stride prefetching schemes, and compared their performance with the standard implementations of those schemes, on both conventional and secure cache designs. More specifically, our results show that the use of our secure prefetching policy delivers original prefetching performance when integrated with a stride prefetcher. Finally, we demonstrate how a disruptive prefetching scheme can protect the cache from an access based side-channel attack.
Implementation of a data collection mechanism in electronic triage system using wireless sensor devices

The electronic triage system developed by our research group is a wireless sensor network, constructed by electronic triage tags composed of vital sign sensors and ZigBee modules. The system assumes a network of hundresds of patients, simultaneously transmitting data to a remote sink. We have investigated the performance of a simple data collection mechanism in real scenarios, based on IEEE 802.15. 4 in a ZigBee device like SunSPOT, and have examined some challenges in such scenarios. The data delivery ratio of 98% has been recorded while sending data equivalent to that of 100 devices in a triage tent scenario, where every device is one hop away from the sink. Adjustment of hello packet interval according to the scenarios has been observed to be an important factor. The results are found to be useful in adjusting parameters in our future work.
Decreased connexin43 expression in the mouse heart potentiates pacing-induced remodeling of repolarizing currents

Gap junction redistribution and reduced expression, a phenomenon termed gap junction remodeling (GJR), is often seen in diseased hearts and may predispose toward arrhythmias. We have recently shown that short-term pacing in the mouse is associated with changes in connexin43 (Cx43) expression and localization but not with increased inducibility into sustained arrhythmias. We hypothesized that short-term pacing, if imposed on murine hearts with decreased Cx43 abundance, could serve as a model for evaluating the electrophysiological effects of GJR. We paced wild-type (normal Cx43 abundance) and heterozygous Cx43 knockout (Cx43+/−; 66% mean reduction in Cx43) mice for 6 h at 10–15% above their average sinus rate. We investigated the electrophysiological effects of pacing on the whole animal using programmed electrical stimulation and in isolated ventricular myocytes with patch-clamp studies. Cx43+/− myocytes had significantly shorter action potential durations (APD) and increased steady-state (Iss) and inward rectifier (IK1) potassium currents compared with those of wild-type littermate cells. In Cx43+/− hearts, pacing resulted in a significant prolongation of ventricular effective refractory period and APD and significant diminution of Iss compared with unpaced Cx43+/− hearts. However, these changes were not seen in paced wild-type mice. These data suggest that Cx43 abundance plays a critical role in regulating currents involved in myocardial repolarization and their response to pacing. Our study may aid in understanding how dyssynchronous activation of diseased, Cx43-deficient myocardial tissue can lead to electrophysiological changes, which may contribute to the worsened prognosis often associated with pacing in the failing heart.
Increased transmissibility explains the third wave of infection by the 2009 H1N1 pandemic virus in England

In the 2009 H1N1 pandemic, the United Kingdom experienced two waves of infection, the first in the late spring and the second in the autumn. Given the low level of susceptibility to the pandemic virus expected to be remaining in the population after the second wave, it was a surprise that a substantial third epidemic occurred in the UK population between November 2010 and February 2011, despite no evidence for any significant antigenic evolution of the pandemic virus. Here, we use a mathematical model of influenza transmission embedded within a Bayesian synthesis inferential framework to jointly analyze syndromic, virological, and serological surveillance data collected in England in 2009–2011 and thereby assess epidemiological mechanisms which might have generated the third wave. We find that substantially increased transmissibility of the H1N1pdm09 virus is required to reproduce the third wave, suggesting that the virus evolved and increased fitness in the human host by the end of 2010, or that the very cold weather experienced in the United Kingdom at that time enhanced transmission rates. We also find some evidence that the preexisting heterologous immunity which reduced attack rates in adults during 2009 had substantially decayed by the winter of 2010, thus increasing the susceptibility of the adult population to infection. Finally, our analysis suggests that a pandemic vaccination campaign targeting adults and school-age children could have mitigated or prevented the third wave even at moderate levels of coverage.
Longitudinal changes of circadian leptin, insulin and cortisol plasma levels and their correlation during refeeding in patients with anorexia nervosa.

OBJECTIVE To study the longitudinal changes in plasma levels of leptin, insulin and cortisol during the transition from the state of starvation to the state of refeeding focussing on diurnal secretion characteristics and their temporal relationships. DESIGN Leptin, insulin and cortisol were measured every 2h for 24h during acute starvation (T1). Sampling was repeated after reaching half the target-body mass index (BMI) (T2) and again at target-BMI (17. 5kg/m(2); T3). The temporal relationships between the diurnal secretion patterns were assessed by cross-correlation analysis. RESULTS Although BMIs at T1 were uniformly low, leptin levels varied widely within a range clearly below normal levels (0.03-1. 7microg/l). With increasing body fat during the course of refeeding, mean leptin levels increased from 0.64microg/l (range: 0.27-1. 73microg/l) (T1) to 1.61microg/l (range: 0.36-4.2microg/l) (T2) and to 3.67microg/l (range: 0.7-9.8microg/l) (T3). Circadian leptin secretion patterns showed maximal values uniformly around 0200h and minimal values around 0800h at all stages of the study. At all three weight levels, plasma leptin levels were highest between midnight and the early morning hours and lowest around the late morning hours. Refeeding neither profoundly changed secretion patterns of leptin nor did it change the positive, time-delayed relationship between leptin and insulin with increments in insulin secretion preceding those of leptin by 6h. A temporal relationship between leptin and cortisol could not be demonstrated in the state of semistarvation but emerged after a substantial weight gain; at that time, leptin increases preceded cortisol increases by 8h. CONCLUSIONS Absolute leptin, insulin and cortisol levels are profoundly changed during starvation in anorectic patients, while refeeding, paralleled by a BMI gain, reverses these changes. During refeeding the relationship between leptin and cortisol changed profoundly, showing no significant correlation in the state of starvation, whereas at T3 after refeeding a strong inverse relationship could be observed. Leptin and insulin did not correlate significantly at any of the three stages studied.
Electrospinning of Gelatin Functionalized with Silver Na-noparticles for Nanofiber Fabrication

The present paper deals with gelatin nanofibres functionalized with silver nanoparticles, prepared by electrospinning using solutions of gelatin mixed with silver nitrate (AgNO3). As a common solvent for gelatin and silver nitrate (AgNO3), a mixture of acetic acid and water (70:30 v/v) was selected. In this system, acetic acid was used as a solvent for gelatin, and at the same time reducing agent for silver ions in solution. Silver nanoparticles (nAg) were stabilized through a mechanism that involves an interaction of the oxygen atoms of the carbonyl groups of gelatin. The viscosity and the conductivity of the gelatinous solutions were found to increase with the solution concentration. There is an observed decrease in the viscosity of the nAg containing gelatin solutions with the aging time increasing, whereas the conductiity of the AgNO3—containing gelatin solutions was greater than that of the base gelatin solution. The gelatin nanofibres functionalized with silver nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and antimicrobial test. The results of investigations by TEM and XRD confirmed the presence of silver nanoparticles with diameters in the range of (2 - 10 nm), uniformly distributed over the surface of smooth nanofibres with an average diameter of 70 nm. The release of silver ions from both the 2- and 4-hrs crosslinked nAg containing gelatin fiber mats by a total immersion method in buffer and distilled water occurred rapidly during the first 60 minutes, and increased gradually afterwards. Lastly, the tests demonstrated that gelatin/Ag nanofibers have a good antimicrobial activity against some common bacteria found on burned wounds. The anti-bacterial activity of these materials was greatest against Staphylococcus aureus, followed by Escherichia coli, and Pseudomonas aeroginosa ≈ Candida albicans.
Time Critical Isosurface Refinement and Smoothing

Multi-resolution data-structures and algorithms are key in Visualization to achieve real-time interaction with large data-sets. Research has been primarily focused on the off-line construction of such representations mostly using decimation schemes. Drawbacks of this class of approaches include: (i) the inability to maintain interactivity when the displayed surface changes frequently, (ii) inability to control the global geometry of the embedding (no self-intersections) of any approximated level of detail of the output surface. In this paper we introduce a technique for on-line construction and smoothing of progressive isosurfaces (see Figure 1). Our hybrid approach combines the flexibility of a progressive multi-resolution representation with the advantages of a recursive subdivision scheme. Our main contributions are: (i) a progressive algorithm that builds a multi-resolution surface by successive refinements so that a coarse representation of the output is generated as soon as a coarse representation of the input is provided, (ii) application of the same scheme to smooth the surface by means of a 3D recursive subdivision rule, (iii) a multi-resolution representation where any adaptively selected level of detail surface is guaranteed to be free of self-intersections.
An analysis of some specific background factors influencing communicative curriculum design and development : an Environmental Science Case Study

This paper initially summarizes and later analyses several background factors to curriculum design in Communication I and II based on Alexander's Framework. Looking at factors, such as the institutional context, student's motivation, as well as tensions between specified, enacted and experienced curricula, the author evaluates his current and former communicative curricula and proposes areas which can be altered and amplified, particularly in the textbook arena. The new curriculum wil be enacted from the Autumn Semester 2004, and feedback from the initiatives are forthcoming. Note: This article is drawn from data gathered for a post-graduate research thesis submitted to the Open University, London.
The Pro-inflammatory Mediator Leukotriene D4 Induces Phosphatidylinositol 3-Kinase and Rac-dependent Migration of Intestinal Epithelial Cells*

Inflammatory bowel diseases are associated with increased risk of developing colon cancer. A possible role of the pro-inflammatory leukotriene D4 (LTD4) in this process has been implicated by the findings that LTD4 can signal increased proliferation and survival, both hallmarks of a cancer cell, in non-transformed intestinal epithelial cells. Here we make the novel finding that LTD4 can also signal increased motility in these cells. In parallel, we found that LTD4 induced a simultaneous transient 10-fold increase in Rac but not Cdc42 activity. These data were also supported by the ability of LTD4 to activate the Rac GDP/GTP exchange factor Vav2. Further, LTD4 triggered a 3-fold transient increase in phosphatidylinositol 3-kinase (PI3K) phosphorylation, a possible upstream activator of the Vav2/Rac signaling pathway. The activation of Rac was blocked by the PI3K inhibitors LY294002 and wortmannin and by transfection of a kinase-negative mutant of PI3K or a dominant-negative form of Vav2. Furthermore, Rac was found to co-localize with actin in LTD4-generated membrane ruffles that were formed by a PI3K-dependent mechanism. In accordance, the inhibition of the PI3K and Rac signaling pathway also blocked the LTD4-induced migration of the intestinal cells. The present data reveal that an inflammatory mediator such as LTD4 cannot only increase proliferation and survival of non-transformed intestinal epithelial cells but also, via a PI3K/Rac signaling pathway, trigger a motile response in such cells. These data demonstrate the capacity of inflammatory mediators to participate in the process by which inflammatory bowel conditions increase the risk for colon cancer development.
Improved approximation guarantees for minimum-weight k-trees and prize-collecting salesmen

Consider a salesperson that must sell some quota of brushes in order to win a trip to Hawaii. This salesperson has a map (a weighted graph) in which each city has an attached demand specifying the number of brushes that can be sold in that city. What is the best route to take to sell the quota while traveling the least distance possible? Notice that unlike the standard traveling salesman problem, not only do we need to figure out the order in which to visit the cities, but we must decide the more fundamental question: which cities do we want to visit? In this paper we give the first approximation algorithms with poly-logarithmic performance guarantees for this problem, as well as for the slightly more general PCTSP problem of Balas, and a variation we call the "bank-robber problem" (also called the "orienteering problem" by Golden, Levi, and Vohra). We do this by providing an O(log^2 k) approximation to the k-MST problem which is defined as follows. Given an undirected graph on n nodes with non-negative edge weights and an integer k > n, find the tree of least weight that spans k vertices. (If desired, one may specify in the problem a "root vertex" that must be in the tree as well.) Our result improves on the previous best bound of O(k^0.5) of Ravi et al. and comes quite close to the bound of O(log k) of Garg and Hochbaum for the special case of points in 2-dimensional Euclidean space.