bluuebunny/crossref_metadata_2025 huggingface dataset:
Uptake and Cellular Degradation of Low-Density Lipoprotein
Authors: Thompson G.R.
Published: November 2008

In vitro data suggest that low-density lipoprotein (LDL) is bound to specific receptors located in pits on the surface of fibroblasts by a high-affinity process and subsequently undergoes catabolism in lysosomes. This binding seems to be mediated by ionic interaction between LDL and its receptor, the latter being totally or partially absent from the fibroblasts of patients with familial hypercholesterolaemia (FH). In vivo data suggest that LDL is also catabolised by a concentration-dependent, low-affinity pathway which is probably mainly located in the liver. LDL catabolism is reduced in FH and after saturated fat feeding, whereas polyunsaturated fat has the reverse effect. Hypocatabolism of LDL alters LDL composition, accelerates atherosclerosis and may lead to premature death from coronary heart disease.
Heated Oils – Chemistry and Nutritional Aspects
Authors: Billek G.
Published: November 2008

Used frying oil can be separated by means of column chromatography on silica gel into an unpolar fraction, which contains predominantly the unaltered tri-glycerides, and a polar fraction consisting of all oxidation and decomposition products formed during the heating process. The size of the polar fraction indicates the degree of fat deterioration. A similar procedure was applied to obtain fractions from a heated oil to be used in long-term feeding experiments. Several tons of a sunflower oil which had been used in the industrial production offish fingers were separated into a polar fraction(l) and an unpolar fraction (2). The sunflower oil had not been overheated and was taken at the moment when the production would have been stopped, according to factory practice, and the oil discarded. Fractions 1 (group U) and fraction 2 (group P) as well as the original unheated sunflower oil (group F) and the heated sunflower oil (group H) were fed to rats over 18 months at a level of 20% in the diet. Fraction 1 caused a highly significant reduction in weight gain of the animals as compared with unheated sunflower oil but had only an insignificant detrimental effect upon the many biochemical, histological and clinical parameters. The order of the weight gain caused by the four samples was: U < H < P < F. The changes of other parameters as well as the implications of these long-term feeding studies will be discussed in detail.
Collagen-Based Matrices Improve the Delivery of Transplanted Circulating Progenitor Cells
Authors: Zhang Yan , Thorn Stephanie , DaSilva Jean N. , Lamoureux Marc , deKemp Robert A. , Beanlands Rob S. , Ruel Marc , Suuronen Erik J.
Published: November 2008

Background—

Collagen delivery matrices have been reported to improve the results of cell therapy, but knowledge of their mechanisms of action is limited. To evaluate whether a collagen matrix improves early engraftment posttransplantation, 2-[
18
F]fluoro-2-deoxy-
d
-glucose (
18
F-FDG) was used to label transplanted circulating progenitor cells (CPCs) and track them in vivo with positron-emission tomography.

Methods and Results—

Efficiency of
18
F-FDG cell labeling was CPC-concentration dependent (
r
=0.61,
P
<0.001) but not
18
F-FDG-dose dependent. Labeled human CPCs (2�10
6
) were injected with or without a collagen-based matrix in the ischemic hind limb of rats (n=12 per group) 2 weeks after femoral artery ligation. Imaging of labeled cells, acquired by small animal positron-emission tomography at 150 minutes postinjection, revealed greater CPC retention in the ischemic hind limb and less nonspecific leakage to other tissues (retention ratio, 0.44�0.08) when CPCs were delivered within the matrix, compared with cells injected alone (0.22�0.13,
P
=0.040) and with
18
F-FDG injected with or without the matrix (0.10�0.05 and 0.11�0.05, respectively,
P
<0.005). Tissue radionuclide biodistribution was performed after completion of positron-emission tomography imaging. When
18
F-FDG-labeled cells were injected with the collagen matrix, accumulation was significantly increased (by 69.6%,
P
=0.021) in the target ischemic hind limb muscle and significantly reduced (by 14.8% to 31.4%,
P
<0.05) in nonspecific tissues, compared with cells injected alone. Histology confirmed the increased retention in target tissue associated with the matrix.

Conclusions—

Early posttransplantation, a collagen matrix enhances progenitor cell retention and limits distribution to nonspecific tissues, as measured by the use of
18
F-FDG labeled cells and positron-emission tomography imaging and confirmed by biodistribution and histology.
The Cardiovascular Research Network
Authors: Go Alan S. , Magid David J. , Wells Barbara , Sung Sue Hee , Cassidy-Bushrow Andrea E. , Greenlee Robert T. , Langer Robert D. , Lieu Tracy A. , Margolis Karen L. , Masoudi Frederick A. , McNeal Catherine J. , Murata Glen H. , Newton Katherine M. , Novotny Rachel , Reynolds Kristi , Roblin Douglas W. , Smith David H. , Vupputuri Suma , White Robert E. , Olson Jean , Rumsfeld John S. , Gurwitz Jerry H.
Published: November 2008

Background—

A clear need exists for a more systematic understanding of the epidemiology, diagnosis, and management of cardiovascular diseases. More robust data are also needed on how well clinical trials are translated into contemporary community practice and the associated resource use, costs, and outcomes.

Methods and Results—

The National Heart, Lung, and Blood Institute recently established the Cardiovascular Research Network, which represents a new paradigm to evaluate the epidemiology, quality of care, and outcomes of cardiovascular disease and to conduct future clinical trials using a community-based model. The network includes 15 geographically distributed health plans with dedicated research centers, National Heart, Lung, and Blood Institute representatives, and an external collaboration and advisory committee. Cardiovascular research network sites bring complementary content and methodological expertise and a diverse population of ≈11 million individuals treated through various health care delivery models. Each site’s rich electronic databases (eg, sociodemographic characteristics, inpatient and outpatient diagnoses and procedures, pharmacy, laboratory, and cost data) are being mapped to create a standardized virtual data warehouse to facilitate rapid and efficient large-scale research studies. Initial projects focus on (1) hypertension recognition and management, (2) quality and outcomes of warfarin therapy, and (3) use, outcomes, and costs of implantable cardioverter defibrillators.

Conclusions—

The Cardiovascular Research Network represents a new paradigm in the approach to cardiovascular quality of care and outcomes research among community-based populations. Its unique ability to characterize longitudinally large, diverse populations will yield novel insights into contemporary disease and risk factor surveillance, management, outcomes, and costs. The Cardiovascular Research Network aims to become the national research partner of choice for efforts to improve the prevention, diagnosis, treatment, and outcomes of cardiovascular diseases.
Intracranial Aneurysm Enlargement on Serial Magnetic Resonance Angiography
Authors: Burns Joseph D. , Huston John , Layton Kennith F. , Piepgras David G. , Brown Robert D.
Published: November 2008

Background and Purpose—

Size of an unruptured intracranial aneurysm (UIA) may be an important risk factor for rupture. Accordingly, serial noninvasive imaging is commonly used to assess untreated UIA for enlargement. Few data exist regarding the frequency and predictors of enlargement. We obtained this information from a group of patients followed with serial MR angiography (MRA).

Methods—

We retrospectively identified 165 patients with 191 UIA followed with serial MRA. Fusiform aneurysms, UIA <2 mm, and UIA that were surgically or endovascularly treated before the first MRA were excluded. MRA was performed using 1.5-T and 3-T MRI. Maximal diameter was determined on MRA source images. Multivariate regression analysis was used to determine independent risk factors for growth.

Results—

Twenty aneurysms (10%) grew over a median follow-up period of 47 months. Frequency of enlargement was 6.9%, 25%, and 83% for aneurysms <8 mm, 8 to 12 mm, and ≥13 mm, respectively (
P
<0.001 for trend). Of the variables we evaluated, original aneurysm diameter (OR, 1.28 per mm; 95% CI, 1.07 to 1.58) was the only independent predictor of enlargement. Aneurysms ≥8 mm in diameter were at highest risk for enlargement (OR, 7.25; 95% CI, 1.96 to 27.1). There was a trend toward increased risk of enlargement in patients with multiple aneurysms (OR, 2.50; 95% CI, 0.86 to 7.53).

Conclusions—

Over a median follow-up period of 47 months, 10% of UIA enlarged. Larger aneurysms had a significantly increased risk of enlargement. The likelihood of enlargement was highest in aneurysms with diameters ≥8 mm. However, a clinically significant proportion of small aneurysms grow, and this growth can be detected by serial MRA.
Wide-Band Information Transmission at the Calyx of Held
Authors: Yang Zhijun , Hennig Matthias H. , Postlethwaite Michael , Forsythe Ian D. , Graham Bruce P.
Published: November 2008

We use a mathematical model of the calyx of Held to explore information transmission at this giant glutamatergic synapse. The significant depression of the postsynaptic response to repeated stimulation in vitro is a result of various activity-dependent processes in multiple timescales, which can be reproduced by multiexponential functions in this model. When the postsynaptic current is stimulated by Poisson-distributed spike trains, its amplitude varies considerably with the preceding interspike intervals. Here we quantify the information contained in the postsynaptic current amplitude about preceding interspike intervals and determine the impact of different pre- and postsynaptic factors on information transmission. The mutual information between presynaptic spike times and the amplitude of the postsynaptic response in general decreases as the mean stimulation rate increases, but remains high even at frequencies greater than 100 Hz, unlike at many neocortical synapses. The maintenance of information transmission is attributable largely to vesicle recycling rates at low frequencies of stimulation, shifting to vesicle release probability at high frequencies. Also, at higher frequencies, the synapse operates largely in a release-ready mode in which most release sites contain a release-ready vesicle and release probabilities are low.
Delays and Oscillations in Networks of Spiking Neurons: A Two-Timescale Analysis
Authors: Castro Dotan Di , Meir Ron , Yavneh Irad
Published: November 2008

Oscillations are a ubiquitous feature of many neural systems, spanning many orders of magnitude in frequency. One of the most prominent oscillatory patterns, with possible functional implications, is that occurring in the mammalian thalamocortical system during sleep. This system is characterized by relatively long delays (reaching up to 40 msec) and gives rise to low-frequency oscillatory waves. Motivated by these phenomena, we study networks of excitatory and inhibitory integrate-and-fire neurons within a Fokker-Planck delay partial differential equation formalism and establish explicit conditions for the emergence of oscillatory solutions, and for the amplitude and period of the ensuing oscillations, for relatively large values of the delays. When a two-timescale analysis is employed, the full partial differential equation is replaced in this limit by a discrete time iterative map, leading to a relatively simple dynamic interpretation. This asymptotic result is shown numerically to hold, to a good approximation, over a wide range of parameter values, leading to an accurate characterization of the behavior in terms of the underlying physical parameters. Our results provide a simple mechanistic explanation for one type of slow oscillation based on delayed inhibition, which may play an important role in the slow spindle oscillations occurring during sleep. Moreover, they are consistent with experimental findings related to human motor behavior with visual feedback.
A Rate and History-Preserving Resampling Algorithm for Neural Spike Trains
Authors: Harrison Matthew T. , Geman Stuart
Published: November 2008

Resampling methods are popular tools for exploring the statistical structure of neural spike trains. In many applications, it is desirable to have resamples that preserve certain non-Poisson properties, like refractory periods and bursting, and that are also robust to trial-to-trial variability. Pattern jitter is a resampling technique that accomplishes this by preserving the recent spiking history of all spikes and constraining resampled spikes to remain close to their original positions. The resampled spike times are maximally random up to these constraints. Dynamic programming is used to create an efficient resampling algorithm.
On the Asymptotic Equivalence Between Differential Hebbian and Temporal Difference Learning
Authors: Kolodziejski Christoph , Porr Bernd , Wörgötter Florentin
Published: November 2008

In this theoretical contribution, we provide mathematical proof that two of the most important classes of network learning—correlation-based differential Hebbian learning and reward-based temporal difference learning—are asymptotically equivalent when timing the learning with a modulatory signal. This opens the opportunity to consistently reformulate most of the abstract reinforcement learning framework from a correlation-based perspective more closely related to the biophysics of neurons.
Parameter Estimation for α-GMM Based on Maximum Likelihood Criterion
Authors: Wu Dalei
Published: November 2008

α-integration and α-GMM have been recently proposed for integrated stochastic modeling. However, there has not been an approach to date for estimating model parameters for α-GMM in a statistical way, based on a set of training data. In this letter, parameter updating formulas are mathematically derived based on maximum likelihood criterion using an adapted expectation-maximization algorithm. With this method, model parameters for α-GMM are reestimated in an iterative way. The updating formulas were found to be simple and systematically compatible with the GMM equations. This advantage renders the α-GMM a superset of the GMM but with similar computational complexity. This method has been effectively applied to realistic speaker recognition applications.
Fledføring – elder care and the protection of the interests of heirs in Danish medieval laws
Authors: Vogt Helle
Published: November 2008

The Danish fledføring is a legal term referring to an institution which combined assistance to persons who, because of old age, illness or otherwise, were no longer able to provide for their own support, and the protection of their heirs' interests. During formal proceedings before the local court, the person in need would offer himself and all his property to his heirs, who would in return offer him food and shelter. The institution did not only entail material consequences regarding the property and the duty of maintenance, it also affected the legal status of the fledførte person, who lost all his personal rights and was placed under the guardianship of his heirs. Traditionally, the fledføring has been presented as an ancient form of care for the elderly. That view, however, should be questioned, for, arguably, the institution was more concerned about determining who was entitled in law to land and other property than about the care of those in need.
Testamentary cases in fifteenth-century Chancery
Authors: Biancalana Joseph
Published: November 2008

The church courts in England traditionally had jurisdiction over testaments and the litigation arising from testaments. In the fifteenth century, however, Chancery also took jurisdiction over testamentary cases. This article surveys the testamentary litigation in fifteenth-century English Chancery.
Bibliotheca frisica juridica II Bio-bibliografische notities over enkele weinig bekende Friese juristen
Authors: Feenstra R.
Published: November 2008

Bibliotheca Frisica juridica II, Bio-bibliographical notes on some little known Frisian jurists. – Second part of a series on some early Frisian jurists who have left printed editions of their works (for the first part see TR 75 (2007), p. 125–137. The present contribution deals with: Joachimus Hopperus (1523–1576), professor in Louvain, judge in the Grote Raad (Malines), member of the Privy Council (Brussels) and Philip II's secretary for the affairs of the Netherlands (Madrid); Regnerus Sixtinus (1543–1617), professor in Marburg and member of the Privy Council of the Count of Nassau (Kassel); Ausonius Popma (ca. 1553–1621), private scholar in IJlst; Tiallingius ab Eijssingha (van Eysinga; 1562–1603), grietman of Menaldumadeel; Thomas Herbaius (ca. 1570–1613), Attorney-General at the Hof van Friesland; Sibrandus Siccama (1571–1622), syndic of the city of Bolsward.
Near-Surface Shear Flow in the Tropical Pacific Cold Tongue Front*
Authors: Cronin Meghan F. , Kessler William S.
Published: November 2008

Near-surface shear in the Pacific cold tongue front at 2°N, 140°W was measured using a set of five moored current meters between 5 and 25 m for nine months during 2004–05. Mean near-surface currents were strongly westward and only weakly northward (∼3 cm s−1). Mean near-surface shear was primarily westward and, thus, oriented to the left of the southeasterly trades. When the southwestward geostrophic shear was subtracted from the observed shear, the residual ageostrophic currents relative to 25 m were northward and had an Ekman-like spiral, in qualitative agreement with an Ekman model modified for regions with a vertically uniform front. According to this “frontal Ekman” model, the ageostrophic Ekman spiral is forced by the portion of the wind stress that is not balanced by the surface geostrophic shear. Analysis of a composite tropical instability wave (TIW) confirms that ageostrophic shear is minimized when winds blow along the front, and strengthens when winds blow oblique to the front. Furthermore, the magnitude of the near-surface shear, both in the TIW and diurnal composites, was sensitive to near-surface stratification and mixing. A diurnal jet was observed that was on average 12 cm s−1 stronger at 5 m than at 25 m, even though daytime stratification was weak. The resulting Richardson number indicates that turbulent viscosity is larger at night than daytime and decreases with depth. A “generalized Ekman” model is also developed that assumes that viscosity becomes zero below a defined frictional layer. The generalized model reproduces many of the features of the observed mean shear and is valid both in frontal regions and at the equator.
A New Apparatus for Monitoring Sea Ice Thickness Based on the Magnetostrictive-Delay-Line Principle
Authors: Lei Ruibo , Li Zhijun , Cheng Yanfeng , Wang Xin , Chen Yao
Published: November 2008

High-precision ice thickness observations are required to gain a better understanding of ocean–ice–atmosphere interactions and to validate numerical sea ice models. A new apparatus for monitoring sea ice and snow thickness has been developed, based on the magnetostrictive-delay-line (MDL) principle for positioning sensors. This system is suited for monitoring fixed measurement sites on undeformed ice. The apparatus presented herein has been tested on landfast ice near Zhongshan Station, East Antarctica, for about 6 months during the austral autumn and winter of 2006; valid data records from the deployment are available for more than 90% of the deployment’s duration. The apparatus’s precision has been estimated to be ±0.002 m for the deployment. Therefore, it is possible that this apparatus may become a standard for sea ice/snow thickness monitoring.
An Example of the Use of Mobile, Doppler Radar Data for Tornado Verification
Authors: French Michael M. , Bluestein Howard B. , Wicker Louis J. , Dowell David C. , Kramar Matthew R.
Published: November 2008

On 16 May 2003, two ground-based, mobile, Doppler radars scanned a potentially tornadic supercell in the Texas Panhandle intermittently from ∼0200 to 0330 UTC. The storm likely was tornadic, but because it was dark, visual confirmation of any tornadoes was not possible. A damage survey was completed after the storm moved through the area. The final conclusion of the damage survey prior to this analysis was that there were two tornadoes near Shamrock, Texas: one that formed prior to 0300 UTC and one that formed at or after 0300 UTC. High-resolution, mobile, Doppler radar data of the supercell were compared with the damage survey information at different times. The location of the first tornado damage path was not consistent with the locations of the low-level circulations in the supercell identified through the mobile, Doppler radar data. The damage within the first path, which consisted mostly of downed trees, may have been caused by straight-line winds in a squall line that moved through the area after the passage of the supercell. The mobile, Doppler radar data did not provide any supporting evidence for the first tornado, but the data did support the existence of the second tornado in Wheeler County on the evening of 15 May 2003. Ground-based, mobile, Doppler radar data may be used as an important tool to help to confirm (or deny) tornado damage reports in situations in which a damage survey cannot be completed or in which the survey does not provide clear evidence as to what phenomenon caused the damage.
Structural Equation Modeling for High School Principals' Data-Driven Decision Making: An Analysis of Information Use Environments
Authors: Mingchu Luo
Published: November 2008

Background: Accountability demands are increasingly pushing school leaders to explore more data and do more sophisticated analyses. Data-driven decision making (DDDM) has become an emerging field of practice for school leadership and a central focus of education policy and practice.

Purpose: This study examined principals' DDDM practices and identified the factors influencing DDDM using the theoretical frame of information use environments.

Participants: Participants were 183 public high school principals in a Midwestern state.

Research Design: The research design was cross-sectional survey research.

Data Collection and Analysis: Survey instruments were developed and administered to principals. Structural equation modeling was conducted to determine what factors significantly affect principals' DDDM practices in different leadership dimensions.

Findings: Principals used data more frequently in instructional and organization operational leadership than in the leadership dimensions of school vision and collaborative partnerships. Different contextual factors affected data use in different leadership dimensions. Human-related factors such as perceptions of data quality and data analysis skills seemed to have direct effects on data use in addressing administrative problems in instruction and organizational operation, in which data were used frequently. Organization-related factors such as school district requirement and accessibility of data tended to have more direct influence on data use in the leadership dimensions of school vision and collaborative partnerships, where data were used less often.

Conclusions: This study supports the proposition that as information behavior, DDDM is situational, multidimensional, and dynamic. Results provide insights into practice, research, and theoretical foundation for the emerging topic of DDDM.
Dark Continent, Dark Stage
Authors: Konkobo Christophe
Published: November 2008

This article examines inscriptions of the Black body in French colonial performances. It shows how stage representations of the Negro in exhibitions, theatre, and cinema have consistently portrayed Africans predominantly in bodily terms and thus invented an archetype of the colonial subject akin to an animal. In addition, the article points that although the imperial system purposely characterized the Other as merely physical—in opposition to the European defined as cognitive and intellectual—a number of African intellectuals and artists have involuntarily continued to promote the same stereotypes and archetypes in discourses portraying African identities in mostly corporeal terms.
Veil and Veneer of Intellectual Aesthetics
Authors: Wilson Khonsura A.
Published: November 2008

This article examines Imani Perry’s explanation of the African creation and development of hip hop music. Through the lens of critical theory, she argues in her book Prophets of the Hood that hip hop is primarily African American in its aesthetic values even though it has embraced and absorbed the views, values, and practices of the dominant ruling class and culture. The premise of her book is valid and Perry largely provides a useful text that affirms the African American creation, development, and contribution to hip hop music, but Perry’s text has problems that speak to the location of the intellectual framework she relies on for explanation—the critical race framework.
Qigong as a Mindfulness Practice for Counseling Students
Authors: Chrisman Jennifer A. , Chambers Christopher John , Lichtenstein Sarah J.
Published: November 2008

This qualitative study explores the effects of qigong, an ancient Chinese mindfulness practice involving movement, on master's-level counseling students. Students responded in writing both after an initial experience of qigong and after practicing the movements for 15 weeks during a mindfulness-based course in self-care. Themes of physical, emotional, and mental changes were present in both sets of responses. Additional themes of familiarity with the practice as well as group consciousness and interdependence emerged in the final experience of qigong. The results of this study indicate qigong is a contemplative practice that could have positive outcomes for counseling students. Because of its accessible nature, immediate results, and ability to foster connectedness, qigong is currently underutilized as a form of teaching mindfulness.
An Assessment of Scales Measuring Constructs in Tests of Criminological Theory Based on National Youth Survey Data
Authors: Armstrong Todd A. , Lee Daniel R. , Armstrong Gaylene S.
Published: November 2008

Researchers have utilized the National Youth Survey (NYS) data to test a variety of theoretical explanations of criminal behavior. Here, the authors offer an assessment of scales used in tests of criminological theory based on NYS data. The authors conducted this assessment to provide results informing future tests of theory. Their analyses focus on understanding the extent to which scales representative of different theories are actually based on the same item content. They test for two distinct processes that may explain this phenomenon. In the first process, scales measuring a given construct are attributed to different theories. In the second process, scales measuring different constructs are based on the same items. Results show that both of the processes described above contribute to the use of the same NYS items in scales that are attributed to different theories. To inform future tests of theory, the authors identify the sections of the NYS where each of these processes are most prevalent, in effect identifying the areas of the NYS that future tests of theory should treat with the greatest care. Based on the implications of each process identified above, the authors also offer some suggestions to strengthen future tests of theory using NYS data.
Modern War on an Ancient Battlefield
Authors: Cheng Victor Shiu Chiang
Published: November 2008

This article studies a hitherto unexplored dimension of the Chinese Civil War: the disparity between modern military technology and the conceptual and logistical capacities of the two warring sides. It argues that the advanced weaponry received by the Nationalists from their ally, the United States, as well as that of the Chinese Communist Party forces, often captured on the battlefield, proved to be a liability because the Chinese armies, burdened by insufficient logistical capability and antiquated military thinking, were unable to use the weaponry effectively. By examining the intersection of Chinese and modern Western ways of warfare and technological capacities, the article contends that the difficulties experienced by the Chinese leaders in sustaining a modern army created technophobic misperceptions that had a significant effect on their decision making. In this sense, the implication of this article transcends the history of the Chinese Civil War and solidifies often abstract discussions about “modernity” and “tradition.”
A Multi-Level Review of Impression Management Motives and Behaviors
Authors: Bolino Mark C. , Kacmar K. Michele , Turnley William H. , Gilstrap J. Bruce
Published: November 2008

This article selectively reviews studies of impression management (IM) published since 1988 and identifies strengths, limitations, and future research directions in three key areas: research investigating the use of IM at the individual level of analysis (e.g., performance appraisal); research that applies IM theory, concepts, and thinking to better understand organizational phenomena (e.g., feedback seeking); and research investigating organizational-level IM (e.g., how firms create legitimacy). Following their review, the authors offer some overarching recommendations for future examinations of IM in organizations, giving particular attention to the need for clear definitions and categories of IM behaviors and the value of multi-level investigations.
On the Crush Behavior of an Ultra Light Multi-Cell Foam-Filled Composite Structure under Axial Compression
Authors: Taher Siavash T. , Oshkour Azim A. , Zahari Rizal , Mustapha Faizal , Basri Shahnor
Published: November 2008

In this article the results of experimental works pertaining to the crash behavior and crashworthiness characteristics of a novel multi-cell cost-effective crashworthy composite sandwich structure are presented. All the samples are based on the concept of the ‘triple-layered’ foam-filled block, i.e., three polyurethane foam core sheets, which are wrapped by reinforcement fiberglass woven fabric, that acts as the reinforcement face and meanwhile ties the foam layers and faces together, thus preventing catastrophic failure. The design, manufacturing, and crush testing of rectangular blocks are described. Experimental results indicate an efficient progressive collapse mechanism with high values of crushing force efficiency and specific energy absorption.
Research on Rural Caregiving
Authors: Goins R. Turner , Spencer S. Melinda , Byrd Joshua C.
Published: November 2008

The goals of this article are to present a systematic review of rural caregiving research and provide suggestions for future research efforts. The review, conducted through a search of databases, was limited to original research articles published between 1990 and 2007. The articles focused on informal caregiving of dependent older adults in rural settings. Thirty-one articles met the inclusion criteria, with 11 being rural/urban comparative studies and 20 being rural only studies. The majority of the studies were quantitative and cross-sectional. Areas for improvement in future research include incorporating theory, defining key terms, using probability sampling, examining data longitudinally, including objective measures, recruiting more racially/ethnically diverse samples, and using a mixed-method approach. Currently, it is difficult to know the extent to which the rural environment influences informal caregiving. Additional research is needed to develop a more thorough understanding of caregiving in the rural context.
A Schoolwide Model for Service Delivery
Authors: Simonsen Brandi , Shaw Stan F. , Faggella-Luby Michael , Sugai George , Coyne Michael D. , Rhein Barbara , Madaus Joseph W. , Alfano Michael
Published: November 2008

General and special education are confronting tremendous change resulting from legal mandates related to closing the achievement gap under No Child Left Behind and a focus on early intervention and prevention in the Individuals With Disabilities Education Act, 2004. As a result, schoolwide intervention approaches are under rapid development, evaluation, and implementation across the country. Based on these approaches, the authors present a conceptual model for redefining special educators as interventionists who focus on the adoption and use of evidence-based, schoolwide academic and behavioral interventions. Examples of the roles and responsibilities for interventionists within the schoolwide model are provided.
Multiple Organ Failure Following Near-fatal Exertional Heat Stroke
Authors: Trujillo Maximo H. , Bellorin-Font Ezequiel , Fragachan Carlos F. , Perret-Gentil Ricardo
Published: November 2008

We describe the clinical features of a patient with near-fatal heat stroke who was admitted to our intensive care unit. A 14-year-old girl became convulsive and hyperthermic when participating in a strenuous hike under direct sunlight in a hilly area in Venezuela on a very hot and humid day. During the following days, she developed multiple organ failure, including neurological impairment, acute renal failure, disseminated intravascular coagulation, and extensive hepatic and muscle damage. Treatment consisted of ventilatory support, hemodialysis, corticosteroids, and enteral nutrition. This case of multiple organ failure following near-fatal heat stroke illustrates that although there are no specific techniques and measures for the treatment of this condition, intensive care management and conservative strategies can result in patient survival and complete recovery.
Analytic Reviews: Postoperative Infectious Complications of Abdominal Solid Organ Transplantation
Authors: Hlava Nicole , Niemann Claus U. , Gropper Michael A. , Melcher Marc L.
Published: November 2008

There is a rapidly growing population of immunocompromised organ transplant recipients. These patients are at risk of a large variety of infections that have significant consequences on mortality, graft dysfunction, and graft loss. The diagnosis and treatment of these infections are facilitated by an understanding of the preoperative, perioperative, and postoperative risk factors; the typical pathogens; and their characteristic time of presentation. On the basis of these factors, we put forth an algorithm for diagnosing and treating suspected infections in solid organ transplant recipients.
Oligodendrocytes Changing the Rules: Action Potentials in Glia and Oligodendrocytes Controlling Action Potentials
Authors: Fields R. Douglas
Published: November 2008

Two long-standing rules in cellular neuroscience must now be amended with the publication of two studies on myelin-forming glia in the CNS: 1) Neurons can no longer be considered the only cells that fire electric impulses in the brain. 2) Synapses between neurons are not the only way electrical information is regulated as it propagates through neural circuits: oligodendrocytes can cause rapid activity-dependent changes in spike latency. A category of oligodendrocyte precursor cells (OPCs) has been identified that can fire action potentials, and their excitation is driven by synapses from axons. This finding has relevance to excitotoxicity in ischemia, but the normal function may be to regulate myelination according to functional activity in axons. A second study reveals that action potential propagation through CNS axons can be rapidly regulated by oligodendrocytes. Mature oligodendrocytes in the rat hippocampus are depolarized by theta burst stimulation of axons, and when the oligodendrocytes are depolarized by current injection in paired whole-cell recordings with CA1 pyramidal neurons, the latency of impulse conduction through the axons it ensheathes rapidly decreases. This unprecedented finding suggests a dynamic role for myelin in regulating impulse transmission through axons, promoting neural synchrony among the multiple axons under the domain of an individual oligodendrocyte.
Limitations of ADAMTS-13 Activity Level in Diagnosing Thrombotic Thrombocytopenic Purpura in Pregnancy
Authors: Ehsanipoor Robert M. , Rajan Priya , Holcombe Randall F. , Wing Deborah A.
Published: November 2008

In pregnancy, it may be difficult to differentiate the syndrome of hemolysis, elevated liver enzymes, and low platelets from thrombotic thrombocytopenia purpura. Severely depressed (<5%) or absence of a disintegrin and metalloproteinase with thrombospondin motifs-13 activity levels are associated with thrombotic thrombocytopenia purpura and mildly decreased levels are associated with other disease processes, including pre-eclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome. We present a case of a patient that presented at 20 weeks gestation with elevated liver enzymes and thrombocytopenia. The diagnosis was unclear at the time of presentation. She underwent induction of labor, and during the postpartum course, she was eventually diagnosed with thrombotic thrombocytopenia purpura; however, her activity level of a disintegrin and metalloproteinase with thrombospondin motifs-13 was only moderately depressed at 15% (normal pregnancy value 41%-105%).
Coagulation and Fibrinolysis are in Balance After Moderate Exercise in Middle-aged Participants
Authors: Menzel Kathleen , Hilberg Thomas
Published: November 2008

Increased age is associated with a higher risk of thrombotic events. The aim of this study was to investigate the age-related changes in hemostasis before and after moderate exercise controlled by individual anaerobic threshold as recommended for rehabilitation training. In this study, 24 young (25 + 1 years) and 24 middle-aged healthy nonsmokers (48 + 1 years) underwent an individualized exercise test with 80% of individual anaerobic threshold (young individuals: 127 + 6 W; middle-aged individuals: 128 + 5 W; values are expressed as mean + standard error of mean) for 60 minutes. The blood samples were collected before and after the exercise. The age-related higher (P ≤ .05) levels could be detected in factors II, VII, VIII, IX, XI, XII, prothrombin fragment 1+2, in tissue plasminogen activator antigen and activity, as well as in plasminogen. The relative exercise-induced increases in these parameters were similar in both groups, although beginning at a higher level for those in the middle-aged group. A statistically enhanced increase after exercise in the middle-aged group could be shown in prothrombin fragment 1+2 (young individuals: 98 + 6 to 102 + 6 pmol/L; middle-aged individuals: 138 + 7 to 156 + 8 pmol/L) and in thrombin—antithrombin complex (young individuals: 2.2 + 0.1 to 3.1 + 0.2 μg/L; middle-aged individuals: 2.4 + 0.3 to 3.9 + 0.6 μg/L); the latter only showing a tendency. The data show the age-related changes with a rise in blood coagulation and fibrinolysis in a healthy middle-aged group compared with younger participants. Moderate exercise leads to comparably relative increases in hemostatic parameters but starting at higher levels. However, the exercise-induced thrombin generation (prothrombin fragment 1+2) is enhanced in the middle-aged participants in comparison with younger participants, but may be compensated by a sufficient fibrinolysis, and therefore the hemostatic system remains in balance.
Public—Private Partnerships
Authors: Vining Aidan R. , Boardman Anthony E.
Published: November 2008

This article provides eight rules for government concerning the administration of public—private partnerships (P3s). The basis for these rules draws on transaction cost economics. First, however, the article provides some background on alternative modes for the provision of infrastructure and their associated transactions costs. Second, it outlines a positive theory perspective of P3s that takes into account the divergent goals of the partners in a P3 (the profit maximization goals of private sector participants, and the budgetary and political goals of public sector participants). This section throws light on the adoption and outcomes of P3s. Third, it shows that many aspects of the theory are illustrated in the Metronet (the London Underground P3) case, which went bankrupt in 2007. Finally, the article proposes rules that governments should follow in the P3 process if they wish to avoid high transaction costs and poor P3 outcomes.
Placental Insufficiency: Programming of Leptin Secretion, Blood Pressure, and Postnatal Growth in Two Generations of Sprague-Dawley Rats
Authors: Anderson Cindy M. , Lopez Faye , Sandeen Ashley , Johnson LuAnn
Published: November 2008

Regulatory process may be altered in response to the intrauterine environment, leading to the development of altered growth trajectory and disease later in life. Previously, our lab reported reduced leptin levels in pregnant hypertensive Sprague-Dawley rat dams with placental insufficiency. The purposes of this study were to investigate the relationship between leptin levels, growth and hypertension in two generations of offspring exposed to placental insufficiency. Leptin levels were significantly different only at 12 weeks in female first generation offspring (p < 0.05). Variations in postnatal body and organ weights were evident in first generation females at 3 and 12 weeks of age. There were no significant correlations with plasma leptin levels and systolic blood pressure in offspring groups at any age point. Our findings indicate that fetal exposure to maternal hypertension and hypoleptinemia is associated with altered leptin and growth patterns in mature female offspring and not perpetuated to a second generation.
Prediction of solidification behaviour of weld pool through modelling of heat transfer and fluid flow during gas tungsten arc welding of commercial pure aluminium
Authors: Farzadi A. , Serajzadeh S. , Kokabi A. H.
Published: November 2008

A mathematical model is developed to assess the solidification behaviour of the weld pools. To do so, during gas tungsten arc welding of commercial pure aluminium, equations of conversation of mass, energy and momentum are numerically solved considering three-dimensional steady state heat transfer and fluid flow conditions. The weld pool geometry, weld thermal cycles and various solidification parameters are calculated using temperature and velocity fields acquiring from the utilised model. The solidification behaviour of the weld pool at the weld centreline and the fusion line is then studied using the solidification parameters including temperature gradient G, solidification rate R and the combined forms G/R and GR. In order to verify the predictions, welding experiments are performed and geometry of the weld fusion zone is measured. The calculated geometry of the weld fusion zone is found to be in good agreement with the corresponding experimental result. The predictions show that the cooling rate GR increases toward the centreline while the other solidification parameter G/R shows a different behaviour. In addition, it is found that under the employed welding conditions, as the welding speed increases temperature gradients both at the weld centreline and at the fusion line are reduced.
Calibration of residual stress measurements obtained from EDM hole drilling method using physical material properties
Authors: Lee H. T. , Liu C.
Published: November 2008

When using the electrodischarge machining (EDM) hole drilling method to measure residual stress, the stress induced by the metallurgical transformation layer formed during the drilling process can lead to significant measurement errors. In this study, it is shown that provided the dielectric fluid retains a high level of purity, the stress induced during the drilling process is determined primarily by the thermal conductivity and carbon equivalent of the specimen. Accordingly, these two material properties are used as the basis of two calibration equations designed to compensate the residual stress measurement obtained using the EDM hole drilling method. It is shown that the calibration equations reduce the discrepancy between the actual simulated residual stress values produced by the prestress loadings and the measured residual stress values to less than 8 MPa. The calibration equations provide a significant improvement in the accuracy of the measurement results obtained using the EDM hole drilling technique.
Heat shock protein 70 (HSP70) induces cytotoxicity of T-helper cells
Authors: Figueiredo Constança , Wittmann Miriam , Wang Dong , Dressel Ralf , Seltsam Axel , Blasczyk Rainer , Eiz-Vesper Britta
Published: November 2008

Heat shock protein 70 (HSP70) has gained plenty of attention because of its adjuvant capability to induce CD8+ cytotoxic T lymphocyte and CD4+ T-helper cell responses. We investigated the behavior of T-cell subsets stimulated with endotoxin-free HSP70 with respect to proliferation, cytokine expression, cytotoxicity against allogeneic B-lymphoblastoid cell line and K562 cells, as well as target-independent cytotoxicity. CD4+ cells exhibited a strong increase in proliferation after stimulation with HSP70 (29%). In the presence of targets, a 35-fold up-regulation of granzyme B was observed after stimulation of CD4+ T cells with HSP70 in combination with interleukin-7 (IL-7)/IL-12/IL-15. The target cell-independent secretion of granzyme B by CD4+ cells was greatly augmented after stimulation with HSP70 plus IL-2 or IL-7/IL-12/IL-15. In this study, we showed that HSP70 is capable of inducing a cytotoxic response of T-helper cells in the absence of lipopolysaccharide. The granzyme B secretion and cytolytic activity of T-helper cells are induced in a target-independent way, whereas the cytotoxic activity of CD3+ and CD8+ T cells can be further enhanced in the presence of target cells. Our data provide novel insights into the role of extracellular HSP70 on T-cell immune response concerning the induction of target-independent T-helper cell cytotoxicity.
Study protocol. A prospective cohort study of unselected primiparous women: the pregnancy outcome prediction study
Authors: Pasupathy Dharmintra , Dacey Alison , Cook Emma , Charnock-Jones D Stephen , White Ian R , Smith Gordon CS
Published: November 2008

Background

There have been dramatic changes in the approach to screening for aneuploidy over the last 20 years. However, the approach to screening for other complications of pregnancy such as intra-uterine growth restriction, pre-eclampsia and stillbirth remains largely unchanged. Randomised controlled trials of routine application of high tech screening methods to the general population have generally failed to show improvement in outcome. We have previously reviewed this and concluded it was due, in large part, to poor performance of screening tests. Here, we report a study design where the primary aim is to generate clinically useful methods to screen women to assess their risk of adverse pregnancy outcome.

Methods/design

We report the design of a prospective cohort study of unselected primiparous women recruited at the time of their first ultrasound scan. Participation involves serial phlebotomy and obstetric ultrasound at the dating ultrasound scan (typically 10–14 weeks), 20 weeks, 28 weeks and 36 weeks gestation. In addition, maternal demographic details are obtained; maternal and paternal height are measured and maternal weight is serially measured during the pregnancy; maternal, paternal and offspring DNA are collected; and, samples of placenta and membranes are collected at birth. Data will be analysed as a prospective cohort study, a case-cohort study, and a nested case-control study.

Discussion

The study is expected to provide a resource for the identification of novel biomarkers for adverse pregnancy outcome and to evaluate the performance of biomarkers and serial ultrasonography in providing clinically useful prediction of risk.