bluuebunny/crossref_metadata_2025 huggingface dataset:
Patient‐specific finite element analysis of chronic contact stress exposure after intraarticular fracture of the tibial plafond
Authors: Li Wendy , Anderson Donald D. , Goldsworthy Jane K. , Marsh J. Lawrence , Brown Thomas D.
Published: April 2008

The role of altered contact mechanics in the pathogenesis of posttraumatic osteoarthritis (PTOA) following intraarticular fracture remains poorly understood. One proposed etiology is that residual incongruities lead to altered joint contact stresses that, over time, predispose to PTOA. Prevailing joint contact stresses following surgical fracture reduction were quantified in this study using patient‐specific contact finite element (FE) analysis. FE models were created for 11 ankle pairs from tibial plafond fracture patients. Both (reduced) fractured ankles and their intact contralaterals were modeled. A sequence of 13 loading instances was used to simulate the stance phase of gait. Contact stresses were summed across loadings in the simulation, weighted by resident time in the gait cycle. This chronic exposure measure, a metric of degeneration propensity, was then compared between intact and fractured ankle pairs. Intact ankles had lower peak contact stress exposures that were more uniform and centrally located. The series‐average peak contact stress elevation for fractured ankles was 38% (p = 0.0015; peak elevation was 82%). Fractured ankles had less area with low contact stress exposure than intact ankles and a greater area with high exposure. Chronic contact stress overexposures (stresses exceeding a damage threshold) ranged from near zero to a high of 18 times the matched intact value. The patient‐specific FE models represent substantial progress toward elucidating the relationship between altered contact stresses and the outcome of patients treated for intraarticular fractures. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1039–1045, 2008
Joint capsule mast cells and neuropeptides are increased within four weeks of injury and remain elevated in chronic stages of posttraumatic contractures
Authors: Hildebrand Kevin A. , Zhang Mei , Hart David A.
Published: April 2008

The purpose of this article was to determine mast cell and neuropeptide nerve fiber numbers in joint capsules in posttraumatic contractures, as elevated numbers have been implicated in other fibrotic and contracture conditions. Twelve skeletally mature rabbits had intraarticular cortical windows removed from the medial and lateral femoral condyles and the knee joint immobilized. The contralateral unoperated limb served as a control. Equal numbers of rabbits were sacrificed 4 weeks after surgery or 40 weeks after the first surgery that included 32 weeks of remobilization. Six patients with chronic posttraumatic elbow joint contractures and six age‐matched organ donor controls free of elbow contractures were also studied. Joint capsule myofibroblast, mast cell, and neuropeptide containing nerve fiber numbers were assessed with immunohistochemistry. The numbers of myofibroblasts, mast cells, and neuropeptide containing nerve fibers expressed as a percentage of total cells were significantly greater in the contracture capsules when compared to the control capsules at all time points (p < 0.0001). The range of percentages for the three components in the contracture capsules versus the controls were 41–48% versus 9–10%, 44–50% versus 11–13%, and 45–50% versus 10–12% for the acute and chronic stages of the rabbit model and the chronic stages in the human elbows, respectively. These data support the hypothesis that a myofibroblast–mast cell–neuropeptide fibrosis axis may underlie some of the pathologic changes in the joint capsule in posttraumatic contractures. Approaches designed to manipulate this axis, such as preventing degranulation of mast cells, warrant further investigation. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1313–1319, 2008
Disaster mental health workers responding to ground zero: One year later
Authors: Daly Erin Scott , Gulliver Suzy Bird , Zimering Rose T. , Knight Jeffrey , Kamholz Barbara W. , Morissette Sandra B.
Published: April 2008

The current study examined anniversary reactions in mental health disaster relief workers following traumatic exposure at the site of the World Trade Center terrorist attacks. Despite relatively low levels of symptom reporting, workers endorsed an increase in both negative mood symptoms and functional impairment at the one‐year anniversary of their traumatic exposure (compared to 6 months postexposure). For those individuals who met at least partial criteria for PTSD immediately following exposure, overall self‐reported PTSD symptoms tended to increase from 6 to 12 months. This tendency resulted specifically from an increase in hyperarousal symptoms. Although few endorsed symptoms at clinical levels, our results demonstrate that disaster relief workers may experience an increase in symptomatology at the anniversary of their traumatic exposure.
Accumulated childhood trauma and symptom complexity
Authors: Briere John , Kaltman Stacey , Green Bonnie L.
Published: April 2008

The relationship between accumulated exposure to different types of traumatic events (cumulative trauma) in childhood and the total number of different types of symptomatology reported (symptom complexity) in adulthood was examined in a sample of 2,453 female university students. There was a linear relationship between the number of trauma types experienced by participants before 18 and symptom complexity. This effect remained even when controlling for specific traumatic events, suggesting a generalized effect of cumulative trauma.
Meta‐analysis of alexithymia in posttraumatic stress disorder
Authors: Frewen Paul A. , Dozois David J. A. , Neufeld Richard W. J. , Lanius Ruth A.
Published: April 2008

The authors present a meta‐analysis investigating the prevalence of alexithymia in 12 studies encompassing 1,095 individuals with posttraumatic stress disorder (PTSD). A large effect size was found associating PTSD with alexithymia. Effect sizes were higher in studies of male combat PTSD samples in comparison with studies of other PTSD samples. Clinical and research directions are discussed.
Entering exile: Trauma, mental health, and coping among Tibetan refugees arriving in Dharamsala, India
Authors: Sachs Emily , Rosenfeld Barry , Lhewa Dechen , Rasmussen Andrew , Keller Allen
Published: April 2008

Each year thousands of Tibetans escape Chinese‐controlled Tibet. The authors present findings on the experiences, coping strategies, and psychological distress (depression, anxiety, somatization, and posttraumatic stress disorder) of 769 Tibetan refugees arriving in Dharamsala, India (2003–2004). Distress increased significantly with greater trauma exposure. However, despite a high prevalence of potentially traumatizing events, levels of psychological distress were extremely low. Coping activity (primarily religious) and subjective appraisals of trauma severity appeared to mediate the psychological effects of trauma exposure. The potential impact of other variables, including culturally determined attitudes about trauma and timing of assessment, are discussed.
Elevated rates of current PTSD among Hispanic veterans in the NVVRS: True prevalence or methodological artifact?
Authors: Lewis‐Fernández Roberto , Turner J. Blake , Marshall Randall , Turse Nicholas , Neria Yuval , Dohrenwend Bruce P.
Published: April 2008

The elevated rate of current posttraumatic stress disorder (PTSD) among Hispanic Vietnam veterans has been attributed to culturally based expressiveness that inflates symptom self‐reports. To investigate this possibility, the authors conducted three hypothesis‐driven analyses with National Vietnam Veterans Readjustment Study (NVVRS) data from the Structured Clinical Interview for DSM‐III‐R (SCID‐) diagnosed subsample of male Vietnam Theater veterans (N = 260). First, persistence of the Hispanic elevation after adjusting for war‐zone stress exposure initially suggested the effect of greater expressiveness. Second, symptom‐based analyses isolated this effect to the self‐report Mississippi Scale for Combat‐Related PTSD and not to the clinician‐rated SCID interview. Third, objective measures of functioning did not reveal a unique Hispanic pattern of lower impairment associated with current PTSD. These tests suggest that greater Hispanic expressiveness does not account for the Hispanic elevation in current PTSD in the NVVRS SCID‐diagnosed subsample.
Kinetics of omeprazole degradation in the presence of 2‐mercaptoethanol
Authors: Al‐Matar Ali Kh. , El‐Eswed Bassam , Tutunji Maha F.
Published: April 2008

The reactions of omeprazole, a potent proton pump inhibitor, were investigated in the presence of 2‐mercapotoethanol. Reactions were monitored in solutions buffered to pH values ranging from 2.0 to 5.0 using differential pulse polarography at the static mercury drop electrode. First‐order reaction network was proposed for all conversions. It is demonstrated that acid degradation predominates at pH values ∼2–3, whereas the reaction of sulfenic acid with the more nucleophilic thiol becomes prominent at pH values around 4–5. The acidic medium is necessary for the formation of sulfenic acid, the key intermediate believed to be the active inhibitor, but acid also converts this sulfenic acid into other degradation products that are unreactive toward thiol. The present work suggests that acid inhibition may occur at pH values higher than those previously thought. Thus, “highly acidic medium is required to achieve both accumulation and activation of omeprazole in the parietal cell, but less acidic medium is necessary for the reaction of sulfenic acid intermediate with the sulfhydryl groups of cysteine residues of H+/K+‐ATPase proton pump in vivo.” © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 352–358, 2008
Ammonia–dimethylchloramine system: Kinetic approach in an aqueous medium and comparison with the mechanism involving liquid ammonia
Authors: Stephan J. , Pasquet V. , Elkhatib M. , Goutelle V. , Delalu H.
Published: April 2008

After an exhaustive study of the system ammonia–dimethylchloramine in liquid ammonia, it was interesting to compare the reactivity of this system in liquid ammonia with the same system in an aqueous medium. Dimethylchloramine prepared in a pure state undergoes dehydrohalogenation in an alkaline medium: the principal products formed are N‐methylmethanimine, 1,3,5‐trimethylhexahydrotriazine, formaldehyde, and methylamine. The kinetics of this reaction was studied by UV, GC, and HPLC as a function of temperature, initial concentrations of sodium hydroxide, and chlorinated derivative. The reaction is of the second order and obeys an E2 mechanism (k1 = 4.2 × 10−5 M−1 s−1, ΔH○# = 82 kJ mol−1, ΔS○# = −59 J mol−1 K−1). The oxidation of unsymmetrical dimethylhydrazine by dimethylchloramine involves two consecutive processes. The first step follows a first‐order law with respect to haloamine and hydrazine, leading to the formation of an aminonitrene intermediate (k2 = 150 × 10−5 M−1 s−1). The second step corresponds to the conversion of aminonitrene into formaldehyde dimethylhydrazone at pH 13). This reaction follows a first‐order law (k3 = 23.5 × 10−5 s−1). The dimethylchloramine–ammonia interaction corresponds to a SN2 bimolecular mechanism (k4 = 0.9 × 10−5 M−1 s−1, pH 13, and T = 25°C). The kinetic model formulated on the basis of the above reactions shows that the formation of the hydrazine in an aqueous medium comes under strong competition from the dehydrohalogenation of dimethylchloramine and the oxidation of the hydrazine formed by the original chlorinated derivative. A global model that explains the mechanisms both in an anhydrous and in an aqueous medium was elaborated. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 340–351, 2008
Study of association thermodynamics between crystal violet and sodium bis(2‐ethylhexyl)sulfosuccinate and kinetics of basic fading of crystal violet in microemulsions
Authors: Chen Zhi Yun , Zhao Ji Hua , He Wei , An Xue Qin , Shen Wei Guo
Published: April 2008

The thermodynamics of the association between 4,4′,4″‐tris(dimethyl‐amino)triphenylmethyl chloride (crystal violet or CV) and sodium bis(2‐ethylhexyl)‐sulfosuccinate (aerosol OT or AOT) in water/AOT/n‐decane microemulsion and the kinetics of the basic hydrolysis of CV in a water‐in‐oil microemulsion were investigated by UV–vis spectroscopic measurements. An association model of CV and AOT was used to analyze the experimental data to obtain the association constants at various temperatures. By taking the association into account, the “actual” rate constants and the activation energies of the basic hydrolysis of CV in the media of water/AOT/oil were obtained. The difference in thermodynamics and kinetics between the two media of water/AOT/n‐decane and water/AOT/isooctane is discussed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 294–300, 2008
Juvenile and adult immature and in vitro matured ovine oocytes evaluated in relation to membrane electrical properties, calcium stores, IP3 sensitivity and apoptosis occurrence in cumulus cells
Authors: Boni R. , Cocchia N. , Silvestre F. , Tortora G. , Lorizio R. , Tosti E.
Published: April 2008

The analysis of differences between juvenile and adult oocytes may provide useful information on the acquisition of meiotic and developmental competence of the female gamete. In oocytes collected from either ewes or 40‐day‐old lambs, we evaluated membrane electrical proprieties, such as resting potential, conductance, activation ion currents, L‐type Ca2+ currents as well as calcium stores and IP3 sensitivity; in addition, the incidence of apoptosis in cumulus cells in these two age categories was compared. The analysis was carried out in oocytes both prior to and after in vitro maturation. Significant differences were found in all the examined parameters in relation to maturational stages whereas minor differences were recorded in relation to age of the donor. IP3 sensitivity strongly increased after in vitro maturation following a dose‐dependent pattern from 1 to 500 µmol/L with a significant interaction (P < 0.01) between dose and maturational stage. The incidence of apoptosis in cumulus cells strongly increased after in vitro maturation and was greater in adult than in juvenile cumulus cells (39.2 ± 5.8% vs. 21.9 ± 3.5%; P < 0.01). In conclusion, all the examined parameters were greatly affected by the maturational stage, whereas minor differences were due to age‐related oocyte quality, that is, at plasma membrane levels to conductance, activation current peaks and calcium currents, at cytosol level to calcium stores and IP3 sensitivity, and to incidence of apoptosis in cumulus cells. These parameters were compared with previous data in bovine to analyze oocyte quality in juvenile and adult individuals or between species. Mol. Reprod. Dev. 75: 1752–1760, 2008. © 2008 Wiley‐Liss, Inc.
The computational complexity of graph contractions II: Two tough polynomially solvable cases
Authors: Levin Asaf , Paulusma Daniel , Woeginger Gerhard J.
Published: April 2008

For a fixed pattern graph H, let H‐CONTRACTIBILITY denote the problem of deciding whether a given input graph is contractible to H. This article is part II of our study on the computational complexity of the H‐CONTRACTIBILITY problem. In the first article we pinpointed the complexity for all pattern graphs with five vertices except for two pattern graphs H. Here, we present polynomial time algorithms for these two remaining pattern graphs. Interestingly, in all connected cases that are known to be polynomially solvable, the pattern graph H has a dominating vertex, whereas in all cases that are known to be NP‐complete, the pattern graph H does not have a dominating vertex. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
New poly(ester amide)s from alkyl 2‐(carboethoxyhydroxymethyl)acrylates
Authors: Morizur Jean‐François , Mathias Lon J.
Published: April 2008

The synthesis of alkyl 2‐(carboethoxyhydroxymethyl)acrylates via the Bayllis‐Hillmann reaction pathway is described. These compounds are found to be poor monomers when involved in free radical polymerizations but present an extremely high reactivity upon Michael addition with primary amines leading to a simple, mild and efficient route to the preparation of new multifunctional heterocycles and polymers with potential applications in biodegradable coatings. Real‐time NMR spectroscopy permitted monitoring the extent of the reaction sequence and determining the conversion profile of reactants and Michael adduct intermediate. Poly(ester amide)s derived from diamine and hexane bis‐2‐(carboethoxyhydroxymethyl)acrylate were synthesized at room temperature by means of a very efficient Michael addition/cyclization polymerization. These polymers display excellent adhesion to metal, glass, and paper substrates and interesting hydrolytic susceptibility. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3182–3192, 2008
Microwave‐assisted ring‐opening polymerization of p‐dioxanone
Authors: Chen Yu‐Yan , Wu Gang , Qiu Zhi‐Cheng , Wang Xiu‐Li , Zhang Yuan , Lu Fang , Wang Yu‐Zhong
Published: April 2008

The ring‐opening polymerization (ROP) of p‐dioxanone (PDO) under microwave irradiation with triethylaluminum (AlEt3) or tin powder as catalyst was investigated. When the ROP of PDO was catalyzed by AlEt3, the viscosity‐average molecular weight (Mv) of poly(p‐dioxanone) (PPDO) reached 317,000 g mol−1 only in 30 min, and the yield of PPDO achieved 96.0% at 80 °C. Tin powder was successfully used as catalyst for synthesizing PPDO by microwave heating, and PPDO with Mv of 106,000 g mol−1 was obtained at 100 °C in 210 min. Microwave heating accelerated the ROP of PDO catalyzed by AlEt3 or tin powder, compared with the conventional heating method. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3207–3213, 2008
Simulation of the self‐assembly of poly(α‐glutamate) and dodecyltrimethylammonium: Diffusive role of the surfactant cations
Authors: Zanuy David , Alemán Carlos
Published: April 2008

The self‐assembly process of stoichiometric complexes formed by poly(α‐glutamate) and dodecyltrimethylammonium molecular cations has been studied at the atomistic by molecular dynamics simulations. The results presented in this work depict a time‐dependent succession of events. Among them, the formation of the assembled complex is an extraordinarily fast event. On the other side, the surfactant units do not influence the kinetics of the polypeptide folding process, showing that the characteristic independent organization experimentally detected for the charged groups and aliphatic tails has its reflection during the assembly process. Through these results, it is possible to infer new strategies to engineer the final nano‐organization that these stoichiometric complexes can adopt. The instantaneous assembly of the oppositely charged components allows a further kinetic control over the polypeptide folding process, which is expected to take place in time scales that are between 10 and 100 times larger than those explored in this work. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 917–924, 2008
Taming mechanical integrity
Authors: Hobbs Douglas
Published: April 2008

A well designed and executed mechanical integrity (MI) program is essential to loss prevention. A MI program perpetually behind the unrelenting schedule of completing essential equipment condition monitoring tasks or the function tests of process safeguards is symptomatic of not understanding the resource requirements and the technical requirements for a MI program. A key to preventing this outcome is to define a realistic MI program that meets your resource constraints, but delivers the right information on schedule. A realistic MI program is designed by plant personnel understanding why each activity is performed to the frequency and extent you have specified and the benefit it brings to the integrity of the equipment. This topic is applicable to facilities of any size or extent of process hazards, but the emphasis for this discussion will be for smaller facilities. This is accomplished by defining a MI program that is matched to your resources with a realistic suite of activities and schedules that you understand. A thorough PHA should address the process hazards, describe the potential consequences and their causes and identify safeguards. © 2008 American Institute of Chemical Engineers Process Saf Prog 2008
Biologically inspired climbing with a hexapedal robot
Authors: Spenko M. J. , Haynes G. C. , Saunders J. A. , Cutkosky M. R. , Rizzi A. A. , Full R. J. , Koditschek D. E.
Published: April 2008

This paper presents an integrated, systems‐level view of several novel design and control features associated with the biologically inspired, hexapedal, RiSE (Robots in Scansorial Environments) robot. RiSE is the first legged machine capable of locomotion on both the ground and a variety of vertical building surfaces including brick, stucco, and crushed stone at speeds up to 4 cm/s, quietly and without the use of suction, magnets, or adhesives. It achieves these capabilities through a combination of bioinspired and traditional design methods. This paper describes the design process and specifically addresses body morphology, hierarchical compliance in the legs and feet, and sensing and control systems that enable robust and reliable climbing on difficult surfaces. Experimental results illustrate the effects of various behaviors on climbing performance and demonstrate the robot's ability to climb reliably for long distances. © 2008 Wiley Periodicals, Inc.
ORIGAMI: A Novel and Effective Approach for Mining Representative Orthogonal Graph Patterns
Authors: Chaoji Vineet , Al Hasan Mohammad , Salem Saeed , Besson Jeremy , J. Zaki Mohammed
Published: April 2008

In this paper, we introduce the concept of α‐orthogonal patterns to mine a representative set of graph patterns. Intuitively, two graph patterns are α‐orthogonal if their similarity is bounded above by α. Each α‐orthogonal pattern is also a representative for those patterns that are at least β similar to it. Given user defined α, β ∈ [0, 1], the goal is to mine an α‐orthogonal, β‐representative set that minimizes the set of unrepresented patterns.

We present ORIGAMI, an effective algorithm for mining the set of representative orthogonal patterns. ORIGAMI first uses a randomized algorithm to randomly traverse the pattern space, seeking previously unexplored regions, to return a set of maximal patterns. ORIGAMI then extracts an α‐orthogonal, β‐representative set from the mined maximal patterns. We show the effectiveness of our algorithm on a number of real and synthetic datasets. In particular, we show that our method is able to extract high‐quality patterns even in cases where existing enumerative graph mining methods fail to do so. Copyright © 2008 Wiley Periodicals, Inc., A Wiley Company Statistical Analy Data Mining 1: 000‐000, 2008
Estrous state influences on investigative, aggressive, and tail flicking behavior in captive female Asian elephants
Authors: Slade‐Cain Barbara E. , Rasmussen L. E. L. , Schulte Bruce A.
Published: April 2008

Females of species that live in matrilineal hierarchies may compete for temporally limited resources, yet maintain social harmony to facilitate cohesion. The relative degree of aggressive and nonaggressive interactions may depend on the reproductive condition of sender and receiver. Individuals can benefit by clearly signaling and detecting reproductive condition. Asian elephants (Elephas maximus) live in social matrilineal herds. Females have long estrous cycles (14–16 weeks) composed of luteal (8–12 weeks) and follicular (4–8 weeks) phases. In this study, we observed the behavior of four captive Asian elephant females during multiple estrous cycles over 2 years. We evaluated whether investigative, aggressive, and tail flicking behaviors were related to reproductive condition. Investigative trunk tip contacts showed no distinct pattern by senders, but were more prevalent toward female elephants that were in their follicular compared with their luteal phase. The genital area was the most frequently contacted region and may release reproductively related chemosignals. Aggression did not differ significantly with estrus; however, rates of aggression were elevated when senders were approaching ovulation and receivers were in the luteal phase. Females in the follicular phase may honestly advertise their condition. Contacts by conspecifics may serve to assess condition and reduce aggression. A behavior termed “tail flicking” was performed mainly during the mid‐follicular phase when estrogen and luteinizing hormone levels are known to spike. Tail flicking may disperse chemical signals in urine or mucus as well as act as a tonic signal that could provide a means of anticipating forthcoming ovulation by elephants and also for human observers and caretakers. Zoo Biol 27:167–180, 2008. © 2008 Wiley‐Liss, Inc.
Emission of Volatile Aldehydes from DAG‐Rich and TAG‐Rich Oils with Different Degrees of Unsaturation During Deep‐Frying
Authors: Katsuta Izumi , Shimizu Masao , Yamaguchi Tohru , Nakajima Yoshinobu
Published: April 2008

The purpose of the present study was to compare the emission of volatile aldehydes from diacylglycerol‐rich oils (DAG‐OILs) and triacylglycerol‐rich oils (TAG‐OILs) with different degrees of unsaturation of fatty acid moieties during the deep‐frying of sliced potatoes. To examine the effect of fatty acid composition, four kinds of oils with different fatty acid compositions were selected: rape seed (RS); sunflower oil as a high oleic (HO); safflower oil as high linoleic (HL); and, perilla oil as high linolenic (HLn) oils. The emissions of volatile aldehydes were determined during the deep‐frying of sliced potatoes by using the above fresh test oils or deteriorated RS oils. The statistical analysis showed no significant difference in volatile aldehyde emission and profile between the DAG‐OIL and TAG‐OIL with the fatty acid composition of RS, HL, and HLn. Although a statistically significant difference was noted in the volatile aldehyde emission between the DAG‐OIL and TAG‐OIL with HO, this difference was extremely small when compared to the variations found in the oils with four types of fatty acid composition. Finally, no difference was found in the volatile aldehyde emissions between the deteriorated DAG‐OIL and TAG‐OIL, although volatile aldehyde emissions increased with frying time. In addition, the acrylamide contents in potato chips prepared with RS–DAG or RS–TAG were at comparable levels.
The amyloid cascade hypothesis
Authors: Korczyn Amos D.
Published: April 2008

The amyloid deposits in the brains of patients with Alzheimer's disease have attracted attention and are now considered not only an essential requirement for pathological diagnosis but also an important clue to the pathogenesis of the disease. This article looks critically at the basis of the “amyloid cascade hypothesis” to conclude that there are many issues that need to be resolved since they are inconsistent with the hypothesis.
The Little Ice Age and the Jews: Environmental History and the Mercurial Nature of Jewish– Christian Relations in Early Modern Germany
Authors: Bell Dean Phillip
Published: April 2008

Scholars have frequently portrayed early modern German Jewish history as underresearched and fragmentary, with an underdeveloped pool of historical sources. Even the very productive historian Stefan Rohrbacher, for example, has rued that “[t]he early modern period numbers among the till now very little researched epochs in the history of the Jews in Germany. It has recently received increased attention from historians, however, this interest is distributed very unevenly in the various areas and aspects of Jewish life.”
Navigating Rough Waters: Alexander Kohut and the Hungarian Roots of Conservative Judaism
Authors: Lupovitch Howard N.
Published: April 2008

With these words, Alexander Kohut engaged the radical Reform stance of Kaufman Kohler in the spring of 1885. The exchange with Kohler crystallized Kohut's raison d'être for Conservative Judaism: an authentic alternative to what he termed “stupid Orthodoxy and insane Reform.” Kohut articulated a fully developed version of this view in Ethics of the Fathers, a compilation of his polemics against Kohler that he published a few months later. This earned Kohut a place among the Conservative movement's pantheon of nineteenth-century founders, along with Sabato Morais, Benjamin Szold, and Marcus Jastrow.
Luis de Carvajal and His People
Authors: Temkin Samuel
Published: April 2008

This work discusses some aspects of the life of Luis de Carvajal, the head of the well-known Carvajal family. This man was Portuguese by birth, which meant that he was not allowed to go to the Spanish New World. Nevertheless, in 1579, Philip II awarded him a vast territorial entity in New Spain, called Nuevo Reino de León, and allowed him to bring to it a large number of people without having to certify their being Old Christians. Nearly ten years later, he was apprehended by orders of Viceroy Manrique de Zuñiga and brought to Mexico City, where he was jailed in the Crown's prison. On April 14, 1589, he was transferred to the secret jails of the Spanish Inquisition, where he was subjected to a nine-month-long trial, accused of heresy, of knowingly bringing Jews to New Spain, and of concealing their religious activities. Ultimately, he was found guilty of the last two charges and was sentenced to a six-year exile from New Spain. However, before the sentence was carried out, he was returned to the Crown's jail, where he died a year later.
Job the Patient/Maimonides the Physician: A Case Study in the Unity of Maimonides' Thought
Authors: Kalman Jason
Published: April 2008

The study of Moses ben Maimon's works is ultimately tied into scholars' assumptions about whether they are reading the writings of Maimonides, the medieval Jewish philosopher par excellence, or Rambam, the premier medieval codifier of halakhah. Three approaches to interpreting his works have dominated scholarship for the last century. Some read the works as consisting of two essentially independent oeuvres: halakhic works written for one audience and philosophical works for another. Thus, Maimonides did not need to be consistent in his views. The supporters of Maimonides the philosopher read his halakhic works as secretly containing philosophical truths consistent with those in the Guide of the Perplexed (referred to as GP herein). The supporters of Rambam prefer to see the Mishneh Torah as the foremost statement of his views and the philosophical stance expressed in the Guide as disingenuous. In the words of Menachem Kellner, Maimonides is presented as “everything from a late convert to Kabbalah to a halakhist, who in truth disdained philosophy, to an Aristotelian philosopher, whose own innermost thoughts stood in conscious opposition to normative Jewish teachings.”
Ground‐based measurements of spatial and temporal variability of snow accumulation in East Antarctica
Authors: Eisen Olaf , Frezzotti Massimo , Genthon Christophe , Isaksson Elisabeth , Magand Olivier , van den Broeke Michiel R. , Dixon Daniel A. , Ekaykin Alexey , Holmlund Per , Kameda Takao , Karlöf Lars , Kaspari Susan , Lipenkov Vladimir Y. , Oerter Hans , Takahashi Shuhei , Vaughan David G.
Published: April 2008

The East Antarctic Ice Sheet is the largest, highest, coldest, driest, and windiest ice sheet on Earth. Understanding of the surface mass balance (SMB) of Antarctica is necessary to determine the present state of the ice sheet, to make predictions of its potential contribution to sea level rise, and to determine its past history for paleoclimatic reconstructions. However, SMB values are poorly known because of logistic constraints in extreme polar environments, and they represent one of the biggest challenges of Antarctic science. Snow accumulation is the most important parameter for the SMB of ice sheets. SMB varies on a number of scales, from small‐scale features (sastrugi) to ice‐sheet‐scale SMB patterns determined mainly by temperature, elevation, distance from the coast, and wind‐driven processes. In situ measurements of SMB are performed at single points by stakes, ultrasonic sounders, snow pits, and firn and ice cores and laterally by continuous measurements using ground‐penetrating radar. SMB for large regions can only be achieved practically by using remote sensing and/or numerical climate modeling. However, these techniques rely on ground truthing to improve the resolution and accuracy. The separation of spatial and temporal variations of SMB in transient regimes is necessary for accurate interpretation of ice core records. In this review we provide an overview of the various measurement techniques, related difficulties, and limitations of data interpretation; describe spatial characteristics of East Antarctic SMB and issues related to the spatial and temporal representativity of measurements; and provide recommendations on how to perform in situ measurements.
Quantifying the role of bed surface topography in controlling sediment stability in water‐worked gravel deposits
Authors: Measures Richard , Tait Simon
Published: April 2008

This study uses measured bed topography scans and fractional bed load transport rate data obtained from previous laboratory studies of gravel transport to examine the influence of the local grain‐scale topography on grain entrainment and fractional transport rates. A simple steady state fluid model is developed to impose fluid forces onto the exposed areas of the bed surface. Image analysis is used to identify the surface grains and simple physically based algorithms are used to include the effects of sheltering. Comparisons of modeled and experimental fractional transport rates show that remote sheltering has a very strong influence on grain entrainment. With the effects of remote sheltering included, the model was found to be able to predict fractional transport rates well for a range of bed topographies and feed conditions. Further studies using a wider range of bed shear stresses would allow the effects of turbulence and bed re‐arrangement to be included in the model.
Healing of simulated fault gouges aided by pressure solution: Results from rock analogue experiments
Authors: Niemeijer André , Marone Chris , Elsworth Derek
Published: April 2008

Slide‐hold‐slide friction experiments are reported on fault gouges of salt and salt‐muscovite mixtures to investigate the effects of fluids and phyllosilicates on strength gain. Healing rates of salt gouges in the presence of saturated brine are an order of magnitude higher than dry salt and water‐saturated quartz at 65°C. Fault gouges consisting of salt‐muscovite (80:20) mixtures show healing rates half that of 100 wt % salt; this is consistent with the effects of lower porosity and reduced dilation resulting from lower friction associated with muscovite. Half of the strength gain can be attributed to dilational work. The remainder of the strength gain can be explained by a microphysical model of compaction via pressure solution. Our model predicts the rate of contact area growth and of frictional restrengthening. The model predicts the observed rate of restrengthening for long hold periods for wet salt but underestimates the values for shorter hold periods. The short time response is attributed to strengthening of the grain boundary, elevating the resistance to frictional sliding on its interface, which is likely to be operative at longer hold periods as well but is masked by the strength gain owing to the increase in contact area. Our observations are consistent with an increased resistance to sliding of the contact at short term, the growth of the contact beyond this, and dilational hardening at all hold durations. To predict the magnitude and rates of healing in natural fault gouges under hydrothermal conditions, knowledge of the “state” of the fault gouge is required.
Statistical reconstruction of daily total ozone over Europe 1950 to 2004
Authors: Krzyścin Janusz W.
Published: April 2008

A statistical model is developed to reconstruct the total ozone field over Europe since 1 January 1950. Daily total ozone data are required for surface UV reconstruction. The model is trained on satellite data (National Institute of Water and Atmosphere Research (NIWA) assimilated total column ozone database) over the period 1979–2004. The model explains ∼80% of variance of the satellite total ozone. Standard deviation of the relative differences, observed minus model daily data in percent of observed data, is ∼4% and ∼6% in May‐September and October‐next year April season, respectively. The total ozone values are reconstructed backward in time using the regression constants derived as a result of the training, time series of various atmospheric indices of the atmospheric circulation, and the meteorological variables. The proxies for the ozone variations are taken from the National Centers for Enivronmental Prediction (NCEP)/National Center for Atmosphere Research (NCAR) reanalysis database. Optimal combination of the proxies is selected using MARS technique. The quality of the database is assured by a comparison of the reconstructed total ozone with the ground‐based data from several Dobson stations functioning in the early 1950s and 1960s. The model explains ∼70–80% variance of the ozone data collected before the satellite era. Bias and the long‐term drift between the reconstructed and measured Dobson ozone are within a range of ±2%. Standard deviation of relative differences between reconstructed and station Dobson daily data is 5–7% and ∼10% in May‐September and October‐next year April season, respectively. The long‐term tendency, comprising an anthropogenic trend and superposition of “natural” long‐term fluctuations, appears almost trendless in the period 1950–1980 with a clear ozone decline after 1980.
Potential energy curve for isomerization of N2H2 and C2H4 using the improved virtual orbital multireference Møller–Plesset perturbation theory
Authors: Chaudhuri Rajat K. , Freed Karl F. , Chattopadhyay Sudip , Sinha Mahapatra Uttam
Published: April 2008

Multireference Møller–Plesset (MRMP) perturbation theory [K. Hirao, Chem. Phys. Lett. 190, 374 (1992)] is modified to use improved virtual orbitals (IVOs) and is applied to study ground state potential energy curves for isomerization and dissociation of the N2H2 and C2H4 molecules. In contrast to traditional MRMP or multistate multiconfiguration quasidegenerate perturbation theory where the reference functions are obtained from (often difficult to converge) state averaged multiconfiguration self-consistent field methods, our reference functions are represented in terms of computationally efficient IVOs. For convenience in comparisons with other methods, a first order complete active space configuration interaction (CASCI) calculation with the IVOs is followed by the use of the IVOs in MRMP to incorporate residual electron correlation effects. The potential energy curves calculated from the IVO-MRMP method are compared with computations using state-of-the-art coupled cluster singles and doubles (CCSD) methods and variants thereof to assess the efficacy of the IVO-MRMP scheme. The present study clearly demonstrates that unlike the CCSD and its variants, the IVO-MRMP approach provides smooth and reliable ground state potential energy curves for isomerization of these systems. Although the rigorously size-extensive completely renormalized CC theory with noniterative triples corrections (CR-CC(2,3)) likewise provides relatively smooth curves, the CR-CC(2,3) calculations overestimate the cis-trans barrier height for N2H2. The ground state spectroscopic constants predicted by the IVO-CASCI method agree well with experiment and with other highly correlated ab initio methods.
Tailoring magnetism in CoNi films with perpendicular anisotropy by ion irradiation
Authors: Stanescu D. , Ravelosona D. , Mathet V. , Chappert C. , Samson Y. , Beigné C. , Vernier N. , Ferré J. , Gierak J. , Bouhris E. , Fullerton E. E.
Published: April 2008

This paper reports on the influence of ion irradiation on the magnetic properties of Co∕Ni multilayers with perpendicular magnetic anisotropy (PMA). This material is a very promising candidate for ultrahigh density spintronic applications since it exhibits high polarization and low damping parameters. We show that PMA can be tailored in a controlled way by using uniform He+ ion irradiation or focused Ga+ ion beam.
The effect of the surface of SnO2 nanoribbons on their luminescence using x-ray absorption and luminescence spectroscopy
Authors: Zhou X. T. , Zhou J. G. , Murphy M. W. , Ko J. Y. P. , Heigl F. , Regier T. , Blyth R. I. R. , Sham T. K.
Published: April 2008

X-ray excited optical luminescence (XEOL) and x-ray absorption near-edge structure in total electron, x-ray fluorescence, and photoluminescence yields at Sn M5,4-, O K-, and Sn K-edges have been used to study the luminescence from SnO2 nanoribbons. The effect of the surface on the luminescence from SnO2 nanoribbons was studied by preferential excitation of the ions in the near-surface region and at the normal lattice positions, respectively. No noticeable change of luminescence from SnO2 nanoribbons was observed if the Sn ions in the near-surface region were excited selectively, while the luminescence intensity changes markedly when Sn or O ions at the normal lattice positions were excited across the corresponding edges. Based on the experimental results, we show that the luminescence from SnO2 nanoribbons is dominated by energy transfer from the excitation of the whole SnO2 lattice to the surface states. Surface site specificity is not observable due to its low concentration and weak absorption coefficient although the surface plays an important role in the emission as a luminescence center. The energy transfer and site specificity of the XEOL or the lack of the site specificity from a single-phase sample is discussed.
Feature of morphotropic phase boundary of yBiGaO3–(1−x−y)BiScO3–xPbTiO3 high-temperature piezoelectric ceramics
Authors: Jiang Yihang , Qin Baoquan , Yue Xi , Zhao Yi , Jiang Yuzhi , Xiao Dingquan , Zhu Jianguo
Published: April 2008

y Bi Ga O 3 – ( 1 − x − y ) Bi Sc O 3 – x Pb Ti O 3 (BGSPT) ternary piezoelectric ceramics were fabricated by using conventional mixed oxide ceramic processing. It was found that the introduction of BiGaO3 into BiScO3–PbTiO3 system would cause a shift of morphotropic phase boundaries (MPBs), from x=0.64, y=0 to x=0.56, y=0.155; and an increase of Curie temperature (TC) near MPB, from 450 up to 494°C, respectively. BGSPT ceramics possessed higher TC (∼494°C) and high piezoelectric coefficient (d33∼180pC∕N), and showed the different rule of the Curie temperature near MPB versus the end member tolerance factor (t). The mechanism of higher TC in BGSPT system was also proposed.
Correlation regions within a localized molecular orbital approach
Authors: Mata Ricardo A. , Werner Hans-Joachim , Schütz Martin
Published: April 2008

A hybrid scheme for the computation of reaction energies in large molecular systems is proposed. The approach is based on localized orbitals and allows for the treatment of different parts of a molecule at different computational levels. The localized orbitals are assigned to regions, and then different local correlation methods, such as local MP2 or local CCSD(T), can be applied to different regions. In contrast to previous hybrid schemes, the molecule does not have to be split into parts and, therefore, it is not necessary to saturate dangling bonds using link atoms. For fixed region sizes, the cost of the high-level calculation becomes independent of the molecular size, and it is demonstrated that O(1) scaling can be achieved. Illustrative applications are presented and the convergence of the results with respect to the size of the regions is investigated for reaction energies, barrier heights, and weakly bound complexes.
Ion condensation on charged patterned surfaces
Authors: Velichko Yuri S. , Solis Francisco J. , Olvera de la Cruz Monica
Published: April 2008

We study ion condensation on a patterned surface with stripes of alternating charge. The competition between adsorbed ion-ion and adsorbed ion-surface interactions leads to the formation of different strongly correlated structures of condensed ions in the low-temperature limit (LTL). We consider two types of arrangements which have lowest energy in the LTL: (1) ions adsorbed onto the stripe center lines and (2) arrays of dipoles at the interfaces between charged domains. We determine the preferred arrangement as a function of surface charge density, the chemical potential of the ions in the surrounding medium, and the geometric parameters of the system. We determine the conditions for the appearance of more complex ionic patterns by considering simple perturbations of the stripe-centered and dipolar array structures.
Dispersion energy from density-fitted density susceptibilities of singles and doubles coupled cluster theory
Authors: Korona Tatiana , Jeziorski Bogumil
Published: April 2008

A new method of calculation of the second-order dispersion energy is proposed. It is based on the Longuet-Higgins formula [Faraday Discuss. Chem. Soc. 40, 7 (1965)], which describes the dispersion interaction in terms of frequency-dependent density susceptibilities of monomers. In this study, the density susceptibilities are obtained from the coupled cluster theory at the singles and doubles level. Density fitting is applied in order to reduce the computational effort for the evaluation of density susceptibilities. It is shown that density fitting improves the scaling of the computational resources with molecular size by one order of magnitude without affecting the accuracy of the resulting dispersion energy. Numerical results are presented for several van der Waals molecules to illustrate the performance of the new approach.
Comment on “Markovian approximation in a coarse-grained description of atomic systems” [J. Chem. Phys. 125, 204101 (2006)]
Authors: Cubero David
Published: April 2008

The authors concluded that the coarse-graining dynamics of a one-dimensional chain of oscillators interacting through Lennard–Jones potentials is Markovian, in contrast with the situation observed for harmonic lattices. However, with the help of a novel equation that relates the correlation of forces and momenta, I show that this conclusion is drawn from an incorrect analysis of the simulation data.
Improved transition path sampling methods for simulation of rare events
Authors: Chopra Manan , Malshe Rohit , Reddy Allam S. , de Pablo J. J.
Published: April 2008

The free energy surfaces of a wide variety of systems encountered in physics, chemistry, and biology are characterized by the existence of deep minima separated by numerous barriers. One of the central aims of recent research in computational chemistry and physics has been to determine how transitions occur between deep local minima on rugged free energy landscapes, and transition path sampling (TPS) Monte-Carlo methods have emerged as an effective means for numerical investigation of such transitions. Many of the shortcomings of TPS-like approaches generally stem from their high computational demands. Two new algorithms are presented in this work that improve the efficiency of TPS simulations. The first algorithm uses biased shooting moves to render the sampling of reactive trajectories more efficient. The second algorithm is shown to substantially improve the accuracy of the transition state ensemble by introducing a subset of local transition path simulations in the transition state. The system considered in this work consists of a two-dimensional rough energy surface that is representative of numerous systems encountered in applications. When taken together, these algorithms provide gains in efficiency of over two orders of magnitude when compared to traditional TPS simulations.