bluuebunny/crossref_metadata_2025 huggingface dataset:
Parental relationships, coping strategies, received support, and well‐being in adolescents of separated or divorced and married parents
Authors: Grossman Mary , Rowat Kathleen M.
Published: April 2007

The purpose of this cross‐sectional study was to examine the impact of the perceived quality of the parental relationship and family status on coping strategies, received support, and well‐being in adolescents from separated or divorced and married parents. Two hundred forty‐four matched adolescents from separated/divorced and married households were drawn from an initial sample of 1,044 students who were tested at five colleges and three high schools of a large metropolitan and rural area. Regression analyses supported the hypothesis that a perceived poor parental relationship, and not family status, was associated with low life satisfaction and sense of future, and high anxiety in adolescents of divorced and married households. Hierarchical regression techniques revealed that coping strategies and received support did not mediate the association between a perceived poor parental relationship and low levels of well‐being in adolescents from divorced and married households. The findings underscore the importance of intervening with adolescents within the context of their family relationships. ©1995 John Wiley & Sons, Inc.
Job satisfaction of nurses employed in rural and urban long‐term care facilities
Authors: Coward Raymond T. , Hogan Tiffany L. , Duncan R. Paul , Horne Claydell H. , Hilker Mary Anne , Felsen Loretta M.
Published: April 2007

Previous investigators have identified residential differences in the job satisfaction of hospital nurses. However, the degree to which the greater job satisfaction of rural nurses can be generalized beyond hospitals to other work settings, including nursing homes, is unknown. The purpose of this research was to examine the job satisfaction of nurses (registered and licensed practical) employed in both rural and urban nursing homes. A total of 281 nurses from 26 participating nursing homes completed a mailed questionnaire that measured the personal and job‐specific characteristics of the nurses and the contextual properties of the facilities in which they worked. The data indicated no statistically significant differences in the overall job satisfaction, or on any of the five subscales of the instrument, between rural and urban nurses. However, a pooled multivariate model identified five factors that predicted the job satisfaction of nurses employed in long‐term care facilities: the employees' race and personal income; the employees' perception that their supervisor was interested in their career aspirations; the length of time that the nurses had intended to stay at the time of their hiring; and their current intent to leave. ©1995 John Wiley & Sons, Inc.
Gender and knowledge about HIV, risky sexual behavior, and safer sex practices
Authors: Jadack Rosemary A. , Hyde Janet Shibley , Keller Mary L.
Published: April 2007

The purpose of this study was to examine gender differences in knowledge about HIV, the reported incidence of risky sexual behavior, and comfort with safer sexual practices among young adults. The conceptual framework was social role theory, which argues for the influence of gender roles on beliefs and social behaviors. Participants were 141 female and 131 male college students who responded to questions regarding their knowledge of HIV, risk‐taking behaviors with respect to HIV, and comfort with safer sexual behaviors. Overall, respondents had accurate knowledge about HIV. However, men reported engaging in significantly more risky behaviors than women. More men reported that intercourse without a condom occurred in unplanned, spontaneous situations, while under the influence of alcohol or drugs, or with a person not well known. More women reported that intercourse without a condom occurred in long‐term relationships. Women were significantly more comfortable abstaining from sexual intercourse and asking partners about their sexual history while men were significantly more comfortable buying condoms. Both men and women reported comfort using condoms. Gender roles help to explain why men are willing to take more risks, and in what situations risk taking is apt to occur. ©1995 John Wiley & Sons, Inc.
Agreement between measures of pulmonary artery and tympanic temperatures
Authors: Lattavo Kathy , Britt Jana , Dobal May
Published: April 2007

The purposes of this study were to compare pulmonary artery, oral, axillary, and two tympanic temperatures and test agreement between measures of pulmonary artery and tympanic temperatures in a convenience sample of 32 Intensive Care Unit patients. The correlation coefficients for pulmonary artery and oral, axillary, and tympanic temperatures were moderate to strong and significant at the p <.01 level. However, intraclass correlation coefficients estimated the intermethod reliability and were below the .75 criterion of acceptability. Thus, one method of temperature measurement could not be interchanged for another. ©1995 John Wiley & Sons, Inc.
Parent‐to‐parent support initiated in the neonatal intensive care unit
Authors: Roman Lee Anne , Lindsay Judith K. , Boger Robert P. , Dewys Mary , Beaumont Ed J. , Jones Alan S. , Haas Bruce
Published: April 2007

A preliminary quasi‐experimental, longitudinal study was conducted to explore differences in maternal mood states, self‐esteem, family functioning, maternal‐infant interaction, and home environment between mothers of preterm infants who participated in a nurse‐managed program of parent‐to‐parent support and those who served as a comparison group. Mothers who participated in the intervention scored significantly higher on the Barnard NCATS interaction measure and the HOME total scale and subscales of maternal responsiveness and organization (N= 58) at 12 months following discharge from a neonatal intensive care unit. Using repeated measures analysis for a subset of mothers (n= 32), there were significant differences between the two groups on the mood state anxiety‐tension (POMS) during the first 4 months postdischarge, with the treatment group having less anxiety. There was also a group by time interaction effect on self‐esteem during the first 4 months, with self‐esteem of the treatment group mothers increasing and comparison mothers decreasing. Findings suggest that one‐to‐one veteran parent support, in a nurse‐managed program, may influence maternal and maternal‐infant interaction outcomes. ©1995 John Wiley & Sons, Inc.
Sustainable governance of natural resources and institutional change–an analytical framework
Authors: Fischer Anke , Petersen Lorenz , Feldkötter Christoph , Huppert Walter
Published: April 2007

This article presents a conceptual framework for analysing the governance of natural resource use, as governance is often the primary issue when natural resources are overexploited and degraded. It addresses both spontaneous and active governance, including institutional change induced by development co‐operation. Drawing on existing frameworks of institutional analysis, fundamental modifications are presented to adapt the concept to the context of international co‐operation, and to include dynamic aspects of institutional change as well as multiple actor interactions. Tested in several case studies, the framework was found suitable and relevant for use in project planning and evaluation, as well as for comparing governance issues across cases in a conceptually rigorous way. Copyright © 2007 John Wiley & Sons, Ltd.
Aryl acrylate porous functional polymer supports from water‐in‐oil‐in‐water multiple emulsions
Authors: Štefanec Dejan , Krajnc Peter
Published: April 2007

Porous functional polymer supports are a class of material of wide interest due to the possibility of immobilising reactive species. A simplified procedure was applied for the preparation of porous polymer supports using a water‐in‐oil‐in‐water multiple emulsion. The primary emulsion was a high internal phase emulsion, having a volume fraction of water phase up to 95%. Two reactive acrylates, namely 4‐nitrophenyl acrylate and 2,4,6‐trichlorophenyl acrylate, were (separately) incorporated in the oil phase in order to obtain porous reactive polymer supports. Both acrylates were crosslinked with either divinylbenzene or ethylene glycol dimethacrylate, and beads of size ca 60 µm were obtained after the polymerisation of droplets suspended into the secondary aqueous phase. In the case of 4‐nitrophenyl acrylate and divinylbenzene as a crosslinker, particles with a star shape, the core being ca 60 µm in diameter and the arms ca 180 µm in length, were obtained. The polymers were functionalised with morpholine, tris(2‐aminoethyl)amine, piperidine or piperazine yielding supports with loadings of reactive groups of between 2.6 and 6.6 mmol g−1. The results show that multiple emulsions can be precursors for porous polymer preparation. Copyright © 2007 Society of Chemical Industry
Factors of complicated grief pre‐death in caregivers of cancer patients
Authors: Tomarken Alexis , Holland Jimmie , Schachter Sherry , Vanderwerker Lauren , Zuckerman Enid , Nelson Christian , Coups Elliot , Ramirez Paul Michael , Prigerson Holly
Published: April 2007

Purpose: Over the past decade, Prigerson and her colleagues have shown that symptoms of ‘complicated grief’—intense yearning, difficulty accepting the death, excessive bitterness, numbness, emptiness, and feeling uneasy moving on and that the future is bleak—are distinct from depression and anxiety and are independently associated with substantial morbidity. Little is known about complicated grief experienced by family caregivers prior to the death. This study sought to examine differences in caregiver age groups and potential risk factors for complicated grief pre‐death.

Method: Two hundred and forty eight caregivers from multiple sites nationwide (20–86 years of age) identified themselves as primary caregivers to a terminally ill cancer patient. Each caregiver was interviewed using the following measures: the Pre‐Death Inventory of Complicated Grief‐Caregiver Version; the Brief Interpersonal Support Evaluation List; the Structured Clinical Interview for the DSM‐IV Axis I; the Life Orientation Test‐Revised; the SEPRATE Measure of Stressful Life Events; the Covinsky Family Impact Survey; and mental health access questions.

Results: The study found that those under 60 years old had higher levels of complicated grief pre‐death than caregivers 60 and older (t(246)=2.30, p<0.05). Significant correlations were also found between levels of complicated grief pre‐loss and the following psychosocial factors: perceived social support (r=−0.415, p<0.001); history of depression (r=−0.169, p<0.05); current depression (r=−0.158, p<0.05); current annual income (Spearman rho =−0.210, p<0.01); annual income at time of patient's diagnosis (Spearman rho =−0.155, p=0.05); pessimistic thinking (r=0.320, p<0.001); and number of moderate to severe stressful life events (Spearman rho = 0.218, p=0.001). In a multi‐variate analysis (R2=0.368), pessimistic thinking (Beta = 0.208, p<0.05) and severity of stressful life events (Beta = 0.222, p<0.05) remained as important factors to developing complicated grief pre‐death.

Conclusions: These results suggest that mental health professionals who work with caregivers should pay particular attention to pessimistic thinking and stressful life events, beyond the stress of the loved one's illness, that caretakers experience. Additionally, although not reaching significance, mental health professionals should also consider younger caregivers at greater risk for complicated grief pre‐loss. Copyright © 2007 John Wiley & Sons, Ltd.
Studies on the metabolism of 4‐methylpiperazine‐1‐carbodithioc acid 3‐cyano‐3,3‐ diphenylpropyl ester hydrochloride in rat bile by high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Jiang Xiaomei , Kong Detao , Han Fangbin , Ling Xiaomei , Liu Xiaoyan , Li Runtao , Cui Jingrong
Published: April 2007

4‐Methylpiperazine‐1‐carbodithioc acid 3‐cyano‐3,3‐diphenylpropyl ester hydrochloride (TM208) is a newly synthesized compound which has shown excellent in vivo and in vitro anticancer activity and low toxicity. In the present study, the major metabolites of TM208 in rat bile were studied by high‐performance liquid chromatography/tandem mass spectrometry with an electrospray ionization (ESI) interface. It was demonstrated that TM208 was extensively metabolized in rat bile and nine metabolites (M1–M9) were definitely or tentatively identified: (2‐aminoethyl)dithiocarbamic acid 3‐cyano‐3,3‐diphenylpropyl ester (M1), (2‐methylaminoethyl)dithiocarbamic acid 3‐cyano‐3,3‐diphenylpropyl ester (M2), 4‐[(4‐methylpiperazin‐1‐yl)thioxomethanesulfinyl]‐2,2‐diphenylbutyronitrile (M3), 4‐methylpiperazine‐1‐carbodithioic acid 3‐cyano‐3‐(4‐hydroxyphenyl)‐3‐phenylpropyl ester(M4), the sulfine of (4‐methylpiperazine‐1‐carbodithioc acid 3‐cyano‐3,3‐diphenylpropyl ester) (M5), 4‐methylpiperazine‐1‐carbothioic acid S‐(3‐cyano‐3,3‐diphenylpropyl) ester (M6), piperazine‐1‐carbodithioic acid 3‐cyano‐3,3‐diphenylpropyl ester (M7), 4‐hydroxymethylpiperazine‐1‐carbothioic acid S‐(3‐cyano‐3,3‐diphenylpropyl) ester (M8) and the sulfine of [4‐methylpiperazine‐1‐carbodithioic acid 3‐cyano‐3‐(4‐hydroxyphenyl)‐3‐phenylpropyl ester] (M9). Copyright © 2007 John Wiley & Sons, Ltd.
Robust tracking control for a class of MIMO nonlinear systems with measurable output feedback
Authors: Pan Ya‐Jun , Marquez Horacio J. , Chen Tongwen
Published: April 2007

This paper proposes a robust output feedback controller for a class of nonlinear systems to track a desired trajectory. Our main goal is to ensure the global input‐to‐state stability (ISS) property of the tracking error nonlinear dynamics with respect to the unknown structural system uncertainties and external disturbances. Our approach consists of constructing a nonlinear observer to reconstruct the unavailable states, and then designing a discontinuous controller using a back‐stepping like design procedure to ensure the ISS property. The observer design is realized through state transformation and there is only one parameter to be determined. Through solving a Hamilton–Jacoby inequality, the nonlinear control law for the first subsystem specifies a nonlinear switching surface. By virtue of nonlinear control for the first subsystem, the resulting sliding manifold in the sliding phase possesses the desired ISS property and to certain extent the optimality. Associated with the new switching surface, the sliding mode control is applied to the second subsystem to accomplish the tracking task. As a result, the tracking error is bounded and the ISS property of the whole system can be ensured while the internal stability is also achieved. Finally, an example is presented to show the effectiveness of the proposed scheme. Copyright © 2007 John Wiley & Sons, Ltd.
Gallstone Ileus: Diagnosis and Management
Authors: Ayantunde A. A. , Agrawal A.
Published: April 2007

Background

Gallstone ileus is a rare complication of cholelithiasis, mostly in the elderly. It accounts for 1%–4% of mechanical bowel obstruction and is associated with high morbidity and mortality. We present our experience of gallstone ileus and discuss current opinion as reported in the literature.

Patients and Methods

A retrospective review was performed of medical records of patients in our institution coded for gallstone ileus by the International Classification of Diseases (ICD K‐563) coding system between January 1998 and December 2005.

Results

There were 22 patients with mean age of 77 (58–92) years and a female to male ratio of 4.5:1. Most patients presented with abdominal pain and vomiting, with a median duration of symptoms of 3 (1–28) days. Preoperative diagnosis was made in 77% from a combination of plain x‐ray, ultrasonography, and computed tomography (CT) scans; 86.4% of the patients belonged to ASA class of 3 or 4. Twenty patients underwent enterolithotomy alone, and two had one‐stage procedure. The mean size of impacted stones was 3.6 (2.5–4.5) cm, with location in the terminal ileum in 17 and jejunum in 5 patients. There were 5 perioperative deaths and an episode of cholangitis occurring in one patient 18 months after enterolithotomy alone.

Conclusions

Gallstone ileus is a difficult clinical entity to diagnose. Unreserved use of imaging techniques can improve diagnostic accuracy and speed of therapeutic decision making. Management of gallstone ileus must be individualized. The one‐stage procedure should be offered only to highly selected patients with good cardiorespiratory reserve and with absolute indications for biliary surgery at the time of presentation.
An evidence‐based review of poorly differentiated thyroid cancer
Authors: Sanders Enoch M. , LiVolsi Virginia A. , Brierley James , Shin Jennifer , Randolph Gregory W.
Published: April 2007

Background

Poorly differentiated thyroid cancer (PDTC) presents the endocrinologist and surgeon with challenges of recognition and treatment given the lack of consensus on histopathologic definition and limited literature on surgical and nonsurgical treatment.

Methods

We offer an operational pathologic definition for PDTC, which should help guide future work in this area. Poorly differentiated thyroid cancer should include insular and trabecular variants but should not include solid type lesions (included by other workers) or more differentiated tumors that may have poor prognosis such as tall cell, columnar, diffuse sclerosing, and oncocytic lesions. Systematic evidence‐based literature reviews focusing on two questions were carried out: (1) is PDTC associated with an intermediate prognosis relative to anaplastic and WDTC? and (2) What are the postoperative treatment options for poorly differentiated thyroid cancer?

Conclusions

We have found level IV evidence that PDTC is intermediate between WDTC and anaplastic cancers in terms of prognosis. It represents a disease where appropriate administration of aggressive treatment not typically necessary for routine WDTC and not effective for anaplastic disease may uniquely result in substantial benefit. Limited level IV data show conflicting results regarding 131I treatment benefit. Given lack of morbidity and potential for benefit, we recommend that 131I therapy be considered in all patients postoperatively. Recommendation regarding external beam radiotherapy (XRT) is based primarily on extrapolation from studies in forms of poor‐prognosis WDTC where substantial data exist regarding treatment benefit. We recommend that external beam treatment be considered in all patients with PDTC with T3 tumors without distant metastasis, all patients with T4 tumors, and all patients with regional lymph node involvement.
Acute Felon as a Complication of Systemic Paclitaxel Therapy: Case Report and Review of the Literature
Authors: Hijjawi John B. , Dennison David G.
Published: April 2007

Breast cancer now affects 1 in 8 American women and the taxane agent paclitaxel (Taxol® Bristol-Myers Squibb) is a major tool in the treatment of many such patients. Hand surgeons are therefore likely to encounter upper extremity complications related to the use of taxane therapy. We present an unusual case of a felon developing in a breast cancer patient on paclitaxel therapy with no antecedent history of trauma. Whereas onycholysis and subungual hemorrhage are reported complications of taxane therapy ( Fig. 1 ), an acute felon with or without associated paronychia is an unusual and more aggressive manifestation of this drug-related nail dystrophy.
The Concomitant Presence of Two Anomalous Muscles in the Forearm
Authors: Ogun Tunç Cevat , Karalezli Nazim , Ogun Cemile Oztin
Published: April 2007

This article describes the concomitant presence of two anomalous forearm muscles in a 20-year-old man, discovered accidentally during an operation for a forearm injury. The first one was similar to a reverse palmaris longus muscle except for its direction to the Guyon's canal. The second one originated from the radial antebrachial fascia, superficial to all other forearm muscles in the lower half of the forearm, then diverged medially and extended into the Guyon's canal and was innervated by the ulnar nerve. The patient had no symptoms related to overcrowding of the Guyon's canal before the injury. A hand surgeon should be well informed about the anatomic variations of the hand to be comfortable during surgical practice.
Technical Tip: New Tools for Protection from Sharps Injuries
Authors: Tate David E.
Published: April 2007

Sharps injuries are an area of concern for healthcare workers. This article discusses clinical use of a blunt suture needle and an absorbable skin staple in upper limb operations. These devices may reduce the need for sharp needles in the surgical field during selected procedures on the upper limb.
Epidermal Lipoxygenase Products of the Hepoxilin Pathway Selectively Activate the Nuclear Receptor PPARα
Authors: Yu Zheyong , Schneider Claus , Boeglin William E. , Brash Alan R.
Published: April 2007

Arachidonic acid can be transformed into a specific epoxyalcohol product via the sequential action of two epidermal lipoxygenases, 12R‐LOX and eLOX3. Functional impairment of either lipoxygenase gene (ALOX12B or ALOXE3) results in ichthyosis, suggesting a role for the common epoxyalcohol product or its metabolites in the differentiation of normal human skin. Here we tested the ability of products derived from the epidermal LOX pathway to activate the peroxisome proliferator‐activated receptors PPARα, γ, and δ, which have been implicated in epidermal differentiation. Using a dual luciferase reporter assay in PC3 cells, the 12R‐LOX/eLOX3‐derived epoxyalcohol, 8R‐hydroxy‐11R,12R‐epoxyeicosa‐5Z,9E,14Z‐trienoic acid, activated PPARα with similar in potency to the known natural ligand, 8S‐hydroxyeicosatetraenoic acid (8S‐HETE) (both at 10 μM concentration). In contrast, the PPARγ and PPARδ receptor isoforms were not activated by the epoxyalcohol. Activation of PPARα was also observed using the trihydroxy hydrolysis products (trioxilins) of the unstable epoxyalcohol. Of the four trioxilins isolated and characterized, the highest activation was observed with the isomer that is also formed by enzymatic hydrolysis of the epoxyalcohol. Formation of a ligand for the nuclear receptor PPARα may be one possibility by which 12R‐LOX and eLOX3 contribute to epidermal differentiation.
Chemiluminescent Methods in Olive Oil Analysis
Authors: Navas M. J. , Jiménez A. M.
Published: April 2007

The present review describes chemiluminescence applications to olive oil analysis and olive mill wastewater and covers the literature published in recent years. The article has been divided into several sections that discuss specific applications for determining phenolic compounds, antioxidant activity, radical scavenging, oxidative stability and the detection of possible adulteration by seed oils. The advantages and disadvantages of the chemiluminescence detection systems for these purposes are evaluated.
Crosstalk between xenobiotics metabolism and circadian clock
Authors: Claudel Thierry , Cretenet Gaspard , Saumet Anne , Gachon Frédéric
Published: April 2007

Many aspects of physiology and behavior in organisms from bacteria to man are subjected to circadian regulation. Indeed, the major function of the circadian clock consists in the adaptation of physiology to daily environmental change and the accompanying stresses such as exposition to UV‐light and food‐contained toxic compounds. In this way, most aspects of xenobiotic detoxification are subjected to circadian regulation. These phenomena are now considered as the molecular basis for the time‐dependence of drug toxicities and efficacy. However, there is now evidences that these toxic compounds can, in turn, regulate circadian gene expression and thus influence circadian rhythms. As food seems to be the major regulator of peripheral clock, the possibility that food‐contained toxic compounds participate in the entrainment of the clock will be discussed.
Long memory in energy futures prices
Authors: Elder John , Serletis Apostolos
Published: April 2007

This paper extends the work in Serletis [Serletis, A. (1992). Unit root behavior in energy futures prices. The Energy Journal 13, 119–128] by re‐examining the empirical evidence for random walk type behavior in energy futures prices. It tests for fractional integrating dynamics in energy futures markets utilizing more recent data (from January 3, 1994 to June 30, 2005) and a new semi‐parametric wavelet‐based estimator, which is superior to the more prevalent GPH estimator (on the basis of Monte‐Carlo evidence). We find new evidence that energy prices display long memory and that the particular form of long memory is anti‐persistence, characterized by the variance of each series being dominated by high frequency (low wavelet scale) components.
Isotope-geochemical systematics of kimberlites and related rocks from the Siberian Platform
Authors: Kostrovitsky S.I. , Morikiyo T. , Serov I.V. , Yakovlev D.A. , Amirzhanov A.A.
Published: April 2007

Using the ICP-MS method we have studied the isotope systematics of Sr and Nd as well as trace element composition of a representative collection of kimberlites and related rocks from the Siberian Platform. The summarized literature and our own data suggest that the kimberlites developed within the platform can be divided into several petrochemical and geochemical types, whose origin is related to different mantle sources. The petrochemical classification of kimberlites is based on persistent differences of their composition in mg# and in contents of indicator oxides such as FeOtot, TiO2, and K2O. The recognized geochemical types of kimberlites differ from one another in the level of concentration of incompatible elements as well as in their ratios.

Most of isotope characteristics of kimberlites and related rocks of the Siberian Platform correspond to the earlier studied Type 1 basaltoid kimberlites from different provinces of the world: Points of isotopic compositions are in the field of primitive and weakly depleted mantle. An exception is one sample of the rocks from veins of the Ingashi field (Sayan area), which is characterized by the Sr and Nd isotopic composition corresponding to Type 2 micaceous kimberlites (orangeites).

The most important feature of distribution of isotopic and trace-element compositions (incompatible elements) is their independence of the chemical rock composition. It is shown that the kimberlite formation is connected with, at least, two independent sources, fluid and melt, responsible for the trace-element and chemical compositions of the rock. It is supposed that, when rising through the heterogeneous lithosphere of the mantle, a powerful flow of an asthenosphere-derived fluid provoked the formation of local kimberlite chambers there. Thus, the partial melting of the lithosphere mantle led to the formation of contrasting petrochemical types of kimberlites, while the geochemical specialization of kimberlites is due to the mantle fluid of asthenosphere origin, which drastically dominated in the rare-metal balance of a hybrid magma of the chamber.
Implications of changes in the atmospheric circulation on the detection of regional surface air temperature trends
Authors: Wu Qigang , Karoly David J.
Published: April 2007

Previous studies have shown that observed significant warming trends in surface air temperature (SAT) consistent with the response to anthropogenic forcing are detected at scales on the order of 500 km in many regions of the globe. However, regional SAT trends project strongly on the dominant natural atmospheric circulation modes, such as the Arctic Oscillation (AO) and the hemispheric Pacific‐North America (PNA)‐like patterns. The warming associated with the changes of atmospheric circulation is not well simulated in current coupled climate models. In this study, we explore the influence of the exclusion of warming related to changes of the atmospheric circulation on the detection of a regional response to combined anthropogenic and natural forcings. We compare observed SAT trends over the second half of the 20th century with those simulated in response to natural and anthropogenic climate forcings in a suite of six current coupled general circulation models. Control runs from these models are used to provide estimates of the internal variability of trends. We find that the detection of the regional response to combined anthropogenic and natural forcing is robust to the exclusion of warming related to changes of the atmospheric circulation considered here.
Ocean circulation at the Last Glacial Maximum: A combined modeling and magnetic proxy‐based study
Authors: Watkins S. J. , Maher B. A. , Bigg G. R.
Published: April 2007

Formation of North Atlantic Deep Water (NADW) is an important component of the ocean thermohaline circulation, but debate exists over the ocean circulation state during glacial stages. Some geological and modeling studies suggest decreased NADW and increased formation of Southern Ocean deep water during the Last Glacial Maximum (LGM); others indicate similar, or higher, rates of NADW advection. Here we test three different potential LGM ocean states by comparing the modeled iceberg trajectories each produces with magnetically mapped patterns and sources of LGM ice‐rafted debris (IRD). The three LGM states are characterized by vigorous NADW formation; deepwater production in the Southern Ocean; and a third, “intermediate” state, with Southern Ocean deepwater formation but also some North Atlantic intermediate water formation. Cluster analysis of sediment magnetic properties was used to characterize North Atlantic IRD patterns and sources, which match most closely iceberg trajectories arising from some combination of the “southern sinking” and “intermediate” ocean circulation states. The magnetic data indicate two major IRD sources, Fennoscandia and Greenland/Iceland, and one minor source, the St. Lawrence region. The model and magnetic data suggest that the LGM North Atlantic circulation was dominated by a cyclonic central North Atlantic gyre, separated from the North Atlantic Current, which was displaced south of ∼42°N.
Soluble Epoxide Hydrolase: A Novel Therapeutic Target in Stroke
Authors: Zhang Wenri , Koerner Ines P , Noppens Ruediger , Grafe Marjorie , Tsai Hsing-Ju , Morisseau Christophe , Luria Ayala , Hammock Bruce D , Falck John R , Alkayed Nabil J
Published: April 2007

The P450 eicosanoids epoxyeicosatrienoic acids (EETs) are produced in brain and perform important biological functions, including protection from ischemic injury. The beneficial effect of EETs, however, is limited by their metabolism via soluble epoxide hydrolase (sEH). We tested the hypothesis that sEH inhibition is protective against ischemic brain damage in vivo by a mechanism linked to enhanced cerebral blood flow (CBF). We determined expression and distribution of sEH immunoreactivity (IR) in brain, and examined the effect of sEH inhibitor 12-(3-adamantan-1-yl-ureido)-dodecanoic acid butyl ester (AUDA-BE) on CBF and infarct size after experimental stroke in mice. Mice were administered a single intraperitoneal injection of AUDA-BE (10 mg/kg) or vehicle at 30 mins before 2-h middle cerebral artery occlusion (MCAO) or at reperfusion, in the presence and absence of P450 epoxygenase inhibitor N-methylsulfonyl-6-(2-propargyloxyphenyl) hexanamide (MS-PPOH). Immunoreactivity for sEH was detected in vascular and non-vascular brain compartments, with predominant expression in neuronal cell bodies and processes. 12-(3-Adamantan-1-yl-ureido)-dodecanoic acid butyl ester was detected in plasma and brain for up to 24 h after intraperitoneal injection, which was associated with inhibition of sEH activity in brain tissue. Finally, AUDA-BE significantly reduced infarct size at 24 h after MCAO, which was prevented by MS-PPOH. However, regional CBF rates measured by iodoantipyrine (IAP) autoradiography at end ischemia revealed no differences between AUDA-BE- and vehicle-treated mice. The findings suggest that sEH inhibition is protective against ischemic injury by non-vascular mechanisms, and that sEH may serve as a therapeutic target in stroke.
Multiple magnetic transitions and magnon gaplike characteristics in the high purity TbB4 single crystal
Authors: Rhyee Jong-Soo , Kim J. Y. , Cho B. K.
Published: April 2007

We synthesized the high purity TbB4 single crystal, which shows quite low resistivity at T=2K, ρ(T=2K)=0.0397μΩcm, resulting in a high residual resistivity ratio RRR≡ρ(300K)∕ρ(2K)=361.9. Because of the geometry of the grown single crystals, temperature-dependent magnetization M(T) was measured with applied magnetic field parallel to (010) and (111) planes. M(T) was found to be anisotropic at high temperature and revealed two magnetic transitions: one is antiferromagnetic transition at TN=44K and the other one at Tm≈23K for both field orientations. These transitions were also manifested by the slope change of temperature-dependent resistivity, i.e., dρ(T)∕dT. The second transition temperature Tm was found to decrease and the transition width broadened with increasing applied magnetic field, indicating that the transition at Tm is suppressed by applied magnetic field. The Fermi liquid and antiferromagnetic (AF) magnon gaplike increase of ρ(T) was found at low temperatures of T⩽20K. The AF magnon gap Δ=15.6K at H=0T was also found to decrease with applying magnetic fields. We will discuss the origin of the second transition Tm in terms of the interaction between magnetic and quadrupolar orbital fluctuations.
Comparison of microstructure and magnetic properties of gas-atomized and melt-spun MRE–Fe–Co–M–B (MRE=Y+Dy+Nd,M=Zr+TiC)
Authors: Tang W. , Wu Y. Q. , Dennis K. W. , Kramer M. J. , Anderson I. E. , McCallum R. W.
Published: April 2007

An MRE2(Fe,Co)14B alloy with Zr substitution and TiC addition was systematically studied. It was found by means of X-ray diffraction, transmission electron microscopy (TEM) and magnetic measurements that the combination of Zr substitution and TiC addition yields adequate microstructural control in both gas atomization (GA) and melt spinning (MS) techniques. For MS ribbons, an Hcj of 11.7kOe and (BH)max of 11.9MGOe at 27°C were obtained in the ribbons spun at 16m∕s and annealed at 700°C for 15min. For GA powders, an Hcj of 9.1kOe and (BH)max of 9.2MGOe at 27°C were obtained in 20–25μm GA powder annealed at 700°C for 15min. The temperature coefficients of Br and Hcj are 0.06 and 0.36%∕°C for the MS ribbon and 0.09 and 0.4%∕°C for the GA powder in the temperature range of 27–100°C, respectively. TEM images revealed that the MS ribbon consists of a fine and uniform microstructure with an average size of 30nm, while the GA spherical powder consists of an interior coarsened microstructure with a grain size of 80nm and a rim area with a grain size of 10nm.
Role of hydrodynamics simulations in laser-plasma interaction predictive capability
Authors: Meezan N. B. , Berger R. L. , Divol L. , Froula D. H. , Hinkel D. E. , Jones O. S. , London R. A. , Moody J. D. , Marinak M. M. , Niemann C. , Neumayer P. B. , Prisbrey S. T. , Ross J. S. , Williams E. A. , Glenzer S. H. , Suter L. J.
Published: April 2007

Efforts to predict and control laser-plasma interactions (LPI) in ignition hohlraum targets for the National Ignition Facility [G. H. Miller et al., Opt. Eng. 43, 2841 (2004)] are based on plasma conditions provided by radiation hydrodynamic simulations. Recent experiments provide compelling evidence that codes such as HYDRA [M. M. Marinak et al., Phys. Plasmas 8, 2275 (2001)] can accurately predict the plasma conditions in laser-heated targets such as gas-filled balloon (gasbag) and hohlraum platforms for studying LPI. Initially puzzling experimental observations are found to be caused by bulk hydrodynamic phenomena. Features in backscatter spectra and transmitted light spectra are reproduced from the simulated plasma conditions. Simulations also agree well with Thomson scattering measurements of the electron temperature. The calculated plasma conditions are used to explore a linear-gain based phenomenological model of backscatter. For long plasmas at ignition-relevant electron temperatures, the measured backscatter increases monotonically with gain and is consistent with linear growth for low reflectivities. These results suggest a role for linear gain postprocessing as a metric for assessing LPI risk.
A temperature modulation photonic crystal Mach-Zehnder interferometer composed of copper oxide high-temperature superconductor
Authors: Pei Ting-Hang , Huang Yang-Tung
Published: April 2007

A tunable Mach-Zehnder interferometer with a two-dimensional photonic crystal structure using copper oxide high-temperature superconductor is proposed. This photonic crystal is composed of rods of which axes are perpendicular to the two-dimensional anisotropic copper oxide plane. By tuning the temperature of the superconductor, the refractive index of the superconductor as well as the photonic band gap can be changed. The photonic band structures of two-dimensional photonic crystals composed of the superconductor are calculated by using the plane-wave expansion method, and interference properties are investigated by using the finite-difference time-domain method. For our designed photonic crystal Mach-Zehnder interferometer, the simulation results show that the light transmission can be modulated from 92.7% to 1.4% with different temperature distributions.
Excitation of macromagnetohydrodynamic mode due to multiscale interaction in a quasi-steady equilibrium formed by a balance between microturbulence and zonal flow
Authors: Ishizawa A. , Nakajima N.
Published: April 2007

This is the first numerical simulation demonstrating that a macromagnetohydrodynamic (macro-MHD) mode is excited as a result of multi-scale interaction in a quasi-steady equilibrium formed by a balance between microturbulence and zonal flow based on a reduced two-fluid model. This simulation of a macro-MHD mode, a double tearing mode, is accomplished in a reversed shear equilibrium that includes zonal flow and turbulence due to kinetic ballooning modes. In the quasi-steady equilibrium, a macroscale fluctuation that has the same helicity as the double tearing mode is a part of the turbulence. After a certain period of time, the macro-MHD mode begins to grow. It effectively utilizes free energy of the equilibrium current density gradient and is destabilized by a positive feedback loop between zonal flow suppression and magnetic island growth. Thus, once the macro-MHD appears from the quasi-equilibrium, it continues to grow steadily. This simulation is more comparable with experimental observations of growing macro-MHD activity than earlier MHD simulations starting from linear macroinstabilities in a static equilibrium.
Electron field emission in air at an atmospheric pressure from sp3-bonded 5H-BN microcones
Authors: Komatsu Shojiro , Ohta Eiichi , Tanaka Hironori , Moriyoshi Yusuke , Nakajima Kiyomi , Chikyo Toyohiro , Shiratani Masaharu
Published: April 2007

Electron field emission (eFE) from sp3-bonded 5H-BN films proved to take place in air at an atmospheric pressure. The eFE started at relatively low electric field (E) of 7.5V∕μm and was reproducible. The eFE in air obeyed the Fowler-Nordheim equation for quantum mechanical tunneling. The BN films with self-organized microcone emitters were prepared by chemical vapor deposition from B2H6+NH3+Ar plasma where 193nm excimer laser irradiated the growing film surface. The laser activates the growth reactions photochemically and induces the cone-shape formation. The eFE from the same sample observed in vacuum showed the threshold E below 1V∕μm. These excellent eFE properties are considered to originate from geometrical field enhancement by the microcone shape and the decrease of work function due to the surface electric dipole moment layer (4.3eV, estimated by molecular orbital method). This atmospheric eFE combined with the robustness of BN may open a wide range of applications.
On the accuracy of the two-fluid formulation in direct numerical simulation of bubble-laden turbulent boundary layers
Authors: Ferrante Antonino , Elghobashi Said
Published: April 2007

The objective of the present paper is to examine the accuracy of the two-fluid (TF) formulation in direct numerical simulation (DNS) of a microbubble-laden spatially developing turbulent boundary layer over a flat plate by comparing the results with those of the Eulerian-Lagrangian (EL) formulation [A. Ferrante and S. Elghobashi, J. Fluid Mech. 543, 93 (2005); A. Ferrante and S. Elghobashi, J. Fluid Mech. 503, 345 (2004)]. Our results show that DNS with TF (TFDNS) does not reproduce the physical mechanisms responsible for drag reduction observed in the EL results. The reason is that TFDNS does not produce accurate instantaneous local bubble concentration C(x,t) gradients which are responsible for the generation of a positive ⟨∇∙U⟩ that is essential for the drag reduction mechanism. The inaccuracy of the TFDNS in computing C(x,t) is due to the invalidity of the bubble-phase continuity equation in regions where the continuum assumption for the bubble-phase breaks down. It is recommended that if the real (experimental or DNS) instantaneous spatial distribution of bubble (or particle) concentration is discontinuous, and if this concentration discontinuity is crucial for the realization of the physical phenomenon of interest, then DNS should use the EL formulation. We propose a Knudsen number criterion for the validity of the two-fluid formulation in DNS of dispersed two-phase flows with strong unsteady preferential concentration.
Frequency domain photothermal radiometry with spherical solids
Authors: Wang Chinhua , Liu Yue , Mandelis Andreas , Shen Jun
Published: April 2007

Motivated by increasing practical and industrial applications of photothermal techniques in the measurement of materials of various shapes with curvature, we extend the applications of photothermal diagnostics to solid spheres, in which both theoretical and experimental photothermal radiometry studies on spherical geometries and thermal diffusivity of the sample are discussed. Based on the Green function method, a full thermal-wave field distribution of a spherical solid is obtained. The characteristics of the thermal-wave field with respect to thermophysical properties of the material, the diameter of the solid, the size of the incident laser beam, and the measurement angle are discussed. Experimental results with steel spheres of different diameters exhibit good agreement between the theory and the experiments.
Ab initio investigation of the NH(X)–N2 van der Waals complex
Authors: Fawzy Wafaa M. , Heaven Michael C.
Published: April 2007

The NH–N2 van der Waals complex has been examined at the CCSD(T) level of theory using aug-cc-pVDZ and aug-cc-pVTZ basis sets. The full basis set superposition error correction was applied. Two minimum energy structures were located for the electronic ground state. The global minimum corresponds to a linear geometry of the complex (NH–N–N), with De=236cm−1 and Rc.m.=4.22Å. The secondary minimum corresponds to a T-shaped geometry of C2v symmetry, where the nitrogen atom of the H–N moiety points toward the center of mass of the N2 unit, aligned with the a-inertial axis of the complex. The binding energy and Rc.m. value for the secondary minimum were 144cm−1 and 3.63Å, respectively. This potential energy surface is consistent with the properties of matrix-isolated NH–N2, and it is predicted that linear NH–N2 will be a stable complex in the gas phase at low temperatures.
Dichromatic InGaN-based white light emitting diodes by using laser lift-off and wafer-bonding schemes
Authors: Lee Y. J. , Lin P. C. , Lu T. C. , Kuo H. C. , Wang S. C.
Published: April 2007

An InGaN-based dual-wavelength blue/green (470nm∕550nm) light emitting diode (LED) with three terminal operations has been designed and fabricated by using sapphire laser lift-off and wafer-bonding schemes. The device is equivalent to a parallel connection of blue and green LEDs; thus the effective electrical resistance of the device could be reduced. The luminous efficiency is 40lm∕W at 20mA, accompanied by a broad electroluminescence emission with a combination of blue and green colors. This monolithically integrated dichromatic lighting structure has great potential in the application of the solid-state lighting.
Thickness dependent critical strain in submicron Cu films adherent to polymer substrate
Authors: Niu R. M. , Liu G. , Wang C. , Zhang G. , Ding X. D. , Sun J.
Published: April 2007

For the polymer-supported metal thin films that are finding increasing applications, the critical strain to nucleate microcracks (εC) should be more meaningful than generally measured rupture strain. In this letter, the εC values of polymer-supported Cu films are simply but precisely determined by measurements of both electrical resistance and statistical microcrack density changes on the film surface. Significant thickness dependence of εC, i.e., the thinner the film the lower the εC, has been revealed for the Cu films with a thickness range from 700 down to 60nm, which is suggested to result from the constraint effect of refining grain size on the dislocation movability.
Water as a molecular hinge in amidelike structures
Authors: Timmer R. L. A. , Bakker H. J.
Published: April 2007

The authors have studied the reorientational dynamics of isolated water molecules in a solution of N,N-dimethylacetamide (DMA). From linear spectra, the authors find that the water in this solution forms double hydrogen bond connections to the DMA molecules, resulting in the formation of DMA-water-DMA complexes. The authors use polarization-resolved mid-infrared pump-probe spectroscopy on the water in these complexes to measure the depolarization of three distinct transition dipole moments, each with a different directionality relative to the molecular frame (OH stretch in HDO, symmetric and asymmetric stretch normal modes in H2O). By combining these measurements, the authors find that the system exhibits bimodal rotational dynamics with two distinct time scales: a slow (7±1ps) reorientation of the entire DMA-water complex and a fast (0.5±0.2ps) “hinging” motion of the water molecule around the axis parallel to the connecting hydrogen bonds. Additionally, the authors observe an exchange of energy between the two normal modes of H2O at a time scale of 0.8±0.1ps and find that the vibrational excitation decays through the symmetric stretch normal mode with a time constant of 0.8±0.2ps.
Energy analysis of field emitted electrons from a ZnO tetrapod
Authors: Al-Tabbakh Ahmed A. , More Mahendra A. , Joag Dilip S. , Ramgir Niranjan S. , Mulla Imtiaz S. , Pillai Vijayamohanan K.
Published: April 2007

The experimental total energy distribution (TED) of the field emitted electrons from a single pod of a ZnO tetrapod has been obtained, exhibiting a two-peak feature. The energy difference between the two peaks in the TED is found to be nearly equal to the band gap of the bulk ZnO. The results show that field emitted electrons originate from both the conduction and valence bands. The peak position dependence on the applied voltage has also been observed. In the present case, the size of the ZnO tetrapod is not small enough to reflect the quantum confinement effects.
Room temperature ferromagnetism in Co-doped La0.5Sr0.5TiO3−δ nanoparticles
Authors: Wongsaprom Kwanruthai , Swatsitang Ekaphan , Maensiri Santi , Srijaranai Somkait , Seraphin Supapan
Published: April 2007

The authors report room temperature ferromagnetism in La0.5Sr0.5Ti0.985Co0.015O3−δ nanoparticles with particle sizes of ∼12–14nm. Nanoparticles of undoped and Co-doped samples were synthesized by a polymerized complex method and were characterized using x-ray diffraction and transmission electron microscopy. The magnetic properties of the nanoparticles were determined using vibrating sample magnetometry. The undoped samples exhibit a diamagnetic behavior, whereas all the Co-doped samples are ferromagnetic having the specific magnetizations of ∼0.011–0.038emu∕g at 10kOe. The finding of room temperature ferromagnetism in the Co-doped samples would allow an enhanced flexibility for applications.