bluuebunny/crossref_metadata_2025 huggingface dataset:
Costimulation blockade inhibits the indirect pathway of allorecognition in nerve allograft rejection
Authors: Ray Wilson Z. , Kasukurthi Rahul , Kale Santosh S. , Santosa Katherine B. , Hunter Daniel A. , Johnson Philip , Yan Ying , Mohanakumar Thalachallour , Mackinnon Susan E. , Tung Thomas H.
Published: December 2010

Nerve allografts provide a temporary scaffold for host nerve regeneration. The need for systemic immunosuppression limits clinical application. Characterization of the immunological mechanisms that induce immune hyporesponsiveness may provide a basis for optimizing immunomodulating regimens. We utilized wild‐type and MHC class II–deficient mice, as both recipients and donors. Host treatment consisted of triple costimulatory blockade. Quantitative assessment was made at 3 weeks using nerve histomorphometry, and muscle testing was performed on a subset of animals at 7 weeks. Nerve allograft rejection occurred as long as either the direct or indirect pathways were functional. Indirect antigen presentation appeared to be more important. Nerve allograft rejection occurs in the absence of a normal direct or indirect immune response but may be more dependent on indirect allorecognition. The indirect pathway is required to induce costimulatory blockade immune hyporesponsiveness. Muscle Nerve, 2011
Doxorubicin causes diaphragm weakness in murine models of cancer chemotherapy
Authors: Gilliam Laura A.A. , Moylan Jennifer S. , Ann Callahan Leigh , Sumandea Marius P. , Reid Michael B.
Published: December 2010

Doxorubicin is a chemotherapeutic agent prescribed for a variety of tumors. While undergoing treatment, patients exhibit frequent symptoms that suggest respiratory muscle weakness. Cancer patients can receive doxorubicin chemotherapy through either intravenous (IV) or intraperitoneal (IP) injections. We hypothesized that respiratory muscle function would be depressed in a murine model of chemotherapy. We tested this hypothesis by treating C57BL/6 mice with a clinical dose of doxorubicin (20 mg/kg) via IV or IP injection. Three days later we measured contractile properties of muscle fiber bundles isolated from the diaphragm. Doxorubicin consistently depressed diaphragm force with both methods of administration (P< 0.01). Doxorubicin IP exaggerated the depression in diaphragm force and stimulated tissue inflammation and muscle fiber injury. These results suggest that clinically relevant doses of doxorubicin cause respiratory muscle weakness and that the loss of function depends, in part, on the route of administration. Muscle Nerve, 2011
Altered mRNA expression after long‐term soleus electrical stimulation training in humans with paralysis
Authors: Adams Christopher M. , Suneja Manish , Dudley‐Javoroski Shauna , Shields Richard K.
Published: December 2010

In humans, spinal cord injury (SCI) induces deleterious changes in skeletal muscle that may be prevented or reversed by electrical stimulation muscle training. The molecular mechanisms underlying muscle stimulation training remain unknown. We studied two unique SCI subjects whose right soleus received >6 years of training (30 minutes/day, 5 days/week). Training preserved torque, fatigue index, contractile speed, and cross‐sectional area in the trained leg, but not the untrained leg. Training decreased 10 mRNAs required for fast‐twitch contractions and mRNA that encodes for myostatin, an autocrine/paracrine hormone that inhibits muscle growth. Conversely, training increased 69 mRNAs that mediate the slow‐twitch, oxidative phenotype, including PGC‐1α, a transcriptional coactivator that inhibits muscle atrophy. When we discontinued right soleus training, training‐induced effects diminished slowly, with some persisting for >6 months. Training of paralyzed muscle induces localized and long‐lasting changes in skeletal muscle mRNA expression that improve muscle mass and function. Muscle Nerve, 2011
Insights into genotype–phenotype correlations in spinal muscular atrophy: A retrospective study of 103 patients
Authors: Petit Florence , Cuisset Jean‐Marie , Rouaix‐Emery Nathalie , Cancés Claude , Sablonnière Bernard , Bieth Eric , Moerman Alexandre , Sukno Sylvie , Hardy Noah , Holder‐Espinasse Muriel , Manouvrier‐Hanu Sylvie , Vallée Louis
Published: December 2010

Spinal muscular atrophy (SMA) is an autosomal recessive disorder associated with homozygous deletion of the survival motor neuron 1 gene (SMN1). Its centromeric copy gene, SMN2, is the major modifying factor. However, the genotype–phenotype correlation is incomplete and is therefore not useful in clinical practice. We studied a cohort of 103 patients in order to refine this correlation. In addition to standard disease severity data, we collected three additional criteria: age at death; brainstem involvement; and loss of ambulation. Gene dosage analysis was conducted by multiplex ligation‐dependent probe amplification (MLPA). SMN2 copynumber was highly correlated with survival duration in SMA type I and ambulation conservation or loss in type III. Among SMA severity groups, it was not significantly different in cases with brainstem involvement. Although the SMN2 copynumber could provide prognostic indications, clinical discrepancies still exist among patients, suggesting the existence of unidentified modifying factors. Muscle Nerve, 2011
Activity‐dependent conduction block in multifocal motor neuropathy
Authors: Straver Dirk C.G. , van den Berg Leonard H. , van den Berg‐Vos Renske M. , Franssen Hessel
Published: December 2010

Previous studies suggested that activity‐dependent conduction block (CB) contributes to weakness in multifocal motor neuropathy (MMN). Obtaining more robust evidence for activity‐dependent CB is important because it may be a novel target for treatment strategies. We performed nerve conduction studies in 22 nerve segments of 19 MMN patients, before and immediately after 60 seconds of maximal voluntary contraction (MVC) of the relevant muscle. We employed supramaximal electrical stimulation, excluded nerves with marked axonal loss, and adopted criteria for activity‐dependent CB. Per segment, the segmental area ratio [area proximal compound muscle action potential (CMAP)/area distal CMAP] was calculated and, per nerve, total area ratio (area CMAP at Erb's point/area distal CMAP) was obtained. MVC induced no changes in mean area ratios and induced no activity‐dependent CB. In segments with CB before MVC, the MVC induced increased duration prolongation. In MMN, MVC induced temporal dispersion but no activity‐dependent CB. Muscle Nerve, 2011
Evaluation of skeletal muscle during calf exercise by 31‐phosphorus magnetic resonance spectroscopy in patients on statin medications
Authors: Wu Jim S. , Buettner Catherine , Smithline Howard , Ngo Long H. , Greenman Robert L.
Published: December 2010

Muscle pain is a common side effect of statin medications, but the cause is poorly understood. We characterized phosphocreatine (PCr) exercise recovery kinetics in 10 patients with hypercholesterolemia before and after a 4‐week regimen of statin therapy using 31‐phosphorus magnetic resonance spectroscopy (31P‐MRS). 31P spectra were obtained before, during, and after exercise on a calf flexion pedal ergometer. Creatine kinase (CK) serum levels were drawn before and after statin therapy. The mean metabolic recovery time constant in subjects increased from 28.1 s (SE = 6.5 s) to 55.4 s (SE = 7.4 s) after statin therapy. The unweighted mean of the pre/post‐recovery time difference was −27.3 s (SE = 12.4 s; P = 0.02). Pre‐ and post‐therapy CK levels were not significantly different (P = 0.50). Metabolic recovery time in the calf is prolonged in patients after statin use. This suggests that statins impair mitochondrial oxidative function, and 31P MRS is a potential study model for statin‐associated myopathy. Muscle Nerve, 2011
Hochpolymeren‐Forschung in der UDSSR
Authors: Mark H.
Published: December 2010

Professor Dr. H. Mark, Brooklyn, hatte kürzlich Gelegenheit, einige sowjetische Institute zu besuchen, die sich mit Arbeiten auf dem Gebiet der Hochpolymeren befassen. Wir bringen hier einige Auszüge aus seinem Reisebericht.
Coaxial electrospinning and emulsion electrospinning of core–shell fibers
Authors: Yarin A.L.
Published: December 2010

The mini‐review is devoted to coaxial electrospinning (co‐electrospinning, emulsion electrospinning), a group of novel methods for making core–shell nanofibers and hollow nanotubes. The physical aspects of the process are described in brief, in particular, its modeling and possible drawbacks of the process resulting in formation of fibers without a long intact core. After that the main applications of co‐electrospinning are considered. They include drug release, encapsulation of different biologically active compounds, cell scaffolds, formation of nanotubes, and nanofluidics. Copyright © 2010 John Wiley & Sons, Ltd.
Applications of controlled electrospinning systems
Authors: Bellan Leon M. , Craighead Harold G.
Published: December 2010

Electrospinning is a powerful technique that uses an electrically forced fluid jet to form nanofibers from a material dissolved in a solvent. While the complex whipping motion of a typical electrospinning jet results in a nonwoven mat of fibers, there have been many developments aimed at controlling the deposition of an electrospinning jet to form more ordered patterns of nanofibers. Such controlled deposition is desirable as it would provide a low‐cost fabrication technique for nanoscale devices such as nanomechanical devices, electronic devices, and light‐emitting systems. Nanofibers may also be used as masks or templates to create nanoscale structures in other materials. Other modifications to a standard electrospinning system allow for atypical nanofiber morphologies such as hollow or coaxial nanofibers, side‐by‐side nanofiber deposition, etc. This review will highlight electrospinning systems modified for controlled or atypical deposition, and will discuss applications of the fibers resulting from such systems. Copyright © 2010 John Wiley & Sons, Ltd.
Direct visualization of Smad1/5/8‐mediated transcriptional activity identifies podocytes and collecting ducts as major targets of BMP signalling in healthy and diseased kidneys
Authors: Leeuwis Jan Willem , Nguyen Tri Q , Chuva de Sousa Lopes Susana M , van der Giezen Dionne M , van der Ven Kevin , Rouw Peter JH , Offerhaus G Johan A , Mummery Christine L , Goldschmeding Roel
Published: December 2010

Bone morphogenetic protein 7 (BMP7) is a key determinant of renal response to injury, exhibiting strong protective as well as regenerative potential in a variety of experimental models. In vitro, beneficial effects of stimulation with BMP7 and other BMPs have been observed in many renal cell types. Still, it remains poorly understood which cells in the native kidney actually respond to BMPs in health and disease. Here, we report the use of BRE:gfp mice expressing green fluorescent protein (GFP) under the control of a pSmad1/5/8‐specific BMP‐responsive element (BRE) to directly visualize the spatiotemporal distribution of transcriptional activity downstream of canonical BMP signalling in healthy kidneys and in two distinct models of kidney disease. BRE–GFP signal coincided with expression of endogenous BMP target genes but, surprisingly, it was much more restricted than expected from the widespread distribution of pSmad1/5/8, a classical component of canonical BMP signal tranduction. BRE–GFP was mainly present in podocytes and collecting duct cells, and both glomerular and medullary BRE–GFP decreased following ischaemia–reperfusion injury as well as following unilateral ureteric obstruction, together with decreased BMP7, pSmad1/5/8 and BMP target gene expression. Remarkably, however, BRE–GFP was increased in injured proximal tubules in association with up‐regulation of BMP receptors ALK2 and ALK3. Thus, native BMP transcriptional activity is much more restricted than previously suggested based on pSmad1/5/8 detection alone, and its response to injury varies according to cell type and nephron segment. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Why Mate Choices are not as Reciprocal as we Assume: The Role of Personality, Flirting and Physical Attractiveness
Authors: Back Mitja D. , Penke Lars , Schmukle Stefan C. , Sachse Karoline , Borkenau Peter , Asendorpf Jens B.
Published: December 2010

Based on a social relations perspective on mating, the actual and assumed reciprocity of mate choices was studied in a real–life speed–dating context. A community sample involving 382 singles aged 18–54 years filled out a questionnaire for the measurement of self–perceived mate value, sociosexuality, extraversion, and shyness and participated in free speed–dating sessions. Immediately after each date, choices and assumed choices were recorded. Measures of physical attractiveness and flirting behaviour were obtained by independent observers. Results show that actual mate choices are not reciprocal although people strongly expect their choices to be reciprocated and flirting behaviour is indeed strongly reciprocal. This interesting pattern of results was explained by investigating individual and dyadic effects of flirting, self–perceived mate value and physical attractiveness on mate choices. Results have important implications for understanding mating behaviour, sex differences and the (in)accuracies of mating decisions. Copyright © 2010 John Wiley & Sons, Ltd.
The mediating effects of social support and self‐efficacy on the relationship between social distress and emotional distress in head and neck cancer outpatients with facial disfigurement
Authors: Deno Minako , Tashiro Mie , Miyashita Mitsunori , Asakage Takahiro , Takahashi Koji , Saito Kenich , Busujima Yasunobu , Mori Yoshiyuki , Saito Hiroto , Ichikawa Yuji
Published: December 2010

Objective: Although social support has been recognized as an important factor in the quality of life of head and neck cancer patients, there has been little investigation of the buffering effect of social support on these patients' social distress or of the coping skill of self‐efficacy. The aim of this study was to examine how social support and self‐efficacy mediate the relationship between social distress and emotional distress in head and neck cancer patients.

Methods: Two hundred twenty‐five head and neck cancer patients completed our questionnaire (effective response rate, 92.2%). Of these, 129 (57.3%) had facial disfigurement. These participants responded to questions about perception of social distress, social support, self‐efficacy, and emotional distress (depression and anxiety). We used structural equation modeling for statistical analysis.

Results: The fit indices of this model were excellent (χ2(7) = 9.147,p= 0.242, goodness of fit index (GFI) = 0.981, adjusted goodness of fit index (AGFI) = 0.922, comparative fit index (CFI) = 0.993, root mean square error of approximation (RMSEA) = 0.049). Self‐efficacy strongly buffered the negative influence of social distress on emotional distress. Social support from family members did not have a direct or indirect influence on emotional distress. Social support from friends was related to lower social distress and higher emotional distress.

Conclusions: Our findings suggest that self‐efficacy might confound the relationship between social support and emotional distress, and that different sources of social support might play different roles in the mediation of social distress on emotional distress. Copyright © 2010 John Wiley & Sons, Ltd.
Relationship of threat appraisal with coping appraisal to fear of cancer recurrence in breast cancer survivors
Authors: McGinty Heather L. , Goldenberg Jamie L. , Jacobsen Paul B.
Published: December 2010

Objectives: Prior research suggests that fear of cancer recurrence (FOR) is very common among cancer survivors. This study examined the extent to which the interaction of threat appraisal and coping appraisal accounted for differences in FOR in cancer patients who recently completed treatment. It was hypothesized that greater FOR would be related to a combination of high threat appraisal and low coping appraisal.

Methods: A sample of 155 early stage breast cancer patients (mean age = 59 years) who completed surgery, chemotherapy, and/or radiotherapy between 6 and 24 months previously (mean = 12 months) completed measures of FOR, threat appraisal (perceived risk and severity of a potential cancer recurrence), and coping appraisal (perceived response efficacy and self‐efficacy to perform diet and exercise recommendations to reduce recurrence risk). Basic demographic and clinical information were also collected.

Results: Threat appraisal accounted for 30% of the variance in FOR (p<0.001) while coping appraisal accounted for 0% (p = 0.64). After accounting for these variables and relevant covariates, the interaction of threat appraisal and coping appraisal explained 2% of the remaining variance in FOR (p = 0.04). As hypothesized, survivors who reported high threat appraisal and low coping appraisal had the highest FOR.

Conclusions: Future research should focus on examining these relationships longitudinally and further assess coping appraisal and how it impacts cancer recurrence fears. Copyright © 2010 John Wiley & Sons, Ltd.
Quality of life of family caregivers 5 years after a relative's cancer diagnosis: follow‐up of the national quality of life survey for caregivers
Authors: Kim Youngmee , Spillers Rachel L. , Hall Daniel L.
Published: December 2010

Background. Although cancer has been considered as a chronic disease for those diagnosed, the long‐term impact of cancer on the family caregivers' quality of life (QOL) remains unknown. Thus, the current study aimed: (a) to characterize family caregivers of cancer survivors, (b) to describe the multidimensional aspects of QOL of family caregivers of cancer survivors, and (c) to identify demographic and caregiving experience factors that may play significant roles in the caregivers' QOL around 5 years after the relative's initial diagnosis.

Methods. A total of 1218 caregivers participated in the 5‐year follow‐up nationwide QOL Survey for Caregivers. Demographics and caregiving experiences were measured 2 years post‐diagnosis of their relative's cancer. Multidimensional aspects of QOL were assessed, including mental and physical health, psychological adjustment, and spirituality at 5 years post‐diagnosis.

Results. Three groups of caregivers were identified: former caregivers due to the recipients being in remission, former caregivers whose recipients were deceased, and current caregivers. Current caregivers reported worst levels of QOL. Bereaved caregivers reported lower levels of psychological and spiritual adjustment than former caregivers whose recipients were in remission. In addition, caregivers' age and stress were consistent predictors of QOL across three caregiver groups at 5 years post‐diagnosis.

Conclusions. The findings help to increase evidence‐based awareness of the long‐term impact of cancer on the family caregivers' QOL. Findings also have implications for developing programs, whereby family caregivers in the various phases of caregivership will benefit by improving their QOL. Copyright © 2010 John Wiley & Sons, Ltd.
Mindfulness‐based cognitive therapy reduces chronic cancer‐related fatigue: a treatment study
Authors: van der Lee Marije L. , Garssen Bert
Published: December 2010

Introduction: About one‐third of cancer survivors suffer from severe chronic fatigue. Aim of this study was to evaluate the efficacy of mindfulness‐based cognitive group therapy in reducing severe chronic fatigue in cancer survivors with mixed diagnoses.

Patients and Methods: Participants (n = 100) were randomly selected from a cohort and allocated to an intervention and a waiting list condition. Analyses were based on 59 participants in the intervention condition and 24 in the waiting‐list condition. Fatigue severity (Checklist Individual Strength), functional impairment (Sickness Impact Profile) and well being (Health and Disease‐Inventory) were assessed before and after the 9‐week intervention. The intervention group had a follow‐up 6 months following the intervention.

Results: At post‐treatment measurement the proportion of clinically improved participants was 30%, versus 4% in the waiting list condition (χ2 (1) = 6.71; p = 0.007). The mean fatigue score at post‐measurement was significantly lower in the intervention group than in the waiting list group corrected for pre‐treatment level of fatigue. The mean well‐being score at post‐measurement was significantly higher in the intervention group than in the waiting list group corrected for pre‐treatment level of well‐being. The treatment effect was maintained at 6‐month follow‐up. No difference between the two conditions was found in functional impairment.

Discussion: Mindfulness‐based cognitive therapy is an effective treatment for chronic cancer‐related fatigue. Copyright © 2010 John Wiley & Sons, Ltd.
Being active or flexible? Role of control coping on quality of life among patients with gastrointestinal cancer
Authors: Cheng Cecilia , Chan Nga‐yan , Chio Jasmine Hin‐man , Chan Pierre , Chan Annie On‐on , Hui Wai‐mo
Published: December 2010

Objectives: This study examined the link between coping and quality of life among patients with gastrointestinal (GI) cancer. Two hypotheses were tested. The active‐personality hypothesis states that quality of life is associated with the predominant use of primary control coping (PCC) in general. The situational‐flexibility hypothesis states that quality of life is related to flexible deployment of PCC and secondary control coping (SCC) according to situational controllability.

Methods: Participants were 180 Chinese adult patients diagnosed with colon or liver cancer. Their perceived controllability of stressors, coping, and quality of life were compared with those of a sex‐and age‐matched community sample.

Results: Three groups with distinct coping patterns were identified: (a) a flexible group characterized by the use of PCC in controllable situations but SCC in uncontrollable situations, (b) an active group characterized by predominant use of PCC in most situations, and (c) a passive group characterized by predominant use of SCC or avoidant coping in most situations. Patients in the active and the flexible groups had higher perceived controllability and psychological well‐being scores than those in the passive group.

Conclusions: Our results provide support for both the active‐personality and the situational‐flexibility hypotheses among GI cancer patients. Clinical and research implications of the findings are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Dysplasia severity, but not experiences during colposcopy, predicts adherence to follow‐up colposcopy
Authors: Kola Susanna , Walsh Jane C.
Published: December 2010

Objective: Patient adherence with treatment recommendations is an essential factor for the effectiveness of cervical cancer screening programs. Psychological factors may play a role in patient adherence to cervical cancer screening. The present study aimed to extend knowledge of women's adherence to follow‐up colposcopy, by examining possible predictive biopsychosocial variables measured at colposcopy and objective attendance rates from patients' medical files.

Methods: Baseline data on psychosocial factors (e.g. demographic variables, state anxiety, and pain) were collected from 141 women prior to undergoing colposcopy for the first time (M age = 29.63, SD = 8.39). Experiences of colposcopy and adherence to follow‐up (within two years) were assessed subsequently.

Results: There were no associations between adherence and demographic variables. Women with severe dysplasia were more likely to adhere to follow‐up colposcopy than women with other histology grades. Women who did not attend for follow‐up reported significantly greater state anxiety and pain unpleasantness following colposcopy than women who did attend. A multivariate logistic regression analysis revealed that the psychological experiences of colposcopy did not predict adherence status. However, dysplasia severity made a significant contribution to the model. The odds of adhering to colposcopy for patients with severe dysplasia were 3.57 times higher than for patients with normal histology, and 4.35 times higher than for patients with moderate dysplasia (p = 0.005).

Conclusions: Colposcopy‐related experiences do not appear to be strong predictors of adherence, but women with dysplasia grades other than ‘severe’ should be targeted for follow‐up recommendations and advice. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of quantum levels for self‐assembled InGaAsN/GaP quantum dots
Authors: Fukami F. , Umeno K. , Furukawa Y. , Urakami N. , Mitsuyoshi S. , Okada H. , Yonezu H. , Wakahara A.
Published: December 2010

We develop the design method of luminescence device with the strained quantum dots (QDs) on Si using a theoretical analysis on realistic structure. We have calculated numerically the first electron and heavy‐hole quantum levels of self‐assembled InGaAsN/GaP QDs using the finite element method, the model‐solid theory and the band‐anticrossing model. The calculation results indicate that N incorporation into InGaAs QDs drastically reduces the conduction band minimum (∼120 meV/N at%), and that it is shown enough energy difference between the first electron‐quantum level and GaP X‐state when N composition is 1∼2%. For self‐assembled In0.5Ga0.5As0.99N0.01/GaP QDs, the calculated transition energy at room temperature (RT) nearly matches with the measured photoluminescence (PL) peak energy. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of AlPN by solid source molecular beam epitaxy
Authors: Kawai Tsuyoshi , Yamane Keisuke , Furukawa Yuzo , Okada Hiroshi , Wakahara Akihiro
Published: December 2010

We reported the growth of AlPN by solid source molecular beam epitaxy (MBE). N content in AlPN showed less temperature dependence than GaPN. The surface morphology degraded at lower growth temperatures even though the N contents were almost the same. A cross‐sectional transmission electron microscopy (X‐TEM) image revealed that the surface roughening leads to stacking faults. In the case of films grown above 600 °C, atomically smooth surface was obtained. A dislocation‐free AlPN layer with abrupt GaP/AlPN heterointerface was obtained (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional theory for green chemical catalyst supported on S‐terminated GaN(0001)
Authors: Yokoyama Mami , Tsukamoto Shiro , Ishii Akira
Published: December 2010

A novel function of nitried‐based semiconductor is suc‐ cessfully developed for organic synthesis, in which palladium supported on the surface of S‐terminated GaN(0001) serves as a unique green chemical catalyst.In this study we determined the structure of Pd‐catalyst supported on Sterminated GaN(0001) surface by means of the density functional theory (DFT) within a Local Density Approximation (LDA).

The important role of S on the case of GaN substrate is to make the number of the valence electron to be close to0, in contrust to the case of GaAs (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MnSb‐based spin LED with side‐wall emission
Authors: Terui W. , Munekata H. , Hanna T. , Yoshida D.
Published: December 2010

Combination of the spin‐dependent optical transition and the spin current would lead us to the opportunity of developing photo‐ and light‐emitting diodes that respectively senses and emits circularly polarized light. Here, we describe preparation of spin LED consisting of an epitaxial MnSb spin injection layer and GaAs‐AlGaAs double hetero‐structures, and show characteristics of EL from a side wall emission. Taking advantage of remnant state of ferromagnet, circular polarization emission has been realized without application of an external field. Demonstration of electrical switching of circular polarization has been carried out with alternative switching between two spin‐LEDs having antiparallel magnetization configuration. While the technique used in the present demonstration was a crude one, it certainly show the feasibility of building a compact and robust light source whose circular polarization is controlled electrically. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the conduction‐type conversion in Si‐doped (631)A GaAs layers grown by molecular beam epitaxy
Authors: Cruz‐Hernández E. , Vázquez‐Cortés D. , Shimomura S. , Méndez‐García V. H. , López‐López M.
Published: December 2010

We report the Si‐doping of GaAs (631)A layers grown by molecular beam epitaxy under different As overpressure. From Hall effect measurements, we have found that the increase of the As pressure induces conduction conversion from p‐ to n‐type, which is presumably related to lattice site switching of Si occupying an As site (where Si is acceptor) to a Ga site (where Si acts as a donor). This conversion is also studied by photoluminescence (PL) spectroscopy. The sharp conductivity conversion, at a critical As pressure value of 1.4‐1.7 x 10‐5 mbar is reflected in the optical properties of the samples by a change of As vacancy defects into pairs of Ga vacancy and Ga antisite defects. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photocurrent characteristics in p‐i‐n diodes with built‐in coupled or uncoupled multi‐quantum wells
Authors: Noda Takeshi , Mano Takaaki , Sakoda Kazuaki , Sakaki Hiroyuki
Published: December 2010

We studied photocurrent characteristics in AlGaAs p‐i‐n diodes, where coupled or uncoupled GaAs/AlGaAs multi‐quantum wells (MQWs) were embedded in their intrinsic layers, to investigate how the electronic–coupling in the MQWs affects the device performance of MQW‐based solar cells. Measurements were done at 77 K to suppress thermal processes. When carriers were generated only in QWs, the photocurrent (PC) in the coupled MQW sample decreased substantially as soon as the forward‐bias voltage V is raised above ∼0.5 V and became almost zero at V ∼1 V. By contrast, in the uncoupled MQW sample the PC did not exhibit such a step‐like decrease but only gradually decreased up to V ∼1.2 V. This step‐like loss in PC observed in the coupled MQW structure is presumably attributable to the accumulation of photogenerated carriers in its MQW region. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vitro anti HSV‐1 and HSV‐2 activity of Tanacetum vulgare extracts and isolated compounds: An approach to their mechanisms of action
Authors: Álvarez Ángel L. , Habtemariam Solomon , Juan‐Badaturuge Malindra , Jackson Caroline , Parra Francisco
Published: December 2010

Herpes simplex viruses (HSV‐1 and HSV‐2) are responsible for long‐term latent infections in humans, with periods of recurring viral replication associated to lesions around the lips, eyes, mucous membrane of the oral cavity or the genitals. The lack of an effective vaccine, the moderate to high toxicity of the available synthetic antiherpes compounds and the appearance of resistant viral strains emphasize the need for new inhibitors. Tanacetum vulgare, commonly known as tansy, has been used for treating rheumatic pain, skin eruption and diuretic conditions as well as an anthelmintic, antihypertensive, stimulant, emmenagogue, carminative, antiseptic, antihypertensive, antispasmodic and antioxidant agent. The anti HSV‐1 activity of tansy aerial parts, ethyl acetate extract and the isolated compound parthenolide, has been reported recently. In this work, through a comprehensive mechanistic‐based antiherpetic activity study, it was revealed that constituents other than parthenolide are responsible for the antiviral activity of tansy. Copyright © 2010 John Wiley & Sons, Ltd.
A comparative study of phase II robust multivariate control charts for individual observations
Authors: Chenouri Shoja'eddin , Variyath Asokan Mulayath
Published: December 2010

Use of Hotelling's T2 charts with high breakdown robust estimates to monitor multivariate individual observations are the recent trend in the control chart methodology. Vargas (J. Qual. Tech. 2003; 35: 367‐376) introduced Hotelling's T2 charts based on the minimum volume ellipsoid (MVE) and the minimum covariance determinant (MCD) estimates to identify outliers in Phase I data. Studies carried out by Jensen et al. (Qual. Rel. Eng. Int. 2007; 23: 615‐629) indicated that the performance of these charts heavily depends on the sample size, amount of outliers and the dimensionality of the Phase I data. Chenouri et al. (J. Qual. Tech. 2009; 41: 259‐271) recently proposed robust Hotelling's T2 control charts for monitoring Phase II data based on the reweighted MCD (RMCD) estimates of the mean vector and covariance matrix from Phase I. They showed that Phase II RMCD charts have better performance compared with Phase II standard Hotelling's T2 charts based on outlier free Phase I data, where the outlier free Phase I data were obtained by applying MCD and MVE T2 charts to historical data. Reweighted MVE (RMVE) and S‐estimators are two competitors of the RMCD estimators and it is a natural question whether the performance of Phase II Hotelling's T2 charts with RMCD and RMVE estimates exhibits similar pattern observed by Jensen et al. (Qual. Rel. Eng. Int. 2007; 23: 615‐629) in the case of MCD and MVE‐based Phase I Hotelling's T2 charts. In this paper, we conduct a comparative study to assess the performance of Hotelling's T2 charts with RMCD, RMVE and S‐estimators using large number of Monte Carlo simulations by considering different data scenarios. Our results are generally in favor of the RMCD‐based charts irrespective of sample size, outliers and dimensionality of Phase I data. Copyright © 2010 John Wiley & Sons, Ltd.
Delay‐dependent robustH∞controller synthesis for discrete singular delay systems
Authors: Feng Zhiguang , Lam James , Gao Huijun
Published: December 2010

In this paper, the problems of delay‐dependent robust stability analysis, robust stabilization and robustH∞control are investigated for uncertain discrete‐time singular systems with state delay. First, by making use of the delay partitioning technique, a new delay‐dependent criterion is given to ensure the nominal system to be regular, causal and stable. This new criterion is further extended to singular systems with both delay and parameter uncertainties. Then, without the assumption that the considered systems being regular and causal, robust controllers are designed for discrete‐time singular time‐delay systems such that the closed‐loop systems have the characteristics of regularity, causality and asymptotic stability. Moreover, the problem of robustH∞control is solved following a similar line. The obtained results are dependent not only on the delay, but also on the partitioning size and the conservatism is non‐increasing with reducing partitioning size. These results are shown, via extensive numerical examples, to be much less conservative than the existing results in the literature. Copyright © 2010 John Wiley & Sons, Ltd.
ℋ︁2/ℋ︁∞ output information‐based disturbance attenuation for differential linear repetitive processes
Authors: Paszke Wojciech , Rogers Eric , Gałkowski Krzysztof
Published: December 2010

Repetitive processes propagate information in two independent directions where the duration of one is finite. They pose control problems that cannot be solved by application of results for other classes of 2D systems. This paper develops controller design algorithms for differential linear processes, where information in one direction is governed by a matrix differential equation and in the other by a matrix discrete equation, in an ℋ︁2/ℋ︁∞ setting. The objectives are stabilization and disturbance attenuation, and the controller used is actuated by the process output and hence the use of a state observer is avoided. Copyright © 2010 John Wiley & Sons, Ltd.
Insomnia severity, combat exposure and mental health outcomes
Authors: Wright Kathleen M. , Britt Thomas W. , Bliese Paul D. , Adler Amy B.
Published: December 2010

Few studies have examined insomnia severity as a moderator of the impact of combat experiences on posttraumatic stress disorder (PTSD) and alcohol problems, such that combat exposure is expected to have more negative consequences for soldiers who report insomnia. In this study, a sample of 522 military personnel completed measures of PTSD and alcohol problems prior to a 12‐month deployment to Iraq, and then completed measures assessing insomnia severity, combat exposure, PTSD, alcohol problems and overall distress 3 months post‐deployment. Results of a moderated multiple regression indicated that insomnia severity interacted with combat exposure to predict PTSD and alcohol problems after controlling for pre‐deployment baseline measures of these outcomes, such that the relationship between combat exposure and the mental health symptoms was stronger when insomnia severity was greater. Results are discussed from the perspective of the role of insomnia in the development of PTSD and alcohol problems, as well as from an occupational health perspective where insomnia may deprive individuals of the resources they need to recover from the effects of severe occupational stressors found in high risk occupations. Published in 2010 by John Wiley & Sons, Ltd.
Phase transition in spatial epidemics using cellular automata with noise
Authors: Sun Gui‐Quan , Jin Zhen , Song Li‐Peng , Chakraborty Amit , Li Bai‐Lian
Published: December 2010

One of the central issues in studying the complex population patterns observed in nature is the role of stochasticity. In this paper, the effects of additive spatiotemporal random variations—noise—are introduced to an epidemic model. The no‐noise model exhibits a phase transition from a disease‐free state to an endemic state. However, this phase transition can revert in a resonance‐like manner depending on noise intensity when introducing nonzero random variations to the model. On the other hand, given a regime where disease can persist, noise can induce disappearance of the phase transition. The results obtained show that noise plays a tremendous role in the spread of the disease state, which has implications for how we try to prevent, and eventually eradicate, disease.
A Network Approach for Evaluating Coherence in Multivariate Systems: An Application to Psychophysiological Emotion Data
Authors: Hsieh Fushing , Ferrer Emilio , Chen Shuchun , Mauss Iris B. , John Oliver , Gross James J.
Published: December 2010

We present an approach for evaluating coherence in multivariate systems that considers all the variables simultaneously. We operationalize the multivariate system as a network and define coherence as the efficiency with which a signal is transmitted throughout the network. We illustrate this approach with time series data from 15 psychophysiological signals representing individuals’ moment-by-moment emotional reactions to emotional films. First, we summarize the time series through nonparametric Receiver Operating Characteristic (ROC) curves. Second, we use Spearman rank correlations to calculate relationships between each pair of variables. Third, based on the obtained associations, we construct a network using the variables as nodes. Finally, we examine signal transmission through all the nodes in the network. Our results indicate that the network consisting of the 15 psychophysiological signals has a small-world structure, with three clusters of variables and strong within-cluster connections. This structure supports an effective signal transmission across the entire network. When compared across experimental conditions, our results indicate that coherence is relatively stronger for intense emotional stimuli than for neutral stimuli. These findings are discussed in relation to multivariate methods and emotion theories.
Transienter neonataler Diabetes und Hypomethylierungssyndrome
Authors: Bens S. , Siebert R. , Caliebe A.
Published: December 2010

Der transiente neonatale Diabetes (TNDM) ist definiert als Manifestation einer diabetogenen Stoffwechsellage in den ersten Lebenswochen und Normalisierung des Glukosestoffwechsels bis zum 18. Lebensmonat. Zu den klinischen Kardinalsymptomen zählen intrauterine Wachstumsverzögerung, Hyperglykämie und Dehydratation bei fehlender Ketoazidose. Die Ätiologie des TNDM ist sehr heterogen. In 70% der Fälle ist die Erkrankung mit Aberrationen in der Chromosomenregion 6q24 assoziiert. Diese Chromosomenregion enthält die genomisch geprägten Gene PLAGL1/ZAC und HYMAI. Durch eine paternale uniparentale Disomie 6 (upd(6)pat), eine paternale Duplikation der geprägten Region in 6q24 oder durch Imprintingdefekte des maternalen Allels kommt es zu einer Überexpression des paternal exprimierten Gens PLAGL1. Imprintingdefekte können isoliert oder im Rahmen eines Hypomethylierungssyndroms mit Beteiligung mehrerer geprägter Loci des Genoms auftreten. Hypomethylierung an multiplen Loci wurde bis jetzt bei Patienten mit TNDM, Silver-Russell-Syndrom (SRS) und Beckwith-Wiedemann-Syndrom (BWS) beobachtet. Das Wiederholungsrisiko hängt wesentlich von der Ursache des TNDM an. Chromosomale Aberrationen der Eltern unter Beteiligung des Chromosoms 6 erhöhen das Risiko sowohl für eine UPD des geprägten Bereichs in 6q24 als auch für eine paternale Duplikation. Jedoch entstehen sowohl UPD als auch Duplikationen zumeist de novo.
Prader-Willi-Syndrom und Angelman-Syndrom
Authors: Albrecht B. , Buiting K.
Published: December 2010

Das Prader-Willi-Syndrom (PWS) und das Angelman-Syndrom (AS) sind distinkte neurogenetische Erkrankungen, die durch den Funktionsverlust geprägter Gene in der Region 15q11q13 hervorgerufen werden. Ein etwa 2 Mb großer Bereich in 15q11q13 unterliegt einer elternspezifischen Prägung („genomic imprinting“). Infolge der Prägung unterscheiden sich die väterliche und mütterliche Kopie dieses Bereichs in der DNA-Methylierung und der Genexpression. Die häufigsten Ursachen für PWS und AS sind eine 5–7 Mb große interstitielle Deletion in der chromosomalen Region 15q11q13, eine uniparentale Disomie 15, ein Imprintingdefekt oder im Fall von AS eine Mutation im UBE3A-Gen. Mikrodeletionen bei einer kleinen Anzahl von Patienten mit einem Imprintingdefekt haben zur Identifizierung eines Imprinting-Centers (IC) „upstream“ vom SNURF-SNRPN-Gen geführt, das die Imprintumschaltung in cis reguliert. Das IC hat eine zweiteilige Struktur: Einen zentromerischen Teil, der bei Patienten mit AS deletiert ist und für die mütterliche Prägung notwendig ist, und einen telomerischen Teil, der bei Patienten mit PWS deletiert ist und der für die Aufrechterhaltung der väterlichen Prägung notwendig ist.
Mechanisms of ionospheric mass escape
Authors: Moore T. E. , Khazanov G. V.
Published: December 2010

The dependence of ionospheric O+ escape flux on electromagnetic energy flux and electron precipitation into the ionosphere is derived for a hypothetical ambipolar pickup process, powered the relative motion of plasmas and neutral upper atmosphere, and by electron precipitation, at heights where the ions are magnetized but influenced by photo‐ionization, collisions with gas atoms, ambipolar and centrifugal acceleration. Ion pickup by the convection electric field produces “ring‐beam” or toroidal velocity distributions, as inferred from direct plasma measurements, from observations of the associated waves, and from the spectra of incoherent radar echoes. Ring beams are unstable to plasma wave growth, resulting in rapid relaxation via transverse velocity diffusion, into transversely accelerated ion populations. Ion escape is substantially facilitated by the ambipolar potential, but is only weakly affected by centrifugal acceleration. If, as cited simulations suggest, ion ring beams relax into nonthermal velocity distributions with characteristic speed equal to the local ion‐neutral flow speed, a generalized “Jeans escape” calculation shows that the escape flux of ionospheric O+ increases with Poynting flux and with precipitating electron density in rough agreement with observations.
Root‐soil mechanical interactions during pullout and failure of root bundles
Authors: Schwarz M. , Cohen D. , Or D.
Published: December 2010

Roots play a major role in reinforcing and stabilizing steep hillslopes. Most studies in slope stability implement root reinforcement as an apparent cohesion by upscaling the behavior of static individual roots. Recent studies, however, have shown that much better predictions of slope stability can be made if the progressive failure of bundles of roots are considered. The characteristics of progressive failure depend on interactions between soil deformation and root bundle geometric and mechanical properties. We present a detailed model for the quantitative description of the mechanical behavior of a bundle of roots under strain‐controlled mechanical forcing. The Root Bundle Model explicitly considers typical values of root‐size spatial distribution (number and dimension of roots), geometric factors (diameter‐length proportion, tortuosity, and branching characteristics), and mechanical characteristics (tensile strength and Young's modulus) and interactions under various soil conditions (soil type, confining pressure, and soil moisture). We provide systematic analyses of the roles of these factors on the mechanical response of the bundle and explore the relative importance of various parameters to the macroscopic root‐soil mechanical response. We distinguish between increased strength imparted by small roots at small deformations and the resilience imparted by larger roots to the growth of large tensile cracks, showing that the maximal reinforcement of fine roots is reached within the first 5 cm of displacement whereas a root of 20 mm diameter may reach its maximal pullout force after 10 cm displacement. The model reproduces the gradual straining and ultimate residual failure behavior of root systems often observed in hillslopes, with progressive growth of tension cracks improving estimations of root reinforcement when considering the effects of root distribution and the variation of the pullout force as a function of displacement. These results enhance understanding of root reinforcement mechanisms and enable more realistic implementation of root reinforcement modeling for stability calculations of vegetated slopes and for guiding ongoing experimental efforts to gather critical root‐soil mechanical information.
Evapotranspiration dynamics in a boreal peatland and its impact on the water and energy balance
Authors: Wu Jiabing , Kutzbach Lars , Jager Daniel , Wille Christian , Wilmking Martin
Published: December 2010

Hydrological conditions play a key role in the carbon cycle of northern peatlands. This study examines the evapotranspiration (ET) dynamics and its impact on the water and energy balance in response to differing meteorological conditions during the exceptionally dry year 2006 and the normal wet year 2007 at a boreal peatland in Finland. Energy and water vapor fluxes were determined continuously using the eddy covariance approach. Daily ET rates varied considerably during the growing season and averaged 2.23 ± 0.15 mm d−1 and 1.59 ± 0.07 mm d−1 in the dry and wet year, respectively. Synoptic weather conditions as reflected by incoming radiation and water vapor pressure deficit (VPD) were the key factors controlling ET. Differences in the precipitation patterns and summer temperature also accounted for some of the observed differences in ET between the 2 years. No evidence was found for a relationship between ET rates and water table level, probably due to the relatively high water table level even in the dry year. Latent heat flux dominated the energy balance, particularly in the dry year 2006 with 60% of cumulative precipitation returned to the atmosphere through ET. In the wet year 2007, runoff dominated the water loss, and only 36% of the cumulative precipitation was returned to the atmosphere through ET. While the annual water balance regime of the peatland was mainly regulated by the precipitation pattern, daily measured ET was closely related to potential evaporation, and latent heat flux could be well modeled by the Penman‐Monteith approach, suggesting two feasible schemes for ET prediction in peatlands under well watered conditions.