bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of iron on defect concentrations and device performance for Cu(In,Ga)Se2 solar cells on stainless steel substrates
Authors: Eisenbarth Tobias , Caballero Raquel , Kaufmann Christian A. , Eicke Axel , Unold Thomas 
Published: July 2012

ABSTRACTThin film Cu(In,Ga)Se2 (CIGSe) solar cells deposited on flexible steel foil substrates by coevaporation are investigated. Iron diffusion from the steel foil substrate material into the CIGSe absorber layers is studied by secondary ion mass spectroscopy (SIMS) for different maximum absorber growth temperatures and solar cell back‐contact configurations. The optimization of the absorber growth temperature, the introduction of a diffusion barrier layer at the back contact, and the adjustment of the sodium doping lead to device efficiencies above 14%. Defect spectroscopy by means of admittance measurements shows a clear correlation of the deep defect concentration with the Fe content in the CIGSe absorber layer and a correlation between the sodium incorporation and the net carrier concentration. It is found that too much Na supports the diffusion of Fe, inducing an increased deep defect concentration. The Fe‐induced deep defects, which form a broad acceptor‐type defect band at 0.44 eV above the valence band maximum, are identified as the cause of bulk recombination, limiting the device performance in these solar cells. Copyright © 2012 John Wiley & Sons, Ltd.
The new low‐band gap polymers comprising C‐, Si‐, or N‐bridged dithiophene and alkoxy‐modified 2,1,3‐benzooxadiazole units for bulk heterojunction solar cells
Authors: Jiang Jian‐Ming , Yang Po‐An , Yu Chia‐Ming , Lin His‐Kuei , Huang Kuei‐Chun , Wei Kung‐Hwa 
Published: July 2012

AbstractIn this study, we used Stille coupling polymerization to synthesize a series of new low‐band gap‐conjugated polymers—PCyTBO, PCySiTBO, and PCyNTBO—comprising mainly electron‐rich C‐, Si‐, and N‐bridged dithiophene units in conjugation with electron‐deficient alkoxy‐modified 2,1,3‐benzooxadiazole moieties. The highest occupied molecular orbital energy levels of these polymers become higher as the electron‐donating ability of C‐, Si‐, or N‐bridged dithiophene units increases. These polymers also displayed excellent thermal stability and broad spectral absorptions, with PCySiTBO revealing some crystallinity. As a result, the photovoltaic device incorporating the PCySiTBO/PC71BM (1:1) blend system and 1,8‐diiodooctane (2 vol %) as an additive exhibited excellent performance, under AM 1.5 G irradiation (100 mW cm−2), with a value of Voc of 0.64 V, a short‐circuit current density of 13.8 mA cm−2, a fill factor of 0.57, and a promising power conversion efficiency of 5.0%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
The mental health of breast cancer survivors and their adolescent daughters
Authors: Inbar Cohen , Ety Berant , Ayala Hubert , Tamer Perez 
Published: July 2012

AbstractObjectiveThis study examines associations between attachment orientations and mental health among breast cancer survivors and their adolescent daughters, while focusing on intergenerational transmission of emotional problems.MethodsA total of 58 breast cancer survivors and their adolescent daughters were recruited 8 months following mothers' completion of treatment and were compared with a matched control group of 48 healthy mothers and their adolescent daughters. Measures included the Experiences in Close Relationships scale and the Mental Health Inventory.ResultsHierarchical regressions revealed the following: First, breast cancer survivors reported higher levels of mental distress and lower levels of well‐being than control women, and the effect of breast cancer on well‐being was significant only among highly anxiously attached women. Second, daughters of breast cancer survivors reported higher levels of mental distress than daughters of control women only if they scored high on avoidant attachment. Third, daughters of breast cancer survivors reported higher levels of mental distress than daughters of control women only if their mothers scored high on anxious attachment.ConclusionsBreast cancer had detrimental effects on survivors' well‐being and daughters' distress mainly when survivors scored high on attachment anxiety. Breast cancer had also detrimental effects of daughters' distress mainly when daughters scored high on avoidant attachment. These findings highlight the importance of attachment security as an inner resource for buffering detrimental mental health effects of breast cancer among survivors and their daughters.Copyright © 2012 John Wiley & Sons, Ltd.
Neutron resonance data exclude random matrix theory
Authors: Koehler P.E. , Bečvář F. , Krtička M. , Guber K.H. , Ullmann J.L. 
Published: July 2012

AbstractAlmost since the time it was formulated, the overwhelming consensus has been that random matrix theory (RMT) is in excellent agreement with neutron resonance data. However, over the past few years, we have obtained new neutron‐width data at Oak Ridge and Los Alamos National Laboratories that are in stark disagreement with this theory. We also have reanalyzed neutron widths in the most famous data set, the nuclear data ensemble (NDE), and found that it is seriously flawed, and, when analyzed carefully, excludes RMT with high confidence. More recently, we carefully examined energy spacings for these same resonances in the NDE using the Δ3 statistic. We conclude that the data can be found to either confirm or refute the theory depending on which nuclides and whether known or suspected p‐wave resonances are included in the analysis, in essence confirming results of our neutron‐width analysis of the NDE. We also have examined radiation widths resulting from our Oak Ridge and Los Alamos measurements, and find that in some cases they do not agree with RMT. Although these disagreements presently are not understood, they could have broad impact on basic and applied nuclear physics, from nuclear astrophysics to nuclear criticality safety.
Shape invariance in phase space
Authors: Rasinariu C. 
Published: July 2012

AbstractShape invariance is a powerful solvability condition, that allows for complete knowledge of the energy spectrum, and eigenfunctions of a system. After a short introduction into the deformation quantization formalism, this paper explores the implications of the supersymmetric quantum mechanics and shape invariance techniques to the phase space formalism. We show that shape invariance induces a new set of relations between the Wigner functions of the system, that allows for their direct calculation, once we know one of them. The simple harmonic oscillator and the Morse potential are solved as examples.
GENOTOXICITY IN CHIRONOMUS KIIENSIS (CHIRONOMIDAE: DIPTERA) AFTER EXPOSURE TO POLLUTED SEDIMENTS FROM RIVERS OF NORTH PENINSULAR MALAYSIA: IMPLICATION FOR ECOTOXICOLOGICAL MONITORING
Authors: Al‐Shami Salman A. , Che Salmah Md Rawi , Mohd Nor Siti Azizah , Ahmad Abu Hassan , Mohd Ishadi Nur Adibah , Dieng Hamady 
Published: July 2012

ABSTRACTRapid industrialization and urbanization has led to increasing input of chemical contaminants into the aquatic environment of Malaysia. Despite the threat civilization poses to the biota, there are still very few relevant studies on ecotoxicological testing of river ecosystems. To overcome this knowledge gap, we examined lethal and genotoxic effects of sediments from different rivers of the northern Malaysia against Chironomus kiiensis, a group well represented in the aquatic fauna of this region. We exposed the larvae to sediments from Selama River (SR), Permatang Rawa River (PRR) and Kilang Ubi River (KUR) at various durations (0, 6, 12, 24 and 48 h). The larval mortality was monitored, whereas DNA damage in survivors' cells was determined using the comet assay. Pollution level indexed by the amounts of heavy metals and other organic contaminants in the sediment showed progressive increases from SR to PRR to KUR. Highly polluted sediments (PRR to KUR) were detrimental to C. kiiensis larvae, most of which did not survive following exposure for long periods. DNA analyses revealed greater damages in nuclei derived from larvae maintained on polluted sediments, in particular, those from KUR. The effects on the genomic material of C. kiiensis larvae occurred in a time‐dependent manner, with damage level increasing as exposure time progressed. Our results highlight the genotoxic properties of polluted sediments. More importantly, this study showed that C. kiiensis larvae could respond to different levels of pollution with respect to exposure time. It is concluded that C. kiiensis larvae is a potential candidate for river ecotoxicological monitoring. Copyright © 2012 John Wiley & Sons, Ltd.
PATTERNS OF BENTHIC INVERTEBRATE RICHNESS AND DIVERSITY IN THE REGULATED MAGPIE RIVER AND NEIGHBOURING NATURAL RIVERS
Authors: Jones N. E. 
Published: July 2012

ABSTRACTFluctuating flows common in hydropeaking operations present biota with contrasting and challenging environments. Taxa that require a narrow range of water velocity or are not adapted to withstand sudden changes in discharge will likely be eliminated or competitively disadvantaged under such circumstances, perhaps leading to reduced biodiversity. I investigated the whole river, longitudinal and lateral patterns of benthic invertebrate abundance, Shannon–Wiener diversity, and rarefied taxa density and richness in the hydropeaking Magpie River and 16 neighbouring natural rivers. The Magpie River had greater abundances of benthic invertebrates than natural rivers, particularly near the dam. General differences in benthic community characteristics were largely based on the near absence of Odonata and Plecoptera and an abundance of snails and worms in the Magpie River. Family density, richness and diversity were greater in the regulated Magpie River and unregulated upper Magpie River than found in natural rivers. Longitudinally, family density, diversity and particularly richness increased downstream in the Magpie River. Laterally, diversity did not show any trends with increasing depth along transects, except at near the dam where it decreased sharply with depth, velocity, and an abundance of filter feeding invertebrates. Taxa density did not show any lateral trends in natural rivers, whereas in the Magpie River, it increased with water velocity and depth. The results of this study are contradictory to the general findings of others implying reduced biodiversity below hydropower facilities. Possible explanations are examined and contrasted with other examinations of benthic invertebrate response below hydropeaking dams. © Her Majesty the Queen in Right of Canada 2012.
Secured and fast handoff in wireless mesh networks
Authors: Zarai Faouzi , Daly Ikbel , Obaidat Mohammad S. ,   Fellow of IEEE,   Fellow of SCS, Kamoun Lotfi 
Published: July 2012

ABSTRACTWireless mesh networks are one of the most important improvements in the world of wireless technologies. In fact, they offer many advantages to ensure a free mobility and a self‐configuration of the various network equipment, a better quality of services, as well as an extensible domain and area. In spite of all of these contributions, mesh technology still suffers from some problems such as security especially in handoff phases. In this study, we propose an authentication scheme that is designed to reduce the authentication delay during a wireless mesh network handoff process. The proposed mechanism takes into account the mobility of clients as well as the router movements. This work takes advantage of some existing techniques such as Blom key predistribution scheme and Du key process generation method. Our simulation results prove the effectiveness of our proposed scheme. Our performance evaluation results shows that the suggested solution outperforms existing schemes in improving handoff latency values (<15 ms) and in the ability of satisfying the requirements of security as well as the quality of services in terms of having low loss rate (less than 1%) and having a low blocking rate. Copyright © 2012 John Wiley & Sons, Ltd.
Precipitation Behavior of Modified as Cast High Nitrogen Super Hard High‐Speed Tool Steel
Authors: Halfa Hossam , Mattar Taha , Eissa Mamdouh 
Published: July 2012

AbstractThe properties of high‐speed tool steels can be improved by modifying their chemical composition or the technology of production. Nitrogen alloying is an attractive technology to enhance the mechanical and physical properties of tool steels. In this work, modified super hard high‐speed tool steel was produced through nitrogen alloying and decreasing the level of cobalt content in investigated steels. This work aims to study the effect of nitrogen as alloying element on carbides and carbo‐nitrides precipitates type, shape, and size for investigated steels. From the results obtained from Thermo‐Calc, it was concluded that nitrogen alloying produced large amount of stable austenite, also eutectic carbides precipitates (M6C and M7C3) were stable at room temperature. Transmission electron microscope (TEM) images for traditional grade showed that the as cast structure contains beside the carbides network other single carbides precipitates. While on the other hand the selected area diffraction pattern (SADP) images of nitrogen alloyed grade shows fine carbides and carbo‐nitrides precipitates with more amount of retained austenite in the ferrite matrix, they showed also the presence of the eutectic precipitates as well as the dislocations.
Brief report: Does exposure to violent video games increase moral disengagement among adolescents?
Authors: Gabbiadini Alessandro , Andrighetto Luca , Volpato Chiara 
Published: July 2012

ABSTRACTSeveral studies have repeatedly shown that violent/action video games increase aggressive tendencies. The present study provides preliminary evidence that exposure to these games also affects the process of moral disengagement. High school students (N = 385) were recruited, and the impact of both recency and frequency of their exposure to the video game Grand Theft Auto IV (GTA; 2008) on moral disengagement was explored. Results showed that exposure to GTA predicted higher levels of moral disengagement. Recency of exposure had a primary impact on the considered mechanisms of moral disengagement. These findings provide insights into a relevant detrimental effect of exposure to video games, to our knowledge not explored yet. Future research is needed to provide evidence of the causal link in the observed relationships.
Cardiovascular responses to and modulation of pressure pain sensitivity in normotensive, pain-free women
Authors: Mohn Christine , Vassend Olav , Knardahl Stein 
Published: July 2012

Abstract

Background and purpose
The psychophysiological responses to and modulation of pressure pain stimulation are relatively new areas of investigation. The aims of the present study were to characterize subjective and cardiovascular (CV) responses to pressure pain stimulation, and to examine the relationship between CV responding and pain pressure pain sensitivity.

Methods
Thirty-nine pain-free, normotensive women were included in the study and tested during the follicular phase of their menstrual cycles. Pain threshold and tolerance were recorded at the right masseter muscle and the sternum, and visual analogue scales (VAS) were used to rate both pain intensity (the sensory dimension) and discomfort (the affective dimension). Mean arterial pressure (MAP), heart rate (HR), and facial and digital skin blood flux (SBF) were registered continuously.

Results
The pain threshold and tolerance were significantly higher at the sternum compared with the masseter, but the level of affective distress was higher at the masseter tolerance point. No associations emerged between pressure pain threshold and tolerance stimulation levels, and the corresponding VAS ratings. Pressure pain stimulation of the masseter induced significant increases in MAP, HR, and a decrease in digital SBF. During sternum pressure stimulation a significant change in HR and digital SBF was observed. There were no significant correlations between CV responding and pressure pain sensitivity.

Conclusion
Healthy women seem to display higher pressure pain sensitivity at the masseter region relative to the sternum. Pressure pain stimulation was associated with significant changes in MAP, HR, and SBF, but was not modulated by CV responses. The validity of these findings is strengthened by our control for menstrual cycle events, weekend-related changes in physiology, and CV changes during pain stimulation.

Implications
This study extends previous reports of SBF sensitivity to electrocutaneous pain into the field of pressure stimulation. Moreover, this study suggests that the often demonstrated association between high BP and low pain sensitivity may not apply to pressure pain specifically. Alternatively, this finding adds to the literature of gender differences in the relationship between CV responding and acute pain sensitivity in general.
The effect of a mental stressor on conditioned pain modulation in healthy subjects
Authors: Nilsen Kristian B. , Christiansen Sunniva E. , Holmen Line B. , Sand Trond 
Published: July 2012

Abstract

Background and purpose
In animal studies, enhanced sensitivity to painful stimuli succeeding chronic stress has been reported, while acute stress is reported to induce analgesia. Human studies on the effect of mental stress on pain are more equivocal. A disturbed stress-response resulting in an increased sensitivity to painful stimuli has also been discussed as a potential mechanism for e.g., the fibromyalgia syndrome. Endogenous analgesia may be studied in humans by measuring the analgesic effect of heterotopic noxious conditioning stimulation. In neurophysiological animal studies this phenomenon was originally denoted “diffuse noxious inhibitory controls” (DNIC), but for human studies it has been suggested to use the term conditioned pain modulation (CPM).
The clinical relevance of aberrances in CPM is not clear. Inhibitory CPM is reported as being reduced in several medically unexplained syndromes with musculoskeletal pain aggravated by mental stress. However, whether the reported reduced CPM effects are causally related to clinical pain is unknown.
In the present study the effect of a mental stressor on CPM is studied.

Methods
With tourniquet-induced pain as the conditioning stimulus we estimated the CPM effect in twenty healthy subjects. Heat pain threshold (HPT), supra-threshold heat pain level (SHPL) and pressure pain threshold (PPT) were used as test stimuli. Measurements were performed at baseline, after a stressful task and after a non-stressful task presented in a blinded cross-over design. We used repeated-measures ANOVAs in the analysis with simple contrasts for post hoc analysis.

Results
With a ANOVA repeated measures model we found a significant task effect (F = 18.5, p ≤ 0.001), indicating that CPM was successfully induced. In our ANOVA model, we found a significant effect of stress in the contrast analysis (F = 5.2, p = 0.037), indicating that CPM was affected by the stressful task. The effects on PPT could not be analyzed due to a significant carry-over effect (for PPT only).

Conclusions
In the present blinded crossover study, we found a significant small to medium inhibitory effect of mental stress upon the CPM of thermal pain.

Implications
Our results suggest that previously reported reduced inhibitory CPM in several medically unexplained syndromes with musculoskeletal pain aggravated by mental stress possibly can be related to confounding or clinically relevant stress level differences. However, the result might be modality-specific. Further studies in patients are obviously needed, and the impact of mental stress on CPM should be investigated also with other stressors.
Na+/K+-ATPase dependent regulation of astrocyte Ca2+ signalling: A novel mechanism for modulation of long-term pain?
Authors: Hansson Elisabeth , Block Linda , Forshammar Johan , Lundborg Christopher , Biber Björn 
Published: July 2012

Abstract

Background
Long-term or chronic pain represents a major health problem and is associated with significant socio-economic costs. During injury, pain can be dissociated from its normal physiological role. It can persist for a longer period of time, even after the primary noxious stimulus has more or less subsided. Analgesic drugs, with predominant neuronal sites of actions, seem to be relatively ineffective. Chronic pain is probably partly a consequence of ongoing neuroinflammation. The mechanisms behind these phenomena, and how the neuronal and non-neuronal activities evoked by painful stimuli and inflammation are processed in the brain and throughout the CNS, are not well understood.

Methods
Primary cultures, calcium imaging, immunocyto-chemistry, Western blotting, cytokine release.

Results
Following pain stimuli increased activity of inflammatory receptors and shifts in intra- and extracellular ion concentrations occur within the CNS. One signalling pathway in astrocytes propagates Ca2+ waves, which initially decrease and then increase in form of oscillations in the astrocyte networks. This causes dysfunction in the astrocytic Ca2+ signalling resulting in down-regulation of Na+ transporters, and increased release of pro-inflammatory cytokines. The neurons will then increase their excitability and, hypothetically, also increase the sensitivity for development or potentiation of neuropathic pain states. Low-dose of potential anti-inflammatory and analgesic drugs restore the disturbed astrocytic Ca2+ signalling, and modulate the activity of inflammatory receptors and Na+/K+-ATPase. We recently report, in patients with long-term pain, changes in neurotrophic factors and pro-inflammatory cytokines in blood and CSF.

Conclusions
Dysfunction in downregulation of Na+ transporters, changed Ca2+ signalling in the astrocyte networks and release of cytokines from glial cells can lead to pathogenic chronic neuroinflammation. Modulation of the Na+/K+-ATPase activity and restoration with anti-inflammatory substances will lead to a balance between inflammatory and anti-inflammatory mediators in inflammatory reactive cells. The pharmacological treatment of today is directed towards neuronal over-excitability, unfortunately with less success. A novel pharmacological treatment strategy would thus be directed towards the activated astrocytes and microglial cells, being the source of the neuroinflammation. This will be an important knowledge for treatment in clinical therapy.
Effect of specific trapezius exercises vs. coordination training on corticomotor control of neck muscles
Authors: Rittig-Rasmussen B. , Kasch H. , Fuglsang-Frederiksen A. , Jensen T.S. , Svensson P. 
Published: July 2012

Abstract

Objective
To test the effect of different neck training methods on motor evoked potentials (MEPs) from the trapezius muscle. We hypothesized that training of the trapezius muscle would significantly increase MEPs, indicating facilitation of the corticomotor pathways. Additional experiments investigated the influence of muscle strength, muscle fatigue, and correlations between MEP amplitudes and behavioral aspects of motor learning.

Methods
Transcranial magnetic stimulation (TMS) was used to elicit MEPs from the trapezius muscle and the abductor pollicis brevis (APB) muscle in 60 healthy subjects in three conditions: (1) specific trapezius training, (2) coordination training of the neck, and (3) no training.

Results
Specific training yielded an increase in MEPs 1 h (p = 0.001) and 7 days (p = 0.001) after training compared with baseline; no significant changes were seen after coordination training or no training. MEPs from the APB muscle did not change over time in any of the conditions. Muscle strength increased by 8% after specific training, but no subjective or objective measures of fatigue were observed.

Conclusions
The results showed that only specific training significantly increased trapezius MEPs for up to 7 days, indicating facilitation of the corticomotor pathways. These findings may help improve the future clinical management of neck pain.