bluuebunny/crossref_metadata_2025 huggingface dataset:
Managing a dual role—experiences and coping strategies of parents donating haploidentical G‐CSF mobilized peripheral blood stem cells to their children
Authors: van Walraven S. M. , Ball L. M. , Koopman H. M. , Switzer G. E. , Ropes‐de Jong C. M. H. , de Jong A. , Bredius R. G. M. , Egeler R. M.
Published: December 2010

Hematopoietic stem cell transplantation is an effective therapy for life‐threatening hematological diseases. Parents may be asked to donate hematopoietic stem cells for their child when no compatible related or unrelated donor is available.

Objective: Parents donating G‐CSF mobilized peripheral blood stem cells simultaneously and uniquely fulfill the dual role of donor and caregiver for their ill child. The experiences of both sibling and unrelated stem cell donors have been extensively reported but not those of parental donors.

Methods: We therefore undertook a study specifically to investigate the experiences and coping strategies of parental stem cell donors. In‐depth qualitative interviews were conducted with 13 parental donors, which were subsequently transcribed and subjected to thematic analysis. In addition, parental coping was assessed utilizing the Utrecht Coping List.

Results: Qualitative analyses revealed four main thematic categories describing the way parental stem cell donation was experienced, namely ‘Hope and Fear’, ‘Need for Information’, ‘Do Anything for your Child’ and ‘Transplant Outcome’ In addition parents noted similar difficulties which were unrelated to their specific role as a donor, for example they felt socially isolated.

Conclusions: Individual information for the parents needs to address not only the transplantation procedure but particularly those aspects related to the donation process. We feel there is a need for a protocol specifically designed to support and coach parental donors. Copyright © 2010 John Wiley & Sons, Ltd.
Does psychological adjustment of melanoma survivors differs between genders?
Authors: Hamama‐Raz Y.
Published: December 2010

Objective: Survival rates of cancer have significantly increased. However, cancer survivors face physical, psychological and social difficulties, while adjusting to post‐illness status. We examined between‐gender differences in the psychological adjustment (mental well‐being, distress and subjective level of functioning), the putative origin of those differences, and the roles of cognitive appraisal, hardiness and attachment style in the psychological adjustment of melanoma survivors.

 Methods: Our sample included 300 malignant melanoma survivors (182 women and 118 men). Most were diagnosed in stages IA and IB of the disease, and had no evidence of disease for 5 years or more. Participants completed self‐report questionnaires regarding personal data, adjustment measured by sense of well‐being, distress and subjective functioning, cognitive appraisal (primary and secondary) and personal resources (hardiness and attachment style).

 Results: Between‐gender differences were revealed in psychological adjustment and in various components of cognitive appraisal and attachment styles. Women revealed more distress, less secondary cognitive appraisal and were more secure in attachment styles. Men showed higher secondary appraisal and were more dismissing‐avoidant in attachment. No between‐group differences were found in mental well‐being, subjective functioning, and primary cognitive appraisal or in the global measure of hardiness.

 Conclusions: We present social processes that seem to account for gender differences in behavior and response to stress, and psychological explanations for these findings. This study contributes to the field of psycho‐oncology by identifying factors that promote adjustment among melanoma survivors. Copyright © 2010 John Wiley & Sons, Ltd.
Determinants of the burden and positivity of family caregivers of terminally ill cancer patients in Korea
Authors: Park Chang‐Hae , Shin Dong Wook , Choi Jin Young , Kang Jina , Baek Young Ji , Mo Ha Na , Lee Mee‐Sook , Park Seon‐Ju , Park Sang Min , Park Sohee
Published: December 2010

Objective: Caregivers may experience positive or negative feelings about their role. The study investigated the determinants of the burden and positivity of family caregivers of Korean terminal cancer patients.

Methods: A multicenter cross‐sectional survey was conducted with 139 family caregivers. Determinants of caregiver's burden and positivity were assessed by the Caregiver Reaction Assessment Scale and by three questions based on a previous study, respectively. Two separate hierarchical multiple regression models were used.

Results: Each domain of the caregiver's burden and positivity was explained by different factors, with the total explained variance ranging between 14.4–33.6% and 2.6–18.3%, respectively. Caregivers who were unmarried, less educated, and/or had low incomes were more likely to be negatively affected, while those who shared caregiving responsibilities were less prone to negative consequences. Caregivers who were male, religious practitioners, and who perceived a higher burden of schedule disruptions were more likely to have a positive perception of their role, while those who perceived a lack of family support were less likely.

Conclusions: Our results highlight the importance of sharing the caregiving burden with the other family members. Organizing a family meeting can provide an opportunity for other family members to acknowledge the feelings and reactions of the primary caregivers, and can prompt the sharing of caregiving responsibilities. Copyright © 2010 John Wiley & Sons, Ltd.
Cancer Treatment Survey (CaTS): development and validation of a new instrument to measure patients' preparation for chemotherapy and radiotherapy
Authors: Schofield Penelope , Gough Karla , Ugalde Anna , Carey Mariko , Aranda Sanchia , Sanson‐Fisher Rob
Published: December 2010

Objective: Cancer patients experience high levels of pre‐treatment anxiety. Chemotherapy and radiotherapy are threatening medical procedures. Preparation for these procedures should include the provision of sensory and procedural information, and addressing fears. The aim of this study was to develop a cancer treatment survey (CaTS) to assess the preparation for chemotherapy and radiotherapy in cancer patients.

Methods: Drawing on evidence for how to prepare patients for threatening procedures, items were generated by psychosocial/clinical experts and pilot tested with cancer patients. The 36‐item draft CaTS was administered to 192 cancer patients commencing chemotherapy for lymphoma, breast or colon cancer. Participants also completed the Hospital Anxiety and Depression Scale (HADS) and basic medical and demographic information was recorded.

Results: A systematic process of item selection removed 11 items. Factor analysis indicated a two‐factor solution, with 11 items representing sensory/psychological concerns and 14 items representing procedural concerns. The two subscales demonstrated excellent internal reliability with Cronbach's alpha both over 0.90 and the average inter‐item correlation for each scale exceeded 0.30. Divergent validity was established for both CaTS subscales with the HADS‐A and‐T (allr<0.30). Younger participants (under 65 years of age) had significantly greater procedural concerns (p= 0.001; medium effect).

Conclusions: The CaTS is a two factor, 25‐item measure that assesses sensory/psychological concerns and procedural concerns relating to cancer treatment. The instrument provides a reliable and valid outcome measure for interventions to prepare cancer patients for chemotherapy and radiotherapy. Copyright © 2010 John Wiley & Sons, Ltd.
Using the theory of planned behavior to understand health professionals' attitudes and intentions to refer cancer patients for psychosocial support
Authors: Kam Ling Yu Keith , Knott Vikki E. , Wilson Carlene , Chambers Suzanne K.
Published: December 2010

Objective: To describe oncology professionals' patterns of referral to existing community and psychosocial support services, including complementary therapies utilizing the theory of planned behavior (TPB).

Methods: An exploratory cross‐sectional survey of 72 oncology professionals including nurses (73.6%), medical practitioners (19.4%) and allied health professionals (6.9%) from health institutions in South Australia assessed past referral patterns, perceived attitudes of peers, control over and attitudes toward, referral, past referral practices and how these impact on intention to refer.

Results: Referral to support services such as a cancer helpline, allied health or complementary services was infrequent. A hierarchical regression entering awareness, past referral and the TPB variables (attitude, subjective norm and perceived control) explained 51% of the variance on the outcome ‘intention to refer’. Barriers to referral for support included lack of local services for remote patients, and financial considerations.

Conclusion: Interventions with health professionals should focus on the development of a culture, which recognizes the importance of addressing a breadth of patient needs across the cancer trajectory. Education and support for health professionals is required to ensure that they feel comfortable discussing support needs and referring to appropriate support services. Copyright © 2010 John Wiley & Sons, Ltd.
Impact on the replacement of Phe by Trp in a short fragment of Aβ amyloid peptide on the formation of fibrils
Authors: Chaudhary Nitin , Nagaraj Ramakrishnan
Published: December 2010

Aβ16–22 (Ac‐KLVFFAE‐NH2) is one of the shortest amyloid fibril‐forming sequences identified in β‐amyloid peptide. At neutral pH, the peptide forms fibrils in the concentration range of 0.2–2.0 mM after ≥ 10 days of incubation. Structures of the fibrils proposed based on solid‐state NMR and MD simulations studies suggest antiparallel arrangement of β‐strands and aromatic interactions between the Phe residues. In an effort to examine the role of aromatic interactions between two Phe residues in Aβ16–22, we have studied the self‐assembly of Aβ16–22 (AβFF) and two of its variants, Ac‐KLVFWAE‐NH2 (AβFW) and Ac‐KLVWFAE‐NH2 (AβWF). The peptides were dissolved in methanol (MeOH) at a concentration of 1 mM and in water (AβFW and AβWF, 1 mM; AβFF, 330 µM). Peptide solutions (100 µM) were prepared in 50 mM sodium phosphate buffer at pH 7 by diluting from MeOH and water stock solutions. AβFW forms amyloid‐like fibrils immediately from MeOH, as indicated by atomic force microscopy. Dilution of AβFW into phosphate buffer from stock solution prepared in MeOH results in fibrils, but with different morphology and dimensions. The secondary structure potentiated by MeOH seems to be important for the self‐assembly of AβFW, as fibrils are not formed from water where the peptide is unordered. On the other hand, AβFF and AβWF do not form amyloid fibrils rapidly from any of the solvents used for dissolution. However, drying of AβWF from MeOH on mica surface gives rod‐like and fibrous structures. Our study indicates that positioning of the aromatic residues F and W has an important role to play in promoting self‐assembly of the Aβ16–22 peptides. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Development of a high transconductance GaN MMIC technology for millimeter wave applications
Authors: Haupt C. , Maroldt S. , Quay R. , Pletschen W. , Leuther A. , Ambacher O.
Published: December 2010

In this paper we report on the development of high transconductance GaN‐based high electron mobility transistors (HEMTs) to improve the performance at W‐Band frequencies. At first, the influence of the barrier thickness on the maximum transconductance (gm,max) was investigated by using two different technologies: growth of thin barrier layers and deep gate recess. Second, the effect of a gate length reduction down to 100 nm on gm,max was examined. The reduction of the barrier thickness results in a strong increase of the extrinsic transconductance up to 600 mS/mm. The technology was then used to fabricate HEMTs, with a cut‐off frequency of 110 GHz, which are compatible to a MMIC technology (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lasing of whispering‐gallery modes in GaInP waveguide micro‐discs and rings with InP quantum dots
Authors: Chu Y. , Mintairov A. M. , He Y. , Merz J. L. , Kalugnyy N. A. , Lantratov V. M. , Mintairov S. A.
Published: December 2010

Whispering‐gallery‐mode (WGM) GaInP micro‐disc (MD) and micro‐ring (MR) resonators (diameters D=1‐3 mm, quality factors Q up to 5×103) with embedded InP quantum dots (size/density ∼100 nm/∼109cm‐2, emission range 720‐770 nm) have been fabricated using a wet oxidation technique. Ultralow (sub‐nanoWatt) lasing thresholds for a single InP quantum dot have been demonstrated for these resonators at 15 K under optical pumping. Observed thresholds are two orders of magnitude lower than for single InAs QD lasing (M. Nomura et al., Opt. Express 17, 15975 (2009) [1]). (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hole emission mechanism in Ge/Si quantum dots
Authors: Kaniewska M. , Engström O. , Karmous A. , Kirfel O. , Kasper E. , Raeissi B. , Piscator J. , Zaremba G. , Kaczmarczyk M. , Surma B. , Wnuk A. , Wzorek M. , Czerwinski A.
Published: December 2010

The mechanisms determining emission of holes in self‐assembled Ge quantum dots (QDs) embedded in the p‐type Si matrix have been investigated. Specimens were prepared by molecular beam epitaxy (MBE). Electrical methods such as deep level transient spectroscopy (DLTS) and capacitance versus voltage (C‐V) measurements were used for the study. The emission mechanisms were identified by measuring a QD‐related signal as a function of the repetition frequency of the filling pulses with the reverse voltage and the pulse voltage as a parameter. An observed shift of the signal position or its absence versus the voltage parameters was interpreted in terms of thermal, tunnelling and mixed processes and attributed to the presence of a Coulomb barrier formed as a result of the charging effect. Thermal emission properties of the QDs were characterized under such measurement conditions that tunnelling contributions to the DLTS spectra could be neglected (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High breakdown voltage AlGaN/GaN HEMT by employing selective fluoride plasma treatment
Authors: Kim Young‐Shil , Lim Ji‐Yong , Kim Min‐Ki , Han Min‐Koo
Published: December 2010

Fluoride‐based plasma treatment was employed to improve reverse characteristics. The fluoride‐based plasma treatment using CF4 gas was performed on drain‐side gate edge region, where field plate metal is deposited, at an RF power of 30W for 120 sec. Experimental results showed that fluoride based plasma treated AlGaN/GaN HEMT had stable reverse blocking capability by successfully suppressing leakage current as well as increasing off‐state breakdown voltage (VBR) with minimized degradation in forward characteristics. Leakage current of untreated sample was increased in proportional to reverse bias voltage while that of fluoride plasma treated sample was remained at nano level. Fluoride plasma treatment improved breakdown voltage of device from 900 V to 1400 V with 16% decrease in output current (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of database mistakes on journal citation analysis: remarks on the paper by Franceschini and Maisano, QREI (2010)
Authors: Franceschini Fiorenzo , Maisano Domenico
Published: December 2010

This short note contains some remarks on a recent bibliometric survey about some of the major scientific journals in the field of Quality Engineering/Management (Qual. Reliab. Engng. Int. 2010; 26(6):593–604). In particular, thanks to Professor Woodall's precious indication, it has been freshly noticed that some results in the original work are biased by mistakes in the bibliometric databases (in this case Google Scholar). After a careful examination and correction of biased data, a synthetic analysis of the typical mistakes of bibliometric databases is presented, focussing the attention on the importance of using robust bibliometric indicators. Copyright © 2010 John Wiley & Sons, Ltd.
Robust multiple model adaptive control: Modified using ν‐gap metric
Authors: Mahdianfar Hessam , Ozgoli Sadjaad , Momeni Hamid Reza
Published: December 2010

A new robust adaptive control method is proposed, which removes the deficiencies of the classic robust multiple model adaptive control (RMMAC) using benefits of the ν‐gap metric. First, the classic RMMAC design procedure cannot be used for systematic design for unstable plants because it uses the Baram Proximity Measure, which cannot be calculated for open‐loop unstable plants. Next, the %FNARC method which is used as a systematic approach for subdividing the uncertainty set makes the RMMAC structure being always companion with the µ‐synthesis design method. Then in case of two or more uncertain parameters, the model set definition in the classic RMMAC is based on cumbersome ad hoc methods. Several methods based on ν‐gap metric for working out the mentioned problems are presented in this paper. To demonstrate the benefits of the proposed RMMAC method, two benchmark problems subject to unmodeled dynamics, stochastic disturbance input and sensor noise are considered as case studies. The first case‐study is a non‐minimum‐phase (NMP) system, which has an uncertain NMP zero; the second case‐study is a mass‐spring‐dashpot system that has three uncertain real parameters. In the first case‐study, five robust controller design methods (H2, H∞, QFT, H∞ loop‐shaping and µ‐synthesis) are implemented and it is shown via extensive simulations that RMMAC/ν/QFT method improves disturbance‐rejection, when compared with the classic RMMAC. In the second case‐study, two robust controller design methods (QFT and mixed µ‐synthesis) are applied and it is shown that the RMMAC/ν/QFT method improves disturbance‐rejection, when compared with RMMAC/ν/mixed−µ. Copyright © 2010 John Wiley & Sons, Ltd.
The effects of a mindfulness‐based stress reduction programme on pre‐sleep cognitive arousal and insomnia symptoms: a pilot study
Authors: Cincotta Andrea L. , Gehrman Philip , Gooneratne Nalaka S. , Baime Michael J.
Published: December 2010

The use of mindfulness meditation for stress management has grown in recent years. Practising mindfulness meditation has been shown to help manage stress and decrease arousal, both of which are associated with difficulty sleeping; thus, mindfulness‐based stress management programmes may have a positive impact on sleep. The effects of an 8‐week mindfulness‐based stress management programme on pre‐sleep cognitive arousal and insomnia symptoms were examined. Sleep was assessed with self‐report measures and objectively with actigraphy. Results showed lower levels of pre‐sleep arousal and milder subjective insomnia symptoms post‐intervention. Longer duration of meditation practice in the final week was associated with greater decreases in cognitive arousal scores. No improvements were found in objectively measured sleep variables. The results of this study suggest that mindfulness‐based stress management can lead to improvements in cognitive arousal and self‐reports of sleep, even in the absence of objective evidence of sleep improvement. Copyright © 2010 John Wiley & Sons, Ltd.
The role of perceived control in the relationship between job insecurity and psychosocial outcomes: moderator or mediator?
Authors: Elst Tinne Vander , De Cuyper Nele , De Witte Hans
Published: December 2010

The aim of the current study was to address the intervening role of perceived control in the job insecurity–strain relationship. Two alternatives were investigated: (1) perceived control as a buffer of the relationship between job insecurity and outcome variables (i.e. job satisfaction, organizational commitment, psychological distress and turnover intentions); and (2) perceived control as a mediator of the relationship between job insecurity and the outcomes. Cross‐sectional data of 211 employees were used to test the hypotheses. The results showed that perceived control did not buffer the relationship between job insecurity, and job satisfaction, organizational commitment, psychological distress and turnover intentions. However, perceived control was found to partially mediate the association between job insecurity and these outcomes. The results are explained using the cognitive theory of stress and coping of Lazarus and Folkman, and suggest that job insecurity is stressful because it decreases the experience of control. Copyright © 2010 John Wiley & Sons, Ltd.
Longitudinal relations between psychosocial work environment, stress and the development of musculoskeletal pain
Authors: Larsman Pernilla , Lindegård Agneta , Ahlborg Gunnar
Published: December 2010

Exposure to psychosocial stressors at work is hypothesized to be related to the development of musculoskeletal pain through the mechanism of work‐related stress. This hypothesis has received support in cross‐sectional studies. Few longitudinal studies that specifically address this hypothesized mediating mechanism are however reported in the literature. The aim of the present study was to test this hypothesis in a longitudinal process model. A 3‐wave mixed occupations cohort‐study was performed with a baseline questionnaire survey in 2004; and with 2‐year follow‐ups in 2006 and 2008. A latent variable process model was tested using structural equation modeling. Since focus of the study was on the process of pain development, only those participants considered pain free at baseline were included (n = 1 133). The results indicate that exposure to high work demands may cause long‐term work‐related stress. The hypotheses that work demands and control influence the development of pain, and that this relation is mediated by work‐related stress were not supported. No indications of reversed causality were found. In order to further elucidate the hypothesized stress mechanism, future research needs to focus on the development of site‐specific musculoskeletal pain in longitudinal studies including repeated measures with shorter lags between measurement waves. Copyright © 2010 John Wiley & Sons, Ltd.
Interplay Between Size and Crystal Structure of Molybdenum Dioxide Nanoparticles—Synthesis, Growth Mechanism, and Electrochemical Performance
Authors: Koziej Dorota , Rossell Marta D. , Ludi Bettina , Hintennach Andreas , Novák Petr , Grunwaldt Jan‐Dierk , Niederberger Markus
Published: December 2010

A detailed study is presented on the formation of MoO2 nanoparticles from the dissolution of the precursor to the final rodlike product, with a focus on the exploration of the inorganic reaction occurring ahead of the nucleation step, and interplay between size and crystal structure of MoO2. In situ X‐ray absorption spectroscopy experiments show that the crystallization and the growth process of MoO2 nanorods is initiated by rapid reduction of the MoO2Cl2 precursor in benzyl alcohol and acetophenone. This reaction triggers the nucleation of 2 nm MoO2 particles with spherical shape and hexagonal crystal structure. The transformation from spheres into rods emerges as a complex process driven by oriented attachment. High‐resolution transmission electron microscopy and X‐ray diffraction results provide evidence that the 2 nm particles first aggregate into 5–20 nm‐large oriented assemblies. The increase in particle size induces the phase transition from hexagonal to the less symmetrical monoclinic crystal structure, and finally the transformation into rods. Is it shown that electrodes for lithium‐ion batteries based on MoO2 nanorods have a long‐term cycling life. The specific discharge capacity even after 200 cycles at a discharge rate of 1 C is about 300 Ah kg−1.
Generalized continua and non‐homogeneous boundary conditions in homogenisation methods
Authors: Forest S. , Trinh D.K.
Published: December 2010

Extensions of classical homogenization methods are presented that are used to replace a composite material by an effective generalized continuum model. Homogeneous equivalent second gradient and micromorphic models are considered, establishing links between the macroscopic generalized stress and strain measures and the fields of displacement, strain and stress inside a volume element of composite material. Recently proposed non‐homogeneous boundary conditions to be applied to the unit cell, are critically reviewed. In particular, it is shown that such polynomial expansions of the local displacement field must be complemented by a generally non‐periodic fluctuation field. A computational strategy is introduced to unambiguously determine this fluctuation. The approach is well‐suited for elastic as well as elastoplastic composites.
The undulatory motion of a chain of particles in a resistive medium
Authors: Bolotnik N. , Pivovarov M. , Zeidis I. , Zimmermann K.
Published: December 2010

The motion of a finite chain of identical bodies along a straight line in a resistive medium is studied. The major aim of this study is to investigate the fundamental properties of such systems, in particular, their ability to move from a state of rest and sustain the motion at constant average velocity in media with different resistance properties and the influence of the control strategy on the motion. The motion is excited and controlled by changing the distances between the bodies of the chain. For a given friction law, the necessary and sufficient conditions for the system to be able to move from rest are established.
An efficient representation for kernels in the 2d dynamic displacement discontinuity method for cracked elastic materials
Authors: Sumbatyan M. , Brigante M.
Published: December 2010

The displacement discontinuity method is a rather standard approach to study cracks in elastic materials. This is in fact a certain technique to construct the system of Boundary Integral Equations (BIE), or equivalently, Boundary Element Methods (BEM). In the static case this typically results in explicit expressions for the kernels of respective BIE, both in 2d and 3d problems. In the work the authors give efficient representations for such kernels in explicit form.
Leiomyoma of the Foot: Sonographic Features with Pathologic Correlation
Authors: Stock Harlan , Perino Giorgio , Athanasian Edward , Adler Ronald
Published: December 2010

Leiomyomas arising outside of the uterus and gastrointestinal tract are uncommon, though these benign soft tissue neoplasms have been reported in the lower extremity and foot. To our knowledge, the sonographic appearance of a lower extremity leiomyoma has not been described in the literature. This report involves a case of leiomyoma of the foot and its sonographic imaging features. MR correlative imaging and histopathology are also provided.
Genomisches Imprinting und Imprintingfehler
Authors: Horsthemke B.
Published: December 2010

Genomisches Imprinting ist ein epigenetischer Prozess, bei dem die männliche und die weibliche Keimbahn bestimmte Genregionen durch Histonmodifikationen und DNA-Methylierung so prägen, dass nur das väterliche oder nur das mütterliche Allel eines Gens aktiv ist. Genomische Imprints werden in primordialen Keimzellen gelöscht, während späterer Phasen der Keimzellentwicklung neu etabliert und bei den somatischen Zellteilungen während der postzygotischen Entwicklung stabil weitergegeben. Fehler in der Entfernung der Imprints, ihrer Etablierung oder ihrer Erhaltung führen zu falschen epigenetischen Mustern und Expressionsprofilen, die spezifische Erkrankungen verursachen können. Imprintingfehler können spontan, ohne jegliche Änderungen in der DNA-Sequenz, auftreten (primäre Imprintingfehler) oder als Folge einer Mutation in einemcis-regulatorischen Element oder einemtrans-aktiven Faktor (sekundäre Imprintingfehler). Die Unterscheidung zwischen primären und sekundären Imprintingfehlern ist für die Abschätzung des Wiederholungsrisikos in betroffenen Familien wesentlich.
La chronique de la gynécologie: les techniques chirurgicales micro-invasives à visée diagnostique ont-elles leur place en pathologie testiculaire ?
Authors: Seznec C.
Published: December 2010

C’est dans le cadre de bilan d’infertilité masculine que des pathologies occultes testiculaires peuvent être découvertes grâce aux échographies. Différentes publications font état de techniques chirurgicales micro-invasives dans la prise en charge diagnostique de ces images, mais l’abord chirurgical du testicule doit répondre à des règles strictes de sécurité carcinologique suivant les recommandations de l’association européenne d’urologie (EAU guidelines, 2010 édition).
A graph clustering algorithm based on a clustering coefficient for weighted graphs
Authors: Nascimento Mariá C. V. , Carvalho André C. P. L. F.
Published: December 2010

Graph clustering is an important issue for several applications associated with data analysis in graphs. However, the discovery of groups of highly connected nodes that can represent clusters is not an easy task. Many assumptions like the number of clusters and if the clusters are or not balanced, may need to be made before the application of a clustering algorithm. Moreover, without previous information regarding data label, there is no guarantee that the partition found by a clustering algorithm automatically extracts the relevant information present in the data. This paper proposes a new graph clustering algorithm that automatically defines the number of clusters based on a clustering tendency connectivity-based validation measure, also proposed in the paper. According to the computational results, the new algorithm is able to efficiently find graph clustering partitions for complete graphs.
Pneumatosis intestinalis versus pseudo-pneumatosis: review of CT findings and differentiation
Authors: Wang Jin Hong , Furlan Alessandro , Kaya Diana , Goshima Satoshi , Tublin Mitchell , Bae Kyongtae T.
Published: December 2010

Pneumatosis intestinalis is defined as the presence of gas within the wall of the gastrointestinal tract. Originally described on plain abdominal radiographs, it is an imaging sign rather than a specific diagnosis and it is associated with both benign and life-threatening clinical conditions. The most common life-threatening cause of pneumatosis intestinalis is bowel ischaemia. Computed tomography (CT) is usually requested to detect underlying disease. The presence of pneumatosis intestinalis often leads physicians to make a diagnosis of serious disease. However, an erroneous diagnosis of pneumatosis intestinalis may be made (i.e. pseudo-pneumatosis) when intraluminal beads of gas are trapped within or between faeces and adjacent mucosal folds. The purpose of this pictorial essay is to review and describe the CT imaging findings of pneumatosis and pseudo-pneumatosis intestinalis and to discuss key discriminatory imaging features.
Phosphorus imbalance in the global ocean?
Authors: Wallmann Klaus
Published: December 2010

The phosphorus budget of the prehuman modern ocean is constrained applying the most recent estimates of the natural riverine, eolian, and ice‐rafted input fluxes; the phosphorus burial in marine sediments; and the hydrothermal removal of dissolved phosphate from the deep ocean. This review of current flux estimates indicates that the phosphorus budget of the ocean is unbalanced since the accumulation of phosphorus in marine sediments and altered oceanic crust exceeds the continental input of particulate and dissolved phosphorus. The phosphorus mass balance is further tested considering the dissolved phosphate distribution in the deep water column, the marine export production of particulate organic matter, rain rates of phosphorus to the seafloor, benthic dissolved phosphate fluxes, and the organic carbon to phosphorus ratios in marine particles. These independent data confirm that the phosphate and phosphorus budgets were not at steady state in the prehuman global ocean. The ocean is losing dissolved phosphate at a rate of ≥11.6 × 1010 mol yr−1 corresponding to a decline in the phosphate inventory of ≥4.5% kyr−1. Benthic data show that phosphate is preferentially retained in pelagic deep‐sea sediments where extended oxygen exposure times favor the degradation of particulate organic matter and the uptake of phosphate in manganese and iron oxides and hydroxides. Enhanced C: P regeneration ratios observed in the deep water column (>400 m water depth) probably reflect the preferential burial of phosphorus in pelagic sediments. Excess phosphate is released from continental margin sediments deposited in low‐oxygen environments. The dissolved oxygen threshold value for the enhanced release of dissolved phosphate is ∼20 μM. Benthic phosphate fluxes increase drastically when oxygen concentrations fall below this value.
Upper ocean bubble measurements from the NE Pacific and estimates of their role in air‐sea gas transfer of the weakly soluble gases nitrogen and oxygen
Authors: Vagle Svein , McNeil Craig , Steiner Nadja
Published: December 2010

Simultaneous observations of upper‐ocean bubble clouds, and dissolved gaseous nitrogen (N2) and oxygen (O2) from three winter storms are presented and analyzed. The data were collected on the Canadian Surface Ocean Lower Atmosphere Study (C‐SOLAS) mooring located near Ocean Station Papa (OSP) at 50°N, 145°W in the NE Pacific during winter of 2003/2004. The bubble field was measured using an upward looking 200 kHz echosounder. Direct estimates of bubble mediated gas fluxes were made using assumed bubble size spectra and the upward looking echosounder data. A one‐dimensional biogeochemical model was used to help compare data and various existing models of bubble mediated air‐sea gas exchange. The direct bubble flux calculations show an approximate quadratic/cubic dependence on mean bubble penetration depth. After scaling from N2/O2 to carbon dioxide, near surface, nonsupersaturating, air‐sea transfer rates, KT, for U10 > 12 m s−1 fall between quadratic and cubic relationships. Estimates of the subsurface bubble induced air injection flux, VT, show an approximate quadratic/cubic dependence on mean bubble penetration depth. Both KT and VT are much higher than those measured during Hurricane Frances over the wind speed range 12 < U10 < 23 m s−1. This result implies that over the open ocean and this wind speed range, older and more developed seas which occur during winter storms are more effective in exchanging gases between the atmosphere and ocean than younger less developed seas which occur during the rapid passage of a hurricane.
Three‐dimensional volcanic aerosol dispersal: A comparison between Multiangle Imaging Spectroradiometer (MISR) data and numerical simulations
Authors: Scollo S. , Folch A. , Coltelli M. , Realmuto V. J.
Published: December 2010

The three‐dimensional reconstruction of volcanic plumes is a central goal to enhance our understanding on dispersal processes. In this paper we use data from the Multiangle Imaging Spectroradiometer (MISR) on board NASA's Terra spacecraft combined with a stereo matching retrieval procedure. We show the potential of MISR in capturing important features of volcanic plumes like column height, optical depth, type, and shape of the finest particles of two highly explosive eruptions occurring on Mount Etna in 2001 and 2002. This work tests how tephra dispersal models reconstruct the 3‐D shape of volcanic clouds. We compare MISR data with FALL3D, an Eulerian model for the transport and deposition of volcanic ash and aerosols coupled with the Weather Research and Forecasting mesoscale meteorological model. Agreement between simulations and MISR data is good regarding both events, although it could be improved by increasing the accuracy of the meteorological data, a better constraint on volcanological input parameters like the height of the eruptive column and improving our understanding of processes such as aggregation phenomena and volcanic cloud microphysics.
Iceberg calving as a primary source of regional‐scale glacier‐generated seismicity in the St. Elias Mountains, Alaska
Authors: O'Neel Shad , Larsen Christopher F. , Rupert Natalia , Hansen Roger
Published: December 2010

Since the installation of the Alaska Regional Seismic Network in the 1970s, data analysts have noted nontectonic seismic events thought to be related to glacier dynamics. While loose associations with the glaciers of the St. Elias Mountains have been made, no detailed study of the source locations has been undertaken. We performed a two‐step investigation surrounding these events, beginning with manual locations that guided an automated detection and event sifting routine. Results from the manual investigation highlight characteristics of the seismic waveforms including single‐peaked (narrowband) spectra, emergent onsets, lack of distinct phase arrivals, and a predominant cluster of locations near the calving termini of several neighboring tidewater glaciers. Through these locations, comparison with previous work, analyses of waveform characteristics, frequency‐magnitude statistics and temporal patterns in seismicity, we suggest calving as a source for the seismicity. Statistical properties and time series analysis of the event catalog suggest a scale‐invariant process that has no single or simple forcing. These results support the idea that calving is often a response to short‐lived or localized stress perturbations. Our results demonstrate the utility of passive seismic instrumentation to monitor relative changes in the rate and magnitude of iceberg calving at tidewater glaciers that may be volatile or susceptible to ensuing rapid retreat, especially when existing seismic infrastructure can be used.
Scale‐invariant stress orientations and seismicity rates near the San Andreas Fault
Authors: Day‐Lewis Amy , Zoback Mark , Hickman Stephen
Published: December 2010

We analyzed measurements of the direction of maximum horizontal compressive stress as a function of depth in two scientific research wells near the San Andreas Fault in central and southern California. We found that the stress orientations exhibit scale‐invariant fluctuations over intervals from tens of cm to several km. Similarity between the scaling of the stress orientation fluctuations and the scaling of earthquake frequency with fault size suggests that these fluctuations are controlled by stress perturbations caused by slip on faults of various sizes in the critically‐stressed crust adjacent to the fault. The apparent difference in stress scaling parameters between the two studies wells seem to correspond to differences in the earthquake magnitude‐frequency statistics for the creeping versus locked sections of the fault along which these two wells are located. This suggests that stress heterogeneity adjacent to active faults like the San Andreas may reflect variations in stresses and loading conditions along the fault.
Response of mantle heat flux to plate evolution
Authors: Stein C. , Lowman J. P.
Published: December 2010

By analyzing convection characteristics and surface and basal heat flux we investigate the influence on mantle convection of finite thickness plates with dynamically determined velocities and mobile boundaries. Our 6 × 6 × 1 Cartesian geometry numerical model features periodic sidewall boundary conditions, a lower mantle that increases in viscosity and a Rayleigh number of 5 × 106 (based on the uniform viscosity upper mantle). A calculation with 9 plates and fixed plate boundaries is compared with a second calculation incorporating evolving plate boundaries. The number of plates in the latter case fluctuates between 6 and 9. We find that mean heat flux output decreases during periods characterized by the presence of larger plates and that evolving plate boundaries cause surface (and basal) heat flux output to vary much more than the heat flux observed with either fixed plate boundaries or a free‐slip surface.
Air‐sea energy exchanges measured by eddy covariance during a localised coral bleaching event, Heron Reef, Great Barrier Reef, Australia
Authors: MacKellar Mellissa C. , McGowan Hamish A.
Published: December 2010

Despite the widely claimed association between climate change and coral bleaching, a paucity of data exists relating to exchanges of heat, moisture and momentum between the atmosphere and the reef‐water surface. We present in situ measurements of reef‐water‐air energy exchanges made using the eddy covariance method during a summer coral bleaching event at Heron Reef, Australia. Under settled, cloud‐free conditions and light winds, daily net radiation exceeded 800 W m−2, with up to 95% of the net radiation during the morning partitioned into heating the water column, substrate and benthic cover including corals. Heating was exacerbated by a mid‐afternoon low tide when shallow reef flat water reached 34°C and near‐bottom temperatures 33°C, exceeding the thermal tolerance of corals, causing bleaching. Results suggest that local to synoptic scale meteorology, particularly clear skies, solar heating, light winds and the timing of low tide were the primary controls on coral bleaching.
Structural joint inversion of time‐lapse crosshole ERT and GPR traveltime data
Authors: Doetsch Joseph , Linde Niklas , Binley Andrew
Published: December 2010

Time‐lapse geophysical monitoring and inversion are valuable tools in hydrogeology for monitoring changes in the subsurface due to natural and forced (tracer) dynamics. However, the resulting models may suffer from insufficient resolution, which leads to underestimated variability and poor mass recovery. Structural joint inversion using cross‐gradient constraints can provide higher‐resolution models compared with individual inversions and we present the first application to time‐lapse data. The results from a synthetic and field vadose zone water tracer injection experiment show that joint 3‐D time‐lapse inversion of crosshole electrical resistance tomography (ERT) and ground penetrating radar (GPR) traveltime data significantly improve the imaged characteristics of the point injected plume, such as lateral spreading and center of mass, as well as the overall consistency between models. The joint inversion method appears to work well for cases when one hydrological state variable (in this case moisture content) controls the time‐lapse response of both geophysical methods.
Elliptical model of cutoff boundaries for the solar energetic particles measured by POES satellites in December 2006
Authors: Dmitriev A. V. , Jayachandran P. T. , Tsai L.‐C.
Published: December 2010

Experimental data from a constellation of five NOAA Polar Orbiting Environmental Satellites (POES), satellites were used for studying the penetration of solar energetic particles (SEP) to high latitudes during long‐lasting SEP events on 5–15 December 2006. We determined cutoff latitudes for electrons with energies >100 keV and >300 keV and for protons with energies from 240 keV to >140 MeV. The large number of satellites allowed us to derive snapshots of the cutoff boundaries with 1‐hour time resolution. The boundaries were fitted well by ellipses. On the basis of the elliptical approach, we developed a model of cutoff latitudes for protons and electrons in the northern and southern hemispheres. The cutoff latitude is represented as a function of rigidity, R, of particles; MLT, geomagnetic indices Dst, Kp, and AE; and dipole tilt angle PS. The model predicts tailward and duskward shifting of the cutoff boundaries in relation to intensification of the cross‐tail current, field‐aligned currents, and symmetrical and asymmetrical parts of the ring current. The model was applied for prediction of polar cap absorption (PCA) effects observed at high latitudes by the Canadian Advanced Digital Ionosonde network of ionosondes. It was found that the PCA effects are related mainly to intense fluxes of >2.5 MeV protons and >100 keV electrons, which contribute mostly to the ionization of ionospheric D‐layer at altitudes of ∼75 to 85 km. This finding was confirmed independently by FORMOSAT‐3/COSMIC observations of the SEP‐associated enhancements of electron content at altitudes of ∼80 km.
Global response to local ionospheric mass ejection
Authors: Moore T. E. , Fok M.‐C. , Delcourt D. C. , Slinker S. P. , Fedder J. A.
Published: December 2010

We revisit a reported “Ionospheric Mass Ejection” using prior event observations to guide a global simulation of local ionospheric outflows, global magnetospheric circulation, and plasma sheet pressurization, and comparing our results with the observed global response. Our simulation framework is based on test particle motions in the Lyon‐Fedder‐Mobarry (LFM) global circulation model electromagnetic fields. The inner magnetosphere is simulated with the Comprehensive Ring Current Model (CRCM) of Fok and Wolf, driven by the transpolar potential developed by the LFM magnetosphere, and includes an embedded plasmaspheric simulation. Global circulation is stimulated using the observed solar wind conditions for the period 24–25 September 1998. This period begins with the arrival of a Coronal Mass Ejection, initially with northward, but later with southward interplanetary magnetic field. Test particles are launched from the ionosphere with fluxes specified by local empirical relationships of outflow to electrodynamic and particle precipitation imposed by the MHD simulation. Particles are tracked until they are lost from the system downstream or into the atmosphere, using the full equations of motion. Results are compared with the observed ring current and a simulation of polar and auroral wind outflows driven globally by solar wind dynamic pressure. We find good quantitative agreement with the observed ring current, and reasonable qualitative agreement with earlier simulation results, suggesting that the solar wind driven global simulation generates realistic energy dissipation in the ionosphere and that the Strangeway relations provide a realistic local outflow description.
Combining incoherent scatter radar data and IRI‐2007 to monitor the open‐closed field line boundary during substorms
Authors: Woodfield E. E. , Wild J. A. , Kavanagh A. J. , Senior A. , Milan S. E.
Published: December 2010

The size of the polar cap is very important for understanding the substorm process as well as reconnection rates in general. In this work we build on previous studies which use a combination of European Incoherent Scatter radar (EISCAT) electron temperature (Te) measurements from two radars running simultaneously to track the motion of the open‐closed field line boundary (OCB). The second radar gives an estimate of the background variation of Te with altitude, which can then be subtracted from the radar beam being used to estimate the OCB location. We demonstrate that using the international reference ionosphere 2007 (IRI‐2007) model can remove the second radar requirement and therefore increase the number of cases which could benefit from background Te subtraction. In this paper we focus our analysis on substorm intervals. We find that the IRI‐2007 method produces an OCB proxy location which on average is 0.25° altitude adjusted corrected geomagnetic coordinate latitude equatorward of the two‐radar method. On comparing both the two‐radar and IRI‐2007 Te OCB finding methods with the OCB identified in the DMSP particle data and IMAGE satellite data we find that both EISCAT methods perform quite well, and neither method is particularly favored over the other. We find that the magnitude of the mean offset to the IMAGE OCB varies between 0.1° and 2.7° latitude, dependent on the event and the IMAGE camera used.