bluuebunny/crossref_metadata_2025 huggingface dataset:
Disc formation in turbulent massive cores: circumventing the magnetic braking catastrophe
Authors: Seifried D. , Banerjee R. , Pudritz R. E. , Klessen R. S.
Published: April 2012

We present collapse simulations of 100 M⊙ turbulent cloud cores threaded by a strong magnetic field. During the initial collapse phase, filaments are generated which fragment quickly and form several protostars. Around these protostars Keplerian discs with typical sizes of up to 100 au build up in contrast to previous simulations neglecting turbulence. We examine three mechanisms potentially responsible for lowering the magnetic braking efficiency and therefore allowing for the formation of Keplerian discs. Analysing the condensations in which the discs form, we show that the build-up of Keplerian discs is neither caused by magnetic flux loss due to turbulent reconnection nor by the misalignment of the magnetic field and the angular momentum. It is rather a consequence of the turbulent surroundings of the disc which exhibit no coherent rotation structure while strong local shear flows carry large amounts of angular momentum. We suggest that the ‘magnetic braking catastrophe’, i.e. the formation of sub-Keplerian discs only, is an artefact of the idealized non-turbulent initial conditions and that turbulence provides a natural mechanism to circumvent this problem.
On the behaviour of the magnetorotational instability when the Rayleigh criterion is violated
Authors: Balbus Steven A.
Published: April 2012

An elementary but revealing analysis of the dispersion relation of the magnetorotational instability (MRI) in the Ralyeigh-unstable regime is described. The defining properties of the MRI – its maximum growth rate and the direction of the associated eigenvector displacement – remain unchanged as the Rayleigh discriminant passes from positive to negative values. At sufficiently negative discriminant values, however, the spectrum of unstable modes becomes dominated by zero wavenumber disturbances, and the problem loses its local character. These results may be relevant to understanding the level of turbulent fluid stress near the innermost stable circular orbit (ISCO) in an accretion disc around a black hole, since the Rayleigh discriminant changes sign at this location. Our conclusions are consistent with numerical simulations that find finite stress at the ISCO, some dependence of the stress magnitude with scale height, and a plunging region much closer to the event horizon than the ISCO radius.
Zur Kenntnis der enzymatischen Oxydationsprozesse in phosphatfreiem bzw. phosphathaltigem Medium1
Authors: Thunberg T.
Published: April 2012

Bei den früher veröffentlichten Versuchen des Verfassers über Dehydrogenasen aus Pflanzensamen ist zur Extraktion dieser Enzyme durchweg eine schwach alkalische Phosphatlösung zur Anwendung gelangt. Die Untersuchung der Aktivität der Dehydrogenasen geschah deshalb auch regelmäßig in einer Phosphatlösung. Unter solchen Umständen ist bei diesen Versuchen nicht beachtet worden, wie es sich mit der Aktivität der Enzyme in Abwesenheit von Phosphat verhält. Verf. hat nun Samenpulver mit 1% igem KCl extrahiert und die Aktivität dieses KCl‐Extraktes teils ohne und teils mit Zusatz von Phosphat untersucht, wobei auch der pH‐Wert verändert wurde. Bezüglich der Hexosediphosphorsäure‐Dehydrogenase, wie sie durch Extraktion mit KCl‐Lösung aus Samen von Cucumis sativus, Corchorus capsularis und Phaseolus multiflorus erhalten wird, teilt nun Verf. mit, daß dieselbe nicht die Fähigkeit besitzt, den Wasserstoff der Hexosediphosphorsäure auf Mb. zu überführen. Diese Fähigkeit tritt erst bei Zusatz einer geeigneten Menge von Phosphat und bei geeignetem pH auf. KCl‐Extrakt aus Samen von Citrus aurantium dulcis zeigt ein anderes Verhalten.

Der Stiftung Therese och Johan Anderssons Minne danke ich für finanzielle Unterstützung der vorliegenden Untersuchung.
Der kleinste Sehwinkel bei Verwendung lichtloser Quadrate auf selbstleuchtendem Grund und seine Beziehung zur Größe und Funktion der retinalen Einheiten, bzw. dem „Auflösungsvermögen” des emmetropen Auges1
Authors: Berger Curt
Published: April 2012

. Es wird eine Anordnung beschrieben, mit welcher der Abstand zwischen zwei lichtlosen Quadraten auf selbstleuchtendem Grund bis auf o mm herab beliebig vergrößert oder verkleinert werden kann. Genauigkeit ist Hundertstel Millimeter.

. Im Gegensatz zu der Abhängigkeit des →>Auflösungsvermögens← (selbstleuchtende Quadrate) von der Beleuchtung nimmt der kleinste Sehwinkel bei Verwendung lichtloser Quadrate auf selbstleuchtendem Grund mit zunehmender Helligkeit ab, d. h. die Unterschiedsempfindlichkeit nimmt zu.

. Diese Zunahme der Unterschiedsempfindlichkeit mit zunehmender Beleuchtung ist kontinuierlich, aber sie ist geringer als die Abnahme des Auflösungsvermögens. Sie ist dieselbe, gleichgültig ob man große oder kleine Quadrate verwendet.

. Die Unterschiedsempfindlichkeit des Auges bei Verwendung lichtloser Quadrate nimmt — genau wie das Auflösungsvermögen — zu mit der Größe des gereizten Netzhautbildes, jedoch ist der kleinste Sehwinkel bei lichtlosen Quadraten und Schwellenhelligkeit bei allen Größen kleiner als bei selbstleuchtenden.

. Kleine, künstliche Pupillen haben so gut wie keinen Einfluß auf die Unterschiedsempfindlichkeit. Nur bei sehr kleinen Pupillen von 0,5 mm Durchmesser tritt infolge der Beugungserscheinungen eine erhebliche Verschlechterung der Funktion ein.

. Kleine, schwarze Quadrate werden erst sichtbar, wenn das entsprechende Netzhautbild die Größe von etwa 72 μ2 erreicht. Unterhalb dieser Größenordnung sind sie unsichtbar.

. Die Abhängigkeit des kleinsten Sehwinkels von der Beleuchtung ist wahrscheinlich eine Folge der Lichtzerstreuung in den optischen Medien des Auges hinter der Pupille. Die Unterschiede bei schwarzen Quadraten gegenüber selbstleuchtenden sind möglicherweise eine Folge von Streulicht über der ganzen Retina infolge des praktisch konstanten, großen Grundes, wodurch feinere Abweichungen und die Lichtzerstreuung überhaupt weniger sichtbar werden. Die Abnahme des kleinsten Sehwinkels mit zunehmender Größe der Quadrate bestätigt die frühere Annahme (Berger und Buchthal (1938)), wonach die Fovea aus verschieden großen, funktionellen Einheiten besteht. Die Tatsache, daß schwarze Quadrate unsichtbar sind, solange ihre Bilder auf der Netzhaut kleiner als etwa 72 μ2 ausmachen, bestätigt besonders klar, daß die durchschnittliche funktionelle Einheit aus 2–3 Zapfen besteht.

Herrn Dr. F. Buchthal sage ich auch an dieser Stelle für mannigfachen, wertvollen Rat bei Durchführung der Arbeit meinen besten Dank.

Die Arbeit wurde mit Unterstützung des Insulin‐Fonds ausgeführt.
Über das Vermögen des Igels Carotin und Vitamin A auszunutzen1
Authors: Suomalainen Paavo
Published: April 2012

Als Igel zwei Monate lang bei carotin‐ und vitamin‐A‐freier Diät gehalten wurden, verringerte sich der Vitamin‐A‐Gehalt des Serums ebenso wie der Carotingehalt der Leber und insbesondere des Serums. Der Vitamin‐A‐Gehalt der Leber erfuhr dagegen keine Abnahme.

Verfütterung von Vitamin A bewirkte bei Igeln, die zuvor bei carotin‐ und vitamin‐A‐freier Nahrung gehalten worden waren, eine geringe Steigerung des Vitamin‐A‐Gehalts im Serum, eine erhebliche dagegen in der Leber. Etwa die Hälfte des verabreichten Vitamins A wurde in der Leber aufgespeichert. Durch Carotinfütterung wurde der Carotingehalt von Serum und Leber auf das Vielfache gesteigert, obwohl nur etwa 3 % des Carotins in der Leber aufgespeichert wurde. Die Carotinfütterung führte auch zu einer Erhöhung des Vitamin‐A‐Gehalts der Leber, doch war diese im Verhältnis zu der durch die Vitamin‐A‐Fütterung bewirkten Steigerung gering. Auf Grund des Versuchsmaterials läßt sich indes nicht schließen, ob die geringe Zunahme des Vitamin‐A‐Gehalts der Leber infolge der Carotinfütterung lediglich auf der schlechten Resorption des Carotins oder auf dem geringen Vermögen des Igels, Carotin in Vitamin A umzuwandeln, beruht.

Anschließend gibt Verfasser eine kurze Übersicht über das Vermögen der verschiedenen Tiere, Carotin in Vitamin A umzuwandeln, ebenso wie über die Fähigkeit der Tiere, Carotin und Vitamin A zu resorbieren.
Early Judeo‐Arabic Biblical Translations
Authors: Tobi Yosef
Published: April 2012

During the last generation, there has been published no small or insignificant number of loose pages of different Judeo Arabic (henceforth: JA) translations of the Bible, preserved in the Cairo Genizah. The prevailing view among Judaic Studies scholars is that these translations predated the earliest JA Biblical translation known hitherto, namely, that produced by Rabbi Sa’adia Gaon (882‐942). Sa’adia was familiar with these older translations and occasionally used them for his translation (tafsīr), but on the whole he composed his own translation with a view of being a critique on their two main traits: (a) the phonetic orthography which does not fit the strict rules of classical Arabic grammar; (b) the literary translation, namely, giving an Arabic word for each Hebrew word, according to the order of the words in the Bible, and ignoring Arabic syntax.

What is known about the life of the Jewish communities in the north‐western regions of the Arabian Peninsula during the centuries that preceded Sa’adia mostly comes from early Muslim sources. We may conjecture that these translations already existed prior to the advent of Islam, that is to say, not later than the beginning of the seventh century. They were produced and used for teaching the Torah (Pentateuch), and for the Bible as a whole, in the schoolrooms where Jewish children were gathered in the Arabic speaking Jewish communities of north‐western Arabia. A related genre of biblical translation written in non‐classical JA is the ŠarḥAlfāẓ, that is to say, lists of difficult words in the Scripture according to their order in any given book with their Arabic translation. The didactic, or educational advantages of having these translations is proven as well by their wide‐ranging commentaries found written for variant translations, and interspersed within the texts, and which have no other function in liturgy within the congregation.
Negotiators’ Information Sharing: The Effects of Opponent Behavior and Information about Previous Negotiators’ Performance
Authors: Zarankin Tal G. , Wall James A.
Published: April 2012

In this study, we investigate the effects of three factors upon negotiators’ information sharing: (a) the opponent’s information sharing, (b) the opponent’s call for information sharing, and (c) information about previous negotiators’ performance. To test the effects of the factors, we had 120 subjects participate in a laboratory experiment wherein they negotiated over three issues. The results indicate that negotiators share more information (i.e., disclose information about their BATNA and about their payoffs) when their opponents share information (i.e., disclose information about BATNA and about payoffs) and when their opponents call for the negotiators to share information. Information about the previous negotiators’ performance did not affect the negotiators’ own information sharing. However, the negotiators did have high aspirations when presented with a mix of information—that some previous negotiators had attained high outcomes and others had attained low outcomes.
Conceptualizing Managerial Influence in Organizational Conflict—A Qualitative Examination
Authors: Siira Kalle
Published: April 2012

The purpose of this article is to broaden the understanding of managerial conflict influence by suggesting a social complexity perspective on organizational conflict. From this perspective, influence is essentially a meaning‐based phenomenon that represents an interpretive view of organizational communication. Although some research exists that holds similar notions of managerial conflict influence, most research embodies a transmission view of communication and influence. Based on a qualitative analysis of 30 semi‐structured interviews, managerial conflict influence can be conceptualized according to two theoretical dimensions, directness and communicative influence, including five subdimensions: direct, indirect, distant, constraining, and enabling. A tentative typology of managerial conflict influence using the identified dimensions is proposed. Finally, theoretical and practical notions as well as limitations of the study are discussed.
Fusing Creativity: Cultural Metacognition and Teamwork in Multicultural Teams
Authors: Crotty Susan K. , Brett Jeanne M.
Published: April 2012

This study elaborates theoretically and tests empirically a model linking fusion teamwork to creativity in multicultural teams (Janssens & Brett, 2006). The study also introduces cultural metacognition, a dimension of cultural intelligence (Earley & Ang, 2003), as an antecedent of fusion teamwork and creativity. Data were from 246 members of 37 multicultural teams. Results generated from a multilevel modeling analysis were consistent with hypotheses: Across teams, when team members were more highly culturally metacognitive, fusion teamwork and creativity were more likely. All analyses were controlled for generalized affect toward the team to reduce threats to validity of common method bias and affect. The results suggest the value of fusion teamwork for generating creativity in multicultural teams and the importance of having members of multicultural teams who have high versus low levels of cultural metacognition.
IRGM gene polymorphisms and risk of gastric cancer
Authors: BURADA Florin , PLANTINGA Theo S , IOANA Mihai , ROSENTUL Diana , ANGELESCU Cristina , JOOSTEN Leo A , NETEA Mihai G , SAFTOIU Adrian
Published: April 2012

OBJECTIVE:  The study aimed to assess the possible association of polymorphisms in the autophagy gene IRGM (rs13361189 and rs4958847) with the risk of gastric cancer.

METHODS:  A total of 102 patients with gastric adenocarcinoma, 52 with chronic gastritis and 351 healthy controls were included in this study. IRGM allelic variants were genotyped by quantitative real‐time polymerase chain reaction. The association between polymorphisms and gastric cancer risk was estimated by odds ratios (OR) and 95% confidence interval (CI).

RESULTS:  A significant difference was found for rs4958847 A allele. Carriers of the A allele were protected against gastric cancer (OR = 0.58, 95% CI 0.35–0.97, P = 0.038). Moreover, the presence of this allele seems to play an important role in decreasing the risk for the intestinal type of gastric cancer (OR = 0.47, 95% CI 0.23–0.94, P = 0.03). In contrast, the rs13361189 IRGM polymorphism was not associated with susceptibility to gastric cancer. None of the targeted polymorphisms were associated with chronic gastritis.

CONCLUSION:  IRGM rs4958847 polymorphism influences susceptibility to gastric cancer, mainly for the intestinal type.
IDH2 mutations are frequent in Chinese patients with acute myeloid leukemia and associated with NPM1 mutations and FAB‐M2 subtype
Authors: CHAO H.‐Y. , JIA Z.‐X. , CHEN T. , LU X.‐Z. , CEN L. , XIAO R. , JIANG N.‐K. , YING J.‐H. , ZHOU M. , ZHANG R.
Published: April 2012

Introduction:  Gene mutations play an important role in acute myeloid leukemia (AML) pathogenesis. Several genes have been identified in AML, such as FLT3, KIT, NPM1, and JAK2. This study investigated the frequency of novel mutations in IDH1 (amino acid R132) and IDH2 (R140 and R172) and analyzed their impact on disease biology and interaction with other mutations in Chinese patients with de novo AML.

Methods:  A total of 195 patients were screened for mutations in the IDH1, IDH2, JAK2 V617F, NPM1, FLT3, and KIT genes, using polymerase chain reaction (PCR)‐based and direct sequencing assays.

Results:  IDH mutations occurred at a considerable frequency of 15.89% in Chinese AML cases; IDH2 R140Q was the most frequent genetic alteration and was associated with older age, normal karyotype, and French‐American‐British classification M2 at diagnosis. There was a strong association of IDH2 mutation with NPM1 mutations and a trend with FLT3‐internal‐tandem duplication.

Conclusion:  IDH mutations may be a novel genetic marker in cytogenetically normal AML and may cooperate in leukemogenesis.
Hb Haaglanden: a new nonsickling β7Glu>Val variant. Consequences for basic diagnostics, screening, and risk assessment when dealing with HbS‐like variants
Authors: HARTEVELD C. L. , PONJEE G. , BAKKER‐VERWEIJ M. , ARKESTEIJN S. G. J. , PHYLIPSEN M. , GIORDANO P. C.
Published: April 2012

Introduction:  To report a new hemoglobin variant undistinguishable from the common HbS on HPLC. To show the efficiency of the simplest confirmation method for HbS and to discuss the implications that may occur if HbS‐like variants are wrongly reported as HbS.

Methods:  Basic hematology, separation and measurement of the Hb fractions, ‘sickle test,’ and molecular analysis.

Results:  The abnormal Hb fractions were eluting in the HbS window on HPLC, sickle test was however negative, and DNA sequencing of the beta globin gene revealed an unclassified variant HBBc.23A>T, p.Glu8Val in heterozygous form.

Conclusions:  Although the amino acid substitution of this new variant is identical to that of HbS and shifted of a single amino acid position, no polymerization occurs in vitro. The sickle test is a valid method to confirm or exclude HbS trait in individual cases. Whenever the case is part of a possible couple at risk, then one has to use full DNA analysis in both partners not to miss hidden concomitant defects important for genetic risk predictions.
Comparison of radiation treatment delivery for pancreatic cancer: Linac intensity‐modulated radiotherapy versus helical tomotherapy
Authors: Taylor Robert , Opfermann Krisha , Jones Brian D , Terwilliger Lacy E , McDonald Daniel G , Ashenafi Michael S , Garrett‐Meyer Elizabeth , Marshall David T
Published: April 2012

Introduction: Intensity‐modulated radiotherapy (IMRT) has been shown to reduce dose to organs at risk (OAR) while adequately treating tumour volume. This study quantitatively compares the dosimetric differences from step‐and‐shoot IMRT compared with helical tomotherapy (HT) for pancreatic head cancer.

Methods: Twelve consecutive patients with non‐metastatic, stage T3 or T4, unresectable pancreatic head cancer were planned for step‐and‐shoot IMRT as well as HT. Radiotherapy was planned to deliver 45.9 Gy to the clinical target volume in 30 fractions with an integrated boost to 54 Gy to the gross tumour volume (planning target volume 5400 including a 1‐cm set‐up margin). The uniformity index (UI) and conformity index (CI) were used to compare the quality of target coverage, while the quality index (QI) compared the dosimetric performance for OAR.

Results: Both methods were effective at covering the tumour with no significant difference in UI or CI. However, HT dosimetry exhibited superior sparing of OAR with significantly less stomach (mean QIStomV30 = 0.84, P = 0.006) and small bowel dosing (mean small bowel QISBV30 = 0.84, P = 0.005). HT reduced dose to the kidney receiving the highest dose but the overall volume of kidney receiving 18 Gy was not significantly different between the two systems, indicating that HT spread the dose more uniformly through the kidneys.

Conclusions: Target coverage is equivalent between the two systems; however, HT shows significantly better sparing of the stomach and small bowel. The decreased dose to OAR with HT is likely to improve the therapeutic ratio in the radiotherapy of pancreatic head cancers.
CT‐based estimation of intracavitary gas volumes using threshold‐based segmentation: In vitro study to determine the optimal threshold range
Authors: McWilliams Sebastian Robert , O'Connor Owen J , McGarrigle Anne Marie , O'Neill Siobhan B , Quigley Eamonn MM , Shanahan Fergus , Maher Michael M
Published: April 2012

Introduction: This study investigated the optimal Hounsfield unit (HU) threshold range when using threshold‐based segmentation to estimate volumes of contained gas (i.e. intestinal gas) on CT.

Methods: A water‐filled cylindrical acrylic imaging phantom containing two saline bags modified to allow injection of known volumes of gas (room air) was constructed. The phantom was imaged with CT following injection of known gas volumes. Images were analysed using standard threshold‐based 3D region growing with human‐entered seed points. The lower threshold was −1024 HU, and upper thresholds between −700 HU and −200 HU were tested for each volume. Appropriate statistical analysis was performed.

Results: Measurements were normally distributed. There was excellent correlation between measured and injected volumes for all thresholds (Pearson's r > 0.99). The optimal upper threshold for small gas volumes (1–6 mL) was −550 HU with 0.1% ± 3.9% (mean ± standard deviation) error. The optimal upper threshold for large gas volumes (10–50 mL) was −350 HU with 0.7 ± 3.6% (mean ± standard deviation) error with Pearson correlations of r > 0.99 for both.

Conclusion: Accurate estimation of gas volumes on CT is possible using threshold‐based segmentation software with a wide range of upper thresholds. The optimal upper threshold for estimation of small volumes (1–6 mL) was −550 HU and −350 HU for volumes of 10–50 mL.
Is Lewis's Mixed Theory Mixed Up?
Authors: RAVEN MICHAEL J.
Published: April 2012

My aim is to rekindle interest in David Lewis's (1983) infamous but neglected Mixed Theory of mental states. The Mixed Theory is a mix of physicalism and functionalism designed to capture the intuitions that both Martians and abnormal human Madmen can be in pain. The Mixed Theory is widely derided. But I offer a new development of the Mixed Theory immune to its most prominent objections. In doing so, I uncover a new motivation for the Mixed Theory: its unique ability to explain cases in which it is plausibly indeterminate whether something is in pain. The Mixed Theory, whether or not it is ultimately correct, at least deserves renewed attention.
THE ROLE OF MELATONIN IN PATIENTS WITH CHRONIC KIDNEY DISEASE UNDERGOING HAEMODIALYSIS
Authors: Aperis Georgios , Prakash Preeth , Paliouras Christos , Papakonstantinou Nikolaos , Alivanis Polichronis
Published: April 2012

Patients with chronic kidney disease including those undergoing haemodialysis have deranged sleep‐wake pattern. In large part this is due to an abnormal circadian cycle of melatonin, a hormone secreted by the pineal gland in the evening and induces sleep. Subjects undergoing automated peritoneal dialysis or nocturnal haemodialysis have better sleep profile compared to those on daytime dialysis. Studies have shown that exogenous melatonin improves sleep‐wake cycle in daytime haemodialysis patients. However, large randomised controlled trials are needed in order to establish its role in this patient population.
Relationship between Toe Temperature and Lower Urinary Tract Symptoms
Authors: INOUE Hiroo , ISHIZUKA Osamu , IMAMURA Tetsuya , YAMAGISHI Takahiro , NOGUCHI Wataru , YOKOYAMA Hitoshi , KURIZAKI Yoshiki , NISHIZAWA Osamu
Published: April 2012

Objective: Cold stress can elicit increases in urinary urgency and frequency. We determined if there was a relationship between finger and toe temperatures and lower urinary tract symptoms (LUTS).

Methods: We studied 50 people who visited a public health management seminar. The participants were divided into two groups according to self‐described sensitivity to cold stress. The cold non‐sensitive (CNS) group consisted of 3 males and 20 females (66.9 ± 10.8 years old), and the cold sensitive (CS) group consisted of 4 males and 23 females (65.8 ± 8.01 years old). Each participant was assessed to determine international prostate symptom score (IPSS), overactive bladder symptom score (OABSS), and quality of life (QOL) score. They were then instructed on lifestyle changes and exercises that could improve peripheral blood flow and provide relief for their LUTS. Next, the temperatures of their middle fingers and toes were measured before and after 5–10 min of the exercises. Two weeks later, the IPSS, OABSS, and QOL scores were reassessed.

Results: Before exercise, the middle fingers were significantly warmer than the middle toes. Exercise had no significant effect on the middle finger temperature of either group; however, it did increase the middle toe temperature for both groups. The increase was greatest for the CS group. The CS group had higher LUTS storage symptoms than the CNS group, and these improved after 2 weeks of lifestyle changes and exercise.

Conclusion: Improvements in lifestyle and daily exercise may be effective for LUTS in CS people.
Common mental disorders in Malaysia: Malaysian mental health survey, 2003–2005
Authors: Krishnaswamy Saroja , Subramaniam Kavitha , Jemain Abdul Aziz , Low Wah Yun , Ramachandran Padma , Indran Tishya , Patel Vikram
Published: April 2012

Introduction

Mental disorders are emerging as serious health threats in both developed and developing nations and contribute to greater Disability Adjusted Life Years (DALY) than infectious disease and unintentional injuries. This study aims to determine the prevalence and factors associated with the presence of common mental disorders in the Malaysian population.

Methods

Multistage cluster sampling method was used to obtain samples, with racial proportion as the main sampling criteria. Required sample size was calculated to be 4300 at 90% confidence level. Trained enumerators carried out the interview, with the Clinical Interview Scheduled‐ Revised (CIS‐R).

Results

A total of 3666 respondents were interviewed (85% response rate). The one‐week prevalence of Common Mental Disorders was 5.3% (95% CI of 4.57–6.03%). Findings from multivariate logistic regression analysis showed that associated factors were female gender (adjusted OR = 1.91, P < 0.01), being divorced (adjusted OR = 3.95, P < 0.05), difficulties at workplaces (adjusted OR = 3.58, P < 0.01) experiencing life events, such as divorce/marital separation (adjusted OR = 2.58,P < 0.01), unsolvable financial problems (adjusted OR = 3.87, P < 0.01), and serious problems with friends and neighbours (adjusted OR = 4.35, P < 0.01) in the year prior to data collection. Chinese ethnicity was least likely to be associated with CMD (adjusted OR = 0.27).

Discussion

There is a 5% prevalence of Common Mental Disorders in the Malaysian population. Socio‐demographic factors and experience of certain life events, particularly divorce, problems with neighbours and friends and severe financial problems in the previous year were found to be significantly associated with the prevalence of common mental disorders.
Two‐phase survey to determine social anxiety and gender differences in Omani adolescents
Authors: Al‐Sharbati Marwan , Al‐Adawi Samir , Petrini Karin , Bait Amer Ahmed SA , Al‐Suleimani Abdullah , Al‐Lawatiya Salwa , Zaidan Ziad , Al‐Adawi Sara S. , Al Hussaini Ala'Alddin
Published: April 2012

Introduction

There is a lack of studies examining the effectiveness of some of the commonly used instruments to elicit the presence of social anxiety disorder (SAD) in Arab‐speaking populations, such as those in Oman. The aim of this study was to establish the influence of social anxiety and the role of gender among Omani adolescents.

Methods

A two‐phase protocol was used, entailing the psychometric properties of the Arabic version of the Liebowitz Social Anxiety Scale (LSAS) against the gold standard, the Diagnostic and Statistical Manual of Mental Disorders (DSM).

Results

According to DSM and LSAS, the prevalence of social phobia among Omani students was generally higher compared to what has been reported in other parts of the world and the crosstabs analysis showed a significant correlation between gender and SAD.

Discussion

The Arabic version of LSAS proved to be an effective tool for assessing and quantifying the presence of SAD. This study discusses the sociocultural factors affecting social phobia in Omani society.
Conducting community research in rural China: Addressing the methodological challenges of recruiting participants in rapidly changing social environments
Authors: Dai Jing , Chiu Helen F.K. , Hou Zai‐Jin , Caine Eric D.
Published: April 2012

Introduction

The present paper addresses a unique challenge for public health and community research in rural China, i.e. the very large percentage of young adults that comprises a highly mobile working population that has been an essential component of the country's economic transformation. Fluid local demographic patterns potentially have a substantial impact on sample representativeness and data validity.

Methods

This report is based upon a cross‐sectional survey with face‐to‐face interviews of residents aged 16–34 years in rural communities of Mianyang, Sichuan Province, China. Two waves of fieldwork and other strategies were adopted in response to recruitment challenges.

Results

1654 of 3008 potential participants took part in the study; this constituted 98% of those individuals approached and 55% of the persons enumerated in the local household registration system (hukou). Analyses revealed substantial differences among those who were interviewed during September and October 2005, versus those seen during the Chinese Lunar New Year of 2006 when many migrant workers and students returned to their homes. Both groups together differed from those who were unavailable during either recruiting episode.

Discussion

We discuss potential responses to associated methodological challenges, including (i) permanent hukou mismatches; (ii) temporary hukou mismatches; (iii) difficulties faced by potential participants to fully understand the purpose of research, the informed consent process, and specific research questions; and (iv) appreciation of the importance of local social networks, as they pertain in particular to rural China. These findings underscore that there may be a need to make “on‐the‐ground” adjustments to varying local conditions to maximize sample representativeness and data validity.
Meiotic studies in some selected angiosperms from the Kashmir Himalayas
Authors: JEELANI Syed Mudassir , KUMARI Santosh , GUPTA Raghbir Chand
Published: April 2012

Abstract  As a part of our program to explore and evaluate genetic diversity of flowering plants of the Kashmir Himalayas, meiotic studies have been carried out on 150 wild species. Of these, Caltha alba (2n= 32), Delphinium roylei (2n= 16), D. uncinatum (2n= 16), Ranunculus palmatifidus (2n= 28), and Sedum heterodontum (2n= 14) have been cytologically worked out for the first time. New intraspecific diploid or polyploid cytotypes have been recorded for Alchemilla vulgaris (2n= 34, 96), Arabis amplexicaulis (2n= 16), Impatiens amphorata (2n= 14), I. racemosa (2n= 12), I. sulcata (2n= 16, 12), Meconopsis latifolia (2n= 14), Potentilla supina (2n= 14), Saxifraga cernua (2n= 16), Sium latijugam (2n= 24), and Vicatia coniifolia (2n= 44). Four species, Arabidopsis thaliana (2n= 10), Berberis vulgaris (2n= 28), Potentilla nubicola (2n= 14), and P. sericea (2n= 28), have been cytologically reported for the first time from India. A large number of meiotic abnormalities have been observed in most of these species, leading to a reduction in pollen fertility and production of heterogeneous‐sized pollen grains.
Bartonella henselaeSeroprevalence in Cattle Breeders and Veterinarians in the Rural Areas of Aydin and Denizli, Turkey
Authors: Sayin‐Kutlu S. , Ergin C. , Kutlu M. , Akkaya Y. , Akalin S.
Published: April 2012

Bartonella henselaeinfections are usually detected among people who have close contact with animals. Veterinarians and cattle breeders, in particular, are considered as the risk groups forB. henselaeinfections. In this study, the seroprevalence of antibodies toB. henselaewas investigated in these two groups of subjects in the two cities of Aydin and Denizli, which are located in the same region in the southwest of Turkey. Total antibodies toB. henselaewere evaluated by indirect immunofluorescence assay in serum samples taken from 63 cattle breeders and 27 veterinarians. Twenty samples (22.2%) were found to react on 1/64 titre withB. henselaeantigens.Bartonella henselaeseroprevalence was found to be significantly related to age (P = 0.033) and higher in those living in Aydin (P = 0.047). Age was the only independent factor in multivariate analysis (P = 0.008). Seroprevalence was found to be 2‐fold higher in those people who had had tick contact (P = 0.093). In conclusion, the physicians in the region should considerB. henselaeinfection among veterinarians and breeders in their differential diagnosis list of fever of unknown origin.
A dragonfly (δ2H) isoscape for North America: a new tool for determining natal origins of migratory aquatic emergent insects
Authors: Hobson Keith A. , Soto David X. , Paulson Dennis R. , Wassenaar Leonard I. , Matthews John H.
Published: April 2012

1. Tracking insect migration at continental scales is intractable using exogenous markers because of tiny body size and high improbability of recapture. Naturally occurring endogenous isotopic markers, such as tissue δ2H and δ18O, are a means of assigning origins to both vertebrate and invertebrate populations, but the success depends upon derivation of a robust algorithm linking measured tissue isotope values with large‐scale geospatial isotopic patterns (isoscapes) in the terrestrial hydrosphere.

2. We derived a North American dragonfly wing δ2H and δ18O isoscape from known‐origin dragonflies of three species (Aeshna interrupta, Aeshna umbrosa and Pachydiplax longipennis) obtained across North America. A strong relationship (r2 = 0·75) was found between wing δ2H and hydrologic geospatial δ2H patterns, and between wing δ2H and δ18O (r2 = 0·92). The strong coupling between emergent insect tissue and hydrologic spatial patterning suggested that this dragonfly isoscape may be applicable to other aquatic emergent migratory insects in North America and elsewhere.

3. As a proof of concept, we used the wing isoscape algorithm to map the probability of natal origin of Common Green Darners (Anax junius) migrating through southern Texas. Results showed that these Texan dragonflies were a mix of local and far‐distant migrant (e.g. northern United States) individuals. We suggest that this isoscape algorithm opens new opportunities to quantify the migration and natal origins of dragonflies and other aquatic emergent insects where conventional methods have failed.
Ethnicity and childhood overweight/obesity in England
Authors: Higgins V. , Dale A.
Published: April 2012

Background

Some studies suggest that British Afro‐Caribbean girls and Pakistani girls have higher levels of obesity than girls in the general population of England. However, the interplay between child obesity, ethnicity, mother's socioeconomic status and other parental characteristics is unclear and requires exploration.

Objectives

This study examines the relationship between child ethnicity and child overweight/obesity after controlling for a wide range of mothers′ socioeconomic characteristics and parental overweight/obesity.

Methods

Health Survey for England data (1999 and 2004) are used to examine 7047 children aged 2–15 years. Body mass index (BMI) for children is classified using the International Obesity Task Force age‐specific BMI thresholds for obesity and overweight.

Results

After controlling for a wide range of maternal socioeconomic characteristics and parental overweight/obesity, there are no ethnic differences in childhood overweight/obesity.

Conclusions

Having overweight or obese parents is a stronger predictor of childhood overweight/obesity than ethnic origin of the child. Interventions aimed at reducing childhood overweight/obesity should focus on parental characteristics rather than the ethnicity of the child, but they also need to be sensitive to gender and ethnic differences. Future research should aim to repeat the analyses using a measure of abdominal obesity such as waist circumference, if data become available.
Exploiting mathematical models to illuminate electrophysiological variability between individuals
Authors: Sarkar Amrita X. , Christini David J. , Sobie Eric A.
Published: April 2012

Abstract  Across individuals within a population, several levels of variability are observed, from the differential expression of ion channels at the molecular level, to the various action potential morphologies observed at the cellular level, to divergent responses to drugs at the organismal level. However, the limited ability of experiments to probe complex interactions between components has hitherto hindered our understanding of the factors that cause a range of behaviours within a population. Variability is a challenging issue that is encountered in all physiological disciplines, but recent work suggests that novel methods for analysing mathematical models can assist in illuminating its causes. In this review, we discuss mathematical modelling studies in cardiac electrophysiology and neuroscience that have enhanced our understanding of variability in a number of key areas. Specifically, we discuss parameter sensitivity analysis techniques that may be applied to generate quantitative predictions based on considering behaviours within a population of models, thereby providing novel insight into variability. Our discussion focuses on four issues that have benefited from the utilization of these methods: (1) the comparison of different electrophysiological models of cardiac myocytes, (2) the determination of the individual contributions of different molecular changes in complex disease phenotypes, (3) the identification of the factors responsible for the variable response to drugs, and (4) the constraining of free parameters in electrophysiological models of heart cells. Together, the studies that we discuss suggest that rigorous analyses of mathematical models can generate quantitative predictions regarding how molecular‐level variations contribute to functional differences between experimental samples. These strategies may be applicable not just in cardiac electrophysiology, but in a wide range of disciplines.
Sympathetic inhibition attenuates hypoxia induced insulin resistance in healthy adult humans
Authors: Peltonen Garrett L. , Scalzo Rebecca L. , Schweder Melani M. , Larson Dennis G. , Luckasen Gary J. , Irwin David , Hamilton Karyn L. , Schroeder Thies , Bell Christopher
Published: April 2012

Key points

In low‐oxygen environments, such as high‐altitude, control of blood sugar is disrupted. Further, the activity of the sympathetic nervous system is known to increase when the availability of oxygen is decreased.

We have investigated the possibility that the increase in sympathetic activity is partially responsible for the disruption in blood sugar control.

Using gasbags filled with low‐oxygen gas, together with a commonly used blood pressure medication (clonidine) that inhibits the sympathetic nervous system, we have shown that breathing low oxygen disrupts blood sugar control, and that this disruption is prevented when the nervous system is inhibited.

This finding has important implications for people travelling to high altitudes, and for people who suffer from conditions characterized by low oxygen, such as sleep apnoea and lung diseases.
Quantitative measurement of mitochondrial membrane potential in cultured cells: calcium‐induced de‐ and hyperpolarization of neuronal mitochondria
Authors: Gerencser Akos A. , Chinopoulos Christos , Birket Matthew J. , Jastroch Martin , Vitelli Cathy , Nicholls David G. , Brand Martin D.
Published: April 2012

Key points

Within cells, mitochondria oxidize carbohydrates, and fatty and amino acids to use the released energy to form ATP, and in the process, they also generate reactive oxygen species. Their maximal rates are linked to the magnitude of the mitochondrial membrane potential.

Here we derive a model of fluorescent potentiometric probe dynamics, and on these principles we introduce an absolute quantitative method for assaying mitochondrial membrane potential in millivolts in individual cultured cells.

This is the first micro‐scale method to enable measurement of differences in mitochondrial membrane potential between cells with different properties, e.g. size, mitochondrial density and plasma membrane potential, including cases when plasma membrane potential fluctuates.

Mitochondrial membrane potential in cultured rat cortical neurons is −139 mV at rest. In response to electrical stimulation of the cells, it is regulated between −108 mV and −158 mV by concerted increases in energy demand and metabolic activation.
Phosphodiesterase‐4 inhibition as a therapeutic approach to treat capillary leakage in systemic inflammation
Authors: Schick Martin Alexander , Wunder Christian , Wollborn Jakob , Roewer Norbert , Waschke Jens , Germer Christoph‐Thomas , Schlegel Nicolas
Published: April 2012

Key points

A specific therapy to treat capillary leakage in systemic inflammation and sepsis is not available at present.

Recent studies demonstrated that reduced cAMP levels in endothelial cells contribute to inflammation‐induced breakdown of the endothelial barrier.

The present study demonstrates that systemically applied phosphodiesterase‐4 inhibitors to increase endothelial cAMP are effective to prevent and to treat capillary leakage followed by improved microcirculation in a rodent model of systemic inflammation.

These data suggest a highly clinically relevant and applicable approach to stabilize capillary leakage in sepsis and systemic inflammation.
Exploring 57Co as a new isotope for brachytherapy applications
Authors: Enger Shirin A. , Lundqvist Hans , D'Amours Michel , Beaulieu Luc
Published: April 2012

Purpose:

The characteristics of the radionuclide 57Co make it interesting for use as a brachytherapy source. 57Co combines a possible high specific activity with the emission of relatively low‐energy photons and a half‐life (272 days) suitable for regular source exchanges in an afterloader. 57Co decays by electron capture to the stable 57Fe with emission of 136 and 122 keV photons.

Methods

: A hypothetical57Co source based on the Flexisource brachytherapy encapsulation with the active core set as a pure cobalt cylinder (length 3.5 mm and diameter 0.6 mm) covered with a cylindrical stainless‐steel capsule (length 5 mm and thickness 0.125 mm) was simulated using Geant4 Monte Carlo (MC) code version 9.4. The radial dose function, g(r), and anisotropy function F(r,θ), for the line source approximation were calculated following the TG‐43U1 formalism. The results were compared to well‐known 192Ir and 125I radionuclides, representing the higher and the lower energy end of brachytherapy, respectively.

Results:

The mean energy of photons in water, after passing through the core and the encapsulation material was 123 keV. This hypothetical57Co source has an increasing g(r) due to multiple scatter of low‐energy photons, which results in a more uniform dose distribution than 192Ir.

Conclusions:

57Co has many advantages compared to 192Ir due to its low‐energy gamma emissions without any electron contamination. 57Co has an increasing g(r) that results in a more uniform dose distribution than 192Ir due to its multiple scattered photons. The anisotropy of the 57Co source is comparable to that of 192Ir. Furthermore, 57Co has lower shielding requirements than 192Ir.
Ultrasound temperature estimation based on probability variation of backscatter data
Authors: Tsui Po‐Hsiang , Shu Yu‐Chen , Chen Wen‐Shiang , Liu Hao‐Li , Hsiao Ing‐Tsung , Chien Yu‐Ting
Published: April 2012

Purpose:

In recent years, ultrasound imaging has become an attractive modality for noninvasive temperature monitoring. Temperature variations that occur during tissue heating could induce changes in various acoustic parameters that may affect the echo interference so as to make ultrasound backscattering a random process. In this study, we assumed that the degree of variation in the probability distribution of the backscattered signals is temperature dependent. The feasibility of using the variation in the backscatter statistics for ultrasound temperature estimation was investigated in this study.

Methods:

We tested this hypothesis by carrying out experiments on agar phantoms and tissue samples using a temperature‐regulated water tank and a microwave ablation system. During heating, raw images of the backscattered‐signal envelope of each phantom and tissue at temperatures ranging between 37 °C and 45 °C were acquired to construct the parametric matrix based on the ratio of the change in the Nakagami parameter (RCN), which was used as a quantitative measure of the backscatter statistics. The absolute value of the RCN (ARCN) matrix was obtained, to which a polynomial approximation was applied to obtain the ARCNpa image.

Results:

The results showed that the RCN matrix locally increased or decreased with increasing temperature, indicating bidirectional changes in the backscatter statistics. We also found that the ARCN significantly increased with the temperature, demonstrating that the magnitude of the variation in the probability distribution of the backscattered‐signal envelope is a monotonic function of temperature. Unlike the phantom, tissues tended to exhibit a nonlinear dependency of the ARCN on the temperature that may be attributable to tissue denaturation. Especially, the ARCNpa image is highly suitable for visualizing the contour of the temperature distribution during microwave ablation of tissue samples.

Conclusions:

This study has demonstrated that temperature changes are reflected in variations in the envelope statistics. This novel approach makes it possible to develop an ultrasound temperature imaging method for simultaneously estimating the thermal dose and the tissue properties.
Adverse Metabolic Consequences in Humans of Prolonged Sleep Restriction Combined with Circadian Disruption
Authors: Buxton Orfeu M. , Cain Sean W. , O’Connor Shawn P. , Porter James H. , Duffy Jeanne F. , Wang Wei , Czeisler Charles A. , Shea Steven A.
Published: April 2012

Sleep deficiency and out-of-synch circadian rhythms impair pancreatic insulin secretion, a possible precursor to metabolic syndrome and diabetes.
From Lundberg to SIM-ICP: Computational Physiology and Modeling Intracranial Pressure
Authors: Goldstein Brahm , Tasker Robert C. , Wakeland Wayne
Published: April 2012

A simplified dynamic model generates patient-specific estimates of intracranial pressure and suggests a path forward for bringing simulated (SIM) physiologic models to the patient’s bedside.
Breaking Up the Clot
Authors: Methe Heiko
Published: April 2012

Crosstalk between platelets and immune cells is essential for the pathogenesis of deep vein thrombosis.