bluuebunny/crossref_metadata_2025 huggingface dataset:
Repolarization Changes Underlying Long-Term Cardiac Memory Due to Right Ventricular Pacing
Authors: Marrus Scott B. , Andrews Christopher M. , Cooper Daniel H. , Faddis Mitchell N. , Rudy Yoram
Published: July 2012

Background—

Cardiac memory refers to the observation that altered cardiac electrical activation results in repolarization changes that persist after the restoration of a normal activation pattern. Animal studies, however, have yielded disparate conclusions, both regarding the spatial pattern of repolarization changes in cardiac memory and the underlying mechanisms. The present study was undertaken to produce 3-dimensional images of the repolarization changes underlying long-term cardiac memory in humans.

Methods and Results—

Nine adult subjects with structurally normal hearts and dual-chamber pacemakers were enrolled in the study. Noninvasive electrocardiographic imaging was used before and after 1 month of ventricular pacing to reconstruct epicardial activation and repolarization patterns. Eight subjects exhibited cardiac memory in response to ventricular pacing. In all subjects, ventricular pacing resulted in a prolongation of the activation recovery interval (a surrogate for action potential duration) in the region close to the site of pacemaker-induced activation from 228.4±7.6 ms during sinus rhythm to 328.3±6.2 ms during cardiac memory. As a consequence, increases are observed in both apical-basal and right-left ventricular gradients of repolarization, resulting in a significant increase in the dispersion of repolarization.

Conclusions—

These results demonstrate that electrical remodeling in response to ventricular pacing in human subjects results in action potential prolongation near the site of abnormal activation and a marked dispersion of repolarization. This dispersion of repolarization is potentially arrhythmogenic and, intriguingly, was less evident during continuous right ventricular pacing, suggesting the novel possibility that continuous right ventricular pacing at least partially suppresses pacemaker-induced cardiac memory.
Molecular Insights into Arrhythmogenic Right Ventricular Cardiomyopathy Caused by Plakophilin-2 Missense Mutations
Authors: Kirchner Florian , Schuetz Anja , Boldt Leif-Hendrik , Martens Kristina , Dittmar Gunnar , Haverkamp Wilhelm , Thierfelder Ludwig , Heinemann Udo , Gerull Brenda
Published: July 2012

Background—

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiac disorder mainly caused by dominant mutations in several components of the cardiac desmosome including plakophilin-2 (PKP2), the most prevalent disease gene. Little is known about the underlying genetic and molecular mechanisms of missense mutations located in the armadillo (ARM) domains of PKP2, as well as their consequences on human cardiac pathology.

Methods and Results—

We focused on in vivo and in vitro studies of the PKP2 founder mutation c.2386T>C (p.C796R), and demonstrated in cardiac tissue from 2 related mutation carriers a patchy expression pattern ranging from unchanged to totally absent immunoreactive signals of PKP2 and other desmosomal proteins. In vitro expression analysis of mutant PKP2 in cardiac derived HL-1 cells revealed unstable proteins that fail to interact with desmoplakin and are targeted by degradation involving calpain proteases. Bacterial expression, crystallization, and structural modeling of mutated proteins impacting different ARM domains and helices of PKP2 confirmed their instability and degradation, resulting in the same remaining protein fragment that was crystallized and used to model the entire ARM domain of PKP2.

Conclusions—

The p.C796R and other ARVC-related PKP2 mutations indicate loss of function effects by intrinsic instability and calpain proteases mediated degradation in in vitro model systems, suggesting haploinsufficiency as the most likely cause for the genesis of dominant ARVC due to mutations in PKP2.
In Vivo Noninvasive Characterization of Brown Adipose Tissue Blood Flow by Contrast Ultrasound in Mice
Authors: Baron David M. , Clerte Maeva , Brouckaert Peter , Raher Michael J. , Flynn Aidan W. , Zhang Haihua , Carter Edward A. , Picard Michael H. , Bloch Kenneth D. , Buys Emmanuel S. , Scherrer-Crosbie Marielle
Published: July 2012

Background—

Interventions to increase brown adipose tissue (BAT) volume and activation are being extensively investigated as therapies to decrease the body weight in obese subjects. Noninvasive methods to monitor these therapies in animal models and humans are rare. We investigated whether contrast ultrasound (CU) performed in mice could detect BAT and measure its activation by monitoring BAT blood flow. After validation, CU was used to study the role of uncoupling protein 1 and nitric oxide synthases in the acute regulation of BAT blood flow.

Methods and Results—

Blood flow of interscapular BAT was assessed in mice (n=64) with CU by measuring the signal intensity of continuously infused contrast microbubbles. Blood flow of BAT estimated by CU was 0.5±0.1 (mean±SEM) dB/s at baseline and increased 15-fold during BAT stimulation by norepinephrine (1 µg·kg
−1
·min
−1
). Assessment of BAT blood flow using CU was correlated to that performed with fluorescent microspheres (
R
2
=0.86,
P
<0.001). To evaluate whether intact BAT activation is required to increase BAT blood flow, CU was performed in uncoupling protein 1–deficient mice with impaired BAT activation. Norepinephrine infusion induced a smaller increase in BAT blood flow in uncoupling protein 1–deficient mice than in wild-type mice. Finally, we investigated whether nitric oxide synthases played a role in acute norepinephrine-induced changes of BAT blood flow. Genetic and pharmacologic inhibition of nitric oxide synthase 3 attenuated the norepinephrine-induced increase in BAT blood flow.

Conclusions—

These results indicate that CU can detect BAT in mice and estimate BAT blood flow in mice with functional differences in BAT.
Mitofusin 2-Containing Mitochondrial-Reticular Microdomains Direct Rapid Cardiomyocyte Bioenergetic Responses Via Interorganelle Ca
2+
Crosstalk
Authors: Chen Yun , Csordás György , Jowdy Casey , Schneider Timothy G. , Csordás Norbert , Wang Wei , Liu Yingqiu , Kohlhaas Michael , Meiser Maxie , Bergem Stefanie , Nerbonne Jeanne M. , Dorn Gerald W. , Maack Christoph
Published: July 2012

Rationale:

Mitochondrial Ca
2+
uptake is essential for the bioenergetic feedback response through stimulation of Krebs cycle dehydrogenases. Close association of mitochondria to the sarcoplasmic reticulum (SR) may explain efficient mitochondrial Ca
2+
uptake despite low Ca
2+
affinity of the mitochondrial Ca
2+
uniporter. However, the existence of such mitochondrial Ca
2+
microdomains and their functional role are presently unresolved. Mitofusin (Mfn) 1 and 2 mediate mitochondrial outer membrane fusion, whereas Mfn2 but not Mfn1 tethers endoplasmic reticulum to mitochondria in noncardiac cells.

Objective:

To elucidate roles for Mfn1 and 2 in SR-mitochondrial tethering, Ca
2+
signaling, and bioenergetic regulation in cardiac myocytes.

Methods and Results:

Fruit fly heart tubes deficient of the
Drosophila
Mfn ortholog MARF had increased contraction-associated and caffeine-sensitive Ca
2+
release, suggesting a role for Mfn in SR Ca
2+
handling. Whereas cardiac-specific Mfn1 ablation had no effects on murine heart function or Ca
2+
cycling, Mfn2 deficiency decreased cardiomyocyte SR-mitochondrial contact length by 30% and reduced the content of SR-associated proteins in mitochondria-associated membranes. This was associated with decreased mitochondrial Ca
2+
uptake (despite unchanged mitochondrial membrane potential) but increased steady-state and caffeine-induced SR Ca
2+
release. Accordingly, Ca
2+
-induced stimulation of Krebs cycle dehydrogenases during β-adrenergic stimulation was hampered in Mfn2-KO but not Mfn1-KO myocytes, evidenced by oxidation of the redox states of NAD(P)H/NAD(P)
+
and FADH
2
/FAD.

Conclusions:

Physical tethering of SR and mitochondria via Mfn2 is essential for normal interorganelle Ca
2+
signaling in the myocardium, consistent with a requirement for SR-mitochondrial Ca
2+
signaling through microdomains in the cardiomyocyte bioenergetic feedback response to physiological stress.
LRP1-Dependent Endocytic Mechanism Governs the Signaling Output of the Bmp System in Endothelial Cells and in Angiogenesis
Authors: Pi Xinchun , Schmitt Christopher E. , Xie Liang , Portbury Andrea L. , Wu Yaxu , Lockyer Pamela , Dyer Laura A. , Moser Martin , Bu Guojun , Flynn Edward J. , Jin Suk-Won , Patterson Cam
Published: July 2012

Rationale:

Among the extracellular modulators of Bmp (bone morphogenetic protein) signaling, Bmper (Bmp endothelial cell precursor-derived regulator) both enhances and inhibits Bmp signaling. Recently we found that Bmper modulates Bmp4 activity via a concentration-dependent, endocytic trap-and–sink mechanism.

Objective:

To investigate the molecular mechanisms required for endocytosis of the Bmper/Bmp4 and signaling complex and determine the mechanism of Bmper's differential effects on Bmp4 signaling.

Methods and Results:

Using an array of biochemical and cell biology techniques, we report that LRP1 (LDL receptor-related protein 1), a member of the LDL receptor family, acts as an endocytic receptor for Bmper and a coreceptor of Bmp4 to mediate the endocytosis of the Bmper/Bmp4 signaling complex. Furthermore, we demonstrate that LRP1-dependent Bmper/Bmp4 endocytosis is essential for Bmp4 signaling, as evidenced by the phenotype of lrp1-deficient zebrafish, which have abnormal cardiovascular development and decreased Smad1/5/8 activity in key vasculogenic structures.

Conclusions:

Together, these data reveal a novel role for LRP1 in the regulation of Bmp4 signaling by regulating receptor complex endocytosis. In addition, these data introduce LRP1 as a critical regulator of vascular development. These observations demonstrate Bmper's ability to fine-tune Bmp4 signaling at the single-cell level, unlike the spatial regulatory mechanisms applied by other Bmp modulators.
Cardiac Rehabilitation Attendance and Outcomes in Coronary Artery Disease Patients
Authors: Martin Billie-Jean , Hauer Trina , Arena Ross , Austford Leslie D. , Galbraith P. Diane , Lewin Adriane M. , Knudtson Merril L. , Ghali William A. , Stone James A. , Aggarwal Sandeep G.
Published: July 2012

Background—

Cardiac rehabilitation (CR) is an efficacious yet underused treatment for patients with coronary artery disease. The objective of this study was to determine the association between CR completion and mortality and resource use.

Methods and Results—

We conducted a prospective cohort study of 5886 subjects (20.8% female; mean age, 60.6 years) who had undergone angiography and were referred for CR in Calgary, AB, Canada, between 1996 and 2009. Outcomes of interest included freedom from emergency room visits, hospitalization, and survival in CR completers versus noncompleters, adjusted for clinical covariates, treatment strategy, and coronary anatomy. Hazard ratios for events for CR completers versus noncompleters were also constructed. A propensity model was used to match completers to noncompleters on baseline characteristics, and each outcome was compared between propensity-matched groups. Of the subjects referred for CR, 2900 (49.3%) completed the program, and an additional 554 subjects started but did not complete CR. CR completion was associated with a lower risk of death, with an adjusted hazard ratio of 0.59 (95% confidence interval, 0.49–0.70). CR completion was also associated with a decreased risk of all-cause hospitalization (adjusted hazard ratio, 0.77; 95% confidence interval, 0.71–0.84) and cardiac hospitalization (adjusted hazard ratio, 0.68; 95% confidence interval, 0.55–0.83) but not with emergency room visits. Propensity-matched analysis demonstrated a persistent association between CR completion and reduced mortality.

Conclusions—

Among those coronary artery disease patients referred, CR completion is associated with improved survival and decreased hospitalization. There is a need to explore reasons for nonattendance and to test interventions to improve attendance after referral.
Impaired Increase of Retinal Capillary Blood Flow to Flicker Light Exposure in Arterial Hypertension
Authors: Ritt Martin , Harazny Joanna M. , Ott Christian , Raff Ulrike , Bauernschubert Philipp , Lehmann Marina , Michelson Georg , Schmieder Roland E.
Published: July 2012

We hypothesized that the increase of retinal capillary blood flow (RCF) to flicker light exposure is impaired in subjects with arterial hypertension. In 146 nondiabetic untreated male subjects with (n=50) or without (n=96) arterial hypertension, RCF was measured before and after flicker light exposure noninvasively and in vivo using scanning laser Doppler flowmetry. In addition, in a subgroup of 28 subjects, the change of RCF to flicker light exposure was again assessed during parallel infusion of nitric oxide synthase inhibitor N-monomethyl-
l
-arginine (L-NMMA). The increase of RCF to flicker light exposure was lower in patients with untreated hypertension compared with normotensive subjects when expressed in absolute terms (7.69±54 versus 27.2±44 AU;
P
adjusted=0.013) or percent changes (2.95±14 versus 8.33±12%;
P
adjusted=0.023). Systolic (β=−0.216;
P
=0.023) but not diastolic blood pressure (β=−0.117;
P
=0.243) or mean arterial pressure (β=−0.178;
P
=0.073) was negatively related to the percent change of RCF to flicker light exposure, independently of other cardiovascular risk factors. In the subgroup of 28 subjects, the increase of RCF to flicker light exposure was similar at baseline and during parallel infusion of L-NMMA when expressed in absolute terms (20.0±51 versus 22.6±56 AU;
P
=0.731) or percent changes (7.12±16 versus 8.29±18%;
P
=0.607). The increase of RCF to flicker light exposure is impaired in arterial hypertension. In the subgroup of the total study cohort, nitric oxide was not a major determinant of the increase of RCF to flicker light exposure.
Land Surface Controls on Hydroclimatic Means and Variability
Authors: Koster Randal D. , P. Mahanama Sarith P.
Published: July 2012

Hydroclimatic means and variability are determined in large part by the control of soil moisture on surface moisture fluxes, particularly evapotranspiration and runoff. This control is examined here using a simple water balance model and multidecadal observations covering the conterminous United States. Under the assumption that the relevant soil moisture–evapotranspiration and soil moisture–runoff relationships are, to first order, universal, the simple model illustrates the degree to which they interact to determine spatial distributions of hydroclimatic means and variability. In the process, the simple model provides estimates for the underlying relationships that operate in nature. The hydroclimatic sensitivities established with the simple water balance model can be used to evaluate more complex land surface models and to guide their further development, as demonstrated herein with an example.
The Formation of Nonzonal Jets over Sloped Topography
Authors: Boland Emma J. D. , Thompson Andrew F. , Shuckburgh Emily , Haynes Peter H.
Published: July 2012

Coherent jets are ubiquitous features of the ocean’s circulation, and their characteristics, such as orientation and energetics, may be influenced by topography. In this study, the authors introduce a large-scale, topographic slope with an arbitrary orientation into quasigeostrophic, doubly periodic, barotropic and baroclinic systems. In both systems, the flow organizes itself into coherent tilted nonzonal jets that are aligned perpendicular to the barotropic potential vorticity (PV) gradient. In the two-layer system, the upper layer, the lower layer, and the barotropic PV gradients all have different orientations and therefore the jets cross the layer-wise PV gradients. The fact that the jets cross layer-wise PV gradients and the requirement of conservation of PV for fluid parcels together results in the drift of the tilted jets across the domain. Like their zonal counterparts, the tilted jets exhibit strong transport anisotropy. The dynamical response to jet deflection is very strong in the two-layer baroclinic case, with eddy energy production increasing by orders of magnitude as the topographic slope becomes more zonal. This increase in eddy energy is also reflected in an increase in jet spacing and a reduction in strength of the across-jet transport barriers, shown using an effective diffusivity diagnostic. The dynamics identified here, while formally valid within the constraints of quasigeostrophic scalings, provide important insight into the sensitive relationship between flow orientation and flow stability in regions with broad topographic slopes.
The Wavenumber–Frequency Content of Resonantly Excited Equatorial Waves
Authors: Durland Theodore S. , Farrar J. Thomas
Published: July 2012

The theoretical resonant excitation of equatorial inertia–gravity waves and mixed Rossby–gravity waves is examined. Contrary to occasionally published expectations, solutions show that winds that are broadband in both zonal wavenumber and frequency do not in general produce peaks in the wavenumber–frequency spectrum of sea surface height (SSH) at wavenumbers associated with vanishing zonal group velocity.

Excitation of total wave energy in inertia–gravity modes by broadband zonal winds is virtually wavenumber independent when the meridional structure of the winds does not impose a bias toward negative or positive zonal wavenumbers. With increasing wavenumber magnitude |k|, inertia–gravity waves asymptote toward zonally propagating pure gravity waves, in which the magnitude of meridional velocity υ becomes progressively smaller relative to the magnitude of zonal velocity u and pressure p. When the total wave energy is independent of wavenumber, this effect produces a peak in |υ|2 near the wavenumber where group velocity vanishes, but a trough in |p|2 (or SSH variance). Another consequence of the shift toward pure gravity wave structure is that broadband meridional winds excite inertia–gravity modes progressively less efficiently as |k| increases and υ becomes less important to the wave structure. Broadband meridional winds produce a low-wavenumber peak in total wave energy leading to a subtle elevation of |p|2 at low wavenumbers, but this is due entirely to the decrease in the forcing efficiency of meridional winds with increasing |k|, rather than to the vanishing of the group velocity. Physical conditions that might alter the above conclusions are discussed.
Observations and Forecasts from the Landfall of Tropical Cyclones John, Lane, and Paul (2006) over Northwestern Mexico
Authors: Farfán Luis M. , Romero-Centeno Rosario , Raga G. B.
Published: July 2012

This study focuses on track and intensity changes of three tropical cyclones that, during the season of 2006, developed in the eastern North Pacific basin and made landfall over northwestern Mexico. Observational datasets, including satellite and radar imagery and a rain gauge network, are used to document regional-scale structures. Additionally, gridded fields are applied to determine the large-scale environment. John made landfall as a category-2 hurricane on the Saffir–Simpson scale and moved along the Baja California Peninsula during more than 40 h, resulting in total rainfall of up to 506 mm. The largest accumulations were located over mountains and set new records with respect to daily rates from the 1969–2005 period. Later in the season, Lane and Paul made landfall over the mainland and brought moderate rainfall over the coastal plains. Lane became a category-3 hurricane and was the third strongest hurricane to make landfall since 1969. In contrast, Paul followed a recurving track to reach the coastline as a weakening tropical depression. Strong wind shear, associated with a midlatitude trough, is found to be related to the intensity change. Examination of the official forecasts reveals that first inland positions were predicted several days before the actual landfall events. An assessment of the forecasts issued 1–3 days prior to landfall shows large track errors associated with some of the above tropical cyclones and this resulted in a westward bias. It is suggested that the track errors are due to an inadequate representation of the large-scale environment that steered the tropical cyclones.
Linking Cut-Scores Given Changes in the Decision-Making Process, Administration Time, and Proportions of Item Types Between Successive Administrations of a Test for a Large-Scale Assessment Program
Authors: Radwan Nizam , Reckase Mark D. , Rogers W. Todd
Published: July 2012

There is a continuing tension in testing programs to equate forms and maintain score scales and at the same time allow for changing conditions in the educational system, such as curriculum shifts or practical limits on testing time. When such changes occur, psychometric staff members are challenged to develop linking methods that allow for comparable reporting but meet requirements for psychometric rigor. This article describes a method addressing such shifts in testing programs. The application of the method is demonstrated on a large-scale educational testing program that had changes in test length, content distribution, and decision-making process. The method used to accomplish the linkage was to develop a pseudo test from the items included in the longer test before the change that was designed to mimic the test after the change. The linking of the tests using the pseudo test process resulted in a percentage of successful students that was similar to the percentages obtained prior to the changes. The linked scores were treated as comparable rather than equated scores.
Circadian Rhythms as a Basis for Work Organization
Authors: Guimarães Lia Buarque de Macedo , Ribeiro Jose Luis Duarte , Saurin Tarcísio Abreu , Homem de Bittencourt Paulo Ivo
Published: July 2012

Objective:

With the assumption that circadian rhythms influence human performance, the work of live line electricians was reorganized and evaluated. The hypothesis was that in highly physical and attention-demanding work, the organization of tasks, according to the ideal period of day and day of week, should diminish stress and consequent work risks.

Background:

There are only a few studies reporting the work of electricians and even fewer approaching work organization. Moreover, these investigations often do not consider human physiological limitations and capabilities as well as task demands.

Method:

A new work system was proposed with consideration of (a) the circadian cycles and homeostatic processes; (b) the effect of heat, which is a zeitgeber (synchronizer) for the biological clocks; and (c) the degree of physical and mental demands of the different performed tasks, which was assessed on the basis of opinions of the electricians and physiological markers of stress that are controlled by circadian rhythms. The traditional and new systems were compared on the basis of two cognitive indices (the arrangement of matchsticks and the perception of a minute) and three physiological markers of mental-to-physical loads (heart frequency and the level of adrenaline and noradrenaline).

Results:

Both physical and mental loads were reduced in the new system. Conclusion: Work organization should include consideration of human circadian rhythms, mainly when stressful and high-risk tasks are involved.

Application:

The findings can be applied in any work design, but they are especially suited for highly demanding work carried out outdoors.
The Moderating Effect of Individual Differences in Error-Management Training
Authors: Loh Vanessa , Andrews Sally , Hesketh Beryl , Griffin Barbara
Published: July 2012

Objective:

We investigated the effectiveness of error-encouragement training and the influence of ability and personality attribute-treatment interactions using a dynamic decision-making task.

Background:

Error-encouragement training is said to be more effective than error-avoidance training because active exploration and error encouragement promote better learning and transfer. Past research, which is limited by confounded experimental designs involving simple tasks with little consideration of individual differences, provides evidence for the value of active exploration but less so for error encouragement.

Method:

We randomly allocated 164 participants to receive error-encouragement, error-avoidance, or no error-related instructions in training on ATC-lab, a dynamic computer simulated air traffic control task. Active exploration and task information were controlled, and ability and personality were assessed.

Results:

Error encouragement yielded better transfer performance than did error avoidance but was no better than the control training. Higher- rather than lower-ability trainees benefited from training with an error orientation (positive or negative), suggesting that learning from errors in training requires greater cognitive resources. Trainees higher in openness to experience and agreeableness performed more poorly with error-avoidance training than with error-encouragement and control training.

Conclusion:

Error-avoidance training had a detrimental effect especially for those less open to experience, lower in agreeableness, and of lower ability. The significant benefits of error-encouragement training reported in previous research were probably attributable to confounding factors, such as active exploration and differential task information.

Application:

Although errors and active exploration can be useful learning tools in training, trainers should be mindful that focusing on errors, whether positively or negatively, may not suit everyone.
A price worth fighting for? Natural resources and conflict recurrence
Authors: Rustad Siri Aas , Binningsbø Helga Malmin
Published: July 2012

While a number of publications show that natural resources are associated with internal armed conflict, surprisingly little research looks at how natural resources affect post-conflict peace. This article therefore investigates the relationship between natural resources and post-conflict peace by analyzing new data on natural resource conflicts. We argue that the effect of natural resources on peace depends on how a country’s natural resources can constitute a motive or opportunity for armed conflict. In particular, three mechanisms may link natural resources to conflict recurrence: disagreements over natural resource distribution may motivate rebellion; using natural resources as a funding source creates an opportunity for conflict; and natural resources may aggravate existing conflict, acting either as motivation or opportunity for rebellion, but through other mechanisms than distributional claims or funding. Our data code all internal armed conflicts between 1946 and 2006 according to the presence of these resource–conflict links. We claim such mechanisms increase the risk of conflict recurrence because access to natural resources is an especially valuable prize worth fighting for. We test our hypotheses using a piecewise exponential survival model and find that, bivariately, armed conflicts with any of these resource–conflict mechanisms are more likely to resume than non-resource conflicts. A multivariate analysis distinguishing between the three mechanisms reveals that this relationship is significant only for conflicts motivated by natural resource distribution issues. These findings are important for researchers and policymakers interested in overcoming the ‘curse’ associated with natural resources and suggest that the way forward lies in natural resource management policies carefully designed to address the specific resource–conflict links.
Solidarity beyond Sexuality: The Personal Communities of Gay Men
Authors: Wilkinson Jennifer , Bittman Michael , Holt Martin , Rawstorne Patrick , Kippax Susan , Worth Heather
Published: July 2012

The relevance of community in the face of mounting individualism remains a pressing sociological issue. Social fragmentation challenges traditional communities of shared identifications and collective memberships while flexible relationship options lead sociologists to question the real benefits of friendships and the viability of personal commitments. These issues are sharply defined in current debates about ‘gay community’ and whether sexual practices can generate solidarity among a diversified social group. AIDS educators have long relied on notions of ‘gay community attachment’ and sociologists enthusiastically explore the innovative potential of gay and lesbian friendships for rethinking community today. Drawing evidence from a national e-male survey of the social relationships and sexual behaviour of over 4000 gay and bisexual men, we suggest that community pessimism is exaggerated. We contest unified sexualized notions of (gay) community and identify a potential for solidarity within these men’s friendships, sexual relationships and personal communities.
Face-to-Face Exports
Authors: Belenkiy Maksim , Riker David
Published: July 2012

In this study, we investigate the contribution of international business travel to U.S. exports. We present a Dixit-Stiglitz monopolistic competition model that relates business travel to the volume of international trade. Then we estimate the parameters of the model. To avoid the likely bias in OLS estimation, we develop an instrumental variable estimator. We find that lowering the costs of business travel to a country will have a significant positive impact on U.S. commodity exports to the visited country. The elasticity of exports with respect to international business travel is approximately 0.46. Using this estimate, we calculate that each additional international business trip will increase U.S. commodity exports to the visited country by $36,693 per year on average.
Let ’em Talk!
Authors: Snook Brent , Luther Kirk , Quinlan Heather , Milne Rebecca
Published: July 2012

The real-life questioning practices of Canadian police officers were examined. Specifically, 80 transcripts of police interviews with suspects and accused persons were coded for the type of questions asked, the length of interviewee response to each question, the proportion of words spoken by interviewer(s) and interviewee, and whether or not a free narrative was requested. Results showed that, on average, less than 1% of the questions asked in an interview were open-ended, and that closed yes–no and probing questions composed approximately 40% and 30% of the questions asked, respectively. The longest interviewee responses were obtained from open-ended questions, followed by multiple and probing question types. A free narrative was requested in approximately 14% of the interviews. The 80–20 talking rule was violated in every interview. The implications of these findings for reforming investigative interviewing of suspects and accused persons are discussed.
Labour market specific institutions and the working conditions of labour migrants: The case of Polish migrant labour in the Danish labour market
Authors: Arnholtz Jens , Hansen Nana Wesley
Published: July 2012

Based on a respondent driven sampling survey with 500 Polish migrant workers in Denmark, this article argues that specific labour market institutions and sector differences need to be taken into account when explaining the working conditions of migrant workers. Comparing the working conditions of Polish and Danish workers, it is shown that labour market institutional arrangements provide a better explanation for the differences found between the two groups than differences in individual characteristics of the migrants and the Danish workforce. In addition, the article argues that factors such as institutionalized wage variability within sectors and the decentralized regulation of working conditions are important when assessing the potential implication of migrant workers in the labour market.
Determinants of employee work schedule and method control
Authors: Masso Märt
Published: July 2012

Employee control over the work schedule and work method has long been considered an important quality of work and has received attention in different social science disciplines. Oftentimes the research has focused on the implications of control rather than variability in employee control. The current study constructs a conceptual framework of employee work control determinants. Relying on previous theoretical and empirical research, the framework outlines plausible explanations for selecting and interpreting both organization-level and employee-level determinants. Using a nationally representative linked study of organizations and their employees, the article tests the proposed theoretical model. The study shows that there are significant differences in employee work control that could be explained only by taking into account both employee-level and organization-level determinants. It was found that job design and characteristics, skills and competencies and managerial practices explain variance in both employee work schedule control and work method control.
Exile media, global news flows and democratization: the role of Democratic Voice of Burma in Burma’s 2010 elections
Authors: Pidduck Julianne
Published: July 2012

This article explores the links between transnational media flows and social and political change in authoritarian regimes through a conjunctural study of Democratic Voice of Burma (DVB), a Burmese exile media organization. Drawing on observation and interviews conducted at DVB’s Oslo studio during the 2010 elections in Burma as well as documentary research, the article explores how diasporic media may contribute to democratization in a military regime where press freedoms and political expression are severely curtailed. The first section draws on Appadurai’s theory of global flows to scrutinize transnational flows of people, capital, media, ideas and technology contributing to DVB’s operations from 1992 to 2010. The next section engages with theories of media and democracy in order to examine DVB’s innovative satellite television coverage of the 2010 elections. The article concludes with a brief discussion of the ongoing relevance of opposition media based outside of Burma amid liberalization measures undertaken by Thein Sein’s nominally civilian government in 2011.
To be prepared when the time has come: Argentina’s new media regulation and the social movement for democratizing broadcasting
Authors: Mauersberger Christof
Published: July 2012

Concentrated and usually conservative media are characteristic of Latin American countries, and at the same time these structures undermine meaningful democracy. Given the political influence of large media conglomerates, even most center-left governments are reluctant to limit the power of influential companies. Argentina, however, passed a new comprehensive media law in 2009 designed to democratize the media sector. This article traces the origins of the law and analyzes the strategies of the actors involved, with the focus resting on the roles of social movements and large media companies. The article then presents the main features of the new regulation that social movements now take as a model case for other countries. I argue that the new law originates from an unusually participatory legislative process and furthers the democratization of communication. The passage of this law is explained through the associational capabilities of the movement, the potent framing of media regulation as a matter of democracy and the changing media–state dynamics that disrupted the long-standing mutually supporting ties between the dominant Clarín Group and the government.
The development and consequences of new information infrastructures: the case of mashup platforms
Authors: Constantinides Panos
Published: July 2012

The advent of Web 2.0 has led to the development of new information infrastructures, where the logic of collective action is becoming more heterogeneous and multilayered, derived not from a single core structure (e.g. a corporation), but from networked interdependencies. Although lay users and expert user-developers act collectively towards commonly shared goals (e.g. producing, mixing, ripping and sharing digital content), their actions are not collective but rather are instigated under complex motivational structures whereby no single individual or group of individuals has complete information regarding all likely combinations of future events. This article explores the complex interactions of distributed networks of lay users, expert developers and owners of new information infrastructures such as Flickr. The article then focuses on the challenge of governing the consequences of these new information infrastructures and concludes with implications for further research.
Determining directional dependency in causal associations
Authors: Pornprasertmanit Sunthud , Little Todd D.
Published: July 2012

Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012) , including: encouraging the use of the signs of skewness and excessive kurtosis of both variables, discouraging the use of D’Agostino’s K2, and encouraging the use of directional dependency to compare variables only within time points. We offer improved steps for determining directional dependency that fix the problems we note. Next, we discuss how to integrate directional dependency into longitudinal data analysis with two variables. We also examine the accuracy of directional dependency evaluations when several regression assumptions are violated. Directional dependency can suggest the direction of a relation if: (a) the regression error in population is normal; (b) an unobserved explanatory variable correlates with any variables equal to or less than .2; (c) a curvilinear relation between both variables is not strong (standardized regression coefficient ≤ .2); (d) there are no bivariate outliers; and (e) both variables are continuous.
Judgment of land ownership by young refugee Palestinian and U.S. children
Authors: Zebian Samar , Rochat Philippe
Published: July 2012

Children’s sense and reasoning about territory and land ownership may develop differently in contexts of poverty and where narratives of dispossession are a part of daily life and are of political and historical significance, as is the case in the Palestinian refugee context in Lebanon. In this study we looked at how 3- and 5-year-old refugee Palestinian and American children distribute land among neighbors disputing over an unoccupied piece of land separating their properties. Children were required to make distributive justice decisions about 4 scripted scenarios that involved a pretend conflict between different types of neighbors (rich/poor; ingroup vs. outgroup; neighbors of the same material wealth and neighbors that were either poor or rich as well as ingroup members). Both 5-year-old Palestinian and American children showed inequality aversion, favoring the poor neighbor over the rich in their distributive justice decisions. This first finding suggests that being born into poverty does not make young children more sensitive to material inequity, even if the object of dispute is of particular cultural relevance. However, a second main finding suggests that extreme circumstances potentially translate into enhanced ingroup partialities, above and beyond the universal normative trend toward inequity aversion.
A qualitative exploration of higher self-efficacy string students preparing for a competition
Authors: Cahill Clark Jennifer
Published: July 2012

This study examined and qualitatively described the music practice behaviors, strategies, and thoughts of four high school string students who indicated a high string playing self-efficacy. Concepts of practice, motivation, achievement, and self-efficacy were linked together to analyze tendencies and summarize strategies. These students were chosen from previous research where eight high and eight low self-efficacy string students were narrowed and compared after 101 string students’ self-efficacy scores were determined and 65 of those correlated to achievement. Each of the four students for the current study was videotaped practicing, interviewed, and given a two-week practice journal. Triangulation was used for reliability. The participants in this study were higher self-efficacy students who had common elements that enabled them to succeed, such as studying with expert teachers, practicing outside of orchestra at school and home, and owning a quality instrument. Practice strategies varied and were qualitatively described, but all four tended to show higher order thinking skills and organization. Any differences were noted and the student who did succeed had unique approaches seen in past research as advanced practicing.
Towards a theoretical framework on ethical practice in ICT4D programmes
Authors: Mthoko Hafeni LWT , Pade-Khene Caroline
Published: July 2012

Information and Communication Technologies (ICTs) are widely known as tools for poverty reduction. However, before ICTs can be utilized as tools for development, one needs to assess the various development challenges facing a country and then analyse where and how ICTs could positively impact development in a sustainable way. As technology influences the way people relate toward each other, it is important to view ICTs from an ethical perspective. This research theoretically explores the key aspects of ethics that should be applied to ICT projects in rural communities. Understanding the key aspects of ethics related to ICTs would foster the adoption of ICTs in rural communities and ensure that the integration of such ICTs is compatible with existing development strategies in developing countries. Four existing frameworks on ethical practice are explored which serve as a foundation for a theoretical framework of ethical practice in ICT4D. The proposed framework highlights four ethical themes that should be considered in rural ICT4D initiatives. These themes include: collaboration and participation, socio-economic context, cost and benefits and underlying stakeholder interests. It is suggested that further research and practical application can inform the framework.
Information seeking behaviour of physicians in Tanzania
Authors: Norbert Gadau Lotalis , Lwoga Edda Tandi
Published: July 2012

The study investigated the information seeking behaviour of physicians at the Muhimbili National Hospital (MNH) in Tanzania. Questionnaires were personally distributed to all physicians ( n = 259) at MNH. The rate of response was 83 percent ( n = 215). Based on the literature review, a Wilson (1996) model was used to systematically guide the assessment of the physicians’ information seeking behaviour at MNH. The study found that physicians needed specific medical information to enhance their knowledge on a daily basis, particularly they needed information on patient care, rather than information for research and further education purposes. In order to fulfil their information needs, physicians preferred to seek information from formal sources, which included printed textbooks, electronic resources and printed journals. However, there was low use of the Internet for prescribing various drugs and diagnosis. Factors such as poor ICT infrastructure, lack of access to a computer, frequent power cuts and lack of time were the major barriers that inhibited physicians to seek information. It is thus important for the MNH management to promote information literacy (IL) issues, improve ICT infrastructure, establish a resource centre, and integrate use of the Internet and e-resources for patient care within clinicians working hours; and for the government to improve the supply of reliable electricity at MNH for effective medical practices.
What inhibits authors to self-archive in Open Access repositories? A Malaysian case
Authors: Singeh Feria Wirba , Abrizah A. , Karim Noor Harun Abdul
Published: July 2012

This paper reports on a survey carried out on academics in five Malaysian research-intensive universities, investigating their readiness to self archive in Open Access institutional repositories. The study revolves around the following issues: (a) academics’ awareness of self archiving in an institutional repository within their institution; (b) their perceptions about self archiving scientific information into institutional repositories; (c) their perceptions regarding obligations to self archive in institutional repositories; and (d) the possible reasons that inhibit them in contributing to institutional repositories. The answers were identified from 72 academics through a web-based survey. The study reveals that the majority of academics in this study have no or little knowledge of, or experience with, institutional repositories and are unfamiliar with self-archiving opportunities. However most of them endorse the principle of Open Access and are willing to contribute content to an institutional repository if an opportunity arises or if mandated by their funding institutions. Those who agree to self archiving see it to be beneficial in the author’s life as it enhances visibility and recognition of the author’s work, but the main problem encountered is the fact that researchers feel it is time consuming. The major barrier to self archiving is fear of plagiarism. In light of these results, there is a need to create more awareness and to educate authors on the importance of self archiving. Ensuring free electronic access to public-funded research lies with the funding institutions, especially universities, which should set up appropriate repository infrastructures, advocate the public good and ethical implications of open access and even mandate self-archiving of research they fund.
Publishing and sharing library resources with the ABCD Site
Authors: de Smet Egbert , Dhamdhere Sangeeta N
Published: July 2012

In spite of the library website being a very good medium and platform to communicate details of various print and electronic resources of the library to its users, still many libraries, especially in the South, fail to share their resources due to a lack of technical or computer skills. Yet many interactive tools to share library contents are available as Content Management System solutions, e.g. Joomla, Drupal, etc. These facilitate the use of Web 2.0 techniques such as blogs, RSS, instant messaging, social networking services, wikis, and social tagging applications. In this context we present the ABCD-Site module, one of the easiest tools for libraries to use in developing their interactive library website, as part of the ABCD integrated library automation suite. With a minimum of time and effort, libraries can easily become active members of the digital age in publishing and sharing their information to a wide audience.
An Experiential Exercise in Service Environment Design
Authors: Fowler Kendra , Bridges Eileen
Published: July 2012

A new experiential exercise affords marketing students the opportunity to learn to design service environments. The exercise is appropriate for a variety of marketing courses and is especially beneficial in teaching services marketing because the proposed activity complements two other exercises widely used in this course. Service journal and blueprinting exercises are commonly assigned to examine the impact of “people” and “process” decisions; the exercise proposed in this article offers an opportunity to examine the influence of “physical evidence” on the customer experience. Thus, these three exercises expose students to hands-on activities related to all three of the additional Ps related to services marketing. In addition to explaining how to carry out the exercise, this article provides evidence of how it actively engages students in all four steps of the experiential learning cycle (concrete experience, abstract conceptualization, reflective observation, and active testing). Finally, the ability of this exercise to close the loop in experiential learning is discussed.