bluuebunny/crossref_metadata_2025 huggingface dataset:
Synaptic Scaling Stabilizes Persistent Activity Driven by Asynchronous Neurotransmitter Release
Authors: Volman Vladislav , Gerkin Richard C.
Published: January 2011

Small networks of cultured hippocampal neurons respond to transient stimulation with rhythmic network activity (reverberation) that persists for several seconds, constituting an in vitro model of synchrony, working memory, and seizure. This mode of activity has been shown theoretically and experimentally to depend on asynchronous neurotransmitter release (an essential feature of the developing hippocampus) and is supported by a variety of developing neuronal networks despite variability in the size of populations (10–200 neurons) and in patterns of synaptic connectivity. It has previously been reported in computational models that “small-world” connection topology is ideal for the propagation of similar modes of network activity, although this has been shown only for neurons utilizing synchronous (phasic) synaptic transmission. We investigated how topological constraints on synaptic connectivity could shape the stability of reverberations in small networks that also use asynchronous synaptic transmission. We found that reverberation duration in such networks was resistant to changes in topology and scaled poorly with network size. However, normalization of synaptic drive, by reducing the variance of synaptic input across neurons, stabilized reverberation in such networks. Our results thus suggest that the stability of both normal and pathological states in developing networks might be shaped by variance-normalizing constraints on synaptic drive. We offer an experimental prediction for the consequences of such regulation on the behavior of small networks.
Enhanced Stimulus Encoding Capabilities with Spectral Selectivity in Inhibitory Circuits by STDP
Authors: Coulon Antoine , Beslon Guillaume , Soula Hédi A.
Published: January 2011

The ability to encode and transmit a signal is an essential property that must demonstrate many neuronal circuits in sensory areas in addition to any processing they may provide. It is known that an appropriate level of lateral inhibition, as observed in these areas, can significantly improve the encoding ability of a population of neurons. We show here a homeostatic mechanism by which a spike-timing-dependent plasticity (STDP) rule with a symmetric timing window (swSTDP) spontaneously drives the inhibitory coupling to a level that ensures accurate encoding in response to input signals within a certain frequency range. Interpreting these results mathematically, we find that this coupling level depends on the overlap of spectral information between stimulus and STDP window function. Generalization to arbitrary swSTDP and arbitrary stimuli reveals that the signals for which this improvement of encoding takes place can be finely selected on spectral criteria. We finally show that this spectral overlap principle holds for a variety of neuron types and network characteristics. The highly tunable frequency-power domain of efficiency of this mechanism, together with its ability to operate in very various neuronal contexts, suggest that it may be at work in most sensory areas.
Molecular Diffusion Model of Neurotransmitter Homeostasis Around Synapses Supporting Gradients
Authors: Mohan Ashwin , Pendyam Sandeep , Kalivas Peter W. , Nair Satish S.
Published: January 2011

Neurotransmitter homeostasis in and around a synapse involves complex random processes such as diffusion, molecular binding, and uptake by glial transporters. A three-dimensional stochastic diffusion model of a synapse was developed to provide molecular-level details of neurotransmitter homeostasis not predicted by alternative models based on continuum approaches. The development was illustrated through an example case cortico-accumbens synapse that successfully integrated neuroadaptations observed after chronic cocaine. By incorporating cystine-glutamate exchanger as a nonsynaptic release site for glutamate, the stochastic model was used to quantify the relative contributions of synaptic and nonsynaptic sources to extracellular concentration and to estimate molecular influx rates into the perisynapse. A perturbation analysis showed that among the parameters considered, variation in surface density of glial transporters had the largest effect on glutamate concentrations. The stochastic diffusion model of the example synapse was further generalized to characterize glial morphology by studying the role of diffusion path length in supporting neurotransmitter gradients and isolating the synapse. For the same set of parameters, diffusion path length was found to be proportional to the gradient supported.
Birth Control and Socialism: The Frustration of Margaret Sanger and Ishimoto Shizue's Mission
Authors: Takeuchi-Demirci Aiko
Published: January 2011

This article explores the ties between the early birth control movements in the United States and Japan, both of which emerged from a transnational socialist network after the Russian Revolution of 1917. By closely examining the activism of two symbolic figures in the movements, Margaret Sanger (1879-1966) and Ishimoto Shizue (1897-2001), their roles abroad, and the public responses in both nations, the article studies the possibilities and limits of the transnational birth control movement in the 1920s and 1930s. It argues that, while the socialist network helped expand their original goal of relieving working women across the world from the dual burden of reproductive and wage labor, the moment they crossed national borders, they simultaneously became bound by nationalist frameworks and gender biases. Their liberal and reformist, rather than revolutionary, approaches to birth control based on the Western model of progress and the eugenic concept of racial survival ultimately blunted the dream of universal sisterhood and female liberation.
Belief in a Just World When Encountering the 5/12 Wenchuan Earthquake
Authors: Xiaofei Xie  , Huimin Liu  , Yiqun Gan
Published: January 2011

The objective of the current study was to explore the influence of the belief in a just world (BJW) on the psychological well-being among earthquake victims following the Great Wenchuan Earthquake. A sample of Chinese undergraduates ( N = 494) completed a battery of questionnaires, including the Just World Scale, the Feelings of Uncertainty Scale, the Future Scale, the Hope Scale, the Self-Rating Depression Scale, and the Self-Rating Anxiety Scale. Results provided strong support for the important role of personal BJW in maintaining postquake mental health. BJW had a greater effect on particularly vulnerable victim groups, such as woman participants and participants who had suffered the loss of their families or friends in the earthquake. Besides, feelings of uncertainty and future orientation partially mediated the relationship between BJW and psychological well-being (depression, anxiety, and hope). Theoretical and practical implications were discussed, and future research directions were provided.
Walk or Bike to a Healthier Life: Commuting Behavior and Recreational Physical Activity
Authors: Terzano Kathryn , Morckel Victoria C.
Published: January 2011

This study surveyed faculty and staff at universities in three cities: Youngstown (Ohio), Columbus (Ohio), and Washington, D.C.A total of 111 participants (50% women, 45% men, 5% no answer) completed an online survey, which asked about their habits concerning their work commute, physical activity related to their commute, and physical activity engaged in for recreation. The study revealed that a significant relationship exists between the mode(s) of transit used in commuting for work and the amount of time participants reported engaging in recreational physical activity outside of the commute. Commuters who had some physical activity in their commute spent more time engaging in additional physical activity for recreation and exercise and participated in a greater number of physical activities. The study findings suggested that some groups, such as health researchers, governmental entities, planners, and transportation analysts, might benefit from further studying this connection.
Do Perceptions of Social Cohesion, Social Support, and Social Control Mediate the Effects of Local Community Participation on Neighborhood Satisfaction?
Authors: Dassopoulos Andrea , Monnat Shannon M.
Published: January 2011

This article investigates the effects of social cohesion, social support, social control, and active local community participation on neighborhood satisfaction among individuals living in Los Angeles County. Utilizing the LAFANS dataset and proportional odds regression models, the authors find that net of individual demographic and socioeconomic status, perceptions of social cohesion, and social control are associated with greater levels of neighborhood satisfaction, whereas perceptions of neighborhood social support have no effect on satisfaction. Furthermore, formal involvement in one’s neighborhood is associated with greater levels of satisfaction only in certain contexts and only for certain types of involvement.
Organic Tomatoes Versus Canned Beans
Authors: Tobler Christina , Visschers Vivianne H. M. , Siegrist Michael
Published: January 2011

The assessment of a food product’s environmental friendliness is highly challenging for consumers because such an assessment requires the consideration of various product characteristics. Furthermore, products often show conflicting features. This study uses a choice task and a questionnaire to examine how consumers judge the environmental friendliness of several vegetables. The consumers’ assessment is compared with life cycle assessment (LCA) results, which represent the overall environmental impact of a product throughout its lifespan. In contrast to the LCA, consumers consider transportation distance rather than transportation mode and perceive organic production as very relevant for the environmental friendliness. Furthermore, consumers assess the environmental impact of packaging and conservation as more important than the LCA results show. Findings also suggest the current product information for vegetables is insufficient for judging their environmental friendliness. Implications for information campaigns and ecological food labeling are discussed.
Mind Wandering Behind the Wheel
Authors: He Jibo , Becic Ensar , Lee Yi-Ching , McCarley Jason S.
Published: January 2011

Objective: An experiment studied the frequency and correlates of driver mind wandering.

Background: Driver mind wandering is associated with risk for crash involvement. The present experiment examined the performance and attentional changes by which this effect might occur.

Method: Participants performed a car-following task in a high-fidelity driving simulator and were asked to report any time they caught themselves mind wandering. Vehicle control and eye movement data were recorded.

Results: As compared with their attentive performance, participants showed few deficits in vehicle control while mind wandering but tended to focus visual attention narrowly on the road ahead.

Conclusion: Data suggest that mind wandering can engender a failure to monitor the environment while driving.

Application: Results identify behavioral correlates and potential risks of mind wandering that might enable efforts to detect and mitigate driver inattention.
Relationship of cognitions and symptoms of agoraphobia in Hong Kong Chinese: A combined quantitative and qualitative study
Authors: Hui Lung Kit , Ng Roger M.K. , Pau Lui , Yip K.C.
Published: January 2011

Objectives: The aim of this study was to explore and describe the subjective experiences of agoraphobia in Hong Kong Chinese.

Method: This was a cross-sectional descriptive study, using a combined qualitative–quantitative approach. In the qualitative part, two focus groups were held with nine participants suffering from DSM-IV panic disorder with agoraphobia, followed up in a regional hospital in Hong Kong. The audiotaped material was transcribed and analysed into four main categories and 13 subcategories based on a grounded theory approach. One subcategory (‘Fear of making others worried and being a burden to others’) was identified as a novel, culture-specific concept in agoraphobia that was not reported in Western literature. In the quantitative part, this subcategory was redefined and measured by a two-item, self-rated questionnaire survey in another 35 participants suffering from DSM-IV defined panic disorder with agoraphobia.

Results: Qualitative data showed that the clinical manifestations of agoraphobia were specifically related to the underlying corresponding catastrophic cognitions. An individual’s agoraphobic cognitions and symptoms were highly related to the identity of the surrounding people during panic attacks in agoraphobic situations, which reflected the characteristic structure of the Chinese interpersonal network. Participants preferred reliance on self to cope with the anxiety first, then turned to their family members for help due to higher interpersonal trust. Participants also expressed fear of affecting others due to their illness. A new sub-theme of agoraphobia (‘Fear of making others worried and being a burden to others’) was extracted from the qualitative data. Its validity was confirmed by the quantitative description of this new theme using a self-rated questionnaire as a methodological triangulation.

Conclusions: The central theme to emerge from the qualitative data was that agoraphobia is a clinical condition that has a close relationship to Chinese cultural factors. ‘Fear of making others worried and being a burden to others’ is a new concept in agoraphobia worthy of further study.
Acoustic Correlates of Stress in Central Catalan and Castilian Spanish
Authors: Ortega-Llebaria Marta , Prieto Pilar
Published: January 2011

The general literature on the phonetic correlates of stress agrees that duration, and in stress accent languages, F0 are consistent correlates of stress. However, the role of amplitude changes in the speech signal is more controversial. In particular, the conflicting results of spectral tilt as a correlate of stress have been attributed to the effects of vowel reduction. We examined the stress correlates of duration, overall intensity and spectral tilt in Catalan and Spanish in both accented and unaccented contexts while controlling for formant frequency differences between morphologically corresponding vowels in stressed and unstressed environments by comparing vowels that maintain the same quality across stress contexts with those that do not. Duration was a consistent stress correlate in all vowels in both languages, regardless of their formant frequency differences across stress contexts and of the absence of pitch accents. In fact, stress-related formant frequency differences between corresponding vowels amplify the duration cues to the stress contrast. On the other hand, the use speakers made of intensity was not as pervasive as that of duration. Specifically, changes in spectral tilt were significant only in Catalan and in those vowels that alternate a more open and peripheral realization in stressed syllables with a mid-central realization in unstressed syllables, indicating that spectral tilt is related to the formant frequency differences linked to the centralization processes rather than to the stress contrast.
Body Mass Index and Physical Attractiveness: Evidence From a Combination Image-Alteration/List Experiment
Authors: Conley Dalton , McCabe Brian J.
Published: January 2011

The list experiment is used to detect latent beliefs when researchers suspect a substantial degree of social desirability bias from respondents. This methodology has been used in areas ranging from racial attitudes to political preferences. Meanwhile, social psychologists interested in the salience of physical attributes to social behavior have provided respondents with experimentally altered photographs to test the influence of particular visual cues or traits on social evaluations. This experimental research has examined the effect of skin blemishes, hairlessness, and particular racial attributes on respondents’ evaluation of these photographs. While this approach isolates variation in particular visual characteristics from other visual aspects that tend to covary with the traits in question, it fails to adequately deal with social desirability bias. This shortcoming is particularly important when concerned with potentially charged visual cues, such as body mass index (BMI). The present article describes a novel experiment that combines the digital alteration of photographs with the list experiment approach. When tested on a nationally representative sample of Internet respondents, results suggest that when shown photographs of women, male respondents report differences in levels of attractiveness based on the perceived BMI of the photographed confederate. Overweight individuals are less likely than their normal weight peers to report different levels of attractiveness between high-BMI and low-BMI photographs. Knowing that evaluations of attractiveness influence labor market outcomes, the findings are particularly salient in a society with rising incidence of obesity.
Nonparametric Tests of Panel Conditioning and Attrition Bias in Panel Surveys
Authors: Das Marcel , Toepoel Vera , van Soest Arthur
Published: January 2011

Over the past decades there has been an increasing use of panel surveys at the household or individual level. Panel data have important advantages compared to independent cross sections, but also two potential drawbacks: attrition bias and panel conditioning effects. Attrition bias arises if dropping out of the panel is correlated with a variable of interest. Panel conditioning arises if responses are influenced by participation in the previous wave(s); the experience of the previous interview(s) may affect the answers to questions on the same topic, such that these answers differ systematically from those of respondents interviewed for the first time. In this study the authors discuss how to disentangle attrition and panel conditioning effects and develop tests for panel conditioning allowing for nonrandom attrition. First, the authors consider a nonparametric approach with assumptions on the sample design only, leading to interval identification of the measures for the attrition and panel conditioning effects. Second, the authors introduce additional assumptions concerning the attrition process, which lead to point estimates and standard errors for both the attrition bias and the panel conditioning effect. The authors illustrate their method on a variety of repeated questions in two household panels. The authors find significant panel conditioning effects in knowledge questions, but not in other types of questions. The examples show that the bounds can be informative if the attrition rate is not too high. In most but not all of the examples, point estimates of the panel conditioning effect are similar for different additional assumptions on the attrition process.
The Effects of Asking Filter Questions in Interleafed Versus Grouped Format
Authors: Kreuter Frauke , McCulloch Susan , Presser Stanley , Tourangeau Roger
Published: January 2011

When filter questions are asked to determine respondent eligibility for follow-up items, they are administered either interleafed (follow-up items immediately after the relevant filter) or grouped (follow-up items after multiple filters). Experiments with mental health items have found the interleafed form produces fewer yeses to later filters than the grouped form. Given the sensitivity of mental health, it is unclear whether this is due to respondent desire to avoid sensitive issues or simply the desire to shorten the interview. The absence of validation data in these studies also means the nature of the measurement error associated with the filter types is unknown. We conducted an experiment using mainly nonsensitive topics of varying cognitive burden with a sample that allowed validation of some items. Filter format generally had an effect, which grew as the number of filters increased and was larger when the follow-up questions were more difficult. Surprisingly, there was no evidence that measurement error for filters was reduced in the grouped version; moreover, missing data for follow-up items was increased in that version.
Estimating Propensity Adjustments for Volunteer Web Surveys
Authors: Valliant Richard , Dever Jill A.
Published: January 2011

Panels of persons who volunteer to participate in Web surveys are used to make estimates for entire populations, including persons who have no access to the Internet. One method of adjusting a volunteer sample to attempt to make it representative of a larger population involves randomly selecting a reference sample from the larger population. The act of volunteering is treated as a quasi-random process where each person has some probability of volunteering. One option for computing weights for the volunteers is to combine the reference sample and Web volunteers and estimate probabilities of being a Web volunteer via propensity modeling. There are several options for using the estimated propensities to estimate population quantities. Careful analysis to justify these methods is lacking. The goals of this article are (a) to identify the assumptions and techniques of estimation that will lead to correct inference under the quasi-random approach, (b) to explore whether methods used in practice are biased, and (c) to illustrate the performance of some estimators that use estimated propensities. Two of our main findings are (a) that estimators of means based on estimates of propensity models that do not use the weights associated with the reference sample are biased even when the probability of volunteering is correctly modeled and (b) if the probability of volunteering is associated with analysis variables collected in the volunteer survey, propensity modeling does not correct bias.
Seeking More Information and Conversations: Influence of Competitive Frames and Motivated Processing
Authors: Borah Porismita
Published: January 2011

A consistently growing body of research focuses on the concept of framing. The present study contributes to framing effects literature in three ways: the study examines frames in competitive environment, investigates the influence of motivated processing, and the effects on behavioral intentions of participants. The data were collected using an experiment embedded in a Web-based survey of participants employing the issue of civil liberties conflict. The study used a 2 (motivated processing) × 3 (framed conditions) between-subjects design. Findings show that in case of both the outcomes of behavioral intent, willingness to seek information and talk, motivated processing intensified framing effects and specifically so in the mixed frame condition.
The French Military Reserve: Real or Abstract Force?
Authors: Weber Claude
Published: January 2011

This article reports on the current status of the system of the French military reserve. By reviewing a brief history of France’s military, the author shows the existing ambivalence regarding the establishment of a permanent part-time force. In France, conscription was suspended in 1996, and a smaller professional military was created. This smaller force required a review of the needs and role of the French reserve force. Today, in France there are two reserve types: the operational and the ‘‘citizen’’ reserves. Each is examined in terms of its activities and the role, profiles, and motivations of its members. This analysis sheds light on the initial question of whether the French reserve is a real or an abstract force. The French military reserve plays not just a symbolic but also a purposive role, although essentially limited to the national territory.
Is the Moratorium Over? African American Psychology Professionals’ Views on Intelligence Testing in Response to Changes to Federal Policy
Authors: Graves Scott , Mitchell Angela
Published: January 2011

Collectively, advocates for the well-being of African American children have long called for a moratorium on the use of intelligence testing for the placement of children in special education. With the 2004 reauthorization of the Individuals with Disabilities Education Act, intelligence testing is no longer required and in some states prohibited as a tool for assessing learning disabilities. As such, the purpose of this descriptive study is to give an overview of these changes and how they will affect the assessment of African American children. A national sample of African American psychology professionals was surveyed, and the majority indicated that response to intervention (RTI) methodologies alone are not sufficient for special education placement. In addition, there was uncertainty if RTI procedures will reduce African American disproportionality in special education. Results are discussed in terms of the need to increase the number of intervention articles that include African American children and recruiting more African American school psychologists.
The theoretical fundamentals of an adaptive active control using periodic Helmholtz resonators for duct-borne transmission noise in ventilation systems
Authors: Yun Y , Mak CM
Published: January 2011

This article theoretically proposes an innovative semi-active noise control method for the control of duct-borne transmission noise. This method is designed to be a more efficient, robust and broad-band adaptive attenuating effect than the traditional pass noise control methods used in duct-borne sound control. Based on the fundamental theory on the pass-stop band structure of sound waves propagating in a one-dimensional periodic duct system, the proposed control method combines band-gap attenuation using the side-branch resonators array with the auto-adaptive system of noise control. Using this method in the simulation and analysis, the transmission noise in an air duct can be effectively controlled in relatively wide bands by periodic alternate resonators of small variable parameters. The developed semi-active control method is numerically designed to efficiently reduce the duct-borne transmission noise at frequencies around a variable major tone in various working conditions.

Practical applications: The proposed semi-active noise control method with band-gap attenuation of a periodic adaptive resonator array is generally an efficient, robust and broad-band noise control system. It has the potential to be used to control duct-borne transmission noise in order to satisfy stringent indoor acoustical requirements such as those of the indoor air-conditioned environments of a hospital, a scientific laboratory, a council hall and a living room.
Effect of balconies on thermal comfort in wind-induced, naturally ventilated low-rise buildings
Authors: Ai ZT , Mak CM , Niu JL , Li ZR
Published: January 2011

The presence of the parapet and floor of a balcony is expected to have a range of effects on a building’s environmental behaviour, in terms of aspects, such as natural ventilation, thermal comfort, pollutant transportation and shading and daylighting. The authors have previously reported that the presence of a balcony can significantly increase the air flow rate of most rooms in a naturally ventilated building. In this study, the CFD technique and Fanger and Toftum’s extended PMV—PPD model are combined to investigate numerically the effect of a balcony on thermal comfort for naturally ventilated buildings in tropical-humid regions. The results show that although a balcony reduces the indoor average velocity for most rooms, and in turn increases the PMVnv value in both the seated and standing positions, it does not change the indoor thermal comfort level. However, the presence of a balcony improves comfort by increasing the uniformity of indoor air distribution. PMVnv is also shown to be less sensitive to velocity than PMV, allowing for a wider thermal comfort range for naturally ventilated buildings.

Practical application: This study will help designers and engineers who are considering the use of a balcony at the design stage to have a better understanding of its effect on thermal comfort in naturally ventilated buildings.
The Development of a Pilot Training Program for Peer Leaders in Diabetes
Authors: Tang Tricia S. , Funnell Martha M. , Gillard Marylou , Nwankwo Robin , Heisler Michele
Published: January 2011

Purpose

The goal of this study is to describe the process of developing a program that trains peers to facilitate an empowerment-based diabetes self-management support intervention.

Methods

To guide and advise the development process, the authors formed a peer leader training action committee. The committee was an interdisciplinary group (principal investigator, nurse—certified diabetes educators, dietitian— certified diabetes educators, nutritionist, physician, and 3 community members) that met every 3 months over a 1-year period for continuous quality improvement meetings. During meetings, the committee reviewed and supervised the curriculum development, provided feedback, and informed modifications and improvements.

Results

The resulting peer leader training program is a 46-hour program with 2 training sessions conducted per week over a 12-week period. The competency-based training program is based on the theory of experiential learning, and it consists of 3 major components—namely, building a diabetes-related knowledge base, developing skills (communication, facilitation, and behavior change), and applying skills in experiential settings. All components are integrated within each training session using a range of instructional methods, including group brainstorming, group sharing, role-play, peer leader simulations, and group facilitation simulations.

Conclusion

Through the process described above, the authors developed a training program that equips peer leaders with the knowledge and skills to facilitate empowerment-based diabetes self-management support interventions. Future directions include conducting and evaluating the peer training program.
Intragastric Balloon Therapy in the Management of Obesity
Authors: Evans Joshua T. , DeLegge Mark H.
Published: January 2011

For the first time in the history of the United States, in the 21st century, there may be a decline in life expectancy, as a result of the increasing rate of obesity. It is known that even the modest reduction of 10% of excess body weight significantly reduces obesity‐associated comorbidities. Conservative measures such as diet and exercise seldom give durable results in the long term. Bariatric surgery has been shown to achieve durable weight loss but is not without significant risks and complications. As a result, greater focus has turned toward minimally invasive endoscopic therapies for the management of obesity. There have been multiple reports of creative endoscopic devices and techniques in the literature, but most have only demonstrated early pilot data. By far, the most widely studied of the minimally invasive endoscopic therapies for obesity is the gastric balloon. Now obsolete, the Garren‐Edwards gastric bubble was removed from the market in the United States after several sham‐controlled studies showed that diet and behavior modification were equally efficacious and that the device was associated with a prohibitive number of complications. However, the concept and technique of intragastric balloon placement has evolved considerably since that time, and we now have data on nearly 3,000 patients who have undergone placement of the BioEnterics Intragastric Balloon (Carpenteria, CA) worldwide. The balloon is approved as part of a multifaceted approach to obesity in many countries and has been shown to result in at least a 10% excess weight loss durable over 1 year. However, the device is not yet approved for use in the United States. In this article, the authors review the efficacy, indications, complications, and potential uses for the intragastric balloon. The intragastric balloon might be the best start as gastroenterologists in the United States begin to play an increasing role in the treatment of the obesity pandemic.
Predictive Factors of Mortality After PEG Insertion
Authors: Zopf Yurdagül , Maiss Jürgen , Konturek Peter , Rabe Christina , Hahn Eckhart G. , Schwab Dieter
Published: January 2011

Background: Percutaneous endoscopic gastrostomy (PEG) is considered the preferred route for long‐term enteral feeding. The aim of this study was to determine predictors of an increased mortality risk after PEG insertion. Methods: A retrospective study was conducted during a 13‐year period in the gastroenterology department of Erlangen University Hospital. The authors completed a questionnaire with details of demographic data, diagnosis, indication for PEG, type of tube, and cause of death. Patients were contacted regularly at scheduled appointments. Results: In total, 787 patients (574 male [72.9%]) underwent PEG placement by the pull technique. The main underlying disease was malignant (75.6%). By the end of the study period, 614 patients had died. The average survival time was 720 days. The 30‐, 60‐, 90‐day and 1‐, 3‐, and 5‐year mortality rates amounted to 6.5%, 9.8%, 13%, 32.1%, 59.3%, and 69.8%, respectively. Predictive factors of increased 30‐day mortality were higher age, lower body mass index (BMI), and the presence of diabetes mellitus. The presence of all 3 variables served as an indicator to detect high‐risk patients, with a sensitivity of 0.80 and a specificity of 0.64. Conclusion: Mortality predictors for patients after PEG insertion are higher age, lower BMI, and the presence of diabetes mellitus. To avoid unnecessary and dangerous examinations in high‐risk patients, the above‐mentioned predictive factors of mortality should be checked before PEG placement.
Critical Literacy Programs: Can Business Literacy be a Catalyst for Economic and Social Change?
Authors: Corus Canan , Ozanne Julie L.
Published: January 2011

While literacy is widely believed to be a driver of well-being and economic development, the actual performance of many literacy programs fails to deliver on these promises. Many existing literacy programs are based on an autonomous model of literacy, which assumes that literacy skills are ideologically neutral and can be easily applied, regardless of the social context. Yet literacy practices are socially constructed and can serve to reinforce the status quo and existing interests or these practices can be used to challenge inequities and inspire social change. An ideological model of literacy is used to critique a range of literacy programs that employ livelihood training and various forms of business literacy. Finally, the role of business literacy practices as an impetus for change is explored.
The embryo research debate in Brazil: From the National Congress to the Federal Supreme Court
Authors: Cesarino Letícia , Luna Naara
Published: January 2011

New forms of life produced by biomedical research, such as human embryonic stem cells (hESC), have been the object of public debate beyond the scientific fields involved. This article brings to light the case of Brazil, where recently passed federal legislation has authorized research with in vitro human embryos. It focuses on the legislative debate in the Brazilian National Congress between 2003 and 2005 on the Biosafety Bill of Law, which cleared for hESC research a certain share of supernumerary and unviable human embryos frozen in the country’s assisted reproduction clinics.The passing of this Bill triggered other public reactions, chiefly a Direct Action of Unconstitutionality in Brazil’s Federal Supreme Court. This study adopts an anthropological perspective for describing and analyzing the chief arguments in both debates, in terms of how the notion of ‘life’ was deployed and negotiated by contending parties. If, on the one hand, the definition of life appeared firmly attached to a conception of both the in vitro embryo and the fetus as a human person, on the other a movement towards breaking down life along utilitarian lines was found when the potential beneficiaries of stem cell therapy came into the equation. In all cases, however, notions of life were negotiated from a hybrid continuum of (biological) facts and (religious, moral and juridical) values, and resonated in different ways with the idea of the individual as privileged mode of constructing personhood in the context of modern nation states.
Intra-arterial application of nimodipine in reversible cerebral vasoconstriction syndrome: A diagnostic tool in select cases?
Authors: Linn J , Fesl G , Ottomeyer C , Straube A , Dichgans M , Bruckmann H , Pfefferkorn T
Published: January 2011

Introduction: Differential diagnoses of the reversible cerebral vasoconstriction syndrome (RCVS) include all forms of intracranial stenotic disease, such as primary or secondary vasculitis of the central nervous system. Here, we tested the hypothesis that angiographic response to intra-arterial nimodipine application may be helpful in differentiating between RCVS and other entities.

Methods: A digital subtraction angiographic (DSA) series of nine consecutive patients with suspected RCVS that were treated by intra-arterial nimodipine due to clinical worsening were retrospectively analyzed. Pre- and post-therapeutic DSA findings of patients with later-confirmed RCVS were compared to those in which another diagnosis was finally made.

Results: Intra-arterial nimodipine resulted in a normalization of both the diameter of the main trunks of the cerebral vessels and the caliber of the peripheral vessels in all RCVS patients. This was not the case in the non-RCVS patients, in whom only a slight general vasodilatation was observed.

Discussion: Our preliminary results indicate that angiographic response to intra-arterial application might be a helpful differential diagnostic tool in select patients with suspected RCVS.
Risk factors for high-altitude headache in mountaineers
Authors: Burtscher Martin , Mairer Klemens , Wille Maria , Broessner Gregor
Published: January 2011

Aim: The aim was to identify most relevant risk factors of high-altitude headache within a broad mountaineering population through a prospective, observational, rater-blinded study.

Methods: A total of 506 mountaineers were enrolled after their first overnight stay in one of seven alpine huts between 2200–3817 m. Structured interview including information on mountaineering histories, caffeine intake, smoking habits, alcohol consumption, intake of medication, rate of ascent, physical fitness, the level of exertion and the amount of fluids intake at the day of ascent were recorded along with a standardized medical examination.

Results: High-altitude headache occurred in 31% of study participants. Logistic regression analysis revealed a migraine history, low arterial oxygen saturation, high ratings of perceived exertion and fluid intake below 2 l to be independent risk factors for the development of high-altitude headache.

Conclusion: Given the high prevalence, high-altitude headache is a relevant medical condition and a better understanding of risk factors has important impact and may facilitate patient behaviour and future study design.
Arthroscopic Prevalence of Ramp Lesion in 868 Patients With Anterior Cruciate Ligament Injury
Authors: Liu Xin , Feng Hua , Zhang Hui , Hong Lei , Wang Xue Song , Zhang Jin
Published: January 2011

Background: A special type of repairable meniscal lesion involving the peripheral attachment of the posterior horn of the medial meniscus is commonly associated with anterior cruciate ligament deficiency and is termed a “ramp lesion.” However, there are no previously published articles reporting the epidemiologic characteristics of ramp lesions.

Hypothesis: The ramp lesion is a special type of medial meniscal tear with high prevalence associated with anterior cruciate ligament rupture; the prevalence increases with time from anterior cruciate ligament injury. Age and gender are risk factors affecting the prevalence of the ramp lesion.

Study Design: Cross-sectional study; Level of evidence, 3.

Methods: From April 2002 to October 2007, 868 consecutive knees were diagnosed as having an anterior cruciate ligament injury and received arthroscopic surgery for anterior cruciate ligament reconstruction. All the patients had verified tears of the ramp area under arthroscopy. The prevalence of the ramp lesion was evaluated retrospectively. Then, all cases were divided into different groups depending on the time interval from anterior cruciate ligament injury to anterior cruciate ligament reconstruction and other relevant risk factors such as age and gender. The effects of age, gender, and time from injury on the prevalence of ramp lesions were analyzed.

Results: Among 868 knees that underwent surgery for anterior cruciate ligament reconstruction, 144 knees were diagnosed as having a ramp lesion. The mean age was 24.7 years; there were 113 male and 31 female patients. The mean time from injury to anterior cruciate ligament reconstruction was 27.2 months. The prevalence of ramp lesions was 16.6%, which was analyzed as a logarithmic correlation with time from injury. Patients younger than 30 years of age and male patients had a significantly higher prevalence of ramp lesions.

Conclusion: The ramp lesion is a common meniscal injury that can occur at the time of anterior cruciate ligament rupture or as a result of knee laxity associated with anterior cruciate ligament insufficiency. The prevalence of ramp lesion in this patient group was 16.6%, which increased with time until 24 months after initial injury. Patients younger than 30 years of age and male patients had a higher prevalence of ramp lesions.
Is Supplementary Fixation Necessary in Anterior Cruciate Ligament Reconstructions?
Authors: Lee John J. , Otarodifard Karimdad , Jun Bong Jae , McGarry Michelle H. , Hatch George F. , Lee Thay Q.
Published: January 2011

Background: There has been concern regarding the fixation of anterior cruciate ligament reconstruction, with soft tissue grafts being strong and stiff enough to allow for early accelerated postoperative rehabilitation. Therefore, some have recommended supplementary fixation for soft tissue tibia interference screw fixation with a staple, to improve the strength and stiffness of the fixation. Unfortunately, with staple supplementation, there is a risk for symptomatic hardware, which may require a second surgery to remove the staple.

Hypothesis: Supplementary fixation with a bioabsorbable knotless suture anchor will improve the structural properties of soft tissue tibia bioabsorbable interference screw (BIS) fixation and be comparable with supplementary fixation with a staple.

Study Design: Controlled laboratory study.

Method: Fifteen porcine tibias and flexor profundus tendons were randomized into 3 fixation study groups: group 1, BIS; group 2, BIS + staple; and group 3, BIS + push-lock screw. The structural properties of the 3 fixation groups were tested under displacement-controlled cyclic loading and load to failure.

Results: No significant difference in mean stiffness (N/mm ± SEM) under cyclic loading was found for BIS (335.31 ± 15.43), BIS + staple (344.81 ± 44.97), and BIS + push-lock (353.28 ± 38.93). Under load-to-failure testing, there were no differences found in stiffness, yield load, displacement at yield load, displacement at ultimate load, and energy absorbed among the 3 fixation methods. BIS + push-lock fixation had a significantly higher ultimate load than BIS alone and BIS + staple (917.85 ± 58.30 N vs 479.83 ± 66.04 N, P = .0003 vs 618.89 ± 8.94 N, P = .004).

Conclusion: Supplementary fixation with staple or push-lock screw did not significantly increase the structural strength and stiffness of the BIS soft tissue graft fixation under cyclic loading, but it did show improvement under load-to-failure testing for ultimate tensile load.

Clinical Relevance: The indication for supplementary fixation for tibial BIS soft tissue graft fixation depends on the fixation that the BIS achieves at the time of the surgery because the tensile load is transferred to the secondary fixation if and only when there is slippage of graft at the primary fixation. The supplementary fixation may be of value in those cases with poor bone quality, such as revision surgery with tunnel widening and/or graft-tunnel mismatch, or possibly in cases with older patients or patients with disorders affecting bone mineral density.
Pandemic Influenza
Authors: Manuell Mary-Elise , Co Mary Dawn T. , Ellison Richard T.
Published: January 2011

In a 5-week span during the 1918 influenza A pandemic, more than 2000 patients were admitted to Cook County Hospital in Chicago, with a diagnosis of either influenza or pneumonia; 642 patients, approximately 31% of those admitted, died, with deaths occurring predominantly in patients of age 25 to 30 years. 1 This review summarizes basic information on the biology, epidemiology, control, treatment and prevention of influenza overall, and then addresses the potential impact of pandemic influenza in an intensive care unit setting. Issues that require consideration include workforce staffing and safety, resource management, alternate sites of care surge of patients, altered standards of care, and crisis communication.
Sleep Deprivation in Critical Illness
Authors: Kamdar Biren B. , Needham Dale M. , Collop Nancy A.
Published: January 2011

Critically ill patients frequently experience poor sleep, characterized by frequent disruptions, loss of circadian rhythms, and a paucity of time spent in restorative sleep stages. Factors that are associated with sleep disruption in the intensive care unit (ICU) include patient-ventilator dysynchrony, medications, patient care interactions, and environmental noise and light. As the field of critical care increasingly focuses on patients’ physical and psychological outcomes following critical illness, understanding the potential contribution of ICU-related sleep disruption on patient recovery is an important area of investigation. This review article summarizes the literature regarding sleep architecture and measurement in the critically ill, causes of ICU sleep fragmentation, and potential implications of ICU-related sleep disruption on patients’ recovery from critical illness. With this background information, strategies to optimize sleep in the ICU are also discussed.
Managing Sales Employees’ Compensation: A Countercyclical Investment Approach
Authors: Madhani Pankaj M.
Published: January 2011

This article explains a “contrarian” human resource investment strategy: countercyclical hiring. Human capital is a critical resource and provides sustainable competitive advantages. This article focuses on a resource-based view and describes a VRIO (value, rarity, imitability, organization) framework for human capital. It also describes procyclical and countercyclical hiring and corresponding compensation strategies. Countercyclical hiring by firms provides numerous advantages. However, there are also many costs associated with it. The article provides a cost—benefit analysis of countercyclical hiring, presents a model for optimal levels of countercyclical hiring and provides a matrix for establishing the relationship between firm characteristics and levels of countercyclical hiring.