bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional Ischemic Vulnerability of the Brain to Hypoperfusion
Authors: Payabvash Seyedmehdi , Souza Leticia C.S. , Wang Yifei , Schaefer Pamela W. , Furie Karen L. , Halpern Elkan F. , Gonzalez R. Gilberto , Lev Michael H.
Published: April 2011

Background and Purpose—

To characterize the spatial pattern of cerebral ischemic vulnerability to hypoperfusion in stroke patients.

Methods—

We included 90 patients who underwent admission CT perfusion and MRI within 12 hours of ischemic stroke onset. Infarcted brain lesions (“core”) were segmented from admission diffusion-weighted imaging and, along with the CT perfusion parameter maps, coregistered onto MNI-152 brain space, which was parcellated into 125 mirror cortical and subcortical regions per hemisphere. We tested the hypothesis that the percent infarction increment per unit of relative cerebral blood flow (rCBF) reduction differs statistically between regions using regression analysis to assess the interaction between regional rCBF and region variables. Next, for each patient, a “vulnerability index” map was constructed with voxel values equaling the product of that voxel's rCBF and infarction probability (derived from the MNI-152–transformed, binary, segmented, diffusion-weighted imaging lesions). Voxel-based rCBF threshold for core was determined within the upper 20
th
percentile of vulnerability index map voxel values.

Results—

Different regions had different percent infarction increase per unit rCBF reduction (
P
=0.001). The caudate body, putamen, insular ribbon, paracentral lobule, and precentral, middle, and inferior frontal gyri had the highest ischemic vulnerability to hypoperfusion. A voxel-based rCBF threshold of <0.42 optimally distinguished infarct core in the highly-vulnerable regions, whereas rCBF <0.16 distinguished core in the remainder of the brain.

Conclusions—

We demonstrated regional ischemic vulnerability of the brain to hypoperfusion in acute stroke patients. Location-specific, rather than whole-brain, rCBF thresholds may provide a more accurate metric for estimating infarct core using CT perfusion maps.
Global Cerebral Edema and Brain Metabolism After Subarachnoid Hemorrhage
Authors: Helbok Raimund , Ko Sang-Bae , Schmidt J. Michael , Kurtz Pedro , Fernandez Luis , Choi H. Alex , Connolly E. Sander , Lee Kiwon , Badjatia Neeraj , Mayer Stephan A. , Claassen Jan
Published: April 2011

Background and Purpose—

Global cerebral edema is common among patients with poor-grade subarachnoid hemorrhage and is associated with poor outcome. Currently no targeted therapy exists largely due to an incomplete understanding of the underlying mechanisms.

Methods—

This is a prospective observational study including 39 consecutive patients with poor-grade subarachnoid hemorrhage with multimodal neuromonitoring. Levels of microdialysate lactate–pyruvate ratio, episodes of cerebral metabolic crisis (lactate-pyruvate ratio >40 and brain glucose <0.7 mmol/L), brain tissue oxygen tension, cerebral perfusion pressure, and transcranial Doppler sonography flow velocities were analyzed.

Results—

Median age was 54 years (range, 45 to 61 years) and 62% were female. Patients with global cerebral edema on admission (n=24 [62%]) had a higher incidence of metabolic crisis in the first 12 hours of monitoring (n=15 [15% versus 2%],
P
<0.05) and during the total time of neuromonitoring (20% versus 3%,
P
<0.001) when compared to those without global cerebral edema. There was no difference in brain tissue oxygen tension or cerebral perfusion pressure between the groups; however, in patients with global cerebral edema, a higher cerebral perfusion pressure was associated with lower lactate–pyruvate ratio (
P
<0.05). Episodes of metabolic crisis were associated with poor outcome (modified Rankin Scale score 5 or 6,
P
<0.05).

Conclusions—

In patients with poor-grade subarachnoid hemorrhage, global cerebral edema is associated with early brain metabolic distress.
Retinal Microvascular Signs and Functional Loss in Older Persons
Authors: Kim Dae Hyun , Newman Anne B. , Hajjar Ihab , Strotmeyer Elsa S. , Klein Ronald , Newton Elizabeth , Sarnak Mark J. , Burke Gregory L. , Lipsitz Lewis A.
Published: April 2011

Background and Purpose—

We hypothesized that retinal microvascular signs are associated with executive dysfunction, slow gait, and depressive mood, which are characteristic features of microvascular disease affecting frontal subcortical regions of the brain.

Methods—

In the Cardiovascular Health Study, 1744 participants (mean age, 78) free of stroke had retinal photographs and carotid ultrasound during the 1997 to 1998 visit. We examined the cross-sectional association of retinal signs with the digit-symbol substitution test (DSST) score, gait speed, the Center for Epidemiologic Studies–Depression score, and depressive mood, defined as Center for Epidemiologic Studies–Depression score >9 or antidepressant use.

Results—

After adjusting for potential confounders, retinal signs were associated with lower DSST score (generalized arteriolar narrowing and arteriovenous nicking), slower gait (retinopathy), and depressive mood (generalized arteriolar narrowing). A higher number of retinal signs was associated with lower DSST score (−0.76 and −2.79 points for 1 sign and ≥2 signs versus none;
P
<0.001) and slower gait (−0.009 and −0.083 m/s;
P
=0.047), but not with the square root of Center for Epidemiologic Studies–Depression score (0.079 and −0.208;
P
=0.072). In addition, coexistence of retinal signs (generalized arteriolar narrowing and arteriovenous nicking) and carotid atherosclerosis was associated with lower DSST score compared with either process alone (
P
for interaction <0.01). Notably, further adjustment for ventricular size, white matter disease, and infarcts on MRI did not attenuate the association.

Conclusions—

Retinal signs are associated with executive dysfunction and slow gait, and possibly with depressive mood, suggesting a common process involving small vessels.
High NIHSS Values Predict Impairment of Cardiovascular Autonomic Control
Authors: Hilz Max Josef , Moeller Sebastian , Akhundova Aynur , Marthol Harald , Pauli Elisabeth , De Fina Philipp , Schwab Stefan
Published: April 2011

Background and Purpose—

Stroke is frequently associated with autonomic dysfunction, which causes secondary cardiovascular complications. Early diagnosis of autonomic imbalance prevents complications, but it is only available at specialized centers. Widely available surrogate markers are needed. This study tested whether stroke severity, as assessed by National Institutes of Health Stroke Scale (NIHSS) scores, correlates with autonomic dysfunction and thus predicts risk of autonomic complications.

Methods—

In 50 ischemic stroke patients, we assessed NIHSS scores and parameters of autonomic cardiovascular modulation within 24 hours after stroke onset and compared data with that of 32 healthy controls. We correlated NIHSS scores with parameters of total autonomic modulation (total powers of R-R interval [RRI] modulation; RRI standard deviation [RRI-SD], RRI coefficient of variation), parasympathetic modulation (square root of the mean squared differences of successive RRIs, RRI-high-frequency-powers), sympathetic modulation (normalized RRI-low-frequency-powers, blood pressure-low-frequency-powers), the index of sympatho-vagal balance (RRI-LF/HF-ratios), and baroreflex sensitivity.

Results—

Patients had significantly higher blood pressure and respiration, but lower RRIs, RRI-SDs, RRI coefficient of variation, square root of the mean squared differences of successive RRIs, RRI-low-frequency-powers, RRI-high-frequency-powers, RRI-total powers, and baroreflex sensitivity than did controls. NIHSS scores correlated significantly with normalized RRI-low-frequency-powers and RRI-LF/HF-ratios, and indirectly with RRIs, RRI-SDs, square root of the mean squared differences of successive RRIs, RRI-high-frequency-powers, normalized RRI-high-frequency-powers, RRI-total-powers, and baroreflex sensitivity. Spearman-Rho values ranged from 0.29 to 0.47.

Conclusions—

Increasing stroke severity was associated with progressive loss of overall autonomic modulation, decline in parasympathetic tone, and baroreflex sensitivity, as well as progressive shift toward sympathetic dominance. All autonomic changes put patients with more severe stroke at increasing risk of cardiovascular complications and poor outcome. NIHSS scores are suited to predict risk of autonomic dysregulation and can be used as premonitory signs of autonomic failure.
Surgical Revascularization Reverses Cerebral Cortical Thinning in Patients With Severe Cerebrovascular Steno-Occlusive Disease
Authors: Fierstra Jorn , MacLean David B. , Fisher Joseph A. , Han Jay S. , Mandell Daniel M. , Conklin John , Poublanc Julien , Crawley Adrian P. , Regli Luca , Mikulis David J. , Tymianski Michael
Published: April 2011

Background and Purpose—

Chronic deficiencies in regional blood flow lead to cerebral cortical thinning without evidence of gross tissue loss at the same time as potentially negatively impacting on neurological and cognitive performance. This is most pronounced in patients with severe occlusive cerebrovascular disease in whom affected brain areas exhibit “steal physiology,” a paradoxical reduction of cerebral blood flow in response to a global vasodilatory stimulus intended to increase blood flow. We tested whether surgical brain revascularization that eliminates steal physiology can reverse cortical thinning.

Methods—

We identified 29 patients from our database who had undergone brain revascularization with pre- and postoperative studies of cerebrovascular reactivity using blood oxygen(ation) level-dependent MRI and whose preoperative study exhibited steal physiology without MRI-evident structural abnormalities. Cortical thickness in regions corresponding to steal physiology, and where applicable corresponding areas in the normal hemisphere, were measured using Freesurfer software.

Results—

At an average of 11 months after surgery, cortical thickness increased in every successfully revascularized hemisphere (n=30). Mean cortical thickness in the revascularized regions increased by 5.1% (from 2.40±0.03 to 2.53±0.03;
P
<0.0001).

Conclusions—

Successful regional revascularization and reversal of steal physiology is followed by restoration of cortical thickness.
Neighborhood Cohesion Is Associated With Reduced Risk of Stroke Mortality
Authors: Clark Cari Jo , Guo Hongfei , Lunos Scott , Aggarwal Neelum T. , Beck Todd , Evans Denis A. , Mendes de Leon Carlos , Everson-Rose Susan A.
Published: April 2011

Background and Purpose—

Greater social cohesion is related to lower rates of coronary heart disease, but its relation to stroke risk is unstudied. This study examined whether neighborhood social cohesion was protective against stroke mortality and incidence.

Methods—

Data come from 5789 participants (60% female; 62% black; mean age, 74.7 years) in a longitudinal study of chronic diseases in the elderly. Stroke mortality, ascertained through December 31, 2007, was verified through the National Death Index; 186 stroke deaths were identified in 11 years of follow-up. Stroke incidence was determined in a subset (N=3816) with linkage to Medicare claims files; 701 first-ever strokes were identified. Cohesion was measured by 6 items assessing frequency of contact and social interactions with neighbors; items were z-scored and averaged. Individual scores were averaged across 82 census block groups, forming a neighborhood-level measure of social cohesion. Marginal Cox proportional hazard models tested the association of neighborhood-level cohesion with stroke mortality and incidence.

Results—

Each 1-point increase in cohesion related to a 53% reduced risk of stroke mortality (hazard ratio, 0.47; 95% CI, 0.24 to 0.90), adjusting for relevant covariates, including sociodemographics, known stroke risk factors, and neighborhood-level socioeconomic status. A race×cohesion interaction (
P
=0.04) revealed cohesion was protective in whites (hazard ratio, 0.34; 95% CI, 0.17 to 0.67) but not blacks (hazard ratio, 1.17; 95% CI, 0.35 to 3.86). Cohesion was unrelated to stroke incidence (
P
>0.5).

Conclusions—

Neighborhood-level social cohesion was independently protective against stroke mortality. Research is needed to further examine observed race differences and pathways by which cohesion is health-protective.
A Neural Network Model for the Acquisition of a Spatial Body Scheme Through Sensorimotor Interaction
Authors: Roschin Vadim Y. , Frolov Alexander A. , Burnod Yves , Maier Marc A.
Published: April 2011

This letter presents a novel unsupervised sensory matching learning technique for the development of an internal representation of three-dimensional information. The representation is invariant with respect to the sensory modalities involved. Acquisition of the internal representation is demonstrated with a neural network model of a sensorimotor system of a simple model creature, consisting of a tactile-sensitive body and a multiple-degrees-of-freedom arm with proprioceptive sensitivity. Acquisition of the 3D representation as well as a distributed representation of the body scheme, occurs through sensorimotor interactions (i.e., the sensory-motor experience of the creature). Convergence of the learning is demonstrated through computer simulations for the model creature with a 7-DoF arm and a spherical body covered by 20 tactile fields.
Spiking Neurons and the First Passage Problem
Authors: Sirovich Lawrence , Knight Bruce
Published: April 2011

We derive a model of a neuron’s interspike interval probability density through analysis of the first passage problem. The fit of our expression to retinal ganglion cell laboratory data extracts three physiologically relevant parameters, with which our model yields input-output features that conform to laboratory results. Preliminary analysis suggests that under common circumstances, local circuitry readjusts these parameters with changes in firing rate and so endeavors to faithfully replicate an input signal. Further results suggest that the so-called principle of sloppy workmanship also plays a role in evolution’s choice of these parameters.
Openness and the Politics of Potable Water
Authors: Rudra Nita
Published: April 2011

Improving access to potable water has become an increasingly urgent concern for developing nations in the current era of globalization. According to standard wisdom, if developing countries undertake certain domestic reforms, such as investing in infrastructure and engineering, then safe and clean drinking water will improve. This analysis uncovers, however, that in addition to such domestic efforts, one of the greatest factors affecting water uncertainty is, in fact, internationally induced: trade. Surprisingly, both scholars and practitioners have neglected the potential impacts of expanding trade on access to potable water. This analysis is the first large- N cross-national study of water that focuses on the interplay of trade and politics—both international and domestic—as the primary driving forces behind improvements in (or constraints to) water access. The author hypothesizes that growing export pressures are constraining drinkable water in poor countries, but a particular domestic condition can mitigate this effect: the existence of lower levels of income inequality. As the socioeconomic actors disadvantaged by openness, particularly in more equal countries, seek reparations for the growing threats to potable water, the adverse affects of trade on water may be averted. Empirical evidence from 77 developing countries and case studies of Vietnam and India provide support for this hypothesis.
Executive Elections in the Arab World: When and How Do They Matter?
Authors: Brownlee Jason
Published: April 2011

Although elections loom large in the study of nondemocracies, scholars continue debating what function those elections play. This article sets evidence from the Arab world in a global context to evaluate three theorized roles for elections: safety valve, patronage network, and performance ritual. Executive elections in the Middle East and North Africa remain less common and less competitive than polls in sub-Saharan Africa and Asia. This profile is largely consistent with the observable implications of leading theories. The data, though, also show theoretically rich differences. Although levels of competition and participation in Yemen, Tunisia, and Algeria fit expectations about elections being safety valves or political spectacles, Egypt’s presidential election stands apart, with exceptionally meager public involvement. In such circumstances, where competition and turnout are both unusually low, other social and political phenomena may matter more than elections for regime survival, resource distribution, and the manifestation of state power.
Psychological Regimes of Truth and Father Identity: Challenges for Work/Life Integration
Authors: Eräranta Kirsi , Moisander Johanna
Published: April 2011

Based on a case study, this paper elaborates on the psychological regimes of truth that organize and regulate male parenting and partly constitute the conditions of possibility for male identity and subjectivity both as fathers and employees. The aim is to contribute to a better understanding of the discursive-cultural constraints that Western managers and employees — males in particular — may face when trying to pursue a better work/life balance. Based on an empirical analysis of expert literature on male parenting, the paper argues that prevalent psychological regimes of truth about fathers and fathering do not necessarily render enactable the sorts of identities that enable both men and women to achieve a better work/life balance.
Experimental analysis of clamped AA5010 and steel plates subjected to blast loading and underwater explosion
Authors: Zamani J , Safari K H , Ghamsari A K , Zamiri A
Published: April 2011

The dynamic plastic response of structures under blast loading and underwater explosion has found important applications in the design of energy-absorbing and collision protection devices. This paper presents the results of analytical and experimental studies on the response of steel and aluminium circular plates in two different media of air and water. Results of experimental observation of fully clamped plates have been presented. The results obtained are compared with existing empirical relations, a theoretical procedure, and a modified relation offered by Wierzbicki and Symonds. Comparing the experimental and theoretical results, it was observed that considering strain rate effect in the theoretical procedure is essential in obtaining a more accurate prediction of the deflection of the plate. The reasonable agreement between experimental results and relations proves the validity of the proposed predictions, especially when strain rate effect is considered. Since, in the case of air-blast-loaded plates, the deviation from experimental results was noticeable, a new relation for dynamic plastic response of circular plates is suggested, which is based on Zhao damage number. Furthermore, the effect of material and medium is investigated.
How Australian Female Adolescents Prioritize Pregnancy Protection
Authors: Smith Jennifer L. , Skinner S. Rachel , Fenwick Jennifer
Published: April 2011

Grounded theory principles were systematically employed to reveal key differences in pregnancy risk and underlying disparities in contraceptive use in (a) never-pregnant (b) pregnant-terminated and (c) pregnant-continued teenagers. Analysis of 69 semistructured interviews revealed a bicausal model of pregnancy protection that accounted for variation in contraceptive use across the sample. Diverging pregnancy/childbearing desires and risk perceptions were conceptualized into three behavioral patterns that represented higher and lower levels of commitment to prevent pregnancy. The various ways that teenagers made sense of their behavior highlight the importance of acknowledging and respecting diversity in perspectives and experiences and provide a useful framework for educational and practitioner-delivered interventions with greater relevance and impact.
Peer Status in Emerging Adulthood
Authors: Lansu Tessa A. M. , Cillessen Antonius H. N.
Published: April 2011

Although peer status has been studied extensively in childhood and adolescence, little is known about social status in peer groups of emerging adults. The current study filled this gap by testing whether preference and popularity are distinct dimensions of peer status and uniquely associated with social behavior in emerging adulthood. Participants were 235 18- to 25-year-old emerging adults in a professional college who completed a sociometric instrument. Popularity and preference were moderately correlated. Both types of status were positively related to prosocial leadership and negatively to social exclusion. Popularity was positively related to dominant leadership and relational aggression, whereas preference was negatively related to relational aggression. The results were compared with findings in adolescence and their generalizability to emerging adults in other social contexts was discussed.
Leukoencephalopathy With Brain Stem and Spinal Cord Involvement and High Lactate: A Genetically Proven Case Without Elevated White Matter Lactate
Authors: Sharma Suvasini , Sankhyan Naveen , Kumar Atin , Scheper Gert C. , van der Knaap Marjo S. , Gulati Sheffali
Published: April 2011

A 17-year-old Indian boy with gradually progressive ataxia with onset at 12 years of age is described. Magnetic resonance imaging (MRI) of the brain revealed extensive, inhomogeneous signal abnormalities in the cerebral white matter, with involvement of selected tracts in the brain stem and spinal cord. The imaging findings were characteristic of leukoencephalopathy with brain stem and spinal cord involvement and high lactate, a recently described leukodystrophy. Interestingly, magnetic resonance spectroscopy of the abnormal white matter did not reveal elevated lactate. The patient was compound heterozygous for 2 new mutations in DARS2, genetically confirming the diagnosis.
The Conceptualization of Anorexia: The Pro-Ana Perspective
Authors: Roberts Strife Samantha , Rickard Kathryn
Published: April 2011

This qualitative content analysis examined mission statements of pro-anorexia websites to gain a better understanding of how these individuals conceptualize the function of self-starvation. The results indicated that there is substantial diversity within this online community. Specifically, some pro-anorexia authors defined anorexia as an illness and disease from which recovery is not possible, while others suggested that anorexia is a lifestyle and chosen way of life. Clinical implications are discussed, including assessment and treatment considerations.
Age-Related Androgen Deficiency and Type 2 Diabetes
Authors: Ryan Gina J. , Jobe Lynetta J.
Published: April 2011

There is a higher prevalence of low testosterone levels in males with type 2 diabetes compared to those without. Additionally, there is evidence that low testosterone levels may predict the development of type 2 diabetes. Symptoms of hypogonadism include decreased libido, decreased bone mineral density (BMD), and decreased lean muscle mass. The majority of the published cases in men with diabetes were attributed to age-related idiopathic hypogonadotropic hypogonadism. This paper reviews the link between type 2 diabetes and age-related hypogonadism and the treatment options for hypogonadism. Pharmacists who provide care for males with diabetes should be aware of the increased incidence of hypogonadism, know how to screen for it, and be able to recommend appropriate therapy.
Activism as ‘Part-Time’ Activity: Searching for Commitment and Solidarity in Lebanon
Authors: Hermez Sami
Published: April 2011

This article is a reflection on activism and ethnography during times of conflict in Lebanon. It focuses on this through activist work the researcher was involved in during the July 2006 war and beyond. The article looks at commitment as one technique of activism, asking how activists achieve their goals, following this by asking what a commitment to ethnography looks like in the midst of conflict. Solidarity and commitment become tropes to think through the changing roles of activists and ethnographers.
Paradox lost: Explaining and modeling seemingly random individual behavior in social dilemmas
Authors: Oppenheimer Joe , Wendel Stephen , Frohlich Norman
Published: April 2011

Despite a large body of experimental data demonstrating consistent group outcomes in social dilemmas, a close look at individual behavior at the micro level reveals a more complicated story. From round to round, individual behavior appears to be almost random. Using a combination of formal deduction and agent-based simulations, we argue that any theory of individual choice that accounts for the observed behavior of real people is likely to require 1) premises of probabilistic choice, 2) preferences that are a function of others’ previous behavior (i.e., context dependent), and 3) preferences that are other-regarding rather than simply self-interested. We present a model that fits the requirements.
Coordination dilemmas and the valuation of women in the U.S. Senate: Reconsidering the critical mass problem
Authors: Kanthak Kristin , Krause George A.
Published: April 2011

We offer a model of colleague valuation to illuminate the coordination challenges women legislators face. Our model predicts that women members’ strategies depend upon whether they value women colleagues as much as men do, or instead value fellow women colleagues more highly. We test these predictions by analyzing leadership PAC campaign contributions U.S. Senators made to incumbent and challenger women during the 105th—108th Congresses. We find that women Senators value fellow incumbent women colleagues less highly than do men Senators, whereas they value women challengers more highly than do men. Attaining a critical mass of women in legislatures is thus not sufficient for creating a successful working environment, but instead creates a coordination problem that supplants the previous token minority problem.
The origins of social institutions
Authors: Urpelainen Johannes
Published: April 2011

How do individual agents enact the institutions that govern collective behavior in a social situation? How do individuals come to share self-enforcing expectations about collective behavior, so that societal rules and constraints have an effect on individual choice? Conventional accounts, such as contract and evolutionary theories or the analysis of conventions and social conflict, cannot explain the origins of social institutions because they do not address the origins of shared and self-enforcing expectations about collective behavior in a social situation. I analyze two separate stages of institutionalization. First, agents must imagine collective intentionality, so that an ‘imagined institution’ entailing a symbolic representation of collective behavior becomes common knowledge. Second, they must ‘enact’ it through shared and self-enforcing expectations on the path of play. In my model, the agents are goal-oriented, so the process is strategic throughout.
General Action and Inaction Goals
Authors: Albarracin Dolores , Hepler Justin , Tannenbaum Melanie
Published: April 2011

Since the 1970s, researchers on motivation and behavior have taken the stance that important human behaviors are determined by specific attitudes, intentions, and goals. In the present article, we review evidence suggesting that, in addition to specific motivational constructs, general goals of action and inaction are also vital determinants of many important human behaviors. This research examines the effects of these goals on motor behavior, cognitive performance, and political participation. Furthermore, we connect these general action and inaction goals with other important areas in psychology, including affect, approach/avoidance, energization, material resources, mindsets, and power. Finally, we conclude with a discussion of individual and regional/cultural differences in action and inaction. Overall, general goals for action and inaction are shown to influence a vast array of important behaviors, suggesting that in addition to considering specific attitudes, intentions, and goals, researchers may gain important insight into human behavior by considering general motivations.
Precarious Manhood and Its Links to Action and Aggression
Authors: Bosson Jennifer K. , Vandello Joseph A.
Published: April 2011

Unlike womanhood, manhood is widely viewed as a status that is elusive (it must be earned) and tenuous (it must be demonstrated repeatedly through actions). This focus on the structure—rather than the content—of gender roles can shed new light on men’s use of action and physical aggression. Here, we review theory and research connecting manhood, action, and aggression. We interpret men’s aggression and aggressive displays as behaviors that effectively demonstrate manhood and thus quell men’s concerns about their gender status. Moreover, we suggest that situational and cultural factors that heighten the precariousness of manhood also increase the likelihood of male aggression.
Evaluating Individual Differences in Psychological Processes
Authors: Bauer Daniel J.
Published: April 2011

Better understanding individual differences in social, cognitive, and behavioral processes is a core goal of much psychological theory and research. Although great progress has been made toward this goal, I argue here that the classical design and analysis approach that dominates individual difference research, namely, the collection of single-time-point data and application of standard linear regression models, potentially limits further advances. In particular, the opportunity to evaluate individual differences in psychological processes is restricted by the estimation of a single effect to represent the relationship between variables. I discuss alternative analysis and design options that offer the opportunity to more fully examine individual differences in psychological processes.
An Interactionist Perspective on Interpersonal Dependency
Authors: Bornstein Robert F.
Published: April 2011

Interpersonal dependency—the tendency to look to others for nurturance, guidance, protection, and support, even in situations where autonomous functioning is possible—has become associated with passivity, immaturity, and dysfunction in the minds of mental health professionals. However, research suggests that dependent persons behave quite actively—even aggressively—in certain contexts. Although dependency is associated with certain forms of dysfunction (e.g., perpetration of domestic violence when close relationships are threatened), it is also linked with an array of adaptive behaviors (e.g., conscientiousness in complying with medical and psychotherapeutic treatment regimens). The cognitive/interactionist (C/I) model of interpersonal dependency provides a framework for understanding contextual variations in dependency-related responding: Although dependent behaviors vary from situation to situation based on perceived opportunities and risks, the dependent person’s core beliefs (a perception of oneself as helpless and weak) and motives (a desire to strengthen ties to potential caregivers) remain constant. Here I discuss theoretical and practical implications of the C/I model and summarize current trends in research on interpersonal dependency.
Grandparental Investment
Authors: Coall David A. , Hertwig Ralph
Published: April 2011

From changing diapers and minding the kids when school is out to providing support when they set fire to the carpet, grandparents can be invaluable to have around. What motivates grandparents to lend a hand? Several disciplines have offered answers. The most important accounts come from life-history theory and evolutionary psychology, sociology, and economics. These accounts exist side-by-side, but there is little theoretical integration among them. But regardless of whether grandparental investment is traced back to ancestral selection pressure or attributed to an individual grandparent’s values or norms, one important question is, What impact does it have in industrialized, low-fertility, low-mortality societies? We briefly review the initial evidence concerning the impact of grandparental investment in industrialized societies and conclude that in difficult circumstances, grandparents can provide the support that safeguards their grandchildren’s development. Additional cross-disciplinary research to examine the effects of intergenerational transfers in our evolutionarily unique environment of grandparenthood is needed.
Change Trajectories During Home-Based Services With Chronic Child Welfare Cases
Authors: Chaffin Mark , Bard David , Hecht Debra , Silovsky Jane
Published: April 2011

This study examines how risk factor change patterns vary with case chronicity, and whether risk factor improvement still predicts lower recidivism risk among chronic cases. 2,175 parents in home based child welfare services were surveyed for risk factors at pre-treatment, post-treatment and 6-month follow-up. Mixture modeling of latent difference scores identified change trajectory classes related retrospectively to chronicity and prospectively to recidivism. Five change trajectories were identified: stable low problem, stable high problem, sustained improvement, relapsing, and paradoxical. Chronicity was associated with a decreasing probability of membership in the stable low problem trajectory and increasing probability of membership in the stable high problem and sustained improvement trajectories. Cases with more favorable trajectories recidivated less across levels of chronicity. Findings suggest that chronic cases may improve little, but still retain a stable or increasing chance of sustained improvement associated with lower risk. A cumulative service benefit might be one possible explanation for this observation, and might suggest that repeated intervention efforts are not always wasted on chronic cases. The current episodic and reactive service delivery model in child welfare may be a mismatch with chronic cases where progress is absent or tends to occur cumulatively across service episodes.
Evaluation of a new computer-assisted surgical planning and navigation system based on two-dimensional fluoroscopy for insertion of a proximal femoral nail
Authors: Müller M C , Belei P , de la Fuente M , Strake M , Kabir K , Weber O , Radermacher K , Wirtz D C
Published: April 2011

Pertrochanteric femoral fractures are common and intramedullary nailing is an accepted method for their surgical treatment. Accurate placement of the implant is essential to ensure fixation. The conventional technique can require multiple guide wire passes, and relies heavily on fluoroscopy. A computer-assisted planning and navigation system based on two-dimensional fluoroscopy for guide wire placement in the femoral neck has been developed, in order to perform intramedullary pertrochanteric fracture fixation using the proximal femoral nail (PFNA®). The planning process was supported by a ‘zero-dose C-arm navigation’ system. The PFNA was inserted into 12, intact, femoral sawbones guided by the computer-based navigation, and into 12, intact, femoral sawbones using a conventional fluoroscopic-assisted technique. Guide wire and subsequent blade placement in the femoral neck was evaluated. The computer-assisted technique achieved a significant decrease in the number of required fluoroscopic images and in the number of guide wire passes. The obtained average blade placement accuracy in the femoral neck was equivalent to the conventional technique. The operation time was significantly longer in the navigation-assisted group. The addition of computer-assisted planning and surgical guidance to the intramedullary nailing of pertrochanteric femoral fractures offers a number of clinical benefits based on the results of this sawbone study. Further studies including fractured sawbones and cadaver models with extension of the navigation process to all steps of PFNA introduction and with the goal of reducing operation time are indispensable before integration of this navigation system into clinical practice.
Load transfer in the proximal tibia following implantation with a unicompartmental knee replacement
Authors: Simpson D J , Kendrick B J L , Dodd C A F , Price A J , Gill H S , Murray D W
Published: April 2011

Unicompartmental knee replacement (UKR) is an appealing alternative to total knee replacement when the patient has isolated medial compartment osteoarthritis. A common observation post-operatively is radiolucency between the tibial tray wall and the bone. In addition, some patients complain of persistent pain over the proximal tibia antero-medially; this may be related to elevated bone strains in the tibia. Currently, there is no intentionally made mechanical bond between the vertical wall of an Oxford UKR and the adjacent bone; whether one exists or not will influence the load transmission in the proximal tibia and may affect the elevated tibia strain. The aim of this study was to investigate how introducing a mechanical tie between the tibial tray wall and the adjacent bone might alter the load carried into the tibia for both cemented and cementless UKRs. Strain energy density in the region of bone adjacent to the tray wall was considerably increased when a mechanical tie was introduced; this has the potential of reducing the likelihood of a radiolucency occurring in that region. Moreover, a mechanical tie had the effect of reducing proximal tibia strain, which may decrease the incidence of pain following implantation with a UKR.
A purpose-built dynamometer to objectively measure static and dynamic knee torque
Authors: Ugbolue U C , Kaliarntas K T , Wearing S C , Rowe P J
Published: April 2011

This paper reports the development of a purpose-built knee dynamometer (PBKD) to evaluate passive range of motion (ROM) and isometric muscle strength measurements of the knee. The PBKD uses a TorqSense rotary torque transducer and objectively measures isometric knee muscle strength in a valid and reliable manner and passive resistance to motion through range. The device and all associated instrumentation underwent dynamic and static calibration to ensure consistent and accurate measurements were obtained in terms of knee joint angular position, passive torque measures, and isometric torque measures. Eleven healthy male participants performed a knee flexion and extension task designed to evaluate knee function. The validation of the PBKD entailed measuring the consistency of measurement and accuracy of measurement. Accuracy of the PBKD was determined by comparing peak isometric muscle strength measurements against a KIN-COM machine. No significant differences were observed both passively and isometrically between cycles and between trials. This device can have widespread applications within the rehabilitation and clinical environment and could be used as a functional outcome measuring tool to distinguish pathological from non-pathological knees. The presented preliminary results indicate that reliable and accurate measurements of knee ROM and muscle strength can be obtained.
Peripheral T-cell lymphoma
Authors: Foss Francine M. , Zinzani Pier Luigi , Vose Julie M. , Gascoyne Randy D. , Rosen Steven T. , Tobinai Kensei
Published: April 2011

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of clinically aggressive diseases associated with poor outcome. Studies that focus specifically on PTCL are emerging, with the ultimate goal of improved understanding of disease biology and the development of more effective therapies. However, one of the difficulties in classifying and studying treatment options in clinical trials is the rarity of these subtypes. Various groups have developed lymphoma classifications over the years, including the World Health Organization, which updated its classification in 2008. This article briefly reviews the major lymphoma classification schema, highlights contributions made by the collaborative International PTCL Project, discusses prognostic issues and gene expression profiling, and outlines therapeutic approaches to PTCL. These include the standard chemotherapeutic regimens and other modalities incorporating antifolates, conjugates, histone deacetylase inhibitors, monoclonal antibodies, nucleoside analogs, proteasome inhibitors, and signaling inhibitors. As this review emphasizes, the problem has now evolved into an abundance of drugs and too few patients available to test them. Collaborative groups will aid in future efforts to find the best treatment strategies to improve the outcome for patients with PTCL.
Plasticity of human Th17 cells and iTregs is orchestrated by different subsets of myeloid cells
Authors: Hoechst Bastian , Gamrekelashvili Jaba , Manns Michael P. , Greten Tim F. , Korangy Firouzeh
Published: April 2011

CD4+ T helper cell differentiation is essential for mounting robust immune responses without compromising unresponsiveness toward self-tissue. Here, we show that different subsets of myeloid cells isolated from human peripheral blood modulate TGF-β–dependent CD4+ T-cell developmental programs ex vivo. Human CD14+HLA-DR−/low myeloid-derived suppressor cells (MDSCs) induce Foxp3+ regulatory T cells, whereas CD14+HLA-DR+ monocytes promote generation of IL-17–secreting RORc+ Th17 cells when cocultured with naive CD4+ T cells. More importantly, not only do these 2 subsets modulate the de novo induction of Tregs and Th17 cells from CD4+ T cells, but MDSCs also catalyze the transdifferentiation of Foxp3+ regulatory T cells from monocyte-induced Th17 cells. The mechanism of such Th17 plasticity is dependent on MDSC-derived TGF-β and retinoic acid. Our results identify a previously unknown feature of the different subsets of CD14+ myeloid cells namely their pivotal role in immune response regulation and plasticity of CD4+ T helper cells. We propose that different subsets of myeloid cells in humans can orchestrate the differentiation of naive CD4+ T cells into effector/regulatory T-cell subsets. The balance between these 2 subsets can impact the outcome of immune reaction from inflammation to tolerance.
Chronic GVHD risk score: a Center for International Blood and Marrow Transplant Research analysis
Authors: Arora Mukta , Klein John P. , Weisdorf Daniel J. , Hassebroek Anna , Flowers Mary E. D. , Cutler Corey S. , Urbano-Ispizua Alvaro , Antin Joseph H. , Bolwell Brian J. , Boyiadzis Michael , Cahn Jean-Yves , Cairo Mitchell S. , Isola Luis , Jacobsohn David A. , Jagasia Madan , Klumpp Thomas R. , Lee Stephanie J. , Petersdorf Effie W. , Santarone Stella , Gale Robert Peter , Schouten Harry C. , Spellman Stephen , Wingard John R. , Horowitz Mary M. , Pavletic Steven Z.
Published: April 2011

Several risk factors are associated with increased mortality in patients with chronic graft-versus-host disease (cGVHD), but there is considerable variability in the reported factors. Therefore, we evaluated patient, transplantation, and cGVHD characteristics to develop a risk score in 5343 patients with cGVHD. Ten variables were identified as being significant in multivariate analysis of overall survival and nonrelapse mortality (NRM): age, prior acute GVHD, time from transplantation to cGVHD, donor type, disease status at transplantation, GVHD prophylaxis, gender mismatch, serum bilirubin, Karnofsky score, and platelet count. These 10 variables were used to build a cGVHD risk score, and 6 risk groups (RGs) were identified. The 5-year NRM was 5% (1%-9%) in RG1, 20% (19%-23%) in RG2, 33% (29%-37%) in RG3, 43% (40%-46%) in RG4, 63% (53%-74%) in RG5, and 72% (59%-85%) in RG6. The 5-year overall survival was highest at 91% (95% confidence interval [CI]:85%-97%) in RG1, followed by 67% (65%-69%) in RG2, 51% (46%-55%) in RG3, 40% (37%-43%) in RG4, 21% (12%-30%) in RG5, and 4% (0%-9%) in RG6 (all P < .01). This analysis demonstrates the usefulness of data from a large registry to develop risk-score categories for major transplantation outcomes. Validation of this cGVHD risk score is needed in a different population to ensure its broad applicability.
The impact of the competence quorum sensing system on Streptococcus pneumoniaebiofilms varies depending on the experimental model
Authors: Trappetti Claudia , Gualdi Luciana , Di Meola Lorenzo , Jain Prashant , Korir Cindy C , Edmonds Paul , Iannelli Francesco , Ricci Susanna , Pozzi Gianni , Oggioni Marco R
Published: April 2011

Background

Different models for biofilm inStreptococcus pneumoniaehave been described in literature. To permit comparison of experimental data, we characterised the impact of the pneumococcal quorum-sensing competence system on biofilm formation in three models. For this scope, we used two microtiter and one continuous culture biofilm system.

Results

In both microtiter models the competence system influences stability and structure of biofilm in the late attachment phase and synthetic competence stimulating peptide (CSP) restored wild type phenotypes in thecomCmutants unable to produce the peptide. Early attachment of single cells to well bottoms was found for both systems to be competence independent, while later phases, including microcolony formation correlated to an intact competence system. The continuous culture biofilm model was not affected by mutations in the competence locus, but deletion of capsule had a significant impact in this model.

Conclusions

Since biofilm remains a largely uncharacterised multi-parameter phenotype it appears to be advisable to exploit more than one model in order to draw conclusion of possible relevance of specific genotypes on pneumococcal physiology.
Impact of interventions to prevent and manage preeclampsia and eclampsia on stillbirths
Authors: Jabeen Mehnaz , Yakoob Mohammad Yawar , Imdad Aamer , Bhutta Zulfiqar A
Published: April 2011

Background

Pre-eclampsia and Eclampsia are relatively common complications of pregnancy, leading to considerable maternal and fetal mortality and morbidity. We sought to review the effect of aspirin, calcium supplementation, antihypertensive agents and magnesium sulphate on risk stillbirths.

Methods

A systematic literature search was conducted to identify studies evaluating the above interventions. We used a standardized abstraction and grading format and performed meta-analyses where data were available from more than one studies. The estimated effect on stillbirths was determined by applying the standard Child Health Epidemiology Reference Group (CHERG) rules for multiple outcomes. For interventions with insufficient evidence for overall effect, a Delphi process was undertaken to estimate effectiveness.

Results

We identified 82 relevant studies. For aspirin, maganesium sulphate and use of antihypertensive we found an insignificant decrease in stillbirth and perinatal mortality. For calcium supplementation, there was a borderline significant reduction in stillbirths (RR 0.81, 95 % CI 0.63-1.03). We undertook a Delphi consultation among experts to assess the potential impact of a package of interventions for the management of pre-eclampsia and eclampsia (antihypertensive, magnesium sulphate and C-section if needed). The Delphi process suggested 20% reduction each in both antepartum and intrapartum stillbirths with the use of this package.

Conclusions

Despite promising benefits of calcium supplementation and aspirin use cases on maternal morbidity and eclampsia in high risk cases, further work is needed to ascertain their benefits in relation to stillbirths. The Delphi process undertaken for assessing potential impact of a package of interventions indicated that this could be associated with 20% reduction in stillbirths, for input into LiST.