bluuebunny/crossref_metadata_2025 huggingface dataset:
Immersive Video Teleconferencing with User-Steerable Views
Authors: Yang Ruigang , Kurashima Celso Setsuo , Towles Herman , Nashel Andrew , Zuffo Marcelo Knörich
Published: March 2007

Existing video teleconferencing techniques suffer from limited field of view, low resolution, and fixed viewpoint. We present a set of novel techniques to overcome these limitations. Based on the light field rendering concept, we utilize an array of cameras to capture the participant(s) from multiple view angles. Based on either assumed or estimated scene geometry, these images are assembled to create a high-resolution seamless image from a user-controllable viewpoint. Two different camera configurations, one dense and one sparse, are presented; the dense format is optimized for high-fidelity view synthesis while the sparse configuration is for expanded viewing volume. For the dense configuration, we provide a detailed analysis on the number of camera images required. For the sparse configuration, we present a robust technique to estimate an approximation of the scene geometry to provide smooth transition when the viewpoint is changed.

The novelty of our approach is that it allows the users to electronically steer the viewpoint in real time for a live scene. Therefore it can be used in 3D teleconferencing systems to generate stereoscopic views, or in group teleconferencing to provide virtual camera views that minimize the overall perspective distortions. We demonstrate the effectiveness of our approach with a point-to-point teleconferencing system distributed in several locations across the continental United States.
Theater Nuclear and Conventional Force Improvements
Authors: Cimbaia Stephen J.
Published: March 2007

This article discusses the modernization of NATO conventional and long-range intermediate nuclear forces. Depending upon the perspective chosen, one can logically defend improvements in either, or both, long-range theater nuclear and conventional forces. Such choices cannot be removed from the divergence in priorities and perspectives between the United States and its European NATO allies on these issues. Although there is no single "European" view, central tendencies pull Europeans away from conventional force improvements and toward increased reliance on nuclear deterrence and retaliation.
Development Under Military Rule: Factionalism in Brazil
Authors: Bacchus Wilfred A.
Published: March 2007

Opinion in essays by the Brazilian military elite, published in their professional journals, is analyzed-prior to the military takeover, and at regular intervals during their 21 years of political control-to consider aspects and patterns of ideologic differences concerning national development strategy. This study finds one major and another minor faction existed, in addition to the recognized moderate and hard-line groups that alternatively headed Brazil's military regimes. Using their articles as a data base, the author detects the rising importance of an independence-minded nationalist cadre in the 1970s, which was also divided between those with authoritarian and democratic attitudes. Neither was dominant and in fact had to share ruling power with a moderate, internationalist faction to preserve necessary unity. The democratic nationalists, initially suppressed in the wake of purges of the reformist, leftist faction who had been Goulart appointees, gained strength during the presidencies of Geisel and Figuereido, thereby influencing and sustaining the promised transition toward civilian rule and democratic political processes. Development strategy did not shift toward the independent, nationalist direction, however, because of adverse external factors, the prior successes of the first military regimes, and the continuing need to preserve armed forces unity.
Strategic Limitations Of "A Nation in Arms"
Authors: Horowitz Dan
Published: March 2007

Since wartime force ratios among adversaries do not merely reflect population ratios, a high degree of manpower mobilization can make up for the quantitative demographic inferiority of a small nation. In this context, a sizable, well-trained, combat-ready, militia-type reserve force is integral to the wartime order of battle. This reserve force can bridge the gap in manpower requirements of the armed forces, minimizing redundancy in the military's peacetime strength without reducing the size of its effective wartime strength. Strategic analysts and political sociologists tend to agree that the role of the reserves within this three-tier system has enabled Israel to become an effective regional military power despite her quantitative inferiority in regular forces. The proposition that a sizable combat-ready reserve force can be a central component of an effective defense posture is upheld by Israel's experiences in the 1956, 1967, 1973, and 1982 wars. However, these wars have also exposed the built-in sociopolitical constraints and military-operational limitations of a reserve-based defense posture that reduce the range of strategic options available to "a nation in arms." Some ambitious strategic objectives may be unattainable for a small nation in arms because the use of force needed to achieve them tends to overburden the civilian component of the nation's defense posture.
Dimensions of Militarization in the Third World
Authors: Ross Andrew L.
Published: March 2007

Observers increasingly have expressed concern about what has been described as the militarization of the Third World. Yet it is seldom clear what is meant by the term. This paper represents an attempt to cut through the multitude of conflicting conceptualizations, provide a more precise and operational meaning of the term, and differentiate between militarization and militarism. Two forms of militarization are identified and its multiple dimensions are operationalized and utilized in an evaluation of its nature and extent in the contemporary Third World. According to recent data, it seems that militarization in developing countries is not advancing as rapidly as it once was; and it may not be the problem some have assumed it to be.
"Ceausescuismn" and Civil-Military Relations in Romania
Authors: Crowther William
Published: March 2007

This article discusses the relationship between the Romanian armed forces and the leadership of the Romanian Communist party. It suggests that this relationship has been complicated, and made more difficult, by Romania's pursuit of foreign policy autonomy from the Soviet Union. Ceausescu has relied more on direct political intervention and less on positive inducements to retain control of the armed forces than have his counterparts elsewhere in Eastern Europe. Romania's defense establishment, like other institutions in that country, has been reduced to a state of stagnation and cannot under present circumstances be expected to provide the basis for leadership alternative to that of the current Communist party elite.
A Seat at the Table: Canada and Its Alliances
Authors: Sokolsky Joel J.
Published: March 2007

Canada's alliance relationships, NATO and NORAD, constitute nearly the sum total of Canadian defense policy. In addition to providing national security through collective Western defense, these alliances have been viewed in Canada as affording Ottawa a seat at the table, where important issues of international security and U.S.Soviet relations are discussed. While enjoying this access, Canada has, nonetheless, been concerned about the overwhelming U.S. influence over its defense policy. For the Canadian military, the problem has been obtaining adequate funding for the Allied commitments made by the government. The 1987 White Paper on defense promised sufficient resources, but recent budget cuts have cast serious doubt on Canada's future role in its alliances and on Ottawa's ability to make use of its seat in Allied councils.
The Evolution of Military Intelligence in Canada
Authors: Wark Wesley K.
Published: March 2007

The historical evolution of a military intelligence system in Canada, like that of other Western powers, developed largely under the stimuli of the two world wars. Yet within this evolutionary framework, unique national characteristics emerged. One was the underlying Canadian concern with intelligence on a variety of threatened frontiers, especially after 1945 with the remote northern flank. Another unique feature of Canadian history was the response to the lessons of the Second World War. Rather than consolidating the wartime intelligence community to serve postwar needs, Canada restricted itself to subordinate partnership in an intelligence alliance with the United States and the United Kingdom, forfeited a strategic intelligence capability, and concentrated on domestic security problems. This article attempts to analyze these developments as a preliminary step toward the still unwritten history of the intelligence function in Canada.
Do Engineers Make Better Naval Officers?
Authors: Bowman William R.
Published: March 2007

The hypothesis that engineering graduates are best suited for junior officer positions aboard increasingly sophisticated surface and submarine warships is tested empirically for a subset of 1,560 U.S. Naval Academy graduates from the classes 1976-80. Following the guidelines set by Admiral Rickover, policymakers presume the best preparation for leadership positions is provided by college majors that emphasize mathematics, sciences, and (especially) engineering. The results of the study, based on advanced multivariate regression techniques, fail to support this common notion. For the subset of USNA graduates, neither academic major selection nor achievement within defined academic class groupings is found to be statistically related to performance and retention of junior officers at the completion of their initial tour of duty. The results are applicable to both the conventional surface and nuclear navies for the subset of academy graduates. The study suggests the approach be applied to the Officer Candidate School and the Reserve Officers' Training Corps commissioned officers for a more general test of the Rickover hypothesis.
The Eritrean War
Authors: Pateman Roy
Published: March 2007

The Eritrean War has been in process for over 20 years. The Eritrean People's Liberation Front, which has borne the brunt of the fighting against the Ethiopian government forces in the last decade, is one of the world's most important-and unknownliberation movements. Its military wing, the Eritrean People's Liberation Army has battle experience of many years. This article examines the organization, strategy, and tactics that have made it one of the world's most effective forces. The article places the conflict into the context of geopolitical issues in the Horn of Africa and deals with the attempts at a peaceful resolution of the conflict.
HIV-1/AIDS and U.S. Military Manpower Policy
Authors: Burrelli David F.
Published: March 2007

On 19 March 1991 the Department of Defense released its most current Directive on Human Immunodeficiency Virus-1. Under this directive, persons with HIV-1 are excluded from recruitment. In addition, those in uniform who are or become infected may be limited in terms of assignments. This directive also details DoD policy concerning testing, safety of the blood supply, appropriate uses of information concerning those infected, efforts to control the spread of the illness, as well as arrangements pertaining to civilian authorities and employees. This article presents the status of HIV-1 infection among military personnel and discusses DoD's policy. Finally, those issues that result from or are a consideration in the formulation of this policy are analyzed.
Coup d'Etat Attempt in Trinidad: Its Causes and Failure
Authors: Collihan Kathleen M. , Danopoulos Constantine P.
Published: March 2007

This article analyzes the factors and processes involved in the failed coup attempt in Trinidad and Tobago by the Jamaat Muslimeen in July 1990. After a brief overview of historical and economic development, the analysis finds a close relationship between export dependency and political stability. The article also documents that intraMuslim jealousies and religious fundamentalism contributed to the Muslimeen's decision to attempt a coup against the Robinson government. The group's small size, poor planning, and inability to enlist the support of other social groups, including the military, contributed to the coup's failure.
The Looking-Glass Army: Patriotism in the Post-Cold War Era
Authors: Faris John H.
Published: March 2007

Thirty one-on-one, in-depth interviews with current members of the U.S. Army were conducted in April of 1993. The majority of interviewees indicated that a sense of patriotic service to country was a significant element in their sense of the meaning of being in the military. Most interviewees expressed a belief in America as special, primarily in terms of specific freedoms and based to a considerable degree on personal observation and experience in other countries. While there was no evidence that the end of the Cold War had created either a feeling of triumphant success or a crisis in the meaningfulness of military service, there were indications that interpretations of the meaning and importance of being in the military are partially contingent on the soldiers' perceptions of civilian perceptions of the military. Based on the interviews, a series of hypotheses is presented and discussed.
Saddam Surprises the United States: Learning from "The Revolution of August 2"
Authors: Haley P. Edward
Published: March 2007

Little attention has been paid to Saddam Hussein's strategic surprise in the invasion of Kuwait. This is unfortunate, because in Saddam's invasion lies an exceptionally useful extension of what is known about surprise in strategy and diplomacy, an extension of particular value in the post-Cold War world where the risks of nuclear proliferation and the possible spread of other weapons of mass destruction heighten the importance of properly understanding surprise. This article argues that Saddam surprised Kuwait and its allies because they had deceived themselves about his intention to attack. It also argues that decision-makers and analysts are especially likely to indulge in self-deception when they believe they have found a way to avoid the dangers of their chosen path. American decision-makers minimized Saddam's rapacity and unpredictability because they thought the policy of tilting toward Iraq would convert him into a responsible international actor. The article first examines the literature on surprise attack for guidance in understanding Saddam's achievement of surprise. It then develops the concept of self-deception and illustrates the part it played in preparing for Saddam's surprise. The article. concludes with some advice to policymakers on how to avoid self-deception in evaluating another state's intentions.
Circling the Welcome Wagons: Area, Income, Race, and Legal Handgun Concealment
Authors: Costanza Stephen E. , Kilburn John C.
Published: March 2007

Using data from Louisiana State Police records on concealed weapon permits, this article analyzes factors related to regional differences in rates of handgun permit holding. Although protection from victimization may be considered a common motive for carrying a concealed weapon, the authors found no relationship between crime rates and rates of handgpn permit holding. Instead, factors such as median household income and race-related factors were found to be more salient predictors of an area's rate of permit holding.
Exploring the Link between Recurrent Acts of Childhood and Adolescent Animal Cruelty and Subsequent Violent Crime
Authors: Tallichet Suzanne E. , Hensley Christopher
Published: March 2007

Studies demonstrating the potential link between childhood and adolescent acts of animal cruelty and later interpersonal violence toward humans remain ambiguous. Unfortunately, most of the research examining this possible link has failed to investigate repeated acts of animal cruelty or recurrent acts of violence toward humans. Using a sample of 261 inmates surveyed at medium and maximum security prisons in a southem state, this article examines how demographic attributes, childhood and adolescent characteristics, and repeated acts of cruelty toward animals impacted recurrent acts of interpersonal violence during adulthood. Respondents who had more siblings and who had committed repeated acts of animal cruelty were more likely to have engaged in recurrent acts of interpersonal violence, showing a possible link between recurrent acts of childhood and adolescent animal cruelty and subsequent violent crime.
A Systematic Review of Nonpharmacologic Adjunctive Therapies for Symptom Management in Children With Cancer
Authors: Rheingans Jennifer I.
Published: March 2007

Symptom management in pediatric oncology remains a problem. Despite remarkable pharmacologic and surgical advances, children continue to report symptoms as the most troublesome aspect of cancer treatment. However, there are additional therapies that are not considered standard symptom management, such as acupuncture and guided imagery. These nonpharmacologic adjunctive therapies are a potential source of assistance for children with unrelenting pain, nausea, or other unpleasant symptoms due to cancer treatment. This article summarizes research studies that have examined nonpharmaco-logic therapies for symptom management in pediatric oncology.
Anxiety and depression in children with ADHD: Unique associations with academic and social functioning
Authors: Karustis J. L. , Power T. J. , Rescorla L. A. , Eiraldi R. B. , Gallagher P. R.
Published: March 2007

This study investigated the relationship of internalizing symptoms to impairments in academic and social functioning among 125 elementary school children diagnosed with Attention-Deficit/ Hyperactivity Disorder (ADHD). Anxiety and depression were assessed using both child and parent reports, and a multimethod battery was employed to assess academic and social functioning. Internalizing symptoms generally were not related to academic functioning, although parent-reported depression was related to parent-reported homework problems. Overall, social functioning was correlated significantly with anxiety and depression when examined both within and across informants. The findings were consistent with a tripartite model of internalizing symptoms in demonstrating that a broad-band internalizing construct as well as the narrow-band constructs of anxiety and depression each demonstrated an association with level of social functioning. The results are discussed in relation to studies examining the association between anxiety and antisocial behavior in children.
Pharmacotherapy of High-Altitude Illness
Authors: Spooner Linda M. , Olin Jacqueline L. , Debellis Ronald J.
Published: March 2007

High-altitude illness (HAI) encompasses an array of conditions that may occur in individuals who travel to high elevations, including acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema. Individuals with a history of HAI are predisposed to developing HAI; however, other risk factors are not well defined. The primary method of preventing HAI is acclimatization through gradual ascent to high altitude. In addition, many studies have assessed the use of pharmacologic prophylaxis. The most studied and widely recommended prophylactic agent is acetazolamide; additional agents that have been considered include dexamethasone, Gingko biloba, antioxidant vitamins, nifedipine, aspirin, and salmeterol. The treatment of choice for all forms of HAI is descent to lower altitude. The use of additional treatments, including supplemental oxygen, varies depending on the severity of the clinical presentation. Acetazolamide and dexamethasone have been studied as adjunctive treatments for acute mountain sickness, while nitric oxide and nifedipine have been evaluated for the treatment of high-altitude pulmonary edema. Data with analgesics and phosphodiesterase-5 inhibitors, while limited, are promising. This review will present the evidence supporting the use of pharmacotherapy for prevention and treatment of HAI.
Building a Footbridge From Research to Practice in Cardiovascular Risk Reduction
Authors: Terre Lisa
Published: March 2007

As Rippe, Angelopoulos, and Zukley noted in their State-of-the-Art Review, empirically supported lifestyle modification strategies offer numerous advantages over other modalities for reducing cardiovascular risks. Yet, despite compelling evidence for their implementation, the translation of lifestyle interventions from research to practice has been challenging. Their review prompts discussion of several especially thorny barriers including the persistent tensions between (1) research and practice, (2) main effects and mediators, (3) single and multifactor approaches to risk management, and (4) primary care and communitybased systems of health delivery.
Physiological-social score (PMEWS) vs. CURB-65 to triage pandemic influenza: a comparative validation study using community-acquired pneumonia as a proxy
Authors: Challen Kirsty , Bright John , Bentley Andrew , Walter Darren
Published: March 2007

Background

An influenza pandemic may increase Emergency Department attendance 7-fold. In the absence of a validated "flu score" to assess severity and assist triage decisions from primary into secondary care, current UK draft management recommendations have suggested the use of CURB-65 and chest X-ray as a proxy. We developed the Pandemic Medical Early Warning Score (PMEWS) to track and triage flu patients, taking into account physiological and social factors and without requiring laboratory or radiology services.

Methods

Validation of the PMEWS score against an unselected group of patients presenting and admitted to an urban UK teaching hospital with community acquired pneumonia. Comparison of PMEWS performance against CURB-65 for three outcome measures: need for admission, admission to high dependency or intensive care, and inpatient mortality using area under ROC curve (AUROC) and the Hanley-McNeil method of comparison.

Results

PMEWS was a better predictor of need for admission (AUROC 0.944) and need of higher level of care (AUROC 0.83) compared with CURB-65 (AUROCs 0.881 and 0.640 respectively) but was not as good a predictor of subsequent inpatient mortality (AUROC 0.663).

Conclusion

Although further validation against other disease datasets as a proxy for pandemic flu is required, we show that PMEWS is rapidly applicable for triage of large numbers of flu patients to self-care, hospital admission or HDU/ICU care. It is scalable to reflect changing admission thresholds that will occur during a pandemic.
High serum levels of soluble CD40-L in patients with undifferentiated nasopharyngeal carcinoma: pathogenic and clinical relevance
Authors: Caggiari Laura , Guidoboni Massimo , Vaccher Emanuela , Barzan Luigi , Franchin Giovanni , Gloghini Annunziata , Martorelli Debora , Zancai Paola , Bortolin Maria Teresa , Mazzucato Mario , Serraino Diego , Carbone Antonino , De Paoli Paolo , Dolcetti Riccardo
Published: March 2007

Background

Engagement of CD40 promotes survival of undifferentiated nasopharyngeal carcinoma (UNPC) cells and similar effects are induced by the EBV oncoprotein LMP-1 that is expressed in a fraction of cases. Considering that CD40 may be activated also by the soluble isoform of CD40L (sCD40L), we investigated the serum levels of sCD40L in a series of 61 UNPC patients from Italy, a non-endemic area for this disease.

Results

At diagnosis, serum samples of UNPC patients contained significantly higher levels of sCD40L than age-matched healthy controls (p < 0.001). High levels of sCD40L (i.e., >18 ng/ml) were more frequently found in patients <40 years of age (p = 0.03) and with distant metastases at presentation (p = 0.03). Serum levels of sCD40L were inversely associated with the expression of the EBV oncoprotein LMP-1 (p = 0.03), which mimics a constitutively activated CD40. The amount of sCD40L decreased in a fraction of patients treated with local radiotherapy alone. Moreover, CD40L+lymphoid cells admixed to neoplastic UNPC cells were detected in cases with high serum levels of sCD40L, suggesting that sCD40L is probably produced within the tumor mass.

Conclusion

sCD40L may contribute to CD40 activation in UNPC cells, particularly of LMP-1-negative cases, further supporting the crucial role of CD40 signalling in the pathogenesis of UNPC. sCD40L levels may be useful to identify UNPC patients with occult distant metastases at presentation.
Calcium-Calmodulin Kinase II Is the Common Factor in Calcium-Dependent Cardiac Expression and Secretion of A- and B-Type Natriuretic Peptides
Authors: Ronkainen Jarkko J. , Vuolteenaho Olli , Tavi Pasi
Published: March 2007

Peptides derived from the precursor of A- and B-type natriuretic peptides (ANP and BNP) are powerful clinical markers of cardiac hypertrophy and dysfunction. It is known that many stimuli affecting the intracellular calcium concentration also induce ANP and BNP secretion. It was our intention to study the mechanisms by which calcium regulates the secretion of ANP and BNP. The effects of pacing and calcium-calmodulin kinase II activity on natriuretic peptide secretion were studied in isolated perfused rat atria and cultured rat neonatal cardiomyocytes. In isolated rat atrium pacing induced an increase in diastolic, systolic, and averaged intracellular free calcium concentration and a frequency-dependent increase in the secretion of both ANP and BNP. The molar ratio of the secreted natriuretic peptides (ANP to BNP) remained nearly constant (∼1000) at all the pacing frequencies tested (1, 3, 6, and 8 Hz). Calmodulin kinase II inhibitor KN-93 (3 μm) did not affect intracellular free calcium concentration but showed a frequency-dependent inhibitory effect on ANP and BNP secretion without a change in ANP to BNP ratio. In the neonatal cardiomyocytes, KN-93 (3 μm) suppressed the secretion and gene expression of both ANP and BNP. Overexpression of constitutively active (T286D) or nuclear (δB) calcium-calmodulin kinase II induced an increase in ANP and BNP gene expression. The results indicate that the calcium-dependent secretion and gene expression of A- and B-type natriuretic peptides are similarly regulated by calmodulin kinase II-dependent mechanisms. This is a plausible mechanism contributing to exercise-induced natriuretic peptide secretion and the augmented secretion in heart dysfunction due to impaired calcium handling.
Deterrence and Crime Results
Authors: Ferrante Marcelo
Published: March 2007

This article offers a comprehensive study of the merits of the legal practice of punishing accomplished crimes more severely than attempted crimes all other things being equal (differential punishment)vis-à-vis the alternative of punishing them with equal sanctions (equal punishment).Unlike the overwhelming majority of the literature on the issue--which focuses on which practice better mirrors the offenders' relative moral deserts--the article evaluates both practices from a consequentialist, deterrence-based point of view. In particular, it shows first that traditional economic theories of the criminal law should yield the conclusion that differential punishment is not superior to equal punishment.The few arguments that the economic literature offers against such conclusion, the article shows, are mistaken. Secondly, drawing on social and psychological findings, the article advances three new arguments showing that, under some likely social and psychological conditions, differential punishment is in fact a superior alternative to equal punishment.
The Trial of the Expert: Épreuve and Preuve
Authors: Hildebrandt Mireille
Published: March 2007

This article explores the complex relationship between law and (scientific) expertise. The author first discusses the difference between scientific knowledge and scientific expertise, tracing the historical roots of the concept of proof in a legal rather than a mathematical context. Second, the historical roots of the fair trial are discussed in terms of the premodern épreuve and the modern preuve, demonstrating the relationship with coordinate and subordinate types of justice. Third, Foucault's analysis of épreuve, enquête, and examèn is extended to clarify how preuve and épreuve have been integrated into the fair trial, which is explained in relation to the formal and the substantive notions of the "Rechtsstaat." This analysis finally allows the author to discuss the difference between two approaches of scientific expertise in court: one claiming that judges should defer to science and another claiming that a court of law is one of the spaces in which such expertise can be contested. The article concludes that the integration of subordinate and coordinate justice exemplified in the fair trial, opens new perspectives for the testing of scientific expertise, taking into account whose interests are at stake.
Scurvy and Rickets Masked by Chronic Neurologic Illness: Revisiting “Psychologic Malnutrition”
Authors: Noble James McCallum , Mandel Arthur , Patterson Marc C.
Published: March 2007

The North American epidemic of overeating, combined with a sedentary lifestyle, has led to a growing prevalence of obesity, diabetes, and the “metabolic syndrome” in children. Excessive caloric intake does not imply adequate nutrition, and vitamin-deficiency syndromes still occur in some American children. Here we describe cases of scurvy and vitamin D deficiency in 2 children with cognitive disorders. Thorough dietary histories suggested the diagnosis in each patient and, had they been obtained at presentation, would likely have obviated invasive diagnostic workup, unnecessary stress to the patients and their families, and significant functional disability. Overnutrition and malnutrition may coexist, particularly among those with abnormal cognition or autistic spectrum disorders. Classic nutritional deficiencies must not be omitted from the differential diagnosis. A comprehensive dietary history and screening for vitamin deficiencies in at-risk children are important aspects of preventive health care and are essential for prompt diagnosis and treatment.
How Children With Special Needs Travel With Their Parents: Observed Versus Reported Use of Vehicle Restraints
Authors: Korn Taube , Katz-Leurer Michal , Meyer Shirley , Gofin Rosa
Published: March 2007

OBJECTIVES. The difficulties entailed in transporting children with special physical and behavioral needs could influence child restraint misuse and nonuse within this population. Although parental interview is often used to assess child vehicle restraint use, little research had been performed to validate this approach, and none has been done in the special-needs population. The objectives of this study were to assess the prevalence of nonuse and misuse of child restraints in the special-needs population and to assess the validity of using parental report as a measure of child restraint use.

METHODS. Restraint use in 115 children with special needs, aged 0 to 18 years, was observed on their arrival at the parking lot of the Alyn Hospital Pediatric Rehabilitation Center in Jerusalem. The observation noted type of restraint used or absence thereof. If a restraint was used, correct use/misuse was recorded. In 94 cases, the parents were interviewed later that day in the clinic.

RESULTS. Seventy percent of the children were observed as traveling unrestrained or with a restraint that was grossly misused to the extent that it provided no meaningful protection. The remaining children were observed displaying a variety of errors in the selection or use of the restraint that compromised their safety to varying degrees. Analysis of the observation results versus parental reporting revealed a 44% overreporting of child restraint use. Sensitivity was 71%, and specificity was 86%.

CONCLUSIONS. The high prevalence of restraint nonuse and misuse within the special-needs population defines this as a population at risk and emphasizes the need for intervention. Cautious interpretation is required of information acquired from parental reporting of child restraint use. The results of this study should raise awareness among professionals working with children with special needs as to the need for tailored assessment and intervention in the area of child-passenger safety.
Calcium and Vitamin D: What Is Known About the Effects on Growing Bone
Authors: Demay Marie B. , Sabbagh Yves , Carpenter Thomas O.
Published: March 2007

The objective of these investigations was to determine if the receptor-dependent effects of 1,25-dihydroxyvitamin D were essential for normal skeletal growth. Mice with targeted ablation of the vitamin D receptor were engineered, and the skeletal consequences of vitamin D receptor ablation were studied in the presence of normal and abnormal mineral ion homeostasis. Prevention of abnormal mineral ion homeostasis resulted in the development of a normal skeleton in the absence of a functional vitamin D receptor. The metabolic cause of rickets was found to be hypophosphatemia. The major receptor-dependent actions of 1,25-dihydroxyvitamin D on skeletal development are indirect and are a reflection of the role of this hormone on intestinal calcium absorption.
Stress Predicts Brain Changes in Children: A Pilot Longitudinal Study on Youth Stress, Posttraumatic Stress Disorder, and the Hippocampus
Authors: Carrion Victor G. , Weems Carl F. , Reiss Allan L.
Published: March 2007

OBJECTIVE. Does stress damage the brain? Studies of adults with posttraumatic stress disorder have demonstrated smaller hippocampal volumes when compared with the volumes of adults with no posttraumatic stress disorder. Studies of children with posttraumatic stress disorder have not replicated the smaller hippocampal findings in adults, which suggests that smaller hippocampal volume may be caused by neurodevelopmental experiences with stress. Animal research has demonstrated that the glucocorticoids secreted during stress can be neurotoxic to the hippocampus, but this has not been empirically demonstrated in human samples. We hypothesized that cortisol volumes would predict hippocampal volume reduction in patients with posttraumatic symptoms.

PATIENTS AND METHODS. We report data from a pilot longitudinal study of children (n = 15) with history of maltreatment who underwent clinical evaluation for posttraumatic stress disorder, cortisol, and neuroimaging.

RESULTS. Posttraumatic stress disorder symptoms and cortisol at baseline predicted hippocampal reduction over an ensuing 12- to 18-month interval.

CONCLUSIONS. Results from this pilot study suggest that stress is associated with hippocampal reduction in children with posttraumatic stress disorder symptoms and provide preliminary human evidence that stress may indeed damage the hippocampus. Additional studies seem to be warranted.
Predictors of Pain and/or Fever at 3 to 7 Days for Children With Acute Otitis Media Not Treated Initially With Antibiotics: A Meta-analysis of Individual Patient Data
Authors: Rovers Maroeska M. , Glasziou Paul , Appelman Cees L. , Burke Peter , McCormick David P. , Damoiseaux Roger A. , Little Paul , Le Saux Nicole , Hoes Arno W.
Published: March 2007

OBJECTIVE. The goal was to determine the predictors of a prolonged course for children with acute otitis media.

METHODS. A meta-analysis of data with the observation groups of 6 randomized, controlled trials was performed. Participants were 824 children, 6 months to 12 years of age, with acute otitis media. The primary outcome was a prolonged course of acute otitis media, which was defined as fever and/or pain at 3 to 7 days.

RESULTS. Of the 824 included children, 303 had pain and/or fever at 3 to 7 days. Independent predictors of a prolonged course were age of <2 years and bilateral acute otitis media. The absolute risk of pain and/or fever at 3 to 7 days for children <2 years of age with bilateral acute otitis media (20% of all children) was 55%, and that for children ≥2 years of age with unilateral acute otitis media (47% of all children) was 25%.

CONCLUSIONS. The risk of a prolonged course was 2 times higher for children <2 years of age with bilateral acute otitis media than for children ≥2 years of age with unilateral acute otitis media. Clinicians can use these features (ie, age of <2 years and bilateral acute otitis media) to inform parents more explicitly about the expected course of their child's otitis media and to explain which features should prompt parents to contact their clinician for reexamination of the child.
Steroid Use Among Adolescents: Longitudinal Findings From Project EAT
Authors: vandenBerg Patricia , Neumark-Sztainer Dianne , Cafri Guy , Wall Melanie
Published: March 2007

OBJECTIVE. We examined the prevalence, persistence, secular and longitudinal trends, and predictors of steroid use in a diverse sample of adolescents.

PARTICIPANTS AND METHODS. Data are from Project EAT-II (Eating Among Teens), a 5-year longitudinal study of eating, activity, weight, and related variables in 2516 middle and high school students. Data were collected in 1999 (time 1) and 2004 (time 2).

RESULTS. Approximately 1.5% of adolescents reported steroid use at time 2. Use differed by ethnicity but not socioeconomic status. Steroid use was not stable across time, although the risk of use at time 2 was higher for girls and (marginally) for boys who used steroids at time 1. No secular trends were noted in middle adolescents’ steroid use between 1999 and 2004. Developmentally, steroid use decreased as adolescents grew older. Predictors of use for male adolescents included wanting to weigh more and reporting higher use of healthy weight-control behaviors. Female time 2 steroid users had higher BMIs and were less satisfied with their weight, had poorer nutrition knowledge and concern for health, and were marginally more likely to have participated in weight-related sports at time 1.

CONCLUSIONS. The prevalence of steroid use in adolescents was low but of concern. Although use was not persistent over 5 years, time 1 use was a risk factor for time 2 use in female adolescents. There was no change in the prevalence of steroid use by middle adolescents between 1999 and 2004 despite a great deal of public interest in steroids during this time period. Steroid use decreased as adolescents grew older. Weight-related variables predicted adolescents’ steroid use 5 years later, and health and nutrition knowledge and concern and (marginally) participation in weight-related sports further predicted use in female adolescents. These findings suggest that early preventive efforts may be most useful.
The Influence of the Timing of Cord Clamping on Postnatal Cerebral Oxygenation in Preterm Neonates: A Randomized, Controlled Trial
Authors: Baenziger Oskar , Stolkin Florian , Keel Mathias , von Siebenthal Kurt , Fauchere Jean-Claude , Das Kundu Seema , Dietz Vera , Bucher Hans-Ulrich , Wolf Martin
Published: March 2007

OBJECTIVE. Our goal was to investigate the effect of placentofetal transfusion on cerebral oxygenation in preterm infants by near-infrared spectroscopy.

SUBJECTS. A total of 39 preterm infants with a median gestational age of 30.4 weeks were randomly assigned to an experiment group (n = 15) and a control group (n = 24).

INTERVENTIONS. The delivery of the infants in the experiment group was immediately followed by maternal administration of syntocinon, the infant was placed 15 cm below the placenta, and cord clamping was delayed by 60 to 90 seconds. The infants in the control group were delivered conventionally. At the ages of 4 and 24 hours, cerebral hemoglobin concentrations, cerebral blood volume, and regional tissue oxygenation were measured by near-infrared spectroscopy.

RESULTS. Cerebral blood volume was not different between the 2 groups at the age of 4 hours (6.1 vs 5.8 mL/100 g of tissue) nor at the age of 24 hours (6.2 vs 6.2 mL/100 g of tissue). Mean regional tissue oxygenation of the experiment group was higher at the ages of 4 hours (69.9% vs 65.5%) and of 24 hours (71.3% vs 68.1%).

CONCLUSION. Delayed clamping of the umbilical cord improves cerebral oxygenation in preterm infants in the first 24 hours.
Cell-Cell and Cell-Extracellular Matrix Interactions Regulate Embryonic Stem Cell Differentiation
Authors: Chen Silvia S. , Fitzgerald Wendy , Zimmerberg Joshua , Kleinman Hynda K. , Margolis Leonid
Published: March 2007

Cell interactions with the extracellular matrix (ECM) play a critical role in their physiology. Here, we sought to determine the role of exogenous and endogenous ECM in the differentiation of nonhuman primate ESCs. We evaluated cell differentiation from expression of lineage gene mRNA and proteins using real-time polymerase chain reaction and immunohistochemistry. We found that ESCs that attached to and spread upon highly adhesive collagen do not differentiate efficiently, whereas on the less adhesive Matrigel, ESCs form aggregates and differentiate along mesoderm and especially endoderm lineages. To further decrease ESC attachment to the substrate, we cultured them either on nonadhesive agarose or in suspension. In both cases, ESCs formed aggregates and efficiently differentiated along endoderm and mesoderm lineages, most strikingly into cardiomyocytes. Aggregates formed by thus-differentiated ESCs started to beat with a frequency of 50–100 beats per minute and continued to beat for approximately a month. In spite of the presence of exogenous ECM, ESCs were dependent on endogenous ECM for their survival and differentiation, as the inhibition of endogenous collagen induced a gradual loss of ESCs and neither a simple matrix, such as type I collagen, nor the complex matrix Matrigel was able to rescue these cells. In conclusion, adhesiveness to various ECM and nonbiological substrates determines the differentiation of ESCs in such a way that efficient cell-cell aggregation, together with less efficient cell attachment and spreading, results in more efficient cell differentiation.
Characterization of the Limbal Epithelial Stem Cell Niche: Novel Imaging Techniques Permit In Vivo Observation and Targeted Biopsy of Limbal Epithelial Stem Cells
Authors: Shortt Alex J. , Secker Genevieve A. , Munro Peter M. , Khaw Peng T. , Tuft Stephen J. , Daniels Julie T.
Published: March 2007

It is anticipated that stem cell (SC) therapy will enable the regeneration of diseased tissues and organs. Understanding SC niches is an essential step toward realizing this goal. By virtue of its optical transparency and physical separation of SC and transient amplifying cell compartments, the human cornea provides a unique opportunity to visualize and observe a population of adult stem cells, limbal epithelial stem cells (LESCs), in their niche environment. To date, the characteristics of the LESC niche have remained unclear. State-of-the-art imaging techniques were used to construct a three-dimensional (3D) view of the entire human corneal limbus and identify the structural characteristics of the LESC niche. Two distinct candidate LESC niche structures were identified. Cells within these structures express high levels of the putative limbal stem cell markers p63α and ABCG2; however, current methods cannot identify for certain which exact cells within this cell population are truly LESCs. These structures could be located and observed in vivo in normal human subjects, but not in patients with clinically diagnosed corneal LESC deficiency. The distribution of these structures around the corneal circumference is not uniform. Biopsies targeted to limbal regions rich in LESC niche structures yielded significantly higher numbers of LESCs in culture. Our findings demonstrate how adult stem cell niches can be identified and observed in vivo in humans and provide new biological insight into the importance of LESC niche structures in maintaining normal LESC function. Finally, the concept of targeted biopsy of adult SC niches improves stem cell yield and may prove to be essential for the successful development of novel adult stem cell therapies.

Disclosure of potential conflicts of interest is found at the end of this article.
Impact of maternal undernutrition on the hypothalamic–pituitary–adrenal axis responsiveness in sheep at different ages postnatal
Authors: Chadio S E , Kotsampasi B , Papadomichelakis G , Deligeorgis S , Kalogiannis D , Menegatos I , Zervas G
Published: March 2007

Epidemiological and experimental data support the hypothesis of ‘fetal programming’, which proposes that alterations in fetal nutrition and endocrine status lead to permanent adaptations in fetal homeostatic mechanisms, producing long-term changes in physiology and determine susceptibility to later disease. Altered hypothalamic–pituitary–adrenal (HPA) axis function has been proposed to play an important role in programming of disease risk. The aim of the present study was to examine the effects of maternal nutrient restriction imposed during different periods of gestation on the HPA axis function in sheep, at different ages postnatal. Pregnant ewes were fed a 50% nutrient-restricted diet from days 0–30 (group R1, n = 7), or from days 31–100 of gestation (group R2, n = 7) or a control 100% diet throughout pregnancy, (Control, n = 8). Blood samples were collected at 10-day intervals from day 40 of gestation to term. Lambs were born naturally and fed to appetite throughout the study period. At 2, 5.5, and 10 months of age lambs were given an i.v. injection of corticotrophin-releasing hormone (CRH) and blood samples were collected at −15, 0, 15, 30, 60, 120, and 180 min postinjection. Maternal cortisol levels were significantly higher (P < 0.05) in group R1 compared with the other two groups, whereas maternal insulin levels were lower (P < 0.05) in group R2 compared with control. Birth weight of lambs was not affected by the maternal nutritional manipulation. The area under the curve for ACTH and cortisol response to CRH challenge was greater (P < 0.05) in lambs of group R1 at two months of age, whereas no difference was detected at the ages of 5.5 and 10 months. However, significantly higher (P < 0.01) basal cortisol levels were observed in lambs of R1 group at 5.5 months of age. There was no interaction between treatment and sex for both pituitary and adrenal responses to the challenge. A significant sex effect was evident with females responding with higher ACTH and cortisol levels at the age of 5.5 months (P < 0.01, P < 0.001 respectively) and with higher cortisol levels (P < 0.01) at 10 months of age than males. It is concluded that the HPA axis is programmable by altered nutrition in utero. The sensitivity of the axis to exogenous stimulation is enhanced during early postnatal life and attenuated with age, suggesting a role for the postnatal influences in resetting of the HPA axis and emphasizing the importance of identifying the impact of maternal undernutrition at several time points after birth.
Design charts for seismic analysis of single piles in clay
Authors: Tabesh A. , Poulos H. G.
Published: March 2007

The pile designer in a seismically active region will generally need to estimate the maximum seismically induced internal moment and shear of the pile in order to provide adequate strength to maintain the structural integrity of the pile. In this paper an effort has been made to provide a simple means of carrying out such an estimation for a single pile embedded in a homogeneous clay layer. The results have been presented in the form of design charts that can be used directly by designers with no or little computational effort. The variables in the design charts include the length and diameter of the pile, the Young's modulus of the pile material, the strength and stiffness of the soil, and the factor of safety against axial failure of the pile. The charts have been obtained from a time domain analysis of pile–soil interaction, and are based on the response of the piles to a range of earthquakes recorded in North America and Australia.