bluuebunny/crossref_metadata_2025 huggingface dataset:
Partial growth of crack in laser scribing of glass
Authors: Yamamoto Koji , Hasaka Noboru , Morita Hideki , Ohmura Etsuji
Published: May 2009

The scribing of glass by a CO2 laser is much more effective compared to the conventional mechanical technology in use because the strength of the cut glass is improved since microcracks and particles along the cut edge are lessened. However, the crack depth of laser scribing is limited because the inner compressive stress region under the cooling area prevents median crack growth. This fact was shown by the experimental and thermal stress analyses with a finite element method (FEM) in the authors’ previous study. In this study, the glass was masked partially on the scribing line so as not to generate an inner compressive stress region, and the authors found that the median crack depth of laser scribing was deeper in the experiment. Thermal stress analysis of this phenomenon was conducted by using three-dimensional FEM. As a result, the stress distribution and the phenomenon of which the median crack grew deeper corresponded qualitatively well. It has been supported that the model of laser scribing mechanism proposed in the authors’ previous study is valid.
Visualization of refraction and attenuation of near-infrared laser beam due to laser-induced plume
Authors: Kawahito Yousuke , Kinoshita Keisuke , Matsumoto Naoyuki , Katayama Seiji
Published: May 2009

This study was performed to obtain a fundamental knowledge of the interaction between a near-infrared laser beam and an induced plume during welding. The plume was characterized by spectroscopy, and the effect and mechanism of the laser-induced plume on the refraction and/or attenuation were investigated by high-speed video observation of the plume and the probe laser, and power meter measurement of the fiber probe laser beam of 1090 nm wavelength which passed horizontally through the plume formed during bead-on-plate welding of an 8-mm-thick type 304 plate with a 1.5 kW yttrium-aluminum-garnet (YAG) laser beam. The plume induced by YAG laser at the focus position grew about 20 mm toward the incident laser beam and was identified to be nonionized metallic vapor of 3600 K in average temperature on the basis of the spectroscopic analyses. The high-speed observation images and the power measuring results revealed that the rapid movement and the low brightness of the probe laser beam, seen after the plume, were caused by refraction due to density difference between the plume and its environment and Rayleigh scattering due to ultrafine particles, respectively. The maximum refraction and attenuation were 1.2 mrad and 3%, which were much lower than the beam divergence and the same levels as power variation in the incident YAG laser beam under argon (Ar) shielding gas, respectively. Moreover, the YAG laser-induced plume hardly affected the reduction in weld penetration under the defocused conditions since the penetration of type 304 weld made without Ar shielding gas was deeper than that produced with Ar shielding gas although the former plume was longer than the latter one. This reason was interpreted in terms of the greater effect of surface tension-driven melt flows. Consequently, the wavelengths of near-infrared laser beams were desirable for laser welding in the case of the laser-induced plume of less than 20 mm height, owing to their weak optical interaction to the plume.
Laser percussion drilling modeling utility
Authors: Eppes Tom A. , Milanovic Ivana M. , Shetty Devdas
Published: May 2009

Laser percussion drilling is widely used in the aerospace industry to produce cooling holes in jet engine components. A variety of theoretical models have been developed to predict the outcome of the drilling process. However, to utilize these models often requires sophisticated software to perform the required numerical analyses. A simple and easy-to-use computer utility Drilling Routine for Estimating, Analyzing, and Modeling (DREAM) was developed. DREAM is a free-standing MATLAB-based design that offers a convenient and flexible way to predict a variety of drilling process outcomes and can be executed on any Windows-based platform. This paper discusses the features that have been incorporated into the latest release.
Revised Norms for the Lollipop Test for Children Ages 42 to 65 Months
Authors: Eno Lawrence , Hunt William C. , Reynolds Trudy
Published: May 2009

Lollipop Test scores were acquired for 1,402 preschoolers in southwestern Indiana. Means and standard deviations for both boys and girls by 6-mo. intervals from the ages of 42 through 65 months showed scores increased significantly across ages, with girls scoring significantly higher than boys in all age groups. Current mean scores are similar to those published in 1988 for boys and slightly higher for girls.
The Relationship of Negative Mood Regulation Expectancies with Rumination and Distraction
Authors: Drwal Jason
Published: May 2009

Individuals high in negative mood regulation expectancies believe that a wide variety of actions has the potential to improve their negative mood. According to response expectancy theory, negative mood regulation expectancies affect mood in a nonvolitional and self-confirming manner. The present study evaluated this claim by assessing the ability of negative mood regulation expectancies to predict current depression after controlling for a variety of volitional coping responses, including rumination, distraction, active coping, and avoidant coping. 105 Introduction to Psychology college students at the University of Connecticut, 47 men and 58 women ( M age = 20.3 yr., SD= 1.5), completed measures of each of the latter constructs for course credit. Results were consistent with response expectancy theory: negative mood regulation expectancies predicted current depression above and beyond coping behaviors. In addition, higher negative mood regulation expectancies were associated with greater use of adaptive coping responses. Results of this study further support the notion that effects of negative mood regulation expectancies on mood cannot be fully accounted for by intentional coping behaviors.
Sex Differences in Online Shopping: An Exploratory Study
Authors: Yang Bijou , Lester David
Published: May 2009

Empirically, predictors of purchasing an item (among 15) online in a sample of 365 undergraduates were dependent upon the sex of the purchaser and the particular item purchased.
Conspiracy Stereotyping and Perceptions of Group Entitativity of Jews, Germans, Arabs and Homosexuals by Polish Students
Authors: Grzesiak-Feldman Monika , Suszek Hubert
Published: May 2009

The relationship among conspiracy stereotypes and perceived entitativity (the degree to which a collection of persons are perceived as being bonded together in a homogeneous entity) of Jews, Germans, Arabs, and homosexuals was examined. 63 volunteer university students answered the Conspiracy Beliefs Scale and the Group Entitativity Scale. The conspiracy stereotypes of all the categories were positively correlated with scores for perceived entitativity. The perception of entitativity seems to be an important factor in conspiracy stereotyping and therefore in intergroup relations.
Eye Color as an Indicator of Behavior: Revisiting Worthy and Scott
Authors: Elias Vicky L. , Nicolas Cindy L. , Abramson Charles I.
Published: May 2009

Phenotypic eye color has been suggested as an indicator of genetic predisposition toward certain behaviors both in humans and in animals. Previous research has yielded mixed results. Phototaxic and ethological behaviors were examined in 14 different strains of Drosophila melanogaster. No significant correlation between phenotypic eye coloration and behavior was found, although significant genotypical behavioral differences were noted even among subjects with similar eye colors. An analysis of cellular defects associated with eye color in D. melanogaster pointed to significant behavioral differences among cell-defect groups, indicating that the cell defect which causes eye color, rather than eye color itself, may serve as a crude indicator of behavior.
Effects of Trauma and Religiosity on Self-Esteem
Authors: Reiland Sarah , Lauterbach Dean
Published: May 2009

Self-esteem is often lower among persons who have experienced trauma, but religiosity may ameliorate these psychological effects. The purpose of this paper was to examine the relationships among religiosity, self-esteem, and childhood exposure to trauma, utilizing data from the National Comorbidity Survey, a large (N = 8,098) nationally representative population survey in the 48 contiguous states of the USA that assessed religious practices, self-esteem, and exposure to trauma. Exposure to trauma in childhood was assessed through self-report of presence or absence of childhood physical abuse, sexual abuse, or neglect. Religiosity was assessed as the sum of responses to 4 self-report items (religious service attendance, use of religion for comfort and guidance, and importance of religion). Self-esteem was assessed on 9 self-report items adapted from the Rosenberg Self-Esteem Scale. Analysis of variance compared scores for persons who reported exposure to childhood abuse and differed in the value they placed on various religious practices on self-esteem. Persons who reported physical abuse, sexual abuse, or neglect in childhood had significantly lower mean self-esteem than those who did not report these events. There was also a main effect for religiosity in a comparison of persons who reported childhood sexual abuse with those who reported none. The High Religiosity group had higher mean self-esteem than the Medium and Low Religiosity groups. There was a significant interaction as those who reported childhood sexual abuse had lower mean self-esteem than peers who reported none in the Low and Medium Religiosity groups. Mean self-esteem for those who reported childhood sexual abuse was comparable to that of those who reported none in the High Religiosity group.
Assigning Trait Adjectives in an Evaluative Context: Quicker, More Consistent, and Less Equivocal
Authors: Mollaret Patrick , Nicol David
Published: May 2009

The objective was to examine the social conditions under which subjects could attribute trait adjectives to an unknown person, the paradigm of impression-formation at zero acquaintance. The situation on which the subject had to base his judgement was a 90-sec. film clip with sound of an individual reading a weather forecast. Analysis showed traits were attributed more quickly and consistently when instructions stipulated subject should evaluate the social utility of an individual (evaluator-recruiter type instructions) rather than describe personality (psychologist-type instructions). Traits were attributed more rapidly, with more consistency and greater certainty. Interpretation of results, which generally corroborate other research, is that the judgement of another person based on a first impression is an evaluation of the social utility of that person.
Insubordination and Genius: Galileo, Darwin, Pasteur, Einstein, and Pauling
Authors: Grumet Gerald W.
Published: May 2009

This essay examines the lives of five great scientists who contributed enormously to mankind. Although their lives were vastly different, they all trod a final common pathway in securing scientific breakthroughs. These were stubborn, egotistical, tenacious, work-oriented people who could not be deterred by obstacles of any sort. They exemplify the unbreakable spirit required to achieve greatness. A surprising finding is the extent of hostility they all aroused from closed-minded people in society who were upset by the implications of their new ideas. It is hoped that this essay will help to stiffen the resolve of creative men and women who can expect to confront fervent opposition from others in society regardless of the value of their discoveries. “Infinite is the throng of fools.” —Galileo, The Assayer, 1623
Development of a Brief Measure of College Stress: The College Student Stress Scale
Authors: Feldt Ronald C.
Published: May 2009

The study included assessment of the psychometric properties of an 11-item measure of perceived stress and control in 273 first-year college students. Results indicated good internal consistency and stability over a 5-week interval, and the total score was highly correlated with another measure of perceived stress. Principal components analysis with varimax rotation indicated two possible factors which explained 55% of the variance. However, given the small number of items and low internal consistency of the second factor (α=.60), use of the Total score is recommended.
Paranoia and Conspiracy Thinking of Jews, Arabs, Germans, and Russians in a Polish Sample
Authors: Grzesiak-Feldman Monika , Ejsmont Anna
Published: May 2009

The study examined the relationship between paranoia and conspiracy thinking of Jews, Arabs, Germans, and Russians among 50 university student volunteers using Fenigstein and Vanable's Paranoia Scale for nonclinical populations and the Conspiracy Beliefs Scale. The scores for conspiracy stereotypes of all the nationalities were positively correlated with paranoia.
Knowing Which Day of the Week it is: Temporal Structure and Dynamics of Memory
Authors: Carreras Ophélie , Lemercier Céline , Valax Marie-Françoise
Published: May 2009

The complementary role of static and dynamic information used when one needs to be located in time was studied. Static information refers to temporal knowledge about days of the week, and dynamic information reflects a sense of time, taking into account the present, the near past, and the future. Each day of an actual 7-day wk., 699 women and 620 men were asked to provide a “right” or “wrong” response to a statement such as “Today is T.,” where X was the name of one of the seven days of the week. Analysis suggested use of a structured temporal representation of the week: the weekend, a landmark, had an anchoring role. Also the dynamics of the content of working memory were indicated. The active “temporal window” participants hold in mind seems directed more towards the future than the past. Results are discussed within the more general context of time management.
The Taxon Concept: Is it Taxonic?
Authors: Grove William M.
Published: May 2009

The question of whether the concept of a “taxon” (a nonarbitrary latent category) is itself categorical, or is a matter of degree, has lain dormant within taxometrics. I analyze the problem conceptually. Part of the meaning of “taxon,” I hold, goes beyond the manifest statistical properties of admixed probability distributions; any of certain forms of causal nexus leading to admixed distributions are involved as well. I defend the thesis that the threshold question, “Is there a taxon?” has a yes-or-no answer, establishing that “taxonicity” is categorical (taxonic), but also that as some taxa are much more readily distinguished from their complement classes than are others, the taxon question is also quantitative. It is on this basis that Meehl and others held the view that taxonicity is a matter of degree; however, they were wrong to hold that it is only a matter of degree.
Correlates of Changes in Voluntary Physical Activity Associated with the Youth Fit for Life™ Intervention during After-School Care
Authors: Annesi James J. , Moore JUlie C. , Dixon Gayle M.
Published: May 2009

Overweight in youth is increasing and physical inactivity has been implicated as a causal factor. An after-school care intervention, Youth Fit For Life™, has been associated with significant improvements in physiological factors and frequency of moderate-to-vigorous physical activity voluntarily completed outside of structured settings. Correlates of the observed changes in physical activity amounts were, however, unknown. A multiple regression equation with simultaneous entry of sex, age, race, initial Body Mass Index, and initial frequency of voluntary physical activity as predictor variables for changes in physical activity was calculated on Euro-American and African-American participants ages 8 to 12 years ( N=217). A statistically significant 16% of the variance in changes in frequency of voluntary physical activity over 12 wk. was accounted for, with only voluntary physical activity at baseline and age making significant, unique contributions. For participants either overweight or at risk for overweight ( n = 72), the changes in physical activity significantly correlated with changes in Body Mass Index. Implications of findings to maximize treatment effects on voluntary physical activity were suggested.
Skin Conductance as an Indicator of Anticipated Concealed Knowledge
Authors: Hu Senqi , Huang Hsin-Yu , McGovern Jamie L. , Jacobs David A.
Published: May 2009

The present study investigated the effects of anticipation on skin conductance while participants were answering a set of questions which included one of concealed knowledge. Two experiments were conducted. In Exp. 1, 26 participants completed one experimental session. Each participant was asked to choose one two-digit number from 10 to 99 and was presented 19 other randomly generated two-digit numbers. The list of numbers was then presented to the participant on a computer screen, with a 60-sec. interval occurring every two questions. The participant-selected number was defined as the target question which was randomly placed within the 4th to 17th item of 20 questions stated as follows: “Is your selected number ____?” The participant was asked to answer “No” to all questions. The skin-conductance response to each question was measured. In Exp. 2, the experimental procedure was the same as that in Exp. 1 except each participant first answered 10 nontarget questions, then answered a target question with the participant's selected number, and then answered another 10 nontarget questions. There were a total of 21 questions. Analysis indicated participants in both experiments generated the highest mean skin conductance while answering the target questions, followed by lower amplitudes to questions prior to and after the target question. The skin-conductance response pattern can be used to identify the psychological process of anticipation of concealed information.
A Stage-Matched Intervention for Exercise Behavior Change Based on the Transtheoretical Model
Authors: Kim Youngho
Published: May 2009

The effectiveness of a stage-matched intervention for enhancing exercise behavior was investigated with related Transtheoretical Model constructs among young Korean adults. 265 university students (147 men, 118 women; M age = 24.1 yr., SD = 3.5) enrolled in Seoul National University of Technology voluntarily participated in an 8-wk. intervention study. In order to measure exercise behavior and its related psychological constructs, the Stages of Readiness for Exercise Behavior Scale, Decision Balance Scale for Exercise, Exercise Self-efficacy Scale, Processes of Change Scale, and Leisure Time Exercise Questionnaire were used. Results indicated that the participants' exercise readiness was significantly changed in a positive way after the 8-wk. intervention. There was a significant main effect of testing time and an interaction between testing time and exercise readiness stage at baseline. There were significant interactions between testing times and groups for all Transtheoretical Model measures, implying that the stage-matched intervention can be an effective tool for increasing exercise readiness and related psychological variables. The present study provides a starting point for stage-matched interventions aimed at increasing exercise levels, and a baseline level from which to evaluate interventions.
Twin—Singleton Differences in Intelligence: A Meta-Analysis
Authors: Voracek Martin , Haubner Tanja
Published: May 2009

Since the emergence of twin studies in the 1920s, time and again the question of possible twin-singleton differences in intelligence has been posed. This study addressed the issue through a meta-analysis of published studies on this theme. Twins on the average seem to have lower IQs than singletons. The best estimate for this group difference is 4.2 IQ points (less than one-third of a standard deviation), with a great divide between study outcomes of less vs more recent birth cohorts (5.1 vs 0.5 IQ points, respectively). The evidence is based on studies from six countries (including population-based ones of entire birth cohorts), a massive database (comparisons of more than 30,000 twins with nearly 1.6 million singletons), a variety of intelligence tests, and birth cohorts spanning most of the 20th century, but, for the most part, on an age range limited to children and adolescents. The effect shows considerable between-study heterogeneity but appears robust (fail-safe N calculations), not due to influential individual studies (sensitivity analysis) or publication bias, was present since the very first published studies (cumulative meta-analysis), and appears generalizable across sex, zygosity, and other intelligence domains beyond the verbal. There are insufficient data as to whether the effect persists over the lifespan, exists as well within families, or has ceased in recent birth cohorts of highly developed countries (Denmark and The Netherlands). Likely causes of the effect appear to be prenatal and perinatal factors (reduced fetal growth and shorter gestation for twins).
Structure factors of binary liquid metal alloys within the square-well model
Authors: Dubinin Nikolay , Filippov Vladimir , Malkhanova Olga , Vatolin Nikolay
Published: May 2009

The procedure suggested previously for the description of the square-well (SW) fluid within the framework of the mean spherical approximation is applied to calculate the structure factors of pure Na, pure K, and 0.5Na-0.5K alloy in liquid state. It is shown that our variations of the SW depth and SW width enable us to achieve a good agreement between calculated and experimental structure factors. The procedure under consideration gives more accurate results than the random phase approximation for the same values of the SW parameters.
Labyrinthine pathways towards supercycle attractors in unimodal maps
Authors: Moyano Luis , Silva D. , Robledo A.
Published: May 2009

As an important preceding step for the demonstration of an uncharacteristic (q-deformed) statisticalmechanical structure in the dynamics of the Feigenbaum attractor we uncover previously unknown properties of the family of periodic superstable cycles in unimodal maps. Amongst the main novel properties are the following: i) The basins of attraction for the phases of the cycles develop fractal boundaries of increasing complexity as the period-doubling structure advances towards the transition to chaos. ii) The fractal boundaries, formed by the pre-images of the repellor, display hierarchical structures organized according to exponential clusterings that manifest in the dynamics as sensitivity to the final state and transient chaos. iii) There is a functional composition renormalization group (RG) fixed-point map associated with the family of supercycles. iv) This map is given in closed form by the same kind of q-exponential function found for both the pitchfork and tangent bifurcation attractors. v) There is final-stage ultra-fast dynamics towards the attractor, with a sensitivity to initial conditions which decreases as an exponential of an exponential of time. We discuss the relevance of these properties to the comprehension of the discrete scale-invariance features, and to the identification of the statistical-mechanical framework present at the period-doubling transition to chaos. This is the first of three studies (the other two are quoted in the text) which together lead to a definite conclusion about the applicability of q-statistics to the dynamics associated to the Feigenbaum attractor.
Training of Walking Skills Overground and on the Treadmill: Case Series on Individuals With Incomplete Spinal Cord Injury
Authors: Musselman Kristin E. , Fouad Karim , Misiaszek John E. , Yang Jaynie F.
Published: May 2009

Background and Purpose: Walking in the home and community is an important goal for individuals with incomplete spinal cord injury (iSCI). Walking in the community requires various skills, such as negotiating curbs, doors, and uneven terrain. This case report describes the use of a method to retrain walking overground that is intensive, variable, and relevant to daily walking (skill training). The aims of this case series were to determine the effectiveness of skill training in a small group of people with iSCI and to compare skill training with body-weight–supported treadmill training (BWSTT) in the same individuals.

Case Description: Four individuals who were a median of 2.7 years (interquartile range [IQR]=12.8) after iSCI participated in alternating phases of intervention, each 3 months long. All patients started with BWSTT. Two patients subsequently engaged in skill training while the other 2 patients engaged in BWSTT, after which a third phase of intervention (opposite to the second) was repeated.

Outcomes: The Modified Emory Functional Ambulation Profile, the 10-Meter Walk Test, the 6-Minute Walk Test, the Berg Balance Scale, and the Activities-specific Balance Confidence Scale were administered before training, monthly throughout training, and 3 months after training.

Discussion: Overall improvements in walking speed met or exceeded the minimal clinically important difference for individuals with iSCI (≥0.05 m/s), particularly during the skill training phase (skill training: median=0.09 m/s, IQR=0.13; BWSTT: median=0.01 m/s, IQR=0.07). Walking endurance, obstacle clearance, and stair climbing also improved with both types of intervention. Three of the 4 patients had retained their gains at follow-up (retention of walking speed: median=92%, IQR=63%). Thus, the findings suggest that skill training was effective in this small group of individuals.
Dural arteriovenous fistulas draining into the petrosal vein or bridging vein of the medulla: possible homologs of spinal dural arteriovenous fistulas
Authors: Mitsuhashi Yutaka , Aurboonyawat Thaweesak , Pereira Vitor Mendes , Geibprasert Sasikhan , Toulgoat Frédérique , Ozanne Augustin , Lasjaunias Pierre
Published: May 2009

Object

Dural arteriovenous fistulas (DAVFs) with leptomeningeal venous reflux generally pose a high risk of aggressive manifestations including hemorrhage. Among DAVFs, there is a peculiar type that demonstrates direct drainage into the bridging vein rather than the dural venous sinus. The purpose of this study was to investigate the characteristics of DAVFs that drain directly into the petrosal vein or the bridging vein of the medulla oblongata.

Methods

Eleven consecutive cases of DAVFs that drained directly into the petrosal vein and 6 that drained directly into the bridging vein of the medulla were retrospectively reviewed. These cases were evaluated and/or treated at Hospital de Bicêtre in Paris, France, over a 27-year period. A review of previously reported cases was also performed.

Results

Both of these “extrasinusal”-type DAVFs demonstrated very similar characteristics. There was a significant male predominance (p < 0.001) for this lesion, and a significantly higher incidence of aggressive neurological manifestations including hemorrhage or venous hypertension than in DAVFs of the transverse-sigmoid or cavernous sinus (p < 0.001). This finding was considered to be attributable to leptomeningeal venous reflux. Regarding treatment, endovascular embolization (either transarterial or transvenous) is frequently difficult, and surgery may be an effective therapeutic choice in many instances.

Conclusions

Embryologically, both the petrosal vein and the bridging vein of the medulla are cranial homologs of the spinal cord emissary bridging veins that drain the pial venous network. The authors believe that DAVFs in these locations may be included in a single category with spinal DAVFs because of their similar clinical characteristics.
Attenuation of subarachnoid hemorrhage–induced apoptotic cell death with 17 beta-estradiol
Authors: Lin Chih-Lung , Dumont Aaron S. , Su Yu-Feng , Dai Zen-Kong , Cheng Juei-Tang , Tsai Yee-Jean , Huang Jih-Hui , Chang Kao-Ping , Hwang Shiuh-Lin
Published: May 2009

Object

Apoptosis is implicated in vasospasm and long-term sequelae of subarachnoid hemorrhage (SAH). The authors observed that 17β-estradiol (E2) can attenuate cerebral vasospasm, lower endothelin-1 production, and preserve normal endothelial nitric oxide synthase expression by reduction of inducible NO synthase expression in experimental SAH. The authors investigated the potential antiapoptotic effects of E2 in an experimental rat model of SAH.

Methods

The authors examined the antiapoptotic effects of E2 in a double-hemorrhage SAH model in male Sprague-Dawley rats. The rats underwent subcutaneous implantation of a Silastic tube containing corn oil either with or without E2, and some E2-treated animals also received ICI 182,780 (a nonselective estrogen receptor [ER] antagonist) for 7 days after SAH. The degree of vasospasm was determined by averaging the cross-sectional areas of the basilar artery 7 days after SAH. The expression of apoptotic indicators, including TNF-α, caspase 3, Bcl-2, Bax, terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick end labeling (TUNEL), and cell death assays were used for detection of apoptosis.

Results

Treatment with E2 significantly attenuated SAH-induced vasospasm. Seven days after the induction of SAH, positive TUNEL-staining was seen, and DNA fragmentation was increased in the dentate gyrus. Increased TNF-α and cleaved caspase-3 protein expression and decreased Bcl-2 protein expression in the dentate gyrus were also observed. These changes were reversed with E2-treatment but not in the presence of ICI 182,780. However, the expression of Bax did not change after SAH either with or without E2 treatment.

Conclusions

The authors found that E2 appears to confer an antiapoptotic effect that reduces secondary brain injury after SAH via estrogen receptor–dependent mechanisms. This finding provides support for possible future applications of E2 treatment for the reduction of secondary injury after SAH in patients.
Benefit of carotid endarterectomy for symptomatic and asymptomatic severe carotid artery stenosis: a Markov model based on data from randomized controlled trials
Authors: Nagaki Tomohito , Sato Koji , Yoshida Takaaki , Yoshimoto Yuhei
Published: May 2009

Object

Several major randomized controlled trials of carotid endarterectomy (CEA) in patients with both symptomatic and asymptomatic carotid artery stenosis have addressed the net effects of CEA on the risk of stroke. However, because the risk of stroke among patients with asymptomatic carotid stenosis is relatively low, whether to treat their stenosis with CEA remains an important public health issue.

Methods

The authors constructed a Markov model to evaluate the effectiveness of CEA. In modeling 4 health states, the probability of transition to another state was estimated using data from major randomized controlled trials. Adopting 3 comorbidity index values for baseline analyses, the authors expressed outcomes in terms of the expected number of quality-adjusted life years (QALYs) for a hypothetical cohort undergoing CEA and another without treatment.

Results

In the authors' baseline analysis, CEA for asymptomatic stenosis yielded a very small benefit (0.07 QALY) for 70-year-old, normal-risk CEA candidates. Benefits decreased further, often becoming negative, as patient age, surgical risk, or comorbidity index increased. In patients with symptomatic stenosis, CEA was always more effective than conservative management, even considering variables such as comorbidities limiting life expectancy, advanced age, and increased perioperative risk.

Conclusions

Carotid endarterectomy for severe carotid stenosis consistently and significantly benefits patients with recent symptoms. However, surgery for asymptomatic stenosis appears justified only in carefully selected conditions: low treatment risks in relatively young individuals without any comorbidities.
Thrombosis: the relationship of hemostatic mechanisms to drug therapy
Authors: Wessler Stanford , Gitel Sanford N.
Published: May 2009

✓ The mechanisms of arteriovenous and microcirculatory thrombosis and embolism are presented. Drugs affecting the hemostatic balance and their specific actions and indications are reviewed.
A method for monitoring antifibrinolytic therapy in patients with ruptured intracranial aneurysms
Authors: Burchiel Kim J. , Schmer Gottfried
Published: May 2009

✓ A rapid fluorometric assay technique has been utilized to assess the degree of fibrinolytic inhibition in 20 patients with ruptured intracranial aneurysms treated with epsilon-aminocaproic acid (EACA). This method quantitates the available plasminogen activity (APA) of plasma, and has proven to be a reliable means of monitoring antifibrinolytic therapy. Determination of the plasma APA also permits correlation of the level of fibrinolytic activity with putative complications of EACA therapy. Normal control plasma APA was 3.1 ± 0.7 CTA units/ml, but in patients with subarachnoid hemorrhage (SAH), pretreatment fibrinolytic activity was supranormal at 3.78 ± 0.88 CTA units/ml. During continuous intravenous administration of EACA (1.5 gm/hr) in patients with SAH, the plasma fibrinolytic activity was decreased to 0.9 ± 0.31 CTA units/ml. A case is described which exemplifies the use of this assay. In addition, an approach to monitoring antifibrinolytic therapy using the plasma APA is proposed.
Gastrointestinal bleeding in patients with spinal cord trauma
Authors: Epstein Nancy , Hood Donald C. , Ransohoff Joseph
Published: May 2009

✓ The frequency and degree of gastrointestinal (GI) bleeding were examined in 131 patients with spinal cord injuries. All patients were randomly assigned to either high- or low-dose steroid regimens and some form of GI prophylaxis. The latter consisted of antacids alone or antacids supplemented with cimetidine when this medication became available. Segments of the population were treated with mini-dose or full-dose heparin. The incidence and degree of GI bleeding did not appear to be affected by steroid dose level, regimen of prophylaxis, or mini-dose heparin. Only full heparinization was found to significantly increase bleeding. These results place in question the benefits of adding cimetidine to antacids as a prophylactic treatment in patients with no history of ulcer.
Long-term prognosis in surgically treated intracranial aneurysms
Authors: Artiola i Fortuny Lydia , Prieto-Valiente Luis
Published: May 2009

✓ An evaluation of long-term results following aneurysm surgery is presented. Five different outcome measures are used in a population of 204 survivors followed for a minimum of 18 months and a maximum of 5½ years. The findings show that 1) results vary depending on the outcome measure used, and 2) outcome can be predicted with a considerable degree of accuracy using preoperative and early postoperative variables. The most important predictive factors were postoperative vasospasm, age, systemic blood pressure on admission, and preoperative neurological status. The results are compared with a control group.
Neurological manifestations of pediatric achondroplasia
Authors: Yamada Hiroshi , Nakamura Shigetoshi , Tajima Masataka , Kageyama Naoki
Published: May 2009

✓ The neurological and neuroradiological manifestations of pediatric achondroplasia are analyzed on the basis of 10 cases. In addition to the classical symptomatology of an enlarging head, with or without increased intracranial pressure, several patients presented symptoms related to a small foramen magnum. Respiratory problems and quadriparesis were also observed in these patients. Six patients who were treated by foramen magnum decompression showed remarkable improvement. Neuroradiological evaluation revealed a significant number of patients with dilated cortical sulci and basal cisterns, and mild dilatation of the ventricles on computerized tomography (CT) and/or ventriculography. Two patients showed signs of obstruction at the fourth ventricle outlets. Some exhibited anomalous dilatation of cerebral veins and dural sinuses, narrowing of the sinuses at the jugular foramen, and enlarged emissary veins. Ventriculoperitoneal or ventriculoatrial shunts were placed in three patients. In the other children with a large head and dilated ventricles, head growth curves paralleled the normal slope, and there was no significant clinical evidence of increased intracranial pressure or enlarging ventricles on follow-up CT scan.
Spontaneous lateral ventriculocisternostomy documented by metrizamide CT ventriculography
Authors: Kapila Ashwani , Naidich Thomas P.
Published: May 2009

✓ In a patient with partially shunted obstructive hydrocephalus from a third ventricular astrocytoma, metrizamide ventriculography combined with computerized tomography demonstrated spontaneous ventriculocisternostomy with passage of contrast material from the atrium into the choroid fissure and posterior subarachnoid space.
Supratentorial and parafalcial subdural empyema diagnosed by computerized tomography
Authors: Borovich Bernardo , Braun Jacob , Honigman Silvia , Joachims Henry Z. , Peyser Eli
Published: May 2009

✓ A case is presented in which computerized tomography (CT) demonstrated a supratentorial and parafalcial purulent collection. However, neither carotid angiography nor CT revealed the small scattered pockets of pus that were found over the convexity at operation. The entire subdural space was exposed by a wide craniectomy, permitting adequate subdural drainage and decompression of the brain. It is thought that thorough drainage of the entire subdural space is crucial for the attainment of a successful result in a singlestage operation.
Giant nevus of the scalp associated with intracranial pigmentation
Authors: Findler Gideon , Hoffman Harold J. , Thomson Hugh G. , Becker Larry
Published: May 2009

✓ A case is reported of aggressive cellular blue nevus of the scalp. Intracranial pigmentation in association with a melanocytic nevus of the scalp may indicate either benign coexisting melanosis, local extension, or invasive malignancy. The importance of accurate diagnosis is discussed, and the need to be prepared to carry the excision deep enough to include the dura is illustrated.
Vascular malformation simulating a glioma on computerized tomography
Authors: Foy Patrick M. , Lozada Leandro , Shaw Malcolm D.
Published: May 2009

✓ A patient with an arteriovenous malformation and giant venous aneurysm was erroneously diagnosed as having an oligodendroglioma on computerized tomography (CT). This case highlights some of the problems of interpretation of CT scans and the dangers of misinterpretation, particularly in the surgical context.
Early management of aneurysmal subarachnoid hemorrhage
Authors: Adams Harold P. , Kassell Neal F. , Torner James C. , Nibbelink Donald W. , Sahs Adolph L.
Published: May 2009

✓ The overall results are presented of early medical management and delayed operation among 249 patients studied during the period 1974 to 1977, treated within 3 days of subarachnoid hemorrhage (SAH) and evaluated 90 days after aneurysm rupture. The results included 36.2% mortality, 17.9% survival with serious neurological sequelae, and 46% with a favorable outcome. Of the patients admitted in good neurological condition, 28.7% had died and only 55.7% had a favorable recovery at 90 days after SAH. These figures represent the results despite effective reduction in early rebleeding by antifibrinolytic therapy and successful surgery in those patients reaching operation. Further therapeutic advances are needed for patients hospitalized within a few days after SAH.
Management mortality and the timing of surgery for supratentorial aneurysms
Authors: Weir Bryce , Aronyk Keith
Published: May 2009

✓ A retrospective analysis of 224 patients with a ruptured supratentorial aneurysm, admitted to the care of one of six neurosurgeons on the day of or the day following their subarachnoid hemorrhage, was carried out. Both postoperative and management mortality rates were calculated by the grade of the patient on admission. There were no statistically significant differences in postoperative and management mortality rates when patients were categorized by time of operation, except for the increased management mortality for Grade 3 and 4 patients who were operated on late.
Treatment of odontoid fractures in cancer patients
Authors: Sundaresan Narayan , Galicich Joseph H. , Lane Joseph M. , Greenberg Harry S.
Published: May 2009

✓ A series of 18 patients with odontoid fractures due to metastatic cancer were treated at Memorial Sloan-Kettering Cancer Center between 1974–1980. The primary source of cancer was breast (12 cases), lung (two cases), nasopharynx (one case), multiple myeloma (one case), colon (one case), and rhabdomyosarcoma (one case). The clinical features consisted of severe neck pain and neck stiffness in 17 patients; signs of cord compression were noted in only four patients. Tomography and computerized tomography were useful in identifying both the osseous and soft-tissue involvement by tumor. Initial treatment in all patients except those with myelopathy consisted of high-dose steroids, and immobilization in a hard collar. Ten patients were treated with radiation therapy alone; six patients underwent surgical fusion (four before and two after radiation therapy); and two patients died before completion of treatment. Conservatively treated patients were allowed to walk with the support of only a collar following radiation therapy. We believe that the initial management of patients with odontoid fractures secondary to cancer should be high-dose steroids and radiation therapy, unless displacement is marked. Assessment for surgical fusion should be made following radiation therapy, since conservative treatment may suffice in most patients. Early recognition is important so that treatment can be instituted before C1–2 subluxation becomes severe.
High-resolution metrizamide CT cisternography in sellar and suprasellar abnormalities
Authors: Ghoshhajra Kalyanmay
Published: May 2009

✓ Metrizamide computerized tomographic cisternography was performed with a small dose and low concentration of intrathecal metrizamide using a newer generation of computerized tomography scanner for the evaluation of sellar and suprasellar abnormalities. The examination was performed with thin sections in axial, direct coronal, and (when feasible) direct sagittal projections in a high-resolution technique. The relationship of the lesions with carotid arteries, optic chiasms, and hypothalamic structures was accurately defined.
Spontaneous resolution of epidural hematomas
Authors: Weaver David , Pobereskin Louis , Jane John A.
Published: May 2009

✓ Two cases of traumatic epidural hematomas are presented. Both patients were minimally symptomatic, and neither required surgical intervention. It is suggested that the use of computerized tomography in head trauma will reveal a new class of epidural hematoma patients who may be treated conservatively.
Cerebrospinal fluid shunt colonization and obstruction by Paecilomyces variotii
Authors: Fagerburg Rodger , Shu Byungse , Buckley Helen R. , Lorber Bennett , Karian John
Published: May 2009

✓ A 57-year-old woman underwent ventriculoperitoneal shunt placement for noncommunicating hydrocephalus. She required several shunt revisions over a 2-year period for recurrent hydrocephalus. The shunt was subsequently found to be obstructed by growth of the saprophytic fungus, Paecilomyces variotii, an infrequent human pathogen. Paecilomyces infections have caused complications associated with prosthetic cardiac valves and synthetic lens implantation; this is the first reported association with a cerebrospinal fluid shunt.
Preservation of facial and acoustic nerves in the total removal of large and small acoustic tumors
Authors: Chai Wanxing
Published: May 2009

✓ Two cases are presented in which an acoustic tumor was totally removed without the aid of an operating microscope. In one of them, a large lesion was excised, with restoration of the patient's hearing postoperatively. The anatomical problems are analyzed, and the relevant literature is reviewed briefly.
Transorbital ventricular puncture for emergency ventricular decompression
Authors: Navarro Ignacio Madrazo , Renteria Jose Antonio Garcia , Peralta Victor Hugo Rosas , Dei Castilli Miguel Angel
Published: May 2009

✓ A transorbital technique for emergency ventricular drainage has been used successfully in comatose hydrocephalic patients. The technique is described.
Suction decompression of aneurysms
Authors: Flamm Eugene S.
Published: May 2009

✓ A technique utilizing suction decompression of large aneurysms to allow safer application of a clip is described. Large aneurysms are punctured with a No. 21 scalp vein needle attached to the operating room suction device. This procedure causes relaxation of the aneurysm itself and allows safer application of the clip. The technique has been used in six cases of giant aneurysms.
A scale for evaluation of spinal cord injury
Authors: Chehrazi Bahram , Wagner Franklin C. , Collins William F. , Freeman Daniel H.
Published: May 2009

✓ A scale has been developed for assessment of the severity of spinal cord injury and the prognosis for recovery. Based on neurological examination, this scale employs numerical grading of selected functions below the level of the injury. The scale is adaptable to prospective as well as retrospective studies, and provides a reliable estimation of prognosis and, therefore, a means of comparing the effectiveness of differing treatment modalities.

In relation to a group of 37 patients with cervical spinal cord injury treated under one protocol and assessed within 24 hours and again at 1 year from injury, a descriptive model of the patterns of recovery has been obtained. Relative recovery of the initial deficit measured as a “percentage recovery ratio” is presented as an analytical tool for comparison of effectiveness of different methods of therapy.
Cervical injuries suffered in automobile crashes
Authors: Huelke Donald F. , O'Day James , Mendelsohn Robert A.
Published: May 2009

✓ The National Crash Severity Study data in which occupants sustained severe, serious, critical-to-life, or fatal cervical injuries were reviewed. Of passenger cars damaged severely enough to be towed from the scene, it is estimated that one in 300 occupants sustained a neck injury of a severe nature. The neck-injury rate rose to one in 14 occupants for those ejected from their cars, although many of these injuries resulted from contacts within the car before or during the process of ejection. Severe neck injuries were rather rare in cars struck in the rear, but were more common in frontal and side impacts. Occupants between 16 and 25 years of age had such injuries more than twice as often as those in any other age group. Most of the neck injuries of a more severe nature involved the cervical spine or spinal cord. Injuries of the anterior aspect of the neck were relatively infrequent, and usually resulted from direct blunt impacts. National projections of the number of fatalities related to cervical injuries indicates that 5940 deaths, or approximately 20% of all in-car deaths, include fatal cervical spine injuries, and that about 500 cases of quadriplegia per year result from automobile accidents.
Diagnosis and treatment of middle fossa arachnoid cysts and subdural hematomas
Authors: Auer Ludwig M. , Gallhofer Bernd , Ladurner Gunther , Sager Wolf-Dieter , Heppner Fritz , Lechner Helmut
Published: May 2009

✓ Nine cases with temporal fossa arachnoid cysts were diagnosed by computerized tomography (CT). Five patients also had subdural hematomas, three of them following head trauma. When the hematoma was chronic and of equal hypodensity with the cyst, a clear-cut differentiation was not possible from the CT scan. The presence of a subdural hematoma could only be suggested by thickened arachnoid structures crossing the hypodense area, indicating the wall between cyst and hematoma. The cyst could often be diagnosed by bulging of the skull bone and a temporal lobe defect. Differences in density between cyst and hematoma, such as in subacute subdural hematoma, delineated both entities. Typical examples are demonstrated. Treatment consisted of evacuation of the hematoma and excision of the cyst in all cases.