bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐year outcome of narrow diameter blasted implants for rehabilitation of maxillas with knife‐edge resorption
Authors: Veltri M. , Ferrari M. , Balleri P.
Published: September 2008

Objectives: This study aimed at assessing the clinical outcome of narrow diameter implants in the treatment of knife‐edge edentulous maxillas of adequate bone height but inadequate width (class IV of Cawood and Howell).

Material and methods: Twelve consecutive patients (eight women and four men, mean age 58 years) with class IV atrophic edentulous maxillas were included in the study. Seventy‐three microthreaded TiO2‐blasted implants were placed and the resonance frequency measured. All the implants had a diameter of 3.5 mm. After 6 months of submerged healing, fixed implant‐supported prostheses were delivered to the patients and resonance frequency and radiographic examinations performed. After the first year of loading, the implant outcome was again evaluated clinically, radiographically and with resonance frequency analysis.

Results: All the implants were followed up to 1 year of loading and their survival rate was 100%. Bone loss after 1 year of loading was (mean±SD) 0.30±0.13 mm. Stability values were (mean±SD) 63±5.8 ISQ at placement, 60±4.7 ISQ at the abutment connection and 61±5 ISQ after 1 year of loading. A significant difference resulted between placement and abutment connection values (P=0.03).

Conclusions: According to the present study, narrow implants may be used to restore edentulous maxillas with atrophies of class IV of Cawood and Howell. When planning the treatment of edentulous maxillas with such a resorption pattern, this possibility has to be considered as an alternative to more demanding grafting techniques.
Maxillary sinus‐floor elevation: an animal model
Authors: Estaca Elisa , Cabezas Javier , Usón Jesús , Sánchez‐Margallo Francisco , Morell Enrique , Latorre Rafael
Published: September 2008

Objectives: To find an animal model for modified Caldwell–Luc procedure training. The animal model should have (1) a proper cortical thickness in the lateral wall; (2) a similar morphology and resistance of the Schneiderian membrane in humans; and, finally, (3) an oral approach.

Materials and methods: Twelve fresh heads (four Merino sheep, four Murciano–Granadina goats and four Large–White pigs). Two skulls from each of these species were also used. Several three‐dimensional imagings from the skulls of each species were acquired using a C‐arm. Two fresh heads of each species were used to perform the modified Caldwell–Luc procedure. Two fresh heads of each species were firstly frozen at −30°C for 48 h and then sawed in blocks containing only the target region of the maxillary sinus.

Results: The average thickness was 2.03 mm in goat and sheep and 2.80 in pig. Releasing and elevation of the Schneiderian membrane from the sinus floor were easy in the three species. The approach of the maxillary sinus in sheep, goat and pig from the buccal vestibule required a previous surgical enlargement of the buccal vestibule.

Conclusions: In conclusion, the cortical bone thickness and Schneider membrane characteristics in Merina sheep and Murciano–Granadina goat allow a perfect training for the modified Caldwell–Luc procedure. However, the approach from the oral cavity needs, in these species, a previous enlargement of the buccal vestibule. The excessive thickness of the cortical bone restricts the use of pigs for this technique.
Performance of dental implants after staged sinus floor elevation procedures: 5‐year results of a prospective study in partially edentulous patients
Authors: Bornstein Michael M. , Chappuis Vivianne , Von Arx Thomas , Buser Daniel
Published: September 2008

Objectives: The aim of this prospective study was to evaluate the 5‐year performance and success rate of titanium screw‐type implants with the titanium plasma spray (TPS) or the sand‐blasted, large grit, acid‐etched (SLA) surface inserted in a two‐stage sinus floor elevation (SFE) procedure in the posterior maxilla.

Material and methods: A total of 59 delayed SFEs were performed in 56 patients between January 1997 and December 2001, using a composite graft with autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) or synthetic porous β‐tricalcium phosphate (β‐TCP). After a healing period averaging 7.75 months, 111 dental implants were inserted. After an additional 8–14‐week healing period, all implants were functionally loaded with cemented crowns or fixed partial dentures. The patients were recalled at 12 and 60 months for clinical and radiographic examination.

Results: One patient developed an acute infection in the right maxillary sinus after SFE and did not undergo implant therapy. Two of the 111 inserted implants had to be removed because of a developing atypical facial pain, and 11 implants were lost to follow‐up and were considered drop‐outs. The remaining 98 implants showed favorable clinical and radiographic findings at the 5‐year examination. The peri‐implant soft tissues were stable over time; the mean probing depths and mean attachment levels did not change during the follow‐up period. The measurement of the bone crest levels (DIB values) indicated stability as well. Based on strict success criteria, all 98 implants were considered successfully integrated, resulting in a 5‐year success rate of 98% (for TPS implants 89%, for SLA implants 100%).

Conclusion: This prospective study assessing the performance of dental implants inserted after SFE demonstrated that titanium implants can achieve and maintain successful tissue integration with high predictability for at least 5 years of follow‐up in carefully selected patients.
Spontaneous progression of peri‐implantitis at different types of implants. An experimental study in dogs. I: clinical and radiographic observations
Authors: Albouy Jean‐Pierre , Abrahamsson Ingemar , Persson Leif G. , Berglundh Tord
Published: September 2008

Aim: The aim of the present study was to analyze tissue reactions to plaque formation following ligature removal at commercially available implants exposed to experimental peri‐implantitis.

Material and methods: Six Labrador dogs about 1 year old were used. All mandibular premolars and the three anterior premolars in both sides of the maxilla were extracted. After 3 months four implants representing four different implant systems with different surface characteristics – implant group A (turned), B (TiOblast), C (sandblasted acid‐etched; SLA) and D (TiUnite) – were placed in a randomized order in the right side of the mandible. Three months after implant installation experimental peri‐implantitis was initiated by placement of ligatures in a submarginal position and plaque accumulation. At week 12, when about 40–50% of the supporting bone was lost, the ligatures were removed. During the subsequent 24‐week period plaque accumulation continued. Radiographic and clinical examinations were performed during the ‘active breakdown’ period (plaque accumulation and ligatures) and the plaque accumulation period after ligature removal. The experiment was terminated at week 36.

Results: The bone loss that took place during the ‘active breakdown’ period varied between 3.5 and 4.6 mm. The additional bone loss that occurred during the plaque accumulation period after ligature removal was 1.84 (A), 1.72 (B), 1.55 (C) and 2.78 mm (D).

Conclusion: Spontaneous progression of experimentally induced peri‐implantitis occurred at implants with different geometry and surface characteristics. Progression was most pronounced at implants of type D (TiUnite surface).
Die Sinngebung des Sinnlosen. Zur Politischen Publizistik Ernst Jüngers
Authors: Schlosser Jan T.
Published: September 2008

Wollte man Ernst Jünger auf einen einheitlichen geistigen Standpunkt festlegen, drängt sich geradezu sein Bestreben auf, fernab der wechselvollen Zeitläufte der zwanziger und frühen dreißiger Jahre einen kontinuierlichen metaphysischen Sinn zu behaupten. Der Sinn‐Begriff tritt als das konstante Gedankengerüst hervor, von dem aus die einzelnen Stellungnahmen zu politischen und zeitgeschichtlichen Problemen zu überblicken und im Hinblick auf ihren tatsächlichen Funktionswert kritisch einzustufen sind. Der ,,politische‘‘ oder ,,unpolitische‘‘ Jünger lässt sich weniger an einzelnen Aussagen zum Problemfeld der Politik als vielmehr am Sinn‐Denken festmachen.
Psychoanalysing the Nation. A Comparative Reading of António Lobo Antunes’Memória de elefante and Luis Martín‐Santos’s Tiempo de silencio
Authors: De Menezes Alison Ribeiro
Published: September 2008

This article argues that Portuguese novelist António Lobo Antunes’ first work of fiction, Memória de elefante, can usefully be viewed in a comparative context alongside Spaniard Luis Martín‐Santos’s novel Tiempo de silencio. Both novels represent a narrative response to dictatorship, and they display common strategies to engage their readers in a psychoanalytic interpretation of late twentieth‐century Spain and Portugal and the existence of complicit attitudes to dictatorship therein. A reading of Lobo Antunes’ little discussed novel in the light of works by a comparable Spanish novelist, about whom there is a strong critical tradition, highlights significant new features and refutes the prevailing view of his early work as being postcolonial.
Silencing for a Reason. Elizabeth Gaskell’s Cousin Phillis
Authors: Hansson Heidi , Norberg Cathrine
Published: September 2008

The view of the emotionally volatile woman as a sharp contrast to the rational man is not compatible with Victorian understandings of women as passionless creatures devoid of true feelings. Elizabeth Gaskell dramatises this contradictory view of womanhood in her novella Cousin Phillis (1864) by showing that although women in nineteenth‐century fiction are depicted as slaves to their feelings, intense emotions are seen as the prerogatives of men. Thus, on the surface Cousin Phillis may be understood as a text that adheres to conventional gender codes. Gaskell’s representation of women and men, however, clearly indicates that women are emotionally and intellectually crippled in patriarchal societies.

Self‐control and control of others are shown to be important factors for the structuring of gendered emotions, and if emotions have historically been gendered female, it is evident that the act of silencing and controlling has been gendered male. The gendered interplay of verbal and emotional expression and silencing, as well as a strict adherence to rationality before emotion, constitute the main themes in Gaskell’s novella. To reinforce the theme of silencing Gaskell’s role as producer of the text is concealed behind the voice of a male narrator.
The Drosophila Epsin 1 is Required for Ubiquitin‐Dependent Synaptic Growth and Function but Not for Synaptic Vesicle Recycling
Authors: Bao Hong , Reist Noreen E. , Zhang Bing
Published: September 2008

The ubiquitin‐proteasome system plays an important role in synaptic development and function. However, many components of this system, and how they act to affect synapses, are still not well understood. In this study, we use the Drosophila neuromuscular junction to study the in vivo function of Liquid facets (Lqf), a homolog of mammalian epsin 1. Our data show that Lqf plays a novel role in synapse development and function. Contrary to prior models, Lqf is not required for clathrin‐mediated endocytosis of synaptic vesicles. Lqf is required to maintain bouton size and shape and to sustain synapse growth by acting as a specific substrate of the deubiquitinating enzyme Fat facets. However, Lqf is not a substrate of the Highwire (Hiw) E3 ubiquitin ligase; neither is it required for synapse overgrowth in hiw mutants. Interestingly, Lqf converges on the Hiw pathway by negatively regulating transmitter release in the hiw mutant. These observations demonstrate that Lqf plays distinct roles in two ubiquitin pathways to regulate structural and functional plasticity of the synapse.
Zinc concentration in serum and cerebrospinal fluid simultaneously decrease in children with febrile seizure: Findings from a prospective study in Bangladesh
Authors: Mollah M Abid Hossain , Rakshit Sudesh Chandra , Anwar Kazi Selim , Arslan M Iqbal , Saha Narayan , Ahmed Shakil , Azad Khademul , Hassan Tariq
Published: September 2008

Objective: Since the underlying mechanisms of febrile seizure (FS) having multi‐factorial aetiology yet remains unclear, we conducted this prospectively designed cross‐sectional study to determine if there was any simultaneous change in zinc (Zn) concentration (conc.) in serum and cerebrospinal fluid (CSF) among the FS children in comparison to their matched non‐seizure febrile (NSF) peers.

Methods: Zn concentration (level) in both serum (intravenous blood) and CSF (lumber puncture: LP) of 50 children with FS and 30 NSF peers (serving as control) were measured employing graphite furnace atomic absorbance spectrophotometer. Data were analysed to compare Zn level between two groups using appropriate statistical tools employing SPSS/Windows 12.0.

Results: Mean Zn conc. in both serum and CSF was less in FS children (464.60 ± 64.57 and 46.28 ± 7.46, respectively) than their matched NSF peers (749.33 ± 73.19 μg/L and 111.28 ± 19.11 μg/L, respectively) showing significant differences both in serum (p < 0.001) and CSF (p < 0.001). None of serum or CSF‐Zn differed significantly with age, degree and duration of fever between FS and NSF peers. CSF‐Zn among these children showed an upward trend in LP specimen taken beyond 12 h following FS episodes.

Conclusion and recommendation: Serum and CSF‐Zn simultaneously decreased in FS children in comparison to their matched NSF peers. Further prospectively designed multicentral studies are recommended to conduct in geographically diverse regions involving larger sample to confirm or refute our findings. It remains crucial in standardizing/strengthening national seizure prevention protocol with adequate Zn supplementation.
The outcome in newborns with congenital diaphragmatic hernia in a Norwegian region
Authors: Fredly S , Aksnes G , Viddal KO , Lindemann R , Fugelseth D
Published: September 2008

Aim: To evaluate the therapeutic strategies used in neonates with congenital diaphragmatic hernia (CDH) during the last 15 years in our department.

Method: A retrospective study of 27 neonates with CDH treated at the Neonatal Intensive Care Unit at Ullevaal University Hospital between 1992 and 2006. Since 1992 we have used delayed operative repair and high‐frequency ventilation (HFV). Because surfactant replacement and inhaled nitric oxide (iNO) therapy have been used since 1997, we divided the patients into two groups; group 1 from 1992 to 1996 (9 patients) and group 2 from 1997 to 2006 (18 patients).

Results: The overall survival was 70%. Group 1 had an exceptionally good outcome, 100% survival versus 56% in the last group.

Conclusion: Pulmonary hypoplasia and pulmonary hypertension are still the most challenging factors in treatment of neonates with CDH, despite novel therapeutic modalities, such as HFV, surfactant and iNO. Delayed surgery in CDH allows pre‐operative stabilization. Extracorporeal membrane oxygenation must be considered in the most severe cases.
Severe psychomotor and metabolic damages caused by a mutant thyroid hormone receptor alpha 1 in mice: can patients with a similar mutation be found and treated?
Authors: Vennström Björn , Mittag Jens , Wallis Karin
Published: September 2008

Individuals suffering from the resistance to thyroid hormone syndrome (RTH) have a mutation in thyroid hormone receptor (TR) β. Surprisingly, no patient with a mutation in TRα1 has been found. To facilitate their identification, animal models with a RTH‐like mutation in TRα1 have been generated. The mutations introduced into the mouse decrease affinity to ligand, resulting in a ‘receptor‐mediated hypothyroidism’ in tissues expressing the mutant receptor: brain, heart and bone. The mice present minor perturbances in thyroid hormone homeostasis, but show major aberrancies in postnatal development, psychomotor behaviour and metabolism. These parameters are akin to those seen in endemic cretinism and untreated congenital hypothyroidism. Treatment of the mice with high doses of triiodothyronine leads to normalization or amelioration of the dysfunctions when applied at adequate developmental periods.

Conclusion: Our studies on mice suggest the existence of a potentially debilitating disease caused by a mutant TRα1, and provide insights for identification and treatment of corresponding patients.
Web‐based consultations for parents of children with atopic dermatitis: results of a randomized controlled trial
Authors: Bergmo Trine S , Wangberg Silje C , Schopf Thomas R , Solvoll Terje
Published: September 2008

Aim: To analyse how web‐based consultations for parents of children with atopic dermatitis affect self‐management behaviour, health outcome, health resource use and family costs.

Methods: Ninety‐eight children with atopic dermatitis were randomly assigned to intervention and control groups. The intervention group received remote dermatology consultations through a secure web‐based communication system. The control group was encouraged to seek treatment through traditional means such as general practitioner visits and hospital care. Both groups received an extensive individual educational session prior to the intervention.

Results: Thirty‐eight percent of the intervention group used web‐based consultations 158 times ranging from 1 to 38 consultations per patient. We found no change in self‐management behaviour, health outcome or costs. The intervention group tended to have fewer visits to practitioners offering complementary therapies than the control group, and we found a positive correlation between emergency visits at baseline and messages sent. Both groups, however, reduced the mean number of skin care treatments performed per week and had fewer total health care visits after the intervention.

Conclusion: We found no effect of supplementing traditional treatment for childhood dermatitis with web‐based consultations. This study showed that web consultations is feasible, but more research is needed to determine its effect on self‐management skills, health outcome and resource use.
BMI and Lipid Levels in Mexican American Children Diagnosed with Type 2 Diabetes
Authors: Fortmeier‐Saucier Linda , Savrin Carol , Heinzer Marjorie , Hudak Christine
Published: September 2008

Purpose: The purpose of this study was to determine potential associations between obesity as measured by body mass index (BMI) and lipid values in Mexican American (MA) children diagnosed with type 2 diabetes.

Background: Obesity in children is considered to be an emerging epidemic that is accompanied by an increase in prevalence of type 2 diabetes. Literature shows that there is a direct and strong relationship between abnormal lipid levels and obesity in Caucasian and African American children without type 2 diabetes. However, it was unknown whether Mexican American children diagnosed with type 2 diabetes have abnormal lipid levels.

Method: A retrospective medical‐record review was conducted on paediatric patients who received medical care from a military medical centre in the Southwest region of the United States. A convenience sample of records was used to study the relationship between obesity as measured by BMI and lipid levels in 49 Mexican American children diagnosed with type 2 diabetes. Total cholesterol, high‐density lipoprotein (HDL), low‐density lipoprotein (LDL), triglycerides (TG), and BMI were reviewed. Data were analysed using descriptive and logistic regression statistics.

Findings: Ninety percent of the sample was obese and 75% had two or more abnormal lipid values. Abnormal levels of total cholesterol, HDL, and triglycerides were found to be statistically significant.

Conclusions: The main findings indicate that MA children diagnosed with type 2 diabetes had significant associations between obesity as measured by BMI and abnormal total cholesterol, HDL, and triglyceride levels. As the BMI increased, the probability of abnormal total cholesterol and triglyceride levels increased. Similarly, as the BMI increased, the probability of abnormal HDL values increased. Mexican American children in this study had obesity levels similar to those in a study by the National Center for Health Statistics. In this study a step has been taken toward understanding a physiologic marker for cardiovascular disease in children.
The Emotional Impact of Obesity on Children
Authors: Cornette Robert
Published: September 2008

Background: Childhood overweight and obesity has become a global epidemic affecting children of all ages and ethnic and socioeconomic backgrounds. While the physical and financial consequences are well documented, little research is available on the emotional effect of overweight and obesity on children and adolescents.

Objectives: To assess the emotional effect of overweight and obesity on a child's self‐esteem and self‐concept.

Search Strategy: The following databases were searched: CINAHL, Clinical Pharmacology, Health Source–Nursing and Academic Edition, MEDLINE, Pre‐CINAHL, Psychological and Behavioral Sciences Collection, PsycINFO, and Sociological Collection, along with the Cochrane Library, Joanna Briggs Institute, National Institute of Health (NIH), and Centers for Disease Control and Prevention (CDC).

Selection Criteria Included: Studies published from January 1995 to December 2005 whose primary aim was to investigate psychological impact of being overweight or obese on children and adolescents of both genders and all ethnic, cultural, and socioeconomic backgrounds. Studies of 50 or more participants with outcomes that included an assessment tool of psychological measurement and weight or body mass index (BMI), and were in English or translated to English were considered.

Findings: All participants reported some level of psychosocial impact from being overweight or obese. Younger children, girls, and those with little control over eating suffered the greatest consequences.

Conclusions: Evidence to determine the emotional impact of being overweight in children and adolescents is limited. There is even less research focused on the efforts to address the problem of low self‐esteem, depression, and other emotional consequences. More attention should be focused on the emotional effect of childhood overweight and obesity in order to provide more holistic care for this pediatric population.
The Drosophila homeodomain transcription factor, Vnd, associates with a variety of co‐factors, is extensively phosphorylated and forms multiple complexes in embryos
Authors: Zhang Huanqing , Syu Li‐Jyun , Modica Vicky , Yu Zhongxin , Von Ohlen Tonia , Mellerick Dervla M.
Published: September 2008

Vnd is a dual transcriptional regulator that is essential for Drosophila dorsal–ventral patterning. Yet, our understanding of the biochemical basis for its regulatory activity is limited. Consistent with Vnd’s ability to repress target expression in embryos, endogenously expressed Vnd physically associates with the co‐repressor, Groucho, in Drosophila Kc167 cells. Vnd exists as a single complex in Kc167 cells, in contrast with embryonic Vnd, which forms multiple high‐molecular‐weight complexes. Unlike its vertebrate homolog, Nkx2.2, full‐length Vnd can bind its target in electrophoretic mobility shift assay, suggesting that co‐factor availability may influence Vnd’s weak regulatory activity in transient transfections. We identify the high mobility group 1‐type protein, D1, and the novel helix–loop–helix protein, Olig, as novel Vnd‐interacting proteins using co‐immunoprecipitation assays. Furthermore, we demonstrate that both D1 and Olig are co‐expressed with Vnd during Drosophila embryogenesis, consistent with a biological basis for this interaction. We also suggest that the phosphorylation state of Vnd influences its ability to interact with co‐factors, because Vnd is extensively phosphorylated in embryos and can be phosphorylated by activated mitogen‐activated protein kinase in vitro. These results highlight the complexities of Vnd‐mediated regulation.
Identification of two late acyltransferase genes responsible for lipid A biosynthesis in Moraxella catarrhalis
Authors: Gao Song , Peng Daxin , Zhang Wenhong , Muszyński Artur , Carlson Russell W. , Gu Xin‐Xing
Published: September 2008

Lipid A is a biological component of the lipo‐oligosaccharide of a human pathogen, Moraxella catarrhalis. No other acyltransferases except for UDP‐GlcNAc acyltransferase, responsible for lipid A biosynthesis in M. catarrhalis, have been identified. By bioinformatics, two late acyltransferase genes, lpxX and lpxL, responsible for lipid A biosynthesis were identified, and knockout mutants of each gene in M. catarrhalis strain O35E were constructed and named O35ElpxX and O35ElpxL. Structural analysis of lipid A from the parental strain and derived mutants showed that O35ElpxX lacked two decanoic acids (C10:0), whereas O35ElpxL lacked one dodecanoic (lauric) acid (C12:0), suggesting that lpxX encoded decanoyl transferase and lpxL encoded dodecanoyl transferase. Phenotypic analysis revealed that both mutants were similar to the parental strain in their toxicity in vitro. However, O35ElpxX was sensitive to the bactericidal activity of normal human serum and hydrophobic reagents. It had a reduced growth rate in broth and an accelerated bacterial clearance at 3 h (P < 0.01) or 6 h (P < 0.05) after an aerosol challenge in a murine model of bacterial pulmonary clearance. O35ElpxL presented similar patterns to those of the parental strain, except that it was slightly sensitive to the hydrophobic reagents. These results indicate that these two genes, particularly lpxX, encoding late acyltransferases responsible for incorporation of the acyloxyacyl‐linked secondary acyl chains into lipid A, are important for the biological activities of M. catarrhalis.
S100–annexin complexes – biology of conditional association
Authors: Miwa Naofumi , Uebi Tatsuya , Kawamura Satoru
Published: September 2008

S100 proteins and annexins both constitute groups of Ca2+‐binding proteins, each of which comprises more than 10 members. S100 proteins are small, dimeric, EF‐hand‐type Ca2+‐binding proteins that exert both intracellular and extracellular functions. Within the cells, S100 proteins regulate various reactions, including phosphorylation, in response to changes in the intracellular Ca2+ concentration. Although S100 proteins are known to be associated with many diseases, exact pathological contributions have not been proven in detail. Annexins are non‐EF‐hand‐type Ca2+‐binding proteins that exhibit Ca2+‐dependent binding to phospholipids and membranes in various tissues. Annexins bring different membranes into proximity and assist them to fuse, and therefore are believed to play a role in membrane trafficking and organization. Several S100 proteins and annexins are known to interact with each other in either a Ca2+‐dependent or Ca2+‐independent manner, and form complexes that exhibit biological activities. This review focuses on the interaction between S100 proteins and annexins, and the possible biological roles of these complexes. Recent studies have shown that S100–annexin complexes have a role in the differentiation of gonad cells and neurological disorders, such as depression. These complexes regulate the organization of membranes and vesicles, and thereby may participate in the appropriate disposition of membrane‐associated proteins, including ion channels and/or receptors.
S100–annexin complexes – structural insights
Authors: Rintala‐Dempsey Anne C. , Rezvanpour Atoosa , Shaw Gary S.
Published: September 2008

Annexins and S100 proteins represent two large, but distinct, calcium‐binding protein families. Annexins are made up of a highly α‐helical core domain that binds calcium ions, allowing them to interact with phospholipid membranes. Furthermore, some annexins, such as annexins A1 and A2, contain an N‐terminal region that is expelled from the core domain on calcium binding. These events allow for the interaction of the annexin N‐terminus with target proteins, such as S100. In addition, when an S100 protein binds calcium ions, it undergoes a structural reorientation of its helices, exposing a hydrophobic patch capable of interacting with its targets, including the N‐terminal sequences of annexins. Structural studies of the complexes between members of these two families have revealed valuable details regarding the mechanisms of the interactions, including the binding surfaces and conformation of the annexin N‐terminus. However, other S100–annexin interactions, such as those between S100A11 and annexin A6, or between dicalcin and annexins A1, A2 and A5, appear to be more complicated, involving the annexin core region, perhaps in concert with the N‐terminus. The diversity of these interactions indicates that multiple forms of recognition exist between S100 proteins and annexins. S100–annexin interactions have been suggested to play a role in membrane fusion events by the bridging together of two annexin proteins, bound to phospholipid membranes, by an S100 protein. The structures and differential interactions of S100–annexin complexes may indicate that this process has several possible modes of protein–protein recognition.
EXPLAINING THE EDUCATIONAL DEFICITS OF DELINQUENT YOUTHS*
Authors: SIENNICK SONJA E. , STAFF JEREMY
Published: September 2008

Why do delinquent youths complete less education than do their conventional peers? Theory and research in criminology and in the sociology of education suggest that two aspects of youths' commitment to education, their future goals and their behavioral investments in those goals, may explain the delinquency‐education relationship, but only when considered jointly. Using panel data from the National Education Longitudinal Study, we find that educational expectations and school effort together explain delinquents' lower rates of college attendance and graduation, but of these two factors, effort provides the more powerful explanation. We also find that transcript grades explain more of the delinquency‐education relationship than do self‐reported grades, which indicates that delinquent youths may not know exactly how they are performing in school. Our findings suggest that the aspirational and behavioral components of commitment to education are only loosely coupled, and that delinquent youths may not understand how their behavior can jeopardize their goals.
CONCENTRATED DISADVANTAGE, TRADITIONAL MALE ROLE MODELS, AND AFRICAN‐AMERICAN JUVENILE VIOLENCE*
Authors: PARKER KAREN F. , RECKDENWALD AMY
Published: September 2008

In a stagnating urban economy, Elijah Anderson's (1999)Code of theStreet depicts a disadvantaged environment where residents face high levels of joblessness, poverty, racial residential isolation, and family disruption. Anderson argues that the loss of job opportunities for African‐American men deprived younger generations of traditional male role models. That is, in a disadvantaged urban setting with a lack of male role models participating in legitimate labor market activity, many young people may turn to violence. Drawing on insights from Anderson's ethnographic work, we assess the generality of Anderson's claims more broadly and explore the potential connection between his work and the macrolevel research on urban violence. Specifically, we explore the influence of male role models (older, employed black males) and the concentration of urban disadvantage on black juvenile arrests for violence across multiple cities in 2000. Overall, we find empirical support for Anderson's concerns over the removal of traditional male role models from urban areas as a result of concentrated disadvantage. Specifically, we find that the presence of traditional male role models reduces the rates of African‐American youth violence. Additionally, our measure of traditional male role models mediates the relationship between structural disadvantage and juvenile violence. We discuss the contributions of Anderson's work to the macrolevel study of urban violence.
IS THE ASSOCIATION BETWEEN ALCOHOL USE AND DELINQUENCY CAUSAL OR SPURIOUS?*
Authors: FELSON RICHARD , SAVOLAINEN JUKKA , AALTONEN MIKKO , MOUSTGAARD HETA
Published: September 2008

We attempt to isolate the effects of alcohol on different types of delinquent behavior by identifying the spurious portion of the relationship. Using data on adolescents from Finland, we compare the relationship between drinking and delinquent behavior while sober to the total relationship between drinking and delinquent behavior (sober or not). For each type of offense, we find a substantial relationship between drinking and sober delinquency, which suggests a good deal of spuriousness. For crimes of petty theft (shoplifting and stealing from home), the relationship between drinking and sober delinquency is just as strong as the total relationship, which suggests the relationship is almost completely spurious. For violence, vandalism, car theft, and graffiti writing, the alcohol‐sober delinquency relationship is weaker, which suggests that alcohol has a causal effect on these offenses.
GENDER, NEIGHBORHOOD DANGER, AND RISK‐AVOIDANCE STRATEGIES AMONG URBAN AFRICAN‐AMERICAN YOUTHS*
Authors: COBBINA JENNIFER E. , MILLER JODY , BRUNSON ROD K.
Published: September 2008

Research consistently reveals that fear of crime and perceived risk are demographically and ecologically patterned. Women and individuals in disadvantaged community settings report increased fear and perceptions of risk. For women, these fears and perceptions are tied to concerns about sexual violence specifically, whereas for individuals in distressed neighborhoods, crime rates, “incivilities,” and poor police‐community relations are often identified as important correlates. Here, we build from the insights of previous research by examining the gendered nature of perceived risk and risk‐management strategies among urban African‐American adolescents. Our findings suggest that both risk and risk‐avoidance strategies are strikingly different for young women and young men and are shaped by the gendered organizational features of neighborhood life. We propose that future research will benefit by continuing to investigate how social vulnerabilities function in tandem to structure risks across ecological settings.
THE EFFECTS OF RESIDENTIAL TURNOVER ON HOUSEHOLD VICTIMIZATION*
Authors: XIE MIN , MCDOWALL DAVID
Published: September 2008

Americans move frequently, and moving alters their risks of victimization. This study uses unique longitudinal, multilevel data from the 1980–1985 National Crime Survey to examine the effects of residential turnover on household victimization. The two major findings of the study are as follows: First, housing turnover is a transition that independently increases the risk that a dwelling will experience a crime. This finding is true even controlling for persistent differences in crime vulnerability between dwellings. Second, changes in the composition and routine activities of households also alter the risks of victimization. These findings provide support for social disorganization and crime opportunity theories.
POLICING CRIME AND DISORDER HOT SPOTS: A RANDOMIZED CONTROLLED TRIAL*
Authors: BRAGA ANTHONY A. , BOND BRENDA J.
Published: September 2008

Dealing with physical and social disorder to prevent serious crime has become a central strategy for policing. This study evaluates the effects of policing disorder, within a problem‐oriented policing framework, at crime and disorder hot spots in Lowell, Massachusetts. Thirty‐four hot spots were matched into 17 pairs, and one member of each pair was allocated to treatment conditions in a randomized block field experiment. The officers engaged “shallow” problem solving and implemented a strategy that more closely resembled a general policing disorder strategy rather than carefully designed problem‐oriented policing responses. Nevertheless, the impact evaluation revealed significant reductions in crime and disorder calls for service, and systematic observations of social and physical disorder at the treatment places relative to the control places uncovered no evidence of significant crime displacement. A mediation analysis of the isolated and exhaustive causal mechanisms that comprised the strategy revealed that the strongest crime‐prevention gains were generated by situational prevention strategies rather than by misdemeanor arrests or social service strategies.
Personality Testing and Industrial–Organizational Psychology: Reflections, Progress, and Prospects
Authors: Hough Leaetta M. , Oswald Frederick L.
Published: September 2008

As the title suggests, this article takes a broad perspective on personality as it is conceptualized and measured in organizational research, and in the spirit of this Society for Industrial and Organizational Psychology journal, we framed the article as a series of 7 questions. These 7 questions deal with (1) personality and multidimensional models of performance, (2) personality taxonomies and the five-factor model, (3) the effects of situations on personality–performance relationships, (4) the incremental validity of personality over cognitive ability, (5) the need to differentiate personality constructs from personality measures, (6) the concern with faking on personality tests, and (7) the use of personality tests in attempting to address adverse impact. We dovetail these questions with our perspectives and insights in the hope that this will stimulate further discussion with our readership.
Stubborn Reliance on Intuition and Subjectivity in Employee Selection
Authors: Highhouse Scott
Published: September 2008

The focus of this article is on implicit beliefs that inhibit adoption of selection decision aids (e.g., paper-and-pencil tests, structured interviews, mechanical combination of predictors). Understanding these beliefs is just as important as understanding organizational constraints to the adoption of selection technologies and may be more useful for informing the design of successful interventions. One of these is the implicit belief that it is theoretically possible to achieve near-perfect precision in predicting performance on the job. That is, people have an inherent resistance to analytical approaches to selection because they fail to view selection as probabilistic and subject to error. Another is the implicit belief that prediction of human behavior is improved through experience. This myth of expertise results in an overreliance on intuition and a reluctance to undermine one’s own credibility by using a selection decision aid.
Unsteady Performance of a PEMFC System Including Autothermal Methane Reforming
Authors: Beil Alexander , Seume Joerg R.
Published: September 2008

A zero-dimensional, dynamic model of a PEM fuel cell with an autothermal methane reformer section is generated. In the model, reformer consists of three reactors for the autothermal steam reforming, the water gas shift, and the selective oxidation. Physical approaches are favored over empirical modeling equations in order to describe the relevant transport phenomena. Thus, in spite of the low order modeling, only physical parameters are required for the input. The aim of the model is the calculation of the cell voltage for a given set of geometrical and thermodynamic data including the current density. The fuel cell water management is modeled with equations for the water transport through the membrane by electro-osmotic drag and diffusion as well as the membrane humidity. Flooding due to liquid water content and dehydration of the membrane is simulated dynamically with this model. These critical conditions are identified by the cell voltage. Due to pressure feedback, dynamic simulations show partial pressure fluctuation in the reformer reactors caused by load changes of the fuel cell.
Robust Design Techniques for Evaluating Fuel Cell Thermal Performance
Authors: Kelly Kenneth J. , Pacifico Gregory C. , Penev Michael , Vlahinos Andreas
Published: September 2008

The National Renewable Energy Laboratory (NREL) and Plug Power Inc. have been working together to develop fuel cell modeling processes to rapidly assess critical design parameters and evaluate the effects of variation on performance. This paper describes a methodology for investigating key design parameters affecting the thermal performance of a high temperature, polybenzimidazole (PBI)-based fuel cell stack. Nonuniform temperature distributions within the fuel cell stack may cause degraded performance, induce thermo-mechanical stresses, and be a source of reduced stack durability. The three-dimensional (3-D) model developed for this project includes coupled thermal/flow finite element analysis (FEA) of a multi-cell stack integrated with an electrochemical model to determine internal heat generation rates. Sensitivity and optimization algorithms were used to examine the design and derive the best choice of the design parameters. Initial results showed how classic design-of-experiment (DOE) techniques integrated with the model were used to define a response surface and perform sensitivity studies on heat generation rates, fluid flow, bipolar plate channel geometry, fluid properties, and plate thermal material properties. Probabilistic design methods were used to assess the robustness of the design in response to variations in load conditions. The thermal model was also used to develop an alternative coolant flow-path design that yields improved thermal performance. Results from this analysis were recently incorporated into the latest Plug Power coolant flow-path design. This paper presents an evaluation of the effect of variation on key design parameters such as coolant and gas flow rates and addresses uncertainty in material thermal properties.
Biomass SOFC-MGT Hybrid System: Effect of Fuel Composition
Authors: Sucipta Made , Kimijima Shinji , Song Tae Won , Suzuki Kenjiro
Published: September 2008

Performance analysis of the solid oxide fuel cell–micro gas turbine (SOFC–MGT) hybrid system has been made assuming the fuel to be methane-based artificial ones including H2, CO, CO2, H2O or N2 of different concentration in preparation for the study of biomass fuelled SOFC–MGT hybrid system. This is based on the fact that the chemical composition of biomass fuel produced from different fuel production processes is diversified, i.e. in one case one chemical species rich in concentration and in another case another chemical species rich. In the analysis is used the multi–stage model for internal reforming SOFC module developed previously with some modification. With this model, studies cover not only the performance of the hybrid system but also the spatial distributions of temperature and concentration of some chemical species inside the module, namely in the cell stack and in the internal reformer.
Liquid Behavior Across Porous Transport Layer in PEM Fuel Cell Cathode
Authors: Jiao Kui , Zhou Biao
Published: September 2008

Liquid water transport inside PEM fuel cells is one of the key challenges for water management in a proton exchange membrane (PEM) fuel cell. Investigation of the air-water flow patterns inside fuel cell gas flow channels with porous transport layer (PTL) would provide valuable information that could be used in fuel cell design and optimization. This paper presents a numerical investigation of air-water flow across a PTL with a serpentine channel on PEM fuel cell cathode by use of a commercial Computational Fluid Dynamics (CFD) software package FLUENT. Detailed flow patterns with air-water across the porous media were investigated and discussed.
A Thermodynamic Analysis of Compressing Hydrogen for Storage
Authors: Lingel Clinten D.
Published: September 2008

Storing hydrogen gas under pressure to provide an energy source for fuel cells or internal combustion engines is a real issue that must be addressed. Diatomic hydrogen does not occur naturally and therefore, must be made through electrolysis, methane reforming or some other process. From the production of pure hydrogen to the final end user, the entire cycle must be considered. Once formed, hydrogen will need to be compressed to a storage container. A hydrogen based transportation system will be both an economic and engineering challenge.
Simulation of Water Vapor Transport Phenomena in Proton Exchange Membrane Fuel Cells (PEMFCs)
Authors: Ma H. K. , Huang S. H.
Published: September 2008

The objective of this paper is to study the influences of water vapor concentration in membrane and flow channels under the different operation conditions. The studied flow channels by CFDRC code include serpentine and interdigitated flow channels which have different gas transportation mechanisms. At the same time, the computer code, based upon Okada’s one dimensional model, was built to predict the influences of the electro-osmosis effect, the foreign impurity cations and the water balance time on water concentration in the membrane by Fortran 90. Both of interdigitated and serpentine flow fields show that water vapor accumulates near the cathode outlet of the membrane. And, the serpentine flow field accumulates more water vapor than interdigitated flow field does. As the inlet water mass fraction below 10%, the drying out problem may happen to reduce current density. In addition, the foreign impurity cations may induce the stronger electro-osmosis effect and reduce the effect of water back diffusion; hence, cause the accumulating of water in the cathode. It needs more water balance time and decreases the membrane performance.
Micromachined Methanol Steam Reforming System Integrated With Catalytic Combustor Using Carbon Nanotubes as Catalyst Supports
Authors: Park Dae-Eun , Kim Tae-Kyu , Kwon Sejin , Kim Choong-Ki , Yoon Euisik
Published: September 2008

In this paper we have successfully demonstrated a new micromachined fuel processing system including vaporizer, catalytic combustor and methanol steam reformer. This fuel processing system utilizes the thermal energy generated from the catalytic hydrogen combustion to heat up the entire system. For the first time, we have used carbon nanotubes as a supporting structure of Pt catalyst for combustion. The catalytic combustor could supply the energy to heat the reformer and maintain its working temperature. We have also developed a new coating method of reforming catalyst (Cu/ZnO/Al2O3) and observed that adequate amount of hydrogen can be generated for PEMFC. We have successfully reported the feasibility of the proposed fuel processing system in each assembled component.
PEM Unit Cell Model Considering Additional Reactions
Authors: Wetton Brian , Kim Gwang-Soo , Promislow Keith , St-Pierre Jean
Published: September 2008

A computational model is developed for a PEM unit cell capable of describing the reactions that occur in the cell in understoich conditions. Such conditions can occur as a result of reactant supply system failure (blockage, leaks, system control, etc.). The model applies to cells with straight channels, and mass transport in the MEA (membrane crossover as well as transport through the GDE) in the channel cross-plane is described only in an average sense assuming linear diffusive mechanisms. Several other major assumptions are made, the most significant being that the cell is always at saturated conditions and is taken to be isothermal. Several electrochemical and mass transport coefficients are not available in the literature and “best guesses” are taken. The results of the model are not yet validated experimentally. However, it is the first model proposed that captures these phenomena in a comprehensive way at the local level and also couples the phenomena through channel flow. Cathode understoich results show the expected Hydrogen evolution at the cathode. Anode understoich results show anode Carbon oxidation. An interesting third run is shown where at low currents, a partial anode understoich condition occurs where the cell voltage remains positive, but the anode is starved of Hydrogen near outlet. Carbon corrosion at the cathode occurs in this case.