bluuebunny/crossref_metadata_2025 huggingface dataset:
TSA‐FEM Comparative Analysis of a Helicopter Component under Multiaxial Load
Authors: Colombo D. , Desiderati S. , Giglio M. , Salerno A.
Published: August 2007

Abstract:  Thermoelastic stress analysis (TSA) is applied to a helicopter titanium tail rotor hub component with complex geometry and subjected to multiaxial loads. The frequency of the loads adopted in the TSA test was 2 Hz because of the fact that hydraulic actuators were used. As a consequence, non‐adiabatic conditions were met in some parts of the component and a correction applied to the raw data obtained by TSA. The reliability of the corrected TSA data was checked by comparing the data with the results of a finite element model, validated previously by strain gauge measures. The good agreement between the experimental and the numerical data shows that TSA can be successfully used for structural components with complex geometry and subjected to multiaxial loads under non‐adiabatic conditions.
Strain Measurement of Nickel Thin Film by a Digital Image Correlation Method
Authors: Hwang S.‐F. , Horn J.‐T. , Wang H.‐J.
Published: August 2007

Abstract:  Digital image correlation is a whole‐field and non‐contact strain‐measuring method. It provides deformation information of a specimen by processing two digital images captured before and after the deformation. To search the deformed images, a hybrid genetic algorithm, in which a simulated annealing mutation process and adaptive mechanisms are combined with a real‐parameter genetic algorithm, is adopted. This method is used to measure the strain during the microtensile testing of nickel thin film. In addition to the conventional single region, a double region in which the strain is inferred from the distance change of two regions is proposed to calculate the strain by digital image correlation. The results indicate that while the strain values obtained by single‐region method are reasonable, those obtained by the double region method are more accurate. Moreover, the mechanical properties of nickel thin film could be obtained.
Evaluation of Residual Stresses During Fatigue Test in an FSW Joint
Authors: Pasta S. , Reynolds A. P.
Published: August 2007

Abstract:  This paper shows an application of the adjusted compliance ratio method (ACR), and the on‐line crack‐compliance technique for determination of the effects of the residual stress during a fatigue test. The fatigue crack growth tests were carried out on a friction stir welded (FSW) joint in Ti‐6Al‐4V titanium alloy. On‐line crack compliance enables the determination of the residual stress intensity factor in real time from a fatigue test. The ACR methodology was used to separate the residual stress effects from the crack growth rate data. Finally, the residual stress distribution of the FSW joint was found from the knowledge of the residual stress intensity factor through an integral solution. It would have to be noted that both methods are based on ratios of displacements; therefore, the practical application does not require the use of the influence functions needed for the cut‐compliance method. Moreover, a specific test, which determines residual stresses, can be avoided because the effect of the same residual stresses on the crack growth is evaluated during the fatigue test. This methodology is more accurate than cut compliance because it reflects the real crack growth behaviour.
Research on the Shear Behaviour of Plain Weave Prepreg at Lateral Compaction Stage
Authors: Lin G. , Wang Y. , Du X. , He X.
Published: August 2007

Abstract:  An investigation of the shear behaviour of plain weave prepreg at lateral compaction stage was undertaken by the picture‐frame test. A unit cell of weave prepreg was modelled and three moments were assumed in the unit cell: (i) the moment of shear force that picture frame applies on the unit cell; (ii) the friction moment at crossover of yarns; and (iii) the compaction moment between the yarns. Through moment balance, a relationship between the load and the shear rate was deduced. A plain sheet shearing film resin model was established to obtain the friction moment at crossover. To get the compaction moment, a constitutive equation of a single prepreged yarn was deduced and a transverse viscosity coefficient equation was given. Moreover, through an equivalent cross‐sectional area model, the lateral contact thickness between the yarns was obtained. The comparison between the experimental and theoretical results shows that the presented model can describe the shear behaviour of weave prepreg at lateral compaction stage well.
Duration of Untreated Psychosis, Referral Route, and Age of Onset in an Early Intervention in Psychosis Service and a Local CAMHS
Authors: Cratsley Kelso , Regan Judith , McAllister Victoria , Simic Mima , Aitchison Katherine J.
Published: August 2007

Background:  The aim of this study was to investigate associations between demographic and clinical variables and duration of untreated psychosis (DUP) in a sample of cases of psychosis across an adult early intervention in psychosis service and a child and adolescent community team.

Method:  Cross‐sectional baseline data for cases of psychosis across the two teams on the caseload at a given time point were collected, including age of onset, gender, ethnicity, referral route, and DUP.

Results:  The median DUP across the entire sample was 91 days, while those patients with initial treatment for psychosis from the child and adolescent team had a median DUP of 69 days. Using multiple linear regression, there were two variables that showed a significant association with DUP: referral route (p < .001), and age of onset, with earlier age of onset associated with shorter DUP (p = .015).

Conclusion:  These findings are discussed in relation to possible explanatory factors, with particular focus on service‐level variables and pathways to care. It is suggested that the involvement of child and adolescent teams is vital to the work of early intervention in psychosis services.
MANAGERIAL INCENTIVES AND THE USE OF FOREIGN‐EXCHANGE DERIVATIVES BY BANKS
Authors: Adkins Lee C. , Carter David A. , Simpson W. Gary
Published: August 2007

We examine the effect of managerial compensation and ownership on the use of foreign‐exchange derivatives by U.S. bank holding companies. We focus on derivatives used for purposes other than trading to investigate derivative use in a hedging framework. We use instrumental variables probit and sample‐selection models to estimate the effects of endogenous and exogenous factors on the probability and extent of foreign‐exchange derivatives used. We find that the use of derivatives is inversely related to option awards but positively related to managerial ownership. Finally, our results suggest that ownership by large institutional shareholders provides incentive for managers to hedge.
Geometric consistency and stability of consumer‐grade digital cameras for accurate spatial measurement
Authors: Wackrow Rene , Chandler Jim H. , Bryan Paul
Published: August 2007

It is known that uncertain internal geometry of consumer‐grade digital cameras limits the accuracy of data that can be extracted. These cameras can be calibrated, but the validity of calibration data over a period of time should be carefully assessed before subsequent photogrammetric measurement. This paper examines the geometric stability and manufacturing consistency of a typical low‐cost digital camera (Nikon Coolpix 5400) by estimating the degree of similarity between interior orientation parameters (IOP), established over a 1‐year period. Digital elevation models (DEMs) were extracted with differing IOP, and accuracies were compared using data obtained from seven identical cameras. An independent self‐calibrating bundle adjustment (GAP) and the Leica Photogrammetry Suite (LPS) software were used to provide these data‐sets. Results are presented that indicate the potential of these cameras to maintain their internal geometry in terms of temporal stability and manufacturing consistency. This study also identifies residual systematic error surfaces or ‘‘domes’’, discernible in ‘‘DEMs of difference’’. These are caused by slightly inaccurately estimated lens distortion parameters, which effectively constrain the accuracies achievable with this class of sensor.
Bronchiolitis Obliterans: A Rare Chronic Pulmonary Complication Associated with Stevens‐Johnson Syndrome
Authors: Bakirtas Arzu , Harmanci Koray , Toyran Muge , Razi Cem Hasan , Turktas Ipek
Published: August 2007

Abstract:  Pulmonary manifestations are well recognized during the acute phase of Stevens‐Johnson syndrome but persistent pulmonary sequela is rarely reported. We report two boys with bronchiolitis obliterans following the acute phase of Stevens‐Johnson syndrome and discuss the clinical picture and treatment of persistent pulmonary complications with reference to earlier reports.
Cranial Fasciitis in an 8‐Year‐Old Boy: Clinical and Histopathologic Features
Authors: Yébenes Mireia , Gilaberte Montserrat , Romaní Jorge , Lloreta Josep , Pujol Ramon M.
Published: August 2007

Abstract: Cranial fasciitis is an uncommon benign disorder characterized by a fibroblast‐like cell proliferation, observed almost exclusively in children. Clinically, it manifests as a rapidly growing, solitary nodule in the head or neck area. Underlying bone involvement (cranial cortical erosion) is frequently detected. Histopathologic analysis allows differentiation between cranial fasciitis and fibrohistiocytic or even sarcomatous lesions observed in children. Cranial fasciitis is considered to be a reactive, non‐neoplastic disorder and is usually cured by a simple excision. An increased awareness of the clinical and histopathologic characteristics of this entity seems important to establish the diagnosis, to adopt an adequate, conservative treatment and to avoid unnecessarily aggressive procedures.
Winnie the Pooh and Psoriasis Too: An Isomorphic Response of Guttate Psoriasis in a Tattoo
Authors: Horner Kyle L. , Chien Andy J. , Edenholm Monica , Hornung Robin L.
Published: August 2007

Abstract:  Since Koebner's first observance of the isomorphic response of psoriasis in a tattoo in 1872, a paucity of written reports has appeared in the literature describing this phenomenon, although it appears to be common knowledge among dermatologists. We report a strep‐induced guttate psoriasis isomorphic response in a Winnie the Pooh tattoo in a 19‐year‐old.
Uncombable Hair Syndrome, Mental Retardation, Single Palmar Crease and Arched Palate in a Patient with Neurofibromatosis Type I
Authors: Schena Donatella , Germi Lerica , Zamperetti Maria Rosa , Darra Francesca , Giacopuzzi Silvia , Girolomoni Giampiero
Published: August 2007

Abstract:  A 2‐year‐old girl presented with hair that naturally stood out from her scalp. Her mother reported that the girl's hair had been impossible to comb since the first month of life. The child's eyebrows and lashes were normal. Scanning electron microscopy confirmed the presence of grooving on the hair shaft. Moreover, eight cafè‐au‐lait macules larger than 5 mm on the trunk and the limbs, and freckles in the axillary regions were observed. Neurologic examination showed some difficulties in motor organization and dyslalia. Magnetic resonance imaging illustrated multiple cerebral hamartomas. Molecular analysis disclosed microdeletion of gene 17q.11.2. Additional features included arched palate, a single palmar crease on one hand and low‐set ears, which, together with bone abnormalities, have been previously associated with uncombable hair. This is the first report, to the best of our knowledge, of uncombable hair syndrome in a patient with neurofibromatosis type I.
Atrichia with Papular Lesions Resulting from Novel Compound Heterozygous Mutations in the Human Hairless Gene
Authors: Michailidis Eleni , Theos Amy , Zlotogorski Abraham , Martinez‐Mir Amalia , Christiano Angela M.
Published: August 2007

Abstract:  Atrichia with papular lesions is a rare form of complete, irreversible alopecia that is inherited in an autosomal recessive manner. Several studies have implicated mutations in the human hairless gene as the underlying cause of this disorder. We describe two novel heterozygous mutations in exons 3 and 8 of the hairless gene in a 2‐year‐old Caucasian boy with complete alopecia of his scalp. These novel mutations add to the growing literature of mutations in the hairless gene found in nonconsanguineous families and expands the allelic series of mutations in this gene.
Plaque‐like Myofibroblastic Tumor of Infancy
Authors: Clarke Jennie T. , Clarke Loren E. , Miller Christopher , Helm Klaus F. , Zaenglein Andrea L.
Published: August 2007

Abstract:  Fibrohistiocytic neoplasms are relatively uncommon in infancy and childhood. We report an unusual spindle cell tumor occurring in two infants within the first 3 months of life. These tumors histologically resembled dermatofibromas, but the young age of onset, large size, and plaque‐like morphology were distinctly different from those of dermatofibromas. The features of these neoplasms are discussed and the differential of other spindle cell tumors of infancy is reviewed.
The Science of Sex Differences in Science and Mathematics
Authors: Halpern Diane F. , Benbow Camilla P. , Geary David C. , Gur Ruben C. , Hyde Janet Shibley , Gernsbacher Morton Ann
Published: August 2007

Amid ongoing public speculation about the reasons for sex differences in careers in science and mathematics, we present a consensus statement that is based on the best available scientific evidence. Sex differences in science and math achievement and ability are smaller for the mid-range of the abilities distribution than they are for those with the highest levels of achievement and ability. Males are more variable on most measures of quantitative and visuospatial ability, which necessarily results in more males at both high- and low-ability extremes; the reasons why males are often more variable remain elusive. Successful careers in math and science require many types of cognitive abilities. Females tend to excel in verbal abilities, with large differences between females and males found when assessments include writing samples. High-level achievement in science and math requires the ability to communicate effectively and comprehend abstract ideas, so the female advantage in writing should be helpful in all academic domains. Males outperform females on most measures of visuospatial abilities, which have been implicated as contributing to sex differences on standardized exams in mathematics and science. An evolutionary account of sex differences in mathematics and science supports the conclusion that, although sex differences in math and science performance have not directly evolved, they could be indirectly related to differences in interests and specific brain and cognitive systems. We review the brain basis for sex differences in science and mathematics, describe consistent effects, and identify numerous possible correlates. Experience alters brain structures and functioning, so causal statements about brain differences and success in math and science are circular. A wide range of sociocultural forces contribute to sex differences in mathematics and science achievement and ability—including the effects of family, neighborhood, peer, and school influences; training and experience; and cultural practices. We conclude that early experience, biological factors, educational policy, and cultural context affect the number of women and men who pursue advanced study in science and math and that these effects add and interact in complex ways. There are no single or simple answers to the complex questions about sex differences in science and mathematics.
Temporal Vulnerability of Fetal Cerebellar Purkinje Cells to Chronic Binge Alcohol Exposure: Ovine Model
Authors: Ramadoss Jayanth , Lunde Emilie R. , Chen Wei‐Jung A. , West James R. , Cudd Timothy A.
Published: August 2007

Background:  Human magnetic resonance imaging (MRI) and autopsy studies reveal abnormal cerebellar development in children who had been exposed to alcohol prenatally, independent of the exposure period. Animal studies conducted utilizing the rat model similarly demonstrate a broad period of vulnerability, albeit the third trimester‐equivalent of human brain development is reported to be the most vulnerable period, and the first trimester‐equivalent exposure produces cerebellar Purkinje cell loss only at high doses of alcohol. However, in the rat model, all 3 trimester‐equivalents do not occur prenatally, requiring the assumption that intrauterine environment, placenta, maternal interactions, and parturition do not play an important role in mediating the damage. In this study, we utilized the ovine model, where all 3 trimester‐equivalents occur in utero, to determine the critical window of vulnerability of fetal cerebellar Purkinje cells.

Methods:  Four groups of pregnant sheep were used: first trimester‐equivalent pair‐fed saline control group, first trimester‐equivalent alcohol group (1.75 g/kg), third trimester‐equivalent pair‐fed saline control group, and third trimester‐equivalent alcohol group (1.75 g/kg). The alcohol exposure regimen was designed to mimic a human binge pattern. Alcohol was administered intravenously on 3 consecutive days beginning on day 4 and day 109 of gestation in the first and third trimester‐equivalent groups, respectively, and the alcohol treatment was followed by a 4‐day inter‐treatment interval when the animals were not exposed to alcohol. Such treatment episodes were replicated until gestational day 41 and 132 in the first and third trimester‐equivalent groups, respectively. All fetal brains were harvested on day 133 and processed for stereological cerebellar Purkinje cell counting.

Results:  Significant deficits were found in the fetal cerebellar Purkinje cell number and density in the first and third trimester‐equivalent alcohol exposed fetuses compared with those in the saline controls. However, there was no difference between the first and third trimester‐equivalent alcohol administered groups. When comparing the present findings to those from a previous study where the duration of alcohol exposure was all 3 trimester‐equivalents of gestation, we did not detect a difference in fetal cerebellar Purkinje cell number.

Conclusions:  We conclude that the fetal cerebellar Purkinje cells are sensitive to alcohol exposure at any time during gestation and that women who engage in binge drinking during the first trimester are at a high risk of giving birth to children with cerebellar damage even if drinking ceases after the first trimester. Our findings also support the hypothesis that only a certain population of Purkinje cells are vulnerable to alcohol‐induced depletion irrespective of the timing or duration of alcohol exposure.
In Vitro Validation of a Technique for Assessment of Canine and Feline Elbow Joint Collateral Ligament Integrity and Description of a New Method for Collateral Ligament Prosthetic Replacement
Authors: FARRELL MICHAEL , DRAFFAN DAVINIA , GEMMILL TOBY , MELLOR DOMINIC , CARMICHAEL STUART
Published: August 2007

Objective—To assess the ability of an operator to differentiate intact from transected canine and feline elbow joint collateral ligaments (CL) using a reported manipulative test (Campbell's test) and to determine the potential for elbow joint luxation in canine and feline elbows with intact, transected, and surgically stabilized CL.

Study Design—In vitro biomechanical study.

Sample Population—Canine (n=6) and feline cadavers (n=3).

Methods—Thoracic limb specimens were mounted on a custom‐built jig with the elbows and carpi fixed in 90° of flexion. Angles of pronation and supination were recorded after applying rotational forces to the manus. Attempts were made to manually luxate each elbow with intact CL. Constructs were re‐evaluated after sequential sectioning of the medial (MCL) and lateral (LCL) collateral ligaments and after insertion of a new CL prosthesis.

Results—Mean (±SD) angles of rotation in dogs increased from 27.3±8° (range, 16.7–41.3°) in pronation to 58.9±9.2° (range, 38–88.3°) after sectioning the MCL and from 45.5±10.8° (range, 30.7–67.3°) in supination to 68.9±17.2° (range, 45–94°) after sectioning the LCL. Angles of pronation and supination were subject to significant interanimal variability, with a strong correlation between increasing animal weight and smaller angles of rotation. Elbow luxation in dogs was not possible unless at least the LCL was transected. In cats, mean angles of rotation increased from 49.8±14.9° (range, 30.7–70°) in pronation to 99.1±17.6° (range, 79–111.7°) after sectioning the MCL and from 128.7±18.8° (range, 108.3–151.7°) in supination to 166.7±13.1° (range, 157.3–181.7°) after sectioning the LCL. Luxation in cats was not possible unless both CL were cut. Use of the ligament prosthesis without primary CL repair reliably prevented reluxation in all canine and feline elbows.

Conclusions—Campbell's test allowed reliable differentiation of intact, transected and surgically stabilized canine and feline elbow joint CL in a cadaveric model. Luxation could not be performed by application of rotational forces to specimens with intact CL.

Clinical Relevance—Clinical examination findings, specifically Campbell's test, can be used to determine elbow CL integrity in dogs and cats. The contralateral elbow should be used as a control, because of interanimal variability in angles of rotation.
Laparoscopic Hernioplasty in Recumbent Horses Using Transposition of a Peritoneal Flap
Authors: ROSSIGNOL FABRICE , PERRIN ROLAND , BOENING K. JOSEF
Published: August 2007

Objective—To evaluate the efficacy of a laparoscopic peritoneal flap hernioplasty (PFH) to close anatomically the vaginal ring and to evaluate its protective effect in horses with a history of strangulated inguinal hernia (SIH) against future herniation.

Study Design—Prospective study.

Animals—A first group of 5 ponies, 3 horses and 1 donkey with no history of SIH and a second group of 4 horses ‘clinical cases’ with a history of SIH.

Methods—A laparoscopic PFH was effected on all horses under general anaesthesia. Peritoneum ventro‐lateral to the vaginal ring was elevated and cut on 3 sides, separated from the underlying muscle, then inverted and attached dorso‐medially and laterally to the parietal wall using intra‐corporeal stitches (6 cases) or laparoscopic staples (7 cases). Animals of the first group (n=9) underwent a standing laparoscopy 7 days post‐operatively to visualize the vaginal rings. Horses of the second group were followed to confirm the absence of re‐herniation.

Results—The laparoscopic check‐up showed that the vaginal ring had been effectively and completely covered in all cases except the first one. No adhesions was observed. In the four clinical cases, none of the horses have had a reccurence of SIH at the time of writing (6 months to 4 years).

Conclusion—Laparoscopic hernioplasty on a recumbent horse is feasible by closing the vaginal ring with a peritoneal flap. This technique was efficient in our cases to prevent recurrence of SIH but more cases are needed. This technique may reduce inflammation and irritation of the spermatic cord, which could otherwise jeopardise the animal's breeding career.

Clinical Relevance—Laparoscopic PFH coud be used in horses with a history of SIH.
Left‐ and Right‐Sided Laparoscopic‐Assisted Nephrectomy in Standing Horses with Unilateral Renal Disease
Authors: RÖCKEN MICHAEL , MOSEL GESINE , STEHLE CHRISTIANE , RASS JULIA , LITZKE LUTZ F.
Published: August 2007

Objective—To describe a technique for, and outcome after, left‐ or right‐sided laparoscopic‐assisted nephrectomy in standing horses with unilateral renal disease.

Study Design—Clinical report.

Animals—Horses (n=3) with unilateral renal disease.

Methods—Horses were sedated with detomidine (0.01 mg/kg intravenously [IV]) and levomethadone (0.05 mg/kg IV). Paravertebral anesthesia and infiltration‐anesthesia with 2% lidocaine were used to create a surgical field incorporating the 17th intercostal space and paralumbar fossa. Two separate, ipsilateral portals and a mini‐laparotomy were used. The perirenal peritoneum was horizontally incised (10–15 cm) using endoscissors and the incision digitally enlarged for manual dissection of the perirenal fat and kidney mobilization. The renal vessels and ureter were individually dissected, ligated, and transected under laparoscopic observation and the kidney removed. The perirenal and laparotomy peritoneal defects were not closed; and the laparotomy was closed in a multilayered fashion. The transverse abdominal muscle was apposed in a continuous pattern using 1 polyglactin 910, the subcutaneous tissue (simple continuous pattern) and skin (simple interrupted pattern) with 2–0 polyglactin 910.

Results—Left (2) and right (1) sided laparoscopic‐assisted nephrectomy (1 nephrolithiasis, 2 hydronephrosis) was performed successfully. Sedation and local anesthesia was adequate for intraoperative immobilization and analgesia. No intraoperative complications occurred. Incisional seroma formation and fever occurred on days 3 and 4 in 1 horse and resolved with medical management.

Conclusion—Laparoscopic‐assisted nephrectomy can be used for removal of the left or right kidney in standing horses with unilateral kidney disease.

Clinical Relevance—To avoid risks associated with general anesthesia and to reduce surgical trauma, laparoscopic‐assisted nephrectomy can be performed in the standing sedated horse using a 2 portal technique and a mini‐laparotomy.
Use of a Latissimus Dorsi Myocutaneous Flap for One‐Stage Reconstruction of the Thoracic Wall After En bloc Resection of Primary Rib Chondrosarcoma in Five Dogs
Authors: HALFACREE ZOE J. , BAINES STEPHEN J. , LIPSCOMB VICTORIA J. , GRIERSON JAMES , SUMMERS BRIAN A. , BROCKMAN DANIEL J.
Published: August 2007

Objective—To describe a thoracic wall reconstructive technique using a latissimus dorsi myocutaneous flap after en bloc resection of primary rib chondrosarcoma and report outcome in 5 dogs.

Study Design—Retrospective study.

Animals—Dogs (n=5) with primary rib chondrosarcoma.

Methods—Medical records (2003–2005) were reviewed for signalment, staging investigations, surgical findings, complications, and outcomes. Owners and veterinary surgeons were contacted for outcome information.

Results—A latissimus dorsi myocutaneous flap provided an air‐tight thoracic wall closure after chondrosarcoma resection. Paradoxical respiratory movement of the flap occurred; however, from physical examination and blood gas analysis (2 dogs), ventilation was adequate. All flaps survived, 1 had superficial skin necrosis distally and 2 had minor wound dehiscence. One dog without tumor‐free margins died of tumor‐related disease 56 days after surgery. Tumor recurrence did not occur in 4 dogs with tumor‐free margins. One dog was euthanatized 10 months after surgery for unrelated disease; 3 dogs were alive at writing (median follow‐up: 20 months; range, 18–27 months) and all had a satisfactory functional and cosmetic outcome.

Conclusions—Reconstruction of ventral thoracic wall defects using a latissimus dorsi myocutaneous flap yields a functional, cosmetic outcome.

Clinical Relevance—A latissimus dorsi myocutaneous flap can be used as a successful 1‐stage reconstructive technique for ventral thoracic wall defects.
Culture‐based bacterial detection systems for platelets: the effect of time prior to sampling and duration of incubation required for detection with aerobic culture
Authors: Ezuki Shoji , Kawabata Kinuyo , Kanno Takahiro , Ohto Hitoshi
Published: August 2007

BACKGROUND: Bacterial contamination of platelet (PLT) products occurs at low concentrations requiring a period of incubation for growth to minimize sampling error. Culture‐based detection methods also need sufficient incubation time; together these periods may limit the useful life of PLTs. This study characterizes the impact of sampling and detection times with two commercially available bacteria detection products.

STUDY DESIGN AND METHODS: Apheresis PLTs inoculated with nine bacterial species at low concentrations were sampled immediately and 24 hours after inoculation. Test results were analyzed after incubation at 16, 20, and 24 hours after sampling with two bacterial detection systems.

RESULTS: When sampled immediately after inoculation, two commercially available bacterial detection systems (BacT/ALERT, bioMérieux; and eBDS, Pall Corp.) failed to detect some PLTs inoculated with Staphylococcus epidermidis, Serratia liquefaciens, or Pseudomonas aeruginosa and S. epidermidis, S. liquefaciens, Bacillus cereus, or P. aeruginosa, respectively. The BacT/ALERT was better at 20 hours (p  < 0.02), but not at 16 or 24 hours for Time 0 sampling. When sampling occurred 24 hours after inoculation, there were no difference between the two systems.

CONCLUSION: Results suggest that for either bacteria detection system, holding PLTs for 24 hours before sampling improves the detection sensitivity for PLTs contaminated with low concentrations of bacteria, and longer incubation periods improve detection.
Echocardiographic Parameters in Athlete and Nonathlete Offspring of Hypertensive Parents
Authors: Horváth Patrícia , Kneffel Z.S. , Lénárd Zsuzsanna , Kispéter Z.S. , Petrekanits M. , Pavlik G.
Published: August 2007

Background: According to several reports, some cardiovascular signs of hypertension (left ventricular [LV] hypertrophy, impaired diastolic filling) can be found in the normotensive offspring of hypertensive parents. It is also well known that regular physical exercise decreases the risk of hypertension. Aim: The aim of the present study is to determine whether or not regular physical training influences these early hypertensive traits in the offspring of hypertensive parents. Methods: Echocardiographic data of 215 (144 males, 71 females) 22‐ to 35‐year‐old nonathlete and athlete offspring of hypertensive (positive family history, FH+) and normotensive parents (negative family history, FH–) were compared in a cross‐sectional design. Results: In the nonathlete FH+ males and females, LV dimensions were not larger than in the FH– subjects. The E/A quotient was lower in the FH+ subjects in both genders. Absolute and heart rate adjusted isovolumetric relaxation times were slightly longer in the FH+ men than in their FH– peers. No differences were seen between athlete FH– and FH+ subjects. Conclusion: Regular physical exercise decreases the incidence of the adverse cardiac signs, which can be associated with hypertension in the normotensive offspring of hypertensive parents.
Interobserver and Intraobserver Variability of Flow‐Mediated Vasodilatation of the Brachial Artery
Authors: Simova Iana , Nossikoff Alexander , Denchev Stefan
Published: August 2007

Flow‐mediated endothelial‐dependent vasodilatation (FMD) of the brachial artery is a method capable of detecting endothelial dysfunction. In order to implement this method in future clinical research studies, its reproducibility and precision have to be assessed. The aim of the study is to evaluate the inter‐ and intraobserver variability of FMD performed in our department. We investigate 40 patients. FMD is measured by two independent observers to test the interobserver variability, and repeated by the first observer to test the intraobserver variability. We compare the baseline and post‐ischemic diameter of the brachial artery and the percent dilatation. The correlation coefficients for these comparisons are high (>0.92) with a significance of less than 0.001. The inter‐ and intraobserver variability is further tested comparing the mean values of the baseline and post ischemic diameter of the brachial artery and the percent dilatation. The absolute values of the mean paired differences and the standard deviations (SDs) of the differences are 0.02850 ± 0.05942, P = 0.004, 0.01175 ± 0.08177, P = 0.369 and 0.28375 ± 1.61561, P = 0.273, respectively for the interobserver variability and 0.00475 ± 0.04663, P = 0.523, 0.00050 ± 0.05267, P = 0.952 and 0.15725 ± 1.19922, P = 0.412, respectively for the intraobserver variability. It can be concluded that the inter‐ and intraobserver variability for FMD performed in our department is acceptable. FMD can be performed precisely and accurately, with a satisfactory reproducibility and can be safely and reliably implemented in future clinical research studies.
Statistical Analysis of Environmental Space‐Time Processes edited by N. D. Le and J. V. Zidek
Authors: Wakefield Jon
Published: August 2007

Statistical Analysis of Environmental Space‐Time Processes

(N. D. Le and J. V. Zidek)       Jon Wakefield

Computer‐Intensive Methods of Data Analysis in Biology

(D. A. Roff)       A. W. Kemp

Randomization, Bootstrap, and Monte Carlo Methods in Biology (3rd Edition)

(B. F. J. Manly)       A. W. Kemp

Applied Mixed Models in Medicine, 2nd edition

(H. Brown and R. Prescott)       Matthew J. Gurka

Stochastic Modeling for Systems Biology

(D. J. Wilkinson)       Olaf Wolkenhauer

Knowledge Discovery in Proteomics

(I. Jurisica and D. Wigle)       Zhen Zhang

Computational Genome Analysis: An Introduction

(R. C. Deonier, S. Tavaré, and        M. S. Waterman)       Marc Suling

Stochastic Orders

(M. Shaked and J. G. Shantikumar)       Subhash Kochar

Brief Reports by the Editor

Measurement Error in Nonlinear Models: A Modern Perspective, 2nd edition

(R. J. Carroll, D. Ruppert, L. A. Stefansky, and C. M. Crainiceanu)

Basic Statistics and Pharmaceutical Statistical Applications, 2nd edition

(J. E. De Muth)

A Handbook of Statistical Analyses Using Stata, 4th edition

(S. Rabe‐Hesketh and B. S. Everitt)

Introduction to Randomized Controlled Clinical Trials, 2nd edition

(J. N. S. Matthews)

Survival and Event History Analysis

(P. K. Andersen and N. Keiding, editors)

A Pocket Guide to Epidemiology

(D. G. Kleinbaum, K. M. Sullivan, and N. D. Barker)
Estimating the Intensity of a Spatial Point Process from Locations Coarsened by Incomplete Geocoding
Authors: Zimmerman Dale L.
Published: August 2007

SummaryThe estimation of spatial intensity is an important inference problem in spatial epidemiologic studies. A standard data assimilation component of these studies is the assignment of a geocode, that is, point‐level spatial coordinates, to the address of each subject in the study population. Unfortunately, when geocoding is performed by the standard automated method of street‐segment matching to a georeferenced road file and subsequent interpolation, it is rarely completely successful. Typically, 10–30% of the addresses in the study population, and even higher percentages in particular subgroups, fail to geocode, potentially leading to a selection bias, called geographic bias, and an inefficient analysis. Missing‐data methods could be considered for analyzing such data; however, because there is almost always some geographic information coarser than a point (e.g., a Zip code) observed for the addresses that fail to geocode, a coarsened‐data analysis is more appropriate. This article develops methodology for estimating spatial intensity from coarsened geocoded data. Both nonparametric (kernel smoothing) and likelihood‐based estimation procedures are considered. Substantial improvements in the estimation quality of coarsened‐data analyses relative to analyses of only the observations that geocode are demonstrated via simulation and an example from a rural health study in Iowa.
Regression Analysis of a Disease Onset Distribution Using Diagnosis Data
Authors: Young Jessica G. , Jewell Nicholas P. , Samuels Steven J.
Published: August 2007

SummaryWe consider methods for estimating the effect of a covariate on a disease onset distribution when the observed data structure consists of right‐censored data on diagnosis times and current status data on onset times amongst individuals who have not yet been diagnosed.Dunson and Baird(2001,Biometrics57,306–403) approached this problem using maximum likelihood, under the assumption that the ratio of the diagnosis and onset distributions is monotonic nondecreasing. As an alternative, we propose a two‐step estimator, an extension of the approach ofvan der Laan, Jewell, and Petersen(1997,Biometrika84,539–554) in the single sample setting, which is computationally much simpler and requires no assumptions on this ratio. A simulation study is performed comparing estimates obtained from these two approaches, as well as that from a standard current status analysis that ignores diagnosis data. Results indicate that the Dunson and Baird estimator outperforms the two‐step estimator when the monotonicity assumption holds, but the reverse is true when the assumption fails. The simple current status estimator loses only a small amount of precision in comparison to the two‐step procedure but requires monitoring time information for all individuals. In the data that motivated this work, a study of uterine fibroids and chemical exposure to dioxin, the monotonicity assumption is seen to fail. Here, the two‐step and current status estimators both show no significant association between the level of dioxin exposure and the hazard for onset of uterine fibroids; the two‐step estimator of the relative hazard associated with increasing levels of exposure has the least estimated variance amongst the three estimators considered.
Modeling Unobserved Sources of Heterogeneity in Animal Abundance Using a Dirichlet Process Prior
Authors: Dorazio Robert M. , Mukherjee Bhramar , Zhang Li , Ghosh Malay , Jelks Howard L. , Jordan Frank
Published: August 2007

Summary In surveys of natural populations of animals, a sampling protocol is often spatially replicated to collect a representative sample of the population. In these surveys, differences in abundance of animals among sample locations may induce spatial heterogeneity in the counts associated with a particular sampling protocol. For some species, the sources of heterogeneity in abundance may be unknown or unmeasurable, leading one to specify the variation in abundance among sample locations stochastically. However, choosing a parametric model for the distribution of unmeasured heterogeneity is potentially subject to error and can have profound effects on predictions of abundance at unsampled locations. In this article, we develop an alternative approach wherein a Dirichlet process prior is assumed for the distribution of latent abundances. This approach allows for uncertainty in model specification and for natural clustering in the distribution of abundances in a data‐adaptive way. We apply this approach in an analysis of counts based on removal samples of an endangered fish species, the Okaloosa darter. Results of our data analysis and simulation studies suggest that our implementation of the Dirichlet process prior has several attractive features not shared by conventional, fully parametric alternatives.
Dynamic Comparison of Kaplan–Meier Proportions: Monitoring a Randomized Clinical Trial with a Long‐Term Binary Endpoint
Authors: Brittain Erica , Follmann Dean , Yang Song
Published: August 2007

Summary The approach to early termination for efficacy in a trial where events occur over time but the primary question of interest relates to a long‐term binary endpoint is not straightforward. This article considers comparison of treatment groups with Kaplan–Meier (KM) proportions evaluated at increasing times from randomization, at increasing calendar testing times. This strategy is employed to improve the ability to detect important treatment effects and provide critical treatments to patients in a timely manner. This dynamic Kaplan–Meier (DKM) approach is shown to be robust; that is, it produces high power and early termination time across a wide range of circumstances. In contrast, a fixed time KM comparison and the log‐rank test are both shown to be more variable in performance. Practical considerations of implementing the DKM method are discussed.
Sample Size Calculations Based on Ranking and Selection in Microarray Experiments
Authors: Matsui Shigeyuki , Zeng Shu , Yamanaka Takeharu , Shaughnessy John
Published: August 2007

Summary We develop formulae to calculate sample sizes for ranking and selection of differentially expressed genes among different clinical subtypes or prognostic classes of disease in genome‐wide screening studies with microarrays. The formulae aim to control the probability that a selected subset of genes with fixed size contains enough truly top‐ranking informative genes, which can be assessed on the basis of the distribution of ordered statistics from independent genes. We provide strategies for conservative designs to cope with issues of unknown number of informative genes and unknown correlation structure across genes. Application of the formulae to a clinical study for multiple myeloma is given.
Doubly Penalized Buckley–James Method for Survival Data with High‐Dimensional Covariates
Authors: Wang Sijian , Nan Bin , Zhu Ji , Beer David G.
Published: August 2007

SummaryRecent interest in cancer research focuses on predicting patients' survival by investigating gene expression profiles based on microarray analysis. We propose a doubly penalized Buckley–James method for the semiparametric accelerated failure time model to relate high‐dimensional genomic data to censored survival outcomes, which uses the elastic‐net penalty that is a mixture ofL1‐ andL2‐norm penalties. Similar to the elastic‐net method for a linear regression model with uncensored data, the proposed method performs automatic gene selection and parameter estimation, where highly correlated genes are able to be selected (or removed) together. The two‐dimensional tuning parameter is determined by generalized crossvalidation. The proposed method is evaluated by simulations and applied to the Michigan squamous cell lung carcinoma study.
Pollution, Politics, and Preferences for Environmental Spending in the States
Authors: Newmark Adam J. , Witko Christopher
Published: August 2007

While state environmental and natural resource spending is designed to address actual environmental problems, the budget process is also inherently political. Thus, in the following article we ask a simple question: to what extent does state environmental and natural resource spending respond to the scope of environmental problems in a state, versus the demands of the political process? Unlike the bulk of previous research, we consider both aggregate spending and program‐specific spending. We also consider how the severity of environmental problems and the political environment may interact to determine spending. The findings show that politics, specifically the strength of the environmental movement, is a more important determinant of state environmental spending than pollution severity. However, for some program areas, it appears that strong environmental groups make state budgets more responsive to the severity of environmental problems.
International Organizations ICTs Policies: E‐Democracy and E‐Government for Political Development
Authors: Amoretti Francesco
Published: August 2007

New technologies provide new channels of access to political information and participation in decision‐making processes. This assumption is clearly important in the action plans and policies of International Organizations (World Bank, Organisation for Economic Co‐operation and Development, United Nations), which have assumed a leadership role in the reform of political institutions. Starting from an analysis of the reasons that have brought the state and processes of institution building back into focus, this paper will reconstruct the International Organizations' vision of the transformative potential of new information technologies and their activity in this field. Particular attention will be devoted to e‐democracy and e‐government as policies to build democracy in developing countries.
Toward Developing a Structured Approach to the Diagnosis and Resolution of Nonperforming Loans: The Case of China and India1
Authors: Istrate Emilia , Das Gupta Debasree , Weissburg Paul
Published: August 2007

This article addresses the issue of nonperforming loans (NPLs) from a public policy perspective. The focus is on three aspects of NPLs that we consider essential for a proper analysis: the degree of the NPL problem, the causes of NPLs and the solutions adopted to address an identified NPL issue. This research analyses the diverse definitions and measurements of an NPL. Further, it introduces the distinction between systemic and situational causes of NPLs. Arguing that different causes require different cures, this study emphasizes a mix of short‐term and long‐term remedial measures as judicious in dealing with the NPL problem. This framework is then applied to two case studies: China and India. The conclusion identifies future directions of research, such as the study of a threshold level beyond which NPLs may pose a barrier to a country's growth and productivity.
Fabrication of Gradient Pore TiO2 Sheets by a Novel Freeze–Tape‐Casting Process
Authors: Ren Linlin , Zeng Yu‐Ping , Jiang Dongliang
Published: August 2007

Gradient pore structure TiO2 sheets were fabricated by a novel freeze–tape‐casting process. Aqueous TiO2 ceramic slurries were prepared by the traditional tape‐casting processing and were then cast onto an aluminum foil carrier. The slurries were immediately frozen on the substrate, whose temperature was about −18°C. After freezing completely, the green sheets were then dried in a lyophilizer. Freeze–tape casting led to formation of a gradient pore microstructure of the TiO2 sheet. The results showed that the solid loading of slurry considerably affected the pore microstructure, pore morphology, and the porosity. Solid loadings of 10, 20, 30, 40, and 50 wt% slurries were used, respectively, and the gradient pore structure TiO2 sheets with different porosities of 75%–88% were obtained.
Porous Pb(Zr0.95Ti0.05)O3 Ceramics from Chemically Prepared Powders Without Pore Formers
Authors: Qiu Shaojun , Fan Huiqing , Yang Chen , Chen Jin
Published: August 2007

Porous Zr‐rich lead zirconate titanate (PZT 95/5) ceramics having 77.9–92.2% of relative densities were prepared without additional pore formers. PZT 95/5 powders were obtained by a one‐step pyrolysis process at 450°C for 10 h using the Pechini method. Although the X‐ray diffractometry results showed an incomplete perovskite phase for the powders, phase‐pure PZT 95/5 ceramics could be obtained after sintering at 1100°–1150°C for 2 h. The density and diameter variations of the PZT 95/5 ceramics as a function of sintering temperature were investigated.
Microstructural Characterization and Role of Glassy Layer Developed on Inconel 690 During a Nuclear High‐Level Waste Vitrification Process
Authors: Sengupta Pranesh , Kaushik Chetan P. , Mishra Raman K. , Kale Gajanan B.
Published: August 2007

The interaction of Inconel 690 metallic components with borosilicate melt leads to development of a partially amorphous and a partially crystalline layer within borosilicate melt adjacent to the interface. Such a heterogeneous layer is referred to here as a glassy layer. In the present investigation, the glassy layer is constituted of several phases, e.g. a Cr2O3 layer, a Ni2CrO4 needle, and NiCr2O4 cubic phases. Incorporation of such a glassy layer within the melt pool can lead to significant microstructural changes in the melt. Formation of barium chromate and nickel silicate has been observed in a sodium barium borosilicate melt with excess amount of Cr2O3 and NiO, respectively.