bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of poly(ester ether siloxane)s
Authors: Vuckovic Marija V , Antic Vesna V , Dojcinovic Biljana P , Govedarica Milutin N , Djonlagic Jasna
Published: June 2006

A series of novel thermoplastic elastomers based on ABA‐type triblock prepolymers, poly[(propylene oxide)–(dimethylsiloxane)–(propylene oxide)] (PPO‐PDMS‐PPO), as the soft segments, and poly(butylene terephthalate) (PBT), as the hard segments, was synthesized by catalyzed two‐step melt transesterification of dimethyl terephthalate (DMT) with 1,4‐butanediol (BD) and α,ω‐dihydroxy‐(PPO‐PDMS‐PPO) (M̄n = 2930 g mol−1). Several copolymers with a content of hard PBT segments between 40 and 60 mass% and a constant length of the soft PPO‐PDMS‐PPO segments were prepared. The siloxane‐containing triblock prepolymer with hydrophilic terminal PPO blocks was used to improve the compatibility between the polar comonomers, i.e. DMT and BD, and the non‐polar PDMS segments. The structure and composition of the copolymers were examined using 1H NMR spectroscopy, while the effectiveness of the incorporation of α,ω‐dihydroxy‐(PPO‐PDMS‐PPO) prepolymer into the copolyester chains was controlled by chloroform extraction. The effect of the structure and composition of the copolymers on the transition temperatures (Tm and Tg) and the thermal and thermo‐oxidative degradation stability, as well as on the degree of crystallinity, and some rheological properties, were studied. Copyright © 2006 Society of Chemical Industry
Synthesis of amphiphilic copolymer brushes: Poly(ethylene oxide)‐graft‐polystyrene
Authors: Li Zhongyu , Li Pengpeng , Huang Junlian
Published: June 2006

A well‐defined amphiphilic copolymer brush with poly(ethylene oxide) as the main chain and polystyrene as the side chain was successfully prepared by a combination of anionic polymerization and atom transfer radical polymerization (ATRP). The glycidol was first protected by ethyl vinyl ether to form 2,3‐epoxypropyl‐1‐ethoxyethyl ether and then copolymerized with ethylene oxide by the initiation of a mixture of diphenylmethylpotassium and triethylene glycol to give the well‐defined polymer poly(ethylene oxide‐co‐2,3‐epoxypropyl‐1‐ethoxyethyl ether); the latter was hydrolyzed under acidic conditions, and then the recovered copolymer of ethylene oxide and glycidol {poly(ethylene oxide‐co‐glycidol) [poly(EO‐co‐Gly)]} with multiple pending hydroxymethyl groups was esterified with 2‐bromoisobutyryl bromide to produce the macro‐ATRP initiator [poly(EO‐co‐Gly)(ATRP). The latter was used to initiate the polymerization of styrene to form the amphiphilic copolymer brushes. The object products and intermediates were characterized with 1H NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, Fourier transform infrared, and size exclusion chromatography in detail. In all cases, the molecular weight distribution of the copolymer brushes was rather narrow (weight‐average molecular weight/number‐average molecular weight < 1.2), and the linear dependence of ln[M0]/[M] (where [M0] is the initial monomer concentration and [M] is the monomer concentration at a certain time) on time demonstrated that the styrene polymerization was well controlled. This method has universal significance for the preparation of copolymer brushes with hydrophilic poly(ethylene oxide) as the main chain. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4361–4371, 2006
A novel method for the pore size control of the battery separator using the phase instability of the ternary mixtures
Authors: Kim L. U. , Kim C. K.
Published: June 2006

The battery separator plays a key role in determining the capacity of the battery. Since separator performance mainly depends on the pore size of membrane, development of a technique for the fabrication of the membrane having controlled pore size is essential in producing a highly functional battery separator. In this study, microporous membranes having the desired pore size were produced via thermally‐induced phase separation (TIPS) process. Control of the phase boundaries of polymer‐diluent blends is the main concern in manipulating pore size in TIPS process, because pore size mainly depends on the temperature gap between phase separation temperature of the blend and the crystallization temperature of polymer. Microporous membranes having controlled pore size were produced from polyethylene (PE)/dioctyl phthalate (DOP) blends, PE/isoparaffin blends, and polymer/diluent‐mixture ternary blends, that is, PE/(DOP/isoparaffin) blends. PE/DOP binary blends and PE/(DOP/isoparaffin) ternary blends exhibited typical upper critical solution temperature (UCST) type phase behavior, while PE formed a homogeneous mixture with isoparaffin above the crystallization temperature of PE. When the mixing ratio of polymer and diluent‐mixture was fixed, the phase separation temperature of PE/diluent‐mixture blend first increased with increasing DOP content in the diluent‐mixture, went through a maximum centered at about 80 wt % DOP and then decreased. Furthermore, the phase separation temperatures of the PE/diluent‐mixture blends were always higher than that of the PE/DOP blend when diluent‐mixture contained more than or equal to 20 wt % of DOP. Average pore size of microporous membrane prepared from PE/DOP blend and that prepared from PE/isoparaffin blend were 0.17 and 0.07 μm, respectively. However, average pore size of microporous membrane prepared from ternary blends was varied from 0.07 to 0.5 μm by controlling diluent mixing ratio. To understand the phase behavior of ternary blend, phase instability of the ternary mixture was also explored. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2025–2034, 2006
Measuring instructional congruence in elementary science classrooms: Pedagogical and methodological components of a theoretical framework
Authors: Luykx Aurolyn , Lee Okhee
Published: June 2006

This article is situated within a theoretical framework,instructional congruence, articulating issues of student diversity with the demands of academic disciplines. In the context of a large‐scale study targeting elementary school science, the article describes a research instrument that aims to combine the strengths of both quantitative and qualitative approaches to classroom data. The project‐developedclassroom observation guidelineis a series of detailed scales that produce numerical ratings based on qualitative observations of different aspects of classroom practice. The article's objectives are both pedagogical and methodological, reflecting the dual functionality of the instrument: (a) to concretize theoretical constructs articulating academic disciplines with student diversity in ways that are useful for rethinking classroom practice; and (b) to take advantage of the strengths of qualitative educational research, but within a quantitative analytical framework that may be applied across large numbers of classrooms. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 424–447, 2007
Sensitivity and Specificity of Intraoperative Recurrent Laryngeal Nerve Stimulation Test for Predicting Vocal Cord Palsy after Thyroid Surgery
Authors: Tomoda Chisato , Hirokawa Yoshihiro , Uruno Takashi , Takamura Yuuki , Ito Yasuhiro , Miya Akihiro , Kobayashi Kaoru , Matsuzuka Fumio , Kuma Kanji , Miyauchi Akira
Published: June 2006

INTRODUCTION

Recurrent laryngeal nerve (RLN) palsy after thyroidectomy, although infrequently encountered, can decrease quality of life. In addition to the hoarseness that occurs with unilateral RLN palsy, bilateral RLN palsy leads to dyspnea and often to life‐threatening glottal obstruction. Therefore, intraoperative awareness of the nerve’s status is of great importance. This study examined the sensitivity and specificity of a palpation technique to detect contraction of the posterior cricoarytenoid muscle (PCA) through the posterior hypopharyngeal wall while the RLN was being stimulated with a disposable nerve stimulator during thyroid surgery (the laryngeal palpation test) to predict postoperative RLN deficits.

Methods

A total of 2197 RLNs in 1376 patients were identified to be at risk of injury during thyroidectomy performed between July 2003 and August 2004. Postoperative RLN integrity was assessed using direct laryngoscopy or laryngofiberoscopy to visualize vocal fold mobility.

Results

Altogether, 76 RLNs failed to elicit a PCA contraction in response to nerve stimulation, and 80 cases of temporary vocal cord palsy and 21 cases of permanent vocal cord palsy were recognized on postoperative evaluation. For postoperative vocal cord palsy, the sensitivity and specificity of the laryngeal palpation test were 69.3% and 99.7%, respectively, with a positive predictive value of 92.1% and negative predictive value of 98.5%. For permanent vocal cord palsy, the sensitivity and specificity were 85.7% and 97.3%, respectively, with a positive predictive value of 23.7% and negative predictive value of 99.8%.

Conclusions

The laryngeal palpation test is not a particularly useful method for predicting the level of RLN function after thyroidectomy. All patients must be examined postoperatively by direct laryngoscopy or laryngofiberoscopy to check vocal cord mobility. Even if there is no contraction of the PCA and we detect vocal cord palsy immediately after surgery, vocal cord palsy often recovers within 1 year when visual preservation of RLN is successful.
Value of Water‐soluble Contrast (Meglumine Amidotrizoate) in the Diagnosis and Management of Small Bowel Obstruction
Authors: Salamah Saleh Moh’d Al , Fahim Fraz , Mirza Shaukat Mahmood
Published: June 2006

Introduction

The object of the present study was to determine the effectiveness of a water‐soluble contrast follow‐through study for differentiating complete from incomplete small bowel obstruction (SBO) and for predicting the need for surgery.

Methods

This prospective study was conducted at Riyadh Medical Complex, Saudi Arabia and spanned 2 years. All adult patients admitted with SBO were included, except those with obstructed hernias, peritonitis, or postabdominal irradiation. The initial resuscitation meglumine amidotrizoate (Gastrografin) follow‐though was performed and was considered positive for complete obstruction if the contrast failed to reach the colon as shown on the 24‐hour film. Patients were operated on only if they developed signs of strangulation or failed to improve within 48 hours.

Results

Our study group consisted of 73 patients, 48 (65.7%) of whom were male. The mean age was 35.70 ± 12.65 years. In 60 (82.2%) patients, contrast reached the ascending colon within 24 hours, giving a definitive diagnosis of incomplete obstruction; among these 60 cases, 49 (81.7%) resolved on conservative management. The other 13 (17.8%) patients were diagnosed as having a complete obstruction; 4 (30.8%) of them were treated conservatively, and 9 (69.2%) underwent surgery. Therefore the sensitivity, specificity, positive predictive value, and negative predictive value for meglumine amidotrizoate follow‐through as an indicator for operative treatment of SBO were 45.0, 92.5, 81.7, and 69.2, respectively. The P value using Fisher’s exact test was 0.0006.

Conclusions

We can confidently diagnose complete and incomplete SBO and differentiate one from the other. This accurate diagnosis indicates a high chance of success with conservative management for incomplete obstruction but does not always correlate with the need for surgical intervention.
Rectal Stenosis after Procedures for Prolapse and Hemorrhoids (PPH)—A Report from China
Authors: Yao Liqin , Zhong Yunshi , Xu Jianmin , Xu Meidong , Zhou Pinghong
Published: June 2006

Objectives

After it was introduced in China in 2000, the surgical procedure for prolapse and hemorrhoids (PPH) has become a widely accepted for third‐ and fourth‐degree hemorrhoids. Stenosis of the lower rectum is one of the delayed complications. In order to evaluate this specific problem following PPH, we reviewed our data with special reference to potential predictive factors or stenotic events.

Methods

A retrospective analysis of 554 consecutive patients that underwent PPH from July 2000 to December 2004 was performed. Only patients with follow‐up check were evaluated; therefore 65 patients (11.7%) Hwere lost to follow‐up, and the analysis therefore includes 489 patients with a mean follow‐up of 324 days (± 18 days). For statistical analysis, the groups with and without stenosis were evaluated using the chi‐square test; using the Kaplan‐Meier statistic, the actuarial incidence for rectal stenosis was plotted.

Results

Rectal stenosis was observed in 12 patients (2.5%) in whom the median time to stenosis was 125 (89 ∼ 134) days. All patients complained of obstructive defecation and underwent strictureplasty with electrocautery or balloon dilation through colonoscopy. A statistical analysis revealed that two factors were significantly more prevalent among patients with stenosis: prior sclerosis therapy for hemorrhoids (P = 0.02) and severe postoperative pain (P = 0.003). Other factors, such as gender (P = 0.32), prior surgery for hemorrhoids (P = 0.11), histological evidence of squamous skin (P = 0.77) or revision (P = 0.53) showed no significance.

Conclusions

Rectal stenosis is an uncommon event after PPH. Early stenosis will occur within the first 4 months after surgery. In most cases, the stenosis can be cured through colonoscopy surgery. Predictive factors for stenosis are previous sclerosis therapy for hemorrhoids and severe postoperative pain.
Predictive Factors of Malignancy in Adults with Intussusception
Authors: Goh Brian K.P. , Quah Hak‐Mien , Chow Pierce K.H. , Tan Kok‐Yang , Tay Khoon‐Hean , Eu Kong‐Weng , Ooi London L.P.J. , Wong Wai‐Keong
Published: June 2006

Introduction

Adult intussusception is an unusual entity, and its etiology differs from that in pediatric patients. The aim of this study was to evaluate our experience of 60 adult patients with intussusception and determine if there are any preoperative factors predictive of malignancy.

Methods

The records of 60 adult patients (> 18 years of age) with a diagnosis of intussusception surgically treated at Singapore General Hospital and Changi General Hospital between 1990 and 2004 were retrospectively reviewed. The intussusceptions were classified as enteric or colonic. Preoperative predictive factors of malignancy were analyzed using univariate and multivariate analyses, and P < 0.05 was considered statistically significant.

Results

There were 60 patients with a median age of 57.5 years (range 21–85 years). Altogether, 34 (56.7%) patients were male, and there were 31 enteric and 29 colonic intussusceptions. A lead point was identified in 54 patients (90%). A total of 22 (36.7%) patients presented with intestinal obstruction, and the correct preoperative diagnosis of intussusception was made in 31 patients (51.7%). Computed tomography was the most useful diagnostic modality, correctly identifying an intussusception in 24 of 30 patients. A malignant pathology was present in 8 of 31 (26%) enteric versus 20 of 29 (69%) colonic intussusceptions. Age (P = 0.009), the presence of anemia (P < 0.001), and the site of the intussusception (P = 0.001) showed significant differences between the benign and malignant groups by univariate analyses. On multivariate analysis, intussusception in the colon (P = 0.004) and the presence of anemia (P = 0.001) were independent predictive factors of malignancy.

Conclusions

Adult intussusception is most commonly secondary to a pathologic lead point. The site of intussusception in the colon and the presence of anemia are independent preoperative predictors of malignancy. All colonic intussusceptions should be resected en bloc without reduction, whereas a more selective approach can be applied for enteric intussusceptions.
Major Vascular Resection and Prosthetic Replacement for Retroperitoneal Tumors
Authors: Fueglistaler Philipp , Gurke Lorenz , Stierli Peter , Obeid Tamim , Koella Christoph , Oertli Daniel , Kettelhack Christoph
Published: June 2006

Introduction

Involvement of major vascular structures has been considered a limiting factor for resecting advanced tumors. The objective of this study was to evaluate the outcome after concomitant retroperitoneal tumor and vascular resection with prosthetic replacement of the aorta/vena cava.

Methods

The authors reviewed a 5‐year series of eight patients with a median age of 50 years (range 11–68 years) who had undergone resection of a retroperitoneal tumor and concomitant resection and replacement of the abdominal aorta, inferior vena cava, or both. The histologic diagnoses were sarcoma (five patients), teratoma (one), transitional cell carcinoma (one), and ganglioneuroma (one). The main outcome measures were early (< 30 days) and late (≥ 30 days) surgical morbidity and mortality. Secondary endpoints were vascular graft patency and tumor‐free survival. Two patients underwent combined graft replacement of the aorta and vena cava. Single aortic and vena cava graft replacement were each done in three patients.

Results

Two patients showed early surgical morbidity necessitating reoperation for a thrombotic graft occlusion. No patient died during the early course of the follow‐up. During a median follow‐up of 14 months (range 1–56 months), two patients had late surgical morbidity. The median tumor‐free survival for patients with malignancy was 14 months (range 1–54 months). One patient developed locoregional tumor recurrence, and two developed distant metastases. The median survival for patients with malignancy was 14 months (range 1–60 months).

Conclusions

An aggressive surgical approach for otherwise unresectable retroperitoneal tumors with vascular resection and prosthetic vascular replacement is justified in selected cases and has acceptable morbidity and mortality.
Pancreatic Serous Oligocystic Adenomas: Clinicopathologic Features and a Comparison with Serous Microcystic Adenomas and Mucinous Cystic Neoplasms
Authors: Goh Brian K.P. , Tan Yu‐Meng , Yap Wai‐Ming , Cheow Peng‐Chung , Chow Pierce K.H. , Chung Yaw‐Fui Alexander , Wong Wai‐Keong , Ooi London L.P.J.
Published: June 2006

Introduction

The preoperative distinction between serous cystic neoplasms (SCNs) and mucinous cystic neoplasms (MCNs) is essential, as all MCNs are considered malignant or potentially malignant and should be surgically resected, whereas SCNs are almost always benign. However, the radiologic distinction between SCNs and MCNs is frequently difficult especially with serous oligocystic adenoma (SOA), a morphologic variant of SCN, as both SOA and MCN appear on cross‐sectional imaging as a solitary macrocystic lesion in the pancreas. We reviewed all SOAs managed at our institution to determine if any clinicopathologic features would prove useful for establishing a preoperative diagnosis.

Methods

Over a 15‐year period, 64 patients with a pathologically confirmed diagnosis of a pancreatic cystadenoma or cystadenocarcinoma treated at Singapore General Hospital were retrospectively reviewed. There were 27 MCNs and 37 SCNs including 12 SOAs. In addition, 40 cases of SOA previously reported in the literature were reviewed and analyzed together with the 12 patients, making this a series of 52 SOAs.

Results

In our experience, SOAs comprised 32.4% of the SCNs, and females predominated (7/12). The median age of the patients was 42.5 years (range 22–74 years), and only 4 of the 12 patients were symptomatic. Most of the cysts were located in the body or tail of the pancreas (9/12), and the median cyst size was 52.5 mm (range 10–190 mm). When the clinicopathologic features of SOAs and serous microcystic adenomas (SMAs) were compared, there was no difference between the patients with SOAs and SMAs in terms of age, sex, presence of symptoms, cyst size, or site of the lesion. However, SOAs occurred in the women less frequently (67.3% vs. 96.3%, P = 0.004), were smaller [40 mm (range 10–190 mm) vs. 95 mm (range 25–180 mm), P < 0.001], and occurred more commonly in the head of the pancreas [25 (48.1%) vs. 2(7.4%)] compared to MCNs. None of the SOAs were frankly malignant compared to the 29.6% of MCNs that were.

Conclusions

SOAs and SMAs have similar clinicopathologic features. On the other hand, SOAs differ from MCNs by their relatively higher male/female ratio, higher frequency of tumors occurring in the head of the pancreas, and smaller cyst size. Knowledge of these distinguishing clinical features when used in combination with other diagnostic modalities such as endoscopic ultrasonography/fine‐needle aspiration will enable clinicians to better differentiate these two pathologic entities preoperatively.
Molecular mechanism of ‘mitocan’‐induced apoptosis in cancer cells epitomizes the multiple roles of reactive oxygen species and Bcl‐2 family proteins
Authors: Neuzil Jiri , Wang Xiu-Fang , Dong Lan-Feng , Low Pauline , Ralph Stephen J.
Published: June 2006

Mitochondria have emerged recently as effective targets for novel anti‐cancer drugs referred to as ‘mitocans’. We propose that the molecular mechanism of induction of apoptosis by mitocans, as exemplified by the drug α‐tocopheryl succinate, involves generation of reactive oxygen species (ROS). ROS then mediate the formation of disufide bridges between cytosolic Bax monomers, resulting in the formation of mitochondrial outer membrane channels. ROS also cause oxidation of cardiolipin, triggering the release of cytochrome c and its translocation via the activated Bax channels. This model may provide a general mechanism for the action of inducers of apoptosis and anticancer drugs, mitocans, targeting mitochondria via ROS production.
A novel nuclear‐localized protein with special adenylate kinase properties from Caenorhabditis elegans
Authors: Zhai Ruitong , Meng Geng , Zhao Yanmei , Liu Bin , Zhang Genfa , Zheng Xiaofeng
Published: June 2006

The adrenal gland protein AD‐004 like protein (ADLP) from Caenorhabditis elegans was cloned and expressed in Escherichia coli. Enzyme assays showed that ADLP has special adenylate kinase (AK) properties, with ATP and dATP as the preferred phosphate donors. In contrast to all other AK isoforms, AMP and dAMP were the preferred substrates of ADLP; CMP, TMP and shikimate acid were also good substrates. Subcellular localization studies showed a predominant nuclear localization for this protein, which is different from AK1–AK5, but similar to that of human AK6. These results suggest that ADLP is more likely a member of the AK6 family. Furthermore, RNAi experiments targeting ADLP were conducted and showed that RNAi treatment resulted in the suppression of worm growth.
Acute oxidative stress is associated with cell proliferation in the mouse liver
Authors: Dragin Nadine , Smani Moneïm , Arnaud-Dabernat Sandrine , Dubost Clément , Moranvillier Isabelle , Costet Pierre , Daniel Jean-Yves , Peuchant Evelyne
Published: June 2006

Oxidative stress is known to produce tissue injury and to activate various signaling pathways. To investigate the molecular events linked to acute oxidative stress in mouse liver, we injected a toxic dose of paraquat. Liver necrosis was first observed, followed by histological marks of cell proliferation. Concomitantly, activation of the MAP kinase pathway and increased levels of the anti‐apoptotic protein Bcl‐XLwere observed. Gene expression profiles revealed that the differentially expressed genes were potentially involved in cell proliferation. These data suggest that paraquat‐induced acute oxidative stress triggers the activation of regeneration‐related events in the liver.
Branchio‐oto‐renal syndrome associated mutations in Eyes Absent 1 result in loss of phosphatase activity
Authors: Rayapureddi Jayanagendra P. , Hegde Rashmi S.
Published: June 2006

The Eyes Absent (Eya) proteins are tyrosine phosphatases and transcriptional activators involved in cell‐fate determination and organ development. Mutations in the gene encoding Eya homologue 1 have been implicated in the multi‐organ developmental disorder branchio‐oto‐renal syndrome (BOR) and in ocular defects. Here we report that BOR‐associated mutations lead to a loss of phosphatase activity in Eya1 proteins, while mutations associated with ocular defects yield Eya1 proteins with near normal levels of phosphatase activity. Furthermore we demonstrate that the N‐terminal domain attenuates the catalytic activity of Eya suggesting a mechanism of regulation.
Vaginal delivery and serum markers of ischemia/reperfusion injury
Authors: Conner E. , Margulies R. , Liu Mengling , Smilen S.W. , Porges R.F. , Kwon C.
Published: June 2006

Objective: Vaginal deliveries have been associated with pelvic organ prolapse and incontinence. The objective was to show whether markers of ischemia/reperfusion injury are dependent upon the mode of delivery and length of labor. Method: Complete venipuncture sets were obtained on 62 subjects. All samples collected were analyzed for serum creatine phosphokinase (CPK) and lactate dehydrogenase (LDH). Lipid peroxidation was analyzed, using thiobarbituric acid reactive substances (TBARS), on a subset of 37 patients. Results: There was a significant increase in CPK from admission to 1 h postpartum and postpartum day 1 in vaginal delivery versus cesarean delivery. Longer second stages were associated with significant increases in CPK. There were no significant changes in either LDH or TBARS from admission to any other time point regardless of mode of delivery. Conclusion: Vaginal delivery and longer second stages were associated with a much greater increase in one of these injury markers.
Global endometrial ablation: A modern day solution to an age‐old problem
Authors: Morgan H. , Advincula A.P.
Published: June 2006

Menorrhagia remains a significant health issue for women worldwide. Traditionally hysterectomy has been the treatment of choice when excessive menstrual bleeding remains unresolved by hormonal manipulation. In an attempt to provide a less invasive alternative to hysterectomy, traditional techniques such as rollerball endometrial ablation were developed 20 years ago. Although extremely effective, they possessed the potential of significant intra‐operative risks and their success depended on high technical proficiency of the surgeon. As surgery and technology evolved, second generation endometrial ablation devices were developed which demonstrated improved safety and efficacy rates that paralleled traditional treatments. Since 1997, the Food and Drug Administration (FDA) has approved five such devices for use in the United States. Each possesses a unique technology profile with supporting level I evidence that allows for the treatment of a wide variety of uterine anatomy.
Percutaneous Fixation of Mallet Fractures By the “Umbrella Handle” Technique
Authors: ROCCHI L. , GENITIEMPO M. , FANFANI F.
Published: June 2006

Over a period of 8 years, 48 fingers with mallet fractures of Wehbé and Schneider Types 1 and 2, subtypes B and C, were treated in 31 men and 17 women of mean age 42 (range 17–61) years. The fractures included 5 Type 1 subtype B, 2 Type 1 subtype C, 23 Type 2 subtype B and 18 Type 2 subtype C fractures. The technique used consisted in passing a K-wire percutaneously from dorsal to volar and pinning the fracture fragment while leaving the distal interphalangeal joint free to allow immediate postoperative mobilisation. Fracture splintage was removed at 6 weeks. The results at 8 weeks, which remained unchanged at 12 months in 46 fingers, were assessed as excellent in 11, good in 35 and fair in two cases by the Crawford rating system. One case of pin track infection required early removal of the pin.
Displaced Fracture of the Neck of the Radius with Complete 180° Rotation of the Radial Head during Closed Reduction
Authors: NAVALI A. M. , SADIGI A.
Published: June 2006

We report a case of fracture of the radial neck in a teenage girl in which 180° rotation of the radial head occurred at close reduction. Although this was corrected, avascular necrosis of the radial head occurred. To our knowledge only four cases of such iatrogenic malpositioning have been described in the literature.
The evolution of a management philosophy: The theory of constraints
Authors: Watson Kevin J. , Blackstone John H. , Gardiner Stanley C.
Published: June 2006

In 2004, the Theory of Constraints celebrated its Silver Anniversary. In twenty‐five years, what started out as a scheduling software has evolved into a management philosophy with practices and principles spanning a multitude of operations management subdisciplines. As the Theory of Constraints has grown, so has its acceptance by both practitioners and academicians. At this point in its development, as it transitions from niche to mainstream, it is important to review what has been accomplished and what deficiencies remain so that both the promise and problems impeding greater acceptance can be examined. To that end, we review the evolution of principal TOC concepts and practices in an objective fashion.
Psychological barriers in gold prices?
Authors: Aggarwal Raj , Lucey Brian M.
Published: June 2006

This paper examines for the first time the existence of psychological barriers in a variety of daily and intra‐day gold price series. This paper uses a number of statistical procedures and presents evidence of psychological barriers in gold prices. We document that prices in round numbers act as barriers with important effects on the conditional mean and variance of the gold price series around psychological barriers.
Speleology and magnetobiostratigraphic chronology of the Buffalo Cave fossil site, Makapansgat, South Africa
Authors: Herries Andy I.R. , Reed Kaye E. , Kuykendall Kevin L. , Latham Alf G.
Published: June 2006

Speleological, stratigraphic, paleomagnetic and faunal data is presented for the Buffalo Cave fossil site in the Limpopo Province of South Africa. Speleothems and clastic deposits were sampled for paleomagnetic and mineral magnetic analysis from the northern part of the site, where stratigraphic relationships could be more easily defined and a magnetostratigraphy could therefore be developed for the site. This is also where excavations recovered the fossil material described. A comparison of the east and South African first and last appearance data with the Buffalo Cave fauna was then used to constrain the magnetostratigraphy to produce a more secure age for the site. The magnetostratigraphy showed a change from normal to reversed polarity in the basal speleothems followed by a short normal polarity period in the base of the clastic deposits and a slow change to reversed directions for the remainder of the sequence. The biochronology suggested an optimal age range of between 1.0 Ma and 600,000 yr based on faunal correlation with eastern and southern Africa. A comparison of the magnetobiostratigraphy with the GPTS suggests that the sequence covers the time period from the Olduvai event between 1.95 and 1.78 Ma, through the Jaramillo event at 1.07 Ma to 990,000 yr, until the Bruhnes–Matuyama boundary at 780,000 yr. The faunal-bearing clastic deposits are thus dated between 1.07 Ma and 780,000 yr with the main faunal remains occurring in sediments dated to just after the end of the Jaramillo Event at 990,000 yr.
Early African hyaenodontid mammals and their bearing on the origin of the Creodonta
Authors: GHEERBRANT EMMANUEL , IAROCHENE MOHAMED , AMAGHZAZ MBAREK , BOUYA BAÂDI
Published: June 2006

We report a new proviverrine hyaenodontid creodont mammal, Boualitomus marocanensis, n.g., n.sp., from the earliest Eocene of Morocco, and provide new comments on Tinerhodon from the late Paleocene of Morocco. Aside from the autapomorphic loss of P/1, Boualitomus is characterized by a primitive morphology (e.g. M/3 subequal to M/2, short molar trigonid, narrow talonid, metaconid comparable to paraconid) which resembles most closely the proviverrine Prototomus. Boualitomus is more primitive than Prototomus, especially in its small size and the talonid of P/4 not being fully simplified, bearing at least two accessory cusps including a bulbous protostylid. These primitive features are remarkably reminiscent of Tinerhodon. The morphological relationship of Boualitomus and Tinerhodon supports the proviverrine affinity of the latter. Significant basal hyaenodontid synapomorphies of Boualitomus and Tinerhodon are the paraconid and paracristid development in M/1–3, anterior premolar morphology and occurrence of diastemata. Boualitomus and Tinerhodon throw new light upon the question of the origin of the Creodonta. Tinerhodon further fills the structural gap between Hyaenodontidae and primitive insectivore-like eutherians, and it provides additional data for the hypothesis of a didelphodontan origin for the Creodonta. The presence of cimolestids (as the stem-group of hyaenodontids) in the late Paleocene of Morocco, and the identification of Boualitomus and Tinerhodon as the most primitive and earliest known Hyaenodontidae, support an African origin of the family and its order.
Geochemical characteristics of the Cretaceous ophiolitic rocks of Ikaria island, Greece
Authors: PE-PIPER GEORGIA , PHOTIADES ADONIS
Published: June 2006

Scattered occurrences of ophiolitic rocks are widespread in the Cyclades islands of Greece and are important for understanding the later Mesozoic ocean spreading and collisional history of the region, which has been obscured by Cenozoic nappe stacking, metamorphism, plutonism and extension. Ophiolitic rocks in the Upper Tectonic Unit of Ikaria are preserved in a mélange underlying Triassic limestones in the Kefala Unit and in a coarse-grained conglomerate at Faros directly overlying the mid-crustal detachment fault. The geochemistry of these rocks has been determined, their mineralogy investigated by electron microprobe, and K–Ar radiometric dating was carried out. Sole rocks are amphibolite of alkaline basalt protolith. Most ophiolitic samples from Ikaria consist of hornblende gabbro with MORB geochemistry that underwent sea-floor hydration, deformation and metamorphism. The large variation in degree of deformation, grade of metamorphism, and radiometric ages suggest syn-spreading extensional deformation at a slow-spreading ridge. The ophiolitic mélange on Ikaria, because it is unaffected by younger metamorphism, provides clear evidence for Late Cretaceous ocean-crust formation in the Cyclades region.
Dicentrodus (Chondrichthyes: Xenacanthida) from the Early Carboniferous (Visean: upper St Louis Formation) of Iowa, USA
Authors: HAMPE OLIVER , JOHNSON GARY D. , TURNER SUSAN
Published: June 2006

Dicentrodus possessed bicuspid teeth with a flat base and nonserrated or finely serrated, labio-lingually compressed, highly unequal cusps. Originally known from the late Visean–early Serpukhovian of Scotland (D. bicuspidatus), it is now known also to occur in the middle Visean of North America. This is the earliest occurrence of a xenacanthid yet reported from North America; its presence is based on incomplete teeth, which are easily distinguished from other xenacanthid genera. The cross-continental distribution of Dicentrodus, like that of other xenacanthid genera, can be explained by an increasing body of data that intimate that xenacanthids were euryhaline sharks and not restricted to a freshwater habitat.
Unidentified extracellular prokaryotes within the byssal threads of the deep-sea vent musselBathymodiolus azoricus
Authors: KÁDÁR E. , AZEVEDO C.
Published: June 2006

Bacterial symbiosis and/or parasitism is widespread in hydrothermal bivalves, and is typically developed in gills, with a lower incidence in mantle and digestive glands, while it has never been described in byssus. Using ultrastructural examination, we provide evidence for the existence of a potentially new group of filamentous prokaryotic organism inBathymodiolus azoricusbyssus, with putative parasitic influence. Additionally, a cystic, undefined organism was found with an unclear physiological role within the spongy net of the byssus plaque. Our results indicate that in spite of its antibacterial protective sheath, byssus gives access to prokaryotic organisms becoming prone to failure through damaged collagen fibres.
Weddell Sea iceberg drift: Five years of observations
Authors: Schodlok M. P. , Hellmer H. H. , Rohardt G. , Fahrbach E.
Published: June 2006

The drift of 52 icebergs tagged with GPS buoys in the Weddell Sea since 1999 has been investigated with respect to prevalent drift tracks, sea ice/iceberg interaction, and freshwater fluxes. Buoys were deployed on small‐ to medium‐sized icebergs (edge lengths ≤ 5 km) in the southwestern and eastern Weddell Sea. The basin‐scale iceberg drift of this size class was established. In the western Weddell Sea, icebergs followed a northward course with little deviation and mean daily drift rates up to 9.5 ± 7.3 km d−1. To the west of 40°W the drift of iceberg and sea ice was coherent. In the highly consolidated perennial sea ice cover of 95% the sea ice exerted a steering influence on the icebergs and was thus responsible for the coherence of the drift tracks. The northward drift of buoys to the east of 40°W was interrupted by large deviations due to the passage of low‐pressure systems. Mean daily drift rates in this area were 11.5 ± 7.2 km d−1. A lower threshold of 86% sea ice concentration for coherent sea ice/iceberg movement was determined by examining the sea ice concentration derived from Special Sensor Microwave Imager (SSM/I) and Advanced Microwave Scanning Radiometer for EOS (AMSR‐E) satellite data. The length scale of coherent movement was estimated to be at least 200 km, about half the value found for the Arctic Ocean but twice as large as previously suggested. The freshwater fluxes estimated from three iceberg export scenarios deduced from the iceberg drift pattern were highly variable. Assuming a transit time in the Weddell Sea of 1 year, the iceberg meltwater input of 31 Gt which is about a third of the basal meltwater input from the Filchner Ronne Ice Shelf but spreads across the entire Weddell Sea. Iceberg meltwater export of 14.2 × 103 m3 s−1, if all icebergs are exported, is in the lower range of freshwater export by sea ice.
Role of methane and biogenic volatile organic compound sources in late glacial and Holocene fluctuations of atmospheric methane concentrations
Authors: Kaplan Jed O. , Folberth Gerd , Hauglustaine Didier A.
Published: June 2006

Recent analyses of ice core methane concentrations suggested that methane emissions from wetlands were the primary driver for prehistoric changes in atmospheric methane. However, these interpretations conflict as to the location of wetlands, magnitude of emissions, and the environmental controls on methane oxidation. The flux of other reactive trace gases to the atmosphere also controls apparent atmospheric methane concentrations because these compounds compete for the hydroxyl radical (OH), which is the primary atmospheric sink for methane. In a series of linked biosphere‐atmosphere chemistry‐climate modeling experiments, we simulate the methane and biogenic volatile organic compound emissions from the terrestrial biosphere from the Last Glacial Maximum (LGM) to the present. Using a state‐of‐the‐art chemistry‐climate model, we simulate the atmospheric concentrations of methane, OH, and other reactive trace gas species. Over the past 21,000 years, methane emissions from wetlands increased slightly to the end of the Pleistocene but then decreased again, reaching levels at the preindustrial Holocene that were similar to the LGM. Global wetland area decreased by 14% from LGM to the preindustrial time. Emissions of biogenic volatile organic compounds (BVOCs), however, nearly doubled over the same period of time. Atmospheric OH burdens and methane concentrations were affected by this major change in BVOC emissions, with methane lifetimes increasing by more than 2 years from LGM to the present. We simulate a change in methane concentration of ∼385 ppb, accounting for 88% of the ∼440 ppb increase in methane concentrations observed in ice cores. Thus glacial‐interglacial changes in atmospheric methane concentrations would have been modulated by BVOC emissions. In addition, the increase in atmospheric methane concentrations since the mid‐Holocene is partly caused in our results by the increases in anthropogenic methane emissions over this period. While the interplay between BVOC and wetland methane emissions since the LGM cannot explain the entire record of ice core methane concentrations, consideration of BVOC source dynamics is central to understanding ice core methane. Rapid changes in atmospheric methane concentrations, also observed in ice cores, require further study.
Globalizing results from ocean in situ iron fertilization studies
Authors: Aumont O. , Bopp L.
Published: June 2006

Despite the growing number of in situ iron fertilization experiments, the efficiency of such fertilization to sequester atmospheric CO2 remains largely unknown. For the first time, a global ocean biogeochemical model has been evaluated against those experiments and then used to estimate the effect of a long‐term and large‐scale iron addition on atmospheric CO2. The model reproduces the observed timing and amplitude in chlorophyll, the shift in ecosystem composition, and the pCO2 drawdown; it also proves to be of utility in interpreting the observations. However, a full ocean fertilization during 100 years results in a 33 μatm decrease in atmospheric CO2, that is 2 to 3 times smaller than found previously.
Neogene overflow of Northern Component Water at the Greenland‐Scotland Ridge
Authors: Poore H. R. , Samworth R. , White N. J. , Jones S. M. , McCave I. N.
Published: June 2006

In the North Atlantic Ocean, flow of North Atlantic Deep Water (NADW), and of its ancient counterpart Northern Component Water (NCW), across the Greenland‐Scotland Ridge (GSR) is thought to have played an important role in ocean circulation. Over the last 60 Ma, the Iceland Plume has dynamically supported an area which encompasses the GSR. Consequently, bathymetry of the GSR has varied with time due to a combination of lithospheric plate cooling and fluctuations in the temperature and buoyancy within the underlying convecting mantle. Here, we reassess the importance of plate cooling and convective control on this northern gateway for NCW flow during the Neogene period, following Wright and Miller (1996). To tackle the problem, benthic foraminiferal isotope data sets have been assembled to examine δ13C gradients between the three major deep water masses (i.e., Northern Component Water, Southern Ocean Water, and Pacific Ocean Water). Composite records are reported on an astronomical timescale, and a nonparametric curve‐fitting technique is used to produce regional estimates of δ13C for each water mass. Confidence bands were calculated, and error propagation techniques used to estimate %NCW and its uncertainty. Despite obvious reservations about using long‐term variations of δ13C from disparate analyses and settings, and despite considerable uncertainties in our understanding of ancient oceanic transport pathways, the variation of NCW through time is consistent with independent estimates of the temporal variation of dynamical support associated with the Iceland Plume. Prior to 12 Ma, δ13C patterns overlap and %NCW cannot be isolated. Significant long‐period variations are evident, which are consistent with previously published work. From 12 Ma, when lithospheric cooling probably caused the GSR to submerge completely, long‐period δ13C patterns diverge significantly and allow reasonable %NCW estimates to be made. Our most robust result is a dramatic increase in NCW overflow between 6 and 2 Ma when dynamical support generated by the Iceland Plume was weakest. Between 6 and 12 Ma a series of variations in NCW overflow have been resolved.
Calcium adsorption and changes of the surface microtopography of cyanobacteria studied by AFM, CFM, and TEM with respect to biogenic calcite nucleation
Authors: Obst M. , Dittrich M. , Kuehn H.
Published: June 2006

We investigated calcium interactions with the surface of individual living cells of the freshwater cyanobacterium Synechococcus leopoliensis PCC 7942 under illumination and calcite supersaturation, with respect to calcium carbonate nucleation on the cell surface. Immobilized living cells were scanned by Atomic Force Microscopy (AFM) with conventional and chemically modified tips which were coated with carboxylic groups, so‐called Chemical Force Microscopy (CFM). Calcium adsorption was heterogeneous and altered the surface charge of the cells. This was confirmed by bulk measurements of the zeta‐potential at different Ca2+ concentrations and compared to measurements made with other bivalent cations (Mg2+, Sr2+, Ba2+). Zeta‐potential increased rapidly (<2 min) from −46.9 mV in calcium‐free solution to +0.8 mV in 22 mmol L−1 CaCl2 solution, using a 1.5 mmol L−1 NaHCO3 solution as background electrolyte in both cases. This was followed by the slow (several hours) formation of nonmineralized protuberances at the cell surface. These changes in the microtopography did not show obvious spatial relationship to surface charge or Ca2+ adsorption. The formation of the protuberances was reversible when Ca2+ was removed from the circumfluent solution. Ca2+ adsorption to the cell surface was faster than calcium‐induced changes in the surface microtopography and much faster than calcite nucleation on the cell surface which was observed on a fraction of the cells in previous bulk experiments under similar supersaturation.
Proposed model for Saturn's auroral response to the solar wind: Centrifugal instability model
Authors: Sittler E. C. , Blanc M. F. , Richardson J. D.
Published: June 2006

We present a model of Saturn's global auroral response to the solar wind as observed by simultaneous Hubble Space Telescope (HST) auroral images and Cassini upstream measurements of the solar wind taken during the month of January 2004. These observations show a direct correlation between solar wind dynamic pressure and (1) auroral brightening toward dawn local time, (2) an increase of rotational movement of auroral features to as much as 75% of the corotation speed, (3) the movement of the auroral oval to higher latitudes, and (4) an increase in the intensity of Saturn Kilometric Radiation (SKR). Our model, referred to as the centrifugal instability model, provides an alternative to the reconnection model of Cowley et al. (2004a, 2004b, 2005); we suggest the above observations result from Saturn's magnetosphere being a fast rotator. Since the torques on Saturn's outer magnetosphere are relatively low, its outer magnetosphere will tend to conserve angular momentum. When compressed on the dayside, the outer magnetosphere spins up to higher angular velocities, and when it expands, the outer magnetosphere spins down to lower angular velocities. This response occurs since Saturn's ionosphere is unable to enforce corotation. The outer boundary of the plasma sheet at L ∼ 15 is identified as the primary source location for the auroral precipitating particles. Enhanced wave activity, which can precipitate the auroral producing particles, may be present at this boundary. If radial transport is dominated by centrifugally driven flux tube interchange motions, when the magnetosphere spins up, outward transport will increase, and the precipitating particles will move radially outward (since the radial gradient in electron energy flux is negative). This mechanism will cause the auroral oval to move to higher latitudes as observed. The Kelvin‐Helmholtz instability may contribute to the enhanced emission along the dawn meridian, as observed by HST, via enhanced wave activity and corresponding charged particle precipitation.