bluuebunny/crossref_metadata_2025 huggingface dataset:
Introducing the First Management Control Systems: Evidence from the Retail Sector
Authors: Sandino Tatiana
Published: March 2008

Focusing on a sample of U.S. retailers, I study the management control systems (MCS) that firms introduce when they first invest in controls, and identify four categories of initial MCS, which are defined in terms of the purposes these MCS fulfill. The first category, “Basic MCS,” is adopted to collect information for planning, setting standards, and establishing the basic operations of the firm. The other three categories are contingent on more specific purposes: “Cost MCS” focus on enhancing operating efficiencies and minimizing costs; “Revenue MCS” are introduced to foster growth and be responsive to customers; and “Risk MCS” focus on reducing risks and protecting asset integrity. I hypothesize and find that the choice among these categories reflects the firms' strategy, and that firms that choose initial MCS better suited to their strategy perform better than others.
Earnings Management and Ownership Retention for Initial Public Offering Firms: Theory and Evidence
Authors: Fan Qintao
Published: March 2008

This paper investigates, both theoretically and empirically, how earnings management and ownership retention interact, and how these two jointly affect the equilibrium market valuation of IPO firms in the presence of information asymmetry. Analytically, this paper extends the univariate signaling framework of Leland and Pyle (1977) and derives an efficient signaling equilibrium in which both reported earnings and ownership retention are endogenously chosen to convey the IPO issuer's private information. It is shown that even though either ownership retention or reported earnings communicates the issuer's type to the market unambiguously, the issuer will strategically employ both signals to achieve separation from potential lower quality imitators at minimal cost. Comparative statics analysis shows that the trade-off between the two signals depends critically on the uncertainty over future earnings. The theoretical analysis generates several empirical implications regarding market efficiency, IPO pricing, and the strategic choice of earnings management. Through systematic econometric analysis, I confirm the major predictions of the model.
An Analysis of Forced Auditor Change: The Case of Former Arthur Andersen Clients
Authors: Blouin Jennifer , Grein Barbara Murray , Rountree Brian R.
Published: March 2008

This study examines former Arthur Andersen clients and provides evidence on the factors involved in their selection of new auditors after Andersen's collapse. Using a unique dataset that identifies whether former Andersen clients followed their audit team to a new auditor, findings reveal companies with greater agency concerns were more likely to sever ties with their former auditor, whereas those with greater switching costs were more likely to follow their former auditor. We also investigate the effect of the forced auditor change on financial statement quality in an effort to provide insight into the mandatory auditor rotation debate. Using performance-adjusted discretionary accruals as a proxy for reporting quality, our results fail to reveal significant improvements for companies with extreme discretionary accruals that severed ties with Andersen, which is inconsistent with the notion that mandatory rotation improves financial reporting.
The Effects of Contracting, Litigation, Regulation, and Tax Costs on Conditional and Unconditional Conservatism: Cross-Sectional Evidence at the Firm Level
Authors: Qiang Xinrong
Published: March 2008

Prior studies propose four explanations for accounting conservatism, and recent studies classify conservatism into two forms: conditional and unconditional conservatism. This paper examines whether each proposed explanation applies to conditional conservatism, unconditional conservatism, or both. The findings are as follows: (1) contracting induces conditional conservatism; (2) litigation induces both forms; (3) regulation induces unconditional conservatism; and (4) taxation induces unconditional conservatism. These findings indicate that the two forms of conservatism play distinct roles in contracting, regulation, and taxation, as well as a common role in litigation. They also play an interrelated role, as suggested by the finding that unconditional conservatism reduces conditional conservatism. The combined evidence implies that because the two forms meet distinct needs but are negatively interrelated, it is necessary to trade them off.
A Simulation Analysis of Interactions among Errors in Costing Systems
Authors: Labro Eva , Vanhoucke Mario
Published: March 2008

Cost accounting systems provide accurate costs only under stringent conditions. However, we know little about the nature, level, and bias of costing errors. This paper reports the results of a simulation study of two-stage cost allocation systems that provide the following main insights: (1) partial improvement in the costing system usually increases the overall accuracy of reported product costs except in specific cases identified in this paper where errors have an offsetting effect, most notably when there is aggregation error in the activity cost pools and measurement error in the resource drivers; (2) the impact of Stage II costing errors on overall accuracy is stronger than that of Stage I errors, so system refinements should focus on Stage II; and (3) the presence of aggregation and measurement errors usually results in relatively more products being under- than over-costed, with large amounts of over-costing for a few “big-ticket” (in dollar terms) products, and small amounts of under-costing for a larger number of less expensive products.
Corporate Governance, Accounting Outcomes, and Organizational Performance
Authors: Larcker David F. , Richardson Scott A. , Tuna I˙rem
Published: March 2008

The empirical research examining the association between typical measures of corporate governance and various accounting and economic outcomes has not produced a consistent set of results. We believe that these mixed results are partially attributable to the difficulty in generating reliable and valid measures for the complex construct that is termed “corporate governance.” Using a sample of 2,106 firms and 39 structural measures of corporate governance (e.g., board characteristics, stock ownership, institutional ownership, activist stock ownership, existence of debtholders, mix of executive compensation, and anti-takeover variables), our exploratory principal component analysis suggests that there are 14 dimensions to corporate governance. We find that these indices have a mixed association with abnormal accruals, little relation to accounting restatements, but some ability to explain future operating performance and future excess stock returns.
Accruals, Investment, and the Accrual Anomaly
Authors: Zhang X. Frank
Published: March 2008

This paper investigates two competing hypotheses for the accrual anomaly: investment/growth and persistence. Both investment/growth and persistence information in accruals are likely to vary cross-sectionally, depending on a firm's business model, a fact that generates different cross-sectional implications for the accrual anomaly. I find that the magnitude of the accrual anomaly monotonically increases with the investment information contained in accruals, as measured by the co-variation between accruals and employee growth. In industries/firms in which accruals co-vary with employee growth, accruals show strong predictive power for future stock returns. In industries/firms in which accruals show little correlations with employee growth, the accrual anomaly is much weaker. In contrast, the evidence from the cross-sectional analysis is inconsistent with the persistence argument. From the earnings perspective, the evidence on one-year-ahead earnings growth is inconclusive, but the results on longer-term earnings growth support the investment argument but not the persistence argument. Collectively, I conclude that these results support the view that the accrual anomaly is attributable to the fundamental investment information contained in accruals.
Long-Run Corporate Tax Avoidance
Authors: Dyreng Scott D. , Hanlon Michelle , Maydew Edward L.
Published: March 2008

We develop and describe a new measure of long-run corporate tax avoidance that is based on the ability to pay a low amount of cash taxes per dollar of pre-tax earnings over long time periods. We label this measure the “long-run cash effective tax rate.” We use the long-run cash effective tax rate to examine (1) the extent to which some firms are able to avoid taxes over periods as long as ten years, and (2) how predictive one-year tax rates are for long-run tax avoidance. In our sample of 2,077 firms, we find there is considerable cross-sectional variation in tax avoidance. For example, approximately one-fourth of our sample firms are able to maintain long-run cash effective tax rates below 20 percent, compared to a sample mean tax rate of approximately 30 percent. We also find that annual cash effective tax rates are not very good predictors of long-run cash effective tax rates and, thus, are not accurate proxies for long-run tax avoidance. While there is some evidence of persistence in annual cash effective tax rates, the persistence is asymmetric. Low annual cash effective tax rates are more persistent than are high annual cash effective tax rates. An initial examination of characteristics of firms successful at keeping their cash effective tax rates low over long periods shows that they are well spread across industries but with some clustering.
Adiponectin Reduces Plasma Triglyceride by Increasing VLDL Triglyceride Catabolism
Authors: Qiao Liping , Zou Chenhui , van der Westhuyzen Deneys R. , Shao Jianhua
Published: March 2008

OBJECTIVE—Adiponectin is an adipocyte-derived hormone that plays an important role in glucose and lipid metabolism. The main aims of this study are to investigate the effects of adiponectin on VLDL triglyceride (VLDL-TG) metabolism and the underlying mechanism.

RESEARCH DESIGN AND METHODS—Adenoviruses were used to generate a mouse model with elevated circulating adiponectin. HepG2 and C2C12 cells were treated with recombinant human adiponectin.

RESULTS—Three days after Ad-mACRP30 adenovirus injection, plasma adiponectin protein levels were increased 12-fold. All three main multimeric adiponectin molecules were proportionally elevated. Fasting plasma TG levels were significantly decreased (∼40%) in the mice with elevated adiponectin in circulation, as were the plasma levels of large and medium VLDL subclasses. Although apolipoprotein B mRNA levels were robustly suppressed in the livers of adiponectin-overexpressing mice and in cultured HepG2 cells treated with recombinant human adiponectin, hepatic VLDL-TG secretion rates were not altered by elevated plasma adiponectin. However, Ad-mACRP30–treated mice exhibited a significant increase of postheparin plasma lipoprotein lipase (LPL) activity compared with mice that received control viral vector. Skeletal muscle LPL activity and mRNA levels of LPL and VLDL receptor (VLDLr) were also increased in Ad-mACRP30–treated mice. Recombinant human adiponectin treatment increased LPL and VLDLr mRNA levels in differentiated C1C12 myotubes.

CONCLUSIONS—These results suggest that adiponectin decreases plasma TG levels by increasing skeletal muscle LPL and VLDLr expression and consequently VLDL-TG catabolism.
Fructose-1,6-Bisphosphatase Overexpression in Pancreatic β-Cells Results in Reduced Insulin Secretion
Authors: Kebede Melkam , Favaloro Jenny , Gunton Jenny E. , Laybutt D. Ross , Shaw Margaret , Wong Nicole , Fam Barbara C. , Aston-Mourney Kathryn , Rantzau Christian , Zulli Anthony , Proietto Joseph , Andrikopoulos Sofianos
Published: March 2008

OBJECTIVE—Fructose-1,6-bisphosphatase (FBPase) is a gluconeogenic enzyme that is upregulated in islets or pancreatic β-cell lines exposed to high fat. However, whether specific β-cell upregulation of FBPase can impair insulin secretory function is not known. The objective of this study therefore is to determine whether a specific increase in islet β-cell FBPase can result in reduced glucose-mediated insulin secretion.

RESEARCH DESIGN AND METHODS—To test this hypothesis, we have generated three transgenic mouse lines overexpressing the human FBPase (huFBPase) gene specifically in pancreatic islet β-cells. In addition, to investigate the biochemical mechanism by which elevated FBPase affects insulin secretion, we made two pancreatic β-cell lines (MIN6) stably overexpressing huFBPase.

RESULTS—FBPase transgenic mice showed reduced insulin secretion in response to an intravenous glucose bolus. Compared with the untransfected parental MIN6, FBPase-overexpressing cells showed a decreased cell proliferation rate and significantly depressed glucose-induced insulin secretion. These defects were associated with a decrease in the rate of glucose utilization, resulting in reduced cellular ATP levels.

CONCLUSIONS—Taken together, these results suggest that upregulation of FBPase in pancreatic islet β-cells, as occurs in states of lipid oversupply and type 2 diabetes, contributes to insulin secretory dysfunction.
Critical Roles for Macrophages in Islet Angiogenesis and Maintenance During Pancreatic Degeneration
Authors: Tessem Jeffery S. , Jensen Jan N. , Pelli Hanna , Dai Xu-Ming , Zong Xiao-Hua , Stanley E. Richard , Jensen Jan , DeGregori James
Published: March 2008

OBJECTIVE— Chronic pancreatitis, characterized by pancreatic exocrine tissue destruction with initial maintenance of islets, eventually leads to insulin-dependent diabetes in most patients. Mice deficient for the transcription factors E2F1 and E2F2 suffer from a chronic pancreatitis-like syndrome and become diabetic. Surprisingly, onset of diabetes can be prevented through bone marrow transplantation. The goal of the described studies was to determine the hematopoietic cell type responsible for maintaining islets and the associated mechanism of this protection.

RESEARCH DESIGN AND METHODS— Mouse models of acute and chronic pancreatitis, together with mice genetically deficient for macrophage production, were used to determine roles for macrophages in islet angiogenesis and maintenance.

RESULTS— We demonstrate that macrophages are essential for preventing endocrine cell loss and diabetes. Macrophages expressing matrix metalloproteinase-9 migrate to the deteriorating pancreas. E2f1/E2f2 mutant mice transplanted with wild-type, but not macrophage-deficient colony stimulating factor 1 receptor mutant (Csf1r−/−), bone marrow exhibit increased angiogenesis and proliferation within islets, coinciding with increased islet mass. A similar macrophage dependency for islet and islet vasculature maintenance is observed during caerulein-induced pancreatitis.

CONCLUSIONS— These findings demonstrate that macrophages promote islet angiogenesis and protect against islet loss during exocrine degeneration, could explain why most patients with chronic pancreatitis develop diabetes, and suggest an avenue for preventing pancreatitis-associated diabetes.
Treatment of Obese Diabetic Mice With a Heme Oxygenase Inducer Reduces Visceral and Subcutaneous Adiposity, Increases Adiponectin Levels, and Improves Insulin Sensitivity and Glucose Tolerance
Authors: Li Ming , Kim Dong Hyun , Tsenovoy Peter L. , Peterson Stephen J. , Rezzani Rita , Rodella Luigi F. , Aronow Wilbert S. , Ikehara Susumu , Abraham Nader G.
Published: March 2008

OBJECTIVE—We hypothesized that the induction of heme oxygenase (HO)-1 and increased HO activity, which induces arterial antioxidative enzymes and vasoprotection in a mouse and a rat model of diabetes, would ameliorate insulin resistance, obesity, and diabetes in the ob mouse model of type 2 diabetes.

RESEARCH DESIGN AND METHODS—Lean and ob mice were intraperitoneally administered the HO-1 inducer cobalt protoporphyrin (3 mg/kg CoPP) with and without the HO inhibitor stannous mesoporphyrin (2 mg/100 g SnMP) once a week for 6 weeks. Body weight, blood glucose, and serum cytokines and adiponectin were measured. Aorta, adipose tissue, bone marrow, and mesenchymal stem cells (MSCs) were isolated and assessed for HO expression and adipogenesis.

RESULTS—HO activity was reduced in ob mice compared with age-matched lean mice. Administration of CoPP caused a sustained increase in HO-1 protein, prevented weight gain, decreased visceral and subcutaneous fat content (P < 0.03 and 0.01, respectively, compared with vehicle animals), increased serum adiponectin, and decreased plasma tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β levels (P < 0.05). HO-1 induction improved insulin sensitivity and glucose tolerance and decreased insulin levels. Upregulation of HO-1 decreased adipogenesis in bone marrow in vivo and in cultured MSCs and increased adiponectin levels in the culture media. Inhibition of HO activity decreased adiponectin and increased secretion of TNF-α, IL-6, and IL-1β levels in ob mice.

CONCLUSIONS—This study provides strong evidence for the existence of an HO-1–adiponectin regulatory axis that can be manipulated to ameliorate the deleterious effects of obesity and the metabolic syndrome associated with cardiovascular disease and diabetes.
C-Reactive Protein in Estimating Inflammatory Status in Patients with Acute Coronary Syndrome
Authors: Dimitrijević Olivera , Đorić-Stojčevski Blagica , Ignjatović Svetlana , Majkić-Singh Nada
Published: March 2008

C-Reactive Protein in Estimating Inflammatory Status in Patients with Acute Coronary Syndrome

Chronic inflammation plays a key role in the pathogenesis of atherosclerosis, and is considered as a risk factor for the occurrence of acute coronary events, together with traditional risk factors such as age, smoking, hypercholesterolemia, diabetes mellitus and genetic predisposition. In this study, inflammatory status was estimated in patients with acute coronary syndrome. C-reactive protein, erythrocyte sedimentation rate and white blood cell count were measured at admission to the hospital in 25 patients with unstable angina pectoris and 31 patients with acute myocardial infarction, and compared with healthy control group (n = 59). C-reactive protein was the only parameter that differed significantly between all three groups (p < 0.0001), and patients with unstable angina had higher levels (median 7.28 mg/L) than patients with myocardial infarction (4.10 mg/L) and control group (1.07 mg/L). The obtained results show that levels of chronic inflammation in patients with acute coronary syndrome are significantly higher than baseline inflammation levels in a healthy population.
Alanine Aminopeptidase, γ-Glutamyl Transferase and β2-microglobulin as Diagnostic Markers in Patients with Rheumatoid Arthritis
Authors: Spasovski Dejan , Gruev Todor , Marina Nada , Calovski Jordan , Rajčevska Ljubinka , Perčinkova Snežana , Kafeđiska Irena , Cakalaroski Kočo , Slaninka-Micevska Maja
Published: March 2008

Alanine Aminopeptidase, γ-Glutamyl Transferase and β2-microglobulin as Diagnostic Markers in Patients with Rheumatoid Arthritis

The purpose of this research is to evaluate the values of alanine aminopeptidase (AAP), γ-glutamyl transferase (γ-GT), and β2-Microglobulin in urine (β2-M), in untreated rheumatoid arthritis (RA) and to define the effect of untreated rheumatoid arthritis on the tubular function and brush border region. We used a kinetic assay for AAP, standard methods by the IFCC for γ-glutamyl transferase and MEIA for the determination of β2-Microglobulin in urine in 70 participants (35 untreated RA patients, 35 healthy individuals). From the total of 35 RA patients, 24 patients had AAP (sensitivity of the test 68.57%), 16 patients had γ-GT enzymuria (sensitivity of the test 45.71%), while the presence of β2-Microglobulin in urine was found in a very low percentage. Out of 18 RF negative patients, 14 patients are AAP positive, 10 patients were γ-GT positive, while the presence of β2-Microglobulin in urine was not detected. Among 17 RF positive RA patients, the presence of AAP was noticed in 10, the presence of γ-GT in 6 patients, while the presence of β2-Microglobulin in urine was not detected. AAP has higher sensitivity than γ-GT and β2-Microglobulin in the detection of asymptomatic renal lesions in untreated RA.
The vestibular aqueduct: site of origin of endolymphatic sac tumors
Authors: Lonser Russell R. , Baggenstos Martin , Kim H. Jeffrey , Butman John A. , Vortmeyer Alexander O.
Published: March 2008

Object

Although endolymphatic sac tumors (ELSTs) frequently destroy the posterior petrous bone and cause hearing loss, the anatomical origin of these neoplasms is unknown. To determine the precise topographic origin of ELSTs, the authors analyzed the imaging, operative, and pathological findings in patients with von Hippel–Lindau disease (VHL) and ELSTs.

Methods

Consecutive VHL patients with small (≤ 1.5 cm) ELSTs who underwent resection at the National Institutes of Health were included. Clinical, imaging, operative, and pathological findings were analyzed.

Results

Ten consecutive VHL patients (6 male and 4 female) with 10 small ELSTs (≤ 1.5 cm; 9 left, 1 right) were included. Serial imaging captured the development of 6 ELSTs and revealed that they originated within the intraosseous (vestibular aqueduct) portion of the endolymphatic duct/sac system. Imaging just before surgery demonstrated that the epicenters of 9 ELSTs (1 ELST was not visible on preoperative imaging) were in the vestibular aqueduct. Inspection during surgery established that all 10 ELSTs were limited to the intraosseous endolymphatic duct/sac and the immediately surrounding region. Histological analysis confirmed tumor within the intraosseous portion (vestibular aqueduct) of the endolymphatic duct/sac in all 10 patients.

Conclusions

ELSTs originate from endolymphatic epithelium within the vestibular aqueduct. High-resolution imaging through the region of the vestibular aqueduct is essential for diagnosis. Surgical exploration of the endolymphatic duct and sac is required for complete resection.
Honoring the 75th anniversary of the American Association of Neurological Surgeons
Authors: Laws Edward R.
Published: March 2008

Ever since the Journal of Neurosurgery (JNS) published its first volume in 1944, the journal has reflected the scientific, technical, and clinical evolution of our specialty and parent organization, first called the Harvey Cushing Society and later the American Association of Neurological Surgeons. The JNS has been an uncompromising arbiter of progress in our specialty, and its superb editorial stewardship has led to its recognition as the premier journal in the field. The impact rating of JNS and its wide circulation among neurosurgeons worldwide are two of the many reasons why most of the truly innovative and paradigm-shifting advances in neurosurgery have been published in its pages.

As part of the 75th anniversary of the American Association of Neurological Surgeons celebration, the JNS Publishing Group has initiated a project of reviewing papers published over the years that have had the highest impact factor and greatest scientific interest: papers that have heralded new knowledge, new concepts, and new techniques that have been at the heart of modern neurosurgery and its continuing excitement and progress. We hope you will enjoy these articles and the accompanying commentaries. In this issue we present the next paper in this series.
Endoscopic transcervical odontoidectomy for pediatric basilar invagination and cranial settling
Authors: McGirt Matthew J. , Attenello Frank J. , Sciubba Daniel M. , Gokaslan Ziya L. , Wolinsky Jean-Paul
Published: March 2008

✓ Pediatric basilar invagination and cranial settling have traditionally been approached through a transoral–transpharyngeal route with or without extended maxillotomy or mandibulotomy for resection of the anterior portion of C-1 and the odontoid. The authors hypothesize that application of a recently described endoscopic transcervical odontoidectomy (ETO) technique would allow an alternative approach for the treatment of ventral pathological entities at the craniocervical junction in pediatric patients.

The authors performed ETO in a consecutive series of pediatric patients presenting with myelopathy or bulbar dysfunction resulting from basilar invagination or cranial settling. All clinical, radiographic, surgical, and follow-up data were prospectively collected. The initial experience with ETO in the pediatric population is analyzed and outcomes are reported. Three patients required ETO for basilar invagination and 1 required ETO with anterior C-1 arch and distal clivus resection for cranial settling. All patients presented with myelopathy. One patient was wheelchair bound with severe quadriparesis. The mean age was 14 ± 3 years (mean ± standard deviation [SD]) in the 2 male and 2 female patients. The ETO and posterior fusion were performed as a 2-stage procedure in 2 (50%) and as a single-stage procedure in 2 (50%) cases. Prolonged intubation or postoperative placement of a gastrostomy tube was not needed in any case. The postoperative hospitalization lasted 9 ± 4 days (mean ± SD). At last follow-up (mean 5 months), head and neck pain had resolved and motor strength had improved or stabilized in all cases. All 4 children were independently functioning and ambulatory at the last follow-up.

In the authors' initial experience, ETO has allowed ventral brainstem decompression without the need for prolonged intubation, worsening dysphagia requiring enteral tube feeding, or prolonged hospitalization, and has resulted in cosmetically appealing results. The ETO technique allows an alternative approach for the treatment of ventral pathological entities at the craniocervical junction in pediatric patients.
Long-Term Neurological and Neurosurgical Outcomes After Surgery Only in Children with Low-Grade Brain Tumors
Authors: Goumnerova Liliana , Drzymalski Dan , Kieran Mark , Pomeroy Scott , Scott R. Michael , Tarbell Nancy
Published: March 2008

Introduction

Brain tumors are the most common solid tumors of childhood. As treatment options such as surgery, chemotherapy, and radiotherapy improve, and affected children's survival increases, the focus has shifted toward understanding long-term outcomes. We hypothesized that tumor recurrence and long-term neurological outcomes can be correlated with age at diagnosis, site and size of tumor, histology, extent of surgery, and presence or absence of hydrocephalus. Thus, the aims of this study were to determine predictive factors for tumor recurrence and long-term morbidity in children who undergo surgery only for low-grade brain tumors. The study was approved by the institutional review board.

Methods

Medical records were reviewed for each child and information collected regarding sex, age at surgery, histology site, size of tumor, presence of hydrocephalus, extent of surgery, and date of tumor recurrence. Preoperative, postoperative, and last follow-up neurological exams were reviewed and patients were evaluated for ataxia, hemiparesis, impaired vision, cranial nerve deficits, presence of seizures or headaches, dysmetria, nystagmus, and depression.

Results

Forty-nine children (29 male, 20 female) ranging from 2.2 to 16.9 years of age at first operation were included; 31% had recurrence/progression. This was significantly correlated with tumors that were subtotally resected (p = 0.002) located in the supratentorial region (p = 0.017) and not astrocytoma or craniopharyngioma (p = 0.041). At last follow-up, 42% of children had no neurological sequelae, 53% had mild neurological sequelae, and 5% had moderate neurological sequelae. No children had experienced depression before or immediately after their initial surgery. However, 6 patients (16% of 38 patients) had depression at long-term follow-up.

Conclusion

These data indicate that we may be able to predict recurrence/progression of low-grade brain tumors based on extent of surgery location and histology. We also see that more than half of these children will experience a variety of surgical and neurological burdens throughout their lives.
Prospective evaluation of transabdominal percutaneous lumbar discectomy for L5–S1 disc herniation: initial clinical experience
Authors: Wu Chun-Gen , Li Yong-Dong , Li Ming-Hua , Gu Yi-Feng , Li Min
Published: March 2008

Object

Anterior approaches to the lumbosacral spine have become an increasingly common procedure in spine surgery, but transabdominal percutaneous lumbar discectomy (TPLD) performed anteriorly under fluoroscopic guidance is challenging. In this study the authors describe the TPLD and evaluate its safety and early clinical results in the management of L5–S1 disc herniation.

Methods

Between January 2005 and June 2007, 30 consecutive patients with L5–S1 disc herniation were treated with L5–S1 TPLD. All procedures were performed with the patient in a state of local anesthesia. After bowel preparation, the hypogastrium was compressed to move the intestinal canal away from the puncture site. The TPLD was then performed with fluoroscopic guidance to remove herniated disc material. Patients were evaluated prospectively using the visual analog scale (VAS) and the Oswestry Disability Index (ODI) during ≤ 30 months of follow-up.

Results

The mean hospital stay was 6.7 days. Scores on the VAS for leg pain (preoperative mean score 7.10, postoperative mean score 0.93) and the ODI (preoperative mean index 62.03, postoperative mean index 10.33) were statistically significantly (p = 0.00) improved at the last follow-up examination compared with preoperative scores. All members of the study group showed favorable results. On the day after the procedure pancreatitis developed in 1 patient but was cured by fasting and intravenous nutrition with antibiotics for 7 days. No other complications occurred during the follow-up.

Conclusions

Transabdominal percutaneous lumbar discectomy is a safe, effective, and minimally invasive procedure for the treatment of disc herniations at the L5–S1 level.
Endonasal endoscopic resection of the odontoid process in a nonachondroplastic dwarf with juvenile rheumatoid arthritis: feasibility of the approach and utility of the intraoperative Iso-C three-dimensional navigation
Authors: Laufer Ilya , Greenfield Jeffrey P. , Anand Vijay K. , Härtl Roger , Schwartz Theodore H.
Published: March 2008

✓The authors report a case of a nonachnodroplastic dwarf with severe basilar invagination and compression of the cervicomedullary junction (CMJ) due to juvenile rheumatoid arthritis. Initially excellent reduction of the invagination and decompression of the CMJ was achieved using posterior fixation. However, 1 month postoperatively symptoms recurred and the authors found imaging evidence of recurrence as well. The patient subsequently underwent an endoscopic transnasal resection of the dens with assistance of Iso-C navigation. He recovered well and tolerated regular diet on postoperative Day 2.
Lumbar disc herniation as a rare cause of stump pain
Authors: Sonmez Erkın , Yılmaz Cem , Caner Hakan , Altınors Nur
Published: March 2008

✓The authors report the first description since 1957 of a lumbar disc herniation as a cause of stump pain. Most amputees frequently experience stump pain or phantom pain. The pathophysiology of phantom pain is not clearly defined; however, there are well-defined reasons for stump pain such as infection, tissue necrosis, hematoma, wound breakdown, bone spur, neuroma, and so on. During the differential diagnosis, radiculopathy due to lumbar disc herniation must also be evaluated.
Relationships and evolution of matK in a group of leafless orchids (Corallorhiza and Corallorhizinae; Orchidaceae: Epidendroideae)
Authors: Freudenstein John V. , Senyo Diana M.
Published: March 2008

Corallorhizinae are a small group of Old and New World temperate orchids of which a core monophyletic group comprises Govenia, Cremastra, Aplectrum, Oreorchis and the leafless Corallorhiza, and which according to phylogenetic analysis of nuclear ITS and plastid matK sequences, are related in this way: (Govenia (Cremastra (Aplectrum (Oreorchis (Corallorhiza))))). This hypothesis is consistent with the progressive deletion of the trnK intron and matK ORF. Frameshift‐resulting indels yield a predicted loss of translation for the critical “domain X” region of matK and are evidence that matK is a probable pseudogene in Aplectrum, Oreorchis, and Corallorhiza. Within Corallorhiza, a previous hypothesis based on plastid DNA restriction site analysis is confirmed, with the thickened‐labellum C. striata group being sister to the thin‐labellum remainder of the genus, within which the circumboreal C. trifida is sister to the remainder, which then comprise two further sister groups: C. maculata + C. bulbosa + C. mertensiana and C. odontorhiza + C. wisteriana. A close relationship between C. striata and the recently described Appalachian C. bentleyi is shown; in particular, C. bentleyi is more closely allied to a southern Mexican population of C. striata than it is to northern North American C. striata populations, suggesting that two lineages, each with Mexican and northern North American populations, exist within the C. striata group.
Development and validation of a measure of dysmorphology: Useful for autism subgroup classification
Authors: Miles Judith H. , Takahashi T. Nicole , Hong Julie , Munden Nicole , Flournoy Nancy , Braddock Stephen R. , Martin Rick A. , Spence M. Anne , Hillman Richard E. , Farmer Janet E.
Published: March 2008

Autism spectrum disorders (ASD) comprise a class of neurodevelopmental disorders that can originate from a variety of genetic and environmental causes. To delineate autism's heterogeneity we have looked for biologically‐based phenotypes found in consistent proportions of ASD individuals. One informative phenotype is that of generalized dysmorphology, based on whole body examinations by medical geneticists trained in the nuances of anomalous embryologic development. We identified a need for a dysmorphology measure that could be completed by medical clinicians not extensively trained in dysmorphology that would still retain the level of sensitivity and specificity of the comprehensive dysmorphology examination. Based on expert‐derived consensus dysmorphology designation of 222 autism patients and a classification validation study of 30 subjects by four dysmorphologists, we determined that dysmorphology designations based on body areas provided superior inter‐rater reliability. Using 34 body area designations, we performed a classification and regression tree (CART) analysis to construct a scoring algorithm. Compared to the consensus classification, the model performed with 81% sensitivity and 99% specificity, and classification of a replication dataset of 31 ASD individuals performed well, with 82% sensitivity and 95% specificity. The autism dysmorphology measure (ADM) directs the clinician to score 12 body areas sequentially to arrive at a determination of “dysmorphic” or “nondysmorphic.” We anticipate the ADM will permit clinicians to differentiate accurately between dysmorphic and nondysmorphic individuals—allowing better diagnostic classification, prognostication, recurrence risk assessment, and laboratory analysis decisions—and research scientists to better define more homogeneous autism subtypes. © 2008 Wiley‐Liss, Inc.
Nickel–metal hydride battery separators fabricated from sulfonated nonwovens
Authors: Jiao Xiaoning , Cheng Bowen , Kang Weimin , Yang Wenjuan
Published: March 2008

In this study, we examined the sulfonation reaction of polyolefin nonwovens and their properties as battery separators. The occurrence of the sulfonation was confirmed by means of X‐ray photoelectron spectroscopy, and the influences of the temperature and time of the sulfonation reaction on the properties of polyolefin nonwoven battery separators were studied. The results show that the process method for producing the separators of sulfonation was capable of realizing high water conservation properties and improving the water absorption rate and K+ exchange capacity while maintaining tensile strength. The nickel–metal hydride batteries with the sulfonated polyolefin as separators had a similar capacity but a lower internal impedance compared to batteries with H&V commercial separators. Furthermore, their properties were stable after 300 charge–discharge cycles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Electrical properties of banana fiber‐reinforced phenol formaldehyde composites
Authors: Joseph Seena , Thomas Sabu
Published: March 2008

The electrical properties of banana fiber‐reinforced phenol formaldehyde composites have been studied with special reference to fiber loading, fiber treatments, and hybridization with glass fibers. The dielectric constant decreased with frequency and fiber loading. Treatments with silanes, NaOH and acetylation, latex treatment, heat treatment, and cyanoethylation decreased the dielectric constant value. The dielectric constant is higher for banana/PF composites than that of glass/PF composites. In hybrid composites, the dielectric constant decreased with increase in glass fiber concentration. The volume resistivity of banana fiber‐reinforced phenol formaldehyde composites decreased with frequency and fiber loading. Chemical modifications in the fiber increased the volume resistivity of the composites. Volume resistivity of banana/glass hybrid composites increased with increase in glass fiber content. Layered composites with glass fiber at periphery were found to have higher volume resistivity than other layering patterns. The loss factor decreased by the chemical treatments and in hybrid composites it decreased with increase in volume fraction of glass fibers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Application of silk sericin to polyester fabric
Authors: Gulrajani M. L. , Brahma K. P. , Kumar P. Senthil , Purwar Roli
Published: March 2008

Sericin powder was prepared from a boiled solution of silk cocoons through salting‐out with ammonium sulfate. The obtained sericin powder was characterized with Fourier transform infrared (FTIR), X‐ray, ultraviolet (UV) absorption, and nitrogen content measurements. The aqueous sericin solution was applied onto the polyester fabric (pretreated with NaOH) along with glutaraldehyde as a crosslinking agent with a pad–dry–cure method. The processing conditions of the crosslinking agent were optimized. The presence of sericin was confirmed by the estimation of the nitrogen content and amino groups on the treated fabric. The dyeability of the treated fabric with acid and reactive dyes was studied. The performance properties, such as the moisture content, UV absorption, antistatic, crease recovery, and bending length, of the treated fabric were tested. The FTIR, X‐ray, UV absorption, and nitrogen content results confirmed the purity of the sericin powder obtained with the salting‐out method. The amino acid content, nitrogen content, and Kubelka Monk function (K/S) values of the sericin‐treated fabric increased with an increase in the concentration of sericin in the padding liquor. The K/S value of the dyed samples was found to be linearly correlated with the number of amino groups present on the samples. There was a noticeable improvement in the moisture content and antistatic and UV absorption properties of the sericin‐treated fabrics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymer blends of steam‐explosion lignin and poly(ε‐caprolactone) by high‐energy ball milling
Authors: Pucciariello Rachele , Bonini Carlo , D'Auria Maurizio , Villani Vincenzo , Giammarino Gaetano , Gorrasi Giuliana
Published: March 2008

Lignin powder, obtained from an abundant and low‐cost source, straw, through a low‐environmental‐impact process, steam explosion, was used for the preparation of blends with a biodegradable polyester, poly(ε‐caprolactone) (PCL), with an innovative technique, high‐energy ball milling. Lignin strongly stabilized PCL against UV radiation. The modulus of the blends increased with the addition of lignin; nevertheless, the elongation at breaking decreased. Through thermal characterization (differential scanning calorimetry and dynamic mechanical analysis), lignin and PCL were found to be immiscible. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Silica‐reinforced natural rubber prepared by the sol–gel process of ethoxysilanes in rubber latex
Authors: Tangpasuthadol V. , Intasiri A. , Nuntivanich D. , Niyompanich N. , Kiatkamjornwong S.
Published: March 2008

Silica‐reinforced natural rubber (NR) composite was prepared by using tetraethoxysilane (TEOS) as a precursor to generate silica particles inside the rubber. The silica was generated in situ by the sol–gel process of TEOS that was mixed directly into commercial‐graded NR latex having 60% dry rubber content and 0.7% ammonia. The conversions of TEOS to silica inside the rubber were ranging from 90 to 97%. The silica particles dispersed evenly without extensive aggregation with sizes between 100 and 500 nm, as determined by scanning electron microscopy (SEM). An experimental design methodology, namely “two‐level factorial design,” was used to evaluate the influence of the amounts of TEOS, ammonia, and gelation time on the tensile modulus, tensile strength, and tear strength of the vulcanizates. The mechanical properties were significantly affected by the amount of TEOS added into the latex. Ammonia in the amount of 0.7% (w/w) present in the commercial latex was found to be sufficient for the conversion reaction of TEOS to silica. Bis‐(3‐triethoxysilylpropyl)tetrasulfide or TESPT, a coupling agent regularly used in rubber industry, was also added with TEOS to prepare the silica‐filled composite. The presence of TESPT resulted in an increase of the mechanical properties and the rate of sulfur cure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Characterization of acrylic copolymers applied in negative‐type photoresist via a ternary composition diagram
Authors: Lee Chih‐Kang , Don Trong‐Ming , Lin Dar‐Jong , Chen Chin‐Chung , Cheng Liao‐Ping
Published: March 2008

Three‐component acrylic copolymers used as a binder for negative‐type photoresists were synthesized and characterized. First, free radical polymerization was employed to synthesize two‐component binders, i.e., acrylic ester copolymers with different ratios of benzyl methacrylate (BZMA) and methacrylic acid (MAA). Thermal behavior, viscosity and molecular weight of the prepared two‐component binders were studied. Then, a series of three‐component binders were prepared through incorporation of another monomer, 2‐hydroxyethyl methacrylate (2‐HEMA). FTIR was used to examine the evolution of chemical bonds at various stages of the synthetic process. Thermal analyses, TGA and DSC, were used to evaluate the level of enhancement on thermal stabilities of the prepared three‐component binders. Finally, an optimal region in the ternary composition diagram of BZMA, MAA, and 2‐HEMA can be identified by comparing the results of acid value, viscosity, and molecular weight of the binder. A negative‐type photoresist was prepared using an optimized composition, for which resolution of the circuit could reach the level of 6 μm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A study of the intention–action gap in knowledge sharing practices
Authors: Kuo Feng‐Yang , Young Mei‐Lien
Published: March 2008

Recently, several researchers have questioned the predicting power of intention to actual system usage (Burton‐Jones & Straub, 2006; Jasperson, Carter, & Zmud, 2005; Kim & Malhotra, 2005; Kim, Malhotra, & Narasimhan, 2005; Limayem & Hirt, 2003). In this article, we report a study that investigates the gap between intention and usage by observing an Internet‐based knowledge management system, SCTNet, from the perspective of volitional control. Relying on the theory of planned behavior and the theory of action control, we investigate four types of volitional control mechanisms that may impact people's knowledge‐sharing practices. Our results show that in knowledge‐management‐based knowledge sharing, people do not always perform in a manner consistent with their espoused beliefs. This intention–action inconsistency can be explained by perceived self‐efficacy, but not by intention and controllability. In addition, a person's action/state orientation moderates his or her enactment of intention toward knowledge sharing into behaviors. The main theoretical implication of this study is that the study of knowledge‐management‐based knowledge sharing has to go beyond intention to include the investigation of both the actual behaviors of knowledge sharing and the volitional control constructs that predict these behaviors. Furthermore, previous research has shown that the environment interacts reciprocally with individuals' psychological control mechanisms in regulating their behaviors. Thus, the management must focus on the social and cultural attributes of organizational settings that may strengthen people's volitional control in practicing knowledge sharing.
Descriptive epidemiologic features shared by birth defects thought to be related to vascular disruption in Texas, 1996–2002
Authors: Husain Tasneem , Langlois Peter H. , Sever Lowell E. , Gambello Michael J.
Published: March 2008

BACKGROUND: In utero vascular disruptions are thought to be associated with a variety of birth defects. This study examined the descriptive epidemiology of several of those defects using data from a large birth defects registry. METHODS: Data on birth defects ascertained from pregnancies in 1996–2002 were obtained from the Texas Birth Defects Registry. Using Poisson regression, we calculated crude and adjusted associations between maternal and infant characteristics and birth defects thought to be related to vascular disruption. We repeated the analysis using isolated cases and cases occurring in mothers <20 years. RESULTS: The most commonly shared pattern was observed for plurality and five defects: large intestinal atresia (PR 3.67; CI: 1.63–7.13), renal agenesis (PR 2.05; CI: 1.55–2.65), transverse limb deficiency (PR 1.85; CI: 1.28–2.57), porencephaly (PR 5.18; CI: 2.40–9.87), and Goldenhar syndrome (PR 3.45; CI: 1.04–8.53). Hispanics had the highest prevalence of gastroschisis (PR 1.21; CI: 1.05–1.40), transverse limb deficiency (PR 1.19; CI: 1.01–1.40), microtia/anotia (PR 2.22; CI: 1.83–2.70), and Poland anomaly (PR 1.90; CI: 1.26–2.93). Male infants were at greatest risk for renal agenesis (PR 1.58; CI: 1.40–1.80), porencephaly (PR 1.66; CI: 1.03–2.72), and Poland anomaly (PR 1.52; CI: 1.05–2.21). CONCLUSIONS: Our study confirmed findings in previous studies, but also uncovered several new associations. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.