bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity Analysis of Structural Equation Models
Authors: Lee Sik-Yum , Wang S. J.
Published: February 2006

The main purpose of this paper is to investigate the sensitivity analysis of structural equation model when minor perturbation is introduced. Some influence measure that based on the general case weight perturbation is derived for the generalized least squares estimation. An influence measure that related to the Cook's distance is also developed for the special case deletion perturbation scheme. Using the proposed methodology, the influential observation in a data set can be detected. Moreover, the general theory can be applied to detect the influential parameters in a model. Finally, some illustrative artificial and real examples are presented.
A Compensatory Approach to Optimal Selection with Mastery Scores
Authors: van der Linden Wim J. , Vos Hans J.
Published: February 2006

A Bayesian approach for simultaneous optimization of test-based decisions is presented using the example of a selection decision for a treatment followed by a mastery decision. A distinction is made between weak and strong rules where, as opposed to strong rules, weak rules use prior test scores as collateral data. Conditions for monotonicity of optimal weak and strong rules are presented. It is shown that under mild conditions on the test score distributions and utility functions, weak rules are always compensatory by nature.
A Note on Multiple and Canonical Correlation for a Singular Covariance Matrix
Authors: Khatri C. G.
Published: February 2006

A weaker generalized inverse (Rao's g-inverse; Graybill's c-inverse) can be used in place of the Moore-Penrose generalized inverse to obtain multiple and canonical correlations from singular covariance matrices.
Procrustes Matching by Congruence Coefficients
Authors: Korth Bruce , Tucker L.R
Published: February 2006

Matching by Procrustes methods involves the transformation of one matrix to match with another. A special least squares criterion, the congruence coefficient, has advantages as a criterion for some factor analytic interpretations. A Procrustes method maximizing the congruence coefficient is given. This solution is identical to Mosier's [1939] approximate solution, but is an exact solution for maximum congruence.
A Look, by Simulation, at the Validity of Some Asymptotic Distribution Results for Rotated Loadings
Authors: Archer Claude O. , Jennrich Robert I.
Published: February 2006

In the last few years, a number of asymptotic results for the distribution of unrotated and rotated factor loadings have been given. This paper investigates the validity of some of these results based on simulation techniques. In particular, it looks at principal component extraction and quartimax rotation on a problem with 13 variables. The indication is that the asymptotic results are quite good.
A Note on Monotone Polygons Fitted to Bivariate Data
Authors: McDonald Roderick P.
Published: February 2006

The monotone regression function of Kruskal and the rank image function of Guttman and Lingoes were fitted to bivariate normal samples and their statistical properties contrasted.
Comment on Levy’s “An Empirical Comparison of the Z-variance and Box-Scheffé Tests for Homogeneity of Variance”
Authors: Martin Charles G.
Published: February 2006

An alternative selection of subsample sizes for the Box-Scheffé test is compared to the single m used in Levy, “An empirical comparison of the Z-variance and Box-Scheffé tests for homogeneity of variance.” Use of the alternative subsample sizes is shown to suggest greater power for the Box-Scheffé test, although the test would still be less powerful than the Z-variance test. Because of the nonrobustness of the Z-variance test and the robustness of the Box-Scheffé test, the latter is recommended as a general technique unless an experimenter has assurance that all populations in the experiment are normal. Alternative techniques are also considered.
External Analyses of Preference Models
Authors: Davison Mark L.
Published: February 2006

Using Carroll's external analysis, several studies have found that unfolding models account for more, although seldom significantly more, variance in preferences than Tucker's vector model. In studies of sociometric ratings and political preferences, the unfolding model again rarely outpredicted the vector model by a significant amount. Yet on cross-validation, the unfolding model consistently accounted for more variance. Results suggest that sometimes significance tests are less sensitive than cross-validation procedures to the small but consistent superiority of the unfolding model. Future researchers may wish to use significance tests and cross-validation techniques in comparing models.
On the Polychoric Series Method for Estimation of ρ in Contingency Tables
Authors: Hamdan M. A.
Published: February 2006

The present note illustrates the application of Lancaster & Hamdan's [1964] polychoric series method for estimating the correlation coefficient in contingency tables. A simple format for the calculations involved, using a desk calculator, is suggested and hence applied to a specific 3 × 3 contingency table.
Bayesian Inference and the Classical Test Theory Model: Reliability and True Scores
Authors: Novick Melvin R. , Jackson Paul H. , Thayer Dorothy T.
Published: February 2006

A general one-way analysis of variance components with unequal replication numbers is used to provide unbiased estimates of the true and error score variance of classical test theory. The inadequacy of the ANOVA theory is noted and the foundations for a Bayesian approach are detailed. The choice of prior distribution is discussed and a justification for the Tiao-Tan prior is found in the particular context of the “n-split” technique. The posterior distributions of reliability, error score variance, observed score variance and true score variance are presented with some extensions of the original work of Tiao and Tan. Special attention is given to simple approximations that are available in important cases and also to the problems that arise when the ANOVA estimate of true score variance is negative. Bayesian methods derived by Box and Tiao and by Lindley are studied numerically in relation to the problem of estimating true score. Each is found to be useful and the advantages and disadvantages of each are discussed and related to the classical test-theoretic methods. Finally, some general relationships between Bayesian inference and classical test theory are discussed.
Sequential Decision Making: An Aggregate Scheduling Methodology
Authors: Ebert Ronald J.
Published: February 2006

Recent studies of sequential decision making performance have utilized optimal dynamic programming solutions as the criteria for evaluating the quality of human decisions. The difficulties incumbent in increasing the dimensionality of dynamic programming formulations effectively prohibit their extension beyond the case of a single decision variable. In the following article an alternative optimization formulation for a two-decision-variable case is presented, followed by the development of a corresponding one-decision-variable problem. In addition, related methodological problems limiting the comparability of results among previous studies are presented. It is suggested that the proposed problem formulation and its accompanying interpretation for the decision maker largely eliminate these previous methodological problems. Furthermore, the problem formulation permits quantification of the relative weights that should optimally be placed on future decision periods in the multiple-stage decision problem.
Rasch Models for Item Bundles
Authors: Wilson Mark , Adams Raymond J.
Published: February 2006

This paper discusses the application of a class of Rasch models to situations where test items are grouped into subsets and the common attributes of items within these subsets brings into question the usual assumption of conditional independence. The models are all expressed as particular cases of the random coefficients multinomial logit model developed by Adams and Wilson. This formulation allows a very flexible approach to the specification of alternative models, and makes model testing particularly straightforward. The use of the models is illustrated using item bundles constructed in the framework of the SOLO taxonomy of Biggs and Collis.
General Estimators for the Reliability of Qualitative Data
Authors: Cooil Bruce , Rust Roland T.
Published: February 2006

We study a proportional reduction in loss (PRL) measure for the reliability of categorical data and consider the general case in which each of N judges assigns a subject to one of K categories. This measure has been shown to be equivalent to a measure proposed by Perreault and Leigh for a special case when there are two equally competent judges, and the correct category has a uniform prior distribution. We consider a general framework where the correct category is assumed to have an arbitrary prior distribution, and where classification probabilities vary by correct category, judge, and category of classification. In this setting, we consider PRL reliability measures based on two estimators of the correct category—the empirical Bayes estimator and an estimator based on the judges' consensus choice. We also discuss four important special cases of the general model and study several types of lower bounds for PRL reliability.
Maximization of Sums of Quotients of Quadratic Forms and Some Generalizations
Authors: Kiers Henk A. L.
Published: February 2006

Monotonically convergent algorithms are described for maximizing six (constrained) functions of vectors x, or matrices X with columns x1, ..., xr. These functions are h1(x)=Σk (x′Akx)(x′Ckx)−1, H1(X)=Σk tr (X′AkX)(X′CkX)−1, h1(X)=Σk Σl (x′lAkxl) (x′lCkxl)−1 with X constrained to be columnwise orthonormal, h2(x)=Σk (x′Akx)2(x′Ckx)−1 subject to x′x=1, H2(X)=Σk tr (X′AkX)(X′AkX)′(X′CkX)−1 subject to X′X=I, and h2(X)=Σk Σl (x′lAkxl)2 (x′lCkXl)−1 subject to X′X=I. In these functions the matrices Ck are assumed to be positive definite. The matrices Ak can be arbitrary square matrices. The general formulation of the functions and the algorithms allows for application of the algorithms in various problems that arise in multivariate analysis. Several applications of the general algorithms are given. Specifically, algorithms are given for reciprocal principal components analysis, binormamin rotation, generalized discriminant analysis, variants of generalized principal components analysis, simple structure rotation for one of the latter variants, and set component analysis. For most of these methods the algorithms appear to be new, for the others the existing algorithms turn out to be special cases of the newly derived general algorithms.
Isotonic Ordinal Probabilistic Models (ISOP)
Authors: Scheiblechner Hartmann
Published: February 2006

The concept of an ordinal instrumental probabilistic comparison is introduced. It relies on an ordinal scale given a priori and on the concept of stochastic dominance. It is used to define a weakly independently ordered system, or isotonic ordinal probabilistic (ISOP) model, which allows the construction of separate “sample-free” ordinal scales on a set of “subjects” and a set of “items”. The ISOP-model is a common nonparametric theoretical structure for unidimensional models for quantitative, ordinal and dichotomous variables.

Fundamental theorems on dichotomous and polytomous weakly independently ordered systems are derived. It is shown that the raw score system has the same formal properties as the latent system, and therefore the latter can be tested at the observed empirical level.
The Relationship Between Fisher's Exact Test and Pearson's Chi-Square Test: A Bayesian Perspective
Authors: Camilli Gregory
Published: February 2006

It is demonstrated in this paper that two major tests for 2 × 2 talbes are highly related from a Bayesian perspective. Although it is well-known that Fisher's exact and Pearson's chi-square tests are asymptotically equivalent, the present analysis shows that a formal similarity also exists in small samples. The key assumption that leads to the resemblance is the presence of a continuous parameter measuring association. In particular, it is shown that Pearson's probability can be obtained by integrating a two-moment approximation to the posterior distribution of the log-odds ratio. Furthermore, Pearson's chi-square test gave an excellent approximation to the actual Bayes probability in all 2×2 tables examined, except for those with extremely disproportionate marginal frequencies.
Statistical Applications of Linear Assignment
Authors: Hubert Lawrence J.
Published: February 2006

A comprehensive statistical framework is presented which encompasses a wide range of existing nonparametric methods. The basic strategy, referred to as linear assignment (LA), depends on a simple index of correspondence defined between two object sets that have been matched in some a priori manner. In this broad sense, LA can be interpreted as a general correlational technique. A variety of extensions are discussed along with the attendant problems of significance testing and the construction of normalized descriptive indices.
Video‐Assisted Thoracoscopic Surgery for Recurrent Spontaneous Pneumothorax: The Long‐term Benefit
Authors: Ben‐Nun A. , Soudack M. , Best L. A.
Published: February 2006

Background

Management of recurrent primary spontaneous pneumothorax by open surgery was considered the treatment of choice until recently. The major drawbacks of this management are the prolonged postoperative pain and cosmetic results. In the last decade, video‐assisted thoracoscopic surgery (VATS) has replaced the routine use of open surgery. Most papers that compared limited open surgery to VATS addressed the early postoperative results, and studies that assessed the long‐term results focused primarily on the rate of recurrence and pulmonary function tests. The aim of this study was to compare the outcome of minithoracotomy and VATS with emphasis on patients’ long‐term, subjective perspective and satisfaction.

Methods

Medical records of patients with recurrent primary spontaneous pneumothorax were retrospectively reviewed. Patients who underwent surgical treatment by limited thoracotomy (63 patients) or VATS (58 patients) more than 3 years ago were enrolled. Hospital medical charts were used to compare the early postoperative results. Outpatient clinic records and a telephone questionnaire were employed to evaluate long‐term results.

Results

There was no mortality or major morbidity in either group, and hospitalization time was similar. Patients in the thoracotomy group needed significantly higher doses of narcotic analgesia for a longer period. There were two cases of recurrence in the VATS group (3%). Seventy‐eight percent of patients in the VATS and 21% in the thoracotomy group classified their pain as insignificant a month following the operation (P < 0.05). Three years following surgery, 97% of the VATS group patients considered themselves completely recovered from the operation compared with only 79% in the thoracotomy group (P < 0.05). Nineteen percent of the thoracotomy group and 3% of the VATS group suffered from chronic or intermittent pain necessitating use of analgesics more than once a month. Thirteen percent of patients from the open procedure group required services from the pain clinic. Patients in the VATS group were, in general, much more satisfied with their operation and with the surgical scars compared with patients from the thoracotomy group.

Conclusion

We recommend video‐assisted surgery as the first‐line surgical treatment for patients with recurrent primary spontaneous pneumothorax. This recommendation is based on its somewhat favorable early postoperative course, the superior long‐term outcome, and patient satisfaction.
Treatment of Bladder Tumors and Benign Prostatic Hyperplasia with a New TUR System Using Physiological Saline as Perfusate
Authors: Yoshimura Rikio , Adachi Takahisa , Funao Kiyoaki , Kobayakawa Hitoshi , Matsuyama Masahide , Tsuchida Kennji , Takemoto Yoshiaki , Nakatani Tatsuya
Published: February 2006

This article presents a new transurethral resection (TUR) system for use in endoscopic surgery. By using an electroconductive solution (physiological saline) as the perfusate in lieu of conventional non‐electroconductive solution (Uromatic), additional anesthesia (e.g., obturator nerve blocking) is not required. The new TUR is carried out in an electroconductive solution such as saline, and because radiofrequency current flows from the resecting electrode through the perfusate to the outer sheath, no counter‐electrode is needed. We have treated both bladder tumor and benign prostatic hyperplasia cases with this new system. Surgery was safely performed in all TUR‐bt cases without requiring obturator nerve blocking. During both TUR‐bt and transurethral resection of the prostate (TUR‐P) using this system, tissue resection and coagulation equivalents were similar to the conventional TUR system. In previous TUR, preoperative obturator nerve blocking was necessary, and in some cases, incomplete blocking or complications occurred. When physiological saline is used as the perfusate, blood electrolyte levels are not greatly changed, even after extensive resection of the bladder wall; as a result, this new system is also cost effective because physiological saline is less expensive than non‐electroconductive solutions and requires no counter‐electrode. Thus, in comparison with conventional TUR, this new system is both significantly safer and more cost effective.
New Prognostic Scales LAST‐1 and LAST‐2: Supporting Prediction and Staging of Thyroid Cancer
Authors: Lachinski Andrzej J. , Stefaniak Tomasz , Kobiela Jarek , Connor Saxon , Gruca Zbigniew , Sledzinski Zbigniew
Published: February 2006

Introduction

Epidemiologically, thyroid gland tumors are lesions of the highest importance among endocrine tumors in humans. Although the results of surgical treatment of the highly differentiated (follicular and papillary) tumors seem to be satisfactory, treatment of the poorly differentiated (medullary and anaplastic) tumor still demands clinical and basic investigations. In this study the authors sought to evaluate clinical and molecular factors that could contribute to preoperative detection of more advanced thyroid cancers (i.e., those that exhibit extrathyroid spread and lymph node invasion).

Methods

A total of 27 patients operated on for thyroid cancer were evaluated according to age, sex, time from the onset of the disease, cytogenetic changes, and loss of heterozygosity (LOH) in 14 microsatellite markers. The output variables were defined according to postoperative findings and the TNM 2002 score. The T1‐2 N0 M0 cases were defined as local malignancy (LM); and T3‐4 any N any M, any T N1 any M, or any T any N M1 were considered advanced malignancy (AM). The control groups consisted of 25 patients with multinodular goiter (MNG) and 32 patients with follicular adenoma (FA). In all cases, clinical and molecular data similar to those listed above were collected, excluding staging and follow‐up information.

Results

There was no predominant specific type of chromosomal aberration observed and no marker lost in more than five patients (18%). The logistic regression identified three input variables as contributing significantly to the dichotomized outcome measure (LM vs. AM): LOH in any of the examined loci, age of the patient at the presentation, and the sex of the patient. Furthermore, discriminant analysis revealed four input variables differentiating among TC, FA, and MNG patients. Based on the multivariate analysis results, two numeric prognostic scales were fashioned: LAST‐1, a scale applicable to differentiation of thyroid cancers at different degrees of clinical advancement; and LAST‐2, a scale applicable to differentiation of any thyroid lumps.

Conclusions

It was concluded that LOH and the age and sex of the patients can provide sufficient data to predict thyroid cancer with a high degree of clinical advancement. LAST‐1 scale is a reliable tool for identifying these patients. The LAST‐2 scale gives supportive information about the character of thyroid lumps, distinguishing TC from MNG and FA.
Incidence of Vascular Injuries after Use of the Angio‐Seal Closure Device following Endovascular Procedures in a Single Center
Authors: Castelli Patrizio , Caronno Roberto , Piffaretti Gabriele , Tozzi Matteo , Lomazzi Chiara
Published: February 2006

Introduction

Percutaneous closure devices have been used to obtain rapid hemostasis and early mobilization of the patient after arterial catheterization. However, we observed challenging problems with the sealing procedure that require further surgical intervention. The present report is a retrospective analysis of the patterns of injury and the final outcome of four cases of femoral artery injury following the use of Angio‐Seal.

Methods

During the last 24 months, in a group of 175 patients (131 men, 44 women; median age 68.4 years, range 47–81 years) underwent percutaneous closure after diagnostic (n = 53) or therapeutic (n = 122) endovascular procedures. Among them we observed four patients (three men, one woman; median age 65.2 ± 10.8 years, range 47–75 years) who developed severe limiting claudication and required vascular repair of an iatrogenic vascular injury following deployment of the Angio‐Seal. They had a femoral thrombosis due to narrowing/severe intimal dissection.

Results

All patients required operative intervention with removal of the device. We performed femoropopliteal thrombectomy and common femoral endarterectomy with patch angioplasty (n = 2), resection of the femoral bifurcation and reimplantation of the deep femoral artery (n = 1), and femoral bifurcation endarterectomy with direct arterial suture (n = 1). The median hospital stay was 6.5 ± 3.8 days (range 4–12 days). Limb salvage was achieved in all of the surviving patients at a mean follow‐up of 7 months (range 1–12 months).

Conclusions

Vascular injuries are uncommon after use of the hemostasis closure device. When they occur, however, they are likely to require challenging surgical correction.
A Prophylactic Infusion of Calcium Solution Reduces the Risk of Symptomatic Hypocalcemia in Patients after Total Thyroidectomy
Authors: Uruno Takashi , Miyauchi Akira , Shimizu Kazuo , Tomoda Chisato , Takamura Yuuki , Ito Yasuhiro , Miya Akihiro , Kobayashi Kaoru , Matsuzuka Fumio , Amino Nobuyuki , Kuma Kanji
Published: February 2006

Background

Several risk factors have been associated with post‐operative transient hypocalcemia after thyroid surgery. However, there are no studies evaluating preventive measures to avoid symptomatic postoperative hypocalcemia. Although intravenous infusion of calcium improves hypocalcemic symptoms, it is unknown whether prophylactic infusion prevents symptoms of postoperative hypocalcemia.

Patients and Methods

Five hundred and forty‐seven patients underwent total thyroidectomy. Two groups were identified: group A (n = 243) received prophylactic intravenous drip infusion of 78–156 mg of calcium solution at 3–8hours after operation, and group B (n = 304) received no prophylactic treatment. Prophylactic infusion was used only once if the patients did not have symptoms of hypocalcemia. Serum calcium (Ca) levels, intact parathyroid hormone (i‐PTH) levels on the first postoperative day (1st POD), and the prevalence of symptoms of hypocalcemia were prospectively analyzed.

Results

The serum Ca levels at the 1st POD in group A patients (7.91 ± 0.49 mg/dl, mean ± SD) was significantly higher than group B patients (7.65 ± 0.54, P < 0.0001), while the serum i‐PTH levels were not significantly different between the two groups. The prevalence of numbness and / or tetany before noon on the 1st POD was significantly lower in group A patients. Prophylactic infusion of calcium solution reduced the prevalence of tetany from 8.6% to 2.1%.

Conclusion

A prophylactic infusion of calcium solution after total thyroidectomy may be useful in reducing the development of symptomatic hypocalcemia and reduces the patients’ risk of having discomfort and anxiety due to hypocalcemia.
Comparison of Kugel and Lichtenstein Operations for Inguinal Hernia Repair: Results of a Prospective Randomized Study
Authors: Dogru Osman , Girgin Mustafa , Bulbuller Nurullah , Cetinkaya Ziya , Aygen Erhan , Camci Cemalettin
Published: February 2006

Introduction

The aim of this prospective randomized clinical study was to compare the Lichtenstein hernia repair with Kugel’s patch hernia repair.

Methods

From September 1999 to August 2002, adult patients with inguinal hernia were randomized into two groups. Group I included patients with the Lichtenstein hernioplasty, and group II included patients with the Kugel hernioplasty. The duration of the operation, surgical findings, and postoperative complications were recorded for the patients in both groups.

Results

A total of 139 patients (134 men, 5 women) were randomized to either group I or group II. No significant differences were observed for the duration of the operation or the complication rates between the groups during the same follow‐up time (53.06 ± 5.6 months vs. 53.41 ± 7.11 months in groups I and II, respectively).

Conclusions

Kugel herniorraphy is a minimally invasive method and as safe as the Lichtenstein hernia repair technique, with similar complication rates.
Perforation of the Gastrointestinal Tract Secondary to Ingestion of Foreign Bodies
Authors: Goh Brian K.P. , Chow Pierce K.H. , Quah Hak‐Mien , Ong Hock‐Soo , Eu Kong‐Weng , Ooi London L.P.J. , Wong Wai‐Keong
Published: February 2006

Introduction

Ingesting a foreign body (FB) is not an uncommon occurrence. Most pass through the gastrointestinal (GI) tract uneventfully, and perforation is rare. The aim of this study was to report our experience with ingested FB perforations of the GI tract treated surgically at our institution.

Methods

A total of 62 consecutive patients who underwent surgery for an ingested FB perforation of the GI tract between 1990 and 2005 were retrospectively reviewed. Three patients with no definite FB demonstrated intraoperatively were included.

Results

The patients had a median age of 58 years, and 37 (60%) were male. Of the 59 FBs recovered, 55 (93%) were toothpicks and dietary FBs such as fish bones or bone fragments. A definitive preoperative history of FB ingestion was obtained for only two patients, and 36 of 52 patients (69%) wore dentures. Altogether, 18 (29%) perforations occurred in the anus or distal rectum, and 44 perforations were intraabdominal, with the most common abdominal site being the distal ileum (39%). Patients with FB perforations in the stomach, duodenum, and large intestine were significantly more likely to be afebrile (P= 0.043), to have chronic symptoms (> 3 days) (P< 0.001), to have a normal total white blood cell count (P< 0.001), and to be asymptomatic or present with an abdominal mass or abscess (P< 0.001) compared to those with FB perforations in the jejunum and ileum.

Conclusions

Ingested FB perforation in the adult population is most commonly secondary to unconscious accidental ingestion and is frequently caused by dietary FBs especially fish bones. A preoperative history of FB ingestion is thus rarely obtained, although wearing dentures is a common risk factor. FB perforations of the stomach, duodenum, and large intestine tend to present with a longer, more innocuous clinical picture than perforations in the jejunum or ileum.
Prospective Comparison of Laparoscopic Left Hemicolectomy for Colon Cancer with Laparoscopic Left Hemicolectomy for Benign Colorectal Disease
Authors: Sarli Leopoldo , Pavlidis Clara , Cinieri Francesco Giovanni , Regina Gabriele , Sansebastiano Giuliano , Veronesi Licia , Ferro Michelina , Morari Silvia , Violi Vincenzo , Roncoroni Luigi
Published: February 2006

Background

Short‐term outcome and anorectal function results after laparoscopic hemicolectomy for colon cancer were compared with results after laparoscopic hemicolectomy for benign diseases.

Methods

A total of 108 patients who underwent laparoscopic left colectomy (60 for colon cancer, 48 for diverticulitis or polyposis) were enrolled in the study. Left hemicolectomy in patients affected by cancer was performed by high ligation of the inferior mesenteric artery. A questionnaire concerning anorectal function was mailed to patients 6 months after surgery.

Results

Complications were more frequent in the cancer group than in the benign disease group: overall morbidity rate (29.6% versus 8.7%; P = 0.009), diarrhea during the first 6 postoperative months (58.7% versus 34.1%; P = 0.022), and anorectal function problems (fecal incontinence and/or the inability to discriminate between gas and stool, and/or urgency, and/or tenesmus) (65.2% versus 31.7%; P = 0.002).

Discussion

The level of ligation of the lower mesenteric artery and damage at the lower mesenteric ganglion could explain the poorer anorectal function outcome in the colon cancer group.
Prognostic Factors of Primary Small Bowel Adenocarcinoma: Univariate and Multivariate Analysis
Authors: Wu Ting‐Jung , Yeh Chun‐Nan , Chao Tzu‐Chieh , Jan Yi‐Yin , Chen Miin‐Fu
Published: February 2006

Background

Adenocarcinoma of the small bowel is relatively less common than malignancies of the esophagus, stomach, and colorectum. In small bowel adenocarcinoma, various prognostic factors influence the disease‐free status and overall survival rates.

Materials and Methods

Eighty patients who were diagnosed with small bowel adenocarcinoma and treated at our institute between 1983 and 2003 were retrospectively reviewed.

Results

The patients included 40 men and 40 women with an age range of 15 to 93 years (median: 62 years). Only 51.3% of patients were accurately proved preoperatively to have a malignancy by endoscopic biopsy. Sixty patients underwent surgical treatment, and 45 of those patients had curative resection. The follow‐up period ranged from 2.5 to 229.7 months, with a median of 9.1 months. The cumulative 1‐, 3‐, and 5‐year survival rates for all patients (excluding 3 patients who died in the immediate postoperative period) were 43.6%, 22.8%, and 17.5%, respectively. The cumulative 1‐, 3‐, and 5‐year disease‐free survival rate for all 43 patients with curative resection (excluding 2 patients who died in the immediate postoperative period) was 54.9%, 30.5%, and 27.4%, respectively. Meanwhile, multivariate analysis with Cox proportional hazards analysis demonstrated that earlier tumor stages (stages I and II) and curative resection were two independent factors influencing favorable overall survival. Lymph node metastasis was the only independent factor predicting poor disease‐free survival in patients undergoing curative resection.

Conclusions

Poor prognosis of small bowel adenocarcinoma may be related to a delay in the diagnosis and treatment of the disease. Curative resection is the aim of surgical treatment for small bowel adenocarcinoma. Lymph node metastasis at presentation of the disease predicts tumor recurrence and distant metastasis after curative surgical treatment.
Popliteal Venous Aneurysm—A Systematic Review
Authors: Bergqvist David , Björck Martin , Ljungman Christer
Published: February 2006

Background

Popliteal vein aneurysm is a rare but potentially problematic disease with a risk of pulmonary embolism.

Method

A systematic literature search was performed.

Results

A total of 105 popliteal vein aneurysms were identified, with a slight female and left‐sided preponderance. Dominating symptoms are caused by pulmonary embolism, followed by local symptoms with a palpable mass. In four patients arterial symptoms were reported. The most frequently used diagnostic test was phlebography, increasingly replaced by duplex ultrasonography in recent years. Because pulmonary embolism is a potential, it motivates surgical removal. In most cases excision and lateral suture is possible. Four fatal cases were reported. Unfortunately follow‐up time and results are poorly documented.

Conclusion

Popliteal venous aneurysm is rare but should be considered as a local source of pulmonary embolism when no other explanation is found.
Effects of dietary protein level on ewe milk yield and nitrogen utilization, and on air quality under different ventilation rates
Authors: Sevi Agostino , Albenzio Marzia , Annicchiarico Giovanni , Caroprese Mariangela , Marino Rosaria , Santillo Antonella
Published: February 2006

The experiment, which lasted 53 d, was conducted during the winter (February and March) of 2004 and used 48 Comisana ewes in mid lactation. A 2×2 factorial design was used, with ewes receiving two levels of dietary crude protein (CP) (moderate, 16% CP v. low, 13% CP) in the dry matter (DM) and being exposed to two ventilation rates (moderate, 47 m3/h v. low, 23·5 m3/h per ewe) for each dietary treatment. Air concentrations of NH3 and of microorganisms were measured twice weekly. Milk yield was recorded daily. Individual milk samples were analysed weekly for composition and fortnightly for bacteriological characteristics. After the last milk sampling (day 49 of the study period), four animals from each group were placed in a metabolism box and their individual faeces and urine were collected for three consecutive days. Amounts of urine and faeces excreted, and urinary and faecal N outputs were measured. The 16% CP diet resulted in a lower milk casein content and a higher milk urea concentration than the 13% CP diet, as well as in a reduced gross efficiency of utilization of dietary N, a greater amount of N excreted and a higher total coliform concentration in milk. The moderate ventilation rate resulted in higher yields of milk, irrespective of CP content. Significant interactions of CP level×ventilation rate were found for the amounts of urine, of total water and of faecal N, and for mesophilic concentration in milk, the highest values being displayed by the ewes fed the 16% CP diet and exposed to the low ventilation rate. The moderate dietary CP level and low ventilation rate had a deleterious effect on air concentrations of microorganisms and ammonia. Results suggested that a reduction of dietary CP level from 16 to 13% of DM had no detrimental effect on ewe milk yield in mid lactation and could even improve some of its nutritional and hygienic characteristics. Our findings also indicate that the choice of a proper ventilation rate is critical for high efficiency of production in the lactating ewe, especially in intensively managed flocks receiving diets high in CP.
Peptides released from acid goat whey by a yeast-lactobacillus association isolated from cheese microflora
Authors: Didelot Sandrine , Bordenave-Juchereau Stephanie , Rosenfeld Eric , Piot Jean-Marie , Sannier Frederic
Published: February 2006

Seven lactobacilli and a variety of microflora extracted from twenty five commercial cheeses were grown on unsupplemented acid goat whey and screened for their capacity to hydrolyse whey proteins [α-lactalbumin (α-la) and β-lactoglobulin (β-lg)] and to generate peptides. Fermentations were performed aerobically or anaerobically at 37 °C using crude or pre-heated whey (10 min at 65, 75 or 85 °C). Under aerobic conditions, growth of lactobacilli was poor and protein hydrolysis did not occur. Anaerobic conditions slightly increased lactobacilli growth but neither β-lg hydrolysis nor peptide generation were observed. More than 50% of α-la was digested into a truncated form of α-la (±12 kDa) in crude whey and whey pre-heated at 65 °C. Twenty-five microflora extracted from raw milk cheeses were screened for their proteolytic activities on acid goat whey under the conditions previously described. Eight of them were able to hydrolyse up to 50% of α-la mainly during aerobic growth on crude or pre-heated whey. The corresponding hydrolysates were enriched in peptides. The hydrolysate involving microflora extracted from Comté cheese after or at 18 months ripening was the only one to exhibit hydrolysis of both α-la and β-lg. Microbiological analysis showed that microorganisms originating from Comté cheese and capable of growth on unsupplemented whey consisted of Candida parapsilosis and Lactobacillus paracasei. Fermentation kinetic profiles suggested that peptides were released from α-la hydrolysis. The co-culture of both microorganisms was required for α-la hydrolysis that occurred concomitantly with the pH decrease. During whey fermentation, Cand. parapsilosis excrete at least one protease responsible for α-la hydrolysis, and Lb. paracasei is responsible for medium acidification that is required for protease activation.
Welfare effects of the use of recombinant bovine somatotropin in the USA
Authors: Losinger Willard C
Published: February 2006

The welfare effects of increased milk production associated with the use of recombinant bovine somatotropin (rBST) on dairy operations in the USA were examined for 1996. Results that derived from three different estimates of the milk-production response to rBST were evaluated and compared. One estimate, derived from a survey of dairy producers in Connecticut, led to economic-impact estimates that were not statistically significant. A second, derived from a national survey that concentrated on the health and management of dairy cattle, led to estimates that were unbelievably high. A third, derived from a national survey that concentrated on the economics of dairy producers, provided the most reasonable estimates of economic impacts. Results of economic analysis, using the latter results, indicated that if rBST had not caused milk production to increase, then the market price of milk would have been 2·2±1·5 cents/kg higher, and the total value of the milk produced would have risen from $23·0±0·6 billion to $24·1±1·0 billion. A welfare analysis demonstrated that the increased milk production (and the reduced market price) associated with the use of rBST in the USA caused the economic surplus of consumers to rise by $1·5±1·0 billion, while the economic surplus of dairy producers fell by $1·1±$0·8 billion. Increased milk production associated with rBST yielded a total gain to the US economy of $440±280 million. An analysis of annual percent changes in the number of dairy cows per operation, milk production per cow, total milk production, total number of dairy cows, and total number of dairy operations in the USA suggested that the dairy industry's long-term economic growth path was stable from 1989–2001 inclusive, and did not receive a shock resulting from the introduction of rBST.
Effectiveness of cognitive-behavioural, person-centred and psychodynamic therapies as practised in UK National Health Service settings
Authors: STILES WILLIAM B. , BARKHAM MICHAEL , TWIGG ELSPETH , MELLOR-CLARK JOHN , COOPER MICK
Published: February 2006

Background. Psychotherapy's equivalence paradox is that treatments have equivalently positive outcomes despite non-equivalent theories and techniques. We compared the outcomes of contrasting approaches practised in routine care.

Method. Patients (n=1309) who received cognitive-behavioural therapy (CBT), person-centred therapy (PCT) and psychodynamic therapy (PDT) at one of 58 National Health Service (NHS) primary and secondary care sites in the UK during a 3-year period completed the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) at the beginning and end of their treatment. Therapists indicated which treatment approaches were used on an End of Therapy form. We compared outcomes of six groups: three treated with CBT, PCT or PDT only, and three treated with one of these plus one additional approach (e.g. integrative, supportive, art), designated CBT+1, PCT+1 or PDT+1 respectively.

Results. All six groups averaged marked improvement (pre–post effect size=1·36). Treatment approach and degree of purity (‘only’ vs. ‘+1’) each accounted for statistically significant but comparatively tiny proportions of the variance in CORE-OM scores (respectively 1% and 0·5% as much as pre–post change). Distributions of change scores were largely overlapping.

Conclusions. Results for these three treatment approaches as practised routinely across a range of NHS settings were generally consistent with previous findings that theoretically different approaches tend to have equivalent outcomes. Caution is warranted because of limited treatment specification, non-random assignment, lack of a control group, missing data and other issues.
Continuity and shallow structures in language processing
Authors: CLAHSEN HARALD , FELSER CLAUDIA
Published: February 2006

The core idea that we argued for in the target article was that grammatical processing in a second language (L2) is fundamentally different from grammatical processing in one's native (first) language (L1). Our major source of evidence for this claim comes from experimental psycholinguistic studies investigating morphological and syntactic processing in child and adult native speakers, and nonnative speakers who acquired their L2 after childhood and for whom their L1 is the dominant language. With respect to child L1 processing, we argued for acontinuity of parsing hypothesisclaiming that the child's structural parser is basically the same as that of mature speakers and does not change over time. Adult L2 learners, in contrast, were seen to underuse syntactic information during sentence processing and to rely more on lexical–semantic cues to interpretation. To account for the observed L1/L2 differences in processing, we proposed the shallow structure hypothesis (SSH) according to which the representations adult L2 learners compute during processing contain less syntactic detail than those of child and adult native speakers.
Antibiogram pattern and seasonality of Salmonella serotypes in a North Indian tertiary care hospital
Authors: MOHANTY S. , RENUKA K. , SOOD S. , DAS B. K. , KAPIL A.
Published: February 2006

The antibiogram pattern and seasonal distribution of Salmonella serotypes were analysed retrospectively over a 6-year period from January 1999 to December 2004. Blood cultures received in the Bacteriology Laboratory were processed by standard procedures and the Salmonella spp. isolates were identified with specific antisera and standard biochemical tests. Antimicrobial susceptibility testing was carried out by a standard disc diffusion method and the minimum inhibitory concentration (MIC) of ciprofloxacin for 332 representative Salmonella isolates was determined by E test. Salmonella Typhi (75·7%) was the predominant serotype among 830 Salmonella spp. isolated during the study period followed by S. Paratyphi A (23·8%). The maximum number of enteric fever cases occurred during April–June (dry season) followed by July–September (monsoon season). There was a decrease in multidrug-resistant (MDR) S. Typhi, but MDR S. Paratyphi A isolates increased. There was also a dramatic increase in nalidixic acid-resistant isolates. All isolates were susceptible to third-generation cephalosporins and ciprofloxacin except one S. Typhi strain which demonstrated high-level ciprofloxacin resistance with a MIC of 16 μg/ml. A knowledge of the seasonal distribution and antibiotic resistance pattern of Salmonella in a particular geographical region is helpful in the delineation of appropriate control measures required for prevention of enteric fever.
Evaluation of the meningitis epidemics risk model in Africa
Authors: SAVORY E. C. , CUEVAS L. E. , YASSIN M. A. , HART C. A. , MOLESWORTH A. M. , THOMSON M. C.
Published: February 2006

Meningitis epidemics have a strong environmental component in Africa with the most severe epidemics occurring in the Sahelian region known as the Meningitis Belt. The objective of this study is to evaluate an ecological model based on absolute humidity and land cover type to predict the location of these epidemics. The risk model is evaluated prospectively based on epidemics occurring in Africa from January 2000 to April 2004. Seventy-one epidemics occurred during this time period affecting 22% of continental African districts. The model predicted their location with a sensitivity of 88%. The evaluation also suggests that epidemics may be extending south of the Sahel, which is consistent with environmental changes in the region. This model could be used to select priority areas for the introduction of the newly developed conjugate meningococcal vaccines. Further studies are needed to enhance our understanding of the complex relationship between meningitis epidemics and the environment.
Is the Water Rising? Reflections on Inequality and
American Democracy
Authors: Bartels Larry M.
Published: February 2006

Many Americans were shocked and shamed by the televised images of New
Orleans in the wake of Hurricane Katrina. Scenes of physical
devastation were juxtaposed with even more disturbing scenes of
human devastation. Thousands of residents, mostly Black and poor,
seemed to be trapped in a Hobbesian state of nature, abandoned by
government and civilized society. An untold number starved to death;
for days their corpses floated in the streets.
Comment on “American Democracy in an Age of Rising
Inequality”
Authors: Bennett Stephen Earl
Published: February 2006

The American Political Science Association's (APSA) Task Force on
Inequality and American Democracy (2004) asserts that inequality is
on the rise in the U.S., and democracy's future may be dim. These
assertions are allegedly supported by empirical evidence.
Politicized Pseudo Science
Authors: Weissberg Robert
Published: February 2006

On June 7th, 2004 the American Political Science
Association (APSA) issued a Media Advisory announcing, “Leading
Political Scientists Warn of Threat to American Democracy in Rare
Nonpartisan Statement” (APSA Press Release 2004). The subtitle
reiterated this alarmist tone: “New Study will Report Economic
Disparities Deny Many Americans A Political Voice; Money Buys
Access; Gains in Civil Rights Threatened as Well.” Note, we are
speaking of “threats”
(to democracy) that are “profound.” Furthermore, “research shows a
devastating erosion of political equality in
America” (italics added). Have these distinguished professors
possibly discovered a conspiracy to cancel elections, repeal the
First Amendment, or otherwise impose a racist plutocracy? Are
retired generals and multinational CEOs about to launch a
coup d'état?
Long Lines, Voting Machine Availability, and Turnout: The
Case of Franklin County, Ohio in the 2004 Presidential
Election
Authors: Highton Benjamin
Published: February 2006

Within polling places, does the scarcity of voting machines cause
longer lines and thereby dissuade some people from voting? Are
voting machines scarce in some areas because turnout would be low,
irrespective of the availability of voting machines? In Ohio in the
aftermath of the 2004 presidential election, the answers to these
questions carried very real and significant political stakes.
Consider the following from Franklin County, the second most
populous county in the state. In precincts where voting machines
were plentiful (i.e., where there were fewer registrants per
available voting machine), turnout was especially high and John
Kerry's share of the presidential vote was low. In contrast, in
areas of machine scarcity (i.e., precincts with many registrants per
available voting machine), turnout was lower and Kerry's vote share
was higher. These relationships are shown in Figures 1A and 1B.
Given the strong association between machine availability and the
Kerry vote, if machine (un)availability was a cause of (low)
turnout, then Kerry may very well have received fewer votes than he
would have had more machines been available or had the distribution
of available machines been less skewed toward precincts that were
more supportive of George W. Bush. I
appreciate input from SSRC Commission members Henry Brady,
Martha Kropf, Walter R. Mebane, Jr., and Michael Traugott with
whom I collaborated on the SSRC's “Interim Report on Alleged
Irregularities in the United States Presidential Election of 2
November 2004” (Brady et al. 2004). I
also thank Benjamin Bishin for comments on the paper. The Social
Science Research Council and its staff, including Jason
McNichol, Dashiell Flynn, and Sarah Alexander, provided generous
support for this work. The views expressed in this paper are not
necessarily shared by other SSRC Commission members or the
Social Science Research Council.