bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regression B‐spline smoothing in Bayesian disease mapping: with an application to patient safety surveillance
Authors: MacNab Ying C. , Gustafson Paul 
Published: March 2007

AbstractIn the context of Bayesian disease mapping, recent literature presents generalized linear mixed models that engender spatial smoothing. The methods assume spatially varying random effects as a route to partially pooling data and ‘borrowing strength’ in small‐area estimation. When spatiotemporal disease rates are available for sequential risk mapping of several time periods, the ‘smoothing’ issue may be explored by considering spatial smoothing, temporal smoothing and spatiotemporal interaction. In this paper, these considerations are motivated and explored through development of a Bayesian semiparametric disease mapping model framework which facilitates temporal smoothing of rates and relative risksviaregression B‐splines with mixed‐effect representation of coefficients. Specifically, we develop spatial priors such as multivariate Gaussian Markov random fields and non‐spatial priors such as unstructured multivariate Gaussian distributions and illustrate how time trends in small‐area relative risks may be explored by splines which vary in either a spatially structured or unstructured manner. In particular, we show that with suitable prior specifications for the random effects ensemble, small‐area relative risk trends may be fit by ‘spatially varying’ or randomly varying B‐splines. A recently developed Bayesian hierarchical model selection criterion, the deviance information criterion, is used to assess the trade‐off between goodness‐of‐fit and smoothness and to select the number of knots. The methodological development aims to provide reliable information about the patterns (both over space and time) of disease risks and to quantify uncertainty. The study offers a disease and health outcome surveillance methodology for flexible and efficient exploration and assessment of emerging risk trends and clustering. The methods are motivated and illustrated through a Bayesian analysis of adverse medical events (also known asiatrogenic injuries) among hospitalized elderly patients in British Columbia, Canada. Copyright © 2007 John Wiley & Sons, Ltd.
Complicated Appendicitis: Laparoscopic or Conventional Surgery?
Authors: Kirshtein Boris , Bayme Michael , Domchik Sergey , Mizrahi Solly , Lantsberg Leonid 
Published: March 2007

AbstractBackgroundThe surgical treatment of complicated appendicitis remains controversial. The aim of this study was to evaluate the role of laparoscopic appendectomy in the treatment of complicated appendicitis in comparison with open surgery.MethodsWe reviewed the medical records of all patients who underwent an appendectomy for complicated appendicitis between January 2001 and August 2005.ResultsWe identified 98 patients with complicated appendicitis. Forty‐eight patients underwent open appendectomy, 42 laparoscopic appendectomy, and 8 initial laparoscopy with conversion to open surgery. Older patients, patients with comorbidities, and female patients were more likely to have been offered a laparoscopic appendectomy. Operating time, time to solid oral intake, and time of hospital stay were prolonged in the laparoscopic group but not significantly. There was no mortality observed in either group, and the complication rate was similar in both groups.ConclusionsLaparoscopic appendectomy is an acceptable procedure for complicated appendicitis, with the same rate of infectious complications as the conventional approach.
Gimbernat y Arbós, Antonio de (1734–1816)
Authors: Loukas Marios , El‐Sedfy Abraham , Tubbs R. Shane , Linganna Sanjay , Salter E. George , Jordan Robert 
Published: March 2007

AbstractDon Manuel Louise Antonio de Gimbernat y Arbós, Spanish anatomist and surgeon, was one of the pioneers during the “age of dissection” (late eighteenth century). A bright young mind, Gimbernat was confident and audacious, which allowed him to become a recognized surgeon with a famed reputation that influenced his colleagues internationally. The Spaniard was most widely recognized for his advancements in the treatment of strangulated femoral hernias, and the lacunar ligament was named “Gimbernat’s ligament” in his honor. In 1793, he published Nuevo Método de operar en la Hernia Crural dedicated to King Charles IV, which was translated into English by Thomas Beddoes 2 years later. Gimbernat’s daring procedures helped improve safety and efficiency of hernia surgery. A person of great determination, he was known as a brilliant, meticulous, and creative man who exemplified the importance of surgeons. His devoted study of anatomy, especially of inguinal anatomy, allowed him to devise a legendary surgical technique in repairing femoral hernias, influencing renowned surgeons of his time and thereafter.
Augmented versus Virtual Reality Laparoscopic Simulation: What Is the Difference?
Authors: Botden Sanne M.B.I. , Buzink Sonja N. , Schijven Marlies P. , Jakimowicz Jack J. 
Published: March 2007

AbstractBackgroundVirtual reality (VR) is an emerging new modality for laparoscopic skills training; however, most simulators lack realistic haptic feedback. Augmented reality (AR) is a new laparoscopic simulation system offering a combination of physical objects and VR simulation. Laparoscopic instruments are used within an hybrid mannequin on tissue or objects while using video tracking. This study was designed to assess the difference in realism, haptic feedback, and didactic value between AR and VR laparoscopic simulation.MethodsThe ProMIS AR and LapSim VR simulators were used in this study. The participants performed a basic skills task and a suturing task on both simulators, after which they filled out a questionnaire about their demographics and their opinion of both simulators scored on a 5‐point Likert scale. The participants were allotted to 3 groups depending on their experience: experts, intermediates and novices. Significant differences were calculated with the paired t‐test.ResultsThere was general consensus in all groups that the ProMIS AR laparoscopic simulator is more realistic than the LapSim VR laparoscopic simulator in both the basic skills task (mean 4.22 resp. 2.18, P < 0.000) as well as the suturing task (mean 4.15 resp. 1.85, P < 0.000). The ProMIS is regarded as having better haptic feedback (mean 3.92 resp. 1.92, P < 0.000) and as being more useful for training surgical residents (mean 4.51 resp. 2.94, P < 0.000).ConclusionsIn comparison with the VR simulator, the AR laparoscopic simulator was regarded by all participants as a better simulator for laparoscopic skills training on all tested features.
Effects of adult neighbour and gap size on seedling emergence and early growth of Bromus inermis Leyss
Authors: Liu Guixia , Mao Peisheng , Wang Yunwen , Han Jianguo 
Published: March 2007

AbstractA field study was conducted to determine the effects of neighbour root exclusion and gap size on the seedling emergence and early growth of Bromus inermis. Seeds of B. inermis were added to artificially created gaps in an improved shortgrass steppe in northern China. Neighbour root exclusion was accomplished using PVC tubes sunk in the soil of gaps. Emergence and survival of seedlings were greater in all gaps than in the control (0‐cm diameter), but better growth performance (height of seedling, leaves, tillers and dry weight per seedling) was observed only in large gaps (20‐ and 40‐cm diameter) with neighbour root present and gaps without neighbour root presence. Seedling growth performance was improved by reducing root and shoot competition. Neighbour root exclusion provided a favourable environment for seedling establishment. Differences between gaps in light levels and topsoil temperature can explain the patterns of germination. These results confirm that B. inermis is a gap‐enhanced species. Our study strongly suggests that asymmetric competition by adult neighbour plants negatively influences the establishment of B. inermis.
Effects of Antioxidants on the Oxidative Stability of Oils Containing Arachidonic, Docosapentaenoic and Docosahexaenoic Acids
Authors: Bartee Shirley D. , Kim Hyun Jung , Min David B. 
Published: March 2007

AbstractThe effects of ascorbyl palmitate at 0, 300, 600, 900, or 1,200 ppm, tocopherol at 0, 200, 400, 600, or 800 ppm, and β‐carotene at 0, 3, 6, 9, or 12 ppm on the oxidative stabilities of Oil 1, Oil 2, and Oil 3 containing 0, 0.55, and 0.67% of combined arachidonic acid (AA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), respectively, were studied by a central composite experimental design. The oxidative stability of oil was evaluated by determining the induction time using the Oxidative Stability Index. Ascorbyl palmitate and tocopherol had a significant effect on the stability of all three oils at α = 0.05. β‐Carotene did not have any effect on the stability of oils at α = 0.05. The interaction effect of ascorbyl palmitate and tocopherol was significant for the three oils at α = 0.05. The induction time of oils decreased as the total amounts of AA, DPA and DHA increased from 0 to 0.55% or 0.55 to 0.67%. The addition of 1,200 ppm ascorbyl palmitate, 800 ppm tocopherol and 12 ppm β‐carotene to Oils 1, 2, and 3 increased the induction time from 13.5 to 29.9 h, from 11.8 to 27.0 h, and from 10.5 to 20.0 h, respectively. The coefficient of determination (r2) for the linear regression between the experimentally determined and statistically predicted induction time of the three oils was greater than 0.95. The use of an optimum combination of ascorbyl palmitate and tocopherols from the response surface analysis could improve the oxidative stabilities of oils containing AA, DPA and DHA.
The management of Legg-Calvé-Perthes’ disease: Is there a consensus?
Authors: Hefti Fritz , Clarke N. M. P. 
Published: March 2007

Purpose The aim of the study was to find out whether or not there is consensus among experienced pediatric orthopaedists about the management of certain clinical scenarios in Legg-Calvé-Perthes’ disease. Methods A questionnaire was sent to all 297 members of the European Paediatric Orthopaedic Society (EPOS) describing four cases of Legg-Calvé-Perthes’ disease (LCPD) with two X-rays each and a short description of the clinical scenario. Two of the patients were younger and two were older than six years of age. From both age groups there was one with a good range of motion and an X-ray classified as Herring A or B, while the other patient had a poor range of motion and an X-ray classified as Herring C. EPO members were asked to choose from various treatment options or to describe any other therapy that they would advise in the clinical scenarios. Results One-hundred and fifty members answered the questionnaire. The participants had an average of 20 years of experience in pediatric orthopaedics. There was a consensus that no surgery should be performed in a young patient with a good range of motion and that there should be no weight relief when older with a good range of motion. Conservative containment treatment (abduction splint, Petrie cast) and arthrodiastasis was suggested in only very few centres. There was a tendency to perform • an operation when the patient is older with a poor range of motion and to perform operative treatment only when there were subluxation or head at risk signs. • pelvic osteotomies or a combination of pelvic and femoral osteotomies rather than femoral osteotomies alone. Age did not determine the indication for treatment and there was no agreement on the indications for physiotherapy. There was also no consensus on the type of pelvic osteotomy to be used. Conclusions The study showed that indications for the treatment of LCPD is based more on the personal experience of the surgeon rather than on scientific data.
Intergenerational discrepancies of parental control among Chinese American families: Links to family conflict and adolescent depressive symptoms
Authors: Juang Linda P. , Syed Moin , Takagi Miyuki 
Published: March 2007

AbstractThis study investigated how discrepancies between adolescents’ and parents’ endorsement of parental control contribute to adolescent depressive symptoms. Family conflict was hypothesized to mediate the link between parent–adolescent discrepancies and depressive symptoms. The sample consisted of 166 pairs of Chinese American adolescents and their parents. The results indicated that, as predicted, greater discrepancies between adolescents and their parents on parental control related to greater adolescent depressive symptoms. Furthermore, adolescent's perceived degree of family conflict partially mediated this relation. Both parents and adolescents are changing and adapting to their cultural contexts; some in synchrony and some not. Identifying areas where parents and adolescents diverge concerning values, behaviors, and beliefs, is an important avenue to understanding Chinese American adolescents’ mental health.
Changing Media and Changing Political Organization: Delegation, Representation and News
Authors: POPKIN SAMUEL L. 
Published: March 2007

This article examines the ways that new communications technologies change the organization of politics as well as the content of news. Changes in the media lead to changes in the mediators, the persons who choose and interpret the news for the public. When new mediators convey different news stories or offer different interpretations from the previous regime, they redistribute control of politics and culture.As media get cheaper, faster and harder to control, state regulation of content becomes less effective. This provides new opportunities for citizens to monitor their leaders and alters the ways that leaders – whether they are democratic or authoritarian – demonstrate accountability.Political leaders are always trying to control the agenda by limiting information available to the public and convincing the public that they know more and know best. New forms of media, such as the commercial television, cable and satellite television, and the internet change political competition by providing new opportunities for insurgent politicians to challenge their elders. I consider these changes within the context of past innovations, including the rise of the printing press, the telegraph, the newspaper, and radio.
A knowledge-based approach for selecting information sources
Authors: EITER THOMAS , FINK MICHAEL , TOMPITS HANS 
Published: March 2007

AbstractThrough the Internet and the World-Wide Web, a vast number of information sources has become available, which offer information on various subjects by different providers, often in heterogeneous formats. This calls for tools and methods for building an advanced information-processing infrastructure. One issue in this area is the selection of suitable information sources in query answering. In this paper, we present a knowledge-based approach to this problem, in the setting where one among a set of information sources (prototypically, data repositories) should be selected for evaluating a user query. We use extended logic programs (ELPs) to represent rich descriptions of the information sources, an underlying domain theory, and user queries in a formal query language (here, XML-QL, but other languages can be handled as well). Moreover, we use ELPs for declarative query analysis and generation of a query description. Central to our approach are declarativesource-selection programs, for which we define syntax and semantics. Due to the structured nature of the considered data items, the semantics of such programs must carefully respect implicit context information in source-selection rules, and furthermore combine it with possible user preferences. A prototype implementation of our approach has been realized exploiting the DLV KR system and its PLP front-end for prioritized ELPs. We describe a representative example involving specific movie databases, and report about experimental results.
Well-founded and stable semantics of logic programs with aggregates
Authors: PELOV NIKOLAY , DENECKER MARC , BRUYNOOGHE MAURICE 
Published: March 2007

AbstractIn this paper, we present a framework for the semantics and the computation of aggregates in the context of logic programming. In our study, an aggregate can be an arbitrary interpreted second order predicate or function. We define extensions of the Kripke-Kleene, the well-founded and the stable semantics for aggregate programs. The semantics is based on the concept of a three-valuedimmediate consequence operatorof an aggregate program. Such an operatorapproximatesthe standard two-valued immediate consequence operator of the program, and induces a unique Kripke-Kleene model, a unique well-founded model and a collection of stable models. We study different ways of defining such operators and thus obtain a framework of semantics, offering different trade-offs betweenprecisionandtractability. In particular, we investigate conditions on the operator that guarantee that the computation of the three types of semantics remains on the same level as for logic programs without aggregates. Other results show that, in practice, even efficient three-valued immediate consequence operators which are very low in the precision hierarchy, still provide optimal precision.
Characterizing an outbreak of vancomycin-resistant enterococci using hidden Markov models
Authors: McBryde E.S , Pettitt A.N , Cooper B.S , McElwain D.L.S 
Published: March 2007

Background
. Antibiotic-resistant nosocomial pathogens can arise in epidemic clusters or sporadically. Genotyping is commonly used to distinguish epidemic from sporadic vancomycin-resistant enterococci (VRE). We compare this to a statistical method to determine the transmission characteristics of VRE.

Methods and findings
. A structured continuous-time hidden Markov model (HMM) was developed. The hidden states were the number of VRE-colonized patients (both detected and undetected). The input for this study was weekly point-prevalence data; 157 weeks of VRE prevalence. We estimated two parameters: one to quantify the cross-transmission of VRE and the other to quantify the level of VRE colonization from sporadic sources. We compared the results to those obtained by concomitant genotyping and phenotyping.

We estimated that 89% of transmissions were due to ward cross-transmission while 11% were sporadic. Genotyping found that 90% had identical glycopeptide resistance genes and 84% were identical or nearly identical on pulsed-field gel electrophoresis (PFGE).
There was some evidence, based on model selection criteria, that the cross-transmission parameter changed throughout the study period. The model that allowed for a change in transmission just prior to the outbreak and again at the peak of the outbreak was superior to other models. This model estimated that cross-transmission increased at week 120 and declined after week 135, coinciding with environmental decontamination.

Significance
. We found that HMMs can be applied to serial prevalence data to estimate the characteristics of acquisition of nosocomial pathogens and distinguish between epidemic and sporadic acquisition. This model was able to estimate transmission parameters despite imperfect detection of the organism. The results of this model were validated against PFGE and glycopeptide resistance genotype data and produced very similar results. Additionally, HMMs can provide information about unobserved events such as undetected colonization.
Edge waves: theories past and present
Authors: Johnson R.S 
Published: March 2007

The problem of edge waves as an example within classical water-wave theory is described by presenting an overview of some of the theories that have been offered for this phenomenon. The appropriate governing equations and boundary conditions are formulated, and then the important discoveries of Stokes and Ursell, concerning the travelling edge wave, are presented. (We do not address the corresponding problem of standing waves.) Thus, the linear problem and its spectrum are constructed; in addition, we also present the linear long-wave approximation to the problem, as well as Whitham's weakly nonlinear extension to Stokes' original theory. All these discussions are based on the same formulation of the problem, allowing an immediate comparison of the results, whether this be in terms of different approximations or whether the theory be for an irrotational flow or not.
Gerstner's exact solution of the water-wave problem is then briefly described, together with a transformation that produces an exact solution of the full equations for the edge wave. The form of this solution is then used as the basis for a multiple-scale description of the edge wave over a slowly varying depth; this leads to a version of the shallow-water equations which has an exact solution that corresponds to the edge wave. Some examples of the theoretical predictions for the run-up pattern are presented. We conclude with three variants of nonlinear model equations that may prove useful in the study of edge waves and, particularly, the interaction of different modes.
Hypoxia increases the motility of lung adenocarcinoma cell line A549 via activation of the epidermal growth factor receptor pathway
Authors: Wang Tao , Niki Toshiro , Goto Akiteru , Ota Satoshi , Morikawa Teppei , Nakamura Yu , Ohara Etsuko , Ishikawa Shumpei , Aburatani Hiroyuki , Nakajima Jun , Fukayama Masashi 
Published: March 2007

Tumor hypoxia is associated with a malignant phenotype of cancer cells and poor patient prognosis. To investigate the role of hypoxia in tumor progression, we studied the effects of hypoxia in the A549 lung adenocarcinoma cell line. First, we showed that hypoxic treatment decreased cell–cell adhesion and induced a scattering of cancer cells. Concomitant with these morphological changes, the motility of cancer cells was increased, as demonstrated by the Boyden chamber assay. Then, we used oligonucleotide array analyses to identify the genes causally related to the hypoxia‐induced motile phenotype. The results showed that the expression of approximately 100 genes was induced more than 5‐fold by hypoxia. These included (among others) epidermal growth factor receptor (EGFR), as well as other well‐known hypoxia‐induced genes, such as vascular endothelial growth factor. Immunohistochemical analyses of primary lung adenocarcinomas confirmed the induction of EGFR in tumor cells in the vicinity of necrotic areas, a histological indicator of tumor hypoxia. Remarkably, the EGFR inhibitor AG1478 (10 M) completely blocked the increased cell motility induced by hypoxia. Thus, the present study demonstrates the importance of the EGFR pathway in the increased motility of cancer cells that occurs in a hypoxic tumor environment. (Cancer Sci 2007; 98: 506–511)