bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical Management of Idiopathic Normal-pressure Hydrocephalus
Authors: Bergsneider Marvin , Black Peter McL. , Klinge Petra , Marmarou Anthony , Relkin Norman
Published: September 2005

OBJECTIVE:

To develop evidence-based guidelines for surgical management of idiopathic normal-pressure hydrocephalus (INPH). Compared with the diagnostic phase, the surgical management of INPH has received less scientific attention. The quality of much of the literature concerning the surgical management has been limited by many factors. These include retrospective analysis, small patient numbers, analysis of a mixed NPH population, and sometimes a lack of detail as to what type of shunt system was used. Many earlier studies predated our current understanding of the hydrodynamics of cerebrospinal fluid shunts, and therefore, the conclusions drawn may no longer be valid.

METHODS:

A MEDLINE and PubMed search from 1966 to the present was conducted using the following key terms: normal-pressure hydrocephalus and idiopathic adult-onset hydrocephalus. Only English-language literature in peer-reviewed journals was reviewed. The search was further limited to articles that described the method of treatment and outcome selectively for INPH patients. Finally, only studies that included 20 or more INPH patients were considered with respect to formulating the recommendations in these Guidelines (27 articles).

RESULTS:

For practical reasons, it is important to identify probable shunt responders diagnosed with INPH. If the patient is an acceptable candidate for anesthesia, then an INPH-specific risk-benefit analysis should be determined. In general, patients exhibiting negligible symptoms may not be suitable candidates for surgical management, given the known risks and complications associated with shunting INPH. The choice of valve type and setting should be based on empirical reasoning and a basic understanding of shunt hydrodynamics. The most conservative choice is a valve incorporating an antisiphon device, with the understanding that underdrainage (despite a low opening pressure) may occur in a small percentage of patients because of the antisiphon device. On the basis of retrospective studies, the use of an adjustable valve seems to be beneficial in the management of INPH.

CONCLUSION:

The treatment of INPH should not be considered lightly, given the seriousness of the potential complications. Within these limitations and the available evidence, guidelines for surgical management were developed.
Development of Guidelines for Idiopathic Normal-pressure Hydrocephalus: Introduction
Authors: Marmarou Anthony , Bergsneider Marvin , Relkin Norman , Klinge Petra , Black Peter McL.
Published: September 2005

OBJECTIVE:

There are no currently accepted evidence-based guidelines for the diagnosis and management of the normal-pressure hydrocephalus (NPH) patient. As a result, an independent study group was assembled to address this issue and determine the feasibility of developing standardized guidelines, which would be acceptable in the United States and abroad and would be based on the available scientific evidence. The guidelines were to encompass value of clinical presentation, value of supplementary diagnostic tests, surgical management, and outcome assessment.

METHODS:

Initially, a series of 10 questions were formulated in the areas of pathophysiology, diagnosis, and treatment to obtain a consensus by panels of experts (see Acknowledgments) assembled in San Antonio, TX, in September 2000. This workshop provided significant insight into the difficulties in developing NPH guidelines, and a consensus was reached as to those questions involving expert opinion. Subsequently, evidentiary tables were developed on the basis of the available evidence. Only those studies with 20 or more idiopathic NPH (INPH) patients were included.

RESULTS:

Sensitivity, specificity, and positive and negative predictive values for INPH diagnostic criteria were assessed, and guidelines were developed on the basis of the available evidence. Recommendations for classification of INPH and additional studies were documented.

CONCLUSION:

The development of the guidelines was made difficult because systematic studies of INPH and patient numbers were few. It was decided to maintain the classification of NPH into two major categories, INPH and those of known cause (secondary NPH). Many studies “mixed” these classifications, and as a result, they could not be used in the evidentiary tables. Despite these problems, evidence-based guidelines were developed, and it is hoped that they will be useful in guiding clinical management of the INPH patient.
A Patient with a Resistant Major Depression Disorder Treated with Deep Brain Stimulation in the Inferior Thalamic Peduncle
Authors: Jiménez Fiacro , Velasco Francisco , Salin-Pascual Rafael , Hernández José A. , Velasco Marcos , Criales José L. , Nicolini Humberto
Published: September 2005

OBJECTIVE AND IMPORTANCE:

The present report explored the effect of electrical stimulation on the inferior thalamic peduncle in a patient with resistant major depression disorder (MDD).

CLINICAL PRESENTATION:

This report refers to a 49-year-old woman with a history of recurrent episodes of major depression for 20 years (12 episodes and 2 hospitalizations), fulfilling Diagnostic and Statistical Manual of Mental Disorders, 4th edition, revised, criteria for MDD; in addition, the patient met criteria for borderline personality disorder and bulimia. Her longest episode of depression with suicidal ideation began 5 years before surgery. The patient's symptom array responded poorly to different combinations of antidepressants, cognitive therapy, and electroconvulsive therapy, which induced improvement only for short periods of time. Immediately before surgery, her Global Assessment of Functioning score was 20 and her Hamilton Depression Scale score ranged from 33 to 42. The patient was proposed for surgery for MDD.

INTERVENTION:

The patient had bilateral eight-contact electrodes stereotactically implanted for stimulation of areas at and around the inferior thalamic peduncle. Electrode position was corroborated by unilateral electrical stimulation searching for recruiting responses and regional direct current shifts in the electroencephalogram. Recording electrodes were replaced by tetrapolar electrodes for deep brain stimulation and connected to an internalized stimulation system for continuous bipolar stimulation at 130 Hz, 0.45 milliseconds, 2.5 V. Bimonthly follow-up included psychiatric and neuropsychological evaluations performed over the course of 24 months. After 8 months of ON stimulation, the patient entered a double-blind protocol with stimulators turned OFF. Improvement of depression measured by the Hamilton Depression Scale score was evident after initial placement of electrodes without electrical stimulation. Depression relapsed partially at the end of the first week. Electrical stimulation further improved depression, normalizing depression scores and neuropsychological performance. Patient depression scores ranked between 2 and 8 during 8 months of ON stimulation without antidepressant medication. After stimulation was turned OFF, spontaneous fluctuations in patient symptoms reflected by Hamilton Depression Scale and Global Assessment of Functioning scores were documented; these fluctuations disappeared after stimulation was turned on by Month 20.

CONCLUSION:

Complicated patients with comorbid conditions are common referrals to psychosurgery services. In this report, we present promising results of electrical stimulation of the inferior thalamic peduncle to treat recurrent unipolar depression in a patient with MDD and borderline personality disorder who responded poorly to treatment.
Prediction of Prolonged Postprocedural Hypotension after Carotid Artery Stenting
Authors: Nonaka Tadashi , Oka Shinichi , Miyata Kei , Mikami Takeshi , Koyanagi Izumi , Houkin Kiyohiro , Yoshifuji Kazuhisa , Imaizumi Toshio
Published: September 2005

OBJECTIVE:

Stent placement for the treatment of carotid artery stenosis may cause hemodynamic instability that induces ischemic complications for patients with bilateral carotid lesions. We carried out this study to define predictors of persistent hypotension after carotid stenting.

METHODS:

Thirty-three lesions in 31 consecutive patients (mean age, 69.2 ± 8.6 yr) who underwent stent deployment for carotid stenosis were studied. Fourteen lesions were treated with Easy Wall stents (Boston Scientific, Tokyo, Japan) and 19 lesions were treated with Smart stents (Johnson & Johnson, Warren, NJ). We reviewed preoperative angiograms and ultrasonograms of the carotid artery and analyzed the predictive factors of postprocedural prolonged hypotension (systolic blood pressure <90 mm Hg and periods >3 h).

RESULTS:

Postprocedural hypotension was observed in 14 lesions (42.4%), of which medical treatment was necessary in seven (21.2%). A distance between carotid bifurcation and maximum stenotic lesion (≤10 mm; P = 0.0028) and type of stenosis (eccentric; P = 0.0287) on angiogram and fibrous plaque morphological features (P = 0.0008) and calcifications at carotid bifurcation (P = 0.0004) on ultrasonograms were determined to be independent risk factors of postprocedural hypotension. We introduced a scoring system for predicting prolonged hypotension that included factors such as the distance from carotid bifurcation to maximum stenotic lesion (≤10 mm), type of stenosis (eccentric), plaque morphological features (echogenic), and calcification at carotid bifurcation. The score was determined by adding one point for each of these factors. Three points or more on this score strongly suggested a high risk of prolonged hypotension.

CONCLUSION:

Our scoring system, which includes angiographic and ultrasonographic findings, may be a good index for the prediction of prolonged hypotension after carotid stenting and may contribute to the reduction of periprocedural ischemic events.
Reconstruction of Anterior Iliac Crest after Bone Graft Harvest Decreases Pain: A Randomized, Controlled Clinical Trial
Authors: Resnick Daniel K.
Published: September 2005

OBJECTIVE:

A substantial number of patients report persistent pain after graft harvest from the anterior iliac crest. There have been several retrospective case series published that suggest that iliac crest reconstruction using a variety of techniques may decrease graft site pain. This study, a randomized, controlled clinical trial at a university hospital, tested the hypothesis that reconstruction of the iliac crest will reduce graft harvest site pain.

METHODS:

A randomized, controlled clinical trial using the McGill Pain Inventory as the primary outcome measure was performed to evaluate the effect of anterior iliac crest reconstruction after graft harvest. Thirty patients who were treated with anterior cervical discectomy and fusion or cervical corpectomy and fusion with autologous iliac crest graft were randomized to one of two groups. Patients in Group 1 were treated with reconstruction of the iliac crest with commercially available tricalcium phosphate bone void filler after graft harvest. Patients in Group 2 were treated without graft site reconstruction. Graft site pain was assessed immediately after surgery, 6 weeks after surgery, and 3 months after surgery.

RESULTS:

Treatment groups were well matched with regard to patient age, sex, and smoking history. Although patients in each group reported persistent pain 6 weeks and 3 months after graft harvest, patients in the reconstruction group reported significantly less severe pain at 6 weeks and tended to have less pain at 3 months after surgery.

CONCLUSION:

Reconstruction of the iliac crest with tricalcium phosphate bone void filler significantly decreases the severity of postoperative pain 6 weeks after surgery.
Radiosurgery in the Treatment of Malignant Gliomas: The University of Florida Experience
Authors: Ulm Arthur J. , Friedman William A. , Bradshaw Patrick , Foote Kelly D. , Bova Frank J.
Published: September 2005

OBJECTIVE:

To review a single-institution's 12-year experience of treating malignant gliomas with linear accelerator-based radiosurgery.

METHODS:

One hundred patients were treated for malignant gliomas at the University of Florida between May 1, 1989, and June 12, 2002. Patient variables were entered into a radiosurgery database in a prospective manner. The endpoint of the study was length of survival from the time of diagnosis. The minimum length of follow-up was 18 months or until death. In an attempt to control for selection bias, we used the Radiation Oncology Therapy Group's (RTOG) recursive partitioning categories to compare survival in our group of radiosurgically boosted patients with the RTOG historical database.

RESULTS:

Recursive partitioning analysis classification was significantly associated with survival. Compared with historical controls, this cohort of patients demonstrated a decreased survival for recursive partitioning analysis Class I and II patients, similar survival for Class III and IV patients, and increased median survival for Class V patients. Other variables demonstrating a statistically significant impact on survival were eloquent location and recurrent disease.

CONCLUSION:

The results of this study and those of RTOG 93-05 suggest that the reported benefit of upfront radiosurgical boost for malignant gliomas is the result of selection bias. The possibility remains that radiosurgical boost is of benefit in recurrent tumors, especially those in RTOG Class V.
A Prospective Study of Quality of Life in Adults with Newly Diagnosed High-grade Gliomas: The Impact of the Extent of Resection on Quality of Life and Survival
Authors: Brown Paul D. , Maurer Matthew J. , Rummans Teresa A. , Pollock Bruce E. , Ballman Karla V. , Sloan Jeff A. , Boeve Bradley F. , Arusell Robert M. , Clark Matthew M. , Buckner Jan C.
Published: September 2005

OBJECTIVE:

To describe the quality of life (QOL) over time for adults with newly diagnosed high-grade gliomas and to examine the relationship between QOL and outcome data collected in three prospective cooperative group clinical trials.

METHODS:

The QOL study was a companion protocol for three Phase II high-grade glioma protocols. Five self-administered forms were completed by patients to assess QOL at study entry, 2 months, and 4 months after enrollment.

RESULTS:

QOL data were available for baseline, first, and second subsequent follow-up evaluations for 89%, 71%, and 69% of patients, respectively. A significant proportion of patients (47.1%) experienced impaired QOL (QOL ≤ 50) in at least one measure at subsequent evaluations, whereas most patients (88%) with impaired QOL at baseline continued to have impaired QOL at subsequent evaluations. On multivariable analyses, baseline QOL measures were predictive of QOL at the time of follow-up. In addition, patients who underwent a gross total resection were much less likely to have impaired QOL (P = 0.006), were less likely to experience worsening depression (P = 0.0008), and were more likely to have improved QOL (P = 0.003) at their first follow-up evaluation. Changes in QOL measures over time were not found to be associated with survival in multivariable analyses that adjusted for known prognostic variables; variables that were independently associated with improved survival were better performance status (P < 0.001), younger age (P < 0.001), and greater extent of resection (P < 0.001).

CONCLUSION:

Baseline QOL was predictive of QOL over time. Gross total resection was associated with longer survival and improved QOL over time for patients with high-grade gliomas.
Diagnosis and Treatment of Atypical and Anaplastic Meningiomas: A Review
Authors: Modha Ashok , Gutin Philip H.
Published: September 2005

ATYPICAL AND ANAPLASTIC meningiomas are uncommon tumors with a poorer prognosis than benign meningiomas. We reviewed the current literature and attempted to integrate and summarize available information to determine a logical approach to these tumors. Both tumors are rare and are often integrated with benign meningiomas when treatments are evaluated. In addition, because there has not been one histopathological classification scheme for atypical and anaplastic meningiomas in the past, there are numerous inconsistencies in the literature. Malignant progression with accumulation of mutations in a benign meningioma can result in an atypical and/or anaplastic meningioma. Both tumors are difficult to manage and have high recurrence and poor survival rates. The extent of tumor resection and histological grade are the key determinants for recurrence. In addition, metastases are unusual, but they do occur. We also review the evidence available that has resulted in the current World Health Organization classification. Radiation therapy can be used as an adjunctive treatment after both total and subtotal resection. In addition, the role of stereotactic radiosurgery is increasing, along with a possible role for brachytherapy. There are no effective chemotherapeutic agents available. A treatment algorithm is suggested.
Analysis of a Decentralized Supply Chain Under Partial Cooperation
Authors: Güllü Refik , van Houtum Geert-Jan , Sargut F. Zeynep , Erkip Nesim
Published: September 2005

In this article, we analyze a decentralized supply chain consisting of a supplier and two independent retailers. In each order cycle, retailers place their orders at the supplier to minimize inventory-related expected costs at the end of their respective response times. There are two types of lead times involved. At the end of the supplier lead time, retailers are given an opportunity to readjust their initial orders (without changing the total order size), so that both retailers can improve their expected costs at the end of respective retailer lead times (the time it takes for items to be shipped from the supplier to the retailers). Because of the possibility of cooperation at the end of supplier lead time, each retailer will consider the other’s order-up-to level in making the ordering decision. Under mild conditions, we prove the existence of a unique Nash equilibrium for the retailer order-up-to levels, and show that they can be obtained by solving a set of newsboy-like equations. We also present computational analysis that provides valuable managerial insight for design and operation of decentralized systems under the possibility of partial cooperation.
Zooming In and Out: Connecting Individuals and Collectivities at the Frontiers of Organizational Network Research
Authors: Ibarra Herminia , Kilduff Martin , Tsai Wenpin
Published: September 2005

The role of individual action in the enactment of structures of constraint and opportunity has proved to be particularly elusive for network researchers. We propose three frontiers for future network research that zoom back and forth between individual and collective levels of analysis. First, we consider how dilemmas concerning social capital can be reconciled. Actors striving to reap maximal network advantages may benefit or detract from the collective good; investigating these trade-offs, we argue, will advance our understanding of learning and knowledge processes in organizations. Second, we explore identity emergence and change from a social network perspective. Insights about how networks mold and signal identity are a critical foundation for future work on career dynamics and the workplace experiences of members of diverse groups. Third, we consider how individual cognitions about shifting network connections affect, and are affected by, larger social structures. As scholarly interest in status and reputational signaling grows, articulating more clearly the cognitive foundations of organizational networks becomes imperative.
Designing Work Within and Between Organizations
Authors: Sinha Kingshuk K. , Van de Ven Andrew H.
Published: September 2005

The design of work has been and will continue to be a central problem challenging organization theory and practice. The system of arrangements and procedures for doing work affects all workers every day throughout the world. Work is changing dramatically. In an increasingly global and knowledge-intensive economy, work design is no longer contained within an organization; it often transcends the boundaries of organizations and countries. These changes call for a renewed research focus on work design. Building on configuration and complexity perspectives, we propose a framework for studying work design. We argue that three issues require attention to advance the knowledge of work design: (1) defining the boundaries of work systems, (2) examining how the system is nested in a hierarchy within and between organizations, and (3) determining interactions between the elements of a work system. We propose a method of frontier analysis for identifying equifinal designs—the set of equally effective work designs for different combinations of inputs (situations or contexts) and outputs (performance criteria). When work designs are examined longitudinally, these methods permit an examination of adaptation processes on changing fitness landscapes, suggesting how work systems may increase, decrease, or sustain their relative performance over time.
Regional Industrial Identity: Cluster Configurations and Economic Development
Authors: Romanelli Elaine , Khessina Olga M.
Published: September 2005

We explore the concept of regional industrial identity as an important missing component in our understanding of the development of metropolitan regions and the spatial arrangements of industries. While economists and sociologists have explained the location of industry clusters on the basis of unevenly distributed resources, and historians have provided rich descriptive insight into the developmental dynamics of particular metropolitan regions, little systematic theory has been advanced to explain cross-regional inflows and outflows of resources, especially with respect to patterns in cluster development. This paper examines the concept of regional industrial identity as a social code that (1) arises from the shared understandings of residents and external audiences about the suitability of a region for particular kinds of business activity and (2) influences decisions about where to locate investments. We argue that such understandings are principally informed by configurations of industry clusters that have already formed in a region. Clusters, which are the results of historical investments, are also important signals about the types of business that can thrive in the future. We develop theoretical propositions linking characteristics of regional industry cluster configurations, in particular cluster dominance and cluster interrelatedness, to the strength and focus of regional identity and, as a result, to the types and amounts of resources that will develop within and flow into and out of regions.
Building Organization Theory from First Principles: The Self-Enhancement Motive and Understanding Power and Influence
Authors: Pfeffer Jeffrey , Fong Christina T.
Published: September 2005

In developing and advancing organization theory, it is useful if we can uncover fundamental constructs that can then be used to integrate larger areas of inquiry, even as we continue to accumulate more knowledge, evidence, and concepts. However, accomplishing this will require a somewhat different approach to theory building and testing. We illustrate the process of building an integrated model from fundamental constructs by using the idea of self-enhancement to explore phenomena of power and influence. We argue that many psychological processes related to power and social influence (such as escalation of commitment, similarity attraction and in-group favoritism, the disinhibiting effects of power, and the persistence of hierarchical structures) can all be logically derived from the self-enhancement idea, the desire to see oneself and one’s actions in a positive light. The conceptual model can help us understand apparently anomalous behavior (such as individuals being willing to tolerate poor treatment at the hands of leaders), bringing together a number of ideas and constructs frequently treated as distinct in the literature and providing some hypotheses for future research.
Full-Cycle Micro-Organizational Behavior Research
Authors: Chatman Jennifer A. , Flynn Francis J.
Published: September 2005

We advocate a full-cycle approach to conducting organizational behavior research. Full-cycle research begins with the observation of naturally occurring phenomena and proceeds by traveling back and forth between observation and manipulation-based research settings, establishing the power, generality, and conceptual underpinnings of the phenomenon along the way. Compared with more traditional approaches, full-cycle research offers several advantages, such as specifying theoretical models, considering actual and ideal conditions, and promoting interdisciplinary integration. To illustrate these advantages, we provide examples of an implicit approach to conducting full-cycle research and present suggestions for fostering more explicit full-cycle research programs in the future. We encourage individual researchers to adopt this approach rather than to assume the field will naturally avoid the inevitable vulnerabilities that emerge from relying on particular methodological approaches. We conclude by discussing the relevant constraints and opportunities for engaging in full-cycle organizational research.
Genetic Variation and Selection Response in Model Breeding Populations of Brassica rapa Following a Diversity Bottleneck
Authors: Briggs William H , Goldman Irwin L
Published: September 2005

Domestication and breeding share a common feature of population bottlenecks followed by significant genetic gain. To date, no crop models for investigating the evolution of genetic variance, selection response, and population diversity following bottlenecks have been developed. We developed a model artificial selection system in the laboratory using rapid-cycling Brassica rapa. Responses to 10 cycles of recurrent selection for cotyledon size were compared across a broad population founded with 200 individuals, three bottleneck populations initiated with two individuals each, and unselected controls. Additive genetic variance and heritability were significantly larger in the bottleneck populations prior to selection and this corresponded to a heightened response of bottleneck populations during the first three cycles. However, the overall response was ultimately greater and more sustained in the broad population. AFLP marker analyses revealed the pattern and extent of population subdivision were unaffected by a bottleneck even though the diversity retained in a selection population was significantly limited. Rapid gain in genetically more uniform bottlenecked populations, particularly in the short term, may offer an explanation for why domesticators and breeders have realized significant selection progress over relatively short time periods.
Human Endogenous Retroviral Elements as Indicators of Ectopic Recombination Events in the Primate Genome
Authors: Hughes Jennifer F , Coffin John M
Published: September 2005

HERV elements make up a significant fraction of the human genome and, as interspersed repetitive elements, have the capacity to provide substrates for ectopic recombination and gene conversion events. To understand the extent to which these events occur and gain further insight into the complex evolutionary history of these elements in our genome, we undertook a phylogenetic study of the long terminal repeat sequences of 15 HERV-K(HML-2) elements in various primate species. This family of human endogenous retroviruses first entered the primate genome between 35 and 45 million years ago. Throughout primate evolution, these elements have undergone bursts of amplification. From this analysis, which is the largest-scale study of HERV sequence dynamics during primate evolution to date, we were able to detect intraelement gene conversion and recombination at five HERV-K loci. We also found evidence for replacement of an ancient element by another HERV-K provirus, apparently reflecting an occurrence of retroviral integration by homologous recombination. The high frequency of these events casts doubt on the accuracy of integration time estimates based only on divergence between retroelement LTRs.
A Hyperspace Model to Decipher the Genetic Architecture of Developmental Processes: Allometry Meets Ontogeny
Authors: Wu Rongling , Hou Wei
Published: September 2005

To better utilize limited resources for their survival and reproduction, all organisms undergo developmental changes in both body size and shape during ontogeny. The genetic analysis of size change with increasing age, i.e., growth, has received considerable attention in quantitative developmental genetic studies, but the genetic architecture of ontogenetic changes in body shape and its associated allometry have been poorly understood partly due to the lack of analytical tools. In this article, we attempt to construct a multivariate statistical framework for studying the genetic regulation of ontogenetic growth and shape. We have integrated biologically meaningful mathematical functions of growth curves and developmental allometry into the estimation process of genetic mapping aimed at identifying individual quantitative trait loci (QTL) for phenotypic variation. This model defined with high dimensions can characterize the ontogenetic patterns of genetic effects of QTL over the lifetime of an organism and assess the interplay between genetic actions/interactions and phenotypic integration. The closed forms for the residual covariance matrix and its determinant and inverse were derived to overcome the computational complexity typical of our high-dimensional model. We used a worked example to validate the utility of this model. The implications of this model for genetic research of evo–devo are discussed.
The Evolution of Antifungal Peptides in Drosophila
Authors: Jiggins Francis M , Kim Kang-Wook
Published: September 2005

An essential component of the immune system of animals is the production of antimicrobial peptides (AMPs). In vertebrates and termites the protein sequence of some AMPs evolves rapidly under positive selection, suggesting that they may be coevolving with pathogens. However, antibacterial peptides in Drosophila tend to be highly conserved. We have inferred the selection pressures acting on Drosophila antifungal peptides (drosomycins) from both the divergence of drosomycin genes within and between five species of Drosophila and polymorphism data from Drosophila simulans and D. melanogaster. In common with Drosophila antibacterial peptides, there is no evidence of adaptive protein evolution in any of the drosomycin genes, suggesting that they do not coevolve with pathogens. It is possible that this reflects a lack of specific fungal and bacterial parasites in Drosophila populations. The polymorphism data from both species differed from neutrality at one locus, but this was not associated with changes in the protein sequence. The synonymous site diversity was greater in D. simulans than in D. melanogaster, but the diversity both upstream of the genes and at nonsynonymous sites was similar. This can be explained if both upstream and nonsynonymous mutations are slightly deleterious and are removed more effectively from D. simulans due to its larger effective population size.
Eliminating Gene Conversion Improves High-Throughput Genetics in Saccharomyces cerevisiae
Authors: Daniel Jewel A , Yoo Jiyoun , Bettinger Blaine T , Amberg David C , Burke Daniel J
Published: September 2005

Synthetic genetic analysis was improved by eliminating leaky expression of the HIS3 reporter and gene conversion between the HIS3 reporter and his3Δ1. Leaky expression was eliminated using 3-aminotriazole and gene conversion was eliminated by using the Schizosaccharomyces pombe his5+ gene, resulting in a 5- to 10-fold improvement in the efficiency of SGA.
Pkc1 Acts Through Zds1 and Gic1 to Suppress Growth and Cell Polarity Defects of a Yeast eIF5A Mutant
Authors: Zanelli Cleslei F , Valentini Sandro R
Published: September 2005

eIF5A is a highly conserved putative eukaryotic translation initiation factor that has been implicated in translation initiation, nucleocytoplasmic transport, mRNA decay, and cell proliferation, but with no precise function assigned so far. We have previously shown that high-copy PKC1 suppresses the phenotype of tif51A-1, a temperature-sensitive mutant of eIF5A in S. cerevisiae. Here, in an attempt to further understand how Pkc1 functionally interacts with eIF-5A, it was determined that PKC1 suppression of tif51A-1 is independent of the cell integrity MAP kinase cascade. Furthermore, two new suppressor genes, ZDS1 and GIC1, were identified. We demonstrated that ZDS1 and ZDS2 are necessary for PKC1, but not for GIC1 suppression. Moreover, high-copy GIC1 also suppresses the growth defect of a PKC1 mutant (stt1), suggesting the existence of a Pkc1-Zds1-Gic1 pathway. Consistent with the function of Gic1 in actin organization, the tif51A-1 strain shows an actin polarity defect that is partially recovered by overexpression of Pkc1 and Zds1 as well as Gic1. Additionally, PCL1 and BNI1, important regulators of yeast cell polarity, also suppress tif51A-1 temperature sensitivity. Taken together, these data strongly support the correlated involvement of Pkc1 and eIF5A in establishing actin polarity, which is essential for bud formation and G1/S transition in S. cerevisiae.
Sister Chromatids Are Often Incompletely Aligned in Meristematic and Endopolyploid Interphase Nuclei of Arabidopsis thaliana
Authors: Schubert Veit , Klatte Marco , Pecinka Ales , Meister Armin , Jasencakova Zuzana , Schubert Ingo
Published: September 2005

We analyzed whether sister chromatids are continuously aligned in meristematic and endopolyploid Arabidopsis interphase nuclei by studying sister-chromatid alignment at various chromosomal positions. FISH with individual BACs to flow-sorted 4C root and leaf nuclei frequently yielded more than two hybridization signals, indicating incomplete or absent sister-chromatid alignment. Up to 100% of 8C, 16C, and 32C nuclei showed no sister-chromatid alignment at defined positions. Simultaneous FISH with BACs from different chromosomal positions revealed more frequent sister-chromatid alignment in terminal than in midarm positions. Centromeric positions were mainly aligned up to a ploidy level of 16C but became separated or dispersed in 32C nuclei. DNA hypomethylation (of the whole genome) and transcriptional activity (at FWA gene position) did not impair sister-chromatid alignment. Only 6.1% of 4C leaf nuclei showed sister-chromatid separation of the entire chromosome 1 top arm territories. Homozygous transgenic tandem repeat (lac operator) arrays showing somatic homologous pairing more often than average euchromatic loci did not promote an increased frequency of sister-chromatid alignment. The high frequency of separated sister-chromatid arm positions in ≥4C nuclei suggests that sister-chromatid cohesion is variable, dynamic, and not obligatory along the entire chromosome arm in meristematic and differentiated Arabidopsis nuclei.
Temporal and Spatial Genetic Structure among Some Pacific Herring Populations in Puget Sound and the Southern Strait of Georgia
Authors: Small Maureen P. , Loxterman Janet L. , Frye Alice E. , Von Bargen Jennifer F. , Bowman Cherril , Young Sewall F.
Published: September 2005

We investigated temporal and spatial genetic variation in Pacific herring Clupea pallasii collections from six sites in Puget Sound (PS) and the southern Strait of Georgia (SOG), using 12 microsatellite loci. Loci were highly variable with up to 70 alleles per locus (mean = 30.67 alleles), and observed heterozygosity was high (mean = 0.823). Analysis of molecular variance (AMOVA) indicated significant structure, with over twice as much variance among sites as among collection years, although among‐site variance was mainly due to Cherry Point and Squaxin Pass collections. In an AMOVA excluding Cherry Point and Squaxin Pass, only temporal variance was significant. With the exception of the Cherry Point and Squaxin Pass collections, pairwise genotypic and FST tests show some differences among collection years within a site and some genetic overlap among most PS and SOG collections. The Cherry Point and Squaxin Pass collections had no differences in genotypic distributions among collection years, and in cluster analyses the Cherry Point and Squaxin Pass collections each formed groups separate from other PS and SOG collections. Cherry Point herring have a later spawning time than other PS and SOG herring, and Squaxin Pass is physically isolated in southern Puget Sound. We hypothesize that spawn timing differences and spatial isolation generated genetic structure among some Pacific herring in PS and SOG. We suspect that, as in the case of Atlantic herring C. harengus, population genetic structure in Pacific herring in PS and southern SOG is a combination of a larval retention model and a metapopulation model. Because Cherry Point and Squaxin Pass herring are genetically and behaviorally differentiated from other PS and SOG herring populations, this unique variation should be preserved through careful management.
Passivity based control of transport reaction systems
Authors: Ruszkowski Martin , Garcia‐Osorio Vianey , Ydstie B. Erik
Published: September 2005

Inventory control is based on the idea manipulating process flows so that the inventories follow their set points. The operator mapping flows to inventories in a coarse grained (macroscopic) system is passive and any input strictly passive (ISP) feedback controller can, therefore, be used to achieve input‐output stability. Examples of ISP controllers include the PID controller, parameter adaptive feedforward control, optimal controllers and many nonlinear and gain scheduling controllers. Input‐output stability and convergence of inventories, such as total mass and energy can be used to show that other internal state variables are bounded and belong to an invariant set. However, this does not necessarily imply convergence of all state variables to stationary valves because a stabilizability condition, known as strict state passivity, must be satisfied. The 2ndlaw of thermodynamics is used to develop sufficient conditions for strict state passivity in the space of intensive variables. The theory relies on following two assumptions concerning nonequilibrium systems: (1) The hypothesis of local equilibrium, and (2) That a local entropy is defined using semiclassical statistical mechanics. These assumptions allow us to define a local entropy function for the coarse grained system which is homogeneous degree one, concave, and has positive temperature. Subject to these conditions stability theory is developed for conjugate variables, such as temperature, pressure and chemical potential in infinite dimensional reaction‐diffusion‐convection systems. In classical irreversible thermodynamics this type of analysis assumes linearity and symmetry of transport relations. The use of Gibbs tangent plane condition allows us to define a Lyapunov like storage function for passivity design, which gives stability criteria for nonlinear problems. The resulting sufficient condition for stability can be expressed in terms of dimensionless groups, similar to the (second) Damkohler number. Simple simulation examples illustrate the application of the theory. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Liquid drop growth on a fiber
Authors: Yarin A. L. , Chase G. G. , Liu W. , Doiphode S. V. , Reneker D. H.
Published: September 2005

A quantitative model is described and verified to predict the growth of oil droplets by coalescence on a single nanofiber. The model considers a stream of fluid carrying many tiny droplets of a different fluid. The mechanisms by which the tiny droplets are captured by a drop growing on a fiber are considered. Different capture mechanisms are examined, including interception, Brownian motion of droplets, and vapor deposition by diffusion. It is shown that droplet interception and Brownian diffusion contribute to drop growth on nanofibers for airborne oil droplets in the size range from 100 to 1000 nm. Merging of growing drops on the fiber is also modeled and experimentally observed. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Detection of low level sex chromosome mosaicism in Ullrich–Turner syndrome patients
Authors: Wiktor Anne E. , Van Dyke Daniel L.
Published: September 2005

Ullrich–Turner syndrome (UTS) is most commonly due to a 45,X chromosome defect, but is also seen in patients with a variety of X‐chromosome abnormalities or 45,X/46,XY mosaicism. The phenotype of UTS patients is highly variable, and depends largely on the karyotype. Patients are at an increased risk of gonadoblastoma when a Y‐derived chromosome or chromosome fragment is present. Since constitutional mosaicism is present in approximately 50% of UTS patients, the identification of minor cell populations is clinically important and a challenge to laboratories. We identified 50 females with a 45,X karyotype as the sole abnormality or as part of a more complex karyotype. Twenty two (44%) had a 45,X karyotype; mosaicism for a second normal or structurally abnormal X was observed in 24 (48%) samples, and mosaicism for Y chromosomal material in 4 (8%) cases. To further investigate the possibility of mosaicism in the 22 patients with an apparently non‐mosaic 45,X karyotype, we performed FISH using centromere probes for the X and Y chromosomes. A minor XX cell line was identified in 3 patients, and the 45,X result was confirmed in 19 samples. No samples with XY mosaicism were identified. We describe our validation process for a FISH assay to be used in clinical practice to identify XX or XY mosaicism. FISH as an adjunct to karyotype analysis provides a sensitive and cost‐effective technique to identify sex chromosome mosaicism in UTS patients. © 2005 Wiley‐Liss, Inc.
Intrachromosomal insertion mimicking a pericentric inversion: Molecular cytogenetic characterization of a three break rearrangement of chromosome 20
Authors: Ardalan Azarnouche , Prieur Marguerite , Choiset Agnès , Turleau Catherine , Goutieres Françoise , Girard‐Orgeolet Sylvie
Published: September 2005

Intrachromosomal insertions are uncommon rearrangements, in which a chromosomal segment is intercalated into another part of the same chromosome. The insertion may occur in the same arm (paracentric) or in the other arm (pericentric). The cytogenetic recognition of these structurally rearranged chromosomes can be difficult, and intrachromosomal insertions can be easily mistaken for inversions. We describe a case of a familial pericentric insertion of chromosome 20, initially misdiagnosed as a pericentric inversion in the healthy carrier and then reinterpreted as insertion in an abnormal child with a recombinant chromosome. Fluorescence in situ hybridization (FISH) allowed us to confirm the mechanism of recombinant formation and to locate the three breakpoints precisely. Our cytogenetically unbalanced epileptic patient carried a 20q deletion and 20p duplication, and the genes, CHRNA4 and KCNQ2 that have been implicated in autosomal dominant epilepsy, were deleted. The haplo‐insufficiency of these two genes may contribute to the cause of epilepsy in patients with ring chromosome 20. © 2005 Wiley‐Liss, Inc.
Prenatal magnetic resonance imaging in Gomez‐Lopez‐Hernandez syndrome and review of the literature
Authors: Tan Tiong Yang , McGillivray George , Goergen Stacy K. , White Susan M.
Published: September 2005

Gomez‐Lopez‐Hernandez syndrome, or cerebello‐trigeminal‐dermal dysplasia (OMIM#601853), is a rare syndrome comprising cerebellar abnormalities, parieto‐occipital alopecia, trigeminal nerve anesthesia, intellectual impairment, craniosynostosis, short stature, and craniofacial anomalies. It has been reported in ten patients, five of whom are Brazilian. Rhombencephalosynapsis is a rare sporadic cerebellar anomaly comprising fusion of the cerebellar hemispheres with agenesis of the cerebellar vermis. Rhombencephalosynapsis is a constant feature of Gomez‐Lopez‐Hernandez syndrome. We present the clinical and imaging findings of a Caucasian male infant with Gomez‐Lopez‐Hernandez syndrome. Rhombencephalosynapsis was diagnosed with fetal magnetic resonance imaging (MRI) after an abnormally shaped small cerebellum was detected by antenatal ultrasound (US). Gomez‐Lopez‐Hernandez syndrome was diagnosed at age 6 weeks when parietal alopecia was noted. Prenatal imaging studies of Gomez‐Lopez‐Hernandez syndrome have not been published before. When rhombencephalosynapsis is diagnosed prenatally, the clinical features of Gomez‐Lopez‐Hernandez syndrome should be sought at postnatal review. Gomez‐Lopez‐Hernandez syndrome and isolated rhombencephalosynapsis may have a common etiology. © 2005 Wiley‐Liss, Inc.
Simulation of oxygen carrier mediated oxygen transport to C3A hepatoma cells housed within a hollow fiber bioreactor
Authors: Sullivan Jesse P. , Gordon Jason E. , Palmer Andre F.
Published: September 2005

A priori knowledge of the dissolved oxygen (O2) concentration profile within a hepatic hollow fiber (HF) bioreactor is important in developing an effective bioartificial liver assist device (BLAD). O2 provision is limiting within HF bioreactors and we hypothesize that supplementing a hepatic HF bioreactor's circulating media with bovine red blood cells (bRBCs), which function as an O2 carrier, will improve oxygenation. The dissolved O2 concentration profile within a single HF (lumen, membrane, and representative extra capillary space (ECS)) was modeled with the finite element method, and compared to experimentally measured data obtained on an actual HF bioreactor with the same dimensions housing C3A hepatoma cells. Our results (experimental and modeling) indicate bRBC supplementation of the circulating media leads to an increase in O2 consumed by C3A cells. Under certain experimental conditions (pO2,IN = 95 mmHg, Q = 8.30 mL/min), the addition of bRBCs at 5% of the average in vivo human red blood cell concentration (% hRBC) results in ∼50% increase in the O2 consumption rate (OCR). By simply adjusting the operating conditions (pO2,IN = 25 mmHg, Q = 1.77 mL/min) and increasing bRBC concentration to 25% hRBC the OCR increase is ∼10‐fold. However, the improved O2 concentration profile experienced by the C3A cells could not duplicate the full range of in vivo O2 tensions (25–70 mmHg) typically experienced within the liver sinusoid with this particular HF bioreactor. Nonetheless, we demonstrate that the O2 transport model accurately predicts O2 consumption within a HF bioreactor, thus setting up the modeling framework for improving the design of future hepatic HF bioreactors. © 2005 Wiley Periodicals, Inc.
[{(Mo)Mo5O21(H2O)3 (SO4)}12(VO)30 (H2O)20] 36‐: A Molecular Quantum Spin Icosidodecahedron.
Authors: Botar Bogdan , Koegerler Paul , Hill Craig L.
Published: September 2005

For Abstract see ChemInform Abstract in Full Text.
Hydrothermal Synthesis and Structure of [(C4N2H12)3] [P2Mo5O23]×H2O and [(C3N2H12)3] [P2Mo5O23]×4H2O.
Authors: Ganesan S. V. , Natarajan Srinivasan
Published: September 2005

For Abstract see ChemInform Abstract in Full Text.
Synthetic Applications of (Me3SiNSN)2E (E: S, Se) in Chalcogen‐Nitrogen Chemistry: Formation and Structural Characterization of Cl2TeESN2 (E: S, Se) and [PPh4]2 [Pd2(μ‐Se2N2S)X4] (X: Cl, Br).
Authors: Konu Jari , Ahlgren Markku , Aucott Stephen M. , Chivers Tristram , Dale Sophie H. , Elsegood Mark R. J. , Holmes Kathryn E. , James Sarah L. M. , Kelly Paul F. , Laitinen Risto S.
Published: September 2005

For Abstract see ChemInform Abstract in Full Text.
Direct Formation of Synthetically Useful Silyl‐Protected Aldol Adducts via the Asymmetric Reductive Aldol Reaction.
Authors: Fuller Nathan O. , Morken James P.
Published: September 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of New Azolyl Azoles and Azinyl Azoles.
Authors: Al‐Saleh Balkis , El‐Apasery Morsy Ahmed , Elnagdi Mohamed Hilmy
Published: September 2005

For Abstract see ChemInform Abstract in Full Text.
Simple, Extremely Fast, and High‐Yielding Oxidation of Thiols to Disulfides
Authors: Alam Ashraful , Takaguchi Yutaka , Tsuboi Sadao
Published: September 2005

For Abstract see ChemInform Abstract in Full Text.