bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-uniform Randomized Sampling for Multivariate Approximation by High Order Parzen Windows
Authors: Zhou Xiang-Jun , Shi Lei , Zhou Ding-Xuan
Published: March 2011

We consider approximation of multivariate functions in Sobolev spaces by high order Parzen windows in a non-uniform sampling setting. Sampling points are neither i.i.d. nor regular, but are noised from regular grids by non-uniform shifts of a probability density function. Sample function values at sampling points are drawn according to probability measures with expected values being values of the approximated function. The approximation orders are estimated by means of regularity of the approximated function, the density function, and the order of the Parzen windows, under suitable choices of the scaling parameter.
Diagnosis and Management of Short Cervix in Singleton Pregnancies
Authors: Wolman Igal , Agmon Arnon , Ariel J
Published: March 2011

Prevention of preterm labor will reduce perinatal mortality. Screening of cervical length by ultrasound should begin at 16 weeks by transvaginal ultrasound. If the cervical length is more than 35 mm, the exam should be repeated every 2 to 3 weeks till 32 weeks. If the cervical length is between 25 and 35 mm the ultrasound screening should be done weekly or biweekly. Fetal fibronectin estimation should provide supplemental information. If the cervical length is less than 25 mm cervical cerclage should be performed if gestational age is less than 22 weeks. Progesterone therapy is preferred if the gestational age is more than 22 completed weeks.
Internal IIiac Artery Occlusion Balloon Catheters to Minimize Blood Loss in Adherent Placenta: A Retrospective Cohort Study
Authors: Firdous Zakia , Aziz Nuzhat
Published: March 2011

Adherent placenta is a rare but life- and fertility-threatening condition, with a rapid increase in incidence in this decade. Cesarean hysterectomy, the traditional management, is associated with very high morbidity due to massive blood loss and adjacent organ damage. The objective was to study the effect of preoperative internal iliac artery balloon catheter placement as a means of reducing morbidity.

Methods

Adherent placenta cases were identified using hospital database over a 9 years period from 2001 to 2009 at Fernandez hospital, a tertiary perinatal center with 5000 deliveries annually. Mothers who had preoperative internal iliac artery balloon placements were compared with those who did not have. Maternal morbidity was assessed in the form of intraoperative blood loss, total units of blood products transfused, mean operative time, length of postoperative hospital stay, use of adjuvant procedures (for control of hemorrhage), adjacent organ damage, cardiac arrest, and maternal mortality.

Results

Forty-one subjects with a diagnosis of adherent placenta were identified out of 32,354 deliveries (incidence of 1:789) and 27 of these had peripartum hysterectomy. Six had preoperative internal iliac artery balloons placement before hysterectomy (study group) and 21 had hysterectomy alone (control group). Significant difference was found in mean amount of blood loss (p = 0.002) and in mean number of blood products given (p = 0.04). No statistically significant difference was found in mean operative time and length of postoperative hospital stay. There were four subjects who had adjacent organ damage, two had cardiac arrest, two required recombinant factor VIIa in the control group when compared with none in the study group.

Conclusion

Preoperative placement of internal iliac artery occlusion balloon catheters reduced morbidity by minimizing blood loss and adjacent organ damage.
Ovarian Ectopic Pregnancy Following Assisted Reproductive Techniques: A Rare Entity
Authors: Bharath Meenakshi , Shetty Nivedita , Shashikala T , Kaur Harpreet
Published: March 2011

Ovarian ectopic pregnancy should be kept in mind as a rare possibility following assisted reproductive techniques. Although early use of quantitative serum â-hCG and pelvic ultrasonography has increased our diagnostic capability for ectopic pregnancy, ovarian pregnancy still represents a diagnostic problem. Laparoscopy is the gold standard for diagnosis and treatment for ovarian ectopic pregnancy.
Neighborhood Archaeology: Exploring the Significance of Volunteers, Communities, and Local Politics for Contemporary Archaeology
Authors: Baram Uzi , Austin Robert J.
Published: March 2011

The expanding discussions of public archaeology have propelled consideration of the roles for descendant communities, both linear descendants and those with social ties to the peoples whose lives are being studied. Consideration of local communities has included the economic potential of heritage tourism and the dynamics of civic engagements. There have been important contributions on issues of race and recently on class. This collection seeks to extend consideration of public archaeology as civic engagements within urban neighborhoods, to explore the implications of archaeological research within and with complex social places.  The integration of volunteers, the significance of archaeological sites and historic structures for communities, and the local politics involved in historic preservation and neighborliness focus the contributions.
Doing Archaeology Publicly: The Bayshore Homes Project, Florida
Authors: Austin Robert J.
Published: March 2011

The Bayshore Homes site is a precolumbian mound and midden complex located in the Parque Narváez neighborhood of Pinellas County, Florida. Over the past decade, archaeological excavation and research have been conducted in a very public environment: the front and back yards of the subdivision’s residents. Involving the residents as partners in the process of discovery about the neighborhood’s ancient past has been an essential component of the project since its inception. This paper discusses the results of such involvement, from the use of volunteers to educating residents about the importance of preserving the neighborhood’s Native American heritage.
Front Yard, Back Yard: Lessons in Neighborhood Archaeology in an Urban Environment
Authors: Weisman Brent
Published: March 2011

Doing archaeology right where people live brings immediacy to the processes of site interpretation and heritage-making not usually present in more remote projects. When people can peer down into their buried history or the history of their neighborhood as they move about in the course of their daily lives, public archaeology suddenly becomes very personal. Memory and imagination blend together to create connections to a past that are both highly idiosyncratic and of the political present. Two projects in Tampa aimed at unearthing the forgotten history of the recent past are examined as case studies.
Epithelial tight junction alterations in nasal polyposis
Authors: Rogers G. Aaron , Beste Kyle Den , Parkos Charles A. , Nusrat Asma , DelGaudio John M. , Wise Sarah K.
Published: March 2011

Objective

To explore alterations in expression of tight junction proteins (TJPs) in nasal polyposis and in respiratory epithelium under inflammatory conditions. Our hypothesis is that exposure of nasal and respiratory epithelium to inflammatory cytokines results in the altered expression of specific TJPs.

Methods

Human sinonasal mucosa (3 nasal polyp specimens and 3 nonpolypoid controls) were stained with immunofluorescent markers specific for TJPs claudin‐1 and occludin and examined with confocal scanning laser microscopy. A complementary in vitro experiment involving exposure of cultured human bronchial epithelium to interferon gamma (IFN‐γ) and tumor necrosis factor alpha (TNF‐α) was also performed. Alterations in claudin‐1 and occludin were localized by immunofluorescence labeling and confocal microscopy and quantified by western blotting.

Results

Nasal polyp epithelium from human tissue specimens had reduced claudin‐1 expression along the basal aspect of the mucosal layer, whereas occludin expression was reduced in the apical and basal epithelial zones. In vitro experiments demonstrated stable or increased TJP expression after 24 hours of cytokine exposure (43% increase for claudin‐1, 9% increase for occludin). However, a reduction in TJP expression was observed after 72 hours of cytokine exposure (18% reduction for claudin‐1, and 43% reduction for occludin).

Conclusion

Nasal polyposis is associated with epithelial TJP alterations. Further, the expression of TJPs in a model of inflamed respiratory mucosa is reduced in a similar fashion. Research on the histopathology of other epithelial inflammatory disorders suggests TJP alterations contribute to a self‐perpetuating inflammatory state. Findings of this preliminary study support a similar process in nasal polyposis. © 2011 ARS‐AAOA, LLC.
Biodegradable nanoparticles containing benzopsoralens: An attractive strategy for modifying vascular function in pathological skin disorders
Authors: Gomes Anderson J. , Lunardi Laurelúcia O. , Caetano Flavio H. , Machado Antonio Eduardo H. , Oliveira‐Campos Ana Maria F. , Bendhack Lusiane M. , Lunardi Claure N.
Published: March 2011

Psoralens are often used to treat skin disorders such as psoriasis, vitiligo, and others. The toxicity and fast degradation of these drugs can be diminished by encapsulation in drug‐delivery systems (DDS). Nanoparticles (NPs) containing the benzopsoralen (BP) (3‐ethoxy carbonyl‐2H‐benzofuro[3,2‐e]‐1‐benzopiran‐2‐one) were prepared by the solvent‐evaporation technique, and parameters such as particle size, zeta potential, drug‐encapsulation efficiency, and external morphology were evaluated. The analysis revealed that the NPs are spherical and with smooth external surface with diameter of 815 ± 80 nm, they present low tendency toward aggregation, and the encapsulation efficiency was of 74%. The intracellular distribution of NPs as well as their uptake by tissues was monitored by using laser confocal microscopy and transmission electron microscopy (TEM). The use of a BP in association with ultraviolet light (360 nm) revealed by TEM morphological characteristics of cell damage such as cytosolic vesiculation, mitochondria condensation, and swelling of both the granular endoplasmic reticulum and the nuclear membrane. The primary target of DDS and drugs in vascular system are endothelial cells and an attractive strategy for modifying vascular function in various pathological states of skin disorders, cancer, and inflammation. The results presented in this work indicate that poly(lactic‐co‐glycolic acid) NP should be a promising sustained release for BP for systemic and local delivery associated with ultraviolet irradiation (PUVA therapy). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A BTB domain‐containing gene is upregulated by immune challenge
Authors: Wang Gang , Liu Peng‐Cheng , Wang Jin‐Xing , Zhao Xiao‐Fan
Published: March 2011

20‐Hydroxyecdysone (20E) is an important hormone that regulates the development of insects. Although previous evidence revealed that 20E promotes innate immunity in insects, the mechanism involved is still unclear. In this study, the HaBBP gene from Helicoverpa armigera is cloned, which contains BTB (broad‐complex, tramtrack, and bric‐a‐brac), a BACK (BTB and carboxyl‐terminus kelch repeats), and PHR (PAM, highwire, and RPM) domains. RT‐PCR analysis of HaBBP and western blot analysis of HaBBP show that the mRNA and protein level are higher in the fat body and hemocytes during the molting and metamorphic stages compared with the feeding stage. HaBBP was upregulated by 20E in hemocytes. Knockdown of the 20E receptor EcR‐B1 and the heterodimeric partner ultraspiracle protein USP1 in an epidermal cell line (HaEpi) blocked the transcription of HaBBP. HaBBP is distributed in granulocytes and plasmatocytes. Immune stimulation by Escherichia coli caused the upregulation of HaBBP in both hemocytes and fat body. Thus, HaBBP is regulated by the 20E signaling pathway, and is likely involved in the insect innate immunity. © 2011 Wiley Periodicals, Inc.
Disjunction Between Probability and Verdict in Juror Decision Making
Authors: Arkes Hal R. , Shoots‐Reinhard Brittany , Mayes Ryan S.
Published: March 2011

Although the law assumes a close relation between the probability that a defendant committed the act in question and the ensuing verdict of the jurors, prior research has shown this assumption to be often violated. We present five experiments designed to show that factors that influence probability also influence verdict, but other factors are capable of directly producing changes in verdict without affecting probability. In Experiment 1, we replicated the Wells Effect; scenarios generating the same probability that the Blue Bus Company was to blame for the same accident, nevertheless, generated significantly different likelihoods of finding the defendant liable. In Experiment 2, we showed that equally diagnostic affirmative and negative evidence had differential effects on mock jurors' probability estimates and verdicts. In Experiment 3, we showed that a completely nondiagnostic witness, who either implicates the same bus company or a different bus company as did a diagnostic witness, significantly influenced mock jurors' verdicts. However, the nondiagnostic witness did not change the probability that the Blue Bus Company was responsible for the accident. In Experiment 4, we demonstrated that base rate and witness reliability information resulted in very similar probability estimates but radically different verdicts. In Experiment 5, we showed that a change in the diagnosticity of the evidence influenced both probability and verdict with the former mediating differences in the later. Because probability is only one of the several determinants of the verdict, the two dependent variables are not as closely related as the law presumes. Copyright © 2011 John Wiley & Sons, Ltd.
Mixed glucose and lactate uptake by Corynebacterium glutamicum through metabolic engineering
Authors: Neuner Andreas , Heinzle Elmar
Published: March 2011

The Corynebacterium glutamicum ATCC 13032 lysCfbr strain was engineered to grow fast on racemic mixtures of lactate and to secrete lysine during growth on lactate as well as on mixtures of lactate and glucose. The wild‐type C. glutamicum only grows well on L‐lactate. Overexpression of D‐lactate dehydrogenase (dld) achieved by exchanging the native promoter of the dld gene for the stronger promoter of the sod gene encoding superoxide dismutase in C. glutamicum resulted in a duplication of biomass yield and faster growth without any secretion of lysine. Elementary mode analysis was applied to identify potential targets for lysine production from lactate as well as from mixtures of lactate and glucose. Two targets for overexpression were pyruvate carboxylase and malic enzyme. The overexpression of these genes using again the sod promoter resulted in growth‐associated production of lysine with lactate as sole carbon source with a carbon yield of 9% and a yield of 15% during growth on a lactate‐glucose mixture. Both substrates were taken up simultaneously with a slight preference for lactate. As surmised from the elementary mode analysis, deletion of glucose‐6‐phosphate isomerase resulted in a decreased production of lysine on the mixed substrate. Elementary mode analysis together with suitable objective functions has been found a very useful tool guiding the design of strains producing lysine on mixed substrates.
Ulva rigida improves carbohydrate metabolism, hyperlipidemia and oxidative stress in streptozotocin‐induced diabetic rats
Authors: Tas Sibel , Celikler Serap , Ziyanok‐Ayvalik Sedef , Sarandol Emre , Dirican Melahat
Published: March 2011

This study was designed to investigate the effects of Ulva rigida, one of the green algae, on the lipid profile and oxidative–antioxidative systems in streptozotocin‐induced diabetic rats. Forty Wistar rats randomly divided into four groups: control (C), control + U. rigida extract (C + URE), diabetes (D) and diabetes + U. rigida extract (D + URE). U. rigida (2%) was administered in drinking water for 5 weeks after the induction of diabetes. U. rigida reduced the blood glucose, serum total cholesterol, triglyceride levels and plasma and tissue malondialdehyde (MDA) levels in the D + URE group. Insulin levels were significantly higher in the D + URE than those of the D group. Serum total cholesterol and tissue MDA levels were reduced in the C + URE group. Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities were higher in the D and C + URE groups compared with the C group. Paraoxonase and arylesterase activities were lower in the D group while U. rigida increased paraoxonase activities in C + URE and D + URE groups. This is the first study which showed U. rigida has antidiabetic and antihyperlipidemic effects and improves oxidative stress in diabetic rats. We conclude that U. rigida might have a potential use as a protective and/or therapeutic agent in diabetes mellitus. Copyright © 2011 John Wiley & Sons, Ltd.
Bullying as a predictor of offending, violence and later life outcomes
Authors: Farrington David P. , Ttofi Maria M.
Published: March 2011

Aim The main aim of this paper is to investigate to what extent self‐reported bullying at age 14 predicts later offending, violence and other life outcomes.

Method In the Cambridge Study in Delinquent Development, 411 South London males were followed up from age 8–10 to age 48–50, using repeated face‐to‐face interviews and searches of criminal records.

Results Bullying at age 14 predicted violent convictions between ages 15 and 20, self‐reported violence at age 15–18, low job status at age 18, drug use at age 27–32, and an unsuccessful life at age 48. These results held up after controlling for explanatory and behavioural childhood risk factors at age 8–10.

Conclusions Bullying might increase the likelihood of these later outcomes. Interventions that decrease bullying would most likely be followed by decreases in violent offending, drug use, and unsuccessful lives. Copyright © 2011 John Wiley & Sons, Ltd.
Quantification of magnetic resonance spectroscopy signals with lineshape estimation
Authors: Osorio‐Garcia M. I. , Sima D. M. , Nielsen F. U. , Himmelreich U. , Van Huffel S.
Published: March 2011

Quantification of magnetic resonance spectroscopy (MRS) signals is required for providing metabolite concentrations of the tissue under investigation. For estimating these concentrations several biochemical and acquisition conditions need to be taken into account. It is still a challenge to obtain reliable concentrations, as experimental conditions may have a detrimental effect on the spectral quality. The lineshape of MRS signals is affected, for instance, by inhomogeneities of the static magnetic field arising from imperfect shimming and tissue heterogeneities. To handle this type of distortions, we propose an extension of the self‐deconvolution method, where a common lineshape is estimated and a robust method with local regression is included to improve the smoothing of the estimated damping (or lineshape) function. This common lineshape is imposed in the metabolite quantification method and the spectral parameters (amplitude, frequency, damping and phase corrections) are obtained via nonlinear least squares. In this study, we considered distorted simulated, in vitro and in vivo rat brain signals which were lineshape corrected and quantitative results were compared in all three cases. Copyright © 2011 John Wiley & Sons, Ltd.
Destruction of normal distribution in small samples by centering and scaling
Authors: Tóth Gergely
Published: March 2011

It is less emphasized in scientific literature that centering and scaling of data may drastically change the original distribution of the data for small samples. The destruction of the original distribution depends on the source of the estimation of the mean (centering) and the divisor (scaling) where the latter is connected to the spread of data. In our comparative study we focus on cases, where the sample is taken from normally distributed data; the means and the standard deviations are population or sample based. We discuss six cases in transforming the data or the sample means. Most of them are studied previously, but some of them have not been theoretically investigated. The transformed data follow normal distribution in three cases, if the scaling is performed with population standard deviation. In one case, the final distribution is related to β‐distribution with astonishing density functions for N = 2 Dirac‐delta, N = 3 Viking helmet like and N = 4 uniform distributions. Another case is the well‐known t‐distribution. For one of the transformed data, we were not able to identify the general form. Here we obtained only numerical results for 3 ≤ N. The effect of the transformations was tested on experimental data representing more or less normally distributed variables. We found that transformations using the sample standard deviation were significantly less normally distributed‐like than the original data for small samples, but the other transformations enhanced the normal distribution‐like feature. The results point out that centering and especially scaling require consideration for small samples up to questioning the reality of subsequent data evaluation processes where normal distribution is assumed. Copyright © 2011 John Wiley & Sons, Ltd.
A review on experimental studies of biosorption of heavy metals by Aspergillus niger
Authors: Mukhopadhyay Mausumi , Noronha S. B. , Suraishkumar G. K.
Published: March 2011

Recent developments in the field of environmental biotechnology lead to the search for adsorbents of biological origin, which is reasonably cheap for toxic trace metal removal. This method is specifically termed as biosorption. In this paper, biosorption of heavy metals by Aspergillus niger is reviewed. Characterisation of A. niger in heavy metal biosorption is extensively discussed. Batch and continuous processes are discussed in details. Influence of process parameters like biomass dosage rate, initial metal ion concentration, and pH of the solution, pretreatment, impact of co‐cations on metal biosorption is also discussed. Modelling for batch and continuous process operations are focused extensively. Mechanism of biosorption by A. niger is elaborated.
Molecular analysis of neurogenic placode development in a basal ray‐finned fish
Authors: Modrell Melinda S. , Buckley David , Baker Clare V.H.
Published: March 2011

Neurogenic placodes are transient, thickened patches of embryonic vertebrate head ectoderm that give rise to the paired peripheral sense organs and most neurons in cranial sensory ganglia. We present the first analysis of gene expression during neurogenic placode development in a basal actinopterygian (ray‐finned fish), the North American paddlefish (Polyodon spathula). Pax3 expression in the profundal placode confirms its homology with the ophthalmic trigeminal placode of amniotes. We report the conservation of expression of Pax2 and Pax8 in the otic and/or epibranchial placodes, Phox2b in epibranchial placode‐derived neurons, Sox3 during epibranchial and lateral line placode development, and NeuroD in developing cranial sensory ganglia. We identify Sox3 as a novel marker for developing fields of electrosensory ampullary organs and for ampullary organs themselves. Sox3 is also the first molecular marker for actinopterygian ampullary organs. This is consistent with, though does not prove, a lateral line placode origin for actinopterygian ampullary organs. genesis 49:278–294, 2011. © 2011 Wiley‐Liss, Inc.
Mechanisms that underlie co‐variation of the brain and face
Authors: Marcucio Ralph S. , Young Nathan M. , Hu Diane , Hallgrimsson Benedikt
Published: March 2011

The effect of the brain on the morphology of the face has long been recognized in both evolutionary biology and clinical medicine. In this work, we describe factors that are active between the development of the brain and face and how these might impact craniofacial variation. First, there is the physical influence of the brain, which contributes to overall growth and morphology of the face through direct structural interactions. Second, there is the molecular influence of the brain, which signals to facial tissues to establish signaling centers that regulate patterned growth. Importantly, subtle alterations to these physical or molecular interactions may contribute to both normal and abnormal variation. These interactions are therefore critical to our understanding of how a diversity of facial morphologies can be generated both within species and across evolutionary time. genesis 49:177–189, 2011. © 2011 Wiley‐Liss, Inc.
Odd‐skipped maintains prohemocyte potency and blocks blood cell development in Drosophila
Authors: Gao Hongjuan , Wu Xiaorong , Fossett Nancy
Published: March 2011

Studies using Drosophila have contributed significantly to our understanding of regulatory mechanisms that control stem cell fate choice. The Drosophila blood cell progenitor or prohemocyte shares important characteristics with mammalian hematopoietic stem cells, including quiescence, niche dependence, and the capacity to form all three fly blood cell types. This report extends our understanding of prohemocyte fate choice by showing that the zinc‐finger protein Odd‐skipped promotes multipotency and blocks differentiation. Odd‐skipped was expressed in prohemocytes and downregulated in terminally differentiated plasmatocytes. Furthermore, Odd‐skipped maintained the prohemocyte population and blocked differentiation of plasmatocytes and lamellocytes but not crystal cells. A previous study showed that Odd‐skipped expression is downregulated by Decapentaplegic signaling. This report provides a functional basis for this regulator/target pair by suggesting that Decapentaplegic signaling limits Odd‐skipped expression to promote prohemocyte differentiation. Overall, these studies are the basis for a gene regulatory model of prohemocyte cell fate choice. genesis, 49:105–116, 2011. © 2011 Wiley‐Liss, Inc.
Vertical mixing of gravel over a long flood series
Authors: Haschenburger Judith K.
Published: March 2011

Vertical sediment exchange is a fundamental component of bedload transport in gravel‐bed channels. This paper describes the characteristic depth of exchange achieved over a long flood series. Analysis is based on 11 recoveries of magnetically tagged gravels deployed in Carnation Creek, Canada, completed between 1990 and 2008. Vertical grain exchange mixes gravels throughout the streambed relatively rapidly. Within one to eight floods the mean burial depth approaches two times the surface layer thickness, quantified by the 90th percentile of the size distribution. Finer gravels are mixed more rapidly into the bed than coarser gravels. Both active and passive grain exchanges throughout most of the bed produce the overall vertical distribution of marked grains. Gravel exchanges exhibit fairly consistent patterns once tracers are well mixed by large floods. Results highlight the role of flood sequence in determining exchange depths, support the notion of an upper limit to exchange, and underscore the importance of passive grain exchange. Copyright © 2011 John Wiley & Sons, Ltd.
A call for standardization of aeolian process measurements: moving beyond relative case studies
Authors: Barchyn Thomas E. , Hugenholtz Chris H. , Ellis Jean T.
Published: March 2011

Progress in some areas of process‐based aeolian sediment transport research is hampered by limited opportunities for data comparison, synthesis, and integration. This is partially due to a lack of reliable comparison methods. Many comparison methods are forms of calibration that are either restrictive (e.g., time‐averages only) or non‐existent (e.g., for field‐based sediment transport thresholds or vertical mass flux profiles). It is believed that the adoption of standard methods for common measurements may improve inter‐study comparison, add value and longevity to data, and advance integrative modeling efforts. Examples of approaches in allied disciplines where standards are used routinely are reviewed and we discuss how the mutual benefits of standardized data could outweigh perceived disadvantages. Overall, the goal of this commentary is to encourage discussion, self‐assessment, and forethought with regard to measurement methods used in process‐based aeolian geomorphology. Copyright © 2011 John Wiley & Sons, Ltd.
Using Firm‐Level Leverage as an Investment Strategy
Authors: Muradoğlu Yaz Gűlnur , Sivaprasad Sheeja
Published: March 2011

We use an investment strategy based on firm‐level capital structures. Investing in low‐leverage firms yields abnormal returns of 4.43% per annum. If an investor holds a portfolio of low‐leverage and low‐market‐to‐book‐ratio firms, abnormal returns increase to 16.18% per annum. A portfolio of low leverage and low market risk yields abnormal returns of 6.67% and a portfolio of small firms with low leverage earns 5.37% per annum. We use the Fama‐Macbeth (1973) methodology with modifications. We confirm that portfolios based on low leverage earn higher returns in longer investment horizons. Our results are robust to other risk factors and the risk class of the firm. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamic monitoring of cytosolic glucose in single astrocytes
Authors: Prebil Mateja , Vardjan Nina , Jensen Jørgen , Zorec Robert , Kreft Marko
Published: March 2011

It is becoming increasingly clear that astrocytes are no longer playing a subservient role to neurons in the central nervous system (CNS), and that these cells are being considered as active communication integrators. They respond to neurotransmitters by the regulated release of gliotransmitters. The delay between neurotransmitter activation and the release of gliotransmitters from astrocytes is in the time‐domain of subseconds, much slower than the submillisecond synaptic delay. Astrocytes also control microcirculation and provide metabolic support for neurons. However, the dynamics of their energy metabolic response to neurotransmitter application is not known. We here used a FRET glucose nanosensor to dynamically measure the cytosolic glucose concentration in single astrocytes. We show that following the adrenaline or noradrenaline stimulation the availability of cytosolic glucose is increased promptly after stimulation with a time‐constant of 116.7 s and 115.9 s, respectively. A decline in cytosolic glucose concentration with a time‐constant of 50.7 s was observed during glutamate and 16.7 s during lactate addition to astrocytes, when these were bathed in the presence of extracellular glucose‐containing solution, likely reflecting predominant glucose engagement in glycogen synthesis. In contrast, in the glucose‐free extracellular solution, glutamate application to astrocytes resulted in a slow increase in cytosolic glucose concentration, consistent with the view that glutamate may be an alternative energy source in hypoglycemic conditions. We conclude that astrocytic cytosolic glucose metabolism responds in the time‐domain of tens of seconds, which is slower compared to the whole brain functional magnetic resonance imaging measurements of the local intravascular hemodynamic response. © 2011 Wiley‐Liss, Inc.
Percutaneous absorption of haloacetonitriles and chloral hydrate and simulated human exposures
Authors: Trabaris Maria , Laskin Jeffrey D. , Weisel Clifford P.
Published: March 2011

Disinfection‐by‐products (DBPs) have long been a human health concern and many are known carcinogens and teratogens. Skin is exposed to DBPs in water through bathing and swimming; however, dermal uptake of many DBPs has not been characterized. The present studies were initiated to measure the permeation coefficients (Kp) for haloacetonitriles (HANs) and chloral hydrate (CH), important cytotoxic DBPs. The Kp values measured using fully hydrated dermatomed torso skin at 37 °C for the HANs ranged from 0.099 to 0.17 cm h−1, and was 0.0039 cm h−1 for CH. Of the HANs, dibromoacetonitrile had the highest permeability while chloroacetonitrile had the lowest permeability and a direct relationship was observed between their Kp and their octanol/water partition coefficients (Kow). The Kp values of the HANs were also approximately 30 times that of CH. The monthly dermal and ingestion doses of HANs and CH of an average American population were estimated using Monte Carlo simulations. The dermal doses of HANs from showering and bathing ranged from 0.39 to 0.78 times their ingestion doses but only approximately 0.02 times their ingestion doses for CH, assuming that the Kp values determined are applicable to shorter water contact times. However, that ratio can vary markedly with chlorinated swimming pool exposures, with a range of 0.30–2.3 for HANs and 0.19–0.25 for CH. Dermal exposure to HANs and CH seems to be a significant route of exposure and should be considered when evaluating their total exposure during the routine usage of water for bathing and swimming. Copyright © 2011 John Wiley & Sons, Ltd.
Stoichiometric and kinetic evaluation of simultaneous nitrification and denitrification in a membrane bioreactor at steady state
Authors: Sarioglu Murat , Insel Guclu , Artan Nazik , Orhon Derin
Published: March 2011

BACKGROUND: This study concerned the stoichiometric evaluation of simultaneous nitrification and denitrification in a membrane bioreactor. The evaluation was made to derive relevant mass balance equations for all parameters affecting nitrogen removal and to set the basis for a rational design procedure.

RESULTS: The basic stoichiometry was defined to include the effect of oxygen diffusion through microbial flocs by means of half saturation constants in corresponding switching functions. The stoichiometric relationships were used as tools for the design procedure targeting the desired level of nitrogen removal.

CONCLUSION: A comparison was made with the outputs associated with a conventional activated sludge system for major design parameters such as denitrification potential, active heterotrophic and autotrophic biomass, oxygen requirements, etc. The proposed rational design for nitrogen removal was tested and validated using model simulation for steady state MBR operation under selected conditions. Copyright © 2011 Society of Chemical Industry
Convex excess in partial cubes
Authors: Klavžar Sandi , Shpectorov Sergey
Published: March 2011

The convex excess ce(G) of a graph G is introduced as where the summation goes over all convex cycles of G. It is proved that for a partial cube G with n vertices, m edges, and isometric dimension i(G), inequality 2n−m−i(G)−ce(G)≤2 holds. Moreover, the equality holds if and only if the so‐called zone graphs of G are trees. This answers the question from Bre r et al. [Tiled partial cubes, J Graph Theory 40 (2002) 91–103] whether partial cubes admit this kind of inequalities. It is also shown that a suggested inequality from Bre r et al. [Tiled partial cubes, J Graph Theory 40 (2002) 91–103] does not hold. Copyright © 2011 John Wiley & Sons, Ltd.
Triple therapy in hospitalized patients: Facts and controversies
Authors: Srour John Fani , Smetana Gerald W.
Published: March 2011

The use of triple therapy (warfarin plus dual antiplatelet therapy) has increased in recent years due to an aging population with a higher risk for atrial fibrillation, as well as the increased use of coronary stents for acute coronary syndromes. Triple therapy confers a higher bleeding risk than either warfarin or dual antiplatelet therapy alone. However, warfarin alone is inadequate for patients with indications for triple therapy because of an unacceptable risk of stent thrombosis, and dual antiplatelet therapy is inferior to warfarin for the prevention of ischemic strokes in patients with atrial fibrillation, mechanical valves, or intraventricular thrombosis. Hospitalists face the challenge of balancing the aforementioned risks; the optimal management of these patients requires knowledge of the relevant literature and expertise. In this paper, we review the current literature on antiplatelet and anticoagulant combinations in patients with atrial fibrillation and coronary stents in order to improve adherence to published guidelines and to reduce the risk of bleeding. Journal of Hospital Medicine 2011;. © 2011 Society of Hospital Medicine
Comparative effectiveness of pleural drainage procedures for the treatment of complicated pneumonia in childhood
Authors: Shah Samir S. , Hall Matthew , Newland Jason G. , Brogan Thomas V. , Farris Reid W. D. , Williams Derek J. , Larsen Gitte , Fine Bryan R. , Levin James E. , Wagener Jeffrey S. , Conway Patrick H. , Myers Angela L.
Published: March 2011

OBJECTIVE:

To determine the comparative effectiveness of common pleural drainage procedures for treatment of pneumonia complicated by parapneumonic effusion (ie, complicated pneumonia).

DESIGN:

Multicenter retrospective cohort study.

SETTING:

Forty children's hospitals contributing data to the Pediatric Health Information System.

PARTICIPANTS:

Children with complicated pneumonia requiring pleural drainage.

MAIN EXPOSURES:

Initial drainage procedures were categorized as chest tube without fibrinolysis, chest tube with fibrinolysis, video‐assisted thoracoscopic surgery (VATS), and thoracotomy.

MAIN OUTCOME MEASURES:

Length of stay (LOS), additional drainage procedures, readmission within 14 days of discharge, and hospital costs.

RESULTS:

Initial procedures among 3500 patients included chest tube without fibrinolysis (n = 1762), chest tube with fibrinolysis (n = 623), VATS (n = 408), and thoracotomy (n = 797). Median age was 4.1 years. Overall, 716 (20.5%) patients received an additional drainage procedure (range, 6.8–44.8% across individual hospitals). The median LOS was 10 days (range, 7–14 days across individual hospitals). The median readmission rate was 3.8% (range, 0.8%‐33.3%). In multivariable analysis, differences in LOS by initial procedure type were not significant. Patients undergoing initial chest tube placement with or without fibrinolysis were more likely to require additional drainage procedures. However, initial chest tube without fibrinolysis was the least costly strategy.

CONCLUSION:

There is variability in the treatment and outcomes of children with complicated pneumonia. Outcomes were similar in patients undergoing initial chest tube placement with or without fibrinolysis. Those undergoing VATS received fewer additional drainage procedures but had no differences in LOS compared with other strategies. Journal of Hospital Medicine 2011;. © 2011 Society of Hospital Medicine
Habitat‐specific trends in ontogeny of body shape in stickleback from coastal archipelago: Potential for rapid shifts in colonizing populations
Authors: Spoljaric M.A. , Reimchen T.E.
Published: March 2011

We investigated ontogenetic trends in body shape of 54 freshwater (48 lake, seven stream) and six anadromous populations of threespine stickleback (Gasterosteus aculeatusL.) from the Haida Gwaii archipelago off the west coast of Canada. Multivariate analysis of covariance on the partial warp scores generated from 12 homologous landmarks on 1,958 digital images of subadult and adult male stickleback indicated that there was considerable variability of population ontogenetic slopes. We used discriminant function analysis to quantify body shape and determined that anadromous stickleback, which are ancestral to the freshwater populations, have a strongly negative ontogenetic slope (−5.62; increased streamlining with increased size). All freshwater populations exhibit a more positive slope (91% differed significantly from the marine slope), with the differences being most accentuated in populations from ponds and streams. In pristine lakes, ontogenetic slope could be predicted by lake volume as well as multivariate measures of habitat. Evidence from field transplant experiments of one of the intact populations indicates a rapid change (5 years) from allometric to isometric growth, equivalent to about half of the total slope variation among intact populations on the archipelago. We interpret this shift as developmental plasticity and suggest this may comprise the precursor for selection of optimal body shapes in these stickleback populations. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
Brain [U‐13C]glucose metabolism in mice with decreased α‐ketoglutarate dehydrogenase complex activity
Authors: Nilsen Linn Hege , Shi Qingli , Gibson Gary E. , Sonnewald Ursula
Published: March 2011

The activity of the α‐ketoglutarate dehydrogenase complex (KGDHC), a mitochondrial enzyme complex that mediates the oxidative decarboxylation of α‐ketoglutarate in the TCA cycle, is reduced in Alzheimer's disease. We investigated the metabolic effects of a partial KGDHC activity reduction on brain glucose metabolism using mice with disrupted expression of dihydrolipoyl succinyltransferase (DLST; gene encoding the E2k subunit of KGDHC). Brain tissue extracts from cortex and cerebellum of 6‐week‐old heterozygote DLST knockout mice (DLST+/−) and corresponding wild‐type mice injected with [U‐13C]glucose and decapitated 15 min later were analyzed. An increase in the concentration of glucose in cortex suggested a decrease in the cortical utilization of glucose in DLST+/− mice. Furthermore, the concentration and 13C labelling of aspartate in cortex were reduced in DLST+/− mice. This decline was likely caused by a decrease in the pool of oxaloacetate. In contrast to results from cell culture studies, no indications of altered glycolysis or GABA shunt activity were found. Glucose metabolism in the cerebellum was unaffected by the decrease in KGDHC activity. Among metabolites not related to glucose metabolism, the concentration of taurine was decreased in the cortex, and that of tyrosine was increased in the cerebellum. These results imply that diminished KGDHC activity has the potential to induce the reduction in glucose utilization that is seen in several neurodegenerative diseases. © 2011 Wiley‐Liss, Inc.
Structure factors of polyelectrolyte solutions revealed by neutron scattering
Authors: Jannink G.
Published: March 2011

The solute structure in concentrated polyelectrolyte solutions is discussed in terms of the following observations:

1) The broad peak in the global structure function measured by radiation scattering (neutron, X rays or light), in the interval q < 2 nm−1,

2) The separate intra and intermolecular structure functions obtained by neutron scattering,

3) The separate polyion‐counterion partial structure factors derived from neutron scattering,

4) The variation with wave vector of neutron and light quasi‐elastic broadening.
New reactive polymers containing nitrogen functionalities: From asymmetric synthesis to supported catalysis
Authors: Fréchet Jean M.J. , Deratani André , Darling Graham , Lecavalier Pierre , Li Nai Hong
Published: March 2011

Several new reactive polymers containing various nitrogen functionalities have been prepared in bead form and tested as catalysts or ligands for reactive moieties in organic synthesis. In particular polymers containing 4‐dialkylaminopyridine pendant groups show good to excellent catalytic activities depending on their structure and their microenvironment. Best results are obtained on polystyrene backbones when the catalytic species are removed from the styrene rings by a three carbon spacer. Poly‐benzimidazole resins prepared by precipitation polymerization are good ligands for transition metal catalysts used in the catalytic hydrogenation of nitro compounds or olefinic double‐bonds. The PBI resins can also be used to prepare a polymeric oxidizing reagent through the binding of Cr(VI); the reagent oxidizes alcohols to the corresponding carbonyls while spent Cr(II) or Cr(III) remains anchored to the polymer. Other polymers containing chiral amino‐alcohol pendant groups show useful properties as chiral auxiliaries in the asymmetric reduction of ketones using polymer‐complexed lithium aluminium hydride.
Surface forces with adsorbed polymers: Direct measurements and model calculations
Authors: Klein Jacob
Published: March 2011

We Have Measured Directly The Forces Between Two Smooth Solid Surfaces Immersed In Liquid Media In The Range Of Surface Separation 0 ∼ 2000Å. By Measuring The Interactions Both With And Without Polymers Adsorbed Onto The Surfaces From The Solution, We Could Characterize The Effects Due To The Adsorbed Polymers Themselves. This Has Been Done For Several Model Polymer Systems In A Wide Range Of Solvency Conditions: Poor‐, Theta‐ And Good Solvents, As Well As For Charged Polymers In Ionic Media. The Present Paper Describes Two Recent Studies Of Adsorbed Polymers In Theta‐Solvent And Good Solvent Conditions, And The Effect Of Polymer Bridging At Low Adsorbance Values. The Experimental Studies Are Extremely Direct, And Can Be Compared With Molecular Models: We Briefly Describe Such A Detailed Comparison For The Case Of Interaction Between Adsorbed Polymer Layers In A poor solvent.
Structural models for some crystalline and liquid crystalline polymers
Authors: Zugenmaier P.
Published: March 2011

Structural models for the crystalline and liquid crystalline smectic phase are presented for polymethylsiloxanes with mesogenic side groups and for some crystalline and lyotropic liquid crystalline cholesteric phases of cellulose derivatives. Optical and X‐ray methods have been applied in these investigations.
Unusual instability effects observed in ionic and non‐ionic water soluble polymers
Authors: Kulicke W.‐M.
Published: March 2011

The solution instability of anionic, cationic and non‐ionic water soluble polymers was observed and examined. This instability can be easily observed by measuring the change in the solution viscosity.

A viscosity increase with storage time was observed in the case of aqueous polyvinylalcohol solutions. A viscosity decrease with storage time was observed in the case of aqueous polyacrylamide solutions and derivates of polyacrylamide, also in the case of aqueous solutions of polystyrene sulfonate, starch‐acrylamide graft copolymers, amylose and poly(L‐glutamic) acid. This unusual solution instability was observed when the solutions were stored in the dark, at room temperature, and without mechanical influence.

This instability effect is of scientific (molecular origin) and of technical (application) interest. The intention of this paper is to present an overall view of polymers which show this unusual instability effect, to report on the experiments done so far and to discuss possible reasons for this.
Photobehaviour of benzyl containing itaconate polymers
Authors: Abuin Elsa , Lissi Eduardo , Gargallo Ligia , Radić Deodato
Published: March 2011

The emission spectra of benzyl containing itaconate polymers were investigated in dilute tetrahydrofuran solutions. The polymers studied were poly(dibenzyl itaconate), poly(monobenzyl itaconate) and a (dibenzyl itaconate‐co‐dicyclohexylmethyl itaconate) copolymer. The photobehaviour of small compounds bearing the same chromophores was also investigated. The results obtained allow a discussion of the effect introduced by the polymer backbone upon the process of excimer formation.
Molecular weight determination of acrylonitrile polymers by gel permeation chromatography in N,N‐dimethylformamide
Authors: Azuma Chiaki , Dias Marcos L. , Mano Eloisa B.
Published: March 2011

Peculiar elution behavior of the GPC of acrylonitrile polymers was investigated. The peculiarity was considered to be due to some substances which form a supermolecular structure with acrylonitrile polymers to cause a large UV absorption, detectable at 280 nm. The Mark‐Houwink‐Sakurada parameters of acrylonitrile polymers in 0.01M LiBr‐DMF at 60°C, needed for GPC universal calibration, were determined to be K=2.12 × 10−4 and a=0.75. The parameters obtained by us were different from the ones by other investigators, however, these values were reasonable for random coil polymers. The addition of inorganic salt, such as LiBr, in DMF removed the peculiar elution behavior of the GPC. The universal calibration using monodisperse poly(ethylene oxide) standards and the Mark‐Houwink‐Sakurada parameters could be applied for the determination of the molecular weights. The invalidity of the universal calibration for acrylonitrile polymers in DMF containing LiBr, seems to be caused by the difficulty in the determination of the molecular weight of polyacrylonitrile standards by absolute methods, such as light scattering and osmometry.