bluuebunny/crossref_metadata_2025 huggingface dataset:
An Evaluation of Stability Indices Using Sensitivity Functions for Active Magnetic Bearing Supported High-Speed Rotor
Authors: Takahashi Naohiko , Fujiwara Hiroyuki , Matsushita Osami , Ito Makoto , Fukushima Yasuo
Published: March 2007

In active magnetic bearing (AMB) systems, stability is the most important factor for reliable operation. Rotor positions in radial direction are regulated by four-axis control in AMB, i.e., a radial system is to be treated as a multi-input multioutput (MIMO) system. One of the general indices representing the stability of a MIMO system is “maximum singular value” of a sensitivity function matrix, which needs full matrix elements for calculation. On the other hand, ISO 14839-3 employs “maximum gain” of the diagonal elements. In this concept, each control axis is considered as an independent single-input single-output (SISO) system and thus the stability indices can be determined with just four sensitivity functions. This paper discusses the stability indices using sensitivity functions as SISO systems with parallel/conical mode treatment and/or side-by-side treatment, and as a MIMO system with using maximum singular value; the paper also highlights the differences among these approaches. In addition, a conversion from usual x∕y axis form to forward/backward form is proposed, and the stability is evaluated in its converted form. For experimental demonstration, a test rig diverted from a high-speed compressor was used. The transfer functions were measured by exciting the control circuits with swept signals at rotor standstill and at its 30,000 revolutions/min rotational speed. For stability limit evaluation, the control loop gains were increased in one case, and in another case phase lags were inserted in the controller to lead the system close to unstable intentionally. In this experiment, the side-by-side assessment, which conforms to the ISO standard, indicates the least sensitive results, but the difference from the other assessments are not so great as to lead to inadequate evaluations. Converting the transfer functions to the forward/backward form decouples the mixed peaks due to gyroscopic effect in bode plot at rotation and gives much closer assessment to maximum singular value assessment. If large phase lags are inserted into the controller, the second bending mode is destabilized, but the sensitivity functions do not catch this instability. The ISO standard can be used practically in determining the stability of the AMB system, nevertheless it must be borne in mind that the sensitivity functions do not always highlight the instability in bending modes.
Inferring Viscoelastic Dynamic Material Properties From Finite Element and Experimental Studies of Beams With Constrained Layer Damping
Authors: Hambric Stephen A. , Jarrett Andrew W. , Lee Gilbert F. , Fedderly Jeffry J.
Published: March 2007

Viscoelastic materials are often used to add damping to metal structures, usually via the constrained layer damping method. The added damping depends strongly on material temperature and frequency, as do the underlying material properties of the viscoelastomer. Several standardized test methods are available to characterize the dynamic material properties of viscoelastomers. However, they rely on limited test data which is extrapolated using the time—temperature superposition technique. The authors have found that the different testing methods typically produce significantly different dynamic material properties, or “master curves.” An approach for inferring viscoelastomer dynamic moduli with better accuracy is suggested here. Several metal bars are treated using constrained layer damping. Experimental modal analyses are conducted on the bars at different temperatures to produce sets of system resonance frequencies and loss factors. Corresponding finite element (FE) models of the treated bars are analyzed using assumed viscoelastomer material properties based on master curves generated using a standardized test technique. The parameters which define the master curves are adjusted by trial and error until the FE-simulated system loss factors match those of the measurements. The procedure is demonstrated on two viscoelastomers with soft and stiff moduli.
Constructal Design of Cooling Channel in Heat Transfer System by Utilizing Optimality of Branch Systems in Nature
Authors: Ding Xiaohong , Yamazaki Koetsu
Published: March 2007

There are similarities between the morphology of branch systems in nature and the layout of cooling channel in heat transfer system in engineering. The branch systems in nature always grow in such a way that approximate global optimal performances can be achieved. By utilizing the optimality of branch systems in nature, an innovative layout design methodology of cooling channel in heat transfer system is suggested in this paper. The emergent process of branch systems in nature is reproduced according to their common growth mechanisms. Branches are grown under the control of a so-called nutrient density so as to make it possible for the distribution of branches to be dependent on the nutrient distribution. The growth of branches also satisfies the hydrodynamic conditions and the minimum energy loss principle. If the so-called nutrient density in the generation process of branch systems is referred to as the heat energy in a heat transfer system, the distribution of branches is responsible for the distribution of cooling channels. Having similar optimality of branch systems in nature, the constructed cooling channel can be designed flexibly and effectively in any shape of perfusion volume to be cooled adaptively to very complex thermal boundary conditions. The design problems of both a conductive cooling channel and a convective cooling channel are studied, and the layouts of two-dimensional and three-dimensional cooling channels are illustrated. The cooling performances of the designed heat transfer systems are discussed by the finite element method analysis and are compared with the results designed by other conventional design methods.
Thermal Performance of Multipass Parallel and Counter-Cross-Flow Heat Exchangers
Authors: Cabezas-Gómez Luben , Aparecido Navarro Hélio , Maria Saiz-Jabardo José
Published: March 2007

A thorough study of the thermal performance of multipass parallel cross-flow and counter-cross-flow heat exchangers has been carried out by applying a new numerical procedure. According to this procedure, the heat exchanger is discretized into small elements following the tube-side fluid circuits. Each element is itself a one-pass mixed-unmixed cross-flow heat exchanger. Simulated results have been validated through comparisons to results from analytical solutions for one- to four-pass, parallel cross-flow and counter-cross-flow arrangements. Very accurate results have been obtained over wide ranges of NTU (number of transfer units) and C* (heat capacity rate ratio) values. New effectiveness data for the aforementioned configurations and a higher number of tube passes is presented along with data for a complex flow configuration proposed elsewhere. The proposed procedure constitutes a useful research tool both for theoretical and experimental studies of cross-flow heat exchangers thermal performance.
Response to Comment on "Why Are There So Many Species of Herbivorous Insects in Tropical Rainforests?"
Authors: Novotny Vojtech , Drozd Pavel , Miller Scott E. , Kulfan Miroslav , Janda Milan , Basset Yves , Weiblen George D.
Published: March 2007

Norton and Didham suggest that differences in plant abundance between tropical and temperate forests may influence the host specificity of herbivores in these forests. We agree in principle but show that this is likely only for very rare plant species in tropical forests. Studies of herbivores hosted by rare plant species would help our understanding of tropical plant-insect interactions.
Development of In Vitro Correlate Assays of Immunity to Infection withYersinia pestis
Authors: Bashaw J. , Norris S. , Weeks S. , Trevino S. , Adamovicz J. J. , Welkos S.
Published: March 2007

Pneumonic plague is a severe, rapidly progressing disease for which there is no effective vaccine. Since the efficacy of new vaccines cannot be tested in humans, it is essential to develop in vitro surrogate assays that are valid predictors of immunity. The F1 capsule antigen stimulates a protective immune response to most strains ofYersinia pestis. However, strains ofY. pestisthat are F1−but still virulent have been isolated, and an in vitro assay, the results which can predict protection against both F1+and F1−strains, is needed. The virulence antigen (V) is an essential virulence factor ofY. pestisand stimulates protective antibodies. We investigated potential correlates of plague immunity that are based on anti-V antibody-mediated neutralization ofYersinia-induced macrophage cytotoxicity. The neutralizing activity of sera from mice vaccinated with an F1-V fusion candidate vaccine was determined. The decrease in the level of the apoptosis-specific enzyme caspase-3 significantly predicted survival in one- and two-dose vaccination experiments. Sera from F1-V-vaccinated nonhuman primates were evaluated with macrophage assays based on caspase-3 and on other markers manifested at the different stages in cell death. Using murine- and human-derived macrophages in microscopic and fluorescence-activated-cell-sorting-based live/dead staining assays of terminal necrosis, we demonstrated a strong association between in vitro neutralization of macrophage cytotoxicity induced by serum-treatedYersiniaand in vivo protection against lethal infection. These results provide a strong base for the development of reliable in vitro correlate bioassays that are predictive of protective immunity to plague.
Structure of Immature West Nile Virus
Authors: Zhang Ying , Kaufmann Bärbel , Chipman Paul R. , Kuhn Richard J. , Rossmann Michael G.
Published: March 2007

The structure of immature West Nile virus particles, propagated in the presence of ammonium chloride to block virus maturation in the low-pH environment of the
trans
-Golgi network, was determined by cryo-electron microscopy (cryo-EM). The structure of these particles was similar to that of immature West Nile virus particles found as a minor component of mature virus samples (naturally occurring immature particles [NOIPs]). The structures of mature infectious flaviviruses are radically different from those of the immature particles. The similarity of the ammonium chloride-treated particles and NOIPs suggests either that the NOIPs have not undergone any conformational change during maturation or that the conformational change is reversible. Comparison with the cryo-EM reconstruction of immature dengue virus established the locations of the N-linked glycosylation sites of these viruses, verifying the interpretation of the reconstructions of the immature flaviviruses.
Mapping the Landscape of the Lymphocytic Choriomeningitis Virus Stable Signal Peptide Reveals Novel Functional Domains
Authors: Saunders April A. , Ting Joey P. C. , Meisner Jeffrey , Neuman Benjamin W. , Perez Mar , de la Torre Juan Carlos , Buchmeier Michael J.
Published: March 2007

The stable signal peptide (SSP) of the lymphocytic choriomeningitis virus surface glycoprotein precursor has several unique characteristics. The SSP is unusually long, at 58 amino acids, and contains two hydrophobic domains, and its sequence is highly conserved among both Old and New World arenaviruses. To better understand the functions of the SSP, a panel of point and deletion mutants was created by in vitro mutagenesis to target the highly conserved elements within the SSP. We were also able to confirm critical residues required for separate SSP functions by
trans
-complementation. Using these approaches, it was possible to resolve functional domains of the SSP. In characterizing our SSP mutants, we discovered that the SSP is involved in several distinct functions within the viral life cycle, beyond translocation of the viral surface glycoprotein precursor into the endoplasmic reticulum lumen. The SSP is required for efficient glycoprotein expression, posttranslational maturation cleavage of GP1 and GP2 by SKI-1/S1P protease, glycoprotein transport to the cell surface plasma membrane, formation of infectious virus particles, and acid pH-dependent glycoprotein-mediated cell fusion.
Studies of the Silencing of Baculovirus DNA Binding Protein
Authors: Quadt Ilja , van Lent Jan W. M. , Knebel-Mörsdorf Dagmar
Published: March 2007

Baculovirus DNA binding protein (DBP) binds preferentially single-stranded DNA in vitro and colocalizes with viral DNA replication sites. Here, its putative role as viral replication factor has been addressed by RNA interference. Silencing of DBP in
Autographa californica
multiple nucleopolyhedrovirus-infected cells increased expression of LEF-3, LEF-4, and P35. In contrast, expression of the structural genes coding for P39 and polyhedrin was suppressed while expression of genes coding for P10 and GP64 was unaffected. In the absence of DBP, viral DNA replication sites were formed, indicating replication of viral DNA. Electron microscopy studies, however, revealed a loss of formation of polyhedra and virus envelopment, suggesting that the primary role of DBP is viral formation rather than viral DNA replication.
The demography of recovery of an overexploited bull trout, Salvelinus confluentus, population
Authors: Johnston Fiona D , Post John R , Mushens Craig J , Stelfox Jim D , Paul Andrew J , Lajeunesse Brian
Published: March 2007

An exploited bull trout, Salvelinus confluentus, population experienced a 28-fold increase in adult density during a 10-year period from a minimum of 60 individuals. This demonstrates the extent to which this population was overharvested. Its ability to respond in fewer than two generations to the implementation of zero-harvest regulations suggests this population was growth-overfished not recruitment-overfished. Examination of stock–recruitment relationships of various life stages indicates that recovery of this population was regulated by the density-dependent survival of juveniles in the rearing creek. This compensatory response occurred between egg deposition and age-1 and regulated the number of fish recruiting into the adult population. A second population bottleneck became apparent later in the recovery process when density-dependent survival of the adult population resulted in its approach to an asymptote, highlighting the necessity of long-term data sets for examining these compensatory responses. Results from this study demonstrate the importance of understanding the influence of individual life stages on the ability of overexploited populations such as threatened bull trout to recover and for their future management.
Variance estimation in integrated assessment models and its importance for hypothesis testing
Authors: Deriso Richard B , Maunder Mark N , Skalski John R
Published: March 2007

Variance in likelihood functions for multiple normally distributed data sets can be reliably estimated in integrated assessment models, and their values are important for accurate hypothesis tests. Commonly, assessment models are fitted to multiple types of observations by constructing a joint likelihood function that is then maximized. When a model contains no random effects and all random variables in the likelihood function represent errors in the prediction of measurements, then variances for each of the error distributions are estimable provided that no likelihood component has zero degrees of freedom. Theory for estimation of variances is reviewed. We show the relationship between concentrated likelihood based on the normal distribution and weighted least squares. Concentrated likelihood and weighted least squares are equivalent when the likelihood is made of normally distributed errors with constant variances, and the least squares weights are inversely proportional to the maximum likelihood estimates of the variances. A simulation study was made to show that variances and several output quantities are reasonably estimated for a herring-like population with moderate amounts of data. The simulation analysis and a case study with application to a herring population show that the choice of variances can strongly affect results of hypothesis tests.
Estimating canopy fuel characteristics in five conifer stands in the western United States using tree and stand measurements
Authors: Reinhardt Elizabeth , Scott Joe , Gray Kathy , Keane Robert
Published: March 2007

Assessment of crown fire potential requires quantification of canopy fuels. In this study, canopy fuels were measured destructively on plots in five Interior West conifer stands. Observed canopy bulk density, canopy fuel load, and vertical profiles of canopy fuels are compared with those estimated from stand data using several computational techniques. An allometric approach to estimating these canopy fuel characteristics was useful, but, for accuracy, estimates of vertical biomass distribution and site-adjustment factors were required. Available crown fuel was estimated separately for each tree according to species, diameter, and crown class. The vertical distribution of this fuel was then modeled within each tree crown on the basis of tree height and crown base height. Summing across trees within the stand at every height yielded an estimated vertical profile of canopy fuel that approximated the observed distribution.
Slow growth, long-lived trees, and minimal disturbance characterize the dynamics of an ancient, montane forest in coastal British Columbia
Authors: Parish Roberta , Antos Joseph A
Published: March 2007

Elucidating the factors that structure very old forests is crucial to understanding their dynamics. We reconstructed the history of an ancient (1000-year-old) stand in the mountains of coastal British Columbia that contained four tree species (Abies amabilis (Dougl.) Forbes, Chamaecyparis nootkatensis (D. Don) Spach., Tsuga mertensiana (Bong.) Carr., and Tsuga heterophylla (Raf.) Sarg.) in the canopy and the seedling bank. Using dendrochronological procedures, we examined the growth patterns of all trees (>4.0 cm diameter at breast height) in four 0.25 ha mapped plots. We also sampled the seedling bank in the four plots. Age structures indicated variable but rather continuous recruitment for all species. Periods of increased amounts of release or rapid early growth occurred but were not pronounced. Overall, we found little evidence for stand-level disturbance or the formation of large gaps. All four tree species appear able to persist in the stand in the absence of major stand-level disturbance, but the mechanisms contributing to coexistence differ. One species, C. nootkatensis, depends primarily on vegetative reproduction for persistence. Single-tree gap dynamics have predominated in the stand for centuries, placing this stand at the far end of the gradient from forests controlled by large, severe disturbances to those where very small-scale processes predominate.
The effect of fires on susceptibility of subalpine forests to a 19th century spruce beetle outbreak in western Colorado
Authors: Kulakowski Dominik , Veblen Thomas T
Published: March 2007

In the subalpine forests of the Colorado Rocky Mountains, research on disturbances that have occurred over the past several decades has shown that prior occurrence of disturbances can alter the extent and severity of subsequent disturbances. In the current study, we consider how fire history affected stand susceptibility to a mid-19th century spruce beetle (Dendroctonus rufipennis Kirby 1837) outbreak. Twenty-one sites were randomly located in an Engelmann spruce – subalpine fir (Picea engelmannii Parry ex Engelm. – Abies lasiocarpa (Hook.) Nutt.) forest across ~2000 km2 of the Grand Mesa area, Colorado. At each site, dendrochronological methods were used to reconstruct the history of severe fires and beetle outbreak. Stand-origin dates were estimated by collecting increment cores from 20–27 of the largest trees at each sample site. The beetle outbreak was reconstructed based on coincident releases among nonhost trees that survived the outbreak. Forest stands originated following severe fires in ca. 1790, ca. 1740, and ca. 1700. The 1840's outbreak affected 67% of these stands. Stands that initiated following the ca. 1790 fire were less susceptible to the outbreak than older stands. These findings indicate that stand-replacing fires have mitigated susceptibility to outbreaks of spruce beetles not only during recent outbreaks, but also over the past centuries.
Bayesian belief networks: applications in ecology and natural resource management
Authors: McCann Robert K , Marcot Bruce G , Ellis Rick
Published: March 2007

In this introduction to the following series of papers on Bayesian belief networks (BBNs) we briefly summarize BBNs, review their application in ecology and natural resource management, and provide an overview of the papers in this section. We suggest that BBNs are useful tools for representing expert knowledge of an ecosystem, evaluating potential effects of alternative management decisions, and communicating with nonexperts about making natural resource management decisions. BBNs can be used effectively to represent uncertainty in understanding and variability in ecosystem response, and the influence of uncertainty and variability on costs and benefits assigned to model outcomes or decisions associated with natural resource management. BBN tools also lend themselves well to an adaptive-management framework by posing testable management hypotheses and incorporating new knowledge to evaluate existing management guidelines.
Temporal Complexity and Heterogeneity of Single-Neuron Activity in Premotor and Motor Cortex
Authors: Churchland Mark M. , Shenoy Krishna V.
Published: March 2007

The relationship between neural activity in motor cortex and movement is highly debated. Although many studies have examined the spatial tuning (e.g., for direction) of cortical responses, less attention has been paid to the temporal properties of individual neuron responses. We developed a novel task, employing two instructed speeds, that allows meaningful averaging of neural responses across reaches with nearly identical velocity profiles. Doing so preserves fine temporal structure and reveals considerable complexity and heterogeneity of response patterns in primary motor and premotor cortex. Tuning for direction was prominent, but the preferred direction was frequently inconstant with respect to time, instructed-speed, and/or reach distance. Response patterns were often temporally complex and multiphasic, and varied with direction and instructed speed in idiosyncratic ways. A wide variety of patterns was observed, and it was not uncommon for a neuron to exhibit a pattern shared by no other neuron in our dataset. Response patterns of individual neurons rarely, if ever, matched those of individual muscles. Indeed, the set of recorded responses spanned a much higher dimensional space than would be expected for a model in which neural responses relate to a moderate number of factors—dynamic, kinematic, or otherwise. Complex responses may provide a basis-set representing many parameters. Alternately, it may be necessary to discard the notion that responses exist to “represent” movement parameters. It has been argued that complex and heterogeneous responses are expected of a recurrent network that produces temporally patterned outputs, and the present results would seem to support this view.
Nation-Building and Integration Policy in the Philippines
Authors: Yamamoto Kazuya
Published: March 2007

The Philippines can be considered a country where successive governments have sought to create a single nation by implementing integration policies. In this article, two formal models are developed —the modernism model and the historicism (primordialism or essentialism) model — to suitably analyze the national integration policy of the Philippines. The analysis reveals that (1) the post-independence national integration policy of the Philippines cannot be regarded as being successful; (2) national integration in the Philippines will continue to be difficult; (3) no deterministic argument can be made regarding the relationship between mobilization and national cleavage; and (4) the modern nation should not be regarded as an extension of pre-modern ethnic groups but as a new identity group that is formed through the process of modernization. In addition, the mathematical implications of the two models are derived. The modernism model implies that (1) in some cases, a ruling group that is in the majority at the time of independence can maintain its position even if it cannot assimilate a majority of the underlying people after independence; (2) in some cases, a ruling group that is not in the majority at the time of independence cannot attain a majority even if it is able to assimilate a majority of the underlying people after independence; and (3) a larger ruling group is not always capable of promoting greater integration than a smaller one can. On the other hand, the historicism model implies that the size of the underlying ethnic group that will comprise the ruling group when mobilized is the key to the success or failure of national integration.
A clinical prediction model for the presence of peripheral arterial disease — the benefit of screening individuals before initiation of measurement of the ankle—brachial index: an observational study
Authors: Bendermacher Bianca L.W. , Teijink Joep A.W. , Willigendael Edith M. , Bartelink Marie-Louise , Peters Ron J.G. , de Bie Rob A. , Büller Harry R. , Boiten Jelis , Langenberg Machteld , Prins Martin H.
Published: March 2007

Measurement of the ankle—brachial index (ABI) can provide important information about the presence of subclinical atherosclerosis. Performing the ABI in the overall population is not feasible, but it can be used in a selected population. A simple prediction rule could be of much use to estimate the risk of an abnormal ABI. This was designed as an observational study in the setting of 955 general practices in The Netherlands. A total of 7454 patients aged ≥ 55 years presenting with at least one vascular risk factor (smoking, hypertension, diabetes, and hypercholesterolemia) and no complaints of intermittent claudication were included. Patients were selected by the general practitioner during visiting hours and from medical records. Main outcome measures included the prevalence of PAD, defined as an ABI below 0.9, which was related to vascular risk factors using regression analyses on which the PREVALENT clinical prediction model was developed. The overall prevalence of PAD was 18.4%. Since the treatment of individuals with a history of coronary heart disease and cerebrovascular disease will not be influenced by the finding of asymptomatic PAD, these individuals were not taken into account for the development of the clinical prediction model. Analyses showed a significantly increased risk for PAD with increasing age, smoking, and hypertension. The clinical prediction model giving risk factor points per factor (age: 1 point per 5 years starting at 55 years; ever smoked: 2 points; currently smoking: 7 points; and hypertension: 3 points), showed a proportional increase of the PAD prevalence with each increasing risk profile (range: 7.0—40.6%). In conclusion, based on the PREVALENT clinical prediction model, the general practitioner is able to identify a high-risk population in which measurement of ABI is useful.
Reporting Questionnaire for Children as a Screening Instrument for Child Mental Health Problems in Iraqi Kurdistan
Authors: Ahmad Abdulbaghi , Abdul-Majeed Anas M. , Siddiq Aras A. , Jabar Fatima , Qahar Jabar , Rasheed Jihan , von Knorring Anne-Liis
Published: March 2007

To identify child mental health problems in a mid-sized to large city in Iraqi Kurdistan, the Reporting Questionnaire for Children (RQC), followed by the Child Behaviour Checklist (CBCL) and the Post-traumatic Stress Symptom Checklist for Children (PTSS-C), were administered in interview form to the caregivers of 806 school-aged children. To cover different categories of children, four samples were randomly selected from among the general population ( n = 201), orphans ( n = 241), primary medical care patients ( n = 199), and hospital patients ( n = 165). The RQC revealed satisfactory validity against a deviant CBCL cut-off. The screening capacity of the RQC was further supported by its similarity to the CBCL in distribution of problem scores among the four samples and its positive correlation with the CBCL, but not with the trauma-related PTSS-C. Although the general population showed lower problem scores than the orphans and the two clinical samples, problem scores in all instruments were considerably higher than those reported from other societies. The RQC seems to be useful as a first-stage screening instrument for child mental health problems in Kurdistan.
Identification of functional endothelial progenitor cells suitable for the treatment of ischemic tissue using human umbilical cord blood
Authors: Nagano Masumi , Yamashita Toshiharu , Hamada Hiromi , Ohneda Kinuko , Kimura Ken-ichi , Nakagawa Tomoki , Shibuya Masabumi , Yoshikawa Hiroyuki , Ohneda Osamu
Published: March 2007

Umbilical cord blood (UCB) has been used as a potential source of various kinds of stem cells, including hematopoietic stem cells, mesenchymal stem cells, and endothelial progenitor cells (EPCs), for a variety of cell therapies. Recently, EPCs were introduced for restoring vascularization in ischemic tissues. An appropriate procedure for isolating EPCs from UCB is a key issue for improving therapeutic efficacy and eliminating the unexpected expansion of nonessential cells. Here we report a novel method for isolating EPCs from UCB by a combination of negative immunoselection and cell culture techniques. In addition, we divided EPCs into 2 subpopulations according to the aldehyde dehydrogenase (ALDH) activity. We found that EPCs with low ALDH activity (Alde-Low) possess a greater ability to proliferate and migrate compared to those with high ALDH activity (Alde-High). Moreover, hypoxia-inducible factor proteins are up-regulated and VEGF, CXCR4, and GLUT-1 mRNAs are increased in Alde-Low EPCs under hypoxic conditions, while the response was not significant in Alde-High EPCs. In fact, the introduction of Alde-Low EPCs significantly reduced tissue damage in ischemia in a mouse flap model. Thus, the introduction of Alde-Low EPCs may be a potential strategy for inducing rapid neovascularization and subsequent regeneration of ischemic tissues.
Glucocorticoid exposure and tissue gene expression of 11β HSD-1, 11β HSD-2, and glucocorticoid receptor in a porcine model of differential fetal growth
Authors: McNeil Christopher J , Nwagwu Margaret O , Finch Angela M , Page Kenneth R , Thain Alan , McArdle Harry J , Ashworth Cheryl J
Published: March 2007

Glucocorticoids play a critical role in fetal development, but inappropriate exposure is associated with reduced fetal growth. We investigated cortisol exposure and supply in a porcine model of differential fetal growth. This model compares the smallest fetus of a litter with an average-sized sibling at three stages of gestation. At day 45, small fetuses had reduced plasma cortisol (16.8 ± 3.4 ng/ml) relative to average fetuses (34.4 ± 3.4 ng/ml, P < 0.001). At day 65 levels had reduced in small and average fetuses to similar concentrations (5.7 ± 1.0 vs 4.8 ± 0.5 ng/ml, P = 0.128). By day 100, elevated levels were found in small fetuses (10.7 ± 1.5 vs 7.6 ± 0.7 ng/ml, P < 0.001). Maternal plasma cortisol was unchanged over gestation (day 45, 56.7 ± 21.6 ng/ml; day 65, 57.8 ± 14.4 ng/ml; day 100, 55.7 ± 6.5 ng/ml). We examined the cause of altered cortisol by investigating the fetal hypothalamic–pituitary–adrenal axis through the measurement of adrenocorticotropic hormone and assessing exposure to maternal cortisol by quantifying placental 11β-hydroxysteroid dehydrogenase-isoform 2 (11β HSD-2) gene expression. These data suggest that altered cortisol supply was of fetal origin. We examined organ glucocorticoid (GC) metabolism by the measurement of GC receptor (GR) and 11β-hydroxysteroid dehydrogenase-isoform 1 (11β HSD-1) gene expression. We found that fetal organs have different temporal patterns of 11β HSD-1 and GR expression, with the liver particularly sensitive to cortisol in late gestation. This study examines GC exposure in naturally occurring differential growth and simultaneously explores tissue GC sensitivity and handling, at three key stages of gestation.
Transcatheter closure of persistent unligated vertical vein after TAPVC surgery using the Amplatzer PDA device
Authors: Narula Nidhi , Wilson Neil , Kumar R. Suresh
Published: March 2007

An unligated vertical vein (VV) after TAPVC surgery is likely to require subsequent closure. Reports of transcatheter closure of the VV are largely unpublished. This report details transcatheter closure of a persistent VV using an Amplatzer PDA occluder, following TAPVC repair in early infancy. We suggest that transcatheter closure should be considered as a treatment option in this condition. © 2007 Wiley‐Liss, Inc.
The International Society for Developmental Psychobiology 39th Annual Meeting Symposium: Alcohol and Development: Beyond fetal alcohol syndrome
Authors: Molina Juan Carlos , Spear Norman E. , Spear Linda P. , Mennella Julie A. , Lewis Michael J.
Published: March 2007

As has been repeatedly demonstrated, alcohol can exert deleterious morphological and physiological effects during early stages in development. The present review examines nonteratological links existing between alcohol and ontogeny. Human and animal studies are taken into consideration for the analysis of fetal, neonatal, infantile, adolescent, and adult responsiveness to the drug. Sensitivity to alcohol's chemosensory and postabsorptive properties, as well as learning and memory processes mediated by such properties, are examined from this developmental perspective. The studies under discussion indicate that, within each stage in development, we can trace alcohol‐related experiences capable of determining or modulating alcohol seeking and intake patterns. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 227–242, 2007.
Influence of Grafting on the Solution Properties and the Dissociation Behavior of Ionic/Nonionic Grafted Copolymers
Authors: Weber Jens , Boyko Volodymyr , Arndt Karl‐Friedrich
Published: March 2007

A new synthetic approach towards grafted terpolymers based on a poly[(methyl vinyl ether)‐alt‐(maleic anhydride)] backbone and poly(ethylene glycol) monomethyl ether (MPEG) side chains is presented. Resulting comb polymers with controllable grafting degree still have highly reactive anhydride moieties along the polymer backbone, as proved by IR spectroscopy. Grafting degree depends on the anhydride hydroxide stoichiometric ratio. It is not influenced by the molecular weight of MPEG. An increase in the grafting degree leads to a contraction of the polymer in the solution. Evaluation of potentiometric titration data gave a deeper insight into the dissociation process. The copolymers showed a two‐step dissociation behavior. No significant influence of the grafting degree on the acidic strength was observed, whilst there is a strong effect of the grafting degree on the free energy change upon neutralization ΔGel. Grafting leads to a higher change in free energy ΔGel,1 for the first step but to lower ΔGel,2 required for the second step.

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Reliability and validity of the eyberg child behavior inventory with African–American and Latino parents of young children
Authors: Gross Deborah , Fogg Louis , Young Michael , Ridge Alison , Cowell Julia , Sivan Abigail , Richardson Reginald
Published: March 2007

This study evaluated the reliability, equivalence, and convergent validity of the Eyberg Child Behavior Inventory (ECBI) in 682, 2‐ to 4‐year‐old children. For analysis, parent informants' data were blocked by race/ethnicity (African–American, Latino, non‐Latino White), family income (low versus middle/upper), child's gender, and ECBI language version (English and Spanish). ECBI scales had high internal consistency reliabilities and good convergence with the Child Behavior Checklist/1–5. Some racial/ethnic and income effects were found. There were no mean differences by ECBI language version or by child gender. Using confirmatory factor analysis, a single‐factor invariant model of the ECBI Intensity Scale provided a good fit with the data across racial/ethnic and income groups. Implications for using the ECBI to measure behavior problems in young children of color are discussed. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30: 213–223, 2007
Enhanced attenuation: Its place in the remediation of chlorinated solvents
Authors: Wilson Kimberly , Sewell Guy , Kean Judie A. , Vangelas Karen
Published: March 2007

The development and regulatory acceptance of monitored natural attenuation (MNA) as a remedial strategy has forever changed the field of environmental cleanup. MNA is continuing to develop but it is challenged by a lack of a clear definition for the appropriate application of the MNA strategy. This challenge has resulted in the lack of a significant record of restoration and site closure. Environmental professionals face challenges in providing guidance that addresses how to manage these sites when technologies, performance monitoring, and even environmental conditions are subject to further development, refinement, and/or altered perspectives. As our experience and institutional knowledge grows around the implementation of MNA, we have the opportunity to develop “second‐generation” management tools and procedures for optimizing sites utilizing MNA as a part of a comprehensive site management plan. This opportunity is the focus of the Enhanced Attenuation: Chlorinated Organics (EACO) Team of the Interstate Technology Regulatory Council (ITRC). The development of the “second‐generation” tools/procedures has included defining EA and evaluating, through the use of a national survey of state regulators, the experience with MNA and interest in EA. The results of these two efforts formed the basis for developing a framework that provides a “bridge” from active treatment to MNA. © 2007 Wiley Periodicals, Inc.
A framework for analysis of contamination on human and ecological receptors at DOE hazardous waste site buffer lands
Authors: Burger Joanna
Published: March 2007

This article discusses a framework and tools for evaluating ecological resources and the effects of cleanup on hazardous waste sites, particularly those with ecological buffer lands. Environmental professionals are faced with assessing the risks of contamination to humans and ecological receptors (organisms and ecosystems) at hazardous waste sites. While exposure assessment has focused largely on human receptors, environmental managers have recently taken a broader view, recognizing the intrinsic value and aesthetic importance of ecological resources and services, and of including a range of stakeholders in remediation decisions. The assessment process involves understanding exposure pathways from source to receptor, and determining how best to interdict these pathways. Environmental characterization and exposure assessment, indicator and biomarker identification, and biomonitoring and surveillance are the major components of ecological assessments. Using the Department of Energy as a case study, this article offers a framework for ecological exposure assessment, recognizing that humans are important components of ecosystems and, like other biota, are exposed to contaminants that move through environmental media. © 2007 Wiley Periodicals, Inc.
Destruction of Aspergillus versicolor, Penicillium chrysogenum, Stachybotrys chartarum, and Cladosporium cladosporioides spores using chemical oxidation treatment process
Authors: Yaari Galia , Tachiev Georgio , Dean Timothy R. , Betancourt Doris , Long Stephanie
Published: March 2007

The survival of aqueous suspensions of Penicillium chrysogenum, Stachybotrys chartarum, Aspergillus versicolor, and Cladosporium cladosporioides spores was evaluated using various combinations of hydrogen peroxide and Fe2+ as catalyst. Spore concentrations of 106–107 colony forming units per milliliter (CFU/mL) were suspended in water and treated with initial hydrogen peroxide and iron concentrations ranging from 0.05 to 10 percent and 100 to 200 ppm, respectively. After four hours of reaction time, samples were plated on agar plates, and the viable fraction of spores was determined by the number of colonies formed. Hydrogen peroxide concentrations above 50,000 ppm resulted in greater than 6‐log10 reduction of viable spores for both catalyzed and noncatalyzed reactions. Iron had a strong catalytic effect when added to solutions with hydrogen peroxide concentration above 5,000 ppm and resulted in two to three orders of magnitude greater reduction compared to hydrogen peroxide alone. Additional samples taken after 24 hours of reaction time showed that the effect of the addition of 100 and 200 ppm of Fe2+ catalyst was mostly kinetic, and noncatalyzed hydrogen peroxide had sporicidal effects similar to catalyzed hydrogen peroxide. This study identified initial reagent concentrations of hydrogen peroxide and Fe2+ that accomplish a 6‐log10 reduction of viable mold spores within reaction times of 4 and 24 hours. © 2007 Wiley Periodicals, Inc.
Conversion of phenolics to lignans: Sinapic acid to thomasidioic acid
Authors: Rubino M. I. , Arntfield S. D. , Charlton J. L.
Published: March 2007

Changes in sinapic acid when exposed to aqueous alkaline conditions were elucidated. Sinapic acid was exposed to a volatile buffer (pH 8.5) for 24 h, lyophilized, acidified, extracted, and characterized using nuclear magnetic resonance and mass spectroscopy. The product obtained was identified as the lignan thomasidioic acid. This identification was confirmed by comparison with a synthesized authentic sample of thomasidioic acid. Conversion of sinapic acid to thomasidioic acid under alkaline conditions previously has not been reported. Thomasidioic acid was present after exposure of sinapic acid to pH 8.5 for as few as 6 h. Thomasidioic acid also was formed at pH 7.
New utilization of vegetable oils
Authors: Nag A. , Bhattacharya S. , De K. B.
Published: March 2007

Energy crisis and growing fuel shortage is a global concern. This phenomenon is more conspicuous in the populous, developing countries. In order to look for alternatives and extenders to the conventional fuels, studies were performed on the seed oil of some relatively unknownPutranjiva roxburghii, a plant that is abundantly available in the Indian tropical subcontinent. In a prototype experiment, the physicochemical properties of theP. roxburghii seed oil were found to be suitable for blending with diesel up to 50% without any sacrifice in performance of an internal combustion engine. Another industrially useful material, factice (vulcanized oil), was also prepared from the same oil. It was found to be suitable for blending with rubber, improving its strength, hardness, viscosity, and scorch time, and also increased its degradation temperature. This oil is not commercially traded in the market and has not yet been recommended as edible; hence industrial exploitation will not affect consumer market directly. A few more preliminary experiments indicated that the by‐product oilcake is a good plant nutrient and the oil exerts profound antifungal activity. These properties need to be investigated more extensively. This plant and its oilseed deserve further attention and investigation, particularly in the tropical, coastal developing countries.
Effect of dietary n−3 and n−6 polyunsaturated fatty acids on lipid‐metabolizing enzymes in obese rat liver
Authors: Niot Isabelle , Gresti Joseph , Boichot Jacqueline , Semporé Georges , Durand Georges , Bézard Jean , Clouet Pierre
Published: March 2007

This study was designed to examine whether n−3 and n−6 polyunsaturated fatty acids at a very low dietary level (about 0.2%) would alter liver activities in respect to fatty acid oxidation. Obese Zucker rats were used because of their low level of fatty acid oxidation, which would make increases easier to detect. Zucker rats were fed diets containing different oil mixtures (5%, w/w) with the same ratio of n−6/n−3 fatty acids supplied either as fish oil or arachidonic acid concentrate. Decreased hepatic triacylglycerol levels were observed only with the diet containing fish oil. In mitochondrial outer membranes, which support carnitine palmitoyltransferase I activity, cholesterol content was similar for all diets, while the percentage of 22∶6n−3 and 20∶4n−6 in phospholipids was enhanced about by 6 and 3% with the diets containing fish oil and arachidonic acid, respectively. With the fish oil diet, the only difference found in activities related to fatty acid oxidation was the lower sensitivity of carnitine palmitoyltransferase I to malonyl‐CoA inhibition. With the diet containing arachidonic acid, peroxisomal fatty acid oxidation and carnitine palmitoyltransferase I activity were markedly depressed. Compared with the control diet, the diets enriched in fish oil and in arachidonic acid gave rise to a higher specific activity of aryl‐ester hydrolase in microsomal fractions. We suggest that slight changes in composition of n−3 or n−6 polyunsaturated fatty acids in mitochondrial outer membranes may alter carnitine palmitoyltransferase I activity.
Risk and protective factors for urban African‐American youth
Authors: Li Susan Tinsley , Nussbaum Karin M. , Richards Maryse H.
Published: March 2007

The present study investigated risk and resilience processes in a sample of urban African‐American youth. Risk and protective factors were assessed across ecological levels including individual, family and community. Both externalizing and internalizing symptomatology were included as measures of child adjustment. Youth and parental reports as well as various methods, such as the Experience Sampling Method, were used to capture the daily experiences of the adolescents from different perspectives. Poverty, hassles, and exposure to violence predicted higher rates of externalizing and internalizing symptoms. Individual and family protective variables emerged as powerful sources of resilience. An inner sense of confidence and helpful family support were associated with reductions in the deleterious effects of community poverty. Two main patterns, protective‐stabilizing and overwhelming‐risk, seemed to characterize most of the risk by protective factor interactions. The present findings are important for understanding the complex experiences of urban youth and furthering the literature on sources of risk and protection for African‐Americans.