bluuebunny/crossref_metadata_2025 huggingface dataset:
Coarse-grained molecular dynamics simulations of nanopatterning with multivalent inks
Authors: Cieplak Marek , Thompson Damien
Published: June 2008

A coarse-grained molecular dynamics (MD) model is developed to study the multivalent, or multisite, binding of small functionalized dendrimer molecules to β-cyclodextrin-terminated self-assembled monolayers, the so-called “molecular printboards” used to print “ink” molecules on surfaces with a high degree of positional control and specificity. Some current and future bionanotechnology applications are in the creation of nanoparticle assemblies, directed protein assembly, platforms for biosensing, and cell:surface attachment. The coarse-grained model allows us to probe up to microsecond timescales and model ink diffusion, crucial for the application of the printboard in, for example, medical diagnostics. Recent all-atom MD simulations identified and quantified the molecular strain limiting the stability of nanopatterns created with small dendrimer inks, and explained the different patterns obtained experimentally with different dendrimer inks. In the present work, the all-atom simulations are “scaled up” to longer timescales via coarse graining, without incurring significant additional computational expense, and, crucially, without significant loss in atom-scale detail, the coarse-grained MD simulations yielding properties similar to those obtained from the all-atom simulations. The anchoring of the ink molecules to the monolayer is of multivalent nature and the degree of multivalency shows a sharp dependence on temperature, control of temperature thus providing a further operational “switch” for directed molecular assembly. The computational protocol developed can, in principle, be extended to model any multivalent assembly, for example, virus-cell complexation.
Transparent organic field-effect transistors with polymeric source and drain electrodes fabricated by inkjet printing
Authors: Zhang X.-H. , Lee S. M. , Domercq B. , Kippelen B.
Published: June 2008

Transparent organic field-effect transistors based on pentacene were fabricated on indium tin oxide (ITO)-coated glass using ITO as the gate electrode, Al2O3 grown by atomic layer deposition as the gate insulator, and an inkjet-printed conducting polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulphonate) as the source and drain electrodes. The transistors combine an overall high transmittance (84% in the channel and 78% through source/drain electrodes) in the visible region, a field-effect mobility value of 0.3cm2∕Vs, a threshold voltage of −0.2V, a subthreshold slope of 0.9V/decade, and an on/off current ratio of 105.
Higher entropic uncertainty relations for anti-commuting observables
Authors: Wehner Stephanie , Winter Andreas
Published: June 2008

Uncertainty relations provide one of the most powerful formulations of the quantum mechanical principle of complementarity. Yet, very little is known about such uncertainty relations for more than two measurements. Here, we show that sufficient unbiasedness for a set of binary observables, in the sense of mutual anticommutation, is good enough to obtain maximally strong uncertainty relations in terms of the Shannon entropy. We also prove nearly optimal relations for the collision entropy. This is the first systematic and explicit approach to finding an arbitrary number of measurements for which we obtain maximally strong uncertainty relations. Our results have immediate applications to quantum cryptography.
The Use of Chromatic Information for Motion Segmentation: Differences between Psychophysical and Eye-Movement Measures
Authors: Dobkins Karen R , Sampath Vanitha
Published: June 2008

Previous psychophysical studies have shown that chromatic (red/green) information can be used as a segmentation cue for motion integration. We investigated the mechanisms mediating this phenomenon by comparing chromatic effects (and, for comparison, luminance effects) on motion integration between two measures: (i) directional eye movements with the notion that these responses are mediated mainly by low-level motion mechanisms, and (ii) psychophysical reports, with the notion that subjects' reports should employ higher-level (attention-based) mechanisms if available. To quantify chromatic (and luminance) effects on motion integration, coherent motion thresholds were obtained for two conditions, one in which the signal and noise dots were the same ‘red’ or ‘green’ chromaticity (or the same ‘bright’ or ‘dark’ luminance), referred to as homogeneous, and the other in which the signal and noise dots were of different chromaticities (or luminances), referred to as heterogeneous. ‘Benefit ratios’ (θHOM/θHET) were then computed, with values significantly greater than 1.0 indicating that chromatic (or luminance) information serves as a segmentation cue for motion integration. The results revealed a high and significant chromatic benefit ratio when the measure was based on psychophysical report, but not when it was based on an eye-movement measure. By contrast, luminance benefit ratios were roughly the same (and significant) for both measures. For comparison to adults, eye-movement data were also obtained from 3-month-old infants. Infants showed marginally significant benefit ratios in the luminance, but not in the chromatic, condition. In total, these results suggest that the use of chromatic information as a segmentation cue for motion integration relies on higher-level mechanisms, whereas luminance information works mainly through low-level motion mechanisms.
Effect of muddy conditions in the field on the liveweight gain of cattle consuming Leucaena leucocephala - Digitaria eriantha pastures in north-west Australia
Authors: Petty S. R. , Poppi D. P.
Published: June 2008

Cattle grazing leucaena (Leucaena leucocephala cv. Cunningham)–pangola grass (Digitaria eriantha cv. Steudel) pastures in the Ord River Irrigation Area in north-west Western Australia, sometimes exhibit higher liveweight gains in the dry season when temperature and humidity are lower. Two factors have been suggested as causing this seasonal difference: the combined effect of the temperature and humidity, and the effect of the muddy conditions in the field associated with rainfall in the wet summer season.
An experiment over 81 days, from August to October 1995, was conducted to evaluate the effect of muddy conditions on the liveweight gain of cattle grazing a leucaena–pangola grass pasture. Replicated paddocks were grazed in a normal irrigated system during this dry season whereas other paddocks were flood irrigated twice weekly to create muddy conditions. Cattle grazing the muddy paddocks had a liveweight gain of 0.29 kg/steer.day, which was lower (P < 0.001) than the animals in the dry paddocks (0.57 kg/steer.day). These cattle spent less time grazing (41.9 v. 67.6% of animals grazing at three observation times, 0600, 1100 and 1500 hours, on each day over the whole 81 days; P ≤ 0.001). It was suggested that the muddy condition of the paddock was the primary factor causing this difference in liveweight gain and grazing behaviour.
Application of gene expression studies in livestock production systems: a European perspective
Authors: Cassar-Malek I. , Picard B. , Bernard C. , Hocquette J.-F.
Published: June 2008

In the context of sustainable agriculture and animal husbandry, understanding animal physiology remains a major challenge in the breeding and production of livestock, especially to develop animal farming systems that respond to the new and diversified consumer demand. Physiological processes depend on the expression of many genes acting in concert. Considerable effort has been expended in recent years on examining the mechanisms controlling gene expression and their regulation by biological and external factors (e.g. genetic determinants, nutritional factors, and animal management). Two main strategies have been developed to identify important genes. The first one has focussed on the expression of candidate genes for key physiological pathways at the level of both the transcripts and proteins. An original strategy has emerged with the advent of genomics that addresses the same issues through the examination of the molecular signatures of all genes and proteins using high-throughput techniques (e.g. transcriptomics and proteomics). In this review, the application of the gene expression studies in livestock production systems is discussed. Some practical examples of genomics applied to livestock production systems (e.g. to optimise animal nutrition, meat quality or animal management) are presented, and their outcomes are considered. In the future, integration of the knowledge gained from these studies will finally result in optimising livestock production systems through detection of desirable animals and their integration into accurate breeding programs or innovative management systems.
Effect of concentrate supplement and sward height on twin-bearing ewe body condition and the performance of their offspring
Authors: Kerslake J. I. , Kenyon P. R. , Morris S. T. , Stafford K. J. , Morel P. C. H.
Published: June 2008

These studies investigated the effects of offering concentrate supplement, from day 102 of pregnancy, to twin-bearing ewes grazing a 2- or 6-cm sward, on the condition of the ewe and the performance of their offspring in 2005 and 2006. In both years, 80 twin-bearing ewes were randomly assigned to either the 2- or 6-cm sward height pasture treatment from day 70 of pregnancy until parturition. From pregnancy day 102, half of the ewes within each sward height were offered 400 g/ewe.day of concentrate supplement. From day 102 until day 140 of pregnancy, ewes offered the concentrate supplement gained more liveweight then ewes offered pasture only. While supplementation affected ewe liveweight, its effects on lamb birthweight and growth were variable. In 2006, concentrate supplementation within the 6-cm sward height treatment increased (P < 0.05) lamb birthweight from an average of 4.8 to 5.3 kg. In 2005, concentrate supplementation increased (P < 0.05) lamb growth by 20 g/day. These inconsistent and minor production gains are unlikely to be cost effective because of the satisfactory performance of lambs from all other nutritional treatments and the extensive feeding of concentrate supplement. Therefore, feeding 400 g/ewe.day of concentrate supplement from day 102 of pregnancy to twin-bearing ewes on a 2- or 6-cm sward height pasture appears not to be a viable management strategy for commercial sheep farmers.
Constitutive nitric oxide synthase activation is a significant route for nitroglycerin-mediated vasodilation
Authors: Bonini Marcelo G. , Stadler Krisztian , Silva Sueli de Oliveira , Corbett Jean , Dore Michael , Petranka John , Fernandes Denise C. , Tanaka Leonardo Y. , Duma Danielle , Laurindo Francisco R. M. , Mason Ronald P.
Published: June 2008

The physiological effects of nitroglycerin as a potent vasodilator have long been documented. However, the molecular mechanisms by which nitroglycerin exerts its biological functions are still a matter of intense debate. Enzymatic pathways converting nitroglycerin to vasoactive compounds have been identified, but none of them seems to fully account for the reported clinical observations. Here, we demonstrate that nitroglycerin triggers constitutive nitric oxide synthase (NOS) activation, which is a major source of NO responsible for low-dose (1–10 nM) nitroglycerin-induced vasorelaxation. Our studies in cell cultures, isolated vessels, and whole animals identified endothelial NOS activation as a fundamental requirement for nitroglycerin action at pharmacologically relevant concentrations in WT animals.
Hormonal carcinogenesis and socio‐biological development factors in endometrial cancer: A clinical review
Authors: TINELLI ANDREA , VERGARA DANIELE , MARTIGNAGO ROBERTA , LEO GIUSEPPE , MALVASI ANTONIO , TINELLI RAFFAELE
Published: June 2008

Objective. Endometrial cancer is one of the most common invasive gynecologic malignancies in developed countries and the eighth leading cause of cancer death in women; it typically arises in the sixth or seventh decade of life. The aim of this review was to evaluate possible roles of genetic and socio‐biological factors in type I endometrial cancer, largely confined to pre‐ and perimenopausal women, with a history of estrogen exposure and/or endometrial hyperplasia. Methods. An extensive literature review, from 1990 to 2007 was performed on modifiable risk factors for type I endometrial cancer. Additionally, carcinogenesis mechanisms, biomarker and hormonal and biomolecular approaches to cancer detection, progression and monitoring and socio‐biological factors were reviewed. Results. Several socio‐biological and lifestyle characteristics, such as hormone replacement therapy, glycemic index, obesity, alcohol use, antipsychotic medication, melatonin, physical activity and variants in hormone metabolism genes have been identified as risk factors for developing endometrial cancer of type I, the majority of which are associated with excess estrogens causing continued stimulation of the endometrium. There is a genetic link to non‐polyposis colorectal cancer syndrome, but association of endometrial cancer risk to other genetic polymorphisms has yielded conflicting results. Conclusions. Many factors linked to hormonal imbalance, such as obesity, weight change, body size, alcohol, hyper‐androgenic states, glycemic index and antidepressant agents, influence the endometrial cancer risk, central to which are endogenous and exogenous estrogen hyperstimulation of the endometrium. Conversely, smoking cigarettes, diet, physical activity and melatonin production seem to reduce the risk of cancer development. Other external factors fit well with the unopposed estrogen theory, but more studies are needed to investigate modifiable and added risk factors for endometrial cancer.
Expression of adhesion molecules in first trimester spontaneous abortions and their role in abortion pathogenesis
Authors: YURDAKAN GAMZE , EKEM TULU E , BAHADIR BURAK , GUN BANU DOGAN , KUZEY GAMZE MOCAN , OZDAMAR SUKRU O
Published: June 2008

Background. Early placental development is associated with complex regulatory mechanisms, and molecular communication problems that arise during the developmental process are dangerous for continuation of the pregnancy. As studies on the process of invasion and migration of trophoblast cells have shown the importance of cell–cell and cell–matrix interactions, we examined the effects of adhesion molecules on the mechanism(s) of spontaneous abortions and compared them to elective abortion materials using histopathological and immunohistochemical methods. To the best of our knowledge, this is the first study to investigate adhesion molecules in spontaneous abortions. Methods. Curettage materials from abortions were examined retrospectively in the Department of Pathology, Zonguldak Karaelmas University School of Medicine, Zonguldak, Turkey. CD31/PECAM‐1 (endothelial cell marker), CD44v (variant 3), E‐cadherin, CD54/ICAM‐1, and CD106/VCAM‐1 expression profiles were evaluated by immunohistochemistry, and cellular localization was determined under light microscopy. The results of spontaneous abortions were compared to those of elective abortions. Results. The staining percentages of CD31, CD44, CD106, and E‐cadherin decreased in cases of spontaneous abortion, but CD54 (ICAM‐1) expression increased. Statistically significant differences were detected between spontaneous and elective abortion materials with regard to cytotrophoblasts (CTs), syncytiotrophoblasts (STs), and extravillous trophoblasts (EVTs) with the anti‐CD31 antibody (p = 0.0001). In addition, CD54 (p = 0.007 and p = 0.002) and E‐cadherin (p = 0.002 and p = 0.02) expression in CTs and STs, respectively, were significantly different. Furthermore, CD44 expression (p = 0.003) in decidual (D) cells and CD106 (p = 0.0001) expression in vessels of endometrial (E) and villous tissues were also significantly different. Conclusions. Decreased CD31 expression in CTs that invade the spiral arterioles and mimic E cells in spontaneous abortion cases suggests that CD31/PECAM‐1 is an important molecule in uteroplacental adequacy. Moreover, diminished expression of CD44 in D cells caused impaired stroma–villous connections. Enhancement of ICAM‐1 in placental and invading STs may be useful as a diagnostic marker for patients who may have a tendency to have spontaneous abortions. A down‐regulation of E‐cadherin was observed, which may be responsible for impaired CT differentiation and loss of the pregnancy. Furthermore, decreased VCAM‐1 expression in spontaneous abortions may be consistent with the importance of VCAM‐1 in trophoblast–endothelial cell interactions. Many adhesion molecules are known to be effective in the normal development of a pregnancy, and the analysis of adhesion molecules in spontaneous abortions will provide useful information for clarifying the physiopathology of spontaneous abortions.
The influence of lunar cycle on frequency of birth, birth complications, neonatal outcome and the gender: A retrospective analysis
Authors: STABOULIDOU ISMINI , SOERGEL PHILIPP , VASKE BERNHARD , HILLEMANNS PETER
Published: June 2008

Objective. The relation of lunar phases to the birth rate has been the focus of considerable research with still controversial results. The purpose of this study was to examine the influence of the lunar cycle on the frequency of birth, on instrumental delivery, neonatal outcome as well as a possible relationship between lunar position at time of conception and the gender of the child. Material and methods. Six thousand seven hundred and twenty five deliveries were retrospectively analyzed from 01 January 2000 to 31 December 2006 at the Department of Obstetrics and Gynaecology of the University Medical School of Hannover. Inclusion criteria were: spontaneous vaginal births without induction, vacuum and forceps extractions as well as non‐elective cesarean sections, all cases without labor induction. Exact lunar phases were determined by means of birthday and birth time by a specific computer software. Results. The analysis revealed no significant correlation of birth rate to lunar phases. There were also no significant differences regarding birth complications, neonatal outcome and gender to the lunar cycle at the time of conception. Conclusion. There is no predictable influence of the lunar cycle on deliveries or delivery complications nor to the gender of the baby. As expected and in agreement with some recent studies this pervasive myth is not evidence based.
A value‐added study of the impact of science curriculum reform using the National Pupil Database
Authors: Bell Jacqueline , Donnelly Jim , Homer Matt , Pell Godfrey
Published: June 2008

This article compares the examination performance of students following General Certificate of Secondary Education Applied Science and Double Award science on a value‐added basis. It uses data from the National Pupil Database, which are analysed by a variety of methods, including multilevel modelling. It argues that the claims made within Office for Standards in Education reports on the impact of the new Applied Science course are inaccurate, and in some cases positively wrong. The authors' analysis, based on the second (2003–05) cohort of students following the course, shows that students of lower attainment at Key Stage 3 appear to perform better than would have been predicted from their Key Stage 3 attainment, but that higher attaining pupils perform less well. Schools offering Applied Science show greater diversity in the value‐added effects they produce than they do with Double Award science. The article argues that analyses of this kind are of value in seeking to understand the impact of curriculum reform, but that they are dangerous as a generalized guide for policy. They must be complemented by work in schools in which the sources of the effects observed and of school diversity are examined.
Early numeracy in low‐performing young children
Authors: Aunio Pirjo , Hautamäki Jarkko , Sajaniemi Nina , Van Luit Johannes E. H.
Published: June 2008

The aim of this study was to explore the early numeracy of low‐performing young children. The mean age of the children was six years and four months. The 511 participants belonged to three groups: multi‐language children, children with special educational needs and children with average performance. The results showed that there were significant group differences in early numeracy: the children in the reference group had better relational and counting skills than those with a multi‐language background and those with special educational needs. Some differences were found in counting skills between the children with multi‐language background and those with special educational needs. Finally, (special) educational support for low‐performing children is discussed.
Assessment and examination stress in Key Stage 4
Authors: Putwain David William
Published: June 2008

Survey research has identified, using questionnaire approaches, that important assessments are a significant source of stress and worry for students in secondary school. In particular, failing important examinations and the consequences of failing these examinations are rated as more important than a range of other personal and social worries. Qualitative approaches have gone further in exploring the meaning of these stressful events for students concerned, highlighting themes such as an over‐identification with academic success and the perception of GCSE examinations as constituting a crucial moment in determining the future life trajectory of a student. However, this area has been neglected by researchers working on the education–psychology disciplinary boundaries, and a number of important features have yet to be specified regarding the development, antecedents and educational consequences of assessment/examination stress in Key Stage 4 (KS4). The aim of this article is to build on previous work to explore some basic questions surrounding KS4 assessments from a student‐centred perspective: (a) what factors lead to the development of assessments in KS4 to be perceived as stressful; and (b) what are the effects for the students concerned? Thirty‐four students were interviewed from six secondary schools in the North of England, identified as being likely to experience examinations as anxiety‐provoking events and analysed using the principles of grounded theory. Twelve themes emerge structured around a central narrative of ‘stress, achievement and esteem’, which highlighted three key findings. First, stress was linked to the motivation to achieve and the fear of failure through esteem judgements and conditions of acceptance from important others. Second, the experience of stress was linked to a wider educational context including practices and policies pursued by teachers and schools. Third, a more specific state, examination anxiety, was associated with facilitating effects prior to examinations and debilitating effects during examinations. These findings have furthered insights into the developmental antecedents and effects of assessment/examination stress in KS4, and highlighted the need to investigate school/teacher practices and policies and to ascertain the mechanism by which examination anxiety might produce debilitating effects.
Magnetic resonance-guided growth plate bone bridge resection at 0.23 tesla: report of a novel technique
Authors: Blanco Sequeiros R. , Vähäsarja V. , Ojala R.
Published: June 2008

Background: Growth plate or physeal cartilage trauma may result in delayed or immediate failure of growth due to bone bridge formation at the insult site. With computed tomography (CT) and magnetic resonance imaging (MRI), the role of imaging has expanded from diagnosis to treatment planning and therapy guidance.

Purpose: To describe a technique for MR-guided growth plate bone bridge resection and to evaluate feasibility of the procedure.

Material and Methods: Three consecutive patients with growth plate bone bridges were treated surgically under MR guidance. All bridges were detected with prior MRI and radiographs. All patients were referred to procedure due to growth plate bridge associated growth anomaly and pertaining clinical symptoms. The effect of the treatment was evaluated after 48 months with a clinical follow-up.

Results: All bridges were successfully detected, marked, and removed under MRI guidance. All patients had relief from their symptoms. Two patients had lasting results from the operation with no further operative treatment needed or scheduled at 48 months from primary treatment. There was one clinical failure, with the patient requiring repeated osteotomies.

Conclusion: We have successfully implemented a novel therapy for growth plate bridge resection.
Book Review
Authors: Koskinen Seppo
Published: June 2008

MR Imaging of Bone and Soft Tissue Tumors and Tumorlike Lesions. By S. P. Meyers. Stuttgart and New York: Thieme Verlag, 2007. ISBN: 978-3-13-135421-1. 798 pages, 2976 illustrations. Price: ???
Bone marrow edema: pathophysiology, differential diagnosis, and imaging
Authors: Starr A. M. , Wessely M. A. , Albastaki U. , Pierre-Jerome C. , Kettner N. W.
Published: June 2008

Bone marrow edema (BME) has been a topic of increasing interest in the literature in recent years. BME is associated with numerous pathologies and is becoming recognized not only as a considerable pain generator, but also as an entity which is, in some cases, significantly linked to the worsening of patient prognosis. To date, no thorough imaging review of BME has been published. An electronic literature search was conducted through PubMed with a time parameter of January 1975 through December 2007. The primary search parameter was “bone marrow edema.” Over 800 papers were listed as written in English and involving humans. Other refining parameters included “AND syndrome,” “AND transient,” “AND arthritis,” “AND infection,” “AND tumor,” “AND neoplasm,” “AND iatrogenic,” “AND radiation therapy,” and “AND inflammation.” More current articles were favored over dated articles on the same topic. A total of 106 journal articles were collected concerning BME and multiple pathologic processes. The data contained therein was compiled and organized into a comprehensive format. BME can be caused by, and found concurrent with, a broad spectrum of pathologies which exhibit a variety of imaging findings. BME is also associated with the deterioration of certain pathologies. This presentation is a comprehensive discussion of different pathological conditions inducing or associated with BME. Differential diagnosis through appropriate imaging is vital to case management and could contribute to the prevention or decreased progression of certain pathologies. Continued investigation into the imaging of BME and its associated diseases, as well as the effect of BME on prognosis, is warranted.
Detection of cholangiocarcinoma with magnetic resonance spectroscopy of bile in patients with and without primary sclerosing cholangitis
Authors: Albiin N. , Smith I. C. P. , Arnelo U. , Lindberg B. , Bergquist A. , Dolenko B. , Bryksina N. , Bezabeh T.
Published: June 2008

Background: Early detection of cholangiocarcinoma (CC) is very difficult, especially in patients with primary sclerosing cholangitis (PSC) who are at increased risk of developing CC.

Purpose: To evaluate 1H magnetic resonance spectroscopy (1H-MRS) of bile as a diagnostic marker for CC in patients with and without PSC.

Material and Methods: The institutional review board approved the study, and all patients gave informed consent. Bile from 49 patients was sampled and investigated using 1H-MRS. MR spectra of bile samples from 45 patients (18 female; age range 22–87 years, mean age 57 years) were analyzed both conventionally and using computerized multivariate analysis. Sixteen of the patients had CC, 18 had PSC, and 11 had other benign findings.

Results: The spectra of bile from CC patients differed from the benign group in the levels of phosphatidylcholine, bile acids, lipid, and cholesterol. It was possible to distinguish CC from benign conditions in all patients with malignancy. Two benign non-PSC patients were misclassified as malignant. The sensitivity, specificity, and accuracy were 88.9%, 87.1%, and 87.8%, respectively.

Conclusion: With 1H-MRS of bile, cholangiocarcinoma could be discriminated from benign biliary conditions with or without PSC.
It's Not Just about Teaching Kids to Read: Helping Preservice Teachers Acquire a Mindset for Teaching Children in Urban Communities
Authors: Lazar Althier M.
Published: June 2008

This study looks at preservice teachers' attitudes toward children and teaching in an urban high-poverty community in relation to their involvement in two different literacy education experiences: one literacy course sequence addressed issues of cultural diversity with respect to this community, and the other did not explicitly address these issues. The study specifically examines preservice teachers' (a) attitudes toward children's literacy potential, (b) confidence in teaching children to read, and (c) interest in teaching in urban schools. The diversity-oriented literacy experience, combined with highly satisfying field placements, positively affected preservice teacher's confidence and interest in teaching children in this community. Further, these preservice teachers tended to recognize children's literacy potential, while those who took the more typical literacy courses tended to doubt these children's literacy abilities. They also exited the diversity-oriented literacy courses with an enriched sense of children's culture and home language, although their awareness of literacy as culturally situated practice remained superficial. Analysis of preservice teachers' cultural autobiographies provided evidence that they acquired many new understandings about race, class, culture, literacy, children, and teaching in the first literacy course. Based on these findings, recommendations are made for reforming preservice teacher curricula and forming stronger alliances with schools in high-poverty communities.

What happens in classrooms is first and foremost about the personal and collective connections that exist among the individuals who inhabit those spaces. Consequently, teachers' beliefs and values, how these are communicated to students through teaching practices and behaviors and their impact on the lives of students—these are the factors that make teaching so consequential in the lives of many people (Nieto, 1999, p. 130).
Evaluation of Curricular Approaches to Enhance Preschool Early Literacy Skills
Authors: Fischel Janet E. , Bracken Stacey Storch , Fuchs-Eisenberg Ariela , Spira Elana G. , Katz Samantha , Shaller Gary
Published: June 2008

Two curricula designed to enhance the early literacy skills of 4-year-old preschool children were evaluated against a third, comparison condition. Thirty-five Head Start preschool classrooms were assigned randomly to incorporate one of two early literacy curricular approaches, Let's Begin with the Letter People® or Waterford Early Reading Program® Level 1, into their current curriculum, the High/Scope® Educational Approach, or to use the High/Scope method alone. Results indicated that children in the literacy intervention classrooms demonstrated significantly stronger outcomes in the areas of emergent writing, book and print knowledge, and general reading readiness skills. Minority language status also played a significant role in outcome, regardless of intervention condition. Implications for early childhood literacy interventions, especially important for children of low-income families, are discussed.
Catch rates as indicators of ecosystem health and exploitation status in the shrimp fishery in the South China sea
Authors: Christensen Steen , Thi Dang van
Published: June 2008

Based on catch and effort data analyses covering the period 1996–2002, time series of catch rates in the trawl fisheries in the South China Sea along the coasts of Bac Lieu and Ca Mau in South East Vietnam were estimated.

The indicators include catch rates for total shrimp catch, five major shrimp catch groups and 15 commercial shrimp groups estimated as quarterly averages for trawlers divided into five size groups.

The analyses indicated that despite a reduction in catch rates, shrimp is still the principal resource for the trawl fleets in South Vietnam. Seasonality in the shrimp catch rates that might reflect seasonality in shrimp recruitment was found, making this resource potentially suitable for a fishery management system based on closed seasons. Further, the data indicate that the major part of the catches are comprised of low value species belonging to the genera Parapenaeopsis; whereas the most valuable species, i.e. the Penaeus and Metapenaeus catch groups have been significantly depleted during the period investigated.

Based on the experiences from the present analysis, recommendations are presented with regard to adjustments of the enumerator data collection programme to fulfil the requirement of a dynamic fishery management system.
Response of vegetation communities in three Lake Huron fens to historical water level fluctuations
Authors: Mortsch Linda , Sabila Geniene , Deadman Peter
Published: June 2008

Historical changes in wetland classes in three shoreline fens, Baie du Dore, Oliphant, and Howdenvale, along the eastern shoreline of Lake Huron were analyzed to determine responses to fluctuating water levels. Wetland classes (lake, floating emergent, emergent marsh, meadow marsh, fen, and exposed substrate) were delineated through interpretation of aerial photographs for the period 1938 to 1995. Scan vectorization was used to develop a digital data base of wetland classes. Spatial and temporal analyses, conducted in a Geographic Information System (GIS), allowed comparison of trends among and within wetland classes which were linked to water level conditions. In periods with low water levels, overall wetland area increased primarily through expansion of the exposed substrate class lakeward; although meadow marsh also contributed to the increase. While wetland area increased during low water levels, exposed substrate did not markedly add to wetland habitat value but represents potential new wetland area that can be recolonized from seed banks. During high water levels, wetland area decreased as the lake class expanded inland and exposed substrate contracted or disappeared. Fen remained consistent in areal extent and location for most years at Howdenvale, but fen at Baie du Dore expanded with lower water levels, and contracted and became more fragmented with higher levels. At Oliphant, during low water levels fen area did not change, and with high levels the lake flooded the fen. With high water levels, lake area and wetter classes dominated and migrated inland. Under low water level conditions, lake was replaced by exposed substrate and drier wetland classes expanded, but did not necessarily colonize exposed substrate.
In Vivo Dynamics ofDrosophilaNuclear Envelope Components
Authors: Katsani Katerina R. , Karess Roger E. , Dostatni Nathalie , Doye Valérie
Published: June 2008

Nuclear pore complexes (NPCs) are multisubunit protein entities embedded into the nuclear envelope (NE). Here, we examine the in vivo dynamics of the essential Drosophila nucleoporin Nup107 and several other NE-associated proteins during NE and NPCs disassembly and reassembly that take place within each mitosis. During both the rapid mitosis of syncytial embryos and the more conventional mitosis of larval neuroblasts, Nup107 is gradually released from the NE, but it remains partially confined to the nuclear (spindle) region up to late prometaphase, in contrast to nucleoporins detected by wheat germ agglutinin and lamins. We provide evidence that in all Drosophila cells, a structure derived from the NE persists throughout metaphase and early anaphase. Finally, we examined the dynamics of the spindle checkpoint proteins Mad2 and Mad1. During mitotic exit, Mad2 and Mad1 are actively imported back from the cytoplasm into the nucleus after the NE and NPCs have reformed, but they reassociate with the NE only later in G1, concomitantly with the recruitment of the basket nucleoporin Mtor (the Drosophila orthologue of vertebrate Tpr). Surprisingly, Drosophila Nup107 shows no evidence of localization to kinetochores, despite the demonstrated importance of this association in mammalian cells.
The Methyltetrahydro‐β‐Carbolines in Maca (Lepidium meyenii)
Authors: Gonzales Gustavo F. , Gonzales-Castañeda Cynthia
Published: June 2008

Maca, a plant native to the Peruvian highlands, contains (1R,3S)‐1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid (MTCA). The family of the tetrahydro‐β‐carbolines has been associated with both biologically helpful and harmful compounds. We present evidence that MTCA is a natural constituent of Maca, and on consumption no toxicity is found. This suggests that, when consumed as multi‐component, MTCA may loose its adversity as drug action.
Electroacupuncture of 2 Hz Has a Rewarding Effect: Evidence from a Conditioned Place Preference Study in Rats
Authors: Xia Wei , Chu Ning-Ning , Liang Jing , Li Yi-Jing , Zhang Rong , Han Ji-Sheng , Cui Cai-Lian
Published: June 2008

Electroacupuncture (EA) has been used to suppress heroin craving in addicts and the conditioned place preference (CPP) for morphine in the rat. The question remained whether EA by itself will produce some rewarding effect. This was investigated using the CPP procedure in the present study. The results indicated that rats showed a significant preference to the 2 Hz EA‐paired compartment. This rewarding effect of EA was prevented by pre‐treatment with the opioid receptor antagonist naloxone [2 mg kg−1, intraperitoneally (i.p.)], CB1 cannabinoid antagonist AM251 (3 μg per rat, intracerebroventricularly) or D1 dopamine receptor antagonist SCH23390 (0.1 mg kg−1, i.p.), respectively. TempspacetempspaceIt is concluded that 2 Hz EA is capable of inducing CPP in the rat via the activation of the endogenous opioid‐, cannabinoid‐ and dopamine‐systems.
Composition, Molecular Structure, Properties, and In Vitro Digestibility of Starches from Newly Released Canadian Pulse Cultivars
Authors: Chung Hyun‐Jung , Liu Qiang , Donner Elizabeth , Hoover Ratnajothi , Warkentin Tom D. , Vandenberg Bert
Published: June 2008

Pulse starches were isolated from different cultivars of pea, lentil, and chickpea grown in Canada under identical environmental conditions. The in vitro digestibility and physicochemical properties were investigated and the correlations between the physicochemical properties and starch digestibility were determined. Pulse starch granules were irregularly shaped, ranging from oval to round. The amylose content was 34.9–39.0%. The amount of short A chains (DP 6‐12) of chickpea starch was much higher than the other pulse starches, but the proportions of B1 and B2 chains (DP 13‐24 and DP 25‐36, respectively) were lower. The X‐ray pattern of all starches was of the C type. The relative crystallinity of lentil (26.2–28.3%) was higher than that of pea (24.4–25.5%) and chickpea starches (23.0–24.8%). The swelling factor (SF) in the temperature range 60–90°C followed the order of lentil ≈ chickpea > pea. The extent of amylose leaching (AML) at 60°C followed the order of pea ≈ chickpea > lentil. However, in the temperature range 70–90°C, AML followed the order of lentil > pea > chickpea. The gelatinization temperatures followed the order of lentil > pea > chickpea. The peak viscosity, setback, and final viscosity of pea starch were lower than those of the other starches. Lentil starch exhibited lower rapidly digestible starch (RDS) content, hydrolysis rate, and expected glycemic index (eGI). The resistant starch (RS) content of both lentil cultivars was nearly similar. However, pea and chickpea cultivars exhibited wide variations in their RS content. Digestibility of the pulse starches were significantly correlated (P < 0.05) with swelling factor (60°C), amylose leaching (60°C), gelatinization temperature, gelatinization enthalpy, relative crystallinity, and chain length distribution of amylopectin (A, B1, and B2 chains).
Gliadin Immunoreactivity and Dough Rheological Properties of Winter Wheat Genotypes Modified by Thioredoxin
Authors: Waga J. , Zientarski J. , Obtułowicz K. , Bilo B. , Stachowicz M.
Published: June 2008

Gliadins are among the most important protein fractions affecting wheat baking quality, but they are also plant allergens and a cause of celiac disease or food intolerance. Therefore, we investigated how gliadin immunoreactivity and dough rheological properties are influenced by thioredoxin, a regulatory disulfide protein that can reduce disulfide bonds, a typical motive in many allergenic proteins. Ten winter wheat genotypes of different qualities were analyzed. Reduction by thioredoxin strongly (>50%) decreased gliadin immunoreactivity as estimated by enzyme‐linked immunosorbent assay with immunoglobulin E (IgE) sera from allergic patients and standard antigliadin antibodies but did not significantly affect dough rheological properties. Most parameters from the Brabender extensigraph were only slightly lower. Simultaneously, the farinograph curve exhibited a drawdown dislocation, possibly due to increased water absorption by modified flour, and dough consistency visibly improved. Results suggest that thioredoxin may be a universal natural beneficial modifier, able to significantly decrease gliadin immunoreactivity (hence its potential allergenicity) without decreasing the unique technological properties of wheat flour.
Colonization processes and the maintenance of genetic diversity: insights from a pioneer rainforest tree,Aucoumea klaineana
Authors: Born Céline , Kjellberg Finn , Chevallier Marie-Hélène , Vignes Hélène , Dikangadissi Jean-Toussaint , Sanguié Jodel , Wickings E. Jean , Hossaert-McKey Martine
Published: June 2008

Despite recurrent episodes of range expansion and contraction, forest trees often harbour high genetic diversity. Studies of temperate forest trees suggest that prolonged juvenile phase and high pollen flow are the main factors limiting founder effects. Here, we studied the local colonization process of a pioneer rainforest tree in central Africa,Aucoumea klaineana. We identified 87% of parents among trees up to 20–25 years old and could thus compare direct parentage structure data with classical population genetics estimators.

In this species, genetic diversity was maintained during colonization. The absence of founder effects was explained by (i) local random mating and (ii) local recruitment, as we showed that 75% of the trees in the close neighbourhood participated in the recruitment of new saplings. Long-distance pollen flow contributed little to genetic diversity: pollen and seed dispersal was mainly within stand (128 and 118 m, respectively). Spatial genetic structure was explained by aggregated seed dispersal rather than by mother–offspring proximity as assumed in classical isolation-by-distance models.

Hence,A. klaineanapresents a genetic diversity pattern typical of forest trees but does not follow the classical rules by which this diversity is generally achieved. We suggest that while high local genetic variability is of general importance to forest tree survival, the proximate mechanisms by which it is achieved may follow very different scenarios.
Resource value and the context dependence of receiver behaviour
Authors: Tibbetts Elizabeth A
Published: June 2008

Many animals use signals of fighting ability to minimize the costs of competition. Theory predicts that signals must be costly to remain reliable indicators of their bearer's abilities, but many signals of fighting ability lack obvious developmental costs. Instead, receivers are thought to maintain signal accuracy by behaving aggressively towards individuals with inaccurate signals (i.e. social costs). Models predict that the evolutionary stability of social cost signals depends on receivers trusting signals in certain contexts and testing signal accuracy in other contexts. Here, I use the signals of agonistic ability inPolistes dominuluswasps to provide the first experimental evidence that receiver responses to social cost signals are context dependent. During contests over low-value resources, wasps trust signals; they avoid patches of food guarded by rivals with elaborate signals. As the value of the resource increases, wasps become more likely to test signal accuracy. In fact, receivers challenge guards regardless of their signal phenotype when the resource is sufficiently valuable. Context-dependent receiver responses are likely to be an important behavioural mechanism underlying the evolution of social costs, as context-dependent responses allow receivers to minimize the costs of conflict while also ensuring signal accuracy.
SAPHIR: a physiome core model of body fluid homeostasis and blood pressure regulation
Authors: Thomas S. Randall , Baconnier Pierre , Fontecave Julie , Françoise Jean-Pierre , Guillaud François , Hannaert Patrick , Hernández Alfredo , Le Rolle Virginie , Mazière Pierre , Tahi Fariza , White Ronald J
Published: June 2008

We present the current state of the development of the SAPHIR project (a Systems Approach for PHysiological Integration of Renal, cardiac and respiratory function). The aim is to provide an open-source multi-resolution modelling environment that will permit, at a practical level, a plug-and-play construction of integrated systems models using lumped-parameter components at the organ/tissue level while also allowing focus on cellular- or molecular-level detailed sub-models embedded in the larger core model. Thus, anin silicoexploration of gene-to-organ-to-organism scenarios will be possible, while keeping computation time manageable. As a first prototype implementation in this environment, we describe a core model of human physiology targeting the short- and long-term regulation of blood pressure, body fluids and homeostasis of the major solutes. In tandem with the development of the core models, the project involves database implementation and ontology development.