bluuebunny/crossref_metadata_2025_split huggingface dataset:
MP2 and DFT study of IR spectra of TCNE‐methylsubstituted benzene complexes: Is charge transfer important?
Authors: Kysel Ondrej , Budzák Šimon , Mach Pavel , Medved̆ Miroslav 
Published: September 2009

AbstractThe second‐order Møller–Plesset (MP2) and density functional theory (DFT; B3LYP, B3LYP‐D) approaches show that the CN (and also CC) stretching IR vibrations are relatively small but reproducibly shifted to lower frequencies in a series of methylbenzenes‐tetracyanoethylene (NMB‐TCNE, N = mono‐, di‐, … , hexa‐) complexes with increasing number of methyl groups (N). These CN stretching IR frequency shifts, ranging from 8 to 12 cm−1, are linearly dependent on number N but still 2‐4 times greater than recently published experimental data [Stires et al., Chem Commun, 2005, 28, 3532; Pawlukojc et al., Chem Phys, 2006, 327, 311]. An explanation of the shifts toward lower frequencies is in literature [Stires et al., Chem Commun, 2005, 28, 3532; Pawlukojc et al., Chem Phys, 2006, 327, 311] usually attributed to the magnitude of transferred electron charge ΔQ from a donor molecule to TCNE (mainly to its π LUMO [lowest unoccupied molecular orbital]). The LUMO has antibonding character on CN and CC bonds, and thus the respective CN and CC bond orders are, due to partial occupation in the complex, decreased. However, the difference by a factor of 2‐4 between our MP2 (and also B3LYP) calculations and experiment is probably also due to the effect of environment, i.e., intermolecular forces between complex and solvent molecules or crystal lattice. The calculated interplanar distance R, dipole moment μ, and transferred charge ΔQ are approximately linearly dependent on number of methyl groups N. However, between N = 2 and 3, the abrupt changes in the dependencies were observed. This is caused by the change of mutual (perpendicular) orientations between respective methyl benzenes and TCNE in the complexes as a consequence of preferred interaction between one of two degenerated or near degenerated π highest occupied molecular orbitals (being orthogonal) on NMB with π LUMO located mainly on TCNE. This fact is important for many properties (especially for electron excited states) of these complexes. A strong dependence of polarizability, namely of its αzz part, of the benzene‐TCNE (Be‐TCNE) complex on soft vibrations was found. The vibrational contribution to αzz value is almost as large as the electronic αzz contribution. Finally, MP2 and B3LYP studies indicate that inclusion of anharmonicity has small, if any, effect on calculated vibrational frequencies of Be‐TCNE. This theoretical finding is quite important especially because it holds also for soft vibrational modes, which are always present at weak intermolecular complexes. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Linking geomorphic changes to salmonid habitat at a scale relevant to fish
Authors: Wheaton Joseph M. , Brasington James , Darby Stephen E. , Merz Joseph , Pasternack Gregory B. , Sear David , Vericat Damiá 
Published: September 2009

AbstractThe influence of geomorphic change on ecohydraulics has traditionally been difficult to quantify. With recent improvements in surveying technology, high‐resolution, repeat and topographic surveys have become a common tool for estimating fluvial sediment budgets and documenting spatial patterns of net erosion and net deposition. Using a case study from a spawning habitat rehabilitation (SHR) project on California's Mokelumne River, some new DEM‐differencing analytical tools and ecohydraulic models were used to test whether hypotheses about pool‐riffle maintenance mechanisms used in designing SHR projects were producing self‐sustaining spawning habitat when subjected to competent flows. Following peak flows associated with the spring snow‐melt, a total of 999.6 m3 of erosion and 810.1 m3 of deposition were recorded throughout the study area, with a net loss of 196.2 m3. Using an ecohydraulic spawning habitat suitability model to segregate the sediment budget, over 53% of the area in which gravel was placed in a 2005 SHR retained the same habitat quality characteristics, and 22% improved. The response to the flood was generically characterized by shallow deposition associated with areas of divergent flow over riffles and scour associated with areas of convergent flow in pools. Areas where habitat remained stable generally experienced only low‐magnitude elevation changes, and accounted for only 19.5% of the total volumetric change. Areas where habitat quality degraded (primarily pool exit slopes) were dominated by larger magnitude erosion and made up 46% of the total volumetric change. By contrast, areas where habitat quality improved (primarily constructed riffle) accounted for 34.5% the total volumetric change, and were dominated by shallow, low magnitude deposition. The results support hypotheses about pool‐riffle maintenance mechanisms used to design the rehabilitation projects, while also highlighting some simple but powerful techniques for linking ecohydraulic and geomorphic field monitoring data at a salmon‐relevant spatial scale. Copyright © 2009 John Wiley & Sons, Ltd.
An analysis of the supports and constraints for scientific discussion in high school project‐based science
Authors: Alozie Nonye M. , Moje Elizabeth Birr , Krajcik Joseph S. 
Published: September 2009

AbstractOne goal of project‐based science is to promote the development of scientific discourse communities in classrooms. Holding rich high school scientific discussions is challenging, especially when the demands of content and norms of high school science pose challenges to their enactment. There is little research on how high school teachers enact scientific discussions using project‐based science curricula, making the kinds of necessary embedded supports unclear. To address that gap in the research literature, this study analyzed curriculum supports and embedded educative features for the enactment of science discussions in one high school project‐based science curriculum. Through a study of teacher enactment and a comparison of the curriculum discussion supports, we observed that while teachers increased their attempts to engage in inquiry‐based discussion practices where supports were offered, they relied on heavily on traditional “recitation” formats, demonstrating that existing curricular supports were not developed enough to support dialogic classroom interactions. We hypothesize about conditions that may contribute to the pervasiveness of typical discourse practices in high school science discussions. We argue for expanded curricular discussion supports for teachers and design research on developing discussions in high school project‐based science classrooms to examine how such supports are taken up, dismissed, or modified in practice. © 2009 Wiley Periodicals, Inc. Sci Ed 94:395–427, 2010
Recommending change clusters to support software investigation: an empirical study
Authors: Robillard Martin P. , Dagenais Barthélémy 
Published: September 2009

AbstractDuring software maintenance tasks, developers often spend a valuable amount of effort investigating source code. This effort can be reduced if tools are available to help developers navigate the source code effectively. We studied to what extent developers can benefit from information contained in clusters of change sets to guide their investigation of a software system. We defined change clusters as groups of change sets that have a certain amount of elements in common. Our analysis of 4200 change sets for seven different systems and covering a cumulative time span of over 17 years of development showed that less than one in five tasks overlapped with change clusters. Furthermore, a detailed qualitative analysis of the results revealed that only 13% of the clusters associated with applicable change tasks were likely to be useful. We conclude that change clusters can only support a minority of change tasks, and should only be recommended if it is possible to do so at minimal cost to the developers. Copyright © 2009 John Wiley & Sons, Ltd.
Acid–Base Equilibrium of Dodecyldimethyl‐Amine‐N‐Oxide Micelles in Water–Butanol Binary at 298 K
Authors: Bouguerra Sabah , Letellier Pierre , Turmine Mireille 
Published: September 2009

AbstractDodecyldimethyl‐amine‐N‐oxide (DDAO) is a zwitterionic surfactant that can be protonated in water to form DDAOH+ if the pH of the medium is appropriate. We proposed, in a previous study, an experimental approach to determine directly the ratio of ionization of the surfactant in the micelle and in the bulk, at a given acidity level, without the need of a presupposed model of protonic exchange. We also showed that the relations of Thermodynamics impose a relationship between the critical micelle concentration (cmc) and the level of protonation of DDAO in the micelle and in the bulk. In order to appreciate the general nature of our approach, we have now modified the protonic exchange equilibrium between DDAO and DDAOH+ by introducing butanol into the solution. We studied three mixed media (2, 4 and 6% alcohol by volume). For all these mixtures, we validated our experimental and theoretical approaches. Moreover, for all the hydroalcoholic mixtures considered and all pH values, the presence of butanol stabilizes the micelle leading to a decrease of the cmc. Similar to pure water (Lair et al. in Langmuir, 20:8490–8495, 2004), we showed that, in these media, the protonic exchange equilibrium between DDAOH+ and DDAO in their micellized forms cannot be characterized by an unique equilibrium constant independent of the pH. However, as the butanol content of the medium increases, the variations in apparent pK with pH decrease, indicating that the behaviour of the acid–base pair in the micelle is classical and corresponds to a stoichiometric proton exchange.
Influence of Ultrasonic Waves on the Processing of Cotton with Cationic Softener
Authors: Parvinzadeh Mazeyar , Memari Naser , Shaver Mohammad , Katozian Bashir , Ahmadi Saeed , Ziadi Issa 
Published: September 2009

AbstractIn recent years, the textile industry has been forced to develop new technologies to reduce energy and water consumption. The use of ultrasound in textile wet processing is one solution to this problem. The aim of this work was to investigate the effects of ultrasonic energy on the processing of cotton with a cationic softener. For this purpose, cotton fabric was treated with a fatty acid amide derivative cationic softener in water using ultrasonic energy during treatment. The physical properties of the fabrics treated under different conditions are discussed. The results show that the treatment of fabrics with softeners in an ultrasound bath is more effective compared to conventional methods and that it enhances the physical properties of the cotton.
High Oleic and Low Trans Fatty Acid Formation by an Electrochemical Process
Authors: Xiao Haiyi , Kim Hyun Jung , Min David B. , Lalvani Shashi B. 
Published: September 2009

AbstractElectrochemical hydrogenation employing a mediator of formate/formic acid resulted in partial hydrogenation of vegetable and soybean oil at 20–40 °C and ambient pressure when palladium supported on alumina was employed as a catalyst. An oleic acid content of 48% with a corresponding iodine value of 81 for the vegetable oil hydrogenated at 20 °C was obtained. The total trans fatty acid content and especially the 18:1 trans fatty acid were found to increase with the reaction temperature and time. Nonetheless, relatively low total trans and 18:1 trans fatty acid (7 and 3.8%, respectively) contents were found when the vegetable oil was partially hydrogenated to achieve an iodine value of 112.
Changing Practice to Stented Percutaneous Nephrolithotomy (PCNL): A 2 Year Experience
Authors: El-Mokadem Ismail , Shaw Matthew , Page Toby , Marsh Ralph , Menezes Pravin , English Peter J. , Johnson Prakash 
Published: September 2009

Introduction: Stented PCNL is an increasingly practiced technique in which PCNL is performed without leaving a post-operative nephrostomy tube. We present our results from one of the biggest UK series to assess the impact of this technique on the safety, efficacy, length of hospital stay and analgesic requirement, to guide our future practice in terms of patient selection. Patients and methods: Case notes of 56 stented PCNLs between October 2005 and 2007 were reviewed retrospectively and compared to a similar group of 50 conventional PCNLs (only a nephrostomy post-operatively) in terms of co-morbidities (ASA grade), stone burden, intra-operative details, complications, length of stay (LOS) and analgesic requirement. The stented technique was employed in complex stones and in anatomical abnormalities (e.g. horseshoe, solitary, and duplex systems). The use of a stent rather than a nephrostomy was decided at the time of surgery when satisfactory haemostasis and stone clearance were achieved at the end of the procedure. Results: Co-morbidities, anatomical abnormalities, stone burden, operative time, number of punctures, access and infection rates were comparable. The stented technique was employed in complex stones (staghorn n = 13, multiple stones n = 11) and in patients with anatomical abnormalities ( n = 9). Overall stone free rate was 92.8% and 82% for the stented and the conventional groups, respectively. No haemorrhage or ureteric obstruction was reported in the stented group. All stent removals were uneventful. Mean LOS and analgesic requirement of diclofenac were markedly less in stented group. The number of stented procedures tripled from year 1 ( n = 14) to year 2 ( n = 42). Mean LOS dropped steadily from 68.6h in the first 6 months ( n = 5) to 47.4h in the last 6 months ( n = 22) with increased experience. Twenty-four patients (42%) were fit for discharge within 35h. Conclusion: In our experience, the stented technique was well tolerated and has reduced the length of hospital stay with no evidence of loss of efficacy or increased morbidity even in complex stones or patients with anatomical abnormalities.
Silicon enhances natural enemy attraction and biological control through induced plant defences
Authors: Kvedaras O.L. , An M. , Choi Y.S. , Gurr G.M. 
Published: September 2009

AbstractSilicon (Si) is known to have a role in constitutive plant defence against arthropod pests, and recent work has illustrated involvement in induced plant defences. The present tri-trophic study tested the hypothesis that Si increases natural enemy attraction to pest-infested plants and improves biological control. Cucumber plants treated with potassium silicate (Si+) and untreated control plants (Si−) were maintained in separately vented glasshouse compartments. Y-tube olfactometer studies showed that adult Dicranolaius bellulus were significantly more attracted to Si+ plants upon which Helicoverpa armigera larvae had fed compared with Si−, pest-infested plants. Predators were not significantly more attracted to Si+ plants when comparing uninfested cucumbers. In a field experiment, we placed H. armigera-infested and uninfested Si+ and Si− cucumber plants in a lucerne stand. Removal rates of H. armigera egg baits showed predation was greater for Si+ infested plants than for other treatments. Results suggest that Si applied to plants with a subsequent pest infestation increases the plants' attractiveness to natural enemies; an effect that was reflected in elevated biological control in the field.
Graptolites in British stratigraphy
Authors: ZALASIEWICZ J. A. , TAYLOR L. , RUSHTON A. W. A. , LOYDELL D. K. , RICKARDS R. B. , WILLIAMS M. 
Published: September 2009

Abstract697 taxa of planktonic graptolites are recorded, and their stratigraphical ranges are given, through 60 biozones and subzones in the Ordovician and Silurian strata of England, Wales and Scotland, in the first such stratigraphical compilation for Great Britain since the synthesis of Elles & Wood (1901–1918).
Soviet Antarctic plans after the International Geophysical Year: changes in policy
Authors: Gan Irina 
Published: September 2009

ABSTRACTThe final months of the International Geophysical Year of 1957–1958 were a period when the political and scientific future of the Antarctic was being shaped, with many of the participating countries reassessing their policies regarding the South Polar region. This paper explores the thinking of both political and scientific figures in the USSR that helped mould Soviet Antarctic policy during this time and demonstrates that the two perspectives did not necessarily coincide. The political perspective is exemplified by the deputy chairman of the USSR council of ministers and member of the central committee of the Communist Party of the Soviet Union Aleksei Kosygin, and the scientific perspective by the deputy director of the Arctic and Antarctic Research Institute, Mikhail Somov. The fact that there was interplay between both viewpoints when planning the Soviet post IGY Antarctic programmes shows that political considerations did not always prevail over the scientific, with national prestige being an area in which their interests overlapped. Ultimately, Somov was instrumental in reducing to some extent the effects of the Soviet government's attempts to curtail Soviet Antarctic research operations when it was reassessing its policy in the light of new international initiatives regarding future collaboration in the Antarctic.
Resilience as process
Authors: Egeland Byron , Carlson Elizabeth , Sroufe L. Alan 
Published: September 2009

AbstractResilience, the development of competence despite severe or pervasive adversity, is examined using data from a longitudinal study of high-risk children and families. The study is guided by an organizationaldevelopmental perspective. Resilience is conceived not as a childhood given, but as a capacity that develops over time in the context of person-environment interactions. Factors related to resilience in our study are examined in terms of this transactional process. From our studies, we have found emotionally responsive caregiving to mediate the effects of high-risk environments and to promote positive change for children who have experienced poverty, family stress, and maltreatment. The implications of these findings are discussed.
Postpartum depression and child development: An investigation of mothers and fathers as sources of risk and resilience
Authors: Carro Michelle G. , Grant Kathryn E. , Gotlib Ian H. , Compas Bruce E. 
Published: September 2009

AbstractWe examined maternal and paternal characteristics at 1 month postpartum as risk and protective factors for children's internalizing and externalizing problems at 2–3 years of age. In a sample of 70 couples and their children, fathers' depressive symptoms at 1 month postpartum predicted children's internalizing and externalizing problems at 2–3 years of age, and the interaction of fathers' and mothers' depressive symptoms predicted subsequent internalizing problems. Mothers' postpartum symptoms did not predict either type of children's behavior problems at age 2–3. When entered in the regression equations, mothers' depressive symptoms when the children were age 2–3 years accounted for all of the effects of paternal and maternal postpartum depressive symptoms. No evidence was found for the protective effects of marital satisfaction or social support, or for low levels of depressive symptoms in a spouse. We highlight directions for future risk and resilience research related to parental postpartum depression.
Resilience and vulnerability in children of multiple-risk families
Authors: Radke-Yarrow Marian , Brown Earnestine 
Published: September 2009

AbstractUnder high-risk conditions of genetic and family environmental origins, some children maintain a high level of adaptive behavior, whereas others develop serious problems. What distinguishes these children? Using measures systematically obtained in a 10-year longitudinal study, standard case studies were developed on 18 resilient children with healthy adaptation throughout development (psychiatric assessment) and on 26 troubled children with serious persistent problems. All children had family risks of affective illness in both parents and a highly chaotic and disturbed family life. Well children of well parents and well-functioning families were a comparison group. The children were preadolescent or adolescent at the time of most recent assessment. The ill and well families had similar demographic characteristics. Resilient and control children were very similar on most measures. Troubled children as a group had lower scores on the Wechsler Intelligence Scale for Children–Revised, were more often shy, had poor academic achievement, and had a history of poor peer relationships. Resilient children elicited more positive reactions from teachers, were more likely to be the favored child in the family, and had more positive self-perceptions. Profiles of each child showed competing processes of vulnerability and coping. Children used a wide range of methods for coping with parental and family pathology. Resilience appeared variably robust or fragile depending on the combinations of risks and supportive factors present and the styles of coping with stress.
Violent communities, family choices, and children's chances: An algorithm for improving the odds
Authors: Richters John E. , Martinez Pedro E. 
Published: September 2009

AbstractData are presented concerning the early predictors of adaptational success and failure among 72 children attending their 1st years of elementary school in a violent Washington, D.C., neighborhood. Adaptational failures were defined as those children who were doing poorly or failing in schoolandrated by their parents as suffering clinically significant levels of behavior problems. Adaptational successes were defined as children whose performance as students was rated in the average to excellent range and whose parent-rated levels of behavior problems were within the normal range. Despite the fact that these children were being raised in violent neighborhoods, had been exposed to relatively high levels of violence in the community, and were experiencing associated distress symptoms, community violence exposure levels were not predictive of adaptational failure or success. Instead, adaptational status was systematically related to characteristics of the children's homes. More specifically, the children's chances of adaptational failure rose dramatically as a function of living in unstable and/or unsafe homes. Moreover, it wasnotthe mere accumulation of environmental adversities that gave rise to adaptational failure in these children. Rather, it was only when such adversities contaminated or eroded the stability and/or safety levels of the children's homes that the odds of their adaptational failure increased. We argue that this erosion of the quality of the child's microsystem (i.e., family) by adversities and pressures in the exosystem (i.e., community) is not an inevitable process. Although not yet well understood, it is a process over which families have and must exercise control. The implications of these data for improving children's chances of physical, psychological, and academic survival in violent neighborhoods are considered.