bluuebunny/crossref_metadata_2025_split huggingface dataset:
A theoretical study of alkali metal atomic clusters: From Lin to Csn (n = 2–8)
Authors: Florez Elizabeth , Fuentealba Patricio 
Published: November 2008

AbstractA theoretical study of the electronic structure of the first members of the alkali metal atomic clusters series Lin to Csn (n = 2–8) has been done. The geometries of some isomers of the neutral, positive, and negative charged clusters have been determined. Some important properties have also been calculated: atomic binding energies, vertical and adiabatic ionization potentials, vertical and adiabatic electron affinities, static dipole polarizabilities, and energy gaps. Whenever possible they have been compared with experimental values yielding a reasonable agreement which supports some new values as reliable predictions. The data have been discussed in light of the periodic table of elements trends. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The Curtius rearrangement of some organic azides: A DFT mechanistic study
Authors: Kakkar Rita , Zaidi Sheza , Grover Rajni 
Published: November 2008

AbstractThe reaction mechanism for the thermal Curtius reaction of formyl azide has been investigated using B3LYP/6‐311+G(d,p). It is found that, while the synisomer undergoes nitrogen elimination via a concerted mechanism, yielding isocyanic acid directly, the anti‐isomer cannot undergo reaction via the concerted mechanism and first eliminates nitrogen, yielding oxazirene, via a transition state which is higher in energy than that for the concerted mechanism. Singlet formyl nitrene does not exist as an independent moiety. Rather, the strong NO interaction yields the cyclic isomer oxazirene. The isomerization of oxazirene to isocyanic acid goes through a transition state which is even higher in energy than that for nitrogen elimination. It is hence proposed that this reaction should take place via the concerted mechanism only, the anti‐isomer undergoing isomerization first to the syn isomer since the activation barrier for this step is very small. The same mechanism is found to prevail for acetyl and benzoyl azide. These findings are in accord with all experimental data. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
4d transition metal monoxides, monocarbides, monoborides, mononitrides, and monofluorides: A quantum chemical study
Authors: Kharat Bhagwat , Deshmukh S. B. , Chaudhari Ajay 
Published: November 2008

AbstractWe have studied 4d transition metal monoboride, monocarbide, mononitride, monoxide, and monofluorides using density functional method at B3LYP/LanL2Dz level. The lowest spin state, relative stability, bond length, atomic charges, electron affinity, ionization potential, binding energy, and vibrational frequencies for these dimers are obtained. The cation and anion of these dimers are also studied. The properties of these dimers are compared. It was found that the ionization potentials for these dimers are much higher than the electron affinities of these dimers. The range of electron affinities is widest for 4d transition metal monocarbides and is narrow for 4d transition metal mononitrides. The range of ionization potential is widest for 4d transition metal monoxides and is narrow for 4d transition metal monocarbides. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Semiautonomous control of multiple networked Lagrangian systems
Authors: Hokayem Peter F. , Stipanović Dušan M. , Spong Mark W. 
Published: November 2008

AbstractIn this paper we study the problem of coordinating the positions of a group of Lagrangian systems with communication constraints exhibited through delays and limited data rates. We show that in a bidirectional connected communication graph structure, it is possible to design PD‐type control laws that render the overall nonnetworked system input‐to‐state stable. Then, we exploit the robustness property of these control laws along with a small‐gain condition on the allowable delays to infer the stability of the overall networked system. We illustrate how the obtained results can be specialized to handle the problem of position–position control for three networked 2DOF manipulators as well as teleoperation of robotic formations. Copyright © 2008 John Wiley & Sons, Ltd.
A communication model with limited information‐processing capacity of recipients
Authors: Pavlov Oleg V. , Plice Robert K. , Melville Nigel P. 
Published: November 2008

AbstractWe develop a system dynamics model of message‐based communication, where the information‐processing capacity of message recipients is limited. Profit‐seeking broadcasters send messages, but only some of these messages are valuable to recipients. Recipients cannot determine whether or not a message is valuable until it is processed. Information overload occurs when more messages arrive than recipients can process. Numerical experiments test alternative approaches for mitigating information overload. We show that message filtering can increase the flow of for‐profit communication. Market‐based mechanisms, while aimed at improving the social outcome, can actually lead to suboptimal results and to a complete collapse of for‐profit communication. Copyright © 2008 John Wiley & Sons, Ltd.
User plane security alternatives in the 3G evolved Multimedia Broadcast Multicast Service (e‐MBMS)
Authors: Teofili Simone , Di Mascolo Michele , Basile Cristina , Bianchi Giuseppe , Salsano Stefano , Zugenmaier Alf 
Published: November 2008

AbstractThe 3GPP architecture includes the Multimedia Broadcast Multicast Service (MBMS) to provide efficient broadcast and multicast services. In the 3GPP long‐term evolution, the evolved MBMS (e‐MBMS) architecture is currently being standardized. Unlike MBMS, the new e‐MBMS architecture explicitly raises, as additional security requirement, the protection of the IP multicast user plane. Currently proposed e‐MBMS security architectures “limit” themselves to suggest the deployment of Group Security Associations (GSA). In this paper, we start by discussing that, on one side, GSA might not be a sufficiently secure solution in the long run, and on the other side GSA integration within the e‐MBMS architecture might not be as straightforward as it might appear. The point made in this paper is that there are sound alternatives to GSA if the goal is to deploy a short‐term solution with basically no impact on the current e‐MBMS architecture. In particular, we propose to adopt a Secure Multicast Overlay (SMO) approach. To prove the straightforward implementation of SMO we describe how a proof‐of‐concept test‐bed over public domain linux routers. Moreover, a functional comparison between GSA and SMO leads us to the following conclusions: (i) not only SMO provides the same level of security of GSA, but also it achieves a reduced risk of denial of service attacks; (ii) SMO has significant advantages over GSA in terms of impact on the architecture and on device requirements; (iii) security association management and key management in GSA has a greater impact on the performance achievable than in the case of SMO. We believe that these advantages outweigh the performance penalties due to overlay networking overhead. Copyright © 2008 John Wiley & Sons, Ltd.
Bias in a binary risk behaviour model subject to inconsistent reports and dropout in a South African high school cohort study
Authors: Chikobvu Perpetual , Lombard Carl J. , Flisher Alan J. , King Gary , Townsend Loraine , Muller Martie 
Published: November 2008

AbstractWe describe a methodology for analysing self‐reported risk behaviour transitional patterns in a binary outcome variable, subject to misclassification and a large loss to follow‐up. The motivation stems from the analysis of self‐reported transitional patterns in responses to the question ‘have you ever smoked a whole cigarette?’ in a cohort of South African school children. The partially complete records analysis (PCRA) introduced, estimates the transitional probability as: the ratio of the joint probability of the response at two time points based on the complete records for this time sequence over the marginal probabilities of the response based on the complete records at the first time point, and assumes a non‐informative missing pattern. A comparison was made using un‐weighted complete records and inverse probability weighted logistic regression. The estimates of the probabilities of reporting ever having smoked a cigarette obtained from the three methods were similar for a particular transition. The PCRA method lacked precision compared with the inverse probability weighted logistic regression. A simulation study indicated an association between bias and reporting error in all three methods. The PCRA method can be considered as a method for the estimation of transition probabilities in a cohort study where there is consistency in the self‐reported risk behaviour pattern and the sample size is large at baseline. The inverse probability weighting approach is more precise and is suitable for this setting in order to determine risk factors for the incidence of self‐reported substance used in a cohort with a high dropout rate. Copyright © 2008 John Wiley & Sons, Ltd.
Design of experiments as a means of lean value delivery to the flight test enterprise
Authors: Tucker Aaron A , Dagli Cihan H 
Published: November 2008

AbstractModern flight test tends to be a complex, expensive undertaking, so any increases in efficiency would result in considerable savings. Lean thinking is an effective method to identify value and eliminate waste and is particularly effective when applied to the entire flight test enterprise. Design of experiments is a statistical methodology that results in highly efficient flight test where only the samples needed are collected and analyzed. The application of design of experiments to flight test's value stream can result in a significant increase in lean value to the stakeholders and a reduction of waste. Design of experiments uses objective, verifiable statistical analysis to plan, execute, and analyze test. With lean stakeholder input, design of experiment's planning process ensures that the variables of interest are measured to provide a specified confidence in the analysis. Statistical confidence provides critical information on both the magnitude and significance of system performance. Further, design of experiments provides a statistical power that tells the stakeholders what magnitude of the effect could have been detected. Another benefit is that system response models are continually generated as test matrices are executed. These models enable the stakeholders to understand and evaluate system performance. This increases test safety and flexibility, which also creates value and eliminates waste in a resource‐limited experiment. A conceptual model is developed which shows how the design of experiments aligns the flight test process along the lean value delivery stream and identifies the stakeholders at each step. © 2009 Wiley Periodicals Inc. Syst Eng
Comparison of Prenatal Risk Calculation (PRC) with PIA Fetal Database software in first‐trimester screening for fetal aneuploidy
Authors: Hörmansdörfer C. , Scharf A. , Golatta M. , Vaske B. , Corral A. , Hillemanns P. , Schmidt P. 
Published: November 2008

AbstractObjectivesIn February 2007 new software, Prenatal Risk Calculation® (PRC), for calculating the risk of fetal aneuploidy was introduced in Germany. Our aim was to investigate its test performance and compare it with that of the PIA Fetal Database® (PIA) software developed and used by The Fetal Medicine Foundation.MethodsBetween 31 August 1999 and 30 June 2004 at the Women's Hospital of the Medical University of Hanover in Germany, 3120 singleton pregnancies underwent combined first‐trimester screening at 11 + 0 to 13 + 6 weeks of gestation. Calculation of risk for fetal aneuploidy was computed prospectively using the PIA software. In a subsequent retrospective analysis, we recalculated risks for the 2653 of these datasets with known fetal outcome using the PRC software and compared the results.ResultsOf the 2653 datasets analyzed, 17 were cases of aneuploidy. At a cut‐off of 1 : 230, for the detection of fetal aneuploidy, the respective sensitivity, false‐positive rate and positive predictive value were 70.6%, 4.1% and 9.9% for PRC and 76.5%, 2.9% and 14.6% for PIA. At a cut‐off of 1 : 300, the equivalent values were 70.6%, 5.6% and 7.5% for PRC and 76.5%, 4.0% and 11.0% for PIA. The differences in test performance between the two types of software were highly significant (P < 0.0001).DiscussionThe test performance of PRC was inferior to that of PIA, the sensitivity for detection of fetal aneuploidy being lower and the false‐positive rate higher. Had PRC been employed prospectively in our study, 40% more women examined would have been offered unnecessarily an invasive procedure for fetal karyotyping. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Status of Involved Lymph Nodes and Direction of Metastatic Lymphatic Flow Between Submucosal and T2‐4 Thoracic Squamous Cell Esophageal Cancers
Authors: Motoyama Satoru , Maruyama Kiyotomi , Sato Yusuke , Usami Shuetsu , Nakatsu Toshinobu , Saito Hajime , Minamiya Yoshihiro , Ogawa Jun‐ichi 
Published: November 2008

AbstractBackgroundThree‐field lymph node dissection for thoracic esophageal cancer is associated with high morbidity and reduced quality of life after surgery. Consequently, minimized lymphadenectomy would be desirable, if appropriate. In the present study, we retrospectively analyzed the status of involved nodes and the direction of metastatic lymphatic flow from tumors into involved nodes to determine whether submucosal squamous cell esophageal cancers are potential candidates for minimized lymphadenectomy.MethodsWe enrolled 199 patients who received esophagectomy with extensive lymph node dissection between 1989 and 2005 and retrospectively analyzed their prognoses, distribution of solitary metastatic lymph nodes, and the direction of metastatic lymphatic flow from the tumor, taking into consideration tumor location and depth.ResultsOf these patients with submucosal cancers, 83% had 1 or 2 involved nodes, and their esophageal cancer‐specific 5‐year survival rate was 66%. Solitary lymph node metastasis did not occur in neck lymph nodes in lower thoracic submucosal esophageal cancers, and the direction of metastatic lymphatic flow from the tumor was almost always in one direction. By contrast, T2–4 cancers with 2–4 involved nodes had bidirectional metastatic lymphatic flow from the tumor.ConclusionsThere was a difference in the status of lymph node metastasis and the direction of metastatic lymphatic flow from tumors into involved nodes between submucosal and T2–4 thoracic squamous cell esophageal cancers. This analysis may be useful for developing an approach to minimized lymphadenectomy for thoracic esophageal cancers.
Association Between EGF, TGF‐β1, VEGF Gene Polymorphism and Colorectal Cancer
Authors: Wu Guo‐yang , Hasenberg Till , Magdeburg Richard , Bönninghoff Roderich , Sturm Jörg W. , Keese Michael 
Published: November 2008

AbstractIntroductionUp to the present, EGF 61 A/G, TGF‐β1 −509 T/C, and VEGF 936 T/C gene polymorphisms have been analyzed in other cancer entities than colorectal cancer. We have now investigated the frequency of these gene polymorphisms among colorectal cancer patients.Material and methodsA total of 157 colorectal cancer patients and 117 cancer‐free healthy people were recruited at the Surgical Department of the Universitätsklinikum Mannheim. All patients and healthy people are Caucasians. Genomic DNA was isolated from peripheral blood, and gene polymorphisms were analyzed by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP).ResultsThe distribution of EGF 61 G/G homozygotes among colorectal cancer patients was more frequent than that in the control group (33.1% versus 11.1%; Odds Ratio [OR] = 3.962; 95% Confidence Interval [CI] = 2.036–7.708). The frequency of the “G” allele in the colorectal cancer patient group was also higher than that in the control group (51.3% versus 33.3%; OR = 2.105; 95% CI = 1.482–2.988). No difference could be found for the TGF‐β1 and VEGF genotypes among colorectal cancer patients and healthy controls.ConclusionsThe EGF 61 G/G genotype and the G allele are significantly related to colorectal cancer. The TGF‐β1 −509 T/C and VEGF 936 T/C gene polymorphisms are not related to colorectal cancer.
Brain metabolism differs in Alzheimer's disease and Parkinson's disease dementia
Authors: Griffith H. Randall , den Hollander Jan A. , Okonkwo Ozioma C. , O'Brien Timothy , Watts Ray L. , Marson Daniel C. 
Published: November 2008

BackgroundFew comparative studies exist of metabolic brain changes among neurodegenerative illnesses. We compared brain metabolic abnormalities in Alzheimer's disease (AD) and in Parkinson's disease with dementia (PDD) as measured by proton magnetic resonance spectroscopy (MRS).MethodsTwelve patients with idiopathic PDD, 22 patients with probable mild AD, and 61 healthy older controls underwent posterior cingulate MRS.ResultsPatients with AD exhibited reduced N‐acetyl aspartate (NAA)/creatine (Cr) (P < .05) and increased choline (Cho)/Cr (P < .05) and myo‐inositol (mI)/Cr (P < .01) compared with controls. Patients with PDD exhibited reduced NAA/Cr (P < .05) and glutamate (Glu)/Cr (P < .01) compared with controls. There was reduced Glu/Cr in PDD compared with AD (P < .01).ConclusionsPatients with AD and patients with PDD exhibited distinct brain metabolic MRS profiles. Findings suggest that comparison of brain MRS profiles across dementias provides useful direction for future study.
Tree-ring crossdates for a First Millennium AD advance of Tebenkof Glacier, southern Alaska
Authors: Barclay David J. , Wiles Gregory C. , Calkin Parker E. 
Published: November 2008

AbstractTree-ring crossdates from glacially killed logs show that Tebenkof Glacier advanced into a forefield forest in the AD 710s and 720s. Recession from this First Millennium AD (FMA) advance occurred before the 950s, after which the ice margin readvanced in the 1280s to 1320s at the start of the Little Ice Age (LIA). A more extensive LIA advance was underway from the 1640s to 1670s, and the terminus stayed at or near its LIA maximum until the 1890s. These are the first absolute tree-ring crossdates for a FMA glacier advance in North America and support growing evidence from northwestern North America and Europe for a significant cool interval in the centuries around AD 500.
Metabolic syndrome signs in Wistar rats submitted to different high-fructose ingestion protocols
Authors: de Moura Rodrigo Ferreira , Ribeiro Carla , de Oliveira Juliana Aparecida , Stevanato Eliane , de Mello Maria Alice Rostom 
Published: November 2008

In search of an adequate model for the human metabolic syndrome, the metabolic characteristics of Wistar rats were analysed after being submitted to different protocols of high fructose ingestion. First, two adult rat groups (aged 90 d) were studied: a control group (C1;n6) received regular rodent chow (Labina, Purina) and a fructose group (F1;n6) was fed on regular rodent chow. Fructose was administered as a 10 % solution in drinking water. Second, two adult rat groups (aged 90 d) were evaluated: a control group (C2;n6) was fed on a balanced diet (AIN-93G) and a fructose group (F2;n6) was fed on a purified 60 % fructose diet. Finally, two young rat groups (aged 28 d) were analysed: a control group (C3;n6) was fed on the AIN-93G diet and a fructose group (F3;n6) was fed on a 60 % fructose diet. After 4–8 weeks, the animals were evaluated. Glucose tolerance, peripheral insulin sensitivity, blood lipid profile and body fat were analysed. In the fructose groups F2 and F3 glucose tolerance and insulin sensitivity were lower, while triacylglycerolaemia was higher than the respective controls C2 and C3 (P < 0·05). Blood total cholesterol, HDL and LDL as well as body fat showed change only in the second protocol. In conclusion, high fructose intake is more effective at producing the signs of the metabolic syndrome in adult than in young Wistar rats. Additionally, diet seems to be a more effective way of fructose administration than drinking water.
Polyphase low-grade metamorphism of the Ingleton Group, northern England, UK: a case study of metamorphic inversion in a mudrock succession
Authors: KEMP S. J. , MERRIMAN R. J. 
Published: November 2008

AbstractA series of boreholes in Horton Quarry, northwest Yorkshire (Horton-in-Ribblesdale Inlier) penetrated mudstones and slates belonging to the Austwick Formation (Windermere Supergroup) overlying laminated mudstones of the Ingleton Group. Illite (IC) and chlorite (ChC) crystallinity measurements indicate a metamorphic inversion between the two groups of mudrocks. The Windermere Supergroup mudrocks are mostly in the high anchizone or epizone, whereas the Ingletonian samples are lower grade in terms of IC, and are mostly deep diagenetic zone or low anchizone. Hence younger strata at higher grades rest on older strata at lower grades, creating a metamorphic inversion. Ingletonian slates exposed at Pecca Falls on the River Twiss show epizonal and anchizonal IC values, and greywacke samples from Ingleton Quarry contain pumpellyite. This suggests that grade in the Ingletonian may increase to the NW from the Horton to Ingleton inliers. K-white mica b cell dimensions show further differences between the Ingleton Group and the Windermere Supergroup. The Ingletonian samples are characterized by low b cell values (8.989–9.035, mean 9.007 Å), whereas the Windermere Supergroup has higher values in the range 9.022–9.034, mean 9.027 Å. The Windermere Supergroup values are similar to those recorded from the Windermere Supergroup of the southern Lake District, and Lower Palaeozoic rocks from the Scottish Southern Uplands, and are consistent with metamorphism in a low heat flow, convergent geotectonic setting. The Ingletonian b cell values suggest metamorphism in a higher heat flow setting, most likely an extensional basin. The metamorphic inversion at Horton and differences in K-white mica b cell dimensions suggest that the Ingleton Group and Windermere Supergroup strata evolved in different geotectonic settings and record two separate metamorphic events. The discovery of the metamorphic inversion at Horton provides further evidence in favour of an Ordovician rather than Neoproterozoic depositional age for the controversial Ingleton Group.
Efficacy of rhizobacteria for growth promotion in sorghum under greenhouse conditions and selected modes of action studies
Authors: IDRIS A. , LABUSCHAGNE N. , KORSTEN L. 
Published: November 2008

SUMMARYThe screening of rhizobacteria for growth promotion of sorghum (Sorghum bicolour(L.) Moench) was conducted under greenhouse conditions for a total of 78 bacteria isolated from the rhizosphere of sorghum in Ethiopia, and 86 isolates from the rhizosphere and rhizoplane of grasses in South Africa. Three isolates from Ethiopia, all identified asBacillus cereus, enhanced growth promotion by resulting in statistically significant increases in at least five parameters. Of these,B. cereus(KBE7-8) resulted in significant increase in shoot and root biomass. Among effective isolates from South Africa,B. cereus(NAS4-3) andStenotrophomonas maltophilia(KBS9-B) showed significant increases in all the parameters measured. The isolates which resulted in significant growth promotion colonized the roots effectively with a count up to ⩾108cfu/g. In the study conducted to elucidate the possible modes of action by these effective isolates, indole 3-acetic acid-like substances were detected in culture filtrates of the isolates ranging from 4·2 μg/ml bySerratia marcescens(KBS9-R) to 22·8 μg/ml byB. cereus(KBS5-H) in the presence of 2 mg tryptophan/g nutrient broth solution. Higher rates of solubilization of tricalcium phosphate on Pikovskaya agar medium were shown byChryseomonas luteola(KBS5-F),S. marcescens(KBS6-H) andB. cereus(KBE9-1). There is very limited knowledge of the use of rhizobacteria in agriculture in Ethiopia and South Africa. The current study therefore generates valuable information towards application of plant growth promoting rhizobacteria as alternatives to chemical fertilizers.