bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compound‐specific bromine isotope analysis of brominated diphenyl ethers using gas chromatography multiple collector/inductively coupled plasma mass spectrometry
Authors: Holmstrand Henry , Unger Maria , Carrizo Daniel , Andersson Per , Gustafsson Örjan 
Published: June 2010

AbstractThe bromine isotope composition is potentially diagnostic in both degradation monitoring and source apportionment of organobromines in the environment. A method for compound‐specific bromine isotope analysis (δ81Br) based on gas chromatography multiple collector inductively coupled plasma mass spectrometry (GC/ICPMS) was developed for common brominated diaromatic compounds. Brominated diphenyl ethers (BDEs) in Bromkal 70‐5DE, a technical flame‐retardant mixture containing mainly BDEs #47, #99 and #100, were used as test substances, with standard bracketing for the samples achieved through co‐injected monobromobenzene (MBB) with a known δ81Br of −0.39‰ vs. Standard Mean Ocean Bromine (SMOBr). Three different heated transfer lines were constructed and tested to achieve efficient conduction of the BDEs from the gas chromatograph to the ICPMS instrument. The MBB was analyzed with a precision of 0.4‰ (1 s, n = 18). The precision for BDEs was 1.4–1.8‰ (1 s, n = 10–12 depending on the congener). The lower precision for the BDEs than for MBB may reflect the heat required to prevent condensation of the analytes in ICP torch assembly. The use of an internal standard of similar chemical structure to the analytes alleviates this problem, as illustrated by a difference of 0.3 ± 0.7‰ (1 s, n = 6) between the δ81Br values of co‐injected methoxy BDE‐47 and BDE‐47 extracted from whale blubber. Improvements in precision and accuracy may be achieved by the use of a more efficient heating of the torch assembly in conjunction with a set of internal standards that match the target compounds. Copyright © 2010 John Wiley & Sons, Ltd.
Three‐dimensional ultrasound image‐guided robotic system for accurate microwave coagulation of malignant liver tumours
Authors: Xu Jing , Jia Zhen‐zhong , Song Zhang‐jun , Yang Xiang‐dong , Chen Ken , Liang Ping 
Published: June 2010

AbstractBackgroundThe further application of conventional ultrasound (US) image‐guided microwave (MW) ablation of liver cancer is often limited by two‐dimensional (2D) imaging, inaccurate needle placement and the resulting skill requirement. The three‐dimensional (3D) image‐guided robotic‐assisted system provides an appealing alternative option, enabling the physician to perform consistent, accurate therapy with improved treatment effectiveness.MethodsOur robotic system is constructed by integrating an imaging module, a needle‐driven robot, a MW thermal field simulation module, and surgical navigation software in a practical and user‐friendly manner. The robot executes precise needle placement based on the 3D model reconstructed from freehand‐tracked 2D B‐scans. A qualitative slice guidance method for fine registration is introduced to reduce the placement error caused by target motion. By incorporating the 3D MW specific absorption rate (SAR) model into the heat transfer equation, the MW thermal field simulation module determines the MW power level and the coagulation time for improved ablation therapy. Two types of wrists are developed for the robot: a ‘remote centre of motion’ (RCM) wrist and a non‐RCM wrist, which is preferred in real applications.ResultsThe needle placement accuracies were < 3 mm for both wrists in the mechanical phantom experiment. The target accuracy for the robot with the RCM wrist was improved to 1.6 ± 1.0 mm when real‐time 2D US feedback was used in the artificial‐tissue phantom experiment. By using the slice guidance method, the robot with the non‐RCM wrist achieved accuracy of 1.8 ± 0.9 mm in the ex vivo experiment; even target motion was introduced. In the thermal field experiment, a 5.6% relative mean error was observed between the experimental coagulated neurosis volume and the simulation result.ConclusionThe proposed robotic system holds promise to enhance the clinical performance of percutaneous MW ablation of malignant liver tumours. Copyright © 2010 John Wiley & Sons, Ltd.
Robotic‐assisted laparoscopic radical cystoprostatectomy and extracorporeal continent urinary diversion: highlight of surgical techniques and outcomes
Authors: Josephson D. Y. , Chen J. A. , Chan K. G. , Lau C. S. , Nelson R. A. , Wilson T. G. 
Published: June 2010

AbstractBackgroundWe report our technique for robotic‐assisted laparoscopic radical cystoprostatectomy (RARCP) and extracorporeal urinary diversion and present their clinical outcomes.MethodsBetween October 2003 and December 2008 we performed 58 RARCPs with extracorporeal continent urinary diversion. Preoperative, operative and postoperative data was evaluated.ResultsMean patient age was 68 (range 46–89) years, with an average American Society of Anesthesiologists classification of 2.9. Mean operative time was 8 (range 5–11) h. Median blood loss was 450 ml. Thirteen patients received intra‐operative blood transfusions and 22 patients received peri‐operative blood transfusions. Continent urinary diversions were performed by means of the Studer technique (n = 42) or Indiana pouch (n = 16). Mean number of lymph nodes examined on lymphadenectomy was 27 (range 0–52).ConclusionsOur RARCP and continent diversion technique is a safe and feasible option for primary urothelial carcinoma of the bladder. Oncological and surgical outcomes are comparable to open cystectomy series. Copyright © 2010 John Wiley & Sons, Ltd.
Elementary teachers' pedagogical content knowledge for teaching the nature of science
Authors: Hanuscin Deborah L. , Lee Michele H. , Akerson Valarie L. 
Published: June 2010

AbstractAlthough teacher educators have achieved some success in improving teachers' understanding of the nature of science (NOS), helping teachers teach NOS has proved a much greater challenge. Currently, there are few examples in the literature of teachers who effectively teach NOS, and fewer still that rely on student outcomes as a measure of teachers' effectiveness. Much remains to be understood regarding the sources, nature, and development of teachers' pedagogical content knowledge (PCK) in regard to NOS. Using S. Magnusson, J. Krajcik, and H. Borko's (1999) framework, we examined the PCK for NOS of three elementary teachers who have been successful in improving their students' understanding of NOS. We relied on interviews, questionnaires, classroom observations, and classroom artifacts collected over a 3‐year period to characterize their PCK for NOS. Although each had robust knowledge of instructional strategies for teaching NOS, teachers lacked the requisite knowledge of assessment that would provide a feedback loop to support continued development of their knowledge of learners and lead to improvement in their teaching of NOS. Our findings highlight a need for professional development that focuses on developing aspects of PCK for NOS such as teachers' knowledge of assessment as well as educative curriculum materials to support continued development of teachers' PCK for NOS in practice. © 2010 Wiley Periodicals, Inc. Sci Ed 95: 145–167, 2011
Progress in the Light Emission of Colloidal Semiconductor Nanocrystals
Authors: Gaponik Nikolai , Hickey Stephen G. , Dorfs Dirk , Rogach Andrey L. , Eychmüller Alexander 
Published: June 2010

AbstractSome 25 years ago it was found that semiconductor nanocrystals emitted light. Since then tremendous progress has been made with respect to increasing the emission quantum yields, extending the spectral range that may be addressed, from the UV across to the near infrared, and improving the color purity. Here some major lines in these developments are reviewed, touching on milestones as well as on the principles of the most successful preparative approaches.
Improved Biomolecule microarrays by Printing on Nanoporous Aluminum Oxide Using a Continuous‐Flow Microspotter
Authors: Kim Jungkyu , Miles Adam , Gale Bruce K. 
Published: June 2010

AbstractBiomolecules, including protein A, albumin, and immunoglobulin G, are spotted on top of a nanoporous substrate by using a continuous‐flow microspotter (CFM) system, which normally produces spots 3 to 4 orders of magnitude more sensitive than conventional biomolecule printing methods. The spots are observed with a fluorescence scanner. By using the CFM to print spots on nanoporous substrates, an additional order of magnitude increase in signal is observed, which leads to high signal‐to‐background ratios, highly saturated spots, and a measurable signal at printing concentrations as low as 1.6 ng mL−1. This technique produces highly concentrated biomolecular spots from dilute samples and significantly increases the sensitivity of sensing platforms.
Combinatorial Drug Conjugation Enables Nanoparticle Dual‐Drug Delivery
Authors: Aryal Santosh , Hu Che‐Ming Jack , Zhang Liangfang 
Published: June 2010

AbstractA new approach to loading multiple drugs onto the same drug‐delivery nanocarrier in a precisely controllable manner, by covalently preconjugating multiple therapeutic agents through hydrolyzable linkers to form drug conjugates, is reported. In contrast to loading individual types of drugs separately, this drug‐conjugates strategy enables the loading of multiple drugs onto the same carrier with a predefined stoichiometric ratio. The cleavable linkers allow the therapeutic activity of the individual drugs to be resumed after the drug conjugates are delivered into the target cells and unloaded from the delivery vehicle. As a proof of concept, the synthesis and characterization of paclitaxel–gemcitabine conjugates are demonstrated. The time‐dependent hydrolysis kinetics and cytotoxicity of the combinatorial drug conjugates against human pancreatic cancer cells are examined. It is shown that the synthesized drug conjugates can be readily encapsulated into a lipid‐coated polymeric drug‐delivery nanoparticle, which significantly improves the cytotoxicity of the drug conjugates as compared to the free drug conjugates.
Regiospecific Analysis of Mono‐ and Diglycerides in Glycerolysis Products by GC × GC‐TOF‐MS
Authors: Indrasti Dias , Che Man Yaakob B. , Chin Sung Tong , Mustafa Shuhaimi , Mat Hashim Dzulkifly , Abdul Manaf Marina 
Published: June 2010

AbstractComprehensive bidimensional gas chromatography coupled with time‐of‐flight mass spectrometry (GC × GC‐TOF‐MS) was used for the characterization of regiospecific mono‐ and diglycerides (MG‐DG) content in the glycerolysis products derived from five different lipids included lard (LA), sun flower seed oil (SF), corn oil (CO), butter (BU), and palm oil (PA). The combination of fast and high temperature non‐orthogonal column set namely DB17ht (6 m × 0.10 mm × 0.10 μm) as the primary column and SLB‐5 ms (60 cm × 0.10 mm × 0.10 μm) as the secondary column was applied in this work. System configuration involved high oven ramp temperature to obtain precise mass spectral identification and highest effluent's resolution. 3‐Monopalmitoyl‐sn‐glycerol (MG 3‐C16) was the highest concentration in LA, BU and PA while monostearoyl‐sn‐glycerol (MG C18) in CO and 1,3‐dilinoleol‐rac‐glycerol (DG C18:2c) in SF. Principal component analysis accounted 82% of variance using combination of PC1 and PC2. The presence of monostearoyl‐sn‐glycerol (MG C18), 3‐Monopalmitoyl‐sn‐glycerol (MG 3‐C16), 1,3‐dilinoleol‐rac‐glycerol (DG C18:2c), 1,3‐dipalmitoyl‐glycerol (DG 1,3‐C16), and 1,3‐dielaidin (DG C18:1t) caused differentiation of the samples tested.
Both high and low serum vitamin D concentrations are associated with tuberculosis: a case–control study in Greenland
Authors: Nielsen Nina O. , Skifte Turid , Andersson Mikael , Wohlfahrt Jan , Søborg Bolette , Koch Anders , Melbye Mads , Ladefoged Karin 
Published: June 2010

Vitamin D deficiency has been associated with increased risk of tuberculosis (TB). Changes from a traditional to a Westernised diet among Greenlanders have resulted in reduced serum vitamin D, leading to considerations of whether preventive vitamin D supplementation should be introduced. The association between vitamin D status and TB was examined to assess the feasibility of vitamin D supplementation in Greenland. This was examined in a case–control study involving seventy-two matched pairs of TB patients (cases) and controls aged 8–74 years. Cases were diagnosed with TB during 2004–6 based on clinical findings in combination with either (1) positiveMycobacterium tuberculosisculture, (2) characteristic X-ray abnormalities together with a positive tuberculin skin test or a positive interferon-γ release assay or (3) characteristic histology. Controls were individually matched on age ( ± 5 years), sex and district. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured and OR of TB were the outcome. Compared with individuals with 25(OH)D concentrations between 75 and 140 nmol/l, individuals with concentrations < 75 nmol/l (OR 6·5; 95 % CI 1·8, 23·5) or>140 nmol/l (OR 6·5; 95 % CI 1·9, 22·2) had higher risks of active TB (P = 0·003; adjustment for alcohol and ethnicity). Supplementing individuals with low vitamin D to normalise serum 25(OH)D concentrations was estimated to result in a 29 % reduction in the number of TB cases. The study indicated that vitamin D supplementation may be beneficial to individuals with insufficient vitamin D concentrations but may increase the risk of TB among individuals with normal or high concentrations.
Reproductive patterns in two deep-water solitary corals from the north-east Atlantic—Flabellum alabastrumandF. angulare(Cnidaria: Anthozoa: Scleractinia)
Authors: Waller Rhian G. , Tyler Paul A. 
Published: June 2010

Gametogenesis and reproductive periodicity of the solitary scleractiniansFlabellum alabastrum(from the Rockall Trough) andF. angulare(from the Porcupine Seabight) were investigated. Samples were collected between depths from 1370 to 2190 m forF. alabastrumand 2412 to 2467 m forF. angulare. Both species showed gonochorism with a 1:1 sex-ratio and broadcast spawning of gametes is inferred from the lack of brooded planulae. Oocyte sizes were large in both species (925 μm inF. alabastrumand 1015 μm inF. angulare), suggesting lecithotrophic larval development. Fecundity and periodicity of oocyte development differed between the two species.Flabellum alabastrumproduced a maximum of 2800 oocytes per polyp quasi-continuously, whereas the deeper speciesF. angulareproduced a maximum of 550 oocytes per polyp either seasonally or periodically. Both species showed size-dependent fecundity. The data show a decrease in oocyte size and fecundity with depth, in concordance with other deep-water scleractinian species.
Group cohomology with coefficients in a crossed module
Authors: Noohi Behrang 
Published: June 2010

AbstractWe compare three different ways of defining group cohomology with coefficients in a crossed module: (1) explicit approach via cocycles; (2) geometric approach via gerbes; (3) group theoretic approach via butterflies. We discuss the case where the crossed module is braided and the case where the braiding is symmetric. We prove the functoriality of the cohomologies with respect to weak morphisms of crossed modules and also prove the ‘long’ exact cohomology sequence associated to a short exact sequence of crossed modules and weak morphisms.
Cladistic and phylogenetic biogeography: the art and the science of discovery
Authors: Van Veller Marco G. P. , Brooks D. R. , Zandee M. 
Published: June 2010

AbstractAll methods used in historical biogeographical analysis aim to obtain resolved area cladograms that represent historical relationships among areas in which monophyletic groups of taxa are distributed. When neither widespread nor sympatric taxa are present in the distribution of a monophyletic group, all methods obtain the same resolved area cladogram that conforms to a simple vicariance scenario. In most cases, however, the distribution of monophyletic groups of taxa is not that simple. A priori and a posteriori methods of historical biogeography differ in the way in which they deal with widespread and sympatric taxa. A posteriori methods are empirically superior to a priori methods, as they provide a more parsimonious accounting of the input data, do not eliminate or modify input data, and do not suffer from internal inconsistencies in implementation. When factual errors are corrected, the exemplar presented by M.C. Ebach & C.J. Humphries (Journal of Biogeography, 2002, 29, 427) purporting to show inconsistencies in implementation by a posteriori methods actually corroborates the opposite. The rationale for preferring a priori methods thus corresponds to ontological rather than to epistemological considerations. We herein identify two different research programmes, cladistic biogeography (associated with a priori methods) and phylogenetic biogeography (associated with a posteriori methods). The aim of cladistic biogeography is to fit all elements of all taxon–area cladograms to a single set of area relationships, maintaining historical singularity of areas. The aim of phylogenetic biogeography is to document, most parsimoniously, the geographical context of speciation events. The recent contribution by M.C. Ebach & C.J. Humphries (Journal of Biogeography, 2002, 29, 427) makes it clear that cladistic biogeography using a priori methods is an inductivist/verificationist research programme, whereas phylogenetic biogeography is hypothetico‐deductivist/falsificationist. Cladistic biogeography can become hypothetic‐deductive by using a posteriori methods of analysis.
The biogeographic and tectonic history of India
Authors: Briggs John C. 
Published: June 2010

AbstractAim  To present an up to date account of the Mesozoic history of India and its relationship to the other Gondwana continents and to Eurasia.Location  Continents surrounding the Western Indian Ocean.Methods  Utilization of recent evidence of continental relationships based upon research in stratigraphy, palaeomagnetism, palaeontology, and contemporary biotas.Results  The physical data revealed a sequence of events as India moved northward: (1) India–Madagascar rifted from east Africa 158–160 Ma (million years ago), (2) India–Madagascar from Antarctica c. 130 Ma, (3) India–Seychelles from Madagascar 84–96 Ma, (4) India from Seychelles 65 Ma, (5) India began collision with Eurasia 55–65 Ma and (6) final suturing took place c. 42–55 Ma. However, data from fossil and contemporary faunas indicate that, throughout the late Cretaceous, India maintained exchanges with adjacent lands. There is an absence in the fossil record of peculiar animals and plants that should have evolved, had India undergone an extended period of isolation just before its contact with Eurasia.Main conclusions  The depiction of India in late Cretaceous as an isolated continent is in error. Most global palaeomaps, including the most recent one, show India, as it moves northward, following a track far out in the Indian Ocean. But the evidence now indicates that India's journey into northern latitudes cannot have taken place under such isolated circumstances. Although real breaks among the lands were indicated by the physical data, faunal links were maintained by vagile animals that were able to surmount minor marine barriers. India, during its northward journey, remained close to Africa and Madagascar even as it began to contact Eurasia.
Faunal composition of geometrid moths changes with altitude in an Andean montane rain forest
Authors: Brehm Gunnar , Fiedler Konrad 
Published: June 2010

AbstractAim The objective of this study was to describe and interpret the changes in faunal composition in the moth family Geometridae (Lepidoptera) along a small‐scale elevational gradient in a tropical montane rain forest. This gradient was compared with a large‐scale latitudinal gradient in Europe.LocationInvestigations were carried out in the province Zamora‐Chinchipe in southern Ecuador along a gradient ranging from 1040 to 2677 m above sea level at twenty‐two sites.Methods Moths were sampled with light‐traps in three field periods in 1999 and 2000 and subsequently sorted and determined to species or morphospecies.Results We analysed 13,938 specimens representing 1010 species of geometrid moths. The proportional contribution of subtaxa to the local geometrid fauna changes along the elevational gradient at all systematic levels considered. While proportions of species of the subfamilies Ennominae, Sterrhinae and Geometrinae significantly decrease, the proportion of Larentiinae increases with increasing altitude. Changes also occur within the subfamilies Ennominae and Larentiinae. The host–plant specialist ennomine tribes Cassymini, Macariini and Palyadini completely vanish, and the proportion of the tribe Boarmiini decreases at high altitudes. In contrast, the remaining tribes (mostly comprising polyphagous species) either do not show proportional changes (Azelinini, Nacophorini, Nephodiini, Ourapterygini) or even increase (Caberini, ‘Cratopteragroup’). Within Larentiinae, the species proportion of the genusEoisdecreases, whereas concomitantly the proportion ofEupitheciaincreases. There is a remarkable similarity between the altitudinal patterns in Ecuador and those found along the latitudinal gradient in Europe.Main conclusions Species of the subfamily Larentiinae seem to be particularly well‐adapted to harsh environmental conditions, towards both high altitudes and latitudes. They might disproportionately profit from lower predation at higher altitudes. Many changes in the faunal composition can be explained by expected host–plant requirements of the species involved. Our results show that diversity estimates based on taxon ratios which are assumed to be constant must be regarded with caution because such ratios can change rapidly along environmental gradients.
A south‐to‐north biogeographic hypothesis for Andean speciation: evidence from the lizard genus Proctoporus (Reptilia, Gymnophthalmidae)
Authors: Doan Tiffany M. 
Published: June 2010

AbstractAim  The lizard genus ProctoporusTschudi, 1845 was used as a model to test the South‐to‐North Speciation Hypothesis (SNSH) for species groups occurring in the Andes Mountains of South America. This hypothesis proposes that speciation of high Andean taxa followed a south‐to‐north pattern, generally coinciding with the progression of final uplift of the Andes. According to SNSH, a phylogenetic hypothesis of relationships of a taxonomic group occurring in the high Andes would show a branching pattern in which the southernmost species diverged first, followed by the more northern species, and so on in a northerly pattern.Location  The central and northern Andes Mountains in South America.Methods A phylogenetic hypothesis was reconstructed for all species of the lizard genus Proctoporus by examining the external morphology of 341 individuals. This phylogeny was then examined to determine monophyly of the genus, distribution patterns of species groups, and congruence with SNSH.Results  The genus Proctoporus did appear to be monophyletic and, therefore, it was valid to use this group to assess SNSH. The southernmost species were found to be the most basal, which was consistent with SNSH. The species occurring in the northern Andes did not exactly match the SNSH prediction. The Venezuelan and Trinidadian species did appear to be highly derived, as predicted by the hypothesis, but the Ecuadorian and Colombian species did not form a particular pattern in relation to the hypothesis.Main conclusions  The SNSH does appear to have predictive power with regard to large‐scale distribution patterns. The finer‐scale patterns of speciation in the Andes, however, appear to be a more complex phenomenon that cannot be fully explained by a simple hypothesis. It is important to have a testable hypothesis in hand with which to compare data from disparate species groups. The incorporation of phylogenetic data of other high Andean taxa with similar distribution patterns is necessary to determine the full utility of SNSH in explaining evolutionary patterns in the Andes of South America.