bluuebunny/crossref_metadata_2025_split huggingface dataset:
The hybrid boundary element method in structural acoustics
Authors: Wagner M. , Gaul L. , Dumont N.A. 
Published: November 2004

AbstractThis paper presents a new symmetric formulation for structural acoustics in the frequency domain. Usually, the structural domain is discretized with the Finite‐Element Method (FEM), whereas the Boundary Element Method (BEM) is used for the treatment of the infinite acoustic domain. Coupling formulations generally suffer from the dense and unsymmetric equation system of the BEM. To circumvent this drawback, the acoustic domain is discretized here with the Hybrid Stress Boundary Element Method (HSBEM), which is based on a variational principle. The discretized formulation consists of a symmetric stiffness‐type equation based on a dynamic flexibility matrix in frequency domain. The HSBEM is thus easily coupled with other symmetric discretization methods, combining the advantages of a boundary formulation and a symmetric approach. An issue of the method is the evaluation of the flexibility matrix. This contribution extends former publications of the authors by a detailed analysis of the implementation of this matrix, leading to a new clustering scheme for an efficient treatment, based on the special structure of the integral kernel. Moreover, the treatment of hyper‐singular integral kernels without integration, based on orthogonality properties for interior and exterior domains is outlined. Examples show the consistency of this approach. Finally, a coupled formulation for structural acoustics employing the HSBEM for the structure and the acoustic domain is introduced. Several numerical tests elucidate the applicability of the method and the proposed improvements.
THE EFFECTS OF SELECTED HERBICIDES ON ZYGOSPORE GERMINATION AND GROWTH OF CHLAMYDOMONAS MOEWUSII (CHLOROPHYCEAE, VOLVOCALES)11
Authors: Cain Jerome R. , Cain Renee K. 
Published: November 2004

ABSTRACTA laboratory study was conducted, to examine and compare the sensitivity of vegetative cells and zygospores of Chlamydomonas moewusii Gerloff to 20 different herbicides. Under the culture conditions employed, both vegetative growth and zygospore germination were affected by certain herbicides and not by others. Over a concentration range from 1.0–80.0 μM, growth was inhibited to various degrees by herbicides containing ametryne, paraquat, endothall, diquat, diuron, linuron, propanil, dinoseb, ioxynil, atrzine, prometon, and alachlor. Zygospore germination was inhibited significantly by herbicides containing dinoseb, endothall, parquet, diquat, propanil, linuron, ioxynil, ametryne, fenac and picloram at 80.0 μM concentrations. Comparisons of the results obtained indicate that concentrations of herbicides which affect growth may or may not effect zygospore germination and vice versa. Zygospores may be more resistant than vegetative cells to some but not all herbicides.
MORPHOMETRY OF BATRACHOSPERMUM POPULATIONS INTERMEDIATE BETWEEN B. BORYANUM AND B. ECTOCARPUM (RHODOPHYTA)1
Authors: Sheath Robert G. , Burkholder Jo Ann M. 
Published: November 2004

ABSTRACT Batrachospermum plants collected as part of a comprehensive study of New England streams were found to be intermediate between B. boryanum Sirdt. find B. ectocarpum Sirdt. Sixty‐four specimens from ten Rhode Island streams were examined for several characteristics in replicates of two to four hundred. The size ranges obtained were then compared with previous published data for B. boryanum and B. ectocarpum from Europe, Asia and North America. The Rhode Inland populations and individuals exhibited as much or even more variability as that reported for both species combined throughout the world. Therefore, it appears that there is no definite basis for separation of these taxa and it is proposed that they be merged under the name B. boryanum. This combined species ran be distinguished from other species of the section Batrachospermum by compressed mature lateral whorls, little secondary fascicle formation, curved distal branching, terminal hairs on a small proportion of branches, predominantly dioecious state, sessile trichogynes and carposporophytes in outer portions of lateral whorls.
ISOLATION OF NUCLEI FROM THE UNICELLULAR ALGA OLISTHODISCUS LUTEUS (CHLOROMONADOPHYCEAE)1
Authors: Rizzo Peter J. , Burghardt Robert C. 
Published: November 2004

ABSTRACTMethods are described for the isolation of nuclei from the marine chloromonad Olisthodiscus luteus. For each of the three alternative methods, the ratios to DNA of RNA, acid‐soluble and acid‐insoluble protein are 0. 17, 1.1 and 2.0, respectively. The nuclear preparations are free of whole cell and organelle contamination, although some membranes are present. The yield is 65–80% based on the recovery of DNA in the nuclear pellet. The nuclei are in DNA‐dependent RNA synthesis.
ORGANIC COMPOUNDS RELEASED FROM A NATURAL POPULATION OF EPIBENTHIC BLUEGREEN ALGAE1
Authors: Hall Shelly L. , Fisher Frank M. 
Published: November 2004

ABSTRACTExtracellular release of dissolved organic compounds by the bluegreen algal community of a brackish marsh was studied using 14C techniques. Mannitol and trehalose were identified as the most commonly released compounds. The proportions of these two extracellular compounds varied in response to light intensity and the water potential of the environment. The presence of mannitol, in particular, suggests that excretion of organic compounds in natural situations is a function of osmotic adjustment.
FLORIDOSIDES IN CYANIDIUM CALDARIUM, CYANIDIOSCHYZON MEROLAE AND GALDIERIA SULPHURARIA(RHODOPHYTA, CYANIDIOPHYCEAE)1
Authors: De Luca Paolo , Moretti Aldo 
Published: November 2004

ABSTRACT Cyanidium caldarium Geitler, Cyanidioschyzon merolae De Luca, Taddei & Varano and Galdieria sulphuraria (Galdieri) Merola are the three thermoacidophilic algae characterized by a chloroplast which is bounded by a single membrane. The presence of this atypical chloroplast made the inclusion of these algae in the Rhodophyta difficult. The discovery in the three algae of floridoside and isofloridoside, typical storage products of red algae, in compatible with their inclusion in the Rhodophyta
Why education matters to anthropology: An interview with Sue Wright
Authors: Houtman Gustaaf 
Published: November 2004

‘Evidence‐based’ methodology has migrated from medical sciences to other disciplines and into policy‐making. An important vector is the US Council for Excellence in Government, which has four ex‐US presidents as honorary cochairs and which targets as principals (members) prestigious individuals who have served as public officials and are now leaders in corporations and NGOs. Through its Coalition for Evidence‐Based Policy, it is working with top federal and state policy makers, arguing that social policies should only be based on this methodology as it reveals ‘what works’ (a phrase echoed by Blair). Education has been a special target, and the Coalition and the US Department of Education cosponsored an OECD meeting on evidence‐based policy research in education in April 2004. It seems US university reform relies more on influencing research methodology than as yet in Europe. This methodology uses statistics and tests which are so large‐scale that they supposedly quash any political agendas harboured by academics. But which political agendas are promoting and prescribing this methodology for academic research into education and social policy?
The Danish meaning of pedagogy is the study of the formation of the person in all informal settings as well as in formal education. This differs from the English meaning of pedagogy which emphasizes principles and practice of teaching in formal education.
Bird–flower interactions in the Macaronesian islands
Authors: Valido Alfredo , Dupont Yoko L. , Olesen Jens M. 
Published: November 2004

AbstractAims  Several bird‐pollinated or ornithophilous flowers are present on the Macaronesian archipelagos, the Canary Islands and Madeira, but absent from nearby NW Africa and Europe. In Macaronesia, no specialist nectar‐feeding birds are found, but several generalist passerine bird species visit flowers for nectar. Two hypotheses attempt to explain the origin and evolution of ornithophily in the Macaronesian flora. According to ‘the island de novo hypothesis’, bird‐flowers evolved from mainland insect‐pollinated ancestors after island colonization. Alternatively, ancestors of the ornithophilous Macaronesian plant species evolved bird‐flowers before reaching the islands (‘the relict hypothesis’). In this study we first compile information of Macaronesian bird–flower interactions from the literature and our own field observations. Secondly, we discuss the two hypotheses of origin of ornithophily in the light of evidence from recent molecular plant phylogenies, palaeontology, historical biogeography of the African avifauna and flora, and present‐day ecological patterns.Location  Madeira and Canary Islands.Results  At least eleven endemic Macaronesian plant species from six genera have typical ornithophilous floral traits. These genera are: Canarina and Musschia (Campanulaceae), Isoplexis (Scrophulariaceae), Echium (Boraginaceae), Lotus (Fabaceae) and Lavatera (Malvaceae). These lineages have clear affinities to the Mediterranean region, except for Canarina whose closest relatives grow in East African mountains. Six generalist passerine bird species of Sylvia, Phylloscopus (Sylviidae), Serinus (Fringillidae) and Parus (Paridae) visit this flora for nectar.Main conclusion  We suggest that the origin and evolution of ornithophilous traits in these plant species took place mostly in mainland areas prior to island colonization. In Canarina and Lavatera, it is well supported that ornithophily is a relict condition, which originated in mainland areas possibly in association with specialist nectar‐feeding birds. For the remaining plant species except Echium wildpretii bird floral traits probably also are a relict condition. These species may be derived from ancestors, which were visited by specialist nectar‐feeding birds during geological periods when the Mediterranean and the Ethiopian vegetation were intermingled in mainland Africa. Probably, these mainland ancestors went extinct due to severe climatic fluctuations, while their Macaronesian descendants survived in ‘refuge’ on the islands. Finally, the island de novo hypothesis may explain the evolution of a mixed bird/insect‐pollination system in the neo‐endemic red‐flowered Echium wildpretii.
What is a node?
Authors: Heads Michael 
Published: November 2004

AbstractBiogeographic nodes can be characterized as sites of biological endemism, high diversity, distribution boundaries, anomalous absences, disjunct populations, taxonomic incongruence, parallelism and altitudinal anomalies. Their interpretation has depended on the evolutionary model used, in particular the mode of speciation: Croizat's vicariance or Mayr's ‘peripatric’ or ‘founder dispersal’ (=Darwin's ‘chance dispersal’, Hennig's ‘speciation by colonization’). All authors agree that the first process, together with movement of individual organisms and diaspores, occurs, but the second is much more controversial, with panbiogeographers and many geneticists denying its importance. Although nodes have often been interpreted as centres of origin – as in refugium theory – this is not accepted here as it fails to account for their constituting both centres and margins of distribution as well as zones of absence. Instead they are interpreted as sites of vicariance related to different kinds of tectonic activity which have been shown to occur in the same locality, such as terrane accretion, subduction, regional metamorphism, granitization, volcanism, faulting, folding, uplift, subsidence and regression of epicontinental seas. It is concluded that the identification of nodes is a more productive approach to biogeographic analysis than dividing a study area into ‘biogeographic regions’, which are usually based firmly on current geography and represent geological and biogeographic composites.
Mining the record: historical evidence for climatic influences on maize –Abutilon theophrasti competition
Authors: McDonald A J , Riha S J , Mohler C L 
Published: November 2004

SummaryVariations in climate are widely recognized as central factors governing the competitive balance in mixed‐species plant communities. In agricultural systems, highly variable patterns of crop yield reduction as a function of weed density have been documented across sites and among years at the same site for several crop–weed combinations. This variation is typically attributed to contrasting environmental conditions. Despite broad acknowledgement of their importance, experimental and temporal limitations have constrained the investigation and systematic understanding of environmental controls on the dynamics of competition. For several well‐studied crop–weed associations, aggregating historical data from similar competition experiments provides an opportunity to explore interference relationships over an array of conditions. In this study, 19 site‐years of maize –Abutilon theophrasti (velvetleaf) data were compiled and the weather characterized (i.e. average ambient temperature and moisture regime) for discrete portions of each growing season. These features were then related to patterns of maize yield loss from A. theophrasti interference at high weed densities. Results of this analysis suggest that temperatures following establishment, together with the presence or absence of water stress during the maize crop's exponential growth phase, account for over 60% of the observed variation in relative yield loss.
Tolerance of competitive spring barley cultivars to weed harrowing
Authors: Rasmussen J , Kurtzmann J I , Jensen A 
Published: November 2004

SummaryTwo experiments were conducted in 14 spring barley cultivars to investigate if crop tolerance to post‐emergence weed harrowing is related to morphological traits that reflect competitiveness. The experiments were carried out in organically grown fields where low weed densities and biomass production were assumed to be without significant influence on crop growth. The experiments showed that different cultivars responded differently to post‐emergence weed harrowing in terms of yield reduction. Taller and higher yielding cultivars with high leaf area index (LAI) tended to be less tolerant to post‐emergence weed harrowing than shorter and lower yielding cultivars with low LAI. This conclusion, however, is only valid for 13 of 14 cultivars because one very tall cultivar was tolerant to harrowing. Although the tallest and highest yielding cultivars were damaged the most, they remained the highest yielding cultivars after weed harrowing. This study is the first attempt to relate competitiveness of cereal cultivars to tolerance to harrowing, and it is thought provoking that competitiveness and tolerance is found to be counterproductive.
Simulating the effects of weed spatial pattern and resolution of mapping and spraying on economics of site‐specific management
Authors: Barroso J , Fernandez‐Quintanilla C , Maxwell B D , Rew L J 
Published: November 2004

SummaryThe economic benefits of using site‐specific weed management (SSWM) are related to the proportion of the field that is weed‐infested, the number of weed patches and the spatial resolution of sampling and spraying technologies. In this paper we simulate different combinations of these factors using parameter values obtained forAvena sterilisssp.ludovicianagrowing in Spanish winter barley crops. The profitability of SSWM systems increased as the proportion of the field infested by this weed decreased and when patch distribution was more concentrated. Under most of the conditions tested, positive net returns for SSWM were obtained when the weed‐infested area was smaller than 30%. The highest net return occurred using a 12 m × 12 m mapping and spraying resolution. The critical parameter that determined the economic viability of patch mapping and spraying resolution was the technology costs. The site specific strategy was economically superior to the standard strategy (overall herbicide application) in most cases. However, the differential between the two strategies decreased when the number of patches and the resolution of mapping and spraying increased, such that the highest net returns were obtained with a single patch covering 14% of the field and using a 12‐m mapping and spraying resolution; whereas the worst net returns were obtained for all patch numbers when 64% of the field was infested and a 3‐m mapping and spraying resolution was used.
Effects of selected pesticides and adjuvants on germination and vegetative growth of Phomopsis amaranthicola, a biocontrol agent for Amaranthus spp.
Authors: Wyss G S , Charudattan R , Rosskopf E N , Littell R C 
Published: November 2004

Summary Phomopsis amaranthicola, a bioherbicide agent for Amaranthus spp., was tested in vitro for its compatibility with commercial formulations of 16 adjuvants, 24 herbicides, nine fungicides and four insecticides at 2X, 1X (highest labelled product dose rate), 0.75X, 0.5X and 0.25X concentrations. These chemicals were tested for their effects on spore germination. Selected herbicides and fungicides at 1X were also tested for their influence on colony growth and sporulation. All tested compounds were finally categorized in compatibility classes regarding germination, mycelial growth and sporulation such as low, medium and high compatibility. High compatibility in terms of germination and fungal colony growth was only observed with the herbicide bentazone. Many of the adjuvants tested were highly compatible in the germination studies. Most fungicides and insecticides had medium and low compatibility with P. amaranthicola. Effects of pesticides on spore germination did not fully correspond with their effects on colony growth. Thus, it is possible to integrate the use of P. amaranthicola with some herbicides, fungicides, insecticides and adjuvants but not others. A case‐by‐case selection of application methods, such as tank‐mix or sequential application, along with proper timing of applications of the fungus and the chemical agents will be necessary.
A novel Bvar allele (547 G>A) demonstrates differential expression depending on the co‐inherited ABO allele
Authors: Cho D. , Kim S. H. , Ki C. S. , Choi K. L. , Cho Y. G. , Song J. W. , Shin J. H. , Suh S. P. , Yazer M. H. , Ryang D. W. 
Published: November 2004

Background and Objectives  Genetic analysis of group B donors in Korea was performed.Materials and Methods  Exons 6 and 7 were sequenced in 12 phenotypically B3 donors 6 B3, 6 A1B3.Results  Consensus sequences all B3 and 2/6 A1B3 donors were present. Four A1B3 donors demonstrated a novel B allele, Bvar, in the context of A101/ or A102/Bvar genotypes. Family studies based on an A1B3 donor with the Bvar allele and on another unrelated subject with identical genotype and phenotype revealed Bvar/O01 genotypes with full B‐antigen expression.Conclusions  B

var
allele is subject to differential expression, depending on the co‐inherited ABO allele.
ENZYMATIC BIOREMEDIATION: FROM ENZYME DISCOVERY TO APPLICATIONS
Authors: Sutherland TD , Horne I , Weir KM , Coppin CW , Williams MR , Selleck M , Russell RJ , Oakeshott JG 
Published: November 2004

SUMMARY1. Enzymatic bioremediation is potentially a rapid method of removing environmental pesticide residues. Applications include the treatment of residues resulting from agricultural production and processing industries, such as the treatment of irrigation waters, surface‐contaminated fruit and vegetables and spent dip liquors.2. A specific application for some organophosphate‐degrading enzymes involves detoxification of nerve agent stockpiles. Effective and affordable remediation requires highly specialized enzymes, so protein engineering techniques are being used to improve properties of various source enzymes to enhance catalytic rates, stability and substrate range.3. Trials with an optimized organophosphate‐degrading enzyme have shown the feasibility of such technology in various applications.4. The enzymes developed for environmental remediation for specific pesticide classes also have applications as antidotes for high‐dose pesticide poisonings and as prophylaxis for people at risk of high pesticide doses.
THE JANUS* FACES OF ADRENOCEPTORS: FACTORS CONTROLLING THE COUPLING OF ADRENOCEPTORS TO MULTIPLE SIGNAL TRANSDUCTION PATHWAYS
Authors: Summers Roger J , Broxton Natalie , Hutchinson Dana S , Evans Bronwyn A 
Published: November 2004

SUMMARY1. The adrenoceptors (AR) are an important subfamily of rhodopsin‐like G‐protein‐coupled receptors that couple to an increasingly large number of signalling mechanisms. Two important factors that determine the pathways that are used are the C‐terminal region of the receptor and the agonist used to activate the receptor.2. Studies of splice variants of the mouse β3‐AR showed that the C‐terminus is a factor controlling the signalling characteristics. Although these receptors differ only at the C‐terminus, the β3b‐AR coupled to both Gs and Gi, whereas the β3a‐AR coupled solely to Gs.3. Examination of four splice variants of the human α1A‐AR showed that all were able to couple to pertussis toxin‐sensitive G‐proteins, even though they have radically different C‐terminal regions.4. Comparison of the effects of the β3‐AR ligands CL316243 and SR59230A showed that both can activate the mouse β3‐AR but that SR59230A uses pathways other than cAMP accumulation in 3T3‐F442A cells.5. Examination of a series of α1‐AR agonists for their ability to activate a number of signalling pathways revealed that A61603 acted as a full agonist in all assays, whereas oxymetazoline was unable to cause cAMP accumulation, suggesting agonist‐selective signalling at the human α1A‐AR.
We Ran One Regression*
Authors: Hendry David F. , Krolzig Hans‐Martin 
Published: November 2004

AbstractThe controversy over the selection of ‘growth regressions’ was precipitated by some remarkably numerous ‘estimation’ strategies, including two million regressions by Sala‐i‐Martin [American Economic Review(1997b) Vol. 87, pp. 178–183]. Only one regression is really needed, namely the general unrestricted model, appropriately reduced to a parsimonious encompassing, congruent representation. We corroborate the findings of Hoover and Perez [Oxford Bulletin of Economics and Statistics(2004) Vol. 66], who also adopt an automatic general‐to‐simple approach, despite the complications of data imputation. Such an outcome was also achieved in just one run ofPcGets, within a few minutes of receiving the data set in Fernández, Ley and Steel [Journal of Applied Econometrics(2001) Vol. 16, pp. 563–576] from Professor Ley.