bluuebunny/crossref_metadata_2025 huggingface dataset:
Supplier Selection and Assessment: Their Impact on Business Performance
Authors: Kannan Vijay R. , Tan Keah Choon
Published: April 2006

Increasingly, firms are allocating more resources to their core competencies and encouraging the outsourcing of non‐core activities, which increases their reliance and dependence on suppliers. This increases the importance of effective supplier selection and assessment. Sparse evidence exists regarding the impact of supplier selection and assessment on a buying firm's business performance. This research describes an empirical study of the importance of supplier selection and assessment criteria of American manufacturing companies for items to be used in products already in production. Moreover, it identifies relationships between criteria and a buying firm's business performance. Results indicate that soft, non‐quantifiable selection criteria, such as a supplier's strategic commitment to a buyer, have a greater impact on performance than hard, more quantifiable criteria such as supplier capability, yet are considered to be less important. Assessment of a supplier's willingness and ability to share information also has a significant impact on the buying firm's performance, yet is again considered to be relatively unimportant.
Gaining and Losing Pieces of the Supply Chain
Authors: Johnson P. Fraser , Leenders Michiel R.
Published: April 2006

This research focused on changes in supply chain responsibilities. The primary research question was: What are the reasons (drivers) for major changes in supply chain responsibilities? Over 200 such changes, comprising 158 additions and 44 deletions, were documented in the research. The findings are based on 10 case studies in large multi‐business unit companies, seven head quartered in the United States and three in Europe, representing a variety of industries. Findings indicated three drivers of change for supply chain responsibilities. The chief purchasing officer and his or her staff members had a great deal of influence, particularly in additions to category 1 (acquisition of specific organizational needs) and category 2 (activities within the total supply chain).
Intensity and Managerial Scope of Supplier Integration
Authors: Wagner Stephan M.
Published: April 2006

Traditionally, research into antecedents, characteristics, and outcomes of supplier integration has mainly focused on integrating suppliers into new product development. What is urgently needed is a more comprehensive analysis of supplier integration activities. This research, which is based on responses from 173 industrial firms as well as supplementary interviews with purchasing executives, develops the notion of a phase‐differentiated approach toward supplier integration. It further provides insights into supplier integration in the development phase and supplier integration in the industrialization phase with respect to, for example, the degree of integration, the distinct managerial approaches, and the benefits sought by the buyer and the supplier. Additionally, results of an industry‐level analysis examine how various industries approach supplier integration.
Supplier Assistance Within Supplier Development Initiatives
Authors: Dunn Steven C. , Young Richard R.
Published: April 2006

Supplier development involves taking those initiatives necessary to change the performance of supplier firms. This paper develops a conceptual model that captures the salient issues from an internal or purchaser's standpoint, as well as from an external or seller's standpoint. The model assists purchasers in pinpointing improvement initiatives that provide the best returns. Moreover, it illustrates that different purchasing firms perceive supplier value differently because of the relative amount of competition in a respective supply market and because of the value offered by various products within the purchasing firm's business. Case studies were conducted to highlight methods of strategically enhancing the supplier/customer relationship to develop exemplary supply chains. Results indicated ineffective measurement criteria as a key impediment to supplier development. Additionally, results indicated that many purchasers are in transition regarding embracing bold and substantive supplier development initiatives.
A Contingency Perspective of Communication, Conflict Resolution and Buyer Search Effort in Buyer‐Supplier Relationships
Authors: Claycomb Cindy , Frankwick Gary L.
Published: April 2006

This study investigates the moderating effects of buying context on the relationship between communication elements and the effort buyers exert while searching for new suppliers throughout a buyer‐supplier relationship development process. A mail survey of members of the Institute for Supply Management™ was conducted and the data were analyzed using moderated regression. The results suggest that company size, buyer experience, relationship duration and relationship importance affect the association between a buyer's search effort and the communication elements. Interestingly, the buying context affects the relationship between search effort and the communication elements in different ways and to a different extent in each stage of the relationship development process.
Comparison of non‐invasive measures of cholinergic and allergic airway responsiveness in rats
Authors: Glaab T. , Hecker H. , Stephan M. , Baelder R. , Braun A. , Korolewitz R. , Krug N. , Hoymann H. G.
Published: April 2006

Aim:  Non‐invasive analysis of tidal expiratory flow parameters such as Tme/TE (time needed to reach peak expiratory flow divided by total expiratory time) or midexpiratory tidal flow (EF50) has been shown useful for phenotypic characterization of lung function in humans and animal models. In this study, we aimed to compare the utility of two non‐invasive measures, EF50 and Tme/TE, to monitor bronchoconstriction to inhaled cholinergic and allergic challenges in Brown‐Norway rats.

Methods:  Non‐invasive measurements of Tme/TE and EF50 were paralleled by invasive recordings of Tme/TE, EF50 and pulmonary conductance (GL).

Results:  First, dose–response studies with acetylcholine were performed in naive rats, showing that EF50 better than Tme/TE reflected the dose‐related changes as observed with the classical invasive outcome parameter GL. The subsequent determination of allergen‐specific early airway responsiveness (EAR) showed that ovalbumin‐sensitized and ‐challenged rats exhibited airway inflammation and allergen‐specific EAR. Again, EF50 was more sensitive than Tme/TE in detecting the allergen‐specific EAR recorded with invasive and non‐invasive lung function methods and agreed well with classical GL measurements.

Conclusion:  We conclude that non‐invasive assessment of EF50 is significantly superior to Tme/TE and serves as a suitable and valid tool for phenotypic screening of cholinergic and allergic airway responsiveness in rats.
Virus-Enabled Synthesis and Assembly of Nanowires for Lithium Ion Battery Electrodes
Authors: Nam Ki Tae , Kim Dong-Wan , Yoo Pil J. , Chiang Chung-Yi , Meethong Nonglak , Hammond Paula T. , Chiang Yet-Ming , Belcher Angela M.
Published: April 2006

The selection and assembly of materials are central issues in the development of smaller, more flexible batteries. Cobalt oxide has shown excellent electrochemical cycling properties and is thus under consideration as an electrode for advanced lithium batteries. We used viruses to synthesize and assemble nanowires of cobalt oxide at room temperature. By incorporating gold-binding peptides into the filament coat, we formed hybrid gold–cobalt oxide wires that improved battery capacity. Combining virus-templated synthesis at the peptide level and methods for controlling two-dimensional assembly of viruses on polyelectrolyte multilayers provides a systematic platform for integrating these nanomaterials to form thin, flexible lithium ion batteries.
Preparation, Solubility, Infrared Spectra and Radiolysis of Tetramethylammonium Hydrogenselenate Monohydrate and Lithium Tetramethylammonium Selenate Tetrahydrate
Authors: Havlíček David , Turek Libor , Plocek Jiří , Mička Zdeněk
Published: April 2006

Solubility in the (Me4N)2SeO4-H2SeO4-H2O and (Me4N)2SeO4-Li2SeO4-H2O systems were studied. The new compounds, tetramethylammonium hydrogenselenate monohydrate ((Me4N)HSeO4·H2O) and lithium tetramethylammonium selenate tetrahydrate (Li(Me4N)SeO4·4H2O), have been found in these systems. Both substances were characterised by chemical analysis and IR molecular spectroscopy. Both of the title substances decompose under the influence of X-radiation and, thus, their structures cannot be determined. The radiolysis of both substances was studied in greater detail. Tetramethylammonium hydrogenselenate monohydrate is dehydrated by X-radiation to form the anhydrous salt. The reaction is controlled by first-order kinetics with a rate constant of 1.30(3) × 10-3 s-1.
Structure Dynamics and Isomerism of Bis[μ-(2-methylphenolato)]bis[(η2:η2-cycloocta-1,5-diene)rhodium(I)] Complex
Authors: Zedník Jiří , Sejbal Jan , Svoboda Jan , Sedláček Jan , Vohlídal Jiří
Published: April 2006

Dinuclear rhodium(I) complex [{RhI(cod)}2(μ-OC6H4-2-Me)2] (1), exhibits the syn-anti isomerism consisting in the orientation of methyl groups of the bridge ligands with respect to the plane or distorted plane involving Rh and O atoms. The syn isomer predominates in CDCl3 solution (above 90%) at room temperature. EXSY 1H NMR measurements showed that, in CDCl3 solution, complex 1 undergoes at least two independent dynamic processes differing substantially in values of activation parameters: (i) rotation of 2-methylphenyl rings in bridge ligands along the O-C axis, and (ii) formal rotation of cod ligands along the Rh-cod axes, which proves fluxional behavior of cod ligand in RhI(cod) complexes.
Causes of death and renal tubular dysfunction in residents exposed to cadmium in the environment
Authors: Nishijo M , Morikawa Y , Nakagawa H , Tawara K , Miura K , Kido T , Ikawa A , Kobayashi E , Nogawa K
Published: April 2006

Objectives:To clarify the causes of death of residents with renal tubular dysfunction induced by cadmium (Cd) in the environment.

Methods:A 15 year follow up study was performed with the inhabitants living in the Cd polluted Kakehashi River basin in Japan. Standardised mortality ratios (SMRs) for causes of death, classified by ICD-9, were computed using the person-years method to investigate the excess mortality of subjects with urinary β2-MG (microglobulin) ⩾1000 μg/gCr. Mortality risk analysis was performed using Cox’s proportional model to compare mortality between subjects with urinary β2-MG ⩾1000 and <1000 μg/gCr, and to investigate the relationship between the degree of urinary β2-MG and mortality.

Results:Excess mortality due to heart failure and cerebral infarction in both sexes, and nephritis and nephrosis in men, was observed among subjects with urinary β2-MG ⩾1000 μg/gCr. Significant increases in mortality risk for cerebral infarction in men and for malignant neoplasms in women with urinary β2-MG ⩾1000 μg/gCr were observed during the first five year observation period. For nephritis and nephrosis, the mortality risks for men and women with urinary β2-MG ⩾1000 μg/gCr significantly increased over the 15 year observation period. The mortality risks for heart failure and cerebral infarction increased in proportion to the increased urinary β2-MG in both sexes. Increased mortality risks for nephritis and nephrosis were identified in the subjects with urinary β2-MG ⩾10000 μg/gCr in both sexes.

Conclusion:Renal tubular dysfunction induced by Cd affected the causes of death, and mortality for heart failure, cerebral infarction, and nephritis and nephrosis was increased among inhabitants living in a Cd polluted area in Japan. In women, cancer mortality may have been increased while Cd pollution was ongoing.
A multi-proxy lithostratigraphic record of Late Glacial and Holocene climate variability from Piper Lake, Nova Scotia
Authors: Spooner Ian S , MacDonald Ian , Beierle Brandon , Jull AJ Timothy
Published: April 2006

A multi-proxy lithostratigraphic record from Piper Lake, Nova Scotia reveals environmental variability during the Late Glacial and Holocene. Piper Lake is a small, shallow (3 m), closed dystrophic basin located in the eastern Nova Scotia Highlands. The site was deglaciated about 14.5 cal (calibrated) ka BP and elevated loss on ignition values and relatively low carbon/nitrogen (C/N) isotope ratios indicate the establishment of a productive aquatic environment consistent with Allerød warming. The Late Glacial Lake record is punctuated by two thin, very fine-grained clay layers that are correlative to the Killarney and Younger Dryas (YD) oscillations; they were deposited when perennial ice covered the lake. The post-YD lithostratigraphy indicates the rapid establishment of an increasingly productive and stable landscape. This trend is reversed three times during the Holocene by minerogenic units. A complex 25 cm thick diamicton unique to Piper Lake was deposited ca. 10.810.3 cal ka BP by slumping that was associated with periglacial slope processes and (or) lake level changes; a direct correlation to early Holocene (Preboreal) cooling appears unlikely. Two thin minerogenic units deposited at ca. 8.1 and ca. 4.9 cal ka BP were likely the result of regional cooling and are broadly correlative with events noted in the GISP2 (Greenland Ice Sheet Project 2) ice-core record. The Holocene lithostratigraphic record from Piper Lake may be a consequence of unique limnological factors. Alternatively, the strong lithostratigraphic response may be the result of the absence of a strong and persistent regional climate mechanism (North Atlantic oscillation?), which if present might have obscured the impact of hemispheric or larger-scale climate forcing.
A midge-based late-glacial temperature reconstruction from southwestern Nova Scotia
Authors: Whitney Bronwen S , Vincent Jessie H , Cwynar Les C
Published: April 2006

We present a quantitative reconstruction of the thermal regime spanning the late-glacial period of Nova Scotia (14 700 to 11 600 BP) as inferred by analyzing fossil midges from a small lake (Lac à Magie) in southwestern Nova Scotia. The GS-1 event (equivalent to the Younger Dryas, dating from 12 700 to 11 600 BP in Maritime Canada) was marked by a 5 °C decline in inferred mean July surface-water temperatures and a 15% drop in organic content. Previous pollen and plant macrofossil analyses of this site demonstrate a response of vegetation to GS-1 cooling. These data, coupled with a midge-inferred temperature reconstruction from a nearby site, suggest that late-glacial climate change was less pronounced in southern Nova Scotia than in other sites in Maritime Canada and adjacent eastern North America.
Global analyses of brachiopod faunas through the Ordovician and Silurian transition: reducing the role of the Lazarus effect
Authors: Rong Jia-yu , Boucot A J , Harper D AT , Zhan Ren-bin , Neuman R B
Published: April 2006

Global analyses of 88 families and 284 genera of brachiopods from middle Ashgill, Late Ordovician, to earlymiddle Rhuddanian, Early Silurian, indicate that 18.6% and 12.5% of families and 51.0% and 41.3% of genera were eliminated in the first and second phases of the end-Ordovician mass extinction, respectively, with the total loss of 28.4% of families and 69.0% of genera in the crisis. New investigation demonstrates that brachiopods, at both generic and familial levels, suffered greater during the first phase than during the second phase. Four groups (victims, relicts, survivors, and new arrivals) are distinguished by their stratigraphical ranges. Generic survivors, occurring in the Kosov Province during the Hirnantian, can be split into three types with respect to their changing abundance: increasing, declining, and Lazarus taxa. Among the 88 genera that survived, numerous declining genera occurred in the Hirnantian: 16 Lazarus families and 18 Lazarus genera are provisionally known and may be regarded as end members of the declining type. Comparison of the abundance, population size, and distribution patterns of declining and Lazarus taxa shows important similarities between these two types which contribute to a better understanding of the nature of Lazarus taxa. In addition to these biological attributes, taphonomic failure and generally poor preservation, together with collecting bias and inadequate systematic data, are clearly involved. More collections will undoubtedly globally reduce the number of Lazarus taxa. A single, common refugium for end-Ordovician brachiopods probably did not exist; rather, these taxa used paleogeographically scattered locations in a range of environments for survival.
New evidence fromSinapis albaL. for ancestral triplication in a crucifer genome
Authors: Nelson Matthew N , Lydiate Derek J
Published: April 2006

We present clear evidence of ancestral genome triplication in Sinapis alba, a close relative of the cultivated Brassica species. Exceptionally high levels of heterozygosity in the parents of an F1intercross permitted the mapping of an estimated 87% of all detected restriction fragment length polymorphism (RFLP) loci, with each RFLP probe typically detecting 2 or 3 loci. These duplicated loci were arranged in 8 triplicated homologous linkage blocks and 2 small, duplicated, homologous linkage blocks covering the majority of the S. alba genome. Several large-scale inversions and translocations appear to have rearranged the order of loci within homologous blocks. The role of successive polyploidization events on the evolution of crucifer species is discussed.Key words: polyploidy, yellow mustard, Brassica hirta, genome duplication, hexaploid ancestor, paralogous loci.
Molecular cloning and chromosomal localization of theBombyx Sex-lethalgene
Authors: Niimi Teruyuki , Sahara Ken , Oshima Hiroyuki , Yasukochi Yuji , Ikeo Kazuho , Traut Walther
Published: April 2006

We cloned Bm-Sxl, an orthologue of the Drosophila melanogaster Sex-lethal (Sxl) gene from embryos of Bombyx mori. The full-length cDNAs were of 2 sizes, 1528 and 1339 bp, and were named Bm-Sxl-L and Bm-Sxl-S, respectively. Bm-Sxl-L consists of 8 exons and spans more than 20 kb of genomic DNA. The open reading frame (ORF) codes for a protein 336 amino acids in length. Bm-Sxl-S is a splice variant that lacks the second exon. This creates a new translation start 138 nucleotides downstream and an ORF that codes for 46 amino acids fewer at the N-terminus. Linkage analysis using an F2panel mapped Bm-Sxl to linkage group 16 at 69.8 cM. We isolated 2 BACs that include the Bm-Sxl gene. With BAC-FISH we located Bm-Sxl cytogenetically on the chromosome corresponding to linkage group 16 (LG16) at position >68.8 cM.Key words: Sex-lethal, Sxl, Bombyx mori, alternative splicing, BAC-FISH.
Zebrafish: chiasmata and interference
Authors: Moens Peter B
Published: April 2006

With immunofluorescence microscopy, the positions of centromeres and MLH1 (MutL homolog) foci representing the sites of presumptive chiasmata are shown for zebrafish (Danio rerio Hamilton 1822) synaptonemal complexes (SCs) in spermatocyte nuclei at meiotic prophase. Most SCs have a single focus and a few (7 of 140) have 2 chiasmata. MLH1 foci tend to be in the distal regions of SCs, with progressively fewer occurring towards the middle of the SCs. This non-random distribution suggests chiasma interference. Synaptic initiation, as well as replication protein A (RPA) foci at the chromosome ends, correlates with the distal localization of MLH1 foci. These observations may provide the physical basis for the reported limited genetic recombination in the centromeric region of androgenetic offspring of a male.Key words: zebrafish, recombination, chiasmata, interference, MLH1, RPA.
Central and peripheral factors in thermal, neuromuscular, and perceptual adaptation of the hand to repeated cold exposures
Authors: Geurts Carla L.M , Sleivert Gordon G , Cheung Stephen S
Published: April 2006

We investigated the role of central and peripheral factors in repeated cold exposure of the hand and their effects on temperature response, neuromuscular function, and subjective thermal sensation. Eleven subjects immersed their left hand repeatedly in 8 °C cold water for 30 min, 5 d/week, for 2 weeks. Before and following the 2 weeks of exposure, neuromuscular function, blood markers, thermal sensation, and temperature responses of both acclimated (left) and control (right) hands were tested. Minimum index finger temperature pre-acclimation was 10.9 ± 3.4 °C and 10.0 ± 2.0 °C in the left and right hand, respectively, and did not change significantly post-acclimation (left, 12.8 ± 4.2 °C; right, 10.2 ± 1.1 °C). Neuromuscular function was impaired with cooling, but this was significantly different neither between the hands nor over time. Central factors, measured by catecholamines and changes in temperature and cardiovascular response over time, did not change and there were no differences in responses between the exposed and non-exposed hand over time (peripheral adaptation) nor were there any differences in local factors endothelian-1 and nitric oxide. Subjective thermal comfort was improved and the discepancy that was found between the change in actual and perceived temperature may increase the risk of cold injury in partially acclimatized individuals, owing to an adjustment in behavioural thermoregulation.Key words: hand, skin temperature, cold-induced vasodilatation, neuromuscular function, manual dexterity.
Actinobacillus actinomycetemcomitansserotype-specific genotypes and periodontal status in Brazilian subjects
Authors: Teixeira Rodrigo Estêvão , Mendes Edilberto Nogueira , Roque de Carvalho Maria Auxiliadora , Nicoli Jacques Robert , Farias Luiz de Macêdo , Magalhães Paula Prazeres
Published: April 2006

Periodontitis is associated with members of the oral microbiota, such as Actinobacillus actino mycetem comitans. To our knowledge, this is the first study to evaluate, by PCR, the occurrence of the six known bacterium serotypes that included subjects with and without periodontitis. Our group comprised 49 Brazilian subjects. We studied 146 bacterial isolates from 23 patients with aggressive or chronic periodontitis and 26 subgingival specimens from subjects with or without periodontitis, all originating in our collection. Serotypes b and c were observed in similar frequencies, and no subject harboured d, e, or f serotype strains. Around 78% subjects had single-serotype infection. Mixed infection was seen only in aggressive periodontitis patients. An association between serotype b and healthy periodontium and between serotype c and chronic periodontitis was observed. Our results diverge from those previously reported, which may be explained by specific distribution patterns in distinct populations. The association of different serotypes with the same periodontal status or conversely of a serotype with different periodontal conditions indicates that organism serotyping should not be used as a sole reliable marker for predicting the outcome of the infection. Evaluation of factors involved in human oral cavity colonization by subsets of A. actinomycetemcomitans is essential for elucidating organism-host-environment relationships.Key words: Actinobacillus actinomycetemcomitans, genotyping, serotyping, periodontitis.
Diversification of tree stands as a means to manage pests and diseases in boreal forests: myth or reality?
Authors: Koricheva Julia , Vehviläinen Harri , Riihimäki Janne , Ruohomäki Kai , Kaitaniemi Pekka , Ranta Hanna
Published: April 2006

Pure forest stands are widely believed to be more prone to pest outbreaks and disease epidemics than mixed stands, leading to recommendations of using stand diversification as a means of controlling forest pests and pathogens. We review the existing evidence concerning the effects of stand tree-species diversity on pests and pathogens in forests of the boreal zone. Experimental data from published studies provide no overall support for the hypothesis that diversification of tree stands can prevent pest outbreaks and disease epidemics. Although beneficial effects of tree-species diversity on stand vulnerability are observed in some cases, in terms of reductions in damage, these effects are not consistent over time and space and seem to depend more on tree-species composition than on tree-species diversity per se. In addition, while mixed stands may reduce the densities of some specialized herbivores, they may be more attractive to generalist herbivores. Given that generalist mammalian herbivores cause considerable tree mortality during the early stages of stand establishment in boreal forests, the net effect of stand diversification on stand damage is unlikely to be positive.
Confined field release of Laricobius nigrinus (Coleoptera: Derodontidae), a predator of the hemlock woolly adelgid, Adelges tsugae (Hemiptera: Adelgidae), in Virginia
Authors: Lamb A B , Salom S M , Kok L T , Mausel D L
Published: April 2006

Laricobius nigrinus Fender is a specialist predator of the hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), a lethal pest of hemlock (Tsuga spp.) in the eastern United States. A release was conducted in 2003 in Virginia to evaluate survival and oviposition of L. nigrinus adults, egg development in the field, and their impact on HWA density. In March, April, and May, groups of zero, one, two, or three L. nigrinus females were caged on 64 hemlock branches. After 10 days, half the branches were removed to determine L. nigrinus adult survival, total eggs laid, and oviposition location with respect to prey abundance. Beetles on branches remaining in the field were recovered and recaged on new branches every 10 days. The estimated 10 344 eggs laid on branches left in the field represent the first field release of L. nigrinus in the eastern United States. The density of L. nigrinus adults affected the total eggs laid per female and oviposition site selection. Branches caged with L. nigrinus had lower densities of HWA than branches without predators. Although F1 adults were not recovered from this release site in fall 2003, F2 adults were recovered in fall 2004. Laricobius nigrinus shows promise as a biological control agent for HWA in the eastern United States.
Mapping stand-level forest biophysical variables for a mixedwood boreal forest using lidar: an examination of scanning density
Authors: Thomas V , Treitz P , McCaughey J H , Morrison I
Published: April 2006

Light detection and ranging (lidar) is becoming an increasingly popular technology among scientists for the development of predictive models of forest biophysical variables. However, before this technology can be adopted with confidence for long-term monitoring applications in Canada, robust models must be developed that can be applied and validated over large and complex forested areas. This will require "scaling-up" from current models developed from high-density lidar data to low-density data collected at higher altitudes. This paper investigates the effect of lowering the average point spacing of discrete lidar returns on models of forest biophysical variables. Validation of results revealed that high-density models are well correlated with mean dominant height, basal area, crown closure, and average aboveground biomass (R2 = 0.84, 0.89, 0.60, and 0.91, respectively). Low-density models could not accurately predict crown closure (R2 = 0.36). However, they did provide slightly improved estimates for mean dominant height, basal area, and average aboveground biomass (R2 = 0.90, 0.91, and 0.92, respectively). Maps were generated and validated for the entire study area from the low-density models. The ability of low-density models to accurately map key biophysical variables is a positive indicator for the utility of lidar data for monitoring large forested areas.
Population differentiation among three species of white oak in northeastern Illinois
Authors: Craft Kathleen J , Ashley Mary V
Published: April 2006

We used microsatellite DNA analysis to examine population differentiation among three species of white oak, Quercus alba L., Quercus bicolor Willd., and Quercus macrocarpa Michx., occurring in both pure and mixed stands in northeastern Illinois. Using individual-based Bayesian clustering or principal components analyses, no strong genetic groupings of individuals were detected. This suggests that the three species do not represent distinct and differentiated genetic entities. Nevertheless, traditional approaches where individuals are pre-assigned to species and populations, including F statistics, allele frequency analysis, and Nei's genetic distance, revealed low, but significant genetic differentiation. Pairwise F statistics showed that some intraspecific comparisons were as genetically differentiated as interspecific comparisons, with the two populations of Q. alba exhibiting the highest level of genetic differentiation (θ = 0.1156). A neighbor-joining tree also showed that the two populations of Q. alba are distinct from one another and from the two other species, while Q. bicolor and Q. macrocarpa were genetically more similar. Pure stands of Q. macrocarpa did not show a higher degree of genetic differentiation than mixed stands.
Conservation-oriented manipulations of coarse woody debris affect its value as habitat for spruce-infesting bark and ambrosia beetles (Coleoptera: Scolytinae) in northern Sweden
Authors: Johansson Therese , Gibb Heloise , Hilszczański Jacek , Pettersson Roger B , Hjältén Joakim , Atlegrim Ola , Ball John P , Danell Kjell
Published: April 2006

Many species of Scolytinae are pests in boreal forests, so factors that affect their abundance are of great interest to forestry. Using emergence and window traps we examined the effects of stand type and substrate characteristics on the abundance of spruce-infesting Scolytinae in northern Sweden. Several species of Scolytinae (Crypturgus subcribrosus, Hylastes cunicularius, Hylurgops palliatus, Pityogenes chalcographus, Polygraphus punctifrons) were captured in greater numbers on snags than on untreated logs. Log exposure also had a significant effect on some species, H. palliatus and Trypodendron lineatum were more abundant in window traps on artificially shaded logs than on naturally shaded or untreated logs. Significantly fewer Dryocoetes autographus, H. palliatus,Hylurgops glabratus, andH. cunicularius were captured on burned logs than on untreated logs. Stand type clearly affected several species, P. chalcographus emerged in greater numbers on clearcuts than in mature managed and old-growth stands, and D. autographus,H. glabratus, and T. lineatum showed the opposite pattern. Historical records suggest that pest outbreaks are rare in northern Sweden; however, improved knowledge of the habitat preferences of potential pest species in this region will allow us to take the necessary precautions against outbreaks, whilst leaving sufficient dead wood to support intact saproxylic assemblages.
Nutrient foraging via physiological and morphological plasticity in three plant species
Authors: Wang Lixin , Mou Paul P , Jones Robert H
Published: April 2006

Physiological and morphological plasticity of roots enhance plant nutrient uptake in spatiotemporally heterogeneous soil environments. We examined these two types of plasticity using three plant species (Solidago altissima (L.) Raf., Pinus taeda L., and Liquidambar styraciflua L.). We grew plants in pots (one plant per pot) with equal quantity of fertilizer applied either evenly over the pot surface (H) or on one-quarter of the pot surface (T). A high-concentration 15N-labeled ammonium nitrate solution was injected twice over 48 h before harvest at a random location in H pots, and in either unfertilized or fertilized portion of T pots. Physiological plasticity of N uptake was observed in S. altissima and L. styraciflua. The highest 15N uptake rate for L. styraciflua occurred in H pots (medium level), and that for S. altissima occurred in fertilized portions of T pots (rich level). When low-concentration 15N was added to S. altissima, no differences in uptake were noted among treatments, possibly because of interroot competition. In S. altissima and P. taeda, either morphological or physiological plasticity was strong. In L. styraciflua, both types of plasticity were strong. Total 15N uptake was enhanced when 15N was added to the fertilized patches. Physiological plasticity contributed >70% of enhanced 15N uptake in S. altissima and L. styraciflua.
Foliar respiration in an old-growth Pseudotsuga-Tsuga forest
Authors: Cooper Clifton E , Thomas Sean C , Winner William E
Published: April 2006

Old-growth forest ecosystems accrue carbon at small mean rates and may function as carbon sinks in some years and as carbon sources in others. Foliar respiration is a large component of stand carbon balance and could be variable enough to substantially affect sourcesink behaviors. However, foliar respiration has not been well studied in old-growth canopies. We examined seasonal, interannual, spatial, and interspecific variation of foliar respiration in an old-growth PseudotsugaTsuga stand in Washington, USA, with measurements made on three species at 3-month intervals, for 4+ years. There were strong seasonal differences, with rates being much larger in June than in December. Rates in March were significantly (p ≤ 0.0001) larger than expected for all species. For data pooled across seasons, the exponential respiration-temperature relationship indicated that a seasonal temperature increase of 10 °C caused rates to increase by 1.78 times. For respiration based on leaf area, but not on leaf mass, rates varied strongly with canopy position (p ≤ 0.0001). Temperature-corrected rates were compared among four consecutive years and declined from 1999 to 2001. Correlation with eddy covariance measurements suggests that interannual changes in foliar respiration did not cause the decline in net ecosystem productivity observed at the site through the same period, but may have instead partially offset a trend toward decreasing net ecosystem productivity caused by other factors.
Logging-induced change (1930-2002) of a preindustrial landscape at the northern range limit of northern hardwoods, eastern Canada
Authors: Boucher Yan , Arseneault Dominique , Sirois Luc
Published: April 2006

Logging-induced changes from preindustrial (1930) to current conditions (2002) were studied in a landscape covering 13 550 ha in eastern Quebec. Age and types of forest cover were compared between 1930 and 2002 forest maps. In addition, we compared relative species abundance between living stems and coarse woody debris to study these changes at the stand scale. More than 90% of the 1930 preindustrial landscape was composed of forest stands older than 100 years. A balsam fir (Abies balsamea (L.) Mill.)  white spruce (Picea glauca (Moench) Voss) dominated conifer cover (77% of the landscape area) formed the landscape matrix across the lowlands and was intermingled with mixed stands of sugar maple (Acer saccharum Marsh.) and conifers on the highlands. As a result of recurrent logging, stands less than 70 years old accounted for 93% of the 2002 landscape. From 1930 to 2002, 37% of the landscape was converted from coniferous to mixed forest, and 19% evolved towards a deciduous cover. The total number of cover patches doubled to 193, whereas mean patch size decreased twofold to 65 ha. Sugar maple, red maple (Acer rubrum L.), striped maple (Acer pennsylvanicum L.), and white birch (Betula papyrifera Marsh.) probably experienced a greater increase in abundance, whereas balsam fir, white spruce, and eastern white-cedar (Thuja occidentalis L.) experienced a more pronounced decrease. Because it does not consider preindustrial landscape patterns, the system of ecological land classification currently in use in this area suggests that potential late-successional cover types should be more similar to present-day than to preindustrial conditions.
Planting black walnut in southern Ontario: midrotation assessment of growth, yield, and silvicultural treatments
Authors: Pedlar John H , McKenney Daniel W , Fraleigh Saul
Published: April 2006

We established 480 remeasurement plots in plantations originally laid out by F.W. von Althen in the 1970s and 1980s for his pioneering work on hardwood planting in southern Ontario. We used 110 of these plots to summarize the growth and yield of black walnut (Juglans nigra L.) plantations in southern Ontario. Overall, walnut growth averaged only 2.3 m3·ha1·year1, reflecting the less than optimal soil conditions at the majority of sites. However, good growth rates (i.e., >5 m3·ha1·year1) were recorded at sites with well-drained loamy soils, particularly when walnut was interplanted with other tree species. We also carried out a detailed analysis of four of the original experiments of F.W. von Althen to examine the long-term impacts of silvicultural treatments applied at an early stage in plantation development. Briefly, these analyses found (i) a significant long-term effect of controlling herbaceous competition at an early point in plantation development, although there is a suggestion that lower herbicide concentrations may be adequate in the long run, (ii) that fertilization effects, which were marginal at the time of application, were not apparent at age 32, (iii) generally better walnut growth when interplanted with other woody species, but autumn olive (Elaeagnus umbellata Thunb.), the species that stimulated the best walnut growth, grew invasively throughout the study area, thus ruling it out as a nurse species, and (iv) weak evidence that an initial spacing of 3 m × 3 m is optimal for walnut development in the absence of thinning up to age 30. This study provides rare insight into black walnut growth rates and best management practices in southern Ontario, although we recognize that the scope of these findings is limited by less than optimal soil conditions at many of the study sites.
Forest development following mudflow deposition, Mount St. Helens, Washington
Authors: Weber Marc H , Hadley Keith S , Frenzen Peter M , Franklin Jerry F
Published: April 2006

Volcanic mudflows are locally important disturbance agents in the Pacific Northwest rarely studied within the context of forest succession. We describe 18 years (19811999) of forest development on the Muddy River mudflow deposit following the 1980 eruption of Mount St. Helens using permanent plot data collected along two transects traversing the Cedar Flats river terrace. We analyze changing forest structure over the study period and compare results with mudflow deposition using correlation and pairwise comparisons, as well as ordination (detrended correspondence analysis) and cluster analysis. Our results show a statistically significant relationship between mudflow deposition and forest change. Following mudflow deposition, the site consisted of patches of high tree mortality caused by deep mudflow deposits in abandoned river channels as well as patches of accelerated regeneration of surviving understory trees in areas of more shallow mudflow deposition and partial overstory mortality. Mudflow deposition at the site initiated multiple stages of stand development with (1) early-colonizing red alder (Alnus rubra Bong.) dominating deep deposition sites with fewer surviving trees, (2) gap recruitment and establishment by western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) on intermediate to deep deposition sites with more postburial surviving trees, and (3) late-seral conditions and accelerated succession on shallow burial sites, where tree mortality was low. The initiation of differing succession trajectories, as well as variability in the extent and timing of tree mortality following mudflow deposition, demonstrates a dynamic response to disturbance in relation to small-scale gradients of mudflow deposition.
DNA barcodes for insect pest identification: a test case with tussock moths (Lepidoptera: Lymantriidae)
Authors: Ball Shelley L , Armstrong Karen F
Published: April 2006

Reliable and rapid identification of exotic pest species is critical to biosecurity. However, identification of morphologically indistinct specimens, such as immature life stages, that are frequently intercepted at borders is often impossible. Several DNA-based methods have been used for species identification; however, a more universal and anticipatory identification system is needed. Consequently, we tested the ability of DNA "barcodes" to identify species of tussock moths (Lymantriidae), a family containing several important pest species. We sequenced a 617 base pair fragment of the mitochondrial gene cytochrome c oxidase 1 for 20 lymantriid species. We used these, together with other Noctuoidea species sequences from GenBank and the Barcoding of Life Database to create a "profile" or reference sequence data set. We then tested the ability of this profile to provide correct species identifications for 93 additional lymantriid specimens from a data set of mock unknowns. Of the unknowns, 100% were correctly identified by the cytochrome c oxidase 1 profile. Mean interspecific sequence (Kimura 2-parameter) divergence was an order of magnitude greater (14%) than mean intraspecific divergence (<1%). Four species showed deeper genetic divergences among populations. We conclude that DNA barcodes provide a highly accurate means of identifying lymantriid species and show considerable promise as a universal approach to DNA-based identification of pest insects.
Oxidative damage in the livers of senescence-accelerated mice: a gender-related response
Authors: Tomás-Zapico Cristina , Álvarez-García Óscar , Sierra Verónica , Vega-Naredo Ignacio , Caballero Beatriz , García José Joaquín , Acuña-Castroviejo Darío , Rodríguez María Isabel , Tolivia Delio , Rodríguez-Colunga María Josefa , Coto-Montes Ana
Published: April 2006

The prevalence of liver diseases emphasizes the need of animal models to research on the mechanism of disease pathogenesis. Furthermore, most of the liver pathologies have the oxidative stress as an important component. The senescence-accelerated mouse strain SAMP8 was proposed as a valuable animal model for the study of liver diseases. To gain a better understanding of the mechanisms underlying degenerative processes in SAMP8 mice livers, we studied the oxidative-induced damage in 5-month-old SAMP8 mice and SAMR1, senescence-accelerated-resistant mice. We found profound differences in the antioxidant response to aging between sexes, with males displaying lowest levels of main antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) in SAMP8; whereas females had no difference in their activities, except for GR, when compared with their SAMR1 controls. The results obtained show the binomial SOD/CAT as an important factor for counteracting reactive oxygen species-dependent damage. There were not pathological differences at the morphological level between both strains, although the decay in protection against free radicals had an immediate response by increasing lipid and protein oxidative damage in SAMP8 mice liver. At 5 months, both male and female SAMP8 mice confront the oxidative stress challenge to different extents. Indeed, proteins seem to be the most vulnerable biomolecule in SAMP8 male mice.
Preventive effects of cyclohexenonic long-chain fatty alcohol on diabetic cystopathy in the rat
Authors: Suzuki Hiroto , Saito Motoaki , Kinoshita Yukako , Satoh Itaru , Kono Tomoharu , ShinBori Chiko , Anastasios Sylakos , Yamada Masashi , Satoh Keisuke
Published: April 2006

In this study, we investigated the preventive effect of n-hexacosanol on diabetes-induced bladder dysfunction in the rat. Diabetes was induced in 8-week-old male Sprague–Dawley rats by administering an injection of streptozotocin (50 mg/kg, i.p.). The rats were randomly divided into 4 groups (age-matched control rats, diabetic rats without treatment with n-hexacosanol, and diabetic rats treated with n-hexacosanol (2 and 8 mg/kg, i.p. every day)) and maintained for 4 weeks. The serum glucose and serum insulin levels were determined, and the functions of bladder were estimated by voiding behavior, cystometric, and functional studies to carbachol and KCl. Furthermore, we examined possible diabetic induced histological changes in these rats. Treatment with n-hexacosanol did not alter diabetic status including body mass, bladder mass, and serum glucose and serum insulin levels, but significantly improved the maximum contraction pressure of the detrusor and residual urine volume in cystometric studies and Emax values to carbachol in functional studies in a dose-dependent manner. Diabetes induced bladder smooth muscle hypertrophy, which tended to be ameliorated by treatment with n-hexacosanol in a dose-dependent manner. Treatment with n-hexacosanol did not alter the diabetic status, but significantly improved diabetic cystopathy in a dose-dependent manner.
Cholecystokinin-2 receptors couple to cAMP–protein kinase A to depress excitatory synaptic currents in rat nucleus accumbens in vitro
Authors: Kombian Samuel B. , Ananthalakshmi Kethireddy V.V. , Parvathy Subramanian S. , Matowe Wandikayi C.
Published: April 2006

We recently reported that the activation of cholecystokinin-2 receptors depress evoked excitatory postsynaptic currents (EPSCs) in nucleus accumbens (NAc) indirectly through γ-aminobutyric acid (GABA) acting on γ-aminobutyric acid-B (GABAB) receptors. Here, we determined the second messenger system that couples cholecystokinin-2 receptors to the observed synaptic depression. Using in vitro forebrain slices of rats and whole-cell patch recording, we tested the hypothesis that cholecystokinin-2 receptors are coupled to cAMP and protein kinase A signaling pathway. Cholecystokinin-8S induced inward currents and depressed evoked EPSCs. Forskolin, an activator of adenylyl cyclase and rolipram that is an inhibitor of phosphodiesterase type IV, independently increased EPSC amplitude and blocked the inward current and synaptic depression induced by cholecystokinin-8S. Furthermore, the membrane-permeable cAMP analog, 8-bromo-cAMP, blocked the cholecystokinin-8S effects. H89, a protein kinase A inhibitor, also blocked cholecystokinin-8S effects. However, depression of the evoked EPSC by baclofen, a GABABreceptor agonist, was not blocked by H89 or forskolin. These findings indicate that cholecystokinin-2, but not GABAB, receptors are coupled to the adenylyl cyclase – cAMP – protein kinase A signaling pathway in the NAc to induce inward currents and cause synaptic depression.
Is methylglyoxal a causative factor for hypertension development?This paper is one of a selection of papers published in this Special Issue, entitled Young Investigator's Forum.
Authors: Wu Lingyun
Published: April 2006

Hypertension is a life-threatening disease that is associated with increased cardiovascular risks. Causes and mechanisms for hypertension development remain poorly understood. Methylglyoxal (MG), a highly reactive molecule, is a metabolite of sugar. Increased circulation and tissue levels of MG have been documented not only in diabetes but also in hypertension. Many recent studies also link MG-induced vascular damage to the pathogenic process of hypertension. As such, an etiological role of MG in hypertension development is proposed.
The ubiquitin–proteasome pathway in viral infectionsThis paper is one of a selection of papers published in this Special Issue, entitled Young Investigator's Forum.
Authors: Gao Guang , Luo Honglin
Published: April 2006

The cellular biological function of the ubiquitin–proteasome pathway as a major intracellular protein degradation pathway, and as an important modulator for the regulation of many fundamental cellular processes has been greatly appreciated over the last decade. The critical role of the ubiquitin–proteasome pathway in viral pathogenesis has become increasingly apparent. Many viruses have been reported to evolve different strategies to utilize the ubiquitin–proteasome pathway for their own benefits. Here, we review the general background and function of the ubiquitin–proteasome pathway, summarize our current understanding of how viruses use this pathway to target cellular proteins, and finally, discuss the roles of this pathway in enteroviral infection, and the potential therapeutic application of proteasome inhibition in myocarditis.