bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning transmission X‐ray microscopy study of microbial calcification
Authors: BENZERARA K. , YOON T. H. , TYLISZCZAK T. , CONSTANTZ B. , SPORMANN A. M. , BROWN G. E.
Published: February 2005

Calcium phosphates and calcium carbonates are among the most prevalent minerals involved in microbial fossilization. Characterization of both the organic and mineral components in biomineralized samples is, however, usually difficult at the appropriate spatial resolution (i.e. at the submicrometer scale). Scanning transmission X‐ray microscopy (STXM) was used to measure C K‐edge, P L‐edge, and Ca L‐edge near‐edge X‐ray absorption fine structure (NEXAFS) spectra of some calcium‐containing minerals common in biomineralization processes and to study the experimental biomineralization by the model microorganism, Caulobacter crescentus. We show that the Ca L2,3‐edges for hydroxyapatite, calcite, vaterite, and aragonite are unique and can be used as probes to detect these different mineral phases. Using these results, we showed that C. crescentus cells, when cultured in the presence of high calcium concentration, precipitated carbonate hydroxyapatite. In parallel, we detected proteins, polysaccharides, and nucleic acids in the mineralizing bacteria at the single‐cell scale. Finally, we discussed the utility of STXM for the study of natural fossilized microbial systems.
THE EARLIEST USE OF CORUNDUM AND DIAMOND, IN PREHISTORIC CHINA*
Authors: LU P. J. , YAO N. , SO J. F. , HARLOW G. E. , LU J. F. , WANG G. F. , CHAIKIN P. M.
Published: February 2005

The majority of prehistoric lithic artefacts were fashioned from rocks and minerals no harder than quartz, and there is no prehistoric evidence for the working of harder materials, such as corundum and diamond. The earliest physical evidence for the use of corundum (ruby, sapphire) is thought to be the abrasive grit recovered from Bronze Age Minoan quartz beads (c. 1700–1500 bc), while diamond is thought to have been used no earlier than 500 bc, in India. Here we show that corundum was worked c. 4000–3500 bc during the Neolithic period in China, in the form of polished axes from the Liangzhu and Sanxingcun cultures. We also present physical evidence that later Liangzhu axes (c. 2500 bc), made from the same previously undescribed rock whose most abundant component is corundum, were polished to a mirror‐like finish with a diamond abrasive. Our findings, which are the first to support the use of corundum and diamond in a prehistoric context, may also help to explain the trademark feature of the Neolithic in China, vast quantities of finely polished nephrite jade artefacts.
FIXED‐FREQUENCY RADIO‐WAVE IMAGING OF SUBSURFACE ARCHAEOLOGICAL FEATURES: A MINIMALLY INVASIVE TECHNIQUE FOR STUDYING ARCHAEOLOGICAL SITES*
Authors: SOMERS L. , LINFORD N. , PENN W. , DAVID A. , URRY L. , WALKER R.
Published: February 2005

In memoriam Tony Clark

Sadly, this research marked the last field visit to the test site that the authors were able to share with their colleague Tony Clark. His enthusiasm, experience and encouragement inspired us to complete this project that, to many, must have appeared as grown men at play in a sand pit.

A new approach to subsurface exploration has been developed, based on fixed‐frequency radio‐wave illumination from a buried transmitter. Data are collected from a buried, continuous wave source with a phase‐coherent surface‐scanning receiver and recorded in a digital archive from which images of the archaeological features are subsequently produced. An important feature of this approach is the opportunity to separate the data collection and archive functions, which form an uncompromised record of the site, from the more subjective image formation function. This paper reports the results of a feasibility assessment programme and discusses the future application of the method to real archaeological sites.
The Contribution of Foot Problems to Mobility Impairment and Falls in Community‐Dwelling Older People
Authors: Menz Hylton B. , Lord Stephen R.
Published: February 2005

OBJECTIVES: To investigate the relationship between foot problems, balance, and functional ability in community‐dwelling older people and to determine whether older people with a history of multiple falls exhibit greater foot impairment than those who have not fallen or who have fallen once only.

DESIGN: A cross‐sectional, retrospective study.

SETTING: Falls and Balance Laboratory, Royal North Shore Hospital, Sydney, Australia.

PARTICIPANTS: One hundred thirty‐five community‐dwelling men and women age 75 to 93 (mean age ± standard deviation, 79.8 ± 4.1).

MEASURES: Foot problem score; postural sway; coordinated stability; stair ascent and descent; an alternate stepping test; timed 6‐meter walk; and tests of vision, sensation, strength, and reaction time.

RESULTS: Eighty‐seven percent of the sample had at least one foot problem. Women had a significantly higher foot problem score than did men. The foot problem score was significantly associated with performance on the coordinated stability test, stair ascent and descent, alternate stepping test, and timed 6‐meter walk. Multiple regression analyses revealed that the foot problem score was a significant independent predictor of performance in the coordinated stability test, stair ascent and descent, and the alternate stepping test. Subjects with a history of multiple falls had a significantly higher foot problem score than did those who had not fallen or who had fallen once only, but the prevalence of individual foot conditions or the presence of foot pain did not differ between these groups.

CONCLUSIONS: Foot problems are common in older people and are associated with impaired balance and performance in functional tests. Furthermore, older people with a history of multiple falls have greater foot impairment than non‐ or once‐only fallers. These findings provide further evidence that foot problems are a falls risk factor and suggest that the cumulative effect of multiple foot problems is more important in increasing falls risk than the presence or absence of individual foot conditions.
Effect of Radiofrequency Catheter Ablation on Plasma B‐type Natriuretic Peptide
Authors: CHEN LIPING , WEI TIEMIN , ZENG CHUNLAI , CHEN QUNYING , SHI ZHENHUA , WANG LEXIN
Published: February 2005

The study was designed to investigate the impact of radiofrequency catheter ablation on the plasma level of B‐type natriuretic peptide (BNP). In 36 patients who underwent catheter ablation of paroxysmal supraventricular tachycardia, the plasma level of BNP was analyzed before and after the ablation procedures. The plasma BNP at baseline, 30 minutes after the ablation, 3 and 24 hours after the ablation was 12.78 ± 2.47, 18.45 ± 4.02 (P = 0.446), 43.54 ± 8.12 (P = 0.0001), and 17.88 ± 4.71 (P = 0.493) pg/mL, respectively. Plasma troponin I was also increased 3 and 24 hours after the ablation (n = 10, P < 0.05). Multivariate regression analysis showed a significant correlation between the levels of BNP 3 hours after ablation and the preablation BNP and the total radiofrequency energy used for the ablation. We conclude that radiofrequency catheter ablation of supraventricular tachycardia increases the plasma level of BNP. The clinical significance of the ablation‐induced increase in BNP needs to be further investigated.
Fair Process: Striving for Justice in Family Business
Authors: Van der Heyden Ludo , Blondel Christine , Carlock Randel S.
Published: February 2005

The social science and business literatures on procedural justice or fair process attest that improvements in procedural fairness can be expected to improve both a firm's performance and the commitment and trust of the individuals involved with it. This article examines the relevance of procedural justice for family business. When a family is an influential component of a particular business system, the application of justice is typically rendered more complex than might be the case for nonfamily firms. Different criteria (need, merit, and equality) guide the application of distributive justice among families, firms, and shareholders. This divergence in criterion also lies at the heart of many conflicts inside the family business. In this article, we argue that the application of procedural justice reduces occurrences of conflict and, in some cases, may eliminate conflict altogether. We propose a definition of fair process that extends and enriches the one existing in the literature. We offer five fundamental criteria essential to the effectiveness of fair process in family firms. We conclude with a series of case studies that illustrate typical questions faced inside family businesses. We show that a lack of fairness in the decision and managerial processes governing these businesses and their associated families is a source of conflict. We describe how increasing fair process practices improves the performance of these businesses while also increasing the satisfaction of those associated with them.
The Use of the Guttman Scale in Development of a Family Orientation Index for Small-to-Medium-Sized Firms
Authors: Uhlaner Lorraine M.
Published: February 2005

This research study tests whether family orientation criteria in small-to-medium-sized businesses (SMEs) can be ordered in difficulty from broad to narrow, using an existing statistical technique referred to as the Guttman scaleogram or scale. The results of the study lend support to the notion of imbeddedness of criteria, at least among SMEs, that is, some criteria are easier to meet than others, and also that the sets of firms meeting the more difficult criteria are subsets of the firms meeting easier criteria. Furthermore, in the sample under study (885 Dutch SMEs), the family orientation index produced via Guttman scaling techniques predicts self-perceptions as a family business almost as well as a statistical approach treating criteria as separate variables in a multiple regression.
Flexibility in Norwegian Family-Owned Enterprises
Authors: Gulbrandsen Trygve
Published: February 2005

This article discusses whether family ownership affects a firm's adoption of flexible manpower and organization practices. The results presented in the article show that the important divide is not between family-owned and nonfamily businesses: family businesses with a professional top manager differ from nonfamily firms only as regards one of seven flexibility measures. More important is whether the owners choose to be in charge of the day-to-day running of the firm themselves (owner-management) or leave it to a professional manager. In owner-managed family businesses, five out of seven practices for increased flexibility prevail less frequently than in both family businesses with a professional manager and nonfamily firms. Owner-managers are, then, more skeptical of adopting new management principles and personnel policies than are professional managers.
Which in vitro Screens Guide the Prediction of Oral Absorption and Volume of Distribution?
Authors: Van De Waterbeemd Han
Published: February 2005

Abstract: The development of medium to high‐throughput in vitro screening of ADME (Absorption, Distribution, Metabolism, Excretion) properties has been the reply to higher demands on drug metabolism scientists to cope with progress in chemistry and biology. Two areas will be discussed here, namely screens for oral absorption and for volume of distribution. The prediction of these human pharmacokinetic parameters can be based on proper combination of simple physicochemical measurements. In the future in vitro screens most likely will be combined with in silico assessments of various ADME properties leading to the concept of in combo screening in drug discovery.
On the Prediction of the Human Response: A Recycled Mechanistic Pharmacokinetic/Pharmacodynamic Approach
Authors: Meno‐Tetang Guy M. L. , Lowe Philip J.
Published: February 2005

Abstract: Although it is routine to predict the blood or plasma pharmacokinetics of compounds for man based upon preclinical studies, the real value of such predictions only comes when linked to drug effects. In the first example, the immunomodulator, FTY720, the first sphingosine‐1‐phosphate receptor agonist, stimulates the sequestration of lymphocytes into lymph nodes thus removing cells from blood circulation. A prior physiology‐based pharmacokinetic model fitted the concentration‐time course of FTY720 in rats. This was connected to an indirect response model of the lymphocyte system to characterise the cell trafficking effects. The IC50 of FTY720 was different in the rat compared with the monkey; man was assumed to be similar to the monkey. The systemic lymphocyte half‐lives were also different between species. To make predictions of the pharmacodynamic behaviour for man, two elements are required, i) systemic exposure, in this case from an upscaled physiology based model, and ii) an estimate of lymphocyte turnover in man, gained from the literature from other drug treatments. Predictions compared well with clinical results. The second example is the monoclonal antibody Xolair, designed to bind immunoglobulin E for atopic diseases. A mechanism based two‐site binding model described the kinetics of both Xolair and endogenous IgE. This model has been reused for other monoclonal antibodies designed to bind fluid‐phase ligands. Sensitivity analysis shows that if differences across species in the kinetics of the endogenous system are not accounted for, then pharmacokinetic/pharmacodynamic models may give misleading predictions of the time course and extent of the response.
Modeling and Monte Carlo Simulations in Oral Drug Absorption
Authors: Dokoumetzidis Aristides , Kosmidis Kosmas , Argyrakis Panos , Macheras Panos
Published: February 2005

Abstract: Drug dissolution, release and uptake are the principal components of oral drug absorption. All these processes take place in the complex milieu of the gastrointestinal tract and they are influenced by physiological (e.g. intestinal pH, transit time) and physicochemical factors (e.g. dose, particle size, solubility, permeability). Due to the enormous complexity issues involved, the models developed for drug dissolution and release attempt to capture their heterogeneous features. Hence, Monte Carlo simulations and population methods have been utilized since both dissolution and release processes are considered as time evolution of a population of drug molecules moving irreversibly from the solid state to the solution. Additionally, mathematical models have been proposed to determine the effect of the physicochemical properties, solubility/dose ratio and permeability on the extent of absorption for regulatory purposes, e.g. biopharmaceutics classification. The regulatory oriented approaches are based on the tube model of the intestinal lumen and apart from the drug's physicochemical properties, take into account the formulation parameters the dose and the particle size.
Signal transduction pathway for the substance P‐induced inhibition of rat Kir3 (GIRK) channel
Authors: Koike‐Tani Maki , Collins John M. , Kawano Takeharu , Zhao Peng , Zhao Qi , Kozasa Tohru , Nakajima Shigehiro , Nakajima Yasuko
Published: February 2005

Certain transmitters inhibit Kir3 (GIRK) channels, resulting in neuronal excitation. We analysed signalling mechanisms for substance P (SP)‐induced Kir3 inhibition in relation to the role of phosphatidylinositol 4,5‐bisphosphate (PIP2). SP rapidly – with a half‐time of ∼10 s with intracellular GTPγS and ∼14 s with intracellular GTP – inhibits a robustly activated Kir3.1/Kir3.2 current. A mutant Kir3 channel, Kir3.1(M223L)/Kir3.2(I234L), which has a stronger binding to PIP2 than does the wild type Kir3.1/Kir3.2, is inhibited by SP as rapidly as the wild type Kir3.1/Kir3.2. This result contradicts the idea that Kir3 inhibition originates from the depletion of PIP2. A Kir2.1 (IRK1) mutant, Kir2.1(R218Q), despite having a weaker binding to PIP2 than wild type Kir3.1/Kir3.2, shows a SP‐induced inhibition slower than the wild type Kir3.1/Kir3.2 channel, again conflicting with the PIP2 theory of channel inhibition. Co‐immunoprecipitation reveals that Gαq binds with Kir3.2, but not with Kir2.2 or Kir2.1. These functional results and co‐immunoprecipitation data suggest that Gq activation rapidly inhibits Kir3 (but not Kir2), possibly by direct binding of Gαq to the channel.
Electrical coupling and release of K+ from endothelial cells co‐mediate ACh‐induced smooth muscle hyperpolarization in guinea‐pig inner ear artery
Authors: Jiang Zhi‐Gen , Nuttall Alfred L. , Zhao Hui , Dai Chun‐Fu , Guan Bing‐Cai , Si Jun‐Qiang , Yang Yu‐Qin
Published: February 2005

The physiological basis of ACh‐elicited hyperpolarization in guinea‐pig in vitro cochlear spiral modiolar artery (SMA) was investigated by intracellular recording combined with dye labelling of recorded cells and immunocytochemistry. We found the following. (1) The ACh‐hyperpolarization was prominent only in cells that had a low resting potential (less negative than −60 mV). ACh‐hyperpolarization was reversibly blocked by 4‐DAMP, charybdotoxin or BAPTA‐AM, but not by Nω‐nitro‐l‐arginine methyl ester, glipizide, indomethacin or 17‐octadecynoic acid. (2) Ba2+ (100 μm) and ouabain (1 μm) each attenuated ACh‐hyperpolarization by ∼30% in smooth muscle cells (SMCs) but had only slight or no inhibition in endothelial cells (ECs). A combination of Ba2+ and 18β‐glycyrrhetinic acid near completely blocked the ACh‐hyperpolarization in SMCs. (3) High K+ (10 mm) induced a smaller hyperpolarization in ECs than in SMCs, with an amplitude ratio of 0.49 : 1. Ba2+ blocked the K+‐induced hyperpolarization by ∼85% in both cell types, whereas ouabain inhibited K+‐hyperpolarization differently in SMCs (19%) and ECs (35%) and increased input resistance. 18β‐Glycyrrhetinic acid blocked the high K+‐hyperpolarization in ECs only. (4) Weak myoendothelial dye coupling was detected by confocal microscopy in cells recorded with a propidium iodide‐containing electrode for longer than 30 min. A sparse plexus of choline acetyltransferase‐immunoreactive (ChAT) fibres was observed around the SMA and its up‐stream arteries. (5) Evoked excitatory junction potentials (EJP) were partially blocked by 4‐DAMP in half of the cells tested. We conclude that ACh‐induced hyperpolarization originates from ECs via activation of Ca2+‐activated potassium channels, and is independent of the release of NO, cyclo‐oxygenase or cytochrome P450 products. ACh‐induced hyperpolarization in smooth muscle cells involves two mechanisms: (a) electrical spread of the hyperpolarization from the endothelium, and (b) activation of inward rectifier K+ channels (Kir) and Na+–K+ pump current by elevated interstitial K+ released from the endothelial cells, these being responsible for about 60% and 40% of the hyperpolarization, respectively. The role ratio of Kir and pump current activation is at 8 : 1 or less.
Functional properties of dopaminergic neurones in the mouse olfactory bulb
Authors: Pignatelli Angela , Kobayashi Kazuto , Okano Hideyuki , Belluzzi Ottorino
Published: February 2005

The olfactory bulb of mammals contains a large population of dopaminergic interneurones within the glomerular layer. Dopamine has been shown both in vivo and in vitro to modulate several aspects of olfactory information processing, but the functional properties of dopaminergic neurones have never been described due to the inability to recognize these cells in living preparations. To overcome this difficulty, we used a transgenic mouse strain harbouring an eGFP (enhanced green fluorescent protein) reporter construct under the promoter of tyrosine hydroxylase, the rate‐limiting enzyme for cathecolamine synthesis. As a result, we were able to identify dopaminergic neurones (TH‐GFP cells) in living preparations and, for the first time, we could study the functional properties of such neurones in the olfactory bulb, in both slices and dissociated cells. The most prominent feature of these cells was the autorhythmicity. In these cells we identified five main voltage‐dependent conductances: the two having largest amplitude were a fast transient Na+ current and a delayed rectifier K+ current. In addition, we observed three smaller inward currents, sustained by Na+ ions (persistent type) and by Ca2+ ions (LVA and HVA). Using pharmacological tools and ion substitution methods we showed that the pacemaking process is supported by the interplay of the persistent Na+ current and of a T‐type Ca2+ current. We carried out a complete kinetical analysis of the five conductances present in these cells, and developed a Hodgkin‐Huxley model of TH‐GFP cells, capable of reproducing accurately the properties of living cells, including autorhytmicity, and allowing a precise understanding of the process.
Loss of Imprinting of
Igf2
Alters Intestinal Maturation and Tumorigenesis in Mice
Authors: Sakatani Takashi , Kaneda Atsushi , Iacobuzio-Donahue Christine A. , Carter Mark G. , de Boom Witzel Sten , Okano Hideyuki , Ko Minoru S. H. , Ohlsson Rolf , Longo Dan L. , Feinberg Andrew P.
Published: February 2005

Loss of imprinting (LOI) of the insulin-like growth factor II gene (
IGF2
) is an epigenetic alteration that results in a modest increase in IGF2 expression, and it is present in the normal colonic mucosa of about 30% of patients with colorectal cancer. To investigate its role in intestinal tumorigenesis, we created a mouse model of
Igf2
LOI by crossing female H19
+/–
mice with male Apc
+/Min
mice. Mice with LOI developed twice as many intestinal tumors as did control littermates. Notably, these mice also showed a shift toward a less differentiated normal intestinal epithelium, reflected by an increase in crypt length and increased staining with progenitor cell markers. A similar shift in differentiation was seen in the normal colonic mucosa of humans with LOI. Thus, altered maturation of nonneoplastic tissue may be one mechanism by which epigenetic changes affect cancer risk.
Retinoic Acid Controls the Bilateral Symmetry of Somite Formation in the Mouse Embryo
Authors: Vermot Julien , Llamas Jabier Gallego , Fraulob Valérie , Niederreither Karen , Chambon Pierre , Dollé Pascal
Published: February 2005

A striking characteristic of vertebrate embryos is their bilaterally symmetric body plan, which is particularly obvious at the level of the somites and their derivatives such as the vertebral column. Segmentation of the presomitic mesoderm must therefore be tightly coordinated along the left and right embryonic sides. We show that mutant mice defective for retinoic acid synthesis exhibit delayed somite formation on the right side. Asymmetric somite formation correlates with a left-right desynchronization of the segmentation clock oscillations. These data implicate retinoic acid as an endogenous signal that maintains the bilateral synchrony of mesoderm segmentation, and therefore controls bilateral symmetry, in vertebrate embryos.
Pathobiology of brain metastases: Table 1
Authors: Nathoo N , Chahlavi A , Barnett G H , Toms S A
Published: February 2005

Brain metastasis is a major cause of systemic cancer morbidity and mortality. Many factors participate in the development and maintenance of brain metastases. The survival of the metastasis depends upon crucial interactions between tumour cells and the brain microenvironment during its development at the new site. This review focuses on the pathobiological mechanisms involved in the establishment and regulation of brain metastases. Developments in molecular biology have vastly expanded our knowledge about the mechanisms of invasion, proliferation, metastatic cell signalling, and angiogenesis in brain metastases. Advances in this understanding of the pathobiology of brain metastasis may lead to novel targeted treatment paradigms and a better prognosis for patients with brain metastatic disease.
Impact of glandular hair exudates on infection of chickpea by Ascochyta rabiei
Authors: Armstrong-Cho C , Gossen B D
Published: February 2005

Ascochyta blight, a fungal disease caused by Ascochyta rabiei (Pass.) Labr. (teleomorph Didymella rabiei (Kovačevski) v. Arx), is a major constraint to chickpea (Cicer arietinum L.) production. An unusual feature of chickpea plants is the secretion of a highly acidic fluid from glandular trichomes. This exudate was shown to promote germination of conidia of A. rabiei at low concentrations (0.012 and 0.06 mg·mL1) but to inhibit germination at higher concentrations (0.3 and 1.5 mg·mL1). The removal of exudates from plants prior to inoculation with A. rabiei increased infection and, subsequently, disease development in susceptible cultivars. On partially resistant cultivars, however, the effect of removing exudates on infection was not apparent until early podding, when genetic resistance declines. Simulated rain applied prior to inoculation increased disease severity as the volume of simulated rain increased from 1 to 4 mm. Since rainfall is required for dispersal of conidia, host exudates are likely to have little impact on secondary disease spread under field conditions. Exudates may, however, contribute to variability in disease studies conducted on older chickpea plants, especially in controlled environments.Key words: ascochyta blight, epidemiology, screening, Didymella rabiei, Cicer arietinum.
Species of Rhytismataceae on needles ofJuniperusspp. from China
Authors: Hou Cheng-Lin , Lin Ying-Ren , Piepenbring Meike
Published: February 2005

Five species in three different genera of Rhytismataceae are described from needles of junipers from China. Hypoderma junipericola C.-L. Hou, Y.-R. Lin, & M. Piepenbr., Lophodermium jianchuanense C.L. Hou & M. Piepenbr., and Soleella junipericola C.L. Hou & M. Piepenbr. are species new to science, while Lophodermium juniperinum (Fr.: Fr.) de Not. and Lophodermium harbinense Y.-R. Lin are species already known for China. This paper provides descriptions and illustrations for these species as well as a key for the eight species of Rhytismataceae now known on junipers worldwide.Key words: Ascomycota, plant pathogens, needle cast, Rhytismatales.
Seed characteristics of the invasive alien vineVincetoxicum rossicumare affected by site, harvest date, and storage duration
Authors: DiTommaso Antonio , Brainard Daniel C , Webster Bradley R
Published: February 2005

The alien vine Vincetoxicum rossicum (Kleopow) Barbar. (Asclepiadaceae) is a major concern in natural areas of the Lower Great Lakes Basin. Reproduction in this perennial occurs largely by polyembryonic seeds that mature from August to November. Many seeds produced in autumn germinate the following spring, but the germinability of seeds produced in late summer is unknown. The influence of parent plant light environment on seed characteristics in this species is also poorly understood. We examined the characteristics of V. rossicum seeds harvested in late August and early November 2002 from three habitats in central New York State, USA, differing in light availability. Site had a significant effect on seed weight and germination percentage, but not on the number of embryos germinating per seed or radicle length. Seeds produced in the shaded habitat in August weighed significantly more and had lower germin ability than seeds produced in an adjacent open habitat, but this was not observed in a second open habitat. The probability of germination decreased with seed size for seeds ranging from 2 to 8 mg. For the open sites, fresh seeds produced in August had approximately double the germination percentages of those produced in November. However, for all sites, germination following 18 weeks of cold storage was greatest for seeds harvested in November. The probability of multiple embryos germinating was influenced by seed weight. The nature of this relationship varied by site, but not by harvest date or storage duration. Larger seed size resulted in longer total radicle length after 7 d, regardless of site.Key words: Cynanchum rossicum, maternal environment, pale swallowwort, polyembryony, resource allocation, seed dormancy.
Anisophylly inAucuba japonica(Cornaceae): An outcome of spatial crowding in the bud
Authors: Ali Md. Sohrab , Kikuzawa Kihachiro
Published: February 2005

Anisophylly in Aucuba japonica Thunb. occurs exclusively in axillary buds on shoots of individuals that have reached reproductive maturity; juvenile plants or sprouts and shoots from terminal vegetative buds on adult plants are isophyllous. The initially smaller leaf primordium in each anisophyllous leaf pair gives rise to the larger final leaf size. Immediately before bud break, the size of the initially smaller primordium is already almost twice as large as the initially larger primordium, and the size differential is further amplified following bud break. The degree of aniso phylly, however, varies among the nodes of a shoot, depending on leaf pair orientation (tangential or parallel to the inflorescence axis) and nodal position. Paired leaves approach isophylly when they originate tangential to an inflorescence but become anisophyllous when originating parallel to an inflorescence. The degree of anisophylly depends on crown light conditions through effects on terminal bud size and foliage distribution on the shoot, but ultimately appears to arise from space limitations and crowding between the leaf primordia and the developing inflorescence in terminal reproductive buds.Key words: Aucuba, anisophylly, bud internal morphology, developmental anatomy, developmental constraints.
Contrasting response of mountain birch to damage by Eriocrania leafminers in polluted and unpolluted habitats
Authors: Kozlov Mikhail V
Published: February 2005

The leafmining larvae of Eriocrania spp. (Lepidoptera, Eriocraniidae) develop in the expanding leaves of mountain birch, Betula pubescens subsp. czerepanovii (Orlova) Hämet-Ahti. The larva usually consumes over a half of the leaf, implying moderate foliar damage to an individual shoot. I demonstrated that in unpolluted forests, effects of damage are restricted to the mined leaf, which grows smaller and demonstrates higher fluctuating asymmetry than intact leaves. In contrast, in heavily polluted industrial barrens, mining of the single leaf adversely affects the entire shoot; timing and expression of responses depend on shoot type. In infested short shoots, intact leaves grow smaller and more asymmetrical than leaves in control shoots, whereas infested long shoots demonstrated no current-year response; this difference suggests that long shoots are more competitive than short shoots and can acquire additional resources to compensate for herbivore damage. In contrast, in the next year after damage, no consequences of mining were detected in short shoots, whereas infested long shoots produced lower numbers of axillary long shoots than controls. The detected interactive effects of pollution and leaf damage most probably result from resource limitation in birches growing on low-nutritive toxic soils.Key words: Betula pubescens subsp. czerepanovii, foliar damage, fluctuating asymmetry, Kola peninsula, leaf size, shoot growth.
Forensic palynology and ethnobotany of Salicornia species (Chenopodiaceae) in northwest Canada and Alaska
Authors: Mudie Petra J , Greer Sheila , Brakel Judith , Dickson James H , Schinkel Clara , Peterson-Welsh Ruth , Stevens Margaret , Turner Nancy J , Shadow Mary , Washington Rosalie
Published: February 2005

Pollen grains from bodies of ancient people provide clues to their diet and domicile. To learn more about Kwädāy Dän Ts'ìnchí (Long Ago Person Found), who died on a British Columbia glacier 550 years ago, we studied the Chenopodiaceae pollen found in his stomach and robe. Environmental scanning electron microscopy was used to distinguish pollen of the native chenopod genera Atriplex, Chenopodium, Eurotia, Suaeda, and Salicornia (here including Sarcocornia). All chenopod pollen grains in one stomach sample were from Salicornia (Tourn.) L. (glasswort), which grows only in saline soils and has been used for food and medicine. Elders from the Champagne and Aishihik, Tagish, Gwitch'in, and Tlingit First Nations report their ethnobotanical and historical knowledge about inland and coastal Salicornia species. There is no common use for the small inland annual glasswort, Salicornia rubra A. Nelson, although other species were used for grain further south; however, Pacific Northwest coastal people have eaten the succulent perennial glasswort, Salicornia perennis Miller, since at least the 1880s. Pollen grains of this perennial salt marsh species are most similar to the chenopod pollen grains in the stomach of Kwädāy Dän Ts'ìnchí and suggest the ancient man's last meal came from the coast rather than from inland.Key words: Chenopodiaceae, Salicornia, Sarcocornia, forensic palynology, frozen body, ethnobotany.
Zonation of vegetation along a burial gradient on the leeward slopes of Lake Huron sand dunes
Authors: Dech Jeffery P , Maun M Anwar
Published: February 2005

The zonation of coastal dune plant communities from the beach to their inland margin is recognized worldwide; however, the cause of this pattern remains controversial because of the covariance of several environmental factors, such as sand burial, salt spray, and microclimate, along a gradient perpendicular to the shoreline. To minimize the confounding influence of this complex shoreinland gradient and determine the direct effects of burial on plant community composition, we examined stands along a burial gradient that extended parallel to the Lake Huron coastline, produced by variable blowout activity amongst a series of parabolic dunes comprising the second ridge inland from the coast. We used the point-quarter method and 1 m × 1 m plots to quantify overstorey and understorey plant communities in each parabolic dune stand and determined species importance, here defined as the sum of density, frequency, and dominance for the overstorey and the sum of frequency and dominance only for the understorey. Correspondence analyses of the species importance  dune stand matrices elucidated a pattern of plant community composition on the primary ordination axis that was strongly related to an index of burial activity (r2 = 0.40 and 0.87 for the overstorey and understorey, respectively). Burial was associated with changes in species richness and diversity, shifts in dominant species, and species replacement based on burial tolerance across the gradient. These data support the hypothesis that burial in sand dunes is a major causative factor of zonation, which can extend beyond the foredunes and include communities of woody species.Key words: coastal dunes, vegetation, zonation, woody plants, burial.
Microfungal endophytes in roots
Authors: Addy H D , Piercey M M , Currah R S
Published: February 2005

A wide range of ascomycetous microfungi inhabits roots without forming the anatomical features typical of mycorrhizas or causing overt signs of pathogenesis. The most-studied taxa have darkly pigmented hyphal walls and are referred to as "dark septate endophytes" (DSE). We provide a dichotomous key and annotated descriptions for a cross-section of the most common dark septate endophytes. The term DSE is sometimes used to imply taxonomic and physiological similarity even though a diverse range of root endophytic taxa form pigmented hyphae. Among these, Phialocephala fortinii Wang & Wilcox is a well-known representative; it is widespread, easily observed in roots, and readily grown in culture and with plants. Nevertheless, the basis of its symbiotic relationship with plants remains ambiguous. It may be a weak pathogen, a saprotroph on senescent root tissues, or a mutualist. More detailed studies of interactions between identified taxa of microfungal endophytes and host plants are necessary to elucidate the functional basis of these symbioses; it may be necessary to look beyond the paradigms of traditional mycorrhizal and pathogenic associations to understand the ecological roles of these fungi. Reports of cryptic speciation in Phialocephala fortinii emphasize the need for accurate identification of isolates of microfungal endophytes used in experiments.Key words: dark septate endophytes (DSE), Phialocephala fortinii, mycorrhiza, fungushost interactions, fungi.
Tailoring palaeolimnological diatom-based transfer functions
Authors: Racca Julien MJ , Gregory-Eaves Irene , Pienitz Reinhard , Prairie Yves T
Published: February 2005

This paper presents a method designed to build species-tailored diatomenvironment models. Using a pruning algorithm of artificial neural networks, powerful species-tailored models constrained to water temperature, water depth, and dissolved organic carbon were developed from a 109-lake training set from northwestern Canada and Alaska. The reasoning behind the approach is that the implementation of a single, gradient-based, organismenvironment relationship should only use species that are comprehensively influenced by the variable of interest. By pruning species according to their relevance to each of the three studied variables, the cross-validated performances of all three models were significantly increased, suggesting that nonrelevant species have corrupting influences and need to be removed. The removal of corrupting species also suggests that palaeolimnological transfer functions based on an appropriate subset of useful species are more independent.
Spatial hierarchical Bayesian models for stock-recruitment analysis of pink salmon (Oncorhynchus gorbuscha)
Authors: Su Zhenming , Peterman Randall M , Haeseker Steven L
Published: February 2005

To improve the understanding of effects of environmental factors on spawner-to-recruit survival rates of pink salmon (Oncorhynchus gorbuscha), we developed several spatial hierarchical Bayesian models (HBMs). We applied these models to 43 pink salmon stocks in the Northeast Pacific. By using a distance-based, spatially correlated prior distribution for stock-specific parameters, these multistock models explicitly allowed for positive correlation among nearby salmon stocks in their productivities and coefficients of early summer coastal sea surface temperature (SST). To our knowledge, this is the first time that such distance-based, spatial prior probability distributions for parameters have been applied to fisheries problems. We found that the spatial HBMs produce more consistent and precise estimates of effects of SST on productivity than a single-stock approach that estimated parameters for each stock separately. Similar to earlier results using mixed-effects models for the same stocks, we found significant positive effects of SST on survival rates of northern pink salmon stocks, but weaker negative effects of SST on survival rates of southern pink salmon stocks. However, we show a smoother transition in magnitude of effects between these regions.
Bias in estimating food consumption of fish by stomach-content analysis
Authors: Rindorf A , Lewy P
Published: February 2005

This study presents an analysis of the bias introduced by using simplified methods to calculate food intake of fish from stomach contents. Three sources of bias were considered: (1) the effect of estimating consumption based on a limited number of stomach samples, (2) the effect of using average contents derived from pooled stomach samples rather than individual stomachs, and (3) the effect of ignoring biological factors that affect the evacuation of prey. Estimating consumption from only two stomach samples yielded results close to the actual intake rate in a simulation study. In contrast to this, a serious positive bias was introduced by estimating food intake from the contents of pooled stomach samples. An expression is given that can be used to correct analytically for this bias. A new method, which takes into account the distribution and evacuation of individual prey types as well as the effect of other food in the stomach on evacuation, is suggested for estimating the intake of separate prey types. Simplifying the estimation by ignoring these factors biased estimates of consumption of individual prey types by up to 150% in a data example.
Spatial distribution of juvenile Atlantic salmon (Salmo salar) in a subarctic river: size-specific changes in a strongly seasonal environment
Authors: Mäki-Petäys Aki , Erkinaro Jaakko , Niemelä Eero , Huusko Ari , Muotka Timo
Published: February 2005

We examined seasonal variation in the spatial distribution and habitat preference of juvenile Atlantic salmon (Salmo salar) in a subarctic river characterized by near-zero water temperatures for 78 months a year. Size-specific differences in habitat use were pronounced in summer but disappeared at the onset of winter, when the habitats preferred by small (≤6 cm) and larger (717 cm) salmon overlapped heavily. Small salmon favoured low-velocity habitats during all seasons, and in summer and autumn they mainly occupied shallow microhabitats along stream margins. In winter and spring, small salmon preferred deeper habitats farther away from the shoreline. Larger salmon favoured deeper habitats in all seasons, but they only occupied slowly flowing areas at low water temperatures. Since all salmon size classes were closely associated with deep and low-velocity habitats in winter and spring, this time of year may represent a size-selective bottleneck for Atlantic salmon populations. Therefore, management schemes aiming to enhance salmonid habitats in boreal streams must rest on the knowledge of season- and size-specific habitat requirements of salmonid species.
The status of Atlantic salmon (Salmo salar): populations and habitats
Authors: Boisclair Daniel
Published: February 2005

The important decline of Atlantic salmon (Salmo salar) across its range during the past three decades, despite numerous management and conservation programmes, is an alarming index of the vulnerability of this species. The following series of papers was produced to summarize current knowledge on specific interactions between biotic and abiotic variables that may contribute to determine the survival of Atlantic salmon. Evaluation of the challenges encountered in spawning grounds (siltation, oxygenation), nursery habitats (substrate, trophic interactions), overwintering habitats (flow conditions, winter feeding opportunities), and coastal and oceanic environments (water temperature, predators, parasites) suggest that all habitats required by Atlantic salmon and all processes that occur in each habitat represent a critical link that allows this species to persist. Management practices employed during artificial fish selection, incubation, and stocking also affect the success of restoration efforts. Because limiting factors may change in time and because our ability to intervene in specific habitats may be minimal, the only strategy within our reach may be to continue gathering information about processes that determine the fragility of Atlantic salmon and, in the light of our findings, to implement scientifically sound actions where and when possible.
Nitric oxide modulates vascular inflammation and intimal hyperplasia in insulin resistance and the metabolic syndrome
Authors: Barbato Joel E. , Zuckerbraun Brian S. , Overhaus Marcus , Raman Kathleen G. , Tzeng Edith
Published: February 2005

Type 2 diabetes mellitus (DM) and the metabolic syndrome, both characterized by insulin resistance, are associated with an accelerated form of atherosclerotic vascular disease and poor outcomes following vascular interventions. These vascular effects are thought to stem from a heightened inflammatory environment and reduced bioavailability of nitric oxide (NO). To better understand this process, we characterized the vascular injury response in the obese Zucker rat by examining the expression of adhesion molecules, the recruitment of inflammatory cells, and the development of intimal hyperplasia. We also evaluated the ability of exogenous NO to inhibit the sequela of vascular injury in the metabolic syndrome. Obese and lean Zucker rats underwent carotid artery balloon injury. ICAM-1 and P-selectin expression were increased following injury in the obese animals compared with the lean rats. The obese rats also responded with increased macrophage infiltration of the vascular wall as well as increased neointima formation compared with their lean counterparts (intima/media = 0.91 vs. 0.52, P = 0.001). After adenovirus-mediated inducible NO synthase (iNOS) gene transfer, ICAM-1, P-selectin, inflammatory cell influx, and oxidized low-density lipoprotein (LDL) receptor expression were all markedly reduced versus injury alone. iNOS gene transfer also significantly inhibited proliferative activity (54% and 73%; P < 0.05) and neointima formation (53% and 67%; P < 0.05) in lean and obese animals, respectively. The vascular injury response in the face of obesity and the metabolic syndrome is associated with increased adhesion molecule expression, inflammatory cell infiltration, oxidized LDL receptor expression, and proliferation. iNOS gene transfer is able to effectively inhibit this heightened injury response and reduce neointima formation in this proinflammatory environment.
Reduced feeding response to muscimol and neuropeptide Y in senescent F344 rats
Authors: Coppola Jessica D. , Horwitz Barbara A. , Hamilton Jock , Blevins James E. , McDonald Roger B.
Published: February 2005

Many mammals experience spontaneous declines in their food intake and body weight near the end of life, a stage we refer to as senescence. We have previously demonstrated that senescent rats have blunted food intake responses to intracerebroventricular injections of neuropeptide Y (NPY). In the present study, we tested the hypothesis that responsiveness to GABA, a putative potentiator of NPY's effect, is also diminished. Young and old male F344 rats received injections of NPY, muscimol, (MUS, a GABA-A receptor agonist), combinations of these two agents, and vehicle [artificial cerebrospinal fluid (aCSF)] into the hypothalamic paraventricular nucleus (PVN). Both young and old presenescent rats increased their food intake in response to NPY, MUS, and the combination of the two (in comparison to injections of aCSF). The combination treatment was generally more effective than either NPY or MUS alone. These data are consistent with suggestions that both NPY and GABA play a role in the regulation of feeding behavior. Senescent rats exhibited an attenuated NPY-induced food intake, no increase in response to MUS, and a response to NPY + MUS that was no larger than that of NPY alone. We conclude that PVN injections of GABA, as well as NPY, are less effective in stimulating feeding in senescent rats and suggest that alterations in their signaling pathways play a role in the involuntary feeding decrease seen near the end of life.
Plasma Levels of Soluble Receptor for Advanced Glycation End Products and Coronary Artery Disease in Nondiabetic Men
Authors: Falcone Colomba , Emanuele Enzo , D’Angelo Angela , Buzzi Maria P. , Belvito Chiara , Cuccia Mariaclara , Geroldi Diego
Published: February 2005

Objective—

The receptor for advanced glycation end products (RAGE) is a cell surface receptor whose signaling pathway has been implicated in atherogenesis. RAGE has an endogenous secretory receptor form, called soluble RAGE (sRAGE), that could exert antiatherogenic effects by acting as a decoy. We sought to determine whether a decreased plasma level of sRAGE could be independently associated with the prevalence of coronary artery disease (CAD) in nondiabetic men.

Methods and Results—

Plasma levels of sRAGE were determined in 328 nondiabetic male patients with angiographically proved CAD and in 328 age-matched healthy controls. The concentration of sRAGE in plasma was significantly lower (
P
<0.0001) in CAD cases [median (interquartile range): 966 (658–1372) pg/mL] than in control subjects [1335 (936–1954) pg/mL]. In logistic regression analysis, the multivariate-adjusted odds ratio for the presence of CAD was 6.719 (95% confidence interval, 3.773 to 11.964;
P
<0.0001) when the lowest quartile of the sRAGE level was compared with the highest quartile.

Conclusions—

Our findings indicate that low levels of sRAGE in plasma are independently associated with the presence of CAD in nondiabetic men and suggest that sRAGE is one of the clinically important molecules associated with atherosclerosis.