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Results 201 - 250 of 606
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Simmons, Rob - - 2009
Charlton, W.A. - - 2009
Aralia elata (Miq.) Seem. has large bipinnate leaves in which the rachis bears pairs of leaflets in the distal region and pairs of rachillae bearing leaflets in the proximal region. A supernumerary leaflet is also inserted on the rachis adjacent to each rachilla. The rachilla and supernumerary leaflet could perhaps ...
Pineiro, Rosalia - - 2009
Low-copy nuclear genes have been suggested as a promising source of independent phylogeographic markers in plants. However, the available studies at the intraspecific level have revealed that extracting information from them is frequently hampered by paralogy and lack of coalescence of alleles. It is thus relevant to test their utility ...
Nowak, Julia - - 2009
Compound palm leaf development is unique and consists of two processes. First, the primordial tissue folds through differential growth, forming plications. Second, these plications separate through an abscission-like process, forming leaflets. The second process of leaflet separation allows for the development of compound leaves. The question that this study addresses ...
Pryor, B.M. - - 2009
Fungal endophytes of Oxytropis kansuensis Bunge from China, previously described as Embellisia oxytropis Q. Wang, Nagao & Kakish, and endophytes of Oxytropis sericea Nutt. and Oxytropis lambertii Pursh from the United States were compared and are reported here as conspecific members of a new genus in the Pleosporaceae, Undifilum, based ...
Lopes, Karina Lucas - - 2009
The occurrence of nonarticulated laticifers has been recorded in the literature for Apocynaceae, but little information is available on their structure and the chemical compounds in their latex. The objective of this study was to describe, anatomically and histochemically, the laticifers and latex found in the roots, stems, and leaves ...
Wloch, Wieslaw - - 2009
Currently it is believed that intrusive growth of fusiform cambial initials adds to the circumference of the cambial cylinder: the initial cells multiplied by anticlinal divisions are produced in excess, and the excess cells are later eliminated from the cambial surface. The present study, dealing with the intrusive growth of ...
Matsumoto, Asako - - 2009
Three white-oak species (Quercus crispula Blume, Quercus dentata Thunb., and Quercus serrata Thunb.) are native, widely distributed, and prominent species in the temperate deciduous forests of Japan. They are closely related to each other and overlapping morphological variation in some traits is observed, although they differ from each other in ...
Sliwinska, Elwira - - 2009
Use of seeds instead of leaves for the flow cytometric measurement of DNA content is of particular interest to botanists and plant ecologists, since it allows estimation of genome sizes for species having reduced leaves or that accumulate staining inhibitors within leaves, and also for species growing in regions where ...
Schreiber, L.A. - - 2009
Previous studies have implicated numerous physical and biotic factors as contributing to the failure of oak to regenerate successfully throughout substantial portions of eastern North America. Recent field evidence in southern Indiana implicated belowground herbivory by pine voles (Microtus pinetorum (LeConte, 1830)) as a potentially important but overlooked mortality agent ...
Martinez, M.L. - - 2009
[F.sub.1] offspring of the African cichlid Pseudocrenilabrus multicolor victoriae Seegers, 1990 from swamp (low oxygen) and lake (high oxygen) origin were raised under normoxia and submitted to hypoxia acclimation (0.8 [+ or -] 0.4 mg * [L.sup.-1]) and normoxia acclimation (7.4 [+ or -] 0.3 mg * [L.sup.-1]) for 4 ...
Dmitriew, C. - - 2009
During both the larval and adult stages, the ladybird beetles Harmonia axyridis (Pallas, 1773) feed primarily on aphids, populations of which may fluctuate dramatically in time and space. Harmonia axyridis were reared under three resource treatments: high, low, and improving. We predicted that beetles experiencing consistently poor larval conditions would ...
Ruckstuhl, K.E. - - 2009
Sexual size dimorphism in ruminants is associated with social and (or) habitat segregation, while monomorphic species often live alone, in monogamous pairs, or in mixed-sex groups. Most research on sexual differences in behaviour has been done on sexually size-dimorphic ruminants, whereas little is known about monomorphic species. We tested the ...
Stevenson, K.T. - - 2009
High-latitude arvicoline rodents usually reproduce in warmer months, but winter breeding has been documented in several species, including the northern red-backed vole (Myodes rutilus (Pallas, 1779) Wilson and Reader, 2005; formerly Clethrionomys rutilus (Pallas, 1779)). We tested whether the reproductive condition of the species is linked to changes in environmental ...
Burles, D.W. - - 2009
Adverse weather conditions frequently have a significant negative influence on survival and reproductive success of insectivorous bats. Low ambient temperatures increase the energetic costs of maintaining euthermia and reduces insect activity, while precipitation likely adds "clutter" making prey more difficult to detect using echolocation. We studied two species of insectivorous ...
Tucker, Strahan - - 2009
Individuals of different age, sex, and morphology are expected to exhibit differences in dietary niches largely owing to sexual dimorphism, ontogenetic niche shifts, and resource polymorphism. Harp (Pagophilus groenlandicus (Erxleben, 1777)) and hooded (Cystophora cristata (Erxleben, 1777)) seals are geographically overlapping and highly migratory predators in the North Atlantic Ocean. ...
Ahlborn, Boye - - 2009
The optimum fineness ratio (X = L/d, where L and d are body length and profile height, respectively) for minimum drag is about 4.5 and many fast swimming fish are characterized by values of this order. However, values for large whales that undergo extensive migrations (e.g., Balaenopteridae, Balaenidae, and Physeteridae) ...
Newbold, T.A. - - 2009
A suite of factors including prey availability and prey defenses influence prey selection by consumers and ultimately define an animal's feeding strategy (e.g., generalist or specialist). Here we examined the relationship between availability and selection of ants by the desert horned lizard (Phrynosoma platyrhinos Girard, 1852) to test the hypothesis ...
Marshal, J.P. - - 2009
We evaluated the relative importance of intrinsic (density-dependent) and extrinsic (density-independent) sources of resource variability in the dynamics of bighorn sheep (Ovis canadensis Shaw, 1804) populations in southwestern USA. We tested the hypothesis that populations experiencing greater variation in forage availability are less likely to be at equilibrium density with ...
Ladero, Victor - - 2009
Lactic acid bacteria (LAB) are recognized as a group of important microorganisms because of their crucial role in food fermentation and their contribution to the maintenance of health homeostasis, as natural inhabitants of the human mucosa. However, the metabolic activities of some strains, such as the ability to synthesize biogenic ...
Yang, Menghua - - 2009
One of the most important signal transduction pathways in bacteria, quorum sensing, is involved in many regulatory circuits in rhizobia, especially in the control of communication between rhizobia and their plant hosts. In this study, we identified 3 autoinducer synthase genes--mrlI1, mrlI2, and mrlI3--in Mesorhizobium loti NZP 2213. We found ...
Freeman, Karen - - 2009
Evidence of biofilms in human chronic wounds are thought to be responsible for preventing healing in a timely manner. However, biofilm evidence in horse wounds has not yet been documented. Consequently, this study aimed to determine whether biofilms could be detected in wounds, and to investigate the microbiology of chronic ...
Tresse, Odile - - 2009
The contribution of growth history and flagella to adhesion of Listeria monocytogenes was analysed. An in-frame deletion on the flagellin encoding gene (f7aA) was performed in L. monocytogenes EGD-e to compare its adhesion ability with the parental strain, after cultivation at various pH values and temperatures. The pH, as well ...
Jagtap, Santosh - - 2009
A multiplex colony PCR assay was developed for the detection of 5 genes encoding Bacillus sphaericus mosquito larvicidal toxins, namely binA, binB, mtx1, mtx2, and mtx3. Primers designed for these 5 genes yielded specific PCR amplicons of the expected size from type cultures of B. sphaericus. This method of detecting ...
Li, Xin - - 2009
Endogenous superoxide anion production was determined by electron spin resonance in wild-type strains and avrXa7 mutants of Xanthomonas oryzae pv. oryzae. The localization of superoxide anion was carried out in the intra- and extra-cellular fractions. Results showed the presence of superoxide anion in multi-locations of X. oryzae pv. oryzae cells. ...
Li, Haiming - - 2009
The catalytic subunit of many Escherichia coli redox enzymes bares a twin-arginine translocation (Tat)-dependent signal peptide in its precursor, which directs the redox enzyme complex to this Sec-independent pathway. NarG of the E. coli nitrate reductase NarGHI complex possesses a vestige twin-arginine motif at its N terminus. During the cofactor ...
Liu, Bo - - 2009
The Ames test has not been very effective in estimating the mutagenicity of histidine-containing samples because external free and (or) protein-bound histidine in these samples would allow the histidine auxotrophs in such test samples to grow more compared with the negative controls that were used as the reference. This could ...
Dynes, James - - 2009
Confocal laser scanning microscopy (CLSM) and scanning transmission X-ray microscopy (STXM) were used to examine the morphological and biochemical changes in Pseudomonas fluorescens biofilms grown in the presence of subinhibitory concentrations of 4 antimicrobial agents: triclosan, benzalkonium chloride, chlorhexidine dihydrochloride, and trisodium phosphate. CLSM analyses using the stains SYT09 and ...
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