bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of polymorphic microsatellite loci in Nothapodytes nimmoniana, a medicinally important tree from the Western Ghats, India
Authors: RAMESHA B. T. , SRIRAMA R. , RAVIKANTH G. , RAVISHANKAR K. V. , DAYANANDAN S. , SREEJAYAN N. , VASUDEVA R. , GANESHAIAH K. N. , UMA SHAANKER R.
Published: November 2008

Nothapodytes nimmoniana is a medicinally important tree species that occur in the Western Ghats, a megadiversity hotspot in southern India. Inner stem bark of the tree contains an important anti‐cancer alkaloid, camptothecin for which the natural population of the tree is heavily harvested. In this paper, we report the isolation and characterization of eight polymorphic microsatellite loci using enrichment hybridization protocol. Analysis of 36 individuals representing two populations revealed three to 12 alleles per locus. Observed heterozygosity ranged from 0.21 to 0.94 for the two populations. None of the loci tested showed linkage disequilibrium. These markers are invaluable for evaluating the genetic structure and assessing the genetic impacts of harvesting of N. nimmoniana in the Western Ghats to formulate strategies for conservation of the species.
Identification and characterization of microsatellite loci in Intsia palembanica (Leguminosae), a valuable tropical timber species
Authors: WONG K. N. , TAN W. L. , CHEW F. T.
Published: November 2008

We present 25 polymorphic microsatellite loci for Intsia palembanica, a highly valued timber species in the Indo‐Malayan region, Australia and western Pacific islands. Microsatellite loci were tested for polymorphism across a total of 76 individuals from three natural populations from Irian Jaya, Indonesia. The average number of alleles for these microsatellites was 12.1 per locus, ranging from four to 19. The observed heterozygosity within the natural populations ranged from 0.01 to 0.96. The markers will enable us to evaluate the spatial–temporal population genetic structure and gene flow dynamics among populations. They can also be used for tracking and tracing wood from legally logged concessions.
Altered plasticity of the parasympathetic innervation in the recovering rat submandibular gland following extensive atrophy
Authors: Carpenter G. H. , Khosravani N. , Ekström J. , Osailan S. M. , Paterson K. P. , Proctor G. B.
Published: November 2008

Adult rat submandibular glands have a rich autonomic innervation, with parasympathetic and sympathetic nerves working in synergy rather than antagonistically. Ligation of the secretory duct rapidly causes atrophy and the loss of most acini, which are the main target cell for parasympathetic nerves. Following deligation, there is a recovery of gland structure and function, as assessed by autonomimetic stimulation. This study examines whether the parasympathetic nerves reattach to new target cells to form functional neuro‐effector junctions. Under recovery anaesthesia, the submandibular duct of adult male rats was ligated via an intra‐oral approach to avoid damaging the chorda‐lingual nerve. Four weeks later, rats were either killed or anaesthetized and the ligation clip removed. Following a further 8 weeks, both submandibular ducts were cannulated under terminal anaesthesia. Salivary flows were then stimulated electrically (chorda‐lingual nerve at 2, 5 and 10 Hz) and subsequently by methacholine (whole‐body infusion at two doses). Glands were excised, weighed and divided for further in vitro studies or fixed for histological examination. Ligation of ducts caused 75% loss of gland weight, with the loss of most acinar cells. Of the remaining acini, only 50% were innervated despite unchanged choline acetyltransferase activity, suggesting few parasympathetic nerves had died. Following deligation, submandibular glands recovered half their weight and had normal morphology. Salivary flows from both glands (per unit of gland tissue) were similar when evoked by methacholine but greater from the deligated glands when evoked by nerve stimulation. This suggests that parasympathetic nerves had reattached to new target cells in the recovered glands at a greater ratio than normal, confirming reinnervation of the regenerating gland.
Detection of
Wolbachia
Bacteria in Multiple Organs and Feces of the Triatomine Insect
Rhodnius pallescens
(Hemiptera, Reduviidae)
Authors: Espino C. I. , Gómez T. , González G. , do Santos M. F. Brazil , Solano J. , Sousa O. , Moreno N. , Windsor D. , Ying A. , Vilchez S. , Osuna A.
Published: November 2008

At least two types of
Wolbachia
bacteria were detected in wild and insectarium-raised
Rhodnius pallescens
, a natural vector of
Trypanosoma cruzi
and
Trypanosoma rangeli. Wolbachia
was detected in all the organs and tissues studied and in the feces, and this provided a methodological advantage for determining the presence of this endosymbiont in this host, obviating the need to kill the specimens. The occurrence of trypanosomatids in wild individuals was also studied.
Continued Protein Synthesis at Low [ATP] and [GTP] Enables Cell Adaptation during Energy Limitation
Authors: Jewett Michael C. , Miller Mark L. , Chen Yvonne , Swartz James R.
Published: November 2008

One of biology's critical ironies is the need to adapt to periods of energy limitation by using the energy-intensive process of protein synthesis. Although previous work has identified the individual energy-requiring steps in protein synthesis, we still lack an understanding of the dependence of protein biosynthesis rates on [ATP] and [GTP]. Here, we used an integratedEscherichia colicell-free platform that mimics the intracellular, energy-limited environment to show that protein synthesis rates are governed by simple Michaelis-Menten dependence on [ATP] and [GTP] (KmATP, 27 ± 4 μM;KmGTP, 14 ± 2 μM). Although the system-level GTP affinity agrees well with the individual affinities of the GTP-dependent translation factors, the system-levelKmATPis unexpectedly low. Especially under starvation conditions, when energy sources are limited, cells need to replace catalysts that become inactive and to produce new catalysts in order to effectively adapt. Our results show how this crucial survival priority for synthesizing new proteins can be enforced after rapidly growing cells encounter energy limitation. A diminished energy supply can be rationed based on the relative ATP and GTP affinities, and, since these affinities for protein synthesis are high, the cells can adapt with substantial changes in protein composition. Furthermore, our work suggests that characterization of individual enzymes may not always predict the performance of multicomponent systems with complex interdependencies. We anticipate that cell-free studies in which complex metabolic systems are activated will be valuable tools for elucidating the behavior of such systems.
Lagging-Strand DNA Replication Origins Are Required for Conjugal Transfer of the Promiscuous Plasmid pMV158
Authors: Lorenzo-Díaz Fabián , Espinosa Manuel
Published: November 2008

The promiscuous streptococcal plasmid pMV158 is mobilizable by auxiliary plasmids and replicates by the rolling-circle mechanism in a variety of bacterial hosts. The plasmid has two lagging-strand origins,ssoAandssoU, involved in the conversion of single-stranded DNA intermediates into double-stranded plasmid DNA during vegetative replication. Transfer of the plasmid also would involve conversion of single-stranded DNA molecules into double-stranded plasmid forms in the recipient cells by conjugative replication. To test whether lagging-strand origins played a role in horizontal transfer, pMV158 derivatives defective in one or in bothsso's were constructed and tested for their ability to colonize new hosts by means of intra- and interspecies mobilization. Whereas eitherssosupported transfer between strains ofStreptococcus pneumoniae, only plasmids that had an intactssoUcould be efficiently mobilized fromS. pneumoniaetoEnterococcus faecalis. Thus, it appears thatssoUis a critical factor for pMV158 promiscuity and that the presence of a functionalssoplays an essential role in plasmid transfer.
Function and Regulation of Class I Ribonucleotide Reductase-Encoding Genes in Mycobacteria
Authors: Mowa Mohube B. , Warner Digby F. , Kaplan Gilla , Kana Bavesh D. , Mizrahi Valerie
Published: November 2008

Ribonucleotide reductases (RNRs) are crucial to all living cells, since they provide deoxyribonucleotides (dNTPs) for DNA synthesis and repair. In
Mycobacterium tuberculosis
, a class Ib RNR comprising
nrdE
- and
nrdF2
-encoded subunits is essential for growth in vitro. Interestingly, the genome of this obligate human pathogen also contains the
nrdF1
(Rv1981c) and
nrdB
(Rv0233) genes, encoding an alternate class Ib RNR small (R2) subunit and a putative class Ic RNR R2 subunit, respectively. However, the role(s) of these subunits in dNTP provision during
M. tuberculosis
pathogenesis is unknown. In this study, we demonstrate that
nrdF1
and
nrdB
are dispensable for the growth and survival of
M. tuberculosis
after exposure to various stresses in vitro and, further, that neither gene is required for growth and survival in mice. These observations argue against a specialist role for the alternate R2 subunits under the conditions tested. Through the construction of
nrdR
-deficient mutants of
M. tuberculosis
and
Mycobacterium smegmatis
, we establish that the genes encoding the essential class Ib RNR subunits are specifically regulated by an NrdR-type repressor. Moreover, a strain of
M. smegmatis
mc
2
155 lacking the 56-kb chromosomal region, which includes duplicates of
nrdHIE
and
nrdF2
, and a mutant retaining only one copy of
nrdF2
are shown to be hypersensitive to the class I RNR inhibitor hydroxyurea as a result of depleted levels of the target. Together, our observations identify a potential vulnerability in dNTP provision in mycobacteria and thereby offer a compelling rationale for pursuing the class Ib RNR as a target for drug discovery.
OryR Is a LuxR-Family Protein Involved in Interkingdom Signaling between PathogenicXanthomonas oryzaepv. oryzae and Rice
Authors: Ferluga Sara , Venturi Vittorio
Published: November 2008

Xanthomonas oryzaepv. oryzae, the causal agent of bacterial leaf blight in rice, contains a regulator that is encoded in the genome, designated OryR, which belongs to theN-acyl homoserine lactone (AHL)-dependent quorum-sensing LuxR subfamily of proteins. However, we previously reported thatX. oryzaepv. oryzae does not make AHLs and does not possess a LuxI-family AHL synthase and that the OryR protein is solubilized by a compound present in rice. In this study we obtained further evidence that OryR interacts with a rice signal molecule (RSM) and that the OryR concentration increases when rice is infected withX. oryzaepv. oryzae. We also describe three OryR target promoters which are regulated differently: (i) the neighboring proline iminopeptidase (pip) virulence gene, which is positively regulated by OryR in the presence of the RSM; (ii) theoryRpromoter, which is negatively autoregulated independent of the RSM; and (iii) the 1,4-β-cellobiosidasecbsAgene, which is positively regulated by OryR independent of the RSM. We also found that the RSM for OryR is small, is not related to AHLs, and is not able to activate the broad-range AHL biosensorAgrobacterium tumefaciensNT1(pZLQR). Furthermore, OryR does not regulate production of the quorum-sensing diffusible signal factor present in the genusXanthomonas. Therefore, OryR has unique features and is an important regulator involved in interkingdom communication between the host and the pathogen.
Complete Genome Sequence of
Rhodobacter sphaeroides
KD131
Authors: Lim Si-Kyu , Kim Sang Jun , Cha Sun Ho , Oh You-Kwan , Rhee Hae-Jin , Kim Mi-Sun , Lee Jeong K.
Published: November 2008

Rhodobacter sphaeroides
is a purple nonsulfur photosynthetic bacterium that is considered a possible source of H
2
production.
R. sphaeroides
KD131, which was isolated from sea mud in South Korea, was found to produce high levels of H
2
. Here we report the complete and annotated genome sequence of
R. sphaeroides
KD131.
A 12-week aerobic training programme reduced plasmatic allantoin in adolescents with Down syndrome: Table 1
Authors: Rosety-Rodriguez M , Rosety I , Fornieles-Gonzalez G , Diaz A , Rosety M , Ordonez F J
Published: November 2008

Objective

To assess the influence of a 12-week training programme on plasmatic levels of allantoin, an in vivo marker for oxidative stress, in adolescents with Down syndrome. This finding would be of great interest, since oxidative damage has been proposed as a pathogenic mechanism of several pathologies in this population.

Materials

To reach this goal, 31 male adolescents with Down syndrome (16.3 (1.1) years; 155.2 (5.7) cm; 70.8 (4.5) kg) performed a 12-week training programme, three sessions per week, consisting of warm-up (15 min) followed by a main part (20–35 min (increasing 5 min each 3 weeks)) at a work intensity of 60–75% of peak heart rate (increasing by 5% each 3 weeks) and then a cool-down period (10 min). According to previous studies, it should be emphasised that the maximal heart rate for individuals with Down syndrome was predicted by the equation HRmax = 194.5–(0.56 age). The control group included seven age-, sex- and BMI-matched adolescents with trisomy 21 that did not perform any training programme. The levels uric acid and allantoin were assayed in plasma by HPLC. This protocol was approved by an institutional ethics committee.

Results

When compared with baseline, plasmatic levels of allantoin were decreased significantly (22.09 (1.62) vs 18.74 (1.38) μmol/l; p<0.001) after being exercised. Furthermore, the allantoin/uric acid ratio was decreased significantly (0.071 (0.006) vs 0.059 (0.004); p<0.05). On the contrary, no changes were reported in controls.

Conclusion

A 12-week aerobic programme significantly reduced oxidative damage expressed in terms of plasmatic allantoin content in adolescents with Down syndrome. Further studies on this topic are required.
No need for nanny
Authors: Daube M , Stafford J , Bond L
Published: November 2008

The term “nanny state” is regularly used to attack health groups or governments, especially by interest groups bereft of arguments and journalists in search of a cliché. It has become a special favourite of tobacco companies and their supporters. In the present work we argue that the term should be retired in favour of genuine debate on substantive issues.
Les esters de l'acide caféique dans la chimiotaxinomie des Teucrium de la section polium (Lamiaceae)
Authors: Andary C. , Rascol J. P. , Puech S. , Roussel J. L. , Privat G.
Published: November 2008

Several species of the genus Teucrium section polium from the mediterranean region are difficult to identify because of their wide morphological variability. The relationship between the morphological variations and the distribution of caffeic acid esters was studied. The results show that the taxonomic value of these markers is different depending on the nature of the molecule. Ecological factors interfere with the presence of verbascoside (diglycoside) more than they do with those of stachyoside and T2 (triglycosides). The presence of these latter molecules confirms the close relationship between T. polium subsp. polium and T. capitatum. The stachyoside present in T. polium subsp. polium also allows the distinction, in overlapping areas, of intermediary forms to T. aureum subsp. aureum, in which it is absent. Poliumoside is a specific marker for the polium section. It is never found in the other sections, where it is replaced by teucrioside and chlorogenic acid.
Les coupes forestières dans les pessières à lichens: effets sur la croissance et la régénération des conifères (Whapmagoostui, Québec subarctique)
Authors: Delwaide Ann , Filion Louise
Published: November 2008

In the Whapmagoostui area (east of Hudson Bay), tree harvesting by Crée Indians in lichen woodlands affects the form and the growth of surviving trees and also the forest population dynamics. A study of the growth form of white spruce (Picea glauca (Moench) Voss.) and black spruce (Picea mariana (Mill.) B.S.P.) that have been pruned shows the efficiency of a total traumatic reiteration process. After several years, the annual radial growth was equivalent to that recorded before pruning. In clear-cutting areas (more than 75% of trees removed), the increase in the radial growth of spared trees was 400 to 700%. The main factors that govern the success of regeneration in cutting areas are the rather small extension of the openings (<0.005 km2), the low intensity of tree harvesting (<75% of trees over 90% of the surface), the physical conditions of the lichenous ground cover and the abundance of the lignified debris after clearing vegetation, and the climatic conditions in the subsequent years.
Photosensitivity of anthocyanin production in dark-grown and light-pretreated Zea mays seedlings
Authors: Rengel Zdenko , Kordan Herbert A.
Published: November 2008

Anthocyanin production in roots and shoots of Zea mays L. seedlings was higher in blue than in red light and was very low in far red light. Under dichromatic irradiation, a phytochrome mediation of a blue-dependent photoreaction was evident. Pretreatments with both white and blue light allowed increased anthocyanin production under subsequent inductive conditions, as did occurs in treatments with continuous blue, red, far red, or white light. It is suggested that the effect of light pretreatments on phytochrome-controlled anthocyanin formation may differ from that controlled by the combination of cryptochrome and phytochrome.
Ultrastructural changes associated with induced systemic resistance of cucumber to disease: host response and development of Colletotrichum lagenarium in systemically protected leaves
Authors: Xuei X. L. , Järlfors U. , Kuć J.
Published: November 2008

Systemic resistance to anthracnose caused by Colletotricum lagenarium was induced in cucumber by inoculation with fungal conidia. Control and immunized leaves were examined by both light and electron microscopy before and after subsequent challenge with the fungus. Penetration through the epidermal wall was evident 36 h after challenge and was followed by hyphal proliferation and host-cell destruction in control tissues. Penetration was rarely seen in immunized tissues before 72 h, but at 24 h, invaginations of the appressorial wall were observed, as well as highly electron opaque epidermal walls beneath the appressoria. At 72 h, thin penetration pegs were seen within the dense host wall, and at 96 h, the peg was embedded within the underlying papilla and aggregates of callose-like material. Penetration through the epidermis was rare in immunized tissue, but when it was observed, development appeared to be similar to that in control leaves. Evidence is presented to show that ultra-structural changes in immunized tissues as well as in the fungus occur within 24 h after challenge of the host. There appears to be a correlation between the comparatively few lesions observed macroscopically in immunized leaves and the sparsity of successful penetrations into host mesophyll cells.
Morphogenèse foliaire et activité photosynthétique chez le soja (Glycine max)
Authors: Barthou H. , Buis R.
Published: November 2008

The main stem development and the photosynthetic activity of leaves 2 to 9 were studied in soja (Glycine max (L.) Merr.) at the leaf blade extension and adult stages. A correlation between the different leaf growth parameters (rates, durations) and the phyllochrone has been demonstrated. That correlation varied with the age and rank of the leaf. Moreover, the existence of correlations between net photosynthesis on one hand and the rate of development and the leaf growth kinetics on the other hand reveals an interdependence between photosynthesis and morphogenesis. [Journal translation]
Pulp composition and the invasion and decay of fruits by microbes
Authors: Borowicz Victoria A.
Published: November 2008

Among temperate-zone plant species, fruits with fat-rich pulp have been predicted to disappear more rapidly than low-fat fruits, in part because of more rapid decay by microbes. The influence of fat content of pulp on the susceptibility of fruits to microbial invasion and the rate of pulp deterioration after invasion were examined using Cornus amomum fruits (approximately 5.8% crude fat) and C. racemosa fruits (approximately 23.1% crude fat). Fruits were surface sterilized, punctured with a sterile needle or left undamaged, and inoculated with sterile water, a suspension of bacteria, or a suspension of fungal spores. The two species did not differ significantly in the number of days to first deterioration (= susceptibility), but whole C amomum fruits deteriorated faster than did whole C. racemosa fruits after invasion was first visible. This difference between species persisted when the difference in mean dry pulp mass was taken into account using an exponential model of pulp decay. The two Cornus species did not differ in rate of pulp deterioration (milligrams dry tissue per day) when a linear model of microbial decay of pulp was used. In these two species, higher fat content of pulp does not yield greater susceptibility to invasion or higher rate of deterioration by microbes.
Hydraulic conductance and tracheid anatomy in six species of extant seed plants
Authors: Schulte Paul J. , Gibson Arthur C.
Published: November 2008

Hydraulic conductance of tracheids was studied in either petioles or young stems of six species of seed plants having various types of intertracheid pitting. Measured conductances were compared with estimates based on Hagen–Poiseuille flow through ideal capillaries and with predictions from a biophysical model incorporating observed anatomical characteristics of tracheids and intertracheid pits. Conductance of the xylem, expressed as a percentage of the ideal capillary flow prediction, varied from an average of 88% for a species containing only very narrow tracheids to less than 35% for species with large-diameter tracheids. The biophysical model allowed fairly close predictions of conductance for all species except one, where an estimate of the pit membrane resistance could not be experimentally obtained. For individual tracheids, conductance was largely a function of lumen diameter, pit membrane resistivity, and the exposed area of the pit membranes, as determined by pit shape, size, and frequency. For wide tracheids, scalariform-pitted elements showed a linear increase in conductance with an increase in lumen diameter; however, for tracheids with large circular pits, the conductance increase afforded by a wider lumen declines as lumen diameter increases. These model simulations demonstrate the increasing significance of intertracheid pitting in obstructing flow as lumen diameter increases.
Vegetation variation among mesic successional forest stands in northern lower Michigan
Authors: Roberts Mark R. , Christensen Norman L.
Published: November 2008

Vegetation composition of the shrub–tree and herb layers was sampled in 70 successional aspen (Populus tremuloides and Populus grandidentata) stands of different ages (1–90 years) on a variety of sites in northern lower Michigan. Physical and chemical characteristics of soil profiles were also measured at each site. Three stand groupings were identified based on site conditions and detrended correspondence analysis (DCA) ordination of the vegetation. Sandy dry-mesic soils support forests of Acer rubrum, Quercus rubra, Pinus resinosa, and Pinus strobus. On lowland sandy soils with a fluctuating water table, Pinus strobus, Abies balsamea, Viburnum lentago, and Viburnum cassinoides are important. Mesic soils with stratified calcareous layers or clay till substrates support Acer saccharum, Fagus grandifolia, Tilia americana, Fraxinus americana, Ostrya virginiana, and Acer pensylvanicum. Canonical correlation analysis (CCA) was used to compare DCA scores with soil variables; first-axis DCA scores were correlated with a suite of soil variables and stand age was correlated with second or third DCA axis scores. Separate DCA ordinations of the dry-mesic and mesic groups revealed successional relations on these sites. On dry-mesic sites, Pinus resinosa and Pinus strobus increase in importance with stand age, while Prunus serotina, Prunus virginiana, Prunus pensylvanica, and the aspens decrease. On mesic sites, early successional species include the aspens, Corylus cornuta, Prunus serotina, and Prunus pensylvanica. Fagus grandifolia, Acer pensylvanicum, Quercus rubra, Viburnum acerifolium, Betula papyrifera, Acer rubrum, and Tilia americana are more abundant in mature mesic-site stands. Ordinations of the herb data were remarkably similar to those for trees and shrubs except on dry-mesic sites. Much of the residual variability in vegetation not accounted for by site conditions and stand age is probably related to historical factors such as the nature of disturbance and variations in seed rain.
Production of haploids in Gerbera jamesonii via ovule culture: influence of fall versus spring sampling on callus formation and shoot regeneration
Authors: Cappadocia Mario , Chrétien Louise , Laublin Geneviève
Published: November 2008

The unfertilized ovules of one clone of Gerbera jamesonii H. Bolus ex Hook. f. were cultured in vitro as a means of producing haploid plants. A total of 4715 ovules were cultivated on 17 media during two distinct periods of the year. All the media tested, except the ones containing 0.5% w/v of activated charcoal, were able to sustain the formation of callus. When these calli were transferred to the regeneration medium, shoot differentiation occurred in about 2 weeks. Usually, callus induction occurred at a higher frequency during the fall experiments. However, the calli produced in the spring displayed a higher morphogenetic capacity. Chromosome and chloroplast counts performed on randomly selected plants revealed that 76% of the regenerants were haploid and 24% were diploid.
The mating system of the fairy ring fungus Marasmius oreades and the genetic relationship of fairy rings
Authors: Mallett K. I. , Harrison L. M.
Published: November 2008

A genetic study, based upon monosporous progeny of 23 distinct basidiocarps of Marasmius oreades (Bolt.: Fr.) Fr., revealed that the fungus is heterothallic and has a unifactorial mating system. Isolates that had clamp connections were determined to be dikaryotic, using the Giemsa-staining technique. Monospore isolates, lacking clamp connections, were mono-karyotic. Fairy rings caused by the fungus were found to be genetically homogeneous. Pairing monosporous progeny from different basidiocarps showed that the locus controlling sexuality was multiallelic, with eight alleles being found in the Brooks, Alta., area. Of the 23 fairy rings studied, there were 13 unique genotypes. Five of these genotypes occurred more than once in the fairy rings studied. Pairings of different dikaryotic isolates, clones, siblings, and parent with offspring showed that a line of demarcation was found in all pairings except those in which an isolate was paired with itself. This technique was used to determine the genetic relationship of rings that shared the same genotype for the mating-type locus. Five of the rings shared the same mating-type genotype but were genetically distinct individuals. Two of the rings were genetically identical and the genetic relationship of the others was not determined.
Surface morphology of aeciospores, urediniospores, and teliospores of Uromyces trifolii-repentis
Authors: Hwang S. F. , Neuwirth M. E. , Chang K. F.
Published: November 2008

The surface markings of the spores from the aecial, uredinial, and telial stages of Uromyces trifolii-repentis Liro on leaves and petioles of small white clover (Trifolium repens L.) were examined using scanning and transmission electron microscopes. The short, cylindrical aecium was borne within a peridium which was one cell layer thick. The peridial cells were rhomboidal with irregular club-shaped ornaments. The yellowish aeciospores were densely ornamented with smooth, knoblike verrucae. Thin areas of the spore wall were differentiated into germ pores. Two or three germ pores were equatorially arranged on the golden-brown urediniospores, which except for a circular hilar region were evenly covered with minute conical spines. The spines were situated singly in very shallow depressions surrounded by circular ridges. The dark-brown teliospores had smooth walls with a few linearly arranged fine warts, and the walls were thicker at the apex than on the side. A pale papilla covered the germ pore at the apex of the teliospore, which was borne singly on the fragile pedicel.
Halographis (Opegraphales), a new endolithic lichenoid from corals and snails
Authors: Kohlmeyer Jan , Volkmann-Kohlmeyer Brigitte
Published: November 2008

Halographis runica Kohlm. et Volkmann-Kohlm. gen. et sp. nov. is described from submerged snails (Vasum muricatum) and coral slabs in Belize (Central America). The ascomycete is loosely associated with cyanobacteria (Chroococcales). This is the first discovery of a submarine member of Opegraphales and the seventh case of a submerged marine lichen or lichenoid.
Microhabitat du Linaria canadensis (Scrophulariceae) dans le Haut-Saint-Laurent (Québec)
Authors: Villard Marc-André , Jean Martin , Bouchard André
Published: November 2008

The influence of vegetation structure on the abundance of Linaria canadensis (L.) Dum.-Cours., a rare species in Quebec, has been studied. Six populations from two bogs of extreme southwestern Quebec have been sampled. These populations were located on recently bumed areas and on the fallow margins of cultivated fields. Linear regressions showed two very highly significant relationships: the species density is directly related to the proportion of bare soil and inversely related to moss layer cover. Thus, in the study area, Linaria canadensis appears to be a transient successional species, the presence and abundance of which is closely linked to disturbances such as fire and clearings. The existence of a wide morphocline is also discussed.
The mycorrhizal status, root anatomy, and phenology of plants in a sugar maple forest
Authors: Brundrett Mark C. , Kendrick Bryce
Published: November 2008

The phenology, root anatomy, and mycorrhizal colonization of vascular plant species occurring in a hardwood forest site were studied. Sugar maple (Acer saccharum), the dominant tree, ash (Fraxinus americana), another important tree, and the most abundant herbaceous plants were examined periodically. Most of the herbaceous species present were highly colonized by vesicular–arbuscular mycorrhizae (VAM), but some consistently had low levels of VAM, or were nonmycorrhizal, and several had orchid mycorrhizae. Most trees were associated with VAM, although several ectomycorrhizal species occurred in low numbers. Herbaceous plants could be divided into four phenological categories of shoot activity, spring, spring–summer, summer, and fall, but many species had periods of root growth that did not parallel their aboveground activity. Almost all species that produced new roots in summer were well colonized by VAM, while those active mainly in late fall or early spring tended to be nonmycorrhizal. Roots of the woodland plants typically had a well-developed exodermis and also tended to be long-lived and coarse. Possible relationships among these root system characteristics, phenological categories, and levels of mycorrhizal colonization of woodland plants are discussed.
Characteristics of the major DNA polymerases found during early and late maize germination
Authors: Vazquez Alejandra , Vazquez-Ramos Jorge
Published: November 2008

Two types of DNA synthesis have been detected during maize germination (0–24 h). To determine if the difference in these two types of synthesis was due to the presence of distinct DNA polymerases, we partially isolated and characterized the enzymes present at 3 (early) and 24 (late) h of germination. The material used was embryo axes. The result indicates that at both 3 and 24 h, enzymes are similar with regard to optimum pH and temperature, absolute requirement of Mg2+ (12 mM), and stimulation by KCl (50 mM). They are also equally inhibited by N-ethylmaleimide and cytosine-β-D-arabinofuranoside. These facts would classify the enzymes as alpha type; however, the enzymes differ in their sensitivity to aphidicolin and the degree of purification. The nature of the enzymes is discussed.
Cellular endosperm formation in Phaseolus vulgaris. I. Light and scanning electron microscopy
Authors: Yeung Edward C. , Cavey Michael J.
Published: November 2008

The formation of the endosperm in Phaseolus vulgaris L. conforms to the nuclear pattern of endosperm development. The endosperm is partially cellularized in the vicinity of the developing embryo, while the rest of the endosperm remains multinucleate. Mitotic activity of the endosperm is gradually confined to the region adjacent to the tips of the enlarging cotyledons. Continuing mitotic activity in this region results in the formation of cellular endosperm in the bean seed. At the cotyledon stage of embryo development, except in the region of the degenerating nucellus, the entire surface of the developing embryo is covered by a layer of cellular endosperm cells. Initially, the cellular endosperm is loosely attached to the inner surface of the seed coat. With the disappearance of the liquid endosperm, it becomes firmly attached. Further expansion of the seed results in the separation of cellular endosperm cells along their long axes. As the seed matures, the cellular endosperm dries, with no apparent degradation of its cells.
The stabilization of latex in laticifers of the Convolvulaceae: application of freezing methods for scanning electron microscopy
Authors: Fineran B. A. , Condon J. M.
Published: November 2008

The high turgor pressure of many laticifers in the Convolvulaceae causes the cell contents to be disturbed when tissues are excised from the plant before specimen preparation for microscopy. This has been overcome by freezing the tissue intact on the plant, or where this is not practicable, excising a length of the organ and freezing the middle portion. Specimens are frozen and fractured in nitrogen slush, then freeze-dried and examined by scanning electron microscopy. With this method, latex particles were well preserved within the central vacuole and the peripheral cytoplasm was retained in several taxa. The need to freeze bulky pieces of tissue, however, results in poor freeze-fixation of the cytoplasm.
Analysis of extracellular proteins by native polyacrylamide gel electrophoresis with infiltrated leaf tissue: application to pathogenesis-related proteins
Authors: Grenier Jean , Côté François , Asselin Alain
Published: November 2008

In addition to polyacrylamide gel electrophoretic analysis of intercellular fluid extracts, a simple method of detection of extracellular pathogenesis-related proteins was based on direct native polyacrylamide gel electrophoresis for acidic and basic proteins with leaf tissue infiltrated with 150 mM sucrose. This technique allowed for the detection of the complete set of tobacco pathogenesis-related proteins without having to extract the intercellular fluid by low-speed centrifugation. A major advantage of the technique is the capacity to observe the distribution of extracellular endogenous or exogenous proteins in the tissue directly subjected to electrophoresis.
The effects of glutamine, citrate, and pH on the growth and sporulation of Melampsora lini in axenic culture
Authors: Boasson Rosalinda , Shaw Michael
Published: November 2008

Growth (protein) and sporulation (extinction at 458 nm) of uredial cultures of races 3 and 210 of flax rust were compared on axenic media containing cysteine plus either high (42 mM) aspartate or glutamate or high (42 mM) or low (4 mM) glutamine as the major source of amino N. On high aspartate, growth of race 210 was 2 times and sporulation 20 times that of race 3. Glutamate substituted for aspartate, but there was no growth on high glutamine unless cultures were first seeded and held on glutamate during an incubation period of 15 days. Growth on low glutamine was poor at pH 5.0. Increased pH or the addition of citrate overcame the inhibitory effect of low pH. Both races grew equally well on low glutamine at pH 5.5 or 6.0, with or without citrate, but growth of race 3 was only one-third to one-half that of race 210 on high aspartate. Sporulation of race 210 on low glutamine under these conditions was 4–5 times that of race 3, being as high as or higher than on aspartate. [14C(U)]Citrate was more rapidly metabolized at pH 5.0 than at 5.5 or 6.0. Evidence is presented that citrate promotes growth on low glutamine at pH 5.0 primarily because it prevents the rapid downward drift in pH that occurs in its absence and that periodic upward adjustment of the pH results in striking increases in sporulation.
MODEL CHECKING OF COMPONENT BASED SOFTWARE USING COMPOSITIONAL REDUCTIONS
Authors: IZADI MOHAMMAD , MOVAGHAR ALI
Published: November 2008

A component-based computing system consists of two main parts: a set of components and a coordination subsystem. Reo is an exogenous coordination language for compositional construction of the coordination subsystem. Constraint automaton has been defined as the operational semantics of Reo. The main goal of this paper is to prepare a model checking method for verifying linear time temporal properties of component-based systems whose coordinating subsystems are modeled by Reo and components are modeled by labeled transition systems. For this purpose, we introduce modified definitions of constraint automata and their composition operators by which, every constraint automaton can be considered as a labeled transition system and each labeled transition system can be translated into a constraint automaton. We show that failure-based equivalences CFFD and NDFD are congruences with respect to the composition operators of constraint automata. Also we present a method for compositional model checking of component-based systems using these equivalences for reducing the sizes of constraint automata models.
INTEGRATING AGENT, SERVICE AND ORGANIZATIONAL COMPUTING
Authors: CAO LONGBING
Published: November 2008

Engineering open complex systems is challenging because of system complexities such as openness, the involvement of organizational factors and service delivery. It cannot be handled well by the single use of existing computing techniques such as agent-based computing and service-oriented computing. Due to the intrinsic organizational characteristics and the request of service delivery, an integrative computing paradigm combining agent, service, organizational and social computing can open complex systems more effectively engineering. In this paper, we briefly introduce an integrative computing approach named OASOC for system analysis and design. It combines and complements the strengths of agent, service and organizational computing to handle the complexities of open complex systems. OASOC provides facilities for organization-oriented analysis and agent service-oriented design. It also supports transition between analysis and design. Compared with the existing approaches, our approach can (1) support service and organization that are either rarely or weakly covered by single computing methods, (2) provide effective mechanisms to integrate agent, service and organizational computing, and (3) complement the strengths of various methods. Experiences in engineering an online trading support system have further shown the workable capability of integrating agent, service and organizational computing for engineering open complex systems.
AGENT BASED DATA STORAGE AND DISTRIBUTION IN DATA WAREHOUSES
Authors: KOLSI NADER , ABDELLATIF ABDELAZIZ , GHEDIRA KHALED
Published: November 2008

The data warehouse (DWH) is usually presented as a centralized database. In this paper, we propose a new approach to manage data storage and distribution in a data warehouse environment. This approach deals with the dynamic data distribution of the DWH on a set of servers. The data distribution that we consider is different from the "classical" one which depends on the data use. The distribution in our approach consists in distributing data when the server reaches its storage capacity limit. This distribution assures the scalability and exploits the storage and processing resources available in the organization using the data warehouse. It is worth noting that our approach is based on a multi-agent model mixed with the scalability distribution proposed by the Scalable Distributed Data Structures.

The proposed multi-agent model is composed of stationary agent classes: Client, Dispatcher, Domain and Server, and a mobile agent class called Messenger. These agents collaborate and interact to achieve automatically the storage, the splitting (distribution), the redirection and the access operations on the distributed data warehouse.

In this paper, we demonstrate the improvements obtained when we have used the multi-agent system and the Messenger agents in the data storage operation.
Optimal postnodal lymphatic network structure that maximizes active propulsion of lymph
Authors: Venugopal Arun M. , Quick Christopher M. , Laine Glen A. , Stewart Randolph H.
Published: November 2008

The lymphatic system acts to return lower-pressured interstitial fluid to the higher-pressured veins by a complex network of vessels spanning more than three orders of magnitude in size. Lymphatic vessels consist of lymphangions, segments of vessels between two unidirectional valves, which contain smooth muscle that cyclically pumps lymph against a pressure gradient. Whereas the principles governing the optimal structure of arterial networks have been identified by variations of Murray's law, the principles governing the optimal structure of the lymphatic system have yet to be elucidated, although lymph flow can be identified as a critical parameter. The reason for this deficiency can be identified. Until recently, there has been no algebraic formula, such as Poiseuille's law, that relates lymphangion structure to its function. We therefore employed a recently developed mathematical model, based on the time-varying elastance model conventionally used to describe ventricular function, that was validated by data collected from postnodal bovine mesenteric lymphangions. From this lymphangion model, we developed a model to determine the structure of a lymphatic network that optimizes lymph flow. The model predicted that there is a lymphangion length that optimizes lymph flow and that symmetrical networks optimize lymph flow when the lymphangions downstream of a bifurcation are 1.26 times the length of the lymphangions immediately upstream. Measured lymphangion lengths (1.14 ± 0.5 cm, n = 74) were consistent with the range of predicted optimal lengths (0.1–2.1 cm). This modeling approach was possible, because it allowed a structural parameter, such as length, to be treated as a variable.
Increased nitrite reductase activity of fetal versus adult ovine hemoglobin
Authors: Blood Arlin B. , Tiso Mauro , Verma Shilpa T. , Lo Jennifer , Joshi Mahesh S. , Azarov Ivan , Longo Lawrence D. , Gladwin Mark T. , Kim-Shapiro Daniel B. , Power Gordon G.
Published: November 2008

Growing evidence indicates that nitrite, NO2−, serves as a circulating reservoir of nitric oxide (NO) bioactivity that is activated during physiological and pathological hypoxia. One of the intravascular mechanisms for nitrite conversion to NO is a chemical nitrite reductase activity of deoxyhemoglobin. The rate of NO production from this reaction is increased when hemoglobin is in the R conformation. Because the mammalian fetus exists in a low-oxygen environment compared with the adult and is exposed to episodes of severe ischemia during the normal birthing process, and because fetal hemoglobin assumes the R conformation more readily than adult hemoglobin, we hypothesized that nitrite reduction to NO may be enhanced in the fetal circulation. We found that the reaction was faster for fetal than maternal hemoglobin or blood and that the reactions were fastest at 50–80% oxygen saturation, consistent with an R-state catalysis that is predominant for fetal hemoglobin. Nitrite concentrations were similar in blood taken from chronically instrumented normoxic ewes and their fetuses but were elevated in response to chronic hypoxia. The findings suggest an augmented nitrite reductase activity of fetal hemoglobin and that the production of nitrite may participate in the regulation of vascular NO homeostasis in the fetus.
NADPH oxidase activity is higher in cerebral versus systemic arteries of four animal species: role of Nox2
Authors: Miller Alyson A. , Drummond Grant R. , De Silva T. Michael , Mast Anja E. , Hickey Haruyo , Williams John P. , Broughton Brad R. S. , Sobey Christopher G.
Published: November 2008

We previously reported that NADPH oxidase activity is greater in intracranial cerebral versus systemic arteries of the rat. Here, we first tested whether NADPH oxidase activity is also greater in intracranial cerebral than systemic arteries of three other animal species, i.e., mouse, rabbit, and pig. Second, using Nox2-deficient mice, we evaluated the involvement of Nox2-containing NADPH oxidases in any such regional differences. NADPH-stimulated superoxide (O2−) production by basilar, middle cerebral arteries (MCA), and common carotid arteries (CA) and thoracic aorta (AO) from rat, mouse, rabbit, and pig was measured using lucigenin-enhanced chemiluminescence. Basal production of O2− and hydrogen peroxide (H2O2) by cerebral arteries, AO, and CA from wild-type (WT) and Nox2−/− mice was measured using L-012-enhanced chemiluminescence and Amplex Red fluorescence, respectively. Western blotting was used to measure Nox2 and SOD1–3 protein expression, and immunofluorescence was used to localize Nox2, in mouse arteries. In rats, WT mice, rabbits, and pigs, NADPH-stimulated O2− production by cerebral arteries was up to 40-fold greater than that in AO and CA. In WT mice, basal O2− and H2O2 production by cerebral arteries was ninefold and ∼2.5-fold higher, respectively, than that in AO and CA and was associated with ∼40% greater expression of Nox2 protein. Nox2 immunofluorescence was localized to the endothelium, and to a lesser extent the adventitia, in all mouse arteries and appeared to be more intense in endothelium of MCA than AO or CA. In Nox2−/− mice, NADPH-stimulated O2− production by cerebral arteries was ∼35% lower than that in WT mice, whereas Nox2 deletion had no significant effect on O2− production by AO or CA. Thus NADPH oxidase activity is greater in intracranial cerebral versus systemic arteries of several animal species and is associated with higher cerebrovascular expression and activity of Nox2.