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1.
We conducted a survey of Cacajao melanocephalus melanocephalusin southern Amazonas, Venezuela, to update information on their distribution and to select a site for a longitudinal study. We surveyed along the Rio Negro, Brazo Casiquiare, Rio Pasimoni, and Rio Baria and interviewed local people. We observed C. m. melanocephalusfour times along the Rio Pasimoni (N =2)and the Rio Baria (N =2).Group size ranged from 3 to 20 individuals. They ate immature seeds from heavily armored fruit of the chicletree (Manilkara bidentataor Manilkara zapota)and Mauritia flexuosa.Local people reported hunting primates, particularly C. m. melanocephalus,once per week. Mercury residue from illegal gold mining may be poisoning local ecosystems. Hunting pressures may have eliminated C. m. melanocephalusfrom much of its range in southern Amazonas. Urgent steps must be taken toward the conservation of C. m. melanocephalus irathis region. 相似文献
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Jean Philippe Boubli 《International journal of primatology》1993,14(6):933-937
Cacajao melanocephalus melanocephalus, a subspecies of black uakari, was thought to be restricted to southern Venezuela. Observations of two groups of them in Pico da Neblina National Park, Brazil, suggest that its distribution should be extended to the Brazilian territory. 相似文献
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Monika Zieliska Piotr Zieliski Pawe Koodziejczyk Pawe Szewczyk Jacek Betleja 《Journal of Ornithology》2007,148(4):543-548
Since 1981, when the first breeding pair of Mediterranean Gull Larus melanocephalus was recorded in Poland, the population of this gull has increased considerably. Its population size was stable until 1997,
not exceeding ten pairs annually; thereafter, an increasing number of sightings were made, and during the last 5 years between
26 and 39 breeding pairs have been recorded in Poland. To date, breeding sites have been established in a total of 45 sites
(maximum of 19 sites in a given year), with 27% of these (43% of all broods) found on islands located in the middle course
of the Vistula River. Breeding sites have also included artificial reservoirs, such as dam reservoirs (20% of sites, 19% of
broods), gravel pits (9% of sites, 13% of broods) and fishponds (24% of places, 8% of broods). Mediterranean Gulls were found
to nest only within the colonies of other Laridae. Single pairs were recorded at 40% of the breeding sites, whereas a maximum
of two to five pairs were recorded at 47% of the other sites. The great majority of breeding attempts were recorded in Black-headed
Gull L. ridibundus colonies. In two cases, Mediterranean Gulls bred within mono-specific colonies of Common Gulls L. canus consisting of 60–150 pairs. The biggest concentrations of breeding sites were along the middle course of the Vistula river
and in the southern part of Poland. 相似文献
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Abdelaal Shamseldin Dietrich Werner 《World journal of microbiology & biotechnology》2007,23(2):285-289
Seven bean rhizobial strains EBRI 2, 3, 21, 24, 26, 27 and 29 identified as Rhizobium etli, and EBRI 32 identified as Rhizobium gallicum, isolated from Egyptian soils and which nodulated Phaseolus vulgaris efficiently, were subjected to hybridization with a nifH probe in order to estimate the copy number of this gene. Seven strains (EBRI 2, 3, 21, 24, 26, 27 and 29) which were only
able to nodulate Phaseolus vulgaris, contained three copies of the nifH gene, consistent with their identification as Rhizobium etli bv. phaseoli. Only one strain (EBRI 32) which nodulated both Phaseolus vulgaris and Leucaena leucocephala, had one copy of nifH gene. This confirmed the classification of this strain as Rhizobium gallicum bv. gallicum. 相似文献
7.
In order to dissect the genetic regulation of leafblade morphogenesis, 16 genotypes of pea, constructed by combining the wild-type
and mutant alleles of MFP, AF, TL and UNI genes, were quantitatively phenotyped. The morphological features of the three domains of leafblades of four genotypes, unknown
earlier, were described. All the genotypes were found to differ in leafblade morphology. It was evident that MFP and TL functions
acted as repressor of pinna ramification, in the distal domain. These functions, with and without interaction with UNI, also
repressed the ramification of proximal pinnae in the absence of AF function. The expression of MFP and TL required UNI function.
AF function was found to control leafblade architecture multifariously. The earlier identified role of AF as a repressor of
UNI in the proximal domain was confirmed. Negative control of AF on the UNI-dependent pinna ramification in the distal domain was revealed. It was found that AF establishes a boundary between proximal
and distal domains and activates formation of leaflet pinnae in the proximal domain. 相似文献
8.
Phaeohelotium nothofagi, sp.nov., found on fallen wood and leaves of Nothofagus dombeyi, is described and illustrated. The fungus is characterized by pale yellow discs, and fumose ascospores with asperulate walls. A key with distributional data for the five species of the genus now known in the Southern Hemisphere is provided. 相似文献
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Gonzalo lvarez Eduardo Uribe Sonia Quijano-Scheggia Amrico Lpez-Rivera Carmen Mario Juan Blanco 《Harmful algae》2009,8(6):938-945
The morphology and toxicity of the four ubiquitous species belonging to the genus Pseudo-nitzschia found in mixed blooms of phytoplankton from northern Chilean waters were studied. The phytoplankton samples and cultures obtained were identified by scanning electron microscopy, revealing the presence of Pseudo-nitzschia australis, P. calliantha, P. pseudodelicatissima and P. subfraudulenta. This is the first report of P. calliantha in northern Chile. Toxin analyses using the LC–MS method confirmed the presence of domoic acid in P. australis and P. calliantha. Domoic acid was not detected in cultures of P. subfraudulenta. This study therefore confirms P. australis and P. calliantha as an unequivocal source of domoic acid in Chilean waters. P. australis is probably the most important producer of amnesic shellfish toxin in view of its domoic acid content. However, more research is needed to evaluate the potential for toxin production in P. pseudodelicatissima. 相似文献
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Thadde Boudjeko Christophe Rihouey Denis Omokolo Ndoumou Ismaïl El Hadrami Patrice Lerouge Azeddine Driouich 《Carbohydrate polymers》2009,78(4):820-827
Many Cola plant species are endemic to West and Central Africa. Cola acuminata and Cola nitida are used as masticatory when fresh, while the dried nuts are used for beverages and pharmaceutical purposes in Europe and North America. Garcinia kola seeds, that serve as a substitute for the true kola nuts, are used in African traditional medicine for the treatment of various diseases, including colic, headache and liver cirrhosis. Seeds extracts of G. kola are also known for their anti-inflammatory, antimicrobial and antiviral properties. To gain information on the chemical properties of the kolas, we have isolated and analyzed cell wall polysaccharides, arabinogalactan-proteins and phenolic substances from the seeds of the three kola species. The sugar composition of cell wall material of C. acuminata, C. nitida and G. kola revealed that Gal (up to 30%), Ara, GalA and Glc as the predominant monosaccharides, representing approximately 90% by mol of the total hydrolysable sugar present in this material. In Ammonium oxalate cell wall fraction, GalA was found to be the major sugar present in all kola species. In the alkali-soluble fraction, there were significant differences in the level of Glc and Gal. The level of Glc was high in C. acuminata and C. nitida while the level of Gal and Xyl were high in C. nitida and G. cola. Isolation and quantification of arabinogalactan-proteins demonstrate that G. kola seeds contained four to eight times more of these proteoglycans than the seeds of the other two species. Finally, analysis of soluble phenolic substances shows that caffeine and catechin were largely represented in C. acumina and C. nitida seeds, with caffeine accounting for 50% of all soluble phenolics. These findings indicate that the three Kola seeds are highly enriched in pectins and proteoglycans and that C. acuminata and C. nitida can be used as a possible source of caffeine and catechin. 相似文献
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The morphology of many hypogeous fungi converges on a homogeneous reduced form, suggesting that disparate lineages are subject to a uniform selection pressure. The primary goal of this study was to evaluate the morphology and infer the phylogeny of the Leucogastrales with Mycolevis siccigleba using a Bayesian methodology. A comprehensive morphological assessment was used for an a priori phylogenetic inference to guide the sequencing effort. All structures except spore ornamentation pointed to the Albatrellaceae as the most likely sister taxon. Polyporoletus sublividus, a close relative of Albatrellus, produces ornamented basidiospores with a similar structure to M. siccigleba basidiospores. The ITS from 30 taxa was used for the molecular phylogenetic analysis. P. sublividus was found sister to Mycolevis. Leucophleps spinispora and L. magnata formed a group sister to the Polyporoletus/Mycolevis group, whereas Leucogaster was polyphyletic with respect to the core of the Leucogastrales and sister to A. caeruleoporus. This relationship was expected as previously undescribed chlamydospores produced by members of Albatrellus had a similar morphology to the basidiospores of L. rubescens. 相似文献
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Xiaoyun Yang Markus Weber Nazanin ZarinKamar Nico Posnien Frank Friedrich Barbara Wigand Rolf Beutel Wim G.M. Damen Gregor Bucher Martin Klingler Markus Friedrich 《Developmental biology》2009,333(1):215-227
The Pax6 genes eyeless (ey) and twin of eyeless (toy) are upstream regulators in the retinal determination gene network (RDGN), which instructs the formation of the adult eye primordium in Drosophila. Most animals possess a singleton Pax6 ortholog, but the dependence of eye development on Pax6 is widely conserved. A rare exception is given by the larval eyes of Drosophila, which develop independently of ey and toy. To obtain insight into the origin of differential larval and adult eye regulation, we studied the function of toy and ey in the red flour beetle Tribolium castaneum. We find that single and combinatorial knockdown of toy and ey affect larval eye development strongly but adult eye development only mildly in this primitive hemimetabolous species. Compound eye-loss, however, was provoked when ey and toy were RNAi-silenced in combination with the early retinal gene dachshund (dac). We propose that these data reflect a role of Pax6 during regional specification in the developing head and that the subsequent maintenance and growth of the adult eye primordium is regulated partly by redundant and partly by specific functions of toy, ey and dac in Tribolium. The results from embryonic knockdown and comparative protein sequence analysis lead us further to conclude that Tribolium represents an ancestral state of redundant control by ey and toy. 相似文献
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A high degree of heterogeneity and an overall increase in number of insertion sites of the mobile elements Doc and copia were revealed in one substock of an isogenic Drosophila melanogaster stock, while in two other substocks the distribution of copia sites was highly homogenous, but that of Doc sites was again heterogenous. We therefore concluded that copia was unstable in one of the substocks and Doc was unstable in all. Doc instability presumably arose earlier than copia instability. Doc and copia transpositions were directly observed in experiments with one substock. An abundance of copia insertions was revealed in the X chromosome where insertions with deleterious effects are exposed to selection in hemizygous condition. The locations of many other mobile elements (mdg1, mdg2, mdg3, mdg4, 297, B104, H.M.S. Beagle, I, P, BS, FB) were found to be conserved in each substock and did not differ between them, indicating that these mobile elements were stable. This homogeneity is a strong argument against any possibility of inadvertent contamination. 相似文献
16.
D. J. Goyder 《Kew Bulletin》2008,63(3):471-472
Summary Four species of tropical African Sarcostemma are transferred to Cynanchum together with two subspecies of S. viminale. In addition, Sarcostemma mulanjense is reduced to subspecific rank under C. viminale. 相似文献
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Summary
T(Y;2) translocations were used to cytologically localise the wingless locus of Drosophila melanogaster. We found that an existing T(Y;2), which is an insertion of a segment of 2L into the Y chromosome, has wg
+ within this insert. This Y chromosome was used to generate an attached XY chromosome containing wg
+. The mutation claret-nondisjunctional (ca
nd) was used to induce the loss of this XY chromosome and thus generate gynandromorphs with wg
1/wg
1 male tissue and wg
+/wg
1/wg
1 female tissue. Analysis of these gynanders demonstrated that a genotypically wingless mutant hemithorax is usually also phenotypically mutant in these half body mosaics; thus wg
1 is discautonomous. This observation is of interest as it is known that wg is not cell autonomous. 相似文献
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Patrice C. Peart Kayanne P. McCook Floyd A. Russell William F. Reynolds Paul B. Reese 《Steroids》2011,76(12):1317-1330
The potential of Fusarium oxysporum var. cubense UAMH 9013 to perform steroid biotransformations was reinvestigated using single phase and pulse feed conditions. The following natural steroids served as substrates: dehydroepiandrosterone (1), pregnenolone (2), testosterone (3), progesterone (4), cortisone (5), prednisone (6), estrone (7) and sarsasapogenin (8). The results showed the possible presence of C-7 and C-15 hydroxylase enzymes. This hypothesis was explored using three synthetic androstanes: androstane-3,17-dione (9), androsta-4,6-diene-3,17-dione (10) and 3α,5α-cycloandrost-6-en-17-one (11). These fermentations of non-natural steroids showed that C-7 hydroxylation was as a result of that position being allylic. The evidence also pointed towards the presence of a C-15 hydroxylase enzyme.The eleven steroids were also fed to Exophialajeanselmei var. lecanii-corni UAMH 8783. The results showed that the fungus appears to have very active 5α and 14α-hydroxylase enzymes, and is also capable of carrying out allylic oxidations.Ceratocystis paradoxa UAMH 8784 was grown in the presence of the above-mentioned steroids. The results showed that monooxygenases which effect allylic hydroxylation and Baeyer–Villiger rearrangement were active. However, redox reactions predominated. 相似文献
19.
H. Thorsten Lumbsch Imke Schmitt Robert Lücking Elisabeth Wiklund Mats Wedin 《Mycological Research》2007,111(3):257-267
Results of molecular studies regarding the phylogenetic placement of the order Ostropales and related taxa within Lecanoromycetes were thus far inconclusive. Some analyses placed the order as sister to the rest of Lecanoromycetes, while others inferred a position nested within Lecanoromycetes. We assembled a data set of 101 species including sequences from nuLSU rDNA, mtSSU rDNA, and the nuclear protein-coding RPB1 for each species to examine the cause of incongruencies in previously published phylogenies. MP, minimum evolution, and Bayesian analyses were performed using the combined three-region data set and the single-gene data sets. The position of Ostropales nested in Lecanoromycetes is confirmed in all single-gene and concatenated analyses, and a placement as sister to the rest of Lecanoromycetes is significantly rejected using two independent methods of alternative topology testing. Acarosporales and related taxa (Acarosporaceae group) are basal in Lecanoromycetes. However, if the these basal taxa are excluded from the analyses, Ostropales appear to be sister to the rest of Lecanoromycetes, suggesting different ingroup rooting as the cause for deviating topologies in previously published phylogenies. 相似文献
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Flaviano S. Martins Aparecida A. Silva Angélica T. Vieira Flávio H. F. Barbosa Rosa M. E. Arantes Mauro M. Teixeira Jacques Robert Nicoli 《Archives of microbiology》2009,191(8):623-630
The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances,
survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation
by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast
was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice.
Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better
microorganism depending on the therapeutic or prophylactic application. 相似文献