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21.
In 1989 a new gelada baboon (Theropithecus gelada) population was found in Arsi, on the opposite side of the Rift Valley to that of the known gelada populations of Semien
and Showa. Previous comparisons of units of the band at Gado Goro, Arsi, in the same season in consecutive years, indicated
that unit structure is less stable among Arsi geladas as compared to the Semien population. Gelada units of the band at Gado-Goro
were studied for 7 months in order to investigate the processes of social changes. Changes in unit structure were observed.
Provisioning was carried out for 1.5 months at the beginning of the 7-month study period, in order to capture and obtain blood
samples from the geladas. Following this, changes in male leadership of some units were observed, presumably as a consequence
of the capture. However, natural changes also occurred. One change in unit structure occurred after a female gave birth, and
changes in another unit occurred after the disappearance of the leader male. These changes involved female desertion of a
unit, her subsequent transfer to a male unit, and culminated in the formation of a unit consisting of one female and one male.
One successful and one attempted case of unification of units, and one case of change of a unit leader male are reported.
These changes occurred among eight resident units in a period of 7 months (196 female months). Though the types of social
changes were not much different from previous observations in Semien National Park, their frequencies seemed to be much higher.
The characteristics of Arsi gelada social changes are proposed to be related to the small size of the units. We also describe
a new confirmed case and one suspected case of infanticide, as well as one case of abortion at the time of male leader change. 相似文献
22.
Mulugeta Belay Mengistu Legesse Adane Mihret Yonas Bekele Tom H. M. Ottenhoff Kees L. M. C. Franken Gunnar Bjune Fekadu Abebe 《PloS one》2015,10(4)
Tuberculosis (TB) is among the leading causes of morbidity and mortality. The causative agent, Mycobacterium tuberculosis (Mtb), has evolved virulent factors for entry, survival, multiplication and immune evasion. Rv2031 (also called alpha crystallin, hspX, 16-kDa antigen), one of the most immunogenic latency antigens, is believed to play a key role in long-term viability of Mtb. Here, we report the dynamics of pro-inflammatory (IFN-γ, TNF-α) and anti-inflammatory (IL-10) cytokines against Rv2031 using whole blood assay in human cohorts in a TB endemic setting. Cytokine responses to ESAT-6-CFP-10 were also measured for comparison. Blood samples were collected from smear positive pulmonary TB patients and their contacts at baseline, 6 and 12 months, and from community controls at entry. At baseline, 54.4% of controls and 73.2% of contacts were QFT-GIT test positive. Baseline IFN-γ, TNF-α and IL-10 responses to Rv2031 were significantly higher in controls compared to contacts and untreated patients (p<0.001). Furthermore, untreated patients had significantly higher TNF-α and IL-10 responses to Rv2031 compared to contacts (p<0.001). In contacts and treated patients, IFN-γ, TNF-α and IL-10 responses to Rv2031 significantly increased over 12 months (p<0.0001) and became comparable with the corresponding levels in controls. There was a positive and significant correlation between Rv2031 and ESAT-6-CFP-10 specific cytokine responses in each study group. The fact that the levels of IFN-γ, TNF-α and IL-10 against Rv2031 were highest during latent TB infection may indicate their potential as markers of protection against TB. Taken together, the findings of this study suggest the potential of IFN-γ, TNF-α and IL-10 against Rv2031 as biomarkers of the host response to Mtb during convalescence from, and the absence of, active tuberculosis. 相似文献
23.
Changes of external morphological characters in three forms (morphotypes) of African barbs from Lake Tana (Ethiopia) belonging
to Barbus intermedius complex were traced using electronic tags. It was shown that within age interval from two to four years individual ontogenetic
allometric curves often cannot be described with a single power function equation. Individual ontogenetic trajectories in
the principal components space within this interval strongly differ in shape meandering within ontogenetic channels outlined
on the basis of cross-sectional data. Morphological differences between siblings are found that do not allow to classify some
of them with the morphotype of their parents. 相似文献
24.
25.
K. F. Dzerzhinskii F. N. Shkil Belay Abdissa Wondie Zelalem M. V. Mina 《Journal of Ichthyology》2007,47(8):639-646
Direct observations on three forms (morph types) of spawning barbs, considered by some authors as different species, were
carried out in September–October 2005 at the Gumara River and its small tributary, the Ducalit, in the Lake Tana basin. The
spawning barbs were sampled using cast nets. Barbs of different morphotypes composed common spawning aggregations and were
caught together. It is likely that troutlike females mate extensively with intermedius males and, probably, with bigmouth
small-eye males. Experiments in artificial fertilization and rearing showed that, during the embryonic period, there was no
increase in mortality of progeny from crosses of barbs of different morphotypes, in comparison with homonomic crosses, thus
suggesting an absence of postzygotic reproductive isolation between the morphotypes. At the same time, mortality of progeny
from crossing barbs with Varicorhinus beso Rüppell, 1836 was very high during the earliest stages of development, suggesting strong, even if incomplete, reproductive
isolation ensured by postzygotic mechanisms.
Published in Voprosy Ikhtiologii, 2007, Vol. 47, No. 5, pp. 676–683.
The article was translated by the authors. 相似文献
26.
Daniel Fitamo Seyoum Leta Gurja Belay Bekele Lemma Mats Olsson 《Soil & Sediment Contamination》2011,20(7):745-766
Irrigation with untreated wastewater from several industrial, commercial, and domestic discharges for decades caused accumulation of various heavy metals and metalloids in soils along the Akaki River in Ethiopia. Assessment of environmental threats and the potential phytoremediation of the soils require understanding of the toxic elements’ uptake and distribution in plant parts. Hence, a greenhouse study was performed to examine the phytoavailability and distribution of Cr, Ni, Co, Cu, Zn, Cd, Pb, Hg, Se, V, and As in forage grasses: Oat (Avena sativa), Rhodes grass (Chloris gayana), Setaria (Setaria sphacelata), and the legumes Alfalfa (Medicago sativa) and Desmodium (Desmodium unicinatum). The average contents of Cr, Ni, Co, Cu, Zn, Pb, Hg, Se, and V in the plants were generally higher than the background levels for forage grasses/legumes, and some of these elements were in the phytotoxic range. Root bioconcentration factor (BCF = root to soil concentration ratio) > 1 was observed for Cu (Oat, Rhodes, Desmodium, and Setaria: Fluvisol), Zn (Setaria: Fluvisol), Cd (Rhodes: Fluvisol; Setaria from both soils) and Hg (Oat and Alfalfa: Fluvisol). Alfalfa and Desmodium displayed translocation factor > 1 (TF = shoot to root concentration ratio) for most heavy metals. Most heavy metals/metalloids may pose a health threat to humans and stock via introduction to the food chain. The plant factors (species and plant part), soil factors (soil type, soil fractions, pH, and CEC), and their interactions significantly (p < 0.05) influenced plant heavy metal and metalloid levels. However, the role of plant part and species emerged as the most important on heavy metal uptake, translocation, sequestration, and ultimately transfer to the food chain. Accordingly, the uptake and distribution of heavy metals/metalloids in the plants reflect the potential environmental and health hazards attributable to the use of fodder grasses, legumes, and cultivation of vegetables in soils with polymetallic and metalloid contamination. 相似文献
27.
Background
The ability to perform quantitative studies using isotope tracers and metabolic flux analysis (MFA) is critical for detecting pathway bottlenecks and elucidating network regulation in biological systems, especially those that have been engineered to alter their native metabolic capacities. Mathematically, MFA models are traditionally formulated using separate state variables for reaction fluxes and isotopomer abundances. Analysis of isotope labeling experiments using this set of variables results in a non-convex optimization problem that suffers from both implementation complexity and convergence problems.Results
This article addresses the mathematical and computational formulation of 13C MFA models using a new set of variables referred to as fluxomers. These composite variables combine both fluxes and isotopomer abundances, which results in a simply-posed formulation and an improved error model that is insensitive to isotopomer measurement normalization. A powerful fluxomer iterative algorithm (FIA) is developed and applied to solve the MFA optimization problem. For moderate-sized networks, the algorithm is shown to outperform the commonly used 13CFLUX cumomer-based algorithm and the more recently introduced OpenFLUX software that relies upon an elementary metabolite unit (EMU) network decomposition, both in terms of convergence time and output variability.Conclusions
Substantial improvements in convergence time and statistical quality of results can be achieved by applying fluxomer variables and the FIA algorithm to compute best-fit solutions to MFA models. We expect that the fluxomer formulation will provide a more suitable basis for future algorithms that analyze very large scale networks and design optimal isotope labeling experiments. 相似文献28.
Denis Baurain Laurent Renquin Stana Grubisic Patsy Scheldeman Amha Belay Annick Wilmotte 《Journal of phycology》2002,38(2):384-393
The internally transcribed spacer (ITS) sequences of 21 Arthrospira clonal strains from four continents and assigned to four different species (A. platensis, A. maxima, A. fusiformis, A. indica) in the culture collections were determined. Two main clusters, I and II, were differentiated by 49 positions out of 475 nt or 477 nt, respectively. Each cluster was further subdivided into two subclusters. Subclusters I.A and I.B were separated by two substitutions, whereas subclusters II.A and II.B were distinguished by four substitutions. After direct sequencing of the PCR products, three dried samples from Chad aged between 3 months and 35 years yielded a sequence belonging to subcluster I.A, as did a recent commercial product. The strains grown in production plants belonged to the same (sub)clusters as strains from culture collections, mainly I.A and II. PCR primers specific for each cluster and subcluster were designed and tested with crude cell lysates of Arthrospira strains. One dried sample (“dihé” 1) and a herbarium sample from Lake Sonachi (Kenya) only contained I.A sequences, whereas the commercial product was a mixture of the four genotypes and the other two dried samples contained minor polymorphisms characteristic of different clusters. Five clonal Arthrospira strains, thought to be duplicates, showed the simultaneous presence of the two forms of the four diagnostic positions that distinguish subclusters genotype II.A and genotype II.B. This is likely to be caused by multiple copies of the rDNA operon, in a intermediate stage of homogenization between subcluster II.A and subcluster II.B. The high conservation of ITS sequences is in contrast with the assignment to four different species, the great morphological variability of the strains, and their wide geographic distribution. 相似文献
29.
KNUT H. R
ED GUNNAR HASLE V. MIDTHJELL GRETHE SKRETTING HANS P. LEINAAS 《Molecular ecology resources》2006,6(4):1165-1167
Ixodes ricinus is the main vector for important infectious diseases in both humans and in animals. Microsatellite loci were isolated from a dinucleotide‐enriched library made from I. ricinus sampled in Norway. Seventeen polymorphic microsatellites were further characterized among 24 individuals sampled from an island in the Oslofjord region. The number of observed alleles ranged from two to 17 and the observed heterozygosities between 0.10 and 0.83. Analysis of family materials gives evidence of non‐Mendelian inheritance of several of the characterized loci, among which most could be explained by presence of null alleles. 相似文献
30.