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1.
Rosa Graciela Cohen 《Hydrobiologia》1995,298(1-3):239-240
The type series of the speciesBrachinecta santacrucensis César 1987, is compared with specimens ofBranchinecta granulosa Daday 1902 collected near Facundo, Chubut Province, Argentina. The great resemblance between them suggest that both sets of material belong to the same species and therefore,B. santacrucensis andB. granulosa are synonyms. 相似文献
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Sasha Newell 《Ethnos》2013,78(3):379-402
In Abidjan, both economic and sexual exchanges are structured around the bluff, a mimetic performance of modern urban identity that is both a form of deception and a means of social transformation. Men and women attempt to seduce each other through the bluff and exploit the relationship for material gain. While marriage is held up as an ideal, it is increasingly elusive as kinship has come to mimic the peer networks of the informal economy. Like drag, the bluff collapses oppositions between appearance and reality, highlighting the performative aspects of ‘modernity’. I suggest that widespread urban sexual antagonism may be constructed around gendered performative consumption, such that the impossible demands of maintaining a deceptive appearance of success produces sexual exploitation and anxiety on both sides of the gender divide. 相似文献
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Nada Horvatin?i? Ines Krajcar Broni?Bogomil Obeli? 《Palaeogeography, Palaeoclimatology, Palaeoecology》2003,193(1):139-157
We studied Holocene speleothems and tufa samples collected in numerous caves and rivers in the Dinaric Karst of Croatia, Slovenia, Bosnia and Herzegovina, as well as Serbia and Montenegro. Differences in the formation process of tufa and speleothems are discussed in the context of their isotopic composition (14C, 13C and 18O), as well as the chemistry of surface water (rivers, lakes) and drip water (in caves). The physical and chemical parameters monitored in the surface water (tufa precipitation) and drip water (speleothem precipitation) show that more stable conditions accompany speleothem rather than tufa formation. This is particularly obvious in the water temperature variations (2-22°C in surface water and 7-12°C in drip water) and in saturation index variation (3-11 in surface water and 1-6 in drip water). The range of 14C ages recorded by Holocene speleothems (∼12?000 yr) is wider by several thousands years than that of Holocene tufa samples (∼6000 yr). δ13C values for tufa samples range from −12‰ to −6‰ and for speleothem samples from −12‰ to +3‰ reflecting higher soil carbon and/or vegetation impact on the process of tufa than on speleothem formation. The differences in δ18O values of tufa and speleothem samples from different areas reflect different temperature conditions and differing isotopic composition in the water. The study shows that speleothems from the Dinaric Karst can be used as global palaeoclimatic records, whereas tufa records changes in the local palaeoenvironment. 相似文献
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Paul J. Buzzard 《International journal of primatology》2006,27(2):529-558
I determined the degree of ecological partitioning among 3 species of guenons (Cercopithecus campbelli, C. petaurista, and C. diana) in the Taï Forest, Côte d’Ivoire and used the partitioning data to understand competitive relationships among them. Over a 13-mo period, I measured ecological partitioning in terms of food and canopy stratum use for 2 habituated groups of each guenon species and also collected data on food availability. I found that the study species diverged primarily in food items consumed and vertical strata occupied. Cercopithecus petaurista ate much more foliage than the other species did and used mostly the middle strata (5–20 m). Cercopithecus diana ate primarily fruit and used mostly the upper strata (>20 m). Cercopithecus campbelli ate mostly fruit together with large amounts of animal matter and primarily occupied the ground and low strata (<5 m). Of the specific pairs, the diets of Cercopithecus campbelli/C. diana overlapped the most overall and decreased during the season of low fruit availability. Cercopithecus campbelli and C. diana age/sex classes also overlapped more than the age/sex classes of other species pairs. The results suggest that the potential for competition was more intense for Cercopithecus campbelli/C.diana relations than it is for other species pairs. I compare my results from Taï with those from other primate and guenon communities and demonstrate that dietary overlaps and seasonal dietary divergence are lower in Taï than in most other guenon communities. 相似文献
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Leaf anatomical, ultrastructural, and CO2-exchange analyses of three closely related species of Flaveria indicate that they are C3–C4 intermediate plants. The leaf mesophyll of F. floridana J.R. Johnston, F. linearis Lag., and F. chloraefolia A. Gray is typical of that in dicotyledonous C3 plants, but the bundle sheath cells contain granal, starch-containing chloroplasts. In F. floridana and F. chloraefolia, the chloroplasts and numerous associated mitochondria are arranged largely centripetally, as in the closely related C4 species, F. brownii A.M. Powell. In F. linearis, fewer mitochondria are present and the chloroplasts are more evenly distributed throughout the bundle sheath cytosol. There is no correlation between the bundle sheath ultrastructure and CO2 compensation concentration. () values of these C3–C4 intermediate Flaveria species. At 21% O2 and 25°C, for F. chloraefolia, F. linearis, and F. floridana is 23–26, 14–19, and 8–10 l CO2 l-1, respectively. The O2 dependence of is the greatest for F. chloraefolia and F. linearis (similar to that for C3–C4 intermediate Panicum and Moricandia species) and the least for F. floridana, whose O2 response is identical to that for F. brownii from 1.5 to 21% O2, but greater at higher pO2. The variation in leaf anatomy, bundle sheath ultrastructure, and O2 dependence of among these Flaveria species may indicate an active evolution in the pathway of photosynthetic carbon metabolism within this genus.Abbreviations
CO2 compensation concentration
- IRGA
infrared gas analysis
Published as Paper No. 7068, Journal Series, Nebraska Agricultural Experiment Station 相似文献
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Marine primary productivity studies pursued in the Canadian Arctic in 1961–1963, using standard techniques (oxygen and carbon-14)
of the time, showed that maximum production developed rapidly in July at 5-m depth under very low light intensities and under
intact but melting sea ice. The time of maximum production was correlated with depths of snow in spring. Low production levels
were found in August in those years and estimated in 1956. Nitrate exhaustion occurred before maximum production and was followed
by rapid sinking of chlorophyll and productivity and reduction of assimilation numbers. Gross production values greatly exceeded
net production values in 1961–1963, and gross production in 2 years was about double that of a third year, which may be due
to different initial conditions of nutrient concentrations in the euphotic zone. Interannual variability in primary production
may be the result of changes in water masses in the surface layer, as driven by atmospheric pressure patterns. 相似文献
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Marital isonymy is frequently used to estimate inbreeding and the repeated pairs method is useful to investigate whether the population under examination has subdivisions. These methods can also be applied to registers, such as population censuses, where both spouses' surnames are noted. In this paper, the 1795 census for Córdoba province is analysed. Numerically speaking, Spanish and mixed-race people are the major ethno-social groups in the register. In order to estimate inbreeding, the isonymic method was applied to both groups, at provincial and at parish level. To appreciate to what extent the parishes were genetically isolated, Wright's Fst was also calculated. The repeated pairs method was also used for both groups to assess if population subdivision existed in the units under study. Finally, to evaluate whether the subdivision based on surnames reflected the ethno-social stratification, the same method was used considering the two groups together. At the provincial scale, both groups displayed low inbreeding and micro-differentiation, although the former was higher for the Spanish and the latter for mixed-race groups, which could indicate a more marked conjugal selectivity in the Spanish. At the parish scale, preferences for isonymic spouses were not pronounced either in Spanish or in mixed-race groups; in the Spanish group population subdivision prevailed, with the opposite occurring in the mixed-race group. The estimations from repeated pairs, taking the two groups together, indicated that for the studied populations the surnames do not allow the two groups to be differentiated into isolated reproductive units. 相似文献
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Four populations of Mollugo verticillata L. were compared on the basis of their photosynthetic products, photosynthetic rates, enhancement under low oxygen concentration, and CO2 compensation points. In addition, pulse-chase labeling experiments were conducted using one of the four populations. Depending on the plant population, C4 acids ranged from 40% to 11% of the primary products under short-term exposure to 14CO2. These compounds were also metabolized during pulse-chase experiments. All four populations had significantly different photosynthetic rates and those rates were correlated with the amounts of labelled C4 acids produced and C4-acid turnover. Three populations of M. verticillata had similar compensation points (40 l/l) and degrees of photosynthetic enhancement under low [O2] (20%), the fourth population was much lower in both characteristics (CO2 compensation, 25 l/l; low-O2 enhancement, 12%). The results verify the intermediate nature of photosynthesis in this species, and illustrate populational differences in its photosynthetic and photorespiratory carbon metabolism.Abbreviations PGA
3-phosphoglyceric acid
- Kan
Kansas
- Mass
Massachusetts
- Mex
Mexico 相似文献
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Recently the antichromosome antisera from several sclerogerma patients have been found to recognize the pellicle of metaphase and anaphase chromosomes.In order to identify the pellicle components,we used these antichromosome antisera to screen a human embryonic cDNA library.The sequences of the positive clones are identical to the cDNA gene sequence of CENP-C (centromere protein C),a human centromere autoantigen.This result suggusts that CENP-C is a component of the pellicle of human metaphase and anaphase chromosomes. 相似文献
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Colantonio S Fuster V Küffer C 《Human biology; an international record of research》2007,79(5):491-500
Surnames analysis is useful for populations in which only written documents remain, as is the case for historical populations. In Córdoba province, Argentina, census records contain nominal data of inhabitants, including information on sex, age, ethnosocial category, civil status, occupation, place of birth, and residence, that can be analyzed using surnames. Relationship indicators within and among ecclesiastic units in Córdoba were estimated by isonymy for the adult white population registered in the 1813 census. The Rii, Rij, and R(ST) coefficients and the surname abundance indicator (a) were calculated. Lasker's distances among categories of population units were used to cluster the 16 provincial population categories. Gradients for kinship within population and for surname diversity were in agreement with the principal areas and waves of original settlement in the province. The main population clusters reflect those areas, whereas minor clusters coincide with the network of roads existing in the territory by 1813. The structure of the white population in Córdoba province was determined by the geographic location of the original waves of settlement, and it followed a pattern of relationships conditioned by the routes connecting population units in the Colonial period. 相似文献
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Ré VE Culasso AC Mengarelli S Farías AA Fay F Pisano MB Elbarcha O Contigiani MS Campos RH 《PloS one》2011,6(5):e19471
The Hepatitis C Virus Genotype 2 subtype 2c (HCV-2c) is detected as a low prevalence subtype in many countries, except in Southern Europe and Western Africa. The current epidemiology of HCV in Argentina, a low-prevalence country, shows the expected low prevalence for this subtype. However, this subtype is the most prevalent in the central province of Córdoba. Cruz del Eje (CdE), a small rural city of this province, shows a prevalence for HCV infections of 5%, being 90% of the samples classified as HCV-2c. In other locations of Córdoba Province (OLC) with lower prevalence for HCV, HCV-2c was recorded in about 50% of the samples. The phylogenetic analysis of samples from Córdoba Province consistently conformed a monophyletic group with HCV-2c sequences from all the countries where HCV-2c has been sequenced. The phylogeographic analysis showed an overall association between geographical traits and phylogeny, being these associations significant (α = 0.05) for Italy, France, Argentina (places other than Córdoba), Martinique, CdE and OLC. The coalescence analysis for samples from CdE, OLC and France yielded a Time for the Most Common Recent Ancestor of about 140 years, whereas its demographic reconstruction showed a “lag” phase in the viral population until 1880 and then an exponential growth until 1940. These results were also obtained when each geographical area was analyzed separately, suggesting that HCV-2c came into Córdoba province during the migration process, mainly from Europe, which is compatible with the history of Argentina of the early 20th century. This also suggests that the spread of HCV-2c occurred in Europe and South America almost simultaneously, possibly as a result of the advances in medicine technology of the first half of the 20th century. 相似文献
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We studied the frequency of malformations induced in two mouse strains (Heiligenberger, C57Bl/6J) by exposure to x-rays 3 h after conception. Whereas there was a high number of malformed fetuses in Heiligenberger mice (mostly gastroschises) on day 19 of pregnancy, C57Bl did not respond to radiation exposure shortly after conception with an increased frequency of malformed fetuses. Cross-breeding of both strains revealed that no statistically significant increase in radiation-induced malformations was obtained in the F1 fetuses when the father was Heiligenberger and the mother C57Bl. In the opposite case (Heiligenberger mother, C57Bl father a small but statistically significant increase was observed. 相似文献
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Sun Jae Yoo Jacques Meyer Catalina Achim James Peterson Michael P. Hendrich E. Münck 《Journal of biological inorganic chemistry》2000,5(4):475-487
Rubredoxins contain a mononuclear iron tetrahedrally coordinated by four cysteinyl sulfurs. We have studied the wild-type protein from Clostridium pasteurianum and two mutated forms, C9S and C42S, in the oxidized and reduced states, with Mössbauer, integer-spin EPR, and magnetic circular dichroism (MCD) spectroscopies. The Mössbauer spectra of the ferric C42S and C9S mutant forms yielded zero-field splittings, D=1.2?cm?1, that are about 40% smaller than the D-value of the wild-type protein. The 57Fe hyperfine coupling constants were found to be ca. 8% larger than those of the wild-type proteins. The present study also revealed that the ferric wild-type protein has δ=0.24±0.01?mm/s at 4.2?K rather than δ=0.32?mm/s as reported in the literature. The Mössbauer spectra of both dithionite-reduced mutant proteins revealed the presence of two ferrous forms, A and B. These forms have isomer shifts δ=0.79?mm/s at 4.2?K, consistent with tetrahedral Fe2+(Cys)3(O-R) coordination. The zero-field splittings of the two forms differ substantially; we found D=?7±1?cm?1, E/D=0.09 for form A and D=+6.2±1.3?cm?1, E/D=0.15 for form B. Form A exhibits a well-defined integer-spin EPR signal; from studies at X- and Q-band we obtained g z =2.08±0.01, which is the first measured g-value for any ferrous rubredoxin. It is known from X-ray crystallographic studies that ferric C42S rubredoxin is coordinated by a serine oxygen. We achieved 75% reduction of C42S rubredoxin by irradiating an oxidized sample at 77?K with synchrotron X-rays; the radiolytic reduction produced exclusively form A, suggesting that this form represents a serine-bound Fe2+ site. Studies in different buffers in the pH?6–9 range showed that the A:B ratios, but not the spectral parameters of A and B, are buffer dependent, but no systematic variation of the ratio of the two forms with pH was observed. The presence of glycerol (30–50% v/v) was found to favor the B form. Previous absorption and circular dichroism studies of reduced wild-type rubredoxin have suggested d-d bands at 7400, 6000, and 3700?cm?1. Our low-temperature MCD measurements place the two high-energy transitions at ca. 5900 and 6300?cm?1; a third d-d transition, if present, must occur with energy lower than 3300?cm?1. The mutant proteins have d-d transitions at slightly lower energy, namely 5730, 6100?cm?1 in form A and 5350, 6380?cm?1 in form B. 相似文献
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