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1.
The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species. All methods delimited two species groups, and these are supported based on colouration patterning and morphology; the Nannocharax multifasciatus and the Nannocharax macropterus species groups and the delimited OTUs were assigned to each. Two putative new species were identified, Nannocharax cf. lineostriatus “Okavango” from the Okavango River in Angola and N. cf. lineostriatus “Kwanza” from the Kwanza River system in Angola. The distribution of Nannocharax dageti was confirmed for the Upper Zambezi and extended to the Okavango system, and an identification key for the southern Africa Nannocharax species is provided.  相似文献   

2.
The Cephalomalthinus semifumatus species group, referred to as the “semifumatus” group henceforth, is interesting because of its heterogeneous morphology resembling either Cephalomalthinus Pic, 1921 or Rhagonycha Eschscholtz, 1830. To elucidate its phylogenetic status, mitochondrial genomes of four species of the “semifumatus” group, 11 Cephalomalthinus species, and 11 Rhagonycha species were sequenced and examined. All analysed mitogenomes were similar with respect to genome size, nucleotide composition, and AT content. Surprisingly, a rearrangement of the trnW-trnC and trnY genes was detected in the “semifumatus” group, presumably caused by tandem duplication and random loss events. Furthermore, genetic distance analyses showed that the proximity of the “semifumatus” group to Cephalomalthinus and to Rhagonycha was comparable to that between the latter two. Moreover, the produced phylogeny strongly supported the monophyly of the “semifumatus” group, and molecular clock analyses dated its divergence from Cephalomalthinus to 32.52 Ma. Thus, the new genus Amphimorphus gen. nov. is suggested to comprise the “semifumatus” group, in which the observed gene rearrangement was a synapomorphy. Moreover, morphological evidence regarding the unique structure of the aedeagus supported this separation. These results indicate that mitochondrial gene rearrangement provide important phylogenetic implications for revising Cephalomalthinus, a speciose genus that is puzzling in the morphology-based taxonomy.  相似文献   

3.
With the use of rabbit antisera against crustacean hyperglycemic hormone (CHH), it is possible to describe a distinct immunopositive reaction in a group of neurosecretory cells in the medulla terminalis ganglionic X-organ2 (MTGX2), in the MTGX-sinus gland tract, and in a considerable part of the sinus gland from several species of prawns belonging to the Palaemonidae. By introductory studies on the CHH system in Palaemon serratus, we can postulate a sequence in the activity cycle of the CHH-producing cells on the basis of differences in staining intensity of the immunoreaction and such morphometric parameters as cellular and nuclear diameter. By studying the CHH-producing system in combination with variations in the glucose level of the blood, an “inverse relationship” is observed between the number of immunoreactive cells and the blood glucose level during different periods of the year as well as during different stages of the molting cycle. A “shift in phase” of this correlation during the diurnal cycle suggests that several rhythmical phenomena may play a role in the regulation of glycemia in Crustacea.  相似文献   

4.
ObjectivesThe aim of this study was to determine the association of “ABO” and “Rhesus” blood groups with incidence of breast cancer.MethodsIn this study, we identified 70 research documents from data based search engines including “PubMed”, “ISI-Web of Knowledge”, “Embase” and “Google Scholar”. The research papers were selected by using the primary key-terms including “ABO blood type”, “Rhesus” blood type and “breast cancer”. The research documents in which “ABO” and “Rhesus” blood types and breast cancer was debated were included. After screening, we reviewed 32 papers and finally we selected 25 research papers which met the inclusion criteria and remaining documents were excluded.ResultsBlood group “A” has high incidence of breast cancer (45.88%), blood group “O” has (31.69%); “B” (16.16%) and blood group “AB” has (6.27%) incidence of breast cancer. Blood group “A” has highest and blood group “AB” has least association with breast cancer. Furthermore, “Rhesus +ve” blood group has high incidence of breast cancer (88.31%) and “Rhesus –ve” blood group has least association with breast cancer (11.68%).ConclusionBlood group “A” and “Rhesus +ve” have high risk of breast cancer, while blood type “AB” and “Rhesus –ve” are at low peril of breast cancer. Physicians should carefully monitor the females with blood group “A” and “Rh +ve” as these females are more prone to develop breast cancer. To reduce breast cancer incidence and its burden, preventive and screening programs for breast cancer especially in young women are highly recommended.  相似文献   

5.
Three groups, each comprising 200 consumers, performed paired preference tests between two flavors of potato chips. For one group, a “No Preference” option was allowed, while for the second group, it was not. For a third group, a “No Preference” option was allowed while the preference responses were differentiated as “Strong Preference” and “Weak Preference.” For all three groups, d′ values representing overall strength of preference did not differ significantly.  相似文献   

6.
7.
Shot hole disease is one of the most important diseases of stone fruit trees in Iran. The disease is wide spread among orchards of Prunus spp. During spring and summer of 2007, 80 monoconidial isolates of the pathogen were recovered from infected leaves, fruits and twigs of different Prunus spp. in West Azerbaijan, Tehran, Ghazvin and Razavi Khorasan provinces of Iran and were studied taxonomically. Based on morphological and physiological characteristics and growth optimal temperature, all isolates were identified as Wilsonomyces carpophilus. Seedlings of stone fruits (apricot, almond, peach, nectarine, plum, sweet cherry and sour cherry) were used for pathogenicity tests. All seedlings were susceptible to the fungal isolates and showed disease symptoms on twigs, leaves, buds and petioles. Genetic diversity of 28 selected fungal isolates was investigated based on DNA fingerprinting by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR), using four random primers. Based on cluster analysis of the PCR results from the four primers, 10 fingerprinting groups (clonal lineages) and 27 haplotypes were identified. Clonal lineages “C”, “D” and “E”, each with six haplotypes formed the biggest clonal lineages, but other clonal lineages (“B”, “F”, “G”, “H”, “I” and “J”) included only one isolate. No correlation was detected among clonal lineages with the location of selected isolates and their host species. A correlation was found between the substrate (fruit, twig or leaf) and clonal lineages, particularly in “C” clonal lineage. The results showed that the fungus population had high genetic diversity which is distributed among the different areas of Iran.  相似文献   

8.
Twelve of 24 monospecific caprine reagents produced by absorption of alloimmune antisera identified a complex blood group system of goats which was designated B, based on the results of a small comparison test with ovine reagents. The frequencies of the 12 B factors differed significantly among the Australian Angora, Texan Angora, Cashmere, and Dairy goat breeds. Three of the antigens detected by the reagents were shown to be related as linear subtypes, designated Ba1, Ba2, and Ba3, and inherited as alleles. The segregations of B factors in 80 sire groups involving 1086 offspring demonstrated that groups of B factors (phenogroups) segregated as products of allelic genes. This work was supported by a grant from the Australian Stud Book, Alison Road, Randwick, New South Wales 2031, Australia.  相似文献   

9.
The triplet consisting of two monophyletic taxa and one paraphyletic taxon as constructive element of the phylogenetic system Evolution has produced very many novelties (apomorphies). Most of them are small and relatively inconstant, these are more or less indicative of the phylogenetic relationships between closely related species. They cannot be the constitutive character of a supraspecific taxon that exists since a long time and comprises many diversified species. Such a taxon of higher rank can only be characterized by an improbable, rare novelty that has developed only once and has been preserved in all descendent species. Two consecutive apomorphies of this persistent type (‘fixed apomorphies’) characterize three supraspecific taxa, the triplet “A”, “B” and “A minus B” (Fig. 1). The group “A minus B” is rejected in Hennig's theory because it is ‘paraphyletic’, but it is not an artefact created by the systematicist. It is an inevitable mathematical consequence of the differentiatison of the group “B” within the group “A”. Being the result of a subtraction, it is necessarily associated with the two monophyletic partners in the triplet, as it is delimited on one side by the synapomorphy of the group “A”, of which it is a part, and on the other side by the autapomorphy of the separate group “B”. Traditional classifications often include paraphyletic groupings that are inconsistent with phylogenetics, e. g. the Reptilia and the Apterygota. The fault in such cases is that these groups are extended beyond the limits of a triplet and cover more than a single interval between consecutive monophyletic taxa. Paraphyletic groups are admitted in the phylogenetic system only for bridging the gaps in our cladistic information. According to HENNIG'S theory, all supraspecific taxa should be arranged two by two as sister-groups originating from one ancestral species and comprising all descendents of that species. The fixed evolutionary novelties which characterize higher supraspecific taxa are, however, rare and scattered. It is highly improbable that they have developed in sister species, therefore the taxa marked by them cannot be sister-groups (except in very rare cases). In HENNIG'S earlier papers, e. g. in his system of Lepidoptera (1953: 46–49), the alleged ‘sister-groups' are, in reality, the groups “B” and “A minus B” of a triplet (see Fig. 2). In his revised concept (1957 and later), two autapomorphic groups which are most closely related in the recent fauna (“B” and “C” in Fig. 3) are called ‘sister-groups’. But these have originated independently from different ancestors in a plesiomorphic complex of extinct species and are more closely related to parts of this complex than to each other. True sister-groups (“Bx” and “Cx” in Fig. 4) would be formed if these related plesiomorphic species were included, but this extension of the ’backward‘ border of the taxon is not justified by synapomorphy (in the terms of logic, it is a ’metabasis‘), and it would make the classification of fossil species impossible, unless these show at least one synapomorphy with either “B” or “C”. In the system of the recent fauna the sister-groups are identical with the autapomorphic groups, because the plesiomorphic species are extinct. The natural system based on synapomorphies and autapomorphies is the triplet-system as outlined in Figure 6. It is not a new type of classification, but its theoretical foundation was missing, and precise instructions were needed for its use in phylogenetics. The information obtained by HENNIG'S method is entirely preserved in this system and can be retrieved from it, and both recent and extinct species can be classified together. The disadvantage of the triplet-system is that it contains twice as many taxa as HENNIG'S classification. This complexity will limit its use in the practice of taxonomy, but it may be simplified by transforming the system into a sequence of paraphyletic taxa terminating in a single monophylum.  相似文献   

10.
Ten-day monospecific mouse antisera prepared against serotypes L1, L2, and L3 ofChlamydia trachomatis were titrated against homologous and heterologous antigens in the microimmunofluorescence (micro-IF) test and by a new microneutralization method. While broad crossreactivity between serotypes was detected in the micro-IF test, the same antisera demonstrated serotype specific neutralizing activity. The microneutralization test could be used for serotyping new chlamydial isolates when equivocal results have been obtained by the microimmunofluorescence method.  相似文献   

11.
First attempt to study polymorphism of erythrocyte antigens of spotted reindeer Cervus (Cervus) nippon Temminck, 1838 blood was made. With the aid of a set of monospecific antisera against blood groups of cattle and pigs, natural antisera of spotted reindeer, iso- and heteroimmune antisera against factors of erythrocytes of spotted reindeer, antigenic picture of blood in cattle of five Primorsk region farms was revealed. Indeces of genetic similarity between populations studied have been calculated and the scheme of their relationships presented.  相似文献   

12.
Over a long time frame, an ecological system may not exhibit constancy due to successional and evolutionary changes in the species composing the system. However, over shorter time frames an ecological system exhibits a certain degree of constancy (i.e., varies within defined bounds). Traditionally, ecologists considered this short-term constancy to reflect a “balance of nature,” which was viewed akin to the simple homeostatic dynamics of physiological systems. This is an appealing perspective because the disruption of the system's “balance” (i.e., its ”health“) can be ascertained by comparing the system's current state after the imposition of a perturbation with the societally desired state (i.e., baseline). Recently, ecologists have started to develop a much more complex, and perhaps more realistic, perspective regarding ecosystem dynamics, which does not depend upon homeostasis with a single baseline state. This new view includes stochastic variation, nonlinear dynamics and alternative states, and poses a challenge for assessing environmental “health” and the risk of creating “unhealthy” ecological systems  相似文献   

13.
Secondary mesenchyme cells (SMCs) of the sea urchin embryo are composed of pigment cells, blastocoelar cells, spicule tip cells, coelomic pouch cells and muscle cells. To learn how and when these five types of SMCs are specified in the veg2 descendants, Notch or Nodal signaling was blocked with γ‐secretase inhibitor or Nodal receptor inhibitor, respectively. All types of SMCs were decreased with DAPT, while sensitivity to this inhibitor varied among them. Pulse‐treatment revealed that five types of SMCs are divided into “early” (pigment cells and blastocoelar cells) and “late” (spicule tip cells, coelomic pouch cells and muscle cells) groups; the “early” group was sensitive to DAPT up to the hatching, and the “late” group was sensitive until the mesenchyme blastula stage. Judging from timing of the shift of Delta‐expressing regions, it was suggested that the “early” group and “late” groups are derived from the lower and the middle tier of veg2 descendants, respectively. Interestingly, numbers of SMCs were also altered with SB431542; blastocoelar cells, coelomic pouch cells and circum‐esophageal muscles decreased, whereas pigment cells and spicule tip cells increased in number. Pulse‐treatment showed that the “early” group was sensitive up to the mesenchyme blastula stage, while the “late” group up to the onset of gastrulation. Thus, it became clear that precursor cells of the “early” and “late” groups, which are located in different regions in the vegetal plate, receive Delta and Nodal signals at different timings, resulting in the diversification of SMCs. Based on the obtained results, the specification processes of five types of SMCs are diagrammatically presented.  相似文献   

14.
The indirect immunofluorescent test employing a monospecific antiserum has been used to detect the tissue localization of Echinococcus granulosus specific antigen “5.”The antigen was revealed in the inner portion of the germinal “membrane” and in the parenchyma of the protoscoleces. In these stages, it was also demonstrated fixed to the walls of some collecting ducts.It is postulated that the synthesis of the antigen “5” may occur in specialized cells of both the germinal “membrane” and the protoscoleces of the hydatid cysts.The osmoregulatory system of E. granulosus larvae seems to be involved in the transfer of the substance to the cystic cavity.  相似文献   

15.
Instead of close and differentiated relationship among adult females, the accepted norm for savanna baboons, groups of Drakensberg mountain baboons (Papio ursinus) showed strong affiliation of females towards a single male. The same male was usually the decision-making animal in controlling group movements. Lactating or pregnant females focused their grooming on this “leader” male, producing a radially patterned sociogram, as in the desert baboon (P. hamadryas); the leader male supported young animals in the group against aggression and protected them against external threats. Unlike typical savanna baboons, these mountain baboons rarely displayed approach-retreat or triadic interactions, and entirely lacked coalitions among adult females. Both groups studied were reproductively one-male; male-female relationships in one were like those in a unit of hamadryas male at his peak, while the other group resembled the unit of an old hamadryas male, who still led the group, with a male follower starting to build up a new unit and already monoplizing mating. In their mountain environment, where the low population density suggests conditions as harsh for baboons as in deserts, adults in these groups kept unusually large distances apart during ranging; kin tended to range apart, and spacing of adults was greatest at the end of the dry, winter season. These facts support the hypothesis that sparse food is responsible for convergence with hamadryas social organization. It is suggested that all baboons, though matrilocal, are better categorized as “cross-sex-bonded” than “female bonded”.  相似文献   

16.
The objective of this study was to resolve key mechanisms driving individual growth patterns of Atlantic cod (Gadus morhua). Growth dynamics were analysed by linking growth patterns with stomach content composition and environmental temperature. Samples were collected in August/September of the years 2009, 2010 and 2011 in the north‐eastern part of the central North Sea. Prey selection was assessed by identification of individual prey items in the stomach content to species. Ten feeding groups were identified consisting of individuals with one prey type dominating their stomach contents (≥75% by mass), of which six were used for growth analyses: “Sandeel”, “Clupeids”, “Norway pout”, “Flatfishes”, “Crustaceans” and “Brittle stars”. For each group, growth patterns were estimated based on measures of otolith growth increments. The stomach contents showed that cod as a species are opportunistic in their prey selection, but at the same time indicated that the total, broad feeding niche width of the population is dominated by individual diet specialization and that many individuals temporally show a preference for a particular prey type. The contribution of invertebrates and particularly crustaceans decreased with increasing cod size, whereas that of fish and predominantly herring increased. Prey type had a significant effect on growth, while temperature had no effect. Slowest growth was observed in the cod group preying on sandeel, while cod preying on Norway pout showed the fastest growth. No significant difference was observed between groups preying on brittle stars, crustaceans, flatfishes and herring. Growth in the year before capture did however not differ between any of these groups. Across sampling years, growth chronology patterns were similar but not significantly influenced by temperature.  相似文献   

17.
Cochliopodium is a lens‐shaped genus of Amoebozoa characterized by a flexible layer of microscopic dorsal scales. Recent taxonomic and molecular studies reported cryptic diversity in this group and suggested that the often‐used scale morphology is not a reliable character for species delineation in the genus. Here, we described three freshwater Cochliopodium spp. from the southeastern United States based on morphological, immunocytochemistry (ICC), and molecular data. A maximum‐likelihood phylogenetic analysis and pairwise comparison of COI sequences of Cochliopodium species showed that each of these monoclonal cultures were genetically distinct from each other and any described species with molecular data. Two of the new isolates, “crystal UK‐YT2” (Cochliopodium crystalli n. sp.) and “crystal‐like UK‐YT3” (C. jaguari n. sp.), formed a clade with C. larifeili, which all share a prominent microtubule organizing center (MTOC) and have cubical‐shaped crystals. The “Marrs Spring UK‐YT4” isolate, C. marrii n. sp., was 100% identical to “Cochliopodium sp. SG‐2014 KJ569724 .” These sequences formed a clade with C. actinophorum and C. arabianum. While the new isolates can be separated morphologically, most of the taxonomic features used in the group show plasticity; therefore, Cochliopodium species can only be reliably identified with the help of molecular data.  相似文献   

18.
Bovine lymphocytotoxicity tests with 20 unabsorbed bovine blood group sera revealed extensive reactivity which in the majority of cases had no indication of blood group relationship. Six of these sera were absorbed with selected lymphocytes to produce eleven antisera of reduced specificity. Again, most of the sera had reaction patterns which could not be related to the hemolytic patterns of any known blood group antibodies. However, five comparisons involving unabsorbed antisera and two comparisons involving absorbed antisera provided statistical evidence of similarities between their lymphocytotoxic reaction patterns and the hemolytic reaction patterns of certain blood group antibodies. Several of the sera appeared to contain related cytotoxic specificities, and three such absorbed sera may have contained an anti-J specificity. All six examined monospecific isoimmune blood group antisera contained lymphocytic reactivities not related to their hemolytic specificites. Two normal sera containing naturally occurring anti-J had no cytotoxic activity. Anti-semen sera likewise were devoid of lymphocytotoxic activity.  相似文献   

19.
Bovine lymphocytotoxicity tests with 20 unabsorbed bovine blood group sera revealed extensive reactivity which in the majority of cases had no indication of blood group relationship. Six of these sera were absorbed with selected lymphocytes to produce eleven antisera of reduced specificity. Again, most of the sera had reaction patterns which could not be related to the hemolytic patterns of any known blood group antibodies. However, five comparisons involving unabsorbed antisera and two comparisons involving absorbed antisera provided statistical evidence of similarities between their lymphocytotoxic reaction patterns and the hemolytic reaction patterns of certain blood group antibodies. Several of the sera appeared to contain related cytotoxic specificities, and three such absorbed sera may have contained an anti-J specificity. All six examined monospecific isoimmune blood group antisera contained lymphocytic reactivities not related to their hemolytic specificities. Two normal sera containing naturally occurring anti-J had no cytotoxic activity. Anti-semen sera likewise were devoid of lymphocytotoxic activity.  相似文献   

20.
The diurnal light cycle has a crucial influence on all life on earth. Unfortunately, modern society has modified this life-governing cycle by stressing maximum production and by giving insufficient attention to the ecological balance and homeostasis of the human metabolism. The aim of this study is to evaluate the effects of exposure or lack of exposure to natural light in a rest/activity rhythm on cortisol and melatonin levels, as well as on psychological variables in humans under natural conditions. This is a cross-sectional study. The subjects were allocated split into two groups according to their workspace (10 employees in the “with window” group and 10 in the “without window” group). All participants were women and wore anactigraph (Actiwatch 2, Philips Respironics), which measures activity and ambient light exposure, for seven days. Concentrations of melatonin and cortisol were measured from the saliva samples. Participants were instructed to collect saliva during the last day of use of the actigraph at 08:00 am, 4:00 pm and 10:00 pm. The subjects answered the Self-Reporting Questionnaire-20 (SRQ-20) to measure the presence of minor psychiatric disorders; the Montgomery-Asberg (MA) scale was used to measure depression symptoms, and the Pittsburgh Sleep Quality Index questionnaire (PSQI) was used to evaluate the quality of sleep. The Rayleigh analysis indicates that the two groups, “with window” an d “without window”, exhibited similar activities and light acrophases. In relation to light exposure, the mesor was significantly higher (t?=??2.651, p?=?0.023) in t he “with window” group (191.04?±?133.36) than in the “without window” group (73.8?±?42.05). Additionally, the “with window” group presented the highest amplitude of light exposure (298.07?±?222.97). Cortisol levels were significantly different between the groups at 10:00 pm (t?=?3.009, p?=?0.008; “without window” (4.01?±?0.91) “with window” (3.10?±?0.30)). In terms of the melatonin levels, the groups differed at two different times of day: 08:00 am (t?=?2.593, p?=?0.018) and 10:00 pm (t?=??2.939, p?=?0.009). The “with window” group had a lower melatonin level at 08:00 am (3.54?±?0.60) but a higher level at 10:00 pm (24.74?±?4.22) than the “without window” group. Higher cortisol levels were positively correlated with minor psychiatric disorders and depressive symptoms (MA) at 10:00 pm. Lower melatonin levels at 10:00 pm were correlated with depressive symptoms and poor quality of sleep (PSQI). Our study demonstrated that not only may light pollution affect human physiology but also lack of exposure to natural light is related to high levels of cortisol and lower levels of melatonin at night, and these, in turn, are related to depressive symptoms and poor quality of sleep.  相似文献   

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