3,523 research outputs found
Conservation Genetics of Mediterranean Brown Trout in Central Italy (Latium): A Multi-Marker Approach
Brown trout is considered a complex of incipient species, including several phylogenetic
lineages, whose natural distribution in the Mediterranean area has been altered, since the beginning
of the 1900s, by massive introductions of domestic strains of Atlantic origin to support fisheries.
Introduced trout naturalize in new suitable environments and extensively hybridize with native
populations. Here, we characterized putatively neutral and adaptive genetic variability and popu lation structure of Mediterranean brown trout from six river catchments in central peninsular Italy,
as revealed by both mitochondrial (Control Region) and nuclear (microsatellites, LDH-C1, major
histocompatibility complex) markers. We quantified the admixture of wild populations with hatchery
strains and evaluated the effects of domestic trout introductions on shaping population genetics. Our
analyses indicated: (1) a composite picture of genetic variability in the area, with the presence of all
native Mediterranean trout mitochondrial lineages (âAdriaticâ, âMediterraneanâ, âmarmoratusâ), vari ous frequencies of allochthonous genotypes and different rates of introgression among sampling sites;
(2) asymmetric mito-nuclear introgression; (3) increasing nuclear marker diversity with increasing
levels of admixture across populations; (4) strong population structure coupled with relatively low
effective population size. Data allowed the identification of five management units and we propose
specific actions to support ongoing and future conservation strategies within the examined are
Recommended from our members
Geographic variability in the grey mullet Mugil cephalus: preliminary results of mtDNA and chromosome analyses
The grey mullet, Mugil cephalus, plays an important role in the fisheries and aquaculture of tropical and subtropical regions of the world. This species is considered cosmopolitan, but its distribution appears peculiar with regard to the coastal ecology of the species. A multidisciplinary study of the geographic variability of this species, through a cytogenetic, molecular and morphometric characterization, was undertaken to detect whether genetically distinct populations occur. The preliminary results from analyses of mitochondrial DNA and of chromosomes of seven different populations around the world are reported. The different populations analysed are well discriminated by mtDNA analyses: samples are clustered in four groups, Mediterranean, East Atlantic, Central Pacific and East Pacific, with a maximum sequence divergence of 3.3%. The karyotype of all the populations studied is uniformly composed of 48 acrocentric chromosomes, and neither heterochromatin distribution nor nucleolus organizer regions allow the identification of chromosomal markers useful in distinguishing these genetically differentiated groups of populations. © 1993
Chromosome analysis in Saccodon wagneri (Characiformes) and insights into the karyotype evolution of Parodontidae
Parodontidae is a relatively small group of Neotropical characiform fishes
consisting of three genera (Apareiodon, Parodon, and Saccodon) with 32 valid
species. A vast cytogenetic literature is available on Apareiodon and Parodon, but
to date, there is no cytogenetic data about Saccodon, a genus that contains only
three species with a trans-Andean distribution. In the present study the karyotype
of S. wagneri was described, based on both conventional (Giemsa staining, Ag-
NOR, C-bands) and molecular (repetitive DNA mapping by fluorescent in situ
hybridization) methods. A diploid chromosome number of 2n = 54 was observed
in both sexes, and the presence of heteromorphic sex chromosomes of the ZZ/
ZW type was detected. The W chromosome has a terminal heterochromatin band
that occupies approximately half of the long arm, being this band approximately
half the size of the Z chromosome. The FISH assay showed a synteny of the
18S-rDNA and 5S-rDNA genes in the chromosome pair 14, and the absence
of interstitial telomeric sites. Our data reinforce the hypothesis of a conservative
karyotype structure in Parodontidae and suggest an ancient origin of the sex
chromosomes in the fishes of this family
Negative immunodiffusion test results obtained with sera of paracoccidioidomycosis patients may be related to low-avidity immunoglobulin G2 antibodies directed against carbohydrate epitopes
Immunodiffusion (ID) is the serologic test most frequently used for the diagnosis and posttherapy follow-up of patients with paracoccidioidomycosis (PCM). The ID test is highly specific (100%), but its sensitivity is relatively low (90%), leading to false-negative results. The aim of this study was to determine the profiles of antibodies in sera from patients with proven PCM and with negative results in the ID test (IDneg) versus positive results in the ID test (IDpos). We analyzed 46 sera from patients with active PCM for total immunoglobulin G (IgG) and IgG subclass responses to Paracoccidioides brasiliensis gp43 antigen (treated or not treated with sodium metaperiodate) by enzyme-linked immunosorbent assay and immunoblotting. Immunoblotting showed that both IDneg and IDpos sera recognized predominantly the gp43 fraction of the P. brasiliensis antigen used in the ID test. IDneg sera contain low-avidity antibodies, low levels of specific IgG (total) and IgGI, and high levels of IgG2 compared with IDpos sera. The antibodies present in IDpos sera were predominantly directed against carbohydrate epitopes, since treatment with sodium metaperiodate resulted in a significant decrease in antibody reactivity. These data suggest that the lack of reactivity of sera from PCM patients in the ID test may be related to the production of low-avidity IgG2 antibodies directed against carbohydrate epitopes.10580280
Surveillance strategies for Classical Swine Fever in wild boar â a comprehensive evaluation study to ensure powerful surveillance
Surveillance of Classical Swine Fever (CSF) should not only focus on livestock, but must also include wild boar. To prevent disease transmission into commercial pig herds, it is therefore vital to have knowledge about the disease status in wild boar. In the present study, we performed a comprehensive evaluation of alternative surveillance strategies for Classical Swine Fever (CSF) in wild boar and compared them with the currently implemented conventional approach. The evaluation protocol was designed using the EVA tool, a decision support tool to help in the development of an economic and epidemiological evaluation protocol for surveillance. To evaluate the effectiveness of the surveillance strategies, we investigated their sensitivity and timeliness. Acceptability was analysed and finally, the cost-effectiveness of the surveillance strategies was determined. We developed 69 surveillance strategies for comparative evaluation between the existing approach and the novel proposed strategies. Sampling only within sub-adults resulted in a better acceptability and timeliness than the currently implemented strategy. Strategies that were completely based on passive surveillance performance did not achieve the desired detection probability of 95%. In conclusion, the results of the study suggest that risk-based approaches can be an option to design more effective CSF surveillance strategies in wild boar
'Asking the right question'. A comparison of two approaches to gathering data on 'herbals' use in survey based studies
BACKGROUND:Over the last decade academic interest in the prevalence and nature of herbal medicines use by pregnant women has increased significantly. Such data are usually collected by means of an administered questionnaire survey, however a key methodological limitation using this approach is the need to clearly define the scope of 'herbals' to be investigated. The majority of published studies in this area neither define 'herbals' nor provide a detailed checklist naming specific 'herbals' and CAM modalities, which limits inter-study comparison, generalisability and the potential for meta-analyses. The aim of this study was to compare the self-reported use of herbs, herbal medicines and herbal products using two different approaches implemented in succession. METHODS:Cross-sectional questionnaire surveys of women attending for their mid-trimester scan or attending the postnatal unit following live birth at the Royal Aberdeen Maternity Hospital, North-East Scotland. The questionnaire utilised two approaches to collect data on 'herbals' use, a single closed yes/no answer to the question "have you used herbs, herbal medicines and herbal products in the last three months"; and a request to tick which of a list of 40 'herbals' they had used in the same time period. RESULTS:A total of 889 responses were obtained of which 4.3% (38) answered 'yes' to herbal use via the closed question. However, using the checklist 39% (350) of respondents reported the use of one or more specific 'herbals' (p<0.0001). The 312 respondents who reported 'no' to 'herbals' use via the closed question but "yes" via the checklist consumed a total of 20 different 'herbals' (median 1, interquartile range 1-2, range 1-6). CONCLUSIONS:This study demonstrates that the use of a single closed question asking about the use of 'herbals', as frequently reported in published studies, may not yield valid data resulting in a gross underestimation of actual use
Dynamic SU(2) Structure from Seven-branes
We obtain a family of supersymmetric solutions of type IIB supergravity with
dynamic SU(2) structure, which describe the local geometry near a stack of four
D7-branes and one O7-plane wrapping a rigid four-cycle. The deformation to a
generalized complex geometry is interpreted as a consequence of nonperturbative
effects in the seven-brane gauge theory. We formulate the problem for
seven-branes wrapping the base of an appropriate del Pezzo cone, and in the
near-stack limit in which the four-cycle is flat, we obtain an exact solution
in closed form. Our solutions serve to characterize the local geometry of
nonperturbatively-stabilized flux compactifications.Comment: 49 pages, 2 figures; v2: minor corrections, references adde
Hereditary Deficiency of gp91(phox) Is Associated With Enhanced Arterial Dilatation Results of a Multicenter Study
Background-NADPH oxidase is believed to modulate arterial tone, but its role in humans is still unclear. The objective of this study was to evaluate whether NADPH oxidase is involved in flow-mediated arterial dilation (FMD). Methods and Results-Twenty-five patients with hereditary deficiency of gp91(phox), the catalytic core of NADPH oxidase, (X-CGD), 25 healthy subjects, and 25 obese patients matched for sex and age were recruited. FMD, platelet gp91(phox), serum levels of nitrite and nitrate as markers of nitric oxide generation, oxidized low-density lipoprotein, and urinary excretion of isoprostanes as markers of oxidative stress were determined. Platelet gp91(phox) expression was downregulated in X-CGD patients (1.0+/-0.8 mean fluorescence; P<0.001) and upregulated in obese patients (4.1+/-2.2 mean fluorescence; P=0.01) compared with healthy subjects (2.9+/-1.7 mean fluorescence). Urinary excretion of isoprostanes was reduced in X-CGD patients (41.7+/-33.3 pg/mg creatinine; P = 0.04) and increased in obese patients (154.4+/-91 pg/mg creatinine; P<0.001) compared with healthy subjects (69.5+/-52.4 pg/mg creatinine). Obese patients had higher serum oxidized low-density lipoprotein than healthy subjects (35.3+/-6.7 versus 24.8+/-9.8 U/L; P<0.001) and X-CGD patients (28.5+/-7.2 U/L; P<0.001). X-CGD patients had significantly higher FMD (14.7+/-5.9%) compared with healthy subjects (7.9+/-2.5%; P<0.001); obese patients had lower FMD (5.3+/-3.0%; P+/-0.028) compared with healthy subjects. Serum nitrite and nitrate levels were significantly higher in patients with X-CGD (36.0+/-10.8+/-mol/L; P<0.016) and lower in obese patients (9.3+/-11.0 mu mol/L; P<0.001) compared with healthy subjects (27.1+/-19.1 mu mol/L). Serum nitrite and nitrate levels significantly correlated with FMD (R-s = 0.403, P<0.001) and platelet gp91(phox) (R-s = -0.515, P<0.001). FMD inversely correlated with platelet gp91(phox) (R-s = -0.502, P<0.001) and isoprostanes (R-s = -0.513, P<0.001). Conclusion-This study provides the first evidence that, in humans, gp91(phox) is implicated in the modulation of arterial ton
- âŠ