Search

The analysis of microscopic images of fish gonad cells ( oocytes) is a useful tool to estimate parameters of fish reproductive ecology and to analyze fish population dynamics. The study of oocyte dynamics is needed to understand ovary development and reproductive cycle of fish. Oocytes go through different developmental states in a continuum temporal sequence providing an interesting example of ordinal classification, which is not exploited by the current oocyte analysis software. This promising paradigm of machine learning known as ordinal classification or ordinal regression focus on classification problems where there exist a natural order between the classes, thus requiring specific methods and evaluation metrics. In this paper we compare 11 ordinal and 15 nominal state-of-the-art classifiers using oocytes of three fish species ( Merluccius merluccius, Trisopterus luscus and Reinhardtius hippoglossoides). The best results are achieved by SVMOD, an ordinal decomposition method of the labelling space based on the Support Vector Machine, varying strongly with the number of states for each specie (about 95 and 80 % of accuracy with three and six states respectively). The classifiers designed specially for ordinal classification are able to capture the underlying nature of the state ordering much better than common nominal classifiers. This is demonstrated by several metrics specially designed to measure misclassification errors associated to states far in the ranking scale. [ABSTRACT FROM AUTHOR]

Genome scans are increasingly used to study ecological speciation, providing a useful genome-wide perspective on divergent selection in the presence of gene flow. Here, we compare current approaches to detect footprints of divergent selection in closely related species. We analyzed 192 individuals from two interfertile European temperate oak species using 30 nuclear microsatellites from eight linkage groups. These markers present little intraspecific differentiation and can be used in combination to assign individual genotypes to species. We first show that different outlier detection tests give somewhat different results, possibly due to model constraints. Second, using linkage information for these markers, we further characterize the signature of divergent selection in the presence of gene flow. In particular, we show that recombination estimates for regions with outlier markers are lower than those for a control region, in line with a prediction from ecological speciation theory. Most importantly, we show that analyses at the haplotype level can distinguish between truly divergent (bi-directional) selection and positive selection in one of the two species, offering a new and improved method for characterizing the speciation process. [ABSTRACT FROM AUTHOR]

Powerful and accurate detection of first-generation (F1) hybrids and backcrosses in nature is needed to achieve a better understanding of the function and dynamics of introgression. To document the frequency of ongoing interspecific gene exchange between two Mediterranean evergreen oaks, the cork oak (Quercus suber) and the holm oak (Q. ilex), we analyzed 1487 individuals originating from across the range of the two species using eight microsatellite loci and two Bayesian clustering approaches (implemented in the programs STRUCTURE and NEWHYBRIDS). Simulated data were used to assess the differences between the two clustering methods and to back up the choice of the threshold value for the posterior probability to discriminate admixed from pure individuals. We found that the use of STRUCTURE resulted in the highest power to detect hybrids, whereas NEWHYBRIDS provided the highest accuracy. Irrespective of the approach, the two species were clearly distinguished as independent genetic entities without any prior information. In contrast with previous reports, we found no evidence for unidirectional introgression. The overall hybridization rate was very low (<2% of introgressed individuals). Only two individuals were identified as F1 hybrids and five as early backcrosses. This work shows that the combined application of the two complementary Bayesian approaches and their systematic validation with simulations, fit for the case at hand, helps gain resolution in the identification of admixed individuals.Heredity (2009) 102, 442–452; doi:10.1038/hdy.2009.8; published online 25 February 2009 [ABSTRACT FROM AUTHOR]

One hundred and thirteen patients underwent the implantation of an ACADEMIA prosthesis between 1999 and 2000. The minimum follow-up period was 5 years. The ACADEMIA prosthesis is available in either uncemented or cemented model, in posterior-cruciate-retaining (PCL) and posterior-stabilised (PS) versions, with a fixed plate. This is a continuous, retrospective, multicenter study; all etiologies were included. Degenerative lesions markedly predominated; there were 106 cases of primary prosthesis. Clinical signs: They were severe with a mean total preoperative 200-point score of 74 points. The surgical procedure: Cement was used for the femoral condyle in 69 surgical procedures, for the tibial platebase in 56 cases; all patients requiring prosthetic patella had a cemented model (93 cases). Postoperative supervision: Patients were asked to undergo the clinical and radiological review required for this study. Criteria for the evaluation of osseointegration of the arthroplasty and possible radiological reactions were recorded. Postoperative complications come down to five cases of phlebitis treated with anticoagulation and two haematomas which did not require any revision procedure for surgical removal. Revision procedures: Seven patients were re-operated for various reasons. Analysis of the “200-point” overall score: The overall evaluation adding the examination score to the functional score gives an idea of the improvements obtained with the operation (74–159). Flexion and pain: The mean preoperative flexion was 107.3°; the mean postoperative flexion is 108.6°. The mean pain grade starts at 10 in the preoperative period and is 42 in the postoperative period. Mechanical axes, varus and valgus displacements: In this series, the knee showed a normal axis in 95.5% of the patients operated on while they were only 13% at the time of the preoperative examination. The HKA angles measured pre- and postoperatively confirm the correction achieved: the mean axis was at 175.2° in the preoperative period; it is at 179.6° in the postoperative period. The femoral condyle was found to be normal in all the patients reviewed, as well as the tibial or patellar implant when the latter was in place. Lucencies: Their thickness is always < 2 mm. At the femoral level, four cases of lucency are noted. At the tibial level, five cases of lucency are found. Patella: Six tilts were observed without detrimental clinical effects. Survival curve: When considering revision surgery with replacement of the prosthesis as the final indicator, the survival rate obtained is 98.23%. The analysis of the results according to the type of implant does not show any statistical significant difference except that complications related to the surgery were only observed in the PS series. At maximum follow-up, no breakage or failure were observed. These early results for the ACADEMIA prosthesis seem encouraging for several reasons: (1) No mechanical complication was noted in relation to the implant either in “PCL” or in “PS”. (2) Surgeons did not make any complaints or comments concerning the use of this prosthesis. (3) The clinical follow-up performed according to the 200-point score of the American Knee Society, shows a clear improvement of the performances of the patient operated on; this result is not altered by the established obesity in most patients and the great number of varus displacements detected during the preoperative evaluation. (4) The most significant improvement in the quality of life is pain relief. (5) Radiological results did not detect any deterioration of the material or significant bone modifications around the prosthesis. [ABSTRACT FROM AUTHOR]

The article presents a roundtable on the revision surgery of total hip prostheses. The session was opened by Philippe Forgeois with an illustrated presentation of the prevalent classifications. They are considered helpful in surgical review since they indicate the lesional stage. Pierre Le Guilloux elaborated on the practical application and examined each point of the preoperative assessment. Pierre Herlin summarized the different approaches and their possible extensions.

Genetic variation in 12 Pinus pinaster (maritime pine) populations spanning most of the distribution range of the species in Portugal was evaluated using six polymorphic chloroplast microsatellite (cpSSR) loci. Thirty-two haplotypes were found. There were indications of very weak differentiation among populations (Weir’s θcoefficient, 0.023), and the RST value, derived from the stepwise mutation model (SMM), was not significantly different from zero. The pattern, in which similarities in allele size, in base pairs, do not contribute to the genetic structure, may be due to the recent mixing of genetic material from different stands through plantations. Overall, a high level of haplotypic variation within populations was detected. Using the SMM estimator (mean genetic distance of individuals within populations, D2sh–––) we divided the populations into two groups, with above and below average values. The first group contained 5 populations, mainly from the central part of the country, which possess, in general, high levels of haplotypic diversity. Among them, 2 populations were divergent from the others based on the pair-wise Nei’s distance. The results indicate that there is no discernible geographic genetic pattern for the Portuguese populations of P. pinaster investigated. The history of expansion of the species range in Portugal during the twentieth century (mainly due to human activity) and extensive gene flow among populations associated with the expansion could explain this finding. [ABSTRACT FROM AUTHOR]

Implants coated with hydroxyapatite (HA) are of very special importance in revisions of total hip prostheses. As far as the fernur is concerned, the rapid bony reconstruction due to the osteoconductive properties which ensure in particular the filling of defects of bony contact guarantee excellent secondary stabilization of the implants, provided that the mechanical assembly secured at operation be stable. The results of a personal series of 46 patients confirm the efficacity of the HA coating by demonstrating the quality of bony reconstruction and the long-term stability of the implants with satisfactory clinical results. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA), which constitutes 65% of the mineral component of human bone, is a crystalline structure whose synthesis was achieved at the beginning of the century. The development of the technology of coating metals with a ceramic material stimulated extensive research throughout the world leading to the use of implants coated with HA in maxillofacial surgery. The application to ostearticular implants was preceded by rigorous and prolonged experimentation, which demonstrated that implants of titanium coated with HA were devoid of risk and made it possible to secure excellent bony fixation. With a follow-up well in excess of 10 years the published results are evidence of considerable improvement and confirm that articular implants coated with HA represent a major advance. However, HA is only involved in bony fixation and cannot compensate for inadequate design of the implants as regards their shape or surface state. [ABSTRACT FROM AUTHOR]

Previous studies have established that chloroplasts are inherited paternally in Actinidia interspecific crosses. However, fertilisation problems in interspecific crosses may affect the transmission of organelles. Six female clones, i.e. ‘Abbott’, ‘Bruno’, ‘Greensill’, ‘Hayward’, ‘Jones’, ‘Monty’, and four male clones were used to identify cpDNA polymorphisms within the cultivated kiwifruit species A. deliciosa. The restriction patterns by HpaII of a chloroplast fragment amplified by PCR with a pair of universal primers revealed a polymorphism at the intraspecific level. The inheritance of cpDNA in 143 seedlings from three intraspecific crosses in kiwifruit ( Actinidia deliciosa) was studied. All offspring displayed the restriction pattern of the paternal parent, indicating that maternal inheritance of cpDNA in kiwifruit is rare at best. Strict maternal inheritance of mtDNA was confirmed in the same crosses used to investigate cpDNA transmission. Studies of cytoplasmic inheritance in the Actinidia genus represent to date the best documented report of differential organelle inheritance of cpDNA and mtDNA in angiosperms. [ABSTRACT FROM AUTHOR]

Copyright of European Journal of Orthopaedic Surgery & Traumatology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Using two-dimensional polyacrylamide gel electrophoresis, the genetic variation of proteins was examined in three organs (needle, bud, and pollen) from 18 trees of maritime pine. Three types of variation were noted: presence/absence, staining intensity, and position variation of the spots. Of the 902 polypeptides scored in the three organs, 245 (27.2%) were polymorphic. Moreover, among these variable spots, 117 were found in a single organ, demonstrating an increased polymorphism of the organ-specific polypeptides (56.0% vs 18.4% for the organ-unspecific polypeptides). Finally, a positive correlation was found between variability level and subunit molecular weight for spots showing position variation but not for spots showing presence/absence or staining intensity variations. Possible explanations for this observation are discussed. [ABSTRACT FROM AUTHOR]

Genetic diversity at nine isozyme loci was surveyed in an endangered tree species, the argan tree, endemic to south-western Morocco. The species is highly diverse (3.6 alleles/locus) with populations strongly differentiated from each other ( F=0.25). This example is used to illustrate a method for standardizing measures of allelic richness in samples of unequal sample sizes, which was developed for the estimation of the number of species and relies on the technique of rarefaction. In addition, it is shown that the measure of subdivision, θ, obtained when allelic richness is used in place of h (Nei's index of diversity), is much larger than the F [e.g. θ=0.52, where (40) indicates the specified sample used to estimate the allelic richness]. This suggests that rare alleles (which strongly influence measures of allelic richness) have a more scattered distribution than more frequent ones, a result which raises special conservation issues for the argan tree. [ABSTRACT FROM AUTHOR]

The restriction patterns of two chloroplast fragments and one mitochondrial DNA fragment, amplified by PCR with universal primers, were studied to determine the mode of inheritance of these organelles in 143 progeny of five intraspecific crosses in pedunculate oak ( Quercus robur L.). The results indicate that both genomes are maternally inherited, an observation which agrees with the commonly observed pattern of inheritance in angiosperms. They confirm that both chloroplast DNA and mitochondrial DNA can be used as a source of seed-specific markers for the study of the geographic structure of oaks. This is the first report of organelle inheritance within the Fagaceae, an important and widespread tree family. [ABSTRACT FROM AUTHOR]

An extension of Nei's analysis of diversity in a subdivided population is proposed for a haploid locus. The differentiation Gbecomes a natural extension of Wright's Fand generalizes Weir and Cockerham's parameter of co-ancestry by relaxing the assumption of identical correlation for all the alleles. Inter- and intrapopulation variances of the estimated diversities and differentiation are derived. Finally, the optimal sampling strategy for measuring Gwhen a fixed number of individuals can be analysed is considered. It is shown that, at a given locus, there is a unique sample size per population which yields the smallest variance of G,regardless of the number of populations studied. These theoretical developments are illustrated with an analysis of chloroplast DNA diversity in a forest tree. The results emphasize the necessity of sampling many populations, rather than many individuals per population, for an accurate measurement of the subdivision of gene diversity at a single locus. [ABSTRACT FROM AUTHOR]

Chloroplast DNA polymorphisms have been detected by the conventional Southern-blotting hybridization method in four species of European oaks ( Quercus petraea, Q. robur, Q. pubescens and Q. pyrenaica). Three polymorphisms, shared by at least three of these species, can be scored directly in ethidium bromidestained gels and were used in a broad survey of the level of differentiation of the oak species and of their pattern of genetic structure in western Europe. The highly significant geographic variation and the high genetic differentiation ( Gst=0.895, S=0.025) indicate a low level of cytoplasmic gene flow. We conclude that cytoplasmic genomes are well suited for the reconstruction of past migrational routes of such a complex of species. [ABSTRACT FROM AUTHOR]

Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of European Journal of Orthopaedic Surgery & Traumatology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this article, the author discusses the genetic consequences of colonization in population genetics. The author presents various studies conducted by researchers on qualitative approaches to study the genetics of colonization with metapopulations models as the first representation of biogeography and palaoecology. A summary of the study which describes the historical view of the genetic structure of populations is also given.