Macroclimate modulates the positive dead-wood influence on bryophyte diversity in managed and unmanaged temperate lowland forests.

Extending the network of strict forest reserves is one of the conservation measures promoted by the French National Strategy for Biodiversity. However, there is a lack of evidence concerning the efficiency of setting aside strict forest reserves to preserve biodiversity in the case of temperate forests. Moreover, there are potentially unexplored underlying ecological mechanisms that forest management could usefully mimic. In order to disentangle the respective roles of management abandonment, stand structural attributes and climatic and topographic variables in determining forest biodiversity, we conducted the first national-scale study in France comparing biodiversity in managed and in unmanaged forests. Here we focus on bryophytes (all species combined and forest specialists separately). We analyzed data from 127 plots in ten lowland forests in France. Our aim was to disentangle the relationships between bryophyte richness and (i) management abandonment per se, (ii) associated forest-structure variables like deadwood volume, and (iii) macroclimatic variables important for bryophytes (temperature, precipitation, relative humidity, solar radiation and vapor pressure deficit). For each studied combination of variables (univariate, additive or interactive models), we compared hierarchical models of several types: linear with a fixed slope, linear with a random slope, quadratic, sigmoid or threshold models. We found that deadwood variables were the main drivers of bryophyte richness in managed as well as in unmanaged stands. We observed a sigmoid relationship of total deadwood volume to overall richness, and a threshold effect of large and very large deadwood volume on forest specialist richness. The effect of management abandonment was globally non-significant, though impact varied strongly among the different forest sites. A combination of deadwood and macroclimatic variables best predicted bryophyte richness, through non-linear relationships: 1) higher solar radiation reinforced the positive effects of large deadwood on forest-specialist bryophyte richness; and 2) higher mean annual temperatures counteracted the positive effects of total deadwood amount on total bryophyte species richness. Maintaining high amounts of deadwood in both managed and unmanaged forests is likely to improve bryophyte richness and will be particularly important under ongoing climate change.

Assessment of an anti-scale low-frequency electromagnetic field device on drinking water biofilms.

Low intensity and very low-frequency electromagnetic fields (EMF) used for preventing scaling in water distribution systems were tested for the first time for their potential impact on drinking water biofilms. The assays were carried out in laboratory-scale flow-through reactors that mimic water distribution systems. The drinking water biofilms were not directly exposed to the core of the EMF generator and only subjected to waterborne electromagnetic waves. The density and chlorine susceptibility of nascent or mature biofilms grown under exposure to EMF were evaluated in soft and hard water. This EMF treatment was able to modify CaCO3 crystallization but it did not significantly affect biofilms. Indeed, over all the tested conditions, there was no significant change in cell number, or in the integrity of the cells (membrane, culturability), and no measurable effect of chlorine on the biofilm.

Inverse mapping the neuronal substrates of face categorizations.

Face perception is a complex process involving a network of brain structures, dynamically processing information to enable judgments about a face to be made (e.g., familiarity, identity, and expression). Here we introduce an analysis methodology that makes it possible to directly study this information processing in the brain from spatially and temporally resolved magnetoencephalographic signals. We apply our methodology to the study of 2 face categorization tasks, gender and expressiveness, and track the processing of 3 key visual features that underlie behavioral performance, over time and throughout the cortex. We find information processing correlates beginning from 90 ms following stimulus onset, where features are processed in isolation in occipital extrastriate regions. Over time, processing of successively more features and feature combinations takes place in occipitotemporal regions, with maximal information processing of visual information coinciding with the well-established face-selective M170 component at 170 ms. Later still, around 250-400 ms, cortical activity responds significantly more to task-specific features and their complex combinations. These results indicate a complex process of visual information processing during face perception with face parts processed in isolation at very early stages, and task-specific processing of combinations of features taking place within 300 ms. Crucially, our approach specifically establishes which information in the visual stimulus the brain signal is responding to and how this varies with time, cortical location, and task demands to establish a more precise tracking of information processing mechanisms in the cortex during face perception.

Time course of the use of chromatic and achromatic facial information for sex categorization.

The most useful facial features for sex categorization are the eyes, the eyebrows, and the mouth. Dupuis-Roy et al. reported a large positive correlation between the use of the mouth region and rapid correct answers [Journal of Vision 9 (2009) 1-8]. Given the chromatic information in this region, they hypothesized that the extraction of chromatic and achromatic cues may have different time courses. Here, we tested this hypothesis directly: 110 participants categorized the sex of 300 face images whose chromatic and achromatic content was partially revealed through time (200 ms) and space using randomly located spatio-temporal Gaussian apertures (i.e. the Bubbles technique). This also allowed us to directly compare, for the first time, the relative importance of chromatic and achromatic facial cues for sex categorization. Results showed that face-sex categorization relies mostly on achromatic (luminance) information concentrated in the eye and eyebrow regions, especially the left eye and eyebrow. Additional analyses indicated that chromatic information located in the mouth/philtrum region was used earlier-peaking as early as 35 ms after stimulus onset-than achromatic information in the eye regions-peaking between 165 and 176 ms after stimulus onset-as was speculated by Dupuis-Roy et al. A non-linear analysis failed to support Yip and Sinha's proposal that processing of chromatic variations can improve subsequent processing of achromatic spatial cues, possibly via surface segmentation [Perception 31 (2002) 995-1003]. Instead, we argue that the brain prioritizes chromatic information to compensate for the sluggishness of chromatic processing in early visual areas, and allow chromatic and achromatic information to reach higher-level visual areas simultaneously.

Efficient information for recognizing pain in facial expressions.

BACKGROUND: The face as a visual stimulus is a reliable source of information for judging the pain experienced by others. Until now, most studies investigating the facial expression of pain have used a descriptive method (i.e. Facial Action Coding System). However, the facial features that are relevant for the observer in the identification of the expression of pain remain largely unknown despite the strong medical impact that misjudging pain can have on patients' well-being. METHODS: Here, we investigated this question by applying the Bubbles method. Fifty healthy volunteers were asked to categorize facial expressions (the six basic emotions, pain and neutrality) displayed in stimuli obtained from a previously validated set and presented for 500 ms each. To determine the critical areas of the face used in this categorization task, the faces were partly masked based on random sampling of regions of the stimuli at different spatial frequency ranges. RESULTS: Results show that accurate pain discrimination relies mostly on the frown lines and the mouth. Finally, an ideal observer analysis indicated that the use of the frown lines in human observers could not be attributed to the objective 'informativeness' of this area. CONCLUSIONS: Based on a recent study suggesting that this area codes for the affective dimension of pain, we propose that the visual system has evolved to focus primarily on the facial cues that signal the aversiveness of pain, consistent with the social role of facial expressions in the communication of potential threats.

Using the full power of linkage analysis in 11 French Canadian families to fine map the oculopharyngeal muscular dystrophy gene.

Oculopharyngeal muscular dystrophy (OPMD) is a late onset autosomal dominant muscular dystrophy with a high prevalence in the French Canadian population. We report linkage analysis with 7 chromosome 14q polymorphic markers in 11 large French Canadian families. An observed recombination in one family establishes D14S283 as the new centromeric flanking marker, therefore reducing the previously reported candidate interval from 5cM to 2cM. The highest two-point LOD score was 26.05 at theta = 0.01 for MYH7.1. Multipoint analysis suggested that the OPMD genes lies within a 1.5cM region around D14S990. This study of large French Canadian families underlines the great power of this population to fine map disease genes.

Why do we SLIP to the basic level? Computational constraints and their implementation.

The authors introduce a new measure of basic-level performance (strategy length and internal practicability; SLIP). SLIP implements 2 computational constraints on the organization of categories in a taxonomy: the minimum number of feature tests required to place the input in a category (strategy length) and the ease with which these tests are performed (internal practicability). The predictive power of SLIP is compared with that of 4 other basic-level measures: context model, category feature possession, category utility, and compression measure, drawing data from other empirical work, and 3 new experiments testing the validity of the computational constraints of SLIP using computer-synthesized 3-dimensional artificial objects.

Friedreich ataxia in Acadian families from eastern Canada: clinical diversity with conserved haplotypes.

The gene for Friedreich ataxia (FRDA), an autosomal-recessive neurodegenerative disease, remains elusive. The current candidate region of about 150 kb lies between loci FR2 and F8101 near the D9S15/D9S5 linkage group at 9q13-21.1. Linkage homogeneity between classical FRDA and a milder, slowly progressive Acadian variant (FRDA-Acad) has been demonstrated. An extended D9S15-D9S5 haplotype (C6) predominates in FRDA-Acad chromosomes from Louisiana. We studied 10 Acadian families from New Brunswick, Canada. In eight families, affected individuals conformed to the clinical description of FRDA-Acad; in one, 2 sibs presented with spastic ataxia (SPA-Acad). In the last family, 2 sibs had FRDA-Acad, and one had SPA-Acad. We found that SPA-Acad is linked to the FRDA gene region. The C6 haplotype and a second major haplotype (B7) were identified. The same ataxia-linked haplotypes segregated with both FRDA-Acad and SPA-Acad in two unrelated families. The parental origins of these haplotypes were different. Our observation of different phenotypes associated with the same combination of haplotypes may point to the influence of the parent of origin on gene expression, indicate the effect of modifier genes, or reflect the presence of different mutations on the same haplotypes. Our findings underline the need to investigate families with autosomal-recessive ataxias for linkage to the FRDA region, despite lack of key diagnostic manifestations such as cardiomyopathy or absent deep-tendon reflexes.

Asymmetric synthesis of the tricyclic core of NGF-inducing cyathane diterpenes via a transition-metal-catalyzed [5 + 2] cycloaddition.

[reaction: see text] A concise asymmetric synthesis of the tricyclic core of cyathane diterpenes is described, based on a novel transition-metal-catalyzed intramolecular [5 + 2] cycloaddition of ynone-vinylcyclopropane 10 (assembled from commercially available (S)-(-)-limonene), which proceeds in 90% yield with >95% selectivity. This strategy provides efficient access (14 steps and 13% overall yield) to potential analogues as well as precursors of nerve growth factor (NGF)-inducing diterpenes.

Prenatal diagnosis of congenital cytomegalovirus infection: prospective study of 237 pregnancies at risk.

OBJECTIVE: To develop recommendations for prenatal diagnosis of congenital cytomegalovirus (CMV) infection and evaluate possible prognostic markers. METHODS: We studied 237 pregnant women who had suspected or confirmed primary CMV infections by amniocenteses with or without funipuncture. Diagnosis of CMV was based on culture and polymerase chain reaction (PCR) done on amniotic fluid (AF) samples; fetal blood tests for CMV immunoglobulin M antibodies, PCR, and nonspecific biologic markers; and repeated ultrasound examinations. In cases of pregnancy termination, viral and pathologic examinations of fetuses were done. At birth, CMV infections were sought in newborns. Pediatric follow-up was scheduled for at least 2 years. RESULTS: Of 210 fetuses and newborns correctly evaluated, 55 had CMV infections. Ten of 38 fetuses infected before 20 weeks' pregnancy had severe congenital disease. The global sensitivity of prenatal diagnosis was 80%. Best sensitivity and 100% specificity were achieved by PCR done on AF sampled after 21 weeks' gestation, respecting a mean interval of 7 weeks between diagnosis of maternal infection and prenatal diagnosis. Fetal thrombocytopenia was associated with severe fetal disease. Ultrasound follow-up missed two fetuses who presented with neurologic impairment due to CMV after birth. CONCLUSION: A reliable prenatal diagnosis of congenital CMV infection based on PCR on amniocentesis samples can be made after 21 weeks' pregnancy, after a 7-week interval between diagnosis of maternal infection and antenatal procedure. Ultrasound and nonspecific biologic parameters are not sufficient to identify all fetuses at risk of severe sequelae.

Red blood cell Cu/Zn superoxide dismutase activity in sporadic amyotrophic lateral sclerosis.

To determine the possible role of Cu/Zn superoxide dismutase (SOD1) in the pathophysiology of sporadic amyotrophic lateral sclerosis (SALS), we measured SOD1 activity in red blood cell lysates in patients with SALS. SOD1 activity in red blood cell lysates was independent of age and sex in control patients, and no significant difference was found between the levels of SOD1 activity in controls (1174.8 +/- 213, n = 29) and SALS patients (1203.4 +/- 214, n = 27). These results suggest that point mutations in the SOD1 gene are apparently unrelated to SALS.

Breast cancer and T-cell-mediated immunity to proteins of the mouse mammary tumour virus (MMTV).

We have previously reported that breast cancer patients and some healthy subjects show positive T-cell-mediated immune responses to a semi-purified mouse mammary tumour viral pool (MMTV). We have now used Western blotting to analyse the specificity of the response and to determine the target polypeptides. Two types of T-cell response to the viral antigens were examined, proliferation and MIF release, the latter implies a DTH status in vivo where primed lymphocytes are involved. Two viral fractions were used, one containing a glycoprotein, the 52 kD major virus envelope, and the other containing the 28 kD main virus core protein. We analysed both patients and healthy subjects whose T-cells proliferated to the MMTV total extract (viral pool). The T-cell response in the patients was shown to be viral specific since both the T-cell proliferation (21/25) and MIF release (17/19) were directed against viral components of the pool (gp 52 and/or p 28). The T-cell response in the healthy control subjects was shown to be mostly directed against a species-specific albumin component of the extract. In addition, the monocyte integrity required for the MIF response was altered in the breast cancer patients. The monocytes from one patient out of three failed to respond to MIF, even though the lymphokine was released normally by the patients' activated T-cells.

Bubbles: a technique to reveal the use of information in recognition tasks.

Everyday, people flexibly perform different categorizations of common faces, objects and scenes. Intuition and scattered evidence suggest that these categorizations require the use of different visual information from the input. However, there is no unifying method, based on the categorization performance of subjects, that can isolate the information used. To this end, we developed Bubbles, a general technique that can assign the credit of human categorization performance to specific visual information. To illustrate the technique, we applied Bubbles on three categorization tasks (gender, expressive or not and identity) on the same set of faces, with human and ideal observers to compare the features they used.

Cytokeratins as molecular markers in the evaluation of the precise differentiation stage of human gingival epithelium reconstituted in vitro.

Cytokeratins are considered to be molecular markers for different types of epithelial differentiation. They were used to investigate the precise differentiation stage of gingival epithelium, reconstituted in vitro, following two different culture procedures. Human trypsin-dissociated gingival keratinocytes were seeded either on a feeder layer of irradiated mouse 3T3 fibroblasts or on a connective tissue equivalent (lattice) made up of human fibroblasts in a collagen gel. The cytokeratins were extracted and analysed by two-dimensional gel electrophoresis. Although both methods showed on histological sections that cultured gingival keratinocytes formed a multilayered non-keratinizing epithelium, the cytokeratins patterns showed great differences. The gingival epithelium-like structure reconstituted on 3T3 feeder layer expressed some cytokeratins characteristic of the in situ gingival epithelium (K 5, 6, 14, 16, 17) and some which do not exist in the normal tissue (K 8, 18, 19, traces of K 13 and K 15) and are specific for embryonic, simple and tumour epithelia. However, the gingival epithelium reconstituted on connective tissue equivalent expressed all the cytokeratins present in the normal tissue (K 5, 6, 14, 16, 17), except those specific for terminal differentiation (K 1, 2, and 10/11). These findings suggest that the culture of gingival keratinocytes on connective tissue equivalents allows them to reproduce physiological stages of differentiation.

Test of mathematical assumptions behind the 'incidence function' estimation process of metapopulations' dynamic parameters.

I question Hanski's [I. Hanski, A practical model of metapopulation dynamics, J. Animal Ecol. 63 (1994) 151] assumption that incidence functions are relevant approximations of the equilibrium dynamics of stochastic metapopulation models to estimate models' parameters based on snapshot data. Based on ten different metapopulation models, this assumption is found to be at least partly unjustified when referring to the asymptotic behaviour of the models. This leads me to recommend the use of explicit extinction-colonisation transition probabilities and process data (rather than snapshot data) in the estimation process of metapopulation models.

[Thin soft hydrogel lenses of high and low water (author's transl)]. / Lentilles souples thérapeutiques de faible épaisseur et de forte teneur en eau: résultats et indications.

The authors relate the results obtained with very thin soft hydrogel lenses (0,10 mm thickness) of high and low water content: the Vergo-Softcon THX of 70% water-content and the Bauch and Lomb Plano-T of 38%. The most frequent indications encountered are bullous keratopathy, epithelial defects and keratitis sicca. The results are positive in 78,2% of cases with 70% w/c soft hydrogel lenses. Results are given for cases of direct fitting of thin lenses, as well as for cases of fitting after failures of classic soft hydrogel lenses and in cases of exchanges of 40% lenses for 70% lenses. The 70% water content lenses seem to give better results main in cases of epithelial defects and keratitis sicca.

[Contribution of contact lenses to the reduction of aniseikonia in myopic patients after unilateral cataract operations (author's transl)]. / L'apport des verres de contact dans la réduction de l'aniséiconie chez les myopes opérés d'une cataracte unilatérale.

The most rapid method for determining the best mode of optical compensation in myopic patients following cataract operations was studied, by employing a graphic method for calculating theoretical aniseikonia and measuring subjective aniseikonia with a new stereo-projector. Several examples of the method chosen are given, this involving optical equipment--glasses, lens, myopisation--aniseikonia being reduced to a maximum.

[Utility of soft hydrogel contact lenses in case of epithelial defects after corneal grafts (19) (author's transl)]. / Utilisation thérapeutique des lentilles souples dans les troubles épithéliaux après greffes de cornée (19 cas).

The authors relate the utility of soft hydrogel contact lenses in 19 cases of epithelial defects after penetrating corneal grafts, 8 of them being primitive and 11 secondary. Out of the 19 cases fitted with lenses, 10 have required a new keratoplasty. An attempt is made to define the indications, the advantages and the drawbacks of this therapy in observing the action of the lens on the epithelium, the stroma, the visual acuity as well as the possible problems due to the wearing of the lenses in the whole of the 19 cases. They try to understand the reasons for a new graft and they study the non-regrafted cases. They evidence the benefits of the wear of soft hydrogel lenses but the limits of their uses too.

[Chorionic villi sampling: experience of the initial 500 samples]. / La choriocentèse: expérience des 500 premiers prélèvements.

We report our experience in first trimester antenatal diagnosis since 1984. Transcervical chorionic villus sampling (CVS) was performed in 498 pregnancies. The rate of abnormal pregnancies was 6%, the rate of chromosomal abnormalities (trisomy) in the indication group "maternal age" was 2%. The fetal loss rate (until 28 weeks) was 3.4% (17 cases), the procedure related loss plus the background loss was 2.4% (12 cases). For 92.8% of the patients a diagnosis was available after 1 CVS procedure. Ultimately an antenatal diagnosis was given to 99% of the women through a second CVS procedure or an amniocentesis or a cordocentesis. No maternal complication was observed.

[Fetomaternal alloimmunization: role of cordocentesis]. / Alloimmunisation foeto-maternelle: rôle de la cordocentèse.

Twenty one pregnancies complicated by alloimmunization were managed by the use of intravascular method on an outpatient basis. One group was made of 9 women having had at least one pregnancy with a severely affected fetus. The other group was composed of 12 women without a previously affected infant; in 5 cases a situation at risk, either a transfusion (4 cases) or a severe obstetrical hemorrhage (1 case), was evidenced. Knowledge of fetal blood type (2 cases) and hematocrit determination obtained by fetal blood sampling allowed treatment individualized to the specific needs of each patient. In total 59 cordocenteses were performed, including 19 intrauterine transfusions.