A female advantage in the recognition of emotional facial expressions: test of an evolutionary hypothesis

A set of computerized tasks was used to investigate sex differences in the speed and accuracy of emotion recognition in 62 men and women of reproductive age. Evolutionary theories have posited that female superiority in the perception of emotion might arise from women's near-universal responsibility for child-rearing. Two variants of the child-rearing hypothesis predict either across-the-board female superiority in the discrimination of emotional expressions (“attachment promotion” hypothesis) or a female superiority that is restricted to expressions of negative emotion (“fitness threat” hypothesis). Therefore, we sought to evaluate whether the expression of the sex difference is influenced by the valence of the emotional signal (Positive or Negative). The results showed that women were faster than men at recognizing both positive and negative emotions from facial cues, supporting the attachment promotion hypothesis. Support for the fitness threat hypothesis also was found, in that the sex difference was accentuated for negative emotions. There was no evidence that the female superiority was learned through previous childcare experience or that it was derived from a sex difference in simple perceptual speed. The results suggest that evolved mechanisms, not domain-general learning, underlie the sex difference in recognition of facial emotions.     

The connection of visual evoked potentials with the subjective differences between emotional expressions of the "schematic face"

Human cortical visual potentials (VEP) were studied to obtain electrophysiological data concerning face discrimination and to compare them with the direct estimates of differences between faces obtained in the previous publications. The present schematic faces varied in curvature of a mouth and/or declination of eyebrows. These features determined the emotional expression of the schematic faces. We recorded the VEP as the response to the instant replacement of one schematic face (referent stimulus) by an other one (test stimulus) rather then to presentation of a single stimulus. Thus we recorded direct electrophysiological differences between schematic faces. A characteristic feature of this approach was the application of the set of functionally connected test stimuli with monotonously increasing values of differences between the referent and test stimuli. In a result of analysis the complex of components P120-N180-P230 in sites O1, O2, P3, P4, T5, T6 was described. Interpeaks amplitudes of the components shows high correlations with subjective differences between the same pairs of stimuli as well as with physical (configurative) differences between stimuli measured as the angles of lines, defining curvature of a mouth and a declination of eyebrows. The highest correlation with subjective estimates of emotional differences between faces was shown by interpeaks amplitudes N180-P230 in sites O1 and P3. In the some time the interpeaks amplitudes P120-N180 in sites O1 and T5 reflected highest correlation between configurative measures and subjective estimates of stimuli differences.     

Beneath the beard: do facial morphometrics influence the strength of judgments of men's beardedness?

Converging evidence suggests men's beards, like many androgen-dependent masculine secondary sexual traits, communicate masculinity and dominance intra-sexually while effects of men's beardedness on attractiveness ratings are more equivocal. Beards may enhance perceived masculinity and dominance via amplifying aspects of underlying craniofacial masculinity, particularly the size of the lower face and jaw. Here we tested these predictions across two studies. In study 1, we tested how three facial metrics - objectively measured craniofacial masculinity, facial-width-to-height ratio (fWHR), and jaw size - calculated while clean-shaven impacted on ratings of attractiveness, masculinity and dominance of 37 men photographed when clean-shaven and with full beards. Results showed that beards exerted significant and positive effects on masculinity, dominance and to a lesser extent attractiveness. However, fWHR did not significantly interact with beardedness to influence the directions of any of the ratings, and while some linear and nonlinear interactions were significant between objective craniofacial masculinity and beardedness as well as between jaw size and beardedness, they tended to be subtle and dwarfed by the large main effect of beardedness on perceptual ratings. In study 2, we measured ratings of attractiveness, masculinity and dominance for composite clean-shaven and bearded stimuli experimentally manipulated in facial shape to represent ±50% the shape of a beard, essentially manipulating the size of the lower face and jaw of the stimuli. We found a strong main effect whereby bearded stimuli enhanced dominance and masculinity ratings over clean-shaven stimuli. Increasing the size of the lower face and jaw augmented ratings of masculinity and dominance in clean-shaven stimuli but did not exert strong effects within bearded stimuli. Attractiveness ratings were highest for bearded faces with smaller jaws followed by bearded and clean-shaven faces with larger jaws and lowest for clean-shaven faces with small jaws. Taken together, our findings suggest that beards exert main effects on masculinity and dominance possibly by amplifying male typical facial shape. Attractiveness ratings of facial hair may reflect a compromise between overly dominant looking faces with larger jaws and the additive effects beardedness has on these ratings.     

Fumarase: a paradigm of dual targeting and dual localized functions

The enzyme fumarase is a conserved protein in all organisms with regard to its sequence, structure and function. This enzyme participates in the tricarboxylic acid cycle in mitochondria which is essential for cellular respiration in eukaryotes. However, a common theme conserved from yeast to humans is the existence of a cytosolic form of fumarase; hence this protein is dual localized. We have coined identical (or nearly identical) proteins situated in different subcellular locations 'echoforms' or 'echoproteins'. Fumarase was the first example of a dual localized protein whose mechanism of distribution was found to be based on a single translation product. Consequently, fumarase has become a paradigm for three unique eukaryotic cellular phenomena related to protein dual localization: (a) distribution between mitochondria and the cytoplasm involves reverse translocation; (b) targeting to mitochondria involves translation coupled import; and (c) there are two echoforms possessing distinct functions in the respective subcellular compartments. Here we describe and discuss these fumarase related phenomena and in addition point out approaches for studying dual function of distributed proteins, in particular compartment-specific depletion. In the case of fumarase, the cytoplasmic function was only recently discovered; the enzyme was found to participate in the cellular response to DNA double strand breaks. Strikingly, upon DNA damage the protein is transported from the cytosol to the nucleus, where by virtue of its enzymatic activity it participates in the DNA damage response.     

Differential response of epiblast stem cells to Nodal and Activin signalling: a paradigm of early endoderm development in the embryo

Mouse epiblast stem cells (EpiSCs) display temporal differences in the upregulation of Mixl1 expression during the initial steps of in vitro differentiation, which can be correlated with their propensity for endoderm differentiation. EpiSCs that upregulated Mixl1 rapidly during differentiation responded robustly to both Activin A and Nodal in generating foregut endoderm and precursors of pancreatic and hepatic tissues. By contrast, EpiSCs that delayed Mixl1 upregulation responded less effectively to Nodal and showed an overall suboptimal outcome of directed differentiation. The enhancement in endoderm potency in Mixl1-early cells may be accounted for by a rapid exit from the progenitor state and the efficient response to the induction of differentiation by Nodal. EpiSCs that readily differentiate into the endoderm cells are marked by a distinctive expression fingerprint of transforming growth factor (TGF)-β signalling pathway genes and genes related to the endoderm lineage. Nodal appears to elicit responses that are associated with transition to a mesenchymal phenotype, whereas Activin A promotes gene expression associated with maintenance of an epithelial phenotype. We postulate that the formation of definitive endoderm (DE) in embryoid bodies follows a similar process to germ layer formation from the epiblast, requiring an initial de-epithelialization event and subsequent re-epithelialization. Our results show that priming EpiSCs with the appropriate form of TGF-β signalling at the formative phase of endoderm differentiation impacts on the further progression into mature DE-derived lineages, and that this is influenced by the initial characteristics of the cell population. Our study also highlights that Activin A, which is commonly used as an in vitro surrogate for Nodal in differentiation protocols, does not elicit the same downstream effects as Nodal, and therefore may not effectively mimic events that take place in the mouse embryo.     

Ethylene signalling and response pathway: a unique signalling cascade with a multitude of inputs and outputs

Plants as immobile organisms need to constantly monitor the changes in the environment to modify and adjust developmental and metabolic pathways accordingly. The responses to these environmental cues require an integrative mechanism where external and internal signals are detected and processed to trigger an appropriate 'reaction' in the plant. Hormones play a key role in mediating some of these integrative processes and in generating the response reactions. The identification and characterization of the basic hormone signalling components and their interactions represent the first step towards comprehensive understanding of plant responses to intrinsic and extrinsic cues. A relatively well-characterized ethylene signalling and response pathway, together with numerous evidences of its interactions with other signalling/response pathways, provide an excellent example to illustrate our current knowledge and perspective on how signal integration occurs in plants.     

The Hsp70 chaperone machines of Escherichia coli: a paradigm for the repartition of chaperone functions

Molecular chaperones are highly conserved in all free-living organisms. There are many types of chaperones, and most are conveniently grouped into families. Genome sequencing has revealed that many organisms contain multiple members of both the DnaK (Hsp70) family and their partner J-domain protein (JDP) cochaperone, belonging to the DnaJ (Hsp40) family. Escherichia coli K-12 encodes three Hsp70 genes and six JDP genes. The coexistence of these chaperones in the same cytosol suggests that certain chaperone-cochaperone interactions are permitted, and that chaperone tasks and their regulation have become specialized over the course of evolution. Extensive genetic and biochemical analyses have greatly expanded knowledge of chaperone tasking in this organism. In particular, recent advances in structure determination have led to significant insights of the underlying complexities and functional elegance of the Hsp70 chaperone machine.     

The influence of visual display terminal use on the physical and mental conditions of administrative staff in Japan

Visual display terminals (VDT) are standard equipment for many office workers. Their use, however, may increase the risk of developing adverse conditions related to vision, the musculoskeletal system, and mental health. We carried out a survey among 3070 workers aged 18 to 67 years (mean, 39.9 years) at a prefectural administrative office, in which 76% of subjects were visual display terminal (VDT) users. We examined the relationship between duration of daily VDT use and eyestrain, neck or upper extremity pain, back pain, and mental health, and estimated the effect of breaks and rest during VDT work on these symptoms. The 12-item General Health Questionnaire (GHQ-12: total scores ranged from 0 to 12) was used to identify potential poor mental health status, and subjects with 4 or more were considered to have symptoms of psychological distress. Seventeen percent of subjects reported eyestrain, 19.1% reported upper extremity pain, 11.6% reported back pain, and 17% of subjects had GHQ-12 scores of 4 or higher. Logistic regression analysis showed that duration of daily VDT use and lack of breaks and rest during VDT work were significantly associated with eyestrain, neck or upper extremity pain, back pain, and psychological distress. In order to protect users from the adverse effects associated with VDT work, reducing daily VDT exposure, taking breaks, and rest during VDT work are important.     

Social perceptions of the effects of Down syndrome facial surgery: a school-based study of ratings by normal adolescents

This study examines how 277 normal adolescents from five Israeli schools perceive the Down syndrome face before and after plastic surgery. A seven-point Likert scale was used to rate slides of normal and Down syndrome faces on four dimensions. Down syndrome patients were seen as less attractive, intelligent, good-hearted, and socially appealing than normal individuals. The slides were in nonapparent order and contained preoperative and 1-year postoperative views of eight plastic surgical patients. Paired t tests were used to examine operative changes, and all four dimensions showed overall postoperative improvement (p less than 0.001), but case-to-case variation was considerable. A linear relationship was found between change in appearance ratings and change in intelligence ratings. Findings suggest that when improvements in facial appearance are realized, peer normal social perceptions of the Down syndrome child may be enhanced. The relationship between school placement, intellectual level, and surgical decision making is discussed.     

Testing the generality of the trophic cascade paradigm for sea otters: a case study with kelp forests in northern Washington,USA

Trophic cascade hypotheses for biological communities, linking predation by upper trophic levels to major features of ecological structure and dynamics at lower trophic levels, are widely subscribed and may influence conservation policy. Few such hypotheses have been evaluated for temporal or spatial generality. Previous studies of sea otter (Enhydra lutris) predation along the outer coast of North America suggest a pattern, often elevated to the status of paradigm, in which sea otter presence leads to reduced sea urchin (Strongylocentrotus spp.) biomass and rapid increases in abundance and diversity of annual algal species, followed by a decline in diversity as one or a few perennial algal species become dominant. Both sea otter predation and commercial sea urchin harvest are ecologically and economically important sources of urchin mortality in nearshore benthic systems in northern Washington marine waters. We recorded changes in density of macroalgae in San Juan Channel, a marine reserve in the physically protected inland waters of northern Washington, resulting from three levels of experimental urchin harvest: (1) simulated sea otter predation (monthly complete harvest of sea urchins), (2) simulated commercial urchin harvest (annual size-selective harvest of sea urchins), and (3) no harvest (control). The two experimental urchin removal treatments did not significantly increase the density of perennial (Agarum and Laminaria) or annual (Desmarestia, Costaria, Alaria and Nereocystis) species of macroalgae after 2 years, despite significant and persistent decreases in urchin densities. Our results suggest that other factors such as grazing by other invertebrates, the presence of dense Agarum stands, and recruitment frequency of macroalgae and macroinvertebrates may play a large role in influencing community structure in San Juan Channel and other physically protected marine waters within the range of sea otters. Handling editor: J. Trexler     

The influence of concentration and relaxation on the EEG power spectra during a CNV paradigm

EEG segments of 1 sec duration, beginning 1 sec before the imperative stimulus were analysed by Fast Fourier Transformation in a CNV paradigm with interstimulus intervals (ISI) of different durations (1, 3, 5 sec) and with constant (K1, K3, K5) and randomized (R1, R3, R5) ISI presentation. In the alpha band, there were found differences in the power spectra between the constant and the longer randomized (R3, R5) ISI conditions, the latter having a slower center frequency, a smaller radius of gyration and a higher kurtosis. This describes a sharper alpha line of slower frequency in the R3 and the R5 ISI condition, due to pronounced synchronisation of alpha activity. It is discussed as an expression of increased relaxation and reduced concentration. In the theta band, differences appeared between the short ISI conditions (K1, R1) and the longer ones.     

Modifications of serum glycoproteins the days following a prolonged physical exercise and the influence of physical training.

Eight male subjects (mean age 24.1 +/- 2.6 years) performed at intervals of 2 weeks successively a 3 h and two 2 h runs of different running speed. The days following the running there were moderate elevations of C-reactive protein, haptoglobin, alpha-1-acid glycoprotein, coeruloplasmin, transferrin, alpha-1-antitrypsin and plasminogen. There were small or no changes of albumin, alpha-2-macroglobulin and hemopexin. The elevations of the "acute phase reactants" were examined in three male subjects following a 2 h run before and after an endurance training period of 9 weeks. This demonstrated a decreased acute phase response after training as illustrated by the changes of C-reactive protein, haptoglobin and alpha-1-acid glycoprotein in spite of higher posttraining running speeds. Well-trained athletes have elevated levels of the serum protease inhibitors alpha-1-antitrypsin, alpha-2-macroglobulin and C1-inhibitor. These antiproteolytic glycoproteins might limit exercise-induced inflammatory reactions.     

Targeted disruption of the mouse cis-retinol dehydrogenase gene: visual and nonvisual functions

It has been proposed that cis-retinol dehydrogenase (cRDH) acts within the body to catalyze the oxidation of 9-cis-retinol, an oxidative step needed for 9-cis-retinoic acid synthesis, the oxidation of 11-cis-retinol [an oxidative step needed for 11-cis-retinal (visual chromophore) synthesis], and 3 alpha-hydroxysteroid transformations. To assess in vivo the physiological importance of each of these proposed actions of cRDH, we generated cRDH-deficient (cRDH-/-) mice. The cRDH-/- mice reproduce normally and appear to be normal. However, the mutant mice do have a mild visual phenotype of impaired dark adaptation. This phenotype is evidenced by electroretinagram analysis of the mice and by biochemical measures of eye levels of retinoid intermediates during recovery from an intense photobleach. Although it is thought that cRDH is expressed in the eye almost solely in retinal pigment epithelial cells, we detected cRDH expression in other retinal cells, including ganglion cells, amacrine cells, horizontal cells, and the inner segments of the rod photoreceptor cells. Aside from the eye, there are no marked differences in retinoid levels in other tissues throughout the body for cRDH-/- compared with cRDH+/+ mice. Moreover, we did not detect any non-visual phenotypic changes for cRDH-/- mice, suggesting that these mice do not have problems in metabolizing 3 alpha-hydroxysteroids.Thus, cRDH may act essentially in the visual cycle but is redundant for catalyzing 9-cis-retinoic acid formation and 3 alpha-hydroxysteroid metabolism.     

Concurrent strength and endurance training: the influence of dependent variable selection

Twenty-six active university students were randomly allocated to resistance (R, n = 9), endurance (E, n = 8), and concurrent resistance and endurance (C, n = 9) training conditions. Training was completed 3 times per week in all conditions, with endurance training preceding resistance training in the C group. Resistance training involved 4 sets of upper- and lower-body exercises with loads of 4-8 repetition maximum (RM). Each endurance training session consisted of five 5-minute bouts of incremental cycle exercise at between 40 and 100% of peak oxygen uptake (.VO2peak). Parameters measured prior to and following training included strength (1RM and isometric and isokinetic [1.04, 3.12, 5.20, and 8.67 rad.s(-1)] strength), .VO2peak and Wingate test performance (peak power output [PPO], average power, and relative power decline). Significant improvements in 1RM strength were observed in the R and C groups following training. .VO2peak significantly increased in E and C but was significantly reduced in R after training. Effect size (ES) transformations on the other dependent variables suggested that performance changes in the C group were not always similar to changes in the R or E groups. These ES data suggest that statistical power and dependent variable selection are significant issues in enhancing our insights into concurrent training. It may be necessary to assess a range of performance parameters to monitor the relative effectiveness of a particular concurrent training regimen.     

First came the link between phosphoinositides and Ca signalling, and then a deluge of other phosphoinositide functions

The link between phosphoinositide turnover and Ca²⁺-regulated cell processes goes back half a century, but only began to be understood in the 1970s. This article briefly outlines how the roles of these minority membrane lipids in Ca²⁺ signalling and then in multifarious other biological processes were recognised during the latter half of the 20th century.