Alcaloïdes steroidiques du Malouetia Brachyloba et du M. Heudelotii

Malouetine and funtumafrine C have been isolated from the leaves of Malouetia brachyloba, indicating that this species is not very different from M. bequaertiana. Five conanine derivatives have been extracted from the leaves of M. heudelotii, a species which does not contain any alkaloid with a quaternary ammonium function.     

Observations on the invading gastropod <Emphasis Type="Italic">Rapana venosa</Emphasis> in Punta del Este,Maldonado Bay,Uruguay

We report on the first sightings of the invasive Rapa Whelk Rapana venosa in Maldonado Bay (Punta del Este Harbor and Gorriti Island) using in vivo, underwater observations and video surveys. The species was first detected in the Río de la Plata (Uruguay and Argentina) in 1999, and by 2004 it had extended its local distribution to Punta del Este at the eastern boundary of the estuary. Observations performed by SCUBA diving showed that R. venosa is preying on native mussels Mytilus edulis and Brachidontes spp., and that formerly abundant mussel beds are being seriously depleted due to a combination of human extraction, habitat deterioration and predation by the Rapa Whelk.     

Impacto de la actividad física sobre el control metabólico y el desarrollo de complicaciones crónicas en pacientes con diabetes mellitus tipo 1

Together with a balanced diet, regular physical activity is one of the pillars of diabetes mellitus (DM) management. Physical activity theoretically provides the same advantages in people with DM as in the general population and also has some beneficial effects in controlling metabolic factors, such as improving blood glucose levels and insulin sensitivity. In this article, we analyze the main clinical studies published to date that evaluate the impact of physical activity on metabolic control or the development of chronic complications in patients with type 1 diabetes mellitus. In conclusion, most of the evaluated studies show that regular physical activity favorably affects metabolic control in DM (or at least does not have adverse effects). However, there is insufficient information about the impact of physical activity on the development and progression of chronic complications.     

Characterization of the endoevaporitic microbial communities in a hypersaline gypsum crust by fatty acid analysis

We have used fatty acid analyses to study the community structure of a layered endoevaporitic microbial community within a gypsum crust that covers the bottom of a saltern evaporation pond in Eilat, Israel. This community, living at a salinity of 218–238 g l⁻¹ total dissolved salts, consists of an upper brown layer dominated by unicellular cyanobacteria, a green layer with filamentous cyanobacteria, a red-purple layer with both Chromatium and Ectothiorhodospira/Halorhodospira type of purple sulfur bacteria, and a black layer in which dissimilatory sulfate reduction occurs. An olive-green layer is sometimes present below the red-purple layer. Analysis by gas chromatography/mass spectrometry of the fatty acid methyl esters prepared from the different fractions showed characteristic patterns in each layer, and these could be related to fatty acid composition data from the literature and to fatty acid analyses of representative halophilic microorganisms isolated from the site. The nature of the fatty acids in the green layer suggests that the cyanobacteria present there use the oxygen-independent pathway for production of unsaturated fatty acids, a pathway only occasionally encountered in filamentous cyanobacteria. The facultative anaerobic nature of the cyanobacteria in the green layer was confirmed by their ability to perform anoxygenic photosynthesis with sulfide as electron donor. Specific signature fatty acids identified for each layer corresponded well with the microscopic and functional analysis of the biota present. Guest Editor: John M. Melack Saline Waters and their Biota     

Regulation of oxygen sensing by ion channels.

O(2) sensing is of critical importance for cell survival and adaptation of living organisms to changing environments or physiological conditions. O(2)-sensitive ion channels are major effectors of the cellular responses to hypoxia. These channels are preferentially found in excitable neurosecretory cells (glomus cells of the carotid body, cells in the neuroepithelial bodies of the lung, and neonatal adrenal chromaffin cells), which mediate fast cardiorespiratory adjustments to hypoxia. O(2)-sensitive channels are also expressed in the pulmonary and systemic arterial smooth muscle cells where they participate in the vasomotor responses to low O(2) tension (particularly in hypoxic pulmonary vasoconstriction). The mechanisms underlying O(2) sensing and how the O(2) sensors interact with the ion channels remain unknown. Recent advances in the field give different support to the various current hypotheses. Besides the participation of ion channels in acute O(2) sensing, they also contribute to the gene program developed under chronic hypoxia. Gene expression of T-type calcium channels is upregulated by hypoxia through the same hypoxia-inducible factor-dependent signaling pathway utilized by the classical O(2)-regulated genes. Alteration of acute or chronic O(2) sensing by ion channels could participate in the pathophysiology of human diseases, such as sudden infant death syndrome or primary pulmonary hypertension.     

Effects of Shift Work on the Postural and Psychomotor Performance of Night Workers

The purpose of the study was to investigate the effects of shift work on the psychomotor and postural performance of night workers. The study included 20 polysomnography technicians working schedule of 12-h night shift by 36-h off. On the first day of protocol, the body mass and height were measured, and an actigraph was placed on the wrist of each participant. On the second day of protocol, sleepiness by Karolinska Sleepiness Scale, postural control by force platform (30 seconds) and psychomotor performance by Psychomotor Vigilance Task (10 minutes) were measured before and after 12-h night work. Results showed that after 12-h night work, sleepiness increased by 59% (p<0.001), postural control variables increased by 9% (p = 0.048), and 14% (p = 0.006). Mean reaction time, and the number of lapses of attention increased by 13% (p = 0.006) and 425% (p = 0.015), respectively, but the mean reciprocal reaction time decreased by 7%. In addition, there were correlations between sleepiness and postural control variables with opened eyes (r = 0.616, 95% confidence interval [CI] = 0.361–0.815; r = 0.538; 95% CI = 0.280–0.748) and closed eyes (r = 0.557; 95% CI = 0.304–0.764, r = 0497; 95% CI = 0.325–0.715) and a pronounced effect of sleepiness on postural sway (R² = 0.393; 95% CI = 0.001–0.03). Therefore, 12-h night work system and sleepiness showed a negative impact in postural and psychomotor vigilance performance of night workers. As unexpected, the force platform was feasibility to detect sleepiness in this population, underscoring the possibility of using this method in the workplace to prevent occupational injuries and accidents.     

Phylogenetic island disequilibrium: evidence for ongoing long‐term population dynamics in two Mediterranean butterflies

Aim Our aims were to verify the existence of phylogenetic disequilibrium between butterfly lineages at the subcontinental scale for islands and the nearest mainland and to test the capacity of islands for hosting ancestral populations of butterflies and the significance of such relict populations. Location The western Mediterranean continental area of Europe and North Africa together with several large and small islands (Balearics, Tuscan Archipelago, Aeolian Archipelago, Capri, Sardinia, Sicily, Corsica). Methods Using geometric morphometrics, the shape of male genitalia was analysed in two common butterflies (Pyronia cecilia and Pyronia tithonus), whose spatial heterogeneity in the Mediterranean region has recently been described. Observed patterns in genital shapes were compared with shapes predicted for islands and fossil islands to assess the contribution of historical and current events in accounting for the transition from a refugial model to an equilibrium model. Measurements were taken for 473 specimens in 90 insular and mainland sites. Results The shape of the genitalia of populations of most islands differed substantially from that predicted by the equilibrium hypothesis while closely fitting the refugial hypothesis. The comparison between different models strongly suggests that islands maintain ancestral lineages similar to those living in Spain (P. cecilia) and France (P. tithonus). A high correlation between observed and predicted patterns on islands and fossil islands occurs during the first steps of modelled introgressive hybridization while the following steps exposed a successively lower fit, suggesting that the process from a refugial to an equilibrium situation is highly skewed towards an earlier non‐equilibrium. Main conclusions The observed non‐equilibrium pattern supports the refugial hypothesis, suggesting that an ancestral lineage was originally distributed from Spain to Italy, and also occupied offshore islands. This lineage, replaced in Italy, has persisted on the islands owing to their isolation. A comparison of the distribution patterns for genetic and morphometric markers in several species indicates that the situation highlighted for Pyronia may represent a common biogeographic feature for many Mediterranean butterflies.     

Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates

Although humans usually prefer mates that resemble themselves, mating preferences can vary with context. Stress has been shown to alter mating preferences in animals, but the effects of stress on human mating preferences are unknown. Here, we investigated whether stress alters men''s preference for self-resembling mates. Participants first underwent a cold-pressor test (stress induction) or a control procedure. Then, participants viewed either neutral pictures or pictures of erotic female nudes whose facial characteristics were computer-modified to resemble either the participant or another participant, or were not modified, while startle eyeblink responses were elicited by noise probes. Erotic pictures were rated as being pleasant, and reduced startle magnitude compared with neutral pictures. In the control group, startle magnitude was smaller during foreground presentation of photographs of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to self-resembling mates. In the stress group, startle magnitude was larger during foreground presentation of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to dissimilar mates. Our findings show that stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates.     

Endocytosis in Trypanosoma cruzi (Euglenozoa: Kinetoplastea) epimastigotes: Visualization of ingested transferrin-gold nanoparticle complexes by confocal laser microscopy

Here we describe the visualization by confocal microscopy of ingested gold (15nm)-labeled transferrin in epimastigote forms of the protozoan Trypanosoma cruzi. Intracellular gold labeling was evident at two sites, which represent the bottom of the cytopharynx and the reservosomes. The gold tracer was best observed by confocal microscopy by using the 633nm excitation wavelength. Intracellular gold clusters larger than 60nm could be visualized by either gold reflection (light scattering) or photoluminescence modes. The gold reflection mode, the gold photoluminescence mode and the anti-transferrin immunofluorescence image of gold-labeled transferrin showed co-localization, thus demonstrating that the gold visualization modes did not represent artifacts or mislocalization of the biomarker. Visualization of protein-gold nanoparticle complexes by confocal microscopy thus emerges as a promising imaging tool to explore the endocytic pathway in trypanosomes and other cell types, as well as to perform immunolocalization studies using gold-labeled secondary antibodies.     

Presence of α-amylase inhibitor in some members of the subtribe Phaseolinae (Phaseoleae: Fabaceae)

The presence of α-amylase inhibitor (αAI), phytohemagglutinin (PHA), and phaseolin was determined by immunochemical and biochemical methods in different members of the subtribe Phaseolinae (Phaseoleae: Fabaceae). Active αAI was present in taxa from the Phaseolus vulgaris–P. coccineus complex (P. vulgaris, P. coccineus, and P. polyanthus), as well as in P. acutifolius in accordance with previous molecular data separating these groups of species from others in the genus. All other Phaseolus species tested lacked α-amylase inhibitory activity, although some of them had immunoreactive polypeptides. αAI was found to be a polymorphic trait among wild and cultivated accessions of P. vulgaris, P. coccineus, and P. acutifolius. The presence of αAI is not exclusive of the genus Phaseolus as one of the Vigna species sampled, V. linearis, also contained α-amylase inhibitory activity.