Comparison of three theories relating facial expressiveness to blood pressure in male and female undergraduates.

Examined differing predictions of how emotional expressions and blood pressure are related. Spontaneous positive and negative facial expressions, resting systolic blood pressure (SBP), and reactive SBP were each measured for 148 male and female undergraduates. The discharge theory of emotions proposes that few expressions will predict higher baseline SBP, and this was found for men. A mismatch theory of emotions proposes that an imbalance between positive and negative expressions will predict higher baseline SBP, and this was supported for women. Finally, coactivation theory proposes that many expressions will predict higher reactive SBP, and this was found for both men and women. These results reconcile previous conflicting findings by clarifying the conditions under which each of these theories may be supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological features of periodontal regeneration and approaches for periodontal tissue engineering utilizing periodontal ligament cells

Experimental studies have shown that the potential of periodontal regeneration seems to be limited by the regenerative capacity of the cells involved. The regeneration of damaged periodontal tissues is mediated by various periodontal cells and is regulated by a vast array of extracellular matrix informational molecules that induce both selective and nonselective responses in different cell lineages and their precursors. In this paper, we first review periodontal ligament tissue and its different cell subpopulations including fibroblasts and paravascular stem cells, and their functions during the development and homeostasis of periodontal tissues. Because conventional periodontal regeneration methods remain insufficient to obtain a complete and reliable periodontal regeneration, the concept of periodontal tissue engineering has been based on the generation of the conditions necessary to improve the healing of periodontal tissues. Additionally, the potential of periodontal ligament cells for use in periodontal tissue engineering to overcome the limitations of conventional periodontal regenerative therapies is discussed, followed by an update of the recent progress and future directions of research utilizing periodontal ligament cells for predictable periodontal regeneration.     

In vitro invasiveness and intracellular survival of Salmonella strains isolated from the aquatic environment

Salmonella has a life cycle between the host and the external environment where it is exposed to stressful conditions that may affect its virulence. In this study, we compared the capability of two aquatic (S. Oranienburg S76 and Saintpaul S70) and one clinical isolates (S. Oranienburg S347) to adhere and invade epithelial cells, and to survive within macrophages. S76 and S70, were less adherent to Caco‐2 cells than S347, but they were more invasive. The intracellular survival and growth of S76 in macrophages was increased with time, while S347 showed the highest peak value and S70 survived at moderate levels. Induced cell death in infected epithelial cells and macrophages revealed no differences between all strains. In conclusion, the contrasting responses detected between environmental and clinical isolates could indicate the importance of the distinct adaptation conditions of the strains to the isolation environment that could differentially affect their interaction with the host.     

Real-space imaging of inelastic Friedel-like surface oscillations emerging from molecular adsorbates

We report real space imaging measurements of inelastic Friedel oscillations. The inelastic electron tunneling spectroscopy, using scanning tunneling microscopy, around dimers of dichlorobenze adsorbates on Au(111) surface display clear spatial modulations that we attribute to inelastic scattering at the molecular sites caused by molecular vibrations. Due to local interactions between the adsorbate and the surface states, the molecular vibrations generate a redistribution of the charge density at energies in a narrow range around the inelastic mode. Our experimental findings are supported by theoretical arguments.     

Accident prevention on ski slopes - Perceptions of safety and knowledge of existing rules

Increases in the numbers of people participating in snow sports raise safety concerns. Despite declining numbers of skiing injuries among recreational skiers, collisions resulting in severe injuries appear to be on the rise. Skiers’ risk of injury depends on a considerable number of different factors but only a few studies have investigated risk-taking behaviour and knowledge of proper skiing behaviour. To promote safe skiing the International Ski Federation (FIS) introduced regulations in 1967.We investigated participants’ familiarity with the FIS regulations on the ski slopes in relation to age, skiing ability and country of origin.Random interviews were conducted with1450 recreational skiers at 17 ski resorts in Tyrol, an Austrian province. A questionnaire assessing skiers’ knowledge of existing rules, their intuitive behaviour in given situations and perceptions of safety was developed. The study revealed that beginners, young skiers and those who were not local residents displayed insufficient knowledge. Risk-inducing situations that could result in collisions, such as moving upwards during carving, were largely assessed incorrectly. Appropriate intuitive behaviour increases with experience, and beginners are less able to implement FIS regulations than more experienced skiers. Ski resorts, the media and schools should direct educational efforts toward these high-risk groups. More research is needed to determine the causal connection between skiing injuries and disregard of the FIS Rules.     

Behavior of Listeria monocytogenes type1 355/98 (85) in meat emulsions as affected by temperature,pH, water activity,fat and microbial preservatives

The aim of this work was to analyze the effect of temperature (10–30 °C), fat content (20–50%), sodium chloride (2.5–5.0%) and preservative concentrations: sodium nitrite (0–150 ppm), lactic acid (50–500 mM) and nisin (0–100 IU/g (international units per gram)) on the growth of Listeria monocytogenes in a meat emulsion system.Individual and simultaneous effects of the parameters were tested and the results were mathematical modeled; inhibition indexes were calculated in each case. The addition of 7.5% NaCI inhibited the growth of L. monocytogenes at 20 and 30 °C, however, at 10 °C, microbial counts reached approximately 10⁶ CFU/g. The addition of 50 mM of lactic acid to obtain a pH ≤ 5 inhibited the growth of L. monocytogenes. The combinations of lactic acid with sodium nitrite or with nisin showed an enhancement of the inhibitory effect. However, considering the low toxicity of nisin, the combination of lactic acid (50 mM) and nisin (20 IU/g) would be more acceptable in the prevention of the growth of Listeria monocytogenes.     

Potential Ecological Roles of Artemisinin Produced by Artemisia annua L.

Artemisia annua L. (annual wormwood, Asteraceae) and its secondary metabolite artemisinin, a unique sesquiterpene lactone with an endoperoxide bridge, has gained much attention due to its antimalarial properties. Artemisinin has a complex structure that requires a significant amount of energy for the plant to synthesize. So, what are the benefits to A. annua of producing this unique compound, and what is the ecological role of artemisinin? This review addresses these questions, discussing evidence of the potential utility of artemisinin in protecting the plant from insects and other herbivores, as well as pathogens and competing plant species. Abiotic factors affecting the artemisinin production, as well as mechanisms of artemisinin release to the surroundings also are discussed, and new data are provided on the toxicity of artemisinin towards soil and aquatic organisms. The antifungal and antibacterial effects reported are not very pronounced. Several studies have reported that extracts of A. annua have insecticidal effects, though few studies have proven that artemisinin could be the single compound responsible for the observed effects. However, the pathogen(s) or insect(s) that may have provided the selection pressure for the evolution of artemisinin synthesis may not have been represented in the research thus far conducted. The relatively high level of phytotoxicity of artemisinin in soil indicates that plant/plant allelopathy could be a beneficial function of artemisinin to the producing plant. The release routes of artemisinin (movement from roots and wash off from leaf surfaces) from A. annua to the soil support the rationale for allelopathy.