Bacterial membrane injuries induced by lactacin F and nisin

The combined action of nisin and lactacin F, two bacteriocins produced by lactic acid bacteria, is additive. In this report, the basis of this effect is examined. Channels formed by lactacin F were studied by experiments using planar lipid bilayers, and bactericidal effects were analyzed by flow cytometry. Lactacin F produced pores with a conductance of 1 ns in black lipid bilayers in 1 mM KClat 10 mV at 20°C. Pore formation was strongly dependent on voltage. Although lactacin F formed pores at very low potential (10 mV), the dependence was exponentialabov e 40 mV. The injuries induced by nisin and lactacin F in the membranes of Lactobacillus helveticus produced different flow cytometric profiles. Probably, when both bacteriocins are present, each acts separately; their cooperation may be due to an increase in the number of single membrane injuries

Unplanned complex suicide by self-strangulation associated with multiple sharp force injuries: a case report.

In cases of ligature strangulation, the importance of distinguishing self-inflicted death from homicide is crucial. This entails objective scene investigation, autopsy and anamnesis in order to elucidate the manner of death correctly. The authors report a case of unplanned complex suicide by means of self-strangulation and multiple sharp force injury. The use of more than one suicide method, consecutively--termed unplanned complex suicide--gives this case particular significance. A brief discussion on this uncommon method of suicide is presented, particularly relevant to the attending forensic physician. In addition, a short overview of the entity of complex suicide is given.

Les lésions de l'intestin grêle et du côlon dans les traumatismes fermés de l'abdomen [Lesions of the small intestine and colon in blunt injuries of the abdomen].

Between 1976 and 1991, we observed lesions of the small bowel or colon in 39 patients having sustained blunt abdominal trauma. 70% of the patients presented with concomitant injuries. Except for 3 cases, all the patients presented with abdominal pain on admission. All the patients were operated on. The delay between admission and operation varied between a few minutes and 48 hours. Indication was hemoperitoneum, peritonitis or progressive abdominal pain. Overall morbidity is high, often related to associated disease. 4 patients died (mortality 10%), including 2 patients with isolated intestinal trauma who were operated on after 20 and 36 hours. Due to the lack of specific laboratory or X-ray test, we suggest a high index of suspicion for bowel lesions in blunt abdominal trauma, especially in unconscious patients. Close observation is mandatory. Indication for laparotomy must not be delayed if any doubt exists regarding the integrity of hollow viscus.

Lack of support for the association between facial shape and aggression: a reappraisal based on a worldwide population genetics perspective

Antisocial and criminal behaviors are multifactorial traits whose interpretation relies on multiple disciplines. Since these interpretations may have social, moral and legal implications, a constant review of the evidence is necessary before any scientific claim is considered as truth. A recent study proposed that men with wider faces relative to facial height (fWHR) are more likely to develop unethical behaviour mediated by a psychological sense of power. This research was based on reports suggesting that sexual dimorphism and selection would be responsible for a correlation between fWHR and aggression. Here we show that 4,960 individuals from 94 modern human populations belonging to a vast array of genetic and cultural contexts do not display significant amounts of fWHR sexual dimorphism. Further analyses using populations with associated ethnographical records as well as samples of male prisoners of the Mexico City Federal Penitentiary condemned by crimes of variable level of inter-personal aggression (homicide, robbery, and minor faults) did not show significant evidence, suggesting that populations/individuals with higher levels of bellicosity, aggressive behaviour, or power-mediated behaviour display greater fWHR. Finally, a regression analysis of fWHR on individual"s fitness showed no significant correlation between this facial trait and reproductive success. Overall, our results suggest that facial attributes are poor predictors of aggressive behaviour, or at least, that sexual selection was weak enough to leave a signal on patterns of between- and within-sex and population facial variation.

The relative salience of facial features when differentiating faces based on an interference paradigm

Research on face recognition and social judgment usually addresses the manipulation of facial features (eyes, nose, mouth, etc.). Using a procedure based on a Stroop-like task, Montepare and Opeyo (J Nonverbal Behav 26(1):43-59, 2002) established a hierarchy of the relative salience of cues based on facial attributes when differentiating faces. Using the same perceptual interference task, we established a hierarchy of facial features. Twenty-three participants (13 men and 10 women) volunteered for the experiment to compare pairs of frontal faces. The participants had to judge if the eyes, nose, mouth and chin in the pair of images were the same or different. The factors manipulated were the target-distractive factor (4 face components 9 3 distractive factors), interference (absent vs. present) and correct answer (the same vs. different). The analysis of reaction times and errors showed that the eyes and mouth were processed before the chin and nose, thus highlighting the critical importance of the eyes and mouth, as shown by previous research.

Reducción del vector de características de reconocimiento facial

In this present work, we are proposing a characteristics reduction system for a facial biometric identification system, using transformed domains such as discrete cosine transformed (DCT) and discrete wavelets transformed (DWT) as parameterization; and Support Vector Machines (SVM) and Neural Network (NN) as classifiers. The size reduction has been done with Principal Component Analysis (PCA) and with Independent Component Analysis (ICA). This system presents a similar success results for both DWT-SVM system and DWT-PCA-SVM system, about 98%. The computational load is improved on training mode due to the decreasing of input’s size and less complexity of the classifier.