N-dimensional dynamical systems exploiting instabilities in full

We report experimental and numerical results showing how certain N-dimensional dynamical systems are able to exhibit complex time evolutions based on the nonlinear combination of N-1 oscillation modes. The experiments have been done with a family of thermo-optical systems of effective dynamical dimension varying from 1 to 6. The corresponding mathematical model is an N-dimensional vector field based on a scalar-valued nonlinear function of a single variable that is a linear combination of all the dynamic variables. We show how the complex evolutions appear associated with the occurrence of successive Hopf bifurcations in a saddle-node pair of fixed points up to exhaust their instability capabilities in N dimensions. For this reason the observed phenomenon is denoted as the full instability behavior of the dynamical system. The process through which the attractor responsible for the observed time evolution is formed may be rather complex and difficult to characterize. Nevertheless, the well-organized structure of the time signals suggests some generic mechanism of nonlinear mode mixing that we associate with the cluster of invariant sets emerging from the pair of fixed points and with the influence of the neighboring saddle sets on the flow nearby the attractor. The generation of invariant tori is likely during the full instability development and the global process may be considered as a generalized Landau scenario for the emergence of irregular and complex behavior through the nonlinear superposition of oscillatory motions

L'intégration de la sexualité en consultation gynécologique : discordances entre les perceptions des femmes et celles des gynécologues.

Dès les années 2000, l'Office Fédéral de la Santé Publique recommande aux médecins de premier recours, dont les gynécologues, d'aborder activement la sexualité en consultation, en raison notamment de l'augmentation des infections sexuellement transmissibles asymptomatiques (1ST). Dans le même sens, comme le montrent nombre d'études, plus de 70% des patientes souhaiteraient être interrogées au sujet de leur sexualité en consultation gynécologique. Or, il semble que peu de médecins intègrent systématiquement des questions de sexualité dans leur anamnèse. La revue de la littérature relève que les recherches réalisées à ce jour ont été menées principalement à l'aide de questionnaire selon une perspective naturaliste, qui étudie la sexualité de manière décontextualisée et qui la conçoit comme un invariant biologique et par conséquent universel. Notre objectif est de saisir en profondeur les perceptions et le vécu des gynécologues et des femmes, face à l'intégration de la sexualité en consultation gynécologique. Nous avons adopté une perspective critique en psychologie de la santé (Santiago-Delefosse & Chamberlain, 2008 ; Murray, 2004a ; Lyons & Chamberlain, 2006) qui permet de privilégier d'une part, l'étude de la signification que les sujets donnent à la sexualité dans leur contexte socio-historique et, d'autre part, une vision de l'être humain comprenant des dimensions corporelles, psychologiques et sociétales (Santiago-Delefosse, 2011). Pour ce faire, nous avons utilisé un dispositif de méthodes mixtes en deux phases. Dans la première phase, nous avons mené 21 entretiens semi directifs avec des gynécologues hommes et femmes. Puis, nous avons réalisé 3 groupes focalisés (N=16) avec des femmes âgées de 23 à 65 ans. La seconde phase a consisté à créer un questionnaire, élaboré à partir des résultats de la première phase, afin d'élargir l'expérience de l'intégration de la sexualité en consultation, à une population plus diversifiée de femmes (N=421). Les données récoltées par le biais de ces trois méthodes nous ont permis d'esquisser un modèle présentant les processus en jeu dans la situation de non intégration de la sexualité en consultation gynécologique. Celui-ci relève non seulement des lacunes dans le cursus universitaire de médecine en matière de sexualité, mais également d'importantes discordances entre les gynécologues et les femmes interviewés concernant le rôle du gynécologue, la perception de l'intime, la perception d'introduire le sujet de la sexualité en consultation, ainsi que de la définition même de la sexualité. Nos résultats ouvrent sur des perspectives pratiques pour la consultation gynécologique, ainsi que sur des pistes pour des recherches futures dans l'étude de la sexualité, selon une perspective plus intégrative. -- Since the 2000's, the Swiss Federal Office of Public Health recommended primary care physicians, including gynaecologists, to actively address sexuality issues in consultation, namely because of the increasing incidence of Sexually Transmitted Infections (STI). In line with this, studies have shown that more than 70% of patients would like to be asked about their sexuality by their gynaecologist. However, physicians do not take systematically sexual histories from their patients. Literature in the field has highlighted that most research has been restricted to using questionnaires following a naturalist theoretical perspective according to which sexual behaviour is defined as biologically invariant, hence, universal. Our objective is to deepen understand perceptions from gynaecologists and women with regard to the integration of sexuality in consultations. A critical health psychology approach allows us to consider on the one hand sexuality as a construct that is inseparable from a given socio-historical context. On the other hand, this approach takes into consideration an embodied, social and psychological definition of human beings. Therefore, we used a mixed methods design that included two main research steps : First, we conducted 21 semi-structured interviews with male and female gynaecologists. In this phase, we also led 3 focus groups made up of 16 women aged from 21 to 65. Second, a survey was implemented (N= 421) based on findings stemming from the first phase. This allowed us to further analyse experiences on the integration of sexuality and to extend findings to a more diversified population of women. The data analysis allowed us to create a model that highlights the processes involved in the non integration of sexuality during gynaecological consultation. It shows a lack of training in sexology within medical programs. Moreover, it emphasises the mismatches on perceptions between gynaecologists and women concerning the gynaecologist's role ; intimacy, the issue of whether introducing sexuality topics, and finally, on the actual definition of sexuality itself. Our findings open new research perspectives for the study of sexuality by proposing a more integrative approach. They also provide practical and clinical perspectives concerning consultations in gynaecology.

Qualidade de vida de adultos com lesão medular: um estudo com WHOQOL-bref

Objetivou-se avaliar a qualidade de vida (QV) de adultos com lesão medular e identificar os domínios que podem influir na qualidade de vida. Para coletar os dados utilizou-se o WHOQOL-bref e um questionário com variáveis sociodemográficas. Participaram 47 sujeitos com média de idade de 42,95 anos, 91,5% do sexo masculino e 8,5% do feminino. Os domínios obtiveram os escores: físico (58,59%), psicológico (63,82%), social (68,79%) e ambiental (55,20%). Por meio de regressão linear múltipla, verificou-se a correlação dos escores dos domínios com a percepção da QV: físico (p < 0,187), psicológico (p < 0,399), social (p < 0,000) e ambiental (p < 0,008). Concluiu-se que a maioria (55,3%) dos participantes está insatisfeita com a QV e que os domínios social e ambiental apresentaram maior correlação com a QV.

Postoperative management of adult central neurosurgical patients: systemic and neuro-monitoring.

Postoperative neurosurgical patients are at risk of developing complications. Systemic and neuro-monitoring are used to identify patients who deteriorate in order to treat the underlying cause and minimize the impact on outcome. Hypotension and hypoxia are likely to be the most frequent insults and can be detected easily with blood pressure monitoring and pulse oximetry. Repeated clinical examination, however, is probably the most important monitor in the postoperative setting. Clinical scores such as the Glasgow Coma Score and the more recently introduced FOUR Score are important tools to standardize the clinical assessment. Intracranial pressure monitoring, cerebral blood flow monitoring, electroencephalography, and brain imaging are often used postoperatively. Despite the numerous publications on this topic only few studies address the impact of postoperative monitoring on outcome. Accordingly, in most patients the decision on which monitors are to be used must be based on the patient's presentation and clinical judgment.

La evolución de la teoría de los efectos de los medios de comunicación de masas: la teoría de la espiral del silencio a partir de la construcción de la realidad social por parte de los medios de comunicación de masas

Este trabajo estudia la evolución de la teoría de los efectos de los medios decomunicación de masas desde su origen, a principios del siglo XX en el contextonorteamericano de la Mass Communication Research, hasta la fecha. Para ello, repasalos diferentes paradigmas en el análisis de la comunicación y sus teorías, haciendo unespecial énfasis en el contexto histórico en que se dan, así como los paradigmassociológicos y psicológicos simultáneos. El trabajo se centra en la teoría de la espiraldel silencio de Noelle-Neumann, como consecuencia de la construcción social de larealidad a partir de los medios de comunicación, y analiza los efectos psicosociales de dicha teoría, principalmente el miedo al aislamiento, la percepción del clima de opinióny la voluntad de expresar opiniones en público.

The impact of fibrosis and steatosis on early viral kinetics in HCV genotype 1-infected patients treated with Peg-IFN-alfa-2a and ribavirin.

Summary.  Hepatitis C viral (HCV) kinetics after initiation of interferon-based therapy provide valuable insights for understanding virus pathogenesis, evaluating treatment antiviral effectiveness and predicting treatment outcome. Adverse effects of liver fibrosis and steatosis on sustained virological response have been frequently reported, yet their impacts on the early viral kinetics remain unclear. In this study, associations between histology status and early viral kinetics were assessed in 149 HCV genotype 1-infected patients treated with pegylated interferon alfa-2a and ribavirin (DITTO trial). In multivariate analyses adjusted for critical factors such as IL28B genotype and baseline viral load, presence of significant fibrosis (Ishak stage > 2) was found to independently reduce the odds of achieving an initial reduction (calculated from day 0 to day 4) in HCV RNA of ≥2 logIU/mL (adjusted OR 0.03, P = 0.004) but was not associated with the second-phase slope of viral decline (calculated from day 8 to day 29). On the contrary, presence of liver steatosis was an independent risk factor for not having a rapid second-phase slope, that is, ≥0.3 logIU/mL/week (adjusted OR 0.22, P = 0.012) but was not associated with the first-phase decline. Viral kinetic modelling theory suggests that significant fibrosis primarily impairs the treatment antiviral effectiveness in blocking viral production by infected cells, whereas the presence of steatosis is associated with a lower net loss of infected cells. Further studies will be necessary to identify the biological mechanisms underlain by these findings.

Intra-arterial hepatic fotemustine for the treatment of liver metastases from uveal melanoma: experience in 101 patients.

BACKGROUND: Exclusive liver metastases occur in up to 40% of patients with uveal melanoma associated with a median survival of 2-7 months. Single agent response rates with commonly available chemotherapy are below 10%. We have investigated the use of fotemustine via direct intra-arterial hepatic (i.a.h.) administration in patients with uveal melanoma metastases. PATIENTS AND METHODS: A total of 101 patients from seven centers were treated with i.a.h. fotemustine, administered intra-arterially weekly for a 4-week induction period, and then as a maintenance treatment every 3 weeks until disease progression, unacceptable toxicity or patient refusal. RESULTS: A median of eight fotemustine infusions per patient were delivered (range 1-26). Catheter related complications occurred in 23% of patients; however, this required treatment discontinuation in only 10% of the patients. The overall response rate was 36% with a median overall survival of 15 months and a 2-year survival rate of 29%. LDH, time between diagnosis and treatment start and gender were significant predictors of survival. CONCLUSIONS: Locoregional treatment with fotemustine is well tolerated and seems to improve outcome of this poor prognosis patient population. Median survival rates are among the longest reported and one-third of the patients are still alive at 2 years.

Considerations on the ASTM Standards 1789-04 and 1422-05 on the Forensic Examination of Ink

The ASTM standards on Writing Ink Identification (ASTM 1789-04) and on Writing Ink Comparison (ASTM 1422-05) are the most up-to-date guidelines that have been published on the forensic analysis of ink. The aim of these documents is to cover most aspects of the forensic analysis of ink evidence, from the analysis of ink samples, the comparison of the analytical profile of these samples (with the aim to differentiate them or not), through to the interpretation of the result of the examination of these samples in a forensic context. Significant evolutions in the technology available to forensic scientists, in the quality assurance requirements brought onto them, and in the understanding of frameworks to interpret forensic evidence have been made in recent years. This article reviews the two standards in the light of these evolutions and proposes some practical improvements in terms of the standardization of the analyses, the comparison of ink samples, and the interpretation of ink examination. Some of these suggestions have already been included in a DHS funded project aimed at creating a digital ink library for the United States Secret Service.

Response Prediction in Chronic Hepatitis C by Assessment of IP-10 and IL28B-Related Single Nucleotide Polymorphisms.

BACKGROUND: High baseline levels of IP-10 predict a slower first phase decline in HCV RNA and a poor outcome following interferon/ribavirin therapy in patients with chronic hepatitis C. Several recent studies report that single nucleotide polymorphisms (SNPs) adjacent to IL28B predict spontaneous resolution of HCV infection and outcome of treatment among HCV genotype 1 infected patients. METHODS AND FINDINGS: In the present study, we correlated the occurrence of variants at three such SNPs (rs12979860, rs12980275, and rs8099917) with pretreatment plasma IP-10 and HCV RNA throughout therapy within a phase III treatment trial (HCV-DITTO) involving 253 Caucasian patients. The favorable SNP variants (CC, AA, and TT, respectively) were associated with lower baseline IP-10 (P = 0.02, P = 0.01, P = 0.04) and were less common among HCV genotype 1 infected patients than genotype 2/3 (P<0.0001, P<0.0001, and P = 0.01). Patients carrying favorable SNP genotypes had higher baseline viral load than those carrying unfavorable variants (P = 0.0013, P = 0.029, P = 0.0004 respectively). Among HCV genotype 1 infected carriers of the favorable C, A, or T alleles, IP-10 below 150 pg/mL significantly predicted a more pronounced reduction of HCV RNA from day 0 to 4 (first phase decline), which translated into increased rates of RVR (62%, 53%, and 39%) and SVR (85%, 76%, and 75% respectively) among homozygous carriers with baseline IP-10 below 150 pg/mL. In multivariate analyses of genotype 1-infected patients, baseline IP-10 and C genotype at rs12979860 independently predicted the first phase viral decline and RVR, which in turn independently predicted SVR. CONCLUSIONS: Concomitant assessment of pretreatment IP-10 and IL28B-related SNPs augments the prediction of the first phase decline in HCV RNA, RVR, and final therapeutic outcome.

Effect of age on intraoperative cerebrovascular autoregulation and near-infrared spectroscopy-derived cerebral oxygenation.

Background. Age is an important risk factor for perioperative cerebral complications such as stroke, postoperative cognitive dysfunction, and delirium. We explored the hypothesis that intraoperative cerebrovascular autoregulation is less efficient and brain tissue oxygenation lower in elderly patients, thus, increasing the vulnerability of elderly brains to systemic insults such as hypotension.Methods. We monitored intraoperative cerebral perfusion in 50 patients aged 18-40 and 77 patients >65 yr at two Swiss university hospitals. Mean arterial pressure (MAP) was measured continuously using a plethysmographic method. An index of cerebrovascular autoregulation (Mx) was calculated based on changes in transcranial Doppler flow velocity due to changes in MAP. Cerebral oxygenation was assessed by the tissue oxygenation index (TOI) using near-infrared spectroscopy. End-tidal CO(2), O(2), and sevoflurane concentrations and peripheral oxygen saturation were recorded continuously. Standardized anaesthesia was administered in all patients (thiopental, sevoflurane, fentanyl, atracurium).Results. Autoregulation was less efficient in patients aged >65 yr [by 0.10 (SE 0.04; P=0.020)] in a multivariable linear regression analysis. This difference was not attributable to differences in MAP, end-tidal CO2, or higher doses of sevoflurane. TOI was not significantly associated with age, sevoflurane dose, or Mx but increased with increasing flow velocity [by 0.09 (SE 0.04; P=0.028)] and increasing MAP [by 0.11 (SE 0.05; P=0.043)].Conclusions. Our results do not support the hypothesis that older patients' brains are more vulnerable to systemic insults. The difference of autoregulation between the two groups was small and most likely clinically insignificant.

Validity of the Katz Index to assess activities of daily living by informants in neuropathological studies

Abstract OBJECTIVE To analyze the evidences of construct validity of the Katz Index for the retrospective assessment of activities of daily living (ADL) by informants, to assist neuropathological studies in the elderly. METHOD A cross-sectional study analyzed the functional ability of ADL measure by the Katz Index, of 650 cases randomly selected from the Brazilian Brain Bank of the Ageing Brain Study Group (BBBABSG) database. Sample was divided in two subsamples for the analysis (N=325, each) and then stratified according to cognitive decline assessed by the Clinical Dementia Rating Scale (CDR). Factor analyses with calculations of internal consistency and invariance were performed. RESULTS Factor analysis evidenced a unidimensional instrument with optimal internal consistency, in all subgroups. Goodness of fit indices were obtained after two treatments of covariance, indicating adequacy of the scale for assessing ADL by informants. The scale is invariant to cognitive decline meaning that it can be used for subjects with or without cognitive impairment. CONCLUSION Katz Index is valid for the retrospective assessment of basic ADL by informants, with optimal reliability.