Development of liquid xenon detectors for medical imaging

In the present paper, we report on our developments of liquid xenon detectors for medical imaging, positron emission tomography and single photon imaging, in particular. The results of the studies of several photon detectors (photomultiplier tubes and large area avalanche photodiode) suitable for detection of xenon scintillation are also briefly described.Comment: 13 pages, 5 figures, presented on the International Workshop on Techniques and Applications of Xenon Detectors (Xenon01), ICRR, Univ. of Tokyo, Kashiwa, Japan, December 3-4, 2001 (submitted to proceedings

Antimicrobial resistance patterns of Salmonella enterica subsp. enterica serovar Derby and Typhimurium isolated from pigs slaughtered in southern Brazil

Salmonella enterica subsp. enterica serovar (S.) Derby and S. Typhimurium were commonly isolated from slaughter pigs and pork. Thus, the monitoring of the resistance profile exhibited by strains of both serovars should be regularly conducted. This study aimed to assess the antimicrobial resistance pattern of strains isolated form pig carcasses and to investigate the genetic relatedness with isolates from intestinal content and lairage environment. Thirty-four S. Derby and seventeen S. Typhimurium strains isolated from carcasses (n=30), intestinal contents (n=16), and lairage environment (n=3) were tested. The antimicrobial resistance was determined by the agar disk diffusion test according to the document M31-A2 of the CLSI using twelve antimicrobials

Hypersomnia in Whipple disease: case report.

Arq Neuropsiquiatr. 2006 Sep;64(3B):865-8. Hypersomnia in Whipple disease: case report. Maia LF, Marta M, Lopes V, Rocha N, Lopes C, Martins-da-Silva A, Monteiro L. SourceDepartment of Neurological Disordes and Senses, Hospital Geral de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal. Abstract Whipple disease (WD) is a rare systemic infection caused by Tropheryma whippelii. Neurological involvement has been recognised in 40% of patients, either as initial manifestations or during the course of the disease. We report on a 45 years-old man with WD with initial, persistent and irresistible episodes of daytime somnolence. The patient was HLA-DQB1*0602 positive (genetic marker for narcolepsy). WD diagnosis was suspected on clinical and MRI basis and confirmed by histological and immunohistochemical study of duodenal biopsy. Forty months later all clinical features improved, narcoleptic-like episodes disappeared and cerebral MRI and CSF normalised. Longitudinal neurophysiological studies revealed persistent sleep pattern abnormalities with sleep fragmentation, paucity of slow wave and of REM sleep. The disruption of the hypocretin circuitry in the hypothalamic - diencephalic region triggered by the infection was the probable cause of the hypersomnia and narcopleptic symptoms. WD should be added to the list of causes of secondary hypersomnia

Knowledge about sugar sources and sugar intake guidelines in portuguese consumers

In this work, we examined knowledge about sugars and guidelines for its consumption and explored the relationship between knowledge and measures related to nutritional information processing as well as sugar consumption. Specifically, we asked participants (n = 1010 Portuguese) to categorize a set of ingredients (e.g., glucose, aspartame) regarding their composition (i.e., intrinsic vs. added/free sugars) and origin (e.g., natural vs. artificial) and if they were aware of the WHO guidelines for sugar intake. Overall, despite using information about sugar frequently and considering attending to such information as very important to stay healthy, most participants were unaware of the WHO guidelines and revealed difficulties in the categorization task. Women, participants with a higher level of education, and those with children in the household reported higher use of sugar content information present in nutritional labels, higher perceived knowledge of nutritional guidelines, and higher hit rates in categorizing sugar sources. Almost one-fourth of the population exceeds the daily limit recommended by the WHO. Therefore, characterizing the knowledge of a Portuguese sample regarding sugar sources and sugar intake guidelines is particularly relevant, and our results emphasize the need to implement effective strategies to reduce sugar intake.info:eu-repo/semantics/publishedVersio

Motivations for sexual behavior and intentions to use condoms: development of the Regulatory Focus in Sexuality (RFS) Scale

Despite recurrent eforts to prevent sexually transmitted diseases through the use of condoms, HIV infections are still prevalent across Europe. Recent research framed by the regulatory focus theory has shown that prevention (vs. promotion)-focused individuals are more likely to adopt strategies to protect their health. Therefore, these individuals should also be more motivated to use condoms, because they are more likely to perceive greater health threats. In two cross-sectional preregistered studies (combined N = 520 Portuguese participants; databases available at https://doi.org/10.17605/osf.io/nzkmn), we developed the new Regulatory Focus in Sexuality (RFS) scale (Study 1), and tested if the association between prevention focus and intentions to use condoms was mediated by the perception of health threat (Study 2). Results from Study 1 suggested that the scale is valid and reliable. Results from Study 2 showed, as expected, that a predominant focus on prevention was associated with more condom use intentions with casual and regular sexual partners, because individuals perceived greater threat to their health. Additional exploratory analyses further showed that this mediation occurred only for individuals without a romantic relationship and was independent of how salient the condom use norm was. In contrast, for romantically involved individuals, there was no evidence for the mediation by perceived health threat. Instead, a predominant focus on prevention was positively associated with condom use intentions with the regular partner, but only when the condom use norm was more salient. Taken together, these results emphasize the importance of examining individual motivations for safe sex practices.info:eu-repo/semantics/acceptedVersio

Predictors of condomless sex and sexual health behaviors in a sample of Portuguese single adults

Introduction: Several theoretical models and intervention programs overlook the importance of individual motivations for the decision to have condomless sex. For instance, people focused on promotion (ie, eager to pursue pleasure) report less intentions to use condoms, because they perceive a lower risk of acquiring sexually transmitted infections. Aim: We aimed at understanding to what extent individual motivations are predictive of condomless sex behavior among single individuals. Methods: A sample of 415 Portuguese individuals (254 women) with ages ranging from 18−46 years (M = 23.30; SD = 5.28) were recruited to a cross-sectional study. All participants were neither dating nor in a romantic relationship at the time of the study. The link to an anonymous web survey was shared in social networking platforms. Main Outcome Measure: The survey included self-reported demographic variables (eg, age and sex), recent condomless sex behavior, and previously validated measures assessing regulatory focus in sexuality, ability in sexual restraint, perceived control over condom use, perceived safety with sex partners, and salience of the condom use norm. Results: More than two-thirds of the sample had recently engaged in condomless sex. A logistic regression showed that condomless sex was more likely for participants predominantly focused on promotion in sexuality. It was also more likely among less educated participants, those with a lower ability to restrain their sexual behavior, those who perceive to have less control over condom use, those for whom the condom use norm was less salient, and those who perceived to be safer with their sex partners. No other results were significant. Clinical Implications: Our results can be informative to sexual health care professionals when planning strategies to increase condom use awareness, by considering the role of specific individual motivations. Strengths & Limitations: This is the first study showing that individual motivations uniquely contribute to the decision to have condomless sex. This study has 2 main limitations that constraint the generalizability of the findings: (a) cross-sectional data prevents us from establishing causality, and (b) individual data does not account for dyadic processes in sexuality (eg, condom use negotiation). Conclusion: Our findings showed that condomless sex results from an individual focus on seeking pleasure, a lack of control in sexual behavior, and a perception of sex partners as more trustworthy. Overall, these findings are likely to help researchers and health care professionals improving theoretical models predicting condom use and preventing the spread of sexually transmitted infections.info:eu-repo/semantics/acceptedVersio

Experimental determination of the non-extensive entropic parameter qq

We show how to extract the $q$ parameter from experimental data, considering an inhomogeneous magnetic system composed by many Maxwell-Boltzmann homogeneous parts, which after integration over the whole system recover the Tsallis non-extensivity. Analyzing the cluster distribution of La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ manganite, obtained through scanning tunnelling spectroscopy, we measure the $q$ parameter and predict the bulk magnetization with good accuracy. The connection between the Griffiths phase and non-extensivity is also considered. We conclude that the entropic parameter embodies information about the dynamics, the key role to describe complex systems.Comment: Submitted to Phys. Rev. Let

Evolution of squeezed states under the Fock-Darwin Hamiltonian

We develop a complete analytical description of the time evolution of squeezed states of a charged particle under the Fock-Darwin Hamiltonian and a time-dependent electric field. This result generalises a relation obtained by Infeld and Pleba\'nski for states of the one-dimensional harmonic oscillator. We relate the evolution of a state-vector subjected to squeezing to that of state which is not subjected to squeezing and for which the time-evolution under the simple harmonic oscillator dynamics is known (e.g. an eigenstate of the Hamiltonian). A corresponding relation is also established for the Wigner functions of the states, in view of their utility in the analysis of cold-ion experiments. In an appendix, we compute the response functions of the FD Hamiltonian to an external electric field, using the same techniques as in the main text

The impact of gluten-free claim on the perceived healthfulness, calories, level of processing and expected taste of food products

In recent years, gluten-free (GF) diet has become quite popular among non-celiac individuals and GF versions are now available for an array of processed foods. In this study, we examined how including a GF label in packaging impacts the evaluation of food products in several evaluative dimensions. Participants (N = 202; 63.2% female, Mage = 27.87, SD = 10.72) were presented with images of four food products and asked to evaluate the healthfulness, caloric content, expected taste and level of processing of each product. Overall, results showed that GF (vs. control) products were perceived as more healthful, as having fewer calories and as less processed. No main effect of the GF label was observed for expected taste. In some cases, the impact of the GF label was moderated by the type of product. These findings were independent of participants’ positive beliefs toward GF diet, and their low self-reported knowledge about GF products. Our findings clarify a potential source of bias for the consumer and may inform evidence-based strategies or policies aiming to promote healthy eating habits.info:eu-repo/semantics/acceptedVersio