313 research outputs found
A list of all integrable 2D homogeneous polynomial potentials with a polynomial integral of order at most 4 in the momenta
We searched integrable 2D homogeneous polynomial potential with a polynomial
first integral by using the so-called direct method of searching for first
integrals. We proved that there exist no polynomial first integrals which are
genuinely cubic or quartic in the momenta if the degree of homogeneous
polynomial potentials is greater than 4.Comment: 22 pages, no figures, to appear in J. Phys. A: Math. Ge
Maintaining families' well-being in everyday life
The aim of this paper is to discuss how everyday life changes for the family in the event of chronic illness or disability. It changes physically due to loss of body function and socially due to time and other constraints related to treatment or lack of mobility. Equally important, there is a psychological impact due to the uncertainty of the future. The article will explore how family participation can help to maintain well-being in everyday life. The family should therefore focus on their own needs as much as on the needs of the family members who are ill. In order to maintain well-being in everyday life, it is crucial for the family to create routines and spend time doing things that they enjoy. By doing this, the family will create a rhythm of well-being regardless of the critical family situation. Family members and professional caregivers also need to come together at the beginning and during the illness or disability event to discuss changes that could be made day-to-day for all those involved, thereby making for an easier transition into care giving
Genetic counselling and the intention to undergo prophylactic mastectomy: effects of a breast cancer risk assessment
Scientific reports suggest that women at risk for familial breast cancer may benefit from prophylactic mastectomy. However, few data are available about how women decide upon this clinical option, and in particular, what role an objective risk assessment plays in this. The purpose of the present study is to assess whether this objective risk information provided in genetic counselling affects the intention for prophylactic mastectomy. Additionally, the (mediating) effects of breast cancer worry and perceived risk are investigated. A total of 241 women completed a questionnaire before and after receiving information about their familial lifetime breast cancer risk in a genetic counselling session. Path analysis showed that the objective risk information had a corrective effect on perceived risk (β=0.38; P=0.0001), whereas the amount of breast cancer worry was not influenced by the counselling session. The objective risk information did not directly affect the intention for prophylactic mastectomy. The intention was influenced by perceived risk after counselling (β=0.23; P=0.002), and by the precounselling levels of perceived risk (β=0.27; P=0.00025) and breast cancer worry (β=0.32; P=0.0001), that is, higher levels of perceived risk and breast cancer worry imply a stronger intention for prophylactic mastectomy. A personal history of breast cancer did not directly influence the intention for prophylactic mastectomy, but affected women who had undergone a mastectomy as surgical treatment were more positively inclined to have a prophylactic mastectomy than women who had had breast-conserving therapy. The impact of objective risk information on the intention for prophylactic mastectomy is limited and is mediated by perceived risk. Important determinants of the intention for prophylactic mastectomy were precounselling levels of breast cancer worry and perceived risk, suggesting that genetic counselling is only one event in the entire process of decision making. Therefore, interventions aimed at improving decision making on prophylactic mastectomy should explicitly address precounselling factors, such as personal beliefs and the psychological impact of the family medical history
Psychological distress in newly diagnosed colorectal cancer patients following microsatellite instability testing for Lynch syndrome on the pathologist’s initiative
According to the Dutch Guideline on Hereditary Colorectal Cancer published in 2008, patients with recently diagnosed colorectal cancer (CRC) should undergo microsatellite instability (MSI) testing by a pathologist immediately after tumour resection if they are younger than 50 years, or if a second CRC has been diagnosed before the age of 70 years, owing to the high risk of Lynch syndrome (MIPA). The aim of the present MIPAPS study was to investigate general distress and cancer-specific distress following MSI testing. From March 2007 to September 2009, 400 patients who had been tested for MSI after newly diagnosed CRC were recruited from 30 Dutch hospitals. Levels of general distress (SCL-90) and cancer-specific distress (IES) were assessed immediately after MSI result disclosure (T1) and 6 months later (T2). Response rates were 23/77 (30%) in the MSI-positive patients and 58/323 (18%) in the MSI-negative patients. Levels of general distress and cancer-specific distress were moderate. In the MSI-positive group, 27% of the patients had high general distress at T1 versus 18% at T2 (p = 0.5), whereas in the MSI-negative group, these percentage were 14 and 18% (p = 0.6), respectively. At T1 and T2, cancer-specific distress rates in the MSI-positive group and MSI-negative group were 39 versus 27% (p = 0.3) and 38 versus 36% (p = 1.0), respectively. High levels of general distress were correlated with female gender, low social support and high perceived cancer risk. Moderate levels of distress were observed after MSI testing, similar to those found in other patients diagnosed with CRC. Immediately after result disclosure, high cancer-specific distress was observed in 40% of the MSI-positive patients
Consistent patterns of common species across tropical tree communities
Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees
Testicular cancer: a longitudinal pilot study on stress response symptoms and quality of life in couples before and after chemotherapy
Goals of work: The current study was designed to longitudinally examine stress response symptoms (SRS) and quality of life (QoL) in couples confronted with disseminated testicular cancer. The objectives were to examine couples' patterns of adjustment over time and possible differences in adjustment between the patient and his partner.Materials and methods: Couples completed the Impact of Event Scale and the QoL subscales physical functioning, social functioning, and mental health of the RAND-36 before chemotherapy (T1), after completion of chemotherapy (T2), and 1 year later (T3). Results: Before chemotherapy 26% of the patients and 50% of partners reported clinically elevated levels of SRS. Patients reported lower physical and social functioning at T2 compared to T1 and T3. Partners reported an improvement in social functioning over the year and no changes in physical functioning or mental health. No relationships between patients and partners' functioning were found. One year after diagnosis, QoL of patients and partners was similar to that of reference groups, and patients even reported better physical functioning than the reference group. SRS of patients and partners were negatively related at T1, and patients and partners' social functioning were positively related at T2. Conclusions: According to stress response levels, the period before the start of chemotherapy was most stressful for couples. Adjustment patterns differ between testicular cancer patients and their partners with patients reporting lowered QoL after completion of chemotherapy. QoL of couples returned to normal levels 1 year after diagnosis. The effect of disseminated testicular cancer on the QoL of patients and their partners seems to be temporary. A minority may need clinical attention for severe SRS
Factors contributing to posttraumatic growth and its buffering effect in adult chidren of cancer patients undergoing treatment
This study examined relationships among demographic, clinical,
and psychosocial variables in adult children of cancer patients.
Two hundred and fourteen participants completed measures of
posttraumatic growth (PTG), distress, posttraumatic stress disorder
(PTSD) symptoms, social support, and family functioning. Significant
gender differences in all PTG dimensions were found, as well
as associations among PTG, gender, parental dependency, distress,
PTSD, and family functioning. Social support was not a mediator
in the relationship between gender and PTG. Gender, education,
disease duration, dependency, distress, and family flexibility predicted
PTG. Finally, PTG had amoderating effect in the relationship
between distress and PTSD/social support. These results may guide
psychosocial interventions in this population.Fundação para a Ciência e Tecnologia (FCT
«La relation de limitation et d’exception dans le français d’aujourd’hui : excepté, sauf et hormis comme pivots d’une relation algébrique »
L’analyse des emplois prépositionnels et des emplois conjonctifs d’ “excepté”, de “sauf” et d’ “hormis” permet d’envisager les trois prépositions/conjonctions comme le pivot d’un binôme, comme la plaque tournante d’une structure bipolaire. Placées au milieu du binôme, ces prépositions sont forcées par leur sémantisme originaire dûment métaphorisé de jouer le rôle de marqueurs d’inconséquence systématique entre l’élément se trouvant à leur gauche et celui qui se trouve à leur droite. L’opposition qui surgit entre les deux éléments n’est donc pas une incompatibilité naturelle, intrinsèque, mais extrinsèque, induite. Dans la plupart des cas (emplois limitatifs), cette opposition prend la forme d’un rapport entre une « classe » et le « membre (soustrait) de la classe », ou bien entre un « tout » et une « partie » ; dans d’autres (emplois exceptifs), cette opposition se manifeste au contraire comme une attaque de front portée par un « tout » à un autre « tout ». De plus, l’inconséquence induite mise en place par la préposition/conjonction paraît, en principe, tout à fait insurmontable. Dans l’assertion « les écureuils vivent partout, sauf en Australie » (que l’on peut expliciter par « Les écureuils vivent partout, sauf [qu’ils ne vivent pas] en Australie »), la préposition semble en effet capable d’impliquer le prédicat principal avec signe inverti, et de bâtir sur une telle implication une sorte de sous énoncé qui, à la rigueur, est totalement inconséquent avec celui qui le précède (si « les écureuils ne vivent pas en Australie », le fait qu’ils « vivent partout » est faux). Néanmoins, l’analyse montre qu’alors que certaines de ces oppositions peuvent enfin être dépassées, d’autres ne le peuvent pas. C’est, respectivement, le cas des relations limitatives et des relations exceptives. La relation limitative, impliquant le rapport « tout » - « partie », permet de résoudre le conflit dans les termes d’une somme algébrique entre deux sous énoncés pourvus de différent poids informatif et de signe contraire. Les valeurs numériques des termes de la somme étant déséquilibrées, le résultat est toujours autre que zéro. La relation exceptive, au contraire, qui n’implique pas le rapport « tout » - « partie », n’est pas capable de résoudre le conflit entre deux sous énoncés pourvus du même poids informatif et en même temps de signe contraire : les valeurs numériques des termes de la somme étant symétriques et égales, le résultat sera toujours équivalent à zéro
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