923 research outputs found

    Surviving on Mars: test with LISA simulator

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    We present the biological results of some experiments performed in the Padua simulators of planetary environments, named LISA, used to study the limit of bacterial life on the planet Mars. The survival of Bacillus strains for some hours in Martian environment is shortly discussed.Comment: To be published on Highlights of Astronomy, Volume 15 XXVIIth IAU General Assembly, August 2009 Ian F Corbett, ed. 2 pages, 1 figur

    Alternative somatic cell count traits exploitable in genetic selection for mastitis resistance in Italian Holsteins

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    The aim of the present study was to characterize alternative somatic cell count (SCC) traits that could be exploited in genetic selection for mastitis resistance. Data were from 66,407 first-parity Holsteins in 404 herds. Novel SCC traits included average somatic cell score (SCS, log-transformation of SCC) in early lactation (SCS_150), standard deviation of SCS of the entire lactation (SCS_SD), the presence of at least one test-day (TD) SCC >400,000 cells/mL in the lactation, and the ratio of number of TD SCC >400,000 cells/mL to total number of TD in the lactation. Novel traits and lactation-mean SCS (SCS_LM) were analyzed using linear mixed or logistic regression models, including month of calving, year of calving, number of TD, and milk yield as fixed effects, and herd and residual as random terms. A multitrait linear animal model was applied to a random subset of 152 herds (n = 22,695 cows) to assess heritability of and genetic correlations between SCC traits. Alternative SCC traits were affected by the environmental factors included in the model; in particular, results suggested a seasonal effect and a tendency toward an improvement of the udder health status in the last years. Association was also found between novel SCC traits and milk production. Alternative SCC traits exhibited coefficients of additive genetic variation that were similar to or larger than that of traditional SCS_LM. Heritability of novel SCC traits was smaller than heritability of SCS_LM (0.126 \ub1 0.014), ranging from 0.044 \ub1 0.008 (SCS_SD) to 0.087 \ub1 0.010 (SCS_150). Genetic correlations between SCC traits ranged from 0.217 \ub1 0.096 (SCS_150 and SCS_SD) to 0.969 \ub1 0.010 (SCS_LM and SCS_150). Alternative SCC traits exhibited additive genetic variation that is potentially exploitable in breeding programs of Italian Holstein population to improve resistance to mastitis

    A systematic review of behavioral outcomes for leadership interventions among health professionals

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    Background: Healthcare requires effective leadership to improve patient outcomes, manage change, and achieve organizational goals. Purpose: The purpose of this study was to evaluate interventions aimed at improving leadership behavior in health professionals. Methods: A systematic literature review of key databases (PubMed, CINAHL, Embase, and Scopus) was performed in September 2018. Data were extracted and synthesized. Results: Thirty-three articles from 31 studies met the inclusion criteria. Self-reported leadership behavior showed a significant postprogram improvement. Objective observations were more likely to show improved leadership behavior than subjective observations. Face-to-face delivery of leadership development was more effective than online delivery. Interventions incorporating the elements of personal development planning, self-directed learning, workplace-based learning, and reflection were more likely to develop leadership behavior. Conclusions/implications for practice: Leadership interventions had a beneficial effect on the leadership behaviors of participants based on both subjective and objective changes in behavior. In addition to focusing on individual skill development, interventions that aim to develop leadership should consider the organizational, social, cultural, and political contexts in which behavioral change is expected. Workplace-based learning should be included in program development

    Parental evaluation of a telemonitoring service for children with Type 1 Diabetes

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    Introduction In the past years, we developed a telemonitoring service for young patients affected by Type 1 Diabetes. That service provides data to the clinical staff and offers an important tool to the parents, that are able to oversee in real time their children. The aim of this work was to analyze the parents' perceived usefulness of the service. Methods The service was tested by the parents of 31 children enrolled in a seven-day clinical trial during a summer camp. To study the parents' perception we proposed and analyzed two questionnaires. A baseline questionnaire focused on the daily management and implications of their children's diabetes, while a post-study one measured the perceived benefits of telemonitoring. Questionnaires also included free text comment spaces. Results Analysis of the baseline questionnaires underlined the parents' suffering and fatigue: 51% of total responses showed a negative tendency and the mean value of the perceived quality of life was 64.13 in a 0-100 scale. In the post-study questionnaires about half of the parents believed in a possible improvement adopting telemonitoring. Moreover, the foreseen improvement in quality of life was significant, increasing from 64.13 to 78.39 ( p-value\u2009=\u20090.0001). The analysis of free text comments highlighted an improvement in mood, and parents' commitment was also proved by their willingness to pay for the service (median\u2009=\u2009200\u2009euro/year). Discussion A high number of parents appreciated the telemonitoring service and were confident that it could improve communication with physicians as well as the family's own peace of mind

    An earthworm-like modular soft robot for locomotion in multi-terrain environments

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    Robotic locomotion in subterranean environments is still unsolved, and it requires innovative designs and strategies to overcome the challenges of burrowing and moving in unstructured conditions with high pressure and friction at depths of a few centimeters. Inspired by antagonistic muscle contractions and constant volume coelomic chambers observed in earthworms, we designed and developed a modular soft robot based on a peristaltic soft actuator (PSA). The PSA demonstrates two active configurations from a neutral state by switching the input source between positive and negative pressure. PSA generates a longitudinal force for axial penetration and a radial force for anchorage, through bidirectional deformation of the central bellows-like structure, which demonstrates its versatility and ease of control. The performance of PSA depends on the amount and type of fluid confined in an elastomer chamber, generating different forces and displacements. The assembled robot with five PSA modules enabled to perform peristaltic locomotion in different media. The role of friction was also investigated during experimental locomotion tests by attaching passive scales like earthworm setae to the ventral side of the robot. This study proposes a new method for developing a peristaltic earthworm-like soft robot and provides a better understanding of locomotion in different environments

    Synthesis and anticancer activity of Pt(0)-olefin complexes bearing 1,3,5-triaza-7-phosphaadamantane and N-heterocyclic carbene ligands

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    A series of Pt(0)-η2-olefin complexes bearing 1,3,5-triaza-7-phosphaadamantane (PTA) or N-heterocyclic carbenes are prepared following different synthetic strategies depending on the nature of coordinated alkene and spectator ligands. These new platinum(0) derivatives have been tested in vitro as anticancer agents toward three different tumor (human ovarian cancer A2780 and A2780cis and K562 myelogenous leukemia) and one non-tumor (Hacat keratinocytes) cell lines, proving to be in several cases highly and selectively cytotoxic against ovarian cancer cells. Furthermore, this antiproliferative effect is associated with the activation of an apoptosis process. In particular, complexes equipped with PTA as spectator ligand give comparable IC50 values on A2780 (cisplatin sensitive) and A2780cis (cisplatin resistant) cell lines, indirectly proving that these new Pt(0) substrates act with a mechanism of action conceivably different from cisplatin. This hypothesis is also confirmed by the fact that our compounds, in contrast to cisplatin, are not able to promote erythroid-differentiation activity on the K562 myelogenous leukemia cell line

    Model for initiation of quality factor degradation at high accelerating fields in superconducting radio-frequency cavities

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    A model for the onset of the reduction in SRF cavity quality factor, the so-called Q-drop, at high accelerating electric fields is presented. Breakdown of the surface barrier against magnetic flux penetration at the cavity equator is considered to be the critical event that determines the onset of Q-drop. The worst case of triangular grooves with low field of first flux penetration Hp, as analyzed previously by Buzdin and Daumens, [1998 Physica C 294: 257], was adapted. This approach incorporates both the geometry of the groove and local contamination via the Ginzburg-Landau parameter kappa, so the proposed model allows new comparisons of one effect in relation to the other. The model predicts equivalent reduction of Hp when either roughness or contamination were varied alone, so smooth but dirty surfaces limit cavity performance about as much as rough but clean surfaces do. When in combination, contamination exacerbates the negative effects of roughness and vice-versa. To test the model with actual data, coupons were prepared by buffered chemical polishing and electropolishing, and stylus profilometry was used to obtain distributions of angles. From these data, curves for surface resistance generated by simple flux flow as a function of magnetic field were generated by integrating over the distribution of angles for reasonable values of kappa. This showed that combined effects of roughness and contamination indeed reduce the Q-drop onset field by ~30%, and that that contamination contributes to Q-drop as much as roughness. The latter point may be overlooked by SRF cavity research, since access to the cavity interior by spectroscopy tools is very difficult, whereas optical images have become commonplace. The model was extended to fit cavity test data, which indicated that reduction of the superconducting gap by contaminants may also play a role in Q-drop.Comment: 15 pages with 7 figure

    Loss of heterozygosity at the 5,10-methylenetetrahydrofolate reductase locus in human ovarian carcinomas.

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    The high-affinity folate-binding protein (FBP) is primarily involved in the uptake of the 5-methyltetrahydrofolate, and its expression may be physiologically regulated by the intracellular folate content. The overexpression of FBP on the cell surface of ovarian carcinoma cells may be responsible for an increased folate uptake. We tested the hypothesis of the existence of a defect in the 5, 10-methylenetetrahydrofolate reductase (MTHFR) in ovarian tumours that could cause reduced intracellular regeneration of the 5-methyltetrahydrofolate and induce increased FBP expression. No sequence mutations were found in the MTHFR gene, but allelic deletions of this gene were frequently detected in ovarian tumours (59%). Chromosomal losses appeared to be confined to the 1p36.3 region to which the MTHFR gene maps. Although it cannot be stated that MTHFR is the target gene of the chromosomal loss involving the 1p36.3 region, a correlation between loss of heterozygosity at this locus and decrease in MTHFR activity was shown, suggesting a role of these allelic deletions in generating a biochemical defect in folate metabolism. Further studies are needed to assess further the relationship between MTHFR and FBP overexpression, but the demonstration of the alteration of a key metabolic enzyme of the folate cycle in a subset of human ovarian tumours is in accordance with the hypothesis of an altered folate metabolism in these neoplasias and might be exploited for therapeutic purposes

    Psychometric properties of the Nepali language version of the Depression Anxiety Stress Scales (DASS-21)

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    Aim: To assess the psychometric properties of the Nepali language version of the Depression Anxiety Stress Scales (DASS-21).Design: Descriptive, cross-sectional survey.Methods: The DASS-21 was administered (May-July 2019) among 794 randomly selected older adults aged ≥60 years. Factor structure was evaluated using exploratory and confirmatory factor analyses. Cronbach's alpha was calculated, and correlation analyses with quality of life evaluated convergent validity.Results: Exploratory factor analysis indicated that the 21 items loaded on three factors, with factor loadings ranging from 0.50-0.88. Confirmatory factor analysis suggested a four-factor model including the three subscales and an additional common 'general distress' factor, which demonstrated a better overall fit. Good reliability was found for each subscale, with Cronbach's alphas 0.79 for Anxiety, 0.91 for Stress, and 0.93 for Depression. The Nepali language version of the DASS-21 satisfied convergent validity with all subscales depicting significant negative correlations with quality of life demonstrating adequate psychometric properties

    A qualitative systematic review of experiences and perceptions of youth suicide

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    Background:Suicide remains a global issue with over 800,000 people dying from suicide every year. Youth suicide is especially serious due to the years of life lost when a young person takes their own life. Social interactions, perceived support, genetic predisposition and mental illnesses are factors associated with suicide ideation.Objectives:To review and synthesize qualitative studies that explored the experiences and perceptions of suicide in people 25 years old and younger.Design:Qualitative systematic review.Data sources:PubMed, PsycINFO, Scopus and CINAHL were searched alongside hand-searching reference lists up to October 2018.Methods:Methodological quality was assessed using the qualitative Critical Appraisal Skills Programme checklist. The 27 studies included in the review centered around youth suicide and included interviews with young people and members of the wider community. Thematic synthesis focused on factors leading to suicide attempts, elements important to recovery, beliefs within the community, and treatment/prevention strategies.Results:Thematic analysis of the articles revealed four categories: i) triggers and risks leading to suicidality; ii) factors involved in recovery; iii) need for institutional treatment/prevention strategies; and iv) beliefs about suicide at a community level. The first category was further subdivided into: i) behaviours; ii) feelings/emotions; iii) family influences; iv) peer influences; and v) other. The second category was split into: i) interpersonal; ii) cultural; and iii) individual influences, while the third category was divided into i) education; and ii) treatment.Conclusion:Youth suicide is a complex issue with many causes and risks factors which interact with one another. For successful treatment and prevention, procedural reform is needed, along with a shift in societal attitudes toward emotional expression and suicide
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