A local density functional for the short-range part of the electron-electron interaction

Motivated by recent suggestions --to split the electron-electron interaction into a short-range part, to be treated within the density functional theory, and a long-range part, to be handled by other techniques-- we compute, with a diffusion Monte Carlo method, the ground-state energy of a uniform electron gas with a modified, short-range-only electron-electron interaction \erfc(\mu r)/r, for different values of the cutoff parameter $\mu$ and of the electron density. After deriving some exact limits, we propose an analytic representation of the correlation energy which accurately fits our Monte Carlo data and also includes, by construction, these exact limits, thus providing a reliable ``short-range local-density functional''.Comment: 7 pages, 3 figure

Hall magnetohydrodynamics of partially ionized plasmas

The Hall effect arises in a plasma when electrons are able to drift with the magnetic field but ions cannot. In a fully-ionized plasma this occurs for frequencies between the ion and electron cyclotron frequencies because of the larger ion inertia. Typically this frequency range lies well above the frequencies of interest (such as the dynamical frequency of the system under consideration) and can be ignored. In a weakly-ionized medium, however, the Hall effect arises through a different mechanism -- neutral collisions preferentially decouple ions from the magnetic field. This typically occurs at much lower frequencies and the Hall effect may play an important role in the dynamics of weakly-ionised systems such as the Earth's ionosphere and protoplanetary discs. To clarify the relationship between these mechanisms we develop an approximate single-fluid description of a partially ionized plasma that becomes exact in the fully-ionized and weakly-ionized limits. Our treatment includes the effects of ohmic, ambipolar, and Hall diffusion. We show that the Hall effect is relevant to the dynamics of a partially ionized medium when the dynamical frequency exceeds the ratio of ion to bulk mass density times the ion-cyclotron frequency, i.e. the Hall frequency. The corresponding length scale is inversely proportional to the ion to bulk mass density ratio as well as to the ion-Hall beta parameter.Comment: 11 page, 1 figure, typos removed, numbers in tables revised; accepted for publication in MNRA

A two DoF finger for a biomechatronic artificial hand

Current prosthetic hands are basically simple grippers with one or two degrees of freedom, which barely restore the capability of the thumb-index pinch. Although most amputees consider this performance as acceptable for usual tasks, there is ample room for improvement by exploiting recent progresses in mechatronics design and technology. We are developing a novel prosthetic hand featured by multiple degrees of freedom, tactile sensing capabilities, and distributed control. Our main goal is to pursue an integrated design approach in order to fulfill critical requirements such as cosmetics, controllability, low weight, low energy consumption and noiselessness. This approach can be synthesized by the definition "biomechatronic design", which means developing mechatronic systems inspired by living beings and able to work harmoniously with them. This paper describes the first implementation of one single finger of a future biomechatronic hand. The finger has a modular design, which allows to obtain hands with different degrees of freedom and grasping capabilities. Current developments include the implementation of a hand comprising three fingers (opposing thumb, index and middle) and an embedded controller

Monitoramento do nematóide das galhas (Meloidogyne spp.) em figueira (Ficus carica L.) no Rio Grande do Sul.

bitstream/item/30485/1/boletim-86.pd

Validation de la version française d'une échelle évaluant les pratiques disciplinaires de parents d'enfants d'âge scolaire

Several decades of research have emphasized the importance of parenting in the development of behavioral problems in children. Prevention and intervention for these difficulties require the assessment of parental practices with reliable measures. This study investigated the psychometric properties of the French version of the Parenting Scale (PS; Arnold et al., 1993). The original version of this scale has shown its usefulness by allowing the identification of the parents whose strategies of discipline are counterproductive, and by quantifying the effects of certain parenting programs. The study included 464 mothers and 347 fathers of elementary school-aged children (between the age of 4 and 13) from Switzerland and Belgium. Parents completed the PS and a measure of child behavior, the Strengths and Difficulties Questionnaire (SDQ; Goodman, 1997). Eight different factorial structures were identified in the literature and tested with Confirmatory Factor Analyses (CFA). The results indicate that the two-factor model — laxness and over-reactivity — proposed by Irvine et al. (1999) best fitted the data. Indeed, it led to the lowest values of RMSEA and SRMR (1999). Furthermore the TLI and CFI indices were greater than .90, supporting a satisfactory fit of the data. Results from multi-group CFA analyses indicated that this factor structure did not vary across child sex and age, or parental sex. In this French version, laxness and over-reactivity had good internal consistency when analyzing either the total sample, or when separating the data according to the sex of the parents or the child's age group. It was possible to propose normative values of laxness and over-reactivity for mothers and fathers, as well as according to the age of the child, which will be useful for clinicians assessing parenting discipline practices of their clients. The results indicated that mothers rated themselves as more over-reactive than fathers (t(809) = 2.89, P < .01, d = .21), but the effect size was small. The difference was non-significant for laxness. The sex and age of the child, as well as the parents’ age did not affect over-reactivity and laxness. However, a weak link was found between education level and over-reactivity, but only for fathers (r = .19, P < .01). The association between the two factors and the child's adjustment were also evaluated. The highest correlation appeared to be between over-reactivity and the Total Score on the SDQ (rs = .28, p < .001). Correlations between over-reactivity and externalized problems (behavior and hyperactivity) were higher than those obtained with internalized problems. As for laxness, the correlations were lower: the highest one was with behavioral disorders (rs = .15, p < .001). Over the entire sample (R2 = .09, β = .27, P < .001) and in fathers (R2 = .10, β = .32, P < .001), over-reactivity was the best predictor of the child's difficulties regardless of the sex of the child. In mothers, both factors predicted the child's difficulties (R2 = .08, P < .001), with over-reactivity explaining more variance of total SDQ (β = .22, P < .001) than laxness (β = .14, P < .05). Over-reactivity appears to correspond to the construct of “coercive discipline” theorized and intensively studied by Patterson and colleagues (1982), which represents parents’ tendencies to criticize their child and to engage in severe disciplinary interactions. In summary, the Parenting Scale provides a quick and inexpensive measure of dysfunctional discipline practices. In contrast to more comprehensive measures of parental attitudes and beliefs, the PS items are specific enough to target concrete behaviors regarding parenting interventions. The PS can therefore be particularly useful in planning cognitive and behavioral therapy, as well as in evaluating the effects of treatment

Electronic Health Diary Campaigns to Complement Longitudinal Assessments in Persons With Multiple Sclerosis: Nested Observational Study.

BACKGROUND Electronic health diaries hold promise in complementing standardized surveys in prospective health studies but are fraught with numerous methodological challenges. OBJECTIVE The study aimed to investigate participant characteristics and other factors associated with response to an electronic health diary campaign in persons with multiple sclerosis, identify recurrent topics in free-text diary entries, and assess the added value of structured diary entries with regard to current symptoms and medication intake when compared with survey-collected information. METHODS Data were collected by the Swiss Multiple Sclerosis Registry during a nested electronic health diary campaign and during a regular semiannual Swiss Multiple Sclerosis Registry follow-up survey serving as comparator. The characteristics of campaign participants were descriptively compared with those of nonparticipants. Diary content was analyzed using the Linguistic Inquiry and Word Count 2015 software (Pennebaker Conglomerates, Inc) and descriptive keyword analyses. The similarities between structured diary data and follow-up survey data on health-related quality of life, symptoms, and medication intake were examined using the Jaccard index. RESULTS Campaign participants (n=134; diary entries: n=815) were more often women, were not working full time, did not have a higher education degree, had a more advanced gait impairment, and were on average 5 years older (median age 52.5, IQR 43.25-59.75 years) than eligible nonparticipants (median age 47, IQR 38-55 years; n=524). Diary free-text entries (n=632; participants: n=100) most often contained references to the following standard Linguistic Inquiry and Word Count word categories: negative emotion (193/632, 30.5%), body parts or body functioning (191/632, 30.2%), health (94/632, 14.9%), or work (67/632, 10.6%). Analogously, the most frequently mentioned keywords (diary entries: n=526; participants: n=93) were "good," "day," and "work." Similarities between diary data and follow-up survey data, collected 14 months apart (median), were high for health-related quality of life and stable for slow-changing symptoms such as fatigue or gait disorder. Similarities were also comparatively high for drugs requiring a regular application, including interferon beta-1a (Avonex) and glatiramer acetate (Copaxone), and for modern oral therapies such as fingolimod (Gilenya) and teriflunomide (Aubagio). CONCLUSIONS Diary campaign participation seemed dependent on time availability and symptom burden and was enhanced by reminder emails. Electronic health diaries are a meaningful complement to regular structured surveys and can provide more detailed information regarding medication use and symptoms. However, they should ideally be embedded into promotional activities or tied to concrete research study tasks to enhance regular and long-term participation

Electronic Health Diary Campaigns to Complement Longitudinal Assessments in Persons With Multiple Sclerosis: Nested Observational Study

BACKGROUND Electronic health diaries hold promise in complementing standardized surveys in prospective health studies but are fraught with numerous methodological challenges. OBJECTIVE The study aimed to investigate participant characteristics and other factors associated with response to an electronic health diary campaign in persons with multiple sclerosis, identify recurrent topics in free-text diary entries, and assess the added value of structured diary entries with regard to current symptoms and medication intake when compared with survey-collected information. METHODS Data were collected by the Swiss Multiple Sclerosis Registry during a nested electronic health diary campaign and during a regular semiannual Swiss Multiple Sclerosis Registry follow-up survey serving as comparator. The characteristics of campaign participants were descriptively compared with those of nonparticipants. Diary content was analyzed using the Linguistic Inquiry and Word Count 2015 software (Pennebaker Conglomerates, Inc) and descriptive keyword analyses. The similarities between structured diary data and follow-up survey data on health-related quality of life, symptoms, and medication intake were examined using the Jaccard index. RESULTS Campaign participants (n=134; diary entries: n=815) were more often women, were not working full time, did not have a higher education degree, had a more advanced gait impairment, and were on average 5 years older (median age 52.5, IQR 43.25-59.75 years) than eligible nonparticipants (median age 47, IQR 38-55 years; n=524). Diary free-text entries (n=632; participants: n=100) most often contained references to the following standard Linguistic Inquiry and Word Count word categories: negative emotion (193/632, 30.5%), body parts or body functioning (191/632, 30.2%), health (94/632, 14.9%), or work (67/632, 10.6%). Analogously, the most frequently mentioned keywords (diary entries: n=526; participants: n=93) were "good," "day," and "work." Similarities between diary data and follow-up survey data, collected 14 months apart (median), were high for health-related quality of life and stable for slow-changing symptoms such as fatigue or gait disorder. Similarities were also comparatively high for drugs requiring a regular application, including interferon beta-1a (Avonex) and glatiramer acetate (Copaxone), and for modern oral therapies such as fingolimod (Gilenya) and teriflunomide (Aubagio). CONCLUSIONS Diary campaign participation seemed dependent on time availability and symptom burden and was enhanced by reminder emails. Electronic health diaries are a meaningful complement to regular structured surveys and can provide more detailed information regarding medication use and symptoms. However, they should ideally be embedded into promotional activities or tied to concrete research study tasks to enhance regular and long-term participation

Pre- and post-transplant minimal residual disease predicts relapse occurrence in children with acute lymphoblastic leukaemia

Relapse remains the leading cause of treatment failure in children with acute lymphoblastic leukaemia (ALL) undergoing allogeneic haematopoietic stem cell transplantation (HSCT). We retrospectively investigated the prognostic role of minimal residual disease (MRD) before and after HSCT in 119 children transplanted in complete remission (CR). MRD was measured by polymerase chain reaction in bone marrow samples collected pre-HSCT and during the first and third trimesters after HSCT (post-HSCT1 and post-HSCT3). The overall event-free survival (EFS) was 50%. The cumulative incidence of relapse and non-relapse mortality was 41% and 9%. Any degree of detectable pre-HSCT MRD was associated with poor outcome: EFS was 39% and 18% in patients with MRD positivity <1 × 10−3 and ≥1 × 10−3, respectively, versus 73% in MRD-negative patients (P < 0·001). This effect was maintained in different disease remissions, but low-level MRD had a very strong negative impact only in patients transplanted in second or further CR. Also, MRD after HSCT enabled patients to be stratified, with increasing MRD between post-HSCT1 and post-HSCT3 clearly defining cohorts with a different outcome. MRD is an important prognostic factor both before and after transplantation. Given that MRD persistence after HSCT is associated with dismal outcome, these patients could benefit from early discontinuation of immunosuppression, or pre-emptive immuno-therapy

Electron scattering from molecules and molecular aggregates of biological relevance

In this Topical Review we survey the current state of the art in the study of low energy electron collisions with biologically relevant molecules and molecular clusters. We briefly describe the methods and techniques used in the investigation of these processes and summarise the results obtained so far for DNA constituents and their model compounds, amino acids, peptides and other biomolecules. The applications of the data obtained is briefly described as well as future required developments