4,559 research outputs found
Artificial neural-network technique for precipitation nowcasting from satellite imagery
The term nowcasting reflects the need of timely and accurate predictions of risky situations related to the development of severe meteorological events. In this work the objective is the very short term prediction of the rainfall field from geostationary satellite imagery entirely based on neural network approach. The very short-time prediction (or nowcasting) process consists of two steps: first, the infrared radiance field measured from geostationary satellite (Meteosat 7) is projected ahead in time (30 min or 1 h); secondly, the projected radiances are used to estimate the rainfall field by means of a calibrated microwave-based combined algorithm. The methodology is discussed and its accuracy is quantified by means of error indicators. An application to a satellite observation of a rainfall event over Central Italy is finally shown and evaluated
Assessing radiative transfer models trained by numerical weather forecasts using sun-tracking radiometric measurements for satellite link characterization up to W band
Radio communications, and in particular Earth-to-satellite
links, are worldwide used for delivering digital services.
The bandwidth demand of such services is increasing
accordingly to the advent of more advanced applications
(e.g., multimedia services, deep-space explorations, etc.)
thus pushing the scientific community toward the
investigation of channel carriers at higher frequencies.
When using carrier frequencies above X band, the main
drawback is how to tackle the impact of tropospheric
processes (i.e., rain, cloud, water vapor). This work
assesses the joint use of weather forecast models, radiative
transfer models and Sun-tracking radiometric
measurements to explore their potential benefits in
predicting path attenuation and sky noise temperature for
slant paths at frequencies between K and W band, thus
paving the way to the optimization of satellite link-budgets
âI canât describe it and they canât see the rain.â an interpretative phenomenological analysis of the experience of self-harm in young adults who report difficulties identifying and describing their feelings.
Self-harm is a serious and increasing public health concern. Self-harm is significantly associated with alexithymia, a trait characterised by a difficulty identifying and describing feelings. Alexithymia has been found to be a barrier to psychological treatment. This article explores the experiences of self-harm among eight young adults who reported difficulties identifying and describing their feelings. Semi-structured interviews were conducted, with the optional use of photographs as visual stimuli for discussion. Transcripts were analysed using Interpretative Phenomenological Analysis. Two themes are presented here: The Obscure Self describes participantsâ struggle to grasp a coherent sense of self, and how self-harm provided a means of physically reconnecting with their bodies. Words Fail Me describes participantsâ difficulties communicating their subjective experience, which increased feelings of isolation and recourse to self-harm. There were also tentative indications that participants were able to recognise their emotional experience when expressed by others. The lack of interpersonal connection, arising from difficulties understanding feelings and communicating them to others, may create or exacerbate the context for self-harm. The findings have relevance for the treatment of self-harm, given the high, but often unacknowledged, prevalence of alexithymia in clinical populations
The relationship between self-harm and alexithymia: a systematic review and meta-analysis
Self-harm, defined for the purpose of this review as any act of self-injury without explicit suicidal intent, is an increasing public health concern, with potential long-term implications for those who engage in it. Previous research has identified a correlational relationship between self-harm and alexithymia, an emotion processing deficit characterised by difficulties identifying and describing feelings, and an externally-orientated thinking style. Through a systematic search of the literature, the current review examines the association between alexithymia and self-harm. A meta-analysis based on 23 studies found a significant, positive relationship between self-harm and alexithymia, with a medium effect size (g = 0.57, 95% CI 0.45 to 0.71). All 23 studies used the Toronto Alexithymia Scale (TAS20) to measure alexithymia. The alexithymia subcomponents difficulty identifying feelings and difficulty describing feelings were significantly associated with self-harm, but there was no significant association between self-harm and externally-orientated thinking. The effect size of the relationship was significantly larger in adolescent samples compared with adult samples and in female compared with male samples. The definition of self-harm did not affect the effect size of the relationship between alexithymia and self-harm and the results are consistent with previous meta-analyses focused more narrowly on non-suicidal self-injury and, separately, suicidal behaviours. Heterogeneity between the included studies was high. The results support an affect regulation model of self-harm, in which self-harm is used to regulate an emotional experience that is poorly understood
Effects of mindfulness-based interventions on alexithymia: a systematic review
Question: Alexithymia has been found to be modifiable through treatment, with associated clinical benefits. Recent studies have begun to test the potential of mindfulness-based interventions to reduce alexithymia, using skills-based, group training to improve non-judgmental, present moment awareness. The objective of this review therefore was to conduct a systematic synthesis to assess the current state of knowledge about the effect of mindfulness-based interventions on alexithymia to inform clinical practice.
Study Selection and Analysis: We carried out a systematic review of the literature and found four randomised controlled trials of the effect of mindfulness-based interventions on alexithymia, with a combined total of 460 participants.
Findings: A random effects meta-analysis, combining study endpoint data, showed a statistically significant effect of mindfulness-based treatment on alexithymia, (Toronto Alexithymia Scale [TAS20]) compared with the control group (mean difference = -5.28, 95% CI -9.28 to -1.28, p=0.010). Subgroup analysis was conducted to investigate sources of heterogeneity (I2=52%). Heterogeneity was reduced when the meta-analysis was restricted to interventions of a similar duration (three months or less).
Conclusions: Findings from our study should be replicated in further research with larger samples; however, the results indicate that mindfulness-based interventions may be an effective treatment in reducing alexithymia
How profitable are FX technical trading rules?
This paper provides a comprehensive empirical investigation of the profitability of foreign exchange technical trading rules over the 1996:10?2015:06 period for 22 currencies quoted in US dollars. It reports evidence of profitability across a universe of 113,148 rules that include traditional moving average rules and those constructed on the basis of technical indicators such as Bollinger bands and the relative strength index. The best trading rules achieve annualised returns of up to 30%. The Step-SPA test (Hsu, Hsu, & Kuan, 2010) results show a sharp fall in the total number of rules that are robust to data snooping bias. Virtually no traditional rule is significant in the 2006?2015 sub-sample, in line with the adaptive markets hypothesis. By contrast, rules based on new technical indicator such as Bollinger Band and relative strength index rules remain robustly profitable across all currencies over the more recent sub-sample
The relationship between alexithymia and self-harm: the mediating role of mindfulness
Objectives. Self-harm, defined as any act of self-injury, irrespective of motivation, is a phenomenon which can have serious consequences for the individual, as well as significant public health costs. Many correlational studies have established a significant association between self-harm and alexithymia, a cognitive deficit in emotion processing, characterised by a difficulty identifying and describing feelings and an externally orientated thinking style. The current study investigated whether this relationship is explained by low levels of dispositional mindfulness. Methods. An opportunity sample of 325 community-based adults completed an online survey measuring their history of self-harm, alexithymia (Toronto Alexithymia Scale) and mindfulness (Five Facets of Mindfulness Questionnaire). Results. Alexithymia was significantly higher among participants with a history of self-harm, compared with participants with no history of self-harm. All mindfulness facets were significantly lower among participants with a history of self-harm except the facet Observe which was significantly higher in that group. A multiple mediation analysis found that the mindfulness facets Non-judge and Non-react were positive, significant mediators of the relationship between alexithymia and self-harm, but the facet Observe suppressed the relationship. Conclusions. The relationship between alexithymia and self-harm can be explained in part by deficits in mindfulness skills, particularly the ability to accept emotional experience without judgment or reaction. Conversely, the external orientation of alexithymia may itself be protective against self-harm, through the avoidance of excessive introspection. Thus, merely learning to observe inner experience, without the ability to understand and accept that experience, may have adverse consequences
"My heart and my brain is what's bleeding, these are just cuts." An interpretative phenomenological analysis of young women's experiences of self-harm
Engagement in self-harm, defined as intentional self-poisoning or self-injury irrespective of the apparent purpose of the act, is increasing, particularly among girls and young women. Understanding the behavior from the perspective of those who self-harm is, therefore, vital in designing effective interventions and treatments. The current brief research report presents a key theme from an Interpretative Phenomenological Analysis of the experience of self-harm among eight young women, aged between 18 and 29. The theme Is Self-Harm Bad? concerns the way in which participants both acknowledged and resisted a negative conception of self-harm that was often constructed from other people's attitudes. Three subthemes explore the reasons why participants were reluctant to endorse self-harm as bad: Self-Harm is the Symptom, Self-Harm Works (Until it Doesn't) and Self-Harm is Part of Me. The findings highlight the disparity between the characterization of self-harm as a highly risky behavior and the lived experience of self-harm as a functional means of emotion regulation. From a clinical perspective, the findings explored in this brief report suggest that highlighting the risks of self-harm may not be a sufficient deterrent. The recently revised draft National Institute for Health and Care Excellence (NICE) guidance recommends that everyone presenting to hospital following self-harm should be given a comprehensive psychosocial assessment, of which the function is, in part, to understand why the person has self-harmed. The current study underlines the importance of seeing past the behavior to the underlying causes and exploring the meaning of self-harm to the individual in order to implement effective preventative interventions
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