920 resultados para Behavioral reactivity


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Management of pain in very low birth weight infants is limited by a lack of empiric knowledge about the multiple determinants of biobehavioral reactivity in infants receiving neonatal intensive care.

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This article explores the literature concerning responses to pain of both premature and term-born newborn infants, the evidence for short-term and long-term effects of pain, and behavioral sequelae in individuals who have experienced repeated early pain in neonatal life as they mature. There is no doubt that pain causes stress in babies and this in turn may adversely affect long-term neurodevelopmental outcome. Although there are methods for assessing dimensions of acute reactivity to pain in an experimental setting, there are no very good measures available at the present time that can be used clinically. In the clinical setting repeated or chronic pain is more likely the norm rather than infrequent discrete noxious stimuli of the sort that can be readily studied. The wind-up phenomenon suggests that, exposed to a cascade of procedures as happens with clustering of care in the clinical setting in an attempt to provide periods of rest for stressed babies, an infant may in fact perceive procedures that are not normally viewed as noxious, as pain. Pain exposure during lifesaving intensive medical care of ELBW neonates may also affect subsequent reactivity to pain in the neonatal period, but behavioral differences are probably not likely to be clinically significant in the long term. Prolonged and repeated untreated pain in the newborn period, however, may produce a relatively permanent shift in basal autonomic arousal related to prior NICU pain experience, which may have long-term sequelae. In the long run, the most significant clinical effects of early pain exposure may be on neurodevelopment, contributing to later attention, learning, and behavior problems in these vulnerable children. Although there is considerable evidence to support a variety of adverse effects of early pain, there is less information about the long-term effects of opiates and benzodiazepines on the developing central nervous system. Current evidence reviewed suggests that judicious use of morphine for adjustment to mechanical ventilation may ameliorate the altered autonomic response. It may be very important, however, to distinguish stress from pain. Animal evidence suggests that the neonatal brain is affected differently when exposed to morphine administered in the absence of pain than in the presence of pain. Pain control may be important for many reasons but overuse of morphine or benzodiazepines may have undesirable long-term effects. This is a rapidly evolving area of knowledge of clear relevance to clinical management likely to affect long-term outcomes of high-risk children.

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To assess the efficacy of trauma-focused cognitive behavioral therapy (TF-CBT) delivered by nonclinical facilitators in reducing posttraumatic stress, depression, and anxiety and conduct problems and increasing prosocial behavior in a group of war-affected, sexually exploited girls in a single-blind, parallel-design, randomized,+ controlled trial.

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A controlled trial was conducted of cue-exposure with dependent drinkers in treatment. All subjects were engaged in an insight-orientated therapy programme, and responses to an alcohol-associated, compared with a neutral, stimulus were assessed at the beginning and end of treatment. Compared with a control group, which did not receive intervening cue-exposure sessions, subjects who received such interventions manifested reductions in heart rate, salivation and arousal responses to the alcohol-associated, compared with the neutral, stimulus. They did not, however, show similar reductions in subjective estimates of craving and anxiety. These results and the desynchrony in reductions in cue-reactivity across response domains are discussed in terms of their implications for cue-exposure in treatment and recent theoretical conceptualizations of the relationship between autonomic reactivity, craving and drinking behaviour.

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The present study investigated the long-term consistency of individual differences in dairy cattles’ responses in tests of behavioural and hypothalamo–pituitary–adrenocortical (HPA) axis reactivity, as well as the relationship between responsiveness in behavioural tests and the reaction to first milking. Two cohorts of heifer calves, Cohorts 1 (N = 25) and 2 (N = 16), respectively, were examined longitudinally from the rearing period until adulthood. Cohort 1 heifers were subjected to open field (OF), novel object (NO), restraint, and response to a human tests at 7 months of age, and were again observed in an OF test during first pregnancy between 22 and 24 months of age. Subsequently, inhibition of milk ejection and stepping and kicking behaviours were recorded in Cohort 1 heifers during their first machine milking. Cohort 2 heifers were individually subjected to OF and NO tests as well as two HPA axis reactivity tests (determining ACTH and/or cortisol response profiles after administration of exogenous CRH and ACTH, respectively) at 6 months of age and during first lactation at approximately 29 months of age. Principal component analysis (PCA) was used to condense correlated response measures (to behavioural tests and to milking) within ages into independent dimensions underlying heifers’ reactivity. Heifers demonstrated consistent individual differences in locomotion and vocalisation during an OF test from rearing to first pregnancy (Cohort 1) or first lactation (Cohort 2). Individual differences in struggling in a restraint test at 7 months of age reliably predicted those in OF locomotion during first pregnancy in Cohort 1 heifers. Cohort 2 animals with high cortisol responses to OF and NO tests and high avoidance of the novel object at 6 months of age also exhibited enhanced cortisol responses to OF and NO tests at 29 months of age. Measures of HPA axis reactivity, locomotion, vocalisation and adrenocortical and behavioural responses to novelty were largely uncorrelated, supporting the idea that stress responsiveness in dairy cows is mediated by multiple independent underlying traits. Inhibition of milk ejection and stepping and kicking behaviours during first machine milking were not related to earlier struggling during restraint, locomotor responses to OF and NO tests, or the behavioural interaction with a novel object. Heifers with high rates of OF and NO vocalisation and short latencies to first contact with the human at 7 months of age exhibited better milk ejection during first machine milking. This suggests that low underlying sociality might be implicated in the inhibition of milk ejection at the beginning of lactation in heifers.

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Radical anions of 1-bromo-4-nitrobenzene (p-BrC6H4NO2) are shown to be reactive in the room temperature ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, ([C(4)mPyrr][NTf2]), by means of voltammetric measurements. In particular, they are shown to react via a DISP type mechanism such that the electrolysis of p-BrC6H4NO2 occurs consuming between one and two electrons per reactant molecule, leading to the formation of the nitrobenzene radical anion and bromide ions. This behaviour is a stark contrast to that in conventional non-aqueous solvents such as acetonitrile, dimethyl sulfoxide or N,N-dimethylformamide, which suggests that the ionic solvent promotes the reactivity of the radical anion, probably via stabilisation of the charged products.

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The structure, thermal stability, and catalytic behavior of a novel highly dispersed silica-supported Pd/Sn catalyst prepared by an organometallic route have been examined by X-ray photoelectron, X-ray diffraction, and X-ray absorption, fine structure spectroscopies, the latter two measurements being carried outwith an in situ reaction cell. Additional reactor measurements were performed on a more Sn-rich catalyst and on a pure Pd catalyst. Varying the temperature of reduction induced large variations in catalytic performance toward ethyne-coupling reactions. These changes are understandable in terms of the destruction of SnO2-like structures surrounding the Pd core, yielding a skin of metallic Sn which subsequently undergoes intermixing with Pd. The overall thermal and catalytic behavior of these highly dispersed materials accords well with the analogous single-crystal model system.

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The chemisorption and reactivity of SO2 on Pt{111} have been studied by HREELS, XPS, NEXAFS and temperature-programmed desorption. At 160 K SO2 adsorbs intact at high coverages, with eta(2) S-O coordination to the surface. On annealing to 270 K, NEXAFS indicates the SO2 molecular plane essentially perpendicular to the surface. Preadsorbed O-a reacts with SO2 to yield adsorbed SO4, identified as the key surface species responsible for SO2-promoted catalytic alkane oxidation. Coadsorbed CO or propene efficiently reduce SO2 overlayers to deposit S-a, and the implications of this for catalytic systems are discussed.

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XPS, HREELS, ARUPS and Delta phi data show that furan chemisorbs non-dissociatively on Pd{111} at 175 K, the molecular plane being significantly tilted with respect to the surface normal. Bonding involves both the oxygen lone pair and significant a interaction with the substrate. The degree of decomposition that accompanies molecular desorption is a strong function of coverage: similar to 40% of the adsorbate desorbs molecularly from the saturated monolayer. Decomposition occurs via decarbonylation to yield COa and H-a followed by desorption rate limited loss of H-2 and CO. It seems probable that an adsorbed C3H3 species formed during this process undergoes subsequent stepwise dehydrogenation ultimately yielding H-2 and C-a.

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Photo-oxidation of amorphous GeS2 films illuminated by band-gap radiation drastically alters the growth mode and reactivity of subsequently deposited Ag. In the former case (monolayer/simultaneous multilayer growth) the Ag reacts with both Ge and S sites. In the latter case (Stranski-Krastanov growth) Ge sites are selectively oxidized and film growth proceeds by Ag nucleation at the unoxidized S sites. The behaviour is very different from that reported earlier for Zn deposition on GeS2, where photo-oxidation results in very large changes in metal sticking probability. XPS, XAES and EXAFS data provide the basis for understanding both this phenomenon and the very different photodiffusion behaviour of Zn and Ag in GeS2.

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Background: Given the worldwide prevalence of overweight and obesity, there is a clear need for meaningful practical healthy eating advice - not only in relation to food choice, but also on appropriate food portion sizes. As the majority of portion size research to date has been overwhelmingly quantitative in design, there is a clear need to qualitatively explore consumers’ views in order to fully understand how food portion size decisions are made. Using qualitative methodology this present study aimed to explore consumers’ views about factors influencing their portion size selection and consumption and to identify barriers to appropriate portion size control.

Methods: Ten focus groups with four to nine participants in each were formed with a total of 66 persons (aged 19–64 years) living on the island of Ireland. The semi-structured discussions elicited participants’ perceptions of suggested serving size guidance and explored the influence of personal, social and environmental factors on their food portion size consumption. Audiotapes of the discussions were professionally transcribed verbatim, loaded into NVivo 9, and analysed using an inductive thematic analysis procedure.
Results: The rich descriptive data derived from participants highlight that unhealthy portion size behaviors emanate from various psychological, social and behavioral factors. These bypass reflective and deliberative control, and converge to constitute significant barriers to healthy portion size control. Seven significant barriers to healthy portion size control were apparent: (1) lack of clarity and irrelevance of suggested serving size guidance; (2) guiltless eating; (3) lack of self-control over food cues; (4) distracted eating; (5) social pressures; (6) emotional eating rewards;
and (7) quantification habits ingrained from childhood.

Conclusions: Portion size control strategies should empower consumers to overcome these effects so that the consumption of appropriate food portion sizes becomes automatic and habitual.
Keywords: Food portion size, Barriers, Obesity, Consumers, Qualitative study. © 2013 Spence et al.; licensee BioMed Central Ltd

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The reactivity of the Ru(0 0 0 1) electrode towards the adsorption and electrooxidation of CO and methanol has been studied by variable-temperature in situ FTIR spectroscopy in both perchloric acid and sodium hydroxide solution, and the results interpreted in terms of the surface chemistry of the Ru(0 0 0 1) electrode. Both linear (CO) and threefold hollow (CO) binding CO adsorbates (bands at 1970-2040 and 1770-1820 cm, respectively) were observed on the Ru(0 0 0 1) electrode in both 0.1 M HClO and 0.1 M NaOH solutions from the CO adsorption. In the acid solution, CO was detected as the main adsorbed species on Ru(0 0 0 1) surface over all the potential region studied. In contrast, in the alkaline solution, more CO than CO was detected at lower potentials, whilst increasing the potential resulted in the transformation of CO to CO. At higher potentials, the oxidation of the adsorbed CO took place via reaction with the active (1 × 1)-O oxide/hydroxide. It was found that no dissociative adsorption or electrooxidation of methanol took place at the Ru(0 0 0 1) at potentials below 900 mV vs Ag/AgCl in perchloric acid solution at both 20 and 55°C. However, in the alkaline solution, methanol did undergo dissociative adsorption, to form linearly adsorbed CO (CO) with little or no CO adsorbed at threefold hollow sites (CO) at both 20 and 55°C. Increasing the temperature from 20 to 55°C clearly facilitated the methanol dissociative adsorption to CO and also enhanced the electrooxidation of the CO. At the higher potentials, significant oxidation of methanol to CO and methyl formate in acid solution and to bicarbonate and formate in alkaline solution, was observed, which was attributed to the formation of an active RuO phase on the Ru(0 0 0 1) surface, in agreement with our previous studies. © 2003 Elsevier Ltd. All right reserved.

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Although regret is assumed to facilitate good decision making, there is little research directly addressing this assumption. Four experiments (N = 326) examined the relation between children's ability to experience regret and the quality of their subsequent decision making. In Experiment 1 regret and adaptive decision making showed the same developmental profile, with both first appearing at about 7 years. In Experiments 2a and 2b, children aged 6–7 who experienced regret decided adaptively more often than children who did not experience regret, and this held even when controlling for age and verbal ability. Experiment 3 ruled out a memory-based interpretation of these findings. These findings suggest that the experience of regret facilitates children's ability to learn rapidly from bad outcomes.