14 resultados para Amount of substance
Resumo:
This article presents a re-conceptualization of moderate adolescent drug use. It is argued that experimentation with alcohol and other drugs during the teenage years may play an important role in the development of regulatory competency in relation to drug consumption in adulthood. When such regulatory skills fail to emerge in young people, during the transition to adulthood, the likelihood of serious alcohol- or drug-related harm is increased. The article reviews the empirical evidence of poor self-regulation as a predictor of long-term alcohol-and drug-related problems, places self-regulation within a broader theoretical framework, and considers the policy and practice implications of this conceptualization.
Resumo:
Aims: The aim of this article was to investigate the factors associated with ecstasy use in school-aged teenagers. Methods: This was a longitudinal study of adolescent drug use, which was undertaken in three towns in Northern Ireland. A questionnaire was administered annually to participants. In this article ecstasy use patterns amongst a cohort of young people aged 14–16 years participating in the Belfast Youth Development Study (BYDS) was explored. Findings: The percentage of those who had used ecstasy at least once increased from 7% when aged 14 years to 9% at 15 and 13% at 16 years. Female gender, delinquency, problem behaviours at school and the number of evenings spent out with friends each week were found to be significant variables predicting ‘ever use’ of ecstasy in all 3 years by logistic regression. Conclusions: The findings suggest that ecstasy use patterns may be changing from their historical perception as a ‘party’ drug, as the demographic profile ecstasy of users in this study reflected the traditional profile of illicit drug use during adolescence, which raises challenges for addressing the problems associated with this drug.
Resumo:
In this paper, we investigate what constitutes the least amount of a priori information on the nonlinearity so that the FIR linear part is identifiable in the non-Gaussian input case. Three types of a priori information are considered including quadrant information, point information and locally monotonous information. In all three cases, identifiability has been established and corresponding identification algorithms are developed with their convergence proofs.
Resumo:
Two peptides with substance-P-like immunoreactivity were isolated in pure form from an extract of the brain of the elasmobranch fish, Scyliorhinus canicula (european common dogfish). One peptide was identical to scyliorhinin I, previously identified in dogfish intestine, and the second was the undecapeptide Lys-Pro-Arg-Pro-Gly-Gln-Phe-Phe-Gly-Leu-Met-CONH2 which is structurally similar to mammalian substance P Scyliorhinin II or a peptide analogous to mammalian neurokinin A were not detected in the extract. Synthetic dogfish substance P ([Lys1, Arg3, Gly5]substance P) was approximately threefold more potent than mammalian substance P (K(d) = 0.21 +/- 0.11 nM versus K(d)= 0.74 +/- 0.17 nM; mean +/- SD; n = 6) in inhibiting the binding of I-125-labelled substance P to neurokinin (NK1) receptors in rat submandibular gland membranes. The vasodilator action of tachykinins in mammals is mediated primarily through interaction with NK1 receptors. Bolus intravenous injections of [Lys1, Arg3, Gly5]substance P (100 pmol) and scyliorhinin I (100 pmol) produced appreciable (>4 kPa) decreases in arterial blood pressure in the rat whereas intravenous injections of up to 5 nmol of the peptides into conscious, unrestrained dogfish produced no change in arterial blood pressure, pulse amplitude or heart rate. Injections of greater amounts of the peptides (10-50 nmol) produced a slight increase (400-667 Pa) in blood pressure. The data indicate that mammalian-type NK1 tachykinin receptors are not involved in cardiovascular regulation in elasmobranch fish.
Resumo:
The ability to distribute quantum entanglement is a prerequisite for many fundamental tests of quantum theory and numerous quantum information protocols. Two distant parties can increase the amount of entanglement between them by means of quantum communication encoded in a carrier that is sent from one party to the other. Intriguingly, entanglement can be increased even when the exchanged carrier is not entangled with the parties. However, in light of the defining property of entanglement stating that it cannot increase under classical communication, the carrier must be quantum. Here we show that, in general, the increase of relative entropy of entanglement between two remote parties is bounded by the amount of nonclassical correlations of the carrier with the parties as quantified by the relative entropy of discord. We study implications of this bound, provide new examples of entanglement distribution via unentangled states, and put further limits on this phenomenon.
Resumo:
Substance P (SP) is a member of the structurally related family of neuropeptides known as the tachykinins. In addition to neurotransmitter roles, the tachykinins are also known to modulate local inflammation which depends on signalling between the neuropeptide molecules and target cells and tissues. SP mediates its effects through a specific receptor, known as the substance P receptor or the neurokinin 1 (NK-1) receptor. The NK-1 receptor is a G-protein associated integral membrane protein and although it has been studied in a wide range of tissues, to date there has been no published data on the localisation of the NK-1 receptor in human gingival tissue. Objective: The aim of this study was to examine the distribution of the NK-1 receptor in human gingival tissue using immunocytochemistry. Method: Gingival tissue was obtained from patients undergoing periodontal surgery. Tissue was fixed in paraformaldehyde and embedded in wax for sectioning. Sections were dewaxed in xylene and then rehydrated in alcohols and phosphate buffered saline. Rehydrated sections were probed with rabbit polyclonal antibody to human NK-1 receptor which was subsequently detected using anti-rabbit horseradish peroxidase conjugate and diaminobenzidine as substrate. Results: Immunocytochemistry revealed that the NK-1 receptor was distributed along nerve fibres and blood vessel endothelial cells, suggesting these areas are main targets for the actions of SP via the NK-1 receptor. Conclusion: This is the first immunocytochemical report of NK-1 receptors in human gingival tissue and provides evidence for possible NK-1 mediated biological effects of SP in human gingival tissue from periodontitis patients.
Resumo:
It is now common for young people in full-time compulsory education to hold part-time jobs. However, whilst the 1990s experienced a rise in illicit drug use particularly among young people and an increase in the level of interest for identifying factors associated with drug use, little attention has been paid to the influence of the money young people have to spend and its potential links with drug use. Four thousand five hundred and twenty-four young people living in Northern Ireland completed a questionnaire in school year 10 (aged 13/14 years). The findings suggested there was a positive association between the amount of money (and its source) young people received and higher rates of drug use. The study concludes that money, and how it is spent by young people, may be an important factor for consideration when investigating drug use during adolescence. The findings may help inform drug prevention strategies particularly through advice on money management, and taking responsibility for their own money.
Resumo:
The localization and distribution of cholinergic, serotoninergic and peptidergic nerve elements in the proteocephalidean tapeworm, Proteocephalus pollanicola, have been investigated by enzyme histochemistry, and by an indirect immunofluorescence technique interfaced with confocal scanning laser microscopy. Cholinesterase (ChE) activity was localized in the major components of the central nervous system (CNS) and the peripheral nervous system (PNS), including the innervation of the reproductive structures of the worm. Serotoninergic (5-HT) nerves were found in the paired cerebral ganglia, transverse commissure and in the 10 longitudinal nerve cords. Antisera to 17 mammalian regulatory peptides and the invertebrate peptide FMRFamide have been used to explore the peptidergic nervous system of the worm. The most extensive immunostaining occurred with antisera raised to members of the neuropeptide Y superfamily, namely neuropeptide Y (NPY), peptide YY (PYY) and pancreatic polypeptide (PP). In all cases, intense immunoreactivity was found in numerous cell bodies and fibres of both the CNS and PNS, including the innervation of the reproductive apparatus. FMRFamide antisera stained the same structures to a comparable degree as those raised to the NPY superfamily. Cholinergic and peptidergic elements were much more prevalent within the CNS, while the serotoninergic nerve fibres tended to dominate in the PNS. The overlap obtained in staining patterns for the peptidergic and cholinergic components suggests that there may be a certain amount of co-localization of peptides with small-molecule transmitter substances in the same neurone. Weak staining for the tachykinin, substance P and for calcitonin gene-related peptide(CGRP) was confined to the major longitudinal nerve cords.
Resumo:
Background
While substance misuse is a key risk factor in suicide relatively little is known about the relationship between lifetime misuse and misuse in suicide.
Aim
To examine the relationship between a history of substance misuse and misuse at the time of a suicide.
Method
Linkage of Coroner reports of 403 suicides occurring over two years with associated primary care records. History of substance misuse was defined as alcohol misuse and/or prescription or illicit drug misuse, for which medical help was sought.
Results
With alcohol misuse: 65% of the cohort had previously sought help and 42% were intoxicated at the suicide (with 30% of these seeing their GP in the previous year). With misuse of other substances: 54% of the cohort were tested for blood toxicology (37% of these tested positive) - with positive toxicology defined as an excess of prescription drugs over the therapeutic minima and/or detection of illicit substances. Those tested were more likely to be young and have a history of drug abuse.
Conclusion
Understanding the links between substance misuse and the use of substances in conjunction with the act of suicide is discussed in light of the study results and current pathology and coroner practices.
Resumo:
Introduction and Aims. While the role of the family in adolescent substance use has been well documented, few studies have attempted to explore in-depth youth perceptions of how these familial processes/dynamics influence teenage substance use. This paper reports the findings from a study exploring risk and protective factors for teenage substance use within the context of the family as perceived by young people with a view to informing current and future family based prevention and education interventions.
Design and Methods. Data collection took place in nine post-primary schools across Northern Ireland. Nine focus groups using participatory techniques were facilitated with a purposive sample of sixty-two young people (age 13-17 years). Data were transcribed verbatim and analysed using a content/thematic analysis.
Results. Three broad themes/aspects of the family emerged from the data, which may serve to protect or attenuate the risk of substance use among young people. Parent-child attachment was a major theme identified in protecting adolescents from substance use in addition to effective parenting particularly an authoritative style of parenting supplemented by parental monitoring and good parent-child communication to encourage child disclosure. Family substance use was deemed to impact on children’s substance use if exposed at an early age and the harms associated with PSM were discussed in detail.
Discussion and Conclusions. The qualitative approach provides insight into current understanding of youth perceptions of substance use in the context of family dynamics. A number of recommendations are outlined. Family based (preventive) interventions/parenting programmes may benefit from components on effective parenting including authoritative styles, parental monitoring, effective communication, spending time together (building attachments), parent-child conflict, adolescent development and factors which impact on parenting. Parenting programmes tailored to mothers and fathers may be beneficial. School based interventions targeting children/adolescents may be best placed to target children living with parental substance misuse.
Keywords: substance/substance related disorders, focus groups, young people/adolescent,