Effect of interparticle force on mixing and segregation of dry granular materials.

In this paper, the effects of interparticle force on mixing, segregation, and stratification in dry granular materials are investigated. Avalanche segregation, stratification and also segregation in rotating drums are examined. A series of binary mixtures of granular materials is prepared which consists of spherical iron particles and a nonmagnetic material. By placing each mixture in a magnetic field, the induced magnetic interparticle force could be altered and the effects on particle segregation observed. Using this technique, the effects of altering interparticle force on both avalanche and radial segregation are examined. It is found that altering interparticle force could induce mixed materials to segregate and also induce segregating granular materials to mix. We also report a complete reversal of segregation and stratification as interparticle force was increased. These results have important implications for the mixing of cohesive powders.

Effects of interparticle force on the packing of spherical granular material.

We present a study of the influence of interparticle cohesive forces on the packing of spheres. This is achieved by changing the external magnetic field on iron spheres in the millimeter size range. The force of cohesion between two spheres is measured by opposing magnetic and gravitational force. The void fraction of the bed resulting from many spheres being poured into a container at a given magnetic field is measured. The void fraction of the packed spheres as a function of interparticle force is thus established. We find that the void fraction is determined only by the ratio of interparticle force to particle weight, regardless of particle size. This is shown to be a universal effect, not limited to magnetic systems.

Effect of applied interparticle force on the static and dynamic angles of repose of spherical granular material.

The static angle of repose for iron spheres in a narrow box, and the dynamic angle of repose for iron spheres in a narrow, half-filled rotating drum is investigated. A feature of this paper is the use of a homogenous magnetic field to induce an attractive interparticle force, allowing a wide range of angles of repose to be investigated and characterized as a function of interparticle force. The static and dynamic angles of repose were found to increase approximately linearly with increasing interparticle force.

A design for strife: alcopops, licit drug - familiar scare story.

In Scotland during the mid 1990s the news media began reporting growing concern about a new form of alcoholic beverage known as 'alcopops'. Fears raised by the press centred on the claim that these drinks were being marketed towards young children and as such were responsible for the rising levels of adolescent drunkenness. In focusing on underage consumption and alleged marketing aimed at children, the press portrayed alcopops use as illicit, allowing these drinks to be reported as if they were an illegal drug. This 'negative' publicity was in contrast to the 'positive' stories and advertising space given over to other alcoholic beverages elsewhere in their pages. This manuscript quantifies the volume of reporting of these drinks in the Scottish press over the life-span of their news-worthiness. It argues that the press's claims could not be supported by the realities of underage drinking at the time. When this became apparent the scare story ended as rapidly as it had begun. Though concerning a licit substance these findings were found to have many illuminating parallels with illegal drug scare stories.

Speed freaks? A literature review detailing the nature and prevalence of dance drugs and driving.

Considerable interest has lately been expressed in motor car driving whilst under the influence of drugs. Unlike depressant drugs (e.g. alcohol) dance drugs are often perceived to enhance driving skills. The physical effects and the current lack of police roadside testing are possible contributing reasons for dance drug driving. This paper aims to show through a literature review on the subject, the demographics of those involved in dance drug driving and the extent to which certain dance drugs are implicated in drug driving incidents. Drug driving is found to be highest amongst the 18-35 year age group and more prevalent amongst adult males. Prevalence figures for driving under the influence of individual drugs are also given. The numbers of people involved in accidents/fatalities and testing positive for amphetamine, cocaine and other dance drugs is small. Although self-reporting especially of illegal activities is difficult to accurately evaluate, most of the reported studies use actual blood/urine samples and so can be considered accurate. The literature does not highlight any real concerns regarding dance drug driving in terms of prevalence although it does highlight the paucity of research in this area, in particular 'Culture E and driving'.

Design and synthesis of potent, selective, and orally bioavailable tetrasubstituted imidazole inhibitors of p38 mitogen-activated protein kinase.

Novel potent and selective diarylimidazole inhibitors of p38 MAP (mitogen-activated protein) kinase are described which have activity in both cell-based assays of tumor necrosis factor-alpha (TNF-alpha) release and an animal model of rheumatoid arthritis. The SAR leading to the development of selectivity against c-Raf and JNK2alpha1 kinases is presented, with key features being substitution of the 4-aryl ring with m-trifluoromethyl and substitution of the 5-heteroaryl ring with a 2-amino substituent. Cell-based activity was significantly enhanced by incorporation of a 4-piperidinyl moiety at the 2-position of the imidazole which also enhanced aqueous solubility. In general, oral bioavailability of this class of compounds was found to be poor unless the imidazole was methylated on nitrogen. This work led to identification of 48, a potent (p38 MAP kinase inhibition IC50 0.24 nM) and selective p38 MAP kinase inhibitor which inhibits lipopolysaccharide-stimulated release of TNF-alpha from human blood with an IC50 2.2 nM, shows good oral bioavailability in rat and rhesus monkey, and demonstrates significant improvement in measures of disease progression in a rat adjuvant-induced arthritis model.

Contrasting levels of adolescent drug use between adjacent urban and rural communities in Scotland.

AIMS: To compare life-time prevalence of illicit drug use between adolescents resident in adjacent urban and rural localities. DESIGN: Samples of schoolchildren attending urban and rural comprehensive schools (n = 2558) were obtained using an identical questionnaire survey method. SETTING: Respondents were recruited from 10 schools in two contrasting adjacent local authorities. Five representative schools in each locality were chosen. PARTICIPANTS: All children present in each school, in the two final compulsory school years, were eligible for this study. MEASUREMENTS: Respondents were asked to provide detailed information about their place of residence and use of illegal drugs. The data obtained in schools were compared with local geographical statistics, such as levels of deprivation. FINDINGS: As expected from the demographics of their respective localities, the urban schools displayed higher levels of deprived children and lower levels of school achievement. These socio-economic differences were not reflected in reported levels of life-time drug use. This was true both between and within the urban and rural samples. CONCLUSION: These findings suggest that adolescent drug use in Scotland is not particularly concentrated in areas of urban deprivation.

Susceptibility of stromelysin 1-deficient mice to collagen-induced arthritis and cartilage destruction.

OBJECTIVE: It has long been proposed that stromelysin is one of the major degradative matrix metalloproteinases responsible for the loss of cartilage in rheumatoid arthritis (RA) and osteoarthritis (OA). This hypothesis was tested by examining the arthritic paws of stromelysin 1 (SLN1)-deficient mice for loss of cartilage and for generation of neoepitopes that would be indicative of aggrecan cleavage. METHODS: The SLN1 gene was inactivated in murine embryonic stem cells, and knockout mice deficient in SLN1 activity were bred onto the B10.RIII background. The incidence and severity of collagen-induced arthritis (CIA) were compared in wild-type and knockout mice. Paws from mice with CIA were examined for loss of cartilage and for proteoglycan staining, as well as for the generation of the neoepitope FVDIPEN341. RESULTS: SLN1-deficient mice developed CIA, as did the wild-type N2 mice. Histologic analyses demonstrated no significant differences among the B10.RIII, wild-type, and knockout mice in loss of articular cartilage and proteoglycan staining. No decrease in the FVDIPEN341 epitope was observed in the SLN1-deficient mice. CONCLUSION: Disruption of the SLN1 gene neither prevents nor reduces the cartilage destruction associated with CIA. Moreover, SLN1 depletion does not prevent the cleavage of the aggrecan Asn341-Phe342 bond.

Musical preference as an indicator of adolescent drug use.

AIMS: This paper aims to demonstrate whether a relationship exists between adolescent drug use and identification with styles of music linked to specific youth culture. DESIGN: Survey data were collected by researchers, under exam conditions, from two contrasting samples of Scottish secondary schoolchildren. SETTING: Fieldwork was conducted in five comprehensive schools in the city of Dundee in 1994 and five comprehensive schools in the rural area of Perth and Kinross District in 1996. PARTICIPANTS: Questionnaires were administered to two randomly selected mixed ability classes in each of the four compulsory school years (S1 to S4), at each participating school. The eventual sample (n = 1523) was approximately 10% of all children in these school years from the geographical areas surveyed. MEASUREMENTS: Comparisons were made between life-time measures of legal and illegal drug use and current favourite style of music. FINDINGS: Although few children in this study had ever taken the drug ecstasy (MDMA), 'fans' of rave music were more likely to have used drugs than those who preferred other styles of music. This relationship held true across a range of drugs used, across two geographical areas, over time and controlling for age, gender and parental social class. CONCLUSIONS: The paper is one of the first to quantify a possible relationship between drug use and music style. On the basis of the evidence presented, a significant relationship was found between identification with rave music and life-time drug use.

Places and patterns of drug use in the Scottish dance scene.

Interviews were conducted with 135 participants in the Glasgow dance (rave) scene. Drug use in this group was varied and not merely restricted to drugs associated with dance events, such as MDMA (Ecstasy). The setting in which each drug was used varied greatly. Amphetamine, nitrites and Ecstasy were the drugs most commonly used at dance events. Pharmaceuticals were least likely to be used in such settings. However, some drugs, such as Temazepam, were sometimes used prior to or after attending rave events. It is suggested that dance drug users are polydrug users who use drugs in a setting specific fashion. As such it would be wrong to classify such users solely on the grounds of their very visible behaviour in the public arena (at dance events). Other forms of substance use engaged in by this group may have a greater potential for harm than that seen at raves. The implications of these findings are discussed.

The dual use of opioids and temazepam by drug injectors in Glasgow (Scotland).

In recent years much attention has been drawn to the use of buprenorphine (Temgesic) by heroin injectors in Glasgow and elsewhere. Glasgow has also witnessed a parallel increase in use of the benzodiazapine temazepam, often used as a 'cocktail' with buprenorphine. This paper presents new evidence that, although buprenorphine use among Glasgow drug injectors may now be declining, the use of temazepam-opioid cocktails has continued.

Adolescent drug use, health and personality.

Four factors have confounded the association between drug use and morbidity: (a) known drug users may be less healthy than unknown drug users; (b) drug users are rarely compared to control subjects; (c) the socio-economic status of drug users predisposes them to ill-health; (d) the personality of drug users predisposes them to ill-health. Here, controlling for these confounds, in a study of 210 adolescent drug users it was found that subjective ill-health was more strongly related to drug use than was objective ill-health. Drug use was related to neuroticism and psychopathic deviance. Controlling for personality, drug use accounted for little additional variance in health. It is concluded that drug use and health are not strongly related amongst adolescent drug users, although, because of their personalities, drug users tend not to feel well. Implications are discussed for the self-treatment explanation of drug use and for the design of preventative programmes.

Variations in needle sharing practices among intravenous drug users in Possil (Glasgow).

Glasgow has an intravenous drug using (IVDU) population which is probably larger but hitherto less infected with the human immunodeficiency virus (HIV) than IVDUs elsewhere in Scotland. This 1988 study of 50 Glasgow IVDUs reports disturbingly high rates of sharing injecting equipment, and points to imprisonment as a possible factor in increasing such risk taking behaviour.