Drug use in Irish schools: a comparison with other countries.

Depending on what criteria one adopts, the most serious drug problem in Irish schools might be 'cigarettes' or 'alcohol' or one of the illegal substances. In order to decide on the seriousness of a drug problem, it is necessary not only to consider the numbers using the substance, but also to compare the findings longitudinally and cross-culturally. This article reported on a three-phase survey of the reported use of cigarettes, alcohol and illegal drugs by 3,000 randomly-selected second-level pupils aged between 12.5 and 18 years in the Dublin area. Twenty-four post-primary schools were involved, representing the full range of socio-economic backgrounds. A self-administered, anonymous questionnaire was used to gather information. The research results showed that over two-thirds of the sample had smoked a cigarette at one time in their lives, while over one-third had smoked in the previous month, and hence were defined as current smokers. When these findings were compared with other countries, the level of smoking among Irish school-goers was found to be 'extremely high'. With regard to drinking, almost two-thirds of those surveyed reported that they had ever consumed an alcoholic drink, and one-third of the sample said that they had felt drunk at least once. When these rates were compared with other countries, it was found that the levels of drinking in Ireland were mid-way between low-consumption countries like Israel and high-consumption countries like France. Regarding drugs, marijuana and glue or other inhalants were found to be the most frequently misused substances; about 13% of the sample reported that they had tried each of these at some time in their lives. The level of illegal drug use found in the present study, however, was judged to be low when compared with that in other countries

Haemoglobin and size dependent constraints on swimbladder inflation in fish larvae

In developmental studies of fish species (especially physostomians) it could be demonstrated, that the lack of haemoglobin during larval and juvenile stages is a relatively common phenomenon. Generally it is linked with body translucency. In representatives of the families Galaxiidae, Osmeridae and Clupeidae, partly reared, partly observed immediately after being caught in the wild, it turned out, that this condition coincides with a considerable delay in swimbladder inflation. To determine the moment of its first inflation, larvae placed in a hermetic chamber were observed under a dissecting microscope. While lowering the pressure, the expanding swimbladder showed whether or not its content is really gaseous. The reason postulated to be responsible for the delayed inflation is that larvae lacking haemoglobin do not have the possibility of oxygen transport to their buoyancy organ by means of the blood. Apart of this, capillarity force calculations and body force estimations show that with decreasing size the constraints linked with surface tension increase overproportionally. While in larger sized larvae like trout we could demonstrate inflation by swallowing air, in species with small larvae this was not the case. Below a certain size, even in physostomians, the ductus pneumaticus is no alternative to the blood pathway for swimbladder inflation

Observation of Buried Phosphorus Dopants near Clean Si(100)-(2x1) with Scanning Tunneling Microscopy

We have used scanning tunneling microscopy to identify individual phosphorus dopant atoms near the clean silicon (100)-(2x1) reconstructed surface. The charge-induced band bending signature associated with the dopants shows up as an enhancement in both filled and empty states and is consistent with the appearance of n-type dopants on compound semiconductor surfaces and passivated Si(100)-(2x1). We observe dopants at different depths and see a strong dependence of the signature on the magnitude of the sample voltage. Our results suggest that, on this clean surface, the antibonding surface state band acts as an extension of the bulk conduction band into the gap. The positively charged dimer vacancies that have been observed previously appear as depressions in the filled states, as opposed to enhancements, because they disrupt these surface bands.Comment: 4 pages, 3 figures. TeX for OSX from Wierde

Pressure Effect and Specific Heat of RBa2Cu3Ox at Distinct Charge Carrier Concentrations: Possible Influence of Stripes

In YBa2Cu3Ox, distinct features are found in the pressure dependence of the transition temperature, dTc/dp, and in DeltaCp*Tc, where DeltaCp is the jump in the specific heat at Tc: dTc/dp becomes zero when DeltaCp*Tc is maximal, whereas dTc/dp has a peak at lower oxygen contents where DeltaCp*Tc vanishes. Substituting Nd for Y and doping with Ca leads to a shift of these specific oxygen contents, since oxygen order and hole doping by Ca influences the hole content nh in the CuO2 planes. Calculating nh from the parabolic Tc(nh) behavior, the features coalesce for all samples at nh=0.11 and nh=0.175, irrespective of substitution and doping. Hence, this behavior seems to reflect an intrinsic property of the CuO2 planes. Analyzing our results we obtain different mechanisms in three doping regions: Tc changes in the optimally doped and overdoped region are mainly caused by charge transfer. In the slightly underdoped region an increasing contribution to dTc/dp is obtained when well ordered CuO chain fragments serve as pinning centers for stripes. This behavior is supported by our results on Zn doped NdBa2Cu3Ox and is responsible for the well known dTc/dp peak observed in YBa2Cu3Ox at x=6.7. Going to a hole content below nh=0.11 our results point to a crossover from an underdoped superconductor to a doped antiferromagnet, changing completely the physics of these materials.Comment: 6 pages, 5 figures Proccedings of the 'Stripes 2000' Conference, Rome (2000

Doubly Illegal: Qualitative Accounts of Underage Alcohol Access Through Theft

This study investigated sources of alcohol for underage drinkers. In-depth, semi-structured interviews were individually conducted with 47 youths, ages 15-18, who reported drinking within the last 12 months, to explore alcohol access. Theft was one method that some youths reported using to obtain alcohol. In addition to 9% of respondents who reported stealing alcohol from commercial outlets themselves, a total of 26% respondents reported occasions when their close friends stole alcohol. Our findings unveiled that teens had a body of knowledge that some drew upon for stealing alcohol. Youths revealed detailed knowledge about store layout, theft protection devices and store policies. In particular, respondents disclosed knowledge about which aisles have blind spots, how to remove security tops on bottles, and nochase policies. Theft of alcohol from commercial sources may be reduced by examining the weaknesses of existing theft prevention practices, and revising store policies

Importance of In-Plane Anisotropy in the Quasi Two-Dimensional Antiferromagnet BaNi2_{2}V2_{2}O8_{8}

The phase diagram of the quasi two-dimensional antiferromagnet BaNi$_{2}$V$_{2}$O$_{8}$ is studied by specific heat, thermal expansion, magnetostriction, and magnetization for magnetic fields applied perpendicular to $\mathbf{c}$. At $\mu_0H^{*}\simeq1.5$ T, a crossover to a high-field state, where $T_N(H)$ increases linearly, arises from a competition of intrinsic and field-induced in-plane anisotropies. The pressure dependences of $T_N$ and $H^{*}$ are interpreted using the picture of a pressure-induced in-plane anisotropy. Even at zero field and ambient pressure, in-plane anisotropy cannot be neglected, which implies deviations from pure Berezinskii-Kosterlitz-Thouless behavior.Comment: 4 pages, 4 figure