Smoking amongst adults experiencing homelessness: a systematic review of prevalence rates, interventions and the barriers and facilitators to quitting and staying quit

Background To date, there has been no review of the research evidence examining smoking cessation among homeless adults. The current review aimed to: (i) estimate smoking prevalence in homeless populations; (ii) explore the efficacy of smoking cessation and smoking reduction interventions for homeless individuals; and (iii) describe the barriers and facilitators to smoking cessation and smoking reduction. Method Systematic review of peer-reviewed research. Data sources included electronic academic databases. Search terms: ‘smoking’ AND ‘homeless’ AND ‘tobacco’, including adult (18+ years) smokers accessing homeless support services. Results Fifty-three studies met the inclusion criteria (n = 46 USA). Data could not be meta-analysed due to large methodological inconsistencies and the lack of randomised controlled trials. Smoking prevalence ranged from 57% to 82%. Although there was no clear evidence on which cessation methods work best, layered approaches with additions to usual care seemed to offer modest enhancements in quit rates. Key barriers to cessation exist around the priority of smoking, beliefs around negative impact on mental health and substance use, and environmental influences. Conclusions Homeless smokers will benefit from layered interventions which support many of their competing needs. To best understand what works, future recommendations include the need for consensus on the reporting of cessation outcomes

An Investigation Into Computerized Estimating Software Used In Accounting For Cost Estimates By Residential Builders

The purpose of this study was to investigate the utilization of information technology in the estimating functions, related to the scale of operations, by Pennsylvania’s home building contractors.  Firm size was examined as to its impact on three issues in construction cost estimating practices; type of estimating technology, whether or not the primary estimating function was computerized, and if computerized, the primary program used for the estimating functions by home builders.  Significant differences existed among firm sizes in the information technology used for estimating costs.  Secondly, significant differences existed among firm sizes as to the use of a computerized estimating system verses a manual estimating system.  Larger firms utilized more advanced technology.  However, the results revealed that there are not significant differences among firm sizes in the primary program used for estimating when a firm has a computerized estimating procedure.  Small firms that are computerized in many cases are taking advantage of the same software used by larger firms

Quantum Monte Carlo calculations of six-quark states

The variational Monte Carlo method is used to find the ground state of six quarks confined to a cavity of diameter R_c, interacting via an assumed non-relativistic constituent quark model (CQM) Hamiltonian. We use a flux-tube model augmented with one-gluon and one-pion exchange interactions, which has been successful in describing single hadron spectra. The variational wave function is written as a product of three-quark nucleon states with correlations between quarks in different nucleons. We study the role of quark exchange effects by allowing flux-tube configuration mixing. An accurate six-body variational wave function is obtained. It has only ~13% rms fluctuation in the total energy and yields a standard deviation of ~<.1%; small enough to be useful in discerning nuclear interaction effects from the large rest mass of the two nucleons. Results are presented for three values of the cavity diameter, R_c=2, 4, and 6 fm. They indicate that the flux-tube model Hamiltonian with gluon and pion exchange requires revisions in order to obtain agreement with the energies estimated from realistic two-nucleon interactions. We calculate the two-quark probability distribution functions and show how they may be used to study and adjust the model Hamiltonian.Comment: 49 pages, 13 figures, submitted to Phys. Rev.

Unraveling of free carrier absorption for terahertz radiation in heterostructures

The relation between free carrier absorption and intersubband transitions in semiconductor heterostructures is resolved by comparing a sequence of structures. Our numerical and analytical results show how free carrier absorption evolves from the intersubband transitions in the limit of an infinite number of wells with vanishing barrier width. It is explicitly shown that the integral of the absorption over frequency matches the value obtained by the f-sum rule. This shows that a proper treatment of intersubband transitions is fully sufficient to simulate the entire electronic absorption in heterostructure THz devices.Comment: 6 pages, accepted by Physical Review

H\u3csup\u3e+\u3c/sup\u3e/OH\u3csup\u3e-\u3c/sup\u3e Excretion and Nutrient Uptake in Upper and Lower Parts of Lupin (\u3cem\u3eLupinus angustifolius\u3c/em\u3e L.) Root Systems

The cultivation of narrow-leafed lupins (Lupinus angustifolius L.) increase rates of subsoil acidification, and this is thought to be partly related to their pattern of nutrient uptake and H+/OH- excretion. The main hypothesis of this study was that H+ and OH- excretion is not distributed evenly over the entire length of the root system but is limited to zones where excess cation or anion uptake occur. Seedlings of nodulated lupins were grown in solution culture using vertically split pots that allowed the upper and lower zones of the root system to be supplied with varying concentrations of K+ and NO-3. Net H+/OH- excretion was equated to the addition of NaOH/HCl required to maintain a constant pH in the nutrient solution during a 4-d treatment period and nutrient uptake was measured by depletion from solution in each zone of the split pots. The excess of cation over anion uptake was positively correlated with H+ excretion in each rooting zone. In zones where K+ was supplied at 1200 µM, cation uptake was dominated by K+ and up to twice as much H+ was excreted than in zones where K+ was absent. In zones where NO-3 was supplied at 750 µM, the anion/cation uptake was balanced, however H+ excretion continued to occur in the zone. When NO-3 was supplied at 5000 µM, anion uptake exceeded cation uptake but there was no OH- excretion. Organic acid anions may be excreted by lupins to maintain their internal electroneutrality when anion uptake exceeds cation uptake. Rhizosphere pH would not increase unless the pKa of the excreted organic anions was greater than the external pH

The role of secondary Reggeons in central meson production

We estimate the contribution of f_2 trajectory exchange to the central \eta and \eta^\prime production. It is shown that secondary Reggeons may give a large contribution to processes of double diffractive meson production at high energy.Comment: 7 pages, Latex, 5 figure

Understanding Search Trees via Statistical Physics

We study the random m-ary search tree model (where m stands for the number of branches of a search tree), an important problem for data storage in computer science, using a variety of statistical physics techniques that allow us to obtain exact asymptotic results. In particular, we show that the probability distributions of extreme observables associated with a random search tree such as the height and the balanced height of a tree have a traveling front structure. In addition, the variance of the number of nodes needed to store a data string of a given size N is shown to undergo a striking phase transition at a critical value of the branching ratio m_c=26. We identify the mechanism of this phase transition, show that it is generic and occurs in various other problems as well. New results are obtained when each element of the data string is a D-dimensional vector. We show that this problem also has a phase transition at a critical dimension, D_c= \pi/\sin^{-1}(1/\sqrt{8})=8.69363...Comment: 11 pages, 8 .eps figures included. Invited contribution to STATPHYS-22 held at Bangalore (India) in July 2004. To appear in the proceedings of STATPHYS-2

A Study of The Local Toxicity of Agents Used for Variceal Injection Sclerotherapy

Injection sclerotherapy is widely used in the treatment of oesophageal varices. However, few studies have compared the local toxicity of sclerosant agents which may be important if serious local complications are to be avoided