11,460 research outputs found
Are U.S. states equally prepared for a carbon-constrained world?
Climate concerns linked to greenhouse gas emissions, particularly carbon dioxide (CO2), have taken center stage in the national energy policy debate. Domestic energy use and carbon emissions continue to rise, and forecasts suggest further increases under the existing regulatory structure. However, heightened international and domestic pressure to reduce U.S. carbon emissions suggests that additional changes to the regulatory framework are probable in coming years. ; Reducing U.S. carbon emissions will likely require a comprehensive national framework that will alter the pattern of energy use and production in all 50 states. At issue for state-level policymakers is that carbon restrictions are unlikely to affect the states equally. Energy use and emission patterns vary widely across states, and there is no accepted framework for allocating shares of a national carbon reduction goal. As a result, states that emit the most carbon or have the most energy- and carbon-intensive economies may shoulder the greatest burden. ; Snead and Jones evaluate the current energy posture of the states and thus how prepared they are to cope with ongoing trends in energy use, especially restrictions on carbon emissions. Their findings suggest that the New England, Mid-Atlantic and West Coast states are generally best prepared. These states have the least energy-intensive economies and use fuel mixes with low average carbon intensity; hence, they already release proportionately less CO2. The states expected to be hardest hit by carbon constraints are the traditional energy-producing and agricultural states. These states have energy-intensive economies, by both domestic and international standards, and will face a considerable challenge in altering their energy use and emissions patterns.
An evaluation of the effectiveness of the Lidcombe program of early stuttering intervention
This thesis presents a randomised controlled trial of the Lidcombe Program of Early Stuttering Intervention. The Lidcombe Program was developed for the treatment of stuttering in preschool-age children. The effectiveness of the Lidcombe Program was compared to a control group in a parallel group randomised controlled trial with blinded outcome assessment. A number of supplementary studies were conducted in support of the trial; two literature reviews, two retrospective file audits and a statistical simulation study. A review of randomised studies of treatments for stuttering showed that there have been 27 such studies published in English language journals. Of these only one was devoted to a treatment for early stuttering and that was the Lidcombe Program. The randomised study showed that 3 months of this treatment was associated with a lower level of stuttering compared to a control group who received no treatment. However, with a sample size of 23, this study lacked power and the children did not receive a full course of treatment. Despite these limitations, this study provided evidence that a medium to large effect size could be anticipated in an adequately powered and properly conducted randomised controlled trial. The second review was of sample size and power in stuttering research studies that had been published in two speech pathology journals; the Journal of Speech, Language and Hearing Research (Vol 39, No. 1 to Vol 40, No, 4) and the Journal of Fluency Disorders (Vol 21, No. 1 to Vol 22, No, 3). Results suggested that the majority (73%) of the 26 studies reviewed were insufficiently powered to detect even large effects. However it was acknowledged that it is very difficult to recruit even moderate sample sizes of people who stutter. It was concluded that one way to help improve this situation is collaboration of multiple research centres or, in the case of a randomised controlled trial, inclusion of multiple recruitment sites in one study. This strategy was adopted in the randomised controlled trial reported in this thesis. Two retrospective file audit studies of children treated with the Lidcombe Program were conducted in Australia and Britain. One purpose of these file audits was to obtain information relevant to the design and conduct of the randomised controlled trial. Data from the case reports on more than 300 children from the two sites were included in a meta-analysis. Results showed that a median of 11 weekly clinic sessions were required for children to attain the criteria for low levels of stuttering for completion of Stage 1 of the Lidcombe Program. Approximately 90% of children had achieved those criteria within 6 months of beginning treatment and almost all children had achieved them within 1 year. In addition two variables were found to be associated with longer treatment duration: more severe pre-treatment stuttering and shorter times from onset of stuttering to the start of treatment. The latter was apparent in the meta-analysis but not for the individual cohorts. As a result of these findings, pre-treatment stuttering severity was stratified along with other relevant variables in the randomised controlled trial and follow up for participants was a minimum of 9 months. A simulation study was conducted prior to analysis of data from the primary outcome measure of the randomised controlled trial: percentage of syllables stuttered (%SS). The distribution of %SS scores is positively skewed. Nonetheless, simulation showed t-test to be an appropriate analysis for this primary outcome measure. There were two treatment sites for the randomised controlled trial: the University of Canterbury (Christchurch, New Zealand) and the Stuttering Treatment and Research Trust (Auckland, New Zealand). A total of 54 preschool-age children were recruited: 29 to the Lidcombe Program and 25 to the control group. Half the proposed sample size was achieved due to slower than anticipated recruitment. This occurred because, as the trial progressed, treatment with the Lidcombe Program became common knowledge among parents in New Zealand and they became increasingly reluctant to agree to have their child randomised to the trial. Analysis with t-test showed a highly statistically significant difference (p = 0.003) at 9-months post-randomisation. The mean percentage of syllables stuttered (%SS) at 9-months post-randomisation was 1.5 (SD = 1.4) for the Lidcombe Program group compared to 3.9 (SD = 3.5) for the control group, resulting in a treatment effect of 2.3 %SS (95% confidence interval: 0.8-3.9). This treatment effect was more than double the minimum clinically worthwhile difference specified in the trial protocol. These results show that the Lidcombe Program is significantly more effective than natural recovery for reducing stuttering levels in preschool children. The Lidcombe Program is the first early stuttering treatment to be shown to be more effective than natural recovery in a randomised controlled trial
An evaluation of the effectiveness of the Lidcombe program of early stuttering intervention
This thesis presents a randomised controlled trial of the Lidcombe Program of Early Stuttering Intervention. The Lidcombe Program was developed for the treatment of stuttering in preschool-age children. The effectiveness of the Lidcombe Program was compared to a control group in a parallel group randomised controlled trial with blinded outcome assessment. A number of supplementary studies were conducted in support of the trial; two literature reviews, two retrospective file audits and a statistical simulation study. A review of randomised studies of treatments for stuttering showed that there have been 27 such studies published in English language journals. Of these only one was devoted to a treatment for early stuttering and that was the Lidcombe Program. The randomised study showed that 3 months of this treatment was associated with a lower level of stuttering compared to a control group who received no treatment. However, with a sample size of 23, this study lacked power and the children did not receive a full course of treatment. Despite these limitations, this study provided evidence that a medium to large effect size could be anticipated in an adequately powered and properly conducted randomised controlled trial. The second review was of sample size and power in stuttering research studies that had been published in two speech pathology journals; the Journal of Speech, Language and Hearing Research (Vol 39, No. 1 to Vol 40, No, 4) and the Journal of Fluency Disorders (Vol 21, No. 1 to Vol 22, No, 3). Results suggested that the majority (73%) of the 26 studies reviewed were insufficiently powered to detect even large effects. However it was acknowledged that it is very difficult to recruit even moderate sample sizes of people who stutter. It was concluded that one way to help improve this situation is collaboration of multiple research centres or, in the case of a randomised controlled trial, inclusion of multiple recruitment sites in one study. This strategy was adopted in the randomised controlled trial reported in this thesis. Two retrospective file audit studies of children treated with the Lidcombe Program were conducted in Australia and Britain. One purpose of these file audits was to obtain information relevant to the design and conduct of the randomised controlled trial. Data from the case reports on more than 300 children from the two sites were included in a meta-analysis. Results showed that a median of 11 weekly clinic sessions were required for children to attain the criteria for low levels of stuttering for completion of Stage 1 of the Lidcombe Program. Approximately 90% of children had achieved those criteria within 6 months of beginning treatment and almost all children had achieved them within 1 year. In addition two variables were found to be associated with longer treatment duration: more severe pre-treatment stuttering and shorter times from onset of stuttering to the start of treatment. The latter was apparent in the meta-analysis but not for the individual cohorts. As a result of these findings, pre-treatment stuttering severity was stratified along with other relevant variables in the randomised controlled trial and follow up for participants was a minimum of 9 months. A simulation study was conducted prior to analysis of data from the primary outcome measure of the randomised controlled trial: percentage of syllables stuttered (%SS). The distribution of %SS scores is positively skewed. Nonetheless, simulation showed t-test to be an appropriate analysis for this primary outcome measure. There were two treatment sites for the randomised controlled trial: the University of Canterbury (Christchurch, New Zealand) and the Stuttering Treatment and Research Trust (Auckland, New Zealand). A total of 54 preschool-age children were recruited: 29 to the Lidcombe Program and 25 to the control group. Half the proposed sample size was achieved due to slower than anticipated recruitment. This occurred because, as the trial progressed, treatment with the Lidcombe Program became common knowledge among parents in New Zealand and they became increasingly reluctant to agree to have their child randomised to the trial. Analysis with t-test showed a highly statistically significant difference (p = 0.003) at 9-months post-randomisation. The mean percentage of syllables stuttered (%SS) at 9-months post-randomisation was 1.5 (SD = 1.4) for the Lidcombe Program group compared to 3.9 (SD = 3.5) for the control group, resulting in a treatment effect of 2.3 %SS (95% confidence interval: 0.8-3.9). This treatment effect was more than double the minimum clinically worthwhile difference specified in the trial protocol. These results show that the Lidcombe Program is significantly more effective than natural recovery for reducing stuttering levels in preschool children. The Lidcombe Program is the first early stuttering treatment to be shown to be more effective than natural recovery in a randomised controlled trial
Efficient Follow-Up of Exoplanet Transits Using Small Telescopes
11 pages, 5 figures, to be published in PASP, comments welcomeHere, we introduce an online tool for the prediction of exoplanet transit light curves. Small telescopes can readily capture exoplanet transits under good weather conditions when the combination of a bright star and a large transiting exoplanet results in a significant depth of transit. However, in reality there are many considerations that need to be made to obtain useful measurements. This paper and the accompanying website lay out a procedure based on timeseries differential photometry that has been successfully employed using 0.4 m aperture telescopes to predict the expected precision for a whole light curve. This enables robust planning to decide whether the observation of a particular exoplanet transit should be attempted, and in particular to be able to readily see when it should not to be attempted. This may result in a significant increase in the number of transit observations captured by non-specialists. The technique and website are also appropriate for planning a variety of variable star observations where a prediction of the light curve can be made.Peer reviewe
Strictly Anomaly Mediated Supersymmetry Breaking
We consider an MSSM extension with anomaly mediation as the source of
supersymmetry-breaking, and a U(1) symmetry which solves the tachyonic slepton
problem, and introduces both the see-saw mechanism for neutrino masses, and the
Higgs mu-term. We compare its spectra with those from so-called minimal anomaly
mediated supersymmetry breaking. We find a Standard Model-like Higgs of mass
125 GeV with a gravitino mass of 140 TeV and tan(beta)=16. However, the muon
anomalous magnetic moment is 3 sigma away from the experimental value.
The model naturally produces a period of hybrid inflation, which can exit to
a false vacuum characterised by large Higgs vevs, reaching the true ground
state after a period of thermal inflation. The scalar spectral index is reduced
to approximately 0.975, and the correct abundance of neutralino dark matter can
be produced by decays of thermally-produced gravitinos, provided the gravitino
mass (and hence the Higgs mass) is high. Naturally light cosmic strings are
produced, satisfying bounds from the Cosmic Microwave Background. The
complementary pulsar timing and cosmic ray bounds require that strings decay
primarily via loops into gravitational waves. Unless the loops are extremely
small, the next generation pulsar timing array will rule out or detect the
string-derived gravitational radiation background in this model.Comment: 38 pages, 1 figure. Discussion of 125GeV Higgs possibility, and of
U(1) decoupling limi
Within-guild dietary discrimination from 3-D textural analysis of tooth microwear in insectivorous mammals
Resource exploitation and competition for food are important selective pressures in animal evolution. A number of recent investigations have focused on linkages between diversification, trophic morphology and diet in bats, partly because their roosting habits mean that for many bat species diet can be quantified relatively easily through faecal analysis. Dietary analysis in mammals is otherwise invasive, complicated, time consuming and expensive. Here we present evidence from insectivorous bats that analysis of three-dimensional (3-D) textures of tooth microwear using International Organization for Standardization (ISO) roughness parameters derived from sub-micron surface data provides an additional, powerful tool for investigation of trophic resource exploitation in mammals. Our approach, like scale-sensitive fractal analysis, offers considerable advantages over twodimensional (2-D) methods of microwear analysis, including improvements in robustness, repeatability and comparability of studies. Our results constitute the first analysis of microwear textures in carnivorous mammals based on ISO roughness parameters. They demonstrate that the method is capable of dietary discrimination, even between cryptic species with subtly different diets within trophic guilds, and even when sample sizes are small. We find significant differences in microwear textures between insectivore species whose diet contains different proportions of ‘hard’ prey (such as beetles) and ‘soft’ prey (such as moths), and multivariate analyses are able to distinguish between species with different diets based solely on their tooth microwear textures. Our results show that, compared with previous 2-D analyses of microwear in bats, ISO roughness parameters provide a much more sophisticated characterization of the nature of microwear surfaces and can yield more robust and subtle dietary discrimination. ISO-based textural analysis of tooth microwear thus has a useful role to play, complementing existing approaches, in trophic analysis of mammals, both extant and extinct
Comparison of Anesthesia for Dental/Oral Surgery by Office-based Dentist Anesthesiologists versus Operating Room-based Physician Anesthesiologists
Few studies have examined the practice characteristics of dentist anesthesiologists and compared them to other anesthesia providers. Using outcomes from the National Anesthesia Clinical Outcomes Registry and the Society for Ambulatory Anesthesia Clinical Outcomes Registry for dental/oral surgery procedures, we compared 7133 predominantly office-based anesthetics by dentist anesthesiologists to 106,420 predominantly operating room anesthetics performed by physician anesthesia providers. These encounters were contrasted with 34,191 previously published encounters from the practices of oral and maxillofacial surgeons. Children younger than 6 years received the greatest proportion of general anesthetic services rendered by both dentist anesthesiologists and hospital-based anesthesia providers. These general anesthesia services were primarily provided for complete dental rehabilitation for early childhood caries. Overall treatment time for complete dental rehabilitation in the office-based setting by dentist anesthesiologists was significantly shorter than comparable care provided in the hospital operating room and surgery centers. The anesthesia care provided by dentist anesthesiologists was found to be separate and distinct from anesthesia care provided by oral and maxillofacial surgeons, which was primarily administered to adults for very brief surgical procedures. Cases performed by dentist anesthesiologists and hospital-based anesthesia providers were for much younger patients and of significantly longer duration when compared with anesthesia administered by oral and maxillofacial surgeons. Despite the limited descriptive power of the current registries, office-based anesthesia rendered by dentist anesthesiologists is clearly a unique and efficient mode of anesthesia care for dentistry
The incidence of mid-infrared excesses in G and K giants
Using photometric data from the 2MASS and GLIMPSE catalogues, I investigate
the incidence of mid-infrared excesses (~10 microns) of G and K stars of
luminosity class III. In order to obtain a large sample size, stars are
selected using a near-IR colour-magnitude diagram. Sources which are candidates
for showing mid-IR excess are carefully examined and modelled to determined
whether they are likely to be G/K giants. It is found that mid-IR excesses are
present at a level of (1.8 +/- 0.4) x 10^-3. While the origin of these excesses
remains uncertain, it is plausible that they arise from debris discs around
these stars. I note that the measured incidence is consistent with a scenario
in which dust lifetimes in debris discs are determined by Poynting-Robertson
drag rather than by collisions.Comment: Accepted for publication in MNRAS. 13 pages, 5 figures, 2 tables (1
landscape table
Mandatory Random Drug-Testing in the United States Department of Transportation--A Fourth Amendment Analysis
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