118 research outputs found
Recommended from our members
Sustainable Energy Options for Austin Energy
During the 2008-2009 academic year the City of Austin, on behalf of Austin Energy (AE), and Solar Austin co-funded a policy research project to review options for AE to achieve sustainable energy generation and become carbon neutral by 2020. This project developed methods to evaluate future power generation options for their feasibility and cost-effectiveness. The report evaluates different power generation technology options as well as demand-side management and other AE investment options to discourage future energy use and meet future projected energy demand. The project team assessed scenarios of alternate investments that could be made between 2009 and 2020 that would allow AE to produce and distribute the electricity its customers demand at a reasonable cost while reducing carbon dioxide emissions. This report describes a set of short-term and long-term investment options that can help AE, its customers, and be of use for developing sustainable electric utilities nationwide. The report comprises three volumes: volume I is a summary; volume II discusses energy demand and the characteristics of available power generation technologies; and volume III is a "Future Resource Portfolio Analysis" which evaluates eight energy portfolio scenarios in detail.
This project was funded in part by the IC² Institute.IC2 Institut
The NASA-UC Eta-Earth Program: III. A Super-Earth orbiting HD 97658 and a Neptune-mass planet orbiting Gl 785
We report the discovery of planets orbiting two bright, nearby early K dwarf
stars, HD 97658 and Gl 785. These planets were detected by Keplerian modelling
of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey.
HD 97658 b is a close-in super-Earth with minimum mass Msini = 8.2 +/- 1.2
M_Earth, orbital period P = 9.494 +/- 0.005 d, and an orbit that is consistent
with circular. Gl 785 b is a Neptune-mass planet with Msini = 21.6 +/- 2.0
M_Earth, P = 74.39 +/- 0.12 d, and orbital eccentricity 0.30 +/- 0.09.
Photometric observations with the T12 0.8 m automatic photometric telescope at
Fairborn Observatory show that HD 97658 is photometrically constant at the
radial velocity period to 0.09 mmag, supporting the existence of the planet.Comment: Submitted to ApJ, 7 pages, 6 figures, 5 table
A randomised controlled trial and cost-effectiveness evaluation of "booster" interventions to sustain increases in physical activity in middle-aged adults in deprived urban neighbourhoods
Background: Systematic reviews have identified a range of brief interventions which increase physical activity in previously sedentary people. There is an absence of evidence about whether follow up beyond three months can maintain long term physical activity. This study assesses whether it is worth providing motivational interviews, three months after giving initial advice, to those who have become more active.
Methods/Design: Study candidates (n = 1500) will initially be given an interactive DVD and receive two telephone follow ups at monthly intervals checking on receipt and use of the DVD. Only those that have increased their physical activity after three months (n = 600) will be randomised into the study. These participants will receive either a "mini booster" (n = 200), "full booster" (n = 200) or no booster (n = 200). The "mini booster" consists of two telephone calls one month apart to discuss physical activity and maintenance strategies. The "full booster" consists of a face-to-face meeting with the facilitator at the same intervals. The purpose of these booster sessions is to help the individual maintain their increase in physical activity. Differences in physical activity, quality of life and costs associated with the booster interventions, will be measured three and nine months from randomisation. The research will be conducted in 20 of the most deprived neighbourhoods in Sheffield, which have large, ethnically diverse populations, high levels of economic deprivation, low levels of physical activity, poorer health and shorter life expectancy. Participants will be recruited through general practices and community groups, as well as by postal invitation, to ensure the participation of minority ethnic groups and those with lower levels of literacy. Sheffield City Council and Primary Care Trust fund a range of facilities and activities to promote physical activity and variations in access to these between neighbourhoods will make it possible to examine whether the effectiveness of the intervention is modified by access to community facilities. A one-year integrated feasibility study will confirm that recruitment targets are achievable based on a 10% sample.Discussion: The choice of study population, study interventions, brief intervention preceding the study, and outcome measure are discussed
Health benefi ts, costs, and cost-eff ectiveness of earlier eligibility for adult antiretroviral therapy and expanded treatment coverage: a combined analysis of 12 mathematical models
Background New WHO guidelines recommend initiation of antiretroviral therapy for HIV-positive adults with
CD4 counts of 500 cells per μL or less, a higher threshold than was previously recommended. Country decision
makers have to decide whether to further expand eligibility for antiretroviral therapy accordingly. We aimed to assess
the potential health benefi ts, costs, and cost-eff ectiveness of various eligibility criteria for adult antiretroviral therapy
and expanded treatment coverage.
Methods We used several independent mathematical models in four settings—South Africa (generalised epidemic,
moderate antiretroviral therapy coverage), Zambia (generalised epidemic, high antiretroviral therapy coverage), India
(concentrated epidemic, moderate antiretroviral therapy coverage), and Vietnam (concentrated epidemic, low
antiretroviral therapy coverage)—to assess the potential health benefi ts, costs, and cost-eff ectiveness of various
eligibility criteria for adult antiretroviral therapy under scenarios of existing and expanded treatment coverage, with
results projected over 20 years. Analyses assessed the extension of eligibility to include individuals with CD4 counts
of 500 cells per μL or less, or all HIV-positive adults, compared with the previous (2010) recommendation of initiation
with CD4 counts of 350 cells per μL or less. We assessed costs from a health-system perspective, and calculated the
incremental cost (in US8040; Zambia: 1489; Vietnam: 237 to 749 per DALY averted. In both
countries results were similar for expansion of eligibility to all HIV-positive adults, and when substantially expanded
treatment coverage was assumed. Expansion of treatment coverage in the general population was also cost eff ective. In
India, the cost for extending eligibility to all HIV-positive adults ranged from 241 per DALY averted, and in
Vietnam extending eligibility to patients with CD4 counts of 500 cells per μL or less cost $290 per DALY averted. In
concentrated epidemics, expanded access for key populations was also cost eff ective.
Interpretation Our estimates suggest that earlier eligibility for antiretroviral therapy is very cost eff ective in lowincome
and middle-income settings, although these estimates should be revisited when more data become available.
Scaling up antiretroviral therapy through earlier eligibility and expanded coverage should be considered alongside other high-priority health interventions competing for health budgets
Aptamer-based multiplexed proteomic technology for biomarker discovery
Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine
Immunity to HIV-1 Is Influenced by Continued Natural Exposure to Exogenous Virus
Unprotected sexual intercourse between individuals who are both infected with HIV-1 can lead to exposure to their partner's virus, and potentially to super-infection. However, the immunological consequences of continued exposure to HIV-1 by individuals already infected, has to our knowledge never been reported. We measured T cell responses in 49 HIV-1 infected individuals who were on antiretroviral therapy with suppressed viral loads. All the individuals were in a long-term sexual partnership with another HIV-1 infected individual, who was either also on HAART and suppressing their viral loads, or viremic (>9000 copies/ml). T cell responses to HIV-1 epitopes were measured directly ex-vivo by the IFN-γ enzyme linked immuno-spot assay and by cytokine flow cytometry. Sexual exposure data was generated from questionnaires given to both individuals within each partnership. Individuals who continued to have regular sexual contact with a HIV-1 infected viremic partner had significantly higher frequencies of HIV-1-specific T cell responses, compared to individuals with aviremic partners. Strikingly, the magnitude of the HIV-1-specific T cell response correlated strongly with the level and route of exposure. Responses consisted of both CD4+ and CD8+ T cell subsets. Longitudinally, decreases in exposure were mirrored by a lower T cell response. However, no evidence for systemic super-infection was found in any of the individuals. Continued sexual exposure to exogenous HIV-1 was associated with increased HIV-1-specific T cell responses, in the absence of systemic super-infection, and correlated with the level and type of exposure
Ticks Associated with Macquarie Island Penguins Carry Arboviruses from Four Genera
Macquarie Island, a small subantarctic island, is home to rockhopper, royal and king penguins, which are often infested with the globally distributed seabird tick, Ixodes uriae. A flavivirus, an orbivirus, a phlebovirus, and a nairovirus were isolated from these ticks and partial sequences obtained. The flavivirus was nearly identical to Gadgets Gully virus, isolated some 30 year previously, illustrating the remarkable genetic stability of this virus. The nearest relative to the orbivirus (for which we propose the name Sandy Bay virus) was the Scottish Broadhaven virus, and provided only the second available sequences from the Great Island orbivirus serogroup. The phlebovirus (for which we propose the name Catch-me-cave virus) and the previously isolated Precarious Point virus were distinct but related, with both showing homology with the Finnish Uukuniemi virus. These penguin viruses provided the second and third available sequences for the Uukuniemi group of phleboviruses. The nairovirus (for which we propose the name Finch Creek virus) was shown to be related to the North American Tillamook virus, the Asian Hazara virus and Nairobi sheep disease virus. Macquarie Island penguins thus harbour arboviruses from at least four of the seven arbovirus-containing genera, with related viruses often found in the northern hemisphere
The impact of power and relationship commitment on the integration between manufacturers and customers in a supply chain
Supply chain integration (SCI) has received increasing attention from scholars and practitioners in recent years. However, our knowledge of what influences SCI is still very limited. Although marketing and management researchers have investigated power and relationship commitment issues between organizations, few have examined their impact on SCI. This paper extends the power–relationship commitment theory established in Western marketing literature and links it with SCI in China, through examining the relationship between power, relationship commitment and the integration between manufacturers and their customers. We propose and empirically test a model using data collected from 617 manufacturing companies in China. The results show that different types of customer power impact manufacturers’ relationship commitment in different ways. Expert power, referent power and reward power are important in improving manufacturers’ normative relationship commitment, while reward power and coercive power enhance instrumental relationship commitment. We also found that normative relationship commitment had a greater impact on customer integration than instrumental relationship commitment. These findings are interpreted in light of national culture differences between China and the U.S. in terms of power distance and collectivism, which provide a new perspective on SCI
- …