15 research outputs found
Kinematic space for conical defects
Kinematic space can be used as an intermediate step in the AdS/CFT dictionary
and lends itself naturally to the description of diffeomorphism invariant
quantities. From the bulk it has been defined as the space of boundary anchored
geodesics, and from the boundary as the space of pairs of CFT points. When the
bulk is not globally AdS the appearance of non-minimal geodesics leads to
ambiguities in these definitions. In this work conical defect spacetimes are
considered as an example where non-minimal geodesics are common. From the bulk
it is found that the conical defect kinematic space can be obtained from the
AdS kinematic space by the same quotient under which one obtains the defect
from AdS. The resulting kinematic space is one of many equivalent
fundamental regions. From the boundary the conical defect kinematic space can
be determined by breaking up OPE blocks into contributions from individual bulk
geodesics. A duality is established between partial OPE blocks and bulk fields
integrated over individual geodesics, minimal or non-minimal.Comment: 29 pages, 9 figures. As published in JHE
INTEGRATED POWER GENERATION SYSTEMS FOR COAL MINE WASTE METHANE UTILIZATION
An integrated system to utilize the waste coal mine methane (CMM) at the Federal No. 2 Coal Mine in West Virginia was designed and built. The system includes power generation, using internal combustion engines, along with gas processing equipment to upgrade sub-quality waste methane to pipeline quality standards. The power generation has a nominal capacity of 1,200 kw and the gas processing system can treat about 1 million cubic feet per day (1 MMCFD) of gas. The gas processing is based on the Northwest Fuel Development, Inc. (NW Fuel) proprietary continuous pressure swing adsorption (CPSA) process that can remove nitrogen from CMM streams. The two major components of the integrated system are synergistic. The byproduct gas stream from the gas processing equipment can be used as fuel for the power generating equipment. In return, the power generating equipment provides the nominal power requirements of the gas processing equipment. This Phase III effort followed Phase I, which was comprised of a feasibility study for the project, and Phase II, where the final design for the commercial-scale demonstration was completed. The fact that NW Fuel is desirous of continuing to operate the equipment on a commercial basis provides the validation for having advanced the project through all of these phases. The limitation experienced by the project during Phase III was that the CMM available to operate the CPSA system on a commercial basis was not of sufficiently high quality. NW Fuel's CPSA process is limited in its applicability, requiring a relatively high quality of gas as the feed to the process. The CPSA process was demonstrated during Phase III for a limited time, during which the processing capabilities met the expected results, but the process was never capable of providing pipeline quality gas from the available low quality CMM. The NW Fuel CPSA process is a low-cost ''polishing unit'' capable of removing a few percent nitrogen. It was never intended to process CMM streams containing high levels of nitrogen, as is now the case at the Federal No.2 Mine. Even lacking the CPSA pipeline delivery demonstration, the project was successful in laying the groundwork for future commercial applications of the integrated system. This operation can still provide a guide for other coal mines which need options for utilization of their methane resources. The designed system can be used as a complete template, or individual components of the system can be segregated and utilized separately at other mines. The use of the CMM not only provides an energy fuel from an otherwise wasted resource, but it also yields an environmental benefit by reducing greenhouse gas emissions. The methane has twenty times the greenhouse effect as compared to carbon dioxide, which the combustion of the methane generates. The net greenhouse gas emission mitigation is substantial
Chlamydia
Chlamydia infection remains the leading sexually-transmitted bacterial infection worldwide, causing damaging sequelae such as tubal scarring, infertility and ectopic pregnancy. As infection is often asymptomatic, prevention via vaccination is the optimal strategy for disease control. Vaccination strategies aimed at preventing bacterial infection have shown some promise, although these strategies often fail to prevent damaging inflammatory pathology when Chlamydia is encountered. Using a murine model of Chlamydia muridarum genital infection, we employed two established independent models to compare immune responses underpinning pathologic development of genital Chlamydia infection. Model one uses antibiotic treatment during infection, with only early treatment preventing pathology. Model two uses a plasmid-cured variant strain of C. muridarum that does not cause pathologic outcomes like the plasmid-containing wild-type counterpart. Using these infection models, contrasted by the development of pathology, we identified an unexpected role for macrophages. We observed that mice showing signs of pathology had greater numbers of activated macrophages present in the oviducts. This may have been due to early differences in macrophage activation and proinflammatory signaling leading to persistent or enhanced infection. These results provide valuable insight into the cellular mechanisms driving pathology in Chlamydia infection and contribute to the design and development of more effective vaccine strategies for protection against the deleterious sequelae of Chlamydia infection of the female reproductive tract.</p
Chlamydia-infected macrophages are resistant to azithromycin treatment and are associated with chronic oviduct inflammation and hydrosalpinx development
Chlamydia infection remains the leading sexually-transmitted bacterial infection worldwide, causing damaging sequelae such as tubal scarring, infertility and ectopic pregnancy. As infection is often asymptomatic, prevention via vaccination is the optimal strategy for disease control. Vaccination strategies aimed at preventing bacterial infection have shown some promise, although these strategies often fail to prevent damaging inflammatory pathology when Chlamydia is encountered. Using a murine model of Chlamydia muridarum genital infection, we employed two established independent models to compare immune responses underpinning pathologic development of genital Chlamydia infection. Model one uses antibiotic treatment during infection, with only early treatment preventing pathology. Model two uses a plasmid-cured variant strain of C. muridarum that does not cause pathologic outcomes like the plasmid-containing wild-type counterpart. Using these infection models, contrasted by the development of pathology, we identified an unexpected role for macrophages. We observed that mice showing signs of pathology had greater numbers of activated macrophages present in the oviducts. This may have been due to early differences in macrophage activation and proinflammatory signaling leading to persistent or enhanced infection. These results provide valuable insight into the cellular mechanisms driving pathology in Chlamydia infection and contribute to the design and development of more effective vaccine strategies for protection against the deleterious sequelae of Chlamydia infection of the female reproductive tract.</p
Usability and Preliminary Effectiveness of a Preoperative mHealth App for People Undergoing Major Surgery: Pilot Randomized Controlled Trial
Background: Major surgery is associated with negative postoperative outcomes such as complications and delayed or poor
recovery. Multimodal prehabilitation can help to reduce the negative effects of major surgery. Offering prehabilitation by means
of mobile health (mHealth) could be an effective new approach.
Objective: The objectives of this pilot study were to (1) evaluate the usability of the Be Prepared mHealth app prototype for
people undergoing major surgery, (2) explore whether the app was capable of bringing about a change in risk behaviors, and (3)
estimate a preliminary effect of the app on functional recovery after major surgery.
Methods: A mixed-methods pilot randomized controlled trial was conducted in two Dutch academic hospitals. In total, 86
people undergoing major surgery participated. Participants in the intervention group received access to the Be Prepared app, a
smartphone app using behavior change techniques to address risk behavior prior to surgery. Both groups received care as usual.
Usability (System Usability Scale), change in risk behaviors 3 days prior to surgery, and functional recovery 30 days after discharge
from hospital (Patient-Reported Outcomes Measurement Information System physical functioning 8-item short form) were
assessed using online questionnaires. Quantitative data were analyzed using descriptive statistics, chi-square tests, and multivariable
linear regression. Semistructured interviews about the usability of the app were conducted with 12 participants in the intervention
group. Thematic analysis was used to analyze qualitative data.
Results: Seventy-nine people—40 in the intervention group and 39 in the control group—were available for further analysis.
Participants had a median age of 61 (interquartile range 51.0-68.0) years. The System Usability Scale showed that patients
considered the Be Prepared app to have acceptable usability (mean 68.2 [SD 18.4]). Interviews supported the usability of the app.
The major point of improvement identified was further personalization of the app. Compared with the control group, the intervention
group showed an increase in self-reported physical activity and muscle strengthening activities prior to surgery. Also, 2 of 2 frequent alcohol users in the intervention group versus 1 of 9 in the control group drank less alcohol in the run-up to surgery. No
difference was found in change of smoking cessation. Between-group analysis showed no meaningful differences in functional
recovery after correction for baseline values (β=–2.4 [95% CI –5.9 to 1.1]).
Conclusions: The Be Prepared app prototype shows potential in terms of usability and changing risk behavior prior to major
surgery. No preliminary effect of the app on functional recovery was found. Points of improvement have been identified with
which the app and future research can be optimized
Usability and Preliminary Effectiveness of a Preoperative mHealth App for People Undergoing Major Surgery: Pilot Randomized Controlled Trial
BACKGROUND: Major surgery is associated with negative postoperative outcomes such as complications and delayed or poor recovery. Multimodal prehabilitation can help to reduce the negative effects of major surgery. Offering prehabilitation by means of mobile health (mHealth) could be an effective new approach. OBJECTIVE: The objectives of this pilot study were to (1) evaluate the usability of the Be Prepared mHealth app prototype for people undergoing major surgery, (2) explore whether the app was capable of bringing about a change in risk behaviors, and (3) estimate a preliminary effect of the app on functional recovery after major surgery. METHODS: A mixed-methods pilot randomized controlled trial was conducted in two Dutch academic hospitals. In total, 86 people undergoing major surgery participated. Participants in the intervention group received access to the Be Prepared app, a smartphone app using behavior change techniques to address risk behavior prior to surgery. Both groups received care as usual. Usability (System Usability Scale), change in risk behaviors 3 days prior to surgery, and functional recovery 30 days after discharge from hospital (Patient-Reported Outcomes Measurement Information System physical functioning 8-item short form) were assessed using online questionnaires. Quantitative data were analyzed using descriptive statistics, chi-square tests, and multivariable linear regression. Semistructured interviews about the usability of the app were conducted with 12 participants in the intervention group. Thematic analysis was used to analyze qualitative data. RESULTS: Seventy-nine people-40 in the intervention group and 39 in the control group-were available for further analysis. Participants had a median age of 61 (interquartile range 51.0-68.0) years. The System Usability Scale showed that patients considered the Be Prepared app to have acceptable usability (mean 68.2 [SD 18.4]). Interviews supported the usability of the app. The major point of improvement identified was further personalization of the app. Compared with the control group, the intervention group showed an increase in self-reported physical activity and muscle strengthening activities prior to surgery. Also, 2 of 2 frequent alcohol users in the intervention group versus 1 of 9 in the control group drank less alcohol in the run-up to surgery. No difference was found in change of smoking cessation. Between-group analysis showed no meaningful differences in functional recovery after correction for baseline values (β=-2.4 [95% CI -5.9 to 1.1]). CONCLUSIONS: The Be Prepared app prototype shows potential in terms of usability and changing risk behavior prior to major surgery. No preliminary effect of the app on functional recovery was found. Points of improvement have been identified with which the app and future research can be optimized. TRIAL REGISTRATION: Netherlands Trial Registry NL8623; https://www.trialregister.nl/trial/8623
Population-level sexual mixing by HIV status and pre-exposure prophylaxis use among men who have sex with men in Montreal, Canada: implications for HIV prevention
There is are limited data on population-level mixing patterns by HIV status or pre- exposure prophylaxis (PrEP) use. Using cross-sectional survey data (Engage, 2017- 2018) of 1137 men who have sex with men (MSM) ≥16 year-old in Montreal, we compared observed seroconcordance in the past-six6-month sexual partnerships to what would have been observed by chance if zero individuals serosort. Of five 5 recent partnerships where both individuals were HIV-negative, we compared observed concordance in PrEP use to the counterfactual if zero individuals selected partners based on PrEP use. We estimated the concordance by chance using a balancing- partnerships approach assuming proportionate-mixing. HIV-positive respondents had a higher proportion of HIV-positive partners (66.4% (95% confidence interval: 64.0%- 68.6%)) than by chance (23.9%(23.1%-24.7%)). HIV-negative respondents (both on and not on PrEP) had higher proportions of HIV-negative partners (82.9%(81.1%- 84.7%), and 90.7%(89.6%-91.7%), respectively) compared with by chance (82.9%(81.1%-84.7%), and 90.7%(89.6%-91.7%), respectively, vs. 76.1%(75.3%- 76.9%)); but those on PrEP had a higher proportion of HIV-positive partners than those not on PrEP (17.1%(15.3%-18.9%) vs. 9.3%(8.3%-10.4%)). Those on PrEP also had a higher proportion of partners on PrEP among their HIV-negative partners (50.6%(42.5%-58.8%)) than by chance (28.5%(27.5%-29.4%)). The influence ofrelationship between PrEP on and sexual-mixing patterns demonstrated by less population-level serosorting among those on PrEP and PrEP-matching warrants consideration during PrEP roll-out.<br/