2,690 research outputs found
Long-Term High-Temperature Stability of Functionalized Graphene Oxide Nanoplatelets in Arab-D and API Brine
Partially reduced graphene oxide (prGO) was covalently functionalized with a zwitterionic polymer polyzwitterionic polymer to afford a composite material with excellent dispersibility and long-term stability in high salinity brines including standard API and Arab-D found in deep oil reservoirs. When heated at 90 °C, the dispersions remained stable in excess of 140 days. These results suggest the utility of imidazolium-based polymers for brine stabilization as well as the use of diazonium containing polymers for a “grafting-to” approach to nanocarbon functionalization.Saudi Aramco (MIT Energy Initiative)Massachusetts Institute of Technology. Institute for Soldier NanotechnologiesCamille & Henry Dreyfus Foundation. Postdoctoral Program in Environmental Chemistry (Fellowship
San Antonio Mission Trails Statewide Transportation Enhancement Project Volume II Construction Packages 2 and 3: Archaeological Testing and Monitoring Construction of the Mission Trails Hike and Bike Trails, City of San Antonio, Bexar County, Texas
Beginning in October 1998, the Center for Archaeological Research (CAR) at the University of Texas at San Antonio (UTSA) provided archival research and archaeological services to the City of San Antonio and the Texas Department of Transportation (TxDOT) as part of the Mission Trails Statewide Transportation Enhancement Project. The project was intended to create a hike and bike trail system connecting the five Spanish missions in San Antonio. The trail should provide easier access to the missions for visitors, allow easier access to pleasant places to walk and cycle, and greatly improve the condition of some of the city streets.
This is the second and final volume issued by the CAR in the series of reports on the Mission Trails project. It describes the findings from archaeological work associated with Packages 2 and 3 of the five part Construction Package, including archival research, intensive survey, and monitoring of the portion of the Mission Trails project from Mitchell Street near Mission Concepción to Padre Drive at SE Military Drive. Both a “Direct” route, consisting of designated lanes along existing roads, and a “Scenic” route, consisting of new hike and bike trails near the San Antonio River, were included. In addition, new utility lines were placed under some streets, in particular Roosevelt Avenue, and Mission and Mitchell Roads. This report provides a historic background based on archival research for the project area and a detailed description of the intensive survey and monitoring done as part of these two Packages.
After preliminary examination of the archives and previous archaeological work (Cox 2000), areas where there was reason to believe that significant cultural resources would be impacted by the project were designated “Areas of Concern”. As part of archaeological investigations associated with Package 3, an intensive survey was undertaken in these areas, including shovel testing and backhoe trenching when appropriate, to assess the potential of an adverse impact to significant cultural resources.
Shovel testing was conducted at the following locations:
(1) Outside the south and west walls of Mission San José y San Miguel de Aguayo (41BX3), where 50 shovel tests were completed to inspect the proposed route of a new section of hike and bike trail;
(2) At the Pyron Homestead (41BX279), where 40 shovel tests were completed to examine the proposed route of an extension of Padre Road;
(3) At the Brown Site (41BX241), where eight shovel test were excavated to confirm that no remnant of the previously recorded site was extant;
(4) Along the southern edge of Padre Park, where 39 shovel tests were completed to investigate the proposed route of a new section of hike and bike trail.
In addition to the shovel testing, three backhoe trenches were dug along the route of a proposed utility line near Mission Road north of the San Antonio River. Undisturbed sediments were located in two trenches, at 140 cmbs and 360 cmbs respectively, but no evidence of cultural deposits was seen. Ten backhoe trenches also were dug along the north bank of the river south of Concepción Park, where they revealed only modern fill. CAR concluded that the project would result in no adverse impact to significant cultural resources in these areas.
Finally, in consultation with TxDOT-ENV and the Texas Historical Commission, and in accord with the original Scope of Work and project protocol, archaeological monitoring was conducted in selected parts of the project area. Specifically, monitoring of construction took place in the following locations:
(1) Along the footprint of the hike and bike trail on the grounds of Mission San José;
(2) On Mission Road where buried utility lines were being replaced;
(3) On Roosevelt Avenue where new utility lines were being installed and old utility lines were being replaced.
None of the sub-surface investigations located undisturbed cultural deposits. All artifacts collected from the shovel tests were in mixed context. Based on the results of these investigations, CAR recommended that continuation of the construction project would not result in adverse impacts to cultural resources in these areas. This recommendation was accepted by TxDOT-ENV and the Texas Historical Commission (TxDOT-ENV letter dated to THC dated 02-26-2007 with THC concurrence signature dated 03-01-2007).
All artifacts and project-associated records are permanently curated at the curation facility of the Center for Archaeological Research
The Washington University MultiMedia eXplorer
The Washington University MultiMedia eXplorer (MMX) is a complete, host-independent multimedia system capable of transmitting and receiving JPEG-compressed video, CD-quality audio, and high-resolution radiographic images over the Washington University broadband ATM network. If the host is equipped with an ATM interface card, normal network traffic is supported via T and Y connections. The MMX consists of an ATMizer and three multimedia subsystems. The ATMizer implements the host interface, the interface to the ATM network, and the interface to the three multimdeia channels. This paper describes the architecture of the MMX, the software used with the system, and the applications which have been developed to demonstrate the capability of broadband ATM networks for multimedia applications
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Proteomic systems evaluation of the molecular validity of preclinical psychosis models compared to schizophrenia brain pathology.
Pharmacological and genetic rodent models of schizophrenia play an important role in the drug discovery pipeline, but quantifying the molecular similarity of such models with the underlying human pathophysiology has proved difficult. We developed a novel systems biology methodology for the direct comparison of anterior prefrontal cortex tissue from four established glutamatergic rodent models and schizophrenia patients, enabling the evaluation of which model displays the greatest similarity to schizophrenia across different pathophysiological characteristics of the disease. Liquid chromatography coupled tandem mass spectrometry (LC-MSE) proteomic profiling was applied comparing healthy and "disease state" in human post-mortem samples and rodent brain tissue samples derived from models based on acute and chronic phencyclidine (PCP) treatment, ketamine treatment or NMDA receptor knockdown. Protein-protein interaction networks were constructed from significant abundance changes and enrichment analyses enabled the identification of five functional domains of the disease such as "development and differentiation", which were represented across all four rodent models and were thus subsequently used for cross-species comparison. Kernel-based machine learning techniques quantified that the chronic PCP model represented schizophrenia brain changes most closely for four of these functional domains. This is the first study aiming to quantify which rodent model recapitulates the neuropathological features of schizophrenia most closely, providing an indication of face validity as well as potential guidance in the refinement of construct and predictive validity. The methodology and findings presented here support recent efforts to overcome translational hurdles of preclinical psychiatric research by associating functional dimensions of behaviour with distinct biological processes.This research was supported by the Stanley Medical Research Institute (SMRI) (R6123) and the NEWMEDS Innovative Medicines Initiative (FP7/2007-2013).This is the author accepted manuscript. The final version is available from Elsevier via https://doi.org/10.1016/j.schres.2016.06.01
Cognitive ability does not predict objectively measured sedentary behaviour: evidence from three older cohorts
Higher cognitive ability is associated with being more physically active. Much less is known about the associations between cognitive ability and sedentary behavior. Ours is the first study to examine whether historic and contemporaneous cognitive ability predicts objectively measured sedentary behavior in older age. Participants were drawn from 3 cohorts (Lothian Birth Cohort, 1936 [LBC1936] [n = 271]; and 2 West of Scotland Twenty-07 cohorts: 1950s [n = 310] and 1930s [n = 119]). Regression models were used to assess the associations between a range of cognitive tests measured at different points in the life course, with sedentary behavior in older age recorded over 7 days. Prior simple reaction time (RT) was significantly related to later sedentary time in the youngest, Twenty-07 1950s cohort (p = .04). The relationship was nonsignificant after controlling for long-standing illness or employment status, or after correcting for multiple comparisons in the initial model. None of the cognitive measures were related to sedentary behavior in either of the 2 older cohorts (LBC1936, Twenty-07 1930s). There was no association between any of the cognitive tests and the number of sit-to-stand transitions in any of the 3 cohorts. The meta-analytic estimates for the measures of simple and choice RT that were identical in all cohorts (n = 700) were also not significant. In conclusion, we found no evidence that objectively measured sedentary time in older adults is associated with measures of cognitive ability at different time points in life, including cognitive change from childhood to older age
Vitamin D Receptor Activation Mitigates the Impact of Uremia on Endothelial Function in the 5/6 Nephrectomized Rats
Endothelial
dysfunction increases cardiovascular disease
risk in chronic kidney disease (CKD). This study
investigates whether VDR activation affects
endothelial function in CKD. The 5/6
nephrectomized (NX) rats with experimental
chronic renal insufficiency were treated with or
without paricalcitol, a VDR activator. Thoracic
aortic rings were precontracted with
phenylephrine and then treated with
acetylcholine or sodium nitroprusside. Uremia
significantly affected aortic relaxation
(−50.0 ± 7.4% in NX rats versus −96.2 ± 5.3% in SHAM at 30 μM acetylcholine). The endothelial-dependent relaxation was improved to –58.2 ± 6.0%, –77.5 ± 7.3%, and –90.5 ± 4.0% in NX rats treated with paricalcitol at 0.021, 0.042, and 0.083 μg/kg for two weeks, respectively, while paricalcitol at 0.042 μg/kg did not affect blood pressure and heart rate. Parathyroid hormone (PTH) suppression alone did not improve endothelial function since cinacalcet suppressed PTH without affecting endothelial-dependent vasorelaxation. N-omega-nitro-L-arginine methyl ester completely abolished the effect of paricalcitol on improving endothelial function. These results demonstrate that VDR activation improves endothelial function in CKD
Crossing the Communication Chasm: Challenges and Opportunities in Transitions of Care from the Hospital to the Primary Care Clinic
Background
Transitions of care from specialty and acute settings to primary care abound. Compared to the continuity in end-of-shift handoffs, care transitions involve provider communication between practices and facilities with their own cultures and bureaucracies. Using the transition from acute care to outpatient primary care for stroke/transient ischemic attack (TIA) patients as a case study, this qualitative research explored communication practices and institutional arrangements among clinical providers responsible for longitudinal management of hypertension. In this study, researchers investigated the barriers and facilitators of effective communication between acute stroke/TIA inpatient and primary care providers at a Veterans Affairs Medical Center.
Methods
A multidisciplinary team conducted consensus-based coding and thematic analysis of semistructured interviews with 21 clinical providers (9 with primary responsibilities for inpatient care and 12 with primary responsibilities in outpatient, primary care).
Results
Thematic analysis of responses identified three factors that influenced communication between clinical providers: (1) consistent, concise but complete medication and treatment plans; (2) reliable, standardized discharge documentation; (3) use of multiple modes of communication. Participants identified cultural barriers, including challenges with rotating providers at a teaching hospital and local discharge practices.
Conclusion
Ambiguity about who is being handed off to and time pressures in the acute setting may lead inpatient providers to give lower priority to discharge communication, leaving outpatient providers with low-quality information. While electronic templates have standardized key components of discharge documentation, improvement opportunities remain. Increased awareness of the challenges and opportunities on each side of the care transfer could foster communication practices that systematically account for the information needs of inpatient and outpatient providers
Genetic continuity across a deeply divergent linguistic contact zone in North Maluku, Indonesia
<p>Abstract</p> <p>Background</p> <p>The islands of North Maluku, Indonesia occupy a central position in the major prehistoric dispersal streams that shaped the peoples of Island Southeast Asia and the Pacific. Within this region a linguistic contact zone exists where speakers of Papuan and Austronesian languages reside in close proximity. Here we use population genetic data to assess the extent to which North Maluku populations experienced admixture of Asian genetic material, and whether linguistic boundaries reflect genetic differentiation today.</p> <p>Results</p> <p>Autosomal and X-linked markers reveal overall Asian admixture of 67% in North Maluku, demonstrating a substantial contribution of genetic material into the region from Asia. We observe no evidence of population structure associated with ethnicity or language affiliation.</p> <p>Conclusions</p> <p>Our data support a model of widespread Asian admixture in North Maluku, likely mediated by the expansion of Austronesian-speaking peoples into the region during the mid Holocene. In North Maluku there is no genetic differentiation in terms of Austronesian- versus Papuan-speakers, suggesting extensive gene flow across linguistic boundaries. In a regional context, our results illuminate a major genetic divide at the Molucca Sea, between the islands of Sulawesi and North Maluku. West of this divide, populations exhibit predominantly Asian ancestry, with very little contribution of Papuan genetic material. East of the Molucca Sea, populations show diminished rates of Asian admixture and substantial persistence of Papuan genetic diversity.</p
M. tuberculosis Ser/Thr Protein Kinase D Phosphorylates an Anti-Anti–Sigma Factor Homolog
Receptor Ser/Thr protein kinases are candidates for sensors that govern developmental changes and disease processes of Mycobacterium tuberculosis (Mtb), but the functions of these kinases are not established. Here, we show that Mtb protein kinase (Pkn) D overexpression alters transcription of numerous bacterial genes, including Rv0516c, a putative anti-anti–sigma factor, and genes regulated by sigma factor F. The PknD kinase domain directly phosphorylated Rv0516c, but no other sigma factor regulator, in vitro. In contrast, the purified PknB and PknE kinase domains phosphorylated distinct sigma regulators. Rather than modifying a consensus site, PknD phosphorylated Rv0516c in vitro and in vivo on Thr2 in a unique N-terminal extension. This phosphorylation inhibited Rv0516c binding in vitro to a homologous anti-anti–sigma factor, Rv2638. These results support a model in which signals transmitted through PknD alter the transcriptional program of Mtb by stimulating phosphorylation of a sigma factor regulator at an unprecedented control site
Production Quality Video Over Broadband Networks: A Description of the System and Two Interactive Applications
The Washington University MultiMedia eXplorer (MMX) is a complete, host-independent multimedia system capable of transmitting and receiving JPEG-compressed video, CD-quality audio, and high-resolution radiographic images over the Washington University broadband ATM network. If the host is equipped with an ATM interface card, normal network traffic can be supported via an ATM extension port on the MMX. The major components of the MMX are an ATMizer and three multimedia channels. The ATMizer implements the host interface, the interface to the ATM network, and hte interface to the three multimdeia channels. This paper describes the architecture of the MMX, the software used with the system, and two applications which have been developed to demonstrate the capability of broadband ATM networks for multimedia applications
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