425 research outputs found
Tissue engineering of a human periodontal ligament fibroblast membrane - Alveolar osteoblast scaffold double construct
Ph.DDOCTOR OF PHILOSOPH
Ultra-stable long distance optical frequency distribution using the Internet fiber network
We report an optical link of 540 km for ultrastable frequency distribution
over the Internet fiber network. The stable frequency optical signal is
processed enabling uninterrupted propagation on both directions. The robustness
and the performance of the link are enhanced by a cost effective fully
automated optoelectronic station. This device is able to coherently regenerate
the return optical signal with a heterodyne optical phase locking of a low
noise laser diode. Moreover the incoming signal polarization variation are
tracked and processed in order to maintain beat note amplitudes within the
operation range. Stable fibered optical interferometer enables optical
detection of the link round trip phase signal. The phase-noise compensated link
shows a fractional frequency instability in 10 Hz bandwidth of 5x10-15 at one
second measurement time and 2x10-19 at 30 000 s. This work is a significant
step towards a sustainable wide area ultrastable optical frequency distribution
and comparison network
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Monitoring Waste to Minimize Waste at the University of Massachusetts Amherst
The University of Massachusetts Amherst is committed to sustainability, however, the campus could further reduce its costs and save energy by optimizing the current method of waste removal. The Intergovernmental Panel on Climate Change predicts that by the end of the century, Earth’s average temperature will rise by 11 degrees Fahrenheit unless society takes action to reduce greenhouse gas emissions. According to the EPA, about one-third of carbon emissions in the U.S. come from transportation. Campus garbage bins are collected by carbon-emitting trucks daily, and large truckable waste compactors are collected about three times per week. The amount of harmful carbon emissions released by trucking all of the compactors to their disposal sites totals 9,600 pounds of CO2 (the weight of 12 grand pianos) every week. In this analysis, the current waste removal system is investigated and a method is proposed to save UMass money and energy by reducing the number of waste collections. Initial research focused on how traditional bins could be replaced with solar-powered compactors from Bigbelly Solar Inc. to reduce pickup frequency and generate revenue from separating waste. Findings indicate that solar compactors alone would not have a worthwhile impact on the energy consumption of the UMass campus. Alternatively, a monitoring system that reduces how frequently waste compactors are hauled from campus would have greater impact, saving $1,000 every two weeks, reducing harmful carbon emissions, and using less diesel fuel. Due to the current environmental crisis, UMass should take action to reduce its carbon footprint through this economically favorable system
Submillimeter Sources behind the Massive Lensing Clusters A370 and A2390
We report 850 μm Submillimeter Array (SMA) observations of four gravitationally lensed submillimeter galaxies (SMGs), A370-2, A2390-1, A2390-3, and A2390-4, which were originally discovered with the Submillimeter Common-User Bolometer Array (SCUBA). Our SMA detection of A370-2 with a submillimeter flux of 7.95 ± 0.60 mJy unambiguously identifies the counterparts to this source at optical and radio wavelengths. A2390-1 is an ultraluminous infrared galaxy with a submillimeter flux of 5.55 ± 0.92 mJy and a redshift of 1.8 ± 0.2 computed from submillimeter/radio flux ratio analysis. We resolve A2390-3 into two components, A2390-3a and A2390-3b, with fluxes of 3.15 ± 0.63 mJy and 1.92 ± 0.60 mJy, respectively. The structure of the system could be consistent with morphological distortion by gravitational lensing. The lack of counterparts in the optical and infrared indicates a heavily dust-enshrouded nature, and a non-detection in the radio implies that these two sources probably lie at z > 4.7, which would make them among the most distant SMGs known to date. Our non-detection of A2390-4 suggests either that there are multiple fainter submillimeter sources within the SCUBA beam or that the SCUBA detection may have been false. Our precise positions allow us to determine accurate amplifications and fluxes for all of our detected sources. Our new results give a shallower power-law fit (–1.10) to the faint-end 850 μm cumulative number counts than previous work. We emphasize the need for high-resolution observations of single dish detected SMGs in order to measure accurately the faint end of the 850 μm counts
Evidence of oxidative stress in young and aged DJ-1-deficient mice
AbstractLoss of DJ-1 function contributes to pathogenesis in Parkinson’s disease. Here, we investigate the impact of aging and DJ-1 deficiency in transgenic mice. Ventral midbrain from young DJ-1-deficient mice revealed no change in 4-hydroxy-2-nonenal (4-HNE), but HSP60, HSP40 and striatal dopamine turnover were significantly elevated compared to wildtype. In aged mice, the chaperone response observed in wildtype animals was absent from DJ-1-deficient transgenics, and nigral 4-HNE immunoreactivity was enhanced. These changes were concomitant with increased striatal dopamine levels and uptake. Thus, increased oxidants and diminished protein quality control may contribute to nigral oxidative damage with aging in the model
Antipsychotic Prescribing Pathways, Polypharmacy, and Clozapine Use in Treatment of Schizophrenia
Objective
To ensure optimal care for patients with schizophrenia, antipsychotic medications must be appropriately prescribed and used. Therefore, the primary objectives of this study were to identify and describe pathways for antipsychotic prescribing, assess the consistency of observed pathways with treatment guidelines, and describe variability across facilities.
Methods
Data from Veterans Affairs administrative data sets from fiscal year (FY) 2003 to FY 2007 were gathered for analysis in this retrospective cohort study of antipsychotic prescribing pathways among 13 facilities across two regional networks. Patients with a new episode of care for schizophrenia or schizoaffective disorder in FY 2005 were identified, and antipsychotic prescribing history was obtained for two years before and after the index diagnosis. Demographic characteristics and distribution of comorbidities were assessed. Median medical center rates of polypharmacy were calculated and compared with Fisher’s exact test.
Results
Of 1,923 patients with a new episode of schizophrenia care, 1,003 (52%) had complete data on prescribing pathways. A majority (74%) of patients were prescribed antipsychotic monotherapy, and 19% received antipsychotic polypharmacy. Of patients receiving antipsychotic polypharmacy, 65% began polypharmacy within 90 days of starting any antipsychotic treatment. There was a fourfold difference in polypharmacy across facilities. Antipsychotic polypharmacy was not associated with geographic location or medical center patient volume. Clozapine utilization was low (0%–2%).
Conclusions
Retrospective examination of longitudinal prescribing patterns identified multiple antipsychotic prescribing pathways. Although most patients received guideline-concordant care, antipsychotic polypharmacy was commonly used as initial treatment, and there was substantial variability among facilities. Study findings suggest the utility of secondary data to assess treatment adaptation or switching for practical clinical trials
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