273 research outputs found
The Search for an Economics Job with a Teaching Focus
This article provides suggestions for new Ph.D. economists relating to the search for an academic job. It provides general information regarding finding job postings, the timing of events, and preparing application materials. It differs from the existing guides by including additional considerations for the teaching-focused, rather than research-oriented segment of the market and by emphasizing what a candidate should do rather than what will happen in the search process. Specifically, it outlines helpful suggestions on effectively answering interview questions, delivering a class lecture on campus, meeting with students, and negotiating a better offer at teaching-focused schools which are absent from other guides.
Spectral broadening Effects on Pulsed-source Digital Holography
Using a pulsed configuration, a digital-holographic system is setup in the off-axis image plane recording geometry, and spectral broadening via pseudo-random bit sequence is used to degrade the temporal coherence of the master-oscillator laser. The associated effects on the signal-to-noise ratio are then measured in terms of the ambiguity and coherence efficiencies. It is found that the ambiguity efficiency, which is a function of signal-reference pulse overlap, is not affected by the effects of spectral broadening. The coherence efficiency, on the other hand, is affected. As a result, the coherence efficiency, which is a function of effective fringe visibility, is shown to be a valid performance metric for pulsed-source digital holography
High Performance Direct Gravitational N-body Simulations on Graphics Processing Units -- II: An implementation in CUDA
We present the results of gravitational direct -body simulations using the
Graphics Processing Unit (GPU) on a commercial NVIDIA GeForce 8800GTX designed
for gaming computers. The force evaluation of the -body problem is
implemented in ``Compute Unified Device Architecture'' (CUDA) using the GPU to
speed-up the calculations. We tested the implementation on three different
-body codes: two direct -body integration codes, using the 4th order
predictor-corrector Hermite integrator with block time-steps, and one
Barnes-Hut treecode, which uses a 2nd order leapfrog integration scheme. The
integration of the equations of motions for all codes is performed on the host
CPU.
We find that for particles the GPU outperforms the GRAPE-6Af, if
some softening in the force calculation is accepted. Without softening and for
very small integration time steps the GRAPE still outperforms the GPU. We
conclude that modern GPUs offer an attractive alternative to GRAPE-6Af special
purpose hardware. Using the same time-step criterion, the total energy of the
-body system was conserved better than to one in on the GPU, only
about an order of magnitude worse than obtained with GRAPE-6Af. For N \apgt
10^5 the 8800GTX outperforms the host CPU by a factor of about 100 and runs at
about the same speed as the GRAPE-6Af.Comment: Accepted for publication in New Astronom
Concert recording 2017-11-15
[Track 1]. Fanfare for barcs / Kerry Turner -- [Track 2]. Three for five / James Naigus -- [Track 3]. Big sky country / Daniel Baldwin
Georgia\u27s Critical Access Hospitals: Financial Performance and Process Improvement
Background: Georgia’s Critical Access Hospitals (CAH) are in crisis. Within the last 2 years, four CAHs have closed their doors due to failed financial and operational performance. Evidence points to the risk that several more are on the brink of closure. CAH closures have far-reaching impact on residents. Negative impacts include the extra distance that patients must travel to seek care, the displacement of health professionals and the unravelling of the entire fabric of the communities these hospitals serve. We hope to help participants understand the financial and operational challenges of CAHs, and to identify realistic strategies to enhance the resilience of these hospitals.
Methods: The Georgia Southern team worked with a cohort of CAHs across the state of Georgia to identify financial and operational best practices. Year 1 of this project focused on data collection, analysis and benchmarking. Year 2 is currently focused on performance improvement through Lean Six Sigma.
Results: CAHs face financial constraints due to factors such as low volume, declining market share, unfavorable payer mix, challenges relating to collections, and difficulties in recruiting providers. CAHs in Georgia performed more poorly on the financial indicators assessed, in comparison to respective national medians. Many CAHs in our cohort are better organized to deal with crises – utilizing strong executive and bureaucratic structures – than to pursue ongoing improvement through employee empowerment and a process focus.
Conclusions: Improvements in the operational and financial management practices of Georgia’s CAHs may significantly improve performance. Evidence-based strategies for operational and financial improvement are vital to sustainability. Opportunities exist for collaboration between public health systems and rural hospitals, including CAHs in assuring healthcare access for rural populations
Operational and Financial Performance of Georgia\u27s Critical Access Hospitals
Background: Georgia’s Critical Access Hospitals (CAHs) face increasingly complex threats to financial sustainability, as demonstrated by the disproportionally high number of closures in comparison to other states in the nation.
Methods: Financial performance measures (including profitability, revenue, liquidity, debt, utilization, and productivity), site visits, key personnel interviews, and a revenue cycle management assessment were used to assess the strategic landscape of CAHs in Georgia, analyze financial and operational performance, and provide recommendations.
Results: For CAHs in Georgia, financial and operating performance indicators, interviews, and assessments depict a challenging operating environment, but opportunities for improvement exist through implementation of a Lean Six Sigma program and improved benchmarking processes.
Conclusions: Georgia’s CAHs operate in a challenging environment, but operational improvement strategies (such as a Lean Six Sigma program) and benchmarking directed towards business processes, including revenue cycle management, provide opportunities for sustainability in the future.
Key words: Critical Access Hospital, financial performance, Process Improvement, LEAN Six Sigma, rural hospita
Recurrence of chronic venous ulcers on the basis of clinical, etiologic, anatomic, and pathophysiologic criteria and air plethysmography
AbstractIntroduction: Leg ulcers associated with chronic venous insufficiency (CVI) frequently recur after healing. The risk of recurrence has not been well defined for patients in different anatomic and hemodynamic groups. We reviewed the risk of ulcer recurrence on the basis of clinical, etiologic, anatomic, and pathophysiologic criteria and hemodynamic characteristics of the affected limb as assessed with air plethysmography (APG). Methods: Ninety-nine limbs with class 6 CVI were assessed clinically and with standing duplex ultrasound scanning and APG for the definition of clinical, etiologic, anatomic, and pathophysiologic criteria. Leg ulcers were treated with high-pressure compression protocols. Surgical correction of venous abnormalities was offered to patients with appropriate conditions. After ulcer healing, the limbs were placed in compressive garments and followed at 6-month intervals for ulcer recurrence. Results: The mean patient age was 54.3 years, and 46% of the patients were female. Corrective venous surgery was performed in 37 limbs. The mean follow-up time for all 99 limbs was 28 months. The ulcer recurrence rate with life table was 37% ± 6% at 3 years and 48% ± 10% at 5 years. The patients who underwent venous surgery had a significantly lower recurrence rate (27% ± 9% at 48 months) than did those patients who had not undergone surgery (67% ± 8% at 48 months; P =.005). The patients with deep venous insufficiency (DVI; n=51) had significantly higher recurrence rates (66% ± 8% at 48 months) than did the patients without DVI (n = 48; 29% ± 9% at 48 months; P =.006). This difference was significant even after accounting for the effects of surgery (P =.03).The hazard ratio of ulcer recurrence increases by 14% for every unit increase in the venous filling index (VFI; P =.001). This remains significant even after accounting for the effects of surgery (P =.001). The combination of DVI and a VFI of more than 4 mL/s yields a risk of ulcer recurrence of 43% ± 9% at 1 year and 60% ± 10% at 2 years. Conclusion: Leg ulcers associated with CVI have a high rate of recurrence. Ulcer recurrence is significantly increased in patients with DVI and in patients who do not have venous abnormalities corrected surgically. The VFI obtained from APG is useful in the prediction of increased risk for recurrence, particularly in association with anatomic data. (J Vasc Surg 2002;35:723-8.
Prespecified Risk Criteria Facilitate Adequate Discharge and Long‐Term Outcomes After Transfemoral Transcatheter Aortic Valve Implantation
Background
Despite the availability of guidelines for the performance of transcatheter aortic valve implantation (TAVI), current treatment pathways vary between countries and institutions, which impact on the mean duration of postprocedure hospitalization.
Methods and Results
This was a prospective, multicenter registry of 502 patients to validate the appropriateness of discharge timing after transfemoral TAVI, using prespecified risk criteria from FAST‐TAVI (Feasibility and Safety of Early Discharge After Transfemoral [TF] Transcatheter Aortic Valve Implantation), based on hospital events within 1‐year after discharge. The end point—a composite of all‐cause mortality, vascular access–related complications, permanent pacemaker implantation, stroke, cardiac rehospitalization, kidney failure, and major bleeding—was reached in 27.0% of patients (95% CI, 23.3–31.2) within 1 year after intervention; 7.5% (95% CI, 5.5–10.2) had in‐hospital complications before discharge and 19.6% (95% CI, 16.3–23.4) within 1 year after discharge. Overall mortality within 1 year after discharge was 7.3% and rates of cardiac rehospitalization 13.5%, permanent pacemaker implantation 4.2%, any stroke 1.8%, vascular‐access–related complications 0.7%, life‐threatening bleeding 0.7%, and kidney failure 0.4%. Composite events within 1 year after discharge were observed in 18.8% and 24.3% of patients with low risk of complications/early (≤3 days) discharge and high risk and discharged late (>3 days) (concordant discharge), respectively. Event rate in patients with discordant discharge was 14.3% with low risk but discharged late and increased to 50.0% in patients with high risk but discharged in ≤3 days.
Conclusions
The FAST‐TAVI risk assessment provides a tool for appropriate, risk‐based discharge that was validated with the 1‐year event rate after transfemoral TAVI.
Registration
URL:
https://www.ClinicalTrials.gov
; Unique identifier: NCT02404467
Identification and characterization of a novel non-structural protein of bluetongue virus
Bluetongue virus (BTV) is the causative agent of a major disease of livestock (bluetongue). For over two decades, it has been widely accepted that the 10 segments of the dsRNA genome of BTV encode for 7 structural and 3 non-structural proteins. The non-structural proteins (NS1, NS2, NS3/NS3a) play different key roles during the viral replication cycle. In this study we show that BTV expresses a fourth non-structural protein (that we designated NS4) encoded by an open reading frame in segment 9 overlapping the open reading frame encoding VP6. NS4 is 77–79 amino acid residues in length and highly conserved among several BTV serotypes/strains. NS4 was expressed early post-infection and localized in the nucleoli of BTV infected cells. By reverse genetics, we showed that NS4 is dispensable for BTV replication in vitro, both in mammalian and insect cells, and does not affect viral virulence in murine models of bluetongue infection. Interestingly, NS4 conferred a replication advantage to BTV-8, but not to BTV-1, in cells in an interferon (IFN)-induced antiviral state. However, the BTV-1 NS4 conferred a replication advantage both to a BTV-8 reassortant containing the entire segment 9 of BTV-1 and to a BTV-8 mutant with the NS4 identical to the homologous BTV-1 protein. Collectively, this study suggests that NS4 plays an important role in virus-host interaction and is one of the mechanisms played, at least by BTV-8, to counteract the antiviral response of the host. In addition, the distinct nucleolar localization of NS4, being expressed by a virus that replicates exclusively in the cytoplasm, offers new avenues to investigate the multiple roles played by the nucleolus in the biology of the cell
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Heme oxygenase-1 regulates cell proliferation via carbon monoxide-mediated inhibition of T-type Ca2+ channels
Induction of the antioxidant enzyme heme oxygenase-1 (HO-1) affords cellular protection and suppresses proliferation of vascular smooth muscle cells (VSMCs) associated with a variety of pathological cardiovascular conditions including myocardial infarction and vascular injury. However, the underlying mechanisms are not fully understood. Over-expression of Cav3.2 T-type Ca2+ channels in HEK293 cells raised basal [Ca2+]i and increased proliferation as compared with non-transfected cells. Proliferation and [Ca2+]i levels were reduced to levels seen in non-transfected cells either by induction of HO-1 or exposure of cells to the HO-1 product, carbon monoxide (CO) (applied as the CO releasing molecule, CORM-3). In the aortic VSMC line A7r5, proliferation was also inhibited by induction of HO-1 or by exposure of cells to CO, and patch-clamp recordings indicated that CO inhibited T-type (as well as L-type) Ca2+ currents in these cells. Finally, in human saphenous vein smooth muscle cells, proliferation was reduced by T-type channel inhibition or by HO-1 induction or CO exposure. The effects of T-type channel blockade and HO-1 induction were non-additive. Collectively, these data indicate that HO-1 regulates proliferation via CO-mediated inhibition of T-type Ca2+ channels. This signalling pathway provides a novel means by which proliferation of VSMCs (and other cells) may be regulated therapeutically
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