1,706 research outputs found
A benchmarking methodology for the centralized-database computer with expandable and parallel database processors and stores
In this paper a benchmarking methodology for a new kind of database computers is introduced. The emergence in the research community and in the commercial world of this kind of database computer (known as the multiple-backed database computers), were each computer system is configured with two or more identical processors and their associated stores for concurrent execution of transactions and for parallel processing of a centralized database spread over separate stores, is evident. The motivation and characterization of the multiple-backend database computer are first given. The need and lack of a methodology for benchmarking the new computer with a variable number of backends for the same database or with a fixed number of backends for different capacities are also evident. The measures (benchmarks) of the new computer are articulated and established and the design of the methodology for conducting the measurements is then given. Because of the novelty of the database computer architecture, the benchmarking methodology is rather elaborate and somewhat complicated. To aid our understanding of the methodology, a concrete sample is given herein. This sample also illustrates the use of the methodology. Meanwhile, a CAD system which computerizes the benchmarking methodology for systematically assisting the design of test databases and test-transaction mixes, for automatically tallying the design data and workloads, and for completely generating the test databases and test-transaction mixes is being implementedPrepared for: Chief of Naval Research
Arlington, VAhttp://archive.org/details/benchmarkingmeth00demu61153N; RRO14-0 8-01
N0001485WR24046NAApproved for public release; distribution is unlimited
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Transcriptional down-regulation of ccr5 in a subset of HIV+ controllers and their family members.
HIV +Elite and Viremic controllers (EC/VCs) are able to control virus infection, perhaps because of host genetic determinants. We identified 16% (21 of 131) EC/VCs with CD4 +T cells with resistance specific to R5-tropic HIV, reversed after introduction of ccr5. R5 resistance was not observed in macrophages and depended upon the method of T cell activation. CD4 +T cells of these EC/VCs had lower ccr2 and ccr5 RNA levels, reduced CCR2 and CCR5 cell-surface expression, and decreased levels of secreted chemokines. T cells had no changes in chemokine receptor mRNA half-life but instead had lower levels of active transcription of ccr2 and ccr5, despite having more accessible chromatin by ATAC-seq. Other nearby genes were also down-regulated, over a region of ~500 kb on chromosome 3p21. This same R5 resistance phenotype was observed in family members of an index VC, also associated with ccr2/ccr5 down-regulation, suggesting that the phenotype is heritable
Cybertools improve reaction time in open heart surgery
Objective: Head-up displays allow the surgeons to simultaneously view the patient and the patient's vital parameters (ECG, blood pressure, etc.) using vision-through over a wireless net, potentially enhancing the speed, accuracy and safety of surgical decisions. The aim was to assess surgical reaction time to AFIB, bigeminy, trigeminy, VTACH, and VFIB and concentration during a surgical intervention comparing standard and cyber tools monitoring. Methods: Using a patient simulator for beating heart surgery able to emulate heart signals and motion (arrhythmias) a group of surgeons performed coronary bypass procedures. Measurements of reaction time, efficiency of the surgeon, time elapsed to display a coronary angiography in a realistic surgical environment were taken. Results: The duration to accomplish the experiment is not different between groups (cyber vs. standard) reaction times, however, are significantly decreased for cyber by a mean of 33%. There is also a measured time difference for displaying a coronary angiography within the head-up display as compared to a remote console. Conclusions: During surgery, modern cyber tools allow for significant improvements of reaction time and concentration due to real time access to vital informatio
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Thromboembolic Risks of Recombinant Factor VIIa Use in Warfarin-Associated Intracranial Hemorrhage: A Case–Control Study
Background: Recombinant factor VIIa (rFVIIa) may be used for rapid hemostasis in life-threatening hemorrhage. In warfarin-associated intracerebral hemorrhage (wICH), FVIIa use is controversial and may carry significant thromboembolic risks. We compared incidence of baseline thromboembolic risk factors and thromboembolism rates in wICH patients treated with additional rFVIIa to those treated with standard therapy of fresh frozen plasma (FFP) and vitamin K alone. Methods: We identified 45 consecutive wICH patients treated with additional rFVIIa over 5-year period, and 34 consecutive wICH patients treated with standard therapy alone as comparison group. We compared the incidence of post-hemorrhage cardiac and extra-cardiac thromboembolic complications between two treatment groups, and used logistic regression to adjust for significant confounders such as baseline thromboembolic risk factors. We performed secondary analysis comparing the quantity of FFP transfused between two treatment cohorts. Results: Both rFVIIa-treated and standard therapy-treated wICH patients had a high prevalence of pre-existing thromboembolic diseases including atrial fibrillation (73% vs 68%), deep venous thrombosis (DVT) or pulmonary embolism (PE) (22% vs 18%), coronary artery disease (CAD) (38% vs 32%), and abnormal electrocardiogram (EKG) (78% vs 85%). Troponin elevation following wICH was prevalent in both groups (47% vs 41%). Clinically significant myocardial infarction (MI), defined as troponin > 1.0 ng/dL, occurred in 13% of rFVIIa-treated and 6% of standard therapy-treated patients (p=0.52). Past history of CAD (p=0.0061) and baseline abnormal EKG (p=0.02) were independently associated with clinically significant MI following wICH while rFVIIa use was not. The incidences of DVT/PE (2% vs 9%; p=0.18) and ischemic stroke (2% vs 0%; p=0.38) were similar between two treatment groups. Recombinant FVIIa-treated patients had lower mean INR at 3 (p=0.0001) and 6 hours (p<0.0001) and received fewer units of FFP transfusion (3 vs 5; p=0.003). Conclusions: Pre-existing thromboembolic risk factors as well as post-hemorrhage troponin elevation are prevalent in wICH patients. Clinically significant MI occurs in up to 13% of wICH patients. rFVIIa use was not associated with increased incidence of clinically significant MI or other venous or arterial thromboembolic events in this wICH cohort
Characteristics and outcome of patients with newly diagnosed advanced or metastatic lung cancer admitted to intensive care units (ICUs)
BACKGROUND: Although patients with advanced or metastatic lung cancer have poor prognosis, admission to the ICU for management of life-threatening complications has increased over the years. Patients with newly diagnosed lung cancer appear as good candidates for ICU admission, but more robust information to assist decisions is lacking. The aim of our study was to evaluate the prognosis of newly diagnosed unresectable lung cancer patients. METHODS: A retrospective multicentric study analyzed the outcome of patients admitted to the ICU with a newly diagnosed lung cancer (diagnosis within the month) between 2010 and 2013. RESULTS: Out of the 100 patients, 30 had small cell lung cancer (SCLC) and 70 had non-small cell lung cancer. (Thirty patients had already been treated with oncologic treatments.) Mechanical ventilation (MV) was performed for 81 patients. Seventeen patients received emergency chemotherapy during their ICU stay. ICU, hospital, 3- and 6-month mortality were, respectively, 47, 60, 67 and 71%. Hospital mortality was 60% when invasive MV was used alone, 71% when MV and vasopressors were needed and 83% when MV, vasopressors and hemodialysis were required. In multivariate analysis, hospital mortality was associated with metastatic disease (OR 4.22 [1.4-12.4]; p = 0.008), need for invasive MV (OR 4.20 [1.11-16.2]; p = 0.030), while chemotherapy in ICU was associated with survival (OR 0.23, [0.07-0.81]; p = 0.020). CONCLUSION: This study shows that ICU management can be appropriate for selected newly diagnosed patients with advanced lung cancer, and chemotherapy might improve outcome for patients with SCLC admitted for cancer-related complications. Nevertheless, tumors' characteristics, numbers and types of organ dysfunction should be taken into account in the decisional process before admitting these patients in ICU.Peer reviewe
Incidental Findings on Cone Beam Computed Tomography Images
Background. Cone beam computed tomography (CBCT) has gained widespread acceptance in dentistry for a variety of applications. Most dentists who are not radiologists/trained in radiology are generally not familiar with interpretation of anatomical structures and/or pathosis outside their area of primary interest, as often this was not within the scope of their training. Objectives. To assess that the number of incidental findings on a CBCT scan is high both within and outside of the primary area of interest, thereby emphasizing the importance of interpretation of all areas visualized on the scan. Materials and Methods. An oral and maxillofacial radiologist reviewed 1000 CBCT scans (382 males and 618 females) for findings both in- and outside the area of interest. Results. Of the 1000 subjects that were reviewed, 943 scans showed findings in the primary regions of interest and/or outside the regions of interest, and 76 different conditions were visualized in these scans both in and outside the areas of interest. Conclusion. From the wide scope of findings noted on these scans, it can be concluded that it is essential that a person trained in advanced interpretation techniques in radiology interprets cone beam computed tomography scans
Prevalence, predictors, and outcomes of poststroke falls in acute hospital setting
Abstract—Falls are a serious medical complication following stroke. The objectives of this study were to (1) confirm the prevalence of falls among patients with stroke during acute hospitalization, (2) identify factors associated with falls during the acute stay, and (3) examine whether in-hospital falls were associated with loss of function after stroke (new dependence at discharge). We completed a secondary analysis of data from a retrospective cohort study of patients with ischemic stroke who were hospitalized at one of four hospitals. We used logistic regression to identify factors associated with inpatient falls and examine the association between falls and loss of function. Among 1,269 patients with stroke, 65 (5%) fell during the acute hospitalization period. We found two characteristics independently associated with falls: greater stroke severity (National Institutes of Health Stroke Scale [NIHSS] 8, adjusted odds ratio [OR] = 3.63, 95% confidence interval [CI]: 1.46–9.00) and history of anxiety (adjusted OR = 4.90, 95% CI: 1.70–13.90). Falls were independently associated with a loss of function (adjusted OR = 9.85, 95% CI: 1.22–79.75) even after adjusting for age, stroke severity, gait abnormalities, and past stroke. Stroke severity (NIHSS 8) may be clinically useful during the acute inpatient setting in identifying those at greatest risk of falling. Given the association between falls and poor patient outcomes, rehabilitation interventions should be implemented to prevent falls poststroke
Enhanced CH absorption within Jupiter's southern auroral oval from Juno UVS observations
Reflected sunlight observations from the Ultraviolet Spectrograph (UVS) on
the Juno spacecraft were used to study the distribution of acetylene
(CH) at Jupiter's south pole. We find that the shape of the CH
absorption feature varies significantly across the polar region, and this can
be used to infer spatial variability in the CH abundance. There is a
localized region of enhanced CH absorption which coincides with the
location of Jupiter's southern polar aurora; the CH abundance poleward
of the auroral oval is a factor of 3 higher than adjacent quiescent,
non-auroral longitudes. This builds on previous infrared studies which found
enhanced CH abundances within the northern auroral oval. This suggests
that Jupiter's upper-atmosphere chemistry is being strongly influenced by the
influx of charged auroral particles and demonstrates the necessity of
developing ion-neutral photochemical models of Jupiter's polar regions.Comment: Accepted in JGR: Planet
Does Learning You Are Autistic at a Younger Age Lead to Better Adult Outcomes? A Participatory Exploration of the Perspectives of Autistic University Students
Many autistic people do not learn they are autistic until adulthood. Parents may wait to tell a child they are autistic until they feel the child is “ready.” In this study, a participatory team of autistic and non-autistic researchers examined if learning one is autistic at a younger age is associated with heightened well-being and Autism-Specific Quality of Life (ASQoL) among autistic university students. Autistic students (n = 78) completed an online survey. They shared when and how they learned they were autistic, how they felt about autism when first learning they are autistic and now, and when they would tell autistic children about their autism. Learning one is autistic earlier was associated with heightened Quality of Life and well-being in adulthood. However, learning one is autistic at an older age was associated with more positive emotions about autism when first learning one is autistic. Participants expressed both positive and negative emotions about autism and highlighted contextual factors to consider when telling a child about autism. Findings suggest that telling a child that they are autistic at a younger age empowers them by providing access to support and a foundation for self-understanding that helps them thrive in adulthood.Output Status: Forthcoming/Available Onlin
Possible Transient Luminous Events observed in Jupiter's upper atmosphere
11 transient bright flashes were detected in Jupiter's atmosphere using the
UVS instrument on the Juno spacecraft. These bright flashes are only observed
in a single spin of the spacecraft and their brightness decays exponentially
with time, with a duration of ~1.4 ms. The spectra are dominated by H2 Lyman
band emission and based on the level of atmospheric absorption, we estimate a
source altitude of 260 km above the 1-bar level. Based on these
characteristics, we suggest that these are observations of Transient Luminous
Events (TLEs) in Jupiter's upper atmosphere. In particular, we suggest that
these are elves, sprites or sprite halos, three types of TLEs that occur in the
Earth's upper atmosphere in response to tropospheric lightning strikes. This is
supported by visible light imaging, which shows cloud features typical of
lightning source regions at the locations of several of the bright flashes.
TLEs have previously only been observed on Earth, although theoretical and
experimental work has predicted that they should also be present on Jupiter.Comment: Accepted in JGR: Planets. 28 pages, 8 figure
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