2,151 research outputs found

    A Navier-Stokes Solution of Hull-Ring Wing-Thruster Interaction

    Get PDF
    Navier-Stokes simulations of high Reynolds number flow around an axisymmetric body supported in a water tunnel were made. The numerical method is based on a finite-differencing high resolution second-order accurate implicit upwind scheme. Four different configurations were investigated, these are: (1) barebody; (2) body with an operating propeller; (3) body with a ring wing; and (4) body with a ring wing and an operating propeller. Pressure and velocity components near the stern region were obtained computationally and are shown to compare favorably with the experimental data. The method correctly predicts the existence and extent of stern flow separation for the barebody and the absence of flow separation for the three other configurations with ring wing and/or propeller

    The Hymenoptera Genome Database

    Get PDF
    The Hymenoptera Genome Database (HGD) is an informatics resource supporting genomics of hymenopteran insect species. This relational database implements open-source software and components providing access to curated data contributed by an extensive, active research community. HGD includes the genome sequences and annotation data of honey bee _Apis mellifera_ and its pathogens ("http://BeeBase.org":BeeBase.org) the parasitoid wasp _Nasonia vitripennis_ ("http://NasoniaBase.org":NasoniaBase.org) and a portal to the genomes of six species of ants. Together, these species cover approximately 200 MY in the phylogeny of Hymenoptera, allowing to leverage genetic, genome sequence, and gene expression data, as well as the biological knowledge of related model organisms. The availability of resources across an order greatly facilitates comparative genomics and enhances our understanding of the biology of agriculturally important Hymenoptera species through genomics. HGD has supported research contributions from an extensive community from almost 80 institutions in 14 countries. Community annotation efforts are made possible thanks to a remote connection to a Chado database by Apollo Genome Annotation client software. Curated data at HGD includes predicted and annotated gene sets supported with evidence tracks such as ESTs/cDNAs, small RNA sequences and GC composition domains. Data at HGD can be queried using genome browsers and / or BLAST/PSI-BLAST servers, and it may also be downloaded to perform local searches. We encourage the public to access and contribute data to HGD at "http://HymenopteraGenome.org":HymenopteraGenome.org.

This poster contains material included in an article accepted for publication in Nucl. Acids Res.©: 2011. The Database Issue. Published by Oxford University Press

    Accuracy of automated urine dipstick test as a screening tool for proteinuria in hypertensive disorders of pregnancy

    Get PDF
    Background: Progressive proteinuria implies worsening of the condition in hypertensive disorders of pregnancy and hence its quantification guides clinician in making decision and planning treatment. The gold standard is 24 hour urine protein estimation. Urine sediment cytology, also known as ‘liquid renal biopsy’ identifies and analyses the extent of renal damage.Methods: Objectives of the study were to compare the efficacy of urine dipstick test to 24 hour urine protein estimation in detecting proteinuria in pre-eclampsic patients and to describe the findings in urine sediment examination in assessing proteinuria in above patients. Urine dipstick test and sediment cytology were performed on the urinary samples of 242 pregnant women with high BP recordings (BP>140/90 mm Hg) which were collected and tested in Department of Pathology, Government Medical College, Kottayam during the study period of 18 months. This was compared with 24 hour urine protein values (gold standard).Results: About 154 patients (63.63%) had significant proteinuria of more than 300mg/24hr. Dipstick method showed 78.57% sensitivity and 81.82% specificity for prediction of significant proteinuria. Positive predictive value and negative predictive value of urine dipstick test were 88.32% and 68.57% respectively. Urine sediment examination revealed the presence of casts only in 11.98% of study population. Conclusions: Diagnostic accuracy of automated urine dipstick test in assessing proteinuria was 79.75%. For grade 1 proteinuria, diagnostic accuracy was 79.81%, for Grade 2 it increased to 93.14% and for grade 3 & 4, accuracy was 98.68%. Urine sediment examination didn’t correlate with proteinuria and hence the extent of renal damage in pre-eclampsia

    Conditions for the Quantum to Classical Transition: Trajectories vs. Phase Space Distributions

    Full text link
    We contrast two sets of conditions that govern the transition in which classical dynamics emerges from the evolution of a quantum system. The first was derived by considering the trajectories seen by an observer (dubbed the ``strong'' transition) [Bhattacharya, et al., Phys. Rev. Lett. 85: 4852 (2000)], and the second by considering phase-space densities (the ``weak'' transition) [Greenbaum, et al., Chaos 15, 033302 (2005)]. On the face of it these conditions appear rather different. We show, however, that in the semiclassical regime, in which the action of the system is large compared to \hbar, and the measurement noise is small, they both offer an essentially equivalent local picture. Within this regime, the weak conditions dominate while in the opposite regime where the action is not much larger than Planck's constant, the strong conditions dominate.Comment: 8 pages, 2 eps figure

    Random walks and random fixed-point free involutions

    Full text link
    A bijection is given between fixed point free involutions of {1,2,...,2N}\{1,2,...,2N\} with maximum decreasing subsequence size 2p2p and two classes of vicious (non-intersecting) random walker configurations confined to the half line lattice points l1l \ge 1. In one class of walker configurations the maximum displacement of the right most walker is pp. Because the scaled distribution of the maximum decreasing subsequence size is known to be in the soft edge GOE (random real symmetric matrices) universality class, the same holds true for the scaled distribution of the maximum displacement of the right most walker.Comment: 10 page

    Urologic surgery and COVID-19: How the pandemic is changing the way we operate

    Get PDF
    The coronavirus disease 2019 (COVID-19) pandemic has had a global impact on all aspects of healthcare, including surgical procedures. For urologists, it has affected and will continue to influence how we approach the care of patients pre-operatively, intra-operatively, and post-operatively. A risk-benefit assessment of each patient undergoing surgery should be performed during the COVID-19 pandemic based on the urgency of the surgery and the risk of viral illness and transmission. Patients with advanced age and comorbidities have a higher incidence of mortality. Routine preoperative testing and symptom screening is recommended to identify those with COVID-19. Adequate personal protective equipment (PPE) for the surgical team is essential to protect healthcare workers and ensure an adequate workforce. For COVID-19 positive or suspected patients, the use of N95 respirators is recommended if available. The anesthesia method chosen should attempt to minimize aerosolization of the virus. Negative pressure rooms are strongly preferred for intubation/extubation and other aerosolizing procedures. Although transmission has not yet been shown during laparoscopic and robotic procedures, efforts should be made to minimize the risk of aerosolization. Ultra low particulate air filters are recommended for use during minimally invasive procedures to decrease the risk of viral transmission. Thorough cleaning and sterilization should be performed post-operatively with adequate time allowed for the operating room air to be cycled after procedures. COVID-19 patients should be separated from non-infected patients at all levels of care including recovery to decrease the risk of infection. Future directions will be guided by outcomes and infection rates as social distancing guidelines are relaxed and more surgical procedures are reintroduced. Recommendations should be adapted to the local environment and will continue to evolve as more data becomes available, the shortage of testing and PPE is resolved, and a vaccine and therapeutics for COVID-19 are developed

    Comparison of Robot-Assisted Nephrectomy with Laparoscopic and Hand-Assisted Laparoscopic Nephrectomy

    Get PDF
    Early experience with robotic assistance for radical and simple nephrectomy offers no significant advantage over traditional laparoscopic or hand-assisted approaches

    Advanced photovoltaic power systems using tandem GaAs/GaSb concentrator modules

    Get PDF
    In 1989, Boeing announced the fabrication of a tandem gallium concentrator solar cell with an energy conversion efficiency of 30 percent. This research breakthrough has now led to panels which are significantly smaller, lighter, more radiation resistant, and potentially less expensive than the traditional silicon flat plate electric power supply. The new Boeing tandem concentrator (BTC) module uses an array of lightweight silicone Fresnel lenses mounted on the front side of a light weight aluminum honeycomb structure to focus sunlight onto small area solar cells mounted on a thin back plane. This module design is shown schematically. The tandem solar cell in this new module consists of a gallium arsenide light sensitive cell with a 24 percent energy conversion efficiency stacked on top of a gallium antimonide infrared sensitive cell with a conversion efficiency of 6 percent. This gives a total efficiency 30 percent for the cell-stack. The lens optical efficiency is typically 85 percent. Discounting for efficiency losses associated with lens packing, cell wiring, and cell operating temperature still allows for a module efficiency of 22 percent which leads to a module power density of 300 Watts/sq. m. This performance provides more than twice the power density available from a single crystal silicon flat plate module and at least four times the power density available from amorphous silicon modules. The fact that the lenses are only 0.010 ft. thick and the aluminum foil back plane is only 0.003 ft. thick leads to a very lightweight module. Although the cells are an easy to handle thickness of 0.020 ft., the fact that they are small, occupying one-twenty-fifth of the module area, means that they add little to the module weight. After summing all the module weights and given the high module power, we find that we are able to fabricate BTC modules with specific power of 100 watts/kg

    Native Nephrectomy with Renal Transplantation Decreases Hypertension Medication Requirements in Autosomal Dominant Polycystic Kidney Disease

    Get PDF
    Purpose We assessed hypertensive control after native nephrectomy and renal transplantation in patients with autosomal dominant polycystic kidney disease. Materials and Methods Blood pressure control was studied retrospectively in 118 patients with autosomal dominant polycystic kidney disease who underwent renal transplantation between 2003 and 2013. Overall 54 patients underwent transplantation alone (group 1) and 64 underwent transplantation with concurrent ipsilateral nephrectomy (group 2). Of these 64 patients 32 underwent ipsilateral nephrectomy only (group 2a) and 32 underwent eventual delayed contralateral native nephrectomy (group 2b). The number of antihypertensive drugs and defined daily dose of each antihypertensive was recorded at transplantation and up to 36-month followup. Results Comparing preoperative to postoperative medications at 12, 24 and 36-month followup, transplantation with concurrent ipsilateral nephrectomy had a greater decrease in quantity (−1.2 vs −0.5 medications, p=0.008; −1.1 vs −0.3, p=0.007 and −1.2 vs −0.4, p=0.03, respectively) and defined daily dose of antihypertensive drug (−3.3 vs −1.0, p=0.0008; −2.9 vs −1.0, p=0.006 and −2.7 vs −0.6, p=0.007, respectively) than transplantation alone at each point. Native nephrectomy continued to be a predictor of hypertensive requirements on multivariable analysis (p <0.0001). The mean decrease in number of medications in group 2b from after ipsilateral nephrectomy to 12 months after contralateral nephrectomy was −0.6 (p=0.0005) and the mean decrease in defined daily dose was −0.6 (p=0.009). Conclusions In patients with autosomal dominant polycystic kidney disease undergoing renal transplantation, concurrent ipsilateral native nephrectomy is associated with a significant decrease in the quantity and defined daily dose of antihypertensive drugs needed for hypertension control. Delayed contralateral native nephrectomy is associated with improved control of blood pressure to an even greater degree
    corecore