374 research outputs found

    The Mission Accessible Near-Earth Objects Survey: Four years of photometry

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    Over 4.5 years, the Mission Accessible Near-Earth Object Survey (MANOS) assembled 228 Near-Earth Object (NEO) lightcurves. We report rotational lightcurves for 82 NEOs, constraints on amplitudes and periods for 21 NEOs, lightcurves with no detected variability within the image signal to noise and length of our observing block for 30 NEOs, and 10 tumblers. We uncovered 2 ultra-rapid rotators with periods below 20s; 2016MA with a potential rotational periodicity of 18.4s, and 2017QG18_{18} rotating in 11.9s, and estimate the fraction of fast/ultra-rapid rotators undetected in our project plus the percentage of NEOs with a moderate/long periodicity undetectable during our typical observing blocks. We summarize the findings of a simple model of synthetic NEOs to infer the object morphologies distribution using the measured distribution of lightcurve amplitudes. This model suggests a uniform distribution of axis ratio can reproduce the observed sample. This suggests that the quantity of spherical NEOs (e.g., Bennu) is almost equivalent to the quantity of highly elongated objects (e.g., Itokawa), a result that can be directly tested thanks to shape models from Doppler delay radar imaging analysis. Finally, we fully characterized 2 NEOs as appropriate targets for a potential robotic/human mission: 2013YS2_{2} and 2014FA7_{7} due to their moderate spin periods and low Δv\Delta v.Comment: Accepted for Publication, The Astrophysical Journal Supplement Serie

    Shock compaction heating and collisional processes in the production of type 3 ordinary chondrites: Lessons from the (nearly) unique L3 chondrite melt breccia Northwest Africa 8709*

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    Northwest Africa (NWA) 8709 is a rare example of a type 3 ordinary chondrite melt breccia and provides critical information for the shock compaction histories of chondrites. An L3 protolith for NWA 8709 is inferred on the basis of oxygen isotope composition, elemental composition, diverse mineral chemistry, and overall texture. NWA 8709 is among the most strongly shocked type 3 chondrites known, and experienced complete melting of the matrix and partial melting of chondrules. Unmelted phases underwent FeO reduction and partial homogenization, with reduction possibly occurring by reaction of olivine and low‐Ca pyroxene with an S‐bearing gas that was produced by vaporization. Chondrules and metal grains became foliated by uniaxial compaction, and during compression, chondrules and fragments became attached to form larger clumps. This process, and possibly also melt incorporation into chondrules to cause “inflation,” may have contributed to anomalously large chondrule sizes in NWA 8709. The melt breccia character is attributed to strong shock affecting a porous precursor. Data‐model comparisons suggest that a precursor with 23% porosity that was impacted by a 3 km/s projectile could have produced the meteorite. The rarity of other type 3 ordinary chondrite melt breccias implies that the immediate precursors to such chondrites were lower in porosity than the NWA 8709 precursor, or experienced weaker shocks. Altogether, the data imply a predominantly “quiet” dynamical environment to form most type 3 ordinary chondrites, with compaction occurring in a series of relatively weak shock events

    Breast-cancer adjuvant therapy with zoledronic acid

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    Background: Data suggest that the adjuvant use of bisphosphonates reduces rates of recurrence and death in patients with early-stage breast cancer. We conducted a study to determine whether treatment with zoledronic acid, in addition to standard adjuvant therapy, would improve disease outcomes in such patients. Methods: In this open-label phase 3 study, we randomly assigned 3360 patients to receive standard adjuvant systemic therapy either with or without zoledronic acid. The zoledronic acid was administered every 3 to 4 weeks for 6 doses and then every 3 to 6 months to complete 5 years of treatment. The primary end point of the study was disease-free survival. A second interim analysis revealed that a prespecified boundary for lack of benefit had been crossed. Results: At a median follow-up of 59 months, there was no significant between-group difference in the primary end point, with a rate of disease-free survival of 77% in each group (adjusted hazard ratio in the zoledronic acid group, 0.98; 95% confidence interval [CI], 0.85 to 1.13; P=0.79). Disease recurrence or death occurred in 377 patients in the zoledronic acid group and 375 of those in the control group. The numbers of deaths — 243 in the zoledronic acid group and 276 in the control group — were also similar, resulting in rates of overall survival of 85.4% in the zoledronic acid group and 83.1% in the control group (adjusted hazard ratio, 0.85; 95% CI, 0.72 to 1.01; P=0.07). In the zoledronic acid group, there were 17 confirmed cases of osteonecrosis of the jaw (cumulative incidence, 1.1%; 95% CI, 0.6 to 1.7; P<0.001) and 9 suspected cases; there were no cases in the control group. Rates of other adverse effects were similar in the two study groups. Conclusions: These findings do not support the routine use of zoledronic acid in the adjuvant management of breast cancer. (Funded by Novartis Pharmaceuticals and the National Cancer Research Network; AZURE Current Controlled Trials number, ISRCTN79831382.

    Breast-cancer Adjuvant Therapy With Zoledronic Acid

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    BACKGROUND: Data suggest that the adjuvant use of bisphosphonates reduces rates of recurrence and death in patients with early-stage breast cancer. We conducted a study to determine whether treatment with zoledronic acid, in addition to standard adjuvant therapy, would improve disease outcomes in such patients. METHODS: In this open-label phase 3 study, we randomly assigned 3360 patients to receive standard adjuvant systemic therapy either with or without zoledronic acid. The zoledronic acid was administered every 3 to 4 weeks for 6 doses and then every 3 to 6 months to complete 5 years of treatment. The primary end point of the study was disease-free survival. A second interim analysis revealed that a prespecified boundary for lack of benefit had been crossed. RESULTS: At a median follow-up of 59 months, there was no significant between-group difference in the primary end point, with a rate of disease-free survival of 77% in each group (adjusted hazard ratio in the zoledronic acid group, 0.98; 95% confidence interval [CI], 0.85 to 1.13; P = 0.79). Disease recurrence or death occurred in 377 patients in the zoledronic acid group and 375 of those in the control group. The numbers of deaths - 243 in the zoledronic acid group and 276 in the control group - were also similar, resulting in rates of overall survival of 85.4% in the zoledronic acid group and 83.1% in the control group (adjusted hazard ratio, 0.85; 95% CI, 0.72 to 1.01; P = 0.07). In the zoledronic acid group, there were 17 confirmed cases of osteonecrosis of the jaw (cumulative incidence, 1.1%; 95% CI, 0.6 to 1.7; P < 0.001) and 9 suspected cases; there were no cases in the control group. Rates of other adverse effects were similar in the two study groups. CONCLUSIONS: These findings do not support the routine use of zoledronic acid in the adjuvant management of breast cancer

    Audit and feedback and clinical practice guideline adherence: Making feedback actionable

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    BACKGROUND: As a strategy for improving clinical practice guideline (CPG) adherence, audit and feedback (A&F) has been found to be variably effective, yet A&F research has not investigated the impact of feedback characteristics on its effectiveness. This paper explores how high performing facilities (HPF) and low performing facilities (LPF) differ in the way they use clinical audit data for feedback purposes. METHOD: Descriptive, qualitative, cross-sectional study of a purposeful sample of six Veterans Affairs Medical Centers (VAMCs) with high and low adherence to six CPGs, as measured by external chart review audits. One-hundred and two employees involved with outpatient CPG implementation across the six facilities participated in one-hour semi-structured interviews where they discussed strategies, facilitators and barriers to implementing CPGs. Interviews were analyzed using techniques from the grounded theory method. RESULTS: High performers provided timely, individualized, non-punitive feedback to providers, whereas low performers were more variable in their timeliness and non-punitiveness and relied on more standardized, facility-level reports. The concept of actionable feedback emerged as the core category from the data, around which timeliness, individualization, non-punitiveness, and customizability can be hierarchically ordered. CONCLUSION: Facilities with a successful record of guideline adherence tend to deliver more timely, individualized and non-punitive feedback to providers about their adherence than facilities with a poor record of guideline adherence. Consistent with findings from organizational research, feedback intervention characteristics may influence the feedback's effectiveness at changing desired behaviors

    Identification of platelet function defects by multi-parameter assessment of thrombus formation.

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    Assays measuring platelet aggregation (thrombus formation) at arterial shear rate mostly use collagen as only platelet-adhesive surface. Here we report a multi-surface and multi-parameter flow assay to characterize thrombus formation in whole blood from healthy subjects and patients with platelet function deficiencies. A systematic comparison is made of 52 adhesive surfaces with components activating the main platelet-adhesive receptors, and of eight output parameters reflecting distinct stages of thrombus formation. Three types of thrombus formation can be identified with a predicted hierarchy of the following receptors: glycoprotein (GP)VI, C-type lectin-like receptor-2 (CLEC-2)>GPIb>α6ÎČ1, αIIbÎČ3>α2ÎČ1>CD36, α5ÎČ1, αvÎČ3. Application with patient blood reveals distinct abnormalities in thrombus formation in patients with severe combined immune deficiency, Glanzmann's thrombasthenia, Hermansky-Pudlak syndrome, May-Hegglin anomaly or grey platelet syndrome. We suggest this test may be useful for the diagnosis of patients with suspected bleeding disorders or a pro-thrombotic tendency.This work was supported by grants from the Center for Translational Molecular Medicine (INCOAG), the Dutch Heart Foundation (2011T6), the Landsteiner Foundation for Blood Transfusion Research (1006) and ZonMW (MKMD 114021004).This is the final published version. It's also available from Nature Communications at http://www.nature.com/ncomms/2014/140716/ncomms5257/full/ncomms5257.html

    The use of different sepsis risk stratification tools on the wards and in emergency departments uncovers different mortality risks: results of the three Welsh national multicenter point-prevalence studies

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    OBJECTIVES: To compare the performance of Sequential Organ Failure Assessment, systemic inflammatory response syndrome, Red Flag Sepsis, and National Institute of Clinical Excellence sepsis risk stratification tools in the identification of patients at greatest risk of mortality from sepsis in nonintensive care environments. DESIGN: Secondary analysis of three annual 24-hour point-prevalence study periods. SETTING: The general wards and emergency departments of 14 acute hospitals across Wales. Studies were conducted on the third Wednesday of October in 2017, 2018, and 2019. PATIENTS: We screened all patients presenting to the emergency department and on the general wards. MEASUREMENTS AND MAIN RESULTS: We recruited 1,271 patients, of which 724 (56.9%) had systemic inflammatory response syndrome greater than or equal to 2, 679 (53.4%) had Sequential Organ Failure Assessment greater than or equal to 2, and 977 (76.9%) had Red Flag Sepsis. When stratified according to National Institute of Clinical Excellence guidelines, 450 patients (35.4%) were in the “High risk” category in comparison with 665 (52.3%) in “Moderate to High risk” and 156 (12.3%) in “Low risk” category. In a planned sensitivity analysis, we found that none of the tools accurately predicted mortality at 90 days, and Sequential Organ Failure Assessment and National Institute of Clinical Excellence tools showed only moderate discriminatory power for mortality at 7 and 14 days. Furthermore, we could not find any significant correlation with any of the tools at any of the mortality time points. CONCLUSIONS: Our data suggest that the sepsis risk stratification tools currently utilized in emergency departments and on the general wards do not predict mortality adequately. This is illustrated by the disparity in mortality risk of the populations captured by each instrument, as well as the weak concordance between them. We propose that future studies on the development of sepsis identification tools should focus on identifying predicator values of both the short- and long-term outcomes of sepsis

    Sheep Updates 2005 - Part 6

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    This session covers seven papers from different authors: PASTURES/GRAZING 1. New annual pastures - quality and quantity for fodder conservation?, Sarah Pugh and Giles Glasson, Department of Agriculture Western Australia 2. Saltland Pastures: Dispelling some Myths, Ed Barrett-Lennard1,3, Hayley Norman2,3, Matt Wilmat2,3, Meir Altman,3, Kelly Pearce2,3, Sally Phelan4, David Masters2,3, 1. Department of Agriculture, Western Australia, 2 CSIRO Livestock Industries, Floreat, WA, 3. CRC for Plant-based Management of Dryland Salinity 4. Saltland Pastures Association 3. Pastures: Putting profit back into sandplain, Nadine Eva, Department of Agriculture Western Australia. 4. Pastures from Space R - Can be used to make profitable strategic and tactical management decisions on farm, Brad Wooldridge, Farmer Wagin WA, Stephen Gherardi, Lucy Anderton, Department of Agriculture Western Australia, Gonzalo Mata, CSIRO Livestock Industries, Wembley, WA 5. Are new farming systems based on perenial pastures in south west Australia more profitable?, P. Sanford, Department of Agriculture Western Australia, J. Young, Farm Systems Analysis, Kojonup WA 6. Sown fodders, rotational grazing and Merinos make money in a drought, Tim Wiley, Department of Agriculture Western Australia, Richard Quinlan, Planfarm, Geraldton 7. Lifetime Wool - The \u27best bet\u27 optimum condition score profile for Merino ewes lambing in winter. Chris Oldham, Mike Hyder, Mandy Curnow, Samantha Giles, Department of Agriculture Western Australia, John Young, Farming Systems Analysis Service, Kojonup, Andrew Thompson, DPI Victoria, Hamilton
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