On jumping lines of vector bundles on P n Ellia, Philippe
Annali dell'Università di Ferrara. Sezione 7. Scienze matematiche,
01/2017, Letnik:
63, Številka:
1
Journal Article
Recenzirano
We give bounds on the rank of non uniform vector bundles on P n with a finite number of jumping lines.
We formulate, and in some cases prove, three statements concerning the purity or, more generally, the naturality of the resolution of various modules one can attach to a generic curve of genus g and ...a torsion point of in its Jacobian. These statements can be viewed an analogues of Green's Conjecture and we verify them computationally for bounded genus. We then compute the cohomology class of the corresponding non-vanishing locus in the moduli space
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•Self-assembled WO3 nanowire bundles were successfully synthesized by a sulfate-assisted solvent-thermal method.•Hierarchical bundles of WO3 nanowires were produced by the synergistic ...effect of oxalic acid and ethylene glycol.•Amino-functionalized WO3 bundles were surface decorated with Au nanoparticles for enhanced gas sensing.•Ordered Au-WO3 nanowire bundles show excellent sensing properties towards both acetone and n-butanol.
This study demonstrates the synthesis of self-assembled hexagonal WO3 nanowire bundles, with both ordered and random structures in the presence of SO42− ions, by a simple but efficient solvent-thermal method. The as-synthesized products are composed of hierarchical bundles with assembled ultrathin nanowire subunits. The growth and assembly mechanisms, regarding WO3 nanowire bundles, may be elucidated through oriented attachment or Ostwald ripening growth, based on a synergistic effect from both oxalic acid and ethylene glycol in dehydrating WO3·xH2O to WO3 nanocrystals and in controlling segregation behavior, along with high surface areas (18.4 m2 g-1 for ordered structures while 11.6 m2 g-1 disordered ones), which makes WO3 bundles great potential for gas sensing. To further enhance gas sensing, gold nanoparticles were chosen to deposit on the surface of WO3 nanowire bundles by acting with amino groups linked with WO3 bundles in the HAuCl4 solution with further oxidation. The Au-WO3 composites were examined towards various reducing gases, with exemplary sensitivities of (S = 127, 82), (S = 72, 52) towards n-butanol and acetone, respectively. The sensing mechanisms of such WO3 bundle structures are further understood in detail. This work will make the unique WO3 bundle nanostructures highly potential for gas sensing applications.
Let (E,I)(E,I) be a Higgs vector bundle over a compact connected KAOhler manifold X. Fix any filtration of EE by coherent analytic subsheaves in which each sheaf is preserved by the Higgs field, and ...each successive quotient is a torsionfree and stable Higgs sheaf. Denote by GG the direct sum of these stable quotients, and let the singular set of GG be called SaXSaX. We construct a 1-parameter family of filtration preserving CaCa isomorphisms IBBt:G|XaSaE|XaSIBBt:G|XaSaE|XaS, and a Hermitian metric h on G|X\SG|X\S, such that as ta+ata+a, the Chern connection for the Hermitian Higgs bundle (IBBtaE,IBBtaI,h)|X\S converges, in the CaCa FrACOchet topology over any relatively compact open subset of X\SX\S, to the direct sum of the YangaMillsaHiggs connections on the direct summands in GG.
OBJECTIVES:To track compliance by an interprofessional team with the Awakening and Breathing Coordination, Choice of drugs, Delirium monitoring and management, Early mobility, and Family engagement ...(ABCDEF) bundle in implementing the Pain, Agitation, and Delirium guidelines. The aim was to study the association between ABCDEF bundle compliance and outcomes including hospital survival and delirium-free and coma-free days in community hospitals.
DESIGN:A prospective cohort quality improvement initiative involving ICU patients.
SETTING:Seven community hospitals within California’s Sutter Health System.
PATIENTS:Ventilated and nonventilated general medical and surgical ICU patients enrolled between January 1, 2014, and December 31, 2014.
MEASUREMENTS AND MAIN RESULTS:Total and partial bundle compliance were measured daily. Random effects regression was used to determine the association between ABCDEF bundle compliance accounting for total compliance (all or none) or for partial compliance (“dose” or number of bundle elements used) and outcomes of hospital survival and delirium-free and coma-free days, after adjusting for age, severity of illness, and presence of mechanical ventilation. Of 6,064 patients, a total of 586 (9.7%) died before hospital discharge. For every 10% increase in total bundle compliance, patients had a 7% higher odds of hospital survival (odds ratio, 1.07; 95% CI, 1.04–1.11; p < 0.001). Likewise, for every 10% increase in partial bundle compliance, patients had a 15% higher hospital survival (odds ratio, 1.15; 95% CI, 1.09–1.22; p < 0.001). These results were even more striking (12% and 23% higher odds of survival per 10% increase in bundle compliance, respectively, p < 0.001) in a sensitivity analysis removing ICU patients identified as receiving palliative care. Patients experienced more days alive and free of delirium and coma with both total bundle compliance (incident rate ratio, 1.02; 95% CI, 1.01–1.04; p = 0.004) and partial bundle compliance (incident rate ratio, 1.15; 95% CI, 1.09–1.22; p < 0.001).
CONCLUSIONS:The evidence-based ABCDEF bundle was successfully implemented in seven community hospital ICUs using an interprofessional team model to operationalize the Pain, Agitation, and Delirium guidelines. Higher bundle compliance was independently associated with improved survival and more days free of delirium and coma after adjusting for age, severity of illness, and presence of mechanical ventilation.
In this paper, we develop the theory of singular Hermitian metrics on vector bundles. As an application, we give a structure theorem of a projective manifold X with pseudo-effective tangent bundle; X ...admits a smooth fibration
$X \to Y$
to a flat projective manifold Y such that its general fibre is rationally connected. Moreover, by applying this structure theorem, we classify all the minimal surfaces with pseudo-effective tangent bundle and study general nonminimal surfaces, which provide examples of (possibly singular) positively curved tangent bundles.
•Vascular bundles (VBs) and fiber strands (FSs) have been extracted from date palm rachis.•The morphology, surface roughness, physicochemical and thermal properties were analyzed.•The low density of ...VBs and FSs promotes lightweight applications.•FSs have tensile strength (530.5 ± 115.2 MPa) more than 4 times higher than VBs.•This research qualifies VBs and FSs for use as reinforcement in composite materials.
Date palm rachis fibers are rich in cellulose, relatively inexpensive, and readily available in Algeria. The aim of this study is to investigate the morphology, structure, mechanical and physicochemical characteristics of both vascular bundles and fiber strands extracted from date palm rachis. The difficulties encountered are associated to the extraction of the fibers without damaging them. The study focuses on the morphological and surface roughness analysis using optical and scanning electron microscopies (SEM), and a non-contact 3D profiler. The chemical, physical and thermal properties have been studied using Fourier-transform infrared (FTIR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The mechanical properties were accessed by tensile tests and they were analyzed using two-parameter Weibull distribution.
IMPORTANCE: Patients undergoing emergency laparotomy have high mortality, but few studies exist to improve outcomes for these patients. OBJECTIVE: To assess whether a collaborative approach to ...implement a 6-point care bundle is associated with reduction in mortality and length of stay and improvement in the delivery of standards of care across a group of hospitals. DESIGN, SETTING, AND PARTICIPANTS: The Emergency Laparotomy Collaborative (ELC) was a UK-based prospective quality improvement study of the implementation of a care bundle provided to patients requiring emergency laparotomy between October 1, 2015, and September 30, 2017. Participants were 28 National Health Service hospitals and emergency surgical patients who were treated at these hospitals and whose data were entered into the National Emergency Laparotomy Audit (NELA) database. Post-ELC implementation outcomes were compared with baseline data from July 1, 2014, to September 30, 2015. Data entry and collection were performed through the NELA. INTERVENTIONS: A 6-point, evidence-based care bundle was used. The bundle included prompt measurement of blood lactate levels, early review and treatment for sepsis, transfer to the operating room within defined time goals after the decision to operate, use of goal-directed fluid therapy, postoperative admission to an intensive care unit, and multidisciplinary involvement of senior clinicians in the decision and delivery of perioperative care. Change management and leadership coaching were provided to ELC leadership teams. MAIN OUTCOME AND MEASURES: Primary outcomes were in-hospital mortality, both crude and Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (P-POSSUM) risk-adjusted, and length of stay. Secondary outcomes were the changes after implementation of the separate metrics in the care bundle. RESULTS: A total of 28 hospitals participated in the ELC and completed the project. The baseline group included 5562 patients (2937 female 52.8% and a mean range age of 65.3 18.0-114.0 years), whereas the post-ELC group had 9247 patients (4911 female 53.1% and a mean range age of 65.0 18.0-99.0 years). Unadjusted mortality rate decreased from 9.8% at baseline to 8.3% in year 2 of the project, and so did risk-adjusted mortality from a baseline of 5.3% to 4.5% post-ELC. Mean length of stay decreased from 20.1 days during year 1 to 18.9 days during year 2. Significant changes in 5 of the 6 metrics in the care bundle were achieved. CONCLUSIONS AND RELEVANCE: A collaborative approach using a quality improvement methodology and a care bundle appeared to be effective in reducing mortality and length of stay in emergency laparotomy, suggesting that hospitals should adopt such an approach to see better patient outcomes and care delivery performance.
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