583 research outputs found
Single Machine Scheduling with Release Dates
We consider the scheduling problem of minimizing the average weighted completion time of n jobs with release dates on a single machine. We first study two linear programming relaxations of the problem, one based on a time-indexed formulation, the other on a completiontime formulation. We show their equivalence by proving that a O(n log n) greedy algorithm leads to optimal solutions to both relaxations. The proof relies on the notion of mean busy times of jobs, a concept which enhances our understanding of these LP relaxations. Based on the greedy solution, we describe two simple randomized approximation algorithms, which are guaranteed to deliver feasible schedules with expected objective value within factors of 1.7451 and 1.6853, respectively, of the optimum. They are based on the concept of common and independent a-points, respectively. The analysis implies in particular that the worst-case relative error of the LP relaxations is at most 1.6853, and we provide instances showing that it is at least e/(e - 1) 1.5819. Both algorithms may be derandomized, their deterministic versions running in O(n2 ) time. The randomized algorithms also apply to the on-line setting, in which jobs arrive dynamically over time and one must decide which job to process without knowledge of jobs that will be released afterwards
Driving Catalyst Reoxidation in Wacker Cyclizations with Acetal-Based Metal-Hydride Abstractors
In traditional Wacker processes, Pd(II) becomes reduced to Pd(0) after C-O bond formation and β-H elimination and must be reoxidized to the electrophilic Pd(II) state via a stoichiometric oxidant like benzoquinone, CuCl2, or O2. We report herein a Pt-catalyzed Wacker-type process that regenerates the electrophilic Pt2+ state by H− abstraction from a [Pt]-H using an oxocarbenium ion generated from an acetal or ketal under acidic conditions
Clustering Properties of restframe UV selected galaxies I: the correlation length derived from GALEX data in the local Universe
We present the first measurements of the angular correlation function of
galaxies selected in the far (1530 A) and near (2310 A) Ultraviolet from the
GALEX survey fields overlapping SDSS DR5 in low galactic extinction regions.
The area used covers 120 sqdeg (GALEX - MIS) down to magnitude AB = 22,
yielding a total of 100,000 galaxies. The mean correlation length is ~ 3.7 \pm
0.6 Mpc and no significant trend is seen for this value as a function of the
limiting apparent magnitude or between the GALEX bands. This estimate is close
to that found from samples of blue galaxies in the local universe selected in
the visible, and similar to that derived at z ~ 3 for LBGs with similar rest
frame selection criteria. This result supports models that predict anti-biasing
of star forming galaxies at low redshift, and brings an additional clue to the
downsizing of star formation at z<1.Comment: Accepted for publication in GALEX Special ApJs, December 200
Autonomy Preference Index - Uroonkologie (API-Uro) : API Fragebogen - Fallbeispiele Uroonkologie
Dieser Vignetten-basierte Fragebogen dient der Erfassung der Beteiligungspräferenz von Patient:innen an Behandlungsentscheidungen in der Uroonkologie (Büdenbender et al., eingereicht). Es werden sieben typische Entscheidungen bei der Diagnose, Behandlung und Nachsorge uroonkologischer Erkrankungen (z.B. Harnblasenkarzinom oder Prostatakarzinom) geschildert. Die Patient:innen beantworten, wer die Entscheidung treffen soll auf einer 5-stufigen Likert-Skala von 1 „Der Arzt alleine“ bis 5 „Der Patient alleine“. Die Vignetten wurden in Anlehnung an die Vignetten des Autonomy Preference Index (Ende et al., 1989) gemeinsam mit uroonokologischen Expert:innen des Universitätsklinikums Mannheim in einem Konsensverfahren erstellt und anschließend mit den Rückmeldungen von Patient:innen verbessert
Predicting decisional conflict - anxiety and depression in shared decision making
Emotional distress can be a potential barrier to shared decision making (SDM), yet affect is typically not systematically assessed in medical consultation. We examined whether urological patients report anxiety or depression prior to a consultation and if emotional distress predicts decisional conflict thereafter.
We recruited a large sample of urological outpatients (N = 397) with a range of different diagnoses (42% oncological). Prior to a medical consultation, patients filled in questionnaires, including the Hospital Anxiety and Depression Scale. After the consultation, patients completed the Decisional Conflict Scale. We scored the rate of anxiety and depression in our sample and conducted multiple regression analysis to examine if emotional distress before the consultation predicts decisional conflict thereafter.
About a quarter of patients reported values at or above cut-off for clinically relevant emotional distress. Emotional distress significantly predicted a higher degree of decisional conflict. There were no differences in emotional distress between patients with and without uro-oncological diagnosis.
Emotional distress is common in urology patients – oncological as well as non-oncological. It predicts decisional conflict after physician consultation.
Emotional distress should be systematically assessed in clinical consultations. This may improve the process and outcome of SDM
Embodied cognitive ecosophy: the relationship of mind, body, meaning and ecology
The concept of embodied cognition has had a major impact in a number of disciplines. The extent of its consequences on general knowledge and epistemology are still being explored. Embodied cognition in human geography has its own traditions and discourses but these have become somewhat isolated in the discipline itself. This paper argues that findings in other disciplines are of value in reconceptualising embodied cognition in human geography and this is explored by reconsidering the concept of ecosophy. Criticisms of ecosophy as a theory are considered and recent work in embodied cognition is applied to consider how such criticisms might be addressed. An updated conceptualisation is proposed, the embodied cognitive ecosophy, and three characteristics arising from this criticism and synthesis are presented with a view to inform future discussions of ecosophy and emotional geography
SWITCH : A randomised, sequential, open-label study to evaluate the efficacy and safety of Sorafenib-sunitinib versus Sunitinib-sorafenib in the treatment of metastatic renal cell cancer
Background
Understanding how to sequence targeted therapies for metastatic renal
cell carcinoma (mRCC) is important for maximisation of clinical benefit.
Objectives
To prospectively evaluate sequential use of the multikinase inhibitors sorafenib followed by sunitinib (So-Su) versus sunitinib followed by sorafenib (Su-So) in patients with mRCC.
Design, setting, and participants
The multicentre, randomised, open-label, phase 3 SWITCH study assessed So-Su versus Su-So in patients with mRCC without prior systemic therapy, and stratified by Memorial Sloan Kettering Cancer Center risk score (favourable or intermediate).
Intervention
Patients were randomised to sorafenib 400 mg twice daily followed, on progression or intolerable toxicity, by sunitinib 50 mg once daily (4 wk on, 2 wk off) (So-Su), or vice versa (Su-So).
Outcome measurements and statistical analysis
The primary endpoint was improvement in progression-free survival (PFS) with So-Su versus Su-So, assessed from randomisation to progression or death during second-line therapy. Secondary endpoints included overall survival (OS) and safety.
Results and limitations
In total, 365 patients were randomised (So-Su, n = 182; Su-So, n = 183). There was no significant difference in total PFS between So-Su and Su-So (median 12.5 vs 14.9 mo; hazard ratio [HR] 1.01; 90% confidence interval [CI] 0.81–1.27; p = 0.5 for superiority). OS was similar for So-Su and Su-So (median 31.5 and 30.2 mo; HR 1.00, 90% CI 0.77–1.30; p = 0.5 for superiority). More So-Su patients than Su-So patients reached protocol-defined second-line therapy (57% vs 42%). Overall, adverse event rates were generally similar between the treatment arms. The most frequent any-grade treatment-emergent first-line adverse events were diarrhoea (54%) and hand-foot skin reaction (39%) for sorafenib; and diarrhoea (40%) and fatigue (40%) for sunitinib.
Conclusions
Total PFS was not superior with So-Su versus Su-So. These results demonstrate that sorafenib followed by sunitinib and vice versa provide similar clinical benefit in mRCC
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