What are Hybrid Development Methods Made Of? An Evidence-Based Characterization

Among the multitude of software development processes available, hardly any is used by the book. Regardless of company size or industry sector, a majority of project teams and companies use customized processes that combine different development methods— so-called hybrid development methods. Even though such hybrid development methods are highly individualized, a common understanding of how to systematically construct synergetic practices is missing. In this paper, we make a first step towards devising such guidelines. Grounded in 1,467 data points from a large-scale online survey among practitioners, we study the current state of practice in process use to answer the question: What are hybrid development methods made of? Our findings reveal that only eight methods and few practices build the core of modern software development. This small set allows for statistically constructing hybrid development methods. Using an 85% agreement level in the participants’ selections, we provide two examples illustrating how hybrid development methods are characterized by the practices they are made of. Our evidence-based analysis approach lays the foundation for devising hybrid development methods

The Curious Case of Palomar 13: The Influence of the Orbital Phase on the Appearance of Galactic Satellites

We investigate the dynamical status of the low-mass globular cluster Palomar 13 by means of N-body computations to test whether its unusually high mass-to-light ratio of about 40 and its peculiarly shallow surface density profile can be caused by tidal shocking. Alternatively, we test - by varying the assumed proper motion - if the orbital phase of Palomar 13 within its orbit about the Milky Way can influence its appearance and thus may be the origin of these peculiarities, as has been suggested by Kuepper et al. (2010). We find that, of these two scenarios, only the latter can explain the observed mass-to-light ratio and surface density profile. We note, however, that the particular orbit that best reproduces those observed parameters has a proper motion inconsistent with the available literature value. We discuss this discrepancy and suggest that it may be caused by an underestimation of the observational uncertainties in the proper motion determination. We demonstrate that Palomar 13 is most likely near apogalacticon, which makes the cluster appear supervirial and blown-up due to orbital compression of its tidal debris. Since the satellites of the Milky Way are on average closer to apo- than perigalacticon, their internal dynamics may be influenced by the same effect, and we advocate that this needs to be taken into account when interpreting their kinematical data. Moreover, we briefly discuss the influence of a possible binary population on such measurements.Comment: Funding acknowledgement adde

Endovascular stroke treatment in orally anticoagulated patients: an analysis from the German Stroke Registry-Endovascular Treatment

Background Endovascular treatment (ET) in orally anticoagulated (OAC) patients has not been evaluated in randomized clinical trials and data regarding this issue are sparse. Methods We analyzed data from the German Stroke Registry-Endovascular Treatment (GSR-ET; NCT03356392, date of registration: 22 Nov 2017). The primary outcomes were successful reperfusion defined as modified thrombolysis in cerebral infarction (mTICI 2b-3), good outcome at 3 months (modified Rankin scale [mRS] 0–2 or back to baseline), and intracranial hemorrhage (ICH) on follow-up imaging at 24 h analyzed by unadjusted univariate and adjusted binary logistic regression analysis. Additionally, we analyzed mortality at 3 months with adjusted binary logistic regression analysis. Results Out of 6173 patients, there were 1306 (21.2%) OAC patients, 479 (7.8%) with vitamin K antagonists (VKA) and 827 (13.4%) with non-vitamin K antagonist oral anticoagulation (NOAC). The control group consisted of 4867 (78.8%) non-OAC patients. ET efficacy with the rates of mTICI 2b-3 was similar among the three groups (85.6%, 85.3% vs 84.3%, p = 0.93 and 1). On day 90, good outcome was less frequent in OAC patients (27.8%, 27.9% vs 39.5%, p < 0.005 and < 0.005). OAC status was not associated with ICH at 24 h (NOAC: odd’s ratio [OR] 0.89, 95% confidence interval [CI] 0.67–1.20; VKA: OR 1.04, CI 0.75–1.46). Binary logistic regression analysis revealed no influence of OAC status on good outcome at 3 months (NOAC: OR 1.25, CI 0.99–1.59; VKA: OR 1.18, CI 0.89–1.56) and mortality at 3 months (NOAC: OR 1.03, CI 0.81–1.30; VKA: OR 1.04, CI 0.78–1.1.37). Conclusions ET can be performed safely and successfully in LVO stroke patients treated with OAC. Clinical trial registration-URL http://www.clinicaltrials.gov. Unique identifier: NCT03356392

High-repetition-rate and high-photon-flux 70 eV high-harmonic source for coincidence ion imaging of gas-phase molecules

Unraveling and controlling chemical dynamics requires techniques to image structural changes of molecules with femtosecond temporal and picometer spatial resolution. Ultrashort-pulse x-ray free-electron lasers have significantly advanced the field by enabling advanced pump-probe schemes. There is an increasing interest in using table-top photon sources enabled by high-harmonic generation of ultrashort-pulse lasers for such studies. We present a novel high-harmonic source driven by a 100 kHz fiber laser system, which delivers 10$^{11}$ photons/s in a single 1.3 eV bandwidth harmonic at 68.6 eV. The combination of record-high photon flux and high repetition rate paves the way for time-resolved studies of the dissociation dynamics of inner-shell ionized molecules in a coincidence detection scheme. First coincidence measurements on CH$_3$I are shown and it is outlined how the anticipated advancement of fiber laser technology and improved sample delivery will, in the next step, allow pump-probe studies of ultrafast molecular dynamics with table-top XUV-photon sources. These table-top sources can provide significantly higher repetition rates than the currently operating free-electron lasers and they offer very high temporal resolution due to the intrinsically small timing jitter between pump and probe pulses

General anesthesia versus conscious sedation in mechanical thrombectomy

BACKGROUND AND PURPOSE Anesthesia regimen in patients undergoing mechanical thrombectomy (MT) is still an unresolved issue. METHODS We compared the effect of anesthesia regimen using data from the German Stroke Registry-Endovascular Treatment (GSR-ET) between June 2015 and December 2019. Degree of disability was rated by the modified Rankin Scale (mRS), and good outcome was defined as mRS 0-2. Successful reperfusion was assumed when the modified thrombolysis in cerebral infarction scale was 2b-3. RESULTS Out of 6,635 patients, 67.1% (n=4,453) patients underwent general anesthesia (GA), 24.9% (n=1,650) conscious sedation (CS), and 3.3% (n=219) conversion from CS to GA. Rate of successful reperfusion was similar across all three groups (83.0% vs. 84.2% vs. 82.6%, P=0.149). Compared to the CA-group, the GA-group had a delay from admission to groin (71.0 minutes vs. 61.0 minutes, P\textless0.001), but a comparable interval from groin to flow restoration (41.0 minutes vs. 39.0 minutes). The CS-group had the lowest rate of periprocedural complications (15.0% vs. 21.0% vs. 28.3%, P\textless0.001). The CS-group was more likely to have a good outcome at follow-up (42.1% vs. 34.2% vs. 33.5%, P\textless0.001) and a lower mortality rate (23.4% vs. 34.2% vs. 26.0%, P\textless0.001). In multivariable analysis, GA was associated with reduced achievement of good functional outcome (odds ratio OR, 0.82; 95{\%} confidence interval CI, 0.71 to 0.94; P=0.004) and increased mortality (OR, 1.42; 95{\%} CI, 1.23 to 1.64; P{\textless}0.001). Subgroup analysis for anterior circulation strokes (n=5,808) showed comparable results. CONCLUSIONS We provide further evidence that CS during MT has advantages over GA in terms of complications, time intervals, and functional outcome

Managed and Continuous Evolution of Dependable Automotive Software Systems / Andreas Rausch, Oliver Brox, Axel Grewe, Marcel Ibe, Stefanie Jauns-Seyfried, Christoph Knieke, Marco Körner, Steffen Küpper, Malte Mauritz, Henrik Peters, Arthur Strasser, Martin Vogel, Norbert Weiss

Automotive software systems are an essential and innovative part of nowadays connected and automated vehicles. Automotive industry is currently facing the challenge to re-invent the automobile. Consequently, automotive software systems, their software systems architecture, and the way we engineer those kinds of software systems are confronted with major challenges: managing complexity, providing flexibility, and guaranteeing dependability of the desired automotive software systems and the corresponding engineering process. In this paper we will present an improved and sophisticated engineering approach. Our approach is based on the managed and continuous evolution of dependable automotive software systems. It helps engineers to manage system complexity based on continous engineering processes to iteratively evolve automotive software systems and therby guarantee the required dependability issues. Based on a running sample, we will present and illustrate the main assets of the proposed engineering approach for managed and continuous evolution of dependable automotive software systems

Managed and Continuous Evolution of Dependable Automotive Software Systems / Andreas Rausch, Oliver Brox, Axel Grewe, Marcel Ibe, Stefanie Jauns-Seyfried, Christoph Knieke, Marco Körner, Steffen Küpper, Malte Mauritz, Henrik Peters, Arthur Strasser, Martin Vogel, Norbert Weiss

Automotive software systems are an essential and innovative part of nowadays connected and automated vehicles. Automotive industry is currently facing the challenge to re-invent the automobile. Consequently, automotive software systems, their software systems architecture, and the way we engineer those kinds of software systems are confronted with major challenges: managing complexity, providing flexibility, and guaranteeing dependability of the desired automotive software systems and the corresponding engineering process. In this paper we will present an improved and sophisticated engineering approach. Our approach is based on the managed and continuous evolution of dependable automotive software systems. It helps engineers to manage system complexity based on continous engineering processes to iteratively evolve automotive software systems and therby guarantee the required dependability issues. Based on a running sample, we will present and illustrate the main assets of the proposed engineering approach for managed and continuous evolution of dependable automotive software systems

CT after interhospital transfer in acute ischemic stroke: Imaging findings and impact of prior intravenous contrast administration

Objectives: Large vessel occlusion (LVO) stroke patients routinely undergo interhospital transfer to endovascular thrombectomy capable centers. Imaging is often repeated with residual intravenous (IV) iodine contrast at post-transfer assessment. We determined imaging findings and the impact of residual contrast on secondary imaging. Anterior circulation LVO stroke patients were selected out of a consecutive cohort. Directly admitted patients were contrast naïve, and transferred patients had previously received IV iodine contrast for stroke assessment at the referring hospital. Two independent readers rated the visibility of residual contrast on non-contrast computed tomography (CT) after transfer and assessed the hyperdense vessel sign. Multivariate linear regression analysis was used to investigate the association of the Alberta Stroke Program Early CT score (ASPECTS) with prior contrast administration, time from symptom onset (TFSO), and CTP ischemic core volume in both directly admitted and transferred patients. Results: We included 161 patients, with 62 (39%) transferred and 99 (62%) directly admitted patients. Compared between these groups, transferred patients had a longer TFSO-to-imaging at our institution (median: 212 vs. 75 min, p < 0.001) and lower ASPECTS (median: 8 vs. 9, p < 0.001). Regression analysis presented an independent association of ASPECTS with prior contrast administration (β = −0.25, p = 0.004) but not with TFSO (β = −0.03, p = 0.65). Intergroup comparison between transferred and directly admitted patients pointed toward a stronger association between ASPECTS and CTP ischemic core volume in transferred patients (β = −0.39 vs. β = −0.58, p = 0.06). Detectability of the hyperdense vessel sign was substantially lower after transfer (66 vs. 10%, p < 0.001). Conclusion: Imaging alterations due to residual IV contrast are frequent in clinical practice and render the hyperdense vessel sign largely indetectable. Larger studies are needed to clarify the influence on the association between ASPECTS and ischemic core

Mechanical Thrombectomy in Patients With Milder Strokes and Large Vessel Occlusions A Multicenter Matched Analysis

Background and Purpose-We aimed to describe the safety and efficacy of immediate mechanical thrombectomy (MT) in patients with large vessel occlusions and low National Institutes of Health Stroke Scale (NIHSS) versus best medical management. Methods-Patients from prospectively collected databases of 6 international comprehensive stroke centers with large vessel occlusions (distal intracranial internal carotid, middle cerebral artery-M1 and M2 segments, or basilar artery with or without tandem occlusions) and NIHSS 0 to 5 were identified and divided into 2 groups for analysis: immediate MT or initial best medical management which included rescue MT after neurological deterioration (best medical management-MT). Uni- and multivariate analyses and patient-level matching for age, baseline NIHSS, and occlusion site were performed to compare baseline and outcome variables across the 2 groups. The primary outcome was defined as good outcome (modified Rankin Scale score, 0-2) at day 90. Safety outcome was symptomatic intracranial hemorrhage as defined by the ECASS (European Cooperative Acute Stroke Study) II and mortality at day 90. Results: Compared with best medical management-MT (n=220), patients with immediate MT (n=80) were younger (65.3 +/- 13.5 versus 69.5 +/- 14.1;P=0.021), had more often atrial fibrillation (44.8% versus 28.2%;P=0.012), higher baseline NIHSS (4, 0-5 versus 3, 0-5;P=0.005), higher Alberta Stroke Program Early CT Score (10, 7-10 versus 10, 5-10;P=0.023), more middle cerebral artery-M1, and less middle cerebral artery-M2 (41.3% versus 21.9% and 28.8% versus 49.3%;P=0.016) occlusions. The adjusted odds ratio for good outcome was 3.1 (95% CI, 1.4-6.9) favoring immediate MT. In the matched analysis, there was a 14.4% absolute difference in good outcome (84.4% versus 70.1%;P=0.03) at day 90 favoring immediate MT. There were no safety concerns. Conclusions: Our retrospective, pilot analysis suggests that immediate thrombectomy in large vessel occlusions patients with low NIHSS on presentation may be safe and has the potential to result in improved outcomes. Randomized clinical trials are warranted to establish the optimal management for this patient population

Low Q^2 Jet Production at HERA and Virtual Photon Structure

The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure