390 research outputs found
Linear growth of quantum circuit complexity
The complexity of quantum states has become a key quantity of interest across various subfields of physics, from quantum computing to the theory of black holes. The evolution of generic quantum systems can be modelled by considering a collection of qubits subjected to sequences of random unitary gates. Here we investigate how the complexity of these random quantum circuits increases by considering how to construct a unitary operation from Haar random two qubit quantum gates. Implementing the unitary operation exactly requires a minimal number of gates this is the operation s exact circuit complexity. We prove a conjecture that this complexity grows linearly, before saturating when the number of applied gates reaches a threshold that grows exponentially with the number of qubits. Our proof overcomes difficulties in establishing lower bounds for the exact circuit complexity by combining differential topology and elementary algebraic geometry with an inductive construction of Clifford circuit
First comparison of retroperitoneal versus transperitoneal robot-assisted nephroureterectomy with bladder cuff : a single center study
Introduction. After recent presentation of the first complete robot-assisted retroperitoneal nephroureterectomy with bladder cuff (RRNU) for patients with upper tract urothelial cancer (UTUC), we aimed to compare this new surgical technique with robot-assisted transperitoneal nephroureter ectomy (TRNU) representing the current standard of care.
Methods. Robot-assisted nephroureterectomies (NUs) were retrospectively analyzed and compared based on two groups: transperitoneal versus retroperitoneal approach.
Baseline data were collected for patient demographics, tumor characteristics, intra- (EAUiaiC) and postoperative (Clavien-Dindo) complications, and perioperative variables.
Tumor characteristics included grade of malignancy, clinical stage, and surgical margin status. Short-term follow-up data including 30-day readmission rates were collected.
Statistical analyses were performed assuming a significant p-value of < 0.05.
Results. The analysis includes perioperative patient data after proven UTUC of 24 TRNU versus 12 RRNU (mean age: 70 versus 71 years; BMI: 25.9 versus 26.1 kg/m 2 ;
CCI score ≥ 4: 83% versus 75%; ASA score ≥ 3: 37% vs 33%). Intraoperative (16.4% vs 0%, p = 0.35) and postoperative (25% vs 12.5%, p = 0.64) complications demonstrated
no significant discrepancy. Notably, RRNU demonstrated significantly shorter surgery time (p < 0.05) and length of stay (p < 0.05). There was no significant difference in
histopathological tumor characteristics, whereas significantly more lymph nodes were removed through RRNU (11.0±3.3 vs. 6.4±5.1, p < 0.05). Finally, no statistical difference was shown in short-term follow-up.
Conclusion. We report the first head-to-head comparison between RRNU and TRNU. RRNU proves to be a safe and feasible approach which appears to be non-inferior to
TRNU. RRNU expands the spectrum of minimally invasive treatment options, particularly for patients with major previous abdominal surgery
Characterization of Testing Locations for Developing Cool-Season Grass Species
The identification of best testing locations facilitates the allocation of resources in a breeding program, allowing emphasis to be placed at the sites best suited for identifying superior plant materials for the target environment. The objective of this study was the identification of best locations for the evaluation and testing of cool-season grass species within the Northern Great Plains and Intermountain regions of the USA. This study also sought to subdivide the locations into meaningful environmental groupings based on similar entry performance. The study characterized initial stand frequency and forage production (over a 3-yr period) of crested wheatgrass [Agropyron cristatum (L.) Gaertn.; A. desertorum (Fisch. ex Link) Schultes; A. fragile (Roth) Candargy], intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey], and smooth bromegrass (Bromus inermis Leyss.) at six locations within these regions. Results suggested the existence of best testing locations and environmental groupings for each of the species. For example, the Ithaca, NE, location was consistently a good location for testing forage production. Although there were some consistencies, generally, the best testing locations and environmental groupings were species and trait specific. Thus, the targeted use of locations appeared to be most useful on an individual species basis, rather than considered across the cool-season grass species
Robot-assisted simple prostatectomy versus open simple prostatectomy : a single-center comparison
PURPOSE
Open simple prostatectomy (OSP) is a standard surgical technique for patients with benign prostatic hyperplasia with prostate size larger than 80 ml. As a minimally invasive approach, robot-assisted simple prostatectomy (RASP) emerged as a feasible surgical alternative. Currently, there are no definite recommendations for the standard use of RASP. Therefore, we aimed at investigating various clinical outcomes comparing RASP with OSP.
METHODS
In this retrospective single-center study, we evaluated clinical data from 103 RASP and 31 OSP patients. Both cohorts were compared regarding different clinical characteristics with and without propensity score matching. To detect independent predictive factors for clinical outcomes, multivariate logistic regression analysis was performed.
RESULTS
Robot-assisted simple prostatectomy patients demonstrated a lower estimated blood loss and need for postoperative blood transfusions as well as less postoperative complications. OSP had a shorter operative time (125 min vs. 182 min) longer hospital stay (11 days vs. 9 days) and longer time to catheter removal (8 days vs. 6 days). In the multivariate analysis, RASP was identified as an independent predictor for longer operative time, lower estimated blood loss, shorter length of hospital stay, shorter time to catheter removal, less postoperative complications and blood transfusions.
CONCLUSION
Robot-assisted simple prostatectomy is a safe alternative to OSP with less perioperative and postoperative morbidity. Whether OSP (shorter operative time) or RASP (shorter length of hospital stay) has a more favorable economic impact depends on the particular conditions of different health care systems. Further prospective comparative research is warranted to define the value of RASP in the current surgical management of benign prostatic hyperplasia
Immersive multi-user decision training games with ARLearn
Serious gaming approaches so far focus mainly on skill development, motivational aspects or providing immersive learning situations. Little work has been reported to foster awareness and decision competencies in complex deci-sion situations involving incomplete information and multiple stakeholders. We address this issue exploring the technical requirements and possibilities to de-sign games for such situations in three case studies: a hostage taking situation, a multi-stakeholder logistics case, and a health-care related emergency case. To implement the games, we use a multi-user enabled mobile game development platform (ARLearn). We describe the underlying real world situations and edu-cational challenges and analyse how these are reflected in the ARLearn games realized. Based on these cases we propose a way to increase the immersiveness of mobile learning games.SALOM
Microsporidia::Why Make Nucleotides if You Can Steal Them?
Microsporidia are strict obligate intracellular parasites that infect a wide range of eukaryotes including humans and economically important fish and insects. Surviving and flourishing inside another eukaryotic cell is a very specialised lifestyle that requires evolutionary innovation. Genome sequence analyses show that microsporidia have lost most of the genes needed for making primary metabolites, such as amino acids and nucleotides, and also that they have only a limited capacity for making adenosine triphosphate (ATP). Since microsporidia cannot grow and replicate without the enormous amounts of energy and nucleotide building blocks needed for protein, DNA, and RNA biosynthesis, they must have evolved ways of stealing these substrates from the infected host cell. Providing they can do this, genome analyses suggest that microsporidia have the enzyme repertoire needed to use and regenerate the imported nucleotides efficiently. Recent functional studies suggest that a critical innovation for adapting to intracellular life was the acquisition by lateral gene transfer of nucleotide transport (NTT) proteins that are now present in multiple copies in all microsporidian genomes. These proteins are expressed on the parasite surface and allow microsporidia to steal ATP and other purine nucleotides for energy and biosynthesis from their host. However, it remains unclear how other essential metabolites, such as pyrimidine nucleotides, are acquired. Transcriptomic and experimental studies suggest that microsporidia might manipulate host cell metabolism and cell biological processes to promote nucleotide synthesis and to maximise the potential for ATP and nucleotide import. In this review, we summarise recent genomic and functional data relating to how microsporidia exploit their hosts for energy and building blocks needed for growth and nucleic acid metabolism and we identify some remaining outstanding questions
Central Bank Communication in the Financial Crisis: Evidence from a Survey of Financial Market Participants
In this paper, we study whether central bank communication has a positive effect on market participants' perception of central banks' (i) credibility, (ii) unorthodox measures, and (iii) independence. We utilise a survey of more than 500 financial market participants from around the world who answered questions in reference to the Bank of England (BoE), the Bank of Japan (BoJ), the European Central Bank (ECB), and the Federal Reserve (Fed). We find that market participants believe that the Fed communicates best, followed by the BoE, ECB, and BoJ. Similar rankings are found on the issues of credibility, satisfaction with unconventional monetary policy, and possible deterioration in independence. Using ordered probit models, we show that central bank communication has a positive effect on how central banks are perceived and understood, as it enhances credibility, increases satisfaction with unorthodox measures, and fosters perceived independence of central banks
Assessment of a novel smartglass-based point-of-care fusion approach for mixed reality-assisted targeted prostate biopsy: A pilot proof-of-concept study
PurposeWhile several biopsy techniques and platforms for magnetic resonance imaging (MRI)-guided targeted biopsy of the prostate have been established, none of them has proven definite superiority. Augmented and virtual reality (mixed reality) smartglasses have emerged as an innovative technology to support image-guidance and optimize accuracy during medical interventions. We aimed to investigate the benefits of smartglasses for MRI-guided mixed reality-assisted cognitive targeted biopsy of the prostate.MethodsFor prospectively collected patients with suspect prostate PIRADS lesions, multiparametric MRI was uploaded to a smartglass (Microsoft® Hololens I), and smartglass-assisted targeted biopsy (SMART TB) of the prostate was executed by generation of a cognitive fusion technology at the point-of-care. Detection rates of prostate cancer (PCA) were compared between SMART TB and 12-core systematic biopsy. Assessment of SMART-TB was executed by the two performing surgeons based on 10 domains on a 10-point scale ranging from bad (1) to excellent (10).ResultsSMART TB and systematic biopsy of the prostate were performed for 10 patients with a total of 17 suspect PIRADS lesions (PIRADS 3, n = 6; PIRADS 4, n = 6; PIRADS 5, n = 5). PCA detection rate per core was significant (p < 0.05) higher for SMART TB (47%) than for systematic biopsy (19%). Likelihood for PCA according to each core of a PIRADS lesion (17%, PIRADS 3; 58%, PIRADS 4; 67%, PIRADS 5) demonstrated convenient accuracy. Feasibility scores for SMART TB were high for practicality (10), multitasking (10), execution speed (9), comfort (8), improvement of surgery (8) and image quality (8), medium for physical stress (6) and device handling (6) and low for device weight (5) and battery autonomy (4).ConclusionSMART TB has the potential to increase accuracy for PCA detection and might enhance cognitive MRI-guided targeted prostate biopsy in the future
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