cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Dark matter and alternative recipes for the missing mass
Creators: name: Tortora, Crescenzo
name: Jetzer, Philippe
name: Napolitano, Nicola R.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Within the standard cosmological scenario the Universe is found to be filled by obscure components (dark matter and dark energy) for ~95% of its energy budget. In particular, almost all the matter content in the Universe is given by dark matter, which dominates the mass budget and drives the dynamics of galaxies and clusters of galaxies. Unfortunately, dark matter and dark energy have not been detected and no direct or indirected observations have allowed to prove their existence and amount. For this reason, some authors have suggested that a modification of Einstein Relativity or the change of the Newton's dynamics law (within a relativistic and classical framework, respectively) could allow to replace these unobserved components. We will start discussing the role of dark matter in the early-type galaxies, mainly in their central regions, investigating how its content changes as a function of the mass and the size of each galaxy and few considerations about the stellar Initial mass function have been made. In the second part of the paper we have described, as examples, some ways to overcome the dark matter hypothesis, by fitting to the observations the modified dynamics coming out from general relativistic extended theories and the MOdyfied Newtonian dynamics (MOND).
description: 8 pages, 1 figure, to appear in the Proceedings of the 3rd Italian-Pakistani Workshop on Relativistic Astrophysics, Lecce 20-22 June 2011, published in Journal of Physics: Conference Series (JPCS), references added
Connected domination dot-critical graphs
Creators: name: Chellali, Mustapha
name: Maffray, Frédéric
name: Tablennehas, Kamel
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: A dominating set in a graph G=(V(G),E(G)) is a set D of vertices

such that every vertex in V(G)\ D has a neighbor in D.  A

connected dominating set of a graph G is a dominating set whose

induce subgraph is connected.  The connected domination number

gamma_c(G) is the minimum number of vertices of a connected

dominating set of G.  A graph G is connected domination

dot-critical (cdd-critical) if contracting any two adjacent vertices

decreases gamma_c(G); and G is totally connected domination

dot-critical (tcdd-critical) if contracting any two vertices decreases

gamma_c(G).  We provide characterizations of tcdd-critical graphs

for the classes of block graphs, split graphs and unicyclic graphs and

a characterization of cdd-critical cacti.
description: Contributions to Discrete Mathematics, Vol 5, No 2 (2010)
Enhanced protection against hypoxia/reoxygenation-induced apoptosis in H9c2 cells by puerarin-loaded liposomes modified with matrix metalloproteinases-targeting peptide and triphenylphosphonium
Creators: name: Li, Fengmei
name: Wang, Yan
name: Li, Wenqun
name: Wu, Junyong
name: Li, Shengnan
name: Hu, Xiongbin
name: Tang, Tiantian
name: Liu, Xinyi
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Space Science
subject: Cell Biology
subject: Molecular Biology
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified

description: Based on the inhibition of mitochondrial permeability transition pore (mPTP) opening, puerarin (PUE) has a good potential to reduce myocardial ischemia/reperfusion injury (MI/RI). However, the lack of targeting of free PUE makes it difficult to reach the mitochondria. In this paper, we constructed matrix metalloproteinase-targeting peptide (MMP-TP) and triphenylphosphonium (TPP) cation co-modified liposomes loaded with PUE (PUE@T/M-L) for mitochondria-targeted drug delivery. PUE@T/M-L had a favorable particle size of 144.9 ± 0.8 nm, an encapsulation efficiency of 78.9 ± 0.6%, and a sustained-release behavior. The results of cytofluorimetric experiments showed that MMP-TP and TPP double-modified liposomes (T/M-L) enhanced intracellular uptake, escaped lysosomal capture, and promoted drug targeting into mitochondria. In addition, PUE@T/M-L enhanced the viability of hypoxia-reoxygenation (H/R) injured H9c2 cells by inhibiting mPTP opening and reactive oxygen species (ROS) production, reducing Bax expression and increasing Bcl-2 expression. It was inferred that PUE@T/M-L delivered PUE into the mitochondria of H/R injured H9c2 cells, resulting in a significant increase in cellular potency. Based on the ability of MMP-TP to bind the elevated expression of matrix metalloproteinases (MMPs), T/M-L had excellent tropism for Lipopolysaccharide (LPS) -stimulated macrophages and can significantly reduce TNF-α and ROS levels, thus allowing both drug accumulation in ischemic cardiomyocytes and reducing inflammatory stimulation during MI/RI. Fluorescence imaging results of the targeting effect using a DiR probe also indicated that DiR@T/M-L could accumulate and retain in the ischemic myocardium. Taken together, these results demonstrated the promising application of PUE@T/M-L for mitochondria-targeted drug delivery to achieve maximum therapeutic efficacy of PUE.
An intermediate framework between WIMP, FIMP, and EWIP dark matter
Creators: name: Yaguna, Carlos E.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: WIMP (Weakly Interacting Massive Particle), FIMP (Feebly interacting Massive Particle) and EWIP (Extremely Weakly Interacting Particle) dark matter are different theoretical frameworks that have been postulated to explain the dark matter. In this paper we examine an intermediate scenario that combines features from these three frameworks. It consists of a weakly interacting particle --a la WIMP-- that does not reach thermal equilibrium in the early Universe --a la FIMP-- and whose relic density is determined by the reheating temperature of the Universe --a la EWIP. As an example, an explicit realization of this framework, based on the singlet scalar model of dark matter, is analyzed in detail. In particular, the relic density is studied as a function of the parameters of the model, and the new viable region within this intermediate scenario is determined. Finally, it is shown that this alternative framework of dark matter allows for arbitrarily heavy dark matter particles and that it suggests a connection between dark matter and inflation.
description: 14 pages, 6 figures
Freiman's theorem for solvable groups
Creators: name: Tao, Terence
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: Freiman's theorem asserts, roughly speaking, if that a finite set in a torsion-free abelian group has small doubling, then it can be efficiently contained in (or controlled by) a generalised arithmetic progression.  This was generalised by Green and Ruzsa to arbitrary abelian groups, where the controlling object is now a coset progression.  We extend these results further to solvable groups of bounded derived length, in which the coset progressions are replaced by the more complicated notion of a ``coset nilprogression''.  As one consequence of this result, any subset of such a solvable group of small doubling is is controlled by a set whose iterated products grow polynomially, and which are contained inside a virtually nilpotent group.  As another application we establish a strengthening of the Milnor-Wolf theorem that all solvable groups of polynomial growth are virtually nilpotent, in which only one large ball needs to be of polynomial size.  This result complements recent work of Breulliard-Green, Fisher-Katz-Peng, and Sanders.
description: Contributions to Discrete Mathematics, Vol 5, No 2 (2010)
Ecological interactions between two non-native clams, Venerupis philippinarum and Nuttallia obscurata, in Baynes Sound, British Columbia
Creators: name: Lum, Tina
Publisher: name: University of British Columbia
Year: 2011

description: Manila (Venerupis philippinarum) and varnish (Nuttallia obscurata) clams represent the most abundant clam species in the Strait of Georgia (SoG), British Columbia (BC), yet they never co-occur at relatively high densities. Transplant experiments were initiated in June 2007 in Baynes Sound, BC to examine the relative importance of ecological (relative abundance of the other species, exclusion of predators) and environmental (intertidal height, substrate composition, season) parameters on clam growth, survival and the relative distribution and abundance of these species. Varnish clam shell growth rates were highest in the high (0.30±0.019 mm wk⁻¹) and low (0.27±0.025 mm wk⁻¹) intertidal zones compared to the mid (0.19±0.019 mm wk⁻¹). Manila clam shell growth rates were higher in the low intertidal zone (0.57e±0.013 mm wk⁻¹) when compared to the high (0.46±0.013 mm wk⁻¹). When the relative density of each species was manipulated, no differences were observed in the growth rates of either species, revealing little or no apparent intra- or inter-specific competition for food or space. Neither species was preferentially preyed upon over the duration of the study (~27 wk). These results suggest intertidal height had a stronger influence than ecological interactions on the relative distribution and abundance of Manila and varnish clams in the SoG. However, the specific environmental variable(s) responsible for the observed differences in clam growth rates between intertidal heights were not tested. Other field studies have shown that varnish clams grow well in the high intertidal zone. This study found that varnish clams grew well in the low intertidal zone in addition to the high intertidal zone. This study suggests that the varnish clam invasion in the SoG was successful because this species was able to occupy the high intertidal zone, an area that appears environmentally stressful for the Manila clam. It is possible that the Manila clam is outcompeting the varnish clam at the juvenile stage. This could explain why varnish clams are not naturally observed in the low intertidal zone in the SoG.
On the Parity of p(n,3) and p_Ψ(n,3)
Creators: name: El Bachraoui, Mohamed
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: A partition of $n$ is \emph{relatively prime} if its parts form a relatively prime set.

   The number of partitions of $n$ into exactly $k$ parts is denoted by $p(n,k)$ and the number

   of relatively prime partitions into exactly $k$ parts is denoted by $p_{\Psi}(n,k)$.

   In this paper we deal with the parities of $p(n,3)$ and $p_{\Psi}(n,3)$.
description: Contributions to Discrete Mathematics, Vol 5, No 2 (2010)
Some Ramsey theorems for finite n-colorable and n-chromatic graphs
Creators: name: Nguyen Van Thé, Lionel
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: Given a fixed integer $n$, we prove Ramsey-type theorems for the classes of all finite ordered $n$-colorable graphs, finite $n$-colorable graphs, finite ordered $n$-chromatic graphs, and finite $n$-chromatic graphs.
description: Contributions to Discrete Mathematics, Vol 5, No 2 (2010)
Industry, Faculty, and Students' Perceptions of the Opportunities and Constraints Regarding the Implementation of Professional Skills into Technical Education Programs
Creators: name: Lenci, Samantha
Publisher: name: Graduate Studies
Year: 2018
Subjects: subject: Education--Administration
subject: Education--Adult and Continuing
subject: Education--Community College
subject: Education--Curriculum and Instruction
subject: Education--Teacher Training
subject: Education--Technology
subject: Education--Vocational

description: Little has been written about the inclusion of professional skills in a two-year technical college program and the connection between stakeholder’s perceptions in defining the skill sets graduates need to be successful in industry. This mixed methods research study explored participant’s perceptions of the opportunities and constraints regarding the integration of professional skills in a technical two-year diploma. For the purposes of this research study, professional skills, also called broad-based skills and soft skills, consisted of a set of 17 predetermined skills that three stakeholder groups—industry, faculty, and students—assessed for personal relevance and as a representative of their respective stakeholder group. Data was compiled through a questionnaire completed by faculty, students, and industry member representatives; analyzing job ads, learner exist surveys, and employer satisfaction surveys; followed by conducting focus groups with 56 participants in total. The significant findings from this study encompassed the following aspects. First, the recognition that professional skills are highly regarded, but not always intentionally taught in two-year technical diploma courses. Second, there was a deep-rooted value attached to the identified skill set, but that the barriers to identification and inclusion were different for each participant group. Finally, the notion of inclusion of professional skills in a two-year technical education was encouraged, but that a concerted effort by faculty, industry, and curriculum designers would need to be made in order for student learning of professional skills to be successful.
Bounds and constructions for n-e.c. tournaments
Creators: name: Bonato, Anthony
name: Gordinowicz, Przemysław
name: Prałat, Paweł
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: Few families of tournaments satisfying the $n$-e.c.\ adjacency property are known. We supply a new random construction for generating infinite families of vertex-transitive $n$-e.c.\ tournaments by considering circulant tournaments. Switching is used to generate exponentially many $n$-e.c.\ tournaments of certain orders. With aid of a computer search, we demonstrate that there is a unique minimum order $3$-e.c.\ tournament of order $19,$ and there are no $3$-e.c.\ tournaments of orders $20,$ $21,$ and $22.$
description: Contributions to Discrete Mathematics, Vol 5, No 2 (2010)
Homotopy types of independence complexes of forests
Creators: name: Kawamura, Kazuhiro
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: Ehrenborg and Hetyei proved that the independence complex of an arbitrary forest is either contractible or homotopy equivalent to a sphere.  The present paper provides an inductive method of detecting the contractibility of the complex or the dimension of the sphere to which the complex is homotopy equivalent.
description: Contributions to Discrete Mathematics, Vol 5, No 2 (2010)
Evolutionary models of the optical component of the LMC X-1/Star 32 binary system
Creators: name: Ziolkowski, Janusz
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Calculations carried out to model the evolution of Star 32 under different assumptions about the stellar wind mass-loss rate provide robust limits on the present mass of the star. The obtained range is 31 to 35.5 Msun, which is in very good agreement with the orbital solution of Orosz et al., namely 28.3 to 35.3 Msun. The initial mass of Star 32 had to be in the range 35 to 40 Msun and the present age of the system is 3.7 to 4.0 Myr.
description: accepted for publication in MNRAS
Some remarks on noncommutative Khintchine inequalities
Creators: name: Dirksen, Sjoerd
name: Ricard, Éric
Publisher: name: arXiv
Year: 2011
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46L52, 46L07

description: Normalized free semi-circular random variables satisfy an upper Khintchine inequality in $L_\infty$. We show that this implies the corresponding upper Khintchine inequality in any noncommutative Banach function space. As applications, we obtain a very simple proof of a well-known interpolation result for row and column operator spaces and, moreover, answer an open question on noncommutative moment inequalities concerning a paper by Bekjan and Chen.
Artificial Fingerprinting for Generative Models: Rooting Deepfake Attribution in Training Data
Creators: name: Yu, Ning
name: Skripniuk, Vladislav
name: Abdelnabi, Sahar
name: Fritz, Mario
Publisher: name: CISPA
Year: 2023

description: Photorealistic image generation has reached a new level of quality due to the breakthroughs of generative adversarial networks (GANs). Yet, the dark side of such deepfakes, the malicious use of generated media, raises concerns about visual misinformation. While existing research work on deepfake detection demonstrates high accuracy, it is subject to advances in generation techniques and adversarial iterations on detection countermeasure techniques. Thus, we seek a proactive and sustainable solution on deepfake detection, that is agnostic to the evolution of generative models, by introducing artificial fingerprints into the models. Our approach is simple and effective. We first embed artificial fingerprints into training data, then validate a surprising discovery on the transferability of such fingerprints from training data to generative models, which in turn appears in the generated deepfakes. Experiments show that our fingerprinting solution (1) holds for a variety of cutting-edge generative models, (2) leads to a negligible side effect on generation quality, (3) stays robust against image-level and model-level perturbations, (4) stays hard to be detected by adversaries, and (5) converts deepfake detection and attribution into trivial tasks and outperforms the recent state-of-the-art baselines. Our solution closes the responsibility loop between publishing pre-trained generative model inventions and their possible misuses, which makes it independent of the current arms race.
Isolation and structure elucidation of antioxidant compounds from stem and root barks of Daphne giraldii
Creators: name: Zhang, Jie
name: Chu, Wan-Chun
name: Li, Ling-Zhi
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Pharmacology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified

description: Two new compounds, aphegiractin A1/A2 (1a/1b), and seven known compounds were isolated by phytochemical work on EtOAc-soluble ingredients extracted from stem and root barks of Daphne giraldii. Their structures were established based on extensive spectroscopic methods, including HRESIMS, CD experiments, 1D and 2D NMR. All compounds were evaluated for their antioxidant activity to DPPH, ABTS radical scavenging activity and inhibitory activity on tyrosinase. Of these compounds, compound 3 exhibited significant antioxidant activities.
Multimodal Person Recognition using Social Behavioral Biometric
Creators: name: Sultana, Madeena
Publisher: name: Graduate Studies
Year: 2018
Subjects: subject: Biometrics
subject: Information Security
subject: Cybersecurity
subject: Social Behavioral Biometrics
subject: Information Fusion
subject: Online Social Network
subject: Person Recognition
subject: Social Behavior
subject: Computer Science

description: The goal of a biometric recognition system is to make a human-like decision on individuals’ identity by recognizing their physiological and/or behavioral traits. Nevertheless, decision-making process by either a human or a biometric recognition system can be highly complicated due to low quality of data or an uncertain environment. Human brain has an advantage over computer system due to its ability to perform a massive parallel processing of auxiliary information such as visual cues, cognitive and social interactions, contextual and spatio-temporal data. Similarly to a human brain, social behavioral cues can aid the reliable decision-making of an automated biometric system. Being an integral part of human behavior, social interactions are likely to possess unique behavioral patterns. However, the significance of social behavior for automated user recognition has been noted in the scientific community only recently. In this doctoral thesis, a novel person recognition approach is presented that relies on the knowledge of individuals’ social behavior in order to enhance the performance of a traditional biometric system. The social behavioral information of individuals’ has been mined from an Online Social Network (OSN) and fused with traditional face and ear biometrics. This research identified a set of Social Behavioral Biometric (SBB) features from the online social information and proposed a framework to utilize these features for an automated person recognition for the first time. Extensive experiments confirm that human social behavior expressed through OSN can provide a unique insight onto person recognition. Performance of the proposed multimodal approach has been evaluated to determine the effectiveness of fusing social behavioral information. Experimental results on virtual and semi-real databases demonstrate significant performance gain in the proposed method over traditional biometric system. This doctoral research contributes to an emerging research direction in biometric domain as well as opens new frontier of studying social behavior in virtual domain.
Robustness Certification for Point Cloud Models
Creators: name: Lorenz, Tobias
name: Ruoss, Anian
name: Balunović, Mislav
name: Singh, Gagandeep
name: Vechev, Martin
Publisher: name: CISPA
Year: 2023

description: The use of deep 3D point cloud models in safety-critical applications, such as autonomous driving, dictates the need to certify the robustness of these models to real-world transformations. This is technically challenging, as it requires a scalable verifier tailored to point cloud models that handles a wide range of semantic 3D transformations. In this work, we address this challenge and introduce 3DCertify, the first verifier able to certify the robustness of point cloud models. 3DCertify is based on two key insights: (i) a generic relaxation based on first-order Taylor approximations, applicable to any differentiable transformation, and (ii) a precise relaxation for global feature pooling, which is more complex than pointwise activations (e.g., ReLU or sigmoid) but commonly employed in point cloud models. We demonstrate the effectiveness of 3DCertify by performing an extensive evaluation on a wide range of 3D transformations (e.g., rotation, twisting) for both classification and part segmentation tasks. For example, we can certify robustness against rotations by ±60° for 95.7% of point clouds, and our max pool relaxation increases certification by up to 15.6%.
Characterization of a two-transmon processor with individual single-shot qubit readout
Creators: name: Dewes, A.
name: Ong, F. R.
name: Schmitt, V.
name: Lauro, R.
name: Boulant, N.
name: Bertet, P.
name: Vion, D.
name: Esteve, D.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We report the characterization of a two-qubit processor implemented with two capacitively coupled tunable superconducting qubits of the transmon type, each qubit having its own non-destructive single-shot readout. The fixed capacitive coupling yields the \sqrt{iSWAP} two-qubit gate for a suitable interaction time. We reconstruct by state tomography the coherent dynamics of the two-bit register as a function of the interaction time, observe a violation of the Bell inequality by 22 standard deviations after correcting readout errors, and measure by quantum process tomography a gate fidelity of 90%.
The regular number of a graph
Creators: name: Ganesan, Ashwin
name: Iyer, Radha R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Discrete Mathematics (cs.DM)
subject: Combinatorics (math.CO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Let $G$ be a simple undirected graph. The regular number of $G$ is defined to be the minimum number of subsets into which the edge set of $G$ can be partitioned so that the subgraph induced by each subset is regular. In this work, we obtain the regular number of some families of graphs and discuss some general bounds on this parameter. Also, some of the lower or upper bounds proved in \cite{Kulli:Janakiram:Iyer:2001} are shown here to hold with equality.
Synthesis of Large-Area MoS2 Atomic Layers with Chemical Vapor Deposition
Creators: name: Lee, Yi-Hsien
name: Zhang, Xin-Quan
name: Zhang, Wenjing
name: Chang, Mu-Tung
name: Lin, Cheng-Te
name: Chang, Kai-Di
name: Yu, Ya-Chu
name: Wang, Jacob Tse-Wei
name: Chang, Chia-Seng
name: Li, Lain-Jong
name: Lin, Tsung-Wu
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Large-area MoS2 atomic layers are synthesized on SiO2 substrates by chemical vapor deposition using MoO3 and S powders as the reactants. Optical, microscopic and electrical measurements suggest that the synthetic process leads to the growth of MoS2 monolayer. The TEM images verify that the synthesized MoS2 sheets are highly crystalline.
description: First submitted on 12-Dec-2011. Accepted in Adv. Mater
Isolation, purification and identification of two new alkaloids metabolites from marine-derived Verrucosispora sp. FIM06025
Creators: name: Chen, Ming-Hong
name: Zhang, Wen-Long
name: Chen, Li
name: Lin, Ru
name: Xie, Yang
name: Fang, Dong-Sheng
name: Lian, Yun-Yang
name: Jiang, Hong
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Virology

description: Chemical investigation of a marine-derived actinomycete strain Verrucosispora sp. FIM06025 isolated from a marine sponge sample collected from the East China Sea, resulted in the discovery of two new alkaloids, (2-(hydroxymethyl)-3-(2-(hydroxymethyl)-3-methylaziridin-1-yl) (2-hydroxyphenyl) methanone (1) and 2-(1-hydroxyethyl)-3,4-dihydrobenzo [f] [1,4]oxazepin-5(2H)-one (2). The structures of compounds 1 and 2 were determined by the detailed analysis of 1D, 2D NMR and HR-TOF-MS data, along with literature data analysis. The bioefficacy investigations revealed that compound 1 exhibited a broad spectrum of antimicrobial activity with MIC (minimum inhibitory concentration) values ranging from 3.4 to 200 μg·mL−1 against H. pylori, P. aeroginosa, A. baumanniiin, E. coli and K. pneumonia, S. aureus, C. albicans and E. faecium, however, compound 2, up to 200 μg/mL, displayed no antibacterial activity against these bacteria.
Preventable adverse events in surgical patients: A meta-analysis and knowledge, attitude, and practice (KAP) assessment
Creators: name: Austin, Janice Lynn
Publisher: name: Cumming School of Medicine
Year: 2018
Subjects: subject: Medical Education
subject: Surgery
subject: survey
subject: meta-analysis
subject: adverse event
subject: error
subject: Education
subject: Medicine and Surgery

description: All surgical procedures come with a risk of adverse events (AEs). To improve patient safety and prevent similar errors in the future, errors must be acknowledged and addressed. In this study a meta-analysis of patient safety literature in surgery was conducted and a Knowledge, Attitudes, and Practice (KAP) assessment survey of Calgary academic surgeons was performed.Results of the meta-analysis demonstrated a preventable adverse event (PAE) rate of 10.5 PAEs per 100 patients across all surgical specialties and a preventable death rate of 0.5 per 100 surgical patients. The KAP survey assessment demonstrated that 20% of surgeons could correctly identify the definition of both AE and error. Participants reported the factors contributing to an error to be multifactorial. The most frequently used methods to teach patient safety were Morbidity and Mortality rounds and individual feedback. Less than 25% of surgeons track their own AE rate. These results have implications for surgical postgraduate education, as well as for surgical practice in Canada. Recommendations are made for the development of a formal patient safety curriculum for all surgical trainees, with the aim of decreasing the number of errors. In addition, it is essential that more high-quality studies that include reproducible methods and consistent definitions of AEs and errors be conducted.
Automatically Eliminating Speculative Leaks from Cryptographic Code with Blade
Creators: name: Vassena, Marco
name: Disselkoen, Craig
name: Cauligi, Sunjay
name: Gleissenthall, Klaus
name: Kici, Rami Gökhan
name: Jhala, Ranjit
name: Stefan, Deian
name: Tullsen, Dean
Publisher: name: CISPA
Year: 2023

description: We introduce Blade, a new approach to automatically and efficiently eliminate speculative leaks from cryptographic code. Blade is built on the insight that to stop leaks via speculative execution, it suffices to cut the dataflow from expressions that speculatively introduce secrets (sources) to those that leak them through the cache (sinks), rather than prohibit speculation altogether. We formalize this insight in a static type system that (1) types each expression as either transient, i.e., possibly containing speculative secrets or as being stable, and (2) prohibits speculative leaks by requiring that all sink expressions are stable. Blade relies on a new abstract primitive, protect, to halt speculation at fine granularity. We formalize and implement protect using existing architectural mechanisms, and show how Blade’s type system can automatically synthesize a minimal number of protects to provably eliminate speculative leaks. We implement Blade in the Cranelift WebAssembly compiler and evaluate our approach by repairing several verified, yet vulnerable WebAssembly implementations of cryptographic primitives. We find that Blade can fix existing programs that leak via speculation automatically, without user intervention, and efficiently even when using fences to implement protect.
Class I methanol masers in low-mass star formation regions
Creators: name: Kalenskii, S. V.
name: Slysh, V. I.
name: Johansson, L. E. B.
name: Bergman, P.
name: Kurtz, S.
name: Hofner, P.
name: Walmsley, C. M.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Four Class I maser sources were detected at 44, 84, and 95 GHz toward chemically rich outflows in the regions of low-mass star formation NGC 1333I4A, NGC 1333I2A, HH25, and L1157. One more maser was found at 36 GHz toward a similar outflow, NGC 2023. Flux densities of the newly detected masers are no more than 18 Jy, being much lower than those of strong masers in regions of high-mass star formation. The brightness temperatures of the strongest peaks in NGC 1333I4A, HH25, and L1157 at 44 GHz are higher than 2000 K, whereas that of the peak in NGC 1333I2A is only 176 K. However, rotational diagram analysis showed that the latter source is also a maser. The main properties of the newly detected masers are similar to those of Class I methanol masers in regions of massive star formation. The former masers are likely to be an extension of the latter maser population toward low luminosities of both the masers and the corresponding YSOs.
description: 5 pages, 1 figure, Proc. IAU Symp. 287 "Cosmic Masers: from OH to H0". LSR velocities of the HH25 masers, which are presented in Table 1, are corrected
Do Observations Favour Galileon Over Quintessence?
Creators: name: Hossain, Md. Wali
name: Sen, Anjan A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the Galileon scalar field model arising as a decoupling limit of the Dvali-Gababdaze-Porrati (DGP) construction for the late time acceleration of the universe. The model has one extra Galileon correction term over and above the standard kinetic and potential energy terms for a canonical quintessence field. We aim to study whether the current observational data can distinguish between this Galileon field and the quintessence field. Our study shows the remarkable result that for potentials like linear, square or exponential, the data prefers the Galileon model over quintessence field. It confirms that the observable universe demands the inclusion of higher derivative Galileon corrections in the standard quintessence scalar field models.
description: 5 pages, Revtex style, three eps figures, revised version with new comments added. Conclusion is unchanged
Melting of a frustration-induced dimer crystal and incommensurability in the J_1-J_2 two-leg ladder
Creators: name: Lavarélo, Arthur
name: Roux, Guillaume
name: Laflorencie, Nicolas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The phase diagram of an antiferromagnetic ladder with frustrating next-nearest neighbor couplings along the legs is determined using numerical methods (exact diagonalization and density-matrix renormalization group) supplemented by strong-coupling and mean-field analysis. Interestingly, this model displays remarkable features, bridging the physics of the J_1-J_2 chain and of the unfrustated ladder. The phase diagram as a function of the transverse coupling J_{\perp} and the frustration J_2 exhibits an Ising transition between a columnar phase of dimers and the usual rung-singlet phase of two-leg ladders. The transition is driven by resonating valence bond fluctuations in the singlet sector while the triplet spin gap remains finite across the transition. In addition, frustration brings incommensurability in the real-space spin correlation functions, the onset of which evolves smoothly from the J_1-J_2 chain value to zero in the large-J_{\perp} limit. The onset of incommensurability in the spin structure-factor and in the dispersion relation is also analyzed. The physics of the frustrated rung-singlet phase is well understood using perturbative expansions and mean-field theories in the large-J_{\perp} limit. Lastly, we discuss the effect of the non-trivial magnon dispersion relation on the thermodynamical properties of the system. The relation of this model and its physics to experimental observations on compounds which are currently investigated, such as BiCu_2PO_6, is eventually addressed.
description: 13 pages, 13 figures
Injective and non-injective realizations with symmetry
Creators: name: Schulze, Bernd
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: In this paper, we introduce a natural classification of bar and joint frameworks that possess symmetry. This classification establishes the mathematical foundation for extending a variety of results in rigidity, as well as infinitesimal or static rigidity, to frameworks that are realized with certain symmetries and whose joints may or may not be embedded injectively in the space. In particular, we introduce a symmetry-adapted notion of `generic' frameworks with respect to this classification and show that `almost all' realizations in a given symmetry class are generic and all generic realizations in this class share the same infinitesimal rigidity properties.

Within this classification we also clarify under what conditions group representation theory techniques can be applied to further analyze the rigidity properties of a (not necessarily injective) symmetric realization.
description: Contributions to Discrete Mathematics, Vol 5, No 1 (2010)
Polarimetric Imaging of Sgr A* in its Flaring State
Creators: name: Melia, Fulvio
name: Falanga, Maurizio
name: Goldwurm, Andrea
Publisher: name: arXiv
Year: 2011
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Galaxy's supermassive black hole, Sgr A*, produces an outburst of infrared radiation about once every 6 hours, sometimes accompanied by an even more energetic flurry of X-rays. The NIR photons are produced by nonthermal synchrotron processes, but we still don't completely understand where or why these flares originate, nor exactly how the X-rays are emitted. The power-law electrons radiating the infrared light may be partially cooled, so the distribution may be a broken power law with a ("cooling break") transition frequency. In addition, the emission region appears to be rather compact, possibly restricted to the inner edge of the accretion disk. In that case, the X-ray outburst may itself be due to synchrotron processes by the most energetic particles in this population. In this paper, we examine several key features of this proposal, producing relativistically correct polarimetric images of Sgr A*'s NIR and X-ray flare emission, in order to determine (1) whether the measured NIR polarization fraction is consistent with this geometry, and (2) whether the predicted X-ray to NIR peak fluxes are confirmed by the currently available multi-wavelength observations. We also calculate the X-ray polarization fraction and position angle (relative to that of the NIR photons) in anticipation of such measurements in the coming years. We show that whereas the polarization fraction and position angle of the X-rays are similar to those of the NIR component for synchrotron-cooled emission, these quantities are measurably different when the X-rays emerge from a scattering medium. It is clear, therefore, that the development of X-ray polarimetry will represent a major new tool for studying the spacetime near supermassive black holes.
description: Accepted for Publication in MNRAS, September 26, 2011
Unavoidable arrays
Creators: name: Markström, Klas
name: Öhman, Lars-Daniel
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: An $n \times n$ array is \emph{avoidable} if for each set of $n$ symbols there is a Latin square on these symbols which differs from the array in every cell. We characterise all unavoidable square arrays with at most 2 symbols, and all unavoidable arrays of order at most 4. We also identify a number of general families of unavoidable arrays, which we conjecture to be a complete account of unavoidable arrays. Next, we investigate arrays with multiple entries in each cell, and identify a number of families of unavoidable multiple entry arrays. We also discuss fractional Latin squares, and their connections to unavoidable arrays.

We note that when rephrasing our results as edge list-colourings of complete bipartite graphs, we have a situation where the lists of available colours are shorter than the length guaranteed by Galvin's theorem to allow proper colourings.
description: Contributions to Discrete Mathematics, Vol 5, No 1 (2010)
Causally simple inextendible spacetimes are hole-free
Creators: name: Minguzzi, E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It is shown that causally simple inextendible spacetimes are hole-free, thus confirming the expectation that causal simplicity removes holes from spacetime. This result is optimal in the sense that causal simplicity cannot be weakened to causal continuity. Physically, it means that if there is some partial Cauchy hypersurface which, for some reason, does not fully develop its influence, then there is some discontinuity in the causal relation.
description: Revtex4, 9 pages. v2: minor corrections
A characterization of the base-matroids of a graphic matroid
Creators: name: Maffioli, Francesco
name: Zagaglia Salvi, Norma
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: Let $M = (E, \mathcal{F})$ be a matroid on a set $E$ and $B$ one of its bases. A closed set $\theta \subseteq E$ is saturated with respect to $B$ when $|\theta \cap B | \leq r(\theta)$, where $r(\theta)$ is the rank of $\theta$. The collection of subsets $I$ of $E$ such that $| I \cap \theta| \leq r(\theta)$ for every closed saturated set $\theta$ turns out to be the family of independent sets of a new matroid on $E$, called base-matroid and denoted by $M_B$. In this paper we prove that a graphic matroid $M$, isomorphic to a cycle matroid $M(G)$, is isomorphic to $M_B$, for every base $B$ of $M$, if and only if $M$ is direct sum of uniform graphic matroids or, in equivalent way, if and only if $G$ is disjoint union of cacti.  Moreover we characterize simple binary matroids $M$ isomorphic to $M_B$, with respect to an assigned base $B$.
description: Contributions to Discrete Mathematics, Vol 5, No 1 (2010)
Intermediate band formation and intraband absorption for electrons in an inhomogeneous chain of quantum dots
Creators: name: Bragar, Igor
name: Machnikowski, Paweł
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the electron states of a chain of non-identical, vertically stacked quantum dots (QDs). We discuss how the pseudo-band formed of the ground states confined in the QDs disintegrates upon increasing the inhomogeneity of the electron energies and analyze the impact of localization on the intraband absorption from the pseudo-band to extended (bulk) states. We describe also the dependence of the intraband absorption spectrum on the QD size.
description: 4 pages, 4 figures. Conference "Jaszowiec" 2011
On the number of  components of a graph
Creators: name: Si Kaddour, Hamza
name: Tahhan Bittar, Elias
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: Let $G:=(V,E)$ be a simple graph; for $I\subseteq V$ we denote by

  $l(I)$ the number of components of $G[I]$, the subgraph of $G$

  induced by $I$.  For $V_1,\ldots , V_n$ subsets of $V$, we define a

  function $\beta (V_1,\ldots , V_n)$ which is expressed in terms of

  $l\left(\bigcup _{i=1} ^{n} V_i\right)$ and $l(V_i\cup

  V_j)$ for $i\leq j$. If $V_1,\ldots , V_n$ are pairwise disjoint

  independent subsets of $V$, the number $\beta (V_1,\ldots , V_n)$

  can be computed in terms of the cyclomatic numbers of

  $G\left[\bigcup _{i=1} ^{n} V_i\right]$ and $G[

  V_i\cup V_j]$ for $i\neq j$.  In the general case, we prove that

  $\beta (V_1,\ldots , V_n)\geq 0$ and characterize when $\beta

  (V_1,\ldots , V_n)= 0$.  This special case yields a formula

  expressing the length of members of an interval algebra \cite{s} as

  well as extensions to pseudo-tree algebras. Other examples are

  given.
description: Contributions to Discrete Mathematics, Vol 5, No 1 (2010)
Experimental realization of strong effective magnetic fields in an optical lattice
Creators: name: Aidelsburger, Monika
name: Atala, Marcos
name: Nascimbène, Sylvain
name: Trotzky, Stefan
name: Chen, Yu-Ao
name: Bloch, Immanuel
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We use Raman-assisted tunneling in an optical superlattice to generate large tunable effective magnetic fields for ultracold atoms. When hopping in the lattice, the accumulated phase shift by an atom is equivalent to the Aharonov-Bohm phase of a charged particle exposed to a staggered magnetic field of large magnitude, on the order of one flux quantum per plaquette. We study the ground state of this system and observe that the frustration induced by the magnetic field can lead to a degenerate ground state for non-interacting particles. We provide a measurement of the local phase acquired from Raman-induced tunneling, demonstrating time-reversal symmetry breaking of the underlying Hamiltonian. Furthermore, the quantum cyclotron orbit of single atoms in the lattice exposed to the magnetic field is directly revealed.
description: 6 pages, 5 figures
Poster: Results of an infection and microbiological surveillance of Panton-Valentine leucocidin (PVL)-forming S. aureus strains
Creators: name: Neuwirth, Meike M.
name: Wendel, Andreas
name: Malecki, Monika
name: Mattner, Frauke
Publisher: name: Zenodo
Year: 2021
Subjects: methicillin resistant Staphylococcus aureus strains (MRSA)
methicillin susceptible Staphylococcus aureus strains (MSSA)
infection surveillance
possible outbreak

description: Introduction:
 The toxin PVL can be produced by both methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) Staphylococcus aureus strains. Due to the lysing effect of PVL on leukocytes, severe infections can be caused by the producing bacteria .A microbiological and infection surveillance of PVL-producing S. aureus was performed in three Cologne hospitals between 2014 and 2020 and triggered by the detection of S. aureus in combination with recurrent skin infections, severe pneumonia or possible outbreaks. Objectives:
 Aim of the study was to investigate if several strains are endemic in the population and if there is an epidemic situation with one strain or a mixture of several strains. The study aimed to investigate if multiple strains are endemic in the population and if there is an epidemic situation with one strain or a mixture of multiple strains. Methods:
 In case of skin infection or pneumonia and detection of community-acquired S. aureus, bacterial isolates were tested by PCR for the production of PVL by amplifying the encoding gene lukS and included in the surveillance if positive. 46 from 55 bacterial isolates were available for further next generation sequencing. Assembled genomes were analysed (core genome MLST by SeqSphere+, Ridom; ResFinder analysis). Results:
 A total of 55 patients (30♂, 25♀) aged 0-81 years (M=15.4±16.9¸MD=10), with an S. aureus strain with lukS gene were recorded (34 patients with PVL-MSSA; 21 with PVL-MRSA). In 10 patients, re-hospitalization was necessary due to recurrent infections caused by PVL-positive S. aureus strains. After positive lukS gene detection, decolonization was performed in 9 individuals, no decolonization was performed in 39, and no information was available for 7 individuals. Infections occurred most frequently on the buttocks (N=10) and thighs (N=8). A high clonal diversity was detected comprising 16 cgMLST types of PVL S. aureus. 5 small clusters were identified, however transmissions were confirmed in only one cluster (tempo-spatial overlap). Conclusion:
 Epidemiologically, an endemic situation with PVL S. aureus and few transmissions were identified in this study. Active surveillance is nevertheless necessary to identify a cluster of PVL-positive cases and possibly an outbreak and to guide therapy and infection control measures.