128 research outputs found

    Service-dominant business design

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    Conceptual Issuess and Assessment of Implicit Theories

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    We reviewed fundamental conceptual issues and the state of research on the definition and assessment of implicit theories. We grappled with the following controversies related to the construct: (a) Are entity theory and incremental theory opposite ends of the same continuum? (b) How can scholars use more sophisticated methodologies to classify individuals into either the entity or incremental theory? (c) Given shifting conceptions of what intelligence is, how can scholars refine the implicit theory of intelligence construct? Given these conceptual issues, we then addressed practical issues related to the assessment of implicit theories. We point to the need for more sophisticated methods such as implicit association tests and the use of virtual environments as more “stealthy” ways to assess the construct

    How Did COVID-19 Affect Education and What Can Be Learned Moving Forward?

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    Abstract: The COVID-19 pandemic drastically impacted the educational sector on a global front. A plethora of research has been conducted to better understand the effects that the pandemic had on education as a whole, including investigations into different topics (e.g., school closures, e-teaching and learning, mental and physical health), populations (e.g., students, teachers), and levels of education (e.g., school, higher education). To summarize the available literature on education during the pandemic both qualitatively and quantitatively, many systematic reviews and meta-analyses have begun to emerge. With the present systematic meta-review, we aimed to synthesize and combine this existing database to derive broader and more comprehensive insights that can aid educational stakeholders. We summarize and evaluate 43 systematic reviews, four meta-analyses, and eight combined systematic reviews and meta-analyses published until November 2022 to provide a comprehensive narrative of how this crisis affected education and what can be learned moving forward

    Higher Education in Times of COVID-19 : University Students' Basic Need Satisfaction, Self-Regulated Learning, and Well-Being

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    In the wake of COVID-19, university students have experienced fundamental changes of their learning and their lives as a whole. The present research identifies psychological characteristics associated with students' well-being in this situation. We investigated relations of basic psychological need satisfaction (experienced competence, autonomy, and relatedness) with positive emotion and intrinsic learning motivation, considering self-regulated learning as a moderator. Self-reports were collected from 6,071 students in Austria (Study 1) and 1,653 students in Finland (Study 2). Structural equation modeling revealed competence as the strongest predictor for positive emotion. Intrinsic learning motivation was predicted by competence and autonomy in both countries and by relatedness in Finland. Moderation effects of self-regulated learning were inconsistent, but main effects on intrinsic learning motivation were identified. Surprisingly, relatedness exerted only a minor effect on positive emotion. The results inform strategies to promote students' well-being through distance learning, mitigating the negative effects of the situation.Peer reviewe

    A Signature-Based Gröbner Basis Algorithm with Tail-Reduced Reductors (M5GB)

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    Gröbner bases are an important tool in computational algebra and, especially in cryptography, often serve as a boilerplate for solving systems of polynomial equations. Research regarding (efficient) algorithms for computing Gröbner bases spans a large body of dedicated work that stretches over the last six decades. The pioneering work of Bruno Buchberger in 1965 can be considered as the blueprint for all subsequent Gröbner basis algorithms to date. Among the most efficient algorithms in this line of work are signature-based Gröbner basis algorithms, with the first of its kind published in the late 1990s by Jean-Charles Faugère under the name F5\texttt{F5}. In addition to signature-based approaches, Rusydi Makarim and Marc Stevens investigated a different direction to efficiently compute Gröbner bases, which they published in 2017 with their algorithm M4GB\texttt{M4GB}. The ideas behind M4GB\texttt{M4GB} and signature-based approaches are conceptually orthogonal to each other because each approach addresses a different source of inefficiency in Buchberger\u27s initial algorithm by different means. We amalgamate those orthogonal ideas and devise a new Gröbner basis algorithm, called M5GB\texttt{M5GB}, that combines the concepts of both worlds. In that capacity, M5GB\texttt{M5GB} merges strong signature-criteria to eliminate redundant S-pairs with concepts for fast polynomial reductions borrowed from M4GB\texttt{M4GB}. We provide proofs of termination and correctness and a proof-of-concept implementation in C++ by means of the Mathic library. The comparison with a state-of-the-art signature-based Gröbner basis algorithm (implemented via the same library) validates our expectations of an overall faster runtime for quadratic overdefined polynomial systems that have been used in comparisons before in the literature and are also part of cryptanalytic challenges

    Reinforced Concrete: A Fast Hash Function for Verifiable Computation

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    We propose a new hash function Reinforced Concrete, which is the first generic purpose hash that is fast both for a zero-knowledge prover and in native x86 computations. It is suitable for a various range of zero-knowledge proofs and protocols, from set membership to generic purpose verifiable computation. Being up to 15x faster than its predecessor Poseidon hash, Reinforced Concrete inherits security from traditional time-tested schemes such as AES, whereas taking the zero-knowledge performance from a novel and efficient decomposition of a prime field into compact buckets. The new hash function is suitable for a wide range of applications like privacy-preserving cryptocurrencies, verifiable encryption, protocols with state membership proofs, or verifiable computation. It may serve as a drop-in replacement for various prime-field hashes such as variants of MiMC, Poseidon, Pedersen hash, and others

    Hash Functions Monolith for ZK Applications: May the Speed of SHA-3 be With You

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    The rising popularity of computational integrity protocols has led to an increased focus on efficient domain-specific hash functions, which are one of the core components in these use cases. For example, they are used for polynomial commitments or membership proofs in the context of Merkle trees. Indeed, in modern proof systems the computation of hash functions is a large part of the entire proof\u27s complexity. In the recent years, authors of these hash functions have focused on components which are verifiable with low-degree constraints. This led to constructions like Poseidon, Rescue, Griffin, Reinforced Concrete, and Tip5, all of which showed significant improvements compared to classical hash functions such as SHA-3 when used inside the proof systems. In this paper, we focus on lookup-based computations, a specific component which allows to verify that a particular witness is contained in a lookup table. We work over 31-bit and 64-bit finite fields Fp\mathbb F_p, both of which are used in various modern proof systems today and allow for fast implementations. We propose a new 2-to-1 compression function and a SAFE hash function, instantiated by the Monolith permutation. The permutation is significantly more efficient than its competitors, both in terms of circuit friendliness and plain performance, which has become one of the main bottlenecks in various use cases. This includes Reinforced Concrete and Tip5, the first two hash functions using lookup computations internally. Moreover, in Monolith we instantiate the lookup tables as functions defined over F2\mathbb F_2 while ensuring that the outputs are still elements in Fp\mathbb F_p. Contrary to Reinforced Concrete and Tip5, this approach allows efficient constant-time plain implementations which mitigates the risk of side-channel attacks potentially affecting competing lookup-based designs. Concretely, our constant time 2-to-1 compression function is faster than a constant time version of Poseidon2 by a factor of 7. Finally, it is also the first arithmetization-oriented function with a plain performance comparable to SHA3-256, essentially closing the performance gap between circuit-friendly hash functions and traditional ones

    Sexuality and erectile function after implantation of an Adjustable Transobturator Male System (ATOMS) for urinary stress incontinence. A multi-institutional prospective study

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    Objectives: To investigate erectile function and sexuality before/after implantation of the ATOMS device including continence outcome, pain perception and co-morbidities. Materials and methods: We collected data from 34 patients (2010-2014) who were provided with an ATOMS implant due to mild or moderate stress urinary incontinence (SUI) after radical prostatectomy (RPE), transurethral resection (TURP) or radiotherapy. Previous failed implants were no contraindication. Sexuality was evaluated with the International Index of Erectile Function (IIEF-5). The Visual Analog Scale (VAS) and Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) were used to analyse pain perception. Results regarding continence, influence of co-morbidities and drug intake were interpreted. Results: IIEF-5 score increased 6 months after ATOMS implantation with a mean difference of 2.18 (Cl: 1.22, 3.14), p < 0,001). Non-sexually active patients had the greatest benefit. However, 50% of patients achieved a mean IIEF-5 of 10.1 and 38% of patients reported a new onset of sexual activity at follow up (mean IIEF-5 score of 12.9). This is in accordance with reduced SUI and absence of persistent pain syndrome. Overall success rate regarding 24h pad-use was 88% (no pad rate 38%). Previous failed implants did not influence results but diabetes, obesity and drug intake (beta-blockers, antidepressants) led to poorer outcomes. Conclusion: Sexuality and erectile function improves significantly 6 months after ATOMS implantation. We postulate that reduced SUI (also during sexual activity) and absence of chronic pain are the improving factors. ATOMS should be offered to men with mild to moderate SUI who are interested in regaining their erectile function and sexual activity

    Analysis of Prototype Foamy Virus particle-host cell interaction with autofluorescent retroviral particles

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    <p>Abstract</p> <p>Background</p> <p>The foamy virus (FV) replication cycle displays several unique features, which set them apart from orthoretroviruses. First, like other B/D type orthoretroviruses, FV capsids preassemble at the centrosome, but more similar to hepadnaviruses, FV budding is strictly dependent on cognate viral glycoprotein coexpression. Second, the unusually broad host range of FV is thought to be due to use of a very common entry receptor present on host cell plasma membranes, because all cell lines tested in vitro so far are permissive.</p> <p>Results</p> <p>In order to take advantage of modern fluorescent microscopy techniques to study FV replication, we have created FV Gag proteins bearing a variety of protein tags and evaluated these for their ability to support various steps of FV replication. Addition of even small N-terminal HA-tags to FV Gag severely impaired FV particle release. For example, release was completely abrogated by an N-terminal autofluorescent protein (AFP) fusion, despite apparently normal intracellular capsid assembly. In contrast, C-terminal Gag-tags had only minor effects on particle assembly, egress and particle morphogenesis. The infectivity of C-terminal capsid-tagged FV vector particles was reduced up to 100-fold in comparison to wild type; however, infectivity was rescued by coexpression of wild type Gag and assembly of mixed particles. Specific dose-dependent binding of fluorescent FV particles to target cells was demonstrated in an Env-dependent manner, but not binding to target cell-extracted- or synthetic- lipids. Screening of target cells of various origins resulted in the identification of two cell lines, a human erythroid precursor- and a zebrafish- cell line, resistant to FV Env-mediated FV- and HIV-vector transduction.</p> <p>Conclusions</p> <p>We have established functional, autofluorescent foamy viral particles as a valuable new tool to study FV - host cell interactions using modern fluorescent imaging techniques. Furthermore, we succeeded for the first time in identifying two cell lines resistant to Prototype Foamy Virus Env-mediated gene transfer. Interestingly, both cell lines still displayed FV Env-dependent attachment of fluorescent retroviral particles, implying a post-binding block potentially due to lack of putative FV entry cofactors. These cell lines might ultimately lead to the identification of the currently unknown ubiquitous cellular entry receptor(s) of FVs.</p
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