268 research outputs found
Saving Plants and Jobs: Union-Management Negotiations in the Context of Threatened Plant Closing
Gerhart uses a case study approach to examine why plants become economically inviable as well as how to prevent this from happening prematurely.https://research.upjohn.org/up_press/1118/thumbnail.jp
The Economics of Plant Closure
Gerhart uses a case study approach to examine why plants become economically inviable as well as how to prevent this from happening prematurely.https://research.upjohn.org/up_press/1118/thumbnail.jp
Measuring Conditional Anonymity—A Global Study
The realm of digital health is experiencing a global surge, with mobile applications extending their reach into various facets of daily life. From tracking daily eating habits and vital functions to monitoring sleep patterns and even the menstrual cycle, these apps have become ubiquitous in their pursuit of comprehensive health insights. Many of these apps collect sensitive data and promise users to protect their privacy - often through pseudonymization. We analyze the real anonymity that users can expect by this approach and report on our findings. More concretely: We introduce the notion of conditional anonymity sets derived from statistical properties of the population; We measure anonymity sets for two real-world applications and present overarching findings from 39 countries; We develop a graphical tool for people to explore their own anonymity set. One of our case studies is a popular app for tracking the menstruation cycle. Our findings for this app show that, despite their promise to protect privacy, the collected data can be used to identify users up to groups of 5 people in 97% of all the US counties, allowing the de-anonymization of the individuals. Given that the US Supreme Court recently overturned abortion rights, the possibility of determining individuals is a calamity
Myo/Nog cells are nonprofessional phagocytes
Myo/Nog cells were discovered in the chick embryo epiblast. Their expression of MyoD reflects a commitment to the skeletal muscle lineage and capacity to differentiate into myofibroblasts. Release of Noggin by Myo/Nog cells is essential for normal morphogenesis. Myo/Nog cells rapidly respond to wounding in the skin and eyes. In this report, we present evidence suggesting that Myo/Nog cells phagocytose tattoo ink in tissue sections of human skin and engulf cell corpses in cultures of anterior human lens tissue and magnetic beads injected into the anterior chamber of mice in vivo. Myo/Nog cells are distinct from macrophages in the skin and eyes indicated by the absence of labeling with an antibody to ionized calcium binding adaptor molecule 1. In addition to their primary roles as regulators of BMP signaling and progenitors of myofibroblasts, Myo/Nog cells behave as nonprofessional phagocytes defined as cells whose primary functions are unrelated to phagocytosis but are capable of engulfment
Myo/Nog Cells Are Present in the Ciliary Processes, on the Zonule of Zinn and Posterior Capsule of the Lens Following Cataract Surgery
Myo/Nog cells, named for their expression of MyoD and noggin, enter the eye during early stages of embryonic development. Their release of noggin is critical for normal morphogenesis of the lens and retina. Myo/Nog cells are also present in adult eyes. Single nucleated skeletal muscle cells designated as myofibroblasts arise from Myo/Nog cells in cultures of lens tissue. In this report we document the presence of Myo/Nog cells in the lens, ciliary body and on the zonule of Zinn in mice, rabbits and humans. Myo/Nog cells were rare in all three structures. Their prevalence increased in the lens and ciliary body of rabbits 24 h following cataract surgery. Rabbits developed posterior capsule opacification (PCO) within one month of surgery. The number of Myo/Nog cells continued to be elevated in the lens and ciliary body. Myo/Nog cells containing alpha smooth muscle actin and striated muscle myosin were present on the posterior capsule and overlaid deformations in the capsule. Myo/Nog cells also were present on the zonule fibers and external surface of the posterior capsule. These findings suggest that Myo/Nog contribute to PCO and may use the zonule fibers to migrate between the ciliary processes and lens
Measuring Conditional Anonymity - A Global Study
The realm of digital health is experiencing a global surge, with mobile applications extending their reach into various facets of daily life. From tracking daily eating habits and vital functions to monitoring sleep patterns and even the menstrual cycle, these apps have become ubiquitous in their pursuit of comprehensive health insights.
Many of these apps collect sensitive data and promise users to protect their privacy - often through pseudonymization. We analyze the real anonymity that users can expect by this approach and report on our findings. More concretely:
1. We introduce the notion of conditional anonymity sets derived from statistical properties of the population.
2. We measure anonymity sets for two real-world applications and present overarching findings from 39 countries.
3. We develop a graphical tool for people to explore their own anonymity set.
One of our case studies is a popular app for tracking the menstruation cycle. Our findings for this app show that, despite their promise to protect privacy, the collected data can be used to identify users up to groups of 5 people in 97% of all the US counties, allowing the de-anonymization of the individuals. Given that the US Supreme Court recently overturned abortion rights, the possibility
of determining individuals is a calamity
Universally Composable Adaptor Signatures
Adaptor signatures extend the functionality of digital signatures by enabling the computation of pre-signatures on messages relative to statements in NP relations.
Pre-signatures are publicly verifiable objects that simultaneously hide and commit to a standard signature on the same message.
Anyone possessing a valid witness for the statement can adapt the pre-signature into a full signature under the underlying signature scheme.
Since adaptor signatures are commonly used as building blocks in larger systems—such as blockchain protocols—it is natural to seek a security definition within the Universal Composability (UC) framework.
A recent attempt by Tairi et al. (CCS\u2723) introduced the first UC functionality for adaptor signatures.
This paper makes both negative and positive contributions. On the negative side, we show that the functionality proposed by Tairi et al. suffers from critical limitations:
- The functionality fails to guarantee extractability and adaptability—the core security properties of adaptor signatures—to higher-level protocols.
- No adaptor signature scheme can realize the functionality.
On the positive side, we propose a new UC functionality that faithfully captures the latest security guarantees of adaptor signatures as formalized via game-based notions by Gerhart et al. (EUROCRYPT\u2724).
- Our functionality guarantees extractability, unique extractability, and pre-signature adaptability in a way that is composable and meaningful for higher-level protocols.
- We show that it is realizable by an enhanced Schnorr-based adaptor signature scheme that we construct. Our construction maintains compatibility with existing infrastructure and is efficient enough for practical deployment, particularly in Bitcoin-like environments
Practical Schnorr Threshold Signatures Without the Algebraic Group Model
Threshold signatures are digital signature schemes in which a set of signers specify a threshold such that any subset of size is authorized to produce signatures on behalf of the group. There has recently been a renewed interest in this primitive, largely driven by the need to secure highly valuable signing keys, e.g., DNSSEC keys or keys protecting digital wallets in the cryptocurrency ecosystem. Of special interest is FROST, a practical Schnorr threshold signature scheme, which is currently undergoing standardization in the IETF and whose security was recently analyzed at CRYPTO\u2722.
We continue this line of research by focusing on FROST\u27s unforgeability combined with a practical distributed key generation (DKG) algorithm. Existing proofs of this setup either use non-standard heuristics, idealized group models like the AGM, or idealized key generation. Moreover, existing proofs do not consider all practical relevant optimizations that have been proposed. We close this gap between theory and practice by presenting the Schnorr threshold signature scheme Olaf, which combines the most efficient known FROST variant FROST3 with a variant of Pedersen\u27s DKG protocol (as commonly used for FROST), and prove its unforgeability. Our proof relies on the AOMDL assumption (a weaker and falsifiable variant of the OMDL assumption) and, like proofs of regular Schnorr signatures, on the random oracle model
SoK: Descriptive Statistics Under Local Differential Privacy
Local Differential Privacy (LDP) provides a formal guarantee of privacy that enables the collection and analysis of sensitive data without revealing any individual\u27s data. While LDP methods have been extensively studied, there is a lack of a systematic and empirical comparison of LDP methods for descriptive statistics. In this paper, we first provide a systematization of LDP methods for descriptive statistics, comparing their properties and requirements. We demonstrate that several mean estimation methods based on sampling from a Bernoulli distribution are equivalent in the one-dimensional case and introduce methods for variance estimation. We then empirically compare methods for mean, variance, and frequency estimation. Finally, we provide recommendations for the use of LDP methods for descriptive statistics and discuss their limitations and open questions
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