Resource Marginal Problems

We introduce the resource marginal problems, which concern the possibility of having a resource-free target subsystem compatible with a given collection of marginal density matrices. By identifying an appropriate choice of resource R and target subsystem T, our problems reduce, respectively, to the well-known marginal problems for quantum states and the problem of determining if a given quantum system is a resource. More generally, we say that a set of marginal states is resource-free incompatible with a target subsystem T if all global states compatible with this set must result in a resourceful state in T. We show that this incompatibility induces a resource theory that can be quantified by a monotone, and obtain necessary and sufficient conditions for this monotone to be computable as a conic program with finite optimum. We further show, via the corresponding witnesses, that resource-free incompatibility is equivalent to an operational advantage in some subchannel discrimination task. Through our framework, a clear connection can be established between any marginal problem (that involves some notion of incompatibility) for quantum states and a resource theory for quantum states. In addition, the universality of our framework leads, for example, to further quantitative understanding of the incompatibility associated with the recently-proposed entanglement marginal problems as well as entanglement transitivity problems. As a byproduct of our investigation, we obtain the first example showing a form of transitivity of nonlocality as well as steerability for quantum states, thereby answering a decade-old question to the positive.Comment: 7+11 pages and 3 figures; with restructured manuscript & improved presentatio

Utilizing the metabolic syndrome component count in workers’ health surveillance: An example of day-time vs. day-night rotating shift workers

Objectives: To establish a practical method for assessing the general metabolic health conditions among different employee groups, this study utilized the total count of metabolic syndrome (MetS) elements as a parameter, and performed a retrospective analysis comparing changes of MetS component count (MSC) of 5 years among day-time work (DW) and day-andnight rotating shift work (RSW) employees. Material and Methods: The data of personal histories, physical examinations, blood tests, abdominal sonographic examinations and occupational records were collected from a cohort of workers in an electronics manufacturing company. We first defined the arithmetic mean value of MSC as MSC density (MSCD) for the employee group; then we compared the changes of MSCD over 5 years between DW and RSW workers. Occupational, personal and health records were analyzed for the 1077 workers with an initial mean age of 32.4 years (standard deviation (SD): 6.2 years), including 565 RSW workers (52%). Results: The initial MSCDs were 1.26 and 1.12 (p = 0.06) for DW and RSW workers, respectively; after 5 years, the increments of MSCD for DW and RSW workers were 0.10 and 0.39, respectively (p < 0.01). By performing multivariate logistic regression analyses, and comparing with DW co-workers, final results indicated that the workers exposed to RSW have 1.7-fold increased risk of elevated MSCD (95% confidence interval (CI): 1.28–2.25, p < 0.01); and are 38% less likely (adjusted rate ratio (aRR) 0.62, 95% CI: 0.45–0.86, p < 0.01) to attain decreased MSCD. Conclusions: These observations demonstrate that changes of MSCD are significantly different between DW and RSW workers, and are increasingly associated with RSW exposure. In conclusion, MSCD can represent the general metabolic health conditions of a given employee group; MSC, MSCD and their transitional changes can be applied as simple and standardized tools for monitoring metabolic health risk profiles when managing employee health, at both the individual and company levels

Remotely-sensed imagery vs. eye-level photography: Evaluating associations among measurements of tree cover density

AbstractThe easy availability and widespread use of remotely-sensed imagery, especially Google Earth satellite imagery, makes it simple for urban forestry professionals to assess a site and measure tree cover density without visiting the site. Remotely-sensed tree cover density has become the dominant criterion for urban forestry regulations in many countries, but it is unclear how much such measures match the eye-level tree cover density that people experience; or the information gained through site visits, eye-level photography, or from consulting with citizens. To address this uncertainty, we assessed associations among two remotely-sensed and three eye-level tree cover density measures for 140 community street sites across the Midwestern United States with low, medium, or high tree cover coverage by using linear regression analysis. We found significant associations among the two remotely-sensed measures and the three eye-level measures across the three levels of tree cover. The associations between any pair of remotely-sensed and eye-level measures, however, diminish dramatically as canopy cover increased. At high levels of canopy cover, all associations between the remotely-sensed measures and the eye-level measures became statistically insignificant. These findings suggest that measures from remotely-sensed imagery fail to represent the amount of tree cover people perceive at eye-level when canopy cover is medium or high at the site scale. Therefore, the current urban forestry planning regulations, which rely heavily on remotely-sensed tree cover density measurements, need to be revised. We suggest strategic spots where eye-level measures of tree cover density should be emphasized

Validation of the Action Research Arm Test using item response theory in patients after stroke

Objective: To validate the unidimensionality of the Action Research Arm Test (ARAT) using Mokken analysis and to examine whether scores of the ARAT can be transformed into interval scores using Rasch analysis. Subjects and methods: A total of 351 patients with stroke were recruited from 5 rehabilitation departments located in 4 regions of Taiwan. The 19-item ARAT was administered to all the subjects by a physical therapist. The data were analysed using item response theory by non-parametric Mokken analysis followed by Rasch analysis. Results: The results supported a unidimensional scale of the 19-item ARAT by Mokken analysis, with the scalability coefficient H = 0.95. Except for the item pinch ball bearing 3rd finger and thumb'', the remaining 18 items have a consistently hierarchical order along the upper extremity function's continuum. In contrast, the Rasch analysis, with a stepwise deletion of misfit items, showed that only 4 items (grasp ball'', grasp block 5 cm(3)'', grasp block 2.5 cm(3)'', and grip tube 1 cm(3)'') fit the Rasch rating scale model's expectations. Conclusion: Our findings indicated that the 19-item ARAT constituted a unidimensional construct measuring upper extremity function in stroke patients. However, the results did not support the premise that the raw sum scores of the ARAT can be transformed into interval Rasch scores. Thus, the raw sum scores of the ARAT can provide information only about order of patients on their upper extremity functional abilities, but not represent each patient's exact functioning