Three qubits can be entangled in two inequivalent ways

Invertible local transformations of a multipartite system are used to define equivalence classes in the set of entangled states. This classification concerns the entanglement properties of a single copy of the state. Accordingly, we say that two states have the same kind of entanglement if both of them can be obtained from the other by means of local operations and classical communcication (LOCC) with nonzero probability. When applied to pure states of a three-qubit system, this approach reveals the existence of two inequivalent kinds of genuine tripartite entanglement, for which the GHZ state and a W state appear as remarkable representatives. In particular, we show that the W state retains maximally bipartite entanglement when any one of the three qubits is traced out. We generalize our results both to the case of higher dimensional subsystems and also to more than three subsystems, for all of which we show that, typically, two randomly chosen pure states cannot be converted into each other by means of LOCC, not even with a small probability of success.Comment: 12 pages, 1 figure; replaced with revised version; terminology adapted to earlier work; reference added; results unchange

Digital therapeutic alliance in psycho-oncology: an overview

ABSTRACT Introduction: After the declaration of the COVID-19 pandemic, health services have had to adapt to be delivered by eHealth tools. Cancer population has extensively experienced this disruption due to non-urgent in-person visits being deferred to avoid disease aggravations caused by the spread of the virus. Despite the extensive literature assessing the efficacy of telepsychology in cancer, clinical effectiveness remains unclear. Since Therapeutic Alliance in digital settings appears to be established by mechanisms different than those of in-person interventions, Digital Therapeutic Alliance could work as a particular predictor, moderator, or mediator variable of telepsychology effectiveness. The aim of this narrative overview is to present a broad summary that describes the use of eHealth in psycho-oncology, to later focus on exploring the state of knowledge regarding the establishment of  Digital Therapeutic Alliance in this particular setting.  Method: The search was conducted from July to September 2021 in four electronic databases. There were three search layers: “telepsychology”, “psycho-oncology” and “therapeutic alliance”. Special attention was paid to reviews and those articles contradicting the regular findings.  Results: The research on Digital Therapeutic Alliance in psycho-oncology is limited. The overview has extrapolated the results of general mental health interventions to cancer patients since the characteristics of patients and their diagnoses do not seem to differ when considering previous reviews on the subject.  Conclusion and future perspectives: The relational dimension between the therapist and the patient is essential in telepsychology for the development of the therapeutic process and for the intervention outcomes. The literature about Digital Therapeutic Alliance presents uneven and inconclusive results, and the professional’s perspective is poorly developed. It is essential to know how this Alliance is established and which are its barriers and facilitators, both in patients and professionals, and in the different digital formats. With that knowledge, the mechanisms of change and the specific moderators between Alliance and intervention outcomes could be identified. Considering the currently limited access to conventional psychosocial care and leveraging the rapid advances in digital cancer care due to the COVID- 19 pandemic, integrating future findings on Digital Therapeutic Alliance to  comprehensive cancer treatments will support the development of more accessible and effective telepsychological interventions

On the improvement of blood sample collection at clinical laboratories

Background: Blood samples are usually collected daily from different collection points, such hospitals and health centers, and transported to a core laboratory for testing. This paper presents a project to improve the collection routes of two of the largest clinical laboratories in Spain. These routes must be designed in a cost-efficient manner while satisfying two important constraints: (i) two-hour time windows between collection and delivery, and (ii) vehicle capacity. Methods: A heuristic method based on a genetic algorithm has been designed to solve the problem of blood sample collection. The user enters the following information for each collection point: postal address, average collecting time, and average demand (in thermal containers). After implementing the algorithm using C programming, this is run and, in few seconds, it obtains optimal (or near-optimal) collection routes that specify the collection sequence for each vehicle. Different scenarios using various types of vehicles have been considered. Unless new collection points are added or problem parameters are changed substantially, routes need to be designed only once. Results: The two laboratories in this study previously planned routes manually for 43 and 74 collection points, respectively. These routes were covered by an external carrier company. With the implementation of this algorithm, the number of routes could be reduced from ten to seven in one laboratory and from twelve to nine in the other, which represents significant annual savings in transportation costs. Conclusions: The algorithm presented can be easily implemented in other laboratories that face this type of problem, and it is particularly interesting and useful as the number of collection points increases. The method designs blood collection routes with reduced costs that meet the time and capacity constraints of the problem.Alex Grasas and Helena Ramalhinho acknowledge financial support from the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-2011-0075). The work of Luciana S. Pessoa was partially supported by HAROSA@IB (CYTED2010-511RT0419

Cascade sensitivity measures

In risk analysis, sensitivity measures quantify the extent to which the probability distribution of a model output is affected by changes (stresses) in individual random input factors. For input factors that are statistically dependent, we argue that a stress on one input should also precipitate stresses in other input factors. We introduce a novel sensitivity measure, termed cascade sensitivity, defined as a derivative of a risk measure applied on the output, in the direction of an input factor. The derivative is taken after suitably transforming the random vector of inputs, thus explicitly capturing the direct impact of the stressed input factor, as well as indirect effects via other inputs. Furthermore, alternative representations of the cascade sensitivity measure are derived, allowing us to address practical issues, such as incomplete specification of the model and high computational costs. The applicability of the methodology is illustrated through the analysis of a commercially used insurance risk model