Applying a transdisciplinary mixed methods research design to explore sustainable diets in rural South Africa

This article describes a conceptual framework for exploring sustainable diets, using a case study example of ongoing research in the Vaalharts region, a rural setting in South Africa. A qualitative research approach is followed with an integrated transdisciplinary mixed methods research design with multiple concurrent components employed during two sequential phases. A successful application of the framework is achieved through a collaborative team effort of researchers with qualitative and quantitative research expertise transcending different disciplines, as well as participation of community members throughout the research process. We demonstrate that transdisciplinary mixed methods research designs are essential to gain a better understanding of the complex concept of sustainable diets

The concept of age in systems analysis

This paper discusses the mathematical concept of ageing. It is shown that while in most cases a probabilistic definition of age is sufficient, in some cases a calendaric definition must be added in order to preserve the relationship between time and age.Hierdie artikel bespreek die wiskundige betekenis van veroudering. Daar word getoon dat alhoewel 'n waarskynlikheidsgebaseerde definisie van ouderdom meestal voldoende is, daar in sommige gevalle 'n tydgebaseerde definisie nodig is om die verwantskap tussen tyd en ouderdom te behou.http://sajie.journals.ac.z

The quantum state vector in phase space and Gabor's windowed Fourier transform

Representations of quantum state vectors by complex phase space amplitudes, complementing the description of the density operator by the Wigner function, have been defined by applying the Weyl-Wigner transform to dyadic operators, linear in the state vector and anti-linear in a fixed `window state vector'. Here aspects of this construction are explored, with emphasis on the connection with Gabor's `windowed Fourier transform'. The amplitudes that arise for simple quantum states from various choices of window are presented as illustrations. Generalized Bargmann representations of the state vector appear as special cases, associated with Gaussian windows. For every choice of window, amplitudes lie in a corresponding linear subspace of square-integrable functions on phase space. A generalized Born interpretation of amplitudes is described, with both the Wigner function and a generalized Husimi function appearing as quantities linear in an amplitude and anti-linear in its complex conjugate. Schr\"odinger's time-dependent and time-independent equations are represented on phase space amplitudes, and their solutions described in simple cases.Comment: 36 pages, 6 figures. Revised in light of referees' comments, and further references adde

Blood Cell Salvage and Autotransfusion Does Not Worsen Oncologic Outcomes Following Liver Transplantation with Incidental Hepatocellular Carcinoma: A Propensity Score-Matched Analysis

BACKGROUND: Intraoperative blood cell salvage and autotransfusion (IBSA) during liver transplantation (LT) for hepatocellular carcinoma (HCC) is controversial for concern regarding adversely impacting oncologic outcomes. OBJECTIVE: We aimed to evaluate the long-term oncologic outcomes of patients who underwent LT with incidentally discovered HCC who received IBSA compared with those who did not receive IBSA. METHODS: Patients undergoing LT (January 2001-October 2018) with incidental HCC on explant pathology were retrospectively identified. A 1:1 propensity score matching (PSM) was performed. HCC recurrence and patient survival were compared. Kaplan-Meier survival analyses were performed, and univariable Cox proportional hazard analyses were performed for risks of recurrence and death. RESULTS: Overall, 110 patients were identified (IBSA, n = 76 [69.1%]; non-IBSA, n = 34 [30.9%]). Before matching, the groups were similar in terms of demographics, transplant, and tumor characteristics. Overall survival was similar for IBSA and non-IBSA at 1, 3, and 5 years (96.0%, 88.4%, 83.0% vs. 97.1%, 91.1%, 87.8%, respectively; p = 0.79). Similarly, the recurrence rate at 1, 3, and 5 years was not statistically different (IBSA 0%, 1.8%, 1.8% vs. non-IBSA 0%, 3.2%, 3.2%, respectively; p = 0.55). After 1:1 matching (26 IBSA, 26 non-IBSA), Cox proportional hazard analysis demonstrated similar risk of death and recurrence between the groups (IBSA hazard ratio [HR] of death 1.26, 95% confidence interval [CI] 0.52-3.05, p = 0.61; and HR of recurrence 2.64, 95% CI 0.28-25.30, p = 0.40). CONCLUSIONS: IBSA does not appear to adversely impact oncologic outcomes in patients undergoing LT with incidental HCC. This evidence further supports the need for randomized trials evaluating the impact of IBSA use in LT for HCC

An international multicentre evaluation of treatment strategies for combined hepatocellular-cholangiocarcinoma

BACKGROUND & AIMS: Management of combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is not well-defined. Therefore, we evaluated the management of cHCC-CCA using an online hospital-wide multicentre survey sent to expert centres. METHODS: A survey was sent to members of the European Network for the Study of Cholangiocarcinoma (ENS-CCA) and the International Cholangiocarcinoma Research Network (ICRN), in July 2021. To capture the respondents\u27 contemporary decision-making process, a hypothetical case study with different tumour size and number combinations was embedded. RESULTS: Of 155 surveys obtained, 87 (56%) were completed in full and included for analysis. Respondents represented Europe (68%), North America (20%), Asia (11%), and South America (1%) and included surgeons (46%), oncologists (29%), and hepatologists/gastroenterologists (25%). Two-thirds of the respondents included at least one new patient with cHCC-CCA per year. Liver resection was reported as the most likely treatment for a single cHCC-CCA lesion of 2.0-6.0 cm (range: 73-93%) and for two lesions, one up to 6 cm and a second well-defined lesion of 2.0 cm (range: 60-66%). Nonetheless, marked interdisciplinary differences were noted. Surgeons mainly adhered to resection if technically feasible, whereas up to half of the hepatologists/gastroenterologists and oncologists switched to alternative treatment options with increasing tumour burden. Fifty-one (59%) clinicians considered liver transplantation as an option for patients with cHCC-CCA, with the Milan criteria defining the upper limit of inclusion. Overall, well-defined cHCC-CCA treatment policies were lacking and management was most often dependent on local expertise. CONCLUSIONS: Liver resection is considered the first-line treatment of cHCC-CCA, with many clinicians supporting liver transplantation within limits. Marked interdisciplinary differences were reported, depending on local expertise. These findings stress the need for a well-defined multicentre prospective trial comparing treatments, including liver transplantation, to optimise the therapeutic management of cHCC-CCA. IMPACT AND IMPLICATIONS: Because the treatment of combined hepatocellular-cholangiocarcinoma (cHCC-CCA), a rare form of liver cancer, is currently not well-defined, we evaluated the contemporary treatment of this rare tumour type through an online survey sent to expert centres around the world. Based on the responses from 87 clinicians (46% surgeons, 29% oncologists, 25% hepatologists/gastroenterologists), representing four continents and 25 different countries, we found that liver resection is considered the first-line treatment of cHCC-CCA, with many clinicians supporting liver transplantation within limits. Nonetheless, marked differences in treatment decisions were reported among the different specialties (surgeo

Positivity properties of phase‐plane distribution functions

The aim of this paper is to compare the members of Cohen's class of phase-plane distributions with respect to positivity properties. It is known that certain averages (which are in a sense compatible with Heisenberg's uncertainty principle) of the Wigner distribution over the phase-plane yield non-negative values for all states. It is shown in this paper that the Wigner distribution is unique in this respect among the members of Cohen's class that have correct marginals or that satisfy Moyal's formula for all states. The subset of members of Cohen's class (not necessarily satisfying one of these two conditions) with positivity properties comparable with those for the Wigner distribution is shown to be rather small