Designing Pre-Departure Orientation as a For-Credit Academic Seminar: Curriculum and Content

International educators widely agree that overseas experiences provide tremendous opportunities for student growth and learning. However, institutions and international education professionals are increasingly recognizing that pre-departure preparation is essential to maximize student learning during overseas programs. Most institutions offer a pre-departure orientation program of some form, such as a weekend workshop, a series of presentations, or weekly sessions prior to departure. These meetings are often mandatory and provide essential “nuts and bolts” information about the international programs and usually some type of cross-cultural training and instruction. A mandatory for-credit pre-departure seminar, called Global Awareness and Competence, was developed to provide prospective study abroad participants at Freed-Hardeman University (FHU) with the tools and knowledge necessary for successful completion of FHU’s semester-long program in Belgium. The seminar replaces the previous pre-departure orientation program and enhances it with experiential learning activities, a self-reflection component, and additional lectures and discussions on culture and cross-cultural exchanges. This paper describes the theoretical foundations, institutional context, goals and objectives, content and curriculum, and other details about the orientation seminar

Comparative Phylogeography in Fijian Coral Reef Fishes: A Multi-Taxa Approach towards Marine Reserve Design

Delineating barriers to connectivity is important in marine reserve design as they describe the strength and number of connections among a reserve’s constituent parts, and ultimately help characterize the resilience of the system to perturbations at each node. Here we demonstrate the utility of multi-taxa phylogeography in the design of a system of marine protected areas within Fiji. Gathering mtDNA control region data from five species of coral reef fish in five genera and two families, we find a range of population structure patterns, from those experiencing little (Chrysiptera talboti, Halichoeres hortulanus, and Pomacentrus maafu), to moderate (Amphiprion barberi, Wst = 0.14 and Amblyglyphidodon orbicularis Wst = 0.05) barriers to dispersal. Furthermore estimates of gene flow over ecological time scales suggest speciesspecific, asymmetric migration among the regions within Fiji. The diversity among species-specific results underscores the limitations of generalizing from single-taxon studies, including the inability to differentiate between a species-specific result and a replication of concordant phylogeographic patterns, and suggests that greater taxonomic coverage results in greater resolution of community dynamics within Fiji. Our results indicate that the Fijian reefs should not be managed as a single unit, and that closely related species can express dramatically different levels of population connectivity

Isoperimetric stability in lattices

We obtain isoperimetric stability theorems for general Cayley digraphs on $\mathbb{Z}^d$. For any fixed $B$ that generates $\mathbb{Z}^d$ over $\mathbb{Z}$, we characterise the approximate structure of large sets $A$ that are approximately isoperimetric in the Cayley digraph of $B$: we show that $A$ must be close to a set of the form $kZ \cap \mathbb{Z}^d$, where for the vertex boundary $Z$ is the conical hull of $B$, and for the edge boundary $Z$ is the zonotope generated by $B$.Comment: 10 page

Isoperimetry in integer lattices

The edge isoperimetric problem for a graph $G$ is to determine, for each $n$, the minimum number of edges leaving any set of $n$ vertices. In general this problem is NP-hard, but exact solutions are known in some special cases, for example when $G$ is the usual integer lattice. We solve the edge isoperimetric problem asymptotically for every Cayley graph on $\mathbb Z^d$. The near-optimal shapes that we exhibit are zonotopes generated by line segments corresponding to the generators of the Cayley graph.Comment: Published in Discrete Analysi

Isoperimetry in integer lattices

Isoperimetry in integer lattices, Discrete Analysis 2018:7, 16 pp. The isoperimetric problem, already known to the ancient Greeks, concerns the minimisation of the size of a boundary of a set under a volume constraint. The problem has been studied in many contexts, with a wide range of applications. The present paper focuses on the discrete setting of graphs, where the boundary of a subset of vertices can be defined with reference to either vertices or edges. Specifically, the so-called edge-isoperimetric problem for a graph $G$ is to determine, for each $n$, the minimum number of edges leaving any set $S$ of $n$ vertices. The vertex isoperimetric problem asks for the minimum number of vertices that can be reached from $S$ by following these edges. For a general graph $G$ this problem is known to be NP-hard, but exact solutions are known for some special classes of graphs. One example is the $d$-dimensional hypercube, which is the graph on vertex set $\{0,1\}^d$ with edges between those binary strings of length $d$ that differ in exactly one coordinate. The edge-isoperimetric problem for this graph was solved by Harper, Lindsey, Bernstein, and Hart, and the extremal sets include $k$-dimensional subcubes obtained by fixing $d-k$ of the coordinates. The edge-isoperimetric problem for the $d$-dimensional integer lattice whose edges connect pairs of vertices at $\ell_1$-distance 1, was solved by Bollobás and Leader in the 1990s, who showed that the optimal shapes consist of $\ell_\infty$-balls. More recently, Radcliffe and Veomett solved the vertex-isoperimetric problem for the $d$-dimensional integer lattice on which edges are defined with respect to the $\ell_\infty$-distance instead. In the present paper the authors solve the edge-isoperimetric problem asymptotically for every Cayley graph on $G=\mathbb{Z}^d$, and determine the near-optimal shapes in terms of the generating set used to construct the Cayley graph. In particular, this solves the edge-isoperimetric problem on $\mathbb{Z}^d$ with the $\ell_\infty$-distance. We now describe the results in more detail. Given any generating set $U$ of $G$ that does not contain the identity, the Cayley graph $\Gamma(G,U)$ has vertex set $G$ and edge set $\{(g,g+u): g\in G, u\in U\}$. This construction includes both the $\ell_1$ and the $\ell_\infty$ graph defined above, by considering the generating sets $U_1=\{(\pm 1, 0,\dots,0),\dots,(0,\dots,0,\pm 1)\}$ and $U_\infty=\{-1,0,1\}^d\setminus\{0,0,0\}$, respectively. The near-optimal shapes obtained by the authors are so-called zonotopes, generated by line segments corresponding to the generators of the Cayley graph. More precisely, if $U=\{u_1,u_2,\dots,u_k\}$ is a set of non-zero generators of $G$, then the near-optimal shapes are the intersections of scaled copies of the convex hull of the sum set $\{0,u_1\}+\{0,u_2\}+\dots+\{0,u_k\}$ with $\mathbb{Z}^d$. For example, when $d=2$, then the zonotope for the $\ell_\infty$ problem is an octagon obtained by cutting the corners off a square through points one third of the way along each side. In contrast to the aforementioned edge-isoperimetry results, which were solved exactly using compression methods, the approach in this paper is an approximate one. It follows an idea of Ruzsa, who solved the vertex-isoperimetry problem in general Cayley graphs on the integer lattice by approximating the discrete problem with a continuous one. While the continuous analogue in the present paper is a natural one, it is not clear that it is indeed a good approximation to the original problem, and it is here that the main combinatorial contribution of the paper lies. It concludes with several open problems and directions for further work

Cost-Effectiveness of Early versus Late Cinacalcet Treatment in Addition to Standard Care for Secondary Renal Hyperparathyroidism in the USA

AbstractObjectivesThe objective of this research was to estimate lifetime cost-effectiveness of treating patients with cinacalcet early (when parathyroid hormone [PTH] levels are in the range of 300–500 pg/ml) versus delaying treatment with cinacalcet (cinacalcet initiated when PTH levels are >800 pg/ml) in patients with secondary hyperparathyroidism (SHPT) in the US setting.MethodsA Markov model was developed to simulate the effects of early versus delayed use of cinacalcet (plus standard of care). Four different PTH ranges (≤300 pg/ml; 301–500 pg/ml; 501–800 pg/ml; >800 pg/ml) were used to represent four different health states within the Markov model. Associated with each Markov state (PTH range) were varying risks of major SHPT complications, including cardiovascular disease (CVD), fracture (Fx), and parathyroidectomy (PTx). Baseline cohort characteristics and risks of CVD, Fx, and PTx by PTH category were derived from a large US renal database and published sources. Costs were estimated from the US Renal Data System database and reported in 2006 US Dollars ($). Clinical and economic outcomes were discounted at 3.0$17,275 per QALY gained.ConclusionsEarly treatment with cinacalcet was associated with improvements in QALYs and would represent good value for money compared to delaying treatment with cinacalcet

Federated Cross Learning for Medical Image Segmentation

Federated learning (FL) can collaboratively train deep learning models using isolated patient data owned by different hospitals for various clinical applications, including medical image segmentation. However, a major problem of FL is its performance degradation when dealing with the data that are not independently and identically distributed (non-iid), which is often the case in medical images. In this paper, we first conduct a theoretical analysis on the FL algorithm to reveal the problem of model aggregation during training on non-iid data. With the insights gained through the analysis, we propose a simple and yet effective method, federated cross learning (FedCross), to tackle this challenging problem. Unlike the conventional FL methods that combine multiple individually trained local models on a server node, our FedCross sequentially trains the global model across different clients in a round-robin manner, and thus the entire training procedure does not involve any model aggregation steps. To further improve its performance to be comparable with the centralized learning method, we combine the FedCross with an ensemble learning mechanism to compose a federated cross ensemble learning (FedCrossEns) method. Finally, we conduct extensive experiments using a set of public datasets. The experimental results show that the proposed FedCross training strategy outperforms the mainstream FL methods on non-iid data. In addition to improving the segmentation performance, our FedCrossEns can further provide a quantitative estimation of the model uncertainty, demonstrating the effectiveness and clinical significance of our designs. Source code will be made publicly available after paper publication.Comment: 10 pages, 4 figure

Translation and psychometric assessment of the mastectomy module of the BREAST-Q questionnaire for use in Nigeria

Background: The majority of non-metastatic breast cancer patients in sub-Saharan Africa are recommended to have mastectomy. The impact of mastectomy on a predominantly young African patient population requires evaluation. The BREAST-Q is a validated patient-reported outcome measure of quality-of-life following breast surgery that has been translated into 30 languages-none in Africa. This study aimed to translate and assess the psychometric properties of the mastectomy module of the BREAST-Q for use in Nigeria. Methods: The BREAST-Q mastectomy module was translated from English to Yoruba and its psychometric properties assessed using best practice guidelines. Translation was performed in 4 steps: forward translation (x2), back translation, back translation review, and cognitive interviews with post-mastectomy patients. The translated BREAST-Q instrument was administered to post-mastectomy patients (n = 21) alongside the EORTC-QLQ BR23 to evaluate construct validity. Test-retest reliability was evaluated using intraclass correlation coefficients (ICC); surveys were re-administered 4 weeks apart. Results: The translation process identified English phrases not amenable to direct translation, including “emotionally healthy” and descriptions of pain (“nagging,” “throbbing,” “sharp”). Translations were amended to reflect local context and question intent. During cognitive interviews, patients provided suggestions to simplify complex phrases, e.g. “discomfort in your breast area.”. Internal consistency within scales was over 0.70 for psychosocial wellbeing (α = 0.84–0.87), sexual wellbeing (α = 0.98–0.99), physical wellbeing in chest (α = 0.84–0.86), and satisfaction with care (α = 0.89–0.93). ICC for test-retest reliability was moderate (0.46–0.63). Conclusions: The Yoruba version of the BREAST-Q mastectomy module presents a unique opportunity to adequately capture the experiences of Nigerian women post mastectomy. This instrument is being used in a pilot study of Nigerian patients to identify targets for intervention to improve the patient experience and compliance with breast cancer surgery

Genome-wide Association of Lipid-lowering Response to Statins in Combined Study Populations

Background: Statins effectively lower total and plasma LDL-cholesterol, but the magnitude of decrease varies among individuals. To identify single nucleotide polymorphisms (SNPs) contributing to this variation, we performed a combined analysis of genome-wide association (GWA) results from three trials of statin efficacy. Methods and Principal Findings: Bayesian and standard frequentist association analyses were performed on untreated and statin-mediated changes in LDL-cholesterol, total cholesterol, HDL-cholesterol, and triglyceride on a total of 3932 subjects using data from three studies: Cholesterol and Pharmacogenetics (40 mg/day simvastatin, 6 weeks), Pravastatin/Inflammation CRP Evaluation (40 mg/day pravastatin, 24 weeks), and Treating to New Targets (10 mg/day atorvastatin, 8 weeks). Genotype imputation was used to maximize genomic coverage and to combine information across studies. Phenotypes were normalized within each study to account for systematic differences among studies, and fixed-effects combined analysis of the combined sample were performed to detect consistent effects across studies. Two SNP associations were assessed as having posterior probability greater than 50%, indicating that they were more likely than not to be genuinely associated with statin-mediated lipid response. SNP rs8014194, located within the CLMN gene on chromosome 14, was strongly associated with statin-mediated change in total cholesterol with an 84% probability by Bayesian analysis, and a p-value exceeding conventional levels of genome-wide significance by frequentist analysis (P = 1.8×10$^{−8}$). This SNP was less significantly associated with change in LDL-cholesterol (posterior probability = 0.16, P = 4.0×10$^{−6}$). Bayesian analysis also assigned a 51% probability that rs4420638, located in APOC1 and near APOE, was associated with change in LDL-cholesterol. Conclusions and Significance: Using combined GWA analysis from three clinical trials involving nearly 4,000 individuals treated with simvastatin, pravastatin, or atorvastatin, we have identified SNPs that may be associated with variation in the magnitude of statin-mediated reduction in total and LDL-cholesterol, including one in the CLMN gene for which statistical evidence for association exceeds conventional levels of genome-wide significance.Trial Registration PRINCE and TNT are not registered. CAP is registered at Clinicaltrials.gov NCT0045182