More on quasi-random graphs, subgraph counts and graph limits

We study some properties of graphs (or, rather, graph sequences) defined by demanding that the number of subgraphs of a given type, with vertices in subsets of given sizes, approximatively equals the number expected in a random graph. It has been shown by several authors that several such conditions are quasi-random, but that there are exceptions. In order to understand this better, we investigate some new properties of this type. We show that these properties too are quasi-random, at least in some cases; however, there are also cases that are left as open problems, and we discuss why the proofs fail in these cases. The proofs are based on the theory of graph limits; and on the method and results developed by Janson (2011), this translates the combinatorial problem to an analytic problem, which then is translated to an algebraic problem.Comment: 35 page

Labor and Technology Change in the Nursery Industry

The U.S. nursery industry is highly complex, and affected on their demand side by the construction industry and on their factor supply side by the market for low-skill labor, which in turn is influenced by gyrating construction activity as well as southern-border immigration. We examine an industry seeking to adapt to a changing demand and labor environment. Our emphasis is on the manner in which nurseries cope with increasing retailer power, increasingly quality- and variety-conscious consumers, and expectations of rising wages. We argue that the gradual growth of such labor aids as potting assembly belts and pruning equipment should be viewed in terms of a tradeoff among labor quantity, labor quality, and capital instead of the more conventional tradeoff between labor and capital. Management invests in training in order to substitute labor quality for quantity, and in on- and off-site-produced equipment in order to substitute capital for either. Capital intensification shifts the distribution of nursery skills. However, the skill distribution's shape can change in a number of ways. In a unimodal shift capital supplants labor continuously more at the lower than the higher skill levels. In a bimodal shift capital supplants mid-level employees, so that the skill distribution bifurcates between a low-skill and a high-skill mode. We argue that the capital substitution now arising in the U.S. nursery sector will take a unimodal form similar to those observed earlier in such farm commodity production as wheat and sugar beets. Low-skilled and seasonal workers, therefore, will be supplanted by more skilled and longer-term ones. Yet, rising product variety and retailer service demands will simultaneously bring a greater return to nursery computing investments, eliminating parts of the larger nurseries’ mid-level workforce and creating a renewed demand for low-skill laborers. In addition, the nursery industry will become more differentiated with respect to labor-intensity.Crop Production/Industries, Labor and Human Capital, Research and Development/Tech Change/Emerging Technologies,

Quantitative and Qualitative Analysis on Sex and Gender in Preparatory Material for National Medical Examination in Germany and the United States

Background: Sex- and gender-based medicine (SGBM) should be a mandatory part of medical education. We compared the quantity and quality of sex- and gender-related content of e-learning materials commonly used by German and American medical students while preparing for national medical examinations. Methods: Quantitative, line-by-line analysis of the preparatory materials AMBOSS 2017 and USMLE Step 1 Lecture Notes (2017) by KAPLAN MEDICAL was performed between April and October 2017. Subjects were allocated to one of the three main fields: clinical subjects, behavioral and social science, and pharmacology. Qualitative analysis comprised binary categorization into sex- and gender-based aspects and qualification with respect to the presence of a pathophysiological explanation for the sex or gender difference. Results: In relation to the total content of AMBOSS and KAPLAN, the sex- and gender-based share of the clinical subjects content was 26.8% (±8.2) in AMBOSS and 21.1% (±10.2) in KAPLAN. The number of sex- and gender-based aspects in the behavioral and social science learning material differed significantly for AMBOSS and KAPLAN (4.4% ± 3.1% vs 10.7% ± 7.5%; P = .044). Most of the sex- and gender-related content covered sex differences. Most learning cards and texts did not include a detailed pathophysiological explanation for sex- or gender-based aspects. The knowledge provided in the preparatory documents represents only a small part of facts that are already known about sex and gender differences. Conclusions: The preparatory materials focused almost exclusively on biological sex differences and the sociocultural dimension in particular is underrepresented. A lot more evidence-based facts are known and should be integrated into the materials to reflect the importance of SGBM as an integral component of patient-centered medicine