Reference point hyperplane trees

Our context of interest is tree-structured exact search in metric spaces. We make the simple observation that, the deeper a data item is within the tree, the higher the probability of that item being excluded from a search. Assuming a fixed and independent probability p of any subtree being excluded at query time, the probability of an individual data item being accessed is (1−p)d for a node at depth d. In a balanced binary tree half of the data will be at the maximum depth of the tree so this effect should be significant and observable. We test this hypothesis with two experiments on partition trees. First, we force a balance by adjusting the partition/exclusion criteria, and compare this with unbalanced trees where the mean data depth is greater. Second, we compare a generic hyperplane tree with a monotone hyperplane tree, where also the mean depth is greater. In both cases the tree with the greater mean data depth performs better in high-dimensional spaces. We then experiment with increasing the mean depth of nodes by using a small, fixed set of reference points to make exclusion decisions over the whole tree, so that almost all of the data resides at the maximum depth. Again this can be seen to reduce the overall cost of indexing. Furthermore, we observe that having already calculated reference point distances for all data, a final filtering can be applied if the distance table is retained. This reduces further the number of distance calculations required, whilst retaining scalability. The final structure can in fact be viewed as a hybrid between a generic hyperplane tree and a LAESA search structure

Public policy (not the coronavirus) should shape what endemic means

Endemicity is not only a biological and health event but has several inter-dependencies cross-cutting with the management of the economy, including governance and policies. Within the context of the discourse on inequity, what does endemicity mean for poor and low-income families, where policies on social inclusion and social welfare need to be re-calibrated

Combined use of gliadins and SSRs to analyse the genetic variability of the Spanish collection of cultivated diploid wheat (Triticum monococcum L. ssp. monococcum)

This work studied the combined use of gliadins and SSRs to analyse inter- and intra-accession variability of the Spanish collection of cultivated einkorn (Triticum monococcum L. ssp. monococcum) maintained at the CRF-INIA. In general, gliadin loci presented higher discrimination power than SSRs, reflecting the high variability of the gliadins. The loci on chromosome 6A were the most polymorphic with similar PIC values for both marker systems, showing that these markers are very useful for genetic variability studies in wheat. The gliadin results indicated that the Spanish einkorn collection possessed high genetic diversity, being the differentiation large between varieties and small within them. Some associations between gliadin alleles and geographical and agro-morphological data were found. Agro-morphological relations were also observed in the clusters of the SSRs dendrogram. A high concordance was found between gliadins and SSRs for genotype identification. In addition, both systems provide complementary information to resolve the different cases of intra-accession variability not detected at the agro-morphological level, and to identify separately all the genotypes analysed. The combined use of both genetic markers is an excellent tool for genetic resource evaluation in addition to agro-morphological evaluation

BLOC-2 targets recycling endosomal tubules to melanosomes for cargo delivery.

Hermansky-Pudlak syndrome (HPS) is a group of disorders characterized by the malformation of lysosome-related organelles, such as pigment cell melanosomes. Three of nine characterized HPS subtypes result from mutations in subunits of BLOC-2, a protein complex with no known molecular function. In this paper, we exploit melanocytes from mouse HPS models to place BLOC-2 within a cargo transport pathway from recycling endosomal domains to maturing melanosomes. In BLOC-2-deficient melanocytes, the melanosomal protein TYRP1 was largely depleted from pigment granules and underwent accelerated recycling from endosomes to the plasma membrane and to the Golgi. By live-cell imaging, recycling endosomal tubules of wild-type melanocytes made frequent and prolonged contacts with maturing melanosomes; in contrast, tubules from BLOC-2-deficient cells were shorter in length and made fewer, more transient contacts with melanosomes. These results support a model in which BLOC-2 functions to direct recycling endosomal tubular transport intermediates to maturing melanosomes and thereby promote cargo delivery and optimal pigmentation

Looking Beyond Lambda with the Union Supernova Compilation

The recent robust and homogeneous analysis of the world's supernova distance-redshift data, together with cosmic microwave background and baryon acoustic oscillation data, provides a powerful tool for constraining cosmological models. Here we examine particular classes of scalar field, modified gravity, and phenomenological models to assess whether they are consistent with observations even when their behavior deviates from the cosmological constant Lambda. Some models have tension with the data, while others survive only by approaching the cosmological constant, and a couple are statistically favored over LCDM. Dark energy described by two equation of state parameters has considerable phase space to avoid Lambda and next generation data will be required to constrain such physics.Comment: 32 pages, 19 figure

Internet-based medical education: a realist review of what works, for whom and in what circumstances

http://creativecommons.org/licenses/by/2.0

Performance of the inFLUenza Patient-Reported Outcome (FLU-PRO) diary in patients with influenza-like illness (ILI)

BACKGROUND: The inFLUenza Patient Reported Outcome (FLU-PRO) measure is a daily diary assessing signs/symptoms of influenza across six body systems: Nose, Throat, Eyes, Chest/Respiratory, Gastrointestinal, Body/Systemic, developed and tested in adults with influenza. OBJECTIVES: This study tested the reliability, validity, and responsiveness of FLU-PRO scores in adults with influenza-like illness (ILI). METHODS: Data from the prospective, observational study used to develop and test the FLU-PRO in influenza virus positive patients were analyzed. Adults (≥18 years) presenting with influenza symptoms in outpatient settings in the US, UK, Mexico, and South America were enrolled, tested for influenza virus, and asked to complete the 37-item draft FLU-PRO daily for up to 14-days. Analyses were performed on data from patients testing negative. Reliability of the final, 32-item FLU-PRO was estimated using Cronbach's alpha (α; Day 1) and intraclass correlation coefficients (ICC; 2-day reproducibility). Convergent and known-groups validity were assessed using patient global assessments of influenza severity (PGA). Patient report of return to usual health was used to assess responsiveness (Day 1-7). RESULTS: The analytical sample included 220 ILI patients (mean age = 39.3, 64.1% female, 88.6% white). Sixty-one (28%) were hospitalized at some point in their illness. Internal consistency reliability (α) of FLU-PRO Total score was 0.90 and ranged from 0.72-0.86 for domain scores. Reproducibility (Day 1-2) was 0.64 for Total, ranging from 0.46-0.78 for domain scores. Day 1 FLU-PRO scores correlated (≥0.30) with the PGA (except Gastrointestinal) and were significantly different across PGA severity groups (Total: F = 81.7, p<0.001; subscales: F = 6.9-62.2; p<0.01). Mean score improvements Day 1-7 were significantly greater in patients reporting return to usual health compared with those who did not (p<0.05, Total and subscales, except Gastrointestinal and Eyes). CONCLUSIONS: Results suggest FLU-PRO scores are reliable, valid, and responsive in adults with influenza-like illness

Impact Factor: outdated artefact or stepping-stone to journal certification?

A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

Managing ethnic conflict : the menu of institutional engineering

The debate on institutional engineering offers options to manage ethnic and other conflicts. This contribution systematically assesses the logic of these institutional designs and the empirical evidence on their functioning. Generally, institutions can work on ethnic conflict by either accommodating (“consociationalists”) or denying (“integrationists”) ethnicity in politics. Looking at individual and combined institutions (e.g. state structure, electoral system, forms of government), the literature review finds that most designs are theoretically ambivalent and that empirical evidence on their effectiveness is mostly inconclusive. The following questions remain open: a) Is politicized ethnicity really a conflict risk? b) What impact does the whole “menu” (not just single institutions) have? and c) How are effects conditioned by the exact nature of conflict risks

Healthy diet in primary care: views of general practitioners and nurses from Europe

Background: Most of the national colleges of general practitioners (GPs) do not have their own dietary/nutritional tools, and GPs and nurses do not have the time, knowledge, or skills to advise their patients about desirable dietary practices. Objective: To assess the usefulness of a simple and practical guide on healthy diet to be used by European GPs and nurses. Design: A postal survey was mailed to 171 GPs and nurses from 12 European countries to obtain information about the usefulness of a guide on healthy diet developed by EUROPREV. Results: The perception of health professionals is that the main source of information on healthy diet for the population was the media. In all, 95% of GPs and nurses reported that the guide was useful; 93, 95, and 82% reported that the concepts were concise, easy to understand, and realistic, respectively. Also, 77% reported that the type of counselling recommended was feasible and could be applied, 94% reported that the implementation measures proposed could be effective and 88% reported that the Traditional Mediterranean Diet Pyramid is useful, but some concerns about the content were mentioned. Conclusions: GPs and nurses from Europe think that a practical guide on healthy diet developed by EUROPREV could be used to advise patients in primary care, although the Traditional Mediterranean Diet Pyramid should be modified