A Modified DBSCAN Clustering Method to Estimate Retail Center Extent

This research introduces a new method for the identification of local retail agglomerations within Great Britain, implementing a modification of the established density based spatial clustering of applications with noise (DBSCAN) method that improves local sensitivity to variable point densities. The variability of retail unit density can be related to both the type and function of retail centers, but also to characteristics such as size and extent of urban areas, population distribution, or property values. The suggested method implements a sparse graph representation of the retail unit locations based on a distance‐constrained k‐nearest neighbor adjacency list that is subsequently decomposed using the Depth First Search algorithm. DBSCAN is iteratively applied to each subgraph to extract the clusters with point density closer to an overall density for each study area. This innovative approach has the advantage of adjusting the radius parameter of DBSCAN at the local scale, thus improving the clustering output. A comparison of the estimated retail clusters against a sample of existing boundaries of retail areas shows that the suggested methodology provides a simple yet accurate and flexible way to automate the process of identifying retail clusters of varying shapes and densities across large areas; and by extension, enables their automated update over time

Integrating the who, what, and where of U.S. retail center geographies

Retail is an important function at the core of urban areas, occupying a key role in determining their economic prosperity, desirability, and vibrancy. Efforts to understand the geographies of retail centers, the cores of retailing in urban areas, have a long academic tradition, often studied through either rich local case studies, or when geographically more expansive, are constrained by limited detail. New data in United States detailing the location and uses of retail creates a significant opportunity to develop a more complete and comprehensive overview of the national retail system, at a high spatial resolution. This research is rooted in a pragmatic effort to provide the first and most comprehensive model of U.S. retail center geographies, through development of an integrated, conceptual, and empirically grounded framework, using data from SafeGraph, to examine where they are located, what characteristics they have, and who uses them. The resulting geographies are of great interest, creating significant potential in the monitoring of the national retail system as it continues to evolve in response to wider structural challenges. Furthermore, by integrating these three geographies (where, what, and who), we establish a conceptual framework that yields substantive insights about the relationships between each of them, and argues that understandings of U.S. retail center geographies are more comprehensive and useful when considering the who, what, and where together

Molluscs of selected water bodies in Warsaw

Malacofauna of lakes: Powsinkowskie, Wilanowskie and Czerniakowskie is composed of a similar number of taxa (14–16), but the species composition differs considerably. Mollusc densities are low, frequencies of individual species mostly do not exceed 25%, dominance structure, not very well marked in the deposits, is very clear among the few molluscs living on emerged macrophytes and macrophytes with floating leaves. Species diversity (Shannon-Weaver index) is higher in the bottom deposits, compared to macrophytes. Taxonomic composition of empty shells found in the bottom deposits, indicates that a few dozen year ago the malacofauna of the lakes was richer and similar between the lakes. It apears that the present composition of the malacofauna is affected, among others, by the character of the bottom deposits, transformations of littoral vegetation, level of pollution and trophy of the lakes; the influence of all these factors varies between species

Beyond retail: new ways of classifying UK shopping and consumption spaces

Early attempts to classify shopping activity often took a relatively simple approach, largely driven by the lack of reliable data beyond fascia name and retail outlet counts by centre. There seems to be a consensus amongst contemporary scholars, commercial research consultancies and retailers that more comprehensive classifications would generate better-informed debate on changes in the urban economic landscape, as well as providing the basis for a more effective comparison of retail centres across time and space, particularly given the availability of new data sources and techniques and in the context of the transformational changes presently affecting the retail sector. This paper seeks to demonstrate the interrelationship between supply and demand for retailing services by integrating newly available data sources within a rigorously specified classification methodology. This in turn provides new insight into the multidimensional and dynamic taxonomy of consumption spaces within Great Britain. First, such a contribution is significant in that it moves debate within the literature past simple linear scaling of retail centre function to a more nuanced understanding of multiple functional forms; and second, in that it provides a nationally comparative and dynamic framework through which the evolution of retail structures can be evaluated. Using non-hierarchical clustering techniques, the results are presented in the form of a two-tier classification with 5 distinctive ‘coarse’ clusters and 15 more detailed and nested sub-clusters. The paper concludes that more nuanced and dynamic classifications of this kind can help deliver more effective insights into changing role of retailing and consumer services in urban areas across space and through time and will have implications for a variety of stakeholders

Effect of biostimulators and herbicides on savouriness and darkening of the flesh of potato tubers

Badania polowe przeprowadzono w latach 2012−2014, na glebie bardzo lekkiej i lekkiej. Doświadczenie założono w trzech powtórzeniach, metodą losowanych podbloków w układzie split-plot, gdzie czynnikiem pierwszym były trzy średnio wczesne odmiany ziemniaka jadalnego: Bartek, Gawin i Honorata, a drugim – stosowanie herbicydów i biostymulatorów: obiekt kontrolny z pielęgnacją wyłącznie mechaniczną i cztery obiekty, na których stosowano herbicydy: Harrier 295 ZC, Harrier 295 ZC i bioregulator Kelpak SL, Sencor 70 WG, Sencor 70 WG i biostymulator Asahi SL. Celem przeprowadzonych badań była ocena wpływu biostymulatorów i herbicydów na wybrane cechy jakości konsumpcyjnej (smakowitość, ciemnienie miąższu bulw surowych po 10 minutach, ciemnienie miąższu bulw ugotowanych po 10 minutach i 24 godzinach) bulw ziemniaka jadalnego. Na podstawie otrzymanych wyników wykazano, że spośród analizowanych cech jakości sensorycznej tylko ciemnienie miąższu bulw ugotowanych zależało istotnie od herbicydów i biostymulatorów, natomiast smakowitość i ciemnienie miąższu bulw surowych nie uległy zmianom w porównaniu do bulw z obiektu kontrolnego. Odmiany i warunki pogodowe w latach badań decydowały o wszystkich analizowanych cechach jakościowych.The potato is the world’s fourth most imported food crop, following after wheat rice and maize. It is an important food staple in Poland and many other countries. The potato quality depends on chemical composition, which modifies its nutritional value. It is very important to protect potato crops against competitive impact of weeds that decrease yield. Plant growth regulator treatment is an alternative way to achieve higher yielding and better quality of potato tubers. The growth substances stimulate life processes of plant by activating the synthesis of hormones and its stimulation, moreover they improve plant resistance to stress factors. The field experiment was carried out in years 2012−2014 on very light and light soil which belonged to a good rye complex. The experiment was designed as a two factors randomized block with three replicates. Factors examined in the experiment included three cultivars of edible potatoes – Bartek, Gawin, Honorata, and five methods application of herbicides and biostimulators. In this experiment application of the following herbicides: Harrier 295 ZC at a dose of 2,0 dm³·ha⁻¹, herbicides Harrier 295 ZC at a dose of 2,0 dm³·ha⁻¹ and growth regulators Kelpak SL at a dose of 2,0 dm³·ha⁻¹, Sencor 70 WG at a dose of 1,0 kg·ha⁻¹, Sencor 70 WG at a dose of 1,0 kg·ha⁻¹ and growth regulators Asahi SL at a dose of 1,0 dm³·ha⁻¹, while the control consisted of mechanical weeding without chemical protection. The aim of the research conducted in 2012–2014 was to determine the effect of the plant growth regulators and herbicides on the selected quality consumption features of potato tubers: savouriness, darkening of raw tubers after 10 minutes, darkening of cooked tubers after 10 minutes and after 24 hours. The obtained results showed that herbicides and biostimulators not affected the savouriness and darkening of raw tubers but resulted in increased darkening of cooked tubers after 10 minutes and after 24 hours. All determined consumption features significantly differentiated by features of the cultivars and weather conditions during the growing season. The smallest darkening flesh raw and cooked characterized by cultivars Gawin and Honorata, while the more cultivars darkened Bartek