1,472 research outputs found

    The Revanchist City: Downtown Chicago and the Rhetoric of Redevelopment in Bronzeville

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    This paper examines and interprets the contrived cycle of disinvestment and reinvestment in Bronzeville the original settlement area of Blacks in Chicago The historical political economic and social policy of confinement and segregation in Chicago created a high concentration of public housing in Bronzeville Data reveals that the disinvestment process in Bronzeville correlates with the concentration of public housing As the cost of local state and federal practices to maintain and concentrate public housing in Bronzeville increased a new public policy of housing demolition to create mixed income housing development coupled with decline of Chicago s manufacturing base and subsequent rise in information and consumption-based economy sparked reinvestment Our data reveal that the process of disinvestment and reinvestment gentrification doesn t just happen by chance but in fact is socially contrived and planned Under the rhetoric and language of being concerned for the well-being of the urban poor the primary goal of downtown Chicago and other public and private interests is to reclaim urban space for the creation of a middle and White upper-class elite consumer base in Bronzeville as well as a space of cultural consumption for tourist

    Material Flow in FSW of T-joints: Experimental and Numerical Analysis

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    In the paper the authors present the results of both an experimental and a numerical campaign focused on the analysis of the occurring material flow in the FSW of T joints of aluminum alloys. In particular to investigate the metal flow experimental tests and observations has been developed utilizing a thin foil of copper as marker placed between the skin and the stringer. In this way, the actual metal flow occurring during the FSW of T-joints has been highlighted together with the real bonding surface. The acquired information is definitively useful in order to choose effective set of process parameters, improving the process mechanics and avoiding the insurgence of defects

    Cetacean strandings and museum collections: A focus on Sicily island crossroads for mediterranean species

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    The study examined the extent of the cetacean strandings in Italy, with a particular focus on Sicily Island. The paper aimed to contribute to the description of a pattern that contemplates the “regular and rare” cetacean species passage along the Sicilian coast. The estimate of marine cetacean strandings was extrapolated from the National Strandings Data Bank (BDS—Banca Dati Spiaggiamenti) and evaluated according to a subdivision in three coastal subregions: the Tyrrhenian sub-basin (northern Sicilian coast), the Ionian sub-basin (eastern Sicilian coast), and the Channel of Sicily (southern Sicilian coast). Along the Italian coast, more than 4880 stranding events have been counted in the period 1990–2019. Most of these were recorded in five Italian regions: Apulia, Sicily, Sardinia, Tuscany, and Calabria. Approximately 15% of the recorded strandings in Italy occurred on the Sicilian coast. In Sicily Island, 725 stranded cetaceans were recorded in 709 stranding events, resulting in approximately 20 carcasses every year; the total number of specimens identified to species level was 539. The distribution along the Sicilian coast was the following: 312 recorded in the Tyrrhenian sub-basin, 193 in the Ionian sub-basin, and 220 in the Channel of Sicily. Stenella coeruleoalba was the species that can be considered as the stable record along the time-lapse investigated, and some rare species have been recorded as well. The role of Sicily Island as a sentinel territory of the cetacean distribution for the central Mediterranean Sea and as a region receiving a marine resource suitable for the scientific research and cetological museum collections is discussed herein

    Using fine-scale field data modelling for planning the management of invasions of Oenothera stucchii in coastal dune systems

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    Invasive alien species risk assessment and adaptive management are often hindered by a lack of information for most species. This work aims at predicting the probability of successful establishment and invasion of Oenothera stucchii Soldano, a neophyte invasive species belonging to the sect. Oenothera subsect. Oenothera, in xerophilous grasslands of grey dunes. Based on fine-scale field data, we modelled O. stucchii presence/absence and abundance as a function of environmental factors, human disturbance, and attributes of the recipient community through a zero-inflated Poisson model. The invasion success of O. stucchii depended on a combination of factors which differed when considering either the patterns of occurrence (species presence/absence) or those of species abundance. While human-driven disturbance strongly influenced the probability of presence/absence of O. stucchii, patterns of abundance were mostly driven by a combination of environmental and biotic features. Attributes of the recipient community remarkably influenced both O. stucchii presence and abundance. Based on fine-scale field data, we determined the mechanisms which drive the spatial patterns of presence and abundance of O. stucchii in xerophilous grasslands and provided quantitative thresholds to identify the most susceptible areas of grey dune habitats prone to invasion, which combine human disturbance (distance from the nearest beach access), attributes of the resident community (resident vegetation cover and structure), and environmental disturbance (foredune ridge height). These results provide useful insights to be used to plan cost-effective measures to prevent O. stucchii establishment and spread in sandy coastal systems. Our model may also be applied to closely related congener species included in the subsect. Oenothera, sharing similar biological and ecological traits

    Are Endothelial Progenitor Cells the Real Solution for Cardiovascular Diseases? Focus on Controversies and Perspectives

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    Advanced knowledge in the field of stem cell biology and their ability to provide a cue for counteracting several diseases are leading numerous researchers to focus their attention on \u201cregenerative medicine\u201d as possible solutions for cardiovascular diseases (CVDs). However, the lack of consistent evidence in this arena has hampered the clinical application. The same condition affects the research on endothelial progenitor cells (EPCs), creating more confusion than comprehension. In this review, this aspect is discussed with particular emphasis. In particular, we describe biology and physiology of EPCs, outline their clinical relevance as both new predictive, diagnostic, and prognostic CVD biomarkers and therapeutic agents, discuss advantages, disadvantages, and conflicting data about their use as possible solutions for vascular impairment and clinical applications, and finally underline a very crucial aspect of EPCs \u201ccharacterization and definition,\u201d which seems to be the real cause of large heterogeneity existing in literature data on this topic

    Joining by forming technologies: current solutions and future trends

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    The progressively more demanding needs of emissions and costs reduction in the transportation industry are pushing engineers towards the use of increasingly lightweight structures. This goal can be achieved only if dissimilar and/or new materials, including polymers and composites, are joined together to create complex structures. Conventional fusion welding processes have often been proven inadequate to this task because of the high heat input reducing the joint mechanical properties or even making the joining process impossible. Joining by forming technologies take advantage on the plastic deformation to create sound joints out of even very dissimilar materials. Over the last 25 years, several new processes, with increasing potential in effectively joining virtually every structural material, have been invented and developed. In the paper, a comprehensive overview of the most utilized joining by forming processes is given. For each process, an analysis of the current research trends and hot topics is provided, highlighting strengths and weaknesses for industrial applications

    Effects of native plants extracts from Córdoba Argentina over foraging activity of the cutting ant Acromyrmex lundi (Guérin)

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    In the search for new alternatives for insect pest management, natural products from plants are an option currently studied for being substances of low toxicity and biodegradable. The leaf-cutting ant Acromyrmex lundi is a very important herbivorous species in the Argentine Chaco phytogeographic region as it can cut various parts of plants and attack almost all cultivated species. The objectives of this study were: 1. determine the effect of plant extracts native of Córdoba-Argentina on the foraging activity of A. lundi in an artificial nest. 2. evaluate the crude extract with highest activity in foraging activity field tests. Extracts were prepares with aerial parts of plants belonging to 28 botanical families. In the laboratory, an artificial nest was installed, which consisted of a main chamber where the queen, the immature and the fungus remained, and smaller chambers that operated as dump and foraging areas. The work was carried out under controlled conditions (27°C, 12:12 hs light/darkness and Hº 25± 3). In free-choice tests, 8 discs of rose leaves of 1 cm of diameter were impregnated with 10μl per cm2 of a 1% solution (10 ug / ul) of each extract or solvent (control). The Inhibitory Dose 50 (ID50) was determined for all the extracts that showed 100% repellency. Aristolochia argentina Griseb. showed the lowest DI50 values, for what it was chosen for field trials. Rose leaves treated with A. argentina extract (1% and 5%) and others with acetone (control) were placed on either side of an actively foraging path of six active nests of A. lundi, 50cm from the nest opening. The percentage of removed material was registered within two hours of observation and on two consecutive days, ending the trial when removed 50% of the total substrate provided. Also, foraging activity was determined by counting at a fixed point and for a period of three minutes, the number of workers who went towards the mound charged. In field trials, the 1% extract of A. argentina (n = 6) did not affect foraging activity (P> 0.05), whereas the 5% dose (n = 5) showed significant differences between treatments (P <0.05). From these preliminary results, future studies arise to deepen different effects of the compound oriented to leaf-cutting ants management.Fil: Nolli, L.C. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Entomología; Argentina.Fil: Nolli, L.C. Centro de Investigaciones Entomológicas de Córdoba; Argentina.Fil: Buffa, L.M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Entomología; Argentina.Fil: Buffa, L.M. Centro de Investigaciones Entomológicas de Córdoba; Argentina.Fil: Defagó, M. T. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Entomología; Argentina.Fil: Defagó, M. T. Centro de Investigaciones Entomológicas de Córdoba; Argentina.Fil: Diaz Napal, G. Universidad Católica de Córdoba. Facultad de Ciencias Químicas. Laboratorio de Química Fina y Productos Naturales; Argentina.Fil: Palacios, S. M. Universidad Católica de Córdoba. Facultad de Ciencias Químicas. Laboratorio de Química Fina y Productos Naturales; Argentina.Zoología, Ornitología, Entomología, Etologí

    Effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus in the Mediterranean Sea

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    The effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus was investigated in the Egadi Islands, Sicily, during spring 2005 using a fixed tuna trap set near shipping routes. Tuna behaviour was observed when exposed to both natural ambient sound and sound generated by hydrofoil passenger ferries, small boats and large car ferries. Acoustical and behavioural analyses were conducted with and without extraneous sound to define a list of behavioural categories. Each vessel produced different engine sounds with regard to their composition and bandwidth, and all were distinctly different from ambient sound levels. In the absence of boat noise, tuna assumed a concentrated coordinated school structure with unidirectional swimming and without a precise shape. When a car ferry approached, tuna changed swimming direction and increased their vertical movement toward surface or bottom; the school exhibited an unconcentrated structure and uncoordinated swimming behaviour. Hydrofoils appeared to elicit a similar response, but for shorter periods. Agonistic behaviour was more evident when exposed to sounds from outboard motors of small boats. This study showed that local noise pollution generated by boats produced behavioural deviations in tuna schools. Schooling enhances tuna homing accuracy during their spawning migration, and an alteration in schooling behaviour can affect the accuracy of their migration to spawning and feeding grounds
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