591 research outputs found
A Model for Confronting Fire Investigation Errors
When faced with the challenge of defending someone accused of arson, counsel has several options but unless there is overwhelming evidence to indicate that this was in fact an arson, the first thing counsel should do is retain an expert. Arson is one of the few crimes for which it is necessary to first prove that a crime was committed. Over this author’s 45-year career, many false accusations of arson have resulted in either civil or criminal litigation. As stated in the 2009 National Academy of Sciences (NAS) report:
The simple reality is that the interpretation of forensic evidence is not always based on scientific studies to determine its validity. This is a serious problem. Although research has been done in some disciplines, there is a notable dearth of peer-reviewed, published studies establishing the scientific bases and validity of many forensic methods.
This description applies to all of the forensic sciences, including fire investigation. Specifically related to fire investigation, the NAS report goes on:
…much more research is needed on the natural variability of burn patterns and damage characteristics and how they are affected by the presence of various accelerants. Despite the paucity of research, some arson investigators continue to make determinations about whether or not a particular fire was set. However, according to testimony presented to the Committee, many of the rules of thumb that are typically assumed to indicate that an accelerant was used have been shown not to be true. Experiments should be designed to put arson investigations on a more solid scientific footing.
The problem is that fires are destructive, and the aftermath of an accidental fire can often look exactly the same as the aftermath of an intentionally set fire. This confounding fact has led to many false accusations, false convictions, and even a wrongful execution.
According to the National Fire Protection Association (NFPA), there were about 387,000 residential structure fires in the United States in 2018. Of these, approximately 25,500 were declared to be incendiary. That means that every year, there are 25,000 chances for fire investigators to make a serious error. Even if the error rate is only 5%, that amounts to 1,250 miscalls per year. Given this author’s experience, a 5% error rate is wildly optimistic.
So the first question that counsel needs to address is “is this actually an arson fire?”
Following that, additional questions arise.
• Is this arson investigator actually qualified to render opinions?
• Did the investigator employ appropriate methodology in reaching his opinions?
• It is origin determination even a valid forensic science discipline? So far, attempts to demonstrate the validity of origin determination have failed
The changing Latin American landscape in provision and regulation of the water and sanitation services
Since the Great Depression of the 1930s, it was common knowledge in the Latin American water and sanitation sector the idea of take advantage of scale economies, typical of these natural monopolies, in a context favorable to state involvement in the activity. In parallel, the development of sanitary engineering and the necessity of improve and extend coverage due to health and merit goods considerations. Until the 1980s centralized state-owned monopolies ruled the sector in urban areas, while in rural places the role was performed by decentralized or municipal services. Between the 1930s and the 1960, important investments in sanitary infrastructure were made in the region. Since the 1970s, growing fiscal stress started to affect the expansion and the maintenance of the inherited infrastructure. In the 1980s the sectors decayed because of public spending cuts in the context of the Debt Crisis, and joint with a different vision, a consensus grown in direction to reforms of the sector (regionalization) and to private sector participation. Nowadays, centralized services are the exception and are generally found in small extension countries and or low population places. More spread is the national regulation. Federal countries as Argentina, Brazil and Mexico do not have a national regulator. Multisectoral regulators are found in a few countries, of small territory and population.water; sanitation; Latin America
Enriched iron(III)-reducing bacterial communities are shaped by carbon substrate and iron oxide mineralogy
© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 3 (2012): 404, doi:10.3389/fmicb.2012.00404.Iron (Fe) oxides exist in a spectrum of structures in the environment, with ferrihydrite widely considered the most bioavailable phase. Yet, ferrihydrite is unstable and rapidly transforms to more crystalline Fe(III) oxides (e.g., goethite, hematite), which are poorly reduced by model dissimilatory Fe(III)-reducing microorganisms. This begs the question, what processes and microbial groups are responsible for reduction of crystalline Fe(III) oxides within sedimentary environments? Further, how do changes in Fe mineralogy shape oxide-hosted microbial populations? To address these questions, we conducted a large-scale cultivation effort using various Fe(III) oxides (ferrihydrite, goethite, hematite) and carbon substrates (glucose, lactate, acetate) along a dilution gradient to enrich for microbial populations capable of reducing Fe oxides spanning a wide range of crystallinities and reduction potentials. While carbon source was the most important variable shaping community composition within Fe(III)-reducing enrichments, both Fe oxide type and sediment dilution also had a substantial influence. For instance, with acetate as the carbon source, only ferrihydrite enrichments displayed a significant amount of Fe(III) reduction and the well-known dissimilatory metal reducer Geobacter sp. was the dominant organism enriched. In contrast, when glucose and lactate were provided, all three Fe oxides were reduced and reduction coincided with the presence of fermentative (e.g., Enterobacter spp.) and sulfate-reducing bacteria (e.g., Desulfovibrio spp.). Thus, changes in Fe oxide structure and resource availability may shift Fe(III)-reducing communities between dominantly metal-respiring to fermenting and/or sulfate-reducing organisms which are capable of reducing more recalcitrant Fe phases. These findings highlight the need for further targeted investigations into the composition and activity of speciation-directed metal-reducing populations within natural environments.This work was supported by a National Science Foundation Graduate Research Fellowship under grant no. DGE-0946799 and DGE-1144152 awarded to Christopher J. Lentini
Wild food plants of popular use in Sicily
In the present work the authors report the result of their food ethnobotanical researches, which have been carried out in Sicily during the last thirty years. Data concerning 188 wild species used in the traditional Sicilian cuisine are reported. The authors underline those species that are partially or completely unknown for their culinary use and they illustrate other species that local inhabitants suggested in the prevention or treatment of symptomatologies caused by a refined diet, poor in vegetables. These data want to contribute to avoid the loss of traditional knowledge on uses and recipes concerning wild food botanicals, and to encourage further studies for those species that have not yet been sufficiently researched in their food chemical and nutritional profile. These studies may also suggest new applications for a few botanicals in medico-nutritional fields. The work includes also a short review of the seaweeds and mushrooms traditionally gathered and consumed in Sicily
A Decision Support System for Land Allocation under Multiple Objectives in Public Production Forests in the Brazilian Amazon
Logging in natural forests is a vital economic activity in the Brazilian Amazon. However, illegal and unplanned logging is exhausting forests rapidly. In 2006, a new forestry law in Brazil (Lei 11,284/2006) established the legal framework to develop state and national public forests for multiple uses. To support public forest planning efforts, we combine spatially explicit data on logging profits, biodiversity, and potential for community use for use within a forest planning optimization model. While generating optimal land use configurations, the model enables an assessment of the market and nonmarket tradeoffs associated with different land use priorities. We demonstrate the model's use for Faro State Forest, a 636,000 ha forest embedded within a large mosaic of conservation units recently established in the state of Pará. The datasets used span the entire Brazilian Amazon, implying that the analysis can be repeated for any public forest planning effort within the region
Economies of scale in the water sector: A survey of the empirical literature
The issue of the most favorable size and optimal industry structure in the water sector is a relevant topic in many countries, due to fragmentation of the water sector and the key role played by municipalities. Important debates are taking place worldwide about how to provide universal access to the water supply and offer an efficient service. Regarding efficiency, the possibility of exploiting economies of scale would imply better resource allocation, the potential for lower water charges, and greater geographical coverage. By surveying the empirical research from different parts of the world, we aim to shed some light on the topic of economies of scale, and to provide a synthesis of the literature. We also aim to determine whether there is a tradeoff between centralization and decentralization. Our survey shows that, for several countries, variations in efficiency of water provision due to economies of scale do exist. Increases in efficiency related to economies of scale are found for populations in the range of 100,000 to 1 million people served. For larger populations, volume-or density-constant returns to scale are observed, followed by decreasing returns to scale; the reverse occurs for smaller values, suggesting that cost savings are derived from consolidation of providers. Returns to scale refer to changes in output resulting where all inputs increase by a constant factor. If output increases by that same proportional change, then there are constant returns to scale. If output increases by less than that proportional change, there are decreasing returns to scale. If output increases by more than that proportional change, there are increasing returns to scale. Returns to scale is a technological phenomenon, due to the relationship between inputs and outputs in the production function. Economies of scale refer to reductions in unit cost as the scale of production increases. Diseconomies of scale are the opposite: increasing in unit costs as the scale of production increases. Scale changes mean a proportional increase in all factors of production. Economies of scale are a economical phenomenon, due to the relationship between unit costs and the level of production.Fil: Ferro, Gustavo Adolfo. Universidad Argentina de la Empresa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Lentini, Emilio J.. Universidad de Buenos Aires; ArgentinaFil: Mercadier, Augusto C.. Universidad Nacional de La Plata; Argentin
EconomĂas de escala en agua y saneamiento: examen de la literatura
Este estudio se ocupa de relevar la literatura internacional sobre economĂas de escala en el sector de agua y saneamiento, reseñarla y extraer hilos conductores. En todo el mundo está en discusiĂłn cĂłmo lograr un acceso más equitativo y una prestaciĂłn más eficiente. Un tema vinculado con la eficiencia es la posibilidad de aprovechar economĂas de escala al dimensionar la prestaciĂłn de agua potable y alcantarillado. La discusiĂłn teĂłrica y los resultados empĂricos sobre economĂas de escala en agua y saneamiento sirven para detectar si hay o no un quid-pro-quo entre concentrar y desconcentrar servicios como medida de polĂtica. Los estudios relevados en un conjunto grande de paĂses, arrojan economĂas de escala (en diversos paĂses con diferentes situaciones) en poblaciones cubiertas por entre 100 mil, hasta cerca de 1 millĂłn de habitantes (en algunos casos se extiende a varios millones), o con densidades poblacionales de hasta 250 habitantes por kilĂłmetro de red, o con volĂşmenes entregados a la red de 70 millones de m3 al año. Con poblaciones, volĂşmenes o densidades mayores, empiezan primero los rendimientos constantes a escala y posteriormente las deseconomĂas de escala; con valores menores, hay ahorros de costos por aglomerar.water; sanitation; scale economies
Estimating local records for Northern and Central Italy from a sparse secular temperature network and from 1961–1990 climatologies
The paper presents monthly 30-arc-second-resolution Northern and Central Italy temperature climatologies and discusses the procedure we adopt to superimpose the information of temperature secular records onto these climatologies. The climatologies are obtained by means of a step-wise linear regression method which aims at determining the temperature dependence on geographical and morphological variables. Such a method is applied to a database of about 800 monthly 1961–1990 temperature normals. In the first regression (temperature vs. elevation) the recorded data are considered; the further regressions concern the residuals obtained after taking into account the effect of each variable, in order of importance. An estimated secular anomaly record can be obtained for each point of the climatology grid by means of a distance-weighted average of the temperature anomaly records of the stations surrounding the grid point
Returns to scale in water and sanitation: estimates for Latin America
Most countries around the world are strongly debating ways to yield more equitable access and a more efficient provision. One issue linked to efficiency is the achievement of scale economies in the industry and the optimal dimension of water and sanitation providers. Changes in the industrial structure of the sector, through mergers in highly atomized services, the breakup of very concentrated services, or the property discussion (private versus public) are major issues. These decisions have often become politicized because of the social complexity of the sector. Empirical findings of the different models reveal the existence of increasing returns to scale in Latin American water provision based on an ADERASA database (a 2005 cross section of 90 providers in 14 countries). The study of returns to scale incorporates a technical argument into the discussion because–as our study suggests–the prescription could be to agglomerate small providers.Fil: Ferro, Gustavo Adolfo. Universidad Argentina de la Empresa. Facultad de Ciencias EconĂłmicas. Instituto de EconomĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Lentini, Emilio J.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; ArgentinaFil: Mercadier, Augusto C.. Universidad Argentina de la Empresa. Facultad de Ciencias EconĂłmicas. Instituto de EconomĂa; ArgentinaFil: Romero, Carlos A.. Universidad Argentina de la Empresa. Facultad de Ciencias EconĂłmicas. Instituto de EconomĂa; Argentin
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