256 research outputs found

    La Forestal en clave fílmica. Un pasado que no termina de pasar

    Get PDF
    The actions of the English company “The Forestal, Land, Timber and Railways Company limited (1906 -1969) -more popularly known as “La Forestal”- in the Austral Chaco and more specifically in the north of Santa Fe, have generated profound environmental and social impacts with consequences that go beyond the present. As a paradigmatic case, it has been approached in different productions, from literature that became a historiographic record (Gori: 1965) to documentary films that range a whole series of documentaries, the remembered film Quebracho (Wullicher: 1974), and, even more recently it is approached from the animation. This work aims to follow up these productions to focus on the analysis of Viaje a la Tierra del Quebracho (Quiñones: 2011), an animated short film that can be classified at the service of memory. In this case it refers to the dispossession, an identity that struggles to free itself from that imaginary of ghost towns. Not only does it show what happened through fiction and the richness of animated images, but it also takes us back to a historical past with its complexity and consequences while opening us up to many other meanings.El accionar en el chaco austral y el norte santafesino de la compañía inglesa “The Forestal, Land, Timber and Railways Company limited” (1906-1969) -conocida más popularmente como “La Forestal”- generó profundos impactos ambientales y sociales con consecuencias que trascienden hasta el presente. El tema, ha sido abordado en distintas producciones; desde la literatura que devino en registro historiográfico (Gori; 1965) a las producciones fílmicas, que abarcan documentales y ficciones como la recordada película Quebracho (Wullicher: 1974). Este trabajo se propone realizar un seguimiento de dichas producciones para focalizar en el análisis de Viaje a la Tierra del Quebracho (Quiñones: 2011), un corto de animación que presenta un pasado histórico complejo y con consecuencias en el presente.O acionar da empresa britânica “The Forestal, Land, Timber and Railways Company limited” (1906-1969) - conhecida mais popularmente como “La Forestal”- no Chaco Austral e mais especificamente no norte de Santa Fe, gerou profundos impactos e ambientais e sociais com consequências que transcendem até hoje. Como caso paradigmático foi abordado em diferentes produções, na literatura que se tornou registro historiográfico (Gori: 1965) às produções cinematográficas que vão desde uma série de documentários ao lembrado filme Quebracho (Wullicher: 1974), até mesmo, mais recentemente, ser abordado a partir da animação. Este trabalho tenciona acompanhar essas produções para concentrar -se na análise de Viaje a la Tierra del Quebracho (Quiñones: 2011), um curta de animação que bem poderia ser classificado como ao serviço da memória, neste caso da espoliação, e de uma identidade que luta para libertar-se daquele imaginário de cidades fantasma. Não só mostra o que aconteceu com a ficção e a riqueza das imagens de animação, mas também leva-nos a um passado histórico com sua complexidade e suas conseqüências, enquanto nos abre a muitos outros significados

    Carbon and nitrogen stable isotope fractionation during abiotic hydrolysis of pesticides

    Get PDF
    Compound-specific Stable Isotope Analysis (CSIA) has been recently established as a tool to study pesticide degradation in the environment. Among degradative processes, hydrolysis is environmentally relevant as it can be chemically or enzymatically mediated. Here, CSIA was used to examine stable carbon and nitrogen isotope fractionation during abiotic hydrolysis of legacy or currently used pesticides (chloroacetanilide herbicides: Acetochlor, Alachlor, S-Metolachlor and Butachlor, acylalanine fungicide: Metalaxyl, and triazine herbicide: Atrazine). Degradation products analysis and Csingle bondN dual-CSIA allowed to infer hydrolytic degradation pathways from carbon and nitrogen isotopic fractionation. Carbon isotopic fractionation for alkaline hydrolysis revealed similar apparent kinetic isotope effects (AKIEC = 1.03–1.07) for the 6 pesticides, which were consistent with SN2 type nucleophilic substitutions. Neither enantio-selectivity (EF ≈ 0.5) nor enantio-specific isotope fractionation occurred during hydrolysis of R (AKIEC = 1.04 ± 0.01) and S (AKIEC = 1.04 ± 0.02) enantiomers of a racemic mixture of Metalaxyl. Dual element isotope plots enabled to tease apart Csingle bondCl bond breaking of alkane (Λ ≈ εN/εC ≈ 0, Acetochlor, Butachlor) and aromatic π-system (Λ ≈ 0.2, Atrazine) from Csingle bondO bond breaking by dealkylation (Λ ≈ 0.9, Metalaxyl). Reference values for abiotic versus biotic SN2 reactions derived from carbon and nitrogen CSIA may be used to untangle pesticide degradation pathways and evaluate in situ degradation during natural and engineered remediation

    Effects of dental probing on occlusal surfaces - A scanning electron microscopy evaluation

    Get PDF
    The aim of this clinical-morphological study was to investigate the effects of dental probing on occlusal surfaces by scanning electron microscopy (SEM). Twenty sound occlusal surfaces of third molars and 20 teeth with initial carious lesions of 17- to 26-year-old patients (n = 18) were involved. Ten molars of each group were probed with a sharp dental probe (No. 23) before extraction; the other molars served as negative controls. After extraction of the teeth, the crowns were separated and prepared for the SEM study. Probing-related surface defects, enlargements and break-offs of occlusal pits and fissures were observed on all occlusal surfaces with initial carious lesions and on 2 sound surfaces, respectively. No traumatic defects whatsoever were visible on unprobed occlusal surfaces. This investigation confirms findings of light-microscopic studies that using a sharp dental probe for occlusal caries detection causes enamel defects. Therefore, dental probing should be considered as an inappropriate procedure and should be replaced by a meticulous visual inspection. Critical views of tactile caries detection methods with a sharp dental probe as a diagnostic tool seem to be inevitable in undergraduate and postgraduate dental education programmes. Copyright (c) 2007 S. Karger AG, Basel

    Selection of diazotrophic bacterial communities in biological sand filter mesocosms used for the treatment of phenolic-laden wastewater

    Get PDF
    Agri effluents such as winery or olive mill waste-waters are characterized by high phenolic concentrations. These compounds are highly toxic and generally refractory to biodegradation. Biological sand filters (BSFs) represent inexpensive, environmentally friendly, and sustainable wastewater treatment systems which rely vastly on microbial catabolic processes. Using denaturing gradient gel electrophoresis and terminal-restriction fragment length polymorphism, this study aimed to assess the impact of increasing concentrations of synthetic phenolic-rich wastewater, ranging from 96 mg L−1 gallic acid and138 mg L−1 vanillin (i.e., a total chemical oxygen demand (COD) of 234 mg L−1) to 2,400mg L−1 gallic acid and 3,442 mg L−1 vanillin (5,842 mg COD L−1), on bacterialcommunities and the specific functional diazotrophic community from BSF mesocosms. This amendment procedure instigated efficient BSF phenolic removal, significant modifications of the bacterial communities, and notably led to the selection of a phenolic-resistant and less diverse diazotrophic community. This suggests that bioavailable N is crucial in the functioning of biological treatment processes involving microbial communities, and thus that functional alterations in the bacterial communities in BSFs ensure provision of sufficient bioavailable nitrogen for the degradation of wastewater with a high C/N ratio.Web of Scienc

    Earlier age of dementia onset and shorter survival times in dementia patients with diabetes

    Get PDF
    Diabetes is a risk factor for dementia, but relatively little is known about the epidemiology of the association. A retrospective population study using Western Australian hospital inpatient, mental health outpatient, and death records was used to compare the age at index dementia record (proxy for onset age) and survival outcomes in dementia patients with and without preexisting diabetes (n = 25,006; diabetes, 17.3%). Inpatient records from 1970 determined diabetes history in this study population with incident dementia in years 1990–2005. Dementia onset and death occurred an average 2.2 years and 2.6 years earlier, respectively, in diabetic compared with nondiabetic patients. Age-specific mortality rates were increased in patients with diabetes. In an adjusted proportional hazard model, the death rate was increased with long-duration diabetes, particularly with early age onset dementia. In dementia diagnosed before age 65 years, those with a ≥15-year history of diabetes died almost twice as fast as those without diabetes (hazard ratio = 1.9, 95% confidence interval: 1.3, 2.9). These results suggest that, in patients with diabetes, dementia onset occurs on average 2 years early and survival outcomes are generally poorer. The effect of diabetes on onset, survival, and mortality is greatest when diabetes develops before middle age and after 15 years’ diabetes duration. The impact of diabetes on dementia becomes progressively attenuated in older age groups

    In vitro evaluation of modified surface microhardness measurement, focus variation 3D microscopy and contact stylus profilometry to assess enamel surface loss after erosive-abrasive challenges

    Get PDF
    The aim of the study was to compare surface loss values after erosion-abrasion cycles obtained with modified surface microhardness measurement (mSMH), focus variation 3D microscopy (FVM) and contact stylus profilometry (CSP). We cut human molars into buccal and lingual halves, embedded them in resin and ground 200 μm of enamel away. The resulting surfaces were polished. To maintain a reference area, we applied Block-Out resin to partly cover the enamel surface. The samples were incubated in artificial saliva (37°C; 1 h), then rinsed in deionized water (10 s) and dried with oil-free air (5 s). We immersed the specimens individually in 30 mL citric acid (1%, pH 3.6) for 2 min (25°C, 70 rpm dynamic conditions) before brushing them (50 strokes, 200 g) in an automatic brushing machine with toothpaste-slurry. We calculated the surface loss as per mSMH, by re-measuring the length of the same six indentations made before the abrasive challenge. The experiment consisted of five experimental groups that received between 2 and 10 erosion-abrasion cycles. Each group contained 15 specimens and samples in groups 1, 2, 3, 4 and 5 underwent a total of 2, 4, 6, 8 and 10 cycles, respectively. The resin was removed from the reference area in one piece under 10× magnification and the FVM and CSP were performed. Agreement between the methods was calculated with the intraclass correlation coefficient (ICC) and depicted in Bland-Altman plots. All methods presented a linear pattern of surface loss measurements throughout the experiment, leading overall to a strong, statistically significant correlation between the methods (ICC = 0.85; p<0.001). So, despite the different surface loss values, all methods presented consistent results for surface loss measurement

    Acidogenic Potential of “Sugar-Free” Cough Drops

    Get PDF
    A patient presented with extensive marginal ditching around restorations recently placed during whole-mouth rehabilitation. The patient was not xerostomic and was otherwise normal except for the self-reported excessive use of “sugar-free” cough drops sweetened with sorbitol and Isomalt® (an equimolar mix of glucosyl-mannitol and glucosylsorbitol). This prompted an in vitro investigation to determine whether Streptococcus sobrinus 6715, a cariogenic streptococcus, could grow and produce acid in growth medium containing an aqueous extract of such “sugar-free” cough drops. The results indicate that S. sobrinus 6715 uses Isomalt® and sorbitol extensively, producing terminal culture pH as low as 4.2 when grown on medium with cough drop extract containing these sugars. This pH is sufficient to demineralize dental enamel. Patients should be cautioned against the chronic overuse of “sugar-free” cough drops and other “sugar-free” confections sweetened with a mixture of Isomalt® and sorbitol

    Evaluation of the Performance of Information Theory-Based Methods and Cross-Correlation to Estimate the Functional Connectivity in Cortical Networks

    Get PDF
    Functional connectivity of in vitro neuronal networks was estimated by applying different statistical algorithms on data collected by Micro-Electrode Arrays (MEAs). First we tested these “connectivity methods” on neuronal network models at an increasing level of complexity and evaluated the performance in terms of ROC (Receiver Operating Characteristic) and PPC (Positive Precision Curve), a new defined complementary method specifically developed for functional links identification. Then, the algorithms better estimated the actual connectivity of the network models, were used to extract functional connectivity from cultured cortical networks coupled to MEAs. Among the proposed approaches, Transfer Entropy and Joint-Entropy showed the best results suggesting those methods as good candidates to extract functional links in actual neuronal networks from multi-site recordings
    corecore