PCB profiles in sediments of Lakes Maggiore, Como and Garda (Italy)

1995 ◽  
Vol 46 (1) ◽  
pp. 129 ◽  
Author(s):  
A Provini ◽  
S Galassi ◽  
L Guzzella ◽  
G Valli

Single PCB congeners were determined in dated sediment cores taken from the three greatest Italian lakes. The PCB profile is fairly constant with time in the three lakes and similar to that of a mixture of Aroclor 1254 and 1260 (35 : 65). Qualitative and quantitative results are consistent with the amounts of Aroclor sold, showing a general trend towards less in recent sediments than in the 1970s. However, this decrease was sharper in Lakes Maggiore and Como, which in the past had PCB concentration peaks of 197 ng g-1 and 822 ng g-1, repectively, than in Lake Garda (peak 38 ng g-1). There is disequilibrium between the top sediment layer and the water column due to freshly settled algae, which can adsorb PCBs to a greater extent than can abiotic particulate matter. A comparison of PCB loads in rain and in sediment shows that there are still local sources of contamination in Lake Como. The net flux of less chlorinated PCBs from Lake Maggiore to the atmosphere indicates that this waterbody can be a source of pollution for the surrounding area.

1985 ◽  
Vol 57 (3) ◽  
pp. 195-206
Author(s):  
Eeva Karppanen ◽  
Aldo Rizzo ◽  
Seija Berg

In the past mycotoxins have been only an occasional minor problem for domestic animals in Finland. In 1982 a large number of intoxicated animals were suspected of being affected by mycotoxicosis. Later on imported maize was found to be the cause of the illness. After 2 years of investigations we concentrated our attention on Fusarium toxins, and in the autumn of 1984 we were able to detect the presence of trichothecenes in feeds. The rainy summer of 1984 created very favourable conditions for the growth of moulds. The production lines of some feed factories were contaminated by Fusarium fungi. The number of intoxicated animals increased drastically. Two strains of Fusaria were isolated at a feed factory. Since the trichothecenes have strong dermotoxic and cytotoxic effects, biological tests were used in this investigation. Capillary gas chromatography and mass spectrometry were used to identify and quantify the trichothecenes. Qualitative and quantitative results are presented together with the symptoms observed in the intoxicated animals. The reliability and the significance of the results have been discussed. Despite what has earlier been believed, itis evident from our results that trichothecenes are unstable in cereals and feeds. In fact, samples which originally proved to be toxic were found to be almost toxin-free after 3 to 6 months storage at +4°C.


Author(s):  
Jerrold L. Abraham

Inorganic particulate material of diverse types is present in the ambient and occupational environment, and exposure to such materials is a well recognized cause of some lung disease. To investigate the interaction of inhaled inorganic particulates with the lung it is necessary to obtain quantitative information on the particulate burden of lung tissue in a wide variety of situations. The vast majority of diagnostic and experimental tissue samples (biopsies and autopsies) are fixed with formaldehyde solutions, dehydrated with organic solvents and embedded in paraffin wax. Over the past 16 years, I have attempted to obtain maximal analytical use of such tissue with minimal preparative steps. Unique diagnostic and research data result from both qualitative and quantitative analyses of sections. Most of the data has been related to inhaled inorganic particulates in lungs, but the basic methods are applicable to any tissues. The preparations are primarily designed for SEM use, but they are stable for storage and transport to other laboratories and several other instruments (e.g., for SIMS techniques).


Author(s):  
John D. Horner ◽  
Bartosz J. Płachno ◽  
Ulrike Bauer ◽  
Bruno Di Giusto

The ability to attract prey has long been considered a universal trait of carnivorous plants. We review studies from the past 25 years that have investigated the mechanisms by which carnivorous plants attract prey to their traps. Potential attractants include nectar, visual, olfactory, and acoustic cues. Each of these has been well documented to be effective in various species, but prey attraction is not ubiquitous among carnivorous plants. Directions for future research, especially in native habitats in the field, include: the qualitative and quantitative analysis of visual cues, volatiles, and nectar; temporal changes in attractants; synergistic action of combinations of attractants; the cost of attractants; and responses to putative attractants in electroantennograms and insect behavioral tests.


2021 ◽  
pp. 175797592110035
Author(s):  
Chia Yu Lien ◽  
Yun-Hsuan Wu

The COVID-19 outbreak has created an unprecedented challenge for governments to convey information to the public, and social media has become a critical method of COVID-19 communication in Taiwan. Objectives: This study examines a total of 1128 Facebook posts published by Taiwan’s principal health authority from December 1, 2019 to May 31, 2020. Methods: Using both qualitative and quantitative approaches, this study investigates strategies used by the Taiwan government to communicate the COVID-19 outbreak and public responses toward these strategies. Result: Novel uses of Facebook posts on outbreak communication were identified, including solidarity, reviews of actions, press conferences, and the use of animal and cartoon images. Quantitative results showed that the public responded significantly more frequently to messages generating positive affects, such as posts that reviewed government actions and public efforts; posts that expressed thanks, approval, or comradeship; and posts that paired text with photographs of frontline workers or cute animals. Conclusion: These results suggest that, amid a disease outbreak, the public not only look for updated situations and guidelines but also for affective affirmation from government agencies.


2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Andrew K. Scherer

The mid-1990s through the first decade of the new millennium marked an increase in publications pertaining to war and violence in the ancient past. This review considers how scholars of the past decade have responded to that work. The emerging consensus is that war and violence were endemic to all societies studied by archaeologists, and yet the frequency, intensity, causes, and consequences of violence were highly variable for reasons that defy simplistic explanation. The general trend has been toward archaeologies of war and violence that focus on understanding the nuances of particular places and historical moments. Nevertheless, archaeologists continue to grapple with grand narratives of war, such as the proposition that violence has decreased from ancient to modern times and the role of war and violence in state formation and collapse. Recent research also draws attention to a more expansive definition of violence. Expected final online publication date for the Annual Review of Anthropology, Volume 50 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Derek A. Jones ◽  
James P. Gaewsky ◽  
Mona Saffarzadeh ◽  
Jacob B. Putnam ◽  
Ashley A. Weaver ◽  
...  

The use of anthropomorphic test devices (ATDs) for calculating injury risk of occupants in spaceflight scenarios is crucial for ensuring the safety of crewmembers. Finite element (FE) modeling of ATDs reduces cost and time in the design process. The objective of this study was to validate a Hybrid III ATD FE model using a multidirection test matrix for future spaceflight configurations. Twenty-five Hybrid III physical tests were simulated using a 50th percentile male Hybrid III FE model. The sled acceleration pulses were approximately half-sine shaped, and can be described as a combination of peak acceleration and time to reach peak (rise time). The range of peak accelerations was 10–20 G, and the rise times were 30–110 ms. Test directions were frontal (−GX), rear (GX), vertical (GZ), and lateral (GY). Simulation responses were compared to physical tests using the correlation and analysis (CORA) method. Correlations were very good to excellent and the order of best average response by direction was −GX (0.916±0.054), GZ (0.841±0.117), GX (0.792±0.145), and finally GY (0.775±0.078). Qualitative and quantitative results demonstrated the model replicated the physical ATD well and can be used for future spaceflight configuration modeling and simulation.


Author(s):  
C. Nataraj

A simple model of a rigid rotor supported on magnetic bearings is considered. A proportional control architecture is assumed, the nonlinear equations of motion are derived and some essential nondimensional parameters are identified. The free and forced response of the system is analyzed using techniques of nonlinear analysis. Both qualitative and quantitative results are obtained and stability criteria are derived for safe operation of the system.


2011 ◽  
Vol 7 (4) ◽  
pp. 1337-1349 ◽  
Author(s):  
G. M. Ganssen ◽  
F. J. C. Peeters ◽  
B. Metcalfe ◽  
P. Anand ◽  
S. J. A. Jung ◽  
...  

Abstract. The oxygen isotopic composition of planktonic foraminifera tests is one of the widest used geochemical tools to reconstruct past changes of physical parameters of the upper ocean. It is common practice to analyze multiple individuals from a mono-specific population and assume that the outcome reflects a mean value of the environmental conditions during calcification of the analyzed individuals. Here we present the oxygen isotope composition of individual specimens of the surface-dwelling species Globigerinoides ruber and Globigerina bulloides from sediment cores in the Western Arabian Sea off Somalia, inferred as indicators of past seasonal ranges in temperature. Combining the δ18O measurements of individual specimens to obtain temperature ranges with Mg/Ca based mean calcification temperatures allows us to reconstruct temperature extrema. Our results indicate that over the past 20 kyr the seasonal temperature range has fluctuated from its present value of 16 °C to mean values of 13 °C and 11 °C for the Holocene and LGM, respectively. The data for the LGM suggest that the maximum temperature was lower, whilst minimum temperature remained approximately constant. The rather minor variability in lowest summer temperatures during the LGM suggests roughly constant summer monsoon intensity, while upwelling-induced productivity was lowered.


2020 ◽  
Author(s):  
Lucas R. V. Messias ◽  
Cristiano R. Steffens ◽  
Paulo L. J. Drews-Jr ◽  
Silvia S. C. Botelho

Image enhancement is a critical process in imagebased systems. In these systems, image quality is a crucial factor to achieve a good performance. Scenes with a dynamic range above the capability of the camera or poor lighting are challenging conditions, which usually result in low contrast images, and, with that, we can have the underexposure and/or overexposure problem. In this work, our aim is to restore illexposed images. For this purpose, we present UCAN, a small and fast learning-based model capable to restore and enhance poorly exposed images. The obtained results are evaluated using image quality indicators which show that the proposed network is able to improve images damaged by real and simulated exposure. Qualitative and quantitative results show that the proposed model outperforms the existing models for this objective.


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