Effects of sensitizers on the photodegradation of the systemic fungicide triadimenol

The photochemical behaviour of triadimenol (1) under various conditions has been examined. Significant degradation is obtained only in the presence of electron-acceptor sensitizers as 9,10-dicyanoanthracene or 2,4,6-triphenylpyrylium tetrafluoroborate, and long irradiation times are required. 1H-1,2,4-Triazole (2), 4-chlorophenyl formate (3), 4-chlorophenol (4), 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one (5), 4-chlorophenyl 2,2-dimethylpropanoate (6) and 4-chlorobenzoic acid (7) were identified as photoproducts by NMR and GC-MS.     

Both evaluation of resource quality and speed of recruited leaf-cutting ants (Acromyrmex lundi) depend on their motivational state

Summary During recruitment, running velocity of both outbound and laden workers of the leaf-cutting ant Acromyrmex lundi depended on the information about resource quality they received from the first successful recruiter. In independent assays, single scout ants were allowed to collect sugar solutions of different concentrations and to recruit nestmates. Recruited workers were presented with standardized paper discs rather than the sugar solution given to the original recruiting ant. Outbound recruited workers were observed to run faster the more concentrated the solution found by the recruiter. Speed of disc-laden workers also depended on the concentration of the solution found by the recruiter, i.e. on the information about food quality they received, since they had no actual contact with the sugar solution. Disc-laden workers ran, as intuitively expected, slower than outbound workers. The reduction in speed, however, could not be attributed to the effects of the load itself, because workers collecting discs of the same weight, but with added sugar, ran as rapidly as outbound, unladen workers. Workers collecting standardized sugared discs reinforced the chemical trail on their way to the nest. The percentage of trail-layers was higher when workers were recruited to 10% than to 1% sugar solution, even though they collected the same kind of discs at the source. Their evaluation of resource quality, therefore, depended on their motivational state, which was modulated by the information they received during recruitment. Using previously published data on energetics of locomotion in leaf-cutting ants, travel costs of A. lundi workers recruited to sugar solutions of different concentration could be estimated. For workers recruited to the more concentrated solution, both speed and oxygen consumption rate increased by a roughly similar factor. Therefore, although workers ran faster to the high-quality resource, their actual energy investment per trip remained similar to that made by workers recruited to the low-quality resource. It is suggested that the more motivated workers reduced travel time without increasing energy costs during the trip. The adaptive value of these responses seems to be related to a rapid transmission of information about a newly discovered food source.     

User experience and operational feasibility of four point-of-collection oral fluid drug-testing devices according to Brazilian traffic agents

Objective: Traffic fatalities in Brazil still rank among the highest worldwide, with an overall rate of 23.4 deaths/100,000 inhabitants/year. Although alcohol and drug use play an important role in traffic accidents, national data about their relative influence are scarce. Drug screening is not routinely performed by traffic agents because alcohol is the only substance regularly investigated in roadblocks. Therefore, we aimed to describe the initial traffic agent user experience for 4 handheld point-of-collection oral fluid drug testing devices used in routine roadblocks in Brazil, focusing on usage perceptions in hopes of generalizing this approach for other developing countries.

Methods: Four different oral fluid collection devices were evaluated: The DDS2, the DOA MultiScreen, the Dräger DrugTest 5000, and the Multi-Drug Multi-Line Twist Screen Device. Fourteen trained traffic agents obtained oral fluid from 164 drivers and performed 37 qualitative evaluations of the devices. Traffic agents filled out a questionnaire focusing on 9 feasibility criteria: Overall simplicity for roadside operation; operational success; saliva sample collection time; sample analysis time; ease of sample preparation and analysis; agreement with observed clinical signs; overall hygiene and safety; sufficient operating instructions; and hygiene of saliva collection. These were weighted based on an expert panel and yielded an overall composite device experience score that ranged from 1 (poor) to 100 (excellent).

Results: Ease of use, operational success, and acceptable collection and analysis time were considered the most important criteria by the expert panel. The results ranged from 27.3 to 88.9% for simplicity of use; 45.5 to 100.0% for operational success; 27.3 to 100% for acceptable collection time; and 36.4 to 100.0% for acceptable analysis time. The final device scores, based on the agents’ user experiences, ranked as follows: DOA MultiScreen: 49.3/100; Dräger DrugTest 5000: 82.4/100; Multi-Drug Multi-Line Twist Screen Device: 84.3/100; DDS2: 88.4/100.

Conclusion: Based on the selected criteria, 3 of the 4 devices were considered useful by traffic agents in routine roadblock operations. The weighted evaluations suggest that their ease of use (handling, sampling analysis, and reliability), as well as their agreement with findings obtained by other means, defined their utility to traffic agents, although such appraisals must be further analyzed in future studies.     

Foraging behavior and habitat use by the Southern Giant Petrel on the Patagonian Shelf

We explored the at-sea behavior and marine habitat use of the Southern Giant Petrel breeding in Patagonia, Argentina by means of satellite telemetry. Adult breeders showed a wide distribution over the Patagonian Shelf, using 74% of its surface. The maximum distance traveled from the colonies was 683 km, but on average birds moved no more than 200 km further away from their colony. Important marine areas were located in the shelf break, middle shelf and coastal waters. Areas of activity by sex overlap between 35 and 94%. Females foraged primarily away from the coast and males mainly on coastal areas. Both sexes were capable of flying up to 4,000 km but most of the foraging trips were of less than 200 km. Our results emphasize the importance of the Patagonian Shelf as foraging habitat for pelagic seabirds and contribute to international efforts to identify and protect a network of marine sites.     

Ecosystem functioning approach applied to a large contaminated coastal site: the study case of the Mar Piccolo of Taranto (Ionian Sea)

Knowledge on ecosystem functioning can largely contribute to promote ecosystem-based management and its application. The Mar Piccolo of Taranto is a densely populated area at a high risk of environmental crisis. Here, planktonic primary production (PP) and heterotrophic prokaryotic production (HPP) were measured as proxies of functioning in three sampling sites located in two inlets at different levels of industrial contamination, during three sampling surveys (June 2013, February and April 2014). To have a better overall view and provide some insights into the benthic-pelagic coupling, we integrated PP and HPP in the water column with those in the sediments and then discussed this with the origin of the organic matter pools based on analysis of stable isotopes. Heavy metals and polychlorobiphenyls (PCBs) were also analysed in the surface (1 cm) sediment layer and related to the overall ecosystem functioning. Multidimensional scaling (MDS) analysis, based on the main data, clearly separated the second inlet from the first one, more severely impacted by anthropogenic activities. The stable isotope mixing model suggested the prevalent terrestrial/riverine origin of the particulate organic matter pools (mean 45.5 %) in all sampling periods, whereas phytoplankton contributed up to 29 % in February. Planktonic PP and HPP rates followed the same pattern over the entire study period and seemed to respond to phytoplankton dynamics confirming this community as the main driver for the C cycling in the water column. On the contrary, benthic PP rates were almost negligible while HPP rates were lower or comparable to those in the water column indicating that although the Mar Piccolo is very shallow, the water column is much more productive than the surface sediments. The sediment resuspension is likely responsible for a pulsed input of contaminants into the water column. However, their interference with the proper functioning of the pelagic ecosystem seems to be limited to the bottom layers.     

A mild photochemical approach to the degradation of phenols from olive oil mill wastewater

Photooxidation of cathecol (1) is carried out in aqueous solution at lambda > 300 nm using different sensitizers: rose bengal (RB), 9,10-dicyanoanthracene (DCA), 2,4,6-triphenylpyrylium tetrafluoroborate (Pyryl). The highest degradation is observed in the UV/RB-sensitized reaction (66% after 15 h of irradiation), mineralization and formation of dimers are the final events. This procedure has been extended to tyrosol (2), caffeic acid (3), vanillic acid (4), 4-hydroxycinnamic acid (5) and 4-hydroxybenzoic acid (6) as well as to a mixture of all phenols. A reduced toxicity of the UV/RB-irradiated solutions of cathecol and tyrosol towards alga Ankistrodesmus braunii is also verified.     

Blood markers among residents from a coal mining area

Environmental Science and Pollution Research - Coal extraction and processing generate environmental contamination, which has several negative impacts on human health. Hematological and biochemical...     

The clinical impact of the first-trimester nuchal translucency between the 95th–99th percentiles

Objectives

To evaluate the clinical significance of nuchal translucency (NT) between the 95th–99th percentile in terms of typical and atypical chromosomal abnormalities (ACAs), associated fetal congenital defects and postnatal outcome.

Methods

A retrospective cohort study of fetuses with NT between the 95th–99th percentile. Data regarding the rate of associated fetal defects, genetic abnormalities and postnatal outcome were collected.

Results

A total of 306 cases of fetuses with an NT between the 95th–99th percentiles were included. The overall rate of genetic abnormalities was 12.1% (37/306). Chromosomal abnormalities were found in 10.1% (31/306) of cases and 2% were ACA (6/306). Within this group, two were pathogenic Copy Number Variants (CNVs) and four were single gene disorders. The overall rate of fetal congenital defects was 13.7% (42/306). All ACAs were found in fetuses with congenital defects. Postnatally, a new diagnosis of a single gene disorder was made in 0.85% of cases (2/236).

Conclusions

The presence of an NT between the 95th–99th percentiles carries a 10-fold increased risk of fetal defects, representing an indication for referral for a detailed fetal anatomy evaluation. The risk of ACA is mainly related to the presence of fetal defects, irrespective of the combined test risk.     

Contrasting temporal trends and relationships of total organic carbon, black carbon, and polycyclic aromatic hydrocarbons in rural low-altitude and remote high-altitude lakes

Historical records of total organic carbon (TOC), black carbon (BC), and polycyclic aromatic hydrocarbons (PAHs) were reconstructed in dated sediment cores from four nearby lakes in central Switzerland. In the sub-Alpine Lake Thun, located at 558 m a.s.l., the proximity to anthropogenic emission sources is reflected in higher input of BC and PAHs into sediments with fluxes only slightly decreasing during the last decades. PAH/BC ratios are relatively high and correlation between levels of total PAHs and BC is almost inexistent in Lake Thun, probably due to the presence of less condensed forms of the BC spectrum (char BC) that is underestimated with the chemothermal oxidation method applied in this study. The sediment profiles of TOC, BC, and PAHs are noticeably different in the mountain lakes located around 2000 m a.s.l. In Lake Engstlen, the PAH/BC ratios, as well as the correlation between PAHs and BC, point towards appreciable amounts of predominantly light soot particles. Light soot particles have higher mobility and can, therefore, be efficiently transported to this remote site. The proglacial Lake Oberaar is shown to be a receptor of BC and PAHs released by the fast melting adjacent glacier acting as a secondary source for these conservative species temporarily stored in the glacier ice. Finally, Lake Stein is in strong contrast to all other lakes. High flux of BC into Lake Stein, combined with constant temporal evolutions of BC and PAHs, and in particular BC/TOC ratios approaching 100% are all strong indications for a geogenic presence of graphite in its catchment area.