A New Ozonated Cassava Film with the Addition of Cellulose Nanofibres: Production and Characterization of Mechanical,Barrier and Functional Properties

Journal of Polymers and the Environment - In this study cassava starch modified by ozone technology and cellulose nanofibres were used to produce films. These nanocomposites were produced by...     

Present and past threats and response on the east coast of Africa: an archaeological perspective

This article addresses two related themes: the response of coastal communities to the impact of environmental processes and human actions as reflected in archaeology, and threats to the archaeological record emanating from current natural and human agencies. The geographical context is the entire east coast of Africa, although emphasis is placed on Swahili settlements in the light of their long-standing dependence upon maritime resources and trading opportunities. Evidence is derived from documentary sources and field studies with detailed data from Kilwa, Tanzania. Physical conditions are relatively benign, but threats are identified in adverse weather events, erosion, and sedimentation processes. Knowledge of past climatic impacts upon shipping is restricted by limited research of the off-shore environment. On-shore, the archaeological record provides evidence of protective construction work, possibly where erosion precipitated by removal of mangroves. However, unless significant port investments required safeguarding, relocation of landing area and settlement was principal response to erosion and sedimentation. Current threats to archaeology are far more significant both from natural processes of marine erosion and vegetation growth encouraged by urban decline and neglect. Limited legislation and resources are seen as the greatest impediments to investigation and protection of heritage from urban and tourism inspired development in future.     

A power-efficiency trade-off in resource use alters epidemiological relationships

Trade-offs play pivotal roles in the ecology and evolution of natural populations. However, trade-offs are probably not static, invariant relationships. Instead, ecological factors can shift, alter, or reverse the relationships underlying trade-offs and create critical genotype x environment (G x E) interactions. But which ecological factors alter trade-offs or create G x E interactions, and why (mechanistically) do they do this? We tackle these questions using resource quality as the central ecological factor and a case study of disease in the plankton. We show that clonal genotypes of a zooplankton host (Daphnia dentifera) exhibit a "power-efficiency" trade-off in resource use, where powerful (fast-feeding) host clones perform well on richer algal resources, but more efficient (slow-feeding) clones perform relatively well on poorer resources. This resource-based trade-off then influences epidemiological relationships due to fundamental connections between resources and fecundity, transmission rate (an index of resistance), and replication of a virulent fungal parasite (Metschnikowia bicuspidata) within hosts. For instance, using experiments and dynamic energy budget models, we show that the power-efficiency trade-off overturned a previously detected trade-off between fecundity and transmission risk of hosts to this parasite. When poorer resources were eaten, transmission risk and fecundity were negatively, not positively, correlated. Additionally, poor resource quality changed positive relationships between yield of infectious stages (spores) and host fecundity: those fecundity-spore relationships with poor food became negative or nonsignificant. Finally, the power-efficiency trade-off set up an interaction between host clone and resource quality for yield of fungal spores: powerful clones yielded relatively more spores on the better resource, while efficient clones yielded relatively more on the poorer resource. Thus, the physiological ecology of resource use can offer potent, mechanistic insight linking environmental factors to epidemiological relationships.     

Blue Tits use fledgling quantity and quality as public information in breeding site choice

Public information (PI), which is the information that can be derived from the behavior and performance of conspecifics, has been demonstrated to be used in many fitness-enhancing decisions. In the context of breeding habitat choice, PI use has been called "habitat copying." We experimentally tested the existence of habitat copying in the Blue Tit (Cyanistes caeruleus), a nonmigratory, short-lived hole-nesting bird. We manipulated the mean number of fledglings raised locally (quantity) and their condition (quality) as components of PI by transferring nestlings from Decreased (D) patches to Increased (I) patches. Our manipulations caused a negative relationship between fledgling quantity and quality that does not exist naturally: I patches had a higher number of fledglings that were in poorer condition, whereas D patches had a lower number in better condition. Control (C) patches, whether manipulated or not, had intermediate levels in terms of fledgling quantity and quality. Adult emigration the following year was higher from D than from C or I patches. Similarly, adult dispersal distance decreased for individuals coming from D to C to I patches. This suggests that resident breeders rely mainly on fledgling quantity to make emigration decisions. Emigration patterns of juveniles did not vary in relation to our patch manipulation. Immigration rates were higher and similar in I and D patches than in C patches. Hence, immigrant Blue Tits seem to rely on one of the manipulated components of PI and are insensitive to the discrepancy between fledgling quantity and quality. This shows that even nonmigratory species, such as Blue Tits, may use PI in their dispersal decisions but weigh its components differently for emigration and immigration. Differences among species in the importance of PI in breeding habitat choices may be explained by differences in life histories.     

Entwicklung und Einsatz eines standardisierten Labortests für Dungkäfer (Aphodius constans) zur Prüfung der Ökotoxizität von Veterinärpharmaka

Goal, Scope, and Background

According to European legislation, an environmental risk assessment of veterinary pharmaceuticals for dung beetles is required if the substance is a parasiticide for the treatment of pasture animals. However, the demonstration of the environmental safety of those substances for dung beetles is strongly hampered by the fact that no standardized test system is available so far. Therefore, starting with recommendations from the SETAC advisory group DOTTS (Dung Organism Toxicity Test Standardization), a test system using the widespread temperate dung beetle species Aphodius constans was developed.

Methods

Using experiences gained at the University of Montpellier (e.g. in field studies) and in other terrestrial tests, details of culturing and testing of A. constans were investigated in a project sponsored by the German Environment Protection Agency (UBA). Basically, the survival of young larvae of A. constans exposed to the test substance spiked into formulated (i.e. dried, grounded and re-wetted) or fresh dung is measured over a period of three weeks. Using the model substance dimethoate (an insecticide required as positive control in tests with the predatory mite Hypoaspis aculeifer) the suitability of the new test was checked. Afterwards, the new test method was used to determine the toxicity of four common veterinary pharmaceuticals (ivermectin, dicyclanil, moxidectin, praziquantel) in formulated and fresh dung. Finally, the effects of ivermectin on the dung beetles were determined in a test using fresh dung from treated cattle.

Results and Conclusions

For Dmethoate LC₅₀-values were found in a range of 1–3 mg a.s./kg dung (dew.), depending on the dung type. Praziquantel did not show eirecis in the tested concentration range (i.e. up to 1000 mg a.s./kg Dung (DW). The LC₅₀-values of the other three pharmaceuticals were very low (<6 mg a.s./kg dung (DW)). With the exception of Dicyclanil no differences between formulated and fresh dung were identified. In the case of ivermectin the LC₅₀-value were even lower: about 0.5 mg a.s./kg dung (DW). No differences between the results of test in which the substance was spiked into dung and those tests which were performed with dung from treated cattle were found. These results prove the sensitivity as well as the robustness of this test method.

Recommendations and Perspectives

Based on the experiences reported here, it is recommended to standardize this test in an international ring test so that it can be incorporated in the risk assessment process for veterinary pharmaceuticals as described in the currently developed international registration guidelines.     

Modelling concentrations of airborne primary and secondary PM10 and PM2.5 with the BelEUROS-model in Belgium

The Eulerian Chemistry-Transport Model BelEUROS was used to calculate the concentrations of airborne PM₁₀ and PM_2.5 over Europe. Both primary as well as secondary particulate matter in the respirable size-range was taken into account. Especially PM_2.5 aerosols are often formed in the atmosphere from gaseous precursor compounds. Comprehensive computer codes for the calculation of gas phase chemical reactions and thermodynamic equilibria between compounds in the gas-phase and the particulate phase had been implemented into the BelEUROS-model. Calculated concentrations of PM₁₀ and PM_2.5 are compared to observations, including both the spatial and daily, temporal distribution of particulate matter in Belgium for certain monitoring locations and periods. The concentrations of the secondary compounds ammonium, nitrate and sulfate have also been compared to observed values. BelEUROS was found to reproduce the observed concentrations rather well. The model was applied to assess the contribution of emissions derived from the sector agriculture in Flanders, the northern part of Belgium, to PM₁₀- and PM_2.5-concentrations. The results demonstrate the importance of ammonia emissions in the formation of secondary particulate matter. Hence, future European emission abatement policy should consider more the role of ammonia in the formation of secondary particles.     

Persistence of Violation and Crash Behavior Over Time

This analysis examines the ability of previous offenses to predict future high-risk offenses, and similarly, the ability of crashes to predict future high-risk crashes, using the complete driver history data (up to 9 years) for a set of young Michigan subjects. As expected, those with previous ticketed offenses or reported crashes are at greater risk for future offenses or crashes; with a previous-year serious offense doubling the odds of serious offenses during the subsequent year, and a previous-year at-fault crash increasing the odds of subsequent-year at-fault crashes by nearly 50%. There is modest evidence that serious offenses and at-fault crashes may better predict subsequent behavior in females and in more experienced drivers. This latter finding is also evidenced by the fact that records of these young drivers are less predictive of subsequent driving history than is true for records of all drivers in general found in other studies. This suggests that, in the early stages of driving, offenses and crashes are, at least in part, attributable to inexperience, and hence, characteristic of all beginning drivers.     

Heavy metal contamination from mining sites in South Morocco: 2. Assessment of metal accumulation and toxicity in plants

Metalliferous soils cover a relatively large surface area in Morocco, and up to now no hyperaccumulating plants have been identified on these mining or these industrial sites. The aim of this work was to assess the extent of metal accumulation by plants found in three mining areas in southern Morocco with the ultimate goal of finding metal hyperaccumulating species by using the MetPAD biotest. The biotest helps to obtain information on the selective metal toxicity of aqueous extracts from the plants. A strong metal toxicity, as revealed by the biotest is an indication of a hyperaccumulating plant. Toxicity tests were run concurrently with chemicals analyses of metals in plants and their water extracts. The chemical analyses allow the determination of the hyperaccumulated metal(s). Specimens of the plant species mainly growing on and in the vicinity of the three mines were sampled with their corresponding soils. The results show that all plants analyzed had lower heavy metal content and toxicity despite the relatively very high soil concentrations. A comparison of our results with the criterion used to classify the hyperaccumulator plants indicates that plants we collected from mining sites were hypertolerant but not hyperaccumulators. This was confirmed by transfer factors generally lower than 1. Nevertheless, these tolerant plants species can be used as tools for revegetation for erosion control in metals-contaminated sites (phytostabilization).     

The role of personality characteristics in young adult driving

BACKGROUND: Motor vehicle injury is the major cause of mortality among young adults. Information about the individual characteristics of those who drive dangerously could enhance traffic safety programs. The goal of this research was to examine the association between various personality-related characteristics and risky driving behaviors. METHODS: Young adults in Michigan, USA (n = 5,362) were surveyed by telephone regarding several personality factors (risk-taking, hostility, aggression, tolerance of deviance, achievement expectations) and driving behaviors (competitive driving, risk-taking driving, high-risk driving, aggressive driving, and drink/driving). Michigan driver records were obtained to examine offenses, serious offenses, driving offense points, crashes and serious crashes in the three pre-interview years. Multivariate regression analyses, adjusting for age, race, and marital status were conducted separately by sex to identify personality factors related to driving. RESULTS: For men and women, greater risk-taking propensity, physical/verbal hostility, aggression, and tolerance of deviance were significant predictors of a competitive attitude toward driving, risk-taking driving, high-risk driving, driving aggression, and drink/driving. Greater risk-taking propensity, physical/verbal hostility, aggression, and to a small degree, expectations for achievement predicted higher numbers of offenses, serious offenses, and points. CONCLUSION: Traffic safety policies and programs could be enhanced through recognition of the role personality factors play in driving behavior and the incorporation of this knowledge into the design and implementation of interventions that modify the behaviors associated with them.     

Implementation of a medical command and control team in Switzerland

In case of a major incident or disaster, the advance medical rescue command needs to manage several essential tasks simultaneously. These include the rapid deployment of ambulance, police, fire and evacuation services, and their coordinated activity, as well as triage and emergency medical care on site. The structure of such a medical rescue command is crucial for the successful outcome of medical evacuation at major incidents. However, little data has been published on the nature and structure of the command itself. This study presents a flexible approach to command structure, with two command heads: one emergency physician and one experienced paramedic. This approach is especially suitable for Switzerland, whose federal system allows for different structures in each canton. This article examines the development of these structures and their efficiency, adaptability and limitations with respect to major incident response in the French‐speaking part of the country.