In Situ Dynamics of F-Specific RNA Bacteriophages in a Small River: New Way to Assess Viral Propagation in Water Quality Studies

The occurrence and propagation of enteric viruses in rivers constitute a major public health issue. However, little information is available on the in situ transport and spread of viruses in surface water. In this study, an original in situ experimental approach using the residence time of the river water mass was developed to accurately follow the propagation of F-specific RNA bacteriophages (FRNAPHs) along a 3-km studied river. Surface water and sediment of 9 sampling campaigns were collected and analyzed using both infectivity and RT-qPCR assays. In parallel, some physico-chemical variables such as flow rate, water temperature, conductivity and total suspended solids were measured to investigate the impact of environmental conditions on phage propagation. For campaigns with low flow rate and high temperature, the results highlight a decrease of infectious phage concentration along the river, which was successfully modelled according to a first-order negative exponential decay. The monitoring of infectious FRNAPHs belonging mainly to the genogroup II was confirmed with direct phage genotyping and total phage particle quantification. Reported k decay coefficients according to exponential models allowed for the determination of the actual in situ distance and time necessary for removing 90 % of infectious phage particles. This present work provides a new way to assess the true in situ viral propagation along a small river. These findings can be highly useful in water quality and risk assessment studies to determine the viral contamination spread from a point contamination source to the nearest recreational areas.     

Oxygen isotope fractionation between bird bone phosphate and drinking water

Oxygen isotope compositions of bone phosphate (δ¹⁸O_p) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δ¹⁸O_p values (from 9.8 to 22.5‰ V-SMOW) and the local rainfall δ¹⁸O_w values estimated from nearby IAEA/WMO stations (from ?16.0 to ?1.0‰ V-SMOW). Linear least square fitting of data provided the following isotopic fractionation equation: δ¹⁸O_w = 1.119 (±0.040) δ¹⁸O_p ? 24.222 (±0.644); R ² = 0.98. The δ¹⁸O_p–δ¹⁸O_w couples of five extant mallard ducks, a common buzzard, a European herring gull, a common ostrich, and a greater rhea fall within the predicted range of the equation, indicating that the relationship established for extant chickens can also be applied to birds of various ecologies and body masses. Applied to published oxygen isotope compositions of Miocene and Pliocene penguins from Peru, this new equation computes estimates of local seawater similar to those previously calculated. Applied to the basal bird Confuciusornis from the Early Cretaceous of Northeastern China, our equation gives a slightly higher δ¹⁸O_w value compared to the previously estimated one, possibly as a result of lower body temperature. These data indicate that caution should be exercised when the relationship estimated for modern birds is applied to their basal counterparts that likely had a metabolism intermediate between that of their theropod dinosaur ancestors and that of advanced ornithurines.     

Reciprocity and trades in wild West African chimpanzees

Why do animals help other individuals and provide benefits to the recipient, sometimes at personal cost? In this study, we aim to determine if some of the helpful behaviors observed in a group of wild chimpanzees (Taï chimpanzee group, Côte d'Ivoire, West Africa) are exchanged among individuals resulting in a net benefit for both participants. We adopted an inclusive view of exchanges by considering that all commodities (i.e., social behaviors as grooming, sex, support, as well as resources, such as meat) can be exchanged. This would result in “market” type social interactions in which debts of one commodity can be met by giving the same or other commodities. We investigated whether both in-kind exchanges and trades of commodities occurred. The Taï chimpanzees reciprocated the amount of grooming they received and were more likely to give support in agonistic conflicts to those who also supported them. In addition, they traded support for meat and meat for sex. Both male and female chimpanzees exchanged many different commodities, which seemed to result in long-term balanced relationships. Our results suggest that wild chimpanzees rely on other group members to obtain many of the important commodities they need.     

Impact of peri-urban landscape on the organic and mineral contamination of pond waters and related risk assessment

Environmental Science and Pollution Research - Ponds are important for their ecological value and for the ecosystem services they provide to human societies, but they are strongly affected by human...     

Assessing sustainability: An assessment framework to evaluate Agenda 21 actions at the local level

In Switzerland, communities are encouraged to define and to report on local Agenda 21. This paper presents an analysis framework to help local communities set sustainable development priorities and to follow through with appropriate actions. Four Swiss communities, from the French-speaking part of Switzerland, actively follow the project: Lausanne (114 304 citizens), Vevey (15 364 citizens), Mannens-Grandsivaz (505 citizens) and Essertines/Yverdon (666 citizens). The analysis framework developed is constituted of four interdependent fields: the societal characteristics, the individual or collective behaviours, the end objectives or sustainability impacts and the inhabitant's perception of these three fields. The link between society and behaviour can be studied through sociological analyses. The link between behaviour and environmental impact can be established thanks to Life Cycle analysis and Input/Output analyses. At each level, sustainable development indicators can be defined. As an application of the framework, the citizen energy consumption has been studied and expressed in energy slaves (= 3150 MJ/Year). A Swiss citizen needs altogether 69 slaves, 20 for his private consumption of goods and services, 19 for housing, 11 for transport, I1 for food and 8 for his consumption of public goods. If one fifth of the inhabitants of Lausanne, wanting to live closer to nature, actually moved out of town, the region would need 10 436 more slaves for 3500 persons happily living in the countryside.     

Fighting behaviour as a correlate of male mating success in black grouse Tetrao tetrix

Fighting is a fundamental determinant of male fitness in species where females prefer socially dominant males as mates or where dominants can prevent subordinates from mating. This in turn can lead to the evolution of honest inter- and intra-sexual cues of male dominance. Fighting as a behaviour comprises both fighting rate (number of fights per unit of time) and fighting performance (success in winning fights), but it is not always clear which of these components are important for female choice and how they link to signals of male quality. To quantify the relative importance of fighting as a cue for females, we recorded detailed behavioural data from male black grouse Tetrao tetrix at leks. We explored the relationship between phenotypic traits (body mass, eye comb size, tail (lyre) length and blue chroma colouration) and fighting performance and rates and how these were related to male mating success. In older males' pairwise fights, winners had lower blue chroma than losers, but there were no differences in other morphological traits. In yearlings, no morphological trait predicted success in pairwise contests. Both fighting rate and performance were positively related to the number of copulations acquired by a male; however, when controlled for lek centrality, fighting performance and not fighting rate was significantly related to mating success. Our results indicate that females may be using components of fighting behaviour as cues for mate choice.     

Visualization of the internal flow properties and the material exchange interface in an entraining viscous Newtonian gravity current

In order to simulate a simple entraining geophysical flow, a viscous Newtonian gravity current is released from a reservoir by a dam-break and flows along a rigid horizontal bed until it meets a layer of entrainable material of finite depth, identical to the current. The goal is to examine the entrainment mechanisms by observing the interaction between the incoming flow and the loose bed. The sole parameter varied is the initial volume of the gravity current, thus altering its height and velocity. The gravity current plunges or spills into the entrainable bed and the velocity of the flow front becomes linear with time. The bed material is directly affected: motion is generated in the fluid far downstream of, and in that lying beneath the encroaching front. Shear bands are identified, separating horizontal flow downstream from flow with a strong vertical component close to the step. Downstream of the step the flow is horizontal and stratified, with no slip on the bottom boundary and very low shear near the surface. Between these two regions may lie transitional zones with linear velocity profiles, separated by horizontal bands of high shear; the number of transitional zones in the cross-section varies with the initial volume of the dam-break.     

A new probability model with application to heavy-tailed hydrological data

Environmental and Ecological Statistics - Because of the dramatic changes that are being observed in the climatic conditions of the world, such as excess of rains, drought and huge floods, we...     

Recent Evolution of Natural Hazard Management Policy in France,the Example of Serre-Chevalier (French Alps)

Since the 1960s, the development of the Serre-Chevalier winter and summer resort has led to a rapid extension of the urban fabric on the territory of the village of St-Chaffrey. On July 9, 1981, the new neighborhoods built on the alluvial fan of the Verdarel torrent were partly devastated by a channeled debris flow. This disaster prompted the civil authorities to set up an extensive fluvial regulation system, which rapidly contributed to recreating a climate of confidence and security favorable to continuing urban expansion. The combination of catastrophic floods in July 1995, and a new security-oriented national policy on natural hazards, nevertheless led to a return to precautionary measures. The St-Chaffrey town council has therefore been forced by the State to accept a building-free zone on the land-use plan. This measure is perceived as a real denial of the local efficacy of the flood and landslide risk management policy as carried out by the council of St-Chaffrey during the previous 20 years.