The Cenozoic evolution of the Roer Valley Rift System integrated at a European scale

International audienceThe Roer Valley Rift System (RVRS) is located between the West European rift and the North Sea rift system. During the Cenozoic, the RVRS was characterized by several periods of subsidence and inversion, which are linked to the evolution of the adjacent rift systems. Combination of subsidence analysis and results from the analysis of thickness distributions and fault systems allows the determination of the Cenozoic evolution and quantification of the subsidence. During the Early Paleocene, the RVRS was inverted (Laramide phase). The backstripping method shows that the RVRS was subsequently mainly affected by two periods of subsidence, during the Late Paleocene and the Oligocene–Quaternary time intervals, separated by an inversion phase during the Late Eocene. During the Oligocene and Miocene periods, the thickness of the sediments and the distribution of the active faults reveal a radical rotation of the direction of extension by about 70–80j (counter clockwise). Integration of these results at a European scale indicates that the Late Paleocene subsidence was related to the evolution of the North Sea basins, whereas the Oligocene–Quaternary subsidence is connected to the West European rift evolution. The distribution of the inverted provinces also shows that the Early Paleocene inversion (Laramide phase) has affected the whole European crust, whereas the Late Eocene inversion was restricted to the southern North Sea basins and the Channel area. Finally, comparison of these deformations in the European crust with the evolution of the Alpine chain suggests that the formation of the Alps has controlled the evolution of the European crust since the beginning of the Cenozoic

Strong increases in flood frequency and discharge of the River Meuse over the late Holocene: impacts of long-term anthropogenic land use change and climate variability

International audienceIn recent years the frequency of high-flow events on the Meuse (northwest Europe) has been relatively great, and flooding has become a major research theme. To date, research has focused on observed discharge records of the last century and simulations of the coming century. However, it is difficult to delineate changes caused by human activities (land use change and greenhouse gas emissions) and natural fluctuations on these timescales. To address this problem we coupled a climate model (ECBilt-CLIO-VECODE) and a hydrological model (STREAM) to simulate daily Meuse discharge in two time-slices: 4000?3000 BP (natural situation), and 1000?2000 AD (includes anthropogenic influence). For 4000?3000 BP the basin is assumed to be almost fully forested; for 1000?2000 AD we reconstructed land use based on historical sources. For 1000?2000 AD the simulated mean annual discharge (260.9 m³ s?1) is significantly higher than for 4000?3000 BP (244.8 m³ s?1), and the frequency of large high-flow events (discharge >3000 m³ s?1) is higher (recurrence time decreases from 77 to 65 years). On a millennial timescale almost all of this increase can be ascribed to land use changes (especially deforestation); the effects of climatic change are insignificant. For the 20th Century, the simulated mean discharge (270.0 m³ s?1) is higher than in any other century studied, and is ca. 2.5% higher than in the 19th Century (despite an increase in evapotranspiration). Furthermore, the recurrence time of large high-flow events is almost twice as short as under natural conditions (recurrence time decreases from 77 to 40 years). On this timescale climate change (strong increase in annual and winter precipitation) overwhelmed land use change as the dominant forcing mechanism

Strong increases in flood frequency and discharge of the River Meuse over the late Holocene: impacts of long-term anthropogenic land use change and climate variability

International audienceIn recent years the frequency of high-flow events on the Meuse (northwest Europe) has been relatively great, and flooding has become a major research theme. To date, research has focused on observed discharge records of the last century and simulations of the coming century. However, it is difficult to delineate changes caused by human activities (land use change and greenhouse gas emissions) and natural fluctuations on these timescales. To address this problem we coupled a climate model (ECBilt-CLIO-VECODE) and a hydrological model (STREAM) to simulate daily Meuse discharge in two time-slices: 4000?3000 BP (natural situation), and 1000?2000 AD (includes anthropogenic influence). For 4000?3000 BP the basin is assumed to be almost fully forested; for 1000?2000 AD we reconstructed land use based on historical sources. For 1000?2000 AD the simulated mean annual discharge (260.9 m³ s?1) is significantly higher than for 4000?3000 BP (244.8 m³ s?1), and the frequency of large high-flow events (discharge >3000 m³ s?1) is higher (recurrence time decreases from 77 to 65 years). On a millennial timescale almost all of this increase can be ascribed to land use changes (especially deforestation); the effects of climatic change are insignificant. For the 20th Century, the simulated mean discharge (270.0 m³ s?1) is higher than in any other century studied, and is ca. 2.5% higher than in the 19th Century (despite an increase in evapotranspiration). Furthermore, the recurrence time of large high-flow events is almost twice as short as under natural conditions (recurrence time decreases from 77 to 40 years). On this timescale climate change (strong increase in annual and winter precipitation) overwhelmed land use change as the dominant forcing mechanism

Competitor phenology as a social cue in breeding site selection

Predicting habitat quality is a major challenge for animals selecting a breeding patch, because it affects reproductive success. Breeding site selection may be based on previous experience, or on social information from the density and success of competitors with an earlier phenology. Variation in animal breeding phenology is often correlated with variation in habitat quality. Generally, animals breed earlier in high-quality habitats that allow them to reach a nutritional threshold required for breeding earlier or avoid nest predation. In addition, habitat quality may affect phenological overlap between species and thereby interspecific competition. Therefore, we hypothesized that competitor breeding phenology can be used as social cue by settling migrants to locate high-quality breeding sites. To test this hypothesis, we experimentally advanced and delayed hatching phenology of two resident tit species on the level of study plots and studied male and female settlement patterns of migratory pied flycatchers Ficedula hypoleuca. The manipulations were assigned at random in two consecutive years, and treatments were swapped between years in sites that were used in both years. In both years, males settled in equal numbers across treatments, but later arriving females avoided pairing with males in delayed phenology plots. Moreover, male pairing probability declined strongly with arrival date on the breeding grounds. Our results demonstrate that competitor phenology may be used to assess habitat quality by settling migrants, but we cannot pinpoint the exact mechanism (e.g. resource quality, predation pressure or competition) that has given rise to this pattern. In addition, we show that opposing selection pressures for arrival timing may give rise to different social information availabilities between sexes. We discuss our findings in the context of climate warming, social information use and the evolution of protandry in migratory animals

Two decades of numerical modelling to understand long term fluvial archives: Advances and future perspectives

The development and application of numerical models to investigate fluvial sedimentary archives has increased during the last decades resulting in a sustained growth in the number of scientific publications with keywords, 'fluvial models', 'fluvial process models' and 'fluvial numerical models'. In this context we compile and review the current contributions of numerical modelling to the understanding of fluvial archives. In particular, recent advances, current limitations, previous unexpected results and future perspectives are all discussed. Numerical modelling efforts have demonstrated that fluvial systems can display non-linear behaviour with often unexpected dynamics causing significant delay, amplification, attenuation or blurring of externally controlled signals in their simulated record. Numerical simulations have also demonstrated that fluvial records can be generated by intrinsic dynamics without any change in external controls. Many other model applications demonstrate that fluvial archives, specifically of large fluvial systems, can be convincingly simulated as a function of the interplay of (palaeo) landscape properties and extrinsic climate, base level and crustal controls. All discussed models can, after some calibration, produce believable matches with real world systems suggesting that equifinality - where a given end state can be reached through many different pathways starting from different initial conditions and physical assumptions - plays an important role in fluvial records and their modelling. The overall future challenge lies in the development of new methodologies for a more independent validation of system dynamics and research strategies that allow the separation of intrinsic and extrinsic record signals using combined fieldwork and modelling

Geolocators lead to better measures of timing and renesting in black-tailed godwits and reveal the bias of traditional observational methods

Long-term population studies can identify changes in population dynamics over time. However, to realize meaningful conclusions, these studies rely on accurate measurements of individual traits and population characteristics. Here, we evaluate the accuracy of the observational methods used to measure reproductive traits in individually marked black-tailed godwits (Limosa limosa limosa). By comparing estimates from traditional methods with data obtained from light-level geolocators, we provide an accurate estimate of the likelihood of renesting in godwits and the repeatability of the lay dates of first clutches. From 2012 to 2018, we used periods of shading recorded on the light-level geolocators carried by 68 individual godwits to document their nesting behaviour. We then compared these estimates to those simultaneously obtained by our long-term observational study. We found that among recaptured geolocator-carrying godwits, all birds renested after a failed first clutch, regardless of the date of nest loss or the number of days already spent incubating. We also found that 43% of these godwits laid a second replacement clutch after a failed first replacement, and that 21% of these godwits renested after a hatched first clutch. However, the observational study correctly identified only 3% of the replacement clutches produced by geolocator-carrying individuals and designated as first clutches a number of nests that were actually replacement clutches. Additionally, on the basis of the observational study, the repeatability of lay date was 0.24 (95% CI 0.17-0.31), whereas it was 0.54 (95% CI 0.28-0.75) using geolocator-carrying individuals. We use examples from our own and other godwit studies to illustrate how the biases in our observational study discovered here may have affected the outcome of demographic estimates, individual-level comparisons, and the design, implementation and evaluation of conservation practices. These examples emphasize the importance of improving and validating field methodologies and show how the addition of new tools can be transformational

Guidelines on uncomplicated urinary tract infections are difficult to follow: perceived barriers and suggested interventions

Contains fulltext : 88451.pdf (publisher's version ) (Open Access)BACKGROUND: Urinary tract infections (UTI) are among the most common health problems seen in general practice. Evidence-based guidelines on UTI are available, but adherence to these guidelines varies widely among practitioners for reasons not well understood. The aim of this study was to identify the barriers to the implementation of a guideline on UTI perceived by Dutch general practitioners (GPs) and to explore interventions to overcome these barriers. METHODS: A focus group study, including 13 GPs working in general practices in the Netherlands, was conducted. Key recommendations on diagnosis and treatment of uncomplicated UTI were selected from the guideline. Barriers to guideline adherence and possible interventions to address these barriers were discussed. The focus group session was audio-taped and transcribed verbatim. Barriers were classified according to an existing framework. RESULTS: Lack of agreement with the recommendations, unavailable and inconvenient materials (i.e. dipslides), and organisational constraints were perceived as barriers for the diagnostic recommendations. Barriers to implementing the treatment recommendations were lack of applicability and organisational constraints related to the availability of drugs in pharmacies. Suggested interventions were to provide small group education to GPs and practice staff members, to improve organisation and coordination of care in out of hour services, to improve the availability of preferred dosages of drugs, and to pilot-test guidelines regionally. CONCLUSIONS: Despite sufficient knowledge of the recommendations on UTI, attitudinal and external barriers made it difficult to follow them in practice. The care concerning UTI could be optimized if these barriers are adequately addressed in implementation strategies. The feasibility and success of these strategies could be improved by involving the target group of the guideline in selecting useful interventions to address the barriers to implementation

The value of nonoperative versus operative treatment of frail institutionalized elderly patients with a proximal femoral fracture in the shade of life (FRAIL-HIP); protocol for a multicenter observational cohort study

BACKGROUND: Proximal femoral fractures are strongly associated with morbidity and mortality in elderly patients. Mortality is highest among frail institutionalized elderly with both physical and cognitive comorbidities who consequently have a limited life expectancy. Evidence based guidelines on whether or not to operate on these patients in the case of a proximal femoral fracture are lacking. Practice variation occurs, and it remains unknown if nonoperative treatment would result in at least the same quality of life as operative treatment. This study aims to determine the effect of nonoperative management versus operative management of proximal femoral fractures in a selected group of frail institutionalized elderly on the quality of life, level of pain, rate of complications, time to death, satisfaction of the patient (or proxy) and the caregiver with the management strategy, and health care consumption. METHODS: This is a multicenter, observational cohort study. Frail institutionalized elderly (70 years or older with a body mass index < 18.5, a Functional Ambulation Category of 2 or lower pre-trauma, or an American Society of Anesthesiologists score of 4 or 5), who sustained a proximal femoral fracture are eligible to participate. Patients with a pathological or periprosthetic fractures and known metastatic oncological disease will be excluded. Treatment decision will be reached following a structured shared decision process. The primary outcome is quality of life (Euro-QoL; EQ-5D-5 L). Secondary outcome measures are quality of life measured with the QUALIDEM, pain level (PACSLAC), pain medication use, treatment satisfaction of patient (or proxy) and caregivers, quality of dying (QODD), time to death, and direct medical costs. A cost-utility and cost-effectiveness analysis will be done, using the EQ-5D utility score and QUALIDEM score, respectively. Non-inferiority of nonoperative treatment is assumed with a limit of 0.15 on the EQ-5D score. Data will be acquired at 7, 14, and 30 days and at 3 and 6 months after trauma. DISCUSSION: The results of this study will provide insight into the true value of nonoperative treatment of proximal femoral fractures in frail elderly with a limited life expectancy. The results may be used for updating (inter)national treatment guidelines. TRIAL REGISTRATION: The study is re

Long-term evidence for ecological intensification as a pathway to sustainable agriculture

Ecological intensification (EI) could help return agriculture into a ‘safe operating space’ for humanity. Using a novel application of meta-analysis to data from 30 long-term experiments from Europe and Africa (comprising 25,565 yield records), we investigated how field-scale EI practices interact with each other, and with N fertilizer and tillage, in their effects on long-term crop yields. Here we confirmed that EI practices (specifically, increasing crop diversity and adding fertility crops and organic matter) have generally positive effects on the yield of staple crops. However, we show that EI practices have a largely substitutive interaction with N fertilizer, so that EI practices substantially increase yield at low N fertilizer doses but have minimal or no effect on yield at high N fertilizer doses. EI practices had comparable effects across different tillage intensities, and reducing tillage did not strongly affect yields