Quantifying forcings from anthropogenic perturbations to the Earth system (ES) is important for understanding changes in climate since the pre-industrial (PI) period. Here, we quantify and analyse a ...wide range of present-day (PD) anthropogenic effective radiative forcings (ERFs) with the UK's Earth System Model (ESM), UKESM1, following the protocols defined by the Radiative Forcing Model Intercomparison Project (RFMIP) and the Aerosol and Chemistry Model Intercomparison Project (AerChemMIP). In particular, quantifying ERFs that include rapid adjustments within a full ESM enables the role of various chemistry-aerosol-cloud interactions to be investigated.
•This limits of acceptability approach is applied for the first time to the SWAT model.•Identifies exact time steps of poor performance during calibration.•Accounts for evaluation data uncertainty in ...calibration.•It may be difficult to obtain sufficient data to drive complex models with confidence.
There is a need to model and predict the transfer of phosphorus (P) from land to water, but this is challenging because of the large number of complex physical and biogeochemical processes involved. This study presents, for the first time, a ‘limits of acceptability’ approach of the Generalized Likelihood Uncertainty Estimation (GLUE) framework to the Soil and Water Assessment Tool (SWAT), in an application to a water quality problem in the Newby Beck catchment (12.5 km2), Cumbria, United Kingdom (UK). Using high frequency outlet data (discharge and P), individual evaluation criteria (limits of acceptability) were assigned to observed discharge and P loads for all evaluation time steps, identifying where the model was performing well/poorly and to infer which processes required improvement in the model structure. Initial limits of acceptability were required to be relaxed by a substantial amount (by factors of between 5.3 and 6.7 on a normalized scale depending on the evaluation criteria used) in order to gain a set of behavioral simulations (1001 and 1016, respectively out of 5,000,000). Of the 39 model parameters tested, the representation of subsurface processes and associated parameters, were consistently shown as critical to the model not meeting the evaluation criteria, irrespective of the chosen evaluation metric. It is therefore concluded that SWAT is not an appropriate model to guide P management in this catchment. This approach highlights the importance of high frequency monitoring data for setting robust model evaluation criteria. It also raises the question as to whether it is possible to have sufficient input data available to drive such models so that we can have confidence in their predictions and their ability to inform catchment management strategies to tackle the problem of diffuse pollution from agriculture.
Excess nutrients in surface waters, such as phosphorus (P) from agriculture, result in poor water quality, with adverse effects on ecological health and costs for remediation. However, understanding ...and prediction of P transfers in catchments have been limited by inadequate data and over-parameterised models with high uncertainty. We show that, with high temporal resolution data, we are able to identify simple dynamic models that capture the P load dynamics in three contrasting agricultural catchments in the UK. For a flashy catchment, a linear, second-order (two pathways) model for discharge gave high simulation efficiencies for short-term storm sequences and was useful in highlighting uncertainties in out-of-bank flows. A model with non-linear rainfall input was appropriate for predicting seasonal or annual cumulative P loads where antecedent conditions affected the catchment response. For second-order models, the time constant for the fast pathway varied between 2 and 15 h for all three catchments and for both discharge and P, confirming that high temporal resolution data are necessary to capture the dynamic responses in small catchments (10–50 km2). The models led to a better understanding of the dominant nutrient transfer modes, which will be helpful in determining phosphorus transfers following changes in precipitation patterns in the future.
1 Virology Division, Kimron Veterinary Institute, PO Box 12, Beit-Dagan 50250, Israel
2 Pathology Division, Kimron Veterinary Institute, PO Box 12, Beit-Dagan 50250, Israel
Correspondence Yehuda ...Stram stramy{at}int.gov.il
Foot-and-mouth disease, caused by foot-and-mouth disease virus (FMDV), is one of the most dangerous diseases of cloven-hoofed animals and is a constant threat to the dairy and beef industries in the Middle East and other regions of the world, despite intensive vaccination programmes. In this work, the ability of specific small interfering (si)RNAs to inhibit virus replication in BHK-21 cells was examined. By using bioinformatic computer programs, all FMDV sequences in public-domain databases were analysed. The analysis revealed three regions of at least 22 bp with 100 % identity in all FMDV entries. From these sequences, three specific siRNA molecules were prepared and used to test the ability of siRNAs to inhibit virus replication. By using real-time quantitative PCR to measure the amount of viral RNA in infected cells, it was shown that virus replication was inhibited in cells that were transfected with siRNAs. When viral titres were examined, 100 % inhibition of growth could be demonstrated in cells transfected with a mixture of all three anti-FMDV siRNAs, compared with control cells transfected with anti- LacZ siRNA.
Toddlers’ ability to understand pretend transformations was assessed. Children at 15‐, 18‐ and 24‐months of age participated in six pretend episodes in which either a single or a double pretend ...transformation was enacted by an experimenter. In the single transformation form of episodes, only one of two props was altered. In the double transformation form, both props were transformed, but then one was returned to its original state. The episodes involved three types of physical change: empty‐to‐full, dry‐to‐wet, and clean‐to‐dirty. After each episode, children made a pretend response to one of the two props. The 15‐month‐olds performed significantly below chance for both forms of episode: in some cases, they tended to imitate the pretend transformations of the experimenter. The 18‐month‐old infants tended to either imitate or make an accurate selection of prop. The 24‐month‐old toddlers’ pretend responses and vocalizations demonstrated that they understood both forms of the episodes. They usually made correct responses, showing that they kept track of the stipulated pretend transformations. Age trends found in these data are discussed with respect to young toddler's emerging skills in participating in collaborative pretend play.
This research investigated the role of person familiarity in the ability of 3.5-month-old infants to recognize emotional expressions. Infants (N = 72) were presented simultaneously with two filmed ...facial expressions, happy and sad, accompanied by a single vocal expression that was concordant with one of the two facial expressions. Infants' looking preferences and facial expressions were coded. Results indicated that when the emotional expressions were portrayed by each infant's own mother, infants looked significantly longer toward the facial expressions that were accompanied by affectively matching vocal expressions. Infants who were presented with emotional expressions of an unfamiliar woman did not. Even when a brief delay was inserted between the presentation of facial and vocal expressions, infants who were presented with emotional expressions of their own mothers looked longer at the facial expression that was sound specified, indicating that some factor other than temporal synchrony guided their looking preferences. When infants viewed the films of their own mothers, they were more interactive and expressed more positive and less negative affect. Moreover, infants produced a greater number of full and bright smiles when the sound-specified emotion was "happy," and particularly when they viewed the happy expressions of their own mothers. The average duration of negative affect was significantly longer for infants who observed the unfamiliar woman than for those who observed their own mothers. These results show that when more contextual information-that is, person familiarity-was available, infants as young as 3.5 months of age recognized happy and sad expressions. These findings suggest that in the early stages of development, infants are sensitive to contextual information that potentially facilitates some of the meaning of others' emotional expressions.
Since 2002 there has been a rise in arthrogryposis/hydranencephaly (AGH) incidence in Israel, caused by Akabane (AKA) and, possibly, Aino viruses.
To test the ability to control the disease, three ...siRNA genes targeted to the S genome segment were designed and prepared in the form of siRNA cassettes. For the design all published S segment were aligned and two conserved target sequences with 100% homology were chosen. A third conserved target that was found exhibited only one base change found in the two Australian isolates and was also designed and tested. It was demonstrated that cells transfected with single siRNA genes showed 99% inhibition, as measured by real-time RT-PCR, virus titration and immunofluoroscence. When cells were transfected with all three genes together the inhibition levels were increased and reached almost 100%.
A 16-box model of the global ocean circulation is constructed to investigate the sensitivity of the thermohaline circulation to upper-ocean density perturbations. The model attempts to represent the ...main geographical components of the global ocean and is tuned to give a present-day circulation broadly compatible with observed volume fluxes. Extensive tests are made of the model's sensitivity to upper-ocean density perturbations, equivalent to a range of plus or minus 3 psu in salinity about the current climate. It is found that there are seven separate modes of thermohaline circulation that can occur within the model's constraints, as well as the possibility of significant variations in the strength of the current circulation mode. These modes are related to possible changes in surface forcing, such as the abrupt increase in freshwater from ice-sheet melting, where such a possibility exists. A mode with North Atlantic upwelling rather than deep- or bottom-water formation was found to occur with large additional inputs of freshwater to the northern Atlantic. These freshwater inputs needed to be equivalent to an instantaneously reduction of upper-ocean salinity by at least 1.8 psu. The model was unable to produce deep-water formation in the northern Pacific, although this may be a constraint of the model formulation. Bottom-water production was possible in the Indian and Pacific Oceans provided the surface density was much enhanced, beyond likely changes in evaporation and precipitation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
