Diffuse water pollution during recent extreme wet-weather in the UK: Environmental damage costs and insight into the future?

Periods of extreme wet-weather elevate agricultural diffuse water pollutant loads and climate projections for the UK suggest wetter winters. Within this context, we monitored nitrate and suspended sediment loss using a field and landscape scale platform in SW England during the recent extreme wet-weather of 2019-2020. We compared the recent extreme wet-weather period to both the climatic baseline (1981-2010) and projected near- (2041-2060) and far- (2071-2090) future climates, using the 95th percentiles of conventional rainfall indices generated for climate scenarios downscaled by the LARS-WG weather generator from the 19 global climate models in the CMIP5 ensemble for the RCP8.5 emission scenario. Finally, we explored relationships between pollutant loss and the rainfall indices. Grassland field-scale monthly average nitrate losses increased from 0.39-1.07 kg ha-1 (2016-2019) to 0.70-1.35 kg ha-1 (2019-2020), whereas losses from grassland ploughed up for cereals, increased from 0.63-0.83 kg ha-1 to 2.34-4.09 kg ha-1. Nitrate losses at landscape scale increased during the 2019-2020 extreme wet-weather period to 2.04-4.54 kg ha-1. Field-scale grassland monthly average sediment losses increased from 92-116 kg ha-1 (2016-2019) to 281-333 kg ha-1 (2019-2020), whereas corresponding losses from grassland converted to cereal production increased from 63-80 kg ha-1 to 2124-2146 kg ha-1. Landscape scale monthly sediment losses increased from 8-37 kg ha-1 in 2018 to between 15 and 173 kg ha-1 during the 2019-2020 wet-weather period. 2019-2020 was most representative of the forecast 95th percentiles of >1 mm rainfall for near- and far-future climates and this rainfall index was related to monitored sediment, but not nitrate, loss. The elevated suspended sediment loads generated by the extreme wet-weather of 2019-2020 therefore potentially provide some insight into the responses to the projected >1 mm rainfall extremes under future climates at the study location.

Low-coherence dye laser with an intracavity radiation diffuser.

Study of a low-coherence dye laser is reported. A cuvette with a 2 mm gap containing a dense mixture (slurry) of LiF crystal granules (70-140 µm) and an immersion liquid with a dye dissolved in it was installed in a double flat mirror cavity as an active element and simultaneously as a diffuser of radiation. The parallel light beam experiences losses in such a cuvette due to refraction at a set of interfaces between solid particles and a liquid in which different parts of the beam are randomly deflected at small angles. Measurements of the loss coefficients, angles of rays' deflection in the cuvette-diffuser were carried out. When this cuvette was pumped by 25 ns pulses of the 2nd harmonic of a Nd:YAG laser, 20 ns pulses of radiation in the region of 550-650 nm with energy ≈1 mJ at a beam divergence 5-80 mrad, and a degree of spatial coherence γ ≲ 0.1 were obtained in slurry with PM567, Rh101 or DCM dyes. The features of spectra and spatial-angular characteristics of these slurry lasers are discussed, tuning of the spatial coherence of radiation is demonstrated. Possible applications of a dye laser with an intracavity diffuser as a source of low-coherence radiation are considered.

Implications of crop model ensemble size and composition for estimates of adaptation effects and agreement of recommendations.

Climate change is expected to severely affect cropping systems and food production in many parts of the world unless local adaptation can ameliorate these impacts. Ensembles of crop simulation models can be useful tools for assessing if proposed adaptation options are capable of achieving target yields, whilst also quantifying the share of uncertainty in the simulated crop impact resulting from the crop models themselves. Although some studies have analysed the influence of ensemble size on model outcomes, the effect of ensemble composition has not yet been properly appraised. Moreover, results and derived recommendations typically rely on averaged ensemble simulation results without accounting sufficiently for the spread of model outcomes. Therefore, we developed an Ensemble Outcome Agreement (EOA) index, which analyses the effect of changes in composition and size of a multi-model ensemble (MME) to evaluate the level of agreement between MME outcomes with respect to a given hypothesis (e.g. that adaptation measures result in positive crop responses). We analysed the recommendations of a previous study performed with an ensemble of 17 crop models and testing 54 adaptation options for rainfed winter wheat (Triticum aestivum L.) at Lleida (NE Spain) under perturbed conditions of temperature, precipitation and atmospheric CO2 concentration. Our results confirmed that most adaptations recommended in the previous study have a positive effect. However, we also showed that some options did not remain recommendable in specific conditions if different ensembles were considered. Using EOA, we were able to identify the adaptation options for which there is high confidence in their effectiveness at enhancing yields, even under severe climate perturbations. These include substituting spring wheat for winter wheat combined with earlier sowing dates and standard or longer duration cultivars, or introducing supplementary irrigation, the latter increasing EOA values in all cases. There is low confidence in recovering yields to baseline levels, although this target could be attained for some adaptation options under moderate climate perturbations. Recommendations derived from such robust results may provide crucial information for stakeholders seeking to implement adaptation measures.

Adapting wheat in Europe for climate change.

Increasing cereal yield is needed to meet the projected increased demand for world food supply of about 70% by 2050. Sirius, a process-based model for wheat, was used to estimate yield potential for wheat ideotypes optimized for future climatic projections for ten wheat growing areas of Europe. It was predicted that the detrimental effect of drought stress on yield would be decreased due to enhanced tailoring of phenology to future weather patterns, and due to genetic improvements in the response of photosynthesis and green leaf duration to water shortage. Yield advances could be made through extending maturation and thereby improve resource capture and partitioning. However the model predicted an increase in frequency of heat stress at meiosis and anthesis. Controlled environment experiments quantify the effects of heat and drought at booting and flowering on grain numbers and potential grain size. A current adaptation of wheat to areas of Europe with hotter and drier summers is a quicker maturation which helps to escape from excessive stress, but results in lower yields. To increase yield potential and to respond to climate change, increased tolerance to heat and drought stress should remain priorities for the genetic improvement of wheat.

Intermolecular hydrogen bonds in hetero-complexes of biologically active aromatic molecules probed by the methods of vibrational spectroscopy.

By the methods of vibrational spectroscopy (Infrared and Raman) the investigation of the hetero-association of biologically active aromatic compounds: flavin-mononucleotide (FMN), ethidium bromide (EB) and proflavine (PRF) was performed in aqueous solutions. It was shown that between the functional groups (CO and NH(2)) the intermolecular hydrogen bonds are formed in the hetero-complexes FMN-EB and FMN-PRF, additionally stabilizing these structures. An estimation of the enthalpy of Н-bonding obtained from experimental shifts of carbonyl vibrational frequencies has shown that the H-bonds do not dominate in the magnitude of experimentally measured total enthalpy of the hetero-association reactions. The main stabilization is likely due to intermolecular interactions of the molecules in these complexes and their interaction with water environment.

Submicrosecond regular and chaotic nonlinear dynamics in a pulsed picosecond Nd:YAG laser with millisecond pumping.

We propose and study both numerically and experimentally a feedback-controlled laser system capable of generating regular bursts with a submicrosecond period. Bursting is obtained in a laser that is controlled by a combination of feedbacks in which the negative feedback loop action is delayed by one cavity round trip with respect to the positive one, and the period is adjusted by relative feedback sensitivity. The proper combination of feedbacks is realized in a Nd:YAG laser with millisecond pumping by means of a single optoelectronic negative feedback unit that utilizes the signal reflected from an intracavity Pockels cell polarizer. Regular bursting (microgroups of picosecond pulses) with controlled periods from 25 to 75 cavity round trips is obtained experimentally. The development of chaotic dynamics displayed by the system at a higher pumping level differs from the Feigenbaum scenario.

[Study of effect of water on the interaction of DNA and actinocin derivatives with various aminoalkyl chain length by infrared spectrophotometry and computer modeling]. / Issledovaniia vliianiia vody na vzaimodeistvie DNK i proizvodnykh aktinotsina s razlichnoi dlinoi aminoalkil'nykh tsepochek metodami IK-spektroskopii i komp'iuternogo modelirovaniia

A comparative study of the effect of water on the interaction of DNA with actinocin derivatives having different numbers of methylene groups in side chains was performed by IR spectroscopy. It was found that, as relative humidity increases, water molecules simultaneously bind to hydrate-active sites of DNA and ligands. The absorption band at v = 1137 cm-1, caused by oscillations of the C-O and P-O groups of atoms in the DNA-ligand complex having two methylene groups, is due to the interactions between the cationic groups of the ligand and the sugar-phosphate backbone of DNA, which may be one of the reasons for the high stability of this complex. Using computer simulation of interaction of DNA fragments and actinocin derivatives in water environment, molecular models of the formation of their complexes for two ways of binding were constructed.

[Hydration and structure of hemiprotonated polycytidylic acid in films]. / Gidratatsiia i strukturnoe sostoianie poluprotonirovannoi politsitidilovoi kisloty v plenkakh.

Structural transitions of poly(rC)-Ka+ in humid films with different water content were studied by infrared spectroscopy and piezogravimetry. From analysis of the hydration isotherms and the dependence of spectral parameters (frequencies and intensities of the main bands) on n the hydration sites of the polynucleotide were determined (C2O, O4', N4H2, N1, PO2-, C2'OH). It was found that the transition of the polynucleotide from the unordered state to a double-stranded complex poly(rC+).poly(rC) occurs in the interval of n from 2 to 8. The value n = 8 corresponds to the total hydration of poly(rC). A model of hydration of poly(rC+).poly(rC) based on the experimental results and known X-ray parameters of this double helix complex is proposed. The most important feature of the model is the presence of single water bridges between PO2(-)-groups in the first hydration shell of each chain and triple water bridges between O4', N4H2 and C2'OH- atomic groups of opposite chains. The experimental results obtained and the proposed structure of hydration environment of poly(rC+).poly(rC) suggest that the stabilization of this complex is stabilized by the intra- and inter-chain water bridges and hydrogen bonds between pairs of cytosine bases.

[Effect of water on the structural modification and stabilization of DNA from Clostridium perfringens]. / Vliianie vidy na strukturnye perekhody i stabil'nost' DNK iz Clostridium perfringens.

By the methods of infrared spectroscopy, piezogravimetry and microcalorimetry the process of forming of the structure and hydration environment of DNA from Clostridium perfringens in the wet films has been investigated. It were found three intervals of relative humidity (r.h.) in which three structural states of DNA: an unordered state (0-44% r.h.), the A-form (46-75% r.h.) and the B-form (80-86% r.h.) are realized. We measured the heat of water evaporation from the DNA-water samples with the differential scanning microcalorimeter. From these calorimetric data the distribution of the water molecules on the bond energy with DNA was determined. The contribution of the water molecules of hydration shell (73%) and hydrogen bonds in the Watson-Crick pairs (27%) to the total energy of stabilization of the helical B-form DNA from Cl. perfringens has been evaluated.

[Functional activity of the liver and lipopolysaccharide-positive neutrophils of peripheral blood in patients with acute dysentery]. / Funktsional'naia aktivnost' pecheni i lipopolisakharidpozitivnye neitrofily perifericheskoi krovi u bol'nykh ostroi dizenteriei.

Acute phase proteins (albumin, prealbumin, transferrin, haptoglobin) and the results of spontaneous and load tests of lipopolysaccharide-positive neutrophils (LPS-PN) in peripheral blood were studied in the course of acute colitic dysentery in 34 patients. It is shown that at the height of the disease there was a fall in the levels of albumin, prealbumin, transferrin while haptoglobin levels were elevated. More persistent and pronounced changes were noted in patients with severe course of acute dysentery. In acute period of the disease there were low values of spontaneous and load LPS-PN tests depending on the disease severity. None of the above parameters returned to control levels within 5-6 days after the start of the treatment.

[Hydration and stability of the double helical complex poly(dA)-poly(dT)]. / Gidratsiia i stabil'nost' dvukhspiral'nogo kompleksa poly(dA)-poly(dT).

IR-spectrometry and thermopiezogravimetry are used to study the structure formation and the water environment of the double-helix Na-poly(dA)-poly(dT) complex in films in the 0-100% interval of the relative humidity (RH). It has been found that three different structures of the complex are formed in the 0-32, 32-76 and 88-100% intervals of RH. The calculations of resonance frequencies of out-of-ring (C-0) and in-ring (C-N) vibrations in adenine and thymine using perturbation theory show that the second and the third forms are the X-ray beta-B'- and alpha-B'-forms. Distribution of the binding energy of water molecules has been found from IRS data about water sorption and isotherms of hydration at different temperatures. The enthalpy of helix-coil transition has been found from microcalorimetry data. These results allow us to estimate the energy contribution of water molecules (about 75%) and other interactions (about 25%) in the total stabilization energy of the complex structure.

[Hydration and structural state of liver DNA of rats exposed to radiation in the Chernobyl AES zone]. / Gidratatsiia i strukturnoe sostoianie DNK iz pecheni krys, obluchennykh v zone Chernobyl'skoi AES.

By methods of IR-spectroscopy, electrophoresis and piezomicrobalance the comparative study on hydration and structural state of liver DNA from rats both intact and exposed within the Chernobyl accident zone was conducted. Modification of primary and secondary DNA structure in irradiated animals demonstrate serious disturbance of hepatocyte genetic apparatus. This is responsible for previously found considerable morphologic and ultra-structural changes in rat liver tissue after prolonged exposure to low-level ionizing radiation in the Chernobyl accident zone.

[Hydration and stability of the B-form of LiDNA]. / Gidratatsiia i stabil'nost' B-formy LiDNK.

Hydration and structure of Li DNA in films and solutions have been investigated by methods of IR spectroscopy, piezogravimentry, UHF dielectrometry, and microcalorimetry. The hydration energy and the water sorption range in which the DNA undergoes the transition from the unordered state to the B-form have been determined, making it possible to evaluate the contribution of water molecules of the DNA hydration shell to the total stabilization energy of the DNA helical structure.

[Physical properties of the DNA-water system]. / Fizicheskie svoistva sistemy DNK-voda.

The review of original and literary data obtained by the different physical methods on the structure, mechanical, electrostatic and energetic properties of DNA-ions-water system was done. On the basis of the examined results the main problem of DNA structure formation its dynamic and stability were discussed.

[Study of the hydratation of the double-helical poly A-poly U complex by IR-spectroscopy and piezogravimetry methods]. / Issledovanie gidratatsii dvuspiral'nogo kompleksa poi A-poli U metodami IK-spektroskopii i p'ezogravimetrii.

IR-spectra of a double-helical poly A-poly U complex and coiled poly U were studied at various r.h. in a 900-3800 cm-1 region. By the method of piezomicrobalance hydration isotherms for these polynucleotides were obtained. It is concluded that, as in the DNA case, simultaneous hydration of nucleic bases the backbone of polynucleotides occurs at lower r.h., and that the poly A-poly U hydration level is higher than poly A and poly U ones separately. Drastic changes in spectral parameters of poly A poly U uracil and adenine in-ring and out-of-ring absorption bands observed in 44-76% r.h. region were interpreted as a transition to helical conformation of the complex. Calculation of resonance frequencies for these normal vibrations in the dipole-dipole approximation agrees with the experimental data.

[Study of conformation-dependent isotherms of DNA hydration]. / Issledovanie konformatsionno-zavisimykh izoterm gidratatsii DNK.

By the method of gravimetry and piezomicrobalance native and denaturated DNA hydration isotherms are obtained. Their adsorptional ability difference observed is interpreted according to IR-data, which show that if sugar-phosphate skeleton hydration levels are similar for these conformations, their nitrous base hydration is strongly different. BET-fitting of isotherms obtained discovered significant water binding energy heterogeneity of native DNA hydration-active sites.

[Study of structural transformations of the sugar-phosphate chain and nitrogen bases of DNA hydrate by IR-spectroscopy]. / Issledovanie strukturnykh prevrashchenii sakharofosfatnoi tsepi i azotistykh osnovanii gidrata DNK metodom IK- spektroskopii.

The IR-spectra (900-1800 cm-1) of films of native and denatured DNA were studied within the temperature range 4-100 degrees C at different relative humidity (r.h.). Two temperature intervals of S-like change of spectral parameters of absorption bands of sugar-phosphate chain of double-helical DNA are found on temperature relationships at high humidity. These two intervals point to two types of cooperative transitions of sugar-phosphate pattern. The band parameters of nitrous bases are changed only under high temperature transition. In the region of structural transitions of different subsystems of DNA hydrate hyperchromism was wound for the bands of sugar-phosphate chain and hydrate cover unlike hyperchromism specific of most nitrous bases bands. From the data obtained it is proposed to use the basic characteristics of temperature relationship of spectral parameters of the absorption bands of sugar-phosphate pattern and hydrate envelope in the region of low-temperature transition for the "in vivo" analysis of the DNA structure in complex biological systems.

[IR-spectroscopic study of the temperature anomaly of water sorbed onto DNA]. / Issledovanie temperaturnoi anomalii vody, sorbirovannoi na DNK, metodom IK-spektroskopii.

IR-spectra of liquid water and that sorbed on native and denaturated DNA at different relative humidity (RH) are obtained in the region of valent OH-(OD)-oscillations within the temperature range 0--100 degrees C. An S-shape decrease of absorption intensity was observed for water sorbed on DNA at 94% RH in two temperature regions (25--45 and 75--95 degrees C). Proceeding from the assumption that individual absorption bands are described by equal symmetrical functions, development of complex absorption contour of D2O in the region 3000--2000 cm-1 into constituents was performed. It enabled to determine band parameters of underphase vuf and synphase vsf valent and overtone of deformation oscillations of OD-groups in liquid and sorbed water and to reveal at higher temperatures the bands of "free" OD-groups (v = 2668 cm-1). Relative contribution of integral intensity of the latter at 96 degrees C in sorbed water is about 4 times lower than in the liquid one.

[Thermogravimetric study of the stability of DNA hydrate]. / Issledovanie stabil'nosti gidrata DNK metodom termograviometrii.

Thermograviometric study of DNA hydrate in the temperature range 0--120 degrees C was carried out. The three-stage hydration was observed: the first stage within 20--32 degrees C, the second--70--95 degrees C and the third one--105--116 degrees C. An assumption is advanced concerning the nature of structural rearrangements related to the loss of water in the system DNA--water. High sensitivity of thermograviometry to initial water content in DNA hydrate was shown.