A New Kind of Graded Lie Algebra and Parastatistical Supersymmetry

In this paper the usual $Z_2$ graded Lie algebra is generalized to a new form, which may be called $Z_{2,2}$ graded Lie algebra. It is shown that there exists close connections between the $Z_{2,2}$ graded Lie algebra and parastatistics, so the $Z_{2,2}$ can be used to study and analyse various symmetries and supersymmetries of the paraparticle systems

An ecological model for the Scheldt estuary and tidal rivers ecosystem: spatial and temporal variability of plankton

This paper presents the formulation, structure, and governing equations of an ecosystem model developed for the Scheldt estuary and the tidal river network. The model has twelve state variables: nitrate, ammonium, phosphate, dissolved silica, freshwater and marine phytoplankton (chlorophytes and diatoms), freshwater zooplankton (ciliates, rotifers, and copepods), and benthic detritus. The ecological model is coupled to the 1-D tidal resolving version of the Second-generation Louvain-la-neuve ice-ocean Model (SLIM) (http://​www.​climate.​be/​SLIM). The model successfully simulates the observed longitudinal and seasonal variation of plankton in the Scheldt estuary. The phytoplankton production in the estuary is governed by temperature, underwater available light, turbidity, nutrients, and discharge. Of all these factors, discharge seems to be dominant. High discharge increases the turbidity in the water column and thus reduces the underwater light, while low discharge means decreased nutrients. The marine phytoplankton species were present as far to the upstream limits of the brackish waters, with diatoms dominating in the spring and chlorophytes in early summer. The freshwater phytoplankton are seen from late spring to summer. Freshwater zooplankton followed the evolution of freshwater phytoplankton

Previous Crop and Cultivar Effects on Methane Emissions from Drill-Seeded, Delayed-Flood Rice Grown on a Clay Soil

Due to anaerobic conditions that develop in soils under flooded-rice (Oryza sativa L.) production, along with the global extent of rice production, it is estimated that rice cultivation is responsible for 11% of global anthropogenic methane (CH4) emissions. In order to adequately estimate CH4 emissions, it is important to include data representing the range of environmental, climatic, and cultural factors occurring in rice production, particularly from Arkansas, the leading rice-producing state in the US, and from clay soils. The objective of this study was to determine the effects of previous crop (i.e., rice or soybean (Glycine max L.)) and cultivar (i.e., Cheniere (pure-line, semidwarf), CLXL745 (hybrid), and Taggart (pure-line, standard-stature)) on CH4 fluxes and emissions from rice grown on a Sharkey clay (very-fine, smectitic, thermic Chromic Epiaquerts) in eastern Arkansas. Rice following rice as a previous crop generally had greater (p<0.01) fluxes than rice following soybean, resulting in growing season emissions (p<0.01) of 19.6 and 7.0 kg CH4-C ha−1, respectively. The resulting emissions from CLXL745 (10.2 kg CH4-C ha−1) were less (p=0.03) than those from Cheniere or Taggart (15.5 and 14.2 kg CH4-C ha−1, resp.), which did not differ. Results of this study indicate that common Arkansas practices, such as growing rice in rotation with soybean and planting hybrid cultivars, may result in reduced CH4 emissions relative to continuous rice rotations and pure-line cultivars, respectively

Nutrient Concentrations in Big Creek Correlate to Regional Watershed Land Use

Nutrient concentrations in several streams of the Boston and Ozark Mountains region of Arkansas, including the Buffalo National River and its tributaries, have garnered tremendous interest. In particular, Big Creek has been the center of attention within the Buffalo River watershed because of a permitted concentrated animal feeding operation (CAFO). The objectives of this paper were to put nutrient concentrations of Big Creek into the context of the stream nutrient and watershed land-use relationship and develop a framework to evaluate regional land-use impacts on regional water quality. Nutrient concentrations in streams draining the Boston and Ozark Mountains region were related to the intensity of watershed land use. Concentrations in Big Creek were similar to other watersheds in the ecoregion with similar land use, suggesting limited impact of the CAFO on Big Creek at the present time. However, this does not preclude future impacts, and longer-term monitoring continues

Design of a sampling strategy to optimally calibrate a reactive transport model: Exploring the potential for <i>Escherichia coli</i> in the Scheldt Estuary

For the calibration of any model, measurements are necessary. As measurements are expensive, it is of interest to determine beforehand which kind of samples will provide maximal information. Using a criterion related to the Fisher information matrix as a measure for information content, it is possible to design a sampling scheme that will enable the most precise parameter estimates. This approach was applied to a reactive transport model (based on the Second-generation Louvain-la-Neuve Ice-ocean Model, SLIM) of Escherichia coli concentrations in the Scheldt Estuary. As this estuary is highly influenced by the tide, it is expected that careful timing of the samples with respect to the tidal cycle can have an effect on the quality of the data. The timing and also the positioning of samples were optimised according to the proposed criterion. In the investigated case studies the precision of the estimated parameters could be improved by up to a factor of ten, confirming the usefulness of this approach to maximize the amount of information that can be retrieved from a fixed number of samples. Precise parameter values will result in more reliable model simulations, which can be used for interpretation, or can in turn serve to plan subsequent sampling campaigns to further constrain the model parameters

Comparison of the Effects of Latanoprostene Bunod and Timolol on Retinal Blood Vessel Density: A Randomized Clinical Trial

PurposeTo compare the differences in retinal vessel density (VD) between topical administration of latanoprostene bunod (LBN) ophthalmic solution 0.024% and timolol maleate 0.5% in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT) and normal subjects.DesignRandomized, single center, crossover clinical trial.MethodsEligible subjects were examined during 6 study visits over 12 weeks. All subjects were randomized in a 1:1 ratio to LBN dosed once daily or timolol dosed twice daily in both eyes (OU) for a duration of 4 weeks each, separated by a 2-week washout period. A comprehensive eye examination OU was performed at each visit. Testing was performed with optical coherence tomography and optical coherence tomography angiography (optic nerve and macula), as well as visual field examination, on the study eye at baseline and before and after each treatment.ResultsOne eye from each of 50 patients was enrolled (10 healthy patients, 26 patients with OHT, and 14 patients with OAG). After administration of LBN there was significantly increased macular VD (0.76% [0.20%-1.33%], P&nbsp;=&nbsp;0.009) and a trend in increasing peripapillary VD in patients with OAG and patients with OHT. In contrast, after administration of timolol, there were no differences in macular VD, and a decrease in peripapillary VD only was observed in the nasal inferior sector (-0.56% [-1.08% to -0.03%], P&nbsp;=&nbsp;.04) in patients with OAG and patients with OHT. No change in peripapillary or macular VD was observed in the normal subjects (P &gt; .05 for all).ConclusionsTopical administration of LBN enhanced macular VD in patients with OAG or patients with OHT. In contrast, timolol administration did not have any effect on VD