Nitrogen inputs best predict farm field nitrate leaching in the Willamette Valley, Oregon.

Nitrate leaching is an important yet difficult to manage contribution to groundwater and surface water contamination in agricultural areas. We examine 14 farm fields over a four year period (2014-2017) in the southern Willamette Valley, providing 53 sets of annual, field-level agricultural performance metrics related to nitrogen (N), including fertilizer inputs, crop harvest outputs, N use efficiency (NUE), nitrate-N leaching and surplus N. Crop-specific nitrate-N leaching varied widely from 10 kg N ha-1yr-1 in hazelnuts to >200 kg N ha-1yr-1 in peppermint. Averaging across all sites and years, most leaching occurred during fall (60%) and winter (32%). Overall NUE was 57%. We used a graphical approach to explore the relationships between N inputs, surplus, crop N harvest removal and NUE by crop type. The blueberry site had high inputs and surplus, peppermint had high inputs but also high crop N removal and NUE and thus lower surplus, and most wheat crops had high NUE and evidence of using soil N. Annual N surplus was not well correlated with leaching, and leaching varied more by crop type and inputs. Grass seed and hazelnuts, which are dominant crop types in the southern Willamette Valley, were intermediate in terms of NUE, leaching and surplus. Of all performance metrics, N input was most closely aligned with field-level crop N harvest and nitrate leaching, therefore optimizing N inputs may well inform local efforts to reduce groundwater nitrate contamination.

The relation between land use and subsidence in the Vietnamese Mekong delta.

The Vietnamese Mekong delta is subsiding due to a combination of natural and human-induced causes. Over the past several decades, large-scale anthropogenic land-use changes have taken place as a result of increased agricultural production, population growth and urbanization in the delta. Land-use changes can alter the hydrological system or increase loading of the delta surface, amplifying natural subsidence processes or creating new anthropogenic subsidence. The relationships between land use histories and current rates of land subsidence have so far not been studied in the Mekong delta. We quantified InSAR-derived subsidence rates for the various land-use classes and past land-use changes using a new, optical remote sensing-based, 20-year time series of land use. Lowest mean subsidence rates were found for undeveloped land-use classes, like marshland and wetland forest (~6-7mmyr-1), and highest rates for areas with mixed-crop agriculture and cities (~18-20mmyr-1). We assessed the relationship strength between current land use, land-use history and subsidence by predicting subsidence rates during the measurement period solely based on land-use history. After initial training of all land-use sequences with InSAR-derived subsidence rates, the land-use-based approach predicted 65-92% of the spatially varying subsidence rates within the measurement error range of the InSAR observations (RMSE=5.8mm). As a result, the spatial patterns visible in the observed subsidence can largely be explained by land use. We discuss in detail the dominant land-use change pathways and their indirect, causal relationships with subsidence. Our spatially explicit evaluation of these pathways provides valuable insights for policymakers concerned with land-use planning in both subsiding and currently stable areas of the Mekong delta and similar systems.

Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam.

Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwater extraction is suggested as the main driver. As groundwater levels drop, subsidence is induced through aquifer compaction. Over the past 25 years, groundwater exploitation has increased dramatically, transforming the delta from an almost undisturbed hydrogeological state to a situation with increasing aquifer depletion. Yet the exact contribution of groundwater exploitation to subsidence in the Mekong delta has remained unknown. In this study we deployed a delta-wide modelling approach, comprising a 3D hydrogeological model with an integrated subsidence module. This provides a quantitative spatially-explicit assessment of groundwater extraction-induced subsidence for the entire Mekong delta since the start of widespread overexploitation of the groundwater reserves. We find that subsidence related to groundwater extraction has gradually increased in the past decades with highest sinking rates at present. During the past 25 years, the delta sank on average ∼18 cm as a consequence of groundwater withdrawal. Current average subsidence rates due to groundwater extraction in our best estimate model amount to 1.1 cm yr-1, with areas subsiding over 2.5 cm yr-1, outpacing global sea level rise almost by an order of magnitude. Given the increasing trends in groundwater demand in the delta, the current rates are likely to increase in the near future.

Changes in osmotic resistance of leucocytes in mental illnesses.

A simple method is described for determining osmotic resistance of leucocytes in peripheral blood: stained leucocytes are counted after 30, 60, 120 and 180 minutes of blood incubation with 0.2% NaCl solution. With this method it was possible to demonstrate a significant decrease in osmotic resistance of leucocytes, primarily granulocytes, in schizophrenics (by about 1/3) and in neurotics (by about 1/5) in comparison to a healthy control sample.

Biological correlates of piracetam clinical effects in psychotic patients.

The purpose of this controlled clinical trial was to demonstrate possible correlations between changes in bioenergetic metabolism and psychotropic drug administration in the treatment of functional psychosis. The study included twenty-six patients, eleven with schizophrenia, three with chronic atypical depression and twelve with drug-resistant endogenous depressions. All patients were kept on continuous psychotropic medication for at least 3 weeks before starting the trial, and piracetam was given additionally in a fixed dosage of 2400 mg daily; the same number of identical capsules was given during the pre- and post-treatment placebo periods. Psycho-pathological evaluation of the patients was by the BPRS; clinical and biochemical data were evaluated statistically by the analysis of regression. The results show that in schizophrenic patients an improvement was observed in those cases who had improved biochemically, i.e. where the ATP values had increased. In drug-resistant depressions there was a rapid and significant clinical improvement after piracetam co-administration, and this went in step with a significant rise in ATP levels.

Relationship between pycnotic indec Qp as a result of oxygen supply and similar indices as a result of in vitro offer of cytochrome c and NADP in psychiatry.

The authors follow up on their previous studies of morphological changes in the properties of white blood cells represented by the oxygen pycnotic index Qp in patients with the schizophrenic syndrome. Several years of research made it obvious to them that this index remains generally unaffected by drugs administered during the treatment although the patient does show a pronounced clinical change. They decided to substitute the offer of oxygen by adding a supply of cytochrome c and NADP, i.e. by substances that give a boost to the oxidoreduction processes within the cell. They found the pycnotic quotient, based on cytochrome c, and - to an even greater degree - the NADP-based quotient to be more responsive to differences in the seriousness of the disease than the oxygen quotient.