The effect of vegetation patterns on Aeolian mass flux at regional scale: a wind tunnel study

Although insight on the effect of vegetation pattern on Aeolian mass transport is essential for re-planting degraded land, only limited knowledge on this effect is available. The objective of this research was to understand the effect of vegetation design on the Aeolian mass flux inside a single land unit and at the borders among land units. A simulation of Atriplex halimus shrubs inside a wind tunnel was made, and sand redistribution was measured after the application of 200-230 seconds wind at a speed of 11 ms-1. The study showed that: 1) sediment maximum transport inside a single land unit is related to the neighboring land units and to the vegetation pattern within both the unit itself and the neighboring land units; 2) the effect of neighboring land units includes the protection effect and the ruling of sediment crossing from one land unit to the neighboring land units; 3) for the designing of re-planting of degraded land the ‘streets’ (zones of erosion areas similar to streets) effect need to be considered; and 4) in addition to the general knowledge needed on the effect of vegetation pattern on the erosion and deposition within an area, it is important to have insight on the redistribution of sediment at small scales upon the aim of the project

Seasonal Predictability of Daily Rainfall Characteristics in Central Northern Chile for Dry-Land Management

The seasonal predictability of daily winter rainfall characteristics relevant to dry-land management was investigated in the Coquimbo region of central northern Chile, with focus on the seasonal rainfall total, daily rainfall frequency, and mean daily rainfall intensity on wet days at the station scale. Three approaches of increasing complexity were tested. First, an index of the simultaneous El Nino–Southern Oscillation (ENSO) was regressed onto May–August (MJJA) observed precipitation; this explained 32% of station-averaged rainfall-amount variability, but performed poorly in a forecasting setting. The second approach used retrospective seasonal forecasts made with three general circulation models (GCMs) to produce downscaled seasonal rainfall statistics by means of canonical correlation analysis (CCA). In the third approach, a nonhomogeneous hidden Markov model (nHMM) driven by the GCM’s seasonal forecasts was used to model stochastic daily rainfall sequences. While the CCA is used as a downscaling method for the seasonal rainfall characteristics themselves, the nHMM has the ability to simulate a large ensemble of daily rainfall sequences at each station from which the rainfall statistics were calculated. Similar cross-validated skill estimates were obtained using both the CCA and nHMM, with the highest correlations with observations found for seasonal rainfall amount and rainfall frequency (up to 0.9 at individual stations). These findings were interpreted using analyses of observed rainfall spatial coherence, and by means of synoptic rainfall states derived from the HMM. The downscaled hindcasts were then tailored to meteorological drought prediction, using the standardized precipitation index (SPI) based on seasonal values, the frequency of substantial rainfall days (>15 mm; FREQ15) and the daily accumulated precipitation deficit. Deterministic hindcasts of SPI showed high hit rates, with high ranked probability skill score for probabilistic hindcasts of FREQ15 obtained via the nHMM

Prenatal diagnosis of isovaleric acidaemia by enzyme and metabolite assay in the first and second trimesters

Isovaleric acidaemia (IVA) is caused by a deficiency of isovaleryl CoA dehydrogenase. The diagnosis can be established biochemically by the demonstration of increased levels of isovalerylglycine (IVG) and 3-hydroxyisovaleric acid in urine and by the deficiency of incorporation of radiolabel from [14C]isovaleric acid in macromolecules in cultured fibroblasts. This paper reports a consecutive series of 24 prenatal diagnoses in pregnancies at high risk, using both methods-metabolite and indirect enzyme assay. Affected fetuses were diagnosed in four pregnancies: three in the second trimester and one recent case in the first trimester. The latter represents the first reported case of a first-trimester diagnosis of IVA by direct analysis of chorionic villi. We also report the first demonstration of strongly accumulated IVG in the amniotic fluid in the 12th week of an affected pregnancy

Exercise-Induced splanchnic hypoperfusion results in gut dysfunction in healthy men

Background Splanchnic hypoperfusion is common in various pathophysiological conditions and often considered to lead to gut dysfunction. While it is known that physiological situations such as physical exercise also result in splanchnic hypoperfusion, the consequences of flow redistribution at the expense of abdominal organs remained to be determined. This study focuses on the effects of splanchnic hypoperfusion on the gut, and the relationship between hypoperfusion, intestinal injury and permeability during physical exercise in healthy men. Methods and Findings Healthy men cycled for 60 minutes at 70% of maximum workload capacity. Splanchnic hypoperfusion was assessed using gastric tonometry. Blood, sampled every 10 minutes, was analyzed for enterocyte damage parameters (intestinal fatty acid binding protein (I-FABP) and ileal bile acid binding protein (I-BABP)). Changes in intestinal permeability were assessed using sugar probes. Furthermore, liver and renal parameters were assessed. Splanchnic perfusion rapidly decreased during exercise, reflected by increased gapg-apCO2 from −0.85±0.15 to 0.85±0.42 kPa (p < 0.001). Hypoperfusion increased plasma I-FABP (615±118 vs. 309±46 pg/ml, p < 0.001) and I-BABP (14.30±2.20 vs. 5.06±1.27 ng/ml, p < 0.001), and hypoperfusion correlated significantly with this small intestinal damage (rS = 0.59; p < 0.001). Last of all, plasma analysis revealed an increase in small intestinal permeability after exercise (p < 0.001), which correlated with intestinal injury (rS = 0.50; p < 0.001). Liver parameters, but not renal parameters were elevated. Conclusions Exercise-induced splanchnic hypoperfusion results in quantifiable small intestinal injury. Importantly, the extent of intestinal injury correlates with transiently increased small intestinal permeability, indicating gut barrier dysfunction in healthy individuals. These physiological observations increase our knowledge of splanchnic hypoperfusion sequelae, and may help to understand and prevent these phenomena in patients

Universal Algebraic Relaxation of Velocity and Phase in Pulled Fronts generating Periodic or Chaotic States

We investigate the asymptotic relaxation of so-called pulled fronts propagating into an unstable state. The ``leading edge representation'' of the equation of motion reveals the universal nature of their propagation mechanism and allows us to generalize the universal algebraic velocity relaxation of uniformly translating fronts to fronts, that generate periodic or even chaotic states. Such fronts in addition exhibit a universal algebraic phase relaxation. We numerically verify our analytical predictions for the Swift-Hohenberg and the Complex Ginzburg Landau equation.Comment: 4 pages Revtex, 2 figures, submitted to Phys. Rev. Let

Short- and long-term changes in symptom dimensions among patients with schizophrenia spectrum disorders and different durations of illness:A meta-analysis

In schizophrenia spectrum disorders, improvement in symptoms varies between patients with short and long durations of illness. In this meta-analysis we provided an overview of both short- and long-term symptomatic improvement for patients with schizophrenia spectrum disorders with distinct durations of illness. We included 82 longitudinal studies assessing the course of positive, negative, depressive and disorganization symptoms. We analyzed effect sizes of change in four subgroups based on durations of illness at baseline: &lt;2 years, 2-5 years, 5-10 years, &gt;10 years. Potential moderators were explored using meta-regression and sensitivity analyses. Overall, we found large improvements of positive symptoms and small improvements of negative, depressive, and disorganization symptoms. Positive and disorganization symptoms improved relatively stronger for patients earlier in the course of illness, whereas negative and depressive symptoms showed modest improvement regardless of duration of illness. Improvement of symptoms was associated with higher baseline severity of positive symptoms, a younger age, a smaller subsample with schizophrenia, and, specifically for negative symptoms, higher baseline severity of depressive symptoms. Future research should focus on exploring ways to optimize improvement in negative and depressive symptoms for patients with schizophrenia spectrum disorders.</p

Changes in social functioning over the course of psychotic disorders:A meta-analysis

In this meta-analysis we investigated changes in social functioning and its moderators in patients with a psychotic disorder but different durations of illness at baseline. We included longitudinal studies assessing the course of five domains of social functioning in patients with a psychotic disorder. Effect sizes of change between baseline and follow-up within these domains were analyzed in four subgroups based on durations of psychotic disorder at baseline: less than 2 years, between 2 and 5 years, between 5 and 10 years, and more than 10 years. The influence of baseline confounders was analyzed using meta-regression and sensitivity analysis. We included 84 studies analyzing 33,456 participants. We found a medium improvement (d = 0.60) in overall social functioning over time, with a greater improvement for studies investigating patients with a duration of illness of less than 5 years. We found minor improvement in specific domains of social functioning, such as vocational functioning (d = 0.31), prosocial behavior (d = 0.36), activities (d = 0.15), and independence (d = 0.25). Improvement in social functioning was associated with lower baseline levels of negative symptoms, higher baseline levels of quality of life, and, specifically, improved vocational functioning, with rehabilitation and combined treatment. Social functioning in patients with psychotic disorders improves over time, especially for patients with shorter illness durations. Reduction of negative symptoms and improving quality of life might reinforce improvement of social functioning

Prediction of water retention of soils from the humid tropics by the nonparametric k-nearest neighbor approach

Nonparametric approaches such as the k-nearest neighbor (k-NN) approach are considered attractive for pedotransfer modeling in hydrology; however, they have not been applied to predict water retention of highly weathered soils in the humid tropics. Therefore, the objectives of this study were: to apply the k-NN approach to predict soil water retention in a humid tropical region; to test its ability to predict soil water content at eight different matric potentials; to test the benefit of using more input attributes than most previous studies and their combinations; to discuss the importance of particular input attributes in the prediction of soil water retention at low, intermediate, and high matric potentials; and to compare this approach with two published tropical pedotransfer functions (PTFs) based on multiple linear regression (MLR). The overall estimation error ranges generated by the k-NN approach were statistically different but comparable to the two examined MLR PTFs. When the best combination of input variables (sand + silt + clay + bulk density + cation exchange capacity) was used, the overall error was remarkably low: 0.0360 to 0.0390 m(3) m(-3) in the dry and very wet ranges and 0.0490 to 0.0510 m(3) m(-3) in the intermediate range (i.e., -3 to -50 kPa) of the soil water retention curve. This k-NN variant can be considered as a competitive alternative to more classical, equation-based PTFs due to the accuracy of the water retention estimation and, as an added benefit, its flexibility to incorporate new data without the need to redevelop new equations. This is highly beneficial in developing countries where soil databases for agricultural planning are at present sparse, though slowly developing

Andreev reflection at QGP/CFL interface

In this letter we address the question of the phenomena of Andreev reflection between the cold quark-gluon plasma phase and CFL color superconductor. We show that there are two different types of reflections connected to the structure of the CFL phase. We also calculate the probability current at the interface and we show that it vanishes for energy of scattering quarks below the superconducting gap.Comment: 6 pages, 1 figure. Minor changes in the "Conclusions

Stable isotope dilution analysis of N-acetylaspartic acid in CSF, blood, urine and amniotic fluid: Accurate postnatal diagnosis and the potential for prenatal diagnosis of canavan disease

A sensitive and selective analytical technique is described for the determination of N-acetylaspartic acid in body fluids using stable isotope dilution in combination with positive chemical ionization mass spectrometry with selected ion monitoring. Control mean and ranges have been established: in urine 19.5 and 6.6-35.4 μmol/mmol creat.; in plasma 0.44 and 0.17-0.81 μmol/L; in cerebrospinal fluid 1.51 and 0.25-2.83 μmol/L; and in amniotic fluid 1.27 and 0.30-2.55 μmol/L. In a patient with Canavan disease, N-acetylaspartic acid concentration was elevated 80-fold in urine and 20-fold in plasma compared to the control means. A subsequent pregnancy of the mother was monitored and the N-acetylaspartic acid concentration in the amniotic fluid was within the control range and a healthy child was born