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The aim of the present study was to evaluate the transformation of applied inorganic phosphorus (P) in highly calcareous soils under two moisture regimes. The experimental design was a factorial combination of two rates of P (0 and 300 mg P [kg.sup.-1] as K[H.sub.2]P[O.sub.4]) and two moisture regimes (field capacity, FC; waterlogged, WL) in a completely randomised design in duplicate with 20 surface soil samples. The fractionation sequence of inorganic P included successive extraction with NaHC[O.sub.3], N[H.sub.4] acetate buffer (N[H.sub.4]OAc), Mg[Cl.sub.2], N[H.sub.4]F, NaOH-[Na.sub.2]C[O.sub.3] (HC), Na citrate-bicarbonate-dithionite (CBD), and [H.sub.2]S[O.sub.4] carried out 80 and 160 days after incubation. Recovery of applied P in each fraction was calculated as the difference between samples treated and untreated with P. Results indicated that NaHC[O.sub.3]-P decreased from 80 to 160 days, and the decrement was higher under WL than FC moisture regime. The N[H.sub.4]OAc-P was lower under WL than FC at 160 days, while P associated with free and crystalline Fe and Al oxides (N[H.sub.4]F-P, HC-P, CBD-P) was higher under WL than FC for both incubation periods. Oxalate-, citrate-, and citrate-ascorbate-extractable iron under FC and in conjunction with oxalate- and CBD-extractable aluminium and quinone- and hydroxylamine-hydrochloride-extractable manganese were the most influential factors regulating all P fractions. Results of the present study revealed that transformation of applied P into Al- and Fe-P fractions is not as low as previously reported in highly calcareous soils and that Al- and Fe-P oxides may be important in P transformation of these soils, especially in waterlogged condition. Additional keywords: inorganic phosphorus, NaHC[O.sub.3]-P, pedogenic Ca-P, Al-P and Fe-P. Received 20 September 2011, accepted 7 May 2012, published online 30 May 2012, Introduction Phosphorus (P) reactions with calcareous soils significantly influence the efficiency of P fertilisers and environmental quality (Sample et al. 1980). Di-calcium phosphate dehydrate is probably the initial product of [...]

The aim of this research was to study and compare release characteristics of copper (Cu) in 2 groups of soils from Guilan province in northern (SNI) and Fars province in southern Iran (SSI) with significant differences in Cu availability and other soil properties. The patterns of Cu release from the soils by ammonium bicarbonatediethylenetriaminepentaacetic acid (AB-DTPA) were studied using 5 kinetic models. Results showed that the power function, simple Elovich, and parabolic diffusion in SSI, and the power function and simple Elovich in SNI, were the best fitted models. The greater rates and magnitude of Cu released from SNI compared with SSI could be interpreted as the greater capability of the former in maintaining Cu concentration in the sufficient range. The difference in Cu release rates was considerable during initial times. Mean initial Cu release rate from SNI was ~3 times higher than that of SSI. The results reveal that the cation exchange capacity (CEC) and pH were the most influential soil factors causing differences in Cu release patterns between these 2 groups of soils. Greater CEC and lower pH in SNI compared with SSI, are mainly responsible for greater initial rates of Cu release in the former. Difference in CEC and pH of these 2 groups of soils was mainly attributed to different soil organic matter, carbonate content, and clay mineralogy. Additional keywords: copper release, cation exchange capacity, pH, kinetics., Introduction Copper (Cu) availability is low in uncontaminated soils, and deficiencies of this element have been reported in some soils (Lehman and Hatter 1984). In most agricultural soils, Cu availability [...]

The objectives of the present study were to evaluate the effect of four eucalyptus species on (i) selected surface soil properties and (ii) the distribution of inorganic and organic phosphorus (Pi and Po) fractions. Soil samples were collected from soil 0-20 cm deep beneath and between trees. The Pi forms were determined by sequential extraction with sodium bicarbonate (NaHCO3-P), ammonium acetate (NH4OAc) (OAc-P), ammonium fluoride (NH4F-P), sodium hydroxide (NaOH)-sodium carbonate (Na2CO3) (HC-P), citrate dithionite (CD-P), and sulfuric acid (H2SO4) (H2SO4-P). The Po forms were sequentially extracted with NaHCO3 (NaHCO3-Po), NaOH (NaOH-Po), and H2SO4 (H2SO4-Po). The NaOH-Po was subdivided into moderately stable (NaOH-Pom) and highly stable Po (NaOH-Pos). Organic matter, clay and silt contents, total nitrogen, and available potassium of the soil beneath the trees increased. The OAc-P and HC-P forms beneath the trees were less than of that between them, which shows that these fractions probably are labile inorganic P pools. The NaHCO3-Po and NaOH-Pos forms were greater beneath the trees than those of interspaces, whereas NaOH-Pom and H2SO4-Po were not affected by plantation. [ABSTRACT FROM AUTHOR]

Motor behavior often occurs in environments with multiple goal options that can vary during the ongoing action. We explored this situation by requiring subjects to select between different target options during an ongoing reach. During split trials the original target was replaced with a left and a right flanking target, and participants had to select between them. This contrasted with the standard jump trials, where the original target would be replaced with a single flanking target, left or right. When participants were instructed to follow their natural tendency, they all tended to select the split target nearest the original. The near-target preference was more prominent with increased spatial disparity between the options and when participants could preview the potential options. Moreover, explicit instruction to obtain the "far" target during split trials resulted many errors compared with a "near" instruction, ~50% vs. ~15%. Online reaction times to target change were delayed in split trials compared with jump trials, ~200 ms vs. ~150 ms, but also highly automatic. Trials in which the instructed far target was correctly obtained were delayed by a further ~50 ms, unlike those in which the near target was incorrectly obtained. We also observed nonspecific responses from arm muscles at the jump trial latency during split trials. Taken together, our results indicate that online selection of reach targets is automatically linked to the spatial distribution of the options, though at greater delays than redirecting to a single target. NEW & NOTEWORTHY This work demonstrates that target selection during an ongoing reach is automatically linked to the option nearest a voided target. Online reaction times for two options are longer than redirection to a single option. Attempts to override the near-target tendency result in a high number of errors at the normal delay and further delays when the attempt is successful.

Unlabelled: Objective was to clarify the etiology and pathogenesis of systemic lupus erythematosus (SLE). Drug-induced lupus (DIL) and SLE are both found in humans, are exacerbated by the same viruses or drugs, and they are both more common in slow acetylators. Thus, DIL can be used as a model for SLE and the Adhami equation of DIL can be applied to SLE. Polyamines are the only possible link between the viral and amine hypotheses of SLE pathogenesis. Based on the Adhami equation, polyamines can explain the actual annual incidence of SLE in the general population. Putrescine is a very weak SLE-causing agent, while spermine and spermidine contribute equally in triggering SLE. The positively charged polyamines bind to negatively charged internucleosomal DNA and change its conformation from B (non-immunogenic) to Z (immunogenic). This is the major contribution of polyamines in triggering SLE. The other effects of polyamines are only secondary. Apoptosis is a necessary step in SLE pathogenesis, because it causes the internucleosomal fragmentation of DNA and exposes Z-DNA to the immune system (due to cell death). The next step is the production of anti-DNA antibodies, followed by other SLE phenomena. Polyamines not only cause SLE, but they are also important in sustaining the disease. Other endogenous and exogenous amines have additive effects with polyamines and may contribute in exacerbating SLE. When SLE is in the active phase, polyamine levels are higher as compared to remissions. Fluctuations in polyamine levels due to diet, metabolic factors, infections, intestinal flora, etc. or the presence of other amines may explain the course of SLE, characterized by remissions and exacerbations. Acetylcysteine is a drug that can be completely metabolized to acetyl groups. As such, this drug is proposed as the ideal acetyl donor for the acetylation of polyamines and other SLE-triggering compounds. Clinical trials will be necessary to test the role of acetylcysteine in the etiologic treatment of SLE., Conclusions: Changes in DNA conformation by polyamines are the first step in SLE pathogenesis. Many genetic and environmental factors may increase or decrease the effects or levels of polyamines, causing SLE exacerbations or remissions. Viruses and other infectious agents may cause SLE by producing polyamines or by increasing the levels of endogenous polyamines. The major autoimmune diseases are characterized by remissions and exacerbations and not by a continuously progressive course, as commonly believed. Consequently, they are not sustained by internal vicious cycles, but by the initial triggering agent(s). While the conventional treatment of autoimmune disorders is important in minimizing tissue damage, the neutralization of their etiology may be important in curing and preventing autoimmunity.

There are 40 patients with Wilson's disease diagnosed in Albania; 24 were males and 16 females with an average age 18.8 +/- 8.47 years. The incidence rate was 1:75.000 and prevalence rate 1:148.000. According to clinical data, the Kayser-Fleischer ring was found in 75% of the cases, the neurologic in 60% and mental disturbances in 27.5%. The liver was damaged in all the cases of acute and chronic hepatitis or liver cirrhosis. In 35% signs of hypersplenism were seen. Comparing these data with a control group of 60 alcoholic or viral cirrhosis with hypersplenism, it was found that hypersplenism is encountered in younger ages (p < 0.0001). The platelets were lower in WD than in the control group (p < 0.05), but leucocytes were lower in the control group (p < 0.001). Portal hypertension was found in 42.5% of the cases. Six of these (35.3%) were complicated by gastrointestinal hemorrhage. In two twins the disease was accompanied with another congenital anomaly: genu valgum bilateralis. Two other patients had hypertrophy of the parotis gland, six patients had signs of acute haemolysis, accompanied by nonspherocytic anemia, Coombs negative.