Amending Soil with Sludge,Manure, Humic Acid,Orthophosphate and Phytic Acid: Effects on Infiltration,Runoff and Sediment Loss

Application of organic wastes to cultivated lands can replace mineral fertilizers but may also alter soil physical properties and enhance pollution potential. The objective of this study was to investigate the effects of biosolids [composted manure (MC) and activated sludge (AS)] and specific biosolid component [orthophosphate (OP), phytic acid (PA) and humic acid (HA)] application on soils differing in texture [loamy‐sand (Ramat‐HaKovesh, RH), loam (Gilat, GL) and clay (Bet‐Dagan, BD)], infiltration rate, runoff volume and soil sediment loss. The soils were packed in erosion boxes (400 × 200 × 40 mm) and subjected to six consecutive simulated rainstorms, each of 186 mm deionized water. The results showed that runoff volume and sediment loss from untreated soils increased with increasing clay contents. In treated soils, the response to AS application differed from the response to other amendments; in the BD clay and GL loam, it was the only amendment that caused a decrease in sediment removed by runoff. In the RH loamy‐sand, all amendments reduced the final infiltration rate, but only AS and HA increased the measured runoff. It is proposed that the difference in the response of the soils to the amendments is associated with the soil's ability to attenuate changes in the negative charge on the clay edges following the increase in the specific adsorption of charged anions, thus controlling clay swelling and maintaining aggregate integrity. The effects of amending soils with a source of organic matter in order to control runoff and soil erosion are not straight forward and depend on soil and amendment properties. Copyright © 2015 John Wiley & Sons, Ltd.     

Phenotypic and genotypic analysis of a commercial cultivar and wild populations of Anemone coronaria

Seven wild populations of Anemonecoronaria were assessed for 11 phenotypic traits, most of them having economic value for the flower industry. The wild populations were sampled to represent the diversity in habitats, climates, rock and soil types, terrains, and elevations in Israel. AFLP analysis was carried out on 12 individuals from each of six out of the seven wild populations and for six individuals from the commercial cultivar ‘Mona-Lisa’. It was found that the Dorot population, which is located in the area bordering the semi-arid zone at the very end of the species distribution, exhibits extreme and different phenotypes with relatively low variability compared withthe other wild populations. The other six wild populations, that grow in more favorable geographic and climatic conditions exhibit phenotypes with larger plants, larger numbers of flowers and less dissected leaves. These populations were less uniform than that of Dorot. Genetic characterization by AFLP markers revealed a total of 165 bands. The wild populations exhibit wide variation within-population, with about 80% polymorphic bands and average gene diversity between pairs of about 30%. The Dorot population has the lowest genetic variation and the Megido population the highest. Thus, the phenotypic variation reflects the genetic variation. The cultivar ‘Mona-Lisa’, as expected, has much lower genetic variation. The Dorot population and the ‘Mona-Lisa’ cultivar were found to have the largest genetic distances from the other wild populations, and the highest genetic variation between themselves. Phenetic analysis yielded a dendrogram describing the genetic relatedness of these populations. This revised version was published online in August 2006 with corrections to the Cover Date.     

Reptile diversity and rodent community structure across a political border

The peace treaty between Israel and Jordan found the Arava desert ecosystem, shared by the two countries, in a state of developmental dichotomy. On the Israeli side, vast lands have been settled and transformed into agricultural fields, while the Jordanian side has remained relatively intact and inhabited by only a few traditional and pastoral societies. This study examined the effect of different landscape units and proximity to agriculture on reptile diversity and rodent community structure on both sides of the border. It appears that in addition to the effect of proximity to agricultural fields and landscape habitat, the border between the two countries may play a role in determining diversity on the respective sides. While reptile abundance was generally higher on the Israeli side of the border, diversity was found to be significantly higher on the Jordanian side. Rodent community structure also revealed significant differences between the two sides of the border, mainly due to the more favorable conditions for psammophilic gerbils in Jordan. When comparing Western society with pastoral traditional society, it appears that development activities of the former have altered diversity and community structure of the taxa studied in the Arava. We suggest that in addition to the effects of habitats and human disturbances, such as modern agricultural practices, cultural differences between societies should be considered when conservation plans are developed for cross-border ecosystems.     

The Xist RNA gene evolved in eutherians by pseudogenization of a protein-coding gene

The Xist noncoding RNA is the key initiator of the process of X chromosome inactivation in eutherian mammals, but its precise function and origin remain unknown. Although Xist is well conserved among eutherians, until now, no homolog has been identified in other mammals. We show here that Xist evolved, at least partly, from a protein-coding gene and that the loss of protein-coding function of the proto-Xist coincides with the four flanking protein genes becoming pseudogenes. This event occurred after the divergence between eutherians and marsupials, which suggests that mechanisms of dosage compensation have evolved independently in both lineages.     

Genetics. Reprogramming X inactivation

Inactivation of one of the two X chromosomes occurs in all cells of female adult mice so that genes are expressed from only one X chromosome. In a Perspective, Clerc and Avner describe an elegant series of experiments in mouse embryos cloned from adult and embryonic female cell nuclei (Eggan et al.) that reveal how the inactivation state of the X chromosomes is reprogrammed.     

Modelling diameter class distribution with a second-order matrix model

Matrix models of forest dynamics rely on four hypotheses: independence hypothesis, Markov’s hypothesis, Usher’s hypothesis, and temporal homogeneity hypothesis. We investigate the consequences of relaxing Markov’s hypothesis, allowing the state of the tree at time t to depend on its states at time t−1 and t−2. The methodology for building and testing the relevance of second-order matrix model is thus proposed. The derivation of second-order transition probabilities turns to be sensitive to the width of the diameter classes. A strategy for choosing diameter classes is proposed. A second-order matrix model is then built for a tropical rain-forest in French Guiana. A different behaviour is detected between small (dbh ≤30 cm) and large trees, the smaller trees being more sensitive to their past history: small trees that have well grown have a tendency to grow well again, and small trees that have not grown tend to have a higher probability to die. The widths of the diameter classes that are selected are much less than the widths usually retained, that favour first-order selection.     

Comparative time-course study on pituitary and branchial response to salinity challenge in Mozambique tilapia (<Emphasis Type="Italic">Oreochromis mossambicus</Emphasis>) and Nile tilapia (<Emphasis Type="Italic">O</Emphasis>. <Emphasis Type="Italic">niloticus</Emphasis>)

The physiological response of Mozambique and Nile tilapia transferred from fresh to brackish (15 ppt) water was compared during a one-week time course. Response in the pituitary was measured by the gene expression pattern of prolactin (PRL I), growth hormone (GH), and calcium-sensing receptor (CaSR), while the response in the gills was measured by the gene expression pattern of the prolactin receptor (PRL-R), Na⁺/K⁺/2Cl⁻ cotransporter (NKCC) and Na⁺/Cl⁻ cotransporter (NCC), and by activity and expression of Na⁺/K⁺-ATPase (NKA). The time-course curves of plasma osmolality levels indicate a rapid elevation 24 h after transfer, which later decreased and maintained at stable level. PRL I expression decreased in both species, but with stronger response in the Nile tilapia, while no differences were found in the slightly elevated levels of GH mRNA. The branchial response demonstrated a faster up-regulation of NKA and NKCC in the Mozambique tilapia, but similar levels after a week, while Nile tilapia had stronger and constant down-regulation of NCC. The time-course response of the measured osmoregulatory parameters indicate that 24 h after transfer is a critical time point for brackish-water adaptation. The differences in responses to saltwater challenge between Mozambique and Nile tilapia shown in this study may be associated with the differences in saltwater tolerance between these two tilapiine species.     

Cold tolerance of tilapia species and hybrids

Several experiments were conducted,involving Oreochromis mossambicus, O. aureusand their F₁ and F₂ hybrids to studythe genetic basis of cold tolerance in tilapiinefishes. Groups of fish, of similar age and grown underidentical conditions, were housed in replicated netenclosures in a controlled cooling water system.Survival time through a regime of controlledtemperature reduction was the observed parameter forcold tolerance. Intra-population variation anddifferences among species, hybrids and repeated spawnswithin a species were examined. There was nocorrelation between cold tolerance and fish size(within the range of 23–105mm standard length), andthe distribution for the trait was not normal. O. mossambicuswas the most cold-sensitive group,followed by the F₂, and the F₁ which wassimilar to O. aureus. Genetic variation in coldtolerance seems to have a large dominance component,based on the similarity of the F₁ hybrid to the O. aureus parent.     

Effect of various thoracic radiographic projections on the appearance of selected thoracic viscera

OBJECTIVES: To assess the effect of different radiographic projections on thoracic width, as well as position and visibility of the trachea, principal bronchi, cardiac silhouette, aorta, caudal vena cava (CVC) and oesophagus. METHODS: Right lateral recumbency (RLR), left lateral recumbency (LLR), dorsoventral (DV) and ventrodorsal (VD) thoracic radiographs of 42 dogs were reviewed retrospectively. RESULTS: In 78 per cent of cases the thoracic width was significantly larger on the VD projection than on the DV projection. The angle of divergence formed by the principal bronchi was significantly larger on the VD projection than on the DV projection in 80 per cent of dogs. A cardiac silhouette bulge at 1 to 2 o'clock was apparent on the VD projection in 22 per cent of dogs but was never seen on DV projections. The descending aorta was more visible at the 4 to 5 o'clock cardiac silhouette level on the DV projection and laterally at the T8 level on LLR projections. The CVC was better seen on VD and LLR projections. The oesophagus was visible as a soft tissue opacity in LLR in large dogs with normal thoracic conformation in 35 per cent of cases. CLINICAL SIGNIFICANCE: The DV projection appears to be more reliable for assessing the cardiac silhouette, the descending aorta and the angle of divergence of the principal bronchi. The VD projection should be considered for evaluating the CVC. LLR should be used for assessing the descending aorta and CVC.     

Molecular coupling of Xist regulation and pluripotency

During mouse embryogenesis, reversion of imprinted X chromosome inactivation in the pluripotent inner cell mass of the female blastocyst is initiated by the repression of Xist from the paternal X chromosome. Here we report that key factors supporting pluripotency-Nanog, Oct3/4, and Sox2-bind within Xist intron 1 in undifferentiated embryonic stem (ES) cells. Whereas Nanog null ES cells display a reversible and moderate up-regulation of Xist in the absence of any apparent modification of Oct3/4 and Sox2 binding, the drastic release of all three factors from Xist intron 1 triggers rapid ectopic accumulation of Xist RNA. We conclude that the three main genetic factors underlying pluripotency cooperate to repress Xist and thus couple X inactivation reprogramming to the control of pluripotency during embryogenesis.