Importance of plant extract formulations in managing different pests attacking beans in new reclaimed area and under storage conditions

Field evaluation of some botanical formulations like Neem Azal T/S, Neem Azal T/S + TS/fort and petroleum ether extract of Curcuma longa for the management of different pests attacking broad bean crop in a new reclaimed area at El- Noubaria and under storage conditions has been carried out. All tested formulations could be considered efficient in controlling Aphis craccivora infesting broad bean under field conditions. As to the leafminer, the number of living Liriomyza trifolii larvae decreased significantly compared to non-treated control. The number of living larvae continued to decrease until seven days post-treatment after which an increase in their number was noticed after 14 days post-treatment. Neem Azal T/S + additive (TS/fort) ranked first in comparison to other treatments for the control of aphids and leafminers attacking broad bean in the field either by killing, deterrent or antifeedant effect. The yield of treated crop increased significantly in comparison to the control. Another spray was used before harvesting the crop with the same formulations for protection of the stored crop. Neem Azal T/S with adjuvant (TS/fort) protected broad bean seeds from weevil attack for one year. Petroleum ether extract of C. longa could protect the stored crops for two months only. The percentage weight loss in one kg stored seeds treated in the field with Neem formulation + adjuvant was very small compared with those seeds treated with petroleum ether extract of C. longa and control.     

Imaging cell interactions with native and crosslinked polyelectrolyte multilayers

The adhesion of primary chondrocytes to polyelectrolyte multilayer films, made of poly(l-lysine) (PLL) and hyaluronan (HA), was investigated for native and crosslinked films, either ending by PLL or HA. Crosslinking the film was achieved by means of a water-soluble carbodiimide in combination with N-hydroxysulfosuccinimide. The adhesion of macrophages and primary chondrocytes was investigated by microscopical techniques (optical, confocal, and atomic), providing useful information on the cell/film interface. Native films were found to be nonadhesive for the, primary chondrocytes, but could be degraded by macrophages, as could be visualized by confocal laser scanning microscopy after film labeling. Confocal microscopy images show that these films can be deformed by the condrocytes and that PLL diffuses at the chondrocyte membrane. In contrast, the cells adhered and proliferated well on the crosslinked films, which were not degraded by the macrophages. These results were confirmed by a MTT test over a 6-d period and by atomic force microscopy observations. We thus prove that chemical crosslinking can dramatically change cell adhesion properties, the cells being more stably anchored on the crosslinked films. Both authors kcontributed equally.     

Biodegradation of Malathion with Indigenous Acclimated Activated Sludge in Batch Mode and in Continuous-Flow Packed-Bed Reactor

Acclimated activated sludge was examined for its ability to degrade malathion with and without the presence of glucose as a potential cometabolite substrate. In this study, a packed-bed reactor (PBR) using three kinds of biofilm carriers was employed for efficient degradation of malathion. The results obtained indicate that microorganisms tested were able to degrade malathion. The observed degradation rate of the pesticide in the presence of glucose was the same as without glucose. The activated sludge was found to be able to use malathion as the sole phosphorus source. In contrast, the degradation ability of the activated sludge was lost when the pesticide was used as the sole source of sulfur. The degradation capacity of the PBR was higher than the performance obtained with the batch reactor. The reactor packed with crushed olive kernels exhibited the best performance, allowing a total removal of malathion (10 mg/dm³) within 12 h.     

Hydraulic redistribution: limitations for plants in saline soils

Hydraulic redistribution (HR), the movement of water from wet to dry patches in the soil via roots, occurs in different ecosystems and plant species. By extension of the principle that HR is driven by gradients in soil water potential, HR has been proposed to occur for plants in saline soils. Despite the inherent spatial patchiness and salinity gradients in these soils, the lack of direct evidence of HR in response to osmotic gradients prompted us to ask the question: are there physical or physiological constraints to HR for plants in saline environments? We propose that build‐up of ions in the root xylem sap and in the leaf apoplast, with the latter resulting in a large predawn disequilibrium of water potential in shoots compared with roots and soil, would both impede HR. We present a conceptual model that illustrates how processes in root systems in heterogeneous salinity with water potential gradients, even if equal to those in non‐saline soils, will experience a dampened magnitude of water potential gradients in the soil–plant continuum, minimizing or preventing HR. Finally, we provide an outlook for understanding the relevance of HR for plants in saline environments by addressing key research questions on plant salinity tolerance.     

Transvection at the vestigial locus of Drosophila melanogaster

Transvection is a phenomenon wherein gene expression is effected by the interaction of alleles in trans and often results in partial complementation between mutant alleles. Transvection is dependent upon somatic pairing between homologous chromosome regions and is a form of interallelic complementation that does not occur at the polypeptide level. In this study we demonstrated that transvection could occur at the vestigial (vg) locus by revealing that partial complementation between two vg mutant alleles could be disrupted by changing the genomic location of the alleles through chromosome rearrangement. If chromosome rearrangements affect transvection by disrupting somatic pairing, then combining chromosome rearrangements that restore somatic pairing should restore transvection. We were able to restore partial complementation in numerous rearrangement trans-heterozygotes, thus providing substantial evidence that the observed complementation at vg results from a transvection effect. Cytological analyses revealed this transvection effect to have a large proximal critical region, a feature common to other transvection effects. In the Drosophila interphase nucleus, paired chromosome arms are separated into distinct, nonoverlapping domains. We propose that if the relative position of each arm in the nucleus is determined by the centromere as a relic of chromosome positions after the last mitotic division, then a locus will be displaced to a different territory of the interphase nucleus relative to its nonrearranged homolog by any rearrangement that links that locus to a different centromere. This physical displacement in the nucleus hinders transvection by disrupting the somatic pairing of homologous chromosomes and gives rise to proximal critical regions.     

Migration of Naphthalene through Low Organic Content Sandy Soil Columns: Comparison of Unsaturated and Saturated Conditions

The transient transport of naphthalene through low organic matter content soil columns was investigated in different water-saturation and flow conditions. Some parameters were tested as flow rate, column height, and water saturation conditions. The soil was a clayed sandy soil from the Algerian coast near Boumerdes. The organic carbon content was 0.13% and the main mineral components were quartz (88%), clays minerals (7%) and calcite (3%). The height of the packing of the soil column (5.1 cm in diameter) varied from 15 to 40 cm. Simultaneous step injections of inert tracer (calcium chloride) and naphthalene at 10 mg L^?1 were performed. Tracer and naphthalene breakthrough curves (BTCs) were measured continuously by conductimetry and UV – 220 nm, respectively. The BTCs were simulated using the classical mixing cells in series with exchange model (MCE). In unsaturated conditions the comparison of the mean residence time of tracer BTCs with the geometrical pore volume gave us access to average water saturation along the column as a function of height. The higher the soil bed was, the higher the mean water saturation. The comparison of naphthalene distribution coefficients (K_d) in different flow conditions with the theoretical value from the Karickhoff law showed that in saturated conditions the obtained value was close to the theoretical one. In unsaturated conditions, the measured naphthalene K_d's were much lower than the theoretical value and correlated to the water saturation.     

Differential toxicity of TAR DNA‐binding protein 43 isoforms depends on their submitochondrial localization in neuronal cells

TAR DNA ‐binding protein 43 (TDP ‐43) is an RNA ‐binding protein and a major component of protein aggregates found in amyotrophic lateral sclerosis and several other neurodegenerative diseases. TDP ‐43 exists as a full‐length protein and as two shorter forms of 25 and 35 kD a. Full‐length mutant TDP ‐43s found in amyotrophic lateral sclerosis patients re‐localize from the nucleus to the cytoplasm and in part to mitochondria, where they exert a toxic role associated with neurodegeneration. However, induction of mitochondrial damage by TDP ‐43 fragments is yet to be clarified. In this work, we show that the mitochondrial 35 kD a truncated form of TDP ‐43 is restricted to the intermembrane space, while the full‐length forms also localize in the mitochondrial matrix in cultured neuronal NSC ‐34 cells. Interestingly, the full‐length forms clearly affect mitochondrial metabolism and morphology, possibly via their ability to inhibit the expression of Complex I subunits encoded by the mitochondrial‐transcribed mRNA s, while the 35 kD a form does not. In the light of the known differential contribution of the full‐length and short isoforms to generate toxic aggregates, we propose that the presence of full‐length TDP ‐43s in the matrix is a primary cause of mitochondrial damage. This in turn may cause oxidative stress inducing toxic oligomers formation, in which short TDP ‐43 forms play a major role.