Provide early desertification warning system based on climate and groundwater criteria (Study area: Aq Qala and Gomishan counties)

In this research, the desertification process is evaluated using 3 climate indicators and 4 groundwater indices in the form of a modal model in a period of 20 years (2008-2017) in the west of Golestan province with the aim of providing a desertification warning system.Then, by determining the threshold limits for the influential indicators in the desertification process of the region, the desertification early warning system was presented based on four indicators. The results of the index change the trend showed that drought indices, total soluble materials, electrical conductivity, and groundwater depth had the greatest impact on desertification in the region, respectively. Desertification warning maps have shown an increase in drought indicators, total solubility, and electrical conductivity from west to east. Also, the groundwater depth index in the central areas has the highest warning range. According to the results obtained from monitoring desertification indicators, the electrical conductivity index during the years 1999, 2001, 2004 to 2006 and 2009, the Total dissolved solids index in the years 1998, 1999, 2001, 2004, 2006 and 2007, Groundwater depth index of 2001, 2002, 2006, 2008 and 2014, Finally, the drought index is in the warning range during the years 1999 to 2003, 2006 to 2008, 2011, 2014, 2015 and 2016. Irrigated lands, drylands and wetlands in the East region affected by desertification warning have been that on this basis is suggested for better management of the land, the threshold defined in this study as the basis for the work to be placed

Assessing unmodified 70-mer oligonucleotide probe performance on glass-slide microarrays

BACKGROUND: Long oligonucleotide microarrays are potentially more cost- and management-efficient than cDNA microarrays, but there is little information on the relative performance of these two probe types. The feasibility of using unmodified oligonucleotides to accurately measure changes in gene expression is also unclear. RESULTS: Unmodified sense and antisense 70-mer oligonucleotides representing 75 known rat genes and 10 Arabidopsis control genes were synthesized, printed and UV cross-linked onto glass slides. Printed alongside were PCR-amplified cDNA clones corresponding to the same genes, enabling us to compare the two probe types simultaneously. Our study was designed to evaluate the mRNA profiles of heart and brain, along with Arabidopsis cRNA spiked into the labeling reaction at different relative copy number. Hybridization signal intensity did not correlate with probe type but depended on the extent of UV irradiation. To determine the effect of oligonucleotide concentration on hybridization signal, 70-mers were serially diluted. No significant change in gene-expression ratio or loss in hybridization signal was detected, even at the lowest concentration tested (6.25 μm). In many instances, signal intensity actually increased with decreasing concentration. The correlation coefficient between oligonucleotide and cDNA probes for identifying differentially expressed genes was 0.80, with an average coefficient of variation of 13.4%. Approximately 8% of the genes showed discordant results with the two probe types, and in each case the cDNA results were more accurate, as determined by real-time PCR. CONCLUSIONS: Microarrays of UV cross-linked unmodified oligonucleotides provided sensitive and specific measurements for most of the genes studied

Homodimerization and heterodimerization of S1P/EDG sphingosine-1-phosphate receptors

Sphingosine-1-phosphate (S1P) binds to and signals through several members of a group of G protein-coupled receptors (GPCRs) known as the S1P/EDG family. Several of these receptors are coexpressed in various cell types and recent reports have shown that biological effects of S1P often require more than one S1P receptor subtype. Recent evidence indicates that many GPCRs exist as dimers. We show that S1P receptors form both homodimers as well as heterodimers with other members of the S1P subfamily of receptors. We also discuss the role that GPCR dimers play in receptor function and what this may mean for S1P signaling. © 2002 Elsevier Science B.V. All rights reserved

Identification of H-Ras, RhoA, Rac1 and Cdc42 responsive genes

The superfamily of small GTP-binding proteins has expanded dramatically in recent years. The Ras family has long been associated with signaling pathways contributing to normal and aberrant cell growth, while Rho-related protein function is to integrate extracellular signals with specific targets regulating cell morphology, cell aggregation, tissue polarity, cell motility and cytokinesis. Recent findings suggest that certain Rho proteins, including RhoA, Racl and Cdc42, can also play a role in signal transduction to the nucleus and cell growth control. However, the nature of the genes regulated by Ras and Rho GTPases, as well as their contribution to their numerous biological effects is still largely unknown. To approach these questions, we investigated the global gene expression pattern induced by activated forms of H-Ras, RhoA, Rac1 and Cdc42 using cDNA microarrays comprising 19 117 unique elements. Using this approach, we identified 1184 genes that were up- or downregulated by at least twofold. Hierarchical cluster analysis revealed the existence of patterns of gene regulation both unique and common to H-Ras V12, RhoA QL, Rac1 QL and Cdc42 QL activation. For example, H-Ras V12 upregulated osteopontin and Akt 1, and H-Ras and RhoA stimulated cyclin G1, cyclin-dependent kinase 8, cyclin A2 and HMGI-C, while Rac1 QL and Cdc42 QL upregulated extracellular matrix and cell adhesion proteins such as alpha-actinin 4, procollagen type I and V and neuropilin. Furthermore, H-Ras V12 downregulated by \u3e eightfold 52 genes compared to only three genes by RhoA QL, Rac1 QL and Cdc42 QL. These results provide key information to begin unraveling the complexity of the molecular mechanisms underlying the transforming potential of Ras and Rho proteins, as well as the numerous morphological and cell cycle effects induced by these small GTPases

Identification of H-Ras, RhoA, Rac1 and Cdc42 responsive genes

The superfamily of small GTP-binding proteins has expanded dramatically in recent years. The Ras family has long been associated with signaling pathways contributing to normal and aberrant cell growth, while Rho-related protein function is to integrate extracellular signals with specific targets regulating cell morphology, cell aggregation, tissue polarity, cell motility and cytokinesis. Recent findings suggest that certain Rho proteins, including RhoA, Racl and Cdc42, can also play a role in signal transduction to the nucleus and cell growth control. However, the nature of the genes regulated by Ras and Rho GTPases, as well as their contribution to their numerous biological effects is still largely unknown. To approach these questions, we investigated the global gene expression pattern induced by activated forms of H-Ras, RhoA, Rac1 and Cdc42 using cDNA microarrays comprising 19 117 unique elements. Using this approach, we identified 1184 genes that were up- or downregulated by at least twofold. Hierarchical cluster analysis revealed the existence of patterns of gene regulation both unique and common to H-Ras V12, RhoA QL, Rac1 QL and Cdc42 QL activation. For example, H-Ras V12 upregulated osteopontin and Akt 1, and H-Ras and RhoA stimulated cyclin G1, cyclin-dependent kinase 8, cyclin A2 and HMGI-C, while Rac1 QL and Cdc42 QL upregulated extracellular matrix and cell adhesion proteins such as alpha-actinin 4, procollagen type I and V and neuropilin. Furthermore, H-Ras V12 downregulated by \u3e eightfold 52 genes compared to only three genes by RhoA QL, Rac1 QL and Cdc42 QL. These results provide key information to begin unraveling the complexity of the molecular mechanisms underlying the transforming potential of Ras and Rho proteins, as well as the numerous morphological and cell cycle effects induced by these small GTPases