Assessment of groundwater quality of the Tatlicay aquifer and relation to the adjacent evaporitic formations (Cankiri, Turkey).

One of the most important hydrogeologic problems in and adjacent areas of evaporitic formations is severe quality degradation of groundwaters. These kinds of groundwaters contain high content of dissolved solids and generally have some limitations for use. Tatlicay basin (north-central Turkey) is an example to effects of the evaporites on groundwater quality in the adjacent alluvium aquifer. Gypsum and anhydrites in the two evaporite formations (Bayindir and Bozkir) effect of the groundwater quality in the alluvium adversely, by dissolution of the evaporites by surface drainage and infiltration into the alluvium aquifer (widespread effect) and by infiltration of low quality gypsum springs (local effect) into the aquifer. Evaporitic formations significantly increased EC, TDS, Ca and SO(4) parameters in the alluvium aquifer in the central and downstream regions. EC has increased roughly from 500-800 to 1,700-2,000 µS/cm, Ca has roughly increased from 3-4 to 10 meq/l, SO(4) has increased 0.5-1 to 11-12 meq/l. Consequently, three clusters were distinguished in the basin; (1) nonevaporitic waters in low TDS, Na, Ca, Mg, Cl and SO(4), (2) diluted waters in high TDS and relatively high Cl, moderate-relatively high Na, Ca, Mg, SO(4), (3) gypsum springs in highest TDS, Ca, SO(4), but moderate Mg and low Na, Cl.

Secretion of Hedgehog-related peptides and WNT during Caenorhabditis elegans development.

There is growing awareness that endocytic trafficking plays a critical role in cell-cell communication during animal development. We are beginning to understand how endocytosis can initiate, modulate or terminate signaling. In contrast, our knowledge of the mechanisms involved in secreting signaling peptides remains more limited, particularly when it comes to secretion at the apical surface in epithelial cells. In this study, we review the mechanisms that control secretion in Caenorhabditis elegans, focusing on the role of Patched family members and the V0 complex of the vacuolar-adenosine triphosphatase (V-ATPase) in secreting Hedgehog-related peptides and of MIG-14/Wls and the retromer complex in secreting EGL-20/WNT.

Response of groundwater to climate variation: fluctuations of groundwater level and well yields in the Halacli aquifer (Cankiri, Turkey).

The aim of this study was to investigate the response of groundwater level and well yields in the Halacli aquifer to climate variations in Central Anatolia, Turkey. The Halacli aquifer is a typical aquifer due to its vulnerability to the climate variations. The aquifer is shallow and its recharge area is small. The waters from rains and snow melts can rapidly infiltrate down to the groundwater body because the vadose zone is thin and formed from coarse material. Therefore, the groundwater system responds to the short-term recharges by raising its level. Although any exploitation did not occur, the groundwater levels have declined from 1989 to 1997. However, the groundwater levels began rising when the exploitation started in the summer of 1998. After the year 2000, although the amount and duration of yearly exploitation was constant, fluctuations of water level continued. Fluctuation of groundwater levels and well yields bewilders the water users and imperils the sustainable water management in the study area and also in arid and semi-arid regions of Turkey. In order to overcome this problem, behavior of groundwater level and discharges of the wells must be recorded and the water users must be informed about the current conditions and the possible trend in the future of the system.

Assessment of irrigation water quality by a Geographic Information System-Multicriteria Decision Analysis-based model: A case study from Ankara, Turkey.

In this study, the irrigation water quality of Eryaman region in Ankara (Turkey) has been investigated using a Geographic Information System-Multicriteria Decision Analysis (GIS-MCDA)-based model. Two different irrigation water quality indices (IWQI-A and IWQI-B) based on Analytic Hierarchy Process (AHP) and Data Envelopment Analysis (DEA) have been developed to provide a single suitability score for all criteria of irrigation water quality. The irrigation water quality indices were composed of 3 main criteria and 11 sub-criteria. Based on irrigation water quality indices, four suitability classes have been identified as (a) excellent, (b) good, (c) permissible, and (d) unsuitable. Irrigation water quality maps were created by using kriging method and the water quality index scores. The temporal variation of irrigation water quality was evaluated using the models created for July 2007, 2010, and 2015 years. The most suitable areas for irrigation water are concentrated in the eastern and western parts of the region where the IWQI-B scores were >0.85. In recent years, the deterioration in irrigation water quality has increased in the southern parts of the basin. This research has demonstrated that the indices created by using DEA and AHP methods are reliable indicators to assess irrigation water quality. PRACTITIONER POINTS: Water quality indices can be used to depict the overall water quality status in water management planning. To avoid problems when modeling groundwater quality, the factors that have the most effect on water quality should be selected. Analytic Hierarchy Process and Data Envelopment Analysis techniques are efficient and reliable methods to determine water quality.

RAL-1 controls multivesicular body biogenesis and exosome secretion.

Exosomes are secreted vesicles arising from the fusion of multivesicular bodies (MVBs) with the plasma membrane. Despite their importance in various processes, the molecular mechanisms controlling their formation and release remain unclear. Using nematodes and mammary tumor cells, we show that Ral GTPases are involved in exosome biogenesis. In Caenorhabditis elegans, RAL-1 localizes at the surface of secretory MVBs. A quantitative electron microscopy analysis of RAL-1-deficient animals revealed that RAL-1 is involved in both MVB formation and their fusion with the plasma membrane. These functions do not involve the exocyst complex, a common Ral guanosine triphosphatase (GTPase) effector. Furthermore, we show that the target membrane SNARE protein SYX-5 colocalizes with a constitutively active form of RAL-1 at the plasma membrane, and MVBs accumulate under the plasma membrane when SYX-5 is absent. In mammals, RalA and RalB are both required for the secretion of exosome-like vesicles in cultured cells. Therefore, Ral GTPases represent new regulators of MVB formation and exosome release.