Platform-basin transect of a middle to late Jurassic large-scale carbonate platform system (Shotori mountains,Tabas area,east-central Iran)

Summary Following a phase of predominantly siliciclastic sedimentation in the Early and Middle Jurassic, a large-scale, low-latitude carbonate depositional system was established in the northern part of the Tabas Block, part of the central-east Iranian microplate, during the Callovian and persisted until the latest Oxfordian/Early Kimmeridgian. Running parallel to the present eastern block margin, a NNW/SSE-trending carbonate platform developed in an area characterized by reduced subsidence rates (Shotori Swell). The growth of this rimmed, flat-topped barrier platform strongly influenced the Upper Jurassic facies pattern and sedimentary history of the Tabas Block. The platform sediments, represented by the predominantly fine-grained carbonates of the Esfandiar Limestone Formation, pass eastward into slope to basin sediments of the Qal'eh Dokhtar Limestone Formation (platform-derived allochthonites, microbialites, and peri-platform muds). Towards the west, they interfinger with bedded limestones and marlstones (Kamar-e-Mehdi Formation), which were deposited in an extensive shelf lagoon. In a N−S direction, the Esfandiar Platform can be traced for about 170 km, in an E-W direction, the platform extended for at least 35–40 km. The width of the eastern slope of the platform is estimated at 10–15 km, the width of the western shelf lagoon varied considerably (>20–80 km). During the Late Callovian to Middle Oxfordian, the Esfandiar Platform flourished under arid climatic conditions and supplied the slope and basinal areas with large amounts of carbonates (suspended peri-platform muds and gravitational sediments). Export pulses of platform material, e.g. ooids and aggregate grains, into the slope and basinal system are interpreted as highstand shedding related to relative sealevel variations. The high-productivity phase was terminated in the Late Oxfordian when the eastern platform areas drowned and homogeneous deep water marls of the Upper Oxfordian to Kimmeridgian Korond Formation onlapped both the Qal'eh Dokhtar Limestone Formation and the drowned Esfandiar Limestone Formation. Tectonic instability, probably caused by faulting at the margins of the Tabas Block in connection with rotational movements of the east-central Iranian block assemblage, was responsible for the partial drowning of the eastern platform areas. In some areas, relicts of the platform persisted to produce shallow-water sediments into the Kimmeridgian.     

SlyD proteins from different species exhibit high prolyl isomerase and chaperone activities

SlyD is a putative folding helper protein from the Escherichia coli cytosol, which consists of an N-terminal prolyl isomerase domain of the FKBP type and a presumably unstructured C-terminal tail. We produced truncated versions without this tail (SlyD) for SlyD from E. coli, as well as for the SlyD orthologues from Yersinia pestis, Treponema pallidum, Pasteurella multocida, and Vibrio cholerae. They are monomeric in solution and unfold reversibly. All SlyD variants catalyze the proline-limited refolding of ribonuclease T1 with very high efficiencies, and the specificity constants (kcat/KM) are equal to approximately 10(6) M(-1) s(-1). These large values originate from the high affinities of the SlyD orthologues for unfolded RCM-T1, which are reflected in low KM values of approximately 1 microM. SlyD also exhibits pronounced chaperone properties. Permanently unfolded proteins bind with high affinity to SlyD and thus inhibit its prolyl isomerase activity. The unfolded protein chains do not need to contain proline residues to be recognized and bound by SlyD. The conservation of prolyl isomerase activity and chaperone properties within the SlyD family suggests that these proteins might act as true folding helpers in the bacterial cytosol. The SlyD proteins are also well suited for biotechnological applications. As fusion partners they facilitate the refolding and increase the solubility of aggregation-prone proteins such as the gp41 ectodomain fragment of HIV-1.     

Thin-film IrOx pH microelectrode for microfluidic-based microsystems

Microsensors are valuable tools to monitor cell metabolism in cell culture volumes. The present research describes the fabrication and characterization of on-chip thin-film iridium oxide pH microsensors with dimensions of 20 microm x 20 microm and 20 microm x 40 microm suitable to be incorporated into nl volumes. IrOx thin films were formed on platinum microelectrodes by electrochemical deposition in galvanostatic mode. Anodically grown iridium oxide films showed a near super-Nernstian response with a slope of -77.6+/-2 mV/pH at 22 degrees C, and linear responses within the pH range of 4-11. Freshly deposited electrodes showed response times as low as 6s. Long-term studies showed a baseline drift of 2-3 mV/month, which could easily be compensated by calibration. This work demonstrated for the first time the use of planar IrOx pH microelectrodes to measure the acidification rate of CHO and fibroblast cells in an on chip cell culture volume of 25 nl with microfluidic control.     

Phosphoinositide 3-Kinase C2beta regulates cytoskeletal organization and cell migration via Rac-dependent mechanisms

Receptor-linked class I phosphoinositide 3-kinases (PI3Ks) induce assembly of signal transduction complexes through protein-protein and protein-lipid interactions that mediate cell proliferation, survival, and migration. Although class II PI3Ks have the potential to make the same phosphoinositides as class I PI3Ks, their precise cellular role is currently unclear. In this report, we demonstrate that class II phosphoinositide 3-kinase C2beta (PI3KC2beta) associates with the Eps8/Abi1/Sos1 complex and is recruited to the EGF receptor as part of a multiprotein signaling complex also involving Shc and Grb2. Increased expression of PI3KC2beta stimulated Rac activity in A-431 epidermoid carcinoma cells, resulting in enhanced membrane ruffling and migration speed of the cells. Conversely, expression of dominant negative PI3KC2beta reduced Rac activity, membrane ruffling, and cell migration. Moreover, PI3KC2beta-overexpressing cells were protected from anoikis and displayed enhanced proliferation, independently of Rac function. Taken together, these findings suggest that PI3KC2beta regulates the migration and survival of human tumor cells by distinct molecular mechanisms.     

Effects of climate change and horticultural use on the spread of naturalized alien garden plants in Europe

Climate warming is supposed to enlarge the area climatically suitable to the naturalization of alien garden plants in temperate regions. However, the effects of a changing climate on the spread of naturalized ornamentals have not been evaluated by spatially and temporarily explicit range modelling at larger scales so far. Here, we assess how climate change and the frequency of cultivation interactively determine the spread of 15 ornamental plants over the 21st century in Europe. We coupled species distribution modelling with simulations of demography and dispersal to predict range dynamics of these species in annual steps across a 250 × 250 m raster of the study area. Models were run under four scenarios of climate warming and six levels of cultivation intensity. Cultivation frequency was implemented as size of the area used for planting a species. Although the area climatically suitable to the 15 species increases, on average, the area predicted to be occupied by them in 2090 shrinks under two of the three climate change scenarios. This contradiction obviously arises from dispersal limitations that were pronounced although we assumed that cultivation is spatially adapting to the changing climate. Cultivation frequency had a much stronger effect on species spread than climate change, and this effect was non‐linear. The area occupied increased sharply from low to moderate levels of cultivation intensity, but levelled off afterwards. Our simulations suggest that climate warming will not necessarily foster the spread of alien garden plants in Europe over the next decades. However, climatically suitable areas do increase and hence an invasion debt is likely accumulating. Restricting cultivation of species can be effective in preventing species spread, irrespective of how the climate develops. However, for being successful, they depend on high levels of compliance to keep propagule pressure at a low level.     

Influence of maternal age, gestational age and fetal gender on expression of immune mediators in amniotic fluid

ABSTRACT: BACKGROUND: Variations in cytokine and immune mediator expression patterns in amniotic fluid due to gestational age, maternal age and fetal gender were investigated. METHODS: Amniotic fluid samples were obtained from 192 women, 82 with a mid-trimester amniocentesis (median gestational age 17 weeks) and 110 with a caesarean section not in labor (median gestational age 39 weeks). Amniotic fluid was screened by commercial ELISAs for the TH1/TH2/TH17 cytokines and immune mediators IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-15, IL-17, TNF alpha, GROalpha, MIP1alpha, MIP1beta, histone, and IP10. Analysis was by Bonferroni correction for multiple comparisons. RESULTS: None of the 15 examined cytokines revealed any differences in expression patterns regarding fetal gender and age of the mothers. Significant differences were found in IL-4, IL-10, IL-12 TNF- alpha and MIP1-beta with respect to gestational age. CONCLUSIONS: Cytokines utilized as biomarkers in the diagnosis of intrauterine infections are not influenced in their expression pattern by fetal gender or maternal age, but may vary with respect to gestational age.     

Laboratory toxicity studies demonstrate no adverse effects of Cry1Ab and Cry3Bb1 to larvae of <Emphasis Type="Italic">Adalia bipunctata</Emphasis> (Coleoptera: Coccinellidae): the importance of study design

Scientific studies are frequently used to support policy decisions related to transgenic crops. Schmidt et al., Arch Environ Contam Toxicol 56:221–228 (2009) recently reported that Cry1Ab and Cry3Bb were toxic to larvae of Adalia bipunctata in direct feeding studies. This study was quoted, among others, to justify the ban of Bt maize (MON 810) in Germany. The study has subsequently been criticized because of methodological shortcomings that make it questionable whether the observed effects were due to direct toxicity of the two Cry proteins. We therefore conducted tritrophic studies assessing whether an effect of the two proteins on A. bipunctata could be detected under more realistic routes of exposure. Spider mites that had fed on Bt maize (events MON810 and MON88017) were used as carriers to expose young A. bipunctata larvae to high doses of biologically active Cry1Ab and Cry3Bb1. Ingestion of the two Cry proteins by A. bipunctata did not affect larval mortality, weight, or development time. These results were confirmed in a subsequent experiment in which A. bipunctata were directly fed with a sucrose solution containing dissolved purified proteins at concentrations approximately 10 times higher than measured in Bt maize-fed spider mites. Hence, our study does not provide any evidence that larvae of A. bipunctata are sensitive to Cry1Ab and Cry3Bb1 or that Bt maize expressing these proteins would adversely affect this predator. The results suggest that the apparent harmful effects of Cry1Ab and Cry3Bb1 reported by Schmidt et al., Arch Environ Contam Toxicol 56:221–228 (2009) were artifacts of poor study design and procedures. It is thus important that decision-makers evaluate the quality of individual scientific studies and do not view all as equally rigorous and relevant.