Formation of Australasian tektites from gravity and magnetic indicators.

The parent impact crater of Australasian tektites has not been discovered so far, but a consensus has been accepted on its location in a wider area of Indochina. Recently, an alternative location has been suggested in the Badain Jaran Desert (BJD), Northwest China. Employing gravity and magnetic data derived from satellites, possible presence of an impact structure in BJD is investigated. The gravity parameters include the free air gravity disturbance, its vertical derivative component and total horizontal gradient (THG), strike alignment (SA), and Bouguer anomaly with its first vertical derivative and tilt angle. The magnetic parameters include the anomalous total magnetic field (TMF), its reduced to the pole transformation (RTP), the first vertical derivative of the TMF vertical component (Bzz), tilt angle (TA), and logistic total horizontal gradient (LTHG). Both the gravity and magnetic indicators support the presence of the impact structure. Gravity parameters display typical annular gravity highs circumscribing a gravity low. SA analysis reveals preferred parallel directions, implying the susceptibility of special zones to the impact shock waves, both within and beyond the rim. TMF reveals a large magnetic anomaly in the southern part of the proposed crater, and RTP displaces and restricts it further into the rim. Bzz weakens the long wavelength anomalies, amplifies the superficial ones, and separates them horizontally. TA and LTHG delineate the deep-seated and shallow magnetic signals related to the peak and border magnetization, respectively.

Comparison between the geological features of Venus and Earth based on gravity aspects.

We probe the gravitational properties of two neighboring planets, Earth and Venus. To justify a comparison between gravity models of the two planets, spherical harmonic series were considered up to a degree and order of 100. The topography and gravity aspects, including [Formula: see text] (vertical derivative of the vertical component of the gravity field), strike alignment (SA), comb factor (CF), and I2 invariant derived from the Marussi tensor, were calculated for the two planets at specifically selected zones that provided sufficient resolution. From Γzz we discovered that the N-NW edge of Lakshmi Planum does not show any subduction-like features. Its Γzz signature resembles passive continental margins on Earth, like those surrounding the Indian Peninsula. Moreover, according to SA and CF, the Pacific and Philippine-North American Contact Zone on Earth indicates significantly higher level of deformation due to convergent motion of the plates, whereas the deformation level on Venus is significantly smaller and local, when considering an equatorial rifting zone (ERZ) of Venus (between Atla-Beta Regios) as diverging boundaries. The strain mode on the East African Rift system is smaller in comparison with ERZ as its Venusian analog. The topography-I2 analysis suggests a complicated nature of the topographic rise on Beta Regio. We show that specific regions in this volcanic rise are in incipient stages of upward motion, with denser mantle material approaching the surface and thinning the crust, whereas some risen districts show molten and less dense underlying crustal materials. Other elevated districts appear to be due to mantle plumes and local volcanic activities with large density of underlying material.

Evaluation of epidermal growth factor receptor signaling effects in gastric cancer cell lines by detailed motility-focused phenotypic characterization linked with molecular analysis.

BACKGROUND: Gastric cancers frequently overexpress the epidermal growth factor receptor (EGFR), which has been implicated in pathological processes including tumor cell motility, invasion and metastasis. Targeting EGFR with the inhibitory antibody cetuximab may affect the motile and invasive behavior of tumor cells. Here, we evaluated the effects of EGFR signaling in gastric cancer cell lines to link the phenotypic behavior of the cells with their molecular characteristics. METHODS: Phenotypic effects were analyzed in four gastric cancer cell lines (AGS, Hs746T, LMSU and MKN1) by time-lapse microscopy and transwell invasion assay. Effects on EGFR signaling were detected using Western blot and proteome profiler analyses. A network was constructed linking EGFR signaling to the regulation of cellular motility. RESULTS: The analysis of the effects of treatment with epidermal growth factor (EGF) and cetuximab revealed that only one cell line (MKN1) was sensitive to cetuximab treatment in all phenotypic assays, whereas the other cell lines were either not responsive (Hs746T, LMSU) or sensitive only in certain tests (AGS). Cetuximab inhibited EGFR, MAPK and AKT activity and associated components of the EGFR signaling pathway to different degrees in cetuximab-sensitive MKN1 cells. In contrast, no such changes were observed in Hs746T cells. Thus, the different phenotypic behaviors of the cells were linked to their molecular response to treatment. Genetic alterations had different associations with response to treatment: while PIK3CA mutations and KRAS mutation or amplification were not obstructive, the MET mutation was associated with non-response. CONCLUSION: These results identify components of the EGFR signaling network as important regulators of the phenotypic and molecular response to cetuximab treatment.

Effects of ionizing radiation in combination with Erufosine on T98G glioblastoma xenograft tumours: a study in NMRI nu/nu mice.

BACKGROUND: Erufosine is a promising anticancer drug that increases the efficacy of radiotherapy in glioblastoma cell lines in vitro. Moreover, treatment of nude mice with repeated intraperitoneal or subcutaneous injections of Erufosine is well tolerated and yields drug concentrations in the brain tissue that are higher than the concentrations required for cytotoxic drug effects on glioblastoma cell lines in vitro. METHODS: In the present study we aimed to evaluate the effects of a combined treatment with radiotherapy and Erufosine on growth and local control of T98G subcutaneous glioblastoma xenograft-tumours in NMRI nu/nu mice. RESULTS: We show that repeated intraperitoneal injections of Erufosine resulted in a significant drug accumulation in T98G xenograft tumours on NMRI nu/nu mice. Moreover, short-term treatment with 5 intraperitoneal Erufosine injections caused a transient decrease in the growth of T98G tumours without radiotherapy. Furthermore, an increased radiation-induced growth delay of T98G xenograft tumours was observed when fractionated irradiation was combined with short-term Erufosine-treatment. However, no beneficial drug effects on fractionated radiotherapy in terms of local tumour control were observed. CONCLUSIONS: We conclude that short-term treatment with Erufosine is not sufficient to significantly improve local control in combination with radiotherapy in T98G glioblastoma xenograft tumours. Further studies are needed to evaluate efficacy of extended drug treatment schedules.

Differential DNA extraction of challenging simulated sexual-assault samples: a Swiss collaborative study.

In sexual-assault cases, autosomal DNA analysis of gynecological swabs is a challenge, as the presence of a large quantity of female material may prevent detection of the male DNA. A solution to this problem is differential DNA extraction, but there is no established best practice for this. We decided to test the efficacy of a number of different protocols on simulated casework samples. Four difficult samples were sent to the nine Swiss laboratories active in forensic genetics. In each laboratory, staff used their routine protocols to separate the epithelial-cell fraction, enriched with the non-sperm DNA, from the sperm fraction. DNA extracts were then sent to the organizing laboratory for analysis. Estimates of male:female DNA ratio without differential DNA extraction ranged from 1:38 to 1:339, depending on the semen used to prepare the samples. After differential DNA extraction, most of the ratios ranged from 1:12 to 9:1, allowing detection of the male DNA. Compared with direct DNA extraction, cell separation resulted in losses of 94-98% of the male DNA. As expected, more male DNA was generally present in the sperm than in the epithelial-cell fraction. However, for about 30% of the samples, the reverse trend was seen. The recovery of male and female DNA was highly variable, depending on the laboratory involved. An experimental design similar to the one used in this study may be of assistance for local protocol testing and improvement.

STR analysis of artificially degraded DNA-results of a collaborative European exercise.

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.