Landslide reconstruction and monitoring in Brienz based on dendrogeomorphology

Mass movements such as landslides and rockfalls are driving forces in mountainous regions and pose a major threat to its people and infrastructure. The alpine village of Brienz in Switzerland is threatened by both an ongoing landslide and the danger of a major rockslide. Regular rockfalls also threaten the village. The entire area is therefore strictly monitored. The additional creation of a drainage system is intended to slow down or stop the landslide by reducing the water pressure in the mountain. While these approaches enable authorities to gain knowledge about the present state of the landscape and to plan on the future course of action, they do not give any information about the past development of the landslide. Dendrogeomorphology offers the possibility to reconstruct the time before the start of monitoring, by analysing the annual formed tree rings. In this Master’s thesis different methods are applied to gather information about past movement in a subarea of the Brienzer landslide. In addition, the approaches used, and the obtained results are compared to each other to assess their reliability. Furthermore, location and visual inclination of individual trees are discussed as indicator of the extent of disturbance to be expected. First, a visual inspection of all chronologies was used to get a basic impression of possible activity phases. Second, the chronologies of each tree were examined individually, and years of disturbance were noted manually. Third, using the eccentricity index with different thresholds (based on the average, median, and artificially set), the years of disturbance of each tree were also calculated. Fourth, an attempt was made to confirm identified event years by making thin sections and search for reaction wood. However, this was not successful, probably due to a too small sample size or errors in setting the cores. The results of tree-ring analyses showed that as far back as the tree rings went (~1820), the area was in motion and still is today. The sites experienced periods of activity, that were separated by resting phases in 1850-1875, 1945-1955, and 1975-1985. The comparison of the different methods has also shown that it is important to interpret the results with caution, as manual assessment and eccentricity index calculations sometimes identified different activity phases. One advantage of the eccentricity approach is that it is sensitive enough to notice the landslide increase, while the manual approach failed to do so. But this sensitivity is also a disadvantage. If the arbitrary threshold is set low, "false" events (noise) are detected, if it is set too high, events are ignored. The manual approach on the other hand is not dependent on a general threshold but on the estimation of each individual event by itself. Lastly, high numbers of disturbances in individual trees could often be associated with cracks in the soil in close proximity. On the other hand, both inclined trees and vertical trees show equally often high numbers of disturbances. Consequently, based on the results of this work, location appears to be a better disturbance indicator than visible damage on the tree. Tree ring analyses not only allow to record the history of a landslide dating back for several centuries, which is a great advantage compared to other monitoring methods, but also to monitor dynamics within a sliding area based on analysis of individual trees and their locations. Some predictions for the future might also be possible for example an acceleration of the slide if the tree ring analysis indicates an increase in event number per year. For all these reasons, the inclusion of dendrogeomorphology in the comprehensive monitoring of landslides should be considered

Effects of environmental estrogens on reproductive biology of the fathead minnow

Since the early 1990s, environmental estrogens have been recognized as an important environmental threat. Wastewater of 10 aerated lagoon treatment facilities in Iowa was evaluated for estrogenic activity using a short-term caged fathead minnow exposure and a plasma vitellogenin (Vtg) assay. Plasma Vtg results indicated that wastewater entering the three-lagoon systems was estrogenic to male fish, but with serial passage through the lagoons, the estrogenic activity decreased to a level that was not sufficient to induce vitellogenesis. Wastewater retention time in the lagoons may have been a key treatment factor.;Feral fathead minnows captured at aerated lagoon wastewater treatment facilities (WWTFs) exhibited plasma Vtg trends similar to those of the caged fish. Incidence of ovotestes in feral fish was low (1 of 65; 1.5%) and similar to that of fathead minnows captured at a reference site (national wildlife refuge). The results of both the caged and feral fish studies indicate that effluents from aerated lagoon WWTFs are low in estrogenic activity, but that raw wastewater was estrogenic to fish. Thus, the potential exists for release of estrogenic effluents from these systems if the treatment is not complete.;The plasma Vtg response of male fish exposed to estradiol for 10 days was dose-dependent and predictable (R2 = 0.988) through the range of estradiol exposure concentrations tested. The lowest observed effects concentration (LOEC) for induction of plasma Vtg was 50 ng/L. The dose-response curve from this study may be used in conjunction with exposure of male fish to surface water or wastewater to estimate the magnitude of the estrogenic potency of the water in terms of estradiol equivalents. ;Atrazine did not cause overt reproductive toxicity to adult fathead minnows in a short-term reproduction assay. However, decreasing trends in relative testis weight, testis maturity, and percent embryo fertilization suggest that further investigation is warranted. Nearly all endpoints concerning fish exposed to estradiol (positive control) were significantly different from atrazine-exposed fish and control fish. The results suggest that atrazine did not have strong estrogenic effects and did not cause endocrine system disruption in fathead minnows at environmentally relevant concentrations

Functional analysis and knock‐down phenotype of BCL9 and BCL9L in cancer cell lines

Therapy‐resistant tumor cells often display EMT and stem cell‐like traits. The canonical Wnt pathway has been associated with these phenotypes in many cancer types. Our group has shown in mice that two proteins of this pathway, Bcl9 and Bcl9l, participate in controlling Wnt-mediated stem cell traits. We hypothesized that inhibition of BCL9/BCL9L could be a potential strategy to revert cells with stem‐cell properties to a differentiated epithelial phenotype, and thus also re‐establish their sensitivity to chemotherapy. Preliminary experiments in a human colon cancer cell line showed that BCL9L single knock‐down (KD) surprisingly already completely abrogated expression of selected Wnt target genes, despite the presence of the second paralog BCL9, which was even up‐regulated upon loss of BCL9L. This observation raised the question whether the remaining BCL9 protein might be dysfunctional, or whether BCL9 and BCL9L are, against our expectation, not functionally redundant. Thus, we characterized Bcl9 expression at transcriptional and genomic level by reverse transcription and DNA sequencing. By sequencing, we identified three different BCL9 mRNA species in SW480 cells (wild‐type (WT) and two isoforms carrying short deletions), which we also confirmed to be present in other carcinoma cell lines. No abnormalities were found on the genomic level. We then assessed Bcl9 and Bcl9l expression at protein level using standard Western blotting. In the different cell lines the proteins showed distinct molecular weights, which may correspond to different posttranslational modifications that could be associated with different functions. To generally explore BCL9 function, we silenced the gene using lentivirus vector‐based expression of shRNAs. Further analysis of the observed Bcl9 KD on a broad panel of Wnt target genes and comparison with the Bcl9l KD phenotype will help elucidating Bcl9 and Bcl9L functio

Visual acuity of dentists under simulated clinical conditions

Objectives: This study examined the near visual acuity of dentists in relation to age and magnification under simulated clinical conditions. Materials and methods: Miniaturized visual tests were performed in posterior teeth of a dental phantom head in a simulated clinical setting (dental chair, operating lamp, dental mirror). The visual acuity of 40 dentists was measured under the following conditions: (1) natural visual acuity, distance of 300mm; (2) natural visual acuity, free choice of distance; (3) Galilean loupes, magnification of ×2.5; (4) Keplerian loupes, ×4.3; (5) operating microscope, ×4, integrated light; (6) operating microscope, ×6.4, integrated light. Results: The visual acuity varied widely between individuals and was significantly lower in the group ≥40years of age (p < 0.001). Significant differences were found between all tested conditions (p < 0.01). Furthermore, a correlation between visual acuity and age was found for all conditions. The performance with the microscope was better than with loupes even with comparable magnification factors. Some dentists had a better visual acuity without optical aids than others with Galilean loupes. Conclusions: Near visual acuity under simulated clinical conditions varies widely between individuals and decreases throughout life. Visual deficiencies can be compensated for with optical aids. Clinical relevance: Newly developed miniaturized vision tests have allowed, in a clinically relevant way, to evaluate the influence of magnification and age on the near visual acuity of dentist

Trend in active transportation to school among Swiss school children and its associated factors: three cross-sectional surveys 1994, 2000 and 2005

BACKGROUND: Giving the rising trend in childhood obesity in many countries including Switzerland, strategies to increase physical activity such as promoting active school travel are important. Yet, little is known about time trends of active commuting in Swiss schoolchildren and factors associated with changes in walking and biking to school. METHODS: Between 1994 and 2005, information about mobility behaviour of children aged 6-14 years was collected within three Swiss population based national travel behaviour surveys. Mode of transport to school was reported for 4244 children. Weighted multivariate logistic regression analyses were used to assess active school travel time trends and their influencing factors. RESULTS: More than 70% of Swiss children walked or biked to school. Nevertheless, the proportion of children biking to school decreased (p = 0.05, linear trend), predominately in urban areas, and motorized transportation increased since 1994 (p = 0.02). Distance to school did not change significantly over time but availability of bikes decreased (p < 0.001) and number of cars per household increased (p < 0.001). The association between survey year and bike use was significantly modified by living in an urban area (OR (95%CI): 1.0, 0.63 (0.44-0.90), 0.71 (0.49-1.03), respectively for 1994, 2000 and 2005) and by distance to school (OR (95%CI): 1.0, 0.65 (0.40-1.05), 0.50 (0.23-0.79) for the same years and for children who lived more than a mile away from school). CONCLUSIONS: Programs to encourage safe biking and to limit car use as mode of transport to school are warranted to stop this tren

Anesthetic Activity of Acetylated MS-222 in Tilapia (Oreochromis Niloticus)

A group of 8 tilapia (Oreochromis niloticus) were anesthetized once per week for six consecutive weeks, using tricaine methanesulfonate (MS-222) in the water. Time for the fish to reach anesthesia decreased significantly over the first four weeks, and then plateaued at about 27% below the first anesthetic exposure. These results suggest induction of the liver enzymes that convert MS-222 into metabolites, one or more of which have higher anesthetic activity than the parent compound. Major metabolites of MS-222 have been identified as part of regulatory studies evaluating residue persistence in food fishes. One of these metabolites, N-acetyl-3-aminobenzoic acid ethyl ester, which is acetylated MS-222, was selected for testing of anesthetic activity in tilapia. This report shows results of the testing, and speculates as to the potential utility of the acetylated metabolite of MS-222 as an alternate anesthetic agent in fish

Upper Thermal Tolerances of Early Life Stages of Freshwater Mussels

Freshwater mussels (order Unioniformes) fulfill an essential role in benthic aquatic communities, but also are among the most sensitive and rapidly declining faunal groups in North America. Rising water temperatures, caused by global climate change, industrial discharges, drought, or land development, could further challenge imperiled unionid communities. The aim of our study was to determine the upper thermal tolerances of the larval (glochidia) and juvenile life stages of freshwater mussels. Glochidia of 8 species of mussels were tested: Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata, Lasmigona complanata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis. Seven of these species also were tested as juveniles. Survival trends were monitored while mussels held at 3 acclimation temperatures (17, 22, and 27°C) were exposed to a range of common and extreme water temperatures (20–42°C) in standard acute laboratory tests. The average median lethal temperature (LT50) among species in 24-h tests with glochidia was 31.6°C and ranged from 21.4 to 42.7°C. The mean LT50 in 96-h juvenile tests was 34.7°C and ranged from 32.5 to 38.8°C. Based on comparisons of LT50s, thermal tolerances differed among species for glochidia, but not for juveniles. Acclimation temperature did not affect thermal tolerance for either life stage. Our results indicate that freshwater mussels already might be living close to their upper thermal tolerances in some systems and, thus, might be at risk from rising environmental temperatures

Occurrence of Ovotestes and Plasma Vitellogenin in Feral Male Fathead Minnows from Lagoons of Municipal Wastewater Treatment Facilities in Central Iowa

Since the early 1990s, endocrine disrupting compounds have been recognized as an important environmental threat. Male fish exposed to effluent from large, metropolitan municipal wastewater treatment facilities (WWTFs) have developed reproductive abnormalities including ovotestes and elevated levels of plasma vitellogenin (Vtg), a plasma protein typically produced by egg-laying females. In the summer of 2000, gonads and plasma Vtg concentrations were examined in feral male fathead minnows (Pimephales promelas) collected from lagoons of 11 small, rural municipal WWTFs and a reference site (a national wildlife refuge) in Iowa. Fathead minnows were captured in traps from five of the 33 lagoons (three per WWTF) sampled. No other fish species were captured. The five lagoons with fathead minnows were found at three WWTFs. Gonad histology indicated only one of 65 (1.5%) male fish living in the lagoons had ovotestes, which was similar to the incidence at a reference site (1 of 29, 3.4%). Plasma Vtg, however, was substantially higher in fish from four of the five lagoons than in fish from the reference site, indicating that fish in lagoons were exposed to estrogenic substances