Quantitative Risk Assessment and Application of Landslide Disaster in Chongqing

Chongqing is located in southwestern China, and geological disasters occur frequently. The amount of potential landslide disasters is far greater than the number of landslides that can be managed by government funds, so the risk assessment for potential landslide disasters is critical. In practical applications, risk assessment methods based on landslide stability and loss are restricted by various factors. These methods can be simplified to semi-empirical assessment methods, which are influenced by the discrimination factors near the limit values of the determined conditions, possibly leading to sudden changes in the evaluation results and distort the conclusions. To solve this problem, we propose a full quantitative risk assessment method according to the probability of landslide damage. The mathematical probability model is used to quantitatively describe the risk assessment impacting factors, weaken the boundary influence, and improve the accuracy of landslide risk assessment. Correspondingly, the software is developed to conduct quantitative risk assessment on six landslides in Feng jie County, Chongqing, which verifies the accuracy and reliability of the full quantitative risk assessment method, and provides an important reference for judging urban landslide geological disasters.

Addressing the Trajectory of Cultural and Gender Discrimination among Marine Women Officers

Seafaring is openly challenging working circumstances for females. For the last twenty-two years, females in western countries have been interested in joining the fleet, but as the captaincy roles aboard, their numbers are minimal compared to other jobs. In every working place, females always face many unusual problems, which are more in seafaring. The manuscript derives the discrimination factors of marine women officers (MWOs) onboard due to cultural (or racial) or being a woman using the experiences of 149 women officers from 18 different countries. Two experiences such as onboard discrimination due to cultural reasons (DDCR) and not being promoted in the company as being women (NPCW) for MWOs are considered the responses in the present study. It was found out that mean DDCR is positively associated with age (P=0.0313), nationality (P=0.0047), current position onboard (P=0.1051), while it is negatively associated with cohabitation (P=0.0137) and type of contract (P=0.0719). Variance of DDCR is negatively associated with male companions' support (P=0.1432). Also, mean NPCW is negatively associated with her male companions' support (P<0.0001), while its variance is positively associated with professional qualification (P=0.1317). It was found out herein that MWOs from other nations (except Spanish) at older ages, second class officers, staying single with temporary contracts are highly discriminated against based on cultural (or racial) reasons. In addition, MWOs with higher male companions' support are very rarely promoted in the company.

Seasonal and Interspecific Variation in Frugivory by a Mixed Resident-Migrant Overwintering Songbird Community

Many temperate passerine bird species switch from diets of mostly invertebrates in the spring and summer to diets that include fruit and seeds in the fall and winter. However, relatively few studies have quantified diet composition or the extent of seasonal shifts during the non-breeding period, particularly among species and across communities with both residents and migrants. We measured carbon and nitrogen stable isotope values in food items (fruits, C3 and C4 seeds, and insects from various trophic levels and plant communities) and in multiple tissues (feathers and plasma/whole blood) from 11 species of songbirds wintering in the southeastern U.S. We combined these diet and tissue values with empirically derived discrimination factors and used concentration-dependent mixing models to quantify seasonal diet shifts. We also validated mixing model results with data from fecal samples. Diets in this bird community, as delineated N and C isotopic space, diverged in the fall and winter relative to the summer as consumption of fruits and seeds increased. Across this songbird community, estimated contributions of fruit to plasma/whole blood increased from 16.2 ± 7.5% in the fall (mean ± SD; range: 4–26%) to 21.7 ± 10.3% (range: 9–37%) in the winter, while contributions of seeds increased from 29.4 ± 2.6% (range: 28–32%) in the fall to 36.6 ± 4.8% (range: 32–42%) in the winter. Fecal data showed qualitatively similar trends to mixing models, but consistently estimated higher contributions of fruit. Our work indicates that fruits and seeds constitute substantial sources of sustenance for non-breeding songbirds, there is considerable separation of resource use among species in the fall and winter, and fecal estimates of contributions to songbird tissues should be interpreted cautiously.

Zinc isotopes from archaeological bones provide reliable tropic level information for marine mammals

In marine ecology, dietary interpretations of faunal assemblages often rely on nitrogen isotopes as the main or only applicable trophic level tracer. We investigate the geographic variability and trophic level isotopic discrimination factors of bone zinc 66Zn/64Zn ratios (δ66Zn value) and compared it to collagen nitrogen and carbon stable isotope (δ15N and δ13C) values. Focusing on ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from multiple Arctic archaeological sites, we investigate trophic interactions between predator and prey over a broad geographic area. All proxies show variability among sites, influenced by the regional food web baselines. However, δ66Zn shows a significantly higher homogeneity among different sites. We observe a clear trophic spacing for δ15N and δ66Zn values in all locations, yet δ66Zn analysis allows a more direct dietary comparability between spatially and temporally distinct locations than what is possible by δ15N and δ13C analysis alone. When combining all three proxies, a more detailed and refined dietary analysis is possible.

Effect of temperature on 13C and 15N incorporation rates and discrimination factors in two North American fishes

The biological parameters needed to interpret isotopic field data on food webs—namely isotopic incorporation and discrimination (Δ13C and Δ15N)—are unknown for many animals. We investigated the effects of temperature on carbon and nitrogen incorporation and discrimination in Creek Chub (Semotilus atromaculatus) and White Sucker (Catostomus commersonii) by rearing wild-caught fish on a distinct diet at 12 °C and 20 °C for 160 days. Mass specific growth rates were higher at 20 °C. Isotopic turnover was mainly influenced by metabolic processes as opposed to growth in both species, especially White Sucker. Cold-reared fish had slower rates of isotopic incorporation and higher isotopic residence times than warm-reared fish. Discrimination factors were generally smaller for Δ15N (range = 1.9 to 3.0) and larger for Δ13C (range = 1.4 to 2.3) than values reported for other fishes. Variable temperature effects on discrimination suggests unmeasured effects of the experimental diet which will require additional experimentation to tease apart. These results support the hypothesis that metabolic rates are correlated with isotopic incorporation rates in animals dependent on environmental temperature.