RAIN EVENTS INFLUENCE SHORT-TERM FEEDING PREFERENCES IN THE SNAIL CEPAEA NEMORALIS

Terrestrial gastropods are both herbivores and detritivores, but the ratio between these two modes of feeding can be highly variable over time. While previous studies have examined long-term seasonal patterns in the consumption of fresh material, mechanisms explaining short-term variation in dietary preferences have not been explored. We used faecal analysis to determine how short-term variation in weather affects the ratio of herbivory to detritivory in the land snail Cepaea nemoralis. Averaged across sampling dates, c. 9% of the faeces were composed of fresh plant material, with the remainder consisting of plant litter and soil. Temperature, relative humidity and soil moisture did not affect the proportional consumption of fresh material; however, snails consumed more soil with increasing temperature. If there had not been a recent precipitation event, the mean proportion of fresh material in the faeces more than doubled on average; however, this increase only occurred in areas of low herbaceous cover. Our results suggest that an increased proportion of snails consume fresh material during dry periods to compensate for water losses. Moreover, our study highlights that studies of dietary composition in the field need to account for short-term variation in feeding
preferences caused by weather.

Modelling and visualisation of material flow in friction stir spot welding

Abstract The material flow in friction stir spot welding of aluminium to both aluminium and steel has been investigated, using pinless tools in a lap joint geometry. The flow behaviour was revealed experimentally using dissimilar Al alloys of similar strength. The effect on the material flow of tool surface features, welding conditions (rotation speed, plunge depth, dwell time), and the surface state of the steel sheet (un-coated or galvanized) have been systematically studied. A novel kinematic flow model is presented, which successfully predicts the observed layering of the dissimilar Al alloys under a range of conditions. The model and the experimental observations provide a consistent interpretation of the stick-slip conditions at the tool-workpiece interface, addressing an elusive and long-standing issue in the modelling of heat generation in friction stir processing.

Urinary thrombomodulin levels were significantly higher following occupational exposure to chemicals, in the presence of dipstick protein, but not in the presence of dipstick blood

Currently, there are no biomarkers which can identify patients with an increased risk of developing urothelial cancer as a result of occupational chemical exposure. The aim of this study was to evaluate the relationships between final diagnosis and 22 biomarkers measured in urine, serum and plasma collected from 156 hematuric patients. Fourteen of the 80 patients (17.5%) with urothelial cancer and 13/76 (17.1%) of the controls were deemed to have a history of chemical exposure. We applied Fisher's exact tests to explore associations between chemical exposure and final diagnosis, and tumor stage and grade, where applicable; ANOVA and t-test to compare age across patients with and without chemical exposure; and Zelen's exact test to evaluate relationships across final diagnosis, chemical exposure and smoking. Following pre-selection of biomarkers using Lasso, we identified biomarkers with differential levels across patients with and without chemical exposure using Welch's t-test. Using a one-sided t-test and considering multiple testing using FDR, we observed that TM levels in urine were significantly higher in samples from patients with a history of chemical exposure regardless of their diagnosis as control or urothelial cancer (one-sided t-test, p_UC = 0.014 and p_CTL = 0.043); in the presence of dipstick protein and when urinary pH levels ≤ 6 (p = 0.003), but not in the presence of dipstick blood (p = 0.115). Urothelial cancer patients with a history of chemical exposure were significantly younger (64.1 years) than those without chemical exposure (70.2 years) (one-sided t-test p-value = 0.012); and their tumors were higher grade (Fisher's exact test; p = 0.008). There was a strong association between a history of chemical exposure and smoking in urothelial cancer patients (Zelen's exact test; p = 0.025). Elevated urinary thrombomodulin levels could have the potential to identify chemical exposure in hematuric patients at high risk of developing urothelial cancer.