The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating

Ice streams in the Pine Island-Thwaites region of West Antarctica currently dominate contributions to sea level rise from the Antarctic ice sheet. Predictions of future ice-mass loss from this area rely on physical models that are validated with geological constraints on past extent, thickness and timing of ice cover. However, terrestrial records of ice sheet history from the region remain sparse, resulting in significant model uncertainties. We report glacial-geological evidence for the duration and timing of the last glaciation of Hunt Bluff, in the central Amundsen Sea Embayment. A multi-nuclide approach was used, measuring cosmogenic 10Be and in situ14C in bedrock surfaces and a perched erratic cobble. Bedrock 10Be ages (118–144 ka) reflect multiple periods of exposure and ice-cover, not continuous exposure since the last interglacial as had previously been hypothesized. In situ14C dating suggests that the last glaciation of Hunt Bluff did not start until 21.1 ± 5.8 ka – probably during the Last Glacial Maximum – and finished by 9.6 ± 0.9 ka, at the same time as ice sheet retreat from the continental shelf was complete. Thickening of ice at Hunt Bluff most likely post-dated the maximum extent of grounded ice on the outer continental shelf. Flow re-organisation provides a possible explanation for this, with the date for onset of ice-cover at Hunt Bluff providing a minimum age for the timing of convergence of the Dotson and Getz tributaries to form a single palaeo-ice stream. This is the first time that timing of onset of ice cover has been constrained in the Amundsen Sea Embayment

A Man-Made ATP-Binding Protein Evolved Independent of Nature Causes Abnormal Growth in Bacterial Cells

Recent advances in de novo protein evolution have made it possible to create synthetic proteins from unbiased libraries that fold into stable tertiary structures with predefined functions. However, it is not known whether such proteins will be functional when expressed inside living cells or how a host organism would respond to an encounter with a non-biological protein. Here, we examine the physiology and morphology of Escherichia coli cells engineered to express a synthetic ATP-binding protein evolved entirely from non-biological origins. We show that this man-made protein disrupts the normal energetic balance of the cell by altering the levels of intracellular ATP. This disruption cascades into a series of events that ultimately limit reproductive competency by inhibiting cell division. We now describe a detailed investigation into the synthetic biology of this man-made protein in a living bacterial organism, and the effect that this protein has on normal cell physiology

Drying colloidal systems: laboratory models for a wide range of applications

The drying of complex fluids provides a powerful insight into phenomena that take place on time and length scales not normally accessible. An important feature of complex fluids, colloidal dispersions and polymer solutions is their high sensitivity to weak external actions. Thus, the drying of complex fluids involves a large number of physical and chemical processes. The scope of this review is the capacity to tune such systems to reproduce and explore specific properties in a physics laboratory. A wide variety of systems are presented, ranging from functional coatings, food science, cosmetology, medical diagnostics and forensics to geophysics and art

The effects of soybean hulls in corn-soybean meal and corn-soybean meal-dried distillers grains with solubles diets on nursery pig performance

Two experiments were conducted to evaluate the effects of soybean hulls in diets with and without corn dried distillers grains with solubles (DDGS) on nursery pig growth performance. In Exp. 1, a total of 600 pigs (PIC C-29 × 359, initially 14.7 lb) were used in a 42-d growth study. Diets contained increasing amounts of soybean hulls (0, 3, 6, 9, or 12%) in either corn-soybean meal or corn-soybean meal-DDGS–based diets (15 and 30% DDGS for Phases 1 and 2, respectively). Pigs were blocked by initial pen weight, gender, and room location, with 10 pigs per pen and 6 replications per treatment. Overall (d 0 to 42), soybean hulls × DDGS interactions (quadratic, P < 0.05) were observed for F/G and caloric efficiency on an ME and NE basis. Increasing soybean hulls worsened F/G quadratically (P < 0.03) when added to diets without DDGS but linearly (P < 0.01) when added to diets with DDGS. Caloric efficiencies improved on an ME and NE basis (quadratic, P < 0.04) with increasing soybean hulls in diets without DDGS but did not influence caloric efficiency when added to diets containing DDGS. Adding DDGS to the diet decreased (P < 0.04) ADG and ADFI but tended to improve (P < 0.06) F/G. Adding soybean hulls to diets containing DDGS further reduced (quadratic, P < 0.05) ADG and tended to reduce (quadratic, P < 0.08) ADFI, whereas adding soybean hulls to diets without DDGS had no effect on ADG or ADFI

The effects of dietary soybean hulls, particle size, and diet form on nursery pig performance

A total of 1,100 nursery pigs (PIC C-29 × 359, initially 15.0 lb BW) were used in a 42-d growth trial to determine the effects of increasing soybean hulls (10 or 20%) and soybean hull particle size (unground or ground) in nursery pig diets fed in both meal and pelleted forms. The average particle size of the unground and ground soybean hulls were 617 and 398 μ, respectively. Pens of pigs (5 barrows and 5 gilts) were balanced by initial BW and randomly allotted to 1 of 8 treatments with 11 replications per treatment. A 2-phase diet series was used with treatment diets fed from d 0 to 14 for Phase 1 and d 14 to 42 for Phase 2. Treatments were arranged in a 2 × 2 × 2 factorial with main effects of 10 or 20% unground or finely ground soybean hulls with diets in pelleted or meal form. For individual phases and overall (d 0 to 42), no soybean hull × particle size × diet form or particle size × soybean hull interactions (P > 0.37 and P > 0.17, respectively) were observed; however, diet form × particle size interactions were observed for F/G and ADFI (P < 0.05 and P < 0.10, respectively). Grinding soybean hulls resulted in improved F/G and reduced ADFI when added to meal diets, but did not change F/G and had less effect on ADFI when added to pelleted diets. Diet form × particle size interactions (P < 0.05) also were observed for caloric efficiency on an ME and NE basis. Grinding soybean hulls slightly improved caloric efficiency in meal diets but worsened NE and ME caloric efficiency in pelleted diets. There was also a tendency for a diet form × soybean hulls interaction (P < 0.06) for ADFI and F/G. Increasing soybean hulls from 10 to 20% increased ADFI and worsened F/G in meal diets but resulted in slightly reduced ADFI and no changes to F/G when added to pelleted diets; furthermore, there were tendencies for diet form × soybean hulls interactions (P < 0.06) on caloric efficiency on an ME and NE basis in which increasing soybean hulls from 10 to 20% improved caloric efficiency to a greater extent in pelleted diets than in meal diets

Effects of energy level and lasalocid on productivity of fall-calving,first-calf heifers

Fall-calving, first-calf heifers (136 head) were fed TDN levels approximating 85% or 100% of NRC recommendations, with or without 200 mg/hd/day lasalocid. Those fed the recommended diet gained more weight from 130 days prepartum to calving and showed more improvement in condition score before calving than those on the low-energy diet. After calving, the group fed the recommended energy level lost less weight and condition and had better reproductive performance than the low-energy group. The only effect of lasalocid was to improve calf performance in the low-energy group

Factors predicting the probability of estrus and pregnancy

A statistical analysis was used to determine which live animal traits are useful in predicting reproductive performance in first-calf heifers. Heifer condition score at calving and change in condition score postcalving, calving difficulty score, and milk production were related to the probability of estrus and pregnancy. Condition score at calving had the greatest impact and, to a great extent, moderates the influence of the other traits