Light-dark O2 dynamics in submerged leaves of C3 and C4 halophytes under increased dissolved CO2: clues for saltmarsh response to climate change

Waterlogging and submergence are the major constraints to which wetland plants are subjected, with inevitable impacts on their physiology and productivity. Global warming and climate change, as driving forces of sea level rise, tend to increase such submersion periods and also modify the carbonate chemistry of the water column due to the increased concentration of CO2 in the atmosphere. In the present work, the underwater O2 fluxes in the leaves of two abundant Mediterranean halophytes were evaluated at different levels of dissolved CO2. Photosynthetic enhancement due to increased dissolved CO2 was confirmed for both Halimione portulacoides and Spartina maritima, probably due to high tissue porosity, formation of leaf gas films and reduction of the oxygenase activity of Rubisco. Enhancement of the photosynthetic rates in H. portulacoides and S. maritima was concomitant with an increase in energy trapping and transfer, mostly due to enhancement of the carboxylation reaction of Rubisco, leading to a reduction of the energy costs for carbon fixation. Transposing these findings to the ecosystem, and assuming increased dissolved CO2 concentration scenarios, the halophyte community displays a new ecosystem function, increasing the water column oxygenation and thus reinforcing their role as principal primary producers of the estuarine system

Repeatability of tensile properties in high pressure die-castings of an Al-Mg-Si-Mn alloy

© 2015 The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht High pressure die-castings of an Al-Mg-Si-Mn alloy have been assessed in terms of the repeatability of the mechanical properties including yield strength, ultimate tensile strength and elongation by the normal standard deviations method and by the Weibull statistical model with three parameters. It was found that the round samples had the maximum Weibull modulus, indicating the best repeatability. The machined samples exhibited the second best of Weibull modulus. Among the square samples, the 2 mm and 5 mm thick samples had the lowest and the highest Weibull modulus respectively, indicating that the repeatability for the castings was influenced by the wall thickness. The microstructural uniformity and porosity levels are critical factors in determining the repeatability of the high pressure die-castings. A less segregation in the microstructure could uniform the stress distribution in the die-castings and a less porosity in the casting could reduce the sources for brittle fracture. These improved the repeatability in casting production.The authors acknowledge the Engineering and Physical Sciences Research Council (EPSRC), Technology Strategy Board (TSB) and Jaguar Land Rover (JLR) in United Kingdom for financial support

Humanity's Last Exam

Benchmarks are important tools for tracking the rapid advancements in large language model (LLM) capabilities. However, benchmarks are not keeping pace in difficulty: LLMs now achieve over 90\% accuracy on popular benchmarks like MMLU, limiting informed measurement of state-of-the-art LLM capabilities. In response, we introduce Humanity's Last Exam (HLE), a multi-modal benchmark at the frontier of human knowledge, designed to be the final closed-ended academic benchmark of its kind with broad subject coverage. HLE consists of 3,000 questions across dozens of subjects, including mathematics, humanities, and the natural sciences. HLE is developed globally by subject-matter experts and consists of multiple-choice and short-answer questions suitable for automated grading. Each question has a known solution that is unambiguous and easily verifiable, but cannot be quickly answered via internet retrieval. State-of-the-art LLMs demonstrate low accuracy and calibration on HLE, highlighting a significant gap between current LLM capabilities and the expert human frontier on closed-ended academic questions. To inform research and policymaking upon a clear understanding of model capabilities, we publicly release HLE at https://lastexam.ai

Role of dihydrotestosterone (DHT) on TGF-β1 signaling pathway in epithelial ovarian cancer cells

Artículo de publicación ISIPurpose One of the hypotheses regarding the genesis of epithelial ovarian cancer involves the action of androgens on the proliferation of epithelial ovarian cells, as well as inclusion cysts. The purpose of the present study was to evaluate whether DHT causes changes in the TGF-beta 1 pathway that might modify the anti-proliferative effect of the latter. Methods The levels of TGF-beta 1 protein, of its receptors (TGFBR1 and TGFBR2), of Smad2/3 (canonical signaling pathway protein) and of p21 (cell cycle protein) were assessed in ovarian tissues, epithelial ovarian cancer cell lines (A2780) and control cell lines (HOSE) through the use of immunohistochemistry and immunocytochemistry. Additionally, cell lines were treated with 100 nmol/L DHT, 10 ng/mL of TGF-beta 1 and DHT + TGF-beta 1 during 72 h in the presence and absence of a siRNA against androgen receptor. After treatment, TGFBR1 and TGFBR2 levels were detected through Western blotting and p21 was assessed through immunocytochemistry. Results Epithelial ovarian cancer tissues showed a decrease in TGF-beta 1 I receptor (p < 0.05) and a change in Smad2/3 protein levels. Additionally, after treatment of cell lines with DHT, protein levels of TGF-beta 1 receptors (TGFBR1-TGFBR2) showed a decrease (p < 0.05) that might cause a potential disorder in TGF-beta 1 response, represented by the significant decrease in p21 protein levels in the presence of DHT (p < 0.001). Conclusions Overall, our results indicate a defect in the canonical TGF-beta signaling pathway in epithelial ovarian cancer caused by androgen action, thus suggesting eventual changes in such tissue proliferation rates.Grant FODECYT 1110372; Proyect CONICYT FONDAP 15130011; CONICY

A novel AVP gene mutation in a Turkish family with neurohypophyseal diabetes insipidus

Purpose Familial neurohypophyseal diabetes insipidus (FNDI) is a rare, autosomal dominant, inherited disorder which is characterized by severe polydipsia and polyuria generally presenting in early childhood. In the present study, we aimed to analyze the AVP gene in a Turkish family with FNDI