Ace Lake: three decades of research on a meromictic, Antarctic lake

Ace Lake (Vestfold Hills, Antarctica) has been investigated since the 1970s. Its close proximity to Davis Station has allowed year-long, as well as summer only, investigations. Ace Lake is a saline meromictic (permanently stratified) lake with strong physical and chemical gradients. The lake is one of the most studied lakes in continental Antarctica. Here we review the current knowledge of the history, the physical and chemical environment, community structure and functional dynamics of the mixolimnion, littoral benthic algal mats, the lower anoxic monimolimnion and the sediment within the monimolimnion. In common with other continental meromictic Antarctic lakes, Ace Lake possesses a truncated food web dominated by prokaryote and eukaryote microorganisms in the upper aerobic mixolimnion, and an anaerobic prokaryote community in the monimolimnion, where methanogenic Archaea, sulphate-reducing and sulphur-oxidizing bacteria occur. These communities are functional in winter at subzero temperatures, when mixotrophy plays an important role in survival in dominant photosynthetic eukaryotic microorganisms in the mixolimnion. The productivity of Ace Lake is comparable to other saline lakes in the Vestfold Hills, but higher than that seen in the more southerly McMurdo Dry Valley lakes. Finally we identify gaps in the current knowledge and avenues that demand further investigation, including comparisons with analogous lakes in the North Polar region

Revista del Museo Nacional N° 17

El Museo Nacional, dirigido por Luis E. Valcárcel desde 1931, publicó la Revista del Museo Nacional a partir del año 1932. El presente volumen N° XVII, fue publicado en 1948. Contenido: “Actividades del Museo de la Cultura Peruana” – “El rol de Nasca, Jaqui y Acarí en el Imperio de los Incas”, por Auza Arce, Carlos -- “Bibliográficas” – “Creación y Programa de la Comisión Panamericana de Historia” – “Colección de textos quechuas del Perú central (Continuación)”, por Farfán, J. M. B. – “Los Productos Textiles del Perú antiguo”, por Holmes, William H. – “Mate Peruano”, por Jiménez Borja, Arturo – “Fundamentos de la Lengua Kkechuwa ( Continuación)”, por Lira, Jorge A. – “Los Antropólogos y la actualidad mundial” – “El estudio del Indígena”, por Muelle, Jorge C. – “Necrologías” -- "El Ullaricuy", por Sabogal Wiesse, José R. -- “El Alimento en el Antiguo Perú”, por Valcárcel, Luis E

Xenohormesis: health benefits from an eon of plant stress response evolution

Xenohormesis is a biological principle that explains how environmentally stressed plants produce bioactive compounds that can confer stress resistance and survival benefits to animals that consume them. Animals can piggyback off products of plants' sophisticated stress response which has evolved as a result of their stationary lifestyle. Factors eliciting the plant stress response can judiciously be employed to maximize yield of health-promoting plant compounds. The xenohormetic plant compounds can, when ingested, improve longevity and fitness by activating the animal's cellular stress response and can be applied in drug discovery, drug production, and nutritional enhancement of diet