Tills Underlying the Sediments of Glacial Lake Souris North-Central North Dakota

During the Pleistocene, the Wisconsinan ice sheet retreated from North Dakota leaving a veneer of glacial drift over the landscape. In the north-central area of the state, as the Souris Lobe retreated, Glacial Lake Souris formed and deposited mostly sand and silt over a large area of till. The purpose of this study was to characterize the till beneath Lake Souris sediments and to determine which descriptive parameters are most useful for till data analysis. The area of study is in McHenry and western Pierce Counties and is contained entirely within the Glacial Lake Souris basin. The North Dakota Geological Survey drilling rig was used to drill holes, 36 of which penetrated till; a total of 109 samples were collected. Till was characterized on the basis of textural and lithologic analyses, in addition to visual hand-sample descriptions. The textural analyses provided sand, silt, and clay percentages, whereas the lithologic analysis provided percentages of fragments of certain rock types (crystalline, carbonate, sandstone and siltstone, shale, and lignite) in the very-coarse sand fraction of the till. The best parameters for characterizing the till were percent normalized silt (silt % / silt % + clay %) plotted against percent normalized crystalline ( xtal % / xtal % + carbonate %) and percent sand. The lithologic data show an increase in percent crystalline rock fragments and a corresponding decrease in percent sandstone and percent carbonate fragments in a southeasterly direction. Percentages of sandstone, siltstone, and lignite fragments peak in the center of the lake basin and decrease toward the edges. The textural data show that percent clay changes little throughout the basin while silt values are high in the basin center and sand is high near the basin margins. The lithologic data indicate that differential resistance of rocks resulted in relative increases in the resistant rock types in the down-glacier direction. With the data obtained from the study, it was possible to identify two tills within the study area. The first till, an older unit, was found in several holes that formed a northwest-to-southeast-trending linear band near the southwest margin of the basin. The second, a younger till, was found throughout the basin

Ice Lens Formation and Frost Heave at the Phoenix Landing Site

Several lines of evidence indicate that the volume of shallow ground ice in the martian high latitudes exceeds the pore volume of the host regolith. Boynton et al. found an optimal fit to the Mars Odyssey Gamma Ray Spectrometer (GRS) data at the Phoenix landing site by modeling a buried layer of 50-75% ice by mass (up to 90% ice by volume). Thermal and optical observations of recent impact craters in the northern hemisphere have revealed nearly pure ice. Ice deposits containing only 1-2% soil by volume were excavated by Phoenix. The leading hypothesis for the origin of this excess ice is that it developed in situ by a mechanism analogous to the formation of terrestrial ice lenses and needle ice. Problematically, terrestrial soil-ice segregation is driven by freeze/thaw cycling and the movement of bulk water, neither of which are expected to have occurred in the geologically recent past on Mars. If however ice lens formation is possible at temperatures less than 273 K, there are possible implications for the habitability of Mars permafrost, since the same thin films of unfrozen water that lead to ice segregation are used by terrestrial psychrophiles to metabolize and grow down to temperatures of at least 258 K

TOO MUCH OF A GOOD THING? THE INFLUENCE OF BENTHIC COMMUNITY & CHRONIC NUTRIENT ENRICHMENT ON REEF MICROBIAL ASSEMBLAGES

Ph.D

Taxonomy and systematic relationships of tui chubs (Siphateles: Cyprinidae) from Oregon's Great Basin

There are three recognized species of Siphateles from the Great Basin; S. alvordensis, S. boraxobius and the tui chub, S. bicolor. One species, S. boraxobius, is endangered and one population of tui chub at Hutton Spring is threatened. Despite several morphological and molecular studies, the taxonomy and relationships of tui chubs are unclear. A recurrent theme in prior studies has been the possibility of translocation of tui chubs, especially into Summer Lake Basin, and probably by bait bucket introductions. I approached this problem by using cytochrome b (cyt b) sequences to define clades and constructed a neighbor-joining tree to examine relationships. Developmental ontogeny and adult meristic characters were used to corroborate clades, and microsatellites (nDNA) used to explore the possibility of hybridization among Summer Lake Basin fish and those from surrounding basins. The cyt b tree recovered a basal polytomy containing a western clade from Sycan Marsh, an eastern clade from the Alvord Basin, and S. bicolor. The Sycan Marsh clade was represented by two fish and requires additional research. Within the Alvord Basin, S. boraxobius and S. alvordensis were well corroborated by morphological characters but sequence divergence was only 0.37%. There were three major clades in S. bicolor – a basal S. newarkensis clade in Nevada, an Oregon Lakes S. bicolor clade, and, sister to it, a disjunct S. obesa clade in Nevada and the Oregon Lakes. In the Oregon Lakes, there were two clades within S. bicolor: S. thalassinus was sister to the remaining S. bicolor and there were two clades within S. obesus: S. oregonensis was sister to a "Summer Lake Basin" clade. There was some morphological corroboration for S. oregonensis, but no corroboration for the others. Clades were geographically disjunct or not confined to single basins. The S. oregonensis clade was sister to a Nevada polytomy and historical evidence implicates that at least one population of S. oregonensis in XL Spring was introduced in the late 1800's. Average sequence divergence with the Nevada clade, 0.62 - 0.88%, did not seem to support possible Miocene or Pliocene vicariance scenarios. Elsewhere, the S. thalassinus clade was found outside of Goose Lake in Summer Lake Basin and the "Summer Lake Basin" clade was found in Goose Lake Basin. Clustering of three microsatellite loci did not match cyt b clades, rather, individuals clustered based on sample location, suggesting that the cyt b patterns were due to introgression. In Summer Lake Basin, evidence of poisoning and subsequent transplants was consistent with these observations. These results suggest the presence of three or four tui chub taxa in the Oregon Lakes and Alvord Basin, however translocation and subsequent introgression appear to have been common in many populations, and will prove challenging for taxonomists and conservation managers

Coral reef biofilm bacterial diversity and successional trajectories are structured by reef benthic organisms and shift under chronic nutrient enrichment

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remple, K. L., Silbiger, N. J., Quinlan, Z. A., Fox, M. D., Kelly, L. W., Donahue, M. J., & Nelson, C. E. Coral reef biofilm bacterial diversity and successional trajectories are structured by reef benthic organisms and shift under chronic nutrient enrichment. Npj Biofilms and Microbiomes, 7(1), (2021): 84, https://doi.org/10.1038/s41522-021-00252-1.Work on marine biofilms has primarily focused on host-associated habitats for their roles in larval recruitment and disease dynamics; little is known about the factors regulating the composition of reef environmental biofilms. To contrast the roles of succession, benthic communities and nutrients in structuring marine biofilms, we surveyed bacteria communities in biofilms through a six-week succession in aquaria containing macroalgae, coral, or reef sand factorially crossed with three levels of continuous nutrient enrichment. Our findings demonstrate how biofilm successional trajectories diverge from temporal dynamics of the bacterioplankton and how biofilms are structured by the surrounding benthic organisms and nutrient enrichment. We identify a suite of biofilm-associated bacteria linked with the orthogonal influences of corals, algae and nutrients and distinct from the overlying water. Our results provide a comprehensive characterization of marine biofilm successional dynamics and contextualize the impact of widespread changes in reef community composition and nutrient pollution on biofilm community structure.This work was supported through grants from the National Science Foundation for Biological Oceanography (1923877 to C.E.N. and M.J.D., 1949033 to C.E.N. and 2118687 to L.W.K., and 1924281 to N.J.S.) and the National Fish and Wildlife Foundation (grant no. 44447 to C.E.N.). This paper is funded in part by the National Oceanic and Atmospheric Administration, Project A/AS-1, which is sponsored by the University of Hawaii Sea Grant College Program, SOEST, under Institutional Grant No. NA18OAR4170076 from NOAA Office of Sea Grant, Department of Commerce. This is CSUN marine biology contribution #365, UH Sea Grant contribution UNIHI-SEAGRANT-JC-21-06, and UH SOEST contribution 11435

Protective Behavior Survey, West Nile Virus, British Columbia

We investigated personal protective behaviors against West Nile virus infection. Barriers to adopting these behaviors were identified, including the perception that DEET (N,N-diethyl-m-toluamide and related compounds) is a health and environmental hazard. Televised public health messages and knowing that family or friends practiced protective behaviors were important cues to action

Plan de acción estratégico para fortalecer la conservación y el uso de los recursos fitogenéticos mesoamericanos para la adaptación de la agricultura al cambio climático – PAEM 2014-2024

El Plan de Acción Estrategico para Fortalecer la Conservacion y el Uso de los Recursos Fitogeneticos Mesoamericanos para la Adaptacion de la Agricultura al Cambio Climatico (PAEM) es un mapa de ruta a diez anos para fortalecer la conservacion, el acceso y el uso de los recursos fitogeneticos de Mesoamerica como elemento estrategico para la seguridad alimentaria y la adaptacion de la agricultura al cambio climatico y otras amenazas

Feldenkrais method and movement education - An alternate therapy in musculoskeletal rehabilitation

Introduction Feldenkrais method (FM) is a movement education technique that emphasizes movement teaching based on sensory motor awareness and cognitive perception of the movement. Although this technique gained popularity in different parts of the world, it is still regarded as a non-conventional science. Aim Absence of in-depth review and high quality scientific studies in this technique necessitates the need for generation of knowledge and scientific review on this efficient method. Discussion This current review paper made an effort to provide conventional scientific explanation about this method that suits the medical paradigm. In this paper, a brief introduction followed by description of the technique is given with a clinical example toward its application. Furthermore, the neurophysiologic explanation and mechanical concepts are provided in the conventional scientific manner. Indications, contra indications and clinical implications were also discussed to accommodate the clinical practice in musculoskeletal rehabilitation. Conclusions Feldenkrais exercises can be used as an alternative therapy in musculoskeletal rehabilitation for movement education