52 research outputs found
Food of Lake Trout in Lake Superior
Stomachs were examined from 1,492 lake trout and 83 siscowets collected from Lake Superior. Data are given on the food of lake trout of legal size (17 inches or longer) by year, season, and depth of water, and on the relation between food and size among smaller lake trout.Fish contributed 96.7 to 99.9 per cent of the total volume of food in the annual samples. Ciscoes (Coregonus spp.) were most common (52.2 to 87.5 per cent of the volume) in 1950 to 1953 and American smelt ranked first (65.6 per cent of the volume) in 1963. Cottids were in 8.9 to 12.3 per cent of the stomachs in 1950 to 1953 but in only 4.3 per cent in 1963. Insects ranked second to fish in occurrence (9.6 per cent for the combined samples) and crustaceans followed at 3.9 per cent.The greatest seasonal changes in the food of lake trout were among fish caught at 35 fathoms and shallower. The occurrence of Coregonus increased from 34.6 per cent in FebruaryâMarch to 71.1 per cent in OctoberâDecember. Smelt were in 76.9 per cent of the stomachs in FebruaryâMarch but in only 2.2 per cent in OctoberâDecember. Cottids, Mysis relicta, and insects were most common in the JulyâSeptember collections.Lake trout taken at depths greater than 35 fathoms had eaten a higher percentage of Cottidae and Coregonus than had those captured in shallower water. Smelt, ninespine sticklebacks, Mysis, and insects were more frequent in stomachs of lake trout from less than 35 fathoms.Crustaceans comprised more than 70 per cent of the total volume of food for 4.0â to 7.9âinch lake trout but their importance decreased as the lake trout grew larger. Pontoporeia affinis was the most common in the stomachs of 4.0â to 6.9âinch lake trout and Mysis held first rank at 7.0 to 12.9 inches. Ostracods were important only to 4.0â to 4.9âinch lake trout. As the lake trout became larger, the importance of fish grew from 4.4âper cent occurrence at 5.0 to 5.9 inches to 93.9 per cent at 16.0 to 16.9 inches. Smelt were most commonly eaten by undersize (less than 17 inches) lake trout.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141203/1/tafs0169.pd
The Role for Coagulation Markers in Mild Snakebite Envenomations
Introduction: The majority of patients seeking medical treatment for snakebites do not suffer from severe envenomation. However, no guidelines exist for ordering coagulation markers in patients with minimal or moderate envenomation, nor in those who do not receive antivenom. In this study, we sought to determine whether it was possible to limit the practice of ordering coagulation studies to those patients suffering severe envenomation, rattlesnake envenomation, or both.Methods: A retrospective chart review was performed on all cases of crotalid snakebite presenting to an adult emergency department (ED) from April 1998 to June 2006. Each chart was abstracted for patientâs age, gender, type of snake (if known), severity of envenomation at initial presentation, coagulation test results, whether antivenom was administered, and whether the patient was admitted.Results: Over an approximately 8-year period, 131 snakebite cases presented that met the inclusion criteria, of which 35 (26.7%) had some type of coagulation marker abnormality. Limiting coagulation testing to patients suffering severe envenomation or rattlesnake envenomation would have resulted in failure to identify 89% or 77%, respectively, of the 35 patients who were found to have at least 1 abnormal coagulation marker.Conclusion: Our study failed to identify a subset of patients that could be defined as low risk or for whom coagulation marker testing could be foregone. This study suggests that coagulation tests should be routinely performed on all patients presenting to the ED with complaints of envenomation by copperheads, moccasins, or rattlesnakes. Further clarification of when coagulation markers are indicated may require a prospective study that standardizes snake identification and the timing of coagulation marker testing. [West J Emerg Med. 2012;13(1):68â74.
Systemic Issues in Asynchronous Delivery of Graduate Engineering Management Programs
The purpose of this paper is to examine systemic issues that impact the design, delivery, and maintenance of asynchronous engineering management educational products. Asynchronous education continues to rapidly evolve as an alternative to traditional classroom delivery. An asynchronous educational system requires the effective integration of technology, supporting processes, and infrastructure design to prepare, deliver, and maintain asynchronous educational products. Currently, the technological capabilities for delivery of asynchronous education have outstripped the ability to maximize those advanced technologies. To help understand this rift between technology and our ability to deploy that technology this paper examines three critical areas. First, the distinctions between asynchronous, distance (interactive televised), and live instruction are examined from a perspective of immediacy. Second, based on initial experiences in preparation and delivery of asynchronous education, a systemic issues perspective is developed. Finally, implications of systems design principles are presented as a guide for more effective future design of asynchronous educational products in engineering management
Tracking icebergs with time-lapse photography and sparse optical flow, LeConte Bay, Alaska, 2016â2017
We present a workflow to track icebergs in proglacial fjords using oblique time-lapse photos
and the Lucas-Kanade optical flow algorithm. We employ the workflow at LeConte Bay, Alaska, where we ran five time-lapse cameras between April 2016 and September 2017, capturing more than 400 000 photos at frame rates of 0.5â4.0 minâ1. Hourly to daily average velocity fields in map coordinates illustrate dynamic currents in the bay, with dominant downfjord velocities (exceeding 0.5 m sâ1 intermittently) and several eddies. Comparisons with simultaneous Acoustic Doppler Current Profiler (ADCP) measurements yield best agreement for the uppermost ADCP levels (⌠12 m and above), in line with prevalent small icebergs that trace near-surface currents. Tracking results from multiple cameras compare favorably, although cameras with lower frame rates (0.5 minâ1) tend to underestimate high flow speeds. Tests to determine requisite temporal and spatial image resolution confirm the importance of high image frame rates, while spatial resolution is of secondary importance. Application of our procedure to other fjords will be successful if iceberg concentrations are high enough and if the camera frame rates are sufficiently rapid (at least 1 minâ1 for conditions similar to LeConte Bay).This work was funded by the U.S. National Science Foundation (OPP-1503910, OPP-1504288, OPP-1504521 and OPP-1504191).Ye
Rapid submarine melting driven by subglacial discharge, LeConte Glacier, Alaska
We show that subglacial freshwater discharge is the principal process driving high rates of submarine melting at tidewater glaciers.We show that subglacial freshwater discharge is the
principal process driving high rates of submarine melting
at tidewater glaciers. This buoyant discharge draws in
warm seawater, entraining it in a turbulent upwelling flow
along the submarine face that melts glacier ice. To capture
the effects of subglacial discharge on submarine melting,
we conducted 4 days of hydrographic transects during
late summer 2012 at LeConte Glacier, Alaska. A major
rainstorm allowed us to document the influence of large
changes in subglacial discharge. We found strong submarine
melt fluxes that increased from 9.1 ± 1.0 to 16.8 ± 1.3 m d1
(ice face equivalent frontal ablation) as a result of the
rainstorm. With projected continued global warming and
increased glacial runoff, our results highlight the direct
impact that increases in subglacial discharge will have on
tidewater outlet systems. These effects must be considered
when modeling glacier response to future warming and
increased runoff.This work was funded by a grant from the
Gordon and Betty Moore Foundation grant GBMF2627 to M.T. and M.F.
Additional support for J.M.A. was provided by NSF grant ANT0944193.
The manuscript was greatly improved by comments from two anonymous re-
viewers. We thank Captain Scott Hursey for vessel support and safely navi-
gating us through icebergs. J. Elliot provided the orthorectified World View image in Figure 1c.Ye
Alinhamento interpessoal, representacional e morfossintĂĄtico na GramĂĄtica Discursivo-Funcional
Este artigo se debruça sobre o mapeamento entre os NĂveis Interpessoal, Representacional e MorfossintĂĄtico da gramĂĄtica, o chamado alinhamento, segundo o arcabouço da GramĂĄtica Discursivo-Funcional (GDF). PropĂ”e uma tipologia das lĂnguas baseada no que a sua organização morfossintĂĄtica codifica: distinçÔes pragmĂĄticas (p.ex. em Tagalo), distinçÔes semĂąnticas (p.ex. em AchĂ©m), ou distinçÔes inerentes Ă morfossintaxe (p.ex. em InglĂȘs, Basco ou a lĂngua Kham). A inclusĂŁo tanto do Sujeito como do Objeto e de lĂnguas tanto acusativas como ergativas no tratamento do alinhamento morfossintĂĄtico permitiu-nos abranger tipos tipologicamente mais variĂĄveis e demonstrar o potencial da GDF para a anĂĄlise contrastiva das lĂnguas.<br>Within the framework of Functional Discourse Grammar (FDG), alignment concerns the relations between the Interpersonal, Representational and Morphosyntactic Levels of grammar. This article proposes a typology of languages based upon what we find to be encoded in their morphosyntactic organization: pragmatic distinctions (as in Tagalog), semantic distinctions (as in Acheh), or distinctions inherent to the morphosyntax (as in English, Basque and Kham). By including both subject and object, and both accusative and ergative languages in our treatment of morphosyntactic alignment, we provide a better coverage of typological variation and show the potential of FDG for cross-linguistic analysis
SLO-2 Is Cytoprotective and Contributes to Mitochondrial Potassium Transport
Mitochondrial potassium channels are important mediators of cell protection against stress. The mitochondrial large-conductance âbigâ K+ channel (mBK) mediates the evolutionarily-conserved process of anesthetic preconditioning (APC), wherein exposure to volatile anesthetics initiates protection against ischemic injury. Despite the role of the mBK in cardioprotection, the molecular identity of the channel remains unknown. We investigated the attributes of the mBK using C. elegans and mouse genetic models coupled with measurements of mitochondrial K+ transport and APC. The canonical Ca2+-activated BK (or âmaxi-Kâ) channel SLO1 was dispensable for both mitochondrial K+ transport and APC in both organisms. Instead, we found that the related but physiologically-distinct K+ channel SLO2 was required, and that SLO2-dependent mitochondrial K+ transport was triggered directly by volatile anesthetics. In addition, a SLO2 channel activator mimicked the protective effects of volatile anesthetics. These findings suggest that SLO2 contributes to protection from hypoxic injury by increasing the permeability of the mitochondrial inner membrane to K+
The Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) on the New Horizons Mission
Catastrophic Valley Entrenchment and Debris Fan Formation in the Bluefields River, Westmoreland Jamaica
Little is known about the geomorphic response of Jamaican rivers to climate, geology, and human disturbance. The southwestern coast of Jamaica received a record of 32 cm of rain on June 12, 1979. Reports indicated that valley areas formed temporary lakes, overtopped small dams, and produced debris flows. This study investigates the effects of this extreme flooding on the geomorphology of the present-day Bluefields River near Belmont, Westmoreland Jamaica. The river drains 4.9 km2 of limestone uplands and mountain slopes. This study evaluates evidence from longitudinal profiles, multiple cross-sections, Colonial maps, historical aerial photographs, oral histories, and sedimentological analysis to identify previous channel bed elevations and evaluate current channel morphology. The Bluefields River was entrenched by nearly 9 meters along its middle and lower reaches. In addition, Goat Gulley, its major tributary, was also incised along its lower and upper segments. Debris flows formed a large debris fan extending over 150 m out into Bluefields Bay. About 70% of the 1979 fan volume still remains today. While Colonial maps indicate that a delta fan always existed at the river mouth, the shoreline configuration was similar from the late 1700s to before the flood with little expression of the debris fan as now present. Therefore, the return period for this type of hydro-geomorphic event is \u3e300 years. While causes are mostly related to climate and geology factors, human modification of the landscape may have contributed to increased rates and extent of channel incision, thus increasing sediment delivery. Bluefields Bay is now a fish sanctuary and further studies of sediment inputs to the bay over different timescales may be important for maintaining a healthy fishery
The Identification of Major Earth Science Principles Common to Biology, Chemistry and Physics
The problem of this study is an attempt to identify those major concepts or principles of earth science that relate to secondary school biology, chemistry, and physics. An apparent relationship between earth science and the other secondary school sciences based upon similarity of major concepts is, in the opinion of the writer, believed to indicate the feasibility of teaching earth science at the ninth grade level. A list of earth science principles was evaluated to select only those principles which appeared to have some relationship to the other sciences. The list of earth science principles that was selected for this study was published in Science education by L.T. Oaldwell in April of 1955. An examination of courses of study in high school science subjects published by Departments of Education in nearby states was undertaken to obtain additional earth science principles. No such Principles were found in these publications. The final phase of the study was an attempt to identify principles of the earth sciences which relate to the other traditional high school science courses: biology, chemistry and physics. Eleven earth science principles were selected that appeared to have good relationship with major concepts of the other sciences. These eleven earth science principles were then compared to, and appeared to relate favorably with, the six conceptual themes of the Earth Science Curriculum project. In the opinion of the writer, the eleven selected earth science principles that relate to secondary school biology, chemistry and physics are worthy of consideration by the prospective ninth grade earth science teacher who desires that students gain favorable conceptual understanding in the sciences
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