scholarly journals The influence of englacial drainage on sediment-transport pathways and till texture of temperate valley glaciers

1996 ◽  
Vol 22 ◽  
pp. 160-166 ◽  
Author(s):  
Martin Kirkbride ◽  
Nick Spedding
Keyword(s):  
Water Pressure ◽  
Sediment Accumulation ◽  
Field Studies ◽  
Transport Pathways ◽  
Running Water ◽  
Sequence Of Events ◽  
Key Factor ◽  
Level Ice ◽  
High Level ◽  
Englacial Drainage

Field studies at Mueller and Tasman Glaciers in New Zealand and in Iceland have revealed extensive ice-marginal moraine sequences fed by a series of debris bands containing characteristic rounded debris. We interpret these debris bands as meltwater deposits from relict conduits. The process of sediment accumulation described requires that debris undergoing basal or high-level ice transport is entrained by running water, becoming comminuted and rounded before being returned to high-level ice transport and eventual deposition in marginal moraines. Tins sequence of events suggests a link between glacier hydrology and ice-marginal sedimentation, possible mechanisms for which are explored. Pronounced moraines with rounded debris can be expected if (a) large quantity of debris is carried within the englacial drainage network; (b) there is a tendency for this debris to be abandoned within the ice; and (c) ice-flow trajectories and ablation ensure that this debris congregates at the ice surface. Streams which flow at high level within the ice can intercept and entrain englacial debris derived from rock fall. However, debris sources at Gigjökull and Steinholtsjökull in Iceland are restricted to the glacier bed, suggesting that, in certain cases, the presence of a basal overdeepening acts as a key factor controlling the accumulation of these moraines. Water pressure rises as channels encounter an overdeepening, forcing debris-laden streams to leave the bed and take an englacial route. That debris may pass from ice to water and back into ice before deposition has gone largely unrecognised in accounts of glacial process systems, yet it provides an explanation of how temperate alpine glaciers can include water-worked debris in their marginal depositional facies.

scholarly journals The influence of englacial drainage on sediment-transport pathways and till texture of temperate valley glaciers

1996 ◽  
Vol 22 ◽  
pp. 160-166 ◽  
Author(s):  
Martin Kirkbride ◽  
Nick Spedding
Keyword(s):  
Water Pressure ◽  
Sediment Accumulation ◽  
Field Studies ◽  
Transport Pathways ◽  
Running Water ◽  
Sequence Of Events ◽  
Key Factor ◽  
Level Ice ◽  
High Level ◽  
Englacial Drainage

Field studies at Mueller and Tasman Glaciers in New Zealand and in Iceland have revealed extensive ice-marginal moraine sequences fed by a series of debris bands containing characteristic rounded debris. We interpret these debris bands as meltwater deposits from relict conduits. The process of sediment accumulation described requires that debris undergoing basal or high-level ice transport is entrained by running water, becoming comminuted and rounded before being returned to high-level ice transport and eventual deposition in marginal moraines. Tins sequence of events suggests a link between glacier hydrology and ice-marginal sedimentation, possible mechanisms for which are explored. Pronounced moraines with rounded debris can be expected if (a) large quantity of debris is carried within the englacial drainage network; (b) there is a tendency for this debris to be abandoned within the ice; and (c) ice-flow trajectories and ablation ensure that this debris congregates at the ice surface. Streams which flow at high level within the ice can intercept and entrain englacial debris derived from rock fall. However, debris sources at Gigjökull and Steinholtsjökull in Iceland are restricted to the glacier bed, suggesting that, in certain cases, the presence of a basal overdeepening acts as a key factor controlling the accumulation of these moraines. Water pressure rises as channels encounter an overdeepening, forcing debris-laden streams to leave the bed and take an englacial route. That debris may pass from ice to water and back into ice before deposition has gone largely unrecognised in accounts of glacial process systems, yet it provides an explanation of how temperate alpine glaciers can include water-worked debris in their marginal depositional facies.

scholarly journals FRI0632-HPR PSYCHOLOGICAL PARTICULIARITIES OF PATIENTS SUFFERING FROM MONOGENIC AUTO-INFLAMMATORY DISEASES.

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 920.1-921
Author(s):  
N. Stepanenko ◽  
E. Fedorov ◽  
S. Salugina ◽  
S. Feoktistova
Keyword(s):  
Inflammatory Diseases ◽  
Life Quality ◽  
Information Storage ◽  
Social Adaptation ◽  
Long Term Memory ◽  
Short Term ◽  
Sequence Of Events ◽  
Communicative Disorders ◽  
Negative Effect ◽  
High Level

Background:Monogenic auto-inflammatory diseases (mAID) are a group of severe chronic multisystemic diseases with recurring episodes of fever and other manifestations that significantly affect the patients’ life quality. Moreover, the hyper expression of pro-inflammatory cytokines (IL1β, etc.) observed in these patients may have a negative effect on the central nervous system.Objectives:to study the state of the cognitive and emotional spheres in children suffering from monogenic auto-inflammatory diseases.Methods:there were examined 22 children at the age of 7 to 17 years old diagnosed with CAPS-9, TRAPS-8, FMF-5. Among them there were 12 boys and 10 girls. The diagnosis in all the patients was confirmed through detection of pathogenic mutations in the NLRP3, TNFRSF1A and MEFV genes. The following methods were used: a clinical conversation; memory diagnostics (learning by heart of 10 words, a pictogram using cues taking into account the patients’ age); attention diagnostics (Schulte tables); thinking diagnostics (establishing a sequence of events, “four is a crwod”, simple analogies, interpretation of proverbs); emotional and communicative fields (the Eight-Color Luscher Test; CMAS (adaptation by A. Prikhozhan); STAI test, a drawing called “an animal that does not exist” and “a house-a tree-a man”).Results:The memory study revealed in all patients with TRAPS and FMF high and medium values of short-term and long-term memory, in patients with CAPS - a low level of short-term auditory-speech memory, information storage and indirect memorization in 1/3 of patients. In 100% of the examined patients with TRAPS, a significant decrease in all processes of attention and distribution of attention. In 1/3 of patients with CAPS, an increased exhaustion of attention was registered and in 11% - a decrease in its stability. In patients with FMF, attention disorders were not detected. In 44% of patients with CAPS, a decrease in the level of generalization and difficulties in establishing causal relationships were registered. In 25% of patients with TRAPS a decrease in the level of generalization, in 12.5%- difficulties in establishing cause-effect relationships, inertia of thinking in 37.5%. In 60% of patients with FMF: a decrease in the level of generalization, in 80%: difficulties in establishing cause-effect relationships, inertia of thinking in 20%. In the emotional sphere, patients with CAPS, TRAPS, and FMF demonstrated signs of aggression (11.1%, 20% and 20% of patients, respectively), communicative disorders (77.8% -80% - 80%), and reduced social adaptation (55.5% - 80% - 80%), a tendency to form neurotic fears (22% - 40% - 40%). A high level of personal anxiety was noted in 1/3 of patients with CAPS and 40% of patients with FMF.Conclusion:various psychological disorders in the cognitive and emotional fields were noted in the majority of the examined patients with monogenic auto-inflammatory diseases. In patients with TRAPS, attention processes are most significantly affected; in patients with CAPS, memory is more often affected. In patients with FMF, disorders in thinking processes are revealed more often. In the emotional sphere, most patients with all the three forms of AID note communicative disorders and social adaptation.Disclosure of Interests:None declared

scholarly journals Analysis of Lipid Peroxidation by UPLC-MS/MS and Retinoprotective Effects of the Natural Polyphenol Pterostilbene

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 168
Author(s):  
Isabel Torres-Cuevas ◽  
Iván Millán ◽  
Miguel Asensi ◽  
Máximo Vento ◽  
Camille Oger ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Diabetic Retinopathy ◽  
Redox Homeostasis ◽  
Ultra Performance Liquid Chromatography ◽  
Protective Effects ◽  
Diabetic Retina ◽  
Key Factor ◽  
Adrenic Acid ◽  
Diabetic Rabbits ◽  
High Level

The loss of redox homeostasis induced by hyperglycemia is an early sign and key factor in the development of diabetic retinopathy. Due to the high level of long-chain polyunsaturated fatty acids, diabetic retina is highly susceptible to lipid peroxidation, source of pathophysiological alterations in diabetic retinopathy. Previous studies have shown that pterostilbene, a natural antioxidant polyphenol, is an effective therapy against diabetic retinopathy development, although its protective effects on lipid peroxidation are not well known. Plasma, urine and retinas from diabetic rabbits, control and diabetic rabbits treated daily with pterostilbene were analyzed. Lipid peroxidation was evaluated through the determination of derivatives from arachidonic, adrenic and docosahexaenoic acids by ultra-performance liquid chromatography coupled with tandem mass spectrometry. Diabetes increased lipid peroxidation in retina, plasma and urine samples and pterostilbene treatment restored control values, showing its ability to prevent early and main alterations in the development of diabetic retinopathy. Through our study, we are able to propose the use of a derivative of adrenic acid, 17(RS)-10-epi-SC-Δ15-11-dihomo-IsoF, for the first time, as a suitable biomarker of diabetic retinopathy in plasmas or urine.

scholarly journals Determining the critical period for weed control in high-yielding cotton using common sunflower as a mimic weed

2019 ◽  
Vol 33 (6) ◽  
pp. 800-807 ◽  
Author(s):  
Graham W. Charles ◽  
Brian M. Sindel ◽  
Annette L. Cowie ◽  
Oliver G. G. Knox
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Field Studies ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Density ◽  
High Level ◽  
The Cost ◽  
Planting Season

AbstractField studies were conducted over six seasons to determine the critical period for weed control (CPWC) in high-yielding cotton, using common sunflower as a mimic weed. Common sunflower was planted with or after cotton emergence at densities of 1, 2, 5, 10, 20, and 50 plants m−2. Common sunflower was added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 growing degree days (GDD) after planting. Season-long interference resulted in no harvestable cotton at densities of five or more common sunflower plants m−2. High levels of intraspecific and interspecific competition occurred at the highest weed densities, with increases in weed biomass and reductions in crop yield not proportional to the changes in weed density. Using a 5% yield-loss threshold, the CPWC extended from 43 to 615 GDD, and 20 to 1,512 GDD for one and 50 common sunflower plants m−2, respectively. These results highlight the high level of weed control required in high-yielding cotton to ensure crop losses do not exceed the cost of control.

scholarly journals Comparison of reliability evaluation methods between China and Canada standards for wood structures featuring duration of load

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Qiongyao Wu ◽  
Shuang Niu ◽  
Enchun Zhu
Keyword(s):  
Reliability Analysis ◽  
Analysis Method ◽  
Safety Level ◽  
Wood Structures ◽  
Load Effect ◽  
Key Factor ◽  
Live Loads ◽  
High Level ◽  
Partial Factor ◽  
Duration Of Load

Abstract Duration of load (DOL) is a key factor in design of wood structures, which makes the reliability analysis of wood structures more complicated. The importance of DOL is widely recognized, yet the methods and models through which it is incorporated into design codes vary substantially by country/region. Few investigations of the effect of different model assumptions of DOL and other random variables on the results of reliability analysis of wood structures can be found. In this paper, comparisons are made on the reliability analysis methods that underlie the China and the Canada standards for design of wood structures. Main characteristics of these two methods, especially the way how DOL is treated are investigated. Reliability analysis was carried out with the two methods employing the same set of material properties and load parameters. The resulted relationships between reliability index β and resistance partial factor γR* (the β–γR* curves) for four load combinations are compared to study the safety level indicated by the two methods. The comparison shows that the damage accumulation model (Foschi–Yao model) in the Canada analysis method is highly dependent on the type and duration of load, resulting in more conservative design than the China analysis method in loading cases dominated by dead load, but less conservative design in cases of high level of live loads. The characteristics of the load effect term of the performance function are also found to make considerable difference in reliability levels between the two methods. This study aims to provide references for researchers and standard developers in the field of wood structures.

scholarly journals Perceptual decisions are biased toward relevant prior choices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helen Feigin ◽  
Shira Baror ◽  
Moshe Bar ◽  
Adam Zaidel
Keyword(s):  
Sensory Information ◽  
Irrelevant Stimulus ◽  
Stimulus Feature ◽  
Serial Dependence ◽  
Low Level ◽  
Subsequent Test ◽  
Key Factor ◽  
High Level ◽  
Motor Actions ◽  
The Brain

AbstractPerceptual decisions are biased by recent perceptual history—a phenomenon termed 'serial dependence.' Here, we investigated what aspects of perceptual decisions lead to serial dependence, and disambiguated the influences of low-level sensory information, prior choices and motor actions. Participants discriminated whether a brief visual stimulus lay to left/right of the screen center. Following a series of biased ‘prior’ location discriminations, subsequent ‘test’ location discriminations were biased toward the prior choices, even when these were reported via different motor actions (using different keys), and when the prior and test stimuli differed in color. By contrast, prior discriminations about an irrelevant stimulus feature (color) did not substantially influence subsequent location discriminations, even though these were reported via the same motor actions. Additionally, when color (not location) was discriminated, a bias in prior stimulus locations no longer influenced subsequent location discriminations. Although low-level stimuli and motor actions did not trigger serial-dependence on their own, similarity of these features across discriminations boosted the effect. These findings suggest that relevance across perceptual decisions is a key factor for serial dependence. Accordingly, serial dependence likely reflects a high-level mechanism by which the brain predicts and interprets new incoming sensory information in accordance with relevant prior choices.

The timing of deglaciation from mountain summits to cirques in Wales: 10Be and 26Al exposure dates from Cadair Idris

2021 ◽  
Author(s):  
Philip Hughes ◽  
Neil Glasser ◽  
David Fink ◽  
Jason Dortch ◽  
Reka Fülöp ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Lake Basin ◽  
Summit Area ◽  
Sheet Surface ◽  
Ice Cap ◽  
Heinrich Event ◽  
Level Ice ◽  
High Level ◽  
Exposure Ages ◽  
Later Phase

<p>Cosmogenic <sup>10</sup>Be and <sup>26</sup>Al exposure ages from 20 erratic samples collected from Cadair Idris (893 m), a mountain in southern Snowdonia, Wales, provide evidence for the timing of deglaciation from summits to cirques at the end of the Late Pleistocene. The summit of the mountain is characterised by intensely modified frost-shattered surfaces that have long been identified as a representing a former nunatak. Numerous glacially-transported quartz boulders on the highest ground indicate that ice overran the summit at some point in the Pleistocene. Two quartz boulders, one with preserved striations, sampled at c. 856 m near the summit of Cadair Idris yielded consistent <sup>10</sup>Be and <sup>26</sup>Al paired exposure ages of 75 ka to 60 ka (using a high-latitude sea level <sup>10</sup>Be spallation production rate of 4.20 at/g/y, scaled by the Lal/Stone scheme). A glacially polished bedrock quartzite outcrop at 735 m gave an age of 17.5 ka. Immediately below this, cirque and down-valley recessional moraine ages, covering an elevation of 480 m to 350 m ranged from 10 to 15 ka respectively.</p><p>These results confirm that Cadair Idris was overridden by the Welsh Ice Cap during marine isotope stage (MIS) 4, when ice was thicker than at the global last glacial maximum (LGM) in MIS 2. This is consistent with findings from northern Snowdonia. The highest Welsh summits, including Cadair Idris, emerged above a thinning Welsh Ice Cap (British Irish Ice Sheet) during the transition from MIS 4 to 3. The summit area above ~800 m then stood as nunataks above the LGM ice sheet surface in MIS 2. The Welsh Ice Cap then rapidly thinned over Cadair Idris at ~20-17 ka based on ages from high-level ice-moulded bedrockThis is supported by more new ages from high-level paired erratics and bedrock samples on several other mountains throughout Snowdonia, leading to a phase of alpine-style deglaciation. Valley glaciers initiated their retreat up-valley from ~17 to 14 ka after Heinrich Event 1. A later phase of glacier stabilisation or still stand formation produced classic cirque moraines near the rim of a present cirque lake basin (480 m elevation) yielding <sup>10</sup>Be ages of 13-10 ka during the Younger Dryas.</p>

A Diagnosis of Urban Poor Housing in Vietnam

2017 ◽  
Vol 42 (2) ◽  
pp. 97-105
Author(s):  
Iftekhar Ahmed
Keyword(s):  
Affordable Housing ◽  
Urban Poor ◽  
Field Studies ◽  
Economic Reforms ◽  
Cultural Dimensions ◽  
Ho Chi Minh City ◽  
Housing Sector ◽  
Housing Supply ◽  
Extensive Field ◽  
Key Factor

This paper presents concepts important for understanding urban poor housing in Vietnam, with a focus on key environmental, socio-economic, and cultural dimensions that bear on the housing sector. The paper draws on extensive field studies and presents a diagnosis of the context of and prospects for housing of the urban poor in Vietnam's two main cities: Hanoi and Ho Chi Minh City. While the literature on this theme is scanty, it points to the market-orientated economic reforms initiated in the 1980s as a key factor in creating imbalance in the housing supply. Recognising the current challenges in balancing affordability and sustainability, the study explores Vietnam's lack of adequate and affordable housing and the problems faced by the urban poor in accessing adequate housing.

scholarly journals THE EPIDEMIOLOGY OF FOWL CHOLERA

1930 ◽  
Vol 51 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Ida W. Pritchett ◽  
F. R. Beaudette ◽  
T. P. Hughes
Keyword(s):  
Field Studies ◽  
Colony Type ◽  
Fowl Cholera ◽  
Poultry Farms ◽  
High Virulence ◽  
Commercial Poultry ◽  
The Individual ◽  
High Level ◽  
Serum Agglutination ◽  
Healthy Carriers

Field studies of fowl cholera on two commercial poultry farms are described. One farm, previously free of cholera, was studied during an active epidemic, which occurred during the winter months. The strains of P. avicida recovered, both from "autopsy" and from "healthy carriers" proved generally similar, and to be of the "fluorescent" or "intermediate" colony type, which is of relatively high virulence. After the subsidence of the epidemic, these strains tended to disappear. The second flock consisted of a small group of birds which had survived an epidemic of cholera the previous year, and in which the infection was prevailing in endemic form. No deaths occurred during the period of observation, but the number of birds with localized lesions and the number of carriers increased to a high level during the winter months. The strains of P. avicida were apparently of the "blue" colony form, although some, as shown by their acid and serum agglutination reactions, resembled the "intermediates." These strains appeared to be spreading rather than dying out. The individual fowls differed in their response to the presence of infection; some showed localized lesions, others were carriers, while still others seemed entirely refractory.

Economic Cycles in Argentina: 1875–1990

2006 ◽  
Vol 38 (3) ◽  
pp. 549-570 ◽  
Author(s):  
ISABEL SANZ-VILLARROYA
Keyword(s):  
Aggregate Demand ◽  
Unit Root Tests ◽  
Economic Cycles ◽  
Long Run ◽  
Economic Forces ◽  
Mode Of Operation ◽  
Key Factor ◽  
Short Run ◽  
High Level ◽  
Level Of Agreement

This article analyses the short-run periods that can be derived from the GDP per capita series for Argentina between 1875 and 1990, after extracting its segmented long-run trend using time series techniques and unit root tests. It also studies the economic forces which, from the aggregate demand side, might provide an explanation for this behaviour. This mode of operation makes it possible to identify successive cycles more accurately than in previous studies. A high level of agreement is observed between the results of this study and arguments in the literature regarding the causes shaping these short-run periods: the analysis demonstrates that exports were the key factor until 1932 while after this year consumption and investment came to predominate.

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