Foraging behaviour in tammar (Macropus eugenii) and parma (Macropus parma) wallabies

2003 ◽  
Vol 51 (3) ◽  
pp. 297
Author(s):  
R. G. Lentle ◽  
S. Haslett ◽  
I. D. Hume ◽  
K. J. Stafford ◽  
M. Kennedy ◽  
...  
Keyword(s):  
Predator Avoidance ◽  
Foraging Behaviour ◽  
Search Time ◽  
Macropus Eugenii ◽  
Food Items ◽  
Significant Difference ◽  
Different Dimensions ◽  
Selection Of

Captive parma and tammar wallabies, when offered ryegrass sward in plots, visited ungrazed plots more frequently and spent longer grazing on them than on plots that were previously grazed but not visibly depleted. There was no significant difference between the two species with respect to the pattern of time spent grazing between plots, but parma wallabies tended to visit ungrazed plots more frequently than tammar wallabies. When offered carrot pieces of different dimensions both species preferred carrot pieces of greater mass, regardless of shape. Both species favoured eating in the upright (bipedal) position despite the fact that the use of this position prolonged search time between bites. Although the two species are able to forage optimally when grazing, the greater efficiency of the bipedal posture in predator avoidance may result in the selection of larger food items whenever possible.

An extensive study of the foraging ecology of beavers (Castor canadensis) in relation to habitat quality

2004 ◽  
Vol 82 (6) ◽  
pp. 922-933 ◽  
Author(s):  
D Gallant ◽  
C H Bérubé ◽  
E Tremblay ◽  
L Vasseur
Keyword(s):  
Habitat Quality ◽  
Foraging Behaviour ◽  
Foraging Ecology ◽  
Castor Canadensis ◽  
Central Place ◽  
Foraging Theory ◽  
Extensive Study ◽  
Food Items ◽  
Partial View ◽  
Selection Of

The objective of this study was to examine the foraging behaviour of the beaver (Castor canadensis Kuhl, 1820) and to explain its selection of terrestrial woody plant species according to central place foraging theory. Limitations in variety of food items in most studies with regard to size and (or) distance from the central place and information on availability of forage choices give a partial view of the subject. In this study, the theory is tested in a natural environment with high variability in food items with regard to these factors. Foraging choices by beavers were inspected by measuring variables on cut and uncut trees of every species encountered within 1 m of trail systems made by 25 beaver colonies in Kouchibouguac National Park in New Brunswick, Canada, thereby quantifying the availability of the different food items. The effect of habitat quality (food availability) on the foraging behaviour of beavers was also tested. The results of this study suggest that with increasing distance from the pond, beavers in high-quality habitats selected fewer, but larger, trees and are more species selective. This selectivity was diminished in habitats of lower quality. The results of this study are consistent with the predictions of the central foraging theory.

Laboratory and Field Studies of the Effect of Predation Risk On Foraging in Three-Spined Sticklebacks (Gasterosteus Aculeatus)

Behaviour ◽  
1989 ◽  
Vol 109 (1-2) ◽  
pp. 46-57 ◽  
Author(s):  
A.A. Ibrahim ◽  
F.A. Huntingford
Keyword(s):  
Field Experiment ◽  
Predation Risk ◽  
Predator Avoidance ◽  
Gasterosteus Aculeatus ◽  
Foraging Behaviour ◽  
Prey Species ◽  
Field Studies ◽  
Diet Choice ◽  
Food Items ◽  
Series Of Experiments

AbstractThis article describes a series of experiments carried out in both field and laboratory on the effects of predators on foraging in threespined sticklebacks (Gasterosteus aculeatus). In a field experiment on habitat use, predation risk did not cause the fish to abandon their preference for vegetated habitat, but led them to increase the use of the lake bed. However, in the presence of a predator, the fish still fed mainly on zooplankton rather than on benthos. In a field experiment on diet choice, predation risk suppressed the amount of food eaten and caused a shift to different prey species and smaller prey. In a laboratory experiment, predation risk slowed the response to the food and caused the fish to cease discrimination in favour of the more profitable food items. The number of feeding attempts was not affected, which could mean that the fish were compensating for their slow start by a higher subsequent rate of bites once feeding began. Thus, predation risk affected the foraging behaviour in such a way that energetic intake was reduced in the interest of predator avoidance.

A Comparison of Four Adolescent Language Tests

1987 ◽  
Vol 18 (3) ◽  
pp. 250-266 ◽  
Author(s):  
R. Jane Lieberman ◽  
Ann Marie C. Heffron ◽  
Stephanie J. West ◽  
Edward C. Hutchinson ◽  
Thomas W. Swem
Keyword(s):  
Test Performance ◽  
Sixth Grade ◽  
Significant Discrepancy ◽  
Language Impaired ◽  
Language Functions ◽  
Language Tests ◽  
Significant Difference ◽  
Sixth Grade Students ◽  
Overall Performance ◽  
Selection Of

Four recently developed adolescent language tests, the Fullerton Test for Adolescents (FLTA), the Test of Adolescent Language (TOAL), the Clinical Evaluation of Language Functions (CELF), and the Screening Test of Adolescent Language (STAL), were compared to determine: (a) whether they measured the same language skills (content) in the same way (procedures); and (b) whether students performed similarly on each of the tests. First, respective manuals were reviewed to compare selection of subtest content areas and subtest procedures. Then, each of the tests was administered according to standardized procedures to 30 unselected sixth-grade students. Despite apparent differences in test content and procedures, there was no significant difference in students' performance on three of the four tests, and correlations among test performance were moderate to high. A comparison of the pass/fail rates for overall performance on the tests, however, revealed a significant discrepancy between the proportions of students identified in need of further evaluation on the STAL (20%) and the proportion diagnosed as language impaired on the three diagnostic tests (60-73%). Clinical implications are discussed.

Caracterização da Peneira Média em Clones de Coffea canephora

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Block Design ◽  
Coffea Canephora ◽  
Coffee Production ◽  
Randomized Block Design ◽  
Significant Difference ◽  
The Mean ◽  
Four Blocks ◽  
Selection Of

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.

Temperature Selection of Rainbow Trout (Salmo gairdneri) Fingerlings in Vertical and Horizontal Gradients

1971 ◽  
Vol 28 (11) ◽  
pp. 1801-1804 ◽  
Author(s):  
R. W. McCauley ◽  
W. L. Pond
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Temperature Preference ◽  
Temperature Selection ◽  
Horizontal Gradients ◽  
Significant Difference ◽  
Preferred Temperatures ◽  
Laboratory Investigations ◽  
Horizontal Temperature Gradients ◽  
Selection Of

Preferred temperatures of underyearling rainbow trout (Salmo gairdneri) were determined in both vertical and horizontal temperature gradients. No statistically significant difference was found between the preferred temperatures by the two different methods. This suggests that the nature of the gradient plays a lesser role than generally believed in laboratory investigations of temperature preference.

scholarly journals 2-Piece Cork Stoppers as Alternative for Valorization of Thin Cork Planks: Analysis by LCA Methodology

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 873
Author(s):  
Francisco Javier Flor-Montalvo ◽  
Agustín Sánchez-Toledo Ledesma ◽  
Eduardo Martínez Cámara ◽  
Emilio Jiménez-Macías ◽  
Jorge Luis García-Alcaraz ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Raw Materials ◽  
Lca Methodology ◽  
Significant Difference ◽  
Different Dimensions ◽  
The Impact ◽  
Different Thickness ◽  
Cork Stoppers ◽  
Wine Bottle

Natural stoppers are a magnificent closure for the production of aging wines and unique wines, whose application is limited by the availability of raw materials and more specifically of cork sheets of different thickness and quality. The growing demand for quality wine bottle closures leads to the search for alternative stopper production. The two-piece stopper is an alternative since it uses non-usable plates in a conventional way for the production of quality caps. The present study has analyzed the impact of the manufacture of these two-piece stoppers using different methodologies and for different dimensions by developing an LCA (Life Cycle Assessment), concluding that the process phases of the plate, its boiling, and its stabilization, are the phases with the greatest impact. Likewise, it is detected that the impacts in all phases are relatively similar (for one kg of net cork produced), although the volumetric difference between these stoppers represents a significant difference in impacts for each unit produced.

scholarly journals Optimising the selection of food items for FFQs using Mixed Integer Linear Programming

2014 ◽  
Vol 18 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Johanna C Gerdessen ◽  
Olga W Souverein ◽  
Pieter van ‘t Veer ◽  
Jeanne HM de Vries
Keyword(s):  
Linear Programming ◽  
Integer Linear Programming ◽  
Mixed Integer Linear Programming ◽  
Selection Process ◽  
Saturated Fat ◽  
Mixed Integer ◽  
Monounsaturated Fat ◽  
Food Items ◽  
Milp Model ◽  
Selection Of

AbstractObjectiveTo support the selection of food items for FFQs in such a way that the amount of information on all relevant nutrients is maximised while the food list is as short as possible.DesignSelection of the most informative food items to be included in FFQs was modelled as a Mixed Integer Linear Programming (MILP) model. The methodology was demonstrated for an FFQ with interest in energy, total protein, total fat, saturated fat, monounsaturated fat, polyunsaturated fat, total carbohydrates, mono- and disaccharides, dietary fibre and potassium.ResultsThe food lists generated by the MILP model have good performance in terms of length, coverage and R2 (explained variance) of all nutrients. MILP-generated food lists were 32–40 % shorter than a benchmark food list, whereas their quality in terms of R2 was similar to that of the benchmark.ConclusionsThe results suggest that the MILP model makes the selection process faster, more standardised and transparent, and is especially helpful in coping with multiple nutrients. The complexity of the method does not increase with increasing number of nutrients. The generated food lists appear either shorter or provide more information than a food list generated without the MILP model.

scholarly journals Untangling the environmental from the dietary: dust does not matter

2016 ◽  
Vol 283 (1838) ◽  
pp. 20161032 ◽  
Author(s):  
Gildas Merceron ◽  
Anusha Ramdarshan ◽  
Cécile Blondel ◽  
Jean-Renaud Boisserie ◽  
Noël Brunetiere ◽  
...  
Keyword(s):  
Critical Role ◽  
Tooth Wear ◽  
Textural Analysis ◽  
Significant Determinant ◽  
Intrinsic Properties ◽  
Dental Microwear ◽  
Natural Conditions ◽  
Evolutionary Mechanisms ◽  
Food Items ◽  
Selection Of

Both dust and silica phytoliths have been shown to contribute to reducing tooth volume during chewing. However, the way and the extent to which they individually contribute to tooth wear in natural conditions is unknown. There is still debate as to whether dental microwear represents a dietary or an environmental signal, with far-reaching implications on evolutionary mechanisms that promote dental phenotypes, such as molar hypsodonty in ruminants, molar lengthening in suids or enamel thickening in human ancestors. By combining controlled-food trials simulating natural conditions and dental microwear textural analysis on sheep, we show that the presence of dust on food items does not overwhelm the dietary signal. Our dataset explores variations in dental microwear textures between ewes fed on dust-free and dust-laden grass or browse fodders. Browsing diets with a dust supplement simulating Harmattan windswept environments contain more silica than dust-free grazing diets. Yet browsers given a dust supplement differ from dust-free grazers. Regardless of the presence or the absence of dust, sheep with different diets yield significantly different dental microwear textures. Dust appears a less significant determinant of dental microwear signatures than the intrinsic properties of ingested foods, implying that diet plays a critical role in driving the natural selection of dental innovations.

scholarly journals Influence of the method of disintegration of biomass of microalga Chlorella sorokiniana on the production of lipid fraction

2019 ◽  
Vol 59 (7) ◽  
pp. 85-91
Author(s):  
Yulia A. Smyatskaya ◽  
◽  
Natalia A. Politaeva ◽  
Amira Toumi ◽  
◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cell Wall ◽  
Microwave Radiation ◽  
High Speed ◽  
Unsaturated Fatty Acids ◽  
Lipid Fraction ◽  
Chlorella Sorokiniana ◽  
Lipid Fractions ◽  
Significant Difference ◽  
Selection Of

This article discusses the effect of the disintegration of the cell wall of the microalgae Chlorella sorokiniana on the output of the lipid fraction. The biomass of the microalgae Chlorella sorokiniana was grown under laboratory conditions in special photobioreactors at a temperature of 25 °C, with a constant aeration of a mixture of carbon dioxide and air at a rate of 1.5 liters/min, illumination 2200-2800 Lx. Nutrient medium for cultivation contained macro – and micronutrients for high-speed growth of microalgae. Selection of optimal cultivation parameters allows obtaining biomass with desired properties. Disintegration was carried out with the homogenization of biomass and under the influence of microwave radiation. Extraction of lipids was carried out on a semi-automatic extractor according to the Randall method, using organic solvents. The output of the lipid fraction without treatment was 10.18% after the destruction of the cell wall 14.45% with the homogenization of biomass and 13.85% under the influence of microwave radiation. A qualitative analysis of the lipid fraction, carried out under gas chromatography, obtained under various conditions showed that there was no significant difference in composition from the disintegration method. Lipid fractions (more than 50%) in both cases consist mainly of unsaturated fatty acids, of which irreplaceable unsaturated fatty acids constitute more than 18% for both samples. The residual biomass formed after the extraction of the lipid fraction can be used as fertilizer in the plant, for the manufacture of sorption materials for the purification of industrial water and as a biofuel. The purpose of this study was to study the effect of cell wall disintegration on the output of the lipid fraction and qualitative composition.

scholarly journals Influence of Foot Progression Angle on Center of Pressure During Stair Ascending in Subjects With Chronic Ankle Instability

2021 ◽  
Vol 15 ◽  
pp. 350-354
Author(s):  
Jung-Hyun Ban ◽  
Tae-Ho Kim
Keyword(s):  
Center Of Pressure ◽  
Ankle Instability ◽  
Chronic Ankle Instability ◽  
Foot Progression Angle ◽  
Significant Difference ◽  
The Stability ◽  
Neutral Posture ◽  
Criteria For Selection ◽  
Anterior Posterior ◽  
Selection Of

The purpose of this study was to identify changes in the center of pressure during stair ascending in subjects with chronic ankle instability while different angles of foot are applied. The subjects of this study were 20 male and female adults with chronic ankle instability were selected from among the employees of D Hospital in Daegu Metropolitan City. The criteria for selection of subjects with chronic ankle instability were those who felt wobbling in the ankle joint and scored not higher than 24 points in a test using the Cumberland Ankle Instability Tool (CAIT). The subjects carried out stair ascending in neutral, toe-in and toe-out postures, respectively, and changes in the center of pressure (COP) were compared and analyzed. The results of this study, no statistically significant difference appeared in the comparison between the toe-in posture and neutral posture or between the neutral posture and the toe-out posture but medial/lateral movements of the center of pressure showed significant differences between the toe-in and toe-out postures. In addition, the total travel range and the moving range of the center of pressure, the average velocity, and the anterior/posterior movements of the center of pressure showed no statistically significant difference among all three postures. As a result, it could be seen that when adults with chronic ankle instability climb the stairs, the toe-in posture reduce the medial/lateral movements of the center of pressure thereby increasing the stability of the ankle and effectively preventing re-injuries.

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