The role of Acacia in the diets of Australian marsupials ? A review.

2003 ◽  
Vol 25 (2) ◽  
pp. 121 ◽  
Author(s):  
NA Irlbeck ◽  
ID Hume
Keyword(s):  
Tammar Wallaby ◽  
Energy Budgets ◽  
Brushtail Possum ◽  
Seasonal Component ◽  
Acacia Gum ◽  
Form Part ◽  
Dry Seasons ◽  
Petaurus Breviceps ◽  
Quantitative Contributions

Many of the 600 species of Acacia found in Australia form part of the diet of several groups of marsupials. Acacia foliage is generally high in tannins but is consumed by several folivorous possums and by some macropods (kangaroos and wallabies), but the macropods eat it mainly as dry leaf litter during times of food shortage (in dry seasons and drought). Acacia gum is an important diet component of two omnivorous possums (Petaurus breviceps, Gymnobelidius leadbeateri) and, to a lesser extent, two rat-kangaroos (Bettongia sp.). Acacia seeds are consumed by marsupials to a limited extent, but are an important seasonal component of the diet of the mountain brushtail possum (Trichosurus cunninghami), and possibly the tammar wallaby (Macropus eugenii) on Kangaroo Island. Likewise, Acacia arils (lipid-rich appendages to the seeds of some species) are an important seasonal component of the diet of the mahogany glider (Petaurus gracilis). Acacia pollen and nectar are consumed by several omnivorous possums (e.g., Petaurus norfolcensis) as well as by at least one species of rock-wallaby (Petrogale sp.), but the quantitative contributions made by these floral products to the protein and energy budgets of the consumers have been difficult to determine. Thus several parts of the Acacia plant are food resources for one or more groups of marsupials, but the contribution of the genus to marsupial nutrition is often overlooked.

scholarly journals Role of PGF2alpha and oxytocin in parturition in the brushtail possum (Trichosurus vulpecula)

Reproduction ◽  
2002 ◽  
pp. 429-434 ◽  
Author(s):  
C Veitch ◽  
L Brown ◽  
C Sernia ◽  
RT Gemmell
Keyword(s):  
Corpus Luteum ◽  
Uterine Contraction ◽  
Adrenal Glands ◽  
Tammar Wallaby ◽  
Brushtail Possum ◽  
Uterine Contractions ◽  
Prostaglandin F ◽  
Birth Position

Maturation of the fetal pituitary and adrenal glands allows the secretion of cortisol, which in turn leads to an increase in prostaglandin and mesotocin production. The production of prostaglandin and mesotocin results in an increase in uterine contractions and initiates birth in marsupials. The major metabolite of PGF(2alpha), 13,14-dihydro-15-keto-prostaglandin F(2alpha) (PGFM), has been found in the plasma of the possum at the time of birth and administration of PGF(2alpha) to female possums induced the adoption of the birth position. Evidence that mesotocin is an integral hormone of birth in the tammar wallaby indicates that both PGF(2alpha) and mesotocin or oxytocin are required for marsupial birth. The presence of PGF(2alpha) receptors in the uterus and corpus luteum of the possum, and the in vitro uterine responsiveness to PGF(2alpha) or oxytocin, were examined. PGF(2alpha) receptors were not observed in possum uteri and the inability of PGF(2alpha) to cause contractions indicates that PGF(2alpha) is not involved directly in contraction of the uterus at parturition. The presence of oxytocin and mesotocin receptors in the uterus of possoms and the ability of oxytocin to induce uterine contraction in vitro supports the view that mesotocin is required for expulsion of the young from the uterus. Low numbers of PGF(2alpha) receptors were found in the possum corpus luteum at birth, indicating an involvement of PGF(2alpha) in regression of the corpus luteum.

scholarly journals The role of IGFs in the regulation of ovarian follicular growth in the brushtail possum (Trichosurus vulpecula)

Reproduction ◽  
2010 ◽  
Vol 140 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Jennifer L Juengel ◽  
Lisa J Haydon ◽  
Brigitta Mester ◽  
Brian P Thomson ◽  
Michael Beaumont ◽  
...  
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Function ◽  
Antral Follicle ◽  
Brushtail Possum ◽  
Follicular Growth ◽  
Theca Cells ◽  
Ovarian Follicular Growth

IGFs are known to be key regulators of ovarian follicular growth in eutherian mammals, but little is known regarding their role in marsupials. To better understand the potential role of IGFs in the regulation of follicular growth in marsupials, expression of mRNAs encoding IGF1, IGF2, IGF1R, IGF-binding protein 2 (IGFBP2), IGFBP4 and IGFBP5 was localized by in situ hybridization in developing ovarian follicles of the brushtail possum. In addition, the effects of IGF1 and IGF2 on granulosa cell function were tested in vitro. Both granulosa and theca cells synthesize IGF mRNAs, with the theca expressing IGF1 mRNA and granulosa cell expressing IGF2 mRNA. Oocytes and granulosa cells express IGF1R. Granulosa and theca cells expressed IGFBP mRNAs, although the pattern of expression differed between the BPs. IGFBP5 mRNA was differentially expressed as the follicles developed with granulosa cells of antral follicles no longer expressing IGFBP5 mRNA, suggesting an increased IGF bioavailability in the antral follicle. The IGFBP protease, PAPPA mRNA, was also expressed in granulosa cells of growing follicles. Both IGF1 and IGF2 stimulated thymidine incorporation but had no effect on progesterone production. Thus, IGF may be an important regulator of ovarian follicular development in marsupials as has been shown in eutherian mammals.

An inter-dependence of flood and drought: disentangling amphibian beta diversity in seasonal floodplains

2017 ◽  
Vol 68 (11) ◽  
pp. 2115 ◽  
Author(s):  
Leonardo F. B. Moreira ◽  
Tainá F. Dorado-Rodrigues ◽  
Vanda L. Ferreira ◽  
Christine Strüssmann
Keyword(s):  
Community Structure ◽  
Environmental Factors ◽  
Quantitative Data ◽  
Explanatory Variable ◽  
Biotic Interactions ◽  
Ecological Role ◽  
Β Diversity ◽  
Amphibian Community ◽  
Dry Seasons

Species composition in floodplains is often affected by different structuring factors. Although floods play a key ecological role, habitat selection in the dry periods may blur patterns of biodiversity distribution. Here, we employed a partitioning framework to investigate the contribution of turnover and nestedness to β-diversity patterns in non-arboreal amphibians from southern Pantanal ecoregion. We investigated whether components of β-diversity change by spatial and environmental factors. We sampled grasslands and dense arboreal savannas distributed in 12 sampling sites across rainy and dry seasons, and analysed species dissimilarities using quantitative data. In the savannas, both turnover and nestedness contributed similarly to β diversity. However, we found that β diversity is driven essentially by turnover, in the grasslands. In the rainy season, balanced variation in abundance was more related to altitude and factors that induce spatial patterns, whereas dissimilarities were not related to any explanatory variable during dry season. In the Pantanal ecoregion, amphibian assemblages are influenced by a variety of seasonal constraints on terrestrial movements and biotic interactions. Our findings highlighted the role of guild-specific patterns and indicated that mass effects are important mechanisms creating amphibian community structure in the Pantanal.

scholarly journals PERANAN TUMBUHAN LIAR DALAM KONSERVASI SERANGGA PENYERBUK ORDO HYMENOPTERA

2016 ◽  
Vol 10 (2) ◽  
pp. 195
Author(s):  
Erniwati Erniwati ◽  
Sih Kahono
Keyword(s):  
Flowering Time ◽  
Food Resources ◽  
Wild Plants ◽  
Cultivated Plants ◽  
Applied Study ◽  
Insect Pollinators ◽  
Cultivated Plant ◽  
Dry Seasons

The role of the wild plants in relation to the conservation of the Indonesian insectpollinators was studied at several areas of Java. Three of direct observationmethods were applied: study of biodiversity and observation on the wild flowersand the insect pollinators as well, and the behaviour of the insects. The flowersof wild plants were relatively smaller and paler in colour, however they were moreattractive to insect pollinators than cultivated plants. Flowering time of the wildplants was mostly during wet seasons, contrary to that of the cultivated plantswhich was mostly during dry seasons. Our observation indicated that these wildplants are the food resources of insect pollinators during wet seasons. Observationdata support the importance of wild plants to supply food to insect pollinatorsduring wet seasons. Management of wild and cultivated plant environments isnecessary to conserve insect pollinators.

Individual Growth and Reproduction

2019 ◽  
pp. 38-56
Author(s):  
Ken H. Andersen
Keyword(s):  
Life History ◽  
Growth Model ◽  
Life Histories ◽  
Maximum Size ◽  
Individual Growth ◽  
Energy Budgets ◽  
Asymptotic Size ◽  
The Individual ◽  
Growth And Reproduction

This chapter develops descriptions of how individuals grow and reproduce. More specifically, the chapter seeks to determine the growth and reproduction rates from the consumption rate, by developing an energy budget of the individual as a function of size. To that end, the chapter addresses the question of how an individual makes use of the energy acquired from consumption. It sets up the energy budgets of individuals by formulating the growth model using so-called life-history invariants, which are parameters that do not vary systematically between species. While the formulation of the growth model in terms of life-history invariants is largely successful, there is in particular one parameter that is not invariant between life histories: the asymptotic size (maximum size) of individuals in the population. This parameter plays the role of a master trait that characterizes most of the variation between life histories.

scholarly journals A spatial-temporal continuous dataset of the transpiration to evapotranspiration ratio in China from 1981–2015

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhongen Niu ◽  
Honglin He ◽  
Gaofeng Zhu ◽  
Xiaoli Ren ◽  
Li Zhang ◽  
...  
Keyword(s):  
Hydrological Cycle ◽  
Terrestrial Ecosystem ◽  
Research Network ◽  
Energy Budgets ◽  
Climate Data ◽  
Area Index ◽  
Large Variability ◽  
Ecosystem Research ◽  
Insight Into

Abstract The ratio of plant transpiration to total terrestrial evapotranspiration (T/ET) captures the role of vegetation in surface-atmosphere interactions. However, several studies have documented a large variability in T/ET. In this paper, we present a new T/ET dataset (also including transpiration, evapotranspiration data) for China from 1981 to 2015 with spatial and temporal resolutions of 0.05° and 8 days, respectively. The T/ET dataset is based on a model-data fusion method that integrates the Priestley-Taylor Jet Propulsion Laboratory (PT-JPL) model with multivariate observational datasets (transpiration and evapotranspiration). The dataset is driven by satellite-based leaf area index (LAI) data from GLASS and GLOBMAP, and climate data from the Chinese Ecosystem Research Network (CERN). Observational annual T/ET were used to validate the model, with R2 and RMSE values were 0.73 and 0.07 (12.41%), respectively. The dataset provides significant insight into T/ET and its changes over the Chinese terrestrial ecosystem and will be beneficial for understanding the hydrological cycle and energy budgets between the land and the atmosphere.

scholarly journals The role of clinical educators in physiotherapy clinical education: The student’s perspective

2000 ◽  
Vol 56 (4) ◽  
pp. 37
Author(s):  
A. T. Dimo ◽  
T. P. Phaswana
Keyword(s):  
Clinical Education ◽  
Survey Methods ◽  
Real Life ◽  
Clinical Educator ◽  
Clinical Educators ◽  
Form Part ◽  
Real Life Situation ◽  
Descriptive Survey ◽  
Physiotherapy Students

Background and aim: Clinical educator’s play an important role in the training of physiotherapy students as they spend most of their time in a clinical setting. Clinical educators facilitate the integration of theoretical and practical components of physiotherapy education with actual patients in a real life situation. The aim of the study was to establish the clinical educator’s role as perceived by students. Methods: Descriptive survey methods utilising a close ended questionnaire were used to collect data from students. A study sample of 80 students was used. Data collected were analysed using the SAS statistical program.Results: Orientation was cited as the most important role of the clinical educator (94%), by the respondents. Teaching activities were the second most important category of the clinical educator’s role (75%). Assessment was the next category considered to form part of clinical educator’s role. Communication were not considered to be part of clinical educator’s role.Conclusion: The students perceive orientation, teaching and assessment of performance activities to constitute the role of the clinical educator. Communication activities were rated not to form part of the clinical educator’s role.

scholarly journals Contrasting Brood Sizes in Common and Arctic Terns: The Roles of Food Provisioning Rates and Parental Brooding

The Condor ◽  
2001 ◽  
Vol 103 (1) ◽  
pp. 108-117
Author(s):  
James A. Robinson ◽  
Keith C. Hamer ◽  
Lorraine S. Chivers
Keyword(s):  
Energy Intake ◽  
Food Delivery ◽  
Metabolizable Energy ◽  
Common Tern ◽  
Energy Budgets ◽  
Breeding Ecology ◽  
Common Terns ◽  
Sterna Paradisaea ◽  
Metabolizable Energy Intake

Abstract Arctic Terns (Sterna paradisaea) and Common Terns (S. hirundo) are similar in many aspects of their breeding ecology, but Common Terns generally lay three eggs per clutch whereas Arctic Terns lay two. In our study, Common Terns had a higher rate of food delivery and energy supply to the nest and higher nest attendance, indicating that they made trips of shorter average duration. This suggests that the number of chicks raised by these two species was primarily limited by the rate at which parents could supply food. However, estimated daily metabolizable energy intake of chicks was about 30% higher in Common Terns than in Arctic Terns. Common Tern chicks apparently spent a higher proportion of daily energy intake on maintenance of body temperature. It remains unknown whether this difference was because Common Tern parents could not brood three chicks as effectively as Arctic Terns brooded two or because the energy requirements for heat production in the third-hatched Common Tern chick were particularly high. If brooding did play a less important role in the energy budgets of Common Terns, the number of chicks that Arctic Terns could raise may have been limited not only by the rate at which parents could supply food to the nest but also by the requirements of chicks for brooding. We suggest that more detailed studies on the role of brooding constraints in limiting brood size in these species are required to clarify this matter.

Isolation and partial characterization of tammar wallaby luteinizing hormone and development of a radioimmunoassay

1997 ◽  
Vol 9 (4) ◽  
pp. 475 ◽  
Author(s):  
James R. McFarlane ◽  
Carl D. Rudd ◽  
Lynda M. Foulds ◽  
Terry P. Fletcher ◽  
Marilyn B. Renfree
Keyword(s):  
Luteinizing Hormone ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Tammar Wallaby ◽  
Exchange Chromatography ◽  
Significant Rise ◽  
Brushtail Possum ◽  
Response Curves ◽  
Antechinus Stuartii

Tammar wallaby (Macropus eugenii) luteinizing hormone (LH) was purified from pituitaries collected from wild and captive populations by salt sequential precipitation, ion exchange chromatography and gel filtration. Pituitary tissue (5 g) yielded 1·8 mg of purified wallaby luteinizing hormone (ME-14B), as verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A heterologous radioimmunoassay has been developed for measurement of LH in plasma of marsupials using a monoclonal antibody raised against bovine LH (518B7). This assay system was able to measure basal LH concentrations in male and female tammars and detected a significant rise in plasma LH in response to oestradiol benzoate in female tammars and luteinizing hormone-releasing hormone (LHRH) in males. Parallel dose–response curves were also obtained from pituitary extracts from four other species of marsupial (brushtail possum, Trichosurus vulpecula; brown antechinus,Antechinus stuartii; kowari, Dasyuroides byrnei; and Eastern pygmy possum,Cercartetus nanus) in this assay, which suggests its usefulness in the measurement of LH in other marsupial species.

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