Response of wild Trumpeter Swan (<em>Cygnus buccinator</em>) broods to wetland drawdown and changes in food abundance

A brief period of drawdown can stimulate wetland productivity and enhance the attractiveness of a site for breeding Trumpeter Swans (Cygnus buccinator) by providing a nutrient pulse. Drawdown of a pond in Aurora, Ontario, lasting about 8 weeks in late summer and fall 2009 followed by re-flooding increased the abundance of invertebrates, especially snails, in the following year. This response was ephemeral, lasting 1 year. Wild Trumpeter Swans and their cygnets responded by selective feeding the year after drawdown, despite the risk of predation by Snapping Turtles (Chelydra serpentina). There was a strong correlation between the feeding activity of two cygnets and the local abundance of snails in the pond in 2010. The nutritional content, especially protein, calcium, phosphorus, and magnesium, of a variety of abundant foods satisfied the requirements for skeletal growth and development and was higher than that of available commercial duck grower rations. The responsive feeding behaviours of the cygnets are typical of specific appetitive behaviour and suggest that swans rapidly exploit unpredictable nutrient fluxes in their local environment.

Download Full-text

Minerals and Total Polyphenolic Content of Some Vegetal Powders

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Animal Science and Biotechnologies ◽

10.15835/buasvmcn-asb:0002 ◽

2017 ◽

Vol 74 (2) ◽

pp. 185

Author(s):

Roxana E. TUFEANU ◽

Cecilia GEORGESCU ◽

Adina FRUM ◽

Mihaela A. TIȚA ◽

Ovidiu TIȚA

Keyword(s):

Inductively Coupled Plasma ◽

Nutritional Content ◽

Total Polyphenol ◽

Inductively Coupled ◽

Bioactive Properties ◽

Watermelon Rind ◽

Polyphenolic Content ◽

Calcium Phosphorus ◽

Total Polyphenolic Content ◽

Ultrasonic Water Bath

The total polyphenolic content and minerals were determined for chia seeds, Psyllium husks and watermelon rind powder. The minerals content was performed by using the Inductively Coupled Plasma Optical Emissions Spectrometer and Atomic Absorption Spectrometer, technique FIAS-Furnace (for Se). The sample with the highest content of polyphenols was chia (2.69 mg GAE/g s.) followed by the watermelon rind powder. Reduced amounts of polyphenols were found in the Psyllium husks. Also, the total polyphenol concentration increased with the increase of the extraction time on the ultrasonic water bath. Minerals analysis indicated that powders obtained from chia seeds and watermelon rind contained large amounts of potassium, calcium, phosphorus and magnesium. The most abundant mineral in the Psyllium husks powder was found potassium, followed by calcium. In conclusion, these powders can be used as ingredients for functional food and food supplements production due to the high nutritional content and bioactive properties.

Download Full-text

FEEDING AND REPRODUCTIVE ACTIVITY OF THE COPEPODS Drepanopus forcipatus AND Calanus australis DURING LATE SUMMER ON THE SOUTHERN PATAGONIAN SHELF (ARGENTINA, 47°-55°S)

Brazilian Journal of Oceanography ◽

10.1590/s1679-87592014073406204 ◽

2014 ◽

Vol 62 (4) ◽

pp. 295-314 ◽

Cited By ~ 10

Author(s):

Julieta Carolina Antacli ◽

Marina E. Sabatini ◽

Ricardo I. Silva ◽

Daniel R. Hernández ◽

Andrés J. Jaureguizar ◽

...

Keyword(s):

Diet Composition ◽

Feeding Activity ◽

Food Pellet ◽

Late Summer ◽

Reproductive Activity ◽

Seasonal Temperature ◽

Patagonian Shelf ◽

Adult Females ◽

Female Reproductive Status ◽

Potential Food

Drepanopus forcipatus and Calanus australis are key planktonic copepods on the southern Patagonian shelf. Their feeding and reproductive patterns and population status were investigated during late summer, when environmental conditions may be critical. The presence of food in the gut and food-pellet length were recorded in adult females and the most abundant copepodite stages. Diet composition was also studied in adult females. Female reproductive status was evaluated by gonad staging. Despite generally low feeding conditions and decreasing seasonal temperature, both copepods fed to some degree. The most numerous copepodites and adult females of both species showed similarly low feeding activity. About half of the adult females of the two species and C5s of C. australis contained food in their guts, but the proportion of fed C4-females of D. forcipatus was much lower. All copepods were generally feeding at low or intermediate levels. Gonad stage distribution and population structure showed low but still ongoing reproduction in both species. Gut content findings suggest a preference for smaller nanoplanktonic particles, especially dinoflagellates by D. forcipatus, and for autotrophic prey, particularly large diatoms by C. australis. The feeding and reproduction patterns of the two copepods were likely influenced by the distributions of potential food resources and temperature.

Download Full-text

О возможности введения примеси железа в узлы A в SrTiO-=SUB=-3-=/SUB=-

Физика твердого тела ◽

10.21883/ftt.2022.03.52095.242 ◽

2022 ◽

Vol 64 (3) ◽

pp. 345

Author(s):

И.А. Случинская ◽

А.И. Лебедев

Keyword(s):

Annealing Temperature ◽

Local Environment ◽

First Principles Calculations ◽

X Ray Diffraction ◽

Xafs Spectroscopy ◽

Deviation From Stoichiometry ◽

High Annealing ◽

A Site ◽

Fe Impurity ◽

Exafs Spectra

The local environment and oxidation state of the Fe impurity in strontium titanate are studied using XAFS spectroscopy. The influence of annealing temperature and deviation from stoichiometry on the possibility of incorporation of the impurity into the A and B sites of the perovskite structure is studied. The results obtained from the X-ray diffraction, XANES spectra, and EXAFS spectra suggest that at high annealing temperature the iron atoms, at least partially (up to 30%), enter the A sites in SrTiO3. The obtained results agree with results of first-principles calculations, according to which the iron at the A site exhibits strong off-centering (the displacement of ~1 Angstrom), similar to that previously established in SrTiO3 samples doped with Mn and Co.

Download Full-text

Anions and Cations in Ice Cores from Dolleman Island and the Palmer Land Plateau, Antarctic Peninsula

Annals of Glaciology ◽

10.1017/s0260305500004286 ◽

1988 ◽

Vol 10 ◽

pp. 121-125 ◽

Cited By ~ 47

Author(s):

Robert Mulvaney ◽

David A. Peel

Keyword(s):

Antarctic Peninsula ◽

Isotope Composition ◽

Seasonal Pattern ◽

Austral Summer ◽

Ice Cores ◽

Late Summer ◽

Ionic Species ◽

Weddell Sea ◽

Seasonal Maximum ◽

A Site

High-resolution anion profiles of Cl-, NO3- and SO4 2− are presented for two cores from the Antarctic Peninsula. A 47.2 m core from a site on the Palmer Land plateau (74°01’S, 70°38’W), spans the period 1942–80, and a 10.5 m core from Dolleman Island (70°35.2’S, 60°55.5’W), on the east coast of the peninsula, spans the period 1973–85. The seasonal pattern of deposition of these species has been determined by reference to the oxygen-isotope composition. Averaged over 38 years, the annual cycle of SO4 2− at Gomez shows a seasonal maximum during the austral summer, and minimum during the winter, whereas the Cl- cycle is more complex and may show the influence of equinoctial storms. The Dolleman core is significantly influenced by the proximity of the Weddell Sea, with a mean Cl- concentration five times greater than in the core from the plateau, and it shows a clear seasonal maximum in late-summer snowfall. There is no significant long-term trend in the 38 years’ data from the plateau site, suggesting that global pollution does not contribute significantly to the anion budget. Both anions and the cations Na+, K+ and H+ have been measured for more than a complete year of snowfall and the balance of ionic species is excellent.

Download Full-text

4-Cyanoindole-2′-deoxyribonucleoside as a Dual Fluorescence and Infrared Probe of DNA Structure and Dynamics

Molecules ◽

10.3390/molecules24030602 ◽

2019 ◽

Vol 24 (3) ◽

pp. 602 ◽

Cited By ~ 3

Author(s):

Ismail A. Ahmed ◽

Arusha Acharyya ◽

Christina M. Eng ◽

Jeffrey M. Rodgers ◽

William F. DeGrado ◽

...

Keyword(s):

Protein Interactions ◽

Rna Structure ◽

High Throughput Screening ◽

Local Environment ◽

Spectroscopic Properties ◽

Site Specific ◽

Structure And Dynamics ◽

High Fluorescence ◽

Fluorescence Quencher ◽

A Site

Unnatural nucleosides possessing unique spectroscopic properties that mimic natural nucleobases in both size and chemical structure are ideally suited for spectroscopic measurements of DNA/RNA structure and dynamics in a site-specific manner. However, such unnatural nucleosides are scarce, which prompts us to explore the utility of a recently found unnatural nucleoside, 4-cyanoindole-2′-deoxyribonucleoside (4CNI-NS), as a site-specific spectroscopic probe of DNA. A recent study revealed that 4CNI-NS is a universal nucleobase that maintains the high fluorescence quantum yield of 4-cyanoindole and that among the four natural nucleobases, only guanine can significantly quench its fluorescence. Herein, we further show that the C≡N stretching frequency of 4CNI-NS is sensitive to the local environment, making it a useful site-specific infrared probe of oligonucleotides. In addition, we demonstrate that the fluorescence-quencher pair formed by 4CNI-NS and guanine can be used to quantitatively assess the binding affinity of a single-stranded DNA to the protein system of interest via fluorescence spectroscopy, among other applications. We believe that this fluorescence binding assay is especially useful as its potentiality allows high-throughput screening of DNA–protein interactions.

Download Full-text

Population and General Biology of Non-Reproductive Colonies of the Monarch Butterfly, Danaus Plexippus (L.) (Lepidoptera: Danaidae) in New South Wales.

Australian Journal of Zoology ◽

10.1071/zo9840663 ◽

1984 ◽

Vol 32 (5) ◽

pp. 663 ◽

Cited By ~ 1

Author(s):

DG James

Keyword(s):

New South ◽

Feeding Activity ◽

New South Wales ◽

Danaus Plexippus ◽

Monarch Butterfly ◽

Sexually Active ◽

General Biology ◽

South Wales ◽

Monarch Butterfly Danaus Plexippus ◽

A Site

Data were obtained on population and general biology of three non-reproductive overwintering colonies ofthe monarch butterfly, Danaus plexippus (Danaidae) during April-August in 1980,1981 and 1982 at a site near Camden in New South Wales. A mark, release and recapture study showed that the 1981 colony was largely stable and the 1982 colony was migratory. In 1980 and 1981 populations comprised less than 500 individuals but in 1982 a peak population of 3500 butterflies was recorded. Males were sexually active throughout clustering. Most females were mated but showed no ovarian development. Periods of flight and feeding activity were common. The condition of most butterflies did not deteriorate markedly during clustering. Comparisons between winter non-reproductive monarch populations in North America and Australia are discussed.

Download Full-text

Winter Carnivory and Diapause Counteract the Reliance on Ice Algae by Barents Sea Zooplankton

Frontiers in Marine Science ◽

10.3389/fmars.2021.640050 ◽

2021 ◽

Vol 8 ◽

Author(s):

Doreen Kohlbach ◽

Katrin Schmidt ◽

Haakon Hop ◽

Anette Wold ◽

Amalia Keck Al-Habahbeh ◽

...

Keyword(s):

Sea Ice ◽

Barents Sea ◽

Feeding Activity ◽

Carbon Sources ◽

Late Summer ◽

Rapid Decline ◽

Amphipod Species ◽

Ice Algae ◽

Sea Ice Extent ◽

Sea Ice Algae

The Barents Sea is a hotspot for environmental change due to its rapid warming, and information on dietary preferences of zooplankton is crucial to better understand the impacts of these changes on food-web dynamics. We combined lipid-based trophic marker approaches, namely analysis of fatty acids (FAs), highly branched isoprenoids (HBIs) and sterols, to compare late summer (August) and early winter (November/December) feeding of key Barents Sea zooplankters; the copepods Calanus glacialis, C. hyperboreus and C. finmarchicus and the amphipods Themisto libellula and T. abyssorum. Based on FAs, copepods showed a stronger reliance on a diatom-based diet. Phytosterols, produced mainly by diatoms, declined from summer to winter in C. glacialis and C. hyperboreus, indicating the strong direct linkage of their feeding to primary production. By contrast, C. finmarchicus showed evidence of year-round feeding, indicated by the higher winter carnivory FA ratios of 18:1(n-9)/18:1(n-7) than its larger congeners. This, plus differences in seasonal lipid dynamics, suggests varied overwintering strategies among the copepods; namely diapause in C. glacialis and C. hyperboreus and continued feeding activity in C. finmarchicus. Based on the absence of sea ice algae-associated HBIs (IP25 and IPSO25) in the three copepod species during both seasons, their carbon sources were likely primarily of pelagic origin. In both amphipods, increased FA carnivory ratios during winter indicated that they relied strongly on heterotrophic prey during the polar night. Both amphipod species contained sea ice algae-derived HBIs, present in broadly similar concentrations between species and seasons. Our results indicate that sea ice-derived carbon forms a supplementary food rather than a crucial dietary component for these two amphipod species in summer and winter, with carnivory potentially providing them with a degree of resilience to the rapid decline in Barents Sea (winter) sea-ice extent and thickness. The weak trophic link of both zooplankton taxa to sea ice-derived carbon in our study likely reflects the low abundance and quality of ice-associated carbon during late summer and the inaccessibility of algae trapped inside the ice during winter.

Download Full-text

Ontogeny of energy allocation reveals selective pressure promoting risk-taking behaviour in young fish cohorts

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2005.3096 ◽

2005 ◽

Vol 272 (1571) ◽

pp. 1443-1448 ◽

Cited By ~ 72

Author(s):

Peter A Biro ◽

John R Post ◽

Mark V Abrahams

Keyword(s):

Risk Taking ◽

Selective Pressure ◽

Somatic Growth ◽

Late Summer ◽

Maximum Growth ◽

Energy Allocation ◽

Early Summer ◽

Temperate Climate ◽

Trade Offs ◽

Risk Of Predation

Given limited food, prey fishes in a temperate climate must take risks to acquire sufficient reserves for winter and/or to outgrow vulnerability to predation. However, how can we distinguish which selective pressure promotes risk-taking when larger body size is always beneficial? To address this question, we examined patterns of energy allocation in populations of age-0 trout to determine if greater risk-taking corresponds with energy allocation to lipids or to somatic growth. Trout achieved maximum growth rates in all lakes and allocated nearly all of their acquired energy to somatic growth when small in early summer. However, trout in low-food lakes took greater risks to achieve this maximal growth, and therefore incurred high mortality. By late summer, age-0 trout allocated considerable energy to lipids and used previously risky habitats in all lakes. These results indicate that: (i) the size-dependent risk of predation (which is independent of behaviour) promotes risk-taking behaviour of age-0 trout to increase growth and minimize time spent in vulnerable sizes; and (ii) the physiology of energy allocation and behaviour interact to mediate growth/mortality trade-offs for young animals at risk of predation and starvation.

Download Full-text