The rice rat Oryzomys palustris in a Delaware salt marsh: annual reproductive cycle

1993 ◽  
Vol 71 (7) ◽  
pp. 1457-1460 ◽  
Author(s):  
Kent E. Edmonds ◽  
Milton H. Stetson
Keyword(s):  
Salt Marsh ◽  
Breeding Season ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Early Summer ◽  
Late Winter ◽  
Annual Reproductive Cycle ◽  
Monthly Basis ◽  
Lactating Females ◽  
Oryzomys Palustris

A population of the rice rat Oryzomys palustris inhabiting the Canary Creek salt marsh in Lewes, Delaware, was sampled on a monthly basis from September 1988 to December 1990. Males were assigned to the following age-classes on the basis of body mass: juveniles, 0 – 30 g; subadults, 31 – 50 g; adults, 51 g or greater. Testicular mass exhibited a seasonal pattern with lowest adult values in late autumn and early winter and peak values in late spring and early summer. Females showed similar patterns in uterine mass and vaginal patency. Pregnant and (or) lactating females were found from March to late September. The data suggest that the breeding season of the rice rat in southern Delaware begins in late winter and extends into late summer. Favorable environmental conditions may extend the breeding season for some individuals into autumn.

scholarly journals Influence of diet on the morphology of the ruminal papillae in reindeer calves (Rangifer tarandus tarandus L.)

Rangifer ◽  
1996 ◽  
Vol 16 (3) ◽  
pp. 119 ◽  
Author(s):  
Terje D. Josefsen ◽  
Tove H. Aagnes ◽  
Svein D. Mathiesen
Keyword(s):  
Dry Matter ◽  
Rangifer Tarandus ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Late Winter ◽  
Feeding Period ◽  
Cross Sectional ◽  
Sample Site ◽  
Different Seasons ◽  
Free Ranging

The influence of diet on the morphology of reindeer ruminal papillae was investigated in 4 groups of 3 free-ranging reindeer calves at different seasons, and in 11 groups of 3 reindeer calves fed experimental diets. Length, cross-sectional perimeter and density (number/cm2) of the ruminal papillae were measured in 4 sample sites in the rumen wall, and the ruminal surface enlargement factor (SEF) was calculated at each sample site. The range of group means were 2.3 to 3.4 mm for overall papillary length (mean of the four sample sites), 2.2 to 3.5 mm for overall cross-sectional perimeter, 85 to 189 papillae/cm2 for overall papillar density and 5.8 to 18.6 for overall SEF. Differences between sample sites wete observed, atrium ruminis having the highest and caudodorsal blind sac the lowest SEF (25% over and 24% below overall value, respectively). The differences between sample sites were considered to be small, indicating a homogenous ruminal content. The SEF of free-ranging animals showed a seasonal pattern, with high overall SEF (18.6) in September (late summer) and lower overall SEF {9.1) in April (late winter). Groups fed timothy silage with low content of cellulose (18.7% of dry matter) showed highest overall SEFs of the fed animals (17.8 and 13.9), while groups fed timothy silage with high content of cellulose (30.4%' of dry matter) showed lowest overall SEFs (5.8 and 7.0), indicating low ability to ferment silage with high content of cellulose. The SEF in animals fed experimental diets seemed partly to be influenced by SEF at the beginning of the feeding period.

Reproduction in Sminthopsis-Longicaudata (Marsupialia, Dasyuridae) - Laboratory Observations

1986 ◽  
Vol 13 (1) ◽  
pp. 7 ◽  
Author(s):  
PA Woolley ◽  
A Valente
Keyword(s):  
Endangered Species ◽  
Breeding Season ◽  
Early Summer ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Late Winter ◽  
Breeding Condition ◽  
Males And Females ◽  
The Mean

Observations on the pattern of reproduction in Sminthopsis longicaudata, at present considered to be an endangered species, are presented. S. longicaudata is polyoestrous and in the laboratory females are in breeding condition from late winter (August) to early summer (December). They enter oestrus up to four times during the breeding season. Two litters were born 17 and 19 days post-mating, but the gestation period may be less than 15 days. The mean length of the oestrous cycle is 34.4 days. Both males and females may be able to breed in more than one season.

Seasonality and global public interest in psoriasis: an infodemiology study

2019 ◽  
Vol 96 (1133) ◽  
pp. 139-143 ◽  
Author(s):  
Qian Wu ◽  
Zhiwei Xu ◽  
Yi-Lin Dan ◽  
Chan-Na Zhao ◽  
Yan-Mei Mao ◽  
...  
Keyword(s):  
New Zealand ◽  
Public Interest ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Early Spring ◽  
Late Winter ◽  
Search Volume ◽  
Early Autumn ◽  
Search Data ◽  
Google Search

ObjectiveAlthough patients with psoriasis frequently report seasonal changes in their symptoms, the seasonality of psoriasis has rarely been explored. This study aims to investigate the seasonal pattern of and global public interest in psoriasis using Google search data.MethodsInternet search data were collected from Google Trends. Data on the relative search volume (RSV) from January 2004 to December 2018 were retrieved using the term psoriasis. Cosinor analyses were conducted to examine the seasonality of psoriasis using data from two southern hemisphere countries (Australia and New Zealand) and four northern hemisphere countries (USA, Canada, UK and Ireland).ResultsOverall, searches for psoriasis steadily decreased between 2004 and 2010, and then rose from 2011 to 2018. On cosinor analyses, RSV of ‘psoriasis’ displayed a significant seasonal variation worldwide (p<0.025). Further analyses confirmed the seasonality of psoriasis-related RSV in Australia, New Zealand, USA, Canada, UK and Ireland (p<0.025 for all), with peaks in the late winter/early spring months and troughs in the late summer/early autumn months. The top 11 rising topics were calcipotriol/betamethasone dipropionate, ustekinumab, apremilast, shampoo, eczema, guttate psoriasis, seborrhoeic dermatitis, dermatitis, psoriatic arthritis, atopic dermatitis and arthritis.ConclusionThere was a significant seasonal pattern for psoriasis, with peaks in the late winter/early spring and troughs in the late summer/early autumn. Further studies are warranted to confirm the seasonal pattern of psoriasis using clinical data and to explore the underlying mechanisms.

scholarly journals Polysaccharide Content and Growth Rate of Lessonia Variegata J. Agardh: Investigating its Potential as a Commercial Species

2021 ◽  
Author(s):  
◽  
Lynaire Jane Abbott
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Brown Alga ◽  
High Growth ◽  
Late Summer ◽  
Late Winter ◽  
Seasonal Patterns ◽  
Dilute Acid ◽  
Monthly Basis ◽  
Commercial Species

<p>The endemic brown alga Lessonia variegata has recently been shown to be four separate lineages. To determine differences between the four morphologically similar lineages, the economically valuable polysaccharides alginate and fucoidan were extracted and yields from each of the lineages were compared. In order to determine seasonal patterns in the yield of alginate and fucoidan, and the growth rate within L.variegata, polysaccharides were extracted and the growth rate measured on a monthly basis from March 2010 until February 2011 on plants from the Wellington lineage. The alginate and fucoidan yields were obtained via stepwise extraction with dilute acid and sodium carbonate as per the previously published methods of Usov et al. (1985). The growth rate of L. variegata from the Wellington lineage was assayed using the hole punch technique first described by Parke (1948). The yield of alginate within the Wellington lineage of L. variegata fluctuated seasonally with the highest percent occurring in spring and summer 2010. The yield of fucoidan in the Wellington lineage was at its highest in mid-autumn and late spring 2010. Two different growth rates were detected for the Wellington lineage of L. variegata. There was a period of significantly high growth from late winter 2010 until late summer 2011.The Wellington lineage had the lowest yield of alginate and the highest yield of fucoidan compared to the Northern lineage, the Kaikoura lineage and the Southern lineage. Based on the findings of this study, an appropriate harvest period for the Wellington lineage of L. variegata would be in early to mid-summer when polysaccharide yields and growth rates are high and the alga is vegetative.</p>

scholarly journals Polysaccharide Content and Growth Rate of Lessonia Variegata J. Agardh: Investigating its Potential as a Commercial Species

2021 ◽  
Author(s):  
◽  
Lynaire Jane Abbott
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Brown Alga ◽  
High Growth ◽  
Late Summer ◽  
Late Winter ◽  
Seasonal Patterns ◽  
Dilute Acid ◽  
Monthly Basis ◽  
Commercial Species

<p>The endemic brown alga Lessonia variegata has recently been shown to be four separate lineages. To determine differences between the four morphologically similar lineages, the economically valuable polysaccharides alginate and fucoidan were extracted and yields from each of the lineages were compared. In order to determine seasonal patterns in the yield of alginate and fucoidan, and the growth rate within L.variegata, polysaccharides were extracted and the growth rate measured on a monthly basis from March 2010 until February 2011 on plants from the Wellington lineage. The alginate and fucoidan yields were obtained via stepwise extraction with dilute acid and sodium carbonate as per the previously published methods of Usov et al. (1985). The growth rate of L. variegata from the Wellington lineage was assayed using the hole punch technique first described by Parke (1948). The yield of alginate within the Wellington lineage of L. variegata fluctuated seasonally with the highest percent occurring in spring and summer 2010. The yield of fucoidan in the Wellington lineage was at its highest in mid-autumn and late spring 2010. Two different growth rates were detected for the Wellington lineage of L. variegata. There was a period of significantly high growth from late winter 2010 until late summer 2011.The Wellington lineage had the lowest yield of alginate and the highest yield of fucoidan compared to the Northern lineage, the Kaikoura lineage and the Southern lineage. Based on the findings of this study, an appropriate harvest period for the Wellington lineage of L. variegata would be in early to mid-summer when polysaccharide yields and growth rates are high and the alga is vegetative.</p>

Arctic summer sea-ice SAR signatures, melt-season characteristics, and melt-pond fractions

Polar Record ◽  
1997 ◽  
Vol 33 (185) ◽  
pp. 101-112 ◽  
Author(s):  
M. O. Jeffries ◽  
K. Schwartz ◽  
S. Li
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Late Summer ◽  
Beaufort Sea ◽  
Early Summer ◽  
The Arctic ◽  
Late Winter ◽  
Melt Pond ◽  
Melt Ponds ◽  
The Arctic Ocean

AbstractVariations in multiyear sea-ice backscatter from the synthetic aperture radar (SAR) aboard the ERS-1 satellite are interpreted in terms of melt-season characteristics (onset of melt in spring and of freeze-up in autumn, and the duration of the snow-decay period, the melt season, and the melt-pond season) from late winter to early autumn 1992 in two regions of the Arctic Ocean: the northeastern Beaufort Sea adjacent to the Queen Elizabeth Islands in the Canadian high Arctic and the western Beaufort Sea north of Alaska. In the northeastern Beaufort Sea, the onset of melt occurs later, and the periods of snow-cover decay and the occurrence of melt ponds are shorter than in the western Beaufort Sea. These melt-season characteristics of each area are consistent with previous observations that the northeastern Beaufort Sea has one of the most severe summer climates in the Arctic Ocean. A model, which assumes that the backscatter from multiyear floes is the sum of backscatter from bare ice and melt ponds, is used to derive the melt-pond fraction during the summer. The results show that melt-pond fractions decrease from an early-summer maximum of about 60% to a late-summer minimum around 10%. The magnitude of the melt-pond fractions and their decline during the summer is consistent with previous, more qualitative data. The SAR model, which gives melt-pond fractions with lower variability and less uncertainty than previous data, offers an improved approach to the reliable estimation of the areal extent of water on ice floes. Suggestions for further improvement of the model include accounting for the consequences of wind-speed variations, summer snowfall, and freeze/thaw cycles and their effects on melt-pond and ice-surface roughness.

Seasonal changes in leaf and stem loline alkaloids in meadow fescue

2011 ◽  
Vol 62 (3) ◽  
pp. 261 ◽  
Author(s):  
Brian Patchett ◽  
Ravi Gooneratne ◽  
Lester Fletcher ◽  
Bruce Chapman
Keyword(s):  
Seasonal Changes ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Early Spring ◽  
Early Summer ◽  
Sharp Decline ◽  
Meadow Fescue ◽  
Accumulation Pattern ◽  
Loline Alkaloids

Leaf and stem loline alkaloid concentration in 10 European meadow fescue (Festuca pratensis Huds.) lines grown in a field in Canterbury, New Zealand, were determined in samples collected six times between early spring 2004 and late autumn 2005. Significant differences in loline alkaloid concentrations were noted between lines and between harvest times. Higher total loline alkaloid concentrations (up to 4990 µg g–1) were found in stems compared to leaf (up to 1770 µg g–1). However, the seasonal accumulation pattern of different loline alkaloid concentrations in leaf and stem varied. In most lines, stem loline concentration peaked sharply in late spring and declined during early summer and autumn. The seasonal pattern of leaf loline alkaloid concentration followed the stem concentration except for a sharp decline in early summer followed by an increase in late summer. In most instances, the concentration of N-formyl loline was the highest > N-acetyl loline > N-acetyl norloline > N-methyl loline. The possible role of stem and leaf loline alkaloids to deter pasture-feeding insects is briefly discussed.

scholarly journals Distribution, abundance and biology of ringed seals (Phoca hispida): an overview

1998 ◽  
Vol 1 ◽  
pp. 9 ◽  
Author(s):  
Randall R Reeves
Keyword(s):  
Polar Bear ◽  
Late Summer ◽  
Early Summer ◽  
Ringed Seal ◽  
Late Spring ◽  
Late Winter ◽  
Polar Cod ◽  
World Population ◽  
Phoca Hispida ◽  
Ringed Seals

The ringed seal (Phoca hispida) has a circumpolar Arctic distribution. Because of its great importance to northern communities and its role as the primary food of polar bears (Ursus maritimus) the ringed seal has been studied extensively in Canada, Alaska, Russia, Svalbard and Greenland as well as in the Baltic Sea and Karelian lakes. No clear-cut boundaries are known to separate ringed seal stocks in marine waters. Adult seals are thought to be relatively sedentary, but sub-adults sometimes disperse over long distances. Stable ice with good snow cover is considered the most productive habitat although production in pack ice has been little studied. Populations appear to be structured so that immature animals and young adults are consigned to sub-optimal habitat during the spring pupping and breeding season. Annual production in ringed seal populations, defined as thepup percentage in the total population after the late winter pupping season, is probably in the order of 18-24%. Most estimates of maximum sustainable yield are in the order of 7%.The world population of ringed seals is at least a few million. Methods of abundance estimation have included aerial surveys, dog searches and remote sensing of lairs and breathing holes, acoustic monitoring, correlation analysis by reference to sizes of polar bear populations, and inference from estimated energy requirements of bear populations. Aerial strip survey has been the method of choice for estimating seal densities over large areas. Adjustment factors to account for seals not hauled out at the time of the survey, for seals that dove ahead of the aircraft, and for seals on the ice within the surveyed strip but not detected by the observers, are required for estimates of absolute abundance.Male and female ringed seals are sexually mature by 5-7 years of age (earlier at Svalbard). Pupping usually occurs in March or early April and is followed by 5-7 weeks of lactation. Breeding takes place in mid to late May, and implantation is delayed for about 3 months. In at least some parts of their range, ringed seals feed mainly on schooling gadids from late autumn through early spring andon benthic crustaceans and polar cod (Boreogadus saida) from late spring through summer. Little feeding is done during the moult, which takes place in late spring and early summer. Pelagic crustaceans offshore and mysids inshore become important prey in late summer and early autumn in some areas. Ringed seals have several natural predators, the most important of which is the polar bear in most arctic regions. Arctic foxes (Alopex lagopus) kill a large percentage of pups in someareas.From a conservation perspective, the ringed seal appears to be secure. Levels of exploitation of arctic populations have usually been considered sustainable, except in the Okhotsk Sea. Large fluctuations in production of ringed seals in the Beaufort Sea and Amundsen Gulf are thought to be driven by natural variability in environmental conditions. While concern has been expressed about thepotential impacts of industrial activity and pollution on ringed seals, such impacts have been documented only in limited areas. Because of their ubiquitous occurrence and availability for sampling, ringed seals are good subjects for monitoring contaminant trends in Arctic marine food chains. 

Breeding of the Stubble Quail, Coturnix pectoralis, in South-Eastern Australia

1980 ◽  
Vol 7 (1) ◽  
pp. 117
Author(s):  
HJ Frith ◽  
SM Carpenter
Keyword(s):  
Breeding Season ◽  
Late Summer ◽  
Early Summer ◽  
Hunting Season ◽  
Annual Cycles ◽  
South Eastern ◽  
Eastern Australia ◽  
Gonad Size ◽  
The One ◽  
Latitudinal Trend

The gonad cycle, breeding season, proportion of the population in primary moult and the relative amount of body fat were examined through the year in stubble quail at eight localities covering seven degrees of latitude and including several types of habitat and climate. There were significant effects of annual cycles and rainfall on each character at each location. In gonad size the seasonal cycle accounted for 39-71% of the variability in males and 21-41% in females according to locality. Effects of rainfall accounted for 5-18 % of the variability in males and 5-19% in females. There was a suggestion of a latitudinal trend in the date of the beginning of the annual gonad cycle. Breeding at all localities was in spring and early summer with a very frequent second peak of gonad size and breeding in late summer and autumn. The timing, the relative values of the spring and summer peaks and the success of the breeding varied from place to place and from year to year in the one locality. In some years breeding was continuous virtually throughout the year. Although in some regions the hunting season is appropriately timed, considering the biology of the birds, in others it is not as it overlaps the breeding season. There is a case for standardization in the south-eastern States to May-July.

Marine zooplanktonic and benthic community respiration rates at Resolute, Canadian high Arctic

1997 ◽  
Vol 54 (5) ◽  
pp. 995-1005 ◽  
Author(s):  
H E Welch ◽  
T D Siferd ◽  
P Bruecker
Keyword(s):  
Benthic Community ◽  
Ecosystem Respiration ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Dry Weight ◽  
High Arctic ◽  
Early Summer ◽  
Community Respiration ◽  
Respiration Rates ◽  
Total Ecosystem Respiration

Benthic community respiration rates and macrozooplankton (>202 µm) biomass and respiration rates were measured throughout a calender year at Resolute (74°42 prime N, 94°50 prime W). The plankton averaged 7.2 g dry weight · m-2 with no seasonal pattern and respired 82 g O2 · m-2 · yr-1. Gelatinous and chaetognath predators made up 10% of macrozooplankton biomass and respired 6.4% of planktonic respiration. The lipid content of the nongelatinous fraction fluctuated seasonaly from 64% of dry weight in midwinter to 46% in early summer. The benthic soft-bottom community inside Resolute Bay respired about 125 g O2 · m-2 · yr-1, with a twofold rate increase in late summer. Offshore on hard bottom the few measurements we obtained suggested a respiration rate of about 75 g O2 · m-2 · yr-1. The macrozooplankton and benthos were therefore approximately equal in energy flow. The total ecosystem respiration of 157 g O2 · m-2 · yr-1 corroborated a previous independent estimate of photosynthesis of 60 g C · m-2 · yr-1 for the region. Microplankton respiration appeared to be relatively low. Our results are consistent with the hypothesis that the proporion of primary production exported to the benthos increases with decreasing water temperature and depth, increasing latitude, and increasing cell size.

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