A quantitative assessment of the reproductive biology of Cyclonaias tuberculata (Bivalvia: Unionidae)

1995 ◽  
Vol 73 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Thomas M. Haggerty ◽  
Jeffrey T. Garner ◽  
George H. Patterson ◽  
Lannis C. Jones Jr.
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Reproductive Performance ◽  
Quantitative Assessment ◽  
Late Summer ◽  
Early Spring ◽  
Short Term ◽  
Tennessee River ◽  
Early Fall

Two hundred and thirty-three purple wartyback unionids (Cyclonaias tuberculata) were collected approximately monthly over a 31-month period from Kentucky Reservoir (Tennessee river mile 201.3), Tennessee, between August 1988 and February 1991. An equal sex ratio and only one case of hermaphroditism were discovered. Histological examinations showed that spermatogenesis and oogenesis occurred throughout the year except during late summer and early fall. "Typical" spermatogenesis was most evident between May and July. Spawning occurred between early spring (March–April) and late summer (August). Brooding variation among females was shown by the presence of embryos in the suprabranchial chambers and gills between early April and late August. Brooding was short term, as indicated by mature larvae being found in the outer demibranchs between early July and late August. Full demibranchs were never found, possibly indicating that the study took place during years of poor reproductive performance.

scholarly journals Reproductive performance in a cat colony over a 10-year period

1970 ◽  
Vol 4 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Roy Robinson ◽  
H. W. Cox
Keyword(s):  
Sex Ratio ◽  
Litter Size ◽  
Reproductive Performance ◽  
Late Summer ◽  
Early Spring ◽  
Inverse Relation ◽  
Future Studies ◽  
Reproductive Life ◽  
Subsequent Loss ◽  
The Mean

Various aspects of reproductive performance in a cat colony are analysed in order to provide a basis for future studies. The aspects considered are: effect of mortality on litter size at different stages, and differential effect of losses on sex ratio of kittens reared; trend in litter size for successive parities; monthly variation in frequency of litters and litter size; output of kittens per queen per year. The sex ratio for live kittens was found to be 99.3 males per 100 females. Significant lower sex ratios of 65.6 and 79.7 were found in stillborn and in kittens which died between birth and weaning respectively. The mean litter size was 4.20 born (4.07 after deducting stillbirths), 3.65 at weaning. An inverse relation was found between incidence of stillbirths and subsequent loss before weaning. The mortality rate in each case was 1.5 kittens per affected litter. The mean litter size was smaller for the first litter but then increased to a constant 'plateau' until almost the end of the queen's reproductive life. Litters were produced throughout the year, but with greater frequency in the early spring months and again in the late summer. Litter size was greater in the summer months. Kitten mortality was lower in the summer than in the winter. A mean of 10.8 kittens were born per queen per year, and the mean number weaned was 9.4, representing a survival rate of 87 per cent.

AIR-BORNE POLLEN SURVEYS IN BRITISH COLUMBIA

1967 ◽  
Vol 47 (3) ◽  
pp. 251-261 ◽  
Author(s):  
I. J. Bassett ◽  
C. W. Crompton
Keyword(s):  
United States ◽  
British Columbia ◽  
North America ◽  
Late Summer ◽  
The United States ◽  
Early Spring ◽  
Causative Agents ◽  
Early Fall ◽  
Trees And Shrubs

Results from 17 pollen collecting stations in British Columbia indicate that air-borne pollen of ragweeds and their relatives, the principal causative agents of hay fever in North America, is practically absent throughout the province. Coniferous trees and shrubs such as pines, spruces, firs, cedars, Douglas fir, hemlocks and junipers produce the greater part of the air-borne pollen from March to early July. Pollen from alders, poplars, willows and birches is also prevalent in some areas in the early spring. The peak periods of grass pollen near the United States–Canadian border occur mainly in June and the early part of July, while further north they are about a month later. Of the four types of plantain pollen identified from the different collecting stations, English plantain was the most common, especially in the southwesterly part of the province. Pollen from the lambs’-quarters and amaranth families and wormwoods occurs mainly in the late summer and early fall and is more abundant in the dry interior than along the coast.

scholarly journals Florida Edible Garden Plants: Hops (Humulus lupulus)

EDIS ◽  
2013 ◽  
Vol 2013 (10) ◽  
Author(s):  
Brian J. Pearson
Keyword(s):  
Late Summer ◽  
Early Spring ◽  
Humulus Lupulus ◽  
Home Garden ◽  
Fact Sheet ◽  
Climbing Plants ◽  
Early Fall ◽  
Garden Plants ◽  
One Year

Hops are perennial, herbaceous climbing plants commonly cultivated for their strobiles or cones (Figure 1). The cones are often used for flavoring and aroma in food, tea, and beer (Burgess 1964). Hops can make a unique addition to a home garden or landscape. It grows rapidly in the early spring to late summer. Plants reach a mature height of 18–25 feet in one year and produce cones from mid-summer to early fall. This 2-page fact sheet was written by Brian J. Pearson, and published by the UF Department of Environmental Horticulture, October 2013. http://edis.ifas.ufl.edu/ep488

scholarly journals Reproductive biology of Thamnodynastes hypoconia (Serpentes: Dipsadidae) in Brazilian subtemperate wetlands

2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1699-1709 ◽  
Author(s):  
MARLUCI M. REBELATO ◽  
GLÁUCIA M.F. PONTES ◽  
ALEXANDRO M. TOZETTI
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Related Species ◽  
Sexual Maturity ◽  
Late Summer ◽  
Abundant Species ◽  
Early Fall ◽  
Macroscopic Analysis

ABSTRACT This study aimed to describe the reproductive biology of populations of Thamnodynastes hypoconia in subtemperate wetlands based on macroscopic analyses of their gonads. We analyzed 101 specimens from the southernmost regions of Brazil. The males had a greater snout-vent length, but the females reached sexual maturity with a greater body size. The reproductive cycle of the females was seasonal, with secondary vitellogenesis occurring between the winter and spring (May-October). Based on macroscopic analysis of gonads, data suggests that males have a continuous reproductive cycle. Parturition occurs between the late summer and early fall (January-April). The clutch size ranged between 4 and 16 embryos and showed no relationship with the female's body size. The recorded reproductive frequency of T. hypoconia is low (38 %) compared to other phylogenetically related species. Conversely, the studied populations appear to have a high reproductive success because it is an abundant species in the study site.

Predatory-Phase Sea Lampreys (Petromyzon marinus) in the Great Lakes

1980 ◽  
Vol 37 (11) ◽  
pp. 2007-2020 ◽  
Author(s):  
B. G. H. Johnson ◽  
William C. Anderson
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Feeding Activity ◽  
Stomach Contents ◽  
Late Summer ◽  
Sea Lamprey ◽  
Fishing Effort ◽  
Early Spring ◽  
Sea Lampreys ◽  
Early Fall

Incidentally caught predatory-phase sea lampreys were obtained from the commercial fisheries of the Laurentian Great Lakes, together with related catch data, in return for a reward offered to fishermen. Catches of sea lampreys per unit of fishing effort in Lake Superior generally paralleled other indices of sea lamprey abundance. Recently metamorphosed sea lampreys tended to appear early in the season in deepwater fisheries, typically those directed toward cisco (Coregonus spp.), whereas older specimens were taken more often in gear set at shallower depths during summer and fall. The proportion of male sea lampreys in the collections decreased annually between spring and fall, due apparently to a shoreward movement of the males. Large lake trout (Salvelinus namaycush) appeared to be the preferred prey of the sea lamprey. From studies of the stomach contents, sea lamprey feeding activity appeared to reach a peak in late summer or early fall, thereafter declining until the cessation of feeding in early spring. Growth rate reached a maximum in late summer or early fall. Greatest length was attained between January and March, after which a decrease in length was observed. Predatory-phase sea lampreys remained concentrated near the mouths of their parent streams if sufficient numbers of prey were present. Their distribution in the Great Lakes was related to the location of prey.Key words: sea lamprey, predation, Great Lakes fishery

304 EFFECT OF THE SEASONAL INFERTILITY PERIOD ON OOCYTE COMPETENCE IN PIGS

2015 ◽  
Vol 27 (1) ◽  
pp. 241
Author(s):  
A. M. Giraldo ◽  
D. Hylan ◽  
R. R. Payton ◽  
J. L. Edwards
Keyword(s):  
Reproductive Performance ◽  
Late Summer ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Blastocyst Development ◽  
Oocyte Competence ◽  
Cell Numbers ◽  
Oocyte Developmental Competence ◽  
Development Rates ◽  
Early Fall

Photoperiod is the principal regulator of seasonal breeding; however, effects of photoperiod on the fertility of the domestic sow are inconclusive. Some evidence indicates that the modern sow exhibits a period of impaired reproductive performance during the late summer and early fall. Seasonal variation in oocyte developmental competence has been described as a contributing factor. Alterations in oocyte quality, along with reductions in blastocyst rates and cell numbers in embryos from summer-sourced oocytes, may be attributed to an alteration in follicular fluid (FF) composition. The objectives of this study were to determine whether seasonal variations in blastocyst development rates are associated with changes in cumulus-oocyte complex (COC) morphology and oocyte developmental competence in sows. This study also compared the effect of FF collected in spring v. summer during in vitro maturation (IVM) on oocyte competence. In experiment 1, oocytes from 3- to 8-mm follicles were aspirated from sow ovaries during 1 calendar year for a total of 77 replicates. Only oocytes with homogeneous dark cytoplasm and at least 2 layers of cumulus cells underwent IVM. Mature oocytes were electrically activated and the resulting embryos were cultured for 6 days. In experiment 2, a total of 1256 good quality COC were divided into 2 groups and cultured in IVM medium containing 10% FF collected in either spring or late summer. Metaphase II oocytes were electrically activated and cultured to generate diploid embryos. Differences between experimental groups were assessed using Student's t-test or X2. The percentage of ovaries exhibiting good-quality follicles and the number of COC per ovary remained constant during the entire calendar year (60% and 6.2 COC/ovary, respectively). However, oocyte quality decreased significantly from 3.6 to 3.2 during late August throughout early October in a 1 to 4 scale. The percentage of good-quality COC decreased significantly during late summer and early fall compared with the rest of the year (54.5 v. 65.5%). However, maturation, cleavage, and blastocyst rates did not show significant differences between the summer and the other seasons (85.5 v. 87.6, 87.8 v. 87.7, and 27.8 v. 27.0%, respectively). The presence of FF collected in either spring or summer in the IVM medium did not affect maturation, cleavage, or blastocyst rates (88.9 v. 87.7, 90.7 v. 90.5, and 42.1 v. 43.7%, respectively). Blastocyst cell numbers (Day 6) did not differ when FF from spring and summer antral follicles was used for supplementing IVM medium (43.6 v. 46.1 cells, respectively). In summary, impaired reproductive performance of domestic sows during late summer and early fall is coincident with a decreased in the number and quality of COC. However, efforts to use strict selection criteria for COC during this time period may result in maturation and development rates comparable to the rest of the seasons. Additionally, the presence of FF collected in either spring or summer in the IVM medium does not seem to affect oocyte maturation and subsequent embryo development.

Detection of Indigenous Enteric Viruses in Raw Sewage Effluents of the City of Athens, Greece, During a Two Year Survey

1985 ◽  
Vol 17 (10) ◽  
pp. 159-164 ◽  
Author(s):  
V. Krikelis ◽  
P. Markoulatos ◽  
N. Spyrou ◽  
Ch Serie
Keyword(s):  
Enteric Viruses ◽  
Late Summer ◽  
Early Spring ◽  
Seasonal Fluctuations ◽  
Urban Sewage ◽  
Sewage Effluents ◽  
Concentration Step ◽  
Early Fall ◽  
The City ◽  
Coxsackie B

In a two year survey of enteric viruses in urban sewage effluents of Athens, Greece, during 1982–1983, indigenous Enteroviruses and Adenoviruses have been detected. Enteroviruses, (Polio, Coxsackie B and Echo) were recovered on Vero or BGM cells by inoculation of samples, after a pre-concentration step utilizing glass powder. Adenoviruses were recovered on Hep2 cells after being Precipitated with protamine sulfate. The viral content was in the order of 102 -103 cytopathogenic units (CPU) per litre of sample. Seasonal fluctuations of the various serotypes recovered were observed. The peak of Adenoviruses was found in early spring whereas Enteroviruses peaked in late summer-early fall. The most frequently recovered serotypes within each group were : Polio III (47%), Coxsackie B5 (56%), Echo 7 (61%) and Adeno 7 (43%). Similar isolation frequencies, except for Polio, were found in humans as well. As regards Polioviruses, all strains recovered from sewage were found to be vaccine-related by the intratypic serodifferentiation test.

scholarly journals For everything there was a season: phenological shifts in the Tetons

2018 ◽  
Vol 41 ◽  
pp. 11-47
Author(s):  
Trevor Bloom ◽  
Corinna Riginos ◽  
Donal O'Leary
Keyword(s):  
Late Summer ◽  
Early Spring ◽  
Individual Species ◽  
Ecological Communities ◽  
Spring Temperature ◽  
Phenological Shifts ◽  
Early Fall ◽  
First Flowering Date ◽  
Photo Collection ◽  
Plant Pollinator

Around the world, phenology — the timing of ecological events — is shifting as the climate warms. This can lead to a variety of consequences for individual species and entire ecological communities. Grand Teton National Park biologists have identified this topic (“effect of earlier plant flowering on pollinators and wildlife”) as one of their priority research needs. We assembled phenological observations of first flowering dates for 49 species collected by Frank Craighead, Jr. in the 1970s, before significant warming occurred. In 2016 we began standardized phenological observations of these same species, plus an additional 61 for a total of 110 species, in the same locations. First flowering date for 65% of the species with historic records correlated significantly with mean spring temperature; these species are therefore expected to flower earlier now than in the 1970s. Early spring flowers had the largest shifts in phenology, emerging an average of 21 days earlier now relative to the 1970s. Yet not all species are emerging earlier. In particular, phenology of late summer/early fall flowering plants was largely unchanged. In 2017, we initiated pollinator collections at our key phenology sites. Additional years of observations will allow us to better understand plant-pollinator interactions and identify potential phenological mismatches.   Featured photo by Shawna Wolf, taken from the AMK Ranch photo collection.

scholarly journals Relationship between variability of the semidiurnal tide in the Northern Hemisphere mesosphere and quasi-stationary planetary waves throughout the global middle atmosphere

2009 ◽  
Vol 27 (11) ◽  
pp. 4239-4256 ◽  
Author(s):  
X. Xu ◽  
A. H. Manson ◽  
C. E. Meek ◽  
T. Chshyolkova ◽  
J. R. Drummond ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Middle Atmosphere ◽  
Low Frequency ◽  
Late Summer ◽  
Early Spring ◽  
Planetary Waves ◽  
Semidiurnal Tide ◽  
Opposite Hemisphere ◽  
Linear Interaction ◽  
Early Fall

Abstract. To investigate possible couplings between planetary waves and the semidiurnal tide (SDT), this work examines the statistical correlations between the SDT amplitudes observed in the Northern Hemisphere (NH) mesosphere and stationary planetary wave (SPW) with wavenumber S=1 (SPW1) amplitudes throughout the global stratosphere and mesosphere. The latter are derived from the Aura-MLS temperature measurements. During NH summer-fall (July–October), the mesospheric SDT amplitudes observed at Svalbard (78° N) and Eureka (80° N) usually do not show persistent correlations with the SPW1 amplitudes in the opposite hemisphere. Although the SDT amplitudes observed at lower latitudes (~50–70° N), especially at Saskatoon (52° N), are often shown to be highly and positively correlated with the SPW1 amplitudes in high southern latitudes, these correlations cannot be sufficiently explained as evidence for a direct physical link between the Southern Hemisphere (SH) winter-early spring SPW and NH summer-early fall mesospheric SDT. This is because the migrating tide's contribution is usually dominant in the mid-high latitude (~50–70° N) NH mesosphere during the local late summer-early fall (July–September). The numerical correlation is dominated by similar low-frequency variability or trends between the amplitudes of the NH SDT and SH SPW1 during the respective equinoctial transitions. In contradistinction, during NH winter (November–February), the mesospheric SDT amplitudes at northern mid-high latitudes (~50–80° N) are observed to be significantly and positively correlated with the SPW1 amplitudes in the same hemisphere in most cases. Because both the SPW and migrating SDT are large in the NH during the local winter, a non-linear interaction between SPW and migrating SDT probably occurs, thus providing a global non-migrating SDT. This is consistent with observations of SDT in Antarctica that are large in summer than in winter. It is suggested that climatological hemispheric asymmetry, e.g. the SH and NH winter characteristics are substantially different, lead to differences in the inter-hemispheric SPW-tide physical links.

Isolation of Stenotrophomonas maltophilia from Clinical Samples in Some Hospitals in Shiraz, Iran

2020 ◽  
pp. 1-3
Author(s):  
Majid Baserisalehi ◽  
Samira Zarezadeh ◽  
Majid Baserisalehi ◽  
Saeed Shoa
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Enterobacter Aerogenes ◽  
Late Summer ◽  
Early Spring ◽  
Clinical Samples ◽  
Bacillus Species ◽  
Microbiological Analysis ◽  
Blood Samples ◽  
Healthcare Facilities ◽  
Phenotypic Methods

Stenotrophomonas maltophilia is an emerging pathogenic non-fermentative Gram-negative Bacillus species. It has caused many nosocomial infections and can be isolated from various hospital wards and healthcare facilities. Research has shown that most of its strains are inherently resistant to many antibiotics and have multidrug resistance. This research intended to determine its occurrence frequency at some Hospitals in shiraz, Iran. The present study was conducted in six months (from early spring to late summer 2019). Clinical samples (Blood, Urine and cerebrospinal fluid (CSF)) collected from 120 patients afflicted with various infections. The samples were transferred to the Laboratory and subjected to microbiological analysis. Identification of the isolates was carried out by phenotypic methods and Stenotrophomonas maltophilia isolates verified using molecular methods. In total, various bacteria were isolated from 84 clinical samples. The isolates were Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Stenotrophomonas maltophilia, Staphylococcus aureus and Pseudomonas aeruginosa. Stenotrophomonas maltophilia was isolated from 17 (20.2%) positive samples and most of them were isolated from blood samples. Our finding indicated that Stenotrophomonas maltophilia isolated more from blood samples follow by CSF sample. In addition, our finding illustrated that Stenotrophomonas maltophilia can be considered as the common nosocomial agent at hospitals in Shiraz, Iran.

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