Cycles of reproduction and condition in Tasmanian blue mussels, Mytilus edulis planulatus

1984 ◽  
Vol 35 (3) ◽  
pp. 307 ◽  
Author(s):  
TG Dix ◽  
A Ferguson
Keyword(s):  
Mytilus Edulis ◽  
Early Spring ◽  
Late Winter ◽  
Reproductive Condition ◽  
Late Autumn ◽  
Blue Mussels ◽  
Early Autumn ◽  
Condition Indices ◽  
One Year ◽  
Autumn And Winter

Major spawning by M. e. planulatus occurred in the late winter or early spring at Hinders Reef, Margate and Birchs Bay in 1980 and 1981. Spawning occurred also over the summer and early autumn although a major spawning was indicated during this period at only one site in one year. At the two sites where temperatures were recorded, the major spring spawning occurred at about or just above 10�C. Gonads built up reproductive condition during late autumn and winter at all sites in 1980 and 1981. Condition indices were highest at these times and fell when spring spawning occurred.

Seasonal variation in susceptibility of apricot to Pseudomonas syringae pv. syringae (bacterial canker), and site of infection in apricot and cherry

1987 ◽  
Vol 27 (3) ◽  
pp. 475 ◽  
Author(s):  
DLS Wimalajeewa
Keyword(s):  
Seasonal Variation ◽  
Pseudomonas Syringae ◽  
Natural Infection ◽  
Late Winter ◽  
Bacterial Canker ◽  
Late Autumn ◽  
Early Autumn ◽  
Autumn And Winter ◽  
And Control ◽  
Made In

The seasonal variation in susceptibility of buds, stems, leaves and fruit of apricot to Pseudomonas syringae pv. syringae, and sites through which infection occurs in apricot and cherry were studied. Infection of apricot and cherry occurred through buds, flowers, leaves, fruit and stems but not leaf scars through which natural infection can occur. Only stem and bud inoculations consistently led to the establishment of cankers. The proportion of buds showing infection was highest with inoculations made in late autumn and winter (May-July), and lowest with inoculations in summer (December-February). The number of stem inoculations, resulting in extensive cankers, was highest in late winter and spring (August-November) and lowest in summer and early autumn (December- March). Leaves and fruit were susceptible only during spring (September-November), when they were immature. The importance of these findings in relation to epidemiology and control of bacterial canker is discussed.

The biology of Gammarus (Crustacea, Amphipoda) in the northwestern Atlantic. X. Gammarus finmarchicus Dahl

1975 ◽  
Vol 53 (8) ◽  
pp. 1110-1115 ◽  
Author(s):  
D. H. Steele ◽  
V. J. Steele
Keyword(s):  
Life Cycle ◽  
New Brunswick ◽  
Long Island ◽  
Long Island Sound ◽  
Western Atlantic ◽  
Late Autumn ◽  
Early Autumn ◽  
Autumn And Winter ◽  
Island Sound

Gammarus finmarchicus is an amphi-Atlantic species. In the western Atlantic it is found from the island of St. Pierre south to Long Island Sound. At St. Andrews, New Brunswick, 50% maturity occurs at 10.5 mm in the females. Reproduction is in progress throughout the year, but small females evidently are in a resting condition during September–October before breeding. The release of young by the population is greater in the spring, summer, and early autumn than it is in late autumn and winter. The young released in the spring and summer do not reproduce until the next year so that the life cycle is annual.

scholarly journals Human Sapovirus among Outpatients with Acute Gastroenteritis in Spain: A One-Year Study

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 144 ◽  
Author(s):  
Miguel F Varela ◽  
Enrique Rivadulla ◽  
Alberto Lema ◽  
Jesús L Romalde
Keyword(s):  
Acute Gastroenteritis ◽  
Age Groups ◽  
The Elderly ◽  
Mean Value ◽  
Early Spring ◽  
Clinical Samples ◽  
Late Winter ◽  
Viral Pathogen ◽  
One Year ◽  
Different Strains

Viral agents of human gastroenteritis affect people of all ages across the globe. As a mainly self-limiting disease, it is difficult to evaluate the real prevalence of etiological agents circulating in each region. Many of the analyzed outbreaks are caused by viruses of the family Caliciviridae, especially the genus Norovirus (NoV). Most studies have focused on other enteric viruses, leaving sapovirus (SaV) underestimated as an important emerging human threat. This one-year study analyzed clinical samples from hospital outpatients with acute gastroenteritis in Spain, with the aim of revealing the importance of human SaV as an emerging viral pathogen. A total of 2667 stools were tested using reverse transcription (RT)-qPCR to detect and quantify SaV. Sapovirus was detected in all age groups, especially in infants, children, and the elderly. The prevalence was 15.64% (417/2667), and was slightly higher in 0–2- and 3–5-year-olds (19.53% and 17.95%, respectively) and much lower in 13–18-year-olds (9.86%). Positive samples were detected throughout the year, with peaks of detection during autumn and the late winter to early spring months. The mean value for the quantified samples was 6.5 × 105 genome copies per gram of stool (GC/g) (range 2.4 × 103–6.6 × 1011 GC/g). RT-nested PCR and sequencing were used for further genotyping. Genetic characterization showed a predominance of genogroup I (GI), followed by GII and GIV. The detection of multiple genotypes suggests the circulation of different strains without any clear tendency. The results obtained suggest SaV as the second major gastroenteritis agent after NoV in the region.

The dynamics of Trifolium repens in a permanent pasture I. The population dynamics of leaves and nodes per shoot axis

1989 ◽  
Vol 237 (1287) ◽  
pp. 133-173 ◽  
Keyword(s):  
Spatial Variation ◽  
Trifolium Repens ◽  
Death Rate ◽  
Birth Rate ◽  
Soil Surface ◽  
Early Spring ◽  
Late Winter ◽  
Seasonal Fluctuations ◽  
Permanent Pasture ◽  
One Year

The framework is developed for a formal quantitative analysis of the vegetative dynamics of Trifolium repens , based on partitioning the components of its growth. The method is used to describe the vegetative dynamics of T. repens in one pasture during the course of one year. Seasonal and spatial variation were analysed by regression on several environmental variables. The present paper includes only a partial analysis, covering the dynamics of leaves and nodes per shoot axis. The remainder of the analysis will be presented in subsequent papers. The production of modules per shoot axis, and the subsequent mortality of leaves, and burial and mortality of nodes, showed different patterns of spatial and seasonal variability, and different types of response to the environment. There was much seasonal and little spatial variation in rates of birth, burial and death of leaves and nodes. In contrast, there was relatively little seasonal and much spatial variation in the numbers of leaves and nodes, even though these numbers are determined by present and past births and deaths. The rate of production of leaves by individual apices varied from 0.01 per day to 0.19 per day. It appeared to be determined largely by temperature, probably of the apex, but also to some extent by genotype. Leaves survived for 1-21 weeks. The risk of leaf mortality varied with the age of the leaf, the number of sheep in the field, and the season. Leaves born in November tended to live longest, and those born in summer with many sheep shortest. At least 56% of leaves were utilized by sheep, the remainder dying from other causes. Seasonal fluctuations in death rate of leaves tended to lag three weeks behind fluctuations in birth rate, but with additional fluctuations caused by changes in grazing. The lag caused there to be a minimum of 1-5 leaves per axis in January, and a maximum of 3-12 in August, although at all times the number of leaves was increasing on some axes and decreasing on others. Axes were progressively buried by worm casts and leaf litter within 0-39 weeks of birth. The rate of burial appeared to be determined largely by earthworm activity and by treading by sheep. In autumn and early spring, nodes and internodes were buried faster than new ones were born. As a result, as few as three internodes were exposed on average in March, compared with a maximum mean of 20 in August. By late winter, some axes were entirely buried and started to grow vertically upwards towards the soil surface. Nodes survived for 14-85 weeks, the mean longevity being 51 weeks. On average, each axis bore 25 nodes, with a range of 10-49 nodes. Seasonal fluctuations in death rate lagged some 4-8 weeks behind those in birth rate. Survivial of nodes and internodes was dependent on the establishment and survival of roots. When the oldest rooted node on an axis died, all of the axis between it and the next rooted node also died. The development of pseudo-taproots increased the longevity of nodes by 100 days. Leaves had much shorter lives than their nodes. The ‘average’ shoot axis bore 3.5 nodes with leaves, 4.2 nodes still visible but without leaves, and 17.6 nodes buried beneath worm casts and litter.

scholarly journals Characterising terrestrial influences on Antarctic air masses using Radon-222 measurements at King George Island

2014 ◽  
Vol 14 (18) ◽  
pp. 9903-9916 ◽  
Author(s):  
S. D. Chambers ◽  
S.-B. Hong ◽  
A. G. Williams ◽  
J. Crawford ◽  
A. D. Griffiths ◽  
...  
Keyword(s):  
Late Summer ◽  
Early Spring ◽  
Late Winter ◽  
South American ◽  
King George Island ◽  
Air Masses ◽  
Diurnal Cycles ◽  
Baseline Values ◽  
One Year ◽  
Radon Measurements

Abstract. We report on one year of high-precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m−3 in late-summer to 44 mBq m−3 in late winter and early spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m−3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47–53° S), with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8–4.0 were estimated for the most terrestrially influenced (South American) air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

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.

Seasonal changes in the germination responses of seeds of Veronica peregrina during burial, and ecological implications

1983 ◽  
Vol 61 (12) ◽  
pp. 3332-3336 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seasonal Changes ◽  
Natural Habitat ◽  
General Pattern ◽  
Late Summer ◽  
Early Spring ◽  
Late Winter ◽  
Seasonal Temperature ◽  
Light In August ◽  
Late Autumn ◽  
Response To Temperature

Seeds of Veronica peregrina collected from a field population in central Kentucky were buried in soil and exposed to seasonal temperature changes. Fresh seeds and those exhumed after 1–26 months were tested in light and darkness at five thermoperiods simulating those in the natural habitat from early spring through late autumn. Freshly matured seeds were dormant, but they came out of dormancy in June and July and germinated to 98–100% in light in August at thermoperiods of 20:10, 25:15, 30:15, and 35:20 °C. Seeds retained the ability to germinate to high percentages at these temperatures until late winter and spring, but they never germinated to high percentages in darkness. Thus, in the natural habitat in July and August germination is prevented only by darkness and (or) insufficient soil moisture. At simulated habitat temperatures, seeds germinated to 88–100% in March and April but to only 21–69% in May and June. Seeds incubated at 15:6 °C showed a decline in germination percentages in late summer and autumn and an increase during late autumn and winter. The same general pattern of seasonal changes in germination response to temperature occurred during the 2nd year of burial.

Dispersal of Juvenile Brushtail Possums, Trichosurus vulpecula, after a Control Operation

1997 ◽  
Vol 24 (3) ◽  
pp. 279 ◽  
Author(s):  
P. E. Cowan ◽  
R. E. Brockie ◽  
R. N. Smith ◽  
M. E. Hearfield
Keyword(s):  
Initial Density ◽  
Early Spring ◽  
Late Winter ◽  
Trichosurus Vulpecula ◽  
Radio Tracking ◽  
Dispersal Behaviour ◽  
Long Distance ◽  
Control Operation ◽  
Preferred Direction ◽  
One Year

Long-distance movements of juvenile brushtail possums (Trichosurus vulpecula) from three habitats on farmland in Hawke’s Bay, New Zealand, were studied by radio-tracking after a poisoning operation. In the five years after the possum population on the study site had been reduced by 90%, the population recovered to about half its initial density. During that time, about 25% of radio-tagged juveniles dispersed 2 km or more, a maximum of 12·8 km from their natal area, with no significantly preferred direction. A greater proportion of males dispersed than females. All but one of the juveniles dispersing did so before they were one year old, and most made several moves before settling. The bimodal timing of dispersal in summer and late winter–early spring reflected an underlying similar pattern of breeding. A higher proportion of possums dispersed from the low-density pastoral and cropping habitat than from the higher-density habitats of swamp and willows. The dispersal behaviour of juveniles after the control operation differed little from that before, suggesting that dispersal of possums is not strongly influenced by density-dependent factors at the natal site.

The winter treatment of grapevines with zinc and its interaction with time of pruning

1964 ◽  
Vol 4 (14) ◽  
pp. 241 ◽  
Author(s):  
BG Coombe
Keyword(s):  
Zinc Sulphate ◽  
Field Experiments ◽  
Early Spring ◽  
Late Winter ◽  
Early Winter ◽  
Zinc Treatment ◽  
One Year ◽  
June July

Field experiments on dormant Sultana vines showed that yields were increased by applying zinc sulphate solutions immediately after pruning. Treatment by the swabbing of pruning cuts gave similar results to a cover spray. Increasing the concentration of zinc sulphate (up to the maximum tested-35 per cent) increased yield and no bud injury was seen. A delay of a day or more between pruning and treatment drastically reduced its effectiveness. Shorter intervals were tested but the results fluctuated ; a possible reason for this is discussed. The movement of zinc along Sultana canes was gauged by analysis of sections of cane cut up at varying times after swabbing the pruned end. In one year zinc moved at least 20 inches within two days, whereas, in another, it moved only 10 inches after one month. The yield of Grenache vines was increased when pruning was delayed from early winter until late winter and early spring. Zinc treatment increased yields in vines pruned in June, July, and August, but depressed yields when applied to vines pruned in September.

scholarly journals A polyphagous, tropical insect herbivore shows strong seasonality in age-structure and longevity independent of temperature and host availability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mst Shahrima Tasnin ◽  
Michael Bode ◽  
Katharina Merkel ◽  
Anthony R. Clarke
Keyword(s):  
Age Structure ◽  
Fruit Fly ◽  
Early Spring ◽  
Late Winter ◽  
Agricultural System ◽  
Wet Season ◽  
Predictive Capacity ◽  
Late Autumn ◽  
Strong Seasonality ◽  
Subtropical Australia

AbstractBactrocera tryoni is a polyphagous fruit fly that is predicated to have continuous breeding in tropical and subtropical Australia as temperature and hosts are not limiting. Nevertheless, in both rainforest and tropical agricultural systems, the fly shows a distinct seasonal phenology pattern with an autumn decline and a spring emergence. Temperature based population models have limited predictive capacity for this species and so the driver(s) for the observed phenology patterns are unknown. Using a demographic approach, we studied the age-structure of B. tryoni populations in subtropical Australia in an agricultural system, with a focus on times of the year when marked changes in population abundance occur. We found that the age-structure of the population varied with season: summer and autumn populations were composed of mixed-age flies, while late-winter and early-spring populations were composed of old to very old individuals. When held at a constant temperature, the longevity of adult reference cohorts (obtained from field infested fruits) also showed strong seasonality; the adults of spring and early autumn populations were short-lived, while late autumn and late winter adults were long-lived. While still expressing in modified landscapes, the data strongly suggests that B. tryoni has an endogenous mechanism which would have allowed it to cope with changes in the breeding resources available in its endemic monsoonal rainforest habitat, when fruits would have been abundant in the late spring and summer (wet season), and rare or absent during late autumn and winter (dry season).

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