Seasonal and Spatial Variability of Bacterial and Archaeal Assemblages in the Coastal Waters near Anvers Island, Antarctica

ABSTRACT A previous report of high levels of members of the domainArchaea in Antarctic coastal waters prompted us to investigate the ecology of Antarctic planktonic prokaryotes. rRNA hybridization techniques and denaturing gradient gel electrophoresis (DGGE) analysis of the bacterial V3 region were used to study variation in Antarctic picoplankton assemblages. In Anvers Island nearshore waters during late winter to early spring, the amounts of archaeal rRNA ranged from 17.1 to 3.6% of the total picoplankton rRNA in 1996 and from 16.0 to 1.0% of the total rRNA in 1995. Offshore in the Palmer Basin, the levels of archaeal rRNA throughout the water column were higher (average, 24% of the total rRNA) during the same period in 1996. The archaeal rRNA levels in nearshore waters followed a highly seasonal pattern and markedly decreased during the austral summer at two stations. There was a significant negative correlation between archaeal rRNA levels and phytoplankton levels (as inferred from chlorophyll a concentrations) in nearshore surface waters during the early spring of 1995 and during an 8-month period in 1996 and 1997. In situ hybridization experiments revealed that 5 to 14% of DAPI (4′,6-diamidino-2-phenylindole)-stained cells were archaeal, corresponding to 0.9 × 104 to 2.7 × 104 archaeal cells per ml, in late winter 1996 samples. Analysis of bacterial ribosomal DNA fragments by DGGE revealed that the assemblage composition may reflect changes in water column stability, depth, or season. The data indicate that changes in Antarctic seasons are accompanied by significant shifts in the species composition of bacterioplankton assemblages and by large decreases in the relative proportion of archaeal rRNA in the nearshore water column.

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Relationship of Spatial Phytoplankton Variability during Spring with Eutrophic Inshore and Oligotrophic Offshore Waters in the East Sea, Including Dokdo, Korea

Journal of Marine Science and Engineering ◽

10.3390/jmse9121455 ◽

2021 ◽

Vol 9 (12) ◽

pp. 1455

Author(s):

Minji Lee ◽

Hyejoo Ro ◽

Yun-Bae Kim ◽

Chan-Hong Park ◽

Seung-Ho Baek

Keyword(s):

Water Column ◽

Vertical Mixing ◽

Early Spring ◽

Late Spring ◽

East Sea ◽

Water Column Stability ◽

Open Sea ◽

Phytoplankton Variability ◽

Abundance And Diversity ◽

Relationship Of

The area near the subpolar front of the East Sea has high primary productivity during the spring season. We conducted two surveys, one in early spring and another in late spring, to assess environmental factors that influence phytoplankton community structure during these times. During early spring, vertical mixing supplied abundant nutrients to the surface. Due to the well-mixed water column, there were high nutrient levels, but total phytoplankton abundances and diversity were relatively low and were dominated by the diatom Chaetoceros spp. During late spring, the water column gradually stratified, with relatively high levels of nutrients in the surface layers near the coastal areas. Phytoplankton abundance and diversity at that time were higher, and there were diatoms (Pseudo-nitzschia spp. and Chaetoceros spp.), cryptophytes, and small flagellates. Pseudo-nitzschia spp. were especially abundant in re-sampled areas. The presence of a stratified and stable water mass and sufficient nitrate led to high phytoplankton growth, even in the open sea during late spring. These findings provide a better understanding of how phytoplankton population dynamics in the East Sea depend on water column stability during both early and late spring seasons.

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Seasonality and global public interest in psoriasis: an infodemiology study

Postgraduate Medical Journal ◽

10.1136/postgradmedj-2019-136766 ◽

2019 ◽

Vol 96 (1133) ◽

pp. 139-143 ◽

Cited By ~ 3

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.

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Depth-dependent molecular composition and photo-reactivity of dissolved organic matter in a boreal lake under winter and summer conditions

Biogeosciences ◽

10.5194/bg-10-6945-2013 ◽

2013 ◽

Vol 10 (11) ◽

pp. 6945-6956 ◽

Cited By ~ 51

Author(s):

M. Gonsior ◽

P. Schmitt-Kopplin ◽

D. Bastviken

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Water Column ◽

Early Spring ◽

Boreal Lakes ◽

Molecular Composition ◽

Late Winter ◽

Photochemical Degradation ◽

Photo Degradation ◽

Boreal Lake

Abstract. Transformations of dissolved organic matter (DOM) in boreal lakes lead to large greenhouse gas emissions as well as substantial carbon storage in sediments. Using novel molecular characterization approaches and photochemical degradation experiments we studied how seasonal patterns in water column stratification affected the DOM in a Swedish lake under early spring and summer conditions. Dissolved organic carbon (DOC) concentrations were consistently higher above the sediment when compared to surface waters throughout the sampling periods. Photobleaching alone could not explain this difference in DOC because the lake was covered by 40 cm-thick ice during late winter sampling and still showed the same DOC trend. The differences in the molecular diversity between surface DOM in winter and summer were consistent with ongoing photobleaching/decarboxylation and a possible bacterial consumption of photo-products. Additional photo-degradation experiments using simulated sunlight showed a production of highly oxidized organic molecules and low molecular weight compounds in all late winter samples and also in the deep water sample in summer. In the surface summer DOM sample, few such molecules were produced during the photo-degradation experiments, confirming that DOM was already photobleached prior to the experiments. This study suggests that photobleaching, and therefore also the ice cover during winter, plays a central role in surface DOM transformation, with important differences in the molecular composition of DOM between surface and deep boreal lake waters. The release of DOC from boreal lake sediments also contribute to this pattern. Photochemical degradation of DOM may be more extensive following ice-out and water column turnover when non-light exposed and thereby photosensitive DOM is photo-mineralized. Hence, the yearly DOM photo-mineralization may be greater than inferred from studies of recently light-exposed DOM.

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SEASON OF BIRTH AND CHESS EXPERTISE

Journal of Biosocial Science ◽

10.1017/s0021932007002222 ◽

2008 ◽

Vol 40 (2) ◽

pp. 313-316 ◽

Cited By ~ 10

Author(s):

FERNAND GOBET ◽

PHILIPPE CHASSY

Keyword(s):

European Union ◽

Union Member ◽

Seasonal Pattern ◽

Early Spring ◽

Late Winter ◽

Season Of Birth ◽

The European Union ◽

The Subject ◽

Chess Players ◽

Intense Debate

SummaryThe origin of talent and expertise is currently the subject of intense debate, with explanations ranging from purely biological to purely environmental. This report shows that the population of expert chess players in the northern hemisphere shows a seasonal pattern, with an excess of births in late winter and early spring. This effect remains when taking into account the distribution of births in the population at large, using statistics from the European Union member countries. A similar pattern has been found with schizophrenia, and the possible link between these two phenomena is discussed.

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Hydrobiological responses of the North Eastern Arabian Sea during late winter and early spring inter-monsoons and the repercussions on open ocean blooms

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315416000795 ◽

2016 ◽

Vol 97 (7) ◽

pp. 1467-1478 ◽

Cited By ~ 6

Author(s):

K. B. Padmakumar ◽

Lathika Cicily Thomas ◽

K. G. Vimalkumar ◽

C. R. Asha Devi ◽

T. P. Maneesh ◽

...

Keyword(s):

Water Column ◽

Arabian Sea ◽

Early Spring ◽

Winter Monsoon ◽

Late Winter ◽

Biological Production ◽

Noctiluca Scintillans ◽

The North ◽

North Eastern ◽

Eastern Arabian Sea

Winter cooling and persistent mixing for more than a quarter of year (November to early March) along the North Eastern Arabian Sea (NEAS) results in nutrient enrichment of the euphotic column thereby triggering biological production. Hydrographic characteristics of NEAS during Late Winter Monsoon (LWM) and Early Spring Inter Monsoon (ESIM) and the influence on biological production are overviewed here. Winter convective mixing signatures were evident during LWM with low SST (24°C), high SSS (36.4), deep mixed layers (>100 m) and increased surface nitrate (~1 µM). Open ocean waters observed high chlorophyll a (1–2 mg m−3) and microphytoplankton abundance (1.2–1.5 × 104 cells l−1). Diatoms and green Noctiluca scintillans were the major microphytoplankton identified. ESIM observed gradual stabilization of water column with curtailment of winter signatures and strengthening of Noctiluca scintillans blooms. Mesozooplankton biomass was higher during LWM and decreased towards ESIM with intensification of Noctiluca blooms. However during ESIM, abundance of gelatinous zooplankton occurred in the bloom region. Inter-annual variations were observed in the biological responses along with the hydrographic changes. Thus the convective process during winter monsoon and stabilization of the water column during ESIM plays a significant role in the production pattern of NEAS.

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Contrasting root overwintering strategies of perennial wetland monocots

Botany ◽

10.1139/cjb-2018-0065 ◽

2018 ◽

Vol 96 (10) ◽

pp. 653-661 ◽

Cited By ~ 4

Author(s):

Tim Nieman ◽

Yvonne Hoogzaad ◽

Susara J.E. Marcotte ◽

Peter Ryser

Keyword(s):

Seasonal Pattern ◽

Resource Economics ◽

Early Spring ◽

Temperate Climate ◽

Root Turnover ◽

Late Winter ◽

Winter Mortality ◽

Northern Ontario ◽

Tetrazolium Chloride ◽

Root Mortality

Root turnover is an important contributor to ecosystem nutrient and carbon cycling, but seasonal aspects of root mortality are not well known. This study tests the hypothesis that in strongly seasonal climates, such as in Northern Ontario, Canada, perennial wetland monocots fall into two distinct categories with respect to their root overwintering strategy: complete senescence or survival over the winter. Root survival in late winter and early spring was tested for a total of 26 species using vitality staining with tetrazolium chloride. Root survival in spring was either over 85% (18 species) or 0% (8 species). Lateral root survival was marginally lower than that of basal roots. In some species, low nutrient supply slightly increased root winter mortality, but did not change the seasonal pattern. We conclude that in a northern temperate climate, the overwintering strategies of roots of herbaceous monocots are binary: either avoidance or tolerance of the long unfavourable season, similar to deciduous and evergreen leaves among woody plants. Roots do not gradually die during the unfavourable season, but either completely senesce in the autumn or survive the winter. The distinct root overwintering strategies presumably affect the species’ resource economics and ecosystem processes.

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Characteristics and vertical distribution of Atlantic cod (Gadus morhua) eggs in the northern Gulf of St. Lawrence, and the possible effect of cold water temperature on recruitment

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f96-297 ◽

1997 ◽

Vol 54 (1) ◽

pp. 211-223 ◽

Cited By ~ 14

Author(s):

P Ouellet

Keyword(s):

Vertical Distribution ◽

Water Column ◽

Intermediate Layer ◽

Gadus Morhua ◽

Cold Water ◽

Atlantic Cod ◽

Early Spring ◽

Ca 125 ◽

Late Winter ◽

Cold Intermediate Layer

In early May from 1993 to 1995 the water column in the northern Gulf of St. Lawrence was weakly stratified, with cold water (<2°C) extending from ca. 125 m to the surface. Cod (Gadus morhua) eggs were distributed throughout the water column, but higher densities were observed in the cold intermediate layer. The vertical distribution of cod eggs was determined by egg size and organic (lipids, proteins) composition. Stage I egg density estimates in May 1994 ranged from 25.0 to 26.0 kg · m-3, which is higher than the water density of the upper mixed layer. Between 1980 and 1989, there was a weak positive relationship between the cold intermediate layer temperature anomalies and cod year-class strength (i.e., abundance of 3-year-old cod). However, it is unlikely that low recruitment levels caused by below-average temperature of the cold intermediate layer alone had a major impact on the recent collapse of the northern Gulf stock. Nevertheless, the poor state of the spawning stock (low abundance, poor fish condition, and less buoyant eggs) and harsh late winter and early spring conditions in the northern Gulf can limit the potential for high recruitment and rapid recovery of the northern Gulf cod stock.

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13 Years of Storms: An Analysis of the Effects of Storms on Lake Physics on the Atlantic Fringe of Europe

Water ◽

10.3390/w12020318 ◽

2020 ◽

Vol 12 (2) ◽

pp. 318 ◽

Cited By ~ 3

Author(s):

Mikkel René Andersen ◽

Elvira de Eyto ◽

Mary Dillane ◽

Russell Poole ◽

Eleanor Jennings

Keyword(s):

Water Column ◽

Western Europe ◽

Thermal Structure ◽

Winter Storms ◽

Water Column Stability ◽

Physical Conditions ◽

Order Of Magnitude ◽

Storm Frequency ◽

Summer Storm ◽

Lake Physics

While winter storms are generally common in western Europe, the rarer summer storms may result in more pronounced impacts on lake physics. Using long-term, high frequency datasets of weather and lake thermal structure from the west of Ireland (2005 to 2017), we quantified the effects of storms on the physical conditions in a monomictic, deep lake close to the Atlantic Ocean. We analysed a total of 227 storms during the stratified (May to September, n = 51) and non-stratified (November to March, n = 176) periods. In winter, as might be expected, changes were distributed over the entire water column, whereas in summer, when the lake was stratified, storms only impacted the smaller volume above the thermocline. During an average summer (May–September) storm, the lake number dropped by an order of magnitude, the thermocline deepened by an average of 2.8 m, water column stability decreased by an average of 60.4 j m−2 and the epilimnion temperature decreased by a factor of five compared to the average change in winter (0.5 °C vs. 0.1 °C). Projected increases in summer storm frequency will have important implications for lake physics and biological pathways.

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Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽

10.1071/sr9941355 ◽

1994 ◽

Vol 32 (6) ◽

pp. 1355 ◽

Cited By ~ 12

Author(s):

RB Garnsey

Keyword(s):

Soil Moisture ◽

Adult Development ◽

Survival Rates ◽

Soil Surface ◽

Early Spring ◽

Lumbricus Rubellus ◽

Late Winter ◽

Cocoon Production ◽

Density And Biomass ◽

Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

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TEMPERATURE RESISTANCE OF GOLDFISH MAINTAINED UNDER CONTROLLED PHOTOPERIODS

Canadian Journal of Zoology ◽

10.1139/z59-050 ◽

1959 ◽

Vol 37 (4) ◽

pp. 419-428 ◽

Cited By ~ 40

Author(s):

William S. Hoar ◽

G. Beth Robertson

Keyword(s):

Temperature Change ◽

Seasonal Variations ◽

Rapid Growth ◽

Endocrine System ◽

Early Spring ◽

Late Winter ◽

Thyroid Activity ◽

Temperature Resistance ◽

Sudden Temperature Change

Goldfish maintained under controlled photoperiods for 6 weeks or longer were relatively more resistant to a sudden elevation in temperature when the daily photoperiods had been long (16 hours) and relatively more resistant to sudden chilling when they had been short (8 hours). The magnitude of the effect varied with the season. Thyroid activity was slightly greater in fish maintained under the shorter photoperiods. The longer photoperiods stimulated more rapid growth of ovaries during late winter and early spring. The endocrine system is considered a link in the chain of events regulating seasonal variations in resistance to sudden temperature change.

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