scholarly journals Foraminiferal community response to seasonal anoxia in Lake Grevelingen (the Netherlands)

2020 ◽  
Vol 17 (6) ◽  
pp. 1415-1435 ◽  
Author(s):  
Julien Richirt ◽  
Bettina Riedel ◽  
Aurélia Mouret ◽  
Magali Schweizer ◽  
Dewi Langlet ◽  
...  
Keyword(s):  
The Netherlands ◽  
Temporal Dynamics ◽  
Community Response ◽  
Food Sources ◽  
Stressful Event ◽  
Delayed Response ◽  
Complete Disappearance ◽  
Short Period ◽  
Wide Range ◽  
Lake Grevelingen

Abstract. Over the last decades, hypoxia in marine coastal environments has become more and more widespread, prolonged and intense. Hypoxic events have large consequences for the functioning of benthic ecosystems. In severe cases, they may lead to complete anoxia and the presence of toxic sulfides in the sediment and bottom-water, thereby strongly affecting biological compartments of benthic marine ecosystems. Within these ecosystems, benthic foraminifera show a high diversity of ecological responses, with a wide range of adaptive life strategies. Some species are particularly resistant to hypoxia–anoxia, and consequently it is interesting to study the whole foraminiferal community as well as species-specific responses to such events. Here we investigated the temporal dynamics of living benthic foraminiferal communities (recognised by CellTracker™ Green) at two sites in the saltwater Lake Grevelingen in the Netherlands. These sites are subject to seasonal anoxia with different durations and are characterised by the presence of free sulfide (H2S) in the uppermost part of the sediment. Our results indicate that foraminiferal communities are impacted by the presence of H2S in their habitat, with a stronger response in the case of longer exposure times. At the deepest site (34 m), in summer 2012, 1 to 2 months of anoxia and free H2S in the surface sediment resulted in an almost complete disappearance of the foraminiferal community. Conversely, at the shallower site (23 m), where the duration of anoxia and free H2S was shorter (1 month or less), a dense foraminiferal community was found throughout the year except for a short period after the stressful event. Interestingly, at both sites, the foraminiferal community showed a delayed response to the onset of anoxia and free H2S, suggesting that the combination of anoxia and free H2S does not lead to increased mortality, but rather to strongly decreased reproduction rates. At the deepest site, where highly stressful conditions prevailed for 1 to 2 months, the recovery time of the community takes about half a year. In Lake Grevelingen, Elphidium selseyense and Elphidium magellanicum are much less affected by anoxia and free H2S than Ammonia sp. T6. We hypothesise that this is not due to a higher tolerance for H2S, but rather related to the seasonal availability of food sources, which could have been less suitable for Ammonia sp. T6 than for the elphidiids.

scholarly journals Foraminiferal community response to seasonal anoxia in Lake Grevelingen (the Netherlands)

2019 ◽  
Author(s):  
Julien Richirt ◽  
Bettina Riedel ◽  
Aurélia Mouret ◽  
Magali Schweizer ◽  
Dewi Langlet ◽  
...  
Keyword(s):  
The Netherlands ◽  
Temporal Dynamics ◽  
Community Response ◽  
Food Sources ◽  
Delayed Response ◽  
Complete Disappearance ◽  
Wide Range ◽  
Species Specific ◽  
Benthic Ecosystems ◽  
Lake Grevelingen

Abstract. Over the last decades, hypoxia in marine coastal environments have become more and more widespread, prolonged and intense. These hypoxic events have large consequences for the functioning of benthic ecosystems. They profoundly modify early diagenetic processes involved in organic matter recycling, and in severe cases, they may lead to complete anoxia and presence of toxic sulphides in the sediment and bottom water, thereby severely affecting biological compartments of benthic marine ecosystems. Within these ecosystems, benthic foraminifera show a high diversity of ecological responses, with a wide range of adaptive life strategies. Some species are particularly resistant to hypoxia/anoxia and consequently, it is interesting to study the whole foraminiferal community as well as species specific responses to such events. Here we investigated the temporal dynamics of living benthic foraminiferal communities (recognised by CellTracker™ Green) at two sites in the saltwater Lake Grevelingen in the Netherlands. These sites are subject to seasonal anoxia with different durations and are characterised by the presence of free sulphide (H2S) in the uppermost part of the sediment. Our results indicate that foraminiferal communities are impacted by the presence of H2S in their habitat, with a stronger response in case of longer exposure times. At the deepest site (34 m), one to two months of anoxia and free H2S in the surface sediment resulted in an almost complete disappearance of the foraminiferal community. Conversely, at the shallower site (23 m), where the duration of anoxia and free H2S was shorter (one month or less), a dense foraminiferal community was found throughout the year. Interestingly, at both sites, the foraminiferal community showed a delayed response to the onset of anoxia and free H2S, suggesting that the combination of anoxia and free H2S does not lead to increased mortality, but rather to strongly decreased reproduction rates. At the deepest site, where highly stressful conditions prevailed for one to two months, the recovery time of the community takes about half a year. In Lake Grevelingen, Elphidium selseyense and Elphidium magellanicum are much less affected by anoxia and free H2S than Ammonia sp. T6. We hypothesise that this is not due to a higher tolerance of H2S, but rather related to the seasonal availability of food sources, which could have been less suitable for Ammonia sp. T6 than for the elphidiids.

scholarly journals Supplementary material to "Foraminiferal community response to seasonal anoxia in Lake Grevelingen (the Netherlands)"

2019 ◽  
Author(s):  
Julien Richirt ◽  
Bettina Riedel ◽  
Aurélia Mouret ◽  
Magali Schweizer ◽  
Dewi Langlet ◽  
...  
Keyword(s):  
The Netherlands ◽  
Community Response ◽  
Supplementary Material ◽  
Lake Grevelingen

scholarly journals Global soil moisture data derived through machine learning trained with in-situ measurements

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sungmin O. ◽  
Rene Orth
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Large Scale ◽  
Short Term Memory ◽  
Temporal Dynamics ◽  
Soil Moisture Data ◽  
Wide Range ◽  
Global Soil

AbstractWhile soil moisture information is essential for a wide range of hydrologic and climate applications, spatially-continuous soil moisture data is only available from satellite observations or model simulations. Here we present a global, long-term dataset of soil moisture derived through machine learning trained with in-situ measurements, SoMo.ml. We train a Long Short-Term Memory (LSTM) model to extrapolate daily soil moisture dynamics in space and in time, based on in-situ data collected from more than 1,000 stations across the globe. SoMo.ml provides multi-layer soil moisture data (0–10 cm, 10–30 cm, and 30–50 cm) at 0.25° spatial and daily temporal resolution over the period 2000–2019. The performance of the resulting dataset is evaluated through cross validation and inter-comparison with existing soil moisture datasets. SoMo.ml performs especially well in terms of temporal dynamics, making it particularly useful for applications requiring time-varying soil moisture, such as anomaly detection and memory analyses. SoMo.ml complements the existing suite of modelled and satellite-based datasets given its distinct derivation, to support large-scale hydrological, meteorological, and ecological analyses.

scholarly journals The Band-Gap Studies of Short-Period CdO/MgO Superlattices

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ewa Przeździecka ◽  
P. Strąk ◽  
A. Wierzbicka ◽  
A. Adhikari ◽  
A. Lysak ◽  
...  
Keyword(s):  
Band Gap ◽  
Layer Thickness ◽  
Energy Gap ◽  
Band Gaps ◽  
Short Period ◽  
Wide Range ◽  
Salt Structure ◽  
Short Period Superlattices ◽  
Direct Band ◽  
Sublayer Thickness

AbstractTrends in the behavior of band gaps in short-period superlattices (SLs) composed of CdO and MgO layers were analyzed experimentally and theoretically for several thicknesses of CdO sublayers. The optical properties of the SLs were investigated by means of transmittance measurements at room temperature in the wavelength range 200–700 nm. The direct band gap of {CdO/MgO} SLs were tuned from 2.6 to 6 eV by varying the thickness of CdO from 1 to 12 monolayers while maintaining the same MgO layer thickness of 4 monolayers. Obtained values of direct and indirect band gaps are higher than those theoretically calculated by an ab initio method, but follow the same trend. X-ray measurements confirmed the presence of a rock salt structure in the SLs. Two oriented structures (111 and 100) grown on c- and r-oriented sapphire substrates were obtained. The measured lattice parameters increase with CdO layer thickness, and the experimental data are in agreement with the calculated results. This new kind of SL structure may be suitable for use in visible, UV and deep UV optoelectronics, especially because the energy gap can be precisely controlled over a wide range by modulating the sublayer thickness in the superlattices.

The functions and positions of political parties in consociational democracies: theoretical and empirical contexts

2020 ◽  
pp. 28-33
Author(s):  
O. Morhuniuk
Keyword(s):  
Political Parties ◽  
The Netherlands ◽  
Party System ◽  
Party Competition ◽  
European Countries ◽  
The Past ◽  
Democratic Regimes ◽  
Wide Range ◽  
Key Aspects ◽  
Further Development

An article is devoted to the analysis of the functions and formats of political parties in consociational democracies. In particular, it is defined that parties that represent the interests of certain subcultures in society and that reach a consensus among themselves at the level of political agreements are called segmental. At the same time, parties that encapsulate different subgroups of the society that cooperate inside the party within main features of the consociational theory (grand coalition, mutual veto, proportionality in representations, and independence of segments or society subcultures) are called consociational. The theory of consociationalism has received a wide range of theoretical additions and criticism from political scientists over the past fifty years. And while political parties should have been, by definition, one of the key aspects of research within such democratic regimes (parties are part of large coalitions and agents of representation of certain subcultures), there is very scarce number of literature that focuses on this aspect. Therefore, the presented article provides a description of the functions of political parties that could be observed as inside their subcultures as well as in interaction with other segmental parties. Based on the experience of two European countries in the period of “classical” consociationalism (Belgium and the Netherlands), we explain the functions of the parties we have defined in such societies with examples of relevant consociational practices in them. Simultaneously with the analysis of segmental parties, the article also offers the characteristics of consociational parties. The emergence of such parties has its own institutional and historical features. The way of further development of the party system and the level of preservation of consociational practices makes it possible to understand the nature of changes in the societies. Similarly, the analysis of the forms of party competition and interaction between segmental parties makes it possible to outline the forms of those consociational changes that are taking place in the research countries.

Carpatho-Ukraine’s defeat as a precursor of WWII

Rusin ◽  
2021 ◽  
pp. 201-222
Author(s):  
A.I. Kudriachenko ◽  
Keyword(s):  
International Relations ◽  
Third Reich ◽  
Historical Period ◽  
International Context ◽  
Short Period ◽  
Wide Range ◽  
Depth Study ◽  
Territorial Claims ◽  
The Third Reich

The paper analyzes the course of events and the international context of Сarpatho- Ukrainian state’s rise and defeat in terms of role and impact of the leading European actors at the end of the 1930’s. Based on an in-depth study of the wide range of literature, documents and relevant archives, the author highlights the role of Carpatho-Ukraine, which for a short period happened to be at the epicenter of the geopolitical interests of the states whose actions or inaction fueled the warmongers. The revival and strengthening of a number of European countries at that historical period deteriorized international relations. The erosion of the Versailles-Washington bases intensified the contradictions in the foreign policy between the victorious and vanquished states. The defeated countries reinforced their positions, since the victors, who were expanding their military might at the expense of Czechoslovak Republic, including Transcarpathia, were becoming more submissive in accommodating territorial claims. This situation largely updated the approaches to the Ukrainian question. The variability of the ways to solve it largely depended on the situational decisions of the Third Reich political leadership.

Glycogenolytic Enzymes of Cod (Gadus callarias) Muscle

1966 ◽  
Vol 23 (4) ◽  
pp. 527-538 ◽  
Author(s):  
J. R. Burt
Keyword(s):  
Muscle Glycogen ◽  
Maximum Activity ◽  
Chloride Ions ◽  
Relative Importance ◽  
Optimum Temperature ◽  
Short Period ◽  
Wide Range

Some properties of the enzymes amylase, phosphorylase, and phosphoglucomutase in homogenates of cod muscle have been investigated. Amylase is activated by a short period of autolysis and by chloride ions; hydrolyses cod muscle glycogen at about half the rate it hydrolyses mussel glycogen; has an optimum temperature of 52 C for up to 5 hr incubation; and has a wide range of activity with maxima around pH 5.1 and between pH. 7.0 and 7.5. Using phloridzin, an estimate of the relative importance of hydrolytic and phosphorolytic cleavage of polysaccharide in cod muscle homogenates has been made. Phosphorylase shows two activity maxima at pH 5.5 and 6.7. The properties of phosphoglucomutase, with the exception of its pH activity, in cod muscle are similar to those reported for this enzyme in other tissues. Cod muscle phosphoglucomutase has maximum activity between pH 8 and 9.

scholarly journals Rainfall spatio-temporal correlation and intermittency structure from micro-γ to meso-β scale in the Netherlands

2021 ◽  
Author(s):  
Thomas C. van Leth ◽  
Hidde Leijnse ◽  
Aart Overeem ◽  
Remko Uijlenhoet
Keyword(s):  
The Netherlands ◽  
Spatial Scales ◽  
Rainfall Variability ◽  
Temporal Structure ◽  
Temporal Correlation ◽  
Exponential Model ◽  
Rain Gauges ◽  
Wide Range ◽  
Spatio Temporal ◽  
Two Parameter

AbstractWe investigate the spatio-temporal structure of rainfall at spatial scales from 7m to over 200 km in the Netherlands. We used data from two networks of laser disdrometers with complementary interstation distances in two Dutch cities (comprising five and six disdrometers, respectively) and a Dutch nationwide network of 31 automatic rain gauges. The smallest aggregation interval for which raindrop size distributions were collected by the disdrometers was 30 s, while the automatic rain gauges provided 10-min rainfall sums. This study aims to supplement other micro-γ investigations (usually performed in the context of spatial rainfall variability within a weather radar pixel) with new data, while characterizing the correlation structure across an extended range of scales. To quantify the spatio-temporal variability, we employ a two-parameter exponential model fitted to the spatial correlograms and characterize the parameters of the model as a function of the temporal aggregation interval. This widely used method allows for a meaningful comparison with seven other studies across contrasting climatic settings all around the world. We also separately analyzed the intermittency of the rainfall observations. We show that a single parameterization, consisting of a two-parameter exponential spatial model as a function of interstation distance combined with a power-law model for decorrelation distance as a function of aggregation interval, can coherently describe rainfall variability (both spatial correlation and intermittency) across a wide range of scales. Limiting the range of scales to those typically found in micro-γ variability studies (including four of the seven studies to which we compare our results) skews the parameterization and reduces its applicability to larger scales.

scholarly journals The Lifelines COVID-19 Cohort: a questionnaire-based study to investigate COVID-19 infection and its health and societal impacts in a Dutch population-based cohort

2020 ◽  
Author(s):  
Kate Mc Intyre ◽  
Pauline Lanting ◽  
Patrick Deelen ◽  
Henry Wiersma ◽  
Judith M. Vonk ◽  
...  
Keyword(s):  
Risk Factors ◽  
Informed Consent ◽  
The Netherlands ◽  
Disease Susceptibility ◽  
Medical Center ◽  
Dutch Population ◽  
Physical And Mental Health ◽  
Weekly Basis ◽  
Wide Range ◽  
Societal Impacts

AbstractThe COVID-19 pandemic has affected billions of people around the world not only through the infection itself but also through its wider impact on public health and daily life. To assess the effects of the pandemic, a team of researchers across a wide range of disciplines developed and implemented the Lifelines COVID-19 questionnaire, leading to the development of the Lifelines COVID-19 cohort. This cohort is recruited from participants of the Lifelines prospective population cohort and the Lifelines NEXT birth cohort, and participants were asked to fill out detailed questionnaires about their physical and mental health and experiences on a weekly basis starting in late March of 2020 and on a bi-weekly basis staring in June 2020. The Lifelines region covers the three Northern provinces of the Netherlands— Drenthe, Groningen and Friesland—which together account for ∼10% of the Dutch population. To date, >70,000 people have responded to the questionnaires at least once, and the questionnaire program is still ongoing. Data collected by the questionnaires will be used to address four aspects of the outbreak: (1) how the COVID-19 pandemic developed in the three northern provinces of the Netherlands, (2) which environmental risk factors predict disease susceptibility and severity, (3) which genetic risk factors predict disease susceptibility and severity and (4) what are the psychological and societal impacts of the crisis.Informed consentAll Lifelines and Lifelines NEXT participants have provided informed consent that provide the opportunity for add-on research.Research involving human participantsBoth the Lifelines and the Lifelines NEXT studies were approved by the ethics committee of the University Medical Center Groningen.

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