scholarly journals A simple nutrient-dependence mechanism for predicting the stoichiometry of marine ecosystems

2015 ◽  
Vol 112 (27) ◽  
pp. 8199-8204 ◽  
Author(s):  
Eric D. Galbraith ◽  
Adam C. Martiny
Keyword(s):  
Ocean Circulation ◽  
Large Scale ◽  
Phytoplankton Community ◽  
Simple Relationship ◽  
Low Latitude ◽  
Average Composition ◽  
Biogeochemical Models ◽  
The Relationship ◽  
Globally Distributed

It is widely recognized that the stoichiometry of nutrient elements in phytoplankton varies within the ocean. However, there are many conflicting mechanistic explanations for this variability, and it is often ignored in global biogeochemical models and carbon cycle simulations. Here we show that globally distributed particulate P:C varies as a linear function of ambient phosphate concentrations, whereas the N:C varies with ambient nitrate concentrations, but only when nitrate is most scarce. This observation is consistent with the adjustment of the phytoplankton community to local nutrient availability, with greater flexibility of phytoplankton P:C because P is a less abundant cellular component than N. This simple relationship is shown to predict the large-scale, long-term average composition of surface particles throughout large parts of the ocean remarkably well. The relationship implies that most of the observed variation in N:P actually arises from a greater plasticity in the cellular P:C content, relative to N:C, such that as overall macronutrient concentrations decrease, N:P rises. Although other mechanisms are certainly also relevant, this simple relationship can be applied as a first-order basis for predicting organic matter stoichiometry in large-scale biogeochemical models, as illustrated using a simple box model. The results show that including variable P:C makes atmospheric CO2 more sensitive to changes in low latitude export and ocean circulation than a fixed-stoichiometry model. In addition, variable P:C weakens the relationship between preformed phosphate and atmospheric CO2 while implying a more important role for the nitrogen cycle.

scholarly journals The relationship between seasonal snow cover in Japan and recent climatic change

1993 ◽  
Vol 18 ◽  
pp. 166-172 ◽  
Author(s):  
Motori Nishimori ◽  
Ryuichi Kawamura
Keyword(s):  
Large Scale ◽  
Correlation Coefficients ◽  
The Sea Of Japan ◽  
Atmospheric Circulation Patterns ◽  
Teleconnection Patterns ◽  
Circulation Patterns ◽  
The Relationship ◽  
Seasonal Snow Cover ◽  
Rotated Empirical Orthogonal Function

Atmospheric circulation patterns associated with snowfall fluctuations in Japan are examined using a rotated empirical orthogonal function (EOF) analysis. We also compute correlation coefficients between the scores of EOF modes in the 500 hPa geopotential height field of the Northern Hemisphere (NH) and amounts of snowfall in Japan on annual, monthly and pentad time scales. It is found that recent variability of snowfall amount in Japan is closely related to the long-term variations of large-scale circulation patterns. It is suggested that the dominance of teleconnection patterns such as Pacific/North American (PNA) and Northern Asian (NA) are responsible for the increase of snowfall in the coastal regions of the Sea of Japan during the cold period for Japan (1977–86).

scholarly journals Parental Divorce and Sibling Relationships

2008 ◽  
Vol 30 (1) ◽  
pp. 74-91 ◽  
Author(s):  
Anne-Rigt Poortman ◽  
Marieke Voorpostel
Keyword(s):  
Relationship Quality ◽  
Large Scale ◽  
Sibling Relationships ◽  
Parental Divorce ◽  
Sibling Relationship ◽  
Parental Conflict ◽  
Long Term Effects ◽  
High Conflict ◽  
The Relationship

This study examines long-term effects of parental divorce on sibling relationships in adulthood and the role of predivorce parental conflict. It used large-scale retrospective data from the Netherlands that contain reports from both siblings of the sibling dyad. Results show limited effects of parental divorce on sibling contact and relationship quality in adulthood but strong effects on sibling conflict. The greater conflict among siblings from divorced families is explained by the greater parental conflict in these families. Parental conflict is a far more important predictor than parental divorce per se. Siblings from high-conflict families have less contact, lower relationship quality, and more conflict than do siblings from low-conflict families. Finally, when it comes to sibling relationship quality, the effect of parental divorce depends on the amount of parental conflict. Parental divorce has little effect on the quality of the relationship in low-conflict families, but it improves the relationship in high-conflict families.

The Relationship between Suicide and Five Climate Issues in a Large-scale and Long Term Study in Japan

2012 ◽  
Vol 61 (5) ◽  
pp. 532-537 ◽  
Author(s):  
K Inoue ◽  
Y Nishimura ◽  
Y Fujita ◽  
Y Ono ◽  
T Fukunaga
Keyword(s):  
Large Scale ◽  
Term Study ◽  
Long Term Study ◽  
The Relationship

scholarly journals Science in Policy Making

2013 ◽  
Vol 8 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Sabine Weiland ◽  
Vivien Weiss ◽  
John Turnpenny
Keyword(s):  
Impact Assessment ◽  
Policy Making ◽  
Large Scale ◽  
Policy Impact ◽  
The European Union ◽  
Global Challenges ◽  
Assessment Systems ◽  
Nature And Society ◽  
The Relationship

Ecological challenges are becoming more and more complex, as are their effects on nature and society and the actions to address them. Calls for a more sustainable development to address these challenges and to mitigate possible negative future impacts are not unproblematic, particularly due to the complexity, uncertainty, and long-term nature of possible consequences (Newig et al. 2008). Knowledge about the various impacts—be they ecological, economic, or social—policies might have is therefore pivotal. But the relationship between such knowledge and the myriad ways it may be used is particularly challenging. The example of policy impact assessment systems is a case in point. Recent years have seen an institutionalization of such systems for evaluating consequences of regulatory activities across the Organisation for Economic Co-operation and Development (OECD 2008) and the European Union (CEC 2002). It is argued that, by utilizing scientific and other evidence, impact assessment has the potential to deliver more sustainable policies and to address large-scale global challenges.

NORTHEAST PACIFIC SEAWATER RADIOCARBON RECORDED IN ABALONE SHELLS OBTAINED FROM OTSUCHI BAY, JAPAN

Radiocarbon ◽  
2019 ◽  
pp. 1-10 ◽  
Author(s):  
Kosuke Ota ◽  
Yusuke Yokoyama ◽  
Yosuke Miyairi ◽  
Jun Hayakawa ◽  
Naomi Satoh ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
Large Scale ◽  
Dissolved Inorganic Carbon ◽  
Coastal Ecosystems ◽  
Coastal Regions ◽  
Otsuchi Bay ◽  
The Pacific ◽  
Abalone Shell ◽  
The Relationship ◽  
Northern Japan

ABSTRACTReconstructing past ocean currents in the coastal regions is necessary to better understand the relationship between oceanographic changes and coastal ecosystems. It is known that variations have occurred with large-scale climate changes such as ENSO (El Niño Southern Oscillations) and PDO (Pacific Decadal Oscillations). Thus, reconstruction of past seawater conditions in coastal regions is needed to better understand the relationship between oceanographic changes and coastal ecosystems. Seawater radiocarbon is a unique proxy to understand the properties of water masses. Reef-building corals have been employed extensively and successfully in conducting this type of research into past ocean circulation histories. However, their distribution is limited to the low latitudes and hence alternative archives are required for studies in mid to high-latitude locations. Here, we use abalone shell samples obtained from Otsuchi Bay located in the Tohoku region on the Pacific coast of Northern Japan. Radiocarbon in abalone shells was compared with dissolved inorganic carbon in two-year-long records of river water as well as seawater. The data indicate that abalone shells can be used to reconstruct past seawater radiocarbon variations in northern Japan where coral skeletons are not available for ocean mixing studies.

scholarly journals Summer hypoxia in Bohai Sea caused by changes in phytoplankton community

2021 ◽  
Vol 4 (1) ◽  
pp. 77-86
Author(s):  
Hao Wei ◽  
Liang Zhao ◽  
Haiyan Zhang ◽  
Youyu Lu ◽  
Wei Yang ◽  
...  
Keyword(s):  
Water Column ◽  
Bohai Sea ◽  
Phytoplankton Community ◽  
Recent Decade ◽  
Northern China ◽  
Oxygen Depletion ◽  
The Bohai Sea ◽  
Biogeochemical Models ◽  
Do Concentration

In the deep central part of the Bohai Sea off the coast of northern China, long-term observations show significantly lower dissolved oxygen (DO) concentration near the bottom in summer during 2006–2018 than during 1978–2005. The decrease in bottom DO is closely linked to changes in phytoplankton community driven by nutrient structure changes in the water column. From literature review, observations in the phytoplankton community structure indicate an increase in the abundant proportion of dinoflagellate to diatom and miniaturization since the 21st century. The new dominate species of dinoflagellate and the pico- and nano-celled algae detritus, with slow sinking rate and long residence time, favor the efficient oxygen consumption in the water column and lead to oxygen depletion enhancement and DO concentration decrease after 2006. Analyses also suggest that water temperature, stratification, and resuspension of sediment play less significant roles in long-term variations of DO. The linkage of hypoxia formation to changes of phytoplankton community answers why hypoxia in the Bohai Sea started to occur in the recent decade while eutrophication began since the 1980s. The identified new mechanism of hypoxia formation may be applicable to other coastal seas where eutrophication has led to changes in the phytoplankton community, and should be considered in biogeochemical models.

scholarly journals Marine denitrification rates determined from a global 3-dimensional inverse model

2012 ◽  
Vol 9 (10) ◽  
pp. 14013-14052 ◽  
Author(s):  
T. DeVries ◽  
C. Deutsch ◽  
P. A. Rafter ◽  
F. Primeau
Keyword(s):  
Ocean Circulation ◽  
Isotopic Ratio ◽  
Circulation Model ◽  
Simple Relationship ◽  
N Losses ◽  
3 Dimensional ◽  
Global Rate ◽  
Nitrate Consumption ◽  
The Difference

Abstract. A major impediment to understanding long-term changes in the marine nitrogen (N) cycle is the persistent uncertainty about the rates, distribution, and sensitivity of its largest fluxes in the modern ocean. We use a global 3-dimensional ocean circulation model to obtain the first estimate of marine denitrification rates that is maximally consistent with available observations of nitrate deficits and the nitrogen isotopic ratio of ocean nitrate. We find a global rate of marine denitrification in suboxic waters and sediments of 120–240 Tg N yr−1, which is lower than most other recent estimates. The difference stems from the ability to represent the 3-D spatial structure of suboxic zones, where denitrification rates of 50–77 Tg N yr−1 result in up to 50% depletion of nitrate. This depletion reduces the effect of local isotopic enrichment on the rest of the ocean, allowing the N isotope ratio of oceanic nitrate to be achieved with a sedimentary denitrification rate about 1.3–2.3 times that of suboxic zones. This balance of N losses between sediments and suboxic zones is shown to obey a simple relationship between isotope fractionation and the degree of nitrate consumption in the core of the suboxic zones. The global denitrification rates derived here suggest that the marine nitrogen budget is likely close to balanced.

Experiments on spin-up and spin-down on a β-plane

1994 ◽  
Vol 271 ◽  
pp. 153-172 ◽  
Author(s):  
W. J. Jillians ◽  
T. Maxworthy
Keyword(s):  
Ocean Circulation ◽  
Large Scale ◽  
Flow Characteristics ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Homogeneous Fluid ◽  
Video Record ◽  
Homogeneous Models ◽  
The One ◽  
The Relationship

Here we study the spin-up and spin-down of a homogeneous fluid with a free surface on an experimental ‘β-plane’ and describe the important features for both cases over a range of parameters. Quantitative values are found for the velocity fields using a new image processing technique that analyses a video record of particle motion and stores the results digitally. Streamlines, pressure fields and vorticity values are found by interpolation techniques and result in a complete description of the flow characteristics. We discuss the relationship between the results of these experiments and those observed in large-scale homogeneous models of ocean circulation, e.g. Moore (1963). This study extends the work of van Heijst et al. (1990) to the case of spin-up in a rectangular container but of non-uniform depth and we note the differences to and similarities with their observations. It is related, also, to more recent results of Maas et al. (1992), who considered spin-up on a β-plane but in a tank of very different proportions to the one considered here.

scholarly journals The Relationship Between Anti-Hypertensive Drugs and Cancer: Anxiety to be Resolved in Urgent

2020 ◽  
Vol 11 ◽  
Author(s):  
Rong Yang ◽  
Yonggang Zhang ◽  
Xiaoyang Liao ◽  
Yi Yao ◽  
Chuanying Huang ◽  
...  
Keyword(s):  
Large Scale ◽  
Clinical Decision Making ◽  
Clinical Decision ◽  
Complementary Therapy ◽  
Causal Link ◽  
Tumor Treatment ◽  
Incident Cancer ◽  
The Common ◽  
The Relationship

Hypertension is the prevailing independent risk factor for cardiovascular disease worldwide. Anti-hypertensive drugs are the common and effective cure for lowering blood pressure in patients with hypertension. However, some large-scale clinical studies have pointed out that long-term ingestion of some oral anti-hypertensive drugs was associated with risks of incident cancer and the survival time. In contrast, other studies argue that anti-hypertensive drugs are not related to the occurrence of cancer, even as a complementary therapy of tumor treatment. To resolve the dispute, numerous recent mechanistic studies using animal models have tried to find the causal link between cancer and different anti-hypertensive drugs. However, the results were often contradictory. Such uncertainties have taken a toll on hypertensive patients. In this review, we will summarize advances of longitudinal studies in the association between anti-hypertensive drugs and related tumor risks that have helped to move the field forward from associative to causative conclusions, in hope of providing a reference for more rigorous and evidence-based clinical research on the topic to guide the clinical decision making.

Working conditions and employee commitment in indigenous private manufacturing firms in Nigeria: managing business organisations for industrial development

2000 ◽  
Vol 38 (2) ◽  
pp. 295-324 ◽  
Author(s):  
Chikwendu Christian Ukaegbu
Keyword(s):  
Working Conditions ◽  
Industrial Development ◽  
Large Scale ◽  
Employee Commitment ◽  
Manufacturing Firms ◽  
Southeastern Nigeria ◽  
Manufacturing Enterprises ◽  
Enterprise Success ◽  
The Relationship

Investment in medium and large-scale manufacturing enterprises by Nigerian entrepreneurs has continued to grow; but little is known about their organisation and management in general, or the nature of working conditions and employee commitment in particular. This study examines the relationship between working conditions and employee commitment in twenty indigenously owned private manufacturing firms in Igbo states of southeastern Nigeria. The findings show that these firms have the potential to contribute to the industrial future of the country. However, a substantial number of their workers were dissatisfied with the extrinsic and equity factors of their work, which are stronger predictors of employee commitment than the intrinsic/responsibility component. To build a viable workforce for enterprise success and industrial development, entrepreneurs should invest in the long-term goals of their workers, and learn to balance their own interests with those of their employees.

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