scholarly journals Long-term warming and nitrogen fertilization affect C-, N- and P-acquiring hydrolase and oxidase activities in winter wheat monocropping soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chuang Zhang ◽  
Wenxu Dong ◽  
Kiril Manevski ◽  
Wenpei Hu ◽  
Arbindra Timilsina ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
C:N Ratio ◽  
Resource Limitation ◽  
N Fertilization ◽  
Organic N ◽  
Resource Limitations ◽  
The North ◽  
The Relationship ◽  
Enzyme Ratio

AbstractThe enzymatic activities and ratios are critical indicators for organic matter decomposition and provide potentially positive feedback to carbon (C) loss under global warming. For agricultural soils under climate change, the effect of long-term warming on the activities of oxidases and hydrolases targeting C, nitrogen (N) and phosphorus (P) and their ratios is unclear, as well as whether and to what extend the response is modulated by long-term fertilization. A 9-year field experiment in the North China Plain, including an untreated control, warming, N fertilization, and combined (WN) treatment plots, compared the factorial effect of warming and fertilization. Long-term warming interacted with fertilization to stimulate the highest activities of C, N, and P hydrolases. Activities of C and P hydrolase increased from 8 to 69% by N fertilization, 9 to 53% by warming, and 28 to 130% by WN treatment compared to control, whereas the activities of oxidase increased from 4 to 16% in the WN soils. Both the warming and the WN treatments significantly increased the enzymatic C:N ratio from 0.06 to 0.16 and the vector length from 0.04 to 0.12 compared to the control soil, indicating higher energy and resource limitation for the soil microorganisms. Compared to WN, the warming induced similar ratio of oxidase to C hydrolase, showing a comparable ability of different microbial communities to utilize lignin substrates. The relationship analyses showed mineralization of organic N to mediate the decomposition of lignin and enzyme ratio in the long-term warming soil, while N and P hydrolases cooperatively benefited to induce more oxidase productions in the soil subject to both warming and N fertilization. We conclude that coupled resource limitations induced microbial acclimation to long-term warming in the agricultural soils experiencing high N fertilizer inputs.

Cable effective length model error-based bridge performance warning method under thermal action

2021 ◽  
pp. 136943322110480
Author(s):  
Yan Wang ◽  
Dong-Hui Yang ◽  
Yu-Zheng Zhou ◽  
Ting-Hua Yi
Keyword(s):  
Thermal Action ◽  
Dynamic Responses ◽  
Effective Length ◽  
Time Variability ◽  
Long Span ◽  
The North ◽  
Static Responses ◽  
Bridge Performance ◽  
The Relationship

The cables of long-span cable-stayed bridges are subjected to substantial tension during long-term service and are more susceptible to corrosion and fatigue failure than concrete structures. Most existing structural health monitoring (SHM) systems do not have monitoring equipment to directly measure cable length, and long-term monitoring of the change in cables is less involved. The displacement response of a bridge is induced by the combination of dynamic effects (wind and highways) and quasi-static effects (temperature). In this paper, the dynamic responses were eliminated by averaging the displacement data for 10 min, and the relationship between temperature and displacement was studied. Based on the monitoring data, the distribution of the thermal field for the bridge was studied and the time variability of the tower displacement was investigated. The correlation was analyzed to study the relationship between the temperature and the tower displacements, the north tower–south tower distance and the tower–girder distances. A strong linear relationship between the temperature and quasi-static responses of the displacements was observed. The thermal expansion coefficient of the effective length of cables was proposed as a quantitative index for long-term cable monitoring. The error in the cable effective length is proposed as the warning index for performance warning research. The results show that the proposed performance warning method can monitor cables and perform warnings when the cable is damaged.

Relationship Between the Number of Days with Thunderstorms and the Duration of Thunderstorms According to Visual and Instrumental Observations

2020 ◽  
pp. 30-36
Author(s):  
A.H. Adzhiev ◽  
G.V. Kupovykh ◽  
R.A. Gyatov ◽  
Z.M. Kerefova
Keyword(s):  
Observation Point ◽  
High Mountain ◽  
North Caucasus ◽  
The North ◽  
Instrumental Observations ◽  
Weather Stations ◽  
Long Term Observation ◽  
The Relationship ◽  
Observation Period

For study the relationship between number of days with a thunderstorm recorded by weather stations and duration of thunderstorms in hours for these days, instrumental observations of the thunder direction-finding network of High-Mountain Geophysical Institute were used. We used data on thunderstorms in the North Caucasus for a long-term observation period in 2008-2019. Based on these data, they are grouped for various territories for analysis: the number of days with thunderstorms per month, per year, and the duration of thunderstorms per month and per year. A correlation analysis was performed between the number of days with thunderstorms and the duration of thunder-storms in hours according to LS 800 data. Thus, the dependence of the number of days with thunderstorms on the duration of thunderstorms is clearly traced - with an increase in the number of days with thunderstorms per year, the observation point increases in direct proportion to the duration of thunderstorms per year. With an increase in the number of days with thunderstorms on a given territory by one day, for the month in question, the duration of thunderstorms increases by 3.89 hours.

Long Term Changes in Abundance of Eggs of the Cornish Pilchard (Sardina Pilchardus Walbaum) Off Plymouth

1974 ◽  
Vol 54 (3) ◽  
pp. 641-649 ◽  
Author(s):  
A. J. Southward
Keyword(s):  
Small Scale ◽  
Personal Communications ◽  
North West ◽  
The North ◽  
History Of ◽  
Inshore Waters ◽  
Relationship Of ◽  
Hearsay Evidence ◽  
The Relationship

The inshore fishery for the pilchard in Cornish waters has existed for several hundred years, and such records as are available concerning fluctuation in catches and market conditions have been reviewed by Couch (1865), Cushing (1957) and Culley (1971). Although pilchard have been landed from Lyme Bay, from the eastern half of the Channel, and from the southern North Sea (Couch, 1865; Furnestin, 1945; Cushing, 1957; personal communications G. T. Boalch) the catches have usually been incidental to other fisheries and more sporadic than in Cornish waters. Traditionally there are three areas fished for the Cornish pilchard: on the north-west coast around St Ives; in Mounts Bay and towards the Scillies; and between the Lizard Pt and Bolt Tail in Devon (Couch, 1865; Culley, 1971). The latter region, constituting the inshore waters of south-east Cornwall and south Devon, effectively forms the eastern limits of the regular occurrence of commercial shoals. Knowledge of the breeding and life-history of the fish in this region has always been scarce and subject to much hearsay evidence (reviewed in Southward, 1963). Up to quite recently it was thought that the main spawning area lay well to the west of the entrance to the Channel, and it was not until the investigations reported by Corbin (1947,195°) a nd Cushing (1957)tnat it was conclusively shown that extensive spawning can occur within the English Channel from May to October. The relationship of the spawning in the western Channel to the other areas of spawning off the entrance to the Channel and in the northern Bay of Biscay is illustrated in a recent series of reports (Arbault & Boutin, 1968; Arbault & Lacroix-Boutin, 1969; Arbault & Lacroix, 1971; Wallace, P. D. & Pleasants, C. A., duplicated ICES meeting paper CM 1972/J: 8), and is further demonstrated by Demir & Southward (1974) in discussing the results of a study of small scale seasonal changes in spawning intensity in inshore waters.

scholarly journals The changes of soil nitrogen and carbon contents in a long-term field experiment under different systems of nitrogen fertilization

2008 ◽  
Vol 54 (No. 11) ◽  
pp. 463-470 ◽  
Author(s):  
V. Nedvěd ◽  
J. Balík ◽  
J. Černý ◽  
M. Kulhánek ◽  
M. Balíková
Keyword(s):  
Field Experiment ◽  
N Fertilization ◽  
Hot Water ◽  
Control Treatment ◽  
Organic N ◽  
Total N ◽  
C And N ◽  
N Compounds ◽  
Term Field

Content of N and C in soil were investigated in a long-term field experiment under different systems of N fertilization. Chernozem and Cambisol were extracted using hot water (N<sub>hws</sub>, C<sub>hws</sub>) and 0.01M CaCl<sub>2</sub> (N<sub>CaCl2</sub>, C<sub>DOC</sub>). The C<sub>t</sub>/N<sub>t</sub> ratio in Chernozem was 9.6:1 and in Cambisol 6.1:1. The lowest C<sub>t</sub>/N<sub>t</sub> ratio in both experiments was found in the control treatment. Results showed that C and N compounds are less stable in Cambisol, which leads to a higher rate of mineralization. In the Chernozem, N<sub>hws</sub> formed 3.66% from the total N content in the soil whereas N<sub>CaCl2</sub> formed only 0.82%. C<sub>hws</sub> formed 2.98% and C<sub>DOC</sub> 0.34% from total C content. Cambisol contains 4.81% of N<sub>hws</sub> and 0.84% of N<sub>CaCl2</sub> from the total N amount and 5.76% of C<sub>hws</sub> and 0.70% of C<sub>DOC</sub> from the total C content, respectively. Nitrogen extracted by 0.01M CaCl2 formed only 22.4% of N extractable by hot water in Chernozem and 17.5% in Cambisol. The lowest C/N ratios were obtained after the CaCl<sub>2</sub> extraction (3.0–6.2:1). The application of manure increased the content of soil organic N and C compared to the sewage sludge treatments.

Politics and Devolution in Northern Ireland, 1998–2007

2021 ◽  
pp. 209-240
Author(s):  
Jonathan Bradbury
Keyword(s):  
Northern Ireland ◽  
Policy Development ◽  
Power Sharing ◽  
The Political ◽  
Resource Limitations ◽  
The North ◽  
Political Management ◽  
Management Approaches ◽  
The Uk

This chapter analyses politics in Northern Ireland in the context, first, of the failed attempts to implement devolution that led to its suspension, then the St Andrews Agreement in 2006, elections and the restoration of devolution in 2007. It reappraises the tortuous years in terms of the territorial strains that were still present in Northern Ireland, the resources available to the Republican/Nationalist and Unionist party leaderships in Northern Ireland as well as to the Blair government, and the political management approaches that they each pursued. It focuses on the political imperatives and constraints that determined the Northern Ireland Assembly's journey between intermittent existence and suspension, and eventually led to the unlikely agreement between the leaders of the extreme representatives of Republicanism and Unionism. The chapter is informed by the proposition that both sides in Northern Ireland still recognised their resource limitations in asserting their ideal outcomes in the short term. The Social Democratic and Labour Party (SDLP) and Sinn Fein still pursued power-sharing devolution in the short to medium term to realise their long-term objectives of Irish unity. This was principally to be achieved through electoral success and the cultivation of the North–South institutions under strand two of the Belfast Agreement to normalise Irish governance through instrumental arguments, shared policy development and functional spillovers. Meanwhile, the Ulster Unionist Party (UUP), as the principal Unionist party, competitively sought to use devolution as a new framework in which to sustain an inter-governmentalist approach to governing within the UK, asserting the very different long-term aim of maintaining Northern Ireland within the Union.

scholarly journals Atmospheric teleconnection patterns and eddy kinetic energy content: wavelet analysis

2004 ◽  
Vol 11 (3) ◽  
pp. 295-301 ◽  
Author(s):  
V. N. Khokhlov ◽  
A. V. Glushkov ◽  
I. A. Tsenenko
Keyword(s):  
Kinetic Energy ◽  
North Atlantic ◽  
Energy Content ◽  
Southern Oscillation ◽  
Eddy Kinetic Energy ◽  
The North ◽  
The North Atlantic ◽  
The Impact ◽  
The Relationship

Abstract. In this paper, we employ a non-decimated wavelet decomposition to analyse long-term variations of the teleconnection pattern monthly indices (the North Atlantic Oscillation and the Southern Oscillation) and the relationship of these variations with eddy kinetic energy contents (KE) in the atmosphere of mid-latitudes and tropics. Major advantage of using this tool is to isolate short- and long-term components of fluctuations. Such analysis allows revealing basic periodic behaviours for the North Atlantic Oscillations (NAO) indices such as the 4-8-year and the natural change of dominant phase. The main results can be posed as follows. First, if the phases of North Atlantic and Southern Oscillations vary synchronously with the 4-8-year period then the relationship between the variations of the NAO indices and the KE contents is the most appreciable. Second, if the NAO phase tends to abrupt changes then the impact of these variations on the eddy kinetic energy contents in both mid-latitudes and tropics is more significant than for the durational dominance of certain phase.

scholarly journals Modelling monthly precipitation with circulation weather types for a dense network of stations over Iberia

2013 ◽  
Vol 17 (2) ◽  
pp. 665-678 ◽  
Author(s):  
N. Cortesi ◽  
R. M. Trigo ◽  
J. C. Gonzalez-Hidalgo ◽  
A. M. Ramos
Keyword(s):  
Model Performance ◽  
Monthly Precipitation ◽  
Weather Types ◽  
Spatial Gradients ◽  
Mountainous Regions ◽  
The North ◽  
Precipitation Increase ◽  
The Relationship ◽  
Variance Explained

Abstract. Precipitation over the Iberian Peninsula (IP) is highly variable and shows large spatial contrasts between wet mountainous regions to the north, and dry regions in the inland plains and southern areas. In this work, we modelled the relationship between atmospheric circulation weather types (WTs) and monthly precipitation for the wet half of the year (October to May) using a 10 km grid derived from a high-density dataset for the IP (3030 precipitation series, overall mean density one station each 200 km2). We detected two spatial gradients in the relationship between WTs and precipitation. The percentage of monthly precipitation explained by WTs varies from northwest (higher variance explained) to southeast (lower variance explained). Additionally, in the IP the number of WTs that contribute significantly to monthly precipitation increase systematically from east to west. Generally speaking, the model performance is better to the west than to the east where the WTs approach produce the less accurate results. We applied the WTs modelling approach to reconstruct the long-term precipitation time series for three major stations of Iberia (Lisbon, Madrid, Valencia).

To the Richest Go the Spoils? Immigration, Development, and the North-South Divide, 1970–2005

2016 ◽  
Vol 2 (3) ◽  
pp. 273-292
Author(s):  
Matthew R. Sanderson
Keyword(s):  
Economic Development ◽  
Global South ◽  
Positive Effects ◽  
The North ◽  
National Economic ◽  
Global North ◽  
First Time ◽  
The Relationship ◽  
North And South

This paper empirically assesses, for the first time, the relationship between immigration and national economic development in both the global North and the global South. A series of panel models demonstrate that immigration exacerbates North-South inequalities through differential effects on average per capita incomes in the global North and global South. Immigration has positive effects on average incomes in both the North and the South, but the effect is larger in the global North. Thus the relationship between immigration and development evinces a Matthew Effect at the world level: by contributing to differential levels of economic development in the North and South, immigration widens international inequalities in the long term, resulting in the accumulation of advantage in the North. The implications of the results are discussed in the context theory and policy on the migration-development nexus.

DROUGHT AND RANGELAND GRASSHOPPER SPECIES DIVERSITY

1994 ◽  
Vol 126 (4) ◽  
pp. 1075-1092 ◽  
Author(s):  
W.P. Kemp ◽  
M.M. Cigliano
Keyword(s):  
Species Richness ◽  
Central Region ◽  
Resource Limitation ◽  
Extreme Drought ◽  
Severe Drought ◽  
Grasshopper Species ◽  
Drought Intensity ◽  
The North ◽  
South Central

AbstractRangeland grasshopper species richness was monitored at 10 sites in Montana, U.S.A., during 1986 through 1992, which included an extreme drought year (1988). We observed significant post-1988 drought reductions in rangeland grasshopper species richness in the eastern and south-central region of Montana where drought intensity has been increasing during the past 20 years. In the north-central region, which also experienced the 1988 drought but showed no long-term drought trend, we did not observe a post-drought reduction in overall rangeland grasshopper species richness. Thus, in terms of rangeland grasshopper species richness, the potential impact of a severe drought in a given year may depend on the timing of such an event within longer-term climatic cycles. Our findings suggest that as regional drought intensity increases temporally, there may be an increased likelihood that a single extreme drought year will not only have a profound impact on abundance but may also result in significant long-term reduction of grasshopper species richness. Our results support the hypothesis that resource limitation is a very important factor in structuring rangeland grasshopper communities in space and time.

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