Vegetation changes in the Hluhluwe-Umfolozi Game Reserve Complex from 1937 to 1975

Bothalia ◽  
1983 ◽  
Vol 14 (2) ◽  
pp. 265-269 ◽  
Author(s):  
H. K. Watson ◽  
I. A. W. Macdonald
Keyword(s):  
Structural Changes ◽  
Woody Plant ◽  
Progressive Increase ◽  
Aerial Photographs ◽  
Short Term ◽  
Tall Grass ◽  
Controlled Burning ◽  
Game Reserve ◽  
Plant Removal

The structural changes that have occurred in the vegetation of the Hluhluwe-Umfolozi Game Reserve Complex have been quantified using 1937, 1960 and 1975 aerial photographs, and related to the management history. A progressive increase in both tree and shrub cover has occurred. In the short term, both intensive woody plant removal operations and controlled burning applications appear to be effective in retarding the rate of encroachment by shrubs and trees. However, neither was effective in the long term. Significant reductions in tall grass cover attributed to sustained overgrazing have occurred.

scholarly journals Perception and risk of Covid-19 and climate change: investigating analogies in a common framework

2020 ◽  
Vol 3 ◽  
Author(s):  
Antonello Pasini ◽  
Fulvio Mazzocchi
Keyword(s):  
Climate Change ◽  
Structural Changes ◽  
Short Term ◽  
Common Features ◽  
Risk Equation ◽  
Related Risk ◽  
Policy Level ◽  
Common Framework

This paper investigates analogies in the dynamics of Covid-19 pandemic and climate change. A comparison of their common features (such as nonlinearity and inertia) and differences helps us to achieve a correct scientific perception of both situations, increasing the chances of actions for their solutions. Besides, applying to both the risk equation provides different angles to analyse them, something that may result useful especially at the policy level. It shows that not only short-term interventions are needed, but also long-term strategies involving some structural changes. More specifically, it also shows that, even if climate change is probably more critical and long-lasting than the Covid-19 crisis, we still have, at least currently, more options for reducing its related risk.

scholarly journals Rapid retreat of permafrost coastline observed with aerial drone photogrammetry

2019 ◽  
Vol 13 (5) ◽  
pp. 1513-1528 ◽  
Author(s):  
Andrew M. Cunliffe ◽  
George Tanski ◽  
Boris Radosavljevic ◽  
William F. Palmer ◽  
Torsten Sachs ◽  
...  
Keyword(s):  
Coastal Erosion ◽  
Average Rate ◽  
Temporal Frequency ◽  
Shoreline Change ◽  
Yukon Territory ◽  
Aerial Photographs ◽  
The Arctic ◽  
Storm Events ◽  
Short Term

Abstract. Permafrost landscapes are changing around the Arctic in response to climate warming, with coastal erosion being one of the most prominent and hazardous features. Using drone platforms, satellite images, and historic aerial photographs, we observed the rapid retreat of a permafrost coastline on Qikiqtaruk – Herschel Island, Yukon Territory, in the Canadian Beaufort Sea. This coastline is adjacent to a gravel spit accommodating several culturally significant sites and is the logistical base for the Qikiqtaruk – Herschel Island Territorial Park operations. In this study we sought to (i) assess short-term coastal erosion dynamics over fine temporal resolution, (ii) evaluate short-term shoreline change in the context of long-term observations, and (iii) demonstrate the potential of low-cost lightweight unmanned aerial vehicles (“drones”) to inform coastline studies and management decisions. We resurveyed a 500 m permafrost coastal reach at high temporal frequency (seven surveys over 40 d in 2017). Intra-seasonal shoreline changes were related to meteorological and oceanographic variables to understand controls on intra-seasonal erosion patterns. To put our short-term observations into historical context, we combined our analysis of shoreline positions in 2016 and 2017 with historical observations from 1952, 1970, 2000, and 2011. In just the summer of 2017, we observed coastal retreat of 14.5 m, more than 6 times faster than the long-term average rate of 2.2±0.1 m a−1 (1952–2017). Coastline retreat rates exceeded 1.0±0.1 m d−1 over a single 4 d period. Over 40 d, we estimated removal of ca. 0.96 m3 m−1 d−1. These findings highlight the episodic nature of shoreline change and the important role of storm events, which are poorly understood along permafrost coastlines. We found drone surveys combined with image-based modelling yield fine spatial resolution and accurately geolocated observations that are highly suitable to observe intra-seasonal erosion dynamics in rapidly changing Arctic landscapes.

Fracture Mechanics when Studying the Long-Term Strength of Concrete

2019 ◽  
Vol 945 ◽  
pp. 957-962
Author(s):  
I.L. Shubin ◽  
V.V. Dorkin ◽  
P.S. Sultygova
Keyword(s):  
Fracture Mechanics ◽  
Structural Changes ◽  
Structural Integrity ◽  
Term Strength ◽  
Short Term ◽  
Heterogeneous Structures ◽  
Temperature Action ◽  
Heating Up ◽  
Experimental And Theoretical Studies

The results of experimental and theoretical studies of the process of destruction of concrete by the methods of fracture mechanics are considered. Results of studies of long-term strength, durability and deformability of concrete subjected to a preliminary short-term temperature action up to 300° C and 400° C under load and without load are presented. It is shown that after short-term heating up to 300о С the long-term strength of concrete decreases insignificantly. It is established that heating up to 400° C can be considered the boundary of the structural integrity of concrete. The conditions for using the results of these studies in determining the values of a function that characterizes the change in the long-term strength of a material in the mechanics of heterogeneous structures are formulated. The function of the material destruction measure is introduced to describe the nature of the structural changes in the material at a given constant continuous load, and its change for different levels of a continuous load is considered.

Statistical Blight

1982 ◽  
Vol 47 (4) ◽  
pp. 836-851 ◽  
Author(s):  
Sheldon Scheps
Keyword(s):  
Peer Review ◽  
Structural Changes ◽  
Peer Review System ◽  
Review System ◽  
Short Term ◽  
American Antiquity ◽  
Academic Degree ◽  
Certification Examinations

A short-term remedy is proposed in the hope of curtailing the proliferation of statistical and inferential error rife within the published archaeological literature. First, a study by Isbell and Schreiber, one that violates rudimentary quantitative and qualitative analytical precepts, yet nevertheless was published in American Antiquity, is discussed in depth in order to exemplify the extent to which matters have deteriorated within the discipline. Then, this analysis, in conjunction with the various compendia of statistical abuse compiled by numerous professionals within the field, is invoked as support for an argument advocating structural changes in the peer review system. Perhaps such solutions could be implemented until previously proposed long-term solutions, such as David Thomas"s call for compulsory courses and certification examinations to satisfy academic degree requirements, are finally instituted.

scholarly journals The evolving relationship between airline profitability and passenger satisfaction

2013 ◽  
Vol 24 (1) ◽  
pp. 7-21
Author(s):  
Kent N Gourdin
Keyword(s):  
Airline Industry ◽  
Structural Changes ◽  
Business Models ◽  
Quality Model ◽  
Short Term ◽  
The Past ◽  
Management Actions ◽  
Passenger Satisfaction ◽  
The U.S

This paper examines the ongoing evolution of the U.S. airline industry under deregulation. After losing money for most of the past 35 years, carriers have made structural changes to their business models that have proven to be, at least in the short term, very profitable. After delineating these management actions, the paper examines their impact on passengers. The author utilizes the Service Quality Model to analyze the long-term implications of this new operating paradigm for passenger satisfaction. Based on this analysis the paper goes on to suggest several actions management could take to improve satisfaction. Finally, conclusions are offered and areas for additional research suggested.

scholarly journals Global Value Chain Resilience: Understanding the Impact of Managerial Governance Adaptations

2022 ◽  
pp. 000812562110666
Author(s):  
Liena Kano ◽  
Rajneesh Narula ◽  
Irina Surdu
Keyword(s):  
Value Chain ◽  
Structural Changes ◽  
Lessons Learned ◽  
Value Chains ◽  
Global Value Chain ◽  
Short Term ◽  
Initial Shock ◽  
Lead Firm ◽  
The Impact

While COVID-19 has caused significant short-term disruptions in global value chains (GVCs), in the longer run, the pandemic will not be the primary catalyst in GVC evolution. As GVCs recover from the initial shock, managers will make GVC restructuring decisions guided by long-term strategic considerations. This article describes barriers that lead firm managers may encounter when rethinking location/control decisions for value chain activities and suggests that, in addition to structural changes, managerial governance adaptations are instrumental in enhancing GVCs’ long-term resilience. Lessons learned from responding to the pandemic can help managers enhance GVC efficiency in the increasingly uncertain global environment.

scholarly journals Excess copper induces structural changes in cultured photosynthetic soybean cells

2006 ◽  
Vol 33 (11) ◽  
pp. 1001 ◽  
Author(s):  
María Bernal ◽  
Pilar Sánchez-Testillano ◽  
María del Carmen Risueño ◽  
Inmaculada Yruela
Keyword(s):  
Cell Wall ◽  
Structural Changes ◽  
Copper Tolerance ◽  
Copper Stress ◽  
Induced Response ◽  
Cytoplasmic Vacuole ◽  
Cell Nuclei ◽  
Short Term ◽  
Excess Copper

Soybean [Glycine max (L.) Merr.] cell suspensions have the capacity to develop tolerance to excess copper, constituting a convenient system for studies on the mechanisms of copper tolerance. The functional cell organisation changes observed in these cell cultures after both short-term (stressed cells) and long-term (acclimated cells) exposure to 10 μm CuSO4 are reported from structural, cytochemical and microanalytical approaches. Cells grown in the presence of 10 μm CuSO4 shared some structural features with untreated cells, such as: (i) a large cytoplasmic vacuole, (ii) chloroplasts along the thin layer of cytoplasm, (iii) nucleus in a peripheral location exhibiting circular-shaped nucleolus and a decondensed chromatin pattern, and (iv) presence of Cajal bodies in the cell nuclei. In addition, cells exposed to 10 μm CuSO4 exhibited important differences compared with untreated cells: (i) chloroplasts displayed rounded shape and smaller size with denser-structured internal membranes, especially in copper-acclimated cells; (ii) no starch granules were found within chloroplasts; (iii) the cytoplasmic vacuole was larger, especially after long-term copper exposure; (iv) the levels of citrate and malate increased. Extracellular dark-coloured deposits with high copper content attached at the outer surface of the cell wall were observed only in cells exposed to a short-term copper stress. Structural cell modifications, mainly affecting chloroplasts, accompanied the short-term copper-induced response and were maintained as stable characters during the period of adaptation to excess copper. Vacuolar changes accompanied the long-term copper response. The results indicate that the first response of soybean cells to excess copper prevents its entry into the cell by immobilising it in the cell wall, and after an adaptive period, acclimation to excess copper may be mainly due to vacuolar sequestration.

scholarly journals EL SISTEMA DE FRANJA DE PRECIOS PARA LOS PRODUCTOS AGRÍCOLAS EN EL PACTO ANDINO: DEFINICION DE CAMBIO ESTRUCTURAL

1995 ◽  
pp. 9-26
Author(s):  
Manuel Del Valle ◽  
Keyword(s):  
Structural Change ◽  
Structural Changes ◽  
Band System ◽  
Short Term ◽  
Monte Carlo Test ◽  
International Prices ◽  
El Sistema ◽  
Andean Pact ◽  
Statistical Criteria

It analyzes the structural change in the context of the price band in the Andean Pact in order to advance proposals for the reform of Decision 37.1 so that it can consider the systematic and sustained changes in the international product market. The focus of the work is statistical, since the system is updated using moving averages and statistical criteria. Thirteen time series used in the price band system are analyzed and univariate models are proposed for each one of them. Furthermore, a rule is proposed to define the structural change, and the univariate models obtained are used to prove said rule using Monte Carlo test for the thirteen products. It is concluded that the price band system can be useful to face short-term fluctuations in international prices, as well as long-term adjustments, but it is not prepared to solve problems generated by structural changes, so it can be modified to consider this issue, but the basic principle of the system should be maintained.

scholarly journals The Incoherence of Institutional Reform: Decentralization as a Structural Solution to Immediate Political Needs

2021 ◽  
Author(s):  
Jean-Paul Faguet ◽  
Mahvish Shami
Keyword(s):  
Side Effects ◽  
Local Government ◽  
Structural Changes ◽  
Institutional Reform ◽  
Short Term ◽  
Institutional Reforms ◽  
Long Term Consequences ◽  
Main Effects ◽  
Structural Solution

AbstractInstitutional reforms are structural changes in the rules and norms of authority, with effects that are long-term and unpredictable on government, politics, and society. But leaders may undertake them to solve unrelated, discrete, short-term political problems. Understanding the latter is key to understanding the characteristics of many real reforms, and hence their fate. We introduce the concept of instrumental incoherence and use it to construct a theory of decentralization where reform is motivated by orthogonal objectives. We show that reformers’ incentives map onto the specifics of reform design via their side effects, not their main effects, which in turn lead to the medium- and long-term consequences eventually realized. We characterize downwardly accountable decentralization, which ties the hands of the center to empower local voters, vs. upwardly accountable decentralization, which ties the hands of local government to empower the center. We use these ideas to explain highly divergent outcomes in two extreme cases, Bolivia and Pakistan, using detailed, original evidence. Our analysis likely extends to a broader class of reforms where the incentives of agents pursuing a change, and the effects of that change, are highly asymmetric in time and dimension.

Monitoring and modelling in urban drainage

1997 ◽  
Vol 36 (8-9) ◽  
pp. 283-287 ◽  
Author(s):  
R. K. Price ◽  
G. J. Catterson
Keyword(s):  
Model Calibration ◽  
Structural Changes ◽  
Urban Drainage ◽  
Drainage Network ◽  
Short Term ◽  
The Future ◽  
Asset Data

A holistic appreciation of the performance of an urban drainage network is needed to understand how best to extend, operate and maintain the asset. These functions are best achieved through the recognition of the complementary roles of monitoring and modelling. A model is needed for planning structural changes to a network. Confirmation of both model asset data and model calibration requires long term as well as short term monitored data. In the future, engineers will make better use of the synergy between monitoring and modelling.

Sign in / Sign up

Export Citation Format

Share Document