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Activity, movement and secretive behavior of a threatened arboreal folivore, the thin-spined porcupine, in the Atlantic forest of southern Bahia, Brazil

Fernandez Gine, Gaston Andres; Barbanti Duarte, Jose Mauricio; Senra Motta, Tatiana Cristina; Faria, Deborah
Fonte: WILEY-BLACKWELL; MALDEN Publicador: WILEY-BLACKWELL; MALDEN
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
45.87%
Activity and behavior patterns are important components of a given species ecological strategy, as they have profound implications for its survival and reproduction. Here, we studied the activities, movements and secretive behavior of the thin-spined porcupine Chaetomys subspinosus (Rodentia: Erethizontidae), a threatened arboreal folivore in the Brazilian Atlantic rainforest. We aimed to ascertain the behavioral strategies used by this species as well as its responses to seasonal and daily climatic changes. Four radio-collared individuals were followed continuously for 72-h in the summer and winter, as well as during 146 half-night sessions conducted from April 2005 to September 2006 in forest remnants in southern Bahia. The thin-spined porcupines were nocturnally active (17:30-05:40 h), with peaks in activity and movement from 19:00 to 20:00 h and 03:00 to 04:00 h. Animals followed a circadian rhythm of activity during both the summer and winter. During the diel cycle, porcupines spent 74% of their time resting, 14% feeding, 11% traveling and 2% performing other activities. Distance traveled during the diel cycle averaged 277.5 +/- 117.9 m sd. The mean movement rate during the night was 21.6 +/- 30.1 m/h sd. No significant changes in activity budget or daily distance traveled were observed between seasons...

Processo legislativo e orçamento público: a função de controle do parlamento; Legislative process and public budget: the public control of parliament.

Assis, Luiz Gustavo Bambini de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/02/2010 PT
Relevância na Pesquisa
36.16%
Esta tese trata do processo legislativo orçamentário e de que maneira uma reformulação dessa atividade exercida pelo Parlamento pode se tomar uma alternativa às limitações que esse Poder tem sofrido no que concerne às suas atividades fundamentais na atual concepção da separação de Poderes no Brasil. A partir do aprimoramento do processo legal de formação das leis do orçamento, o Legislativo pode melhor desempenhar a sua função de elaborador dessas normas e, mais do que isso, pode aprimorar sua atividade de controle sobre as ações da Administração Pública na execução do orçamento. Neste estudo, são apresentadas propostas de mudança do sistema de formação das leis orçamentárias que, além de não exigirem uma alteração substancial na forma do próprio orçamento autorizativo, pressupõem mudanças pontuais e à disposição do Parlamento, que muitas vezes dispensam alterações regimentais, legais ou constitucionais, para bem participar da elaboração das políticas públicas oriundas das peças orçamentárias e, ainda, melhor desempenhar suas atividades de controle sobre os gastos públicos.; This thesis is about the legislative budget process and how a reformulation of this activity practiced by Parliament might become an alternative to the limitations that this power has been going through in regard to their fundamental activities in the current conception of the separation of powers in Brazil. From the improvement of the legal process of forming the budget laws...

O orçamento da seguridade social e a efetividade dos direitos sociais; Social budget and the effectiveness of social rights

Calciolari, Ricardo Pires
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 01/06/2009 PT
Relevância na Pesquisa
35.94%
Atualmente, nos sistemas constitucionais modernos, a dignidade da pessoa humana encontra papel central, verdadeiro embasamento axiológico do sistema jurídico e pedra angular do Estado. No sistema jurídico brasileiro, os direitos sociais são parte importante dos direitos fundamentas, pois garantem a dignidade humana materialmente considerada. Para assegurar os direitos sociais relacionados à Seguridade Social, a Constituição de 88 estabeleceu um meio de custeio específico, as contribuições sociais. O motivo constitucional dessa exação é assegurar financeiramente os direitos sociais relativos à Seguridade Social. O tema adquire relevo quando consideramos que tal modelo de tributação diretamente relacionado com uma atividade estatal específica não encontra efetividade prática. A arrecadação a título de contribuições sociais, na prática, é destinada a finalidade diversa. Isso significa que a União institui tributos para um propósito, mas utiliza o montante arrecadado para finalidade diversa. Ademais, o orçamento da Seguridade Social no Brasil não é utilizado como meio de planejamento de intervenção da União na seara social. Sua principal finalidade seria a de estimar a arrecadação das contribuições sociais e vinculá-las a programas e ações na área específica da Seguridade Social. Contudo isso não ocorre. Dessa forma...

Padrão comportamental e uso de ferramentas em macacos-prego (Sapajus libidinosus) residentes em manguezal; Behavioral pattern and tools use in living capuchin monkeys (Sapajus libidinosus) in mangrove

Cutrim, Fernanda Helena Ribeiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/09/2013 PT
Relevância na Pesquisa
46.14%
A eficiência dos macacos-prego (gênero Sapajus) em uma ampla variedade de ambientes é resultado de sua flexibilidade, oportunismo e adaptabilidade. Esses primatas demonstram padrões de forrageio complexos, exploram manualmente vários estratos do habitat à procura de presas escondidas e apresentam técnicas de forrageio distintas, mostrando-se eficientes no uso de ferramentas para a obtenção de alimento. Embora poucos estudos abordem primatas não-humanos que vivem em manguezais, sabe-se que neste tipo de habitat existem registros do uso de ferramentas de quebra para acessar recursos animais encapsulados. A presente pesquisa é pioneira no estudo da ecologia e do uso de ferramentas em macacos-prego que habitam ambientes fragmentados, com variações sazonais de maré e de recursos alimentares. Os objetivos deste trabalho foram (1) investigar o orçamento de atividade e a dieta de um grupo de macacos-prego (S. libidinosus) residentes em manguezal, avaliando a influência dos fatores ambientais e da disponibilidade de recursos e (2) analisar, sob a perspectiva das hipóteses da necessidade e da oportunidade o uso de ferramentas por esse grupo, estimando a densidade dos sítios de quebra e sua frequência de uso. O estudo foi realizado no fragmento de manguezal Morro do Boi (MB)...

Activity, movement and secretive behavior of a threatened arboreal folivore, the thin-spined porcupine, in the Atlantic forest of southern Bahia, Brazil

Fernandez Gine, Gaston Andres; Barbanti Duarte, Jose Mauricio; Senra Motta, Tatiana Cristina; Faria, Deborah
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 131-139
ENG
Relevância na Pesquisa
45.86%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Activity and behavior patterns are important components of a given species ecological strategy, as they have profound implications for its survival and reproduction. Here, we studied the activities, movements and secretive behavior of the thin-spined porcupine Chaetomys subspinosus (Rodentia: Erethizontidae), a threatened arboreal folivore in the Brazilian Atlantic rainforest. We aimed to ascertain the behavioral strategies used by this species as well as its responses to seasonal and daily climatic changes. Four radio-collared individuals were followed continuously for 72-h in the summer and winter, as well as during 146 half-night sessions conducted from April 2005 to September 2006 in forest remnants in southern Bahia. The thin-spined porcupines were nocturnally active (17:30-05:40 h), with peaks in activity and movement from 19:00 to 20:00 h and 03:00 to 04:00 h. Animals followed a circadian rhythm of activity during both the summer and winter. During the diel cycle, porcupines spent 74% of their time resting, 14% feeding, 11% traveling and 2% performing other activities. Distance traveled during the diel cycle averaged 277.5 +/- 117.9 m sd. The mean movement rate during the night was 21.6 +/- 30.1 m/h sd. No significant changes in activity budget or daily distance traveled were observed between seasons...

Seasonal Activity Budget of Adult Baltic Ringed Seals

Harkonen, Tero; Jüssi, Mart; Jüssi, Ivar; Verevkin, Michail; Dmitrieva, Lilia; Helle, Eero; Sagitov, Roustam; Harding, Karin C.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 16/04/2008 EN
Relevância na Pesquisa
46.1%
Although ringed seals are important components in oceanic and fresh water ecosystems at high latitudes, little is known about how they exploit these harsh environments. Seasonal activity and diving behaviour of 19 adult Baltic ringed seals were studied by satellite telemetry. We elaborated an activity budget for ten months of the year, extending over the period from moult to the breeding season. Seals from three main regions showed explicit site fidelity and the distributions of animals tagged from different areas did not overlap, suggesting separate stocks. Both the mean duration and the mean depth of dives peaked in June and July. Seals spent 70% (females) to 85% (males) of their time diving in June and July which decreased to 50% in late autumn. Less than one percent of dives exceeded 10 min in females, while 10% of male dives lasted longer than 10 min in June to September. Less than one percent of dives lasted for more than 25 min. Both females and males were most active during day time and hauled out predominantly during the night. Activity patterns during the summer are suggested to be correlated to energy accumulation and prey availability. The information on seasonal activity budget is crucial for developing population energetic models where interactions between ringed seals and other trophic levels can be evaluated.

Drivers of Time-Activity Budget Variability during Breeding in a Pelagic Seabird

Rishworth, Gavin M.; Tremblay, Yann; Green, David B.; Connan, Maëlle; Pistorius, Pierre A.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 31/12/2014 EN
Relevância na Pesquisa
45.93%
During breeding, animal behaviour is particularly sensitive to environmental and food resource availability. Additionally, factors such as sex, body condition, and offspring developmental stage can influence behaviour. Amongst seabirds, behaviour is generally predictably affected by local foraging conditions and has therefore been suggested as a potentially useful proxy to indicate prey state. However, besides prey availability and distribution, a range of other variables also influence seabird behavior, and these need to be accounted for to increase the signal-to-noise ratio when assessing specific characteristics of the environment based on behavioural attributes. The aim of this study was to use continuous, fine-scale time-activity budget data from a pelagic seabird (Cape gannet, Morus capensis) to determine the influence of intrinsic (sex and body condition) and extrinsic (offspring and time) variables on parent behaviour during breeding. Foraging trip duration and chick provisioning rates were clearly sex-specific and associated with chick developmental stage. Females made fewer, longer foraging trips and spent less time at the nest during chick provisioning. These sex-specific differences became increasingly apparent with chick development. Additionally...

Strong Activity Rules for Iterative Combinatorial Auctions

Harsha, Pavithra; Barnhart, Cynthia; Parkes, David C.; Zhang, Haoqi
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.19%
Activity rules have emerged in recent years as an important aspect of practical auction design. The role of an activity rule in an iterative auction is to suppress strategic behavior by bidders and promote simple, continual, meaningful bidding and thus, price discovery. These rules find application in the design of iterative combinatorial auctions for real world scenarios, for example in spectrum auctions, in airline landing slot auctions, and in procurement auctions. We introduce the notion of strong activity rules, which allow simple, consistent bidding strategies while precluding all behaviors that cannot be rationalized in this way. We design such a rule for auctions with budget-constrained bidders, i.e., bidders with valuations for resources that are greater than their ability to pay. Such bidders are of practical importance in many market environments, and hindered from bidding in a simple and consistent way by the commonly used revealed-preference activity rule, which is too strong in such an environment. We consider issues of complexity, and provide two useful forms of information feedback to guide bidders in meeting strong activity rules. As a special case, we derive a strong activity rule for non-budget-constrained bidders. The ultimate choice of activity rule must depend...

Estudo sobre orçamento de atividade do Boto Cinza (Sotalia guianensis) no litoral sul do Rio Grande do Norte

Queiroz, Rose Emília Macedo de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Psicobiologia; Estudos de Comportamento; Psicologia Fisiológica Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Psicobiologia; Estudos de Comportamento; Psicologia Fisiológica
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.07%
A fundamental analysis on Behavioral Ecology is the construction of Activities Budget, which can be defined as the quantification of the time that each animal uses in activities that are important for its survival and reproduction. Initially developed for theoretical studies about Optimal Foraging, the construction of Activities Budgets has recently being used for analyses in Conservation Biology. However, the measurement of behavior through an adequate methodology that allows the comparison between different samples is a challenge for researchers in the area of Ethology. This problem is even bigger for the students of cetaceans behavior due to the difficulty of visualization of these animals. The present work deals with two aspects of the specialized literature on cetaceans: i) it explores possible variations of results in quantification of behavioral states decurrent of the application of different methods of data collection, and ii) it describes the activity budget of a population of Sotalia guianensis that inhabits coastal waters, south Rio Grande do Norte. The results showed that the use different methods of data collection result in significant differences, but of small scale, in the quantification of the behavioral frequency. The activity budget of Sotalia in the area here analyzed was similar to that described for other populations of this species inhabiting typically estuarine habitats. Tide and day-hour did not influence the dolphin s behavior...

Undeclared Economic Activity in Central and Eastern Europe : How Taxes Contribute and How Countries Respond to the Problem

Leibfritz, Willi
Fonte: Banco Mundial Publicador: Banco Mundial
Relevância na Pesquisa
35.97%
The paper examines the incentives and distortions created by tax policy and administration structures that motivate individuals to undeclare or under-declare work in the new EU member countries. It analyses the tax level and the tax structure "mix" of tax instruments, the special taxation regimes set up to attract workers and entrepreneurs back into the formal economy and how tax policies such as the introduction of a "flat tax" on income from labor and capital impacted workers and entrepreneurs in terms of formalizing work. It also attempts to gain some insight into the effectiveness of tax administration by comparing some input and output measures As non-tax factors can amplify the adverse effects of taxes on the labor market and reduce the effectiveness of tax reform, some of these other economic framework conditions are also discussed. This paper concludes by refining the main results and possible best practices for tackling undeclared work. The paper argues that the new EU member countries have had mixed success tackling undeclared work. While taxation matters...

Reducing the Transaction Costs of Development Assistance : Ghana’s Multi-Donor Budget Support (MDBS) Experience from 2003 to 2007

Cavalcanti, Carlos
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Relevância na Pesquisa
36.15%
This paper examines whether the structure of the Multi-Donor Budget Support (MDBS) in Ghana evolved over time to minimize transaction costs commonly found in accessing and delivering development assistance in multi-donor settings. While the MDBS was expected to reduce the transaction costs involved in dealing with multiple development agencies, it created three additional sources of transaction costs: coordination failures, the costs of collective action, and measurement costs. The answer that emerges from this paper is that the structure of the MDBS evolved to mitigate these transaction costs. The problems associated with coordination was addressed by delegating the policy dialogue to sector-specific groups aimed at reaching agreements over a narrower set of issues and amongst a smaller group of participants. Also, the MDBS reduced the cost of collective action by devising rules that allowed all the participating agencies to have a role in the decision-making process, and, in doing so, encouraged these agencies to increase the share of their contribution coming through the MDBS...

Assessment of the Impact of the Crisis on New PPI Projects - Update 4 : New Private Infrastructure Activity in Developing Countries Recovered in the First Half of 2009 Thanks to the Electricity Sector, But the Crisis Continues to Impact Projects

World Bank
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Relevância na Pesquisa
35.97%
This review of new private participation in infrastructure (PPI) projects, covering the period up to June 2009, sheds some light on the recent activity and the short-term impact of the financial crisis, compared with the previous updates on the impact of the crisis, this note incorporates several improvements: a larger sample size (714 projects versus 522 in the previous update) over a longer period of time (from January 2008 to June 2009 compared to the previous update, which covered January 2008 to March 2009). The survey finds that the financial crisis significantly affected the rate of project closure rate of new PPI projects in the second half of 2008. The impact of the crisis varies across developing regions with Europe and Central Asia (ECA) being the most affected region so far. This analysis will be refined in the coming quarters to assess the extent to which these trends continue.

Increasing Accountability through Budget Transparency at the Subnational Level in Cameroon

Alton, Martin Luis; Agarwal, Sanjay
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
36.12%
Improving governance is a major development challenge for Cameroon and for many other developing countries, and making public financial management more transparent is a central part of it. While budgets are public documents, accessible to citizens in principle, in practice, budget information is difficult to come by as a result of political, administrative, capacity, and logistical constraints as well as cost barriers at all tiers of government, including the national, regional, and municipal level and at service-delivery points like schools and health centers. In two of Cameroon s 10 regions, a World Bank-supported initiative has piloted a citizen-centered approach for disseminating simplified budget information of 151 schools, 58 health centers, and 28 municipalities and the two regional administrations. Budgets were made public and awareness was raised through various activities, including public community meetings at which the budgets of institutions were read aloud, poster campaigns, art competitions...

Making Education Spending Count for the Children of Autonomous Muslim Region of Mindanao

Australia DFAT; World Bank
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Relatório
EN_US
Relevância na Pesquisa
36.28%
The project builds on support to DepEd ARMM through the Australian Aid Basic Education Assistance for Mindanao (BEAM) activity, and further initiatives by the World Bank and partners. Chapter two of this report proceeds with an introduction to ARMM’s development context, including the evolution of regional institutions and the basic education system. Chapter three describes the unique ARMM Public Expenditure Management ‘syndrome’ that contributes to the weaknesses analyzed in this report, and in turn informs its policy recommendations. Chapter four analyzes pub¬lic expenditures for basic education in terms of aggregate spending, expenditure composi¬tion, and specific challenges that the ARMM PEM syndrome poses for budgeting. Chapter five assesses budget execution and frontline delivery aspects of basic education resources, incorporating findings from the facilities survey. Chapter six summarizes the findings on public expenditure management for education in ARMM and derives recommendations both for reforms to ARMM institutions and for consideration by the transition commission and other stakeholders in the preparations for a new Bangsamoro political entity.

The effects of financial controls of activity operations

Alexander, Maureen.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: xii, 183 p.;28 cm.
EN_US
Relevância na Pesquisa
36%
Approved for public release; distribution unlimited; The Quadrennial Defense Review underscored the importance of reevaluating the operation of the Department of Defense. The Department of the Navy Organization Management and Infrastructure Team is charged with generating analysis to arrive at recommendations for change that will improve decision makers information and incentives. Through the use of survey research, and sorting techniques, this thesis identifies the need for budget flexibility during the execution phase for commanders to address emergent issues at the local level, especially at Recruiting, Supply and Support commands. Financial controls such as fences, floors, ceilings and thresholds erode the commander's ability to manage the organization effectively. The financial controls and reduced funding combine to cause difficulties in command operations. The result is a hierarchy of funding. The mission first, quality of life second and facilities last. A model program, exercising budget flexibility during the budget execution phase, is recommended to provide further concrete evidence; http://archive.org/details/effectsoffinanci00alex; Commander, Fleet Support, United States Navy

New Private Infrastructure Activity in Developing Countries Recovered in the First Half of 2009 Thanks to the Electricity Sector, But the Crisis Continues to Impact Projects

Izaguirre, Ada Karina
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Brief; Publications & Research
ENGLISH
Relevância na Pesquisa
35.97%
New private activity in infrastructure continues to take place in developing countries despite the financial and economic crisis. New projects are being tendered and brought to financial or contractual closure. Measured by amount of investment, the rate of project closure grew by 2 percent in the first half of 2009 compared to the first half of 2008, indicating a strong recovery from the decline of 48 percent experienced in the second half of 2008. This recovery, however, was driven by large projects. Measured by number of projects reaching closure, the rate of project closure continues to be slower than before the full-scale onset of the financial crisis. The number of projects reaching closure in the first half of 2009 was 20 percent lower than the number reported in the first half of 2008. This trend suggests greater project selectivity. Indeed, those projects that are reaching closure are characterized by strong economic and financial fundamentals, the backing of financially solid sponsors and governments. Developing country governments' continuing commitment to their public-private partnership (PPP) programs is confirmed by the number of new projects tendered and awarded. However...

Private Infrastructure : Private Activity Fell by 30 Percent in 1999

Izaguirre, Ada Karina; Rao, Geetha
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Viewpoint; Publications & Research
ENGLISH
Relevância na Pesquisa
36.01%
This note, which draws on the World Bank's Private Participation in Infrastructure (PPI) database, provides an overview of recent trends in infrastructure projects with private participation in developing countries. Three main trends have emerged during the past decade. Private activity in infrastructure grew dramatically between 1990 and 1997, but declined because of the financial crises of 1998-99. Most developing countries have some private activity in infrastructure, but Latin America, and East Asia dominate investments. It is suggested that private infrastructure activity in developing economies will revive as they recover form the economic crisis of the late 1990s, and the fundamental reasons for long-term private activity, - increasing demand for infrastructure, sector inefficiencies, and public budget constraints - will continue.

The Effects of Habitat Parameters on the Behavior, Ecology, and Conservation of the Udzungwa Red Colobus Monkey (Procolobus gordonorum)

Steel, Ruth
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2012
Relevância na Pesquisa
46.06%

A central theme in animal ecology is the study of the relationship between ecology and behavior. This dissertation demonstrates how ecological parameters, particularly food and weather variables, correlate with ranging, activity budget, and diet in Udzungwa red colobus monkeys (URC, Procolobus gordonorum), endemic to the Udzungwa Mountains, Tanzania.

From April 2009 - March 2010, four URC groups were habituated and studied in Mwanihana and Magombera Forests. During all-day follows, ranging, activity budget, and diet data were collected using GPS units and ten-minute scan samples of sustained activities. Food characteristics were assessed using transect and phenology surveys. Preliminary nutritional analyses were conducted on species-specific parts fed upon during October. I designed and employed novel methods for estimating ranging statistics which were compared with conventional methods.

Home range sizes were relatively small (8.8 - 20.8 ha). Home range size may relate to food species diversity and feeding selectivity for species-specific food parts. Variability in dietary composition was partly explained by plant phenology, forest composition, and selectivity differences among groups. URC primarily fed upon young leaves with higher fat content. Some non-nutritive items eaten may function as detoxifying agents. Data suggest that the URC dietary strategy involves nutrient balancing (i.e. maximizing energetic intake and nutrient acquisition while avoiding high concentrations of particular plant secondary compounds).

Mean daily travel distance (DTD) was 970 m...

Hydrothermal activity on near-arc sections of back-arc ridges: Results from the Mariana Trough and Lau Basin

Baker, Edward; Massoth, Gary; Nakamura, Ko-ichi; Embley, Robert; de Ronde, Cornel; Arculus, Richard
Fonte: American Geophysical Union Publicador: American Geophysical Union
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.12%
The spatial density of hydrothermal venting is strongly correlated with spreading rate on mid-ocean ridges (with the interesting exception of hot spot-affected ridges), evidently because spreading rate is a reliable proxy for the magma budget. This correlation remains untested on spreading ridges in back-arc basins, where the magma budget may be complicated by subduction-induced variations of the melt supply. To address this uncertainty, we conducted hydrothermal plume surveys along slow-spreading (40-60 mm/yr) and arc-proximal (10-60 km distant) sections of the southern Mariana Trough and the Valu Fa Ridge (Lau Basin). On both sections we found multiple plumes overlying ∼15-20% of the total length of each section, a coverage comparable to mid-ocean ridges spreading at similar rates. These conditions contrast with earlier reported results from the two nearest-arc segments of a faster spreading (60-70 mm/yr) back-arc ridge, the East Scotia Ridge, which approaches no closer than 100 km to its arc. There, hydrothermal venting is relatively scarce (∼5% plume coverage) and the ridge characteristics are distinctly slow-spreading: small central volcanic highs bookended by deep median valleys, and axial melt lenses restricted to the volcanic highs. Two factors may contribute to an unexpectedly low hydrothermal budget on these East Scotia Ridge segments: they may lie too far from the adjacent arc to benefit from near-arc sources of melt supply...

Stochastic simulation for budget prediction for large surface mines in the South African mining industry

Hager,J.; Yadavalli,V.S.S.; Webber-Youngman,R.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
Relevância na Pesquisa
36.12%
This article investigates the complex problem of a budgeting process for a large mining operation. Strict adherence to budget infers that financial results align with goals. In reality, the budget is not a predetermined entity but emerges as the sum of the enterprise's operational plans. These are highly interdependent, being influenced by unforeseeable events and operational decision-making. Limitations of stochastic simulations, normally applied in the project environment but not in budgeting, are examined and a model enabling their application is proposed. A better understanding of budget failure in large mines emerges, showing that the budget should be viewed as a probability distribution rather than a single deterministic value. The strength of the model application lies with the combining of stochastic simulation, probability theory, financial budgeting, and practical scheduling to predict budget achievement, reflected as a probability distribution. The principal finding is the interpretation of the risk associated with, and constraints pertaining to, the budget. The model utilizes a four-dimensional (space and time) schedule, linking key drivers through activity-based costing to the budget. It offers a highly expressive account of deduction regarding fund application for budget achievement...