bluuebunny/crossref_metadata_2025 huggingface dataset:
“I would rather have a decent job”: Potential barriers preventing street-waste pickers from improving their socio-economic conditions
Authors: Viljoen Kotie , Blaauw Phillip Frederick , Schenck Rinie
Published: April 2017

As a result of the high levels of unemployment in South Africa, many unskilled people are forced to resort to a variety of income-generating activities in the informal economy. The activity of collecting and selling recyclables presents virtually no barriers to entry, making it a viable option. Very little research focusing on street-waste pickers has been undertaken, and, when it has been conducted, it has mostly taken the form of case studies. This paper reports the results of the first countrywide research into the potential barriers that prevent street-waste pickers from improving their socio-economic circumstances. The study used a mixedmethod approach. Structured interviews were conducted between April 2011 and June 2012 with 914 streetwaste pickers and 69 buy-back centres in 13 major cities across all nine provinces in South Africa. Low levels of schooling, limited language proficiency, uncertain and low levels of income, as well as limited access to basic social needs make it difficult for waste pickers to move upwards in the hierarchy of the informal economy. The unique set of socio-economic circumstances in which street-waste pickers operate in the various cities and towns in South Africa make the design of any possible policy interventions a complex one. Policymakers will have to take note of the interdependence of the barriers identified in this research. Failing to do so may cause policies that are aimed at supporting street-waste pickers to achieve the exact opposite, and, ironically, deprive these pickers of their livelihood.
Unfulfilled loan demand among agro SMEs in Namibia
Authors: Amadhila Elina , Ikhide Sylvanus
Published: April 2017

Using a qualitative methodology approach, a case study research design by way of in-depth semi-structured interview(s) was followed to interview farmers, commercial banks, development banks, venture capitals and private equities to determine the financing options available for farmers and provide reasons why some financial institutions shy away from providing finance to agricultural enterprises. This study deviates from prior studies which have focused on small-scale farmers and subjected farmers’ access to finance to rural credit markets, mostly informal money lenders using secondary information mostly from household surveys to build econometric models. The study indicates that only about 33 percent of formal financial institutions are providing finance to agricultural SMEs. The lack of expertise and perception of risk were cited as top reasons why formal financial institutions find it hard to provide finance to agricultural SMEs. Building on opinions from other authors cited in this paper, we maintain that new financing mechanisms can be achieved by all types of financial institutions through learning from experiences by other successful countries.
A customer-focused approach to distribution: The case of SANparks
Authors: Douglas Anneli
Published: April 2017

While the importance of distribution has been recognised in tourism literature, the research has been approached mainly from the perspective of supply, with very little attention given to the customer. To date, there has been even less focus on the distribution channel requirements of the National Park customers. The purpose of this study is to examine how the various distribution channels used by South African National Parks (SANParks) go towards satisfying the customers’ distribution channel requirements and identifying whether there is any relationship between certain variables, such as gender or the frequency of channel use, and the level of satisfaction that customers experience with the various channels. Web-based and paper-based questionnaires are distributed to the customers who have used the SANParks distribution channels before. The results show that, although the SANParks website is the most frequently used channel for making a booking, it is not necessarily the channel with which customers are most satisfied; in fact, they are more satisfied with the satellite walk-in reservation offices and satellite call centres. While the majority of the research studies in the context of tourism distribution channels have shown the importance and popularity of electronic distribution channels among customers, this paper cautions SANParks not to assume the distribution channel requirements of their customers and urges them to continually assess their distribution strategies and to become more customer-focused in their approach.
The quest for process operations variability reduction in manufacturing firms in South Africa
Authors: Katombe Madi , Munapo Elias
Published: April 2017

In an era characterised by a volatile economy, intense competition, and rising energy and material costs, improving operational efficiency has become a necessity for margin purposes and long-term business success. This research study attempts to develop a model for process operations variability reduction that integrates the fundamental drivers, the intermediate measures and the four traditional competitive capabilities: quality, cost, delivery reliability and speed of delivery. In addition, it highlights the precise mechanisms in plants that lead to multiple competitive capabilities development. The concept of a routine-based approach to capabilities development provides a nexus between the earlier actions by the organisation and competitive advantage. Using longitudinal data from the Manufacturing Circle of South Africa, a statistical analysis was conducted to support the model, and path analysis models were developed which confirmed that the performance frontier is really a surface that spans many different dimensions. It is observed that the model clearly outlines pathways to process operations variability reduction through better execution of the routines concerned with maintaining the performance by current processes, improving existing processes, and transforming or changing to new processes.
How do age and location affect a business? Evaluating the objectives, outputs and outcomes of small business policy
Authors: Moos Menisha , Botha Melodi
Published: April 2017

Many scholars have dedicated their studies to understanding the kind of assistance given to small business. Likewise, numerous studies have concentrated on how government in particular, through a small business policy, can be instrumental in providing business support. This article evaluates South Africa‘s small business policy by concentrating on its objectives, outputs and outcomes. Studies evaluating small business policy according to its objectives, outputs and outcomes, have been limited. Such policy evaluation goes beyond merely reporting to understanding why certain phenomena take place. As an emerging economy, South Africa is in dire need of well-developed policies. This article proposes that understanding the link between small business policy and the age and location of a business may help government to refine policy formulation and design. Using a survey method and cross-sectional research design, the sample size of 340 respondents consisted of start-up and established business owners. This study found that not the age of the business, but only its location (the metropolitan municipality where the business is located) has a statistically significant effect on the objectives, outputs and outcomes of the small business policy. These findings should assist both national and international policymakers to identify specific context-bound interventions relevant to the location of businesses with a view to improving them.
Art investment in South Africa: Portfolio diversification and art market efficiency
Authors: Botha Ferdi , Snowball Jen , Scott Brett
Published: April 2017

Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel art price index offered the opportunity to test this theory in the South African context. Moreover, this paper tests whether art prices are efficient. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A vector autoregression of the art price index, Johannesburg stock exchange all-share index, house price index, and South African government bond index were used. Results show that, when there are increased returns on the stock market in a preceding period and wealth increases, there is a change in the Citadel art price index in the same direction. No significant difference was found between the house price index and the art price index, or between the art and government bond price indices. The art market is also found to be inefficient, thereby exacerbating the risk of investing in art. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
Job crafting and its impact on work engagement and job satisfaction in mining and manufacturing
Authors: De Beer Leon T , Tims Maria , Bakker Arnold B
Published: April 2017

The purpose of this study was to investigate job crafting and its relationship with work engagement and job satisfaction within the South African context. This research is important as job crafting has been shown to have a positive influence on employee motivation. A cross-sectional survey design was used to collect primary data from organisations in the mining and manufacturing industries of South Africa (N = 470). The results of multi-group structural equation modelling showed that the original four-factor structure of the job crafting scale was supported by the data, but that a three-factor structure was necessary due to a discriminant validity concern regarding two job crafting dimensions. Regression results revealed that increasing structural job resources with challenging job demands, and increasing social job resources were significant predictors of work engagement in both groups. Contrary to expectations decreasing hindering job demands was a negative predictor of job satisfaction in the mining group. Furthermore, increasing social job resources was also a significant predictor of job satisfaction in both groups. This study indicates the importance of job crafting for work engagement and job satisfaction in organisations.
Board composition, board size and financial performance of Johannesburg stock exchange companies
Authors: Muchemwa Munyradadzi Raymond , Padia Nirupa , Callaghan Chris William
Published: April 2017

On the basis of agency theory and resource dependence theory, as well as other corporate governance literature, it is predicted that board composition measured as the ratio of non-executive to executive board members and the number of directors on a firm’s board can be positively related to firm performance. This study seeks to test the predictions of this body of theory and to investigate the form of the empirical relationships among these effects. In so doing, this study tests theory that relates these variables in the context of a developing country, using data from South Africa’s Johannesburg Stock Exchange, over a seven-year period, 2006–2012.
Sense of coherence: A distinct perspective on financial well-being
Authors: Barnard Antoni
Published: April 2017

With the ongoing financial challenges being faced in the economic environment, research exploring financial and psychological well-being is of significant value because employees’ socio-economic behaviour affects productivity. Research emphasises mainly the effect of income level on psychological well-being, and its orientation to psychological well-being is narrowly derived from a focus on subjective well-being constructs. This study addresses the research gap by exploring the relationship dynamics between sense of coherence, income level and financial well-being. Secondary data were obtained from a cross-sectional online employee-wellness survey (n=7 185). The sample distribution included 66 per cent females and 34 per cent males from various age groups, with 46 per cent of the sample comprising single-household earners and 54 per cent sharing household income. Analysis of variance was conducted to examine the relationship dynamics between sense of coherence, level of income and financial well-being. Demographic variables that formed part of the survey results were included in the analysis. The relationships between sense of coherence and identified significant income level, financial well-being and demographic effects were further explored in Bonferroni multiple comparisons of means test and cross reference frequency tables that included Pearson’s chi-square and/or Cochran–Armitage trend tests. Detail results indicate that high-income employees exhibit a significantly stronger sense of coherence than low-income employees, and that, despite level of income, financial wellbeing is nevertheless positively related to sense of coherence. Results indicate important implications for managing a financially healthy workforce. Limitations are discussed and recommendations for future research are highlighted.
Antecedents to transformational community engagement in South Africa
Authors: Stirling Lauren , Wilson-Prangley Anthony , Hamilton Gillian , Olivier Johan
Published: April 2017

Firms face increasing societal pressures to act responsibly towards stakeholders, and community engagement is a key element of this response. While Bowen, Newenham-Kahindi and Herremans (2010) have found that community engagement strategies fall into the transactional, transitional and transformational categories, more research is needed. Nineteen semi-structured interviews were conducted with CSR practitioners, community beneficiaries and external experts across three companies from different sectors and geographically-associated South African communities. Barriers to and enablers of transformational community engagement are identified and compared with points made in the literature. Prominent barriers identified include community expectation; the internal capacity of the company to engage properly with communities; and, according to a new finding in the literature, community educational levels. The most prominent enabler of engagement was relationshipbuilding. Companies with dedicated CSR practitioners are able to engage more in the community. Regulatory dynamics are found to largely determine the differences across sectors. But there is the risk that engagement is symbolic rather than substantive. Eleven higher-order antecedents to transformational community engagement are then identified. A newly developed firm-oriented decision-making model is proposed for moderating these antecedents. The findings in the community and national context provide granular insight into an African operating environment.
Socio-economic consequences of technical change in palm fruit processing in Osun State, Nigeria
Authors: Alimi T , Bamire AS , Ayanwale AB
Published: April 2017

The traditional palm fruit processing method is basically manual, but is currently undergoing changes. This study identifies the stages that have been mechanised in traditional processing methods and the socio-economic implications of the technical change to assist decision-making on the superiority or otherwise of the mechanised (modern) method over the traditional method used by processors in Osun State of Nigeria. Primary data were collected during the 2004 production season with the aid of a structured questionnaire on the production resources and outputs of the two methods. These were analysed using descriptive and inferential statistics, budgetary technique dominance and sensitivity analyses, and attitudinal measure. Results indicate that only two (pounding to form paste and cracking) of the stages identified in the traditional method were mechanised in the modern method. This resulted in greater efficiency of palm oil extraction, higher labour productivity, more income to stakeholders, greater market orientation, increased volume of operation and unchanged product types and quality. Other consequences are the creation of one additional group of stakeholders (machine owners), dominance, resilience to adverse yield and machine charges by 27 per cent and 150 per cent, respectively; more favourable attitude, less drudgery and health hazards, less labour requirements (female) and lower processing time in the modern method than the traditional method. This made the modern method a better choice, which could boost palm oil production at the aggregate level.
Should the West African countries form a currency union?
Authors: Akinbobola TO , Akinlo AE
Published: April 2017

This paper examines whether or not the Economic Community of West African States (ECOWAS), comprising  fifteen countries, constitutes an Optimum Currency Area (OCA). The paper uses secondary data obtained from the International Financial Statistics Bulletin, covering the period 1986 to 2003. The Vector Autoregressive (VAR) modelling technique was used to investigate the optimality of the community as a currency area. The study found  that shocks to the output growth rate and inflation rates aligned symmetrically. Except for Nigeria and Sierra Leone, shocks to the real exchange rates also aligned symmetrically across countries. However, the degree of openness variable showed asymmetrical disturbance across countries. This paper thus concludes that  a low trade link exists among member countries of ECOWAS, traced principally to the fact that these countries’ exports were competitive rather than complementary. The asymmetric disturbance of real exchange rate shocks and the low degree of openness across the countries implied that the sub-region could not effectively form a successful Optimum Currency Area (OCA). Nevertheless, the sub-region exhibits some potential for forming an optimum currency area in the future.
The voice from the periphery: Towards an African business ethics beyond the Western heritage
Authors: Murove MF
Published: April 2017

This article argues that African business ethics should go beyond the western heritage by taking into account African indigenous values and knowledge systems. While western business practices are part and parcel of Africa’s heritage, African post-colonial scholarly efforts have worked at enriching this heritage by arguing for the incorporation of African indigenous knowledge systems and values in our way of thinking and doing business. There is a realisation that the western homo economicus who is solely self-interested, is irreconcilable with the African understanding of a person. The success of any business venture in Africa depends on incorporating African values in the way it operates.
Management responses to HIV/AIDS in South African workplaces
Authors: Stevens M , Weiner R , Mapolisa S , Dickinson D
Published: April 2017

There are concerns that HIV/AIDS will impact on South African workplaces. This article reports on some of the findings of a baseline national cross-sectional study of 383 companies, each with more than 50 employees. Issues of HIV/AIDS policies, responsibility for workplace programmes, perceived and measured impact of HIV/AIDS and the response of companies are reported. Findings from this survey are compared with results from four other surveys viewing HIV/AIDS and companies. In line with other surveys, the findings indicate limited responses on the part of workplaces. Unreliability of perceptions and lack of impact measurement are highlighted. We argue that this lack of measurement reflects widespread strategic failure on the part of South African management. This failure is resulting in a de facto shift of workplace responsibility for the burden of the disease onto individuals, communities and society.
A preliminary model to identify low-risk MBA applicants
Authors: Bisschoff CA
Published: April 2017

Business schools throughout the world strive to admit “quality” students to their MBA programmes. To achieve this, various measures are employed during the selection processes.  These measures include various tests such as the General Management Admissions Test, Test of English as foreign language and the Common Admission Test, to name but a few.  Although these tests may be successful in indicating the quality of applicants, their predictive capabilities with reference to the academic performance in the discipline of management and leadership are unproven, while some researchers even regard these tests to be biased or unscientific across cultural boundaries.This article attempts to provide a preliminary model that could be applied to applicants in order to predict their academic success on an MBA programme. To do so, the model makes use of historical academic performance of 729 MBA students who enrolled during the years 1999, 2000 and 2001 at the Potchefstroom Business School of the Northwest University.  These students graduated in the years 2001, 2002 and 2003.  A vast array of demographic, academic and historical variables is employed by discriminant analyses to categorise the applicants into 2 groups, namely:• “Low-to-no -isk” applicants for the MBA programme (most preferred applicants that should graduate within the minimum period of 3 years);• Applicants who did not complete their degree in 3 years.  This category contains two groups of students, namely those who extended their studies to 4 years, and those who failed and subsequently  dropped out of the MBA programme. Further analysis of this category identified:o “Medium-to-low-risk” applicants who are expected to complete their degree in 4 years (they need an additional year to complete the 3-year degree).  Although this category is less favourable, they do complete their studies. o “High-risk” applicants are those who are not expected to complete their degrees and would probably exit the programme without obtaining any qualification.  These applicants should not be allowed to enter into the MBA programme.The reliability of the discriminant function rates favourably with 71% (MBA in 3 years), 62% (MBA in 4 years) and 83% (dropping out of the programme) being categorised correctly by the respective discriminant functions. Being a preliminary model, its predictive capabilities need to be verified in practice before it can  be implemented as tool to render assistance in MBA admissions.  The value of this research lies  in the fact that it constitutes a model that could be employed and improved as a predictive tool in an environment where very limited predictive tools exist.  Therefore, although it is by no means a tried and tested model, it sets the scene by supplying a scientific base from which incremental improvements could result.
Industrial strategy and local economic development: The case of the foundry industry in Ekurhuleni Metro
Authors: Phele T , Roberts S , Steuart I
Published: April 2017

This  article explores the challenges for the development of manufacturing through a case study of the foundry industry in Ekurhuleni Metropolitan Municipality. Ekurhuleni Metro covers the largest concentration in South Africa, but the industry’s performance has been poor over the past decade.  The findings reported here highlight the need to understand firm decisions around investment, technology and skills, and the role of local economic linkages in this regard.  The differing performance of foundries strongly supports the need to develop concrete action plans and effective institutions at local level to support the development of local agglomerations.
Widening the digital divide: A study on the possible impact of the convergence Bill of 2003 on the South African cybereconomy
Authors: Da Silva EM , Kruger CJ
Published: April 2017

Business does not exist in a vacuum. The external environment is either conducive to or stifles business growth. Van Rooyen (2004: 399) points out that ‘E-business has important implications for South Africa as an emerging economy, as it creates the possibility of better access to various financial resources and eventually increased economic activity. This will affect all sectors in the economy and may lead to generally improved business infrastructure for the country as a whole and for individual business, local authorities and government treasury departments. This is especially important for South Africa as a developing country, which in turn, will make an important contribution to rapid alleviation of private and more rapid reform in the long run’.  A major determinant of the external environment in which business operates is legislation and regulation. It therefore follows that any regulation or legislation pertaining to E-business must be conducive to growth.  The draft Convergence Bill of 2003 is to be tabled in Parliament during its next session.  In this paper it is argued that in its present form, the proposed Convergence Bill is in fact detrimental to organisational growth, a potential kiss of death for E-enabled organisations.
The responsibility of the internal auditor in managing the risk of HIV/AIDS
Authors: Coetzee P
Published: April 2017

HIV/AIDS is not only a risk to the world population, it is potentially devastating to individual organisations. According to the King Report on Corporate Governance, as well as other governance reports world-wide, risk management is primarily the responsibility of the board and senior management. The internal auditor however, has a responsibility to assist management with this task. This paper aims to determine whether internal auditors are aware of the potential threat that HIV/AIDS holds for their organisations. If ignorance is found to be widespread, recommendations are made to the Institute of Internal Auditors to make their members aware.  If awareness is found to be adequate, the paper aims to determine whether internal auditing departments in various sectors of the South African business community are complying with this responsibility.
The Okavango delta: The value of tourism
Authors: Mopelwa G , Blignaut J
Published: April 2017

In Botswana, tourism is the second most important economic activity after diamond mining and trading. The Okavango Delta in northern Botswana is the largest single tourist centre in the country. This study estimates the total economic value of tourism in the Okavango Delta and compares this value to that of other sectors in the economy of Botswana. The results are compared to results of similar studies for tourist destinations elsewhere in the world, and the policy implications of the findings are highlighted. The study uses secondary data to estimate the direct consumptive and non-consumptive use value, and a survey among tourists to determine the existence value of the Okavango Delta.
Evaluating Bloemfontein’s image as a tourist destination: A tour operator’s perspective
Authors: Strydom AJ , Nel RG
Published: April 2017

Tour operators have been identified as vital information sources influencing the images and decision-making processes of tourists. Bloemfontein is situated in Central South Africa.  Tourism marketers believe that the city is an ideal stopover destination for national tour operators  en route to other destinations.  Research was conducted among national tour operators in Johannesburg, Durban and Cape Town to determine their perceptions of Bloemfontein and whether they regard the city as a tourist or stopover destination.  The research indicates that the city is not regarded as a tourist destination, but is seen as an ideal stopover destination which could be included in future tour itineraries.  It is currently excluded because operators are unfamiliar with the tourism offering(s) of Bloemfontein due to insufficient marketing by the tourism officials of the city.
Does prospect theory warrant a paradigm shift in the economics of risk?
Authors: Mohapi PL
Published: April 2017

This paper assesses whether a paradigm shift should be made from expected utility framework to prospect theory framework – in the economics of choice under risk. A brief overview of the subject is outlined, starting with expected utility theory and noting its descriptive limitations. Proposed theories to make up for these limitations is also provided. Prospect theory emerged as the most serious challenger to expected utility theory. A review of some descriptive predictions of prospect theory, suggests that there is no scientific reason why expected utility should not be ousted from dominance by prospect theory. The shift to prospect theory however is not without costs. Conceptual complexities and non-universality of application associated with prospect theory should be embraced with the shift while not entirely abandoning expected utility theory.
Poverty and soil conservation efforts among smallholder farmers in the central highlands of Ethiopia
Authors: Yirga C , Hassan RM
Published: April 2017

This study explores the influence of incidence of poverty and plot-level perception of soil degradation, on soil conservation behaviour of small subsistence farmers in the central highlands of Ethiopia. The study results confirm that poverty in assets significantly reduces the probability of soil-conservation efforts as measured by use of stone/soil bund structures in the highlands of Ethiopia. Perception of soil degradation, public assistance with sharing initial costs of constructing soil-conservation structures, improved security of land tenure and farmers’ education and access to information on soil degradation are essential for farmers making long-term investment in conserving soil resources. On the other hand, improved access to short-term credit for the purchase of inorganic fertilizers acts as a disincentive for long-term conservation practices, an important trade-off with serious policy implications that should be carefully evaluated.
The feasibility of competitive electricity transmission in South Africa
Authors: Ahwireng-Obeng F , Thobela M
Published: April 2017

The paper investigates whether competitive transmission of electricity is realisable in South Africa by adapting the Delphi research process to survey the opinions of expert panellists drawn from the relevant disciplines. The research propositions revolve around the roles that customers, generators and technology suppliers, among others, could play in providing competitive transmission services. Given that competition in electricity generation is generally accepted, the paper examines the extent to which sunk costs, fixed costs and scale economies are sufficient to block entry into the transmission services sector. The experts were unambiguously convinced that economies of scale in transmission were significant enough to block entry into the industry. Consequently, neither the successful introduction of competition in generation nor Eskom’s successful experiment in power transmission and telecommunications joint ventures provides sufficient grounds to believe that it is feasible to implement a competitive electricity transmission industry in South Africa.
A customer-centric approach towards evaluating single-choice information technology service provision to the parastatal sector of South Africa
Authors: Cant MC , Strydom JW , Moodley VM , Tustin DH
Published: April 2017

The article presents a case study whereby the service performance of a single-choice information technology service provider in the parastatal industry of South Africa is measured against multi-choice private service providers without any provisional agreements.  The outcome of the case study reveals that single-choice service provision options with provisional agreements have a limited chance of success if they are not supported by strong service user inputs.  In fact, provisional strategies that disallow sound competition among service providers are bound to impact negatively on user preferences as well as information technology skills development opportunities that  are required to improve service provision generally and long-term survival in particular.
The views of HR practitioners on ethical issues within organisations: A South African perspective
Authors: Wordsworth R , Erasmus BJ
Published: April 2017

This article reports on the results of a survey conducted among human resource practitioners in South Africa regarding their involvement in and experience of business ethics and unethical behaviour in their organisations. The results of the study concur with the theoretical perception that human resource managers have an important role to play in the institutionalisation of good ethical behaviour in the organisation, with the majority of respondents reporting that the human resource department is a primary resource for ethical initiatives and that human resource professionals are involved in the formulation of ethics policies. The article provides some insights in terms of the role of the human resource managers in the management of ethics. In so doing, an attempt is made to address the question of whether human resource managers should be the drivers of ethics initiatives in the organisation.
On the interval of fluctuation of the singular values of random matrices
Authors: Guédon Olivier , Litvak Alexander E. , Pajor Alain , Tomczak-Jaegermann Nicole
Published: April 2017

Let

A

be a matrix whose columns

X_1,\dots, X_N

are independent random vectors in

\mathbb R^n

. Assume that the tails of the 1-dimensional marginals decay as

\mathbb P(|\langle X_i, a\rangle|\geq t)\leq C t^{-p}

uniformly in

a\in S^{n-1}

and

i\leq N

. Then for

p>4

we prove that with high probability

A/\sqrt{n}

has the Restricted Isometry Property (RIP) provided that Euclidean norms

|X_i|

are concentrated around

\sqrt{n}

. We also show that the covariance matrix is well approximated by empirical covariance matrices and establish corresponding quantitative estimates on the rate of convergence in terms of the ratio

n/N

. Moreover, we obtain sharp bounds for both problems when the decay is of the type exp

(-t^{\alpha})

, with

\alpha \in (0,2]

, extending the known case

\alpha \in (1,2]

.
Soluções nutritivas para produção de porta-enxertos de seringueira
Authors: Olivieri de Nobile Fabio , Paro Gabriel Fernando , Farinelli Rogério
Published: April 2017

O objetivo deste trabalho foi avaliar a produção suspensa de porta-enxertos de seringueira com substrato em fertirrigação. Foram testados quatro tipos de soluções nutritivas em delineamento experimental inteiramente casualizado, com 5 repetições. A fertirrigação foi realizada a cada dois dias, utilizando-se 200 mL da solução por recipiente. Avaliou-se altura de planta, diâmetro de caule (5 cm acima do colo da planta), área foliar, número de par de folhas, matéria seca da parte aérea e raízes, teor foliar de nutrientes e porcentagem de plantas aptas à enxertia. Os maiores valores para altura de plantas, número de pares de folhas, diâmetro de caule e área foliar dos porta-enxertos foram obtidos com a concentração mais elevada de nutrientes. O teor foliar de nutrientes e a porcentagem de plantas aptas à enxertia foram considerados adequados com o uso da fertirrigação na maior dose testada (para 5L: Ca(NO₃) 2,5g, MgSO4 1,75g; KNO3 1,5g; (NH4)(NO3) 1,0g; NH4H2PO4 0,9g; Zn(NO3)2 0,30g; CuSO4 0,20g; EDTA(Fe+2) 0,15g).
Modelagem da distribuição de frequência de teores carbono orgânico do solo sob Floresta Ombrófila Mista no Paraná
Authors: Barreto Tauane Garcia , Klein Hentz Ângela Maria , Netto Sylvio Péllico , Corte Ana Paula Dalla , Sanquetta Carlos Roberto
Published: April 2017

Neste trabalho objetivou-se modelar o teor de carbono no solo de parcelas sob Floresta Ombrófila Mista em condições distintas (predomínio de araucária, de imbuia e vegetação mista com registro de ocorrência de fogo), no Paraná, a partir de distribuições probabilísticas. Para tal, foi avaliada a qualidade de ajuste e aderência de diferentes funções de probabilidade (normal, Weber, Weibull 3P, log-normal, SB de Johnson e Gama), pelo teste de Kolmogorov-Smirnov. Todas as funções densidade de probabilidade resultaram em bons ajustes, podendo então ser utilizadas para modelar os dados de carbono no solo em qualquer uma das parcelas. As funções foram ranqueadas a partir dos valores do teste Kolmogorov-Smirnov, e decidiu-se que a função Gama é a mais apropriada para modelar o teor de carbono nas três parcelas estudadas. Ainda, ao realizar a comparação das distribuições Gama ajustadas pelo teste Kolmogorov-Smirnov nas diferentes condições testadas, observou-se que elas apresentam configurações distintas, portanto, devem ser modeladas individualmente.
Change in Functional Arm Use Is Associated With Somatosensory Skills After Sensory Retraining Poststroke
Authors: Turville Megan , Carey Leeanne M. , Matyas Thomas A. , Blennerhassett Jannette
Published: April 2017

OBJECTIVE. We investigated changes in functional arm use after retraining for stroke-related somatosensory loss and identified whether such changes are associated with somatosensory discrimination skills.

METHOD. Data were pooled (N = 80) from two randomized controlled trials of somatosensory retraining. We used the Motor Activity Log to measure perceived amount of arm use in daily activities and the Action Research Arm Test to measure performance capacity. Somatosensory discrimination skills were measured using standardized modality-specific measures.

RESULTS. Participants’ arm use improved after somatosensory retraining (z = −6.80, p < .01). Change in arm use was weakly associated with somatosensation (tactile, β = 0.31, p < .01; proprioception, β = −0.17, p > .05; object recognition, β = 0.13, p < .05).

CONCLUSION. Change in daily arm use was related to a small amount of variance in somatosensory outcomes. Stroke survivors’ functional arm use can increase after somatosensory retraining, with change varying among survivors.
Rehabilitation Research at the National Institutes of Health: Moving the Field Forward (Executive Summary)
Authors: Frontera Walter R. , Bean Jonathan F. , Damiano Diane , Ehrlich-Jones Linda , Fried-Oken Melanie , Jette Alan , Jung Ranu , Lieber Rick L. , Malec James F. , Mueller Michael J. , Ottenbacher Kenneth J. , Tansey Keith E. , Thompson Aiko
Published: April 2017

Approximately 53 million Americans live with a disability. For decades, the National Institutes of Health (NIH) has been conducting and supporting research to discover new ways to minimize disability and enhance the quality of life of people with disabilities. After the passage of the Americans With Disabilities Act, NIH established the National Center for Medical Rehabilitation Research, with the goal of developing and implementing a rehabilitation research agenda. Currently, 17 institutes and centers at NIH invest more than $500 million per year in rehabilitation research. Recently, the director of NIH, Francis Collins, appointed a Blue Ribbon Panel to evaluate the status of rehabilitation research across institutes and centers. As a follow-up to the work of that panel, NIH recently organized a conference, “Rehabilitation Research at NIH: Moving the Field Forward.” This report is a summary of the discussions and proposals that will help guide rehabilitation research at NIH in the near future.
Changing trends and emissions of hydrochlorofluorocarbons (HCFCs) and their hydrofluorocarbon (HFCs) replacements
Authors: Simmonds Peter G. , Rigby Matthew , McCulloch Archie , O'Doherty Simon , Young Dickon , Mühle Jens , Krummel Paul B. , Steele Paul , Fraser Paul J. , Manning Alistair J. , Weiss Ray F. , Salameh Peter K. , Harth Chris M. , Wang Ray H. J. , Prinn Ronald G.
Published: April 2017

Abstract. High-frequency, in situ global observations of HCFC-22 (CHClF2), HCFC-141b (CH3CCl2F), HCFC-142b (CH3CClF2) and HCFC-124 (CHClFCF3) and their main HFC replacements, HFC-134a (CH2FCF3), HFC-125 (CHF2CF3), HFC-143a (CH3CF3) and HFC-32 (CH2F2), have been used to determine their changing global growth rates and emissions in response to the Montreal Protocol and its recent amendments. Global mean mole fractions of HCFC-22, -141b, and -142b have increased throughout the observation period, reaching 234, 24.3 and 22.4 pmol mol−1, respectively, in 2015. HCFC-124 reached a maximum global mean mole fraction of 1.48 pmol mol−1 in 2007 and has since declined by 23 % to 1.14 pmol mol−1 in 2015. The HFCs all show increasing global mean mole fractions. In 2015 the global mean mole fractions (pmol mol−1) were 83.3 (HFC-134a), 18.4 (HFC-125), 17.7 (HFC-143a) and 10.5 (HFC-32). The 2007 adjustment to the Montreal Protocol required the accelerated phase-out of emissive uses of HCFCs with global production and consumption capped in 2013 to mitigate their environmental impact as both ozone-depleting substances and important greenhouse gases. We find that this change has coincided with a stabilisation, or moderate reduction, in global emissions of the four HCFCs with aggregated global emissions in 2015 of 449 ± 75 Gg yr−1, in CO2 equivalent units (CO2 eq.) 0.76 ± 0.1 Gt yr−1, compared with 483 ± 70 Gg yr−1 (0.82 ± 0.1 Gt yr−1 CO2 eq.) in 2010 (uncertainties are 1σ throughout this paper). About 79 % of the total HCFC atmospheric burden in 2015 is HCFC-22, where global emissions appear to have been relatively similar since 2011, in spite of the 2013 cap on emissive uses. We attribute this to a probable increase in production and consumption of HCFC-22 in Montreal Protocol Article 5 (developing) countries and the continuing release of HCFC-22 from the large banks which dominate HCFC global emissions. Conversely, the four HFCs all show increasing mole fraction growth rates with aggregated global HFC emissions of 327 ± 70 Gg yr−1 (0.65 ± 0.12 Gt yr−1 CO2 eq.) in 2015 compared to 240 ± 50 Gg yr−1 (0.47 ± 0.08 Gt yr−1 CO2 eq.) in 2010. We also note that emissions of HFC-125 and HFC-32 appear to have increased more rapidly averaged over the 5-year period 2011–2015, compared to 2006–2010. As noted by Lunt et al. (2015) this may reflect a change to refrigerant blends, such as R-410A, which contain HFC-32 and -125 as a 50 : 50 blend.
Sensitivity of formaldehyde (HCHO) column measurements from a geostationary satellite to temporal variation of the air mass factor in East Asia
Authors: Kwon Hyeong-Ahn , Park Rokjin J. , Jeong Jaein I. , Lee Seungun , González Abad Gonzalo , Kurosu Thomas P. , Palmer Paul I. , Chance Kelly
Published: April 2017

Abstract. We examine upcoming geostationary satellite observations of formaldehyde (HCHO) vertical column densities (VCDs) in East Asia and the retrieval sensitivity to the temporal variation of air mass factors (AMFs) considering the presence of aerosols. Observation system simulation experiments (OSSE) were conducted using a combination of a global 3-D chemical transport model (GEOS-Chem), a radiative transfer model (VLIDORT), and a HCHO retrieval algorithm developed for the Geostationary Environment Monitoring Spectrometer (GEMS), which will be launched in 2019. Application of the retrieval algorithm to simulated hourly radiances yields the retrieved HCHO VCDs, which are then compared with the GEOS-Chem HCHO VCDs as true values for the evaluation of the retrieval algorithm. In order to examine the retrieval sensitivity to the temporal variation of AMF, we examine three AMF specifications, AMFm, AMFh, and AMFmh, using monthly, hourly, and monthly mean hourly input data for their calculation, respectively. We compare the retrieved HCHO VCDs using those three AMFs and find that the HCHO VCDs with AMFh are in better agreement with the true values than the results using AMFmh and AMFm. AMFmh reflects diurnal variation of planetary boundary layer and other meteorological parameters, so that the results with AMFmh show a better performance than those with AMFm. The differences between AMFh and AMFm range from −0.76 to 0.74 in absolute value and are mainly caused by temporal changes in aerosol chemical compositions and aerosol vertical distributions, which result in −27 to 58 and −34 to 43 % changes in HCHO VCDs over China, respectively, compared to HCHO VCDs using AMFm. We apply our calculated AMF table together with OMI aerosol optical properties to OMI HCHO products in March 2006, when Asian dust storms occurred, and find −32 to 47 % changes in the retrieved HCHO columns due to temporal changes in aerosol optical properties in East Asia. The impact of aerosol temporal variability cannot be neglected for future geostationary observations.
Modeling of the chemistry in oxidation flow reactors with high initial NO
Authors: Peng Zhe , Jimenez Jose L.
Published: April 2017

Abstract. Oxidation flow reactors (OFRs) are increasingly employed in atmospheric chemistry research because of their high efficiency of OH radical production from low-pressure Hg lamp emissions at both 185 and 254 nm (OFR185) or 254 nm only (OFR254). OFRs have been thought to be limited to studying low-NO chemistry (where peroxy radicals (RO2) react preferentially with HO2) because NO is very rapidly oxidized by the high concentrations of O3, HO2, and OH in OFRs. However, many groups are performing experiments aging combustion exhaust with high NO levels, or adding NO in the hopes of simulating high-NO chemistry (where RO2 + NO dominates). This work systematically explores the chemistry in OFRs with high initial NO. Using box modeling, we investigate the interconversion of N-containing species and the uncertainties due to kinetic parameters. Simple initial injection of NO in OFR185 can result in more RO2 reacted with NO than with HO2 and minor non-tropospheric photolysis, but only under a very narrow set of conditions (high water mixing ratio, low UV intensity, low external OH reactivity (OHRext), and initial NO concentration (NOin) of tens to hundreds of ppb) that account for a very small fraction of the input parameter space. These conditions are generally far away from experimental conditions of published OFR studies with high initial NO. In particular, studies of aerosol formation from vehicle emissions in OFR often used OHRext and NOin several orders of magnitude higher. Due to extremely high OHRext and NOin, some studies may have resulted in substantial non-tropospheric photolysis, strong delay to RO2 chemistry due to peroxynitrate formation, VOC reactions with NO3 dominating over those with OH, and faster reactions of OH-aromatic adducts with NO2 than those with O2, all of which are irrelevant to ambient VOC photooxidation chemistry. Some of the negative effects are worst for alkene and aromatic precursors. To avoid undesired chemistry, vehicle emissions generally need to be diluted by a factor of > 100 before being injected into OFR. However, sufficiently diluted vehicle emissions generally do not lead to high-NO chemistry in OFR, but are rather dominated by the low-NO RO2 + HO2 pathway. To ensure high-NO conditions without substantial atmospherically irrelevant chemistry in a more controlled fashion, new techniques are needed.