bluuebunny/crossref_metadata_2025 huggingface dataset:
Reviewing productivity studies of skidders working in coniferous forests and plantations
Authors: Ghaffariyan Mohammad Reza
Published: October 2020

Skidding is an important element of harvesting operations, which contributes to the extraction of wood. A skidder can be used in different types of harvesting operations, such as thinning, clear fell, native forest thinning or salvage work. The main goal of this article was to review the available stud-ies on productivity of skidding operations in coniferous forests/ plantations. Information on skid-der productivity was collected from publications and then was classified in three regions, including North America, Europe and the Southern Hemisphere. The parameters affecting machine productivity included machine type/ size, tree volume/ log volume/ load volume, average skidding distance and slope of the ground for each reported productivity. The average productivity reported in the published reports ranged from 9.3 m3/PMH to 78.0 m3/PMH. Detailed information and conclusions collected from various studies can be of use to forest academic and industry users to gain knowledge about vari-ations of skidder productivity in different regions and site/ operation conditions, which can be helpful for predicting, controlling and improving current levels of productivity. 
Les dispositifs individualisés d’aide aux élèves : lieux de renormalisation. Comparaison entre l’Ontario et la Belgique
Authors: Bélanger Nathalie , Kahn Sabine
Published: October 2020

L’aide individualisée aux élèves se déploie de plus en plus dans les écoles à travers le monde. Les plans individuels d’apprentissage (PIA) pour la Belgique ou d’enseignement individualisé (PEI) pour l’Ontario en sont des exemples. Peuvent-ils être considérés en tant que lieux de renormalisation et de réinterprétation de la forme scolaire ? Ils sont ici analysés en tant que dispositifs à partir d’une approche sociomatérielle et normative de l’activité. Les résultats montrent que le plan prescrit peut être associé à un changement de paradigme qui vise à instruire les conduites des professionnels de l’éducation à partir de nouvelles normes. Tandis que les plans réels révèlent, dans les deux contextes, les renormalisations à l’œuvre mais aussi la persistance de cultures professionnelles encore peu acquises aux nouvelles injonctions et aux normes qui les sous-tendent.
Numérique et apprentissages : prescriptions, conceptions et normes d’usage
Authors: Ferone Georges
Published: October 2020

Nous nous interrogeons sur les conceptions des futurs enseignants en formation, relatives au numérique et aux apprentissages afin d’identifier les normes susceptibles de guider leurs pratiques professionnelles. Une étude de cas menée auprès d’étudiants de l’ESPE de Créteil montre qu’ils partagent les mêmes conceptions que les enseignants titulaires. Ils considèrent que le numérique favorise les apprentissages parce qu’il est ludique, motivant et qu’il développe l’activité et l’autonomie des élèves mais le numérique constitue aussi un obstacle à l’apprentissage de la lecture et de l’écriture. Ces conceptions, marquées par des doxas, font apparaître une tentative de compromis entre de nouvelles normes sociétales et institutionnelles très favorables au numérique et des normes traditionnelles du métier. Ainsi, les étudiants interrogés opposent le livre à l’écran et le stylo au clavier. Cette étude souligne la nécessité de travailler ces conceptions en formation pour construire de nouvelles normes d’usage du numérique éducatif.
Using Qualitative Inquiry and Self-Study to Make Sense of Data Use Practices in Teacher Education
Authors: Wilson Jahnette , Brower Sam , Edgar Teresa , Thompson Amber , Culpepper Shea
Published: October 2020

Accountability and rigor in teacher education have been the focus of recent policy initiatives. Thus, data use practices have become increasingly critical to informing program improvement. Educational researchers have established self-study as a research methodology to intentionally be used by teacher educators to improve their practice. The purpose of the self-study described in this article was to examine the data use practices of one teacher preparation program in an effort to facilitate improvement of the program's capacity in using program data. The qualitative data gathered in this case study proved to be pivotal in the continuous improvement efforts of the teacher preparation program; thus, the usefulness and value of the findings within this case study have implications for how institutional self-study and qualitative data can support quantitative programmatic data in order to facilitate programmatic improvement initiatives.
Knowledge Analytics
Authors: Wang Shouhong , Wang Hai
Published: October 2020

Big data has raised challenges and opportunities for the education sector. Educational analytics encompass a variety of computational techniques to process educational big data for effective teaching, learning, research, service, and administrative decision making. Learning analytics and academic analytics have been widely discussed in the literature of education; however, knowledge analytics have not been discussed in the educational analytics field. Knowledge analytics are a relatively new subject in the knowledge management area. Knowledge analytics lie outside of the definitions of learning analytics and academic analytics, and encompass analytical activities for knowledge management among educators in teaching, research, and services. This paper discusses potential applications of knowledge analytics in educational institutions and issues related to implementation of knowledge analytics in the educational environment.
Debates in English Language Education
Authors: García-Sánchez Soraya
Published: October 2020

Discussing and reasoning remain essential activities in a 21st educational and professional ecosystem, which are often supported by multimodal communication. This paper links learning English as a Foreign Language (EFL) to a professional and communicative approach through the debate task, which is supported by a ubiquitous CALL/MALL environment. This study will show the proposed structure of the debate in order to establish interdependent and collaborative work that can be successfully planned by means of combining 21st cognitive and communicative skills that will enhance students' EFL performance in Higher Education. Students' decisions to explore target content, role positions, and the production of well-linked communicative messages in EFL will be shown at upper intermediate level B1+/B2. The empirical data suggests that interactive patterns and argumentative rebuttals in English encourage a multimodal educational and professional ecosystem for 21st century learners, who use face-to-face and technological devices to interact with each other and to access ubiquitous information.
The Use of Media Convergence in the Preservation and Dissemination of Cultural Assets
Authors: Hoguane José João , Tavares Mirian N. , Boto Sandra
Published: October 2020

This article intends to present the experience and perspectives of the use of media convergence through an artifact/installation in media digital art. The aim of the experience is, as an interface, to contribute to the knowledge dissemination about timbila of Mozambique as cultural asset, especially in the younger strata, and to lead reflection and awareness about the problem due the risc of it disappearance. The article aims to elucidate the role of digital media art in solving humanities' problems.
An Efficient Generalized Error Concealment in Video Codec
Authors: Ahmed Ansari Vaqar , Khot Uday Pandit
Published: October 2020

Efficient error concealment (EC) predictor can recover more significant features or structures of entire lost MBs using a pre-transmission algorithm (PTA) with convolutional neural network (CNN) and fuzzy reasoning to select appropriate EC for reconstruction in generalized video-codec compression scheme such as H.264/H.265, etc. Here, the pixel-based motion vector with partition (PMVP) algorithm is modified by using Mahalanobis distance (MD) rather than Euclidean distance (ED) for better MVs recovery. This modified pixel-based motion vector with partition (MPMVP) algorithm is upgraded by two different strategies: one by using voting priority of available MVs based on the probabilities of similar directions and the second by considering separate horizontal and vertical directions of available MVs in voting priority. Similarly, a modified spiral pixel reconstruction (MSPR) algorithm based on directional edge recovery method using minimum and maximum MD from available pixels of surrounding MBs is proposed. The proposed PTA-based modified ECs gives 20.4%, 3.47%, and 6.66% increase in PSNR.
Brain Tumor Detection Using Multipath Convolution Neural Network (CNN)
Authors: Chandrakar Mukesh Kumar , Mishra Anup
Published: October 2020

Brain tumor segmentation is an emerging application of automated medical image diagnosis. Robust approach of brain tumor segmentation and detection is a research problem, and the performance metrics of the existing tumor detection methods are not appropriately known. Deep neural network using convolution neural network (CNN) is being researched in this direction, but no general architecture is found that can be used as robust method for brain tumor detection. The authors have proposed a multipath CNN architecture for brain tumor segmentation and detection, which provides improved results as compared to existing methods. The proposed work has been tested for datasets BRATS2013, BRTAS2015, and BRATS2017 with significant improvement in dice index and timing values by utilizing the capability of multipath CNN architecture, which combines both local and global paths.
Surface Wave Dispersion in a Layered Medium for Varying Subsurface Scenarios
Authors: Roy Narayan , Desai Aniket , Jakka Ravi S.
Published: October 2020

Surface wave techniques are widely used to characterize a site based on shear wave velocity (Vs) or stiffness variation with depth. It utilizes the dispersion property of Rayleigh wave in a heterogeneous media. Dispersion curve is obtained from analyzing collected field test data and the final Vs profile is extracted from the inversion of the generated dispersion curve. The varying subsoil structures influence whether one or more Rayleigh modes will participate in the resulting wave propagation phenomenon. So, neglecting the higher mode participation may sometimes results in a completely different velocity profile than the actual existing one. In this paper, a detailed and comprehensive numerical study has been performed using finite element method for different types of soil profiles with different half-space impedances to assess how it affects the surface wave dispersion phenomenon. In addition to that, the effect of different data acquisition parameters on surface wave dispersion has also been studied.
Blockchain Traceability Valuation for Perishable Agricultural Products Under Demand Uncertainty
Authors: Zhao Zhuoyi , Min K. Jo
Published: October 2020

Various perishable agricultural products are recalled due to harmful health risks. Blockchain has been used to reduce the amount of such products wasted and disposed. Specifically, a supply chain with a wholesaler, a retailer, and customers is considered where the retailer decides when to switch from a conventional supply chain information management system (SCIMS) to a blockchain-based SCIMS. This article models the uncertain customers' demand as a geometric Brownian motion process and shows how to obtain the optimal demand threshold above which the switch occurs and the corresponding expected time. Next, the model is extended by incorporating two types of government subsidies (i.e., a fixed subsidy on the switching cost and a variable subsidy per unit demand). Through sensitivity analysis and numerical studies, the impacts of key parameters on the optimal demand threshold and expected time of switching are presented. Finally, managerial insights and policy implications are derived.
Implications of the Fourth Industrial Revolution on Gender Participation
Authors: Kisusu Robert W. , Tongori Samson T. , Madiany Donald Okumu
Published: October 2020

An economic development needs to know whether there is concrete implication of the fourth industrial revolution (4IR) on participation of gender, as this has been a key concern in many countries. The paper established implications of 4IR using descriptive techniques and sample T-test. The review concludes that implication of 4IR to gender participation in Tanzania is that women participated more than men in agricultural production and unpaid domestic activities. Inversely, men participated more on productive works than women while gender balance exists in professional and skilled works. The review further notes that the influencing factor on GP is level of education associated with skill and profession. Then to balance GP, the review recommends increasing education to women and gender sensitivity.
An Intelligent Web Caching System for Improving the Performance of a Web-Based Information Retrieval System
Authors: Sathiyamoorthi V.  , Suresh P.  , Jayapandian N.  , Kanmani P.  , Deva Priya M.  , Janakiraman Sengathir
Published: October 2020

With an increasing number of web users, the data traffic generated by these users generates tremendous network traffic which takes a long time to connect with the web server. The main reason is, the distance between the client making requests and the servers responding to those requests. The use of the CDN (content delivery network) is one of the strategies for minimizing latency. But, it incurs additional cost. Alternatively, web caching and preloading are the most viable approaches to this issue. It is therefore decided to introduce a novel web caching strategy called optimized popularity-aware modified least frequently used (PMLFU) policy for information retrieval based on users' past access history and their trends analysis. It helps to enhance the proxy-driven web caching system by analyzing user access requests and caching the most popular web pages driven on their preferences. Experimental results show that the proposed systems can significantly reduce the user delay in accessing the web page. The performance of the proposed system is measured using IRCACHE data sets in real time.
Concept Map Information Content Enhancement Using Joint Word Embedding and Latent Document Structure
Authors: Urkalan Kodaikkaavirinaadan , T. V. Geetha
Published: October 2020

The concept map (CM) can be enhanced by extracting precise propositions, representing compactly, adding useful features that increase the information content (IC). To enhance the IC with domain knowledge of the document, an automatic enhanced CM generation using word embedding based concept and relation representation along with organization using latent semantic structure is proposed. To improve the concept significance, precise identification of similar items, clustering topically associated concepts, and hierarchical clustering of semantically related concepts are carried out. This augments the IC of the CM with additional information and generates CM with concise and informative content. The joint word embedding based on various contexts is utilized to determine distributional features critical for these enhancements. Summarization of the ECM to visualize the document summary is used to illustrate its resourcefulness. The work is evaluated using ACL anthology, Genia, and CRAFT dataset, and the information gain is approximately three times more in comparison with general CM.
Tag's Depth-Based Expert Profiling Using a Topic Modeling Technique
Authors: Kichou Saida , Boussaid Omar , Meziane Abdelkrim
Published: October 2020

Expert finding and expert profiling are two important tasks for organizations, researchers, and work seekers. This importance can also be seen in online communities especially with the explosion of social networks. Expert finding on one hand addresses the task of finding the right person with the appropriate knowledge or skills. Expert profiling on the other hand gives a concise and meaningful description of a candidate expert. This paper focuses on what social tagging can bring to improve expert finding and profiling. A novel expertise indicator that models and assesses an expert based on the expert's tagging activities is proposed. First, tags are used as interest indicator to build candidate's profiles; then, Latent Dirichlet Allocation algorithm (LDA) is used to construct the tags distribution over topics by exploiting the tag's semantic characteristics. Topics of interest are then filtered using tag's depth. The latter is finally used as the expertise indicator. Experiments performed on the stack overflow dataset show the accuracy of the proposed approach.
A Deep Q-Learning Network for Dynamic Constraint-Satisfied Service Composition
Authors: Yu Xuezhi , Ye Chunyang , Li Bingzhuo , Zhou Hui , Huang Mengxing
Published: October 2020

Traditional service composition methods usually address the constraint-satisfied service composition (CSSC) problem with static web services. Such solutions however are inapplicable to the dynamic scenarios where the services or their QoS values may change over time. Some recent studies are proposed to use reinforcement learning, especially, integrate the idea of Q-learning, to solve the dynamic CSSC problem. However, such Q-learning algorithm relies on Q-table to search for optimal candidate services. When the problem of CSSC becomes complex, the number of states in Q-table is very large and the cost of the Q-learning model will become extremely high. In this paper, the authors propose a novel solution to address this issue. By training a DQN network to replace the Q-table, this solution can effectively model the uncertainty of services with fine-grained QoS attributes and choose suitable candidate services to compose on the fly in the dynamic scenarios. Experimental results on both artificial and real datasets demonstrate the effectiveness of the method.
Does attachment style predict quality of life in youth? A cross-sectional study in Iran
Authors: Darban Fatemeh , Safarzai Enayatollah , Koohsari Edris , Kordi Mehri
Published: October 2020

The attachment can be considered as a specific behavioral pattern that is critical to healthy growth in most communities. Medical students are exposed to high levels of psychological stress while being equipped with lower levels of resilience. This study aims to determine the relationship between attachment style and the quality of life of medical students. In this cross-sectional correlational study, 150 students of Iranshahr University of Medical Sciences in 2018 were selected based on convenience sampling with consideration of inclusion criteria. Revised Adult Attachment Scale (RAAS) and Quality of life questionnaire (SF- 36) were used as data gathering scale. The data were analyzed with SPSS ver.19 using the Pearson correlation coefficient and linear regression. The participants’ mean quality of life score was 74.2 ± 16.7. In attachment style, 48.7% of the participants had secure attachment, 26.0% avoidant attachment, and 25.0% ambivalent attachment. The results of this study indicated a significant direct correlation between the quality of life scores and secure attachment style (p value <0.000). Also, there was a significant inverse correlation between the quality of life score and ambivalent attachment style (p value <0.000). Attachment style predicted students’ quality of life. Moreover, the role of Attachment style highlighted potential areas for intervention to improve medical student well-being and provide a foundation for longitudinal follow-up.
The algebra of Boolean matrices, correspondence functors, and simplicity
Authors: Bouc Serge , Thévenaz Jacques
Published: October 2020

We determine the dimension of every simple module for the algebra of the monoid of all relations on a finite set (i.e. Boolean matrices). This is in fact the same question as the determination of the dimension of every evaluation of a simple correspondence functor. The method uses the theory of such functors developed in [3, 4], as well as some new ingredients in the theory of finite lattices.
Drinfeld double of quantum groups, tilting modules, and $\mathbb Z$-modular data associated to complex reflection groups
Authors: Lacabanne Abel
Published: October 2020

Generalizing Lusztig’s work, Malle has associated to some imprimitive complex reflection group

W

a set of “unipotent characters”, which are in bijection of the usual unipotent characters of the associated finite reductive group if

W

is a Weyl group. He also obtained a partition of these characters into families and associated to each family a

\mathbb Z

-modular datum. We construct a categorification of some of these data, by studying the category of tilting modules of the Drinfeld double of the quantum enveloping algebra of the Borel of a simple complex Lie algebra. As an application, we obtain a proof of a conjecture by Cuntz at the decategorified level.
From PDEs to Pfaffian fibrations
Authors: Cattafi Francesco , Crainic Marius , Salazar Maria Amelia
Published: October 2020

We explain how to encode the essential data of a PDE on jet bundle into a more intrinsic object called Pfaffian fibration. We provide motivations to study this new notion and show how prolongations, integrability and linearisations of PDEs generalise to this setting.
Surface groups in the group of germs of analytic diffeomorphisms in one variable
Authors: Cantat Serge , Cerveau Dominique , Guirardel Vincent , Souto Juan
Published: October 2020

We construct embeddings of surface groups into the group of germs of analytic diffeomorphisms in one variable.
Braking Systems for High Performance Electric Vehicles - A Design Study
Authors: Antanaitis David , Robere Matthew
Published: October 2020

Any young person who has taken delight in playing with toy slot cars knows that the world of racing and the world of electric cars has been intertwined for a long time. And anyone who has driven a modern performance electric vehicle knows that the instant acceleration, exhilarating speeds, and joy of driving of slot cars is reflected in these full sized “toys”, with the many more practical benefits that come from being full-sized and steerable. There is strong foreshadowing of a vibrant future for performance cars in some of the EV’s on the market now and in the near future, some offering “ludicrous” acceleration, and others storied nameplates with performance to match. The ease at which powerful electric drives can capably hurtle a massive vehicle around the track at high speeds, combined with the potential for the same electric drives to exert powerful regenerative braking, creates a very interesting situation for brake engineers. What wins out in the end - raw power or regenerative braking? What can change in the course of a track session that would affect how braking energy is shared between the friction brake system and electric drives? How does this affect the brake system design and specification for a performance EV? This paper will walk through a design study to explore these questions, and in the course of doing so, will also explore some methodologies for engineering the brake systems for high performance EV’s that will include Driver In the Loop (DIL) simulations, brake system performance simulations, and inertia dynamometer testing, as well as “simple but sufficient” means of accounting for the drive and regenerative braking system behavior.
An Experimental Setup for Investigations on the Boundary Layer Dynamics
Authors: Ostermeyer Georg-Peter , Rickhoff Felix
Published: October 2020

The frictional behavior of a tribological contact is influenced by the dynamics in the forming boundary layer. Recurring structures, built up through self-organizing effects, were found in various frictional systems. To investigate those phenomena on a macroscopic scale and to better understand dynamical processes such as the formation and decay of contact patches, the first revision of the Wear Debris Investigator (WDI) was introduced in 2017. A friction gap is formed between two coaxial horizontally arranged discs. To mimic the presence of particles, artificial wear dust is fed into the gap. With a camera the formation of the boundary layer is recorded in situ. An implemented normal force and torque sensor enables to recognize correlations between the formed boundary layer and the occurring frictional forces. Numerous measurements revealed an insufficient precision of the previous WDI. Consequently, an innovative measurement and load unit was developed and implemented on the WDI allowing much more accurate statements to be made on the interactions between the contact surfaces and the particles in the friction gap. With the new load unit, much more accurate measurements can be carried out. In combination with an intelligent image data evaluation, it is now possible to show quantitative relationships between the external variables and the patch formation for the first time. We want to show first metrological results on patch dynamics and reservoir dynamics.
Toward a Corrosion Proof Braking System
Authors: Bertasi Federico , Bandiera Marco , Bonfanti Andrea
Published: October 2020

The manuscript firstly overviews the corrosion potentials of several components used in disk-brake systems. Particular attention is devoted to the couplings between materials with different nobility. It is demonstrated that if two materials: a) show a difference in their corrosions potential (Ecorr) >100mV; and b) are in electric contact in the presence of an electrolyte; they can form a galvanic couple (GC) which could undergo severe corrosive phenomena. In the second part, the paper focuses on the anodized Aluminium (ANOD-Al)-stainless steel (SS) GC. This couple is investigated since: 1) anodized Al and SS are often comprised in high-end braking systems and typically constitute the caliper body (anodized Al) and several components (springs, pins, screws, metal plates, rods, shims etc.) included; and 2) it shows one of the largest corrosion potential difference among all materials included in a braking system (>500mV). As a consequence, the ANOD-Al-SS appears to be one of the most strategic GC whose careful electrochemical investigation will allow the development of future corrosion-proof braking systems. Addressing this point, the manuscript investigates the effect on the corrosion rate of the distance (d) and the area ratio (Aratio) between anodized ANOD-Al and SS components using a suitable model system. This approach allows for the first time to obtain design rules based on the corrodibility of different materials with the final aim of customizing the corrosion protection of each brake system component.
Usage of Low-Cost Particulate Matter Sensors for Characterization of Emission Dynamics at a Traffic Intersection and for the Description of Pollution in Urban Areas
Authors: Ostermeyer Georg-Peter , Sandgaard Malte , Otto Johannes
Published: October 2020

Despite the increase in public attention to particulate matter emissions since the millennium and the known effects on the human organism, representative predictions on the dispersion of emissions in both urban and rural areas are hardly possible so far. Especially the validation of simulations with measurement results is not possible due to the limited number and high price of certified measuring instruments. Rather, the temporally high-resolution measuring instruments are only sporadically distributed within the city, so that emission dynamics at traffic hotspots, such as traffic jams or intersections, cannot be depicted. Furthermore, due to the small number of certified measuring instruments, fine dust pollution can only be interpolated over long distances.

In this paper, first results from a study about the transport characteristics of particles at a road intersection will be made by using a variety of so-called low-cost particulate matter sensors. Furthermore, the portable low-cost sensors will be used for the mobile measurement of fine dust concentrations in large areas. 20 sensors of the type Plantower PMS7003 were distributed along a traffic intersection. The sensors, previously calibrated on a test setup, determine the particle classes PM10, PM2.5 and PM1 in real time and additionally the temperature and humidity. This alloes the analysis of the fine dust concentrations in great detail, also with regard to the prevailing weather conditions. Es konnte gezeigt werden, dass lokale Unterschiede mit dem Low-Cost Sensoren festzustellen sind, Zusätzlich können zeitliche Änderungen in der Partikelkonzentration entlang der Kreuzung beobachtet werdn. In the further course of the project, the mobile sensors will be to map an urban area with regard to the fine dust distribution.
Brake Particulate Matter Emissions Measurements for Six Light-Duty Vehicles Using Inertia Dynamometer Testing
Authors: Agudelo Carlos , Vedula Ravi Teja , Collier Sonya , Stanard Alan
Published: October 2020

Emissions of particulate matter, or PM, due to brake wear, are not well quantified in current air pollutant emission inventories. Current emission factor models need to be updated to reflect new technologies and materials and to incorporate the effects of changing driving habits and speeds. While emission regulations drive technical innovations that are significantly reducing PM emissions in vehicle exhaust, non-exhaust automotive emissions remain unregulated. Current emission factor models need to be updated to reflect the changes caused by new technologies, materials, and speed-dependent vehicle usage. Most research regarding brake emissions relies on a laboratory setting. Laboratory testing has allowed researchers, application engineers, data modeling engineers, and environmental agencies to generate large datasets for multiple vehicle configurations and friction couple designs. However, these results can be inconclusive or confusing to compare at best, due to the lack of a standardized method. This paper reports on a six-vehicle campaign conducted under standardized, repeatable, and reproducible conditions. By relying on state-of-the-art speed control systems, the inertia dynamometer can recreate specific driving profiles derived from field measurements. The study involved testing brake corners from six vehicles. The test plan included original equipment service parts, or OES, and aftermarket friction couples, or AM, on an enclosed brake inertia dynamometer. The individual friction couples include the friction material along with the commonly used mating disc or drum per the market survey performed early during the project. This approach reflects the OE brake configuration and subsequent brake replacement jobs. The test cycle used represents vehicle usage in California. The project relied upon approved testing protocols, test system validation, adjustment of cooling airspeeds, and interlaboratory evaluation for filter weighing methods. The results from more than 80 tests show the effects of axle position, friction couple formulation, as well as vehicle size, type, and speed. These results show substantial variation in brake PM emissions by vehicle application and friction couple type.
Influence of transaction costs on choice of marketing outlets among smallholder peach farmers in Lesotho
Authors: Rafoneke L.P. , Mshenga P. M. , Owuor G. , Rantlo A.M.
Published: October 2020

Peach (Prunus persica) production is a major agro-economic activity in Lesotho. However, most smallholder peach farmers in Lesotho still fail to reap the benefits that are in line with peach commercialization. This is because of high transaction costs, which vary along with different peach marketing outlets. This study was conducted to determine the influence of transaction costs on the choice of marketing outlets of peaches in Lesotho. A multistage sampling technique was used to select 90 respondents for this study. Cross-sectional data were collected using a semi-structured questionnaire. A Multivariate probit model was used to analyse transaction costs influencing the choice of marketing outlets among smallholder peach farmers. The study revealed that gender and communication costs positively influenced the choice of farm gate; while the time taken to reach other outlets and average monthly income negatively influenced the choice of farm gate outlets. Sorting, grading and communication costs negatively impacted the local market; whereas, the average monthly income positively influenced it. Household size influenced farmers’ export market choice negatively. Evidence from the results suggests that the improvement of roads and communication infrastructure could enhance farmers’ income through the proper selection of marketing outlets. Access to market information regarding both distance and the time taken to reach each of the outlets should also be improved.
Familiarisme et performance en contexte de petites et moyennes entreprises familiales : Une étude exploratoire
Authors: Binwa B. , Mmenge A. , Gahungu D.
Published: October 2020

Cette étude identifie les attributs du familiarisme en contexte de petites et moyennes entreprises familiales (PMEF) et definit la performance telle que perçue par les entrepreneurs familiaux dans un contexte sans marché financier. Appliquant la méthode d’étude de cas par comparaison inter-sites sur la base d’entretiens semi-directifs organisés avec 32 entrepreneurs familiaux de deux villes et de deux cités de province du Nord et du Sud-Kivu, en République Démocratique du Congo, les résultats indiquent que, comparativement aux indicateurs de l’effet famille assortis de travaux antérieurs, l’opérationnalisation de ce construit s’apprête légèrement moins dans le contexte congolais. Pendant ce temps, la performance perçue par les opérateurs économiques s’éloigne considérablement des considérations théoriques.
Influence of entrepreneurship education on Egerton University’s graduates’ intention to start a business
Authors: Mshenga P.M. , Okello D.O. , Ayuya O.I. , Mwangi D. , Ouma D. , J. J. , Mungai N.W.
Published: October 2020

Entrepreneurship training has been introduced in most Higher Education Institutions (HEI) in sub-Saharan Africa countries to enhance graduate self-employment. The purpose of this study was to examine the impact of entrepreneurship training on Egerton University’s graduates’ intention to start a business. This study used the Ajzen’s theory of planned behaviour (TPB) in a cross sectional survey, conducted during April to May, 2016. A sample of 341 business and non-business Egerton University graduates, enrolled from the year 2008 up to 2015 was used. Data were collected using a semi-structured questionnaire through telephone and face-to-face interviews. They were analysed using Structural Equation Modeling (SEM) and PLS Multi-Group Analysis (PLS-MGA). Findings revealed presence of a significant positive relationship between attitude toward entrepreneurship (b = 0.315, P=0.01), proactiveness (b = 0.042, P=0.01), risk-propensity (b = 0.11, P=0.01), and self-efficacy (b = 0.138, P=0.01) on graduates’ intention to start a business. Furthermore, multi-group analysis showed that the same four attributes significantly predicted entrepreneurship intention among business and non-business graduates to start businesses. Also, subjective norms significantly impacted entrepreneurial intentions of business graduates to start businesses. Finally, business graduates had significant higher scores than non-business graduatesin terms of self-efficacy (b = 0.182, P=0.03) and subjective norms (b = 0.329, P=0.04).
Physico-chemical properties and sensory quality of cassava-cowpea-millet composite flours
Authors: Onyango S.O. , Abong G.O. , Okoth M.W. , Kilalo D. , Mwang’ombe A.W.
Published: October 2020

There is global increase in demand for good health and nutrition. The objective of this study was to formulate nutritious composite flours from cassava (Manihot esculenta L.) roots, cowpea (Vigna unguiculata) leaves, and millet (Pennisetum glaucum), especially for children and expectant women. A Nutrisurvey software was used to formulate three flour products, namely 20:50:30, 10:50:40 and 15:60:25 of cassava roots, cowpea leaves, and millet, respectively to achieve more than 40% daily requirement of protein, iron and zinc for the expectant woman. The products were subjected to a sensory panel and evaluated against a standard commercial flour (Famila) sold in the Kenyan market. The flours were also subjected to accelerated shelf-life study based on physico-chemical properties and growth of yeast and molds. Results indicated that 20:50:30 and 10:50:40 had the highest colour scores on a 7-point hedonic scale, 5.2±1.35 and 5.2±1.48 (P<0.05). The score indicates a near equal acceptability of the flour based on colour for both the standard. The green porridge (15:60:25) was the least accepted flour and had the highest total aerobic count of 3.7 log cfu g-1 after four months of storage. The acid value of the flours ranged from as low as 1.84±0.01mg KOH g-1 for the 20:50:30 at day zero and as high as 12.9±1.73 mg KOH g-1 after six months of storage. The formulated 20:50:30 flours had protein (8.0%), fat (3.5%) carbohydrates (70%), zinc (0.6 mg100 g-1), iron (0.6 mg100g-1) and vitamin C (0.3 mg100 g-1).
Effect of plant growth-promoting rhizobacteria and gibberellic acid on salt stress tolerance in tomato genotypes.
Authors: Esan A.M. , Olaiya C.O. , Anifowose L.O. , Lana I.O. , Ailenokhuoria B.V. , Fagbami O. , Adeyemi H.R.Y.
Published: October 2020

Salinity stress is a limiting factor that affects attainment of optimal yield of many vegetable crops at various growth stages in many arid and semi-arid parts of sub-Saharan Africa. The objective of this study was to explore salt tolerance of tomato (Solanum lycopersicum L.) genotypes under the influence of gibberellic acid (GA3) and Bacillus subtilis under screen house conditions. Tomato seeds were pre-soaked with 0, 0.4, 0.5 or 0.6 mM concentrations of GA3 and control in distilled water, respectively; for 12 hr at room temperature. The seeds were germinated in a screen house in 10 kg of soil contained 0, 100, or 200 mM NaCl treatment in polyethene bags. After two weeks of seed germination, the seedlings were inoculated with B. subtilis with the exception of controls. Results revealed that the single or combined treatments of GA3 (at different concentrations) and Bacillus subtilis significantly (P<0.05) increased photosynthetic pigments, and enhanced the concentrations of potassium, calcium, magnesium and phosphorus ions in the salt-stressed tomato. Both tomato genotypes showed low concentrations of sodium ions at all levels of gibberellic acid with Bacillus subtilis. Also, there were significant (P < 0.05) increases in the compatible solutes, antioxidant enzymes activity and antioxidant potential of salt-stressed tomato genotypes, in the combined treatments of GA3 and Bacillus subtilis. Tomato genotypes treated with GA3 and Bacillus subtilis, showed greater salt-tolerance even at high levels of salinity, than single treatment of either GA3 or Bacillus subtilis. Based on these findings, the genotypes are suitable for future breeding programmes to achieve optimal crop yield in saline conditions.
Karyotype analysis of ten accessions of Hausa potato in Nigeria
Authors: Namo O.A.T. , Egbaji C.I.
Published: October 2020

Plant species may be classified according to their karyotype features. Variation in chromosome features is believed to have accompanied evolutionary divergence of many plant and animal species. The cytological characteristics of crop species vary with geographical location of plants. Knowledge of the karyotype relationships can be explored for effective genetic and breeding studies, especially in crops like the Hausa potato (Solenostemon rotundifolius) that have not received adequate research attention. This paper reports the results of the karyotype analysis of ten accessions of the Hausa potato cultivated in some parts of Nigeria. The accessions were raised in plastic bowls containing vermiculite soil, from which root-tips were harvested for slide preparation and karyotyping. The conventional squashing in aceto-orcein of root tissues after heating was used. The tissues were photographed under Nikon Universal Microscope, equipped with an MC 100 camera. The chromosomes were then measured under x400 magnification using a micrometer. Results showed that all the accessions were diploid with somatic chromosome number of 2n = 2x = 64. The total length of long-arms ranged from 108.80 µm in accession Pankshin to 118.14 µm in accession NRCRI (1). The total length of short arms ranged from 81.88 µm – 89.34 µm. The total length of long plus short arms ranged from 199.88 µm - 200.06 µm. The mitotic phases varied with accessions. Similarly, the arm ratio, r-value, centromeric index, coefficient of variation, total form, intra-chromosomal index and inter-chromosomal index varied with the accessions. The accessions were grouped into four clusters: accessions Hong (1), Hong (2), Manchok and Gembu in cluster I; accessions Pankshin and Langtang in cluster II; accessions NRCRI (1) and NRCRI (2) in cluster III; accessions Bokkos (1) and Bokkos (2) in cluster IV. The principal component analysis showed that variation in the complement length and the centromeric position accounted for 99.997% of the total variation amongst the accessions. The study demonstrated that cytological differences exist in the Hausa potato. Some accessions showed close phylogenetic relationship, but others were distantly related. These differences could be explored for the improvement of the Hausa potato accessions cultivated in Nigeria.
GIS in environmental monitoring and assessment of dredging activites in a perturbed estuarine Lagoon
Authors: Olapoju O.A. , Osibona A.O. , Olayinka D.N. , Edokpayi C.A. , Samuel O.B.
Published: October 2020

The study aimed at mapping and characterizing the benthic communities of Lagos Lagoon based on how the sediment define the distribution of organisms in response to dredging activity of the area. The hydrographic survey of was carried out with the aid of an echo-sounder and side-scan sonar and plotted in ArcGIS 10.3.1. The benthic macroinvertebrate ecology in relation to human activities was defined and studied in ten selected dredged stations. Habitat suitability maps of dominant species were plotted using spatial analyst tool. The removal of organisms with the sediment resulted into increased turbidity, suspended solids and modified sediment characteristics in the study area. The known venus, pachymelania, mangrove, estuarine-amphioplus and estuarine-rock macroinvertebrate communities were intact. However, there were changes in the composition of the communities with Donax acutangulus going into extinction. Multivariate analysis showed that the observed benthic communities and sediment characteristics were sandy in nature. The observed assemblage of organism was mostly dominated by bivalve - Atactodea striata of the family Mesodesmatidae at Ogun river station which was characterised by sand. The results revealed a patchy distribution of organisms having abundant macroinvertebrates with less diversity which may be as a result of the on-going dredging activities in the area.

Keywords: Macrobenthos, bathymetry, sediment, dredging, GIS
Chemical assessment of Polycyclic Aromatic Hydrocarbons (PAHs) on processed Clarias gariepinus (Burchell, 1822) from different energy sources
Authors: Agbabiaka L.A. , Adedokun I.I. , Ojukannaye S.A. , Agbai D.C.
Published: October 2020

Chemical assessment of Polycyclic Aromatic Hydrocarbons (PAHs) on processed African catfish was carried out. Fish samples were processed using charcoal, firewood and gas oven following standard procedures. Gas chromatographic analysis was employed for PAHs determination. Results showed that mean PAHs concentrations in fish samples were observed to be: 737.86ng/μl in firewood-smoked samples, 1451.82ng/μl in charcoal and 1990.23ng/μl in oven-dried fish. The highest mean concentration of PAHs was 906.93±0.01 ng/μl for pyrene from the charcoal-smoked samples. Lower molecular weight PAHs were generally dominant in tested samples. The number of PAHs ring showed significant variation (p<0.05) with respect to processing methods. Inference from the results showed that differently processed fish samples were of good quality and are suitable for human consumption. However, the charcoal processed samples appeared to be the best when considering the case of incomplete combustion of the wood during the drying process. Therefore, the use of charcoal in fish processing is hereby recommended. Also, it is suggested that fish processors be trained on the appropriate handling and processing methods to adopt in order to enhance the production of high-quality contaminants-free fish products.

Keywords: Polycyclic Aromatic Hydrocarbon (PAH), anthropogenic, combustion, smoking methods, contaminants.
Efectos de las enmiendas orgánicas combinadas sobre el rendimiento de berenjena, las características de fertilidad del suelo y la calidad de los ácidos húmicos
Authors: Ian C. Pagán-Roig  , Joaquín A. Chong  , José A. Dumas  , Consuelo Estévez de Jensen
Published: October 2020

La fertilidad de suelos agrícolas así como los niveles de materia orgánica se han visto afectados por prácticas agrícolas no sustentables. Hay una necesidad de desarrollar y entender los efectos de las enmiendas orgánicas y sus combinaciones y el potencial que tienen en aumentar la fertilidad de los suelos y de los sistemas agrícolas sustentables. El uso de composta, coordinación de barbechos y el uso de otras enmiendas biológicas son alternativas para mejorar el suelo y aumentar la producción del cultivo. Poca información está disponible de los efectos de prácticas combinadas de enmiendas orgánicas y sus efectos en las propiedades químicas y su impacto en la producción de hortalizas. El objetivo de este estudio fue enmendar un suelo de la serie San Antón con una combinación de enmiendas orgánicas y observar su impacto en las propiedades químicas del suelo, así como en la producción de berenjenas. Al conjunto de estas prácticas le dimos el nombre de manejo de ciclos de tratamiento de suelo (en inglés, soil treatment management cycles o STMC). Los STMC consistieron en añadir al suelo materia orgánica de composta de pulpa de café, sembrar e incorporar una mezcla de cuatro leguminosas de abono verde, uso de micorriza, así como té de composta. Los tratamientos fueron: el control, no STMC; un STMC (CL1); dos STMC consecutivos (CL2); y tres STMC consecutivos (CL3). Un solo CL1 fue suficiente para aumentar el contenido de materia orgánica, P, K y S en el suelo cuando se compara con el CL0. La concentración de Ca aumentó con CL3 y la de Mg con CL2 y CL3, comparados con los otros tratamientos. Todos los tratamientos cambiaron el pH, reduciéndolo hacia la neutralidad con aumento en STMC cuando se compara con el pH de 7.9 de suelos control. Los tratamientos CL1, CL2 y CL3 aumentaron el contenido de ácidos húmicos en 2.8, 3.8 y 5.9 veces lo encontrado en suelos sin enmendar CL0. Los ácidos húmicos extraídos de suelos sin enmendar exhibieron mayor condensación y aromaticidad cuando se comparan con suelos enmendados, sin embargo, los ácidos húmicos de suelos enmendados demostraron niveles más altos de polimerización. Las mejoras en las propiedades del suelo promovidas por STMC resultaron en un aumento en producción de berenjenas así como en producción de biomasa.
CHAETANAPHOTHRIPS SIGNIPENNIS (BAGNALL) (THYSANOPTERA: THRIPIDAE): UN NUEVO RÉCORD PARA PUERTO RICO
Authors: Irma Cabrera-Asencio  , Alberto L. Vélez
Published: October 2020

CHAETANAPHOTHRIPS SIGNIPENNIS (BAGNALL) (THYSANOPTERA: THRIPIDAE): UN NUEVO RÉCORD PARA PUERTO RICO
ESTRUCTURA MICROSCÓPICA DEL GRANO DE MAÍZ PARTIDO E HIDRATADO Y TRATADO CON LAS ENZIMAS EXÓGENAS a-AMILASA Y PROTEASA
Authors: Abner Rodríguez-Carías  , Beatriz A. Quintana  , Luis C. Solórzano  , Paul F. Randel
Published: October 2020

ESTRUCTURA MICROSCÓPICA DEL GRANO DE MAÍZ PARTIDO E HIDRATADO Y TRATADO CON LAS ENZIMAS EXÓGENAS a-AMILASA Y PROTEASA