bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antioxidant activity and zebrafish teratogenicity of hydroalcoholicMoringa oleiferaL. leaf extracts
Authors: Mohamad Shariff Nurul Fatin Syazleen , Singgampalam Thangam , Ng Chean Hui , Kue Chin Siang 
Published: August 2020

PurposeMoringa oleifera(MO) is a herbal remedy that is rich in essential amino acids and phytochemicals in the leaves, seeds and pods. It is becoming a famous food in various ethnic groups, and the consumption is increasing worldwide. However, there is no safety profile of the hydroalcoholic MO leaf extracts, or documented teratogenicity aspect. This study was sought to compare the antioxidant activity and the teratogenicity of hydroalcoholic MO leaf extracts in the zebrafish embryo.Design/methodology/approachMO leaves were extracted with aqueous alcohols (ethanol or methanol: water, 80:20 v/v) using the Soxhlet method. The antioxidant capacity was determined using DPPH assay. The concentrations of extracts ranging from 3 to 1,000 µg/mL were used to examine the toxicity and teratogenicity on the zebrafish embryo.FindingsBoth hydroalcoholic MO leaf extracts were positive for alkaloids, terpenoids, steroids, tannins, flavonoids, phenols, coumarins, quinones and glycosides, except saponins only absent in aqueous methanol extract. The antioxidant capacity based on lC50, was 15.92 ± 3.62 mg/mL for aqueous methanolic and 25.28 ± 2.89 mg/mL for aqueous ethanolic extract. For acute toxicity, the aqueous methanolic extract has lower LC50(163.87 ± 12.88 µg/mL) compared to aqueous ethanolic extract (337.48 ± 30.04 µg/mL). The embryo treated with aqueous methanolic extract showed phenotypic defect but not on the aqueous ethanolic extract.Originality/valueThis study suggests that aqueous methanol of MO leaves extract has better antioxidant capacity compared to ethanol, and ethanolic leaf extract is safer (higher LC50 and no teratogenicity) than methanolic extract.
Current mode fractional order PID control of wind-based quadratic boost converter inverter system with enhanced time response
Authors: J. Nandha Gopal , N.B. Muthuselvan 
Published: August 2020

Purpose
The purpose of this paper is to enhance the response of quadratic boost converter inverter system (QBCIS) and also investigate proportional integral (PI) and fractional order proportional integral derivative (FOPID)-based space vector modulation inverter (SVMI) systems.

Design/methodology/approach
This paper presents modern expansion in control methods and power electronics have created wind-based AC to AC converters that relays to AC drives. The process includes the flow of quadratic boost converter (QBC) and SVMI locate their technique in associating permanent magnet synchronous generator and three phase load. This effort conveys with digital simulation using MATLAB/Simulink and hardware implementation of current mode wind-based QBCIS.

Findings
The direct current (DC) output from the rectifier is boosted using Quadratic Boost Converter (QBC). The DC yield of QBC is provided to the SVMI. The alternating current (AC) yield voltage is attained by using three-phase filter. The investigations are done with PI and FOPID-based SVMI systems. Current mode FOPID control is proposed to improve the time response of QBCIS system.

Originality/value
The simulation results are compared with the hardware results of QBCIS. The results of the comparison of PI with FOPID controlled by converters are made to show the improvement in terms of settling time and steady-state error.
Development of buck power converter circuit with ANN RL algorithm intended for power industry
Authors: Purohit Chandra Shekher , Manna Saibal , Mani Geetha , Stonier Albert Alexander 
Published: August 2020

Purpose
This paper aims to deal with application of artificial intelligence for solving real time control complication adhered with the controlled operation of a buck power converter. This type of converter finds application for power conversion at various levels for the direct current-direct current power industry to step down the input voltage.

Design/methodology/approach
Use of ANN-RL (Artificial Neural Networks- Reinforcement Learning)-based control algorithm to control buck power converter shows robustness against parameter and load variation. Because of non-linearity instigated by element used for switching, control of this converter becomes an arduous control predicament. All the classical control techniques are based on an approximate linear model of the step down converter and these techniques fail to handle actual non-linearity.

Findings
In this paper, a reinforcement learning-based algorithm has been used to handle and control buck power converter output voltage, without approximating the model of converter. The non-linearity instigated in converter is subjected to state of switch. Model of buck power converter is defined as a multi-step decision problem so that it can be solved using mathematical model of Markov decision process (MDP) and, in turn, reinforcement learning can be implemented. As MDP model is available for a discrete state system so model of converter has to be discretized and then value iteration is applied and output is analyzed. Load regulation and integral time absolute error analysis is done to show efficacy of this technique.

Originality/value
To mitigate the effect of discretization function approximation using neural network is applied. MATrix LABoratory has been used for implementation and result indicates an improvement in the overall response.
Haar wavelets collocation method for a system of nonlinear singular differential equations
Authors: Verma Amit K. , Kumar Narendra , Tiwari Diksha 
Published: August 2020

Purpose
The purpose of this paper is to propose an efficient computational technique, which uses Haar wavelets collocation approach coupled with the Newton-Raphson method and solves the following class of system of Lane–Emden equations:

−(tk1y′(t))′=t−ω1f1(t,y(t),z(t)),

−(tk2z′(t))′=t−ω2f2(t,y(t),z(t)),where t > 0, subject to the following initial values, boundary values and four-point boundary values:

y(0)=γ1, y′(0)=0, z(0)=γ2, z′(0)=0,

y′(0)=0, y(1)=δ1, z′(0)=0, z(1)=δ2,

y(0)=0, y(1)=n1z(v1), z(0)=0, z(1)=n2y(v2),where

n1,n2,v1,v2∈(0,1) and

k1≥0, k2≥0, ω1<1, ω2<1, γ1, γ2, δ1, δ2 are real constants.

Design/methodology/approach
To deal with singularity, Haar wavelets are used, and to deal with the nonlinear system of equations that arise during computation, the Newton-Raphson method is used. The convergence of these methods is also established and the results are compared with existing techniques.

Findings
The authors propose three methods based on uniform Haar wavelets approximation coupled with the Newton-Raphson method. The authors obtain quadratic convergence for the Haar wavelets collocation method. Test problems are solved to validate various computational aspects of the Haar wavelets approach. The authors observe that with only a few spatial divisions the authors can obtain highly accurate solutions for both initial value problems and boundary value problems.

Originality/value
The results presented in this paper do not exist in the literature. The system of nonlinear singular differential equations is not easy to handle as they are singular, as well as nonlinear. To the best of the knowledge, these are the first results for a system of nonlinear singular differential equations, by using the Haar wavelets collocation approach coupled with the Newton-Raphson method. The results developed in this paper can be used to solve problems arising in different branches of science and engineering.
How the C-suite is embracing Agile
Authors: Denning Stephen 
Published: August 2020

Purpose
The authors reviews the leadership responsibilities involved in managing an organization that practices Agile management.

Design/methodology/approach
Outlines the best practices of major corporations that have adopted Agile processes both for teams and C-suite leadership.

Findings
Agile leaders spend less time reviewing the work of subordinates. They add value by adapting corporate strategies, leading critical agile teams, spending time with customers, mentoring individuals and coaching teams.

Practical implications
It is the C-suite leadership’s responsibility to establish and maintain a hierarchy of competence rather than a bureaucratic hierarchy of authority.

Originality/value
Describes how top management at some of the world’s largest and most successful corporations are adopting Agile practices to spur innovation and promote continuously adding customer vale.
Impact of team design and technical factors on team cohesion
Authors: Dey Chitra , M.P. Ganesh 
Published: August 2020

Purpose
Based on the interpersonal interaction perspective of team cohesion, this study aims to examine the effects of team boundedness, formal coordination and organization tenure diversity on both task and social cohesion. The authors test for the interaction effect of organization tenure diversity on the relationships between the independent variables and the dimensions of team cohesion.

Design/methodology/approach
Data was collected from 111 software development teams and aggregated to the team level. Common latent factor test for common method bias showed no significant bias. Structural equation modelling (SEM) was used to test all the hypotheses.

Findings
SEM results show that team boundedness and formal coordination have positive and significant association with both dimensions of team cohesion. Formal coordination was found to be a stronger positive predictor for task cohesion than for social cohesion. Organization tenure diversity was found to be a stronger negative predictor for social cohesion than for task cohesion. Organization tenure diversity in the team moderates the relationship between formal coordination and task cohesion.

Research limitations/implications
The data was collected using a cross-sectional design. However, the authors have mitigated the effect of common method variance by adopting both procedural and statistical methods.

Originality/value
This paper expands extant literature by examining the antecedents of two important components of team cohesion, task and social cohesion. The authors proposed and found that the independent variables have different impacts on task and social cohesion. This study furthers both theory and practice by considering team boundedness as a variable of interest and its impact on internal team dynamics.
Understanding sustainability – the case of building blocks in Tanzania and Uganda
Authors: Isaksson Raine , Buregyeya Apollo 
Published: August 2020

PurposeThe purpose of this paper is to describe sustainability of hollow and solid blocks in sub-Saharan Africa.Design/methodology/approachIndicators of stakeholder value are proposed for measuring block sustainability based on comparisons of user building value price and carbon emissions. Block manufacturing processes in Tanzania and Uganda are described and assessed in this context.FindingsThe results from Uganda indicate that there are economic and environmental advantages in using hollow blocks as long as they are produced to statutory compliance levels. However, where blocks are not produced to standard requirements, the results indicate that it is better to use solid blocks. This surprising result seems to indicate that blocks prepared using low additions of cement might have sufficient functional quality for simple residential building applications even though they might not meet current standard strength requirements and have low cement productivity. These results also indicate that the improvement potential indicated previously cannot be realised when hollow blocks are used for simple construction needs.Research limitations/implicationsClear benchmarks for the best practical level of cement block sustainability seem to be missing. The first reasons is that the lowest acceptable compressive strength has not been defined since standard requirements might not be relevant in the studied context. The second one is that the lowest possible practically achievable cement content with acceptable cement productivity has not been established.Practical implicationsUnderstanding sustainability can be very difficult and substantial work needs to be done to introduce operational sustainability indicators.Originality/valueThe results contribute to the discussion of understanding, defining and measuring sustainability.
Effect of vibrator position and frequency on heat transfer enhancement in counter flow concentric pipe heat exchanger
Authors: Arasavelli Shanmukh Sudhir , Konijeti Ramakrishna , Budda Govinda Rao 
Published: August 2020

Purpose
This paper aims to deal with heat transfer enhancement because of transverse vibration on counter flow concentric pipe heat exchanger. Experiments were performed at different vibrator positions with varying amplitudes and frequencies.

Design/methodology/approach
Tests are carried out at 4 different vibration frequencies (20, 40, 60 and 100 Hz), 3 vibration amplitudes (23, 46 and 69 mm) and at 3 vibrator positions (1/4, 1/2 and 3/4 of pipe length) with respect to hot water inlet under turbulent flow condition.

Findings
Experimental results indicate that Nusselt number is enhanced to a maximum extent of 44% with vibration when compared to Nusselt number without vibration at a frequency of 40 Hz, an amplitude of 69 mm and at a vibrator position of one-fourth of pipe length with respect to hot water inlet.

Originality/value
Empirical correlation is developed from experimental data to estimate the heat transfer coefficient with vibration for experimental frequency range with an error estimate of approximately ±10%.
Expression of discoidin domain receptor 1 and E‐cadherin in epidermis affects melanocyte behavior in rhododendrol‐induced leukoderma mouse model
Authors: Abe Yuko , Hozumi Yutaka , Okamura Ken , Suzuki Tamio 
Published: August 2020

AbstractVitiligo is a depigmentation disease characterized by gradual loss of melanin and melanocytes from the epidermis. The mechanism of melanocyte loss is not yet known. In this report, we showed that the expression of discoidin domain receptor 1 and E‐cadherin, known adhesion molecules, was variable or absent in the epidermis of rhododendrol‐induced leukoderma (RDIL) mice during the depigmentation process. Our findings suggest that melanocyte damage by rhododendrol promotes reduction of adhesion molecules not only in melanocytes but also in keratinocytes, and this is associated with the detachment of melanocytes from the basal layer.
Photosynthetic heat tolerances and extreme leaf temperatures
Authors: Perez Timothy M. , Feeley Kenneth J. 
Published: August 2020

Abstract

Photosynthetic heat tolerances (PHTs) have several potential applications including predicting which species will be most vulnerable to climate change. Given that plants exhibit unique thermoregulatory traits that influence leaf temperatures and decouple them from ambient air temperatures, we hypothesized that PHTs should be correlated with extreme leaf temperatures as opposed to air temperatures.

We measured leaf thermoregulatory traits, maximum leaf temperatures (TMO) and two metrics of PHT (Tcrit and T50) quantified using the quantum yield of photosystem II for 19 plant species growing in Fairchild Tropical Botanic Garden (Coral Gables, FL, USA). Thermoregulatory traits measured at the Garden and microenvironmental variables were used to parameterize a leaf energy balance model that estimated maximum in situ leaf temperatures (TMIS) across the geographic distributions of 13 species.

TMO and TMIS were positively correlated with T50 but were not correlated with Tcrit. The breadth of species' thermal safety margins (the difference between T50 and TMO) was negatively correlated with T50.

Our results provide observational and theoretical support based on a first principles approach for the hypothesis that PHTs may be adaptations to extreme leaf temperature, but refute the assumption that species with higher PHTs are less susceptible to thermal damage. Our study also introduces a novel method for studying plant ecophysiology by incorporating biophysical and species distribution models, and highlights how the use of air temperature versus leaf temperature can lead to conflicting conclusions about species vulnerability to thermal damage.

A free Plain Language Summary can be found within the Supporting Information of this article.
Biocontrol of a prickly pear cactus in South Africa: Reinterpreting the analogous, renowned case in Australia
Authors: Hoffmann John H. , Moran Vincent C. , Zimmermann Helmuth G. , Impson Fiona A. C. 
Published: August 2020

Abstract

We report on a long‐term evaluation of biological control of an invasive cactus, Opuntia stricta, in the Kruger National Park, South Africa. By forming large impenetrable thickets, this weed species posed a major threat to the integrity and biodiversity of the park, and to agroecosystems more widely.

Over 22 years, from 1992 to 2013, counts were made along fixed transects at four different sites to measure the abundance of O. stricta and the prevalence of two of its biological control agents: (a) Cactoblastis cactorum, whose larvae feed in the plants’ cladodes and (b) a sap‐sucking cochineal insect, Dactylopius opuntiae. With only C. cactorum present, the numbers of O. stricta cladodes and fruit remained unchanged at two of the sites but increased annually at the other two. Within 5 years of the introduction of D. opuntiae, the numbers of cladodes and fruit decreased substantially at all the sites and the residual cactus populations have been held at inconsequentially low levels ever since.

Both the C. cactorum and D. opuntiae populations on O. stricta in South Africa were sourced from founder stocks in Australia. This allows direct comparisons of biological control of O. stricta in South Africa with the world‐famous program against O. stricta, in Queensland and in New South Wales, that peaked in the 1920s and 1930s.

Synthesis and applications. Almost all accounts acclaim Cactoblastis cactorum as the dominant contributor to the sustained decline of populations of prickly pears in Australia in the 1930s. Our results provide evidence that this now widely accepted conclusion is incorrect and that cochineal was and is the key role player. Managers and biological control practitioners concerned with the apparent underperformance of C. cactorum in the suppression of invasive Opuntia cacti should interpret the entrenched reports in the literature with circumspection. There may also be less cause for concern about the anticipated devastation of native Opuntia prickly pear species in the southern United States where C. cactorum has become an invasive pest species.
Trade‐off between standing biomass and productivity in species‐rich tropical forest: Evidence, explanations and implications
Authors: Kohyama Takashi S. , Potts Matthew D. , Kohyama Tetsuo I. , Niiyama Kaoru , Yao Tze Leong , Davies Stuart J. , Sheil Douglas 
Published: August 2020

Abstract

Despite its broad implications for community structure and dynamics, we lack a clear understanding of how forest productivity is partitioned among tree species. As leaf mass per unit of standing biomass declines with tree size, species achieving larger stature should show lower relative productivity as compared to smaller stature species. However, many observations indicate large‐stature species grow faster than small‐stature species. In this study, we address this apparent paradox, and clarify interspecific trade‐offs between turnover rates and maximum size in terms of forest‐level productivity and biomass storage.

We examined data from the 1990 and 2000 surveys of the Pasoh 50‐ha plot of Malaysian rain forest. In these data, individual stems ≥1 cm stem diameter (dbh) have been identified, marked, measured and mapped. We applied site‐specific equations to estimate tree biomass from dbh. We estimated species‐level productivity and loss rates that are less influenced by census interval‐related effects and biases.

Among 390 abundant tree species, species with high stand‐level biomass were predominantly those large‐stature species where individuals could achieve large sizes. We found that relative (= per‐species‐biomass) productivity and loss rate, per‐capita recruitment and mortality of species were all negatively correlated to species biomass and maximum size, but not to species abundance.

Large‐stature species grew faster than small‐stature species at the same tree sizes up to 36 cm dbh. However, the relative growth of large species at their maximum size markedly declined. As a result, tree‐level relative growth at maximum size and species‐level relative productivity decreased with species‐level biomass.

Performing further analyses using smaller plots in four old‐growth forests in Indonesia and Japan, we observed a similar interspecific negative relationship between relative productivity and biomass. We expect this phenomenon is widespread across species‐rich forests.

Synthesis. How productivity is partitioned among species determines and reflects forest ecosystem functioning and species coexistence. Many species with low biomass and small maximum stem sizes disproportionally contribute to forest primary productivity, rapid recovery and resilience. In contrast, long‐lived, high‐biomass species contribute disproportionally to ecosystem stability and carbon storage. This complementarity reflects differentiation by adult stature among species.
Creative Cities, Graffiti and Culture‐Led Development in South Africa: Dlala Indima (‘Play Your Part’)
Authors: Sitas Rike 
Published: August 2020

AbstractCreative cities and culture‐led development discourses have come under increasing scrutiny as elite‐centric economic development agendas tend to trump ‘civic creativity’ ideals as imagined by Charles Landry. In South Africa, culture‐led development and cultural policy tends to primarily mimic that of the global North, largely focusing on culture as a catalyst for economic and property development. Public art commissioning processes tend to focus on decorative projects as part of urban upgrading, which are often associated with ensuing gentrification and displacement of the urban poor. In contrast to focusing on these kinds of regeneration strategies, this article investigates Dlala Indima, a hip‐hop‐led graffiti project in a rural township in the Eastern Cape of South Africa. This article situates graffiti as a critical social and spatial practice to argue that this case challenges normative cultural planning paradigms. Dlala Indima's work is an alternative approach to cultural development by and for young people who are usually marginalized by the mainstream practice of culture‐led economic development. The project challenges dominant creative cities and culture‐led development discourses in three ways: first, it challenges the normative processes of regeneration; secondly, it grounds participatory practice; and finally, it shifts participation from ‘tyranny to transformation’ through the ubuntu of hip‐hop, the notion of ubuntu being based on the communitarian notion of ‘ubuntu, ngubuntu ngabantu’—‘I am because you are’.