bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of antimicrobial, antioxidant and cytotoxic properties of bioactive compounds produced from endophytic fungi of Himalayan yew (Taxus wallichiana) in Nepal
Authors: Gauchan Dhurva Prasad , Kandel Pratistha , Tuladhar Astha , Acharya Ashesh , Kadel Upendra , Baral Aayush , Shahi Arjan Bir , García-Gil María Rosario 
Published: October 2020

Background: Endophytic fungi are largely underexplored in the discovery of natural bioactive products though being rich sources of novel compounds with promising pharmaceutical potential. In this study, Taxus wallichiana, which has huge medicinal value, was investigated for its endophytic diversity and capability to produce bioactive secondary metabolites by analyzing antioxidant, antimicrobial and cytotoxic properties. Methods: The endophytes were identified by ITS-PCR using genomic DNA samples. The secondary metabolites were extracted by solvent extraction method using ethyl acetate. The antioxidant activity was analyzed by Thin Layer Chromatography, Total Phenol Content (TPC), Total Flavonoid Content (TFC) and DPPH assay, and the antimicrobial activity was analyzed by agar-well diffusion method. Brine shrimp lethality assay was used to analyze the cytotoxicity of the fungal extracts. Results: Out of 16 different Taxus trees sampled from different locations of Dhorpatan, 13 distinctive endophytic fungi were isolated and grouped into 9 different genera: Bjerkandera, Trichoderma, Preussia, Botrytis, Arthrinium, Alternaria, Cladosporium, Sporormiella and Daldinia. The ethyl acetate extracts isolated from three endophytic fungi: Alternaria alternata, Cladosporium cladosporioides and Alternaria brassicae showed significant TPC values of 204±6.144, 312.3±2.147 and 152.7±4.958µg GAE/mg of dry extract, respectively, and TFC values of 177.9±2.911, 644.1±4.202 and 96.38±3.851µg RE/mg of dry extract, respectively. Furthermore, these three extracts showed a dose dependent radical scavenging activity with IC50 concentration of 22.85, 22.15 and 23.001 µg/ml, respectively. The extracts of C. cladosporioides and A. brassicae also showed promising antimicrobial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis with a minimum inhibitory concentration of 250μg/ml for all bacteria. Both the samples showed cytotoxic property against shrimp nauplii with LC50 of 104.2 and 125.9µg/ml, respectively. Conclusions: The crude fungal extracts obtained from endophytes: A. alternata, C. cladosporioides and A. brassicae upon purification and further identification of the bioactive compounds can be a fascinating source for novel pharmaceutical agents.
UNICORNS: Uveitis in childhood prospective national cohort study protocol
Authors: Kellett Salomey , Rahi Jugnoo S , Dick Andrew D. , Knowles Rachel , Tadić Valerija , Solebo Ameenat Lola 
Published: October 2020

Background: Childhood uveitis is a rare inflammatory eye disease which is typically chronic, relapsing-remitting in nature, with an uncertain aetiology (idiopathic). Visual loss occurs due to structural damage caused by uncontrolled inflammation. Understanding of the determinants of long term outcome is lacking, including the predictors of therapeutic response or how to define disease control. Aims: To describe disease natural history and outcomes amongst a nationally representative group of children with non-infectious uveitis, describe the impact of disease course on quality of life for both child and family, and identify determinants of adverse visual, structural and developmental outcomes. Methods: UNICORNS is a prospective longitudinal multicentre cohort study of children newly diagnosed with uveitis about whom a core minimum clinical dataset will be collected systematically. Participants and their families will also complete patient-reported outcome measures annually from recruitment. The association of patient (child- and treatment- dependent) characteristics with outcome will be investigated using logistic and ordinal regression models which incorporate adjustment for within-child correspondence between eyes for those with bilateral disease and repeated outcomes measurement. Discussion: Through this population based, prospective longitudinal study of childhood uveitis, we will describe the characteristics of childhood onset disease. Early (1-2 years following diagnosis) outcomes will be described in the first instance, and through the creation of a national inception cohort, longer term studies will be enabled of outcome for affected children and families.
Animal assisted activities in the children's hospital: protocol for a scoping review
Authors: Howe Rachel , Nicholson Sandra , Lafferty Attracta , Davies Carmel , Stokes Diarmuid , Kroll Thilo 
Published: October 2020

The introduction of animal interventions in healthcare are relatively common; however, their actual effectiveness and longer term findings are not so well known or published, especially in relation to the children’s hospital setting. It is important to plot where and why animal interventions take place but also to focus on how the human animal bond impacts on children, their parents and staff in a children’s hospital setting. Family members, including companion animals, are important supports which help children to relax and give them a sense of familiarity to navigate the busy and stressful hospital environment. The scoping review of the literature proposed will explore the scientific evidence for animal assisted activities (AAA) in children’s hospitals and will map results prior to undertaking a full scale research project. Arksey and O’Malley’s framework guided by the Joanna Briggs Institute will frame this review protocol. Appendices are used to ensure transparency of methods. The protocol is presented in narrative style to demonstrate flow and fluency and appeal to wider readership.
Prepurchase Information Acquisition and Credible Advertising
Authors: Gardete Pedro M. , Guo Liang 
Published: October 2020

Consumers can decide whether to acquire more information about their valuations prior to purchase. In this paper, we examine pricing and advertising strategies when consumers can engage in prepurchase information acquisition. We show that consumer information acquisition can increase valuation heterogeneity and undermine a firm’s ability to extract consumer surplus. As a result, interestingly, a higher product quality can exert a nonmonotonic impact on equilibrium information acquisition, hurt firm profitability, and lead to lower consumer surplus. We also demonstrate that prepurchase information acquisition can be an endogenous mechanism to enable credible advertising in a cheap-talk setting. We show that quality claims in advertisements can be informative even when the firm can freely misrepresent its advertising message. Informative advertising can arise because a higher perceived quality can not only increase consumers’ expected value, but it also induces more information acquisition and thus hurts the firm’s ability to extract consumer surplus. This novel explanation for the credibility of cheap-talk advertising is distinguished from those identified in the literature (e.g., matching between firm types and heterogenous consumers, restrictive communication on multidimensional attributes). Moreover, we show that a higher quality can soften competition by inducing more information acquisition, thus benefiting the rival firm’s profitability. This paper was accepted by Matthew Shum, marketing.
Affine Modeling of Credit Risk, Pricing of Credit Events, and Contagion
Authors: Monfort Alain , Pegoraro Fulvio , Renne Jean-Paul , Roussellet Guillaume 
Published: October 2020

We propose a discrete-time affine pricing model that simultaneously allows for (i) the presence of systemic entities by departing from the no-jump condition on the factors’ conditional distribution, (ii) contagion effects, and (iii) the pricing of credit events. Our affine framework delivers explicit pricing formulas for default-sensitive securities such as bonds and credit default swaps (CDSs). We estimate a euro-area multicountry version of the model and address economic questions related to the pricing of sovereign credit risk. We find that both frailty (common factors) and contagion phenomena are important to account for the joint dynamics of credit spreads. Our results also provide evidence of credit-event pricing, which is at the source of substantial credit risk premiums, even for short maturities. Finally, we extract measures of depreciation-at-default from CDSs denominated in different currencies. This paper was accepted by Kay Giesecke, finance.
Competition Among Proprietary and Open-Source Software Firms: The Role of Licensing in Strategic Contribution
Authors: August Terrence , Chen Wei , Zhu Kevin 
Published: October 2020

In enterprise software markets, firms are increasingly using services-based business models built on open-source software (OSS) to compete with established, proprietary software firms. Because third-party firms can also strategically contribute to OSS and compete in the services market, the nature of competition between OSS constituents and proprietary software firms can be complex. Moreover, their incentives are likely influenced by the licensing schemes that govern OSS. We study a three-player game and examine how open-source licensing affects competition among an open-source originator, an open-source contributor, and a proprietor competing in an enterprise software market. In this regard, we examine (1) how quality investments and prices are endogenously determined in equilibrium, (2) how license restrictiveness impacts equilibrium investments and the quality of offerings, and (3) how license restrictiveness affects consumer surplus and social welfare. Although some in the open-source community often advocate restrictive licenses such as the GNU General Public License because it is not always in the best interest of the originator for the contributor to invest greater development effort, such licensing can actually be detrimental to both consumer surplus and social welfare when it exacerbates this incentive conflict. We find such an outcome in markets characterized by software providers with similar development capabilities yet cast in favor of the proprietor. In contrast, when these capabilities either become more dispersed or remain similar but tilt in favor of open source, a more restrictive license instead encourages greater effort from the OSS contributor, leads to higher OSS quality, and provides a larger societal benefit. This paper was accepted by Chris Forman, information systems.
Revenue Management with Repeated Customer Interactions
Authors: Calmon Andre P. , Ciocan Florin D. , Romero Gonzalo 
Published: October 2020

Motivated by online advertising, we model and analyze a revenue management problem where a platform interacts with a set of customers over a number of periods. Unlike traditional network revenue management, which treats the interaction between platform and customers as one-shot, we consider stateful customers who can dynamically change their goodwill toward the platform depending on the quality of their past interactions. Customer goodwill further determines the amount of budget that they allocate to the platform in the future. These dynamics create a trade-off between the platform myopically maximizing short-term revenues, versus maximizing the long-term goodwill of its customers to collect higher future revenues. We identify a set of natural conditions under which myopic policies that ignore the budget dynamics are either optimal or admit parametric guarantees; such simple policies are particularly desirable since they do not require the platform to learn the parameters of each customer dynamic and only rely on data that is readily available to the platform. We also show that, if these conditions do not hold, myopic and finite look-ahead policies can perform arbitrarily poorly in this repeated setting. From an optimization perspective, this is one of a few instances where myopic policies are optimal or have parametric performance guarantees for a dynamic program with nonconvex dynamics. We extend our model to the cases where supply varies over time and where customers may not interact with the platform in every period. This paper was accepted by Chung Piaw Teo, optimization.
Financial Intermediation Chains in an Over-the-Counter Market
Authors: Shen Ji , Wei Bin , Yan Hongjun 
Published: October 2020

We analyze financial intermediation chains in a search economy that is populated by investors with heterogeneous valuations of an asset. In equilibrium, investors with moderate valuations choose to be intermediaries, and those with extreme valuations are their customers. The average length of intermediation chains is shown to be decreasing in search cost, search speed, and market size but increasing in investors’ trading needs. These predictions are distinct from those implied by existing models in the literature. Our empirical evidence, based on data from the U.S. corporate bond market, is mostly consistent with our model predictions. This paper was accepted by Tomasz Piskorski, finance.
Are Regulators Effective at Unraveling Accounting Manipulation? Evidence from Public Utility Commissions
Authors: Chakravarthy Jivas , McDermott Katie E. , White Roger M. 
Published: October 2020

Prior research proposes that a monopolist with private information inflates its reported costs under rate regulation to extract an informational rent. Using a sample of U.S. electric utilities from 1990–2011, we first confirm an unexpected increase in operating expense during rate review periods, then decompose operating expense into its cash and accrual components, and find the cash component accounts for 89% of this increase. The observed pattern is consistent with some combination of real activities management and utility managers misrepresenting transitory expense shocks as permanent. We then focus on identifying regulators’ effectiveness at unraveling this manipulation and minimizing the rent. We estimate that, on average, regulators allow 17¢ out of every dollar of abnormal cash expense to be recovered in future annual revenue, a statistically significant amount. Next, we study the effects of regulators’ ability (proxied by experience) and motivation (proxied by whether they were elected) to unravel accounting manipulation. We find that whereas inexperienced and politically appointed regulators allow a significant portion of abnormal cash expense to be recovered (41¢ and 24¢ out of every dollar, respectively), experienced and elected regulators do not (although the difference between appointed and elected regulators is not statistically significant). Our findings suggest that regulators differ in their ability to identify manipulation—with experience enhancing this ability—and that, on average, state regulators effectively unravel most of the effect of accounting manipulation.This paper was accepted by Suraj Srinivasan, accounting.
Evaluation of Tractor Ride Vibrations by Cab Suspension System
Authors: Oh Jooseon , Chung Woo-Jin , Han Hyun-Woo , Kim Ji-Tae , Son Gwan-Hee , Park Young-Jun 
Published: October 2020

HighlightsTractor ride vibrations were evaluated under various conditions according to type of cab suspension.Ride vibrations were measured on flat and bumpy roads using four tractors with different cab suspension types.Tractors with hydro-pneumatic suspension exhibited smaller ride vibrations than tractors with rubber mounts.Semi-active hydro-pneumatic control resulted in smaller ride vibrations than those resulting from passive control.Abstract. In this study, tractor ride vibrations were evaluated under various conditions according to the type of cab suspension, and the effects of different cab support methods on these ride vibrations were determined. Ride vibrations on flat and bumpy roads were measured using four tractors equipped with different cab suspension types and were analyzed based on ISO Standard 2631-1 for human exposure to whole-body vibration. The ride vibration values were evaluated using the weighted root mean square acceleration and fourth-power vibration dose value. The results confirmed that the tractor equipped with semi-active hydro-pneumatic cab suspension at the two rear positions yielded smaller ride vibrations than the tractors with rubber mounts at all four positions. Vibration reduction effects of up to 53.8% and 67.1% were yielded in the flat road test and bumpy road test, respectively. In addition, among the two tractors with hydro-pneumatic cab suspension systems, ride vibrations were reduced by approximately 7.1% in the tractor that used semi-active control as compared to the tractor that used passive control. Keywords: Hydro-pneumatic cab suspension, Ride vibration, Rubber mount, Whole-body vibration.
Experimental Research on the Bending Characteristics of Glycyrrhiza glabra Stems
Authors: Wen Bao-Qin , Li Yang , Kan Za , Li Jing-Bin , Li Liqiao , Ge Jianbing , Ding Longpeng , Wang Kaifei , Zou Shijie , Li Wentao 
Published: October 2020

HighlightsA quadratic orthogonal rotation combination design was used to test the influences of four factors.The significant influence of each factor was obtained using the analysis of variance method.Interactions of the factors were analyzed using the response surface method.Abstract. To provide a theoretical basis for the design of harvesting and processing machinery for Glycyrrhiza glabra stems and for energy conservation during processing, the bending characteristics of G. glabra stems were studied. The comprehensive influences of four factors (loading position diameter, loading speed, span, and moisture content) on the bending characteristics of G. glabra stems were tested using a quadratic orthogonal rotation combination design. The results indicated that the single factors loading position diameter and span had a significant influence on the bending characteristics of G. glabra stems. In addition, as the loading position diameter increased, the maximum bending force and bending energy of G. glabra stems tended to increase, while the bending stress tended to decrease. As the span increased, the maximum bending force and bending energy of G. glabra stems tended to decrease, while the bending stress tended to increase. As the moisture content increased, the maximum bending force and bending stress of G. glabra stems tended to decrease, while the influence on bending energy was not significant. The loading speed had no influence on the bending characteristics of G. glabra stems. The interaction between loading position diameter and span had a significant influence on the maximum bending force and bending energy, and the interactions between loading position diameter and moisture content and between loading speed and span had a significant influence on the maximum bending stress. This study on the bending characteristics of G. glabra stems can provide a theoretical basis for the design of harvesting and processing equipment and for the pretreatment of G. glabra stems. Keywords: Bending characteristics, Licorice, Loading position, Loading speed, Moisture content, Span.
Positioning Control of a Human-Machine Cooperative Grafting Manipulator for Unstructured Environments
Authors: Li Na , Hao Ziyan , Jiang Haiyong , Yu Bo 
Published: October 2020

HighlightsPositioning of a human-machine cooperative grafting manipulator for high-crown grafting of fruit trees is analyzed.PID control based on feedforward compensation of a dynamic model can realize high-precision position control of the braking process in unstructured agricultural environments.A manipulator based on the proposed control method can realize accurate position control and time-varying operating forces and can provide energy savings to meet the requirements of field operations.Abstract. Crown grafting of fruit trees has the disadvantages of high labor intensity and reduced graft survival. Therefore, a human-machine cooperative manipulator that relies on passive joint braking was designed to realize position control. The manipulator can replace manual operations to solve the problem of different positions in the grafting process and provide positioning and force support for canopy grafting. This study determined that the working space of the manipulator can cover the canopy area of fruit trees. Dynamic equations were established for motion simulation and feedforward compensation control of the manipulator. According to the dynamic model, the joint braking process was simulated. The simulation results showed that the joint braking torque needs to be dynamically controlled to ensure positioning accuracy of the manipulator. A process of passive joint braking was designed based on the proposed ideal braking curve. By comparing the position control accuracy of independent proportional integral derivative (PID) control, dynamic model feedforward compensation control, and PID control based on feedforward compensation of the dynamic model in simulations, it was determined that PID control based on feedforward compensation of the dynamic model was suitable for application in the braking torque control system. Finally, prototype tests showed that PID control based on feedforward compensation of the dynamic model can realize high-precision joint braking and position control of the manipulator. The positioning error was less than 5%, and the maximum vibration acceleration amplitude was reduced by 26.7% to 68.5%. The control system of the manipulator, using PID control based on feedforward compensation of the dynamic model, can provide adaptability for unstructured environments and reduce power consumption for application in field operations. Keywords: Controls, Dynamics, Grafting, Positioning, Simulation models, Unstructured agricultural environment.
Innovative Extension Methods in the U.S. to Promote Irrigation Water Management
Authors: Rudnick Daran R. , Stockton Matt , Taghvaeian Saleh , Warren Jason , Dukes Michael D. , Kremen Amy , Henry Christopher G. , Aguilar Jonathan , Ortiz Brenda , Andales Allan , Burr Chuck A. , Qiao Xin , Liang Weizhen , Walthour Steven , Amosson Stephen H. 
Published: October 2020

HIGHLIGHTSUniversity extension has been playing a larger role, serving a larger number of irrigated farms.Extension programs in irrigation water management (IWM) have been transitioning away from lectures and field tours as the primary means of knowledge transfer.New IWM programs focus on experiential learning, development of practitioner networks, and industry participation.Abstract. Promotion and adoption of irrigation water management (IWM) technology, tools, and best management practices are important as water availability concerns are addressed. Traditional extension programs have relied on lecture presentations, field tours, fact sheets, and on-station demonstrations to promote IWM practices and tools. However, these platforms tend not to provide the experience and opportunity for growers to identify and become comfortable with innovative solutions, such as new technology. To address these challenges and to appeal to an ever-changing client base, innovative and locally relevant extension and outreach programs have been devised to engage and educate growers. This article describes some of these programs that extend beyond previous traditional programs to connect growers with IWM. Keywords: Demonstrations, Experiential learning, Grower competition, Outreach, Practitioner networks.