bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of data quality and model parameters on the quantitative phase analysis of X-ray diffraction data by the Rietveld method
Authors: Rowles Matthew R.
Published: May 2021

The quality of X-ray powder diffraction data and the number and type of refinable parameters have been examined with respect to their effect on quantitative phase analysis (QPA) by the Rietveld method using data collected from two samples from the QPA round robin [Madsen, Scarlett, Cranswick & Lwin (2001).J. Appl. Cryst.34, 409–426]. From the analyses of these best-case-scenario specimens, a series of recommendations for minimum standards of data collection and analysis are proposed. It is hoped that these will aid new QPA-by-Rietveld users in their analyses.
Location competitiveness in specific pioneering theories: a condensed overview
Authors: Lepori Damiano
Published: May 2021

Purpose

The purpose of this study is to provide with a condensed overview of location competitiveness from the perspectives of specific pioneering theories to highlight the main factors, which lay the foundations for latter theories specifically dedicated to location-bound advantages, to specialization processes and, in fine, to location competitiveness.

Design/methodology/approach

The study is divided into five major sections. First, location competitiveness is tackled from Smith’s frame of reference in the theory of absolute advantages. Second, Ricardo’s comparative advantages are scrutinized and specific complementary findings to Smith are highlighted. Third, Marshall’s industrial districts are investigated, as they constitute the linchpin of numerous latter approaches on location competitiveness. Fourth, the Keynesian perspective is considered as far as the role of government on location competitiveness is concerned. Fifth, endogenous growth theories are considered as they relate to capital, innovation and knowledge, which are factors intrinsically associated with agglomeration patterns and to location competitiveness.

Findings

The main finding of this literature review suggests that pioneering theories also identify location competitiveness as having a fundamental influence on firms’ ability to prosper in terms of wealth creation and of competitive advantages and vice versa.

Originality/value

The originality of this study is to investigate seminal authors from the perspective of location competitiveness and to highlight how numerous later researches dedicated to the subject are indeed based on pioneering theories. On this basis, it is subsequently possible to capture location competitiveness and to implement relevant policy measures to improve economic prosperity.
Examining the relationship between e-government development, nation’s cyber-security commitment, business usage and economic prosperity: a cross-country analysis
Authors: Krishna Ben , M.P. Sebastian
Published: May 2021

Purpose

This study aims to propose a model to examine the relationships between e-government development, cybersecurity commitment, business usage and economic prosperity of the country.

Design/methodology/approach

Structural equation modeling was used to analyze the country-level variables to explain the second-order impact of e-government development through the mediating role of cybersecurity commitment.

Findings

Findings suggest that e-government development demonstrated a stronger association with cybersecurity commitment and business usage. There is preliminary evidence that the improvement of cybersecurity measures initiated by e-government development will drive business usage and improve macroeconomic conditions.

Research limitations/implications

This paper has constructed a theoretical model and validated it using publicly available archival data. Further, this study hypothesizes and demonstrates empirically the direct, as well as indirect relationships between e-government development, cybersecurity commitment, business usage and economic prosperity. To summarize, the study unearths the role of a nation’s cybersecurity commitment and how it is associated with other macro parameters in a country.

Originality/value

As an initial step, the present study highlights the pivotal role of e-government and its positive influence on cybersecurity commitment at the country level. Further, this study also recognizes the role of cyber commitment to boost information communication and technology usage in business, the use of e-government services for the profitability of the business and effectively influence economic prosperity.
Multi-objective vendor managed inventory system with interval type-2 fuzzy demand and order quantities
Authors: Ashraf Zubair , Shahid Mohammad
Published: May 2021

Purpose

The proposed IT2FMOVMI model intends to concurrently minimize total cost and warehouse space for the single vendor-retailer, multi-item and a consolidated vendor store. Regarding demand and order quantities with the deterministic and type-1 fuzzy numbers, we have also formulated the classic/crisp MOVMI model and type-1 fuzzy MOVMI (T1FMOVMI) model. The suggested solution technique can solve both crisp MOVMI and T1FMOVMI problems. By finding the optimal ordered quantities and backorder levels, the Pareto-fronts are constructed to form the solution sets for the three models.

Design/methodology/approach

A multi-objective vendor managed inventory (MOVMI) is the most recognized marketing and delivery technique for the service provider and the retail in the supply chain in Industry 4.0. Due to the evolving market conditions, the characteristics of the individual product, the delivery period and the manufacturing costs, the demand rate and order quantity of the MOVMI device are highly unpredictable. In such a scenario, a MOVMI system with a deterministic demand rate and order quantity cannot be designed to estimate the highly unforeseen cost of the problem. This paper introduces a novel interval type-2 fuzzy multi-objective vendor managed inventory (IT2FMOVMI) system, which uses interval type-2 fuzzy numbers (IT2FNs) to represent demand rate and order quantities. As the model is an NP-hard, the well-known meta-heuristic algorithm named NSGA-II (Non-dominated sorted genetic algorithm-II) with EKM (Enhanced Karnink-Mendel) algorithm based solution method has been established.

Findings

The experimental simulations for the five test problems that demonstrated distinct conditions are considered from the real-datasets of SAPCO company. Experimental study concludes that T1FMOVMI and crisp MOVMI schemes are outclassed by IT2FMOVMI model, offering more accurate Pareto-Fronts and efficiency measurement values.

Originality/value

Using fuzzy sets theory, a significant amount of work has been already done in past decades from various points of views to model the MOVMI. However, this is the very first attempt to introduce type-2 fuzzy modelling for the problem to address the realistic implementation of the imprecise parameters.
Is leverage a substitute or outcome for governance? Evidence from financial crises
Authors: Tekin Hasan , Polat Ali Yavuz
Published: May 2021

Purpose

The authors investigate the impact of governance on the leverage of East Asian firms in the financial crisis context, in order to understand the puzzle whether debt acts as a substitute for governance or an outcome of the governance mechanism.

Design/methodology/approach

The authors use 86,030 firm-years and the country-level governance data from eight East Asian countries over the period 1996–2017. The authors employ the fixed effects (FE) model, in the main analysis and the weighted least squares model, as a robustness check in order to compare the two competing hypotheses of agency theory, substitute and outcome models.

Findings

The authors’ results show that debt acts as a substitute for governance before the GFC, but during and after the GFC the picture changes. Namely, debt acts as an outcome of the governance mechanism during the GFC and its aftermath. Since during financial downturns both agency costs increase, and information asymmetry widens, firms in poor-governed countries may be reluctant to increase their leverage in order not to face financial distress and additional restrictions. Thus, the results imply that the use of debt as a tool to mitigate agency conflicts and a substitute for governance strongly depends on the environment that the firms operate and the general macroeconomic conditions, such as facing a financial crisis or not.

Research limitations/implications

This study provides an interesting case of the firms' capacity to raise money during a crisis and that governance plays an important role in borrowing activities of firms. This will undoubtedly help motivating owners and policymakers for improving governance. The authors’ findings may be useful for policymakers to develop policies considering the adverse effects caused by exogenous shocks. This is crucial because the severity of GFC as a shock seems to change the macro and institutional environment that firms operate. While the authors properly address the research hypotheses using country governance data, future research may employ corporate governance data to attain firm-level results by testing two competing hypotheses.

Originality/value

There are several important areas where this study makes original contributions. First, while Tsoy and Heshmati (2019) focus on the dynamics of capital structure for only Korean firms, the authors extend the sample including eight East Asian countries considering the impact of country governance on capital structure policy. Specifically, this study is the first in using the robust country governance data, which differs by country and year, in the crisis context. Next, the authors investigate both the AFC and GFC to compare whether these two crises have different effects on capital structure policy of East Asian firms. Finally, the authors aim to understand whether leverage is used as a substitute for governance or an outcome of governance mechanism considering recessions.
A proposed maturity model to improve warehouse performance
Authors: Salhieh Loay , Alswaer Waed
Published: May 2021

Purpose

The purpose of this paper is to propose a maturity model to improve warehouse performance.

Design/methodology/approach

This paper will follow De Bruin et al’s (2005) suggested six relevant phases: scope, design, populate, test, deploy and maintain in developing the proposed maturity model. This study concentrates on the first five phases.

Findings

The proposed warehouse maturity model can be used as descriptive, benchmarking and a prescriptive with a road map for improvement.

Practical implications

The warehouse maturity model was proposed to let warehouse managers evaluate their practices and assess them by maturity level. Then, the proposed warehouse maturity model can be utilized to develop a set of plans for conducting projects to improve the warehouse practices, techniques and tools.

Originality/value

The proposed warehouse maturity model contributes to fill the shortages of maturity model addressing the warehouse environment. In particular, it provides a useful tool to establish the overall maturity level of a warehouse system. The proposed maturity model supports strategic decisions oriented toward improvement capabilities of the warehouse and to compete based on service level provided.
Transfer mechanisms for lean implementation with OHS integration in the garment industry
Authors: Hamja Abu , Hasle Peter , Hansen David
Published: May 2021

Purpose

Lean manufacturing has the potential for simultaneously improving the competitiveness and the social sustainability of the apparel industry in developing countries. However, there is limited research on the ways to a successful lean implementation in developing countries and with an emphasis on occupational health and safety (OHS) improvement.

Design/methodology/approach

The paper investigates four cases of lean implementation in garment factories and uses the design science research strategy, building on the context-intervention-mechanism-outcome (CIMO) framework to identify explanatory mechanisms that can be used for designing future action.

Findings

The study identifies tangible mechanisms that can lead to successful lean implementation. The most important mechanisms relate to practical top management support, worker involvement, application of lean tools and training.

Practical implications

The findings of this study can guide better lean implementation for the many garment factories in developing countries.

Originality/value

While the lean literature provides general recommendations for lean implementation, knowledge about the transfer mechanisms in developing countries as well as the connections between lean and OHS is limited. This paper contributes to lean implementation theory and to the discourse of positive lean by integrating efficiency and working conditions. In addition, the paper identifies transfer mechanisms for lean implementation in the garment industry in a developing country.
Impact of basic psychological needs on organizational justice and helping behavior: a self-determination perspective
Authors: Chou Shih Yung , Nguyen Thuy , Ramser Charles , Chang Tree
Published: May 2021

Purpose

Integrating the social exchange perspective of helping behavior with self-determination theory (SDT), this study seeks to examine the impact of employees' psychological needs on perceived organizational justice and the impact of perceived organizational justice on employees' helping behavior.

Design/methodology/approach

Cross-sectional and cross-organizational data were obtained from 177 full-time employees employed in 12 small- and medium-sized oil and gas service companies. A partial least squares approach using SmartPLS was employed to test the hypotheses.

Findings

Results illustrate that the psychological need for competence and need for autonomy are positively related to perceived distributive and procedural justice, respectively. Moreover, perceived distributive and procedural justice are related to helping behavior. Furthermore, perceived distributive justice fully mediates the relationship between the psychological need for competence and helping behavior, whereas perceived procedural justice partially mediates the relationship between the psychological need for autonomy and helping behavior.

Originality/value

From a theoretical standpoint, this study offers some theoretical explanations for how the basic psychological needs identified by SDT activate employees' perceived organizational justice. Practically, this study offers several managerial recommendations that help managers manage helping behavior in the organization effectively.
Overcoming the business model transformation dilemma: exploring market shaping and stabilizing strategies in incumbent firms
Authors: Carlborg Per Johan , Hasche Nina , Kask Johan
Published: May 2021

Purpose

The purpose of this paper is to extend the knowledge on business model transformation (BMT) by developing an integrative framework for BMT dilemmas, including strategies for shaping and stabilizing market structures.

Design/methodology/approach

The study uses a case-based approach, with data from the Swedish electric utility industry.

Findings

The findings uncover practices related to both shaping and stabilizing market structure. The study contributes with insights for firms to overcome the BMT dilemma. Shaping strategies involve disruptive innovations while stabilizing strategies concerns incremental improvements in existing structures; by balancing these efforts, firms can find ways toward successful BMT.

Originality/value

With a focus on incumbent firms and the balancing act of BMT in a network, the study covers areas that have scarcely been addressed in the existing literature. Even though most business model literature has focused on shaping consumer markets, the need to consider BMT as a dual-directional process in an industrial context is emphasized in this study.
Opportunity knocks? Parking regulations and automotive thefts in the age of coronavirus
Authors: Hasnah George
Published: May 2021

Purpose

This paper aims to explore the relationship between adjustments in parking regulations in major American cities in response to the 2019 novel coronavirus and vehicle thefts.

Design/methodology/approach

Vehicle theft data from the 25 most populous American cities were collected between 2019 and 2020. Information was also collected on the type, severity and number of changes to parking enforcement regulations made in March and April 2020 in response to the outbreak of the coronavirus in the USA.

Findings

This analysis shows that the relaxation of parking regulations is associated with a significant increase in the number of vehicle thefts in major metropolitan areas.

Research limitations/implications

Although this research cannot prove a cause and effect relationship, statistical analysis of the data shows that policy change and vehicle thefts are related variables.

Practical implications

Guide for future policies-increase awareness; promote safety; promote accountability.

Originality/value

The comparison of increased vehicle thefts to parking enforcement policies; to policymakers, the general public.
Prediction of credit risk with an ensemble model: a correlation-based classifier selection approach
Authors: Xiong Zhibin , Huang Jun
Published: May 2021

Purpose

Ensemble models that combine multiple base classifiers have been widely used to improve prediction performance in credit risk evaluation. However, an arbitrary selection of base classifiers is problematic. The purpose of this paper is to develop a framework for selecting base classifiers to improve the overall classification performance of an ensemble model.

Design/methodology/approach

In this study, selecting base classifiers is treated as a feature selection problem, where the output from a base classifier can be considered a feature. The proposed correlation-based classifier selection using the maximum information coefficient (MIC-CCS), a correlation-based classifier selection under the maximum information coefficient method, selects the features (classifiers) using nonlinear optimization programming, which seeks to optimize the relationship between the accuracy and diversity of base classifiers, based on MIC.

Findings

The empirical results show that ensemble models perform better than stand-alone ones, whereas the ensemble model based on MIC-CCS outperforms the ensemble models with unselected base classifiers and other ensemble models based on traditional forward and backward selection methods. Additionally, the classification performance of the ensemble model in which correlation is measured with MIC is better than that measured with the Pearson correlation coefficient.

Research limitations/implications

The study provides an alternate solution to effectively select base classifiers that are significantly different, so that they can provide complementary information and, as these selected classifiers have good predictive capabilities, the classification performance of the ensemble model is improved.

Originality/value

This paper introduces MIC to the correlation-based selection process to better capture nonlinear and nonfunctional relationships in a complex credit data structure and construct a novel nonlinear programming model for base classifiers selection that has not been used in other studies.
The effects of individual differentiation on newcomer group identification
Authors: Chen Jenny , Cooper-Thomas Helena D.
Published: May 2021

Purpose

With organizations hiring from increasingly diverse labor markets, this study aims to examine the implications of newcomers’ individual differentiation for their group identification. The paper proposes and tests a self-verification process in which individual differentiation predicts group identification through role innovation under positive social feedback on innovation (moderated mediation). Simultaneously, a self-categorization pathway is examined of the indirect negative influence of individual differentiation on group identification through role modeling (mediation).

Design/methodology/approach

Survey data were collected at three time points from 161 UK university alumni.

Findings

The analyses support a self-verification pathway: newcomers with high individual differentiation report higher group identification via role innovation only when they receive positive feedback on their innovative actions. However, there was no support for a self-categorization pathway, with no indirect relationship found between individual differentiation and group identification via role modeling.

Practical implications

HR practitioners and managers who are responsible for helping newcomers adjust should consider newcomers’ individual differentiation. Specifically, newcomers with high individual differentiation may more successfully navigate their transition and identify with their workgroup when given appropriate support, such as positive social feedback on their innovative actions.

Originality/value

The study extends organizational socialization research by focusing on when newcomers with high individual differentiation may experience group identification. The findings highlight the important role of positive social feedback on group identification; this suggests a potential means by which newcomers with high individual differentiation can settle successfully.
Knowledge management visualisation in regional innovation system collaborative decision-making
Authors: Weck Marina , Humala Iris , Tamminen Pia , Ferreira Fernando A.F.
Published: May 2021

Purpose

This study was developed in response to the need to develop age-friendly smart living environments due to the complex demands placed on society by the ageing of the population. This study aims to analyse the potential that knowledge visualisation offers collaborative decision-making applied to the development of a multiple criteria framework supporting knowledge management (KM) through knowledge collaboration (KC) and knowledge sharing (KS) in the context of regional innovation systems (RIS).

Design/methodology/approach

Using a socio-technical approach, knowledgeable and experienced representatives of RIS innovation actors were brought together to develop a constructivist multiple criteria framework that integrates knowledge visualisation and collaborative decision-making techniques (i.e. cognitive mapping and system dynamics).

Findings

The study introduces a multiple criteria model supporting KM encompassing conditions and practices of RIS innovation actors facilitating and encouraging KC and KS. The potential for knowledge visualisation in collaborative decision-making is explored in great depth and illustrated in a case study setting.

Practical implications

The panel members who participated in this study consider our methodological proposal to be extremely versatile and see great potential for further applications in RIS contexts.

Originality/value

The combined use of cognitive mapping and system dynamics according to the strategic options development and analysis (SODA) approach offers a holistic and well-informed perspective on the issue in question. The literature reports no prior work of this methodological combination in the same research context.
Interaction generalisation and demographic feedbacks drive the resilience of plant–insect networks to extinctions
Authors: Maia Kate P. , Marquitti Flavia M. D. , Vaughan Ian P. , Memmott Jane , Raimundo Rafael L. G.
Published: May 2021

Understanding the processes driving ecological resilience, that is the extent to which systems retain their structure while absorbing perturbations, is a central challenge for theoretical and applied ecologists. Plant–insect assemblages are well‐suited for the study of ecological resilience as they are species‐rich and encompass a variety of ecological interactions that correspond to essential ecosystem functions.

Mechanisms affecting community response to perturbations depend on both the natural history and structure of ecological interactions. Natural history attributes of the interspecific interactions, for example whether they are mutualistic or antagonistic, may affect the ecological resilience by controlling the demographic feedbacks driving ecological dynamics at the community level. Interaction generalisation may also affect resilience, by defining opportunities for interaction rewiring, the extent to which species are able to switch interactions in fluctuating environments. These natural history attributes may also interact with network structure to affect ecological resilience.

Using adaptive network models, we investigated the resilience of plant–pollinator and plant–herbivore networks to species loss. We specifically investigated how fundamental natural history differences between these systems, namely the demographic consequences of the interaction and their level of generalisation—mediating rewiring opportunities—affect the resilience of dynamic ecological networks to extinctions. We also create a general benchmark for the effect of network structure on resilience simulating extinctions on theoretical networks with controlled structures.

When network structure was static, pollination networks were less resilient than herbivory networks; this is related to their high levels of nestedness and the reciprocally positive feedbacks that define mutualisms, which made co‐extinction cascades more likely and longer in plant–pollinator assemblages. When considering interaction rewiring, the high generalisation and the structure of pollination networks boosted their resilience to extinctions, which approached those of herbivory networks. Simulation results using theoretical networks suggested that the empirical structure of herbivory networks may protect them from collapse.

Elucidating the ecological and evolutionary processes driving interaction rewiring is key to understanding the resilience of plant–insect assemblages. Accounting for rewiring requires ecologists to combine natural history with network models that incorporate feedbacks between species abundances, traits and interactions. This combination will elucidate how perturbations propagate at community level, reshaping biodiversity structure and ecosystem functions.
Threading the needle: How humans influence predator–prey spatiotemporal interactions in a multiple‐predator system
Authors: Murphy Asia , Diefenbach Duane R. , Ternent Mark , Lovallo Matt , Miller David
Published: May 2021

Perceived predation risk and the resulting antipredator behaviour varies across space, time and predator identity. Communities with multiple predators that interact and differ in their use of space, time of activity and hunting mode create a complex landscape for prey to avoid predation. Anthropogenic presence and disturbance have the potential to shift interactions among predators and prey and the where and when encounters occur.

We examined how white‐tailed deer Odocoileus virginianus fawn spatiotemporal antipredator behaviour differed along an anthropogenic disturbance gradient that had black bears Ursus americanus, coyotes Canis latrans, bobcats Lynx rufus and humans present.

We quantified (a) spatial co‐occurrence in species distributions, (b) temporal overlap across the diel cycle and (c) spatiotemporal associations between humans, bears, coyotes, bobcats, adult male deer and fawns. We also examined how deer vigilance behaviour changed across the anthropogenic disturbance gradient and survey duration.

Anthropogenic disturbance influenced spatiotemporal co‐occurrence across multiple scales, often increasing spatiotemporal overlap among species. In general, species’ spatial co‐occurrence was neutral or positive in anthropogenically disturbed environments. Bears and fawns, coyotes and adult male deer, and bobcats and fawns all had higher temporal overlap in the agriculture‐development matrix sites. In addition, factors that influenced deer vigilance (e.g. distance to forest edge and predator relative abundance) in the agriculture‐development matrix sites did not in the forest matrix site.

By taking into account the different antipredator behaviours that can be detected and the different scales these behaviours might occur, we were able to gain a more comprehensive picture of how humans reduce available niche space for wildlife, creating the neutral and positive spatiotemporal associations between species that studies have been seeing in more disturbed areas.
Do fine‐scale experiments underestimate predator consumption rates?
Authors: Bruckerhoff Lindsey A. , Pennock Casey A. , Gido Keith B.
Published: May 2021

Understanding ecological processes across spatial scales helps link observations and predictions from experiments to ecological patterns occurring at coarser scales relevant to management and conservation.

Using fish, we experimentally manipulated the size of arenas to test the spatial scaling of predator–prey interactions.

We measured variation in predator consumption and prey behaviour (prey aggregation, spatial overlap with predators and movement) across arena sizes. Variation in prey behaviour across arena sizes was hypothesized to drive consumption patterns by altering prey vigilance and encounter rates with predators.

Per capita consumption and movement were highest in the largest arena relative to the smallest and we observed a mismatch between where bass were present and the highest densities of prey across all arena sizes. We hypothesize more movement in largest arenas increased encounter rates and drove the observed increase in consumption with increasing arena size.

Consumption estimates obtained in experimental studies may underestimate consumption, but understanding the mechanisms driving bias across scales helps predict the outcomes of predator–prey interactions in natural systems.
Molecular and functional characterization of three novel carboxylesterases in the detoxification of permethrin in the mosquito,Culex quinquefasciatus
Authors: Gong Youhui , Li Ming , Li Ting , Liu Nannan
Published: May 2021

Carboxylesterases (CarEs) belong to a super family of multifunctional enzymes associated with the degradation of endogenous and exogenous compounds. Many insect CarEs are known to play important roles in catalyzing the hydrolysis of organophosphates (OPs), carbamates, and synthetic pyrethroids (SPs). The elevation of esterase activity through gene amplification and overexpression ofestα2andestβ2genes contributes to the development of resistance to OP insecticides in the mosquitoCulex quinquefasciatus. Three additional CarE genes are upregulated in permethrin‐resistantCx. quinquefasciatusaccording to an RNA‐seq analysis, but their function remains unknown. In this study, we, for the first time, characterized the function of these three novel genes using in vitro protein expression, an insecticide metabolism study and molecular docking analysis. All three CarE genes were significantly overexpressed in resistant mosquito larvae, but not adults, compared to susceptible strain. No gene copy differences in these three genes were found in the mosquitoes tested. In vitro high‐performance liquid chromatography (HPLC) revealed that CPIJ018231, CPIJ018232, and CPIJ018233 metabolized 30.4% ± 2.9%, 34.7% ± 6.8%, and 23.2% ± 2.2% of the permethrin, respectively. No mutations in resistant strains might significantly affect their CarE hydrolysis ability. A docking analysis further confirmed that these three CarEs from resistant strain all potentially metabolize permethrin. Taken together, these three carboxylesterase genes could play important roles in the development of permethrin resistance inCx. quinquefasciatuslarvae through transcriptional overexpression, metabolism, and detoxification.
Adaptation to a novel host and performance trade‐off in host‐generalist and host‐specific insect ectoparasites
Authors: Khokhlova Irina S. , van der Mescht Luther , Warburton Elizabeth M. , Stavtseva Nadezhda A. , Krasnov Boris R.
Published: May 2021

We investigated the performance trade‐offs of fleas (Siphonaptera) while adapting to a novel host using two host generalists (Xenopsylla conformis and Xenopsylla ramesis) and one host specialist (Parapulex chephrenis) maintained on their principal hosts (Meriones crassus for Xenopsylla and Acomys cahirinus for P. chephrenis). We asked whether, over generations, (i) a host generalist may become a specialist by evolving the ability to exploit a novel host and losing the ability to exploit an original host and (ii) a host specialist can become a generalist by evolving the ability to exploit a novel host without losing the ability to exploit an original host. We established an experimental line of each species on a novel host (Acomys russatus for Xenopsylla and M. crassus for P. chephrenis) and maintained this line on this host during 23 generations. We compared reproductive performance of progenitors of each line and their descendants when they exploited either original or novel host in terms of egg number and size, hatching success, offspring production, and offspring size. We found changes in performance over generations in female offspring size only. Xenopsylla conformis demonstrated a tendency to become a host specialist (increased performance on the novel host with a concomitant decreased performance on the original host), whereas P. chephrenis demonstrated a tendency to become a host generalist (increased performance on the novel host without a concomitant decreased performance on the original host). We conclude that the probability of generalist to specialist transition, and vice versa, is context‐dependent and varies between species.
Impact of contraceptive hormones on the reproductive potential of male and female commensal black rats (Rattus rattus)
Authors: SELEMANI Mwajabu , MAKUNDI Rhodes H. , MASSAWE Apia W. , MHAMPHI Ginethon , MULUNGU Loth S. , BELMAIN Steven R.
Published: May 2021

The black rat is considered one of the world's top pests. With increased restrictions on rodenticides, new alternatives to manage rats are urgently needed. Research on the use of contraceptive hormones, levonorgestrel (LE), and quinestrol (QU), have been evaluated against some rodent species, and this research is the first study to assess these on black rats. Hormones were incorporated into rodent bait at 10 and 50 ppm concentrations singly and in combination (EP‐1). Groups of 10 animals of each sex were fed the baits over 7 days. Lower bait consumption was observed with slight body mass reductions. On dissection, it was observed that the uterus was in a state of edema and male reproductive organs weighed less with reduced sperm counts/motility. The 2 most promising baits, 50 ppm QU and EP‐1, were used to assess impact on pregnancy and litter size. Pregnancy was reduced from 70% success when both males and females consumed untreated bait, down to 30% when males had consumed contraceptive bait but females had not, and down to 0% when females had consumed contraceptive bait, regardless of whether they had paired with a treated or untreated male. Litter size in the untreated pairs was 8 pups, but only 4 pups in those cases where the male only had consumed the contraceptive. Further studies should investigate how long the effect lasts and its reversibility. Field studies at the population level may also shed light on the practicality of using contraceptive baits for black rats in different habitats.
Firm Unionization and Disruptions in Customer Relationships*
Authors: Chen Gary , Judd J. Scott , Pandit Shailendra (Shail)
Published: May 2021

Relationships with major customers may be advantageous to suppliers due to economies of scale and reputational benefits. In this study, we investigate whether unionization leads to disruptions in a firm's relationships with its customers. Our goal is to provide insights regarding the impact unionization has on a firm's sales relationships with its major customers. We predict that major customers will shift purchases away from suppliers that unionize to avoid potential disruptions. Using a difference‐in‐differences research design, our results show a negative association between supplier unionization and sales to major customers. Our findings are robust to addressing endogeneity concerns through a propensity score matched analysis and regression discontinuity research design. In addition, we find that supplier firm performance declines subsequent to unionization. We also find that suppliers experience significant increases in their cost of goods sold and the number of employees after supplier unionization, suggestive of higher input prices driving the disruption with major customers. Finally, we provide evidence that higher switching costs mitigate the decline in sales to major customers. Overall, our findings suggest that employee unionization can adversely affect a firm's relationships with their major customers.
Tainiasoma gen. nov. (Coleoptera: Salpingidae), a new genus from the Australo‐Pacific region inhabiting palm fronds, with description of the Australian species Tainiasoma palmarum sp. nov. and its larva
Authors: Lawrence John F , Slipinski Adam , Escalona Hermes E
Published: May 2021

The Australo‐Pacific genus Tainiasoma gen. nov. and the north‐eastern Queensland species Tainiasoma palmarum sp. nov. adult and larva are described and illustrated. Tainiasoma palmarum inhabits the rachises of dead palms (Arecaceae), including the Australian fan palm Licuala ramsayi F. Muell. and the Black Palm Normanbya normanbyi (W. Hill) L. H. Bailey. The relationship of the new genus to other members of the family Salpingidae is briefly discussed.
Comparison of morphology and genetic diversity between broodstock and hybrid offspring of oriental river prawn, Macrobrachium nipponense based on morphological analysis and SNP markers
Authors: Li Yiming , Fan Wujiang , Huang Yinying , Huang Yingying , Du Xinglin , Liu Zhiquan , Huang Youhui , Zhao Yunlong
Published: May 2021

Hybridization is an effective method for the genetic improvement of farmed species. In this study, three broodstock populations (Changjiang, CJ, Dongting, DT, and Dianshan, DS) of oriental river prawn, Macrobrachium nipponense were used, and DS was used as the female broodstock. Through three‐line hybridization, two hybrid populations were finally obtained. The F3 generation of the broodstock population and the F1 generation of the hybrid population were cultured indoors for 3 months. Through morphological analysis (cluster analysis, discriminant analysis and path analysis) it was found that the hybrid population and the broodstock had some differences, but not enough to reach the subspecies level, and the dominant traits exhibited differentiation and reorganization. This study identified SNP genetic markers, carried out systematic evolution analysis and genetic diversity analysis and found that the nucleotide diversity π and heterozygosity Het of the hybrid population were higher than those of the broodstock. Among broodstocks, the differentiation index (Fst) of SCD and SDC was smallest (0.055). This research provides some valuable reference for genetic breeding.
Take the T out, put the T in: Gender‐affirming hormones in youth
Authors: Ehrensaft Diane , Tishelman Amy C.
Published: May 2021

Background

An increasing number of adolescents are seeking gender care at clinics and hospital programs, and requesting gender‐affirming hormonal treatment. The interventions can either include suppression of testosterone and introduction of estrogen, or suppression of estrogen and introduction of testosterone.

Aims

This review article focuses on the psychosocial experiences of youth who have completed their endogenous puberty and are now requesting one of these two forms of gender‐affirming hormonal treatment. We investigate the comparative profiles of these two subgroups of transgender/gender‐expansive youth.

Materials and Methods

Review of research data, established standards of care and practice guidelines, and clinical observations.

Results

Differences and similarities are noted and discussed in several realms: gender‐related experiences prior to receiving hormonal treatment; the relationship between the physical changes and psychological experiences that accompany the introduction of testosterone or suppression of testosterone with replacement with estrogen; the intrapersonal and interpersonal implications of the treatment; considerations of fertility preservation for future family building; the role of the family in the decision‐making process prior to starting a course of hormone therapy; and the capacity of youth to make informed decisions about these partially irreversible medical interventions.

Discussion

Medical providers who offer gender‐affirming hormonal care to youth should work with the family and allied professionals to assure that the youth's gender health is enhanced, barriers to care are removed, and mental health risks are reduced, whether the T is coming out or going in.

Conclusion

The cohort of youth who come to medical providers after completing puberty, and request gender‐affirming hormones in the form of increases or reductions in T have a great deal in common, and also extensive variation among them.
Vitamin A deficiency in K14E7HPV expressing transgenic mice facilitates the formation of malignant cervical lesions
Authors: Ocadiz‐Delgado Rodolfo , Serafin‐Higuera Nicolás , Alvarez‐Rios Elizabeth , García‐Villa Enrique , Tinajero‐Rodríguez Manuel , Rodríguez‐Uribe Genaro , Escobar‐Wilches Derly‐Constanza , Estela Albino‐Sánchez Marta , Ramírez‐Rosas Alejandro , Sierra‐Santoyo Adolfo , Hernández‐Pando Rogelio , Lambert Paul , Gariglio Patricio
Published: May 2021

Infection with high‐risk human papillomavirus (HR‐HPV) is the main cause of cervical cancer (CC), but viral infection alone does not guarantee the development of this malignancy. Indeed, deficiencies of dietary micronutrients could favor cervical cancer development in individuals that harbor HR‐HPV infections. The status of retinoid levels, natural and synthetic derivatives of vitamin A, is important in maintaining cellular differentiation of the cervical epithelium. Moreover, many studies show a link between deficient intake of retinoids or alteration of the retinoid receptors and CC development. In spite of this, the effect of vitamin A deficiency (VAD) in presence of HR‐HPV oncoproteins on cervical carcinogenesis in vivo has not been reported. Transgenic mice expressing E6 or E7 oncoproteins (K14E6 or K14E7 mice, respectively) were used to evaluate the possible role of VAD in the development of malignant cervical lesions. The survival of the mice in VAD condition was studied, and histopathological analysis and immunohistochemical detection of molecular cancer markers such as the tumor suppressor retinoic acid receptor beta (RARβ), proliferating cell nuclear antigen (PCNA), cleaved caspase 3, and the tumor suppressor protein p16INK4A (inhibitor of CDK4) were performed. Our results show that K14E6/VAD mice showed moderate cervical dysplasia; notably, K14E7/VAD mice developed severe cervical dysplasia and cervical in situ carcinoma at an early age. VAD synergizes with HPV16E7 oncoprotein expression favoring cervical carcinogenesis in vivo.
Protein supplementation to early lactation dairy cows grazing tropical grass: Performance and ruminal metabolism
Authors: Jado Chagas Lucas , Delveaux Araujo Batalha Camila , de Arruda Camargo Danés Marina , Maurício Santos Neto José , Lopes Macedo Fernanda , da Silva Marques Rodrigo , Augusto Portela Santos Flávio
Published: May 2021

This experiment was designed to evaluate the effects of different concentrate crude protein (CP) concentration on performance, metabolism and efficiency of N utilization (ENU) on early‐lactation dairy cows grazing intensively managed tropical grass. Thirty cows were used in a ten replicated 3 × 3 Latin square design. The treatments consisted of three levels of concentrate CP: 7.9%, 15.4%, and 20.5% offered at a rate of 1 kg (as‐fed basis)/3 kg of milk. The cows fed low and medium CP had negative balance of rumen degradable protein and metabolizable protein. Increasing CP tended to linearly increase DMI, 3.5% FCM and milk casein, and linearly increased the yields of milk fat and protein. Increasing CP linearly increased the intake of N, the concentration of rumen NH3–N, and the losses of N in milk, urine, and feces. Increasing dietary CP linearly increased the molar proportion of butyrate but had no effect on the other rumen VFAs and no effect on microbial yield. In conclusion, feeding a concentrate with 20.5% of CP to early‐lactation dairy cows grazing tropical grasses, leading to a 17.8% CP diet, tended to increase DMI, increased the yield of 3.5% FCM and the milk N excretion, and decreased ENU by 32%.
First‐in‐human trial to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of STR‐324, a dual enkephalinase inhibitor for pain management
Authors: Moss Laurence M. , Berends Cecile L. , van Brummelen Emilie M. J. , Kamerling Ingrid M. C. , Klaassen Erica S. , Bergmann Kirsten , Ville Vanessa , Juarez‐Perez Victor , Benichou Annie‐Claude , Groeneveld Geert Jan
Published: May 2021

Aim

Dual enkephalinase inhibitors (DENKIs) are involved in the regulation of nociception via opioid receptors. The novel compound STR‐324 belongs to the DENKI pharmacological class. This first‐in‐human study evaluated the safety, tolerability, pharmacokinetics and pharmacodynamics of STR‐324 in healthy male participants.

Methods

This was a randomised, double‐blind, placebo‐controlled ascending dosing study in two parts: in part 1, 30 participants received 0.004‐11.475 mg h−1 of STR‐324 or placebo (ratio 4:1) by 4 h intravenous infusion in a two‐group, partial crossover design with four treatment periods separated by 1 month wash‐out, and in part 2, 48 participants divided into three groups received either the active drug (1.25‐11.25 mg h−1) or placebo (ratio 3:1) by 48 h intravenous infusion. Safety and tolerability parameters, pharmacokinetics and pharmacodynamic effects on neurocognitive and neurophysiological tasks and on a nociceptive test battery were evaluated.

Results

No clinically relevant changes in safety parameters were observed. All treatment‐emergent adverse events were mild and transient. The pharmacokinetics of STR‐324 could not be determined due to most concentrations being below quantifiable limits. STR‐324 metabolite concentrations were measurable, showing dose proportionality of Cmax and AUCinf with an estimated t1/2 of 0.2‐0.5 h. Significant changes in pharmacodynamic parameters were observed, but these were not consistent or dose‐dependent.

Conclusion

STR‐324 displayed favourable safety and tolerability profiles at all doses up to 11.475 mg h−1. Although pharmacokinetic characterisation of STR‐324 was limited, dose proportionality could be assumed based on major metabolite data assayed as proxy. No clear effects on nociceptive thresholds or other pharmacodynamic measures were observed.

Trial registry: EudraCT (2014‐002402‐21) and toetsingonline.nl (63085).