bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractUnderstanding 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

Abstract

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

Abstract

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

AbstractCarboxylesterases (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

AbstractWe 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

AbstractThe 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

ABSTRACTRelationships 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

AbstractThe 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

SummaryHybridization 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

AbstractBackgroundAn 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.AimsThis 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 MethodsReview of research data, established standards of care and practice guidelines, and clinical observations.ResultsDifferences 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.DiscussionMedical 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.ConclusionThe 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

AbstractInfection 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

AbstractThis 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

AimDual 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.MethodsThis 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.ResultsNo 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.ConclusionSTR‐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).