bluuebunny/crossref_metadata_2025_split huggingface dataset:
The value of considering demographic contributions to connectivity: a review
Authors: Drake Joseph , Lambin Xavier , Sutherland Chris 
Published: June 2021

Connectivity is a central concept in ecology, wildlife management, and conservation science. Understanding the role of connectivity in determining species persistence is increasingly important in the face of escalating anthropogenic impacts on climate and habitat. These connectivity augmenting processes can severely impact species distributions and community and ecosystem functioning.One general definition of connectivity is that it is an emergent process arising from a set of spatial interdependencies between individuals or populations, and increasingly realistic representations of connectivity are being sought. Generally, connectivity consists of a structural component, relating to the distribution of suitable and unsuitable habitat, and a functional component, relating to movement behavior, yet the interaction of both components often better describes ecological processes. Additionally, although implied by ‘movement', demographic measures such as the occurrence or abundance of organisms are regularly overlooked when quantifying connectivity. Integrating such demographic contributions based on the knowledge of species distribution patterns is critical to understanding the dynamics of spatially structured populations.Demographically‐informed connectivity draws from fundamental concepts in metapopulation ecology while maintaining important conceptual developments from landscape ecology, and the methodological development of spatially‐explicit hierarchical statistical models that have the potential to overcome modeling and data challenges. Together, this offers a promising framework for developing ecologically realistic connectivity metrics.This review synthesizes existing approaches for quantifying connectivity and advocates for demographically‐informed connectivity as a general framework for addressing current problems across ecological fields reliant on connectivity‐driven processes such as population ecology, conservation biology and landscape ecology. Using supporting simulations to highlight the consequences of commonly made assumptions that overlook important demographic contributions, we show that even small amounts of demographic information can greatly improve model performance. Ultimately, we argue demographic measures are central to extending the concept of connectivity and resolves long‐standing challenges associated with accurately quantifying the influence of connectivity on fundamental ecological processes.
Differences in Social Media Monitoring Practices Based on Child and Parent Gender
Authors: Wallace Lacey N. 
Published: June 2021

ObjectiveThis study investigated two research questions. First, how do parents monitor and regulate adolescent use of social media? Second, how do parental monitoring practices vary by adolescent and parent gender?BackgroundSmart phones and Internet access are nearly universal among U.S. adolescents, yet most past research on online parental monitoring examined Internet use generally without a focus on social media.MethodData were obtained in 2019 with a web survey with items addressing parent and adolescent use of social media, parental monitoring of social media use, and parents' perceptions of the impact of social media on adolescents. Respondents were a state‐representative sample of 389 Pennsylvania parents with an adolescent aged 12 to 17 years in their household.ResultsMothers more frequently talked with their adolescent children about social media than fathers, and mothers were more likely to report consequences for breaking household rules about social media use. Mothers used more intrusive monitoring strategies than fathers. Parents were more likely to ask daughters about social media use than sons. Parents monitored social media use of opposite gender adolescents less frequently.ConclusionsResults suggest strong differences in social media monitoring by parent and adolescent gender but in directions that do not necessarily align with the parental monitoring literature more broadly. Heavy use of more intrusive practices in the sample may indicate problems with trust or parental concern with adolescent self‐disclosure.
Blockholder exit threats and corporate cash holdings
Authors: Sun Lingna , Phan Hieu V. , Simpson Thuy 
Published: June 2021

AbstractWe investigate the effects of blockholder exit threats, which increase with stock liquidity, on corporate cash holdings and the value of cash to shareholders. Exploiting decimalization as an exogenous shock to stock liquidity to identify the effects of blockholder exit threats, we find robust evidence that blockholder exit threats have a negative effect on corporate cash holdings and a positive effect on the value of cash to shareholders. Further analysis indicates that exit threat induces firms to increase stock repurchases and improve investment efficiency. Our evidence is consistent with the view that blockholder exit threats are an effective corporate governance mechanism.
Constraints on potential enzyme activities in thermokarst bogs: Implications for the carbon balance of peatlands following thaw
Authors: Heffernan Liam , Jassey Vincent E. J. , Frederickson Maya , MacKenzie M. Derek , Olefeldt David 
Published: June 2021

AbstractNorthern peatlands store a globally significant amount of soil organic carbon, much of it found in rapidly thawing permafrost. Permafrost thaw in peatlands often leads to the development and expansion of thermokarst bogs, where microbial activity will determine the stability of the carbon storage and the release of greenhouse gases. In this study, we compared potential enzyme activities between young (thawed ~30 years ago) and mature (~200 years) thermokarst bogs, for both shallow and deep peat layers. We found very low potential enzyme activities in deep peat layers, with no differences between the young and mature bogs. Peat quality at depth was found to be highly humified (FTIR analysis) in both the young and mature bogs. This suggests that deep, old peat was largely stable following permafrost thaw, without a rapid pulse of decomposition during the young bog stage. For near‐surface peat, we found significantly higher potential enzyme activities in the young bog than in the mature—associated with differences in peat quality derived from differentSphagnumspecies. A laboratory incubation of near‐surface peat showed that differences in potential enzyme activity were primarily influenced by peat type rather than oxygen availability. This suggested that the young bog can have higher rates of near‐surface decomposition despite being substantially wetter than the mature bog. Overall, our study shows that peat properties are the dominant constraint on potential enzyme activity and that peatland site development (successional pathways and permafrost history) through its influence on peat type and chemistry is likely to determine peat decomposition following permafrost thaw.
Small artificial waterbodies are widespread and persistent emitters of methane and carbon dioxide
Authors: Peacock M. , Audet J. , Bastviken D. , Cook S. , Evans C. D. , Grinham A. , Holgerson M. A. , Högbom L. , Pickard A. E. , Zieliński P. , Futter M. N. 
Published: June 2021

AbstractInland waters play an active role in the global carbon cycle and emit large volumes of the greenhouse gases (GHGs), methane (CH4) and carbon dioxide (CO2). A considerable body of research has improved emissions estimates from lakes, reservoirs and rivers but recent attention has been drawn to the importance of small, artificial waterbodies as poorly quantified but potentially important emission hotspots. Of particular interest are emissions from drainage ditches and constructed ponds. These waterbody types are prevalent in many landscapes and their cumulative surface areas can be substantial. Furthermore, GHG emissions from constructed waterbodies are anthropogenic in origin and form part of national emissions reporting, whereas emissions from natural waterbodies do not (according to Intergovernmental Panel on Climate Change guidelines). Here, we present GHG data from two complementary studies covering a range of land uses. In the first, we measured emissions from nine ponds and seven ditches over a full year. Annual emissions varied considerably: 0.1–44.3 g CH4 m−2 year−1 and −36–4421 g CO2 m−2 year−1. In the second, we measured GHG concentrations in 96 ponds and 64 ditches across seven countries, covering subtropical, temperate and sub‐arctic biomes. When CH4 emissions were converted to CO2 equivalents, 93% of waterbodies were GHG sources. In both studies, GHGs were positively related to nutrient status (C, N, P), and pond GHG concentrations were highest in smallest waterbodies. Ditch and pond emissions were larger per unit area when compared to equivalent natural systems (streams, natural ponds). We show that GHG emissions from natural systems should not be used as proxies for those from artificial waterbodies, and that artificial waterbodies have the potential to make a substantial but largely unquantified contribution to emissions from the Agriculture, Forestry and Other Land Use sector, and the global carbon cycle.
A transnational lens into international student experiences of the COVID‐19 pandemic
Authors: Hari Amrita , Nardon Luciara , Zhang Hui 
Published: June 2021

AbstractWe analyse the experiences of international students living in Canada during the COVID‐19 pandemic through the lens of transnationalism that understands mobility as broadly uninterrupted, continuing and taken‐for‐granted, and international student migration (ISM) literature. With the onset of the COVID‐19 pandemic, people had to contend with sudden border closures and stringent restrictions on all forms of travel. International students are regarded as the archetypal trans‐migrants with frequent mobility and often multiple attachments to place. We interrogate these assumptions of mobility by drawing on interview data from 13 international students in Ontario from April to June of 2020. We found that international students experienced the pandemic transnationally and faced increased challenges, which heightened their reliance on support from transnational families, and generated anxieties about their future career and mobilities. We bring transnational theories into conversation with ISM literature to better understand international students’ lived experiences in Canada during a pandemic.
PD‐1‐induced proliferating T cells exhibit a distinct transcriptional signature
Authors: Strazza Marianne , Bukhari Shoiab , Tocheva Anna S. , Mor Adam 
Published: June 2021

SummaryLigation of the inhibitory receptor PD‐1 on T cells results in the inhibition of numerous cellular functions. Despite the overtly inhibitory outcome of PD‐1 signalling, there are additionally a collection of functions that are activated. We have observed that CD4+T cells stimulated through the T‐cell receptor and PD‐1 primarily do not proliferate; however, there is a population of cells that proliferates more than T‐cell receptor stimulation alone. These highly proliferating cells could potentially be associated with PD‐1‐blockade unresponsiveness in patients. In this study, we have performed RNA sequencing and found that following PD‐1 ligation proliferating and non‐proliferating T cells have distinct transcriptional signatures. Remarkably, the proliferating cells showed an enrichment of genes associated with an activated state despite PD‐1 signalling. Additionally, circulating follicular helper T cells were significantly more prevalent in the non‐proliferating population, demonstrated by enrichment of the associated genesCXCR5,CCR7,TCF7,BCL6andPRDM1and validated at the protein level. Translationally, we also show that there are more follicular helper T cells in patients that respond favourably to PD‐1 blockade. Overall, the presence of transcriptionally and functionally distinct T cell populations responsive to PD‐1 ligation may provide insights into the clinical differences observed following therapeutic PD‐1 blockade.
Junior high school students’ readiness to participate in e‐learning and online EFL classes during the COVID‐19 pandemic
Authors: Mabrur Iskhaki Andre Muhammad , Suwartono Tono ,   Lutfiana
Published: June 2021

AbstractMore and more educational institutions have to replace face‐to‐face classes with online learning classes or e‐learning due to the spread of coronavirus (COVID‐19). To create efficient online learning experiences, students’ readiness and willingness to join e‐learning activities must be considered. A few aspects to consider are how accessible online learning technology is to the participants, their proficiency in using e‐learning devices, and their motivation in joining online learning, especially online EFL classes. Therefore, this study attempted to understand those aspects of online learning by gathering survey feedback from a group of students. The survey participants were seventh‐grade students of Muhammadiyah 2 Junior High School of Purwokerto, Indonesia. Data were collected using a five‐point Likert scale questionnaire. The results of the survey would be analysed to find out frequencies, means, and standard deviations. The results have concluded that, despite significant positive feedback regarding the students’ readiness and motivation for joining e‐learning classes and online EFL learning, there were still a number of students who were unsure of their readiness in joining such activities. Therefore, it is suggested that further effort is made to make online learning more accessible to more students.
Microanatomy of the myocardial extensions of the pulmonary valve in light of modern catheter ablation methodology
Authors: Lis Maciej , Solewski Bernard , Chrzanowski Jan , Dudkiewicz Damian , Strona Marcin , Jasińska Katarzyna A. , Wiater Jerzy , Wartalski Kamil , Lis Grzegorz J. , Hołda Mateusz K. 
Published: June 2021

AbstractIntroductionThe muscular sleeves (or myocardial extensions) derived from the right ventricle infundibulum myocardium are considered the true anatomic substrate for right ventricular outflow tract arrhythmias.MethodsPulmonary valve specimens obtained from 65 donors (24.6% females, mean age 45.9 ± 15.8 years) were investigated micro‐anatomically. Specimens were histologically processed, stained with Masson's Trichrome, and examined under a light microscope.ResultsThe myocardial extensions were present in the left anterior pulmonary valve sinus in 86.2% of cases, in the right anterior sinus in 89.2% of cases and in 90.7% of cases in the posterior sinus (p = .699). In 69.2% of examined hearts, the myocardial extensions were present in all sinuses. The mean height of the extensions was 4.12 ± 1.76 (left anterior) versus 3.69 ± 1.47 (right anterior) versus 4.28 ± 1.73 mm (posterior) (p = .137). The myocardial extensions occupied an average of 28.9 ± 10.4% of the left anterior sinus, 26.7 ± 11.2% of the right anterior sinus, and 31.9 ± 11.3% of the posterior sinus (p = .044). Sleeves extending beyond the fibro‐arterial transition zone were present in at least one sinus in 33.8% of hearts (in 7.7% (5/65) of the left and right anterior sinuses and 21.5% (14/65) of posterior sinus, p = .021).ConclusionsThe myocardial extensions of the pulmonary valve are common anatomical entities. Although the length of the myocardial sleeves is similar in all pulmonary valve sinuses, their relative extent is greatest in the posterior sinus. Long sleeves that spread beyond the fibro‐arterial transition zone were observed in one‐third of hearts, predominantly in the posterior sinus. Myocardial and fibrous tissue layer thicknesses varied considerably.
The humeral head: A review of the blood supply and possible link to osteonecrosis following rotator cuff repair
Authors: Keough Natalie , Lorke Dietrich E. 
Published: June 2021

AbstractTrauma, corticosteroid therapy and metabolic diseases are well established aetiologies of humeral head osteonecrosis; however, there is increasing evidence that arthroscopic rotator cuff surgery may be another possible cause. One of the reasons is that there may be inadvertent damage to the arterial blood supply to the humeral head during surgical intervention. The blood supply to the humeral head displays large amounts of variation with regard to origin, course and distribution. Therefore, to shed light on the pathogenesis, the blood supply of the humeral head is reviewed together with a summary of all reported cases of osteonecrosis of the humeral head that occurred following rotator cuff repair. Inconsistencies with regard to terminologies used and contradictions concerning arterial contributions from the anterior circumflex humeral artery and the posterior circumflex humeral artery towards humeral head supply are addressed. Moreover, variations in the course of the anterior circumflex humeral artery and its branches are summarized. The vascular anatomy of the humeral head is clinically relevant due to the close relationship of these blood vessels with the surgical repair sites for rotator cuff surgery and biceps tenotomies or tenodesis procedures. Potential sites of disruption of blood supply following arthroscopic rotator cuff surgery are discussed. Detailed knowledge of the course of the arteries supplying the humeral head may help to minimize the risk of vascular injury and subsequent osteonecrosis. Given the great interindividual variations of vascular anatomy, imaging procedures preceding arthroscopic rotator cuff surgery may be advisable.
Liberal parentalism
Authors: Heifetz Aviad , Minelli Enrico , Polemarchakis Herakles 
Published: June 2021

AbstractWhat normative constraints should bind parents (or policy makers) if they intervene in the choices of children (or constituencies) whose preferences evolve over time? For a sophisticated child who anticipates correctly his preference change, we prove that generically there exist parental interventions that are Pareto improving over the backward induction path that the child will follow on his own. If, in contrast, the child misperceives his future preferences, Pareto improving interventions might not exist, and even nudges might be painfully sobering. The parent may then choose to minimize the maximal disappointment along time that her benevolent intervention would cause.
The role of seasonality in reproduction of multiannual delayed gametophytes ofSaccharina latissima
Authors: Ebbing Alexander P. J. , Pierik Ronald , Fivash Gregory S. , van de Loosdrecht Nienke C. J. , Bouma Tjeerd J. , Kromkamp Jacco C. , Timmermans Klaas 
Published: June 2021

Delayed gametophytes are able to grow vegetatively for prolonged periods of time. As such, they are potentially very valuable for kelp aquaculture given their great promise in opening up novel opportunities for kelp breeding and farming. However, large‐scale application would require more in‐depth understanding of how to control reproduction in delayed gametophytes. For newly formed gametophytes, many environmental factors for reproduction have been identified, with key drivers being light intensity, temperature, and the initial gametophyte density. However, the question of whether delayed gametophytes react similarly to these life cycle controls remains open for exploration. In this study, we performed a full factorial experiment on the influences of light intensity, temperature, and density on the reproduction of multiannual delayed gametophytes ofSaccharina latissima, during which the number of sporophytes formed was counted. We demonstrate that delayed gametophytes ofS. latissimacan reliably reproduce sexually after more than a year of vegetative growth, depending on the effects between light intensity and temperature. Under higher light intensities (≥29 µmol photons · m−2· s−1), optimal reproduction was observed at lower temperatures (10.2°C), while at lower light intensities (≤15 µmol photons · m−2· s−1), optimal reproduction was observed at higher temperatures (≥12.6°C). Given the seasonal lag between solar radiation and sea surface temperature in natural systems, these conditions resemble those found during spring (i.e., increasing light intensity with low temperatures) and autumn (i.e., decreasing light intensity with higher temperatures). Seasonality can be used as an aquaculture tool to better control the reproduction of delayed gametophytes.
How sexual differences affect locomotor performance and metabolism of the Sword Snake: An integrated view from energetics
Authors: Lima‐Santos J. , Carvalho J. E. , Brasileiro C. A. 
Published: June 2021

AbstractIn snakes, behavioral differences between sex and body size can positively influence locomotor performance and metabolic rate. Evidence suggests that larger body size can positively influence the locomotor performance of snakes and affect the metabolic rate of individuals. However, the influence of sexual variation on locomotor performance may not be entirely explained by the variation in body morphology, but also by sexual behavior. Herein, we investigated the locomotor performance, resting metabolic rate, and enzyme activities in the biochemical metabolic pathways of the sexually dimorphic snake Tomodon dorsatus. We used 20 females and 14 males to measure the sprint speed as a proxy for locomotor performance and oxygen consumption to assess the metabolic rate. We also measured the maximum activity of the enzymes: lactate dehydrogenase and citrate synthase in the intercostal skeletal muscle, liver, and heart. Individual snout–vent length was related to tail length, body mass, and sex but was not with the maturity. Males of T. dorsatus are faster than females, and sprint speed and oxygen consumption were found to not be correlated. Males also had higher metabolic rate, while enzyme activities were similar in males and females. These results contributed to understanding the sexual variation in the reproductive behavior of T. dorsatus. Although the results on locomotor performance do not support the hypothesis that locomotion in the species is favored by sexual dimorphism, the increased locomotor performance in males can be explained by courtship behavior. On the other hand, sexual dimorphism and smaller body size can explain the increased metabolic rates in males.
Spectroscopy outperforms leaf trait relationships for predicting photosynthetic capacity across different forest types
Authors: Yan Zhengbing , Guo Zhengfei , Serbin Shawn P. , Song Guangqin , Zhao Yingyi , Chen Yang , Wu Shengbiao , Wang Jing , Wang Xin , Li Jing , Wang Bin , Wu Yuntao , Su Yanjun , Wang Han , Rogers Alistair , Liu Lingli , Wu Jin 
Published: June 2021

Summary

Leaf trait relationships are widely used to predict ecosystem function in terrestrial biosphere models (TBMs), in which leaf maximum carboxylation capacity (Vc,max), an important trait for modelling photosynthesis, can be inferred from other easier‐to‐measure traits. However, whether trait–Vc,max relationships are robust across different forest types remains unclear.

Here we used measurements of leaf traits, including one morphological trait (leaf mass per area), three biochemical traits (leaf water content, area‐based leaf nitrogen content, and leaf chlorophyll content), one physiological trait (Vc,max), as well as leaf reflectance spectra, and explored their relationships within and across three contrasting forest types in China.

We found weak and forest type‐specific relationships between Vc,max and the four morphological and biochemical traits (R2 ≤ 0.15), indicated by significantly changing slopes and intercepts across forest types. By contrast, reflectance spectroscopy effectively collapsed the differences in the trait–Vc,max relationships across three forest biomes into a single robust model for Vc,max (R2 = 0.77), and also accurately estimated the four traits (R2 = 0.75–0.94).

These findings challenge the traditional use of the empirical trait–Vc,max relationships in TBMs for estimating terrestrial plant photosynthesis, but also highlight spectroscopy as an efficient alternative for characterising Vc,max and multitrait variability, with critical insights into ecosystem modelling and functional trait ecology.