bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detecting wildlife poaching: a rigorous method for comparing patrol strategies using an experimental design
Authors: van Doormaal Nick , Lemieux A. M. , Ruiter Stijn , Allin Paul M. R. R. , Spencer Craig R. 
Published: June 2021

AbstractMany studies of wildlife poaching acknowledge the challenges of detecting poaching activities, but few address the issue. Data on poaching may be an inaccurate reflection of the true spatial distribution of events because of low detection rates. The deployment of conservation and law enforcement resources based on biased data could be ineffective or lead to unintended outcomes. Here, we present a rigorous method for estimating the probabilities of detecting poaching and for evaluating different patrol strategies. We illustrate the method with a case study in which imitation snares were set in a private nature reserve in South Africa. By using an experimental design with a known spatial distribution of imitation snares, we estimated the detection probability of the current patrol strategy used in the reserve and compared it to three alternative patrol strategies: spatially focused patrols, patrols with independent observers, and systematic search patterns. Although detection probabilities were generally low, the highest proportion of imitation snares was detected with systematic search strategies. Our study provides baseline data on the probability of detecting snares used for poaching, and presents a method that can be modified for use in other regions and for other types of wildlife poaching.
Classifications at Work: Social Categories and Dutch Bureaucracy in Colonial Sri Lanka
Authors: Lyna Dries , Bulten Luc 
Published: June 2021

AbstractFeeding into current debates on ethnic identities in colonial South Asia, this article questions to what extent Dutch institutions articulated and impacted social categories of people living in coastal Sri Lanka during the eighteenth century. A thorough analysis of three spheres of Dutch bureaucracy (reporting, registering, and litigating) makes it clear that there was no uniform ideology that steered categorisation practices top-down throughout the studied colonial institutions. Rather, the rationale of the organisation as such affected the way people were classified, depending to a large extent on what level of bureaucracy individuals were dealing with, and what the possible negotiation strategies were for the people recorded. Future research should perhaps not ask “when” certain ethnicities were “made up,” but strive to understand the process in which they were created, the institutional contexts in which they were recorded, and how changing bureaucratic practices not only articulated, but also transformed, social categories in the long run.
Does the Presence of On-Site Medical Services at Outdoor Music Festivals Affect Attendees’ Planned Alcohol and Recreational Drug Use?
Authors: Hutton Alison , Munn Matthew Brendan , White Sydney , Kara Peter , Ranse Jamie 
Published: June 2021

AbstractBackground:Dedicated on-site medical services have long been recommended to improve health outcomes at mass-gathering events (MGEs). In many countries, they are being reviewed as a mandatory requirement. While it is known that perceptions of risk shape substance use plans amongst outdoor music festival (OMF) attendees, it is unclear if attendees perceive the presence of on-site medical services as a part of the safety net. The aim of this paper is to better understand whether attendees’ perceptions of on-site medical services influence high-risk behaviors like alcohol and recreational drug use at OMFs.Method:A questionnaire was distributed to a random sample of attendees entering and attending two separate 20,000-person OMFs; one in Canada (Festival A) and one in New Zealand (Festival B). Responses focused on demographics, planned alcohol and recreational drug use, perceptions of medical services, and whether the absence of medical services would impact attendees’ planned substance use.Results:A total of 851 (587 and 264 attendees for Festival A and Festival B, respectively) attendees consented and participated. Gender distribution was equal and average ages were 23 to 25. At Festival A, 48% and 89% planned to use alcohol and recreational drugs, respectively, whereas at Festival B, it was 92% and 44%. A great majority were aware and supportive of the presence of medical services at both festivals, and a moderate number considered them a factor in attendance and something they would not attend without. There was significant (>10%) agreement (range 11%-46%; or 2,200-9,200 attendees for a 20,000-person festival) at both festivals that the absence of medical services would affect attendees’ planned use of alcohol and recreational drugs.Conclusions:This study found that attendees surveyed at two geographically and musically distinct OMFs had high but differing rates of planned alcohol and recreational drug use, and that the presence of on-site medical services may impact attendees’ perceptions of substance use risk. Future research will aim to address the limitations of this study to clarify these findings and their implications.
Impact of Fracture Geometry and Topology on the Connectivity and Flow Properties of Stochastic Fracture Networks
Authors: Zhu Weiwei , Khirevich Siarhei , Patzek Tad W. 
Published: June 2021

AbstractIn a low permeability formation, connectivity of natural and induced fractures determines overall hydraulic diffusivity in fluid flow through this formation and defines effective rock permeability. Efficient evaluation of fracture connectivity is a nontrivial task. Here, we utilize a topological concept of global efficiency to evaluate this connectivity. We address the impact of key geometrical properties of stochastic fracture networks (fracture lengths, orientations, apertures, and positions of fracture centers) on the macro‐scale flow properties of a shale‐like formation. Six thousand different realizations have been generated to characterize these properties for each fracture network. We find that a reduced graph of a fracture network, which consists of the shortest paths from the inlet nodes (fractures) to all outlet nodes, contributes most to fluid flow. Three‐dimensional (3D) fracture networks usually have higher global efficiency than two‐dimensional (2D) ones, because they have better connectivity. All geometrical properties of fractures influence quality of their connectivity. Aperture distribution impacts strongly global efficiency of a fracture network and its influence is more significant when the system is dominated by large fractures. Fracture clustering lowers global efficiency in both 2D and 3D fracture networks. Global efficiency of 2D and 3D fracture networks also decreases with the increasing exponent of the power‐law distribution of fracture lengths, which means that the connectivity of the system decreases with an increasing number of small fractures. Realistic fracture networks, composed of several sets of fractures with constrained preferred orientations, share all the characteristics of the stochastic fracture networks we have investigated.
Characteristics of Resonant Electrons Interacting With Whistler Waves in the Nearest Dipolarizing Magnetotail
Authors: Malykhin A. Y. , Grigorenko E. E. , Shklyar D. R. , Panov E. V. , Le Contel O. , Avanov L. , Giles B. 
Published: June 2021

AbstractThe Magnetospheric Multiscale spacecraft observations in the burst mode allow the determination of the characteristics of resonant electrons interacting with quasi‐parallel whistler waves during prolonged dipolarizations in the near Earth magnetotail at −22 RE < X ≤ −8 RE. We have detected 163 whistler bursts observed during 48 dipolarization events. The bursts were registered within ∼13 min following the dipolarization onset when the burst mode observations were available. In the majority of events, electrons with energies Wres ≥ 10 keV and pitch angles αres ∼ 100°–130° and αres ∼ 50°–80°made the maximum positive contribution to the growth rate of whistler waves propagating quasi‐parallel and antiparallel to the ambient magnetic field, respectively. Our analysis shows that electrons with Wres ∼ 10–20 keV could potentially be scattered into the loss cone by the low frequency whistler waves with fw ∼ (0.05–0.2)fce (fw is the wave frequency and fce is the electron gyrofrequency). The electrons that are scattered into the loss cone can contribute to electron precipitation within ∼13 min following the dipolarization onset. We suggest that whistler waves that are excited due to cyclotron instability driven by the temperature anisotropy of suprathermal electrons (≥2 keV) may, in turn, affect electron distribution in this energy range. Specifically, lower energy resonant electrons transfer a part of their kinetic energy to waves, while more energetic electrons absorb wave energy increasing their kinetic energy. This may lead to the transformation of higher‐energy part of electron distribution from Maxwellian to the power law shape.
Observational Evidence of Ventilation Hotspots in the Southern Ocean
Authors: Dove Lilian A. , Thompson Andrew F. , Balwada Dhruv , Gray Alison R. 
Published: June 2021

AbstractStanding meanders are a key component of the Antarctic Circumpolar Current (ACC) circulation system, and numerical studies have shown that these features may locally enhance subduction, upwelling, as well as lateral and vertical tracer transport. Yet, observational data from these regions remain sparse. Here, we present results based on measurements made by a group of autonomous platforms sampling an ACC standing meander formed due to the interaction of the Polar Front with the Southwest Indian Ridge. Two Seagliders were deployed alongside a Biogeochemical‐Argo float that was advected through the standing meander. In the high eddy kinetic energy region of the standing meander, the glider observations reveal enhanced submesoscale frontal gradients as well as heightened tracer variability at depth, as compared to the more quiescent region further downstream. Vertical gradients in spice and apparent oxygen utilization are reduced in the standing meander despite similarities in the large‐scale vertical stratification, suggesting greater ventilation of the surface ocean. These observations are consistent with numerical studies that highlight standing meanders as hotspots for ventilation and subduction due to enhanced mesoscale stirring and submesoscale vertical velocities. Our results emphasize the need to account for spatial heterogeneity in processes influencing air‐sea exchange, carbon export, and biogeochemical cycling in the Southern Ocean.
Subtropical Eastern North Pacific SST Bias in Earth System Models
Authors: Balaguru Karthik , Van Roekel Luke P. , Leung L. Ruby , Veneziani Milena 
Published: June 2021

AbstractThis study systematically evaluates the warm sea surface temperature (SST) bias in the Subtropical Eastern North Pacific, a problem plaguing most Coupled Model Intercomparison Project Phase 6 models, using the Energy Exascale Earth System Model version 1 (E3SM). In the model at its standard resolution (1° atmosphere, 30–60 km ocean), the SST bias, exceeding several degrees, is mainly concentrated along the coast between 25°N and 40°N. In the high‐resolution (0.25° atmosphere, 18–6 km ocean) version of the model, the nearshore SST bias improves considerably with a better representation of coastal upwelling. However, the offshore SST bias, approximately centered at 125°W and 25°N, is relatively stronger in the high‐resolution version. To better understand the offshore warm bias in the model, a mixed‐layer heat budget analysis is performed. While errors in surface radiative fluxes occur at both resolutions, positive biases in horizontal heat advection also play a role in the SST bias at high‐resolution. Analysis of HighResMIP models indicates that the shift in the location of the prominent SST bias from nearshore to offshore with an increase in model spatial resolution, is not native to E3SM alone.
Insights Into Water Mass Origins in the Central Arctic Ocean From In‐Situ Dissolved Organic Matter Fluorescence
Authors: Stedmon Colin A. , Amon Rainer M. W. , Bauch Dorothea , Bracher Astrid , Gonçalves‐Araujo Rafael , Hoppmann Mario , Krishfield Richard , Laney Samuel , Rabe Benjamin , Reader Heather , Granskog Mats A. 
Published: June 2021

AbstractThe Arctic Ocean receives a large supply of dissolved organic matter (DOM) from its catchment and shelf sediments, which can be traced across much of the basin's upper waters. This signature can potentially be used as a tracer. On the shelf, the combination of river discharge and sea‐ice formation, modifies water densities and mixing considerably. These waters are a source of the halocline layer that covers much of the Arctic Ocean, but also contain elevated levels of DOM. Here we demonstrate how this can be used as a supplementary tracer and contribute to evaluating ocean circulation in the Arctic. A fraction of the organic compounds that DOM consists of fluoresce and can be measured using in‐situ fluorometers. When deployed on autonomous platforms these provide high temporal and spatial resolution measurements over long periods. The results of an analysis of data derived from several Ice Tethered Profilers (ITPs) offer a unique spatial coverage of the distribution of DOM in the surface 800 m below Arctic sea‐ice. Water mass analysis using temperature, salinity and DOM fluorescence, can clearly distinguish between the contribution of Siberian terrestrial DOM and marine DOM from the Chukchi shelf to the waters of the halocline. The findings offer a new approach to trace the distribution of Pacific waters and its export from the Arctic Ocean. Our results indicate the potential to extend the approach to separate freshwater contributions from, sea‐ice melt, riverine discharge and the Pacific Ocean.
A narrative overview of utilizing biomaterials to recapitulate the salient regenerative features of dental-derived mesenchymal stem cells
Authors: Sevari Sevda Pouraghaei , Ansari Sahar , Moshaverinia Alireza 
Published: June 2021

AbstractTissue engineering approaches have emerged recently to circumvent many limitations associated with current clinical practices. This elegant approach utilizes a natural/synthetic biomaterial with optimized physiomechanical properties to serve as a vehicle for delivery of exogenous stem cells and bioactive factors or induce local recruitment of endogenous cells for in situ tissue regeneration. Inspired by the natural microenvironment, biomaterials could act as a biomimetic three-dimensional (3D) structure to help the cells establish their natural interactions. Such a strategy should not only employ a biocompatible biomaterial to induce new tissue formation but also benefit from an easily accessible and abundant source of stem cells with potent tissue regenerative potential. The human teeth and oral cavity harbor various populations of mesenchymal stem cells (MSCs) with self-renewing and multilineage differentiation capabilities. In the current review article, we seek to highlight recent progress and future opportunities in dental MSC-mediated therapeutic strategies for tissue regeneration using two possible approaches, cell transplantation and cell homing. Altogether, this paper develops a general picture of current innovative strategies to employ dental-derived MSCs combined with biomaterials and bioactive factors for regenerating the lost or defective tissues and offers information regarding the available scientific data and possible applications.
Direct observation of chaotic resonances in optical microcavities
Authors: Wang Shuai , Liu Shuai , Liu Yilin , Xiao Shumin , Wang Zi , Fan Yubin , Han Jiecai , Ge Li , Song Qinghai 
Published: June 2021

AbstractOptical microcavities play a significant role in the study of classical and quantum chaos. To date, most experimental explorations of their internal wave dynamics have focused on the properties of their inputs and outputs, without directly interrogating the dynamics and the associated mode patterns inside. As a result, this key information is rarely retrieved with certainty, which significantly restricts the verification and understanding of the actual chaotic motion. Here we demonstrate a simple and robust approach to directly and rapidly map the internal mode patterns in chaotic microcavities. By introducing a local index perturbation through a pump laser, we report a spectral response of optical microcavities that is proportional to the internal field distribution. With this technique, chaotic modes with staggered mode spacings can be distinguished. Consequently, a complete chaos assisted tunneling (CAT) and its time-reversed process are experimentally verified in the optical domain with unprecedented certainty.
Recapitulation of selective nuclear import and export with a perfectly repeated 12mer GLFG peptide
Authors: Ng Sheung Chun , Güttler Thomas , Görlich Dirk 
Published: June 2021

AbstractThe permeability barrier of nuclear pore complexes (NPCs) controls nucleocytoplasmic transport. It retains inert macromolecules while allowing facilitated passage of importins and exportins, which in turn shuttle cargo into or out of cell nuclei. The barrier can be described as a condensed phase assembled from cohesive FG repeat domains. NPCs contain several distinct FG domains, each comprising variable repeats. Nevertheless, we now found that sequence heterogeneity is no fundamental requirement for barrier function. Instead, we succeeded in engineering a perfectly repeated 12mer GLFG peptide that self-assembles into a barrier of exquisite transport selectivity and fast transport kinetics. This barrier recapitulates RanGTPase-controlled importin- and exportin-mediated cargo transport and thus represents an ultimately simplified experimental model system. An alternative proline-free sequence forms an amyloid FG phase. Finally, we discovered that FG phases stain bright with ‘DNA-specific’ DAPI/ Hoechst probes, and that such dyes allow for a photo-induced block of nuclear transport.
Higher cost of finance exacerbates a climate investment trap in developing economies
Authors: Ameli Nadia , Dessens Olivier , Winning Matthew , Cronin Jennifer , Chenet Hugues , Drummond Paul , Calzadilla Alvaro , Anandarajah Gabrial , Grubb Michael 
Published: June 2021

AbstractFinance is vital for the green energy transition, but access to low cost finance is uneven as the cost of capital differs substantially between regions. This study shows how modelled decarbonisation pathways for developing economies are disproportionately impacted by different weighted average cost of capital (WACC) assumptions. For example, representing regionally-specific WACC values indicates 35% lower green electricity production in Africa for a cost-optimal 2 °C pathway than when regional considerations are ignored. Moreover, policy interventions lowering WACC values for low-carbon and high-carbon technologies by 2050 would allow Africa to reach net-zero emissions approximately 10 years earlier than when the cost of capital reduction is not considered. A climate investment trap arises for developing economies when climate-related investments remain chronically insufficient. Current finance frameworks present barriers to these finance flows and radical changes are needed so that capital is more equitably distributed.
The rate and molecular spectrum of mutation are selectively maintained in yeast
Authors: Liu Haoxuan , Zhang Jianzhi 
Published: June 2021

AbstractWhat determines the rate (μ) and molecular spectrum of mutation is a fundamental question. The prevailing hypothesis asserts that natural selection against deleterious mutations has pushed μ to the minimum achievable in the presence of genetic drift, or the drift barrier. Here we show that, contrasting this hypothesis, μ substantially exceeds the drift barrier in diverse organisms. Random mutation accumulation (MA) in yeast frequently reduces μ, and deleting the newly discovered mutator gene PSP2 nearly halves μ. These results, along with a comparison between the MA and natural yeast strains, demonstrate that μ is maintained above the drift barrier by stabilizing selection. Similar comparisons show that the mutation spectrum such as the universal AT mutational bias is not intrinsic but has been selectively preserved. These findings blur the separation of mutation from selection as distinct evolutionary forces but open the door to alleviating mutagenesis in various organisms by genome editing.
SARS-CoV-2-specific T cell memory is sustained in COVID-19 convalescent patients for 10 months with successful development of stem cell-like memory T cells
Authors: Jung Jae Hyung , Rha Min-Seok , Sa Moa , Choi Hee Kyoung , Jeon Ji Hoon , Seok Hyeri , Park Dae Won , Park Su-Hyung , Jeong Hye Won , Choi Won Suk , Shin Eui-Cheol 
Published: June 2021

AbstractMemory T cells contribute to rapid viral clearance during re-infection, but the longevity and differentiation of SARS-CoV-2-specific memory T cells remain unclear. Here we conduct ex vivo assays to evaluate SARS-CoV-2-specific CD4+ and CD8+ T cell responses in COVID-19 convalescent patients up to 317 days post-symptom onset (DPSO), and find that memory T cell responses are maintained during the study period regardless of the severity of COVID-19. In particular, we observe sustained polyfunctionality and proliferation capacity of SARS-CoV-2-specific T cells. Among SARS-CoV-2-specific CD4+ and CD8+ T cells detected by activation-induced markers, the proportion of stem cell-like memory T (TSCM) cells is increased, peaking at approximately 120 DPSO. Development of TSCM cells is confirmed by SARS-CoV-2-specific MHC-I multimer staining. Considering the self-renewal capacity and multipotency of TSCM cells, our data suggest that SARS-CoV-2-specific T cells are long-lasting after recovery from COVID-19, thus support the feasibility of effective vaccination programs as a measure for COVID-19 control.
Tropical deforestation induces thresholds of reproductive viability and habitat suitability in Earth’s largest eagles
Authors: Miranda Everton B. P. , Peres Carlos A. , Carvalho-Rocha Vítor , Miguel Bruna V. , Lormand Nickolas , Huizinga Niki , Munn Charles A. , Semedo Thiago B. F. , Ferreira Tiago V. , Pinho João B. , Piacentini Vítor Q. , Marini Miguel Â. , Downs Colleen T. 
Published: June 2021

AbstractApex predators are threatened globally, and their local extinctions are often driven by failures in sustaining prey acquisition under contexts of severe prey scarcity. The harpy eagleHarpia harpyjais Earth’s largest eagle and the apex aerial predator of Amazonian forests, but no previous study has examined the impact of forest loss on their feeding ecology. We monitored 16 active harpy eagle nests embedded within landscapes that had experienced 0 to 85% of forest loss, and identified 306 captured prey items. Harpy eagles could not switch to open-habitat prey in deforested habitats, and retained a diet based on canopy vertebrates even in deforested landscapes. Feeding rates decreased with forest loss, with three fledged individuals dying of starvation in landscapes that succumbed to 50–70% deforestation. Because landscapes deforested by > 70% supported no nests, and eaglets could not be provisioned to independence within landscapes > 50% forest loss, we established a 50% forest cover threshold for the reproductive viability of harpy eagle pairs. Our scaling-up estimate indicates that 35% of the entire 428,800-km2Amazonian ‘Arc of Deforestation’ study region cannot support breeding harpy eagle populations. Our results suggest that restoring harpy eagle population viability within highly fragmented forest landscapes critically depends on decisive forest conservation action.