742875 research outputs found
Sort by
Diverse perceptions of ecosystem (dis)services in a Himalayan protected area
No full textProtected areas are essential for balancing biodiversity conservation with the delivery of ecosystem services. However, despite extensive research on the economic valuation of these services, understanding local people's perceptions, particularly of ecosystem services and disservices, remains limited. Therefore, we assessed local perceptions and their socio-demographic determinants in Langtang National Park, a protected area in Nepal's Himalayan region. Ecosystem services and disservices were identified through a stakeholder consultation workshop. We conducted semi-structured interviews with 105 respondents. Both quantitative and qualitative analyses combined Fisher's exact test with Monte Carlo simulation (10,000 replicates), Cramer's V, and content analysis. The most highly regarded ecosystem services include drinking water (96 % of respondents), species and habitat conservation (92 %), air quality maintenance (91 %), protecting the environment for future generations (89 %), and water quality maintenance (89 %). The common ecosystem disservices include crop raiding by wildlife (93 %), allergies (58 %), and barriers to development and construction (48 %). Education and occupation are significantly associated with perceptions of ecosystem services, including carbon sequestration, air regulation, tourism, and research. Although ecosystem services are perceived to operate from local to global scales, disservices are mainly experienced at the local level. This emphasizes developing localized solutions in both national and international biodiversity conservation policies and practices, including indicators for ecosystem disservices.</p
Phylogenomic insights into the taxonomy and evolutionary relationships of penduline tits (Remiz spp.)
No full textPenduline tits (genus Remiz) are small passerines distributed across Europe, Central and East Asia, and North Africa, renowned for their elaborate nests and unusually diverse mating systems. However, the taxonomy and evolutionary relationships within this genus have remained contentious due to overlapping breeding distributions and extensive hybridization. Using broad-range geographic sampling and whole-genome sequencing, here we report the phylogenetic relationships within this genus. Our results from maximum likelihood trees, species trees, population structure, and PCA analyses consistently identify four distinct, well-supported monophyletic clades. Based on these robust results, we support dividing Remiz into four species: the Eurasian Penduline Tit (R. pendulinus), Black-headed Penduline Tit (R. macronyx), White-crowned Penduline Tit (R. coronatus), and Chinese Penduline Tit (R. consobrinus). Among these species, R. consobrinus diverged earlier from other species, followed by R. coronatus , and then, R. pendulinus and R. macronyx . R. pendulinus and R. macronyx showed shallow genetic differentiation with recent divergence (∼87,000 years ago) and ongoing gene flow. Our findings demonstrate the effectiveness of phylogenomic approaches in resolving taxonomic ambiguities and provide a robust evolutionary framework for tracing the diversification of life history traits, particularly nest structures and mating systems, across the genus.</p
Biocatalytic Asymmetric Michael Addition of Thiols to α,β‐Unsaturated Aldehydes via Enzyme‐Bound Iminium Ion Intermediates
No full textThe thia-Michael addition is one of the most versatile and practical reactions for C-S bond formation in organic synthesis, but remains a continuing challenge for biocatalysis. Here we report engineered cofactor-independent enzymes, based on the promiscuous enzyme 4-oxalocrotonate tautomerase, for the enantioselective synthesis of various (R)-β-thioenals via the nucleophilic addition of aliphatic thiols to cinnamaldehyde. These engineered enzymes efficiently promote the formation of the carbon–sulfur bond with good stereocontrol, affording the desired (R)-β-thioenal products with excellent conversions (up to 99%) and with moderate-to-high enantiopurity (e.r. up to 95:5). Our results highlight the power of catalytic promiscuity for expanding the biocatalytic repertoire for non-natural reactions
Robust helix photo-transforming in soft matter
No full textHelical organization in soft materials is omnipresent in systems ranging from DNA and peptides to liquid crystal displays. Dynamic transformation and reconfiguration of helicity triggered non-invasively by light are highly desirable, yet challenging to control in soft-condensed matter. Herein, we report the photo-transformation of helicity in soft matter with robust manipulation of the helical pitch and inversion of chirality. The key molecular design is based on the introduction of a multi-branched dendron-like chiral photoswitch, along with balancing long-range order and short-range disorder states, featuring ultra-large helical twisting power (HTP) and initiating an extremely broad dynamic spectral range (400-3000 nm). The resonance coupling between helixes and inherent luminescence of the chiral photoswitch enables stimulated circularly polarized luminescence (CPL), with a dissymmetric factor of 1.97 approaching the theoretical limit. The precise dynamic control allows for photo-tailorable infrared beams and high dimensional coding, offering a robust approach to dynamic soft matter, chiro-optics and information processing.</p
MINDS:Young binary systems with JWST/MIRI: Variable water-rich primaries and extended emission
No full textContext. Dynamical disk-companion interactions can have a significant impact on the evolution of circumstellar disks, as these can produce perturbations to the material distribution, density, and temperature, affecting their potential for planet formation. Aims. As part of the JWST GTO program MINDS, we analyze the mid-infrared (MIR) emission of three Class II binary systems: VW Cha, WX Cha, and RW Aur. Our aim is to investigate the impact of stellar multiplicity on the chemistry and physics of their inner disk. Methods. We analyzed the 1D spectrum from JWST/MIRI-MRS for primary and secondary disks separately, extracted via a combination of forward modeling with a theoretical PSF and aperture photometry. Following the continuum subtraction, we modeled the molecular lines with 0D slab models. We interpreted the results by comparing our JWST spectra to VLT/CRIRES+, Spitzer/IRS. The extended MIR emission was compared to ALMA data, with the inclusion of the binary DF Tau in our sample. Results. Primary and secondary disks are dramatically different in their MIR emission, with primary disks exhibiting H2O-rich spectra and secondary disks being mostly line-poor with respect to the sensitivity of our spectra. When comparing MIRI-MRS to Spitzer/IRS, we observed a broad variability in the line emission of VW Cha A and in the continuum of RW Aur A. The disks around VW Cha BC and RW Aur B show evidence of ionizing radiation and a further comparison with ALMA at high angular resolution dust continuum suggests that the spectrum of RW Aur B is well explained by its ~4 au cavity. All the systems show [Ne II] jet emission and three of them also show spatially resolved emission structures in H2, likely originating from outflows and dynamical interactions. Conclusions. Many of the observed features in the primary disks, such as enhanced water emission, could be linked to the increased accretion and radial drift produced by dynamical disk truncation. However, additional mechanisms are needed to explain the large differences between primary and secondary disks, potentially inner disk substructures. This work highlights the need for combining data from multiple facilities to fully understand the observations from JWST.</p
Networking rural accessibility:A governance perspective on multimodal transport and integrated hubs in rural areas
No full textAccessibility in rural areas is under pressure due to increasing travel distances and travel time to daily amenities, combined with a declining availability of public transport. While access to a private car enables participation in daily activities for most people in rural areas, it marginalises those without, raising concerns about transport justice. Multimodal integration of conventional public transport, demand-responsive transport, and shared transport services has emerged as a strategy to improve spatial and temporal coverage in low-density contexts. Mobility hubs facilitate transfers between trunk and feeder systems. Yet, their implementation is complex, requiring institutional coordination among public and private actors operating across modes and spatial scales.This study examines the enabling conditions for effectively governing multimodal transport and integrated mobility hubs in rural areas. It develops a conceptual framework structured around functional interrelatedness, institutional interdependence, and spatial scale, which is applied in different stages of the policy cycle. Grounded in a pragmatist research philosophy, the study adopts a mixed-methods approach.The findings indicate that multimodal integration in rural areas requires sufficient spatial scale, a balance between central coordination and local adaptability, and clique coordination to connect policy networks across modes and levels of jurisdiction, thereby enhancing rural accessibility
Parameterized Argumentation-based Reasoning Tasks for Benchmarking Generative Language Models
No full textGenerative large language models as tools in the legal domain have the potential to improve the justice system. However, the reasoning behavior of current generative models is brittle and poorly understood, hence cannot be responsibly applied in the domains of law and evidence. This paper presents reasoning benchmarks that are dynamically varied, scalable in their complexity, and have formally unambiguous interpretations. In this study, we illustrate the approach on the basis of witness testimony, focusing on the underlying argument attack structure. We dynamically generate both linear and non-linear argument attack graphs of varying complexity and translate these into reasoning puzzles about witness testimony expressed in natural language. We show that state-of-the-art large language models often fail in these reasoning puzzles, already at low complexity. Obvious mistakes are made by the models, and their inconsistent performance indicates that their reasoning capabilities are brittle. Furthermore, at higher complexity, even state-of-the-art models specifically designed for reasoning make mistakes. We show the viability of using a parametrized benchmark with varying complexity to evaluate the reasoning capabilities of generative language models, which contribute to a better understanding of the limitations of the reasoning capabilities of generative models.</p
Medieval Romance and its Knowledge Economy:From Sorceresses to Scholars
No full textIn her inaugural lecture at the University of Groningen, Prof. Dr. Megan Leitch will show how late-medieval England developed romances, or tales of knights, quests, dragons and princesses, into proto-feminist narratives that deployed magic to question the politics of access to knowledge and power. Just as we work and study in knowledge economy – an economy in which education, innovation and intellectual skills are forms of human capital – so too were these medieval romances shaped by a knowledge economy: one in which knights would not achieve their goals, whether martial or marital, without the help of various knowledgeable and wise interlocutors such as merchants, sorceresses, and female servants, or handmaidens. These stories explore how women’s magic results from book-learning despite the fact that women were not allowed to attend university, using the fantastical to imagine a better future in which marginalised voices drive change and modern universities champion inclusivity and academic freedom
Repurposing anti-CMV T cells to eliminate cancer cells; an alternate form of cancer immunotherapy
No full textImmunotherapy, which harnesses the body's own immune system to fight cancer, has greatly improved treatment options in recent years, but often causes serious side effects. This thesis describes the development and testing of a new approach that redirects immune cells against the common cytomegalovirus (CMV) to attack cancer cells instead. Because these immune cells are already present in the body, this approach is much simpler and less costly than existing methods like CAR-T therapy.The key idea is that by directing existing anti-CMV immune cells toward cancer cells, we may be able to fight cancer effectively with much less side effects. Laboratory experiments and animal studies show that this strategy produces promising results against both solid tumors and blood cancers. Initial safety tests indicate that this approach appears to cause much less side effects than existing immunotherapies, likely because it harnesses a natural immune response.The results demonstrate that this method has potential for future clinical application. Follow-up studies to investigate safety and effectiveness in patients are currently being prepared