Search Results (715)

We review the recent developments on the decoupling limit zooming in on a BPS string state in heterotic string theory. In this limit, the target-space geometry lacks any ten-dimensional metric description and acquires various non-Lorentzian features. We present the supersymmetric worldsheet sigma model in the decoupling limit. This sigma model describes the heterotic version of non-relativistic string theory, whose second quantization is related to heterotic matrix string theory. We introduce bookkeeping to separate the Yang–Mills gauge and gravitational anomaly analyses. We review the Yang–Mills gauge anomaly analysis in the sigma models before and after the decoupling limit is performed and provide further details on how the quantum calculation commutes with the decoupling limit. We comment on how the analogous calculation can be performed for the gravitational anomaly. This contribution is based on a talk at the University of Science and Technology of China. Full article

Because large language models operate through language, they rely on self-reports to access the feeling of understanding, limiting their ability to support students’ learning. A previous study explored whether facial expressions could provide an alternative way of measuring this feeling across phases of understanding in an academic context, but it had limited success. To examine how effective other physiological channels may be in measuring the feeling of understanding, this study investigated whether acoustic feature patterns are associated with nascent understanding, misunderstanding, confusion, emergent understanding, deep understanding, and underconfidence as 198 participants completed a literary analysis task while their speech was recorded over Zoom. CatBoost and logistic regression models showed modest performance, indicating that phases of understanding were not reliably distinguishable at the population level. In contrast, within-person analyses revealed consistent differences between nascent and emergent understanding across several acoustic features, including pitch, jitter, shimmer, and spectral flux. The findings show that acoustic features of speech do not reliably distinguish phases of understanding at the population level in naturalistic academic contexts but do reflect consistent within-person differences between nascent and emergent understanding, highlighting both the potential and the limits of using speech as a physiological measure of the feeling of understanding and pointing to the need for alternative ways to operationalize this feeling as it unfolds across phases. Full article

Background: Telehealth is increasingly positioned as a solution for healthcare access among older adults; yet for transgender older adults, its application remains undertheorized, inconsistently implemented, and frequently reductive. Structural barriers, including provider incompetence, administrative misgendering, insurance precarity, and the clinical invisibility of aging transmasculine bodies, shape this population’s relationship to telehealth in ways that existing frameworks have not adequately addressed. Objective: This study examines the structural conditions shaping transmasculine and gender-nonconforming older adults’ engagement with healthcare and telehealth, and centers their visions for transformed, justice-oriented virtual care. Methods: Four semi-structured focus groups (n = 14 transmasculine and gender-nonconforming older adults, ages 40–67) were conducted via Zoom in June 2024 and analyzed using Braun and Clarke’s reflexive thematic analysis. The study was designed according to community-based participatory research (CBPR) principles. This study followed the Consolidated Criteria for Reporting Qualitative Research guidelines to ensure methodological transparency in reporting. Results: Analysis yielded five themes: (1) the provider competency crisis; (2) administrative violence and the architecture of misgendering; (3) insurance, politics, and the precarity of access; (4) the aging transmasculine body as uncharted clinical territory; and (5) participants’ collective vision for relational, community-centered care. Conclusions: We introduce the Campfire Model of Relational Telehealth, a conceptual framework comprising five empirically derived pillars: gathering, warmth, collective knowledge, safety, and accountability. The model argues that telehealth must move beyond transactional encounters toward a relational ecosystem of care grounded in justice, belonging, and structural transformation. We conclude with a call to action for providers, policymakers, and researchers to dismantle structural barriers and advance telehealth that cultivates dignity, belonging, and equity. Full article

Polarimetric synthetic aperture radar (Pol-SAR) is one of the most important approaches for sea-surface target detection, but under rainfall conditions it tends to be distorted by the electromagnetic (EM) propagation effects and clutter interference of rainfall. To address this problem, this paper proposes a joint compensation method to mitigate the impacts of rainfall on the detection of sea-surface targets. In the method, a composite imaging model that thoroughly takes into account the propagation and scattering effects of rainfall, sea surface, and ship targets is first established. Then, a range-wise algorithm is proposed to effectively estimate the propagation effects, which are used to compensate for the radar echoes distorted by rainfall. Consequently, a hierarchical search strategy is employed to optimize the receiving polarization state to better discriminate the targets from rainfall and sea clutter. Simulation results show that, across the tested sea-surface wind and rainfall conditions, the proposed method improves the signal-to-clutter-plus-noise ratio (SCNR) by 4 to 13 dB compared with the polarimetric whitening filter, demonstrating its effectiveness under coupled rain–sea conditions. Full article

Background/Objectives: Caregivers play a critical role in patient care across the pre- and post-transplant periods. However, the demands of caregiving can negatively impact caregivers’ own physical and psychosocial well-being. The Transplant Wellness Program (TWP) is a behavior change intervention that provides exercise support for pre- and post-kidney, pre- and post-liver, and post-lung transplant patients but has not yet included transplant caregivers. Thus, the purpose of this study was to explore the experiences and needs of organ transplant caregivers to inform the development of caregiver-specific support resources for the TWP. Methods: Semi-structured interviews with family caregivers of patients receiving kidney or liver transplant in the TWP were conducted and recorded via Zoom. Interview recordings were transcribed verbatim and analyzed using conventional content analysis. Results: Eight interviews were conducted, with caregivers in both the pre- (n = 4) and post-transplant (n = 4) periods. Four categories resulted from the data: caregiver strain, life changes, individual wellness needs, and caregiving needs. Nine sub-categories further described caregivers’ experiences and opportunities for wellness support. Conclusions: The caregiving experience was characterized by feelings of overwhelm, stress, and uncertainty. This study highlights the need for comprehensive services such as exercise classes, peer support programs, and tangible aide to support transplant caregivers’ well-being. Three caregiver resources were built out of this study and integrated into the TWP. Full article

Background/Objectives: Quality improvement (QI) is widely used in global health to improve patient outcomes, reduce costs, and strengthen service delivery. The Texas Children’s Global Health Network (TCGHN) includes nine independent non-governmental organizations supporting healthcare in low- and middle-income countries (LMICs), with pediatric HIV clinical centers of excellence in six countries in sub-Saharan Africa (SSA), supported technically by Baylor College of Medicine. We describe the development of a virtual QI Community of Practice (QICoP) to connect geographically dispersed teams and strengthen local QI capacity. Methods: In 2022, QI and global health experts convened to design the QICoP and assess site readiness. Participants were recruited from the sites based on their interest. Meetings were held via Zoom, with attendance, evaluations, and organizer notes tracked. QI tools were used to identify site strengths, challenges, and strategies to improve engagement. Results: From January 2023 to September 2024, the QICoP held 15 sessions, including 3 abstract-writing workshops, averaging 35 participants per session. QI abstract submissions to the annual Network meeting doubled from 2023 to 2024. Across 15 sessions, 83% of participants reported positive experiences. Based on participant feedback and QI sessions from the 2022–2024 Network meetings, we developed a blended QI basics curriculum, recruited site champions to improve communication, and launched a WhatsApp platform to enhance engagement. Conclusions: A virtual QICoP may be a feasible model to support professional development, increase knowledge and idea sharing, and connect individuals across geographies over a shared mission to improve healthcare quality in LMICs. Full article

Optical and Synthetic Aperture Radar (SAR) image registration is a fundamental task in remote sensing information fusion, yet it remains challenging due to significant differences in imaging mechanisms, radiation characteristics, and noise properties between the two modalities. Existing public datasets suffer from limited resolution, small scale, and insufficient scene diversity, and these limitations have hindered algorithm development. This paper constructs a large-scale, high-resolution optical–SAR registration dataset based on the HongTu-1 satellite 3-m SAR imagery and Google Earth optical imagery at zoom level 17, covering diverse scenes across China with a standardized pipeline including terrain correction, geometric alignment, standardized slicing, and quality filtering. Building upon this dataset, a hand-crafted keypoint-based cross-modal registration method is proposed, incorporating multi-level edge filtering and hybrid feature detection. Unlike conventional hand-crafted methods such as RIFT, SRIF, and LNIFT, which mainly refine keypoint detection, description, or matching within a SIFT-style pipeline, the core novelty of this work lies in SAR-specific preprocessing and multi-level hybrid filtering. These components are designed to suppress speckle while extracting more stable and discriminative shared edge responses for cross-modal registration. An improved Log-domain Total Variation (Log-TV) denoising model is introduced for SAR preprocessing. A hybrid edge filtering framework combining phase congruency analysis and Structured Random Forest (SRF) edge detection is constructed within a Gaussian scale space. A dual-branch feature detection scheme integrating blob and corner features is designed with a robust orientation assignment strategy. Feature description uses the Gradient Location–Orientation Histogram (GLOH) descriptor with Principal Component Analysis (PCA) reduction, while geometric estimation employs the Fast Sample Consensus (FSC) algorithm. Experiments on the self-constructed HT dataset and on the public OSdataset and SAR2Opt benchmarks show that the proposed method consistently achieves low RMSE and high success rates. It also maintains competitive efficiency among hand-crafted methods while retaining strong robustness to scale and rotation variations. Full article

Endoscopic imaging plays an important role in minimally invasive surgery, clinical diagnosis, and biomedical research. Conventional endoscopic systems with fixed focal lengths are limited in multi-scale observation, while mechanically driven zoom systems often suffer from increased structural complexity and limited stability. In this work, a dual-degree-of-freedom continuous optical zoom endoscopic system based on liquid lenses is proposed. By employing two independently tunable liquid lenses, the system enables simultaneous modulation of optical power and principal plane position, thereby enhancing the flexibility of continuous focusing and magnification control. A Gaussian-bracket-based model is established to describe optical power redistribution and aberration evolution during the zoom process. The proposed system achieves continuous focusing over a wide range from 10 mm to 1000 mm while maintaining imaging performance close to the diffraction limit. In addition, a 1.2× magnified state is realized at a short focusing distance without significant degradation in image quality. The results demonstrate that the proposed dual-degree-of-freedom design provides a compact and effective solution for high-resolution continuous zoom endoscopic imaging. Full article

Large Language Models are increasingly being used by students in academic contexts, but they can only evaluate and engage with what students express in language. The feeling of understanding is inaccessible to them directly. This matters because the feeling of understanding shapes how students judge their understanding and guides their learning. Feelings have a physiological basis and can therefore be measured through facial action units. This study explored whether action unit patterns are associated with nascent understanding, misunderstanding, confusion, emergent understanding, deep understanding, and underconfidence as 198 participants completed a literary analysis task while their facial expressions were recorded over Zoom. CatBoost and logistic regression models demonstrated limited ability to discriminate phases at the population level, and within-person differences between phases were modest and inconsistent across participants. The findings highlight the difficulty of measuring the feeling of understanding in naturalistic academic contexts and may suggest that the feasibility of AU-based phase detection depends in part on the extent to which phases can be specified with temporal and conceptual precision. Full article

Grotta-Riparo di Uluzzo C (Uluzzo Bay, Apulia, southern Italy) preserves a long and complex stratigraphic sequence spanning from the Middle Palaeolithic to the Bronze Age, offering a valuable context for investigating depositional dynamics and human–environment interactions during the Late Pleistocene. Although recent multidisciplinary research has substantially advanced knowledge of the Uluzzian occupations, the Mousterian faunal record of the site has remained largely unexplored from zooarchaeological and taphonomic perspectives. This study examines the faunal assemblages from the Mousterian layers (E, F, and G), integrating material from historical excavations with those recovered during recent fieldwork. Zooarchaeological, taphonomic, and Zooarchaeology by Mass Spectrometry (ZooMS) analyses are combined to reconstruct local environmental conditions, evaluate the relative contribution of human and non-human agents to bone accumulation, and assess patterns of site use and deposit formation. The faunal spectrum indicates an ecologically heterogeneous landscape, consistent with a Mediterranean refugial setting during the Late Pleistocene. Taphonomic evidence points to complex and cumulative formation processes resulting from repeated, short-term human occupations interspersed with carnivore activity and natural depositional processes. The Mousterian deposits are therefore best interpreted as brief palimpsests rather than the result of continuous or intensive occupation. Placed within a regional framework, the Uluzzo C assemblages contribute to broader discussions on site formation processes and environmental variability in southern Italy and provide an important comparative baseline for the Middle to Upper Palaeolithic period. Full article

Background: Children and adults with disabilities are widely acknowledged to have poorer health and emotional wellbeing than their non-disabled peers, which is further compounded by less access to health services and health-promoting activities. A relatively untried solution is to mobilize community initiatives such as sports to promote better health. Method: Special Olympics (SO) is an international sports organization present in over 200 countries and jurisdictions, engaging with just under four million athletes with intellectual disabilities annually. Research on the perceptions of sports coaches around incorporating health promotion within their sports training has been scarce. Likewise, little attention has been paid to identifying athletes’ understanding of what health means to them and actions that would make them healthier. A qualitative, descriptive study was conducted with eight national SO programs involving 62 coaches and 47 athletes. Group interviews were conducted via Zoom and a thematic content analysis was made of their responses. Results: In all countries, coaches and athletes agreed that the most common needs were healthy eating, healthy weight and exercise. Good mental wellbeing and sleeping well were also named. Ideas were sought from both sets of participants regarding how coaches could assist their athletes to attain better health and the barriers they might face in doing so. Conclusions: Three main conclusions emerged. Athletes and coaches were aware of health deficits and knew of ways to reduce them. Both appreciated the contribution that coaches could make through motivating athletes and providing training activities but were dependent on suitable resources being available to them. Engagement with families and available health and social care services was essential. Health-oriented, sporting activities offer promise in improving the health and wellbeing of persons with developmental disabilities, particularly in less affluent countries with fewer health professionals and poorly developed primary care services. Full article

Chromatic aberration correction remains a major challenge in dual-band infrared continuous zoom optical systems. To address this issue, an achromatic design method based on the equivalent refractive index and equivalent dispersion rate is proposed. Starting from a four-component continuous zoom model, chromatic compensation is introduced into the initial structural parameter calculation, and the initial structural parameters are obtained through an iterative procedure. To validate the proposed method, a MWIR/LWIR dual-band continuous zoom optical system is designed. The final system covers the MWIR (3.7–4.8 μm) and LWIR (8–10 μm) bands with a focal length range of 10–120 mm, and the chromatic focal shift is controlled within the depth of focus. Clear imaging is achieved in both bands over the entire zoom range. These results demonstrate the effectiveness of the proposed achromatic strategy and provide a practical approach for the design of wide-band achromatic zoom optical systems. Full article

This study investigated the impact of image capture distance on the performance of convolutional neural networks (CNNs) in classifying fabrics. Unlike previous works that rely solely on digital zoom and data augmentation to simulate multi-scale variations, this research explores the use of physically captured images at far, mid-range, and near focal lengths using a camera with an attached varifocal lens. Fabric samples from three categories of Cotton, Linen, and Silk were imaged under consistent lighting to create an image dataset with a total of 1350 images used to train CNN models via transfer learning, with MobileNetV2 and ResNet50 as the baseline architectures. Classification performance was evaluated separately on each focal subset and on their combined dataset to test the trained model generalization capability. Results showed an absolute accuracy gain of 20.57% with MobileNetV2 and 9.78% for ResNet50 while performing with an improved accuracy at 98.42% for MobileNetV2 and ResNet50 at 96.30% Full article

Despite being a biodiversity hotspot, the Republic of Seychelles faces a critical challenge with an estimated 90% of its food imported. This dependency exposes the country to global supply disruptions and climate-related risks, while pressure on protected ecosystems continues to rise. In response, the Erasmus+ Capacity Building Higher Education GreenTraINT project (Green Training INTernational Program for agriculture, livestock farming, and conservation), co-funded by the European Union (2024–2026), aims to strengthen local expertise in sustainable agriculture, livestock farming, and biodiversity conservation. Through a transnational partnership involving European and Seychellois universities and institutions, GreenTraINT is co-designing innovative higher education modules tailored to the island’s priorities in agriculture, livestock, and biodiversity conservation. This paper focuses on a detailed needs analysis conducted in early 2025 across a diverse group of 84 stakeholders, including students, educators, NGOs, and professionals. The findings reveal a strong demand for applied training in sustainable food systems and biodiversity conservation, blended teaching methods, and programs that bridge theory with hands-on skills. Inspired by other Erasmus+ projects such as NETCHEM and SPARKLE, GreenTraINT adopts a multi-stakeholder, needs-driven approach that aligns international academic expertise with local development goals. As a key milestone, a Summer School in 2026 will pilot the newly developed modules. In the long term, GreenTraINT seeks to leave a lasting legacy by integrating its curriculum into national education pathways, thereby contributing to food security and environmental resilience. With less than four years remaining to achieve the 2030 Agenda targets, the project positions higher education reform as a strategic accelerator for SDG implementation in small island developing states (SIDS). By linking curriculum innovation to measurable sustainability priorities, GreenTraINT helps narrow the SDG implementation gap in vulnerable island contexts. The project offers a model for international collaboration in higher education for sustainability in SIDS. Full article

Objectives: The transition to complementary feeding represents an important interval in child nutrition and development. Nutrient demands for growth are high, yet less is known regarding how caregivers make decisions regarding the introduction of solid foods to their infants and what influences their choices and feeding practices. Methods: Semi-structured interviews were conducted via Zoom with caregivers (N = 46, 83% mothers) of typically developing children (6–24 months of age) residing in the United States. A content analytic approach, with consensus coding performed by team members, was undertaken. The Developmental Niche framework guided thematic analysis. Results: Four major themes and four subthemes were identified: (1) Caregivers’ Approach Introducing Solid Foods with Anticipation and Concern, including subthemes of the (a) timing and order of complementary foods (CF) offered to children and (b) foods caregivers avoid offering; (2) Caregivers’ and Children’s Learning, including subthemes of (a) children’s rapid learning and skill development, and (b) the concurrent rapid demands for changes in food parenting; (3) Drivers of Caregivers’ Decisions Related to Offering Solid Foods to their Children; and (4) The Goal of CF: Integration of the Child into Family Mealtimes. Conclusions: Caregivers seek to provide adequate nutrition while balancing children’s health needs with the challenge of encouraging acceptance of family foods and respecting individual preferences. Juggling myriad demands (e.g., time, convenience, other family members, cultural traditions, and expectations), caregivers seek to help their children develop a healthy relationship with food. Full article