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Namibian fairy circles: Hostile territory for soil nematodes

Fairy circles are rings of grass (2–12 m diameter) with centers of bare soil that are found in some arid grasslands. Above- and belowground chemical and biological processes have been explored in an ongoing debate about the ultimate causes of this pattern. Belowground biota, including beneficial and pathogenic nematodes in the soil food web, may both influence and respond to the formation of fairy circles. For example, root-feeding nematodes have the potential to enhance plant water stress, promoting the spatial organization into rings to minimize competition. We studied the soil nematode communities associated with Stipagrostis fairy circles along a 900-km range in the Namib Desert of Namibia in southern Africa. Nematode abundance and diversity were highest in soils beneath the vegetation rings that define fairy circles and in soils in the vegetated matrix surrounding the rings, demonstrating the positive impact of plant-derived resources (i.e., roots and organic matter) on nematode communities. Network analysis of nematode communities showed that in many ring soils, fungal or root hair-feeding Aphelenchoides, Ditylenchus, and Hexatylus frequently co-occurred among other plant-parasitic taxa. In contrast, soils from the bare centers of fairy circles had lower organic matter content and were nearly defaunated. Fairy circle centers appear to be a hostile environment for soil nematodes, reflecting a resource-limited soil food web that may contribute to the persistent absence of vegetation. Bacterial-feeding Acrobeloides were over-represented in communities in the centers, which could reflect an association with termites or ants, whose activity has been proposed to play a role in fairy circle formation. These findings show that nematode communities respond to the unique environmental conditions created by fairy circles, and nematode assemblages found in center, ring, and matrix soils also may contribute to sustaining the pattern.

Regulation of CD45 isoforms during human effector and memory CD8 T cell differentiation: Implications for T cell nomenclature

This study examines the expression of CD45 isoforms on human yellow fever virus vaccine (YFV-17D) specific CD8 T cells longitudinally after vaccination. As expected, effector CD8 T cells at day 14 express CD45RO but within 4 to 6 wk these virus-specific CD8 T cells become CD45RA positive and remain CD45RA for >10 y. The journey for these YFV-specific CD8 T cells goes from naive (CD45RA+ CCR7+) to effector/effector memory (CD45RO+ CCR7−) to Temra (CD45RA+ CCR7−) to stem-cell memory (CD45RA+ CCR7+). These YFV-specific CD8 T cells rarely acquire the canonical Tcm phenotype (CD45RO+ CCR7+). This CD45RO to RA switch coincides with clearance of YFV, so we hypothesized that antigen may be playing a role in regulating CD45 expression. We addressed this issue by ex vivo analysis and provide evidence that this switch is indeed regulated by antigen. Sorted YFV-specific CD45RO effector CD8 T cells reexpress CD45RA when cultured ex vivo in the absence of antigen and retain CD45RO in the presence of cognate peptide. We also extended these ex vivo analysis to human cytomegalovirus (CMV)-specific CD8 T cells and show that CD45RO cells transition to CD45RA in the absence of antigen and CD45RA cells become CD45RO when stimulated with CMV peptide. We then show that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike-specific CD8 T cells can repeatedly undergo the same CD45RA to RO to RA transition in vivo after the SARS-CoV-2 mRNA vaccination. Again, the canonical Tcm phenotype spike-specific memory CD8 T cells were not readily detectable. These studies warrant a reevaluation of how human memory CD8 T cells are defined.

Selective conversion of CO2 to C2H6 in pure water photocatalyzed by fluorobenzene-linked perylene diimide

Bioinformatic prediction, annotation and experimental validation of conserved microRNAs in Lactuca sativa Linn

Study of factors affecting the blend of virgin and aged asphalt binder based on molecular dynamics simulation

To understand the blending behavior of virgin and aged asphalt binder in thermally recycled asphalt mixtures, a series of studies on the blending behavior of virgin and aged asphalt based on molecular dynamics simulations have been performed. A blend model was developed for virgin asphalt binder and aged asphalt binder with rejuvenator system, which is saturated with 12 different molecules. In-depth analysis of microscopic blending mechanisms through the effects of rejuvenator content, simulation time, temperature and aged asphalt binder content on the degree of blending of virgin and aged asphalt binder. Using Materials Studio, the blend of virgin and aged asphalt binder under different conditions was quantitatively analyzed. It was found that the degree of blending of virgin and aged asphalt increased gradually with the content of rejuvenator, but the degree of blending decreased slightly when increased to 15%. The degree of blending gradually increased with the increase of time and also with the increase of temperature during the simulation time of 2000 ps. In terms of aged asphalt content, the degree of blending of virgin and aged asphalt gradually decreased with the increase of aged asphalt content. And through the fitting analysis found that the order of correlation between the four factors and the degree of blending was: simulation time > aged asphalt content > temperature > rejuvenator content. To verify the reliability of the results of the molecular dynamics simulation, the performance of recycled asphalt was verified using the asphalt rheological properties test (DSR) and the three major indexes (needle penetration, softening point, and ductility) tests. The results of the combined rheological property test and the three major index tests were found to be consistent with the order of influence of the four factors obtained in the molecular dynamics simulation. Therefore, it can be concluded that the use of molecular dynamics simulation in this study to analyze the blend behavior of virgin and aged asphalt in recycled asphalt is relatively accurate.

A twisted chromophore powers a turn-on fluorescent protein chloride sensor

Fluorescent proteins (FPs) are noninvasive genetically encodable probes that have revolutionized bioimaging and health fields with vivid images and an ever-growing repertoire from jellyfish to sea anemones and corals. Inside the protein matrix, chromophore nonplanarity and flexibility have long been argued to govern the fluorescence efficiency of FPs, yet their fundamental roles and relative importance have been elusive which hinder the rational design of versatile FPs and biosensors. Herein, we tackle this central question by investigating two recently engineered FP-based turn-on chloride (Cl – ) sensors, ChlorON1 and 3, using an ultrafast electronic and vibrational spectroscopic toolset together with advanced multireference simulations for both structure and spectrum. We elucidate that fluorescence enhancement of the chloride-bound ChlorON3 stems from a substantially more twisted chromophore than ChlorON1 via comprehensive simulations starting from the available crystal structure of parent protein (mNeonGreen), also featuring an enhanced radiative pathway due to an adjacent leucine residue in the emissive population. This finding indicates that the commonly stated chromophore planarity is not, but conformational rigidity is, the decisive factor for high fluorescence efficiency. Such mechanistic insights into FPs are generalizable to chromoproteins and other photosensitive biomolecules, which can facilitate the targeted design of brighter and/or tunable biosensors.

Programmable synthetic magnetism and chiral edge states in nano-optomechanical quantum Hall networks

Deciphering functional landscape and clinical implications of enhancer RNAs in lung adenocarcinoma

Facility-level implementation strategies in early childhood education and care to enhance adherence to a provincial physical activity standard: Protocol for the Good Start Matters ATP+ randomised controlled trial

Early childhood education and care (ECEC) facilities represent an important setting to support the healthy development during early childhood through the promotion of active play (AP) and fundamental movement skills (FMS). A mandatory AP standard was enforced in 2017 for licensed ECEC centres in the province of British Columbia, Canada. In conjunction with the AP standard, a suite of capacity building resources were administered (Appetite to Play), which improved the knowledge and confidence of early childhood educators in implementing AP and FMS development activities. Child outcomes were not measured. With implementation of AP practices degrading over time, we set out to enhance existing ATP resources and developed an advanced mobile app-based professional development program title “Appetite to Play Plus (ATP+)”. ATP+ focuses on implementation strategies that integrate AP and FMS into scheduling and curriculum planning and on creating a supportive environment for AP in ECEC facilities. The purpose of the research is to investigate whether advanced mobile app-based training focused on implementation strategies and practical resources for early childhood educators and managers: 1) enhances adherence to the British Columbia Director of Licensing Standard of Practice for AP, and 2) improves 2.5- to 5.9-year-old children’s AP and FMS over a 12-week period. We hypothesise that centres randomised to the ATP+ intervention will: 1) demonstrate greater adherence to the AP standards in comparison to those assigned to the waitlist control group, and 2) children attending intervention centres will spend more time in AP while in care and have greater increases in their FMS scores. A hierarchical mixed effect model incorporating both fixed and random effects at the ECEC centre and child levels will test the impact of ATP + , while considering that children, educators and managers are clustered within ECEC centres. Trial registration ClinicalTrials.gov NCT05669378

Engineering a highly selective, hemoprotein-based scavenger as a carbon monoxide poisoning antidote with no hypertensive effect

Carbon monoxide (CO) poisoning causes 50,000 to 100,000 emergency department visits and ~1,500 deaths in the United States annually. Current treatments are limited to supplemental and/or hyperbaric oxygen to accelerate CO elimination. Even with oxygen therapy, nearly half of CO poisoning survivors suffer long-term cardiac and neurocognitive deficits related to slow CO clearance, highlighting a need for point of care antidotal therapies. Given the natural interaction between CO and ferrous heme, we hypothesized that the hemoprotein RcoM, a transcriptional regulator of microbial CO metabolism, would make an ideal platform for CO-selective scavenging from endogenous hemoproteins. We engineered an RcoM truncate (RcoM-HBD-CCC) that exhibits high CO affinity ( K a,CO = 2.8 × 10 10 M −1 ), remarkable selectivity for CO over oxygen ( K a,O2 = 1.4 × 10 5 M −1 ; K a,CO / K a,O2 = 1.9 × 10 5 ), thermal stability (T m = 72 °C), and slow autoxidation rate ( k ox = 1.1 h −1 ). In a murine model of acute CO poisoning, infused RcoM-HBD-CCC accelerated CO clearance from hemoglobin in red blood cells (RBCs) and was rapidly excreted in urine. Moreover, infused RcoM-HBD-CCC elicited minimal hypertension in mice compared to infused globins (hemoglobin, myoglobin, and neuroglobin), attributed to a comparatively limited reactivity toward nitric oxide (NO) via dioxygenation [ k NOD (RcoM) = 6 to 8 × 10 6 M −1 s −1 vs k NOD (Hb) = 6 to 8 × 10 7 M −1 s −1 ]. These data suggest that RcoM-HBD-CCC is a safe, selective, and efficacious CO scavenger. By limiting hypertension through minimal NO scavenging, RcoM-HBD-CCC improves end-organ adverse effects compared with other hemoprotein-based therapeutics.

Boosting carrier mobility in MgAgSb via in-situ InSb nanoprecipitates for high-efficiency segmented thermoelectric module

Securing gait recognition with homomorphic encryption

Abstract Biometric identification systems offer strong security by relying on unique personal traits. At the same time, they raise significant privacy concerns because compromised biometric data cannot be revoked. This paper explores the use of homomorphic encryption (HE) as a means to protect biometric data during classification and reduce the risk of exposing sensitive information. Our system comprises a feature extractor which operates locally and a classifier which processes encrypted data. We demonstrate the feasibility of our approach on a gait recognition task, employing a vision transformer as a feature extractor and training several HE-compatible classifiers. Through a comprehensive statistical analysis, we evaluate the impact of HE on accuracy and computational complexity, especially with different activation functions and their polynomial approximations. Our results demonstrate the feasibility of secure and accurate gait recognition using HE, while highlighting the trade-off between security and performance.

Medical students: They’re not just little doctors! Impact of an online group-coaching program on medical student well-being: A randomized clinical trial

Introduction Physician burnout begins in medical school. Professional coaching can improve physician well-being, but generalizable evidence in medical students is lacking. We aim to evaluate a coaching program in a national sample of students. Materials and methods A randomized clinical trial assessing a four-month, web-based, group coaching program was conducted between September 1, 2023, and December 31, 2023, among medical students from seven institutions. The primary outcome was burnout measured using the Maslach Burnout Inventory. Secondary outcomes included impostor syndrome, moral injury, self-compassion, and flourishing. A linear mixed effect model analysis was performed on an intent-to-treat basis. Results Among the 390 participating students (mean [SD] age, 25.3 [2.38]), 197 were randomized to the intervention group. There were no significant post-coaching differences in burnout, moral injury or impostor syndrome between groups. After the coaching intervention, the intervention group had significantly greater self-compassion with an absolute difference of 3.00 points (SE = 1.29; 95% CI, 0.48 to 5.53 points; P = 0.021)), and significantly higher flourishing scores, with an absolute difference of 0.45 points (SE = 0.23; 95% CI, 0.01 to 0.90 points; P = 0.048) compared to the control. Conclusion Web-based group coaching did not have an impact on measures of distress in medical students, though did improve well-being outcomes including self-compassion and flourishing. Trial Registration: ClinicalTrials.gov Identifier: NCT05822375

Striatal and cerebellar interactions during reward-based motor performance

Goal-directed motor performance relies on the brain’s ability to distinguish between actions that lead to successful and unsuccessful outcomes. The basal ganglia (BG) and cerebellum (CBL) are integral for processing performance outcomes, yet their functional interactions remain underexplored. We scanned participants’ brains with functional magnetic imaging (fMRI) while they performed a skilled motor task for monetary rewards, where outcomes depended on their motor performance and probabilistic events that were not contingent on their performance. Successful motor outcomes increased activity in the ventral striatum (VS), a functional subregion of the BG, whereas unsuccessful motor outcomes engaged the CBL. In contrast, for probabilistic outcomes unrelated to motor performance, the BG and CBL exhibited no differences in activity between successful and unsuccessful outcomes. Dynamic causal modeling revealed that VS-to-CBL connectivity was inhibitory following successful motor outcomes, suggesting that the VS may suppress CBL error processing for correct actions. Conversely, CBL-to-VS connectivity was inhibitory after unsuccessful motor outcomes, potentially preventing reinforcement of erroneous actions. Additionally, interindividual differences in task preference, assessed by having participants choose between performing the motor task or flipping a coin for monetary rewards, were related to inhibitory VS-CBL connectivity. These findings highlight a performance-mediated functional network between the VS and CBL, modulated by motivation and subjective preferences, that supports goal-directed behavior.

YAP charge patterning mediates signal integration through transcriptional co-condensates

Abstract Transcription factor dynamics are used to selectively engage gene regulatory programs. Biomolecular condensates have emerged as an attractive signaling module in this process, but the underlying mechanisms are not well-understood. Here, we probe the molecular basis of YAP signal integration through transcriptional condensates. Leveraging light-sheet single-molecule imaging and synthetic condensates, we demonstrate charge-mediated co-condensation of the transcriptional regulators YAP and Mediator into transcriptionally active condensates in stem cells. Intrinsically disordered region sequence analysis and YAP protein engineering demonstrate that the signaling specificity of YAP is established, in part, through complementary electrostatic interactions between negatively charged blocks within YAP and positively charged blocks within Mediator. YAP/Mediator co-condensation is counteracted by negative feedback from transcription, driving an adaptive transcriptional response that is well-suited for decoding dynamic inputs. Our work reveals a molecular framework for YAP condensate formation and sheds light on the function of YAP condensates for emergent gene regulatory behavior.

A highly efficient triple band metasurface enabled absorber for 5G/6G millimeter wave applications

“Going hungry, walking, working, and being cold is hard”: Experiences of Venezuelan migrant parents and caregivers of minors

Background The Venezuelan crisis is one of the largest and most neglected migration crises in the Western hemisphere. Driven by economic, humanitarian, and human rights factors, nearly 8 million Venezuelans have migrated to other countries. Colombia hosts the largest group of Venezuelan migrants worldwide, with approximately 2.9 million Venezuelans residing there. Among these migrants are many Venezuelan parents and caregivers of minors who have resettled in different Colombian cities with their children. This descriptive qualitative study aims to identify their needs and highlight key opportunities for intervention. The perspectives of Venezuelan parents and caregivers of minors were complemented by those of service providers to identify systemic challenges and service gaps, providing a more comprehensive understanding of the population’s needs and priority areas for action. Using the Transnational Theory of Cultural Stress, this study explores the ways in which the experiences of Venezuelan migrant parents before, during, and after migration impact their current needs. Methods Using a combination of convenience and probability sampling, we collected semi-structured interviews from 29 Venezuelan parents and caregivers of minors residing in Colombia and 21 service providers who predominantly work with Venezuelan migrants. To analyze the data, we used thematic analysis. Results The analysis revealed three major themes: 1) lack of basic necessities forced Venezuelan families to migrate, 2) physical and emotional hardships experienced during the long migration journey, and 3) accumulation of ongoing challenges in Colombia left migrants feeling defeated. Conclusion The findings from this study underscore the importance of advancing the United Nations Sustainable Development Goals – including no poverty, reduced inequalities, and good health and well-being – in Venezuelan migrant families.

Engineered Un1Cas12f1 with boosted gene-editing activity and expanded genomic coverage

Compact programmable nucleases provide versatile genome editing tools with therapeutic potential, particularly when delivered via adeno-associated virus (AAV) vectors. However, their limited editing efficacy and stringent protospaceradjacent motif (PAM) requirements impose significant limitations in practical application. Here, we engineered MiniCasUltra, an optimized Un1Cas12f1 variant, through rational mutagenesis. MiniCasUltra exhibits sixfold higher editing activity than Un1Cas12f1, minimal off-target effects (on/off-target ratio > 10), and an expanded PAM preference (5′-WBTR). Using a single AAV vector encoding MiniCasUltra and two single-guide RNAs, we achieved simultaneous editing of two disease-causing genes ( Pten and Fah ) in mouse liver, with indel rates of 15.82% and 29.39%, respectively- significantly surpassing CasMINI V3.1 (3.45% and 10.98%). Furthermore, AAV delivery of MiniCasUltra targeting a noncanonical 5′-TCTG PAM site in human vascularendothelial growth factor A reduced choroidal neovascularization (CNV) lesions in a laser-induced CNV mouse model of neovascular age-related macular degeneration, a leading global cause of blindness. The broad and effective targeting capabilities of MiniCasUltra, coupled with its compact size, highlight its potential for in vivo genome editing and therapeutic interventions.

Estimated transmission dynamics of SARS-CoV-2 variants from wastewater are unbiased and robust to differential shedding

Abstract The COVID-19 pandemic has accelerated the development and adoption of wastewater-based epidemiology. Wastewater samples can provide genomic information for detecting and assessing the spread of SARS-CoV-2 variants in communities and for estimating important epidemiological parameters such as the selection advantage of a viral variant. However, despite demonstrated successes, epidemiological data derived from wastewater suffers from potential biases. Of particular concern are shedding profiles, which can affect the relationship between true viral incidence and viral loads in wastewater. Changes in shedding between variants may decouple the established relationship between wastewater loads and clinical test data. Using mathematical modeling, simulations, and Swiss surveillance data, we demonstrate that estimates of the selection advantage of a variant are not biased by shedding profiles. We show that they are robust to differences in shedding between variants under a wide range of assumptions, and identify specific conditions under which this robustness may break down. Additionally, we demonstrate that differences in shedding only briefly affect estimates of the effective reproduction number. Thus, estimates of selective advantage and reproduction numbers derived from wastewater maintain their advantages over traditional clinical data, even when there are differences in shedding among variants.

Investigation on mechanical characteristics of modified TPMS primitive PLA-CF mechanical metamaterials