Wave ripples formed in ancient, ice-free lakes in Gale crater, Mars.

Symmetrical wave ripples identified with NASA's Curiosity rover in ancient lake deposits at Gale crater provide a key paleoclimate constraint for early Mars: At the time of ripple formation, climate conditions must have supported ice-free liquid water on the surface of Mars. These features are the most definitive examples of wave ripples on another planet. The ripples occur in two stratigraphic intervals within the orbitally defined Layered Sulfate Unit: a thin but laterally extensive unit at the base of the Amapari member of the Mirador formation, and a sandstone lens within the Contigo member of the Mirador formation.

Observation of broadband super-absorption of electromagnetic waves through space-time symmetry breaking.

Using time as an additional design parameter in electromagnetism, photonics, and wave physics is attracting considerable research interest, motivated by the possibility to explore physical phenomena and engineering opportunities beyond the limits of time-invariant systems. Here, we report the experimental demonstration of enhanced broadband absorption of electromagnetic waves in a continuously modulated time-varying system, exceeding one of the key theoretical limits of linear time-invariant absorbers. This is achieved by harnessing the frequency-wave vector transitions and enhanced interference effects enabled by breaking both continuous space- and time-translation symmetries in a periodically time-modulated absorbing structure operating at radio frequencies.

Barcoded SARS-CoV-2 viruses define the impact of duration and route of exposure on the transmission bottleneck in a hamster model.

The transmission bottleneck, defined as the number of viruses shed from one host to infect another, is an important determinant of the rate of virus evolution and the level of immunity required to protect against virus transmission. Despite its importance, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission bottleneck remains poorly characterized. We adapted a SARS-CoV-2 reverse genetics system to generate a pool of >200 isogenic SARS-CoV-2 viruses harboring specific 6-nucleotide barcodes, infected donor hamsters with this pool, and exposed contact hamsters to paired infected donors, varying the duration and route of exposure.

Rapid and comprehensive detection of viral antibodies and nucleic acids via an acoustofluidic integrated molecular diagnostics chip: AIMDx.

Precise and rapid disease detection is critical for controlling infectious diseases like COVID-19. Current technologies struggle to simultaneously identify viral RNAs and host immune antibodies due to limited integration of sample preparation and detection. Here, we present acoustofluidic integrated molecular diagnostics (AIMDx) on a chip, a platform enabling high-speed, sensitive detection of viral immunoglobulins [immunoglobulin A (IgA), IgG, and IgM] and nucleic acids.

Targeting TRPC channels for control of arthritis-induced bone erosion.

Arthritis leads to bone erosion due to an imbalance between osteoclast and osteoblast function. Our prior investigations revealed that the Ca-selective ion channel, Orai1, is critical for osteoclast maturation. Here, we show that the small-molecule ELP-004 preferentially inhibits transient receptor potential canonical (TRPC) channels.

Revealing the reaction path of UVC bond rupture in cyclic disulfides with ultrafast x-ray scattering.

Disulfide bonds are ubiquitous molecular motifs that influence the tertiary structure and biological functions of many proteins. Yet, it is well known that the disulfide bond is photolabile when exposed to ultraviolet C (UVC) radiation. The deep-UV-induced S─S bond fragmentation kinetics on very fast timescales are especially pivotal to fully understand the photostability and photodamage repair mechanisms in proteins.

The partisanship of mayors has no detectable effect on police spending, police employment, crime, or arrests.

In this paper, we examine whether mayors' partisan affiliations lead to differences in crime and policing. We use a large new dataset on mayoral elections and three different modern causal inference research designs (a regression discontinuity design centered around close elections and two robust difference-in-differences methods) to determine the causal effect of mayoral partisanship on crime, arrests, and racial differences in arrest patterns in medium and large US cities. We find no evidence that mayoral partisanship affects police employment or expenditures, police force or leadership demographics, overall crime rates, or numbers of arrests.

Hybrid coral reef restoration can be a cost-effective nature-based solution to provide protection to vulnerable coastal populations.

Coral reefs can mitigate flood damages by providing protection to tropical coastal communities whose populations are dense, growing fast, and have predominantly lower-middle income. This study provides the first fine-scale, regionally modeled valuations of how flood risk reductions associated with hybrid coral reef restoration could benefit people, property, and economic activity along Florida and Puerto Rico's 1005 kilometers of reef-lined coasts. Restoration of up to 20% of the regions' coral reefs could provide flood reduction benefits greater than costs.

Cryptic coral diversity is associated with symbioses, physiology, and response to thermal challenge.

Coral persistence in the Anthropocene depends on interactions among holobiont partners (coral animals and microbial symbionts) and their environment. Cryptic coral lineages-genetically distinct yet morphologically similar groups-are critically important as they often exhibit functional diversity relevant to thermal tolerance. In addition, environmental parameters such as thermal variability may promote tolerance, but how variability interacts with holobiont partners to shape responses to thermal challenge remains unclear.

Tracking bottom-fishing activities in protected vulnerable marine ecosystem areas and below 800-m depth in European Union waters.

Numerous studies have highlighted bottom-contact fishing gears as the primary threat to vulnerable marine ecosystems (VMEs). In November 2022, the European Commission closed 87 VME protection polygons to bottom fishing in European waters. Using public automatic identification system (AIS) data, we found an 81% decrease in bottom-contact fishing effort within these areas in the year following the closures.

A tunable metamaterial microwave absorber inspired by chameleon's color-changing mechanism.

A metamaterial absorber capable of swiftly altering its electromagnetic response in the microwave range offers adaptability to changing environments, such as tunable stealth capabilities. Inspired by the chameleon's ability to change color through the structural transformation of photonic lattice crystals, which shift the bandgaps of reflection and transmission of visible light, we designed a crisscross structure that transforms from an expanded to a collapsed form. This transformation enables a switch between broadband absorption and peak transmission in the microwave range (4 to 18 gigahertz).

Development of a recombinant Ang1 variant with enhanced Tie2 binding and its application to attenuate sepsis in mice.

The angiopoietin (Ang)-Tie axis, critical for endothelial cell function and vascular development, is a promising therapeutic target for treating vascular disorders and inflammatory conditions like sepsis. This study aimed to enhance the binding affinity of recombinant Ang1 variants to the Tie2 and explore their therapeutic potential. Structural insights from the Ang1-Tie2 complex enabled the identification of key residues within the Ang1 receptor binding domain (RBD) critical for Tie2 interaction.

Compressing slippery surface-assembled amphiphiles for tunable haptic energy harvesters.

A recurring challenge in extracting energy from ambient motion is that devices must maintain high harvesting efficiency and a positive user experience when the interface is undergoing dynamic compression. We show that small amphiphiles can be used to tune friction, haptics, and triboelectric properties by assembling into specific conformations on the surfaces of materials. Molecules that form multiple slip planes under pressure, especially through π-π stacking, produce 80 to 90% lower friction than those that form disordered mesostructures.

Engineered extracellular vesicles with DR5 agonistic scFvs simultaneously target tumor and immunosuppressive stromal cells.

Small extracellular vesicles (sEVs) are nanosized vesicles. Death receptor 5 (DR5) mediates extrinsic apoptosis. We engineer DR5 agonistic single-chain variable fragment (scFv) expression on the surface of sEVs derived from natural killer cells.

Fully biodegradable hierarchically designed high-performance nanocellulose piezo-arrays.

While piezoelectric sensing and energy-harvesting devices still largely rely on inorganic components, biocompatible and biodegradable piezoelectric materials, such as cellulose nanocrystals, might constitute optimal and sustainable building blocks for a variety of applications in electronics and transient implants. To this aim, however, effective methods are needed to position cellulose nanocrystals in large and high-performance architectures. Here, we report on scalable assemblies of cellulose nanocrystals in multilayered piezoelectric systems with exceptional response, for various application scopes.

Single-cell analysis reveals ESX-1-mediated accumulation of permissive macrophages in infected mouse lungs.

(MTB) ESX-1, a type VII secretion system, is a key virulence determinant contributing to MTB's survival within lung mononuclear phagocytes (MNPs), but its effect on MNP recruitment and differentiation remains unknown. Here, using multiple single-cell RNA sequencing techniques, we studied the role of ESX-1 in MNP heterogeneity and response in mice and murine bone marrow-derived macrophages (BMDM). We found that ESX-1 is required for MTB to recruit diverse MNP subsets with high MTB burden.

HIV pre-exposure prophylaxis prescription initiation and maintenance among homeless-experienced people who use drugs.

Background: HIV pre-exposure prophylaxis (PrEP) remains particularly underutilized among homeless-experienced people who use drugs (PWUD).

Setting: Boston Health Care for the Homeless Program, a Federally Qualified Health Center serving homeless-experienced individuals in Boston, Massachusetts.

Methods: To identify determinants of PrEP prescription initiation and continuation, we analyzed electronic medical records and pharmacy data between April 2018-March 2022.

A population of c-kit IL-17A ILC2s in sputum from individuals with severe asthma supports ILC2 to ILC3 trans-differentiation.

In prednisone-dependent severe asthma, uncontrolled sputum eosinophilia is associated with increased numbers of group 2 innate lymphoid cells (ILC2s). These cells represent a relatively steroid-insensitive source of interleukin-5 (IL-5) and IL-13 and are considered critical drivers of asthma pathology. The abundance of ILC subgroups in severe asthma with neutrophilic or mixed granulocytic (both eosinophilic and neutrophilic) airway inflammation, prone to recurrent infective exacerbations, remains unclear.

Inhaled xenon modulates microglia and ameliorates disease in mouse models of amyloidosis and tauopathy.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder. Antiamyloid antibody treatments modestly slow disease progression in mild dementia due to AD. Emerging evidence shows that homeostatic dysregulation of the brain immune system, especially that orchestrated by microglia, plays an important role in disease onset and progression.

regulates melanocortin 4 receptor transcription and energy homeostasis.

Disruption of hypothalamic melanocortin 4 receptors (MC4Rs) causes obesity in mice and humans. Here, we investigated the transcriptional regulation of in the hypothalamus. In mice, we show that the homeodomain transcription factor Orthopedia (OTP) is enriched in MC4R neurons in the paraventricular nucleus (PVN) of the hypothalamus and directly regulates transcription.

Gene therapy ameliorates bowel dysmotility and enteric neuron degeneration and extends survival in lysosomal storage disorder mouse models.

Children with neurodegenerative disease often have debilitating gastrointestinal symptoms. We hypothesized that this may be due at least in part to underappreciated degeneration of neurons in the enteric nervous system (ENS), the master regulator of bowel function. To test this hypothesis, we evaluated mouse models of neuronal ceroid lipofuscinosis type 1 and 2 (CLN1 and CLN2 disease, respectively), neurodegenerative lysosomal storage disorders caused by deficiencies in palmitoyl protein thioesterase-1 and tripeptidyl peptidase-1, respectively.

Acrobatics at the insect scale: A durable, precise, and agile micro-aerial robot.

Aerial insects are exceptionally agile and precise owing to their small size and fast neuromotor control. They perform impressive acrobatic maneuvers when evading predators, recovering from wind gust, or landing on moving objects. Flapping-wing propulsion is advantageous for flight agility because it can generate large changes in instantaneous forces and torques.

Chemical conditioning approach to post-treat temperature-phased anaerobic digestate to improve resource recovery, odour reduction and biosolids quality.

Biosolids has several challenges, such as its high water content, huge volume, odour, and pathogen presence. Regulations require biosolids to be reused and disposed of safely. Polymer conditioning focuses on volume reduction, leaving pathogen and odour reduction unaddressed.

Migration is associated with increased HIV vulnerability among young transgender women in Lima, Peru.

Background: Latin America-amidst its largest mass migration-has seen minimal progress in curbing new HIV infections. Transgender women (TW) in the region are disproportionately affected, but scant data examines HIV vulnerabilities alongside migration.

Methods: Between February-July 2022, 211 young TW ages 16-24 in Lima participated in a cross-sectional quantitative study accompanied by serological testing (HIV, syphilis, chlamydia, gonorrhea, hepatitis B).

An Incognito Standardized Patient Approach for Measuring and Reducing Intersectional Healthcare Stigma: A Pilot Cluster Randomized Control Trial.

Background: Consistent evidence shows stigma impedes healthcare access in people living with HIV (PLWH) and men who have sex with men (MSM). We evaluated the impact of a stigma reduction training for providers whose design was informed by direct observation of their clinical behaviors obtained through visits by incognito standardized patient (SP).

Setting: We conducted this study in in sexually transmitted infection clinics in Guangzhou, China.