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Abstract Glaciers are sensitive to environmental climatic conditions and show their variability over time. This study investigates the environmental characteristics and variation in glacial cover of the Greenwich, Livingston, Robert and Snow islands, Antarctica, between 1956 and 2023. The glacier extension mapping was based on visual interpretation of the Landsat 4, 7 and 8 optical images and normalised difference indexes combination. The REMA 8 digital elevation model was applied to the islands’ geomorphometric analysis. Results were compared to climatic series and environmental characteristics. The glacial coverage decreased by 16.9% from 1956 to 2023, equivalent to 209.95 ± 0.113 km². Snow Island, with shallow bathymetry near glacial margins and land-terminating ice-fronts, exhibited the smallest retreat rate values. The glacial coverage of Livingston Island decreased significantly (18%, equivalent to 153.2 ± 0.113 km²) from 1956-2021, representing the highest values in the study. The changes in glacial coverage of the Robert and Greenwich islands were more substantial in the 1989-2023 period than in 1956-1989. Sectors with marine-terminating glaciers, associated with high bathymetric amplitudes, exhibited more significant variations compared to other sectors, contributing to the evolution of fjord-type bays. Glacial coverage has been lost in recent decades due to regional atmospheric and oceanic warming.

Abstract Some Antarctic ice-free areas have been affected by changes in lacustrine zones and permafrost thawing due to rising air temperatures over the last 60 years Temperature time-series were analyzed to understand the processes leading to the changes of Boeckella and Buenos Aires lakes, north Antarctic Peninsula. Statistical calculations were applied to average, maximum, and minimum temperatures, as well as to indexes such as Positive Degrees Day, Freezing/Thaw Day, and days with temperatures ≥ 0 °C and ≥ 10 °C. Changes in the region over recent decades were observed in mean and maximum temperatures and an increase in minimum temperature since the mid-1990s. In addition, the Normalized Difference Water Index was extracted from Landsat images from 2003, 2016, 2020, and 2021. These images were used to calculate changes in the areas of Boeckella and Buenos Aires lakes. These data revealed an 87% decrease in the area (m²) of Boeckella Lake and a 60% increase in Buenos Aires Lake´s area (m²). Concern has been raised about the modifying lake areas in the Antarctic Peninsula, where the collapse of Boeckella Lake could be the first case recorded in ice-free areas of Antarctica continent.

Coronavirus disease 2019 (COVID-19) mRNA vaccines that have contributed to controlling the SARS-CoV-2 pandemic induce specific serum antibodies, which correlate with protection. However, the neutralizing capacity of antibodies for emerging SARS-CoV-2 variants is altered. Suboptimal antibody responses are observed in patients with humoral immunodeficiency diseases, ongoing B cell depletion therapy, and aging. Common experimental mouse models with altered B cell compartments, such as B cell depletion or deficiency, do not fully recapitulate scenarios of declining or suboptimal antibody levels as observed in humans. We report on SARS-CoV-2 immunity in a transgenic mouse model with restricted virus-specific antibodies. Vaccination of C57BL/6-Tg(IghelMD4)4Ccg/J mice with unmodified or N1mΨ-modified mRNA encoding for ancestral spike (S) protein and subsequent challenge with mouse-adapted SARS-CoV-2 provided insights into antibody-independent immunity and the impact of antibody titers on mucosal immunity. Protection against fatal disease was independent of seroconversion following mRNA vaccination, suggesting that virus-specific T cells can compensate for suboptimal antibody levels. In contrast, mRNA-induced IgG in the nasal conchae limited the local viral load and disease progression. Our results indicate that parenteral mRNA immunization can elicit nasal IgG antibodies that effectively suppress local viral replication, highlighting the potential of vaccines in controlling SARS-CoV-2 transmission and epidemiology.

Abstract Despite the availability of live-attenuated oral vaccines, rotavirus remains a major cause of severe childhood diarrhea worldwide. Due to the growing demand for parenteral rotavirus vaccines, we developed mRNA-based vaccine candidates targeting the viral spike protein VP8*. Our monomeric P2 (universal T cell epitope)-VP8* mRNA design is equivalent to a protein vaccine currently in clinical development, while LS (lumazine synthase)-P2-VP8* was designed to form nanoparticles. Cyro-electron microscopy and western blotting-based data presented here suggest that proteins derived from LS-P2-VP8* mRNA are secreted in vitro and self-assemble into 60-mer nanoparticles displaying VP8*. mRNA encoded VP8* was immunogenic in rodents and introduced both humoral and cellular responses. LS-P2-VP8* induced superior humoral responses to P2-VP8* in guinea pigs, both as monovalent and trivalent vaccines, with encouraging responses detected against the most prevalent P genotypes. Overall, our data provide evidence that trivalent LS-P2-VP8* represents a promising mRNA-based next-generation rotavirus vaccine candidate.

Immunogenicity of HIV-1 mRNA vaccine regimens was analyzed in a non-human primate animal model. Rhesus macaques immunized with mRNA in lipid nanoparticle (mRNA/LNP) formulation expressing HIV-1 Gag and Gag conserved regions (CE) as immunogens developed robust, durable antibody responses but low adaptive T-cell responses. Augmentation of the dose resulted in modest increases in vaccine-induced cellular immunity, with no difference in humoral responses. The gag mRNA/lipid nanoparticle (LNP) vaccine provided suboptimal priming of T cell responses for a heterologous DNA booster vaccination regimen. In contrast, a single immunization with gag mRNA/LNP efficiently boosted both humoral and cellular responses in macaques previously primed by a gag DNA-based vaccine. These anamnestic cellular responses were mediated by activated CD8+ T cells with a phenotype of differentiated T-bet+ cytotoxic memory T lymphocytes. The heterologous prime/boost regimens combining DNA and mRNA/LNP vaccine modalities maximized vaccine-induced cellular and humoral immune responses. Analysis of cytokine responses revealed a transient systemic signature characterized by the release of type I interferon, IL-15 and IFN-related chemokines. The pro-inflammatory status induced by the mRNA/LNP vaccine was also characterized by IL-23 and IL-6, concomitant with the release of IL-17 family of cytokines. Overall, the strong boost of cellular and humoral immunity induced by the mRNA/LNP vaccine suggests that it could be useful as a prophylactic vaccine in heterologous prime/boost modality and in immune therapeutic interventions against HIV infection or other chronic human diseases.

The Kitaev interaction, found in candidate materials such as α-RuCl_{3}, occurs through the metal (M)-ligand (X)-metal (M) paths of the edge-sharing octahedra because the large spin-orbit coupling (SOC) on the metal atoms activates directional spin interactions. Here, we show that even in 3d transition-metal compounds, where the SOC of the metal atom is negligible, heavy ligands can induce bond-dependent Kitaev interactions. In this work, we take as an example the 3d transition-metal chalcogenophosphate NiPSe_{3} and show that the key is found in the presence of a sizable SOC on the Se p orbital, one which mediates the super-exchange between the nearest-neighbor Ni sites. Our study provides a pathway for engineering enhanced Kitaev interactions through the interplay of SOC strength, lattice distortions, and chemical substitutions.

Abstract: Aim We investigated the hypothesis that flood decreases the taxonomic and functional beta diversity of Chironomidae (Diptera) larvae among floodplain lakes, causing biotic homogenization. Methods We collected benthic samples using a modified Petersen grab in 18 lakes in a flood period (March 2011) and a drought period (September 2011) in the Upper Paraná River floodplain. We compared the taxonomic and functional beta diversity of Chironomidae among lakes in flood and drought periods using a multivariate dispersion analysis (PERMDISP). Results We found similar taxonomic and functional beta diversity of the Chironomidae between hydrological periods. Conclusions We did not find evidence of biotic homogenization due to flood pulse. Our findings suggest other mechanisms besides increasing connectivity and environmental similarity due to flood pulse that may structure the benthic community, such as variation in the identity of flood-tolerant morphospecies across lakes.

Abstract This study investigates the transient snowline (TSL) altitude for summer 2020, as well as glacial area loss in King George Island Icefields since 1988 using Sentinel-1 and 2 and Landsat Thematic Mapper (TM) imagery. Trends and anomalies in atmospheric temperature, U-wind, and V-wind were examined using ERA5 solutions. Results show the wet-snow zone corresponds to values of ≤ -13dB, and 44.3% of the glacial area is located above the TSL (≥ 300 m). Glacial area for 2020 is 999.95 km², and losses in the period represent 104.9 km² (error

Abstract This study aims to investigate the glacier shrinkage and recent proglacial environment in King George Bay, Antarctica, since 1988 in response to climate change. Remote sensing data (SPOT, Sentinel, Landsat and Planet Scope images) were applied to glacial landforms and ice-marginal fluctuations mapping. Annual mean near-surface air temperature reanalysis solutions from ERA-Interim were analyzed. Moraines and glaciofluvial landforms were identified. The Ana Northern Glacier has the highest retreat value (3.64 km) (and area loss of 31%) in response to higher depth in frontal ice-margin and reveal ocean-glacier linkages. The Ana South Glacier changed from a tidewater glacier to land-terminating after 1995, and had an outline minimum elevation variation of 89 meters, a shrinkage of 0.63 km, and a new proglacial subaerial sector. The Ana South Glacier foreland had recessional moraines (probably formed between 1995 and 2022), lagoons, and lakes. There are many flutings in low-relief environments. The 1980-1989, 1990-1999, 2000-2009, 2010-2019 anomaly plots concerning to the 1980-2019 average for atmospheric temperature, are shown to be a driver of the local glacial trends.

The typical sound of George Lucas' laser blaster in the "Star Wars" series is well known. What does a laser blaster in "Star Wars" sound like, and why? Here we show a simple way to produce this sound by using low-cost lab material, like a spring or a Slinky. Building on the work of Crawford, who analyzed the sound of a Slinky using oscilloscopes, we present a technique for analyzing the sound using mobile devices. For a deeper quantitative analysis, a PC with open-source software is used.

A third vaccine dose is often required to achieve potent, long-lasting immune responses. We investigated the effect of three 8-μg doses of CVnCoV, CureVac’s severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine candidate containing sequence-optimized unmodified mRNA encoding the spike (S) glycoprotein, administered at 0, 4, and 28 weeks, on immune responses in rhesus macaques. After the third dose, S-specific binding and neutralizing antibodies increased 50-fold compared with post-dose 2 levels, with increased responses also evident in the lower airways and against the SARS-CoV-2 B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), and B.1.617.2 (Delta) variants. Enhanced binding affinity of serum antibodies after the third dose correlated with higher somatic hypermutation in S-specific B cells, corresponding with improved binding properties of monoclonal antibodies expressed from isolated B cells. Administration of low-dose mRNA led to fewer cells expressing antigen in vivo at the injection site and in the draining lymph nodes compared with a 10-fold higher dose, possibly reducing engagement of precursor cells with the antigen and resulting in the suboptimal response observed after two-dose vaccination schedules in phase IIb/III clinical trials of CVnCoV. However, when immune memory is established, a third dose efficiently boosts the immunological responses and improves antibody affinity and breadth.

Contexto: A pesquisa apresenta a prática pedagógica da super-herói/super-heroína do continente Antártico como recurso para desenvolver a educação polar no Brasil. A metodologia consiste em três etapas. Na primeira etapa, são apresentados materiais como slides, mapas, vídeos e fotografias da Antártica, proporcionando aos alunos uma visão geral desse ambiente remoto e seus problemas ambientais. Na segunda etapa, os alunos participam de debates sobre a Antártica, questionando informações errôneas frequentemente encontradas na mídia, o que permite uma compreensão mais precisa da região. A terceira etapa envolve a criação de desenhos que representem super-heróis/super-heroínas do continente Antártico, com superpoderes para combater os impactos ambientais. Considerações: Embora os alunos enfrentem dificuldades em pensar em soluções concretas para intervir nos problemas ambientais da Antártica, a atividade proporciona resultados relevantes, com avanço significativo na compreensão dos alunos sobre a Antártica. A prática pedagógica mostra-se promissora para promover o aprendizado sobre a educação polar no Brasil, mas é importante incentivar os alunos a desenvolverem soluções mais concretas para os problemas enfrentados na Antártica e explorar abordagens pedagógicas criativas para enriquecer a educação polar no país.

The paper aims to reconstruct the fluctuations of Dobrowolski Glacier, a tidewater glacier located in the inner position of the Admiralty Bay (King George Island, Antarctica), from the Little Ice Age (1400-1700) until the present. Measurements of the glacier’s area and length were based on multitemporal satellite imagery and submarine glacial landforms. The glacier surface area variations between the Little Ice Age and 2014 A.D were estimated. Morainic banks and paleoglacial reconstructions provided evidence of fluctuations in the surface area of the glacier between PIG and 2014 AD. Therefore, four stages of analysis were established: Stage I (Part I) (1400 to 1700), Stage I (Part II) (1700 until the mid-20th century), Stage II (mid-20th century until the 1980s), Stage III (1980 to 2000), and Stage IV (2000 to 2020). The climate during the Little Ice Age triggered the last major glacial advance, and their grounding line position was recorded by an external and prominent morainic bank. After the major glacial advance position of the grounding line, the ice-margin has undergone higher retreat rates (stage I) as response to the warming trend and the loss of anchoring point. The stage II (Unit B) is recorded by distal and discontinuous morainal ridges and glacial lineations formed in the context of an active ice flow at a deeper point in the fjord. During stage III (Unit C) glacial lineations and steep slopes occur, while landforms are less preserved, revealing a fast shrinkage phase. Stage IV is characterized by discontinuous morainic ridges (Unit D), when the glacier presents the highest annual glacial area loss. Currently, the accelerated shrinkage may be linked to the loss of anchorage on seamounts (serving as pinning points) and increased warming. The U-shaped valley geometry has also influenced the glacier shrinkage processes and the redirection of glacial paleoflow during the last 300 years. The retreat rate to mid-20th century-2020 period is higher than Little Ice Age- mid-20th century period.

Human rotavirus (HRV) is still a leading cause of severe dehydrating gastroenteritis globally, particularly in infants and children. Previously, we demonstrated the immunogenicity of mRNA-based HRV vaccine candidates expressing the viral spike protein VP8* in rodent models. In the present study, we assessed the immunogenicity and protective efficacy of two mRNA-based HRV trivalent vaccine candidates, encoding VP8* of the genotypes P[8], P[6], or P[4], in the gnotobiotic (Gn) pig model of Wa (G1P[8]) HRV infection and diarrhea. Vaccines either encoded VP8* alone fused to the universal T-cell epitope P2 (P2-VP8*) or expressed P2-VP8* as a fusion protein with lumazine synthase (LS-P2-VP8*) to allow the formation and secretion of protein particles that present VP8* on their surface. Gn pigs were randomly assigned into groups and immunized three times with either P2-VP8* (30 µg) or LS-P2-VP8* (30 µg or 12 µg). A trivalent alum-adjuvanted P2-VP8* protein vaccine or an LNP-formulated irrelevant mRNA vaccine served as the positive and negative control, respectively. Upon challenge with virulent Wa HRV, a significantly shortened duration and decreased severity of diarrhea and significant protection from virus shedding was induced by both mRNA vaccine candidates compared to the negative control. Both LS-P2-VP8* doses induced significantly higher VP8*-specific IgG antibody titers in the serum after immunizations than the negative as well as the protein control. The P[8] VP8*-specific IgG antibody-secreting cells in the ileum, spleen, and blood seven days post-challenge, as well as VP8*-specific IFN-γ-producing T-cell numbers increased in all three mRNA-vaccinated pig groups compared to the negative control. Overall, there was a clear tendency towards improved responses in LS-P2-VP8* compared to the P2-VP8*mRNA vaccine. The demonstrated strong humoral immune responses, priming for effector T cells, and the significant reduction of viral shedding and duration of diarrhea in Gn pigs provide a promising proof of concept and may provide guidance for the further development of mRNA-based rotavirus vaccines.

Abstract Definitive understanding of superconductivity and its interplay with structural symmetry in the hole-doped lanthanum cuprates remains elusive. The suppression of superconductivity around 1/8th doping maintains particular focus, often attributed to charge-density waves (CDWs) ordering in the low-temperature tetragonal (LTT) phase. Central to many investigations into this interplay is the thesis that La1.875Ba0.125CuO4 and particularly La1.675Eu0.2Sr0.125CuO4 present model systems of purely LTT structure at low temperature. However, combining single-crystal and high-resolution powder X-ray diffraction, we find these to exhibit significant, intrinsic coexistence of LTT and low-temperature orthorhombic domains, typically associated with superconductivity, even at 10 K. Our two-phase models reveal substantially greater tilting of CuO6 octahedra in the LTT phase, markedly buckling the CuO2 planes. This would couple significantly to band narrowing, potentially indicating a picture of electronically driven phase segregation, reminiscent of optimally doped manganites. These results call for reassessment of many experiments seeking to elucidate structural and electronic interplay at 1/8 doping.

Abstract mRNA vaccines can be developed and produced quickly, making them prime candidates for immediate outbreak responses. Furthermore, clinical trials have demonstrated rapid protection following mRNA vaccination. Thus, we sought to investigate how quickly mRNA vaccines elicit antibody responses compared to other vaccine modalities. We first compared the immune kinetics of mRNA and DNA vaccines expressing SARS-CoV-2 spike in mice. We observed rapid induction of antigen-specific binding and neutralizing antibodies by day 5 following mRNA (4 µg/mouse), but not DNA (50 µg/mouse), immunization. Comparing innate responses hours post immunization, the mRNA vaccine induced increased levels of IL-5, IL-6, and MCP-1 cytokines which maybe promoting humoral responses downstream. We then evaluated the immune kinetics of an HIV-1 mRNA vaccine in comparison to DNA, protein, and rhesus adenovirus 52 (RhAd52) vaccines of the same HIV-1 envelope antigen in mice. Again, induction of envelope-specific antibodies was observed by day 5 following mRNA vaccination, whereas antibodies were detected by day 7–14 following DNA, protein, and RhAd52 vaccination. Thus, eliciting rapid humoral immunity may be a unique and advantageous property of mRNA vaccines for controlling infectious disease outbreaks.

In unconventional superconductors, coupled charge and lattice degrees of freedom can manifest in ordered phases of matter that are intertwined. In the cuprate family, fluctuating short-range charge correlations can coalesce into a longer-range charge density wave (CDW) order which is thought to intertwine with superconductivity, yet the nature of the interaction is still poorly understood. Here, by measuring subtle lattice fluctuations in underdoped YBa2Cu3O6+y on quasi-static timescales (thousands of seconds) through X-ray photon correlation spectroscopy, we report sensitivity to both superconductivity and CDW. The atomic lattice shows remarkably faster relaxational dynamics upon approaching the superconducting transition at Tc ≈ 65 K. By tracking the momentum dependence, we show that the intermediate scattering function almost monotonically scales with the relaxation distance of atoms away from their average positions above Tc and in the presence of the CDW state, while this peculiar trend is reversed for other temperatures. These observations are consistent with an incipient CDW stabilized by local strain. This work provides insights into the crucial role of relaxational atomic fluctuations for understanding the electronic physics cuprates, which are inherently disordered due to carrier doping. [ABSTRACT FROM AUTHOR]

Background: Some patients express concerns regarding receipt of allogeneic blood transfusions from donors potentially vaccinated against SARS‐CoV‐2 (COVID‐19). However, limited information exists about patients' expression of these concerns or how to address them during the blood transfusion consent process. In this study, we describe our experience of working collaboratively with patients with vaccine‐related transfusion concerns prior to elective surgery, summarizing treatment decisions and clinical outcomes. Study Design and Methods: This observational descriptive study includes patients seen in our Bloodless Medicine and Surgery clinic between June 2022 and June 2024 for vaccine‐related transfusion concerns prior to elective surgery. A shared decision‐making framework was employed to foster conversation, share information, provide reassurance, reconcile conflict, and match preferences with available care options. Patient characteristics, treatment decisions, and surgical outcomes were reviewed and summarized. Results: Thirty‐five patients were included, with median (1st, 3rd quartile) age of 61 (53, 69) years. Cardiac surgery was the most common type of surgery (29%). Twelve patients (34%) were anemic preoperatively, and all received preoperative treatment. After discussion with a Bloodless Medicine specialist, 24 (68.6%) decided to consent to the use of all blood products, 5 (14.3%) accepted only red blood cells, and 6 (17.1%) declined all blood products. Among 28 patients undergoing surgery, only 4 (14%) received allogeneic transfusion perioperatively. Conclusion: Many patients concerned about the vaccination status of blood donors may ultimately consent to allogeneic blood products after shared decision‐making with a Bloodless Medicine specialist, highlighting the importance of patient empowerment and collaborative care. [ABSTRACT FROM AUTHOR]