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Category: Ankle Arthritis; Ankle Introduction/Purpose: Tantalum coated metal spacers (TCMS) have recently been utilized to fill and provide structure to large bony defects in the hindfoot. TCMS have a porous structure and elastic modulus similar to cancellous bone, increasing resistance to collapse, as well as osteoconductive properties that allow for bony ingrowth. At this time, there is still a paucity of literature assessing the use and outcomes of TCMS in foot and ankle surgery, more specifically as bridging structures for large bony defects when performing tibiotalocalcaneal (TTC) arthrodesis. This study serves to assess clinical outcomes and fusion rates of patients who underwent TTC arthrodesis utilizing intramedullary nailing with tantalum coated metal cup augmentation for large bony defects. Methods: We retrospectively reviewed the charts of 20 patients who underwent TTC fusion with TCMS augmentation at our local tertiary care center between 2015-2021. The CT scans at the six-month post-operative window were reviewed by one orthopaedic surgeon to determine the presence of bony fusion, which was defined as having at least 50% fusion mass. From the initial cohort, we collected the following modified foot function index scores for 13 patients: PROMIS Physical Health (0-20), PROMIS Mental health (0-20), Foot Function Index (0-170), Activity Limitation Scale (0-30), Pain Scale (0-50) and Disability Scale (0-90). Results: The mean age of our cohort was 53.9 (± 12.9) with a mean CCI of 1.54 (± 1.127) and mean follow up of 451.5 days (± 353.3). Mean modified foot function index scores included: PROMIS Physical Health 12.15 (± 3.34), PROMIS Mental health 12.23 (± 4.82), Foot Function Index 91.08 (± 47.59), Activity Limitation Scale 15.00 (± 10.42), Pain Scale 25.00 (± 14.77) and Disability Scale 51.00 (± 25.06). The post-operative complication rate was 30.8% in which 3 patients required a revision surgery via nail dynamization and one patient required a below knee amputation due to an infected nonunion of the TTC arthrodesis. The overall fusion rate at the 6-month postoperative visit was 69.2%. Conclusion: Unlike prior studies, we were able to obtain 6-month post-operative CT scans to delineate successful fusions with a larger number of patients (n=13). Given the paucity of literature looking at TCMS augmented fusions in foot and ankle surgery, our data will contribute to our understanding and efficaciousness of this relatively new use of TCMS in foot and ankle surgery. Further studies are needed to evaluate the efficacy of TCMS augmented fusions as a viable surgical approach as well an alternative to standard nail dynamizations with structural grafts.

Category: Sports; Midfoot/Forefoot Introduction/Purpose: Running-related injuries are common despite technological advances in running shoes. Recently, there has been a movement towards barefoot/minimalist running. Proponents of barefoot running state that this style of running provides beneficial modifications to the gait cycle and prevents running-related injuries. The purpose of this review is to analyze the biomechanical consequences of barefoot/minimalist running and determine if barefoot/minimal style running prevents running- related injuries. Methods: A literature search was done on PUBMED using the keywords: Barefoot running, minimalist running, injury prevention, injury rate, foot-strike pattern, vertical loading rate, biomechanics, and clinical outcomes. Studies were then grouped into biomechanical studies and clinical outcome studies. Biomechanical studies were included if they analyzed outcomes such as: foot strike index/pattern, vertical loading rates, vertical ground reaction forces, joint angles, cadence, step length, or joint energy absorption. Clinical outcome studies were included if they analyzed injury rates and pain. Results: Biomechanical studies indicated that barefoot/minimalist running coincided with a transition to an anterior foot strike, lower vertical loading rates, higher cadences, less energy absorption at the knee joint, and higher energy absorption at the ankle joint. The clinical outcome studies indicated improvement of prior injuries and equivocal injury rates in the barefoot/minimal style running groups. Conclusion: Foot strike pattern is more important than footwear in regard to injury prevention and vertical loading rate. Switching to minimalist footwear improves running biomechanics with a more anterior foot strike, higher cadence, lower vertical loading rate, less knee energy absorption, and a shorter stride length. However, minimalist footwear places higher degrees of stress on the ankle joints and an increased injury rate when abruptly transitioning to barefoot running. Runners must weigh the risks and benefits and take caution to properly strengthen their feet and safely transition to minimalist running.

Category: Ankle Arthritis Introduction/Purpose: Total ankle replacement has risen in popularity as the contemporary treatment-of-choice for end-stage ankle osteoarthritis. INFINITY™ Total Ankle System (Stryker, Kalamazoo, MI) is one of the most frequently used ankle prostheses. Prior studies established positive functional outcomes; however, aseptic baseplate loosening has reported to occur in approximately one-third of patients. Aseptic baseplate loosening is seen radiographically either as shift in talar or tibial components or evidence of periprosthetic lucency. Aseptic baseplate loosening with persistent pain defines prosthesis failure, thus an indication for early surgical revision. Implementing bone cement may fixate and stabilize prostheses, potentially reducing incidence of aseptic baseplate loosening. This study aimed to determine if patients with cemented INFINITY total ankle prostheses had different incidence of aseptic baseplate loosening than those with cementless prostheses. Methods: Patients who underwent total ankle arthroplasty using the INFINITY total ankle prosthesis system between January 2016 and May 2022 (n = 28) were retrospectively identified using keyword search for “infinity” and Current Procedural Terminology (CPT) code 27702. Fourteen patients had prostheses affixed with cement, and fourteen patients had prostheses that were not cemented. Preoperative, immediate postoperative, and most recently available anteroposterior (AP), mortise, and lateral ankle X- rays were reviewed. Tibiotalar angle, talar tilt, and presence of visible postoperative lucency were assessed independently by two reviewers. Wilcoxon rank-sum test on quantitative variables and chi-square test on categorical variables were performed with 0.05 significance level. Results: Inter-rater reliability was above 94% for all measurements. Comparing the cemented to cementless sample group, difference in average age (59.5 years vs. 56.5 years, p=0.32) and sex (57.1% vs. 50.0% female, p=0.70) were not statistically significant. Pre-operative and immediate post-operative tibiotalar and talar tilt angles were not statistically significantly different between cement and cementless groups (p>0.31 for all comparisons). Only one patient in the cement group had evidence of periprosthetic lucency in the immediate postoperative period. Median follow-up was 362.5 days and 544.5 days in the cement and cementless group, respectively (p=0.52). Follow-up tibiotalar angles and talar tilt angle between cement and cementless groups were not significantly different (p>0.51 for all comparisons). Periprosthetic lucency occurred in 50% of both groups in the follow- up period (p=1.0). Conclusion: Patients with cemented INFINITY total ankle prostheses had equal incidence of aseptic baseplate loosening compared to patients with cementless prostheses. Continuing to examine methods for reducing incidence of baseplate loosening is significant for potentially reducing rate of early prosthesis revision and prosthesis failure, consequently improving quality of life for patients.

ABSTRACTThe eukaryome of mammals contains parabasalid protists that dramatically affect host immune function and health. However, the prevalence and diversity of parabasalids in wild reptiles and the consequences of captivity on these symbiotic protists are unknown. Reptiles are ectothermic, which expose their microbiomes to temperature fluctuations such as those driven by climate change. Thus, conservation efforts for threatened reptile species may benefit from understanding how shifts in temperature and captive breeding influence the microbiota, including parabasalids, to impact host fitness and disease susceptibility. Here, we surveyed intestinal parabasalids in wild reptiles from across three continents and compared these to captive animals. Reptiles harbor surprisingly few species of parabasalids compared to mammals, but these protists exhibited a flexible host range, suggesting specific adaptations to reptilian social structures and microbiota transmission. Furthermore, reptile-associated parabasalids are adapted to wide temperature ranges and survive colder temperatures significantly better than human-associated parabasalids. Colder temperatures altered the protist transcriptomes, causing increased expression of genes associated with detrimental interactions with their hosts. Our findings establish that parabasalids are widely distributed in the microbiota of both wild and captive reptiles and highlight how these protists respond to temperature fluctuations encountered in their ectothermic hosts.IMPORTANCEEnvironmental factors like climate change and captive breeding can impact the gut microbiota and host health. Therefore, conservation efforts for threatened species may benefit from understanding how these factors influence animal microbiomes. Parabasalid protists are members of the mammalian microbiota that can modulate the immune system and impact susceptibility to infections. However, little is known about parabasalids in reptiles. Here, we profile reptile-associated parabasalids in wild and captive reptiles and find that captivity has minimal impact on parabasalid prevalence or diversity. However, because reptiles are cold-blooded (ectothermic), their microbiotas experience wider temperature fluctuation than microbes in warm-blooded animals. To investigate whether extreme weather patterns affect parabasalid-host interactions, we analyzed the gene expression in reptile-associated parabasalids and found that temperature differences significantly alter genes associated with host health. These results expand our understanding of parabasalids in this vulnerable vertebrate group and highlight important factors to be taken into consideration for conservation efforts.

Within the United States (US), 2.4 million individuals are living with chronic hepatitis B, but less than 20% are diagnosed. Isolated anti-hepatitis B core (iAHBc) antibodies indicate serology in an individual that is positive for anti-HBc antibodies, while negative for surface antigen (HBsAg) and surface antibodies (anti-HBs). A result of iAHBc could indicate a chronic occult bloodstream infection, necessitating further testing. This study assesses the prevalence and risk factors associated with anti-HBc and iAHBc within community high-risk screening in Greater Philadelphia. Participants (n = 177) were screened for HBsAg, anti-HBs, and anti-HBc during community screening events in 2022. Chi-square tables and Firth logistic regression were used to describe the data and to assess the odds of iAHBc. The findings indicate that there was an iAHBc prevalence of 7.3% (n = 13) within our study. The odds of anti-HBc were increased for immigrants from the Western Pacific (4.5%) and Africa (11.9%). Individuals born in Africa had 7.93 greater odds for iAHBc than those born in the Americas, and these odds are multiplied by 1.01 for every 1-year increase in age. Our data show a high burden of iAHBc within high-risk and often hard-to-reach communities. Triple panel screening should be incorporated into all HBV screening programs, in accordance with current Centers for Disease Control and Prevention (CDC) universal screening recommendations, to ensure a comprehensive picture of the disease burden and reduce the risk of missing people with occult hepatitis B and those at risk for viral reactivation or liver complications.

The coexistence of ferroelectricity and metallicity seems paradoxical, since the itinerant electrons in metals should screen the long-range dipole interactions necessary for dipole ordering. The recent discovery of the polar metal LiOsO3 was therefore surprising [as discussed earlier in Y. Shi et al., Nat. Mater. 2013, 12, 1024]. It is thought that the coordination preferences of the Li play a key role in stabilizing the LiOsO3 polar metal phase, but an investigation from the combined viewpoints of core-state specificity and symmetry has yet to be done. Here, we apply the novel technique of extreme ultraviolet second harmonic generation (XUV-SHG) and find a sensitivity to the broken inversion symmetry in the polar metal phase of LiOsO3 with an enhanced feature above the Li K-edge that reflects the degree of Li atom displacement as corroborated by density functional theory calculations. These results pave the way for time-resolved probing of symmetry-breaking structural phase transitions on femtosecond time scales with element specificity.

Introduction: The readability of prescription drug labels has been found to be faster with labels attached to flat surfaces compared to round surfaces, in persons with visual impairment. This study extends this finding by examining the readability of drug labels, as measured by speed and accuracy, as they interact with factors of age and vision acuity across different container shapes. Methods: A repeated-measure, three-factor design (container shape, age, and vision acuity) with within-subject control was used with 54 adults with vision loss. Participants read 3 unique prescription drug labels across four container shapes, for a total of 12 trials. The amount of time needed to locate and read aloud 6 pieces of label information and the number of errors made in reading were outcome measures. Results: A two-way interaction was found between container shape and acuity for the time it takes to read the label information (Wald X[superscript 2] = 22.836, df = 3, p < 0.001). The legally blind group required more time to read the label and had more variation in mean times across container type, compared to the low vision group. Both age and acuity showed statistically significant (p < 0.001) main effects on reading accuracy. Discussion: Within the legally blind acuity group, cylinder-shaped containers took statistically significantly longer to read compared to the flat label by 18 seconds. Increased age and lower visual acuity negatively affected reading accuracy, across all container shapes. Implications for Practitioners: Individuals with legal blindness may need more time to read prescription drug labels and may benefit from labels adhered to flat surfaces over traditional cylindrical containers. As medication safety is a critical skill for independent living, practitioners should assess their clients' ability to access prescription drug label information, keeping in mind that these abilities may differ across different container shapes.

Abstract Lanthanides in the trivalent oxidation state are typically described using an ionic picture that leads to localized magnetic moments. The hierarchical energy scales associated with trivalent lanthanides produce desirable properties for e.g., molecular magnetism, quantum materials, and quantum transduction. Here, we show that this traditional ionic paradigm breaks down for praseodymium in the tetravalent oxidation state. Synthetic, spectroscopic, and theoretical tools deployed on several solid-state Pr4+-oxides uncover the unusual participation of 4f orbitals in bonding and the anomalous hybridization of the 4f 1 configuration with ligand valence electrons, analogous to transition metals. The competition between crystal-field and spin-orbit-coupling interactions fundamentally transforms the spin-orbital magnetism of Pr4+, which departs from the J eff = 1/2 limit and resembles that of high-valent actinides. Our results show that Pr4+ ions are in a class on their own, where the hierarchy of single-ion energy scales can be tailored to explore new correlated phenomena in quantum materials.

Topological solitons such as magnetic skyrmions have drawn attention as stable quasi-particle-like objects. The recent discovery of polar vortices and skyrmions in ferroelectric oxide superlattices has opened up new vistas to explore topology, emergent phenomena and approaches for manipulating such features with electric fields. Using macroscopic dielectric measurements, coupled with direct scanning convergent beam electron diffraction imaging on the atomic scale, theoretical phase-field simulations and second-principles calculations, we demonstrate that polar skyrmions in (PbTiO3)n/(SrTiO3)n superlattices are distinguished by a sheath of negative permittivity at the periphery of each skyrmion. This enhances the effective dielectric permittivity compared with the individual SrTiO3 and PbTiO3 layers. Moreover, the response of these topologically protected structures to electric field and temperature shows a reversible phase transition from the skyrmion state to a trivial uniform ferroelectric state, accompanied by large tunability of the dielectric permittivity. Pulsed switching measurements show a time-dependent evolution and recovery of the skyrmion state (and macroscopic dielectric response). The interrelationship between topological and dielectric properties presents an opportunity to simultaneously manipulate both by a single, and easily controlled, stimulus, the applied electric field.

The X-ray-induced spin crossover transition of an Fe (II) molecular thin film in the presence and absence of a magnetic field has been investigated. The thermal activation energy barrier in the soft X-ray activation of the spin crossover transition for [Fe{H2B(pz)2 }2 (bipy)] molecular thin films is reduced in the presence of an applied magnetic field, as measured through X-ray absorption spectroscopy at various temperatures. The influence of a 1.8 T magnetic field is sufficient to cause deviations from the expected exponential spin state transition behavior which is measured in the field free case. We find that orbital moment diminishes with increasing temperature, relative to the spin moment in the vicinity of room temperature.

The prevalence of hepatitis B and delta viruses (HBV/HDV) among people who use drugs (PWUD) remains largely unknown. In the context of one Philadelphia-based harm reduction organization (HRO), this study aimed to assess HBV/HDV prevalence and facilitate linkage to care. Participants completed a demographic HBV/HDV risk factor survey and were screened for HBV and reflexively for HDV if positive for HBV surface antigen or isolated core antibody. Fisher’s exact tests and regression were used to understand relationships between risks and HBV blood markers. Of the 498 participants, 126 (25.3%) did not have hepatitis B immunity, 52.6% had been vaccinated against HBV, and 17.9% had recovered from a past infection. Eleven (2.2%) participants tested positive for isolated HBV core antibody, 10 (2.0%) for HBV surface antigen, and one (0.2%) for HDV antibody. History of incarceration was associated with current HBV infection, while transactional sex and experience of homelessness were predictive of previous exposure. This study found high rates of current and past HBV infection, and a 10% HBV/HDV co-infection rate. Despite availability of vaccine, one quarter of participants remained vulnerable to infection. Findings demonstrate the need to improve low-threshold HBV/HDV screening, vaccination, and linkage to care among PWUD. The study also identified gaps in the HBV/HDV care cascade, including lack of point-of-care diagnostics and lack of support for HROs to provide HBV services.

High status occupations support positive health outcomes through providing access to both material and psychosocial resources. However, common measures of occupational status such as occupational prestige scores fail to capture cultural esteem that certain occupations can provide because they are primarily associated with the material dimensions of status, like income. Drawing on Weberian conceptions of status and a body of social psychological research on the measurement of cultural meaning, we argue that measuring people's ratings of their occupations on three dimensions—evaluation (good/bad), potency (powerful/weak), and activity (active/inactive)—provides an occupational status indicator that more fully captures psychosocial resources like esteem that are associated with health than more commonly used occupational prestige scores. Using a nationally representative longitudinal health and wellbeing survey of 940 American law enforcement officers collected between 2020 and 2022, we evaluate the predictive ability of evaluation, potency, and activity (EPA) ratings across thirteen measures of health and wellbeing. We find that EPA ratings were significant and positive predictors of eleven of thirteen outcomes with stronger effects for mental health outcomes compared to physical health outcomes. EPA ratings were more predictive than more commonly used occupational prestige scores. We conclude that EPA ratings are better predictors of health outcomes than occupational prestige scores and so may allow health researchers to better understand the relationship between occupational status and health.

Chiral interactions in magnetic systems can give rise to rich physics manifested, for example, as nontrivial spin textures. The foremost interaction responsible for chiral magnetism is the Dzyaloshinskii-Moriya interaction (DMI), resulting from inversion symmetry breaking in the presence of strong spin-orbit coupling. However, the atomistic origin of DMIs and their relationship to emergent electrodynamic phenomena, such as topological Hall effect (THE), remain unclear. Here, we investigate the role of interfacial DMIs in 3d-5d transition metal-oxide-based LaMnO3/SrIrO3 superlattices on THE from a chiral spin texture. By additively engineering the interfacial inversion symmetry with atomic-scale precision, we directly link the competition between interfacial collinear ferromagnetic interactions and DMIs to an enhanced THE. The ability to control the DMI and resulting THE points to a pathway for harnessing interfacial structures to maximize the density of chiral spin textures useful for developing high-density information storage and quantum magnets for quantum information science.

This paper presents a comprehensive examination of the current and emerging challenges in the governance of space activities, focusing on promoting safety and security. Key international treaties and esolutions, including those under the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS), are discussed, highlighting their evolution in response to changing geopolitical dynamics and the expansion of space activities across various sectors. The paper addresses several critical challenges: ensuring diverse global voices are heard in space governance, managing the dichotomy of space in terms of its strategic value and dual-use nature, achieving consensus among the rapidly growing number of space-faring nations, defining and delimiting space, adapting to the commercialization of space activities, and confronting the growing problem of space debris.

Pollen dispersal regulates the formation of the invasive, wind-pollinated hybrid cattail Typha * glauca Godron, the [F.sub.1] offspring of the broadleaf (Typha latifolia L.) and narrowleaf (Typha angustifolia L.) cattail. An earlier study suggested that pollen dispersal by T. latifolia might be spatially restricted, with most dispersal occurring over distances less than 2 m. Restricted pollen dispersal would imply that hybrid formation primarily occurs within mixed stands of cattails. Hybrid formation might also be affected by preferential receipt of conspecific pollen, but this has not been investigated for cattails. We compared patterns of pollen dispersal for T. latifolia and T. angustifolia using a wind tunnel. We then tested whether patterns of pollen receipt were biased toward the capture of conspecific versus heterospecific pollen using monospecific cattail stands with a single local pollen source. Results from the wind tunnel partially supported the previous finding of spatially restricted pollen dispersal for T. latifolia, the paternal parent of [F.sub.1] hybrids. Pollen receipt by T. angustifolia was biased toward the capture of conspecific pollen. Localized pollen dispersal by T. latifolia and preferential conspecific pollen capture by T. angustifolia should reduce rates of hybrid formation below that expected under random mating. Key words: pollen dispersal, hybridization, Typha, pollen receipt, wind tunnel, dispersal kernels La dispersion du pollen regit la formation de la quenouille hybride, envahissante et pollinisee par le vent, Typha * glauca Godron, la progeniture [F.sub.1] de la quenouille a feuilles larges (Typha latifolia L.) et de la quenouille a feuilles etroites (Typha angustifolia L.). Une etude anterieure a suggere que la dispersion du pollen par T. latifolia pourrait etre limitee dans l'espace, la dispersion se produisant dans la plupart des cas sur des distances inferieures a 2 m. Une dispersion limitee du pollen impliquerait que la formation d'hybrides se produit principalement au sein de peuplements mixtes de quenouilles. La formation d'hybrides pourrait egalement etre affectee par la reception preferentielle de pollen conspecifique, mais cela n'a pas ete etudie chez les quenouilles. Les auteurs ont compare les patrons de dispersion du pollen de T. latifolia et T. angustifolia en utilisant une souf-flerie. Ils ont ensuite teste si les patrons de reception du pollen etaient biaises en faveur de la capture du pollen conspecifique par rapport au pollen heterospecifique, en utilisant des peuplements de quenouilles monospecifiques avec une seule source locale de pollen. Les resultats obtenus en soufflerie ont partiellement corrobore la constatation precedente d'une dispersion du pollen limitee dans l'espace pour T. latifolia, le parent paternel des hybrides [F.sub.1]. La reception du pollen par T. angustifolia etait biaisee vers la capture de pollen conspecifique. La dispersion localisee du pollen par T. latifolia et la capture preferentielle du pollen conspecifique par T. angustifolia devraient reduire les taux de formation d'hybrides en dessous de ceux attendus en cas d'accouplement aleatoire. [Traduit par la Redaction] Mots-cles : dispersion du pollen, hybridation, Typha, reception du pollen, soufflerie, noyaux de dispersion., Introduction Once established, plants do not move but their genes do, and pollen dispersal is a major component of the movement of genes in and among plant populations. For individual [...]

Abstract Background Sparganium (Typhaceae) is a widespread temperate genus of ecologically important aquatic plants. Previous reconstructions of the phylogenetic relationships among Sparganium species are incompletely resolved partly because they were based on molecular markers comprising