Search Results (697)

Clinically, bone mineral density (BMD) accounts for only approximately 50% of the observed variance in bone fragility fractures. This review examines the dynamic and mechanistic role of the non-collagenous organic matrix, specifically proteoglycans (PGs) and glycosaminoglycans (GAGs), in maintaining bone toughness and bone quality. During aging, bulk cortical GAG levels decrease by up to ~17% and are highly associated with reduced bone tissue toughness. We analyze how this age-related loss may arise from uncoupled bone remodeling and tissue aging, including the accumulation of older, interstitial tissue and dysregulated osteocyte-mediated matrix maintenance. We then discuss the functional importance of PG/GAG composition, maturation, and catabolism and how perturbations in these processes can promote pro-inflammatory signaling that accelerates matrix degradation and contributes to systemic aging. Lastly, we discuss potential interventions to preserve or restore GAGs/PGs in bone and improve overall bone quality. Full article

Reducing input costs, especially feed ingredients, remains a priority for production agriculture. Identifying and selecting nutritionally dense ingredients is vital to maximize animal performance. Objectives of the current study were to evaluate the impact of biochar supplementation on goat carcass characteristics and fresh meat quality. Goats (N = 36) were allocated to a diet concentration formulated with or without (Control, Low, Medium, or High g/kg) biochar. After 60 days of feeding, goats were harvested, and carcass measurements were collected. Subprimals from the leg were fabricated into steaks for laboratory analysis of surface color, cook loss, and instrumental tenderness. Biochar supplementation did not alter organ weights (p = 0.0614), dressing percentage (p = 0.8139), loin eye area (p = 0.9570), or tenderness (p = 0.0144). However, marbling scores were lower in goats fed at the medium biochar supplementation rate (p = 0.0114) and high supplementation (p = 0.0102) compared to the control. An interaction between storage day and biochar supplementation was recorded for instrumental surface color lightness (L*; p = 0.0016), redness (a*; p = 0.0547), hue angle (p = 0.0313), and red-to-brown (p = 0.0591). Steaks from the 0.052% supplementation group exhibited greater (p = 0.0003) redness (a*) during a 7-day refrigerated display and increased chroma values (p < 0.0001). Storage duration influenced all color traits, with steak surface discoloration increasing as storage time increased (p < 0.0001). Results conclude that biochar supplementation does not negatively impact all carcass quality or tenderness traits, but may influence fat deposition and improve meat color stability. Full article

Youth mentoring is a popular means for preventing negative psychosocial outcomes (e.g., high-risk behaviors, school dropout) and promoting positive ones (e.g., matriculation, goal setting). Mentors matched with youth through formal programs, such as Big Brothers Big Sisters, are uniquely positioned to promote the development of the mentee’s positive educational attitudes, beliefs, and behaviors (EABBs; e.g., academic engagement, grit, growth mindset). While school staff, such as school psychologists, are often unable to directly serve all students in need of support due to lack of time or large caseloads, youth mentoring may be a means to target EABB development. However, a critical precursor to leveraging mentoring for this purpose is understanding whether and how mentoring relationships influence youth EABBs. Despite extensive research on youth mentoring, relatively little work has examined mentoring outcomes specifically in relation to EABBs. This study addresses this gap by examining how young people benefit from mentoring relationships in relation to EABBs. A scoping review was conducted to determine the effects of program-sponsored mentoring relationships on EABBs, as well as which factors influence these effects. Results from 17 studies indicate small to moderate positive effects of youth mentoring on EABB development. Several factors, such as the relational context, the ecological context, and mentoring processes, appear to impact these effects. We highlight practical implications for how school personnel may use this information to partner with community-based mentoring programs to promote EABBs. Full article

Silicate rocks represent alternative K sources when finely ground, reducing production costs and dependence on imported fertilizers. Therefore, this study aimed to evaluate the effects of potassium (K) dose, application timing, and fertilizer sources on the concentrations and accumulation of K, silicon (Si), and sodium (Na) in maize diagnostic leaves, straw, and grains under a no-tillage system in Savanna. The soil was classified as Typic Haplustox (Oxisol). The experiment followed a randomized block design in a 2 × 4 × 3 factorial scheme, with two application times (30 days before sowing soybean and at sowing soybean), four K₂O rates (0, 40, 80, and 120 kg ha⁻¹), and three sources (KCl, Potasil, and Ekosil). K fertilization was applied by broadcasting without incorporation, before the preceding crop. Potasil provided a higher foliar Si concentration, and Si accumulation in grain and straw increased with the increment of K fertilization using the Potasil. Early fertilization promoted greater K accumulation in maize straw. For grain K accumulation, moderate K₂O doses favor greater accumulation, with Ekosil and Potasil showing superior results compared to KCl. There was less sodium accumulation in the grains with Ekosil compared to KCl. Agronomic efficiency is maximized at 40 kg ha⁻¹ of K₂O, with Ekosil showing the best performance for maize crop. These findings indicate that alternative K sources, applied at optimized rates, improve crop nutrition and promote sustainability in soybean–maize crop rotation. Full article

Transmissible spongiform encephalopathies (TSE) are fatal neurodegenerative diseases caused by the misfolding of proteins generated in the exon 3 region of the prion protein gene (PRNP). Recent investigations using protein misfolding cyclic amplification assays indicated that some canids displayed a low susceptibility to TSE due to a specific nonsynonymous substitution (human: N159D/E; canid: N163D/E; alignment herein: N302D/E) in the prion protein that may confer protection against prion seeding activity and propagation. To examine the molecular evolution underlying this observation, we determined the mammalian taxonomic distribution of the N159D/E substitution in 882 PRNP sequences representing 26 Orders, 132 families, and 686 species. Two families each in Carnivora (Canidae and Mustelidae) and Chiroptera (Mormoopidae and Vespertilionidae), and one family each in Artiodactyla (Moschidae) and Rodentia (Erethrizontidae), possessed N159D/E that has been reported to confer resistance to TSEs. Although no direct evidence linked a pattern of resistance (phylogenetic relatedness, geographic location, etc.) in these diverse species, it may be that coevolutionary pressures led 53 of the examined 686 species (1 domestic species, 52 wild species) to possess N159D/E. Therefore, the presence of N159D/E may not be the only factor in determining sensitivity to prion diseases; consequently, a more detailed investigation into the 53 species, such as knockout experiments, is warranted. Full article

Orientia tsutsugamushi is an obligate intracellular alphaproteobacterium and the causative agent of the potentially fatal rickettsiosis, scrub typhus. During infection, O. tsutsugamushi replicates exclusively in the eukaryotic cytosol near mitochondria and alters host metabolic pathways governed by mitochondria. We report that O. tsutsugamushi induces mitochondrial enzymatic impairment and structural abnormalities without altering mitochondrial abundance or the levels of proteins that maintain mitochondrial homeostasis. Confocal and structured illumination microscopy revealed a selective spatial association between O. tsutsugamushi and the mitochondrial membrane protein, voltage-dependent anion channel (VDAC) but not other mitochondrial proteins. Immunosignal for VDAC paralogs 1 and 3 colocalized with cytosolic O. tsutsugamushi organisms whereas VDAC2 did not. Additionally, the antibody specific for VDAC1 and VDAC3 detected proteins of the expected sizes in Orientia membrane fractions. These findings indicate that O. tsutsugamushi negatively impacts mitochondrial function without overt organelle loss and selectively associates with VDAC1/VDAC3. Full article

Amphibians are threatened globally by habitat loss and emerging diseases, yet information on their diversity and distribution remains scarce in many regions. Ethiopia is renowned for its rich anuran diversity, but little is known about the diversity and abundance of anurans in Chebera Churchura National Park (CCNP). We conducted surveys from June 2022 to April 2024 along transects in various habitats during both dry and wet seasons. Methods included visual encounter surveys, acoustic monitoring, opportunistic observations, and pitfall traps with drift fences. Species identification was primarily based on morphology and subsequently validated through genetic barcoding using mitochondrial 16S rRNA sequence analysis for five species. A total of 2175 individuals were recorded, representing 16 species from 8 families. The families Bufonidae and Ptychadenidae were the most dominant. Riverine forest habitats exhibited the highest anuran diversity, followed by montane forest, woodland, and savannah grassland. These findings underscore the importance of CCNP as a refuge for Ethiopian anuran species and the need for further research into the park’s unexplored areas. Full article

Van Maldergem Syndrome (VMS) is a rare autosomal recessive disorder caused by pathogenic variants in the atypical cadherin genes DCHS1 or FAT4 and is marked by craniofacial, skeletal, and neurodevelopmental abnormalities. Although DCHS1–FAT4 binding is mediated by their respective extracellular domains, the in vivo function of the DCHS1 intracellular domain (ICD) is poorly defined. To test its function, we generated mice in which the DCHS1 ICD was deleted and replaced with a V5 epitope tag (Dchs1^ΔICD-V5). Homozygous Dchs1^{ΔICD-V5/ΔICD-V5} mice are viable but exhibit VMS-like craniofacial flattening with enlarged fontanelles and reduced palatine/maxillary structures, along with airway cartilage abnormalities including reduced mineralization and decreased tracheal circularity. In periventricular regions, wild-type DCHS1 expression shows polarized localization, whereas mice with the ICD deletion exhibit altered cell polarization within the subventricular zone, concomitant with changes in neural cellular distribution. Neonatal brains display reduced pYAP1: YAP1 ratios and increased Ki67+ proliferation with greater Ki67–neuronal co-localization within the periventricular zone. Together, these data identify the DCHS1 ICD as a critical effector for DCHS1 signaling and a regulator of polarity-dependent growth, with associated changes in Hippo pathway activity during craniofacial and neural morphogenesis. Additionally, our data establish Dchs1^{ΔICD-V5/ΔICD-V5} mice as a model that recapitulates core features of VMS, thereby allowing new mechanistic discoveries into its pathogenesis. Full article

Background/Objectives: Fentanyl test strips (FTS) are a harm reduction tool used to detect fentanyl in illicit substances. However, little is known regarding Americans’ beliefs regarding FTS. Therefore, the purpose of this study was to assess the U.S. general public’s FTS knowledge and perceptions. Methods: This study utilized a cross-sectional design. Adults ≥18 residing in the U.S. were recruited to participate in an anonymous online survey via Amazon Mechanical Turk (MTurk). Participants received $5 upon survey completion. The survey instrument was informed by the Health Belief Model, and primary outcome measures included: (1) FTS knowledge (13-items); (2) perceived susceptibility to fentanyl exposure (8-items); (3) perceived severity of fentanyl exposure (10-items); (4) perceived FTS benefits (9-items); (5) perceived barriers to FTS access (13-items); (6) comfort using and accessing FTS (15-items); (7) confidence using and accessing FTS (11-items); and (8) FTS utilization intentions (6-items). Outcomes were measured via 5-point Likert-type scales (1 = strongly disagree, 5 = strongly agree). Data were analyzed using descriptive statistics and Mann–Whitney U tests to compare differences in scale scores across participant sociodemographics. Predictors of FTS utilization intentions were assessed via multiple linear regression, controlling for participant age, race, sex, geographic setting (rural/urban), and recreational drug use history (yes/no) (α = 0.05). Results: Of n = 206 respondents, the majority were male (55.8%) and White (83.0%) with a mean age of 46.4. Approximately 81% resided in urban areas and 58.5% reported a history of recreational drug use. Participants who identified as Black, Asian, Indigenous, Pacific Islander, or Multiracial reported significantly higher mean (SD) perceived susceptibility compared to White participants (2.06 [0.54] vs. 1.91 [0.58]; p = 0.034). Participants residing in urban areas reported significantly higher comfort using and accessing FTS (3.61 [0.86]) than those in rural areas (3.29 [0.92]; p = 0.048), and younger individuals (≤44.5 years) were more confident in their ability to access FTS (3.75 [0.73]) compared to their older counterparts (3.60 [0.64]; p = 0.048). Perceived susceptibility (β = 0.442; p < 0.001), benefits (β = 0.250; p = 0.020), and comfort (β = 0.453; p < 0.001) were positive predictors of FTS utilization intention (R² = 0.417). Conclusions: Perceptions regarding FTS varied across race, geographic setting, and age. Perceived susceptibility, perceived benefits, and comfort positively predicted the U.S. general public’s FTS utilization intentions. Future interventions may leverage these influential factors to enhance FTS uptake. Full article

The method of X-ray footprinting and mass spectrometry (XFMS) using high flux synchrotron X-ray sources has become an established method in structural biology and is based on the radiolytic production of hydroxyl radicals, which oxidatively modify protein sidechains. While other methods of producing hydroxyl radicals are available, one benefit of using high flux density sources is that hydroxyl radical scavenging reactions can be minimized, and exposure times kept short to minimize secondary reactions. Here we present an application of the XFMS method using low dose rate X-rays from a commercial instrument. We demonstrate the feasibility of the approach using short peptides, characterizing the oxidative modifications +14, +16, and +32 Da under both aerobic and low oxygen conditions, and we additionally quantify the hydrogen peroxide production for various doses using the low dose rate source. These results provide fundamental information on the oxidative damage to peptides due to hydroxyl radicals using a low dose rate X-ray source. Full article

This entry surveys the role of extra dimensions in Newtonian quantum cosmology, with particular emphasis on large, compactified, and warped dimensional geometries and their impact on the Newtonian potential in the early universe. The discussion begins with a review of Kaluza–Klein type toy models, followed by models with large extra dimensions in which gravity propagates into a higher-dimensional bulk, producing Yukawa-like modifications to the inverse-square law at submillimeter scales. Compactification schemes on toroidal and spherical dimensions are then examined, yielding the spectrum of Kaluza–Klein modes and quantifying their corrections to the Newtonian potential. Warped extra dimensions of the Randall–Sundrum type are also considered, in which a warp factor dimension is introduced; the resulting modifications to the Newtonian interaction in quantum-corrected cosmological settings are discussed in detail. Full article

Background: Agriculture degrades soils, affects the delivery of ecosystem services, and contributes to climate change. Methods: This research examined nitrogen and sulfur recycling in soils under cropland expansion in Ghana at (a) reconnaissance scale in northern Guinea savannah (NGS), southern Guinea savannah (SGS), forest–savannah transition (FST), and semi-deciduous forest (SDF) agro-ecological zones (AEZs), and (b) farm level in rain Forest and the FST AEZs based on “duration of cultivation”. Fresh soils (20 cm depth) were incubated for 28 days at 28 °C, followed by the determination of mineralized nitrogen and sulfur at 14 and 28 days using standard methods. Results: Low nitrogen and sulfur contents led to predominant nitrogen and minor sulfur immobilizations, particularly in FST and savannah AEZs. Microbial biomass and pedogenic Fe controlled much of the nitrogen immobilization. At the farm level, dithionite Al and soil pH controlled nitrogen immobilization, particularly in relatively older farms, being pronounced in forest-related AEZs. Conclusions: Although the study is laboratory-based, it highlights the severe nature of soil degradation (SD) under cropland expansion in regions prone to poor nutrient budgets. Therefore, it calls for drastic measures to halt SD by adopting ecozone- and climate-driven sustainable soil management and agricultural systems. Full article

Influenza is a persistent public health concern worldwide. The elucidation of influenza A virus (IAV)–host interactions and the identification of host factors that regulate IAV infection would be beneficial for combating and treating the disease. Ceramides, comprising a host sphingolipid family, have been shown to regulate virus infections. However, the effect of IAV on individual ceramides remains unknown. This study aimed to investigate the changes in ceramide species during the infection of human lung epithelial A549 cells and human primary tracheal epithelial cells with IAV. We established a method utilizing UHPLC-MS analysis to measure individual ceramides (C14- to C26-ceramide). The results indicate that two main ceramide species, C16- and C24-ceramide, constitute approximately 80% of the ceramide population in human respiratory epithelial cells. Following IAV infection, these ceramides were found to undergo a shift in abundance, with a reduction in C16-ceramide and an increase in C24-ceramide, under various infection conditions. Primarily, IAV infection led to an increase in multiple long-chain ceramides. These findings could provide details for understanding how the ceramide system is disrupted during influenza virus infection and to further support the ongoing efforts to understand influenza–host interactions. Full article

The Atlantic sharpnose (Rhizoprionodon terraenovae), blacknose (Carcharhinus acronotus), blacktip (Carcharhinus limbatus), and bonnethead (Sphyrna tiburo) sharks are commonly encountered large mobile consumers found in the estuaries along the western North Atlantic coast. The bulk of the dietary data for these species has been coarsely recorded at a broad taxonomic level (e.g., “teleost fish”). Here, we used DNA metabarcoding of fecal DNA collected using non-lethal cloacal swabs to identify the species of prey contributing to the diets of these shark species and measure the degree of trophic overlap. Samples were collected from 24 Atlantic sharpnose, 33 blacknose, six blacktip, and 17 bonnethead sharks in the summer of 2020. Based on previous dietary research on these shark species, we targeted teleost fishes and crustaceans using two previously published primer sets. From the 80 sharks sampled off the coast of North Carolina, we identified 38 prey taxa, with 82% classified to the species level and all assigned to at least the genus and family levels. The most common prey taxa found in the diet of the bonnethead was Atlantic blue crab (Callinectes sapidus; 44.75%, based on percent of occurrence) followed by penaeid shrimp (Penaeus spp.; 24.41%), mantis shrimp (Squilla empusa; 20.34%), and spot (Leiostomus xanthurus; 4.75%). Atlantic sharpnose and blacknose sharks had the largest Levin’s niche overlap, with both species relying on the same two most frequently consumed prey taxa: penaeid shrimp (Atlantic sharpnose: 33.33%, percent of occurrence, and blacknose: 34.78%) and spot (Atlantic sharpnose: 32.70% and blacknose: 22.32%). Bonnetheads and blacktips had the least amount of overlap between all shark species, where blacktips primarily consumed menhaden (Brevoortia spp.; 58.62%) and penaeid shrimp (26.44%). Our findings highlight the value of DNA metabarcoding in refining our understanding of predator diets, moving beyond broad taxonomic classifications to identify species-level prey associations and trophic interactions. As coastal habitats undergo increasing alteration due to anthropogenic impacts, such information is crucial for fisheries management, helping to identify key prey dependencies and anticipate potential ecosystem shifts. Full article

The world is experiencing incredible biodiversity loss, including the decline of iconic species, such as elephants. The species faces an uncertain future due to habitat loss, human-elephant conflict, poaching and climate change, reminding us of the urgency of acting on a local and global scale. Art has historically been a powerful medium for expressing ideas and emotions, fostering deep connections for people. Therefore, this paper explores the impact of the sharing of scientific content through dance on conservation values in young people. Understanding conservation needs and analyzing what drives people to gain an emotional affinity towards the environment has shown the potential to support and innovate traditional education. The work presented here uses a dance piece, performed through a choreographic process with dance students, to educate an audience about the importance and behavior of the African savannah elephant and the threats to its survival. Our findings indicated differences between the level of knowledge and opinion of the audience throughout the different phases of the methodology explored here, revealing that dance (and artistic) education can provide knowledge and stimulate more empathy for species conservation. Full article