Microanatomy and histology of bone pathologies of extant and extinct phocid seals

This study investigates three presumed fractured phocid seal bones: An isolated metapodial and an ulna belonging to different individuals of the extinct phocid, Homiphoca capensis, from Langebaanweg and a mandible of a juvenile elephant seal (Mirounga leonina), which was included to assess the validity of the assumption that changes to bones caused by fractures are consistent across extant and extinct members of the same groups. The bones were studied using a multi-method approach, including gross morphology, microcomputed tomography (micro-CT) and histology. Micro-CT showed that the metapodial was not fractured and information drawn from other analyses suggested that the pathology was an osteosarcoma. Histology of normal and fractured regions of the mandible and ulna permitted an estimate about the fracture healing stage, and showed the bone tissue at the fracture sites to be histologically similar. A birth line found on the lateral surface of the elephant seal mandible emphasised its young age and marked the first example of a birth line in a bone of a semi-aquatic mammal. A large scope of information was obtained using this multi-method approach, which could permit insight into the life events and lifestyles of modern and extinct individuals, such as H. capensis.NRF-DST Centre of Excellence in Palaeosciences to Megan Rose Woolley, NRF African Origins Programme (AOP) Grant awarded to Prof A Chinsamy-Turan (Grant No. 117716) NRF African Origins Programme (AOP) Grant awarded to Dr R Govender (Grant No. 98834).https://www.tandfonline.com/loi/ghbi202020-11-12hj2020Mammal Research InstituteZoology and Entomolog

Reduced fire severity offers near-term buffer to climate-driven declines in conifer resilience across the western United States

Increasing fire severity and warmer, drier postfire conditions are making forests in the western United States (West) vulnerable to ecological transformation. Yet, the relative importance of and interactions between these drivers of forest change remain unresolved, particularly over upcoming decades. Here, we assess how the interactive impacts of changing climate and wildfire activity influenced conifer regeneration after 334 wildfires, using a dataset of postfire conifer regeneration from 10,230 field plots. Our findings highlight declining regeneration capacity across the West over the past four decades for the eight dominant conifer species studied. Postfire regeneration is sensitive to high-severity fire, which limits seed availability, and postfire climate, which influences seedling establishment. In the near-term, projected differences in recruitment probability between low- and high-severity fire scenarios were larger than projected climate change impacts for most species, suggesting that reductions in fire severity, and resultant impacts on seed availability, could partially offset expected climate-driven declines in postfire regeneration. Across 40 to 42% of the study area, we project postfire conifer regeneration to be likely following low-severity but not high-severity fire under future climate scenarios (2031 to 2050). However, increasingly warm, dry climate conditions are projected to eventually outweigh the influence of fire severity and seed availability. The percent of the study area considered unlikely to experience conifer regeneration, regardless of fire severity, increased from 5% in 1981 to 2000 to 26 to 31% by mid-century, highlighting a limited time window over which management actions that reduce fire severity may effectively support postfire conifer regeneration. © 2023 the Author(s)

GA4GH: International policies and standards for data sharing across genomic research and healthcare.

The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits

Real time visualization and characterization of platelet deposition under flow onto clinically relevant opaque surfaces

<p>Although the thrombogenic nature of the surfaces of cardiovascular devices is an important aspect of blood biocompatibility, few studies have examined platelet deposition onto opaque materials used for these devices in real time. This is particularly true for the metallic surfaces used in current ventricular assist devices (VADs). Using hemoglobin depleted red blood cells (RBC ghosts) and long working distance optics to visualize platelet deposition, we sought to perform such an evaluation. Fluorescently labeled platelets mixed with human RBC ghosts were perfused across six opaque materials (a titanium alloy (Ti6Al4V), silicon carbide (SiC), alumina (Al₂O₃), 2-methacryloyloxyethyl phosphorylcholine polymer coated Ti6Al4V (MPC-Ti6Al4V), yttria partially stabilized zirconia (YZTP), and zirconia toughened alumina (ZTA)) for 5 min at wall shear rates of 400 and 1000 s⁻¹. Ti6Al4V had significantly increased platelet deposition relative to MPC-Ti6Al4V, Al₂O₃, YZTP, and ZTA at both wall shear rates (<em>p</em> < 0.01). For all test surfaces, increasing the wall shear rate produced a trend of decreased platelet adhesion. The described system can be a utilized as a tool for comparative analysis of candidate blood-contacting materials with acute blood contact.</p

Microanatomy and histology of bone pathologies of extant and extinct phocid seals

This study investigates three presumed fractured phocid seal bones: An isolated metapodial and an ulna belonging to different individuals of the extinct phocid, Homiphoca capensis, from Langebaanweg and a mandible of a juvenile elephant seal (Mirounga leonina), which was included to assess the validity of the assumption that changes to bones caused by fractures are consistent across extant and extinct members of the same groups. The bones were studied using a multi-method approach, including gross morphology, microcomputed tomography (micro-CT) and histology. Micro-CT showed that the metapodial was not fractured and information drawn from other analyses suggested that the pathology was an osteosarcoma. Histology of normal and fractured regions of the mandible and ulna permitted an estimate about the fracture healing stage, and showed the bone tissue at the fracture sites to be histologically similar. A birth line found on the lateral surface of the elephant seal mandible emphasised its young age and marked the first example of a birth line in a bone of a semi-aquatic mammal. A large scope of information was obtained using this multi-method approach, which could permit insight into the life events and lifestyles of modern and extinct individuals, such as H. capensis.NRF-DST Centre of Excellence in Palaeosciences to Megan Rose Woolley, NRF African Origins Programme (AOP) Grant awarded to Prof A Chinsamy-Turan (Grant No. 117716) NRF African Origins Programme (AOP) Grant awarded to Dr R Govender (Grant No. 98834).https://www.tandfonline.com/loi/ghbi202020-11-12hj2020Mammal Research InstituteZoology and Entomolog