Tail Weaponry in Ankylosaurs and Glyptodonts: An Example of a Rare but Strongly Convergent Phenotype

The unusual clubbed tails of glyptodonts among mammals and ankylosaurines among dinosaurs most likely functioned as weapons of intraspecific combat or interspecific defense and are characterized by stiffening of the distal tail and, in some taxa, expansion of the distal tail tip. Although similarities in tail weaponry have been noted as a potential example of convergent evolution, this hypothesis has not been tested quantitatively, particularly with metrics that can distinguish convergence from long-term stasis, assess the relative strength of convergence, and identify potential constraints in the appearance of traits during the stepwise, independent evolution of these structures. Using recently developed metrics of convergence within a phylomorphospace framework, we document that convergence accounts for over 80% of the morphological evolution in traits associated with tail weaponry in ankylosaurs and glyptodonts. In addition, we find that ankylosaurs and glyptodonts shared an independently derived, yet constrained progression of traits correlated with the presence of a tail club, including stiffening of the distal tail as a precedent to expansion of the tail tip in both clades. Despite differences in the anatomical construction of the tail club linked to lineage-specific historical contingency, these lineages experienced pronounced, quantifiable convergent evolution, supporting hypotheses of functional constraints and shared selective pressures on the evolution of these distinctive weapons. Anat Rec, 303:988–998, 2020. © 2019 Wiley Periodicals, Inc.     

The relationship between physical activity facility proximity and leisure-time physical activity in persons with spinal cord injury

BackgroundWithin the general able-bodied population, proximity of one's home to physical activity facilities is modestly associated with physical activity behavior. Currently, no research has examined whether facility proximity is related to physical activity among persons living with disabilities.ObjectiveTo examine (1) the level of agreement between perceived and actual proximity to accessible physical activity facilities and (2) the relationship between facility proximity (perceived and actual) and leisure-time physical activity (LTPA) among persons with spinal cord injury (SCI). It was hypothesized that (1) perceived and actual proximity measures would exhibit low agreement and (2) a small, positive relationship would emerge between proximity (perceived and actual) and LTPA.MethodsData from 50 Ontario residents living with SCI (70% male; 52% tetraplegia) were collected for proximity and LTPA. Perceived facility proximity was determined by a self-report “YES” versus “NO” presence measure, while actual facility proximity was assessed using Geographical Information Systems. An SCI-specific instrument, the PARA-SCI, was used to measure LTPA.ResultsLow agreement levels were found between perceived and actual proximity. LTPA status (active versus inactive) was shown to moderate the relationship, with higher agreement levels found for participants who reported engaging in mild or heavy LTPA versus their inactive counterparts, but only for the 30-minute wheeling boundary. Contrary to hypothesis, people living within a 30-minute wheel from an accessible facility were less likely to engage in heavy LTPA than were people who did not have an accessible facility located within a 30-minute wheel. No significant associations were found between LTPA and perceived proximity.ConclusionsLiving in close proximity to a facility that provides accessible programming and equipment does not necessarily translate into greater physical activity behavior.     

A new clinically relevant approach to expand myelin specific T cells

Human self-reactive T cells are potentially involved in many autoimmune diseases. Although ex vivo detection of self-reactive T cells is possible, exhaustive functional characterization of these cells is impeded by their low frequency. In vitro expansion of antigen (Ag) specific T cells is typically achieved by using autologous (fresh or frozen) irradiated peripheral blood mononuclear cells (PBMCs), EBV-immortalized B cells or dendritic cells in the presence of Ag. These approaches require a large blood volume. We explored a method successfully applied for tumor specific T cells using in vitro expanded autologous B cells. PBMCs were stimulated with irradiated CD40L-expressing fibroblasts and IL-4, resulting in an enriched population of B cell that expressed high levels of MHC and co-stimulatory molecules, essential hallmarks of antigen presenting cells (APCs). Expanded B cells were loaded with Ag, irradiated and then used as APCs to stimulate T cells. The specificity of T cell lines was assessed by comparing their proliferation and IFN-γ secretion when cultured with antigen-loaded B cells vs. unloaded B cells. T cell lines exhibiting antigen-specific proliferation and/or IFN-γ secretion were expanded. Using this method, MBP and MOG specific CD4⁺ and CD8⁺ T cell lines were obtained from multiple donors in comparable numbers to those obtained using the traditional approach (i.e. fresh PBMCs as APCs) and were kept in culture for many weeks. We have shown that myelin specific CD4⁺ and CD8⁺ T cells can be expanded from a relatively small volume of blood (50–100 ml) from multiple donors using expanded B cells as APCs.     

Experimental study of velocity fields in a human nasal fossa by laser anemometry

Velocity fields for various cross sections of a model of a normal human nasal fossa were determined by laser anemometry, a dynamic, quantitative and non-invasive technique. Velocity fields showed, in the laboratory, the very definite influence of the irregular architecture of the fossa on the characteristics of flow namely the streamlining action of the turbinates, the directional effect of the liminal valve and the greater velocity near the floor and the septum. They also allow a more precise evaluation of the flow mode than the Reynolds number. The aerodynamic effects of certain non-obstructive deformities were discussed.     

Prolongation of human neutrophil survival by low-level mercury via inhibition of spontaneous apoptosis

Low levels of organic and inorganic mercury compounds have been reported previously to induce cell death by apoptosis in human peripheral blood mononuclear cells (MNC). but little is known about their potential effects on the viability and death of polymorphonuclear neutrophils (PMN). In contrast to MNC, PMN are known to undergo readily spontaneous apoptosis both in vivo and in vitro. Therefore, it was hypothesized that PMN may differ from MNC in their reactions to low mercury levels. The effects of methylmercuric chloride (MeHgCl) and mercuric chloride (HgCl2) were evaluated in concentration-response and time-course studies on human PMN viability and on their modes of cell death after in vitro incubation at 37 degrees C. Cell death by apoptosis or necrosis was assessed by annexin V-fluorescein isothiocyanate binding to externalized phosphatidylserine in conjunction with propidium iodide, and flow cytometry analysis. Morphologic counting of pyknotic nuclei and the fluorescence properties of the DNA-binding dye Hoechst 33342 in combination with propidium iodide were used to further confirm apoptotic cell death and to characterize the sequence of Hg-induced cell death. Results show that low concentrations of MeHgCl (1-7.5 microM) that were cytotoxic to MNC actually inhibited PMN spontaneous apoptosis. Low-level HgCl, reproduced the anti-apoptotic effects of MeHgCl on PMN, but to a lower extent. Higher concentrations of MeHgCl and HgCl2 were necrogenic to PMN, but MeHgCl was about an order of magnitude more toxic, and discrete differences were observed in the modalities of cell death induced by both species. These data reveal for the first time that (1) low levels of organic and inorganic mercury species protect human PMN from cell death via inhibition of spontaneous apoptosis, and (2) PMN are more resistant than MNC to mercury-induced cytotoxicity. Since delayed apoptosis and increased resistance to toxicant-induced cell death may lead to excessive accumulation of senescent PMN, evidence indicates that findings of this study may have implications for mercury-induced autoimmunity and inflammation.     

Understanding aerodynamics in the correction of the narrow nose

Nasal obstruction can be relieved in the prominent and narrow nose by a nasal widening procedure called the "let out" based on the "en bloc" mobilization used in the "push down" rhinoplasty. Calculations using measurements made on the cadaver show that widening of the angle of the liminal valve and an increased rigidity of the upper lateral cartilage are responsible for the improved airway rather a presumed increase of the cross section of the valve. The associated increase of intranasal velocity provides an aerodynamic explanation for certain phenomenons observed after cosmetic rhinoplasties. A clinical case is presented and the principles of "en bloc" mobilization are shown by line drawings.     

Age differences in vitamin A intake among Canadian Inuit

BACKGROUND: Inuit traditional food provides ample amounts of preformed vitamin A. However, the dietary transition away from traditional food raises concerns regarding dietary adequacy. Vitamin A is an essential nutrient with inadequate and excessive exposures having adverse effects. OBJECTIVE: To evaluate total dietary vitamin A intake for Canadian Inuit from market food and traditional food sources and to evaluate retinol concentrations in liver and blubber. METHODS: Dietary surveys were conducted in 18 communities representing 5 Inuit regions, and traditional food items were evaluated for nutrient content. RESULTS: Among those 15-40 years of age, 68% of men and 60% of women had a dietary vitamin A intake below the estimated average requirement (EAR) for retinol activity equivalents (RAE)/day. Among those over 40 years of age, only 11 % of men and 15% of women had a dietary vitamin A intake below the EAR. Young Inuit men had a relative risk of 6.2 (95% CI= 4.5-8.4), and young Inuit women had a relative risk of 4.0 (95% CI= 3.1-5.0) for dietary inadequacy compared to the older Inuit men and women, respectively. The median retinol content of liver of ringed seal, caribou, and fish were comparable to levels observed in market food liver. Liver was less frequently consumed by those 15-40 years of age than among older Inuit. DISCUSSION: Sub-optimal vitamin A intake is the predominant nutritional concern rather than excessive exposures. Public health education campaigns are needed to improve vitamin A intake among the younger generations of Inuit men and women.     

Continuous nervous system monitoring,EEG, the bispectral index,and neuromuscular transmission

In critically ill patients, the central nervous system remains vulnerable to multiple insults including ischemia, hemorrhagic events, and encephalopathy. The peripheral nervous system is vulnerable in the setting of neuro-muscular blockade (NMB), related drug-drug interactions, and drug-clinical state interactions. Optimal assessment of the nervous system is done by means of the clinical neurological examination. In this manner, orientation, arousal, and responsiveness to stimulation provide feedback on focal and global stability of the central nervous system. Where clinical evaluation is compromised, such as with deep sedation and NMB, risk of undetected seizure activity, and/or progression of neurological injury increases dramatically. A patient receiving NMB risks breakthrough awareness and pain. Long-term complications of NMB including prolonged weakness or paralysis as well as post-traumatic stress dramatically increase morbidity and length of stay. Technologies such as electroencephalogram (EEG) and bispectral index (BIS trade mark ) monitoring are effective for assessing cerebral function as well as level of sedation or arousal, respectively, in patients with a compromised neurological assessment. Neuromuscular transmission (NMT) monitoring by means of peripheral nerve stimulation and assessment of the evoked response may be utilized, within the context of clinical assessment, to determine level of chemical paralysis and minimize dosing of NMB agents. This article explores utilization and differentiates technologies such as EEG, BIS, and NMT monitoring. Monitoring parameters are illustrated using a case study approach.