Rapid volcanic ash entombment reveals the 3D anatomy of Cambrian trilobites.

Knowledge of Cambrian animal anatomy is limited by preservational processes that result in compaction, size bias, and incompleteness. We documented pristine three-dimensional (3D) anatomy of trilobites fossilized through rapid ash burial from a pyroclastic flow entering a shallow marine environment. Cambrian ellipsocephaloid trilobites from Morocco are articulated and undistorted, revealing exquisite details of the appendages and digestive system. Previously unknown anatomy includes a soft-tissue labrum attached to the hypostome, a slit-like mouth, and distinctive cephalic feeding appendages. Our findings resolve controversy over whether the trilobite hypostome is the labrum or incorporates it and establish crown-group euarthropod homologies in trilobites. This occurrence of moldic fossils with 3D soft parts highlights volcanic ash deposits in marine settings as an underexplored source for exceptionally preserved organisms.

"So, Do Not Fear": Religion and the prevalence, persistence, and severity of anxiety disorders among Black Americans.

BACKGROUND: There is a dearth of scholarship that explicates the effects of religious participation on anxiety disorders among Black Americans. A better understanding of the links between religious participation, a coping resource, and anxiety disorders among Black Americans remains essential, given Black Americans are less likely than their white counterparts to seek professional treatment for mental health problems, leading to greater unmet mental health needs. The aim of this study was to investigate whether religious participation is associated with the prevalence, persistence, and severity of anxiety disorders among Black adults. METHODS: We used a national sample of Black adults (N = 4999) from the National Survey of American Life, a cross-sectional study conducted from 2001 to 2003. Five anxiety disorders were assessed: posttraumatic stress disorder, generalized anxiety disorder, panic disorder, social anxiety disorder, and agoraphobia. Three dimensions of religious participation were assessed: organizational, non-organizational, and subjective religious participation. Weighted logistic and linear regressions were estimated to examine the associations between religious participation and anxiety disorders. RESULTS: Findings indicate that organizational religious participation and subjective religiosity were associated with lower odds of anxiety disorders and decreased severity. Findings for non-organizational religious participation in relation to the prevalence, persistence, and severity of anxiety disorders were mixed. LIMITATIONS: The study limitations include the utilization of self-reported measures, cross-sectional study design, and age of the data set. CONCLUSIONS: Different dimensions of religious participation have differing effects on anxiety disorders. Religious participation may be an important resource for Black Americans in coping and preventing anxiety disorders.

Accelerating Chloroplast Engineering: A New System for Rapid Generation of Marker-Free Transplastomic Lines of Chlamydomonas reinhardtii.

'Marker-free' strategies for creating transgenic microorganisms avoid the issue of potential transmission of antibiotic resistance genes to other microorganisms. An already-established strategy for engineering the chloroplast genome (=plastome) of the green microalga Chlamydomonas reinhardtii involves the restoration of photosynthetic function using a recipient strain carrying a plastome mutation in a key photosynthesis gene. Selection for transformant colonies is carried out on minimal media, such that only those cells in which the mutated gene has been replaced with a wild-type copy carried on the transgenic DNA are capable of phototrophic growth. However, this approach can suffer from issues of efficiency due to the slow growth of C. reinhardtii on minimal media and the slow die-back of the untransformed lawn of cells when using mutant strains with a limited photosensitivity phenotype. Furthermore, such phototrophic rescue has tended to rely on existing mutants that are not necessarily ideal for transformation and targeted transgene insertion: Mutants carrying point mutations can easily revert, and those with deletions that do not extend to the intended transgene insertion site can give rise to a sub-population of rescued lines that lack the transgene. In order to improve and accelerate the transformation pipeline for C. reinhardtii, we have created a novel recipient line, HNT6, carrying an engineered deletion in exon 3 of psaA, which encodes one of the core subunits of photosystem I (PSI). Such PSI mutants are highly light-sensitive allowing faster recovery of transformant colonies by selecting for light-tolerance on acetate-containing media, rather than phototrophic growth on minimal media. The deletion extends to a site upstream of psaA-3 that serves as a neutral locus for transgene insertion, thereby ensuring that all of the recovered colonies are transformants containing the transgene. We demonstrate the application of HNT6 using a luciferase reporter.

Speciation across the Earth driven by global cooling in terrestrial orchids.

Although climate change has been implicated as a major catalyst of diversification, its effects are thought to be inconsistent and much less pervasive than localized climate or the accumulation of species with time. Focused analyses of highly speciose clades are needed in order to disentangle the consequences of climate change, geography, and time. Here, we show that global cooling shapes the biodiversity of terrestrial orchids. Using a phylogeny of 1,475 species of Orchidoideae, the largest terrestrial orchid subfamily, we find that speciation rate is dependent on historic global cooling, not time, tropical distributions, elevation, variation in chromosome number, or other types of historic climate change. Relative to the gradual accumulation of species with time, models specifying speciation driven by historic global cooling are over 700 times more likely. Evidence ratios estimated for 212 other plant and animal groups reveal that terrestrial orchids represent one of the best-supported cases of temperature-spurred speciation yet reported. Employing >2.5 million georeferenced records, we find that global cooling drove contemporaneous diversification in each of the seven major orchid bioregions of the Earth. With current emphasis on understanding and predicting the immediate impacts of global warming, our study provides a clear case study of the long-term impacts of global climate change on biodiversity.

A PETase enzyme synthesised in the chloroplast of the microalga Chlamydomonas reinhardtii is active against post-consumer plastics.

Polyethylene terephthalate hydrolases (PETases) are a newly discovered and industrially important class of enzymes that catalyze the enzymatic degradation of polyethylene terephatalate (PET), one of the most abundant plastics in the world. The greater enzymatic efficiencies of PETases compared to close relatives from the cutinase and lipase families have resulted in increasing research interest. Despite this, further characterization of PETases is essential, particularly regarding their possible activity against other kinds of plastic. In this study, we exploited for the first time the use of the microalgal chloroplast for more sustainable synthesis of a PETase enzyme. A photosynthetic-restoration strategy was used to generate a marker-free transformant line of the green microalga Chlamydomonas reinhardtii in which the PETase from Ideonella sakaiensis was constitutively expressed in the chloroplast. Subsequently, the activity of the PETase against both PET and post-consumer plastics was investigated via atomic force microscopy, revealing evidence of degradation of the plastics.

Developmental Expression of the Cell Cycle Regulator p16INK4a in Retinal Glial Cells: A Novel Marker for Immature Ocular Astrocytes?

Retinal astrocytes are vital for neuronal homeostasis in the retina. Together with Müller glia, they provide retinal cells with neurotrophic factors, antioxidative support, and defense mechanisms such as the formation of the blood-retinal barrier. Substantial heterogeneity of astrocyte morphology and function represents a challenge for identification of distinct subtypes which may be potential targets for therapeutic purposes. Hence, identification of novel markers of astrocyte subpopulations is highly relevant to better understand the molecular mechanisms involved in retinal development, homeostasis, and pathology. In this study, we observed that the cell cycle regulator, p16INK4a, is expressed in immature astrocytes in the mouse retina. Immunohistochemical analysis showed p16INK4a expression in the optic nerve of wild-type mice from 3 days to 3 months of age and in the nerve fiber layer of the adult mouse retina. Colocalization of p16INK4a expression and glial fibrillary acidic protein (immature/mature astrocyte marker) tends to decrease with age. However, colocalization of p16INK4a expression and vimentin (immature astrocyte marker) remains high in the optic nerve from the early postnatal period to adulthood. The observations from this study provide a valuable tool for further investigations of ocular astrocytes in the developing retina as well as in degenerative retinopathies.

Sociodemographic Factors and Neighborhood/Environmental Conditions Associated with Social Isolation Among Black Older Adults.

Objectives: To investigate sociodemographic factors and neighborhood/environmental conditions associated with social isolation (SI) among Black older adults. Methods: We utilized data from the 2014 and 2016 Leave-Behind Questionnaire from the Health and Retirement Study (HRS LBQ) among those who self-identified as Black (N = 2.323). Outcome variables for our study included SI from adult children, other family members, friends, disengagement from social participation and religious services, being unmarried, and living alone. These indicators were also combined into an overall SI index. Critical predictors included gender, age, household income, education, employment status, neighborhood cohesion, neighborhood disorder, urbanicity, and region of residence. Results: Sociodemographic factors of gender, education and household income were significantly associated with SI indicators. Additionally, some neighborhood/environmental conditions were associated with SI indicators. Discussion: SI was found to be patterned by sociodemographic factors. These results can be used to develop effective interventions to mitigate SI among Black older adults.

A Novel Postoperative Drop Regimen Reduces Risk of Ocular Hypertension Following Pars Plana Vitrectomy.

INTRODUCTION: Postoperative steroid/antibiotic drop regimens are known to effectively suppress inflammation and infection following pars plana vitrectomy (PPV), but the steroid frequently induces ocular hypertension (OHT). The aim of this contemporaneous cohort-control study was to assess safety and efficacy of a novel post-PPV drop regimen conceived to address this problem. METHODS: Electronic case notes of consecutive eyes undergoing PPV between December 2020 and April 2021 at St. Thomas' Hospital, London, UK, were reviewed retrospectively. Postoperative drops in the intervention cohort consisted of 1-week g. dexamethasone 0.1%/antibiotic QDS and 1-month g. ketorolac TDS. Standard care controls received 1-month g. dexamethasone 0.1%/antibiotic QDS. RESULTS: Fifty-eight patients were in the intervention cohort, and 151 received standard care. The primary outcome measure was IOP ≥30 mm Hg 2 weeks postoperatively. This occurred in none of the intervention group but in 14% of controls (p = 0.01). Secondary outcomes of rates of anterior uveitis and cystoid macular edema did not differ significantly between the groups, but those in the intervention cohort had fewer hospital visits (p = 0.0004). CONCLUSION: A post-PPV drop regimen of 1-week dexamethasone 0.1%/antibiotic and 1-month ketorolac may be as effective as an anti-inflammatory but safer in terms of OHT incidence than standard care 1-month dexamethasone 0.1%.

Treatment with MDL 72527 Ameliorated Clinical Symptoms, Retinal Ganglion Cell Loss, Optic Nerve Inflammation, and Improved Visual Acuity in an Experimental Model of Multiple Sclerosis.

Multiple Sclerosis (MS) is a highly disabling neurological disease characterized by inflammation, neuronal damage, and demyelination. Vision impairment is one of the major clinical features of MS. Previous studies from our lab have shown that MDL 72527, a pharmacological inhibitor of spermine oxidase (SMOX), is protective against neurodegeneration and inflammation in the models of diabetic retinopathy and excitotoxicity. In the present study, utilizing the experimental autoimmune encephalomyelitis (EAE) model of MS, we determined the impact of SMOX blockade on retinal neurodegeneration and optic nerve inflammation. The increased expression of SMOX observed in EAE retinas was associated with a significant loss of retinal ganglion cells, degeneration of synaptic contacts, and reduced visual acuity. MDL 72527-treated mice exhibited markedly reduced motor deficits, improved neuronal survival, the preservation of synapses, and improved visual acuity compared to the vehicle-treated group. The EAE-induced increase in macrophage/microglia was markedly reduced by SMOX inhibition. Upregulated acrolein conjugates in the EAE retina were decreased through MDL 72527 treatment. Mechanistically, the EAE-induced ERK-STAT3 signaling was blunted by SMOX inhibition. In conclusion, our studies demonstrate the potential benefits of targeting SMOX to treat MS-mediated neuroinflammation and vision loss.

CpPosNeg: A positive-negative selection strategy allowing multiple cycles of marker-free engineering of the Chlamydomonas plastome.

The chloroplast represents an attractive compartment for light-driven biosynthesis of recombinant products, and advanced synthetic biology tools are available for engineering the chloroplast genome ( = plastome) of several algal and plant species. However, producing commercial lines will likely require several plastome manipulations. This presents issues with respect to selectable markers, since there are a limited number available, they can be used only once in a serial engineering strategy, and it is undesirable to retain marker genes for antibiotic resistance in the final transplastome. To address these problems, we have designed a rapid iterative selection system, known as CpPosNeg, for the green microalga Chlamydomonas reinhardtii that allows creation of marker-free transformants starting from wild-type strains. The system employs a dual marker encoding a fusion protein of E. coli aminoglycoside adenyltransferase (AadA: conferring spectinomycin resistance) and a variant of E. coli cytosine deaminase (CodA: conferring sensitivity to 5-fluorocytosine). Initial selection on spectinomycin allows stable transformants to be established and driven to homoplasmy. Subsequent selection on 5-fluorocytosine results in rapid loss of the dual marker through intramolecular recombination between the 3'UTR of the marker and the 3'UTR of the introduced transgene. We demonstrate the versatility of the CpPosNeg system by serial introduction of reporter genes into the plastome.

COVID-19 and Psychological Distress: Racial Differences Among Middle-Aged and Older Adults.

BACKGROUND AND OBJECTIVES: COVID-19 has disproportionately impacted older adults and Black individuals. Research has focused on physical outcomes, with less attention to the psychological effects of COVID-19. The objective of this study was to examine the interplay between perceptions of the COVID-19 outbreak as a threat to one's day-to-day life, race, and psychological distress among middle-aged and older men and women. RESEARCH DESIGN AND METHODS: Analyses were conducted on a subsample of self-identified non-Latino Whites and Black individuals aged 50 and older (N = 3,834) from the American Trends Panel. Psychological distress was assessed with 5 items adapted from the Center for Epidemiologic Studies Depression Scale and Generalized Anxiety Disorder-7. Perceived COVID-19 day-to-day threat was assessed with a single question. Negative binomial regressions tested the study aim. RESULTS: Perceptions of COVID-19 day-to-day threat were positively associated with psychological distress. Black individuals reported lower distress than Whites. Regardless of gender, greater perceptions of COVID-19 day-to-day threats were associated with greater distress among both White respondents and Black respondents. However, this association was weaker among Black respondents than White respondents. Among men only, the association between COVID-19 day-to-day threat and distress varied by race, patterned similarly to the race differences identified in the total sample. This association did not vary by race among women. DISCUSSION AND IMPLICATIONS: This study contributes to the emerging literature focused on older adults and COVID-19 related stressors and psychological distress. An intersectional lens shows how structural oppression may shape perceptions of the pandemic. Future work should consider coexisting intersections in marginalized identities and mental health during COVID-19.

Discrimination and Hypertension Among Older African Americans and Caribbean Blacks: The Moderating Effects of John Henryism.

OBJECTIVES: Discrimination is a major contributor to health disparities between Black and White older adults. Although the health effects of discrimination are well established, less is known about factors that may intervene in the discrimination-health connection, such as coping strategies. The study aim was to determine whether John Henryism (JH; high-effort coping) moderates the association between racial discrimination and hypertension in nationally representative samples of older African Americans and Caribbean Blacks. METHODS: The analytic sample was drawn from the National Survey of American Life-Reinterview, which was conducted 2001-2003, and included African Americans (N = 546) and Caribbean Blacks (N = 141) aged 55 and older. Study variables included racial discrimination, JH, and hypertension. Logistic regressions, which controlled key sociodemographic differences, were used to test the study aim. RESULTS: Among both Black ethnic groups, discrimination and JH were not associated with hypertension. For African Americans low and moderate in JH, discrimination was unrelated to hypertension; discrimination was positively associated with hypertension for African Americans high in JH. For Caribbean Blacks, discrimination was positively associated with hypertension among respondents low in JH. Among Caribbean Blacks moderate and high in JH, discrimination was not associated with hypertension. DISCUSSION: The findings indicate that JH, in the face of discrimination, is associated with hypertension of older African Americans but may be an effective coping strategy for older Caribbean Blacks due to cultural and sociodemographic differences between the 2 ethnic groups. Future research should investigate the differing mechanisms by which JH influences health in heterogeneous older Black populations.

The Algal Chloroplast as a Testbed for Synthetic Biology Designs Aimed at Radically Rewiring Plant Metabolism.

Sustainable and economically viable support for an ever-increasing global population requires a paradigm shift in agricultural productivity, including the application of biotechnology to generate future crop plants. Current genetic engineering approaches aimed at enhancing the photosynthetic efficiency or composition of the harvested tissues involve relatively simple manipulations of endogenous metabolism. However, radical rewiring of central metabolism using new-to-nature pathways, so-called "synthetic metabolism", may be needed to really bring about significant step changes. In many cases, this will require re-programming the metabolism of the chloroplast, or other plastids in non-green tissues, through a combination of chloroplast and nuclear engineering. However, current technologies for sophisticated chloroplast engineering ("transplastomics") of plants are limited to just a handful of species. Moreover, the testing of metabolic rewiring in the chloroplast of plant models is often impractical given their obligate phototrophy, the extended time needed to create stable non-chimeric transplastomic lines, and the technical challenges associated with regeneration of whole plants. In contrast, the unicellular green alga, Chlamydomonas reinhardtii is a facultative heterotroph that allows for extensive modification of chloroplast function, including non-photosynthetic designs. Moreover, chloroplast engineering in C. reinhardtii is facile, with the ability to generate novel lines in a matter of weeks, and a well-defined molecular toolbox allows for rapid iterations of the "Design-Build-Test-Learn" (DBTL) cycle of modern synthetic biology approaches. The recent development of combinatorial DNA assembly pipelines for designing and building transgene clusters, simple methods for marker-free delivery of these clusters into the chloroplast genome, and the pre-existing wealth of knowledge regarding chloroplast gene expression and regulation in C. reinhardtii further adds to the versatility of transplastomics using this organism. Herein, we review the inherent advantages of the algal chloroplast as a simple and tractable testbed for metabolic engineering designs, which could then be implemented in higher plants.

Mirtron-mediated RNA knockdown/replacement therapy for the treatment of dominant retinitis pigmentosa.

Rhodopsin (RHO) gene mutations are a common cause of autosomal dominant retinitis pigmentosa (ADRP). The need to suppress toxic protein expression together with mutational heterogeneity pose challenges for treatment development. Mirtrons are atypical RNA interference effectors that are spliced from transcripts as short introns. Here, we develop a novel mirtron-based knockdown/replacement gene therapy for the mutation-independent treatment of RHO-related ADRP, and demonstrate efficacy in a relevant mammalian model. Splicing and potency of rhodopsin-targeting candidate mirtrons are initially determined, and a mirtron-resistant codon-modified version of the rhodopsin coding sequence is validated in vitro. These elements are then combined within a single adeno-associated virus (AAV) and delivered subretinally in a RhoP23H knock-in mouse model of ADRP. This results in significant mouse-to-human rhodopsin RNA replacement and is associated with a slowing of retinal degeneration. This provides proof of principle that synthetic mirtrons delivered by AAV are capable of reducing disease severity in vivo.

The successful treatment of multiple organ dysfunction syndrome and severe hypernatremia, secondary to joint supplement toxicity in a dog.

OBJECTIVE: To describe a case of the successful management of hypernatremia and multiple organ dysfunction syndrome secondary to joint supplement toxicity in a dog. CASE SUMMARY: A 6-year-old neutered male Dachshund was presented for severe hypernatremia and neurological abnormalities after ingestion of a large quantity of joint supplements. The patient developed evidence of multiple organ dysfunction in the form of increased hepatocellular enzymes, prolongation of prothrombin and partial thromboplastin times, azotemia, and thrombocytopenia. Treatment was successful at correcting the hypernatremia and restoring neurological function, and organ dysfunction was successfully managed. Following multiple days of hospitalization and aggressive supportive care, the patient survived to discharge. NEW OR UNIQUE INFORMATION PROVIDED: This case report describes the successful management and survival of multiple organ dysfunction associated with joint supplement toxicity. It also serves to highlight the potential for joint supplement overdose in veterinary patients, which is currently believed to be underrecognized.

CHA2DS2-VASc Is Associated With In-Hospital Mortality in Patients With Infective Endocarditis: A Cross-Sectional Cohort Study.

Background and objective The CHA2DS2-VASc score is a stroke risk stratification tool that is used in patients with atrial fibrillation (AF). Most of its clinical variables have been associated with poor outcomes in patients with infective endocarditis (IE). In this study, we aimed to determine its utility in predicting outcomes in IE patients. Methods We included 35,570 patients with IE from the National Inpatient Sample (NIS), 2009-2012. The CHA2DS2-VASc score was calculated for each patient. Hierarchical logistic regression was used to estimate the adjusted odds ratio for in-hospital mortality for CHA2DS2-VASc scores from 1 to 9, using a score of 0 as the reference score. All clinical characteristics were defined using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Results The mean age of the sample was 57.81 ±14 years. Higher CHA2DS2-VASc scores were associated with increased mortality, and the scores among the sample ranged from 0 for 8.1% to 8 for 21.7%. In the hierarchical logistic regression, after adjusting for age, sex, and relevant comorbidities, as the score increased, so did the odds for overall mortality. Conclusion In patients with IE, the CHA2DS2-VASc score may serve as a risk assessment tool with which to predict outcomes. Further studies are needed to replicate these findings.

Depressive Symptoms and Loneliness Among Black and White Older Adults: The Moderating Effects of Race.

BACKGROUND AND OBJECTIVES: Loneliness is consistently linked to worse depression/depressive symptoms; however, there are few studies that have examined whether the relationship between loneliness and depressive symptoms varies by race. The purpose of this study was to determine whether race moderated the relationship between loneliness and depressive symptoms. RESEARCH DESIGN AND METHODS: Data come from the 2014 wave of the Health and Retirement Study (HRS) Core survey and Psychosocial Leave-Behind Questionnaire; only black and white older adults were included in the analysis (N = 6,469). Depressive symptoms were operationalized by the eight-item Center for Epidemiological Studies-Depression scale; however, the "felt lonely" item was removed given concerns with collinearity. Loneliness was operationalized using the Hughes 3-Item Loneliness Scale. Sociodemographic variables included gender, age, education, household income, employment status, marital status, and living alone or with others. Furthermore, social support and negative interactions from family members and friends, and religious service attendance were included in the analysis. Lastly, we created an interaction term between race and loneliness. All analyses used survey weights to account for the complex multistage sampling design of the HRS. Missing data were multiply imputed. RESULTS: In multivariable analysis, we found race significantly moderated the relationship between loneliness and depressive symptoms while controlling for sociodemographic covariates, social support and negative interaction variables, and religious service attendance. DISCUSSION AND IMPLICATIONS: Our findings demonstrate a differential racial effect for loneliness and depressive symptoms. For both blacks and whites, greater loneliness affected depressive symptoms; however, the effect was stronger among whites than it was for blacks. Given this is one of the first studies to examine the differential effects of race on loneliness and depressive symptoms, more research is necessary to determine the consistency of these results.

Successful Radiofrequency Ablation of Recurrent Supraventricular Tachycardia in a Patient with Complex Congenital Heart Disease.

BACKGROUND Radiofrequency ablation (RFA) is the criterion standard treatment for patients with atrioventricular nodal reentrant tachycardia (AVNRT). Knowledge about RFA in patients with dextrocardia and situs inversus is limited due to their rare incidence and complexity. The incidence of dextrocardia is reported to be 1 in 12 000 births, with situs inversus occurring in one-third of the cases. The incidence of congenital heart disease is about 5% in these patients. However, data on rhythm and conduction disorders in this group of patients are currently limited, making management more difficult owing to their individual anatomy. CASE REPORT We report the case of an obese 21-year-old man with complex congenital heart disease (CCHD) (situs inversus dextrocardia, pulmonary atresia, single ventricle, common atrium with single atrioventricular valve), asplenia, and multiple cardiac-corrective surgeries (Fontan repair, bidirectional Glenn anastomosis, and Blalock-Taussig shunt) who underwent successful RFA of recurrent supraventricular tachycardia. CONCLUSIONS Supraventricular arrhythmias are common in the setting of CCHD. Although catheter ablation procedures are technically challenging to perform in patients with CCHD, they remain the best therapeutic option for these arrhythmias. To our knowledge, this case is the first to be described in the literature of successful ablation of AVNRT in a patient with situs inversus dextrocardia, pulmonary atresia, a single ventricle, a common atrium with a single atrioventricular valve, and multiple cardiac-corrective surgeries.