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1.
J Clin Microbiol ; 62(4): e0001924, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38483169

ABSTRACT

Tongue dorsum swabbing is a potential alternative to sputum collection for tuberculosis (TB) testing. Previous studies showed that Cepheid Xpert MTB/RIF Ultra (Xpert Ultra) can detect Mycobacterium tuberculosis DNA on tongue swabs stored in buffer, with 72% sensitivity and 100% specificity relative to a sputum microbiological reference standard (sputum MRS). The present study evaluated a more convenient sample collection protocol (dry swab storage), combined with streamlined sample processing protocols, for evaluating two commercial TB diagnostic tests: Xpert Ultra and Molbio Truenat MTB Ultima (MTB Ultima). Copan FLOQSwabs were self-collected or collected by study workers from 321 participants in Western Cape, South Africa. All participants had symptoms suggestive of TB, and 245 of them had sputum MRS-confirmed TB (by sputum MGIT culture and/or Xpert Ultra). One tongue swab per participant was tested on Xpert Ultra, and another tongue swab was tested with MTB Ultima. Xpert Ultra was 75.5% sensitive and 100% specific relative to sputum MRS, similar to previous methods that used swabs stored in buffer. MTB Ultima was 71.6% sensitive and 96.9% specific relative to sputum MRS. When sample lysates that were false-negative or invalid by MTB Ultima were frozen, thawed, and re-tested, MTB Ultima sensitivity rose to 79.1%. Both tests were more sensitive with swabs from participants with higher sputum Xpert Ultra semi-quantitative results. Although additional development could improve diagnostic accuracy, these results further support tongue swabs as easy-to-collect samples for TB testing. IMPORTANCE: Tongue dorsum swabbing is a promising alternative to sputum collection for tuberculosis (TB) testing. Our results lend further support for tongue swabs as exceptionally easy-to-collect samples for high-throughput TB testing.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis, Pulmonary , Tuberculosis , Humans , Tuberculosis, Pulmonary/diagnosis , Mycobacterium tuberculosis/genetics , Sensitivity and Specificity , Tuberculosis/diagnosis , Tuberculosis/microbiology , South Africa , Sputum/microbiology
2.
Policy Polit Nurs Pract ; 25(1): 47-57, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37750219

ABSTRACT

The COVID-19 pandemic in the US prompted a sudden shift to telehealth in nurse-led care sites which provide services to diverse geolocations. Using a lens of intersectionality, this study characterizes provider and patient-perceived best and promising practices emerging from geographical variation. The aim of this study was to identify best practices of implementing telehealth in nurse-led care models in Colorado through patient and provider experiences of the sudden implementation of telehealth that can enhance health equity. In this exploratory/descriptive qualitative study, a purposive sample of 18 providers and 30 patients were interviewed using a guide informed by the RE-AIM implementation and evaluation framework to capture the contextual experiences related to the sudden shift to telehealth. Textual theme analysis and reflexive team strategies guided the interpretation. Four primary themes of perceived best practices were identified: using multiple modalities, tailoring triage and scheduling, cultivating safety through boundaries and expectations, and differentiating established versus new patient relationships. The findings suggest that telehealth is a flexible and powerful tool to enhance the delivery of equitable care through nurse-led care models within diverse communities such as the one represented in this study. Nurse leaders are positioned to participate in innovative research and create policies and protocols to ensure telehealth is a viable resource to deliver equitable, safe, and accessible high-quality healthcare.


Subject(s)
COVID-19 , Telemedicine , Humans , Pandemics , Nurse's Role , Qualitative Research
3.
BMC Cardiovasc Disord ; 23(1): 462, 2023 09 15.
Article in English | MEDLINE | ID: mdl-37715115

ABSTRACT

BACKGROUND: Rheumatic heart disease (RHD) is the most common form of acquired heart disease worldwide. In RHD, volume loading from mitral regurgitation leads to left ventricular (LV) dilatation, increased wall stress, and ultimately LV dysfunction. Improved understanding of LV dynamics may contribute to refined timing of intervention. We aimed to characterize and compare left ventricular remodelling between rheumatic heart disease (RHD) severity groups by way of serial echocardiographic assessment of volumes and function in children. METHODS: Children with RHD referred to Perth Children's Hospital (formally Princess Margaret Hospital) (1987-2020) were reviewed. Patients with longitudinal pre-operative echocardiograms at diagnosis, approximately 12 months and at most recent follow-up, were included and stratified into RHD severity groups. Left ventricular (LV) echocardiographic parameters were assessed. Adjusted linear mixed effect models were used to compare interval changes. RESULTS: 146 patients (median age 10 years, IQR 6-14 years) with available longitudinal echocardiograms were analysed. Eighty-five (58.2%) patients had mild, 33 (22.6%) moderate and 28 (19.2%) severe RHD at diagnosis. Mean duration of follow-up was 4.6 years from the initial diagnosis. Severe RHD patients had significantly increased end-systolic volumes (ESV) and end-diastolic volumes (EDV) compared to mild/moderate groups at diagnosis (severe versus mild EDV mean difference 27.05 ml/m2, p < 0.001, severe versus moderate EDV mean difference 14.95 ml/m2, p = 0.006). Mild and moderate groups experienced no significant progression of changes in volume measures. In severe RHD, LV dilatation worsened over time. All groups had preserved cardiac function. CONCLUSIONS: In mild and moderate RHD, the lack of progression of valvular regurgitation and ventricular dimensions suggest a stable longer-term course. Significant LV remodelling occurred at baseline in severe RHD with progression of LV dilatation over time. LV function was preserved across all groups. Our findings may guide clinicians in deciding the frequency and timing of follow-up and may be of clinical utility during further reiterations of the Australia and New Zealand RHD Guidelines.


Subject(s)
Mitral Valve Insufficiency , Rheumatic Heart Disease , Child , Humans , Rheumatic Heart Disease/diagnostic imaging , Follow-Up Studies , Ventricular Remodeling , Heart , Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve Insufficiency/etiology
4.
Appl Nurs Res ; 73: 151716, 2023 10.
Article in English | MEDLINE | ID: mdl-37722784

ABSTRACT

AIM: This study investigated the phenomenon of nurse loneliness as a potential contributor to burnout. BACKGROUND: Nurse wellbeing is critical for safe and efficient healthcare delivery. However, evidence indicates nurses' wellbeing is at risk. The levels of burnout, the most commonly measured symptom of suboptimal wellbeing, are rising and may relate to a largely unexplored phenomenon: loneliness. METHODS: A mixed-methods approach was used to investigate burnout and loneliness in direct-care nurses in four diverse hospitals in the midwestern and southeastern United States. Burnout and loneliness were measured, prevalence was estimated, and correlation was examined. Interpretive descriptive inquiry and analysis was used to develop a richer understanding of nurse loneliness in the context of burnout. While this study did not explicitly explore the impact of the global pandemic, data was collected in late 2021 and early 2022, during the Delta variant wave. RESULTS: In the study population (n = 117), rates of burnout are high and positively correlate with loneliness. Qualitative interviews (n = 11) revealed that nurses feel unseen, emotionally detached from their work, and dehumanized. However, social connection with peers is protective and nurses still report a strong sense of devotion to the profession and solidarity with peers. CONCLUSIONS: This study offers insight into nurse loneliness, highlighting the importance of social connectedness to improve nurse wellbeing.


Subject(s)
COVID-19 , Loneliness , Humans , SARS-CoV-2 , Burnout, Psychological
5.
Nephrol Nurs J ; 50(3): 203-235, 2023.
Article in English | MEDLINE | ID: mdl-37437169

ABSTRACT

Nurses are crucial to the health care workforce, yet their well-being is often overlooked, adversely affecting patient care. This article examines the intersection of loneliness and burnout among nephrology nurses, and its impact on their well-being and job performance. Loneliness, defined as inadequate social connections, is identified as a significant contributor to burnout and suboptimal well-being among nurses. Findings emphasize the importance of addressing loneliness and promoting social connectedness within the nursing profession. Strategies, such as fostering supportive relationships, creating support groups, and implementing policies to reduce emotional burdens and workload pressures, are recommended. We emphasize the need to prioritize nurse well-being for a resilient health care workforce and improved patient outcomes, and discuss its implications for nursing practice, education, and policy.


Subject(s)
Loneliness , Nephrology , Humans , Burnout, Psychological , Emotions , Health Personnel
6.
Univers Access Inf Soc ; : 1-27, 2023 Mar 04.
Article in English | MEDLINE | ID: mdl-37361673

ABSTRACT

Purpose: Customizing the accessibility and ease-of-use settings of a computer can improve the overall user experience for people with and without disabilities. However, the adoption of such settings remains poor. This study investigates why various factors may influence people as they personalize and when they choose to integrate those changes into everyday use. Methods: To better understand how these factors may impact people's personalization process, we conducted a series of interviews involving 15 people with and without disabilities across several months in 2020 when computer usage became required due to the COVID-19 lockdown. We used grounded theory to analyze 49 semi-structured interviews with participants. During these interviews, people reflected upon: past attempts at personalization using built-in accessibility or ease-of-use features of their Operating System (OS) or other assistive technologies (AT), current customization activities using the personalization software, Morphic, and future opportunities for personalization systems and features. Results: We identified several barriers, facilitators, and perpetuating factors that can influence why and when people choose to adopt and integrate their personalization changes. We also outline the overall personalization lifecycle, which illustrates when various factors may impact computer personalization. Conclusion: Personalization activities are complex and easily affected by an ecosystem of influential factors that surround them. When paired with the three design considerations and ten lessons learned from this qualitative study, the overall personalization lifecycle may be useful during the design and development of future personalization systems or features for people with and without disabilities.

7.
Immunology ; 165(3): 312-327, 2022 03.
Article in English | MEDLINE | ID: mdl-34826154

ABSTRACT

Anti-CD52 antibody (anti-CD52-Ab) leads to a rapid depletion of T and B cells, followed by reconstitution of immune cells with tolerogenic characteristics. However, very little is known about its effect on innate immune cells. In this study, experimental autoimmune encephalomyelitis mice were administered murine anti-CD52-Ab to investigate its effect on dendritic cells and monocytes/macrophages in the periphery lymphoid organs and the central nervous system (CNS). Our data show that blood and splenic innate immune cells exhibited significantly increased expression of MHC-II and costimulatory molecules, which was associated with increased capacity of activating antigen-specific T cells, at first day but not three weeks after five daily treatment with anti-CD52-Ab in comparison with controls. In contrast to the periphery, microglia and infiltrating macrophages in the CNS exhibited reduced expression levels of MHC-II and costimulatory molecules after antibody treatment at both time-points investigated when compared to controls. Furthermore, the transit response of peripheral innate immune cells to anti-CD52-Ab treatment was also observed in the lymphocyte-deficient SCID mice, suggesting the changes are not a direct consequence of the mass depletion of lymphocytes in the periphery. Our study demonstrates a dynamic and tissue-specific modulation of the innate immune cells in their phenotype and function following the antibody treatment. The findings of differential modulation of the microglia and infiltrating macrophages in the CNS in comparison with the innate immune cells in the peripheral organs support the CNS-specific beneficial effect of alemtuzumab treatment on inhibiting neuroinflammation in multiple sclerosis patients.


Subject(s)
Encephalomyelitis, Autoimmune, Experimental , Alemtuzumab/pharmacology , Animals , Antibodies , CD52 Antigen/metabolism , Central Nervous System/metabolism , Humans , Immunity, Innate , Mice , Mice, Inbred C57BL , Mice, SCID
8.
J Clin Microbiol ; 60(8): e0043122, 2022 08 17.
Article in English | MEDLINE | ID: mdl-35913145

ABSTRACT

Testing for mycobacterial lipoarabinomannan (LAM) in urine is a practical but insensitive alternative to sputum testing to diagnose tuberculosis (TB) in people with HIV (PWH). Here, we evaluated urine LAM testing alongside PCR-based tests for Mycobacterium tuberculosis (MTB) DNA in tongue swabs. We hypothesized that the two nonsputum samples would deliver complementary, not redundant, results. The study included 131 South African patients of whom 64 (48.1%) were confirmed to have TB by GeneXpert MTB/RIF Ultra (Xpert Ultra) or culture analysis of sputum. A total of 120 patients (91.6%) were coinfected with HIV and 130 yielded a valid urine LAM result (Alere DETERMINE LAM Ag). Tongue swab samples were tested by IS6110-targeted qPCR with a quantification cycle (Cq) cutoff of 32. Relative to reference sputum testing (TB culture and Xpert Ultra), combined urine LAM and oral swab testing (either sample positive) was significantly more sensitive than either nonsputum sample alone (57% sensitivity for combined testing versus 35% and 39% sensitivity for urine LAM and tongue swabs; P = 0.01 and 0.04, respectively). Specificity of combined testing (neither sample positive) was 97%. On average, tongue swab-positive participants had higher sputum signal strength than urine-LAM positive participants, as measured by sputum Xpert Ultra Cq value (P = 0.037). A subset of tongue swabs (N = 18) was also tested by using Xpert Ultra, which reproduced true positive and true negative IS6110 qPCR results and resolved the two false-positive tongue swabs. With further development, tongue swabs and urine may feasibly serve as complementary nonsputum samples for diagnosis of TB in PWH.


Subject(s)
HIV Infections , Mycobacterium tuberculosis , Tuberculosis , Diagnostic Techniques and Procedures , HIV Infections/complications , Humans , Lipopolysaccharides/urine , Mycobacterium tuberculosis/genetics , Polymerase Chain Reaction , Sensitivity and Specificity , Sputum/microbiology , Tuberculosis/diagnosis , Tuberculosis/urine
9.
Harm Reduct J ; 19(1): 140, 2022 Dec 12.
Article in English | MEDLINE | ID: mdl-36503439

ABSTRACT

BACKGROUND: The measures implemented to contain the spread of the COVID-19 virus disrupted the provision of substance misuse treatment and support. However, little is known about the impact of this disruption on individuals seeking treatment for drug- and/or alcohol-related problems (henceforth service users). This study aimed to help substance misuse services learn lessons and identify ways of optimising delivery and minimising harm in the event of any future lockdowns or global crises. METHODS: The study was co-produced by a team of peer researchers, practitioners, policymakers and academics. Telephone interviews were conducted with 202 substance misuse service users over a 6-month period commencing June 2020. The interviews were conducted by a small group of seven peer researchers each with lived experience of substance use problems. The interview data were recorded by the peers in an anonymous online questionnaire survey and analysed using standard quantitative and qualitative methods. RESULTS: Service users responded to the COVID-19 pandemic in a variety of ways. Diverse responses were noted in relation to their substance use patterns, their personal lives and their substance misuse treatment experiences. For some, the pandemic acted as a new risk environment factor that increased their vulnerability to substance-related harm. For others, it facilitated aspects of the enabling environment, thereby reducing the risk of harm. CONCLUSIONS: Service users are not a homogenous group, and an individualised approach to treatment that recognises the potential for varied responses to the same stimuli is needed. The findings suggest that service users would benefit from having a choice in how they access treatment and from greater access to outreach programmes that take treatments and harm reduction tools such as naloxone into the community. The research also supports the involvement of people with lived experience in substance use research, policy and practice.


Subject(s)
COVID-19 , Drug Users , Substance-Related Disorders , Humans , Pandemics , Communicable Disease Control , Substance-Related Disorders/therapy
10.
Appl Nurs Res ; 66: 151609, 2022 08.
Article in English | MEDLINE | ID: mdl-35840269

ABSTRACT

Nurse burnout is a threat to safe, efficient health care delivery, yet estimated rates of nurse burnout are above 40 %. A critical step in reducing burnout is identifying phenomena that are amenable to intervention. Loneliness may be one such factor, yet the relationship between loneliness and burnout is not clearly described. This review aims to summarize existing literature documenting this connection. A systematic search was performed to identify studies reporting a relationship between burnout and loneliness with social support serving as a proxy construct. Twenty-four articles met inclusion criteria: 18 quantitative, two mixed-methods, and four qualitative studies. These studies identified a relationship between burnout and social support, with social support explaining approximately a third of the variability in burnout. Qualitative data suggest that social support is critical to coping with work stressors and is likely related to burnout. This review provides evidence that reducing nurse loneliness is a promising strategy for improving nurse wellbeing.


Subject(s)
Burnout, Professional , Nurses , Adaptation, Psychological , Burnout, Psychological , Humans , Loneliness , Social Support
11.
Nature ; 512(7514): 306-9, 2014 Aug 21.
Article in English | MEDLINE | ID: mdl-25143113

ABSTRACT

The timing of Neanderthal disappearance and the extent to which they overlapped with the earliest incoming anatomically modern humans (AMHs) in Eurasia are key questions in palaeoanthropology. Determining the spatiotemporal relationship between the two populations is crucial if we are to understand the processes, timing and reasons leading to the disappearance of Neanderthals and the likelihood of cultural and genetic exchange. Serious technical challenges, however, have hindered reliable dating of the period, as the radiocarbon method reaches its limit at ∼50,000 years ago. Here we apply improved accelerator mass spectrometry (14)C techniques to construct robust chronologies from 40 key Mousterian and Neanderthal archaeological sites, ranging from Russia to Spain. Bayesian age modelling was used to generate probability distribution functions to determine the latest appearance date. We show that the Mousterian ended by 41,030-39,260 calibrated years bp (at 95.4% probability) across Europe. We also demonstrate that succeeding 'transitional' archaeological industries, one of which has been linked with Neanderthals (Châtelperronian), end at a similar time. Our data indicate that the disappearance of Neanderthals occurred at different times in different regions. Comparing the data with results obtained from the earliest dated AMH sites in Europe, associated with the Uluzzian technocomplex, allows us to quantify the temporal overlap between the two human groups. The results reveal a significant overlap of 2,600-5,400 years (at 95.4% probability). This has important implications for models seeking to explain the cultural, technological and biological elements involved in the replacement of Neanderthals by AMHs. A mosaic of populations in Europe during the Middle to Upper Palaeolithic transition suggests that there was ample time for the transmission of cultural and symbolic behaviours, as well as possible genetic exchanges, between the two groups.


Subject(s)
Acculturation/history , Extinction, Biological , Geography , Neanderthals , Spatio-Temporal Analysis , Animals , Bayes Theorem , History, Ancient , Humans , Mass Spectrometry , Neanderthals/genetics , Neanderthals/physiology , Radiometric Dating , Time Factors , Tool Use Behavior , Uncertainty
12.
J Clin Microbiol ; 57(3)2019 03.
Article in English | MEDLINE | ID: mdl-30541931

ABSTRACT

Diagnostic tests for tuberculosis (TB) usually require collection of sputum, a viscous material derived from human airways. Sputum can be difficult and hazardous to collect and challenging to process in the laboratory. Oral swabs have been proposed as alternative sample types that are noninvasive and easy to collect. This study evaluated the biological feasibility of oral swab analysis (OSA) for the diagnosis of TB. Swabs were tested from South African adult subjects, including sputum GeneXpert MTB/RIF (GeneXpert)-confirmed TB patients (n = 138), sputum GeneXpert-negative but culture-positive TB patients (n = 10), ill non-TB patients (n = 37), and QuantiFERON-negative controls (n = 34). Swabs were analyzed by using a manual, nonnested quantitative PCR (qPCR) targeting IS6110 Two swab brands and three sites within the oral cavity were compared. Tongue swabbing yielded significantly stronger signals than cheek or gum swabbing. A flocked swab performed better than a more expensive paper swab. In a two-phase study, tongue swabs (two per subject) exhibited a combined sensitivity of 92.8% relative to sputum GeneXpert. Relative to all laboratory-diagnosed TB, the diagnostic yields of sputum GeneXpert (1 sample per subject) and OSA (2 samples per subject) were identical at 49/59 (83.1%) each. The specificity of the OSA was 91.5%. An analysis of "air swabs" suggested that most false-positive results were due to contamination of manual PCRs. With the development of appropriate automated methods, oral swabs could facilitate TB diagnosis in clinical settings and patient populations that are limited by the physical or logistical challenges of sputum collection.


Subject(s)
Diagnostic Tests, Routine/methods , Tuberculosis, Pulmonary/diagnosis , Tuberculosis, Pulmonary/microbiology , Adult , Humans , Mycobacterium tuberculosis/genetics , Sensitivity and Specificity , Sputum
13.
Bioscience ; 69(11): 877-887, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31719710

ABSTRACT

Drivers of Late Quaternary megafaunal extinctions are relevant to modern conservation policy in a world of growing human population density, climate change, and faunal decline. Traditional debates tend toward global solutions, blaming either dramatic climate change or dispersals of Homo sapiens to new regions. Inherent limitations to archaeological and paleontological data sets often require reliance on scant, poorly resolved lines of evidence. However, recent developments in scientific technologies allow for more local, context-specific approaches. In the present article, we highlight how developments in five such methodologies (radiocarbon approaches, stable isotope analysis, ancient DNA, ancient proteomics, microscopy) have helped drive detailed analysis of specific megafaunal species, their particular ecological settings, and responses to new competitors or predators, climate change, and other external phenomena. The detailed case studies of faunal community composition, extinction chronologies, and demographic trends enabled by these methods examine megafaunal extinctions at scales appropriate for practical understanding of threats against particular species in their habitats today.

14.
J Hum Evol ; 134: 102638, 2019 09.
Article in English | MEDLINE | ID: mdl-31446971

ABSTRACT

The migration of anatomically modern humans (AMH) from Africa to every inhabitable continent included their dispersal through Island Southeast Asia (ISEA) to Australia. Significantly, this involved overwater dispersal through the Lesser Sunda Islands between Sunda (continental Southeast Asia) and Sahul (Australia and New Guinea). However, the timing and direction of this movement is still debated. Here, we report on human skeletal material recovered from excavations at two rockshelters, known locally as Tron Bon Lei, on Alor Island, Indonesia. The remains, dated to the Late Pleistocene, are the first anatomically modern human remains recovered in Wallacea dated to this period and are associated with cultural material demonstrating intentional burial. The human remains from Tron Bon Lei represent a population osteometrically distinct from Late Pleistocene Sunda and Sahul AMH. Instead, morphometrically, they appear more similar to Holocene populations in the Lesser Sundas. Thus, they may represent the remains of a population originally from Sunda whose Lesser Sunda Island descendants survived into the Holocene.


Subject(s)
Fossils/anatomy & histology , Human Migration , Skull/anatomy & histology , Archaeology , Humans , Indonesia
15.
Anesth Analg ; 128(6): e97-e99, 2019 06.
Article in English | MEDLINE | ID: mdl-31094796

ABSTRACT

Anesthetic agents are known greenhouse gases with hundreds to thousands of times the global warming impact compared with carbon dioxide. We sought to mitigate the negative environmental and financial impacts of our practice in the perioperative setting through multidisciplinary staff engagement and provider education on flow rate reduction and volatile agent choice. These efforts led to a 64% per case reduction in carbon dioxide equivalent emissions (163 kg in Fiscal Year 2012, compared with 58 kg in Fiscal Year 2015), as well as a cost savings estimate of $25,000 per month.


Subject(s)
Air Pollutants , Anesthesia, Inhalation , Conservation of Natural Resources , Greenhouse Gases/analysis , Nebulizers and Vaporizers , Anesthesiology , Anesthetics , Anesthetics, Inhalation/economics , Automobiles , Carbon Dioxide , Cost Savings , Desflurane , General Surgery , Global Warming , Humans , Information Technology , Inservice Training , Interdisciplinary Communication , Isoflurane , Nitrous Oxide/analysis , Nurses , Sevoflurane , Switzerland
17.
Proc Biol Sci ; 285(1870)2018 01 10.
Article in English | MEDLINE | ID: mdl-29321296

ABSTRACT

The ability to encrust in order to secure and maintain growth on a substrate is a key competitive innovation in benthic metazoans. Here we describe the substrate growth dynamics, mode of biomineralization and possible affinity of Namapoikia rietoogensis, a large (up to 1 m), robustly skeletal, and modular Ediacaran metazoan which encrusted the walls of synsedimentary fissures within microbial-metazoan reefs. Namapoikia formed laminar or domal morphologies with an internal structure of open tubules and transverse elements, and had a very plastic, non-deterministic growth form which could encrust both fully lithified surfaces as well as living microbial substrates, the latter via modified skeletal holdfasts. Namapoikia shows complex growth interactions and substrate competition with contemporary living microbialites and thrombolites, including the production of plate-like dissepiments in response to microbial overgrowth which served to elevate soft tissue above the microbial surface. Namapoikia could also recover from partial mortality due to microbial fouling. We infer initial skeletal growth to have propagated via the rapid formation of an organic scaffold via a basal pinacoderm prior to calcification. This is likely an ancient mode of biomineralization with similarities to the living calcified demosponge Vaceletia. Namapoikia also shows inferred skeletal growth banding which, combined with its large size, implies notable individual longevity. In sum, Namapoikia was a large, relatively long-lived Ediacaran clonal skeletal metazoan that propagated via an organic scaffold prior to calcification, enabling rapid, effective and dynamic substrate occupation and competition in cryptic reef settings. The open tubular internal structure, highly flexible, non-deterministic skeletal organization, and inferred style of biomineralization of Namapoikia places probable affinity within total-group poriferans.


Subject(s)
Biomineralization , Fossils , Porifera/growth & development , Animals , Coral Reefs , Fossils/microbiology , Fossils/ultrastructure , Geologic Sediments , Porifera/microbiology , Porifera/ultrastructure
18.
Proc Biol Sci ; 284(1851)2017 Mar 29.
Article in English | MEDLINE | ID: mdl-28356454

ABSTRACT

Why large and diverse skeletons first appeared ca 550 Ma is not well understood. Many Ediacaran skeletal biota show evidence of flexibility, and bear notably thin skeletal walls with simple, non-hierarchical microstructures of either aragonite or high-Mg calcite. We present evidence that the earliest skeletal macrobiota, found only in carbonate rocks, had close soft-bodied counterparts hosted in contemporary clastic rocks. This includes the calcareous discoidal fossil Suvorovella, similar to holdfasts of Ediacaran biota taxa previously known only as casts and moulds, as well as tubular and vase-shaped fossils. In sum, these probably represent taxa of diverse affinity including unicellular eukaryotes, total group cnidarians and problematica. Our findings support the assertion that the calcification was an independent and derived feature that appeared in diverse groups where an organic scaffold was the primitive character, which provided the framework for interactions between the extracellular matrix and mineral ions. We conclude that such skeletons may have been acquired with relative ease in the highly saturated, high alkalinity carbonate settings of the Ediacaran, where carbonate polymorph was further controlled by seawater chemistry. The trigger for Ediacaran biomineralization may have been either changing seawater Mg/Ca and/or increasing oxygen levels. By the Early Cambrian, however, biomineralization styles and the range of biominerals had significantly diversified, perhaps as an escalating defensive response to increasing predation pressure. Indeed skeletal hardparts had appeared in clastic settings by Cambrian Stage 1, suggesting independence from ambient seawater chemistry where genetic and molecular mechanisms controlled biomineralization and mineralogy had become evolutionarily constrained.


Subject(s)
Calcification, Physiologic , Calcium Carbonate , Fossils , Animals , Minerals , Seawater
19.
Paediatr Perinat Epidemiol ; 31(4): 338-345, 2017 07.
Article in English | MEDLINE | ID: mdl-28621463

ABSTRACT

BACKGROUND: The Apgar score has been shown to be predictive of neonatal mortality in clinical and population studies, but has not been used for international comparisons. We examined population-level distributions in Apgar scores and associations with neonatal mortality in Europe. METHODS: Aggregate data on the 5 minute Apgar score for live births and neonatal mortality rates from countries participating in the Euro-Peristat project in 2004 and 2010 were analysed. Country level associations between the Apgar score and neonatal mortality were assessed using the Spearman rank correlation coefficient. RESULTS: Twenty-three countries or regions provided data on Apgar at 5 minutes, covering 2 183 472 live births. Scores <7 ranged from 0.3% to 2.4% across countries in 2004 and 2010 and were correlated over time (ρ = 0.88, P < 0.01). There were large differences in healthy baby scores: scores of 10 ranged from 8.8% to 92.7% whereas scores of 9 or 10 ranged from 72.9% to 96.8%. Countries more likely to score 10 s, as opposed to 9 s, for healthy babies had lower proportions of Apgar <7 (ρ = -0.43, P = 0.04). Neonatal mortality rates were weakly correlated with Apgar score <7 (ρ = -0.06, P = 0.61), but differences over time in these two indicators were correlated (ρ =0.56, P = 0.02). CONCLUSIONS: Large variations in the distribution of Apgar scores likely due to national scoring practices make the Apgar score an unsuitable indicator for benchmarking newborn health across countries. However, country-level trends over time in the Apgar score may reflect real changes and merit further investigation.


Subject(s)
Apgar Score , Infant Health , Europe/epidemiology , Health Status Indicators , Humans , Infant , Infant Health/statistics & numerical data , Infant Mortality , Infant, Newborn
20.
Proc Natl Acad Sci U S A ; 110(8): 2781-6, 2013 Feb 19.
Article in English | MEDLINE | ID: mdl-23382220

ABSTRACT

It is commonly accepted that some of the latest dates for Neanderthal fossils and Mousterian industries are found south of the Ebro valley in Iberia at ca. 36 ka calBP (calibrated radiocarbon date ranges). In contrast, to the north of the valley the Mousterian disappears shortly before the Proto-Aurignacian appears at ca. 42 ka calBP. The latter is most likely produced by anatomically modern humans. However, two-thirds of dates from the south are radiocarbon dates, a technique that is particularly sensitive to carbon contaminants of a younger age that can be difficult to remove using routine pretreatment protocols. We have attempted to test the reliability of chronologies of 11 southern Iberian Middle and early Upper Paleolithic sites. Only two, Jarama VI and Zafarraya, were found to contain material that could be reliably dated. In both sites, Middle Paleolithic contexts were previously dated by radiocarbon to less than 42 ka calBP. Using ultrafiltration to purify faunal bone collagen before radiocarbon dating, we obtain ages at least 10 ka (14)C years older, close to or beyond the limit of the radiocarbon method for the Mousterian at Jarama VI and Neanderthal fossils at Zafarraya. Unless rigorous pretreatment protocols have been used, radiocarbon dates should be assumed to be inaccurate until proven otherwise in this region. Evidence for the late survival of Neanderthals in southern Iberia is limited to one possible site, Cueva Antón, and alternative models of human occupation of the region should be considered.

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