32 research outputs found

    Insights into coral recovery based on symbiont state and environmental conditions in the temperate, facultatively symbiotic coral Astrangia poculata

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    Coral reefs are declining globally, calling for better ways to quantify coral health and predict resilience to future stress. The relationship between bleaching and fitness is key, as is reserve capacity to deal with physical trauma. This dissertation is an integrative study of the coral-algal symbiosis, holobiont performance under varied environmental conditions, and interactions between holobiont and environment on coral colony health and ability to recover from routine partial damage. I utilize the facultatively symbiotic, temperate coral Astrangia poculata as a natural model to explore the dynamics of colony health, performance, and the influence of environmental and nutritional stress under stable aposymbiotic and symbiotic states. Unlike most tropical hermatypic corals that rely heavily upon photosynthetic symbionts for energy, A. poculata can (1) flexibly use both heterotrophic and autotrophic nutritional pathways and (2) exist in naturally occurring, stable, and measurable aposymbiotic and symbiotic states. I begin by describing the impacts of environmentally relevant (winter, summer, and above range) temperatures on small-scale wound healing and recovery. Next, I explore the effects of nutritional and symbiotic states by comparing wound recovery, total colony health, host behavior, and symbiont performance in fed and starved colonies. Finally, I generate a novel reference transcriptome for A. poculata, and use computational approaches to characterize variation in gene expression between the symbiotic and aposymbiotic states. This analysis reveals that regardless of temperature, and with or without the potential for heterotrophic nutritional sources, a relationship with Symbiodinium enhances wound recovery and resilience to stress. Compromised healing ability and tissue cover at low temperatures suggest that in temperate stony corals, recovery and survival are more impacted by winter conditions than by exposure to high summer temperatures. Differential expression analysis revealed predictable enhancements to photosynthesis-related gene expression in symbiotic colonies. Together these results illuminate the complex interactions among symbiotic state, stress, recovery, and performance. We propose that studies like ours that examine the effects of combined stressors, as opposed to a monotonic focus on coral bleaching per se, are essential to clinical diagnosis and stewardship for coral reefs subjected to intense, cumulative human impacts

    Qualitative Examination of Strategies to Overcome Resistance to Change in Lean Manufacturing

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    Approximately 80% of lean manufacturing program initiatives are abandoned in the first year of implementation. Only 2% of organizations that embark on the lean journey complete it with the results and the sustainability they expected. There is a gap in past research regarding, the leadership strategies organizations can use to overcome resistance to change during lean manufacturing program implementations. The problem in this study was that leaders have limited information to overcome resistance to change when implementing these programs. The purpose of this study was to explore how leaders within manufacturing organizations may overcome resistance to change through leadership strategy. The conceptual framework was Kotter\u27s 8 steps of change. Data were collected from 20 participant interviews with leaders who implemented lean manufacturing programs successfully and sustainably in their organizations. The data analysis for this study consisted of repeated reviews of transcription and audio-recorded data that resulted in the coding of themes from participant interviews. The data analysis resulted in 12 themes that emerged from significant statements made through participant responses. Results indicated that senior leadership participation and communication are the main strategies needed to overcome resistance to change during lean manufacturing program implementations. Followed by allowing employees to experiment with processes for their areas, training, and process alignment for a comprehensive strategy. The implications of positive social change within this study are to provide a positive perspective to organizational leaders looking to deploy lean manufacturing change initiatives and to help leaders overcome employee resistance to the organizational changes

    Corals of the genus Porites are a locally abundant component of the epibiont community on mangrove prop roots at Calabash Caye, Turneffe Atoll, Belize

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    Mangroves are generally regarded as inhospitable for corals, but recent reports suggest they provide ecological refuge for some species. We surveyed diverse mangrove habitats on Turneffe Atoll, Belize, documenting 127 colonies of Porites divaricata (Thin Finger Coral) along 1858 m of mangrove prop roots at Calabash Caye and a much more diverse coral assemblage at Crooked Creek. At Calabash, corals were highly clumped, and varied widely in size and morphology, including large well-arborized colonies, encrusting forms with few branches, and new recruits with no branches, suggesting an age-structuredpopulation exhibiting extensive morphological plasticity. The data described here contributeto an emerging picture of mangroves as potentially critical habitat for many Caribbeancoral species.Accepted manuscrip

    The impact of autotrophic versus heterotrophic nutritional pathways on colony health and wound recovery in corals

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    For animals that harbor photosynthetic symbionts within their tissues, such as corals, the different relative contributions of autotrophy versus heterotrophy to organismal energetic requirements have direct impacts on fitness. This is especially true for facultatively symbiotic corals, where the balance between host‐caught and symbiont‐produced energy can be altered substantially to meet the variable demands of a shifting environment. In this study, we utilized a temperate coral–algal system (the northern star coral, Astrangia poculata, and its photosynthetic endosymbiont, Symbiodinium psygmophilum) to explore the impacts of nutritional sourcing on the host's health and ability to regenerate experimentally excised polyps. For fed and starved colonies, wound healing and total colony tissue cover were differentially impacted by heterotrophy versus autotrophy. There was an additive impact of positive nutritional and symbiotic states on a coral's ability to initiate healing, but a greater influence of symbiont state on the recovery of lost tissue at the lesion site and complete polyp regeneration. On the other hand, regardless of symbiont state, fed corals maintained a higher overall colony tissue cover, which also enabled more active host behavior (polyp extension) and endosymbiont behavior (photosynthetic ability of Symbiondinium). Overall, we determined that the impact of nutritional state and symbiotic state varied between biological functions, suggesting a diversity in energetic sourcing for each of these processes.PADI Foundation; Cell Signaling Technologies; Boston University Marine Program Warren McLeod Fellowship; New England Aquarium; National Science Foundation, Grant/Award Number: IOS-1354935 (PADI Foundation; Cell Signaling Technologies; Boston University Marine Program Warren McLeod Fellowship; New England Aquarium; IOS-1354935 - National Science Foundation)Published versio

    The impact of autotrophic versus heterotrophic nutritional pathways on colony health and wound recovery in corals

    Get PDF
    For animals that harbor photosynthetic symbionts within their tissues, such as corals, the different relative contributions of autotrophy versus heterotrophy to organismal energetic requirements have direct impacts on fitness. This is especially true for facultatively symbiotic corals, where the balance between host‐caught and symbiont‐produced energy can be altered substantially to meet the variable demands of a shifting environment. In this study, we utilized a temperate coral–algal system (the northern star coral, Astrangia poculata, and its photosynthetic endosymbiont, Symbiodinium psygmophilum) to explore the impacts of nutritional sourcing on the host's health and ability to regenerate experimentally excised polyps. For fed and starved colonies, wound healing and total colony tissue cover were differentially impacted by heterotrophy versus autotrophy. There was an additive impact of positive nutritional and symbiotic states on a coral's ability to initiate healing, but a greater influence of symbiont state on the recovery of lost tissue at the lesion site and complete polyp regeneration. On the other hand, regardless of symbiont state, fed corals maintained a higher overall colony tissue cover, which also enabled more active host behavior (polyp extension) and endosymbiont behavior (photosynthetic ability of Symbiondinium). Overall, we determined that the impact of nutritional state and symbiotic state varied between biological functions, suggesting a diversity in energetic sourcing for each of these processes.PADI Foundation; Cell Signaling Technologies; Boston University Marine Program Warren McLeod Fellowship; New England Aquarium; National Science Foundation, Grant/Award Number: IOS-1354935 (PADI Foundation; Cell Signaling Technologies; Boston University Marine Program Warren McLeod Fellowship; New England Aquarium; IOS-1354935 - National Science Foundation)Published versio

    Efficacy and Safety of Subcutaneous Golimumab in Methotrexate-Naive Patients With Rheumatoid Arthritis: Five-Year Results of a Randomized Clinical Trial

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    Objective: To evaluate the safety and efficacy of golimumab through 5 years in adults with active rheumatoid arthritis (RA) who had not previously received methotrexate (MTX). Methods: In the GO-BEFORE study, 637 MTX-naive adult patients with active RA were randomized (1:1:1:1) to placebo + MTX (group 1), golimumab 100 mg + placebo (group 2), golimumab 50 mg + MTX (group 3), or golimumab 100 mg + MTX (group 4). Inadequate responders in groups 1, 2, and 3 entered early escape at week 28 to golimumab 50 mg + MTX, golimumab 100 mg + MTX, or golimumab 100 mg + MTX, respectively; remaining patients in group 1 could cross over to golimumab 50 mg + MTX at week 52. Assessments included the American College of Rheumatology 20%/50%/70% improvement criteria (ACR20/50/70) response, the Disease Activity Score in 28 joints (DAS28) using C-reactive protein (CRP) level, and the modified Sharp/van der Heijde score (SHS). Efficacy was analyzed using an intent-to-treat (ITT) analysis. Pharmacokinetics and immunogenicity were evaluated at selected visits. Results: A total of 422 patients completed golimumab treatment through week 256. At week 256, 72.8%, 54.6%, and 38.0% of all patients in the full ITT population (n = 637) had an ACR20/50/70 response, respectively; 84.1% had a good or moderate DAS28-CRP response; and 72.7% had a clinically meaningful improvement in physical function. Radiographic progression was minimal in all treatment groups through week 256, and the overall mean change from baseline in SHS was 1.36. Serum trough golimumab concentrations were approximately dose proportional and maintained through week 256. Antibodies to golimumab occurred in 9.6% of patients through week 256. Infections were the most common type of adverse event (AE); 204 of 616 patients (33.1%) had ≥1 serious AE. Conclusions: Clinical efficacy with golimumab treatment was maintained through week 256 of the GO-BEFORE trial of MTX-naive RA patients. No unexpected AEs occurred; safety results through 5 years are consistent with earlier reports

    Rheumatoid arthritis - clinical aspects: 134. Predictors of Joint Damage in South Africans with Rheumatoid Arthritis

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    Background: Rheumatoid arthritis (RA) causes progressive joint damage and functional disability. Studies on factors affecting joint damage as clinical outcome are lacking in Africa. The aim of the present study was to identify predictors of joint damage in adult South Africans with established RA. Methods: A cross-sectional study of 100 black patients with RA of >5 years were assessed for joint damage using a validated clinical method, the RA articular damage (RAAD) score. Potential predictors of joint damage that were documented included socio-demographics, smoking, body mass index (BMI), disease duration, delay in disease modifying antirheumatic drug (DMARD) initiation, global disease activity as measured by the disease activity score (DAS28), erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and autoantibody status. The predictive value of variables was assessed by univariate and stepwise multivariate regression analyses. A p value <0.05 was considered significant. Results: The mean (SD) age was 56 (9.8) years, disease duration 17.5 (8.5) years, educational level 7.5 (3.5) years and DMARD lag was 9 (8.8) years. Female to male ratio was 10:1. The mean (SD) DAS28 was 4.9 (1.5) and total RAAD score was 28.3 (12.8). The mean (SD) BMI was 27.2 kg/m2 (6.2) and 93% of patients were rheumatoid factor (RF) positive. More than 90% of patients received between 2 to 3 DMARDs. Significant univariate predictors of a poor RAAD score were increasing age (p = 0.001), lower education level (p = 0.019), longer disease duration (p < 0.001), longer DMARD lag (p = 0.014), lower BMI (p = 0.025), high RF titre (p < 0.001) and high ESR (p = 0.008). The multivariate regression analysis showed that the only independent significant predictors of a higher mean RAAD score were older age at disease onset (p = 0.04), disease duration (p < 0.001) and RF titre (p < 0.001). There was also a negative association between BMI and the mean total RAAD score (p = 0.049). Conclusions: Patients with longstanding established RA have more severe irreversible joint damage as measured by the clinical RAAD score, contrary to other studies in Africa. This is largely reflected by a delay in the initiation of early effective treatment. Independent of disease duration, older age at disease onset and a higher RF titre are strongly associated with more joint damage. The inverse association between BMI and articular damage in RA has been observed in several studies using radiographic damage scores. The mechanisms underlying this paradoxical association are still widely unknown but adipokines have recently been suggested to play a role. Disclosure statement: C.I. has received a research grant from the Connective Tissue Diseases Research Fund, University of the Witwatersrand. All other authors have declared no conflicts of interes

    Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

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    Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

    Técnicas de relajación y visualización para disminución de ansiedad en deportistas federadas de voleibol de la categoría infanto juvenil femenina.

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    Evidencia que la aplicación conjunta de las técnicas de relajación y visualización disminuye los estados de ansiedad de las deportistas integrantes de la Selección Infanto-juvenil de la Federación Nacional de Voleibol de Guatemala del año 2010. La muestra estuvo conformada por 14 deportistas, comprendidas entre los 15 a 17 años de edad. Para recolectar datos se utilizaron las técnicas siguientes: entrevista, observación estructurada, test de ansiedad IDARE y auto informe. Analiza e interpreta los resultados y concluye que, se determinó la efectividad de la aplicación conjunta de las técnicas de relajación y visualización en la disminución de estados de ansiedad de las atletas de voleibol próximas a competir. Se desarrolló un programa de enseñanza de la técnica (abreviada) de relajación de Schütz con deportistas próximas a competir de la Federación Nacional de voleibol
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