258 research outputs found

    A comparison of fish communities over different reef configurations in the northwestern Gulf of Mexico

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    High fishing pressure and limited natural habitat characterize the otherwise barren northwestern Gulf of Mexico. South Texas lacks extensive research of local natural and artificial reefs, and few studies report fish community and sportfish analysis of different reef densities. To alleviate this lack of data, fish abundances were monitored at different reef configurations in the PS-1047 Reef, 13 km off Port Mansfield, Texas, where 4000 concrete culverts were placed in 2011. Four culvert categories (CC1: 1-30 culverts, CC2: 31-70 culverts, CC3: 71-120 culverts, and CC4: 121-190 culverts in a 30-m radius), natural reefs and bare areas were sampled. Species abundances were assessed with 15- min SCUBA surveys, and total lengths of commercially valuable Lutjanus campechanus were measured. In summer 2013, water temperatures were warmer (25.1 ± 0.4°C), and surveys had significantly more adults and more even juvenile populations than in the summer of 2014 (22.8 ± 0.2°C). No fishes were observed at bare areas, whereas sites with structure had 186 ± 28 individuals from 13 ± 1 species. Fish communities did not significantly differ between reefs, yet significantly more adult individuals were seen on natural reefs than CC1, CC2, and CC4. CC3 resembled natural reefs with similarly high species richness and total abundance values. Lutjanus campechanus were found at all sites with structure, with an average 41 ± 6 individuals per site, and abundances did not significantly differ among reef categories. CC1 exhibited the largest Lutjanus campechanus, 362.9 ± 8.7 mm, whereas all other reef categories exhibited average lengths ranging from 296.5 to 322.8 mm. Longer individuals at CC1 may result from aggressive behaviors exhibited at sites with less suitable habitat. Using a previous study that assessed total length to age ratios in South Texas, the predicted age of Lutjanus campechanus was two years old. Findings suggest that culvert reefs are substantial improvements to otherwise bare areas, and reefs with about 100 culverts closely mimic species diversity of nearby natural reefs. Thus, it is recommended that future culvert reefs be deployed with 100 culverts in 100 m increments to cover four times more area than at PS-1047

    Recruitment Patterns of Juvenile Fish at an Artificial Reef Area in the Gulf of Mexico

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    In 2011 the Texas Parks and Wildlife Department and the Coastal Conservation Association of Texas deployed over 4,000 concrete culverts in a designated artificial reef area off Port Mansfield, Texas, to enhance habitat for sport fish species in the Gulf of Mexico. A study was conducted to assess juvenile fish recruitment at varying culvert densities within the artificial reef area. Standard monitoring units for the recruitment of reef fish (SMURFs) were used to sample juvenile fish, and these collections were compared with visual scuba surveys. The 0.027-m3 SMURFs were placed at four different culvert densities (0, 1–50, 51–100, and 101+ culverts in a 30-m radius) and sampled during 2013 to 2014. Measurements of rugosity, vertical relief, and percent cover were collected to elucidate factors that drive juvenile recruitment. Average species richness was highest at sites with no culverts and lowest at dense culvert sites. Species compositions were significantly different between sampling locations with no culverts and all locations with culverts; average similarity was 33.8%. Belted Sandfish Serranus subligarius was the most ubiquitous species among all sampling locations. Visual scuba surveys at the same locations showed lower diversity indices of the juvenile fish community than observed by SMURFs and were only 14% similar to the community sampled by the SMURFs. These findings suggest SMURFs are a more effective tool for examining juvenile fish at an artificial reef due to the cryptic nature of juveniles and the low visibility around shallow reefs. Additionally, commercially important Yellowedge Grouper Hyporthodus flavolimbatus, Warsaw Grouper H. nigritus, and Red Snapper Lutjanus campechanus juveniles were only found at SMURFs at sampling locations with no culverts. The presence of juveniles of these key species suggest that fisheries management may benefit from creating low-relief reef patches away from the main reef where juvenile fish can recruit and grow

    Pieter Braecke beeldhouwer (1858-1938). Als de ziele luistert

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    Model validation for a noninvasive arterial stenosis detection problem

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    Copyright @ 2013 American Institute of Mathematical SciencesA current thrust in medical research is the development of a non-invasive method for detection, localization, and characterization of an arterial stenosis (a blockage or partial blockage in an artery). A method has been proposed to detect shear waves in the chest cavity which have been generated by disturbances in the blood flow resulting from a stenosis. In order to develop this methodology further, we use both one-dimensional pressure and shear wave experimental data from novel acoustic phantoms to validate corresponding viscoelastic mathematical models, which were developed in a concept paper [8] and refined herein. We estimate model parameters which give a good fit (in a sense to be precisely defined) to the experimental data, and use asymptotic error theory to provide confidence intervals for parameter estimates. Finally, since a robust error model is necessary for accurate parameter estimates and confidence analysis, we include a comparison of absolute and relative models for measurement error.The National Institute of Allergy and Infectious Diseases, the Air Force Office of Scientific Research, the Deopartment of Education and the Engineering and Physical Sciences Research Council (EPSRC)

    Submucosal Tunnel Endoscopic Resection of Gastric Lesion Before Obesity Surgery: a Case Series

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    Background: Submucosal tumors (SMTs) of the gastrointestinal tract are a rare pathological entity comprising a wide variety of neoplastic and non-neoplastic lesions. Even if most SMTs are benign tumors (e.g., leiomyomas), a smaller portion may have a malignant potential (e.g., gastrointestinal stromal tumor (GIST)). Preoperative diagnosis of SMT in bariatric patients may arise challenging clinical dilemmas. Long-term surveillance may be difficult after bariatric surgery. Moreover, according to SMT location, its presence may interfere with planned surgery. Submucosal tunneling endoscopic resection (STER) has emerged as an effective approach for minimally invasive en bloc excision of SMTs. This is the first case series of STER for SMTs before bariatric surgery. Methods: Seven female patients underwent STER for removal of SMTs before bariatric surgery. All lesions were incidentally diagnosed at preoperative endoscopy. STER procedural steps comprised mucosal incision, submucosal tunneling, lesion enucleation, and closure of mucosal defect. Results: En bloc removal of SMT was achieved in all cases. Mean procedural time was of 45 min (SD 18.6). No adverse event occurred. Mean size of the lesions was 20.6 mm (SD 5.8). Histological diagnoses were 5 leyomiomas, 1 lipoma, and 1 low grade GIST. Bariatric procedure was performed after a mean period of 4.1 months (SD 1.6) from endoscopic resection. Conclusion: STER is a safe and effective treatment for the management of SMT even in bariatric patients awaiting surgery. Preoperative endoscopic resection of SMTs has the advantages of reducing the need for surveillance and removing lesions that could interfere with planned surgery. STER did not altered accomplishment of bariatric procedures

    Clinical Study Weight Loss after Sleeve Gastrectomy in Super Superobesity

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    Objective. This prospective study evaluated laparoscopic sleeve gastrectomy for its safety and efficiency in excess weight loss (%EWL) in super superobese patients (BMI > 60 Kg/m 2 ). Results. Thirty patients (33 women and 7 men) were included, with mean age of 35 years (range 18 to 59). Mean preoperative BMI was 66 Kg/m 2 (range 60 to 85). The study included one patient with complete situs inversus and 4 (14%) with previous restrictive gastric banding. The mean operative time was 120 minutes (range 80 to 220 min) and the mean hospital stay was 7.5 days (4 to 28 days). There was no postoperative mortality or need for a laparotomy conversion. Two subphrenic hematomas, one gastric fistula, and one pulmonary embolism, were the major complications. After 18 months 17 (77%) had sufficient weight loss and six had insufficient results, leading to either re-sleeve gastrectomy (3), or gastric bypass (2). Three years after the initial laparoscopic sleeve gastrectomy, the mean EWL was 51% (range 21 to 82). Conclusion. The laparoscopic sleeve gastrectomy is a safe and efficient operating procedure for treating super superobesity. In the case of insufficient weight loss, a second-stage operation like resleeve gastrectomy or gastric bypass can be proposed

    A novel human iPSC model of COL4A1/A2 small vessel disease unveils a key pathogenic role of matrix metalloproteinases

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    Cerebral small vessel disease (SVD) affects the small vessels in the brain and is a leading cause of stroke and dementia. Emerging evidence supports a role of the extracellular matrix (ECM), at the interface between blood and brain, in the progression of SVD pathology, but this remains poorly characterized. To address ECM role in SVD, we developed a co-culture model of mural and endothelial cells using human induced pluripotent stem cells from patients with COL4A1/A2 SVD-related mutations. This model revealed that these mutations induce apoptosis, migration defects, ECM remodeling, and transcriptome changes in mural cells. Importantly, these mural cell defects exert a detrimental effect on endothelial cell tight junctions through paracrine actions. COL4A1/A2 models also express high levels of matrix metalloproteinases (MMPs), and inhibiting MMP activity partially rescues the ECM abnormalities and mural cell phenotypic changes. These data provide a basis for targeting MMP as a therapeutic opportunity in SVD.</p

    PLoS One

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    Diffusion MRI is extensively used to investigate changes in white matter microstructure. However, diffusion measures within white matter tissue can be affected by partial volume effects due to cerebrospinal fluid and white matter hyperintensities, especially in the aging brain. In previous aging studies, the cingulum bundle that plays a central role in the architecture of the brain networks supporting cognitive functions has been associated with cognitive deficits. However, most of these studies did not consider the partial volume effects on diffusion measures. The aim of this study was to evaluate the effect of free water elimination on diffusion measures of the cingulum in a group of 68 healthy elderly individuals. We first determined the effect of free water elimination on conventional DTI measures and then examined the effect of free water elimination on verbal fluency performance over 12 years. The cingulum bundle was reconstructed with a tractography pipeline including a white matter hyperintensities mask to limit the negative impact of hyperintensities on fiber tracking algorithms. We observed that free water elimination increased the ability of conventional DTI measures to detect associations between tissue diffusion measures of the cingulum and changes in verbal fluency in older individuals. Moreover, free water content and mean diffusivity measured along the cingulum were independently associated with changes in verbal fluency. This suggests that both tissue modifications and an increase in interstitial isotropic water would contribute to cognitive decline. These observations reinforce the importance of using free water elimination when studying brain aging and indicate that free water itself could be a relevant marker for age-related cingulum white matter modifications and cognitive decline

    Cancer risk and tumour spectrum in 172 patients with a germline SUFU pathogenic variation : a collaborative study of the SIOPE Host Genome Working Group

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    Background Little is known about risks associated with germline SUFU pathogenic variants (PVs) known as a cancer predisposition syndrome. Methods To study tumour risks, we have analysed data of a large cohort of 45 unpublished patients with a germline SUFU PV completed with 127 previously published patients. To reduce the ascertainment bias due to index patient selection, the risk of tumours was evaluated in relatives with SUFU PV (89 patients) using the Nelson-Aalen estimator. Results Overall, 117/172 (68%) SUFU PV carriers developed at least one tumour: medulloblastoma (MB) (86 patients), basal cell carcinoma (BCC) (25 patients), meningioma (20 patients) and gonadal tumours (11 patients). Thirty-three of them (28%) had multiple tumours. Median age at diagnosis of MB, gonadal tumour, first BCC and first meningioma were 1.5, 14, 40 and 44 years, respectively. Follow-up data were available for 160 patients (137 remained alive and 23 died). The cumulative incidence of tumours in relatives was 14.4% (95% CI 6.8 to 21.4), 18.2% (95% CI 9.7 to 25.9) and 44.1% (95% CI 29.7 to 55.5) at the age of 5, 20 and 50 years, respectively. The cumulative risk of an MB, gonadal tumour, BCC and meningioma at age 50 years was: 13.3% (95% CI 6 to 20.1), 4.6% (95% CI 0 to 9.7), 28.5% (95% CI 13.4 to 40.9) and 5.2% (95% CI 0 to 12), respectively. Sixty-four different PVs were reported across the entire SUFU gene and inherited in 73% of cases in which inheritance could be evaluated. Conclusion Germline SUFU PV carriers have a life-long increased risk of tumours with a spectrum dominated by MB before the age of 5, gonadal tumours during adolescence and BCC and meningioma in adulthood, justifying fine-tuned surveillance programmes.Peer reviewe
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