1,100 research outputs found

    Auditory-visual interactions in egocentric distance perception: Ventriloquism effect and aftereffect

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    This article was published in The Journal of the Acoustical Society of America, 2021

    A Precise Geoid Model for Africa: AFRgeo2019

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    In the framework of the IAG African Geoid Project, an attempt towards a precise geoid model for Africa is presented in this investigation. The available gravity data set suffers from significantly large data gaps. These data gaps are filled using the EIGEN-6C4 model on a 15′× 15′ grid prior to the gravity reduction scheme. The window remove-restore technique (Abd-Elmotaal and Kühtreiber, Phys Chem Earth Pt A 24(1):53–59, 1999; J Geod 77(1–2):77–85, 2003) has been used to generate reduced anomalies having a minimum variance to minimize the interpolation errors, especially at the large data gaps. The EIGEN-6C4 global model, complete to degree and order 2190, has served as the reference model. The reduced anomalies are gridded on a 5′× 5′ grid employing an un-equal weight least-squares prediction technique. The reduced gravity anomalies are then used to compute their contribution to the geoid undulation employing Stokes’ integral with Meissl (Preparation for the numerical evaluation of second order Molodensky-type formulas. Ohio State University, Department of Geodetic Science and Surveying, Rep 163, 1971) modified kernel for better combination of the different wavelengths of the earth’s gravity field. Finally the restore step within the window remove-restore technique took place generating the full gravimetric geoid. In the last step, the computed geoid is fitted to the DIR_R5 GOCE satellite-only model by applying an offset and two tilt parameters. The DIR_R5 model is used because it turned out that it represents the best available global geopotential model approximating the African gravity field. A comparison between the geoid computed within the current investigation and the existing former geoid model AGP2003 (Merry et al., A window on the future of geodesy. International Association of Geodesy Symposia, vol 128, pp 374–379, 2005) for Africa has been carried out

    Implant-based immediate reconstruction in prophylactic mastectomy: is the caudal dermis flap a reliable alternative to synthetic mesh or acellular dermal matrix?

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    Introduction The demand for prophylactic mastectomy has increased significantly over the last 10 years. This can be explained by a substantial gain of knowledge about the clinical risk and outcome of patients with high risk mutations such as BRCA1 and 2, the improved diagnostic possibilities for detecting the genetic predisposition for the development of breast cancer and the awareness for those mutations by health care professionals as well as patients. In addition to expander-to-implant reconstruction and microsurgical flap surgery, definitive immediate reconstruction with subpectoral insertion of breast implants is often preferred. The prosthesis is covered at its inferior pole by a synthetic mesh or acellular dermal matrix. In these cases, in addition to the silicone prosthesis, a further foreign body must be implanted. This can be exposed in the event of wound healing disorder or necrosis of the usually thin soft tissue covering after subcutaneous mastectomy, thus calling into question the reconstructive result. In this study, the coverage of the lower pole by a caudal deepithelialized dermis flap, which allows the implant to be completely covered with well vascularized tissue, is compared to coverage by a synthetic mesh or acellular dermal matrix. Patients and methods From January 2014 to June 2020, 74 patients (106 breasts) underwent breast reconstruction following uni or bilateral prophylactic mastectomy. Reconstruction was performed with autologous tissue (15 breasts), with tissue expander or implant without implant support (15 breasts), with implant and use of an acellular dermal matrix or synthetic mesh (39 breasts) and with implant and caudal dermis flap (37 breasts). In this study, we compared the patients with implant and dermal matrix/mesh to the group reconstructed with implant and dermal flap. Results In the group with the caudal dermis flap, 4 patients developed skin necrosis, which all healed conservatively due to the sufficient blood supply through the dermis flap. In the group with the use of a synthetic mesh or acellular dermal matrix, skin necrosis was found in three cases. In one of these patients the implant was exposed and had to be removed. Discussion For patients with excess skin or macromastia, the caudal dermis flap is a reliable and less expensive option for complete coverage of an implant after prophylactic mastectomy. In particular, the vascularized dermis flap can protect the implant from the consequences of skin necrosis after prophylactic mastectomy

    AFRgeo_v1.0: A Geoid Model for Africa

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    The paper presents an attempt to compute a geoid model for Africa in the framework of the IAG African Geoid Project. The available gravity data set consists of land point gravity data as well as shipborne and altimetry-derived gravity anomaly data, having a lot of significant gaps allover the continent. The reduced gravity anomalies are gridded on a 50´ x 50´ grid using an iterative process employing a tailored reference model, to fill in the data gaps, and a weighted least-squares prediction technique. The tailored reference model, up to degree and order 2160, has been used to compute a geoid model for Africa within the window remove-restore technique employing the Stokes integral in frequency domain by the 1-D FFT technique. For the sake of comparison, another geoid model for Africa has been computed using a different approach. This approach renounces the use of the topographic-isostatic reduction and uses the recent global combined geopotential model EIGEN-6C4, complete to degree and order 2190, serving as the reference model. The computed geoids are scaled using the GO_CONS_GCF_2_DIR_R5 GOCE satellite-only model, which represents the best available global geopotential model approximating the African gravity field. An extensive comparison between the geoids computed within the current investigation and the former geoid model for Africa has been carried out

    Similarities in DSG1 and KRT3 Downregulation through Retinoic Acid Treatment and PAX6 Knockdown Related Expression Profiles: Does PAX6 Affect RA Signaling in Limbal Epithelial Cells?

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    Congenital PAX6-aniridia is a rare panocular disease resulting from limbal stem cell defi ciency. In PAX6-aniridia, the downregulation of the retinol-metabolizing enzymes ADH7 (All-trans retinol dehydrogenase 7) and ALDH1A1/A3 (Retinal dehydrogenase 1, Aldehyde dehydrogenase family 1 member A3) have been described in limbal epithelial cells (LECs) and conjunctival epithelial cells. The aim of this study was to identify the role of retinol derivates in the differentiation of human LEC and its potential impact on aniridia-associated keratopathy development. Human LEC were isolated from healthy donor corneas and were cultured with retinol, retinoic acid, or pan-retinoic acid receptor antagonist (AGN 193109) acting on RARα, β, γ (NR1B1, NR1B2 NR1B3) or were cultured with pan-retinoid X receptor antagonist (UVI 3003) acting on RXR α, β, γ (retinoid X receptor, NR2B1, NR2B2, BR2B3). Using qPCR, differentiation marker and retinoid-/fatty acid metabolism-related mRNA expression was analysed. DSG1 (Desmoglein 1), KRT3 (Keratin 3), and SPINK7 (Serine Pepti dase Inhibitor Kazal Type 7) mRNA expression was downregulated when retinoid derivates were used. AGN 193109 treatment led to the upregulation of ADH7, KRT3, and DSG1 mRNA expression and to the downregulation of KRT12 (Keratin 12) and KRT19 (Keratin 19) mRNA expression. Retinol and all-trans retinoic acid affect some transcripts of corneal LEC in a similar way to what has been observed in the LEC of PAX6-aniridia patients with the altered expression of differentiation markers. An elevated concentration of retinol derivatives in LEC or an altered response to retinoids may contribute to this pattern. These initial findings help to explain ocular surface epithelia differentiation disorders in PAX6-aniridia and should be investigated in patient cells or in cell models in the future in more detail

    Clinical effectiveness of hymenoptera venom immunotherapy

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    Treatment failure during venom immunotherapy (VIT) may be associated with a variety of risk factors. Our aim was to evaluate the association of baseline serum tryptase concentration (BTC) and of other parameters with the frequency of VIT failure during the maintenance phase. In this observational prospective multicenter study, we followed 357 patients with established honey bee or vespid venom allergy after the maintenance dose of VIT had been reached. In all patients, VIT effectiveness was either verified by sting challenge (n = 154) or patient self-reporting of the outcome of a field sting (n = 203). Data were collected on BTC, age, gender, preventive use of anti-allergic drugs (oral antihistamines and/or corticosteroids) right after a field sting, venom dose, antihypertensive medication, type of venom, side effects during VIT, severity of index sting reaction preceding VIT, and duration of VIT. Relative rates were calculated with generalized additive models. 22 patients (6.2%) developed generalized symptoms during sting challenge or after a field sting. A strong association between the frequency of VIT failure and BTC could be excluded. Due to wide confidence bands, however, weaker effects (odds ratios <3) of BTC were still possible, and were also suggested by a selective analysis of patients who had a sting challenge. The most important factor associated with VIT failure was a honey bee venom allergy. Preventive use of anti-allergic drugs may be associated with a higher protection rate. It is unlikely that an elevated BTC has a strong negative effect on the rate of treatment failures. The magnitude of the latter, however, may depend on the method of effectiveness assessment. Failure rate is higher in patients suffering from bee venom allergy
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