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"protrusion"
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Eco-engineering urban infrastructure for marine and coastal biodiversity: Which interventions have the greatest ecological benefit?
by
Cumbo, Vivian
,
Olabarria, Celia
,
Dafforn, Katherine A.
in
artificial structure
,
Biodiversity
,
Body size
2018
1. Along urbanised coastlines, urban infrastructure is increasingly becoming the dominant habitat. These structures are often poor surrogates for natural habitats, and a diversity of eco-engineering approaches have been trialled to enhance their biodiversity, with varying success. 2. We undertook a quantitative meta-analysis and qualitative review of 109 studies to compare the efficacy of common eco-engineering approaches (e.g. increasing texture, crevices, pits, holes, elevations and habitat-forming taxa) in enhancing the biodiversity of key functional groups of organisms, across a variety of habitat settings and spatial scales. 3. All interventions, with one exception, increased the abundance or number of species of one or more of the functional groups considered. Nevertheless, the magnitude of effect varied markedly among groups and habitat settings. In the intertidal, interventions that provided moisture and shade had the greatest effect on the richness of sessile and mobile organisms, while water-retaining features had the greatest effect on the richness of fish. In contrast, in the subtidal, small-scale depressions which provide refuge to new recruits from predators and other environmental Stressors such as waves, had higher abundances of sessile organisms while elevated structures had higher numbers and abundances of fish. The taxa that responded most positively to eco-engineering in the intertidal were those whose body size most closely matched the dimensions of the resulting intervention. 4. Synthesis and applications. The efficacy of eco-engineering interventions varies among habitat settings and functional groups. This indicates the importance of developing site-specific approaches that match the target taxa and dominant stressors. Furthermore, because different types of intervention are effective at enhancing different groups of organisms, ideally a range of approaches should be applied simultaneously to maximise niche diversity.
Journal Article
Dependable covering of keratoprosthesis with temporal fascia autograft
by
Nefedova, O.N.
,
Golovin, A.V.
,
Kataev, M.G.
in
keratoprosthesis
,
keratoprosthesis protrusion
,
leucoma covering
2024
Abstract Dependable covering of keratoprosthesis with temporal fascia autograft M.G. Kataev, A.V. Golovin, O.N. Nefedova, I.Yu. Trofimova S. Fyodorov Eye Microsurgery Federal State Institution, Moscow, Russian Federation Purpose. To propose a surgical technique to secure keratoprosthesis from protrusion by covering the plate with temporal fascia autograft. Material and methods. This study included 17 patients (17 eyes) with corneal leucoma, who underwent surgery of covering the leucoma with temporal fascia autograft at the first stage of keratoprosthesis implantation (6 eyes), or transplantation of corneal-prosthetic complex (4 eyes) or protrusion of the keratoprosthesis supporting plate (7 eyes). 4 cm long skin linear incision was performed, temporal fascia autograft 15–18 mm in diameter was harvested and placed on cornea, fixed to the sclera by 8 peripheral not absorbable sutures. Flaps of Tenon’s capsule was undermined in the intermuscular quadrants and sutured together by purse absorbable suture covering the autograft. Conjunctiva was closed by running absorbable suture. Eyelids were secured together by one blepharorrhaphy stich. Patients were examined before surgery, 7–10 days and 6 months after surgery. The follow-up period was on average 18 months. Results. The depth of the keratoprosthesis supporting plate at least 6 months after surgery was on average 1141 µm. The following postoperative complications were noted: in 6 (35.3%) cases the optical cylinder of keratoprosthesis became overgrown. In one case (5.9%) the optical cylinder was opened by a local excision of the conjunctiva. In 5 cases (29.4%) the optical cylinder was replaced with a higher one. In one case (5.9%) protrusion of the keratoprosthesis supporting plate occurred and the leucoma was re-covered with temporal fascia autograft. In other cases, the keratoprosthesis supporting plate was tightly fused with the underlying tissues of the leucoma and its position was stable. Conclusion. The use of a temporal fascia autograft is an accessible and effective method of dependable covering of leucoma in the prevention of protrusions during the simultaneous first stage of keratoprosthesis, transplantation of the corneal-prosthetic complex and at the beginning stage of keratoprosthesis protrusion. Key words: keratoprosthesis, keratoprosthesis protrusion, temporal fascia, leucoma covering
Journal Article
Use of Sections in the Engineering Practice
2017
Thanks to 3D CAD modelling software the role of sections has been grown significantly. In this article we discuss the increasing role of sections. First we present some practical applications such as a section of a track and wheel and we also show how they can be used for mechanical calculations through an example of a shaft weakened with a keyway. The principle of additive manufacturing is also based on sections. Finally sections can be also used at optimizing parts, but in this paper we discuss only the case of shape optimizing.
Journal Article
A Novel MEMS Capacitive Microphone with Semiconstrained Diaphragm Supported with Center and Peripheral Backplate Protrusions
2021
Audio applications such as mobile phones, hearing aids, true wireless stereo earphones, and Internet of Things devices demand small size, high performance, and reduced cost. Microelectromechanical system (MEMS) capacitive microphones fulfill these requirements with improved reliability and specifications related to sensitivity, signal-to-noise ratio (SNR), distortion, and dynamic range when compared to their electret condenser microphone counterparts. We present the design and modeling of a semiconstrained polysilicon diaphragm with flexible springs that are simply supported under bias voltage with a center and eight peripheral protrusions extending from the backplate. The flexible springs attached to the diaphragm reduce the residual film stress effect more effectively compared to constrained diaphragms. The center and peripheral protrusions from the backplate further increase the effective area, linearity, and sensitivity of the diaphragm when the diaphragm engages with these protrusions under an applied bias voltage. Finite element modeling approaches have been implemented to estimate deflection, compliance, and resonance. We report an 85% increase in the effective area of the diaphragm in this configuration with respect to a constrained diaphragm and a 48% increase with respect to a simply supported diaphragm without the center protrusion. Under the applied bias, the effective area further increases by an additional 15% as compared to the unbiased diaphragm effective area. A lumped element model has been also developed to predict the mechanical and electrical behavior of the microphone. With an applied bias, the microphone has a sensitivity of −38 dB (ref. 1 V/Pa at 1 kHz) and an SNR of 67 dBA measured in a 3.25 mm × 1.9 mm × 0.9 mm package including an analog ASIC.
Journal Article
Bladder calculi concomitant with benign prostatic enlargement: is prostate surgery mandatory in patients who have never received medical therapy?
by
Ünal, Umut
,
Anil, Hakan
,
Karamik, Kaan
in
Aged
,
benign prostate hyperplasia; bladder calculi; intravesical prostatic protrusion; medical therapy; prostate surgery
,
Bladder
2023
The historical dogma that bladder calculi comprise the main indication for prostatic surgery has recently been questioned. In this study, we aimed to predict which patients should undergo simultaneous prostate and bladder calculi surgery or only bladder calculi removal by evaluating preoperative risk factors. One hundred and seventeen men with bladder stones and concomitant benign prostate enlargement (BPE) who had not received medical treatment before were included in the study. In the first step, only the bladder calculi of patients were removed and medical treatment was given for BPE. The patients who benefited from medical treatment during the follow-up were defined as Group 1 and the patients who required prostate surgery for any indication comprised Group 2. Risk factors for prostate surgery requirements were determined by comparing preoperative characteristics between the two groups with a cox regression model. In the follow-up of 117 patients with bladder stones removed and medical treatment initiated, 49 (41.9%) patients had prostate surgery indications. The indication for 33 (67.3%) of 49 patients was medical treatment failure. The presence of intravesical prostatic protrusion (IPP; hazard ratio: 2.071, 95% confidence interval [CI]: 1.05-4.05, P = 0.034), and high postvoiding residual urine volume (hazard ratio: 1.013, 95% CI: 1.007-1.019, P < 0.001) were found to be preoperative risk factors for needing future prostate surgery. In patients who have not received medical treatment for BPE before, bladder calculi developing secondary to BPE do not always constitute an indication for prostate surgery.
Journal Article
Steering cell migration by alternating blebs and actin-rich protrusions
by
Romanczuk, Pawel
,
Ivanovitch, Kenzo
,
Salbreux, Guillaume
in
Actins - metabolism
,
Animals
,
Beyond Mendel: modeling in biology
2016
Background
High directional persistence is often assumed to enhance the efficiency of chemotactic migration. Yet, cells in vivo usually display meandering trajectories with relatively low directional persistence, and the control and function of directional persistence during cell migration in three-dimensional environments are poorly understood.
Results
Here, we use mesendoderm progenitors migrating during zebrafish gastrulation as a model system to investigate the control of directional persistence during migration in vivo. We show that progenitor cells alternate persistent run phases with tumble phases that result in cell reorientation. Runs are characterized by the formation of directed actin-rich protrusions and tumbles by enhanced blebbing. Increasing the proportion of actin-rich protrusions or blebs leads to longer or shorter run phases, respectively. Importantly, both reducing and increasing run phases result in larger spatial dispersion of the cells, indicative of reduced migration precision. A physical model quantitatively recapitulating the migratory behavior of mesendoderm progenitors indicates that the ratio of tumbling to run times, and thus the specific degree of directional persistence of migration, are critical for optimizing migration precision.
Conclusions
Together, our experiments and model provide mechanistic insight into the control of migration directionality for cells moving in three-dimensional environments that combine different protrusion types, whereby the proportion of blebs to actin-rich protrusions determines the directional persistence and precision of movement by regulating the ratio of tumbling to run times.
Journal Article
Classification of Intervertebral Disc Disease
2020
Intervertebral disc disease (IVDD) has been recognized in dogs since the 1800s, when the first descriptions of extruded disc material within the vertebral canal were published. In the intervening time our understanding of intervertebral disc pathology in dogs and cats has increased dramatically, with many variations of IVDD described. Whilst the volume of literature and collective understanding of IVDD has expanded, there has also been scope for confusion as the definition of intervertebral disc disease, with its myriad different manifestations, becomes more complicated. A large volume of literature has aimed to combine the use of histopathology, diagnostic imaging and clinical findings to better understand the various ways in which IVDD can be classified. Much of this research has focused on the classification of mechanisms of intervertebral disc degeneration, centering around the differences between, and overlaps in, IVDD in chondrodystrophic and non-chondrodystrophic dog breeds. However, with the increasing availability of advanced imaging modalities allowing more accurate antemortem diagnosis, the concept of IVDD has expanded to include other clinical presentations that may not fit into traditional models of classification of IVDD. This review aims to provide an up to date overview of both historical and current systems of IVDD classification, highlighting the important findings and controversies underpinning them.
Journal Article
Thermo-Hydraulic Performance Characteristics and Optimization of Protrusion Rib Roughness in Solar Air Heater
by
Alam, Tabish
,
Meena, Chandan
,
Kumar, Ashok
in
artificial roughness
,
conical protrusion rib
,
Efficiency
2021
To enhance the thermal performance of solar air heaters (SAHs), protrusion ribs on the absorber are considered to be an attractive solution due to their several advantages. These ribs do not cause a significant pressure drop in the SAH duct and help to enhance the heat transfer to flowing air. On the other hand, a degree of roughness of the protrusion rib on the absorber can be produced by pressing the indenting device without adding additional mass. In this paper, the thermo-hydraulic performances of different roughnesses of the conical protrusion rib on the absorber plate have been evaluated by the mutual consideration of thermal as well as hydraulic performance in term of net effective efficiency. Therefore, an analytical technique has been exploited to predict the characteristics of the net effective efficiency under various operating conditions, such as the flow Reynolds number, temperature increase parameter and insolation. The effects of the conical protrusion rib roughness—namely the relative rib pitch (p/e) and relative rib height e/D) in the ranges of 6–12 and 0.200–0.044, respectively—have been evaluated. The highest value of net effective efficiency of 70.92% was achieved at a p/e of 10 and e/D of 0.0289. The optimization of the rib parameters has been carried out in different ranges of temperature increase parameters for the highest values of net effective efficiency. A unique combination of rib parameters—a p/e of 10 and e/D of 0.044—are observed to lead to the best performance when operating a solar air heater with a temperature increase parameter of more than 0.00789 K·m2/W.
Journal Article
Correlation Between Degree of Mandibular Incisors Crowding, Lower Incisor Position and Vertical Craniofacial Configuration in Different Malocclusions
2022
Objective: To evaluate the correlation between the degree of mandibular incisor crowding, lower incisor position and vertical craniofacial configuration in different malocclusions. Study Design: Cross-sectional analytical study. Place and Duration of Study: Orthodontics department, Armed Forces Institute of Dentistry, Rawalpindi Pakistan, from Jan to Dec 2018. Methodology: This study was conducted on 100 pre-treatment study casts and lateral cephalographs of orthodontic, aged 10 to 26 years. Patients who presented with complaints of lower incisors crowding were included in the study. The cephalogram tracings, calculations and lower incisor crowding measurements were taken. All the fifteen parameters of vertical craniofacial configuration, lower incisors position and sagittal skeletal base relationship were measured. Result: Out of 100 patients, 45 were males and 55 were females with a mean age of 16.11 ± 3.53 years. According to this study, there was no statistically significant correlation between the degree of lower incisor crowding and vertical facial proportions and incisor position in studied malocclusions. Conclusion: The lower incisor crowding was a local and independent discrepancy. It was a frequently encountered problem, successful therapy depends upon several contributing factors that must be identified for successful management.
Journal Article