scholarly journals Are suspensory ligaments important for middle ear reconstruction?

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255821
Author(s):  
Eileen Y. Brister ◽  
Robert H. Withnell ◽  
Pavel Shevchenko ◽  
Claus-Peter Richter
Keyword(s):  
Middle Ear ◽  
Significant Role ◽  
Sound Transmission ◽  
Ossicular Chain ◽  
Ear Reconstruction ◽  
Hearing Sensitivity ◽  
Wide Range ◽  
Middle Ear Reconstruction ◽  
The Impact

As the resolution of 3D printing techniques improves, the possibility of individualized, 3-ossicle constructions adds a new dimension to middle ear prostheses. In order to optimize these designs, it is essential to understand how the ossicles and ligaments work together to transmit sound, and thus how ligaments should be replicated in a middle ear reconstruction. The middle ear ligaments are thought to play a significant role in maintaining the position of the ossicles and constraining axis of rotation. Paradoxically, investigations of the role of ligaments to date have shown very little impact on middle ear sound transmission. We explored the role of the two attachments in the gerbil middle ear analogous to human ligaments, the posterior incudal ligament and the anterior mallear process, severing both attachments and measuring change in hearing sensitivity. The impact of severing the attachments on the position of the ossicular chain was visualized using synchrotron microtomography imaging of the middle ear. In contrast to previous studies, a threshold change on the order of 20 dB across a wide range of frequencies was found when both ligaments were severed. Concomitantly, a shift in position of the ossicles was observed from the x-ray imaging and 3D renderings of the ossicular chain. These findings contrast with previous studies, demonstrating that these ligaments play a significant role in the transmission of sound through the middle ear. It appears that both mallear and incudal ligaments must be severed in order to impair sound transmission. The results of this study have significance for middle ear reconstructive surgery and the design of 3D-printed three-ossicle biocompatible prostheses.

History and Morality

2020 ◽  
Author(s):  
Donald Bloxham
Keyword(s):  
Foreign Country ◽  
Moral Thought ◽  
Majority Opinion ◽  
The Past ◽  
Wide Range ◽  
Moral Judgements ◽  
Value Judgements ◽  
The Impact

Against majority opinion within his profession, Donald Bloxham argues that it is legitimate, often unavoidable, and frequently important for historians to make value judgements about the past. History and Morality draws on a wide range of historical examples, and its author’s insights as a practising historian. Examining concepts like impartiality, neutrality, contextualization, and the use and abuse of the idea of the past as a foreign country, Bloxham’s book investigates how the discipline has got to the point where what is preached can be so inconsistent with what is practised. It illuminates how far tacit moral judgements infuse works of history, and how strange those histories would look if the judgements were removed. Bloxham argues that rather than trying to eradicate all judgemental elements from their work historians need to think more consistently about how, and with what justification, they make the judgements that they do. The importance of all this lies not just in the responsibilities that historians bear towards the past—responsibilities to take historical actors on those actors’ own terms and to portray the impact of those actors’ deeds—but also in the role of history as a source of identity, pride, and shame in the present. The account of moral thought in History and Morality has ramifications far beyond the activities of vocational historians.

Problems in Alloplastic Middle Ear Reconstruction

1992 ◽  
Vol 112 (2) ◽  
pp. 322-327 ◽  
Author(s):  
A. W. Blayney ◽  
K. R. Williams ◽  
J.-P. Erre ◽  
T. H. J. Lesser ◽  
M. Portmann
Keyword(s):  
Middle Ear ◽  
Ear Reconstruction ◽  
Middle Ear Reconstruction

Soft Impact in a Biomechanical System With Shape Memory Element

2017 ◽  
Vol 12 (6) ◽  
Author(s):  
R. Rusinek ◽  
M. Szymanski ◽  
J. Warminski
Keyword(s):  
Shape Memory ◽  
Middle Ear ◽  
Polynomial Function ◽  
Ossicular Chain ◽  
Excitation Amplitude ◽  
Patient Needs ◽  
Memory Element ◽  
The Impact ◽  
Irregular Behavior ◽  
Two Degree Of Freedom

The analysis of the shape memory prosthesis (SMP) of the middle ear is presented in this paper. The shape memory prosthesis permits the adjustment of its length to individual patient needs, but sometimes the prosthesis cannot be properly fixed to the stapes. In this case, the impact between the prosthesis and stapes is important. Therefore, the reconstructed middle ear is modeled as a two degree-of-freedom system with a nonlinear shape memory element and soft impact to represent its behavior when the prosthesis is not properly placed or fixed. The properties of the shape memory prosthesis, in the form of a helical spring, are represented by a polynomial function. The system exhibits advisable periodic and undesirable aperiodic and irregular behavior depending on the excitation amplitude, the frequency, and the prosthesis length. The prosthesis length can change, resulting in a modification of the distance between the prosthesis and the stapes. The results of this study provide an answer in terms of how the prosthesis length, which produces the ossicular chain tension, influences the system dynamics and its implication in medical practice.

scholarly journals Scale dependence of cirrus heterogeneity effects. Part II: MODIS NIR and SWIR channels

2018 ◽  
Vol 18 (16) ◽  
pp. 12105-12121 ◽  
Author(s):  
Thomas Fauchez ◽  
Steven Platnick ◽  
Tamás Várnai ◽  
Kerry Meyer ◽  
Céline Cornet ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Spatial Resolution ◽  
Thermal Infrared ◽  
Radiative Effects ◽  
Ice Clouds ◽  
Plane Parallel ◽  
Wide Range ◽  
The Impact ◽  
Side Illumination

Abstract. In a context of global climate change, the understanding of the radiative role of clouds is crucial. On average, ice clouds such as cirrus have a significant positive radiative effect, but under some conditions the effect may be negative. However, many uncertainties remain regarding the role of ice clouds on Earth's radiative budget and in a changing climate. Global satellite observations are particularly well suited to monitoring clouds, retrieving their characteristics and inferring their radiative impact. To retrieve ice cloud properties (optical thickness and ice crystal effective size), current operational algorithms assume that each pixel of the observed scene is plane-parallel and homogeneous, and that there is no radiative connection between neighboring pixels. Yet these retrieval assumptions are far from accurate, as real radiative transfer is 3-D. This leads to the plane-parallel and homogeneous bias (PPHB) plus the independent pixel approximation bias (IPAB), which impacts both the estimation of top-of-the-atmosphere (TOA) radiation and the retrievals. An important factor that determines the impact of these assumptions is the sensor spatial resolution. High-spatial-resolution pixels can better represent cloud variability (low PPHB), but the radiative path through the cloud can involve many pixels (high IPAB). In contrast, low-spatial-resolution pixels poorly represent the cloud variability (high PPHB), but the radiation is better contained within the pixel field of view (low IPAB). In addition, the solar and viewing geometry (as well as cloud optical properties) can modulate the magnitude of the PPHB and IPAB. In this, Part II of our study, we simulate TOA 0.86 and 2.13 µm solar reflectances over a cirrus uncinus scene produced by the 3DCLOUD model. Then, 3-D radiative transfer simulations are performed with the 3DMCPOL code at spatial resolutions ranging from 50 m to 10 km, for 12 viewing geometries and nine solar geometries. It is found that, for simulated nadir observations taken at resolution higher than 2.5 km, horizontal radiation transport (HRT) dominates biases between 3-D and 1-D reflectance calculations, but these biases are mitigated by the side illumination and shadowing effects for off-zenith solar geometries. At resolutions coarser than 2.5 km, PPHB dominates. For off-nadir observations at resolutions higher than 2.5 km, the effect that we call THEAB (tilted and homogeneous extinction approximation bias) due to the oblique line of sight passing through many cloud columns contributes to a large increase of the reflectances, but 3-D radiative effects such as shadowing and side illumination for oblique Sun are also important. At resolutions coarser than 2.5 km, the PPHB is again the dominant effect. The magnitude and resolution dependence of PPHB and IPAB is very different for visible, near-infrared and shortwave infrared channels compared with the thermal infrared channels discussed in Part I of this study. The contrast of 3-D radiative effects between solar and thermal infrared channels may be a significant issue for retrieval techniques that simultaneously use radiative measurements across a wide range of solar reflectance and infrared wavelengths.

scholarly journals Hearing Status After Ossiculoplasty in Open Cavity Mastoidectomy

2020 ◽  
Vol 23 (2) ◽  
pp. 195-198
Author(s):  
Md Zakaria Sarker ◽  
DC Talukder ◽  
Khabir Uddin Patuary ◽  
Md Rafiqul Islam ◽  
Saif Rahman Khan ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Ossicular Chain ◽  
Ear Reconstruction ◽  
Canal Wall ◽  
Prospective Longitudinal Study ◽  
Hearing Gain ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Middle Ear Reconstruction ◽  
Prospective Longitudinal

To evaluate the hearing outcome in canal wall down mastoidectomy with middle ear reconstruction, prospective longitudinal study was done at National Institute of ENT, Dhaka from March 2015 to September 2016. Total 22 patients were included in the study undergoing canal wall down mastoidectomy with 6 months postoperative followup. Hearing outcomes were observed and compared with the preoperative hearing tests. Among the 22 patients 9 (39.1% of subjects) patients had hearing gain, 12 (52.2%) had hearing loss and 1 (4.3%) had no change in hearing postoperatively.Although disease clearance is the main objective in canal wall down mastoidectomy, hearing gain can be achieved if combined with ossiculoplasty and tympanoplasty. The hearing gain or loss depends upon the extension of disease and status of the ossicular chain. Most patients usually experience hearing loss more than the preoperative period due to removal of ossicle or ossicles for the sake of disease clearance. Bangladesh J Otorhinolaryngol; October 2017; 23(2): 195-198

Listening between the Lines: Alexander’s Musical Legacy in Italy (13th–15th Centuries)

2019 ◽  
pp. 87-100
Author(s):  
Donatel Restani
Keyword(s):  
Music Education ◽  
Significant Role ◽  
Medieval Literature ◽  
Musical Performance ◽  
Human Voice ◽  
Early Modern Era ◽  
Alexander Romance ◽  
The Impact ◽  
Modern Era

This chapter consists of three examples of sound and music tales in Alexander’s life as transmitted in Italian medieval literature, and a coda pertaining to the early modern era. It deals with the Italian segment of Alexander’s musical legacy in medieval European literature, elaborated from vulgarisations and adaptations of the so-called Alexander Romance. Three main topics are focused on: human voice vs non-human voice, music education for a king and sonorous mirabilia. Two features are introduced: the significant role of music in shaping Alexander’s knowledge and his image as a chivalric king; the impact of the literature on Alexander upon 13th–14th century travellers by Europeans in Asia. The coda concerns the possibility that Alexander was imitated as idealised patron of the sciences and arts in the musical performance (intermedi) organised for the 1589 Florentine wedding of Ferdinand I de’ Medici and Christina of Lorraine.

Business Ethics is Socio-Political, or Not at All

2015 ◽  
pp. 251-281
Author(s):  
Ana-Maria Pascal
Keyword(s):  
Business Ethics ◽  
Theoretical Background ◽  
Kantian Ethics ◽  
Political Responsibility ◽  
Wide Range ◽  
Mining Project ◽  
Public Ethics ◽  
High Degree ◽  
The Impact

This chapter explores the moral aspects of commercial deals that allegedly democratic governments enter into with foreign investors. These are discussed against a twofold theoretical background – where the philosophical ideal of public ethics based on truth and transparency meets business ethics theories. The Kantian ethics of duty proves to be the key link between these, as particularly relevant for cases where the impact on a wide range of stakeholders is considerable. The main case under consideration is the controversial USD $2 billion Romanian mining project at Rosia Montana, which highlights the need for accountability mentioned above and lends itself well to a multi-fold business ethics analysis. The role of the civil society in effectively stopping the project is a good illustration of the stakeholder theory. The chapter concludes with the thesis that a high degree of socio-political responsibility may be best achieved when trying to combine principle-based and utilitarian thinking.

scholarly journals Second hits exacerbate alcohol-related organ damage: an update

2020 ◽  
Vol 56 (1) ◽  
pp. 8-16
Author(s):  
Natalia A Osna ◽  
Murali Ganesan ◽  
Devanshi Seth ◽  
Todd A Wyatt ◽  
Srivatsan Kidambi ◽  
...  
Keyword(s):  
Liver Injury ◽  
Alcohol Exposure ◽  
Organ Damage ◽  
Lifestyle Factor ◽  
Matrix Stiffness ◽  
Reactive Aldehydes ◽  
Wide Range ◽  
Excessive Alcohol ◽  
The Impact

Abstract Chronic and excessive alcohol abuse cause direct and indirect detrimental effects on a wide range of body organs and systems and accounts for ~4% of deaths worldwide. Many factors influence the harmful effects of alcohol. This concise review presents newer insights into the role of select second hits in influencing the progression of alcohol-induced organ damage by synergistically acting to generate a more dramatic downstream biological defect. This review specifically addresses on how a lifestyle factor of high fat intake exacerbates alcoholic liver injury and its progression. This review also provides the mechanistic insights into how increasing matrix stiffness during liver injury promotes alcohol-induced fibrogenesis. It also discusses how hepatotropic viral (HCV, HBV) infections as well as HIV (which is traditionally not known to be hepatotropic), are potentiated by alcohol exposure to promote hepatotoxicity and fibrosis progression. Finally, this review highlights the impact of reactive aldehydes generated during alcohol and cigarette smoke coexposure impair innate antimicrobial defense and increased susceptibility to infections. This review was inspired by the symposium held at the 17th Congress of the European Society for Biomedical research on Alcoholism in Lille, France entitled ‘Second hits in alcohol-related organ damage’.

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