Aspects of the ontogenesis of the avian columella auris

Observations on embryological material from Spheniscus demersus, Acridotheres tristis, Geopelia cuneata and Gallus domesticus strongly suggest that the avian stapes represents part of an infrapharyngohyal while the rest of the pharyngohyal material (supra- plus infrapharyngohyal) together with the epihyal and a secondary laterohyal component form the extracolumella. The latter structure bears three so-called processes: the supracolumellar arcade or process (de Beer's lateral prong) whose inner limb is derived from the suprapharyngohyal and the outer limb (comprising at least part of the intercalary) from the laterohyal blasteme; the tympanic process (extracolumellar process) also derived from laterohyal blasteme; and the infracolumellar process (formed by the distal tip of the epihyal and a composite interhyal) which is continuous with the ceratohyal in most birds. Our investigation suggests that the supposed great variation in the development of the columella among birds is a fallacy.Waarnemings op embriologiese preparate van Spheniscus demersus, Acridotheres tristis, Geopelia cuneata en Gallus domesticus dui sterk daarop dat die stapes by voSIs deel van 'n infrafaringohiale verteenwoordig terwyl die res van die faringohiale materiaal (supra- plus infrafaringohiale) saam met die epihihiale en 'n sekonddre laterohiale komponent die ekstrakolumella vorm. Laasgenoemde struktuur dra drie sogenaamde uitsteeksels: die suprakolumellaar-uitsteeksel of -arkade (‘lateral prong’ van de Beer) waarvan die ‘binnebeen’ van die suprafaringohiale afkomstig is en die ‘buitebeen’ (wat minstens 'n deel van die interkalare insluit) deur die laterohiale blasteem bygedra word; die timpaniese uitsteeksel of ekstrakolumellaar-uitsteeksel wat ook van die laterohiale blasteem afkomstig is; en die infrakolumellaar-uitsteeksel (gevorm deur die distale punt van die epihiale enn saamgestelde interhiale) wat by meeste vo荤is aaneenlopend met die keratohiale voorkom. Ons ondersoek dui daarop dat die vermeende groot variasie wat ten opsigte van die ontwikkeling van die kolumella by vofils sou bestaan, 'n dwaling is

The early ontogeny of the Columella auris of Crocodilus niloticus and its bearing on problems concerning the upper end of the reptilian hyoid arch

No Abstract

The morphogenesis of the avian Columella auris with special reference to Struthio camelus

The columella auris of the ostrich is derived as in the crocodile from three sources; the two upper segments of the hyoid arch (pharyngohyal and epihyal) and a laterohyal component. The latter contributes the homologue of the crocodilian suprastapedial (or lacertilian intercalary) as well as the tympanic process and the material of the lateral limb (which is not lacking as stated in the literature) of the lateral prong (supracolumellar arcade). Conditions in Struthio camelus confirm the views expressed by the authors in their paper on Crocodilus niloticus regarding the homologies of the columellar processes. The avian infracolumellar process represents the crocodilian infrastapedial plus the interhyal which in addition to primary arch material, includes a secondary subepidermal part. The ceratohyal (usually called stylohyal in the literature) remains attached to the columella through the infracolumellar process

Does Social Media Sentiment Predict Bitcoin Trading Volume?

Social media sentiment is proven to be an important feature in financial forecasting. While the effect of sentiment is complex and time-varying for traditional financial assets, its role in cryptocurrency markets is unclear. This research explores the predictive power of public sentiment on Bitcoin trading volume. We develop a novel sentiment analysis pipeline for processing Bitcoin-related tweets and achieve state-of-the-art accuracy on a benchmark dataset. Our pipeline also leverages information gain theory to incorporate the impact of textual and non-textual features. We use such features to discern a non-linear relationship between public sentiment and Bitcoin trading volume and discover the optimal predictive horizon for Bitcoin. This research provides a useful module and a foundation for future studies and understanding of Bitcoin market dynamics, and its interaction with social media buzzing

Street-level desires, Discovering the city on foot:

In the spring of 2004, Delft University of Technology was approached by Norwich City Council with a request to participate in their project Spatial Metro. Spatial Metro was developed within the framework of Interreg IIIB. Interreg is a community initiative which aims to stimulate interregional cooperation within the EU, financed by the European Regional Development Fund (ERDF). The programme aspires to strengthen economic and social cohesion throughout the EU by fostering the balanced development of the continent through cross-border, transnational and interregional cooperation. The B strain of Interreg deals with transnational cooperation. As an Interreg IIIB project in the North-west European region, Spatial Metro brings together partners from the United Kingdom, France, Germany, The Netherlands and even Switzerland. The original Spatial Metro project proposal is straightforward. It claims that cities are chaotic places. It states that tourists, visiting business people, shoppers and even residents rarely have a clear or coherently expressed view of what a city has to offer geographically or thematically. The proposal assumes that people’s stay is shortened by their lack of overview of or information on what a town can offer them. As lead partner of the project, Norwich explains in quantitative terms what this means to the economy of a city: Visitors who plan a day trip to a city will stay in town for an average four to four-and-half hours and spend about £ 100. If the welcome they receive is inhospitable, the destination is confusing, and demands are not met, the same visitor will tend to leave after only two hours and spend less than £ 50. If their arrival is welcoming, the destination is safe, clean, relaxed and intelligible and if visitors can navigate their way around and their initial expectations are fulfilled or surpassed, they will stay for six to seven hours and spend more than £ 150. At first glance, these statements may seem somewhat narrow in scope. Not every city is chaotic and surely there is more to life than just money. However, placed in their proper context, these words make perfect sense. Five cities are participating in Spatial Metro: Norwich and Bristol (UK), Rouen (F), Koblenz (D) and Biel/Bienne (CH). Each of these cities is characterised by a historic city centre. Norwich itself is proud to have the most intact mediaeval street pattern of the United Kingdom. Mediaeval street patterns are the product of spontaneous urban growth and lack the sometimes rigid clarity of modern planned developments. Mediaeval street patterns are indeed difficult to navigate and pose a true challenge. Norwich also developed a successful and long-standing policy to prevent out of town shopping by strengthening the vitality of its original historic district. Such a policy requires a city to take a serious look at its economic performance. From this perspective, it is a sound approach to optimise conditions allowing people to discover a city on foot. As such, the Spatial Metro project prompted the Delft University of Technology to tap into a greater European experience that integrates aspects such as urban renaissance, built heritage, public space, pedestrian mobility, leisure economy and even sustainability. The partnership also included knowledge organisations. Each of these partners has supported the project in their own unique way. The University of East Anglia deployed its automated modelling software to visualise the original historic centres. The University Koblenz/Landau delivered a so-called Blue Box that provides on the spot information by means of Bluetooth technology. The Swiss Pedestrian Association made various contributions as a strategic and competent expert organisation on pedestrian mobility. The Delft University of Technology examined the question as to how to assess the effectiveness of the investments made in Norwich, Rouen and Koblenz. How can aspects like the accessibility and navigability of public spaces be measured? Much of the effectiveness hereof naturally depends on the way people use the public space. We used novel tools to analyse in detail the movement patterns of people visiting these three city centres. Finally, Delft decided to capture the essence of the Spatial Metro experience in a document reflecting the versatility of the transnational response to pedestrian mobility and the regeneration of the historic European city centre. The document became this book, ‘Street Level Desires’. The book aims to disseminate our experience and knowledge to further strengthen social and economic cohesion throughout Europe. &nbsp

Estimating the risk of HIV transmission from homosexual men receiving treatment to their HIV-uninfected partners

Objective To determine how the risk of HIV transmission from homosexual men receiving antiretroviral treatment is related to patterns of patient monitoring and condom use. Methods A stochastic mathematical simulation model was developed of cohorts of men in the Netherlands who have sex with men (MSM), defining the parameters of the model using observational cohort data. The model incorporates viral load trends during first-line treatment, patient monitoring and different scenarios for the way in which condom use may depend on recent viral load measurements. The model does not include the effect of sexually transmitted infections on HIV transmission. Results For MSM receiving treatment, the risk of transmitting HIV to their long-term partner is 22% (uncertainty interval: 9-37%) if condoms are never used. With incomplete use (in 30% of sex acts) the risk is reduced slightly, to 17% (7-29%). However, the risk is as low as 3% (0.2-8%) when men receiving treatment use condoms only 6 months beyond their last undetectable viral load measurement. The risk is further reduced when 3 months is the time period beyond which condoms are used. Conclusions When condom use by HIV-infected men receiving combination treatment with antiretroviral agents is based on their last viral load measurement, the transmission risk is much lower than with incomplete condom use. The key message for patients is that although always using condoms during treatment is the best way to protect partners from the risk of HIV transmission, when such use cannot be achieved, the second best strategy is to use condoms whenever the last undetectable viral load was measured more than 3 months ag

Late Entry to HIV Care Limits the Impact of Anti-Retroviral Therapy in the Netherlands

To explain differences in survival in the first three years of combination anti-retroviral therapy (cART) between HIV treatment centres in The Netherlands.We developed a mathematical simulation model, parameterised using data from the ATHENA cohort that describes patients entering care, being monitored and starting cART. Three scenarios were used to represent three treatment centres with widely varying mortality rates on cART that were differentiated by: (i) the distribution of CD4 counts of patients entering care; (ii) the age distribution of patients entering care; (iii) the average rate of monitoring the patients not on cART. At the level of the treatment centre, the fraction of Dutch MSM dying in the first three years of treatment ranged from 0% to 8%. The mathematical model captured the large variation in observed mortality between the three treatment centres. Manipulating the age-distribution of patients or the frequency of monitoring did not affect the model predictions. In contrast, when the same national average distribution of CD4 count at entry was used in all the scenarios, the variation in predicted mortality between all centres was diminished.Patients entering care with low CD4 counts appears to be the main source of variation in the mortality rates between Dutch treatment centres. Recruiting HIV-infected individuals to care earlier could lead to substantial improvements in cART outcomes. For example, if patients were to present with at least 400 CD4 cells/mm(3), as they do already in some centres, then our model predicts that the mortality in the first three years of cART could be reduced by approximately 20%

Variación de las propiedades físico-mecánicas del adobe estabilizado con dos tipos de polímeros y el uso de barro fermentado, Cajamarca 2022

Esta investigación tuvo como objetivo determinar las propiedades físico-mecánicas del adobe estabilizado, con dos tipos de polímeros (5% Penca y 5% Tuna) y el uso de barro fermentado (10%, 25% y 50%), siguiendo un diseño Experimental aplicado a una muestra de 112 adobes, en cumplimiento a lo establecido por la norma E.080. Por ello los materiales fueron extraídos del Caserío Frutillo Bajo, ya que allí se elabora el ladrillo artesanal. Iniciamos con los estudios de mecánica suelos, tales como: Contenido de humedad, granulometría, límites de consistencia y el ensayo de proctor modificado método A, a continuación se elaboró los adobes compactados en la máquina CINVA RAM, dejándolos secar a temperatura de ambiente, para luego ensayarlos y concluir que los adobes al ser sometidos al ensayo a compresión y flexión superaron el valor mínimo de 10.20 kg/cm² y 0.81 kg/cm² que exige la norma E.080, los adobes ensayados a compresión con 5% de tuna y 5% de penca más la adición a cada muestra del 10%, 25% y 50% de barro fermentado, superaron la resistencia de la muestra patrón en un 109.94% (Tuna) y 95.22% (Penca), siendo la mejor muestra de 5% de tuna más 50% de barro fermentado con un esfuerzo admisible de 21.66 kg/cm². Por el contrario, la resistencia a la absorción de agua fue negativa lo que indica que no se obtuvieron mejoras. Por último, la hipótesis se rechaza debido a que los datos obtenidos difieren con los planteados inicialmente

Longitudinal visualization for exploratory analysis of multiple sclerosis lesions

In multiple sclerosis (MS), the amount of brain damage, anatomical location, shape, and changes are important aspects that help medical researchers and clinicians to understand the temporal patterns of the disease. Interactive visualization for longitudinal MS data can support studies aimed at exploratory analysis of lesion and healthy tissue topology. Existing visualizations in this context comprise bar charts and summary measures, such as absolute numbers and volumes to summarize lesion trajectories over time, as well as summary measures such as volume changes. These techniques can work well for datasets having dual time point comparisons. For frequent follow-up scans, understanding patterns from multimodal data is difficult without suitable visualization approaches. As a solution, we propose a visualization application, wherein we present lesion exploration tools through interactive visualizations that are suitable for large time-series data. In addition to various volumetric and temporal exploration facilities, we include an interactive stacked area graph with other integrated features that enable comparison of lesion features, such as intensity or volume change. We derive the input data for the longitudinal visualizations from automated lesion tracking. For cases with a larger number of follow-ups, our visualization design can provide useful summary information while allowing medical researchers and clinicians to study features at lower granularities. We demonstrate the utility of our visualization on simulated datasets through an evaluation with domain experts.publishedVersio

Abelian Dominance in Chiral Symmetry Breaking

Calculations of the chiral condensate $\langle \bar{\psi} \psi \rangle$ on the lattice using staggered fermions and the Lanczos algorithm are presented. Three gauge fields are considered: the quenched non-Abelian field, the Abelian field projected in the maximal Abelian gauge, and the monopole field further decomposed from the Abelian field. The results show that the Abelian monopoles largely reproduce the chiral condensate values of the full non-Abelian theory, both in SU(2) and in SU(3).Comment: 4 pages in Latex with 4 embedded Postscript figures, uses espcrc2.sty, psfig.sty. All are uuencoded, gzipped in a self-extracting file. Contribution to Lattice'95, Melbourne, Australi