Solving the riddle of codon usage preferences: a test for translational selection

Translational selection is responsible for the unequal usage of synonymous codons in protein coding genes in a wide variety of organisms. It is one of the most subtle and pervasive forces of molecular evolution, yet, establishing the underlying causes for its idiosyncratic behaviour across living kingdoms has proven elusive to researchers over the past 20 years. In this study, a statistical model for measuring translational selection in any given genome is developed, and the test is applied to 126 fully sequenced genomes, ranging from archaea to eukaryotes. It is shown that tRNA gene redundancy and genome size are interacting forces that ultimately determine the action of translational selection, and that an optimal genome size exists for which this kind of selection is maximal. Accordingly, genome size also presents upper and lower boundaries beyond which selection on codon usage is not possible. We propose a model where the coevolution of genome size and tRNA genes explains the observed patterns in translational selection in all living organisms. This model finally unifies our understanding of codon usage across prokaryotes and eukaryotes. Helicobacter pylori, Saccharomyces cerevisiae and Homo sapiens are codon usage paradigms that can be better understood under the proposed model

Mega-regional trade Agreements: Costly distractions for developing countries?

This paper examines the relationship between mega-regional trade Agreements and diet-related health given that such Agreements aim to liberalize “substantially all trade and investment” that could potentially impact on health through tariff elimination and stronger intellectual property commitments in partner countries. We analyse two interlinked policy concerns: first, how tariff reduction/elimination under mega-regional Agreements impact on the production of sugar? Second, how mega-regional Agreements with Trade-Related Aspects of Intellectual Property Rights (TRIPS)-style and TRIPS-plus commitments modify intellectual property rules among partner countries and impact on developing countries’ access to life-saving drugs and medicines? Using a dynamic Global Trade Analysis Project model, we find there are significant health consequences of trade commitments undertaken by developing countries with potential detrimental health effect on populations such that first, higher production of sugar alters consumption trends. Second, despite stricter intellectual property rules, which result in net global gains, developing countries suffer from the regulatory chill effect

Instructional constraints faced by learners with duchenne muscular dystrophy: A case study of Joy Town Special Primary School, Thika, Kenya.

The study is about the instructional constraints facing learners with Duchenne muscular dystrophy (DMD) at Salvation Army (SA) Joy Town special primary school, Thika, Kenya. Instructional constraints in this study are the academic challenges encountered by the learners that include: poor teaching methods, inappropriate curriculum, and lack of a modified learning and teaching environment among others. The study adopted a descriptive design because it aims at getting a true picture of a situation, behavior or attitude of individuals and the community at large. The target population was 43, and the study population was 23. The researcher used interviews and observation guide to collect data. Piloting was done at Dagoretti special school for the physically handicapped (PH), content-related validity was used as a measure to determine validity, and descriptive statistics where tables of frequencies and percentages were used in analyzing data. Results revealed that there were major instructional constraints facing learners with DMD.Keywords: Instructional constraints, Duchenne muscular dystrophy, learners with special educational needs

Analysis of linear-doped Si/SiC power LDMOSFETs based on device simulation

This paper presents the design and optimization of a 600 V silicon-on-silicon carbide (Si/SiC) laterally diffused MOSFET with linear doping profile in the drift region for high-temperature applications. The proposed structure has an embedded silicon-on-insulator (SOI) layout through which the traditional graded doping theory for SOI can be applied in the Si/SiC architecture. An SOI counterpart is introduced as a benchmark and modeled alongside the proposed structure. Comparisons between them show that they have the near-identical OFF-state and breakdown characteristics, with a significant tunneling leakage component emerging above 450 V. In the ON state, the Si/SiC device has higher electrical resistance but much lower thermal resistance, leading to less self-heating and higher reliability

Fragments of the earliest land plants

The earliest fossil evidence for land plants comes from microscopic dispersed spores. These microfossils are abundant and widely distributed in sediments, and the earliest generally accepted reports are from rocks of mid-Ordovician age (Llanvirn, 475 million years ago). Although distribution, morphology and ultrastructure of the spores indicate that they are derived from terrestrial plants, possibly early relatives of the bryophytes, this interpretation remains controversial as there is little in the way of direct evidence for the parent plants. An additional complicating factor is that there is a significant hiatus between the appearance of the first dispersed spores and fossils of relatively complete land plants (megafossils): spores predate the earliest megafossils (Late Silurian, 425 million year ago) by some 50 million years. Here we report the description of spore-containing plant fragments from Ordovician rocks of Oman. These fossils provide direct evidence for the nature of the spore-producing plants. They confirm that the earliest spores developed in large numbers within sporangia, providing strong evidence that they are the fossilized remains of bona fide land plants. Furthermore, analysis of spore wall ultrastructure supports liverwort affinities

The ethics of pharmaceutical industry relationships with medical students

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Little research has been done on the extent of the relationship between the pharmaceutical industry and medical students, and the effect on students of receiving gifts. Potential harms to patients are documented elsewhere; we focus on potential harms to students. Students who receive gifts may believe that they are receiving something for nothing, contributing to a sense of entitlement that is not in the best interests of their moral development as doctors. Alternatively, students may be subject to recognised or unrecognised reciprocal obligations that potentially influence their decision making. Medical educators have a duty of care to protect students from influence by pharmaceutical companies.Wendy A Rogers, Peter R Mansfield, Annette J Braunack-Mayer and Jon N Jureidin

Simulation of a new hybrid Si/SiC power device for harsh environment applications

A new power device structure is proposed, conceived to operate in a high temperature, harsh environment, for example within a motor drive application down hole, as an inverter in the engine bay of an electric car, or as a solar inverter in space. The lateral silicon power device resembles a laterally diffused MOSFET (LDMOS), such as those implemented within silicon on insulator (SOI) substrates. However, unlike SOI, the Si thin film has been transferred directly onto a semi-insulating 6H silicon carbide (6H-SiC) substrate via a wafer bonding process. Thermal simulations of the hybrid Si/SiC substrate have shown that the high thermal conductivity of the SiC will have a junction-to-case temperature approximately 4 times less that an equivalent SOI device, reducing the effects of self-heating. Electrical simulations of a 600 V power device, implemented entirely with the silicon thin film, suggest that it will retain the ability of SOI to minimise leakage at high temperature, but does so with 50% less conduction losses

Investigation into the use of water based brake fluid for light loads

This paper addresses the possibility of using water based fluid as a bake. fluid for light loads. Characterization of.both standard and water based brruced fluids formulated was carried out. The properties of ttie latter were com pared with that of a standard commercial brake fluid. The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus· of University of Uyo and the· braking effiqiency obtained at test to its suitability for light loads.Keywords·: Water-based, Brake fluid properties, Light loads, Efficienc

PARTISIPASI MASYARAKAT DALAM MENJAGA KEBERSIHAN LINGKUNGAN DI KELURAHAN WAHA KECAMATAN TOMIA KABUPATEN WAKATOBI

Penelitian ini bertujuan: (1) Untuk mengetahui bagaimana bentuk-bentuk partisipasi masyarakat dalam menjaga kebersihan lingkungan di Kelurahan Waha Kecamatan Tomia Kabupaten Wakatobi, (2) Untuk mengetahui bagaimana tingkat partisipasi masyarakat dalam menjaga kebersihan lingkungan di Kelurahan Waha Kecamatan Tomia Kabupaten Wakatobi. Penelitian ini dilaksanakan di Kelurahan Waha Kecamatan Tomia Kabupaten Wakatobi selama 7 hari pada bulan Februari sampai dengan Maret 2020. Metode pengumpulan data yang digunakan yaitu wawancara dan dokumentasi. Responden dalam penelitian ini yaitu masyarakat di Kelurahan Waha sebanyak 7 orang yang ikut berpartisipasi dalam menjaga kebersihan lingkungan. Sedangkan informan dalam penelitian ini yaitu 3 Aparat Kelurahan, 1 orang Kepala Lingkungan, dan 1 orang Tokoh Masyarakat. Jenis penelitian ini bersifat deskriptif kualitatif, yaitu memberikan gambaran/deskripsi mengenai partisipasi masyarakat dalam menjaga kebersihan lingkungan di Kelurahan Waha Kecamatan Tomia Kabupaten Wakatobi. Hasil penelitian menunjukan bahwa: (1) Bentuk-bentuk partisipasi masyarakat dalam menjaga kebersihan lingkungan di Kelurahan Waha Kecamatan Tomia Kabupaten Wakatobi yaitu partisipasi secara langsung dan partisipasi secara tidak langsung. (2) Tingkat partisipasi masyarakat dalam menjaga kebersihan lingkungan di Kelurahan Waha adalah sedang. Kesimpulan dari penelitian ini adalah Secara teoritis bentuk-bentuk partisipasi masyarakat dalam menjaga kebersihan lingkungan yaitu partisipasi secara langsung dan partisipasi secara tidak langsung. Akan tetapi, di Kelurahan Waha Kecamatan Tomia Kabupaten Wakatobi bentuk-bentuk partisipasi masyarakat dalam menjaga kebersihan lingkungan yaitu bentuk partisipasi secara langsung seperti menyepakati pengambilan keputusan dalam kebersihan lingkungan karena kebersihan itu berada dalam sekitar kita. Dengan adanya di setiap rumah yang memiliki tempat sampah, masyarakat dengan mudah terbantu dalam menjaga kebersihan lingkungan masing-masing. Sedangkan Tingkat partisipasi masyarakat dalam menjaga kebersihan lingkungan yaitu tinggi, sedang dan rendah. Akan tetapi, di Kelurahan Waha Kecamatan Tomia Kabupaten Wakatobi tingkat partisipasi masyarakat dalam menjaga kebersihan lingkungan yang dominan adalah pada tingkat yang sedang.

Dynamics of apparent horizons in quantum gravitational collapse

We study the gravitational collapse of a massless scalar field within the effective scenario of loop quantum gravity. Classical singularity is avoided and replaced by a quantum bounce in this model. It is shown that, quantum gravity effects predict a threshold scale below which no horizon can form as the collapse evolves towards the bounce.Comment: Contribution to the Spanish Relativity Meeting in Portugal 2012 (ERE2012), Guimaraes, Portuga