Somatic piRNAs and Transposons are Differentially Regulated During Skeletal Muscle Atrophy and Programmed Cell Death [preprint]

PiWi-interacting RNAs (piRNAs) are small single-stranded RNAs that can repress transposon expression via epigenetic silencing and transcript degradation. They have been identified predominantly in the ovary and testis, where they serve essential roles in transposon silencing in order to protect the integrity of the genome in the germline. The potential expression of piRNAs in somatic cells has been controversial. In the present study we demonstrate the expression of piRNAs derived from both genic and transposon RNAs in the intersegmental muscles (ISMs) from the tobacco hawkmoth Manduca sexta. These piRNAs are abundantly expressed, are ~27 nt long, map antisense to transposons, are oxidation resistant, exhibit a uridine bias at their first nucleotide, and amplify via the canonical ping-pong pathway. An RNA-seq analysis demonstrated that 20 piRNA pathway genes are expressed in the ISMs and are developmentally regulated. The abundance of piRNAs does not change when the muscles initiate developmentally-regulated atrophy, but are repressed when cells become committed to undergo programmed cell death at the end of metamorphosis. This change in piRNA expression is associated with the targeted repression of several retrotransposons and the induction of specific DNA transposons. The developmental changes in the expression of piRNAs, piRNA pathway genes, and transposons are all regulated by 20-hydroxyecdysone, the steroid hormone that controls the timing of ISM death. Taken together, these data provide compelling evidence for the existence of piRNA in somatic tissues and suggest that they may play roles in developmental processes such as programmed cell death

Somatic piRNAs and Transposons are Differentially Expressed Coincident with Skeletal Muscle Atrophy and Programmed Cell Death

PIWI-interacting RNAs (piRNAs) are small single-stranded RNAs that can repress transposon expression via epigenetic silencing and transcript degradation. They have been identified predominantly in the ovary and testis, where they serve essential roles in transposon silencing in order to protect the integrity of the genome in the germline. The potential expression of piRNAs in somatic cells has been controversial. In the present study we demonstrate the expression of piRNAs derived from both genic and transposon RNAs in the intersegmental muscles (ISMs) from the tobacco hawkmoth Manduca sexta. These piRNAs are abundantly expressed, ∼27 nt long, map antisense to transposons, are oxidation resistant, exhibit a 5’ uridine bias, and amplify via the canonical ping-pong pathway. An RNA-seq analysis demonstrated that 19 piRNA pathway genes are expressed in the ISMs and are developmentally regulated. The abundance of piRNAs does not change when the muscles initiate developmentally-regulated atrophy, but are repressed coincident with the commitment of the muscles undergo programmed cell death at the end of metamorphosis. This change in piRNA expression is correlated with the repression of several retrotransposons and the induction of specific DNA transposons. The developmentally-regulated changes in the expression of piRNAs, piRNA pathway genes, and transposons are all regulated by 20-hydroxyecdysone, the steroid hormone that controls the timing of ISM death. Taken together, these data provide compelling evidence for the existence of piRNA in somatic tissues and suggest that they may play roles in developmental processes such as programmed cell death

Management of ‘disorders of sex development’/intersex variations in children: Results from a freedom of information exercise

From SAGE Publishing via Jisc Publications RouterHistory: accepted 2021-02-26, epub 2021-06-17Publication status: PublishedNon-therapeutic medical interventions on the bodies of children born with disorders of sex development (DSD)/intersex variations have been subject to increasing critical scrutiny. In response to recent criticism directed at the United Kingdom, and early moves to consider reform, we report on a freedom of information exercise that sought to evaluate whether National Health Service England is meeting international standards on optimal clinical management of DSD/intersex variations. The study explored what medical protocols are being followed to help inform potential reform, particularly with regard to non-therapeutic surgery. While the exercise revealed limited examples of promising practice, current protocols in the majority of Trusts appear unlikely to meet the complex needs of these children. We identify areas where significant improvement is needed, including data management, consistency in guideline use, composition of multidisciplinary teams and addressing disciplinary hierarchies within teams. These concerns sharpen criticisms of the lack of recognition of children’s rights in this context

A genetic linkage map for the saltwater crocodile (Crocodylus porosus)

<p>Abstract</p> <p>Background</p> <p>Genome elucidation is now in high gear for many organisms, and whilst genetic maps have been developed for a broad array of species, surprisingly, no such maps exist for a crocodilian, or indeed any other non-avian member of the Class Reptilia. Genetic linkage maps are essential tools for the mapping and dissection of complex quantitative trait loci (QTL), and in order to permit systematic genome scans for the identification of genes affecting economically important traits in farmed crocodilians, a comprehensive genetic linage map will be necessary.</p> <p>Results</p> <p>A first-generation genetic linkage map for the saltwater crocodile (<it>Crocodylus porosus</it>) was constructed using 203 microsatellite markers amplified across a two-generation pedigree comprising ten full-sib families from a commercial population at Darwin Crocodile Farm, Northern Territory, Australia. Linkage analyses identified fourteen linkage groups comprising a total of 180 loci, with 23 loci remaining unlinked. Markers were ordered within linkage groups employing a heuristic approach using CRIMAP v3.0 software. The estimated female and male recombination map lengths were 1824.1 and 319.0 centimorgans (cM) respectively, revealing an uncommonly large disparity in recombination map lengths between sexes (ratio of 5.7:1).</p> <p>Conclusion</p> <p>We have generated the first genetic linkage map for a crocodilian, or indeed any other non-avian reptile. The uncommonly large disparity in recombination map lengths confirms previous preliminary evidence of major differences in sex-specific recombination rates in a species that exhibits temperature-dependent sex determination (TSD). However, at this point the reason for this disparity in saltwater crocodiles remains unclear.</p> <p>This map will be a valuable resource for crocodilian researchers, facilitating the systematic genome scans necessary for identifying genes affecting complex traits of economic importance in the crocodile industry. In addition, since many of the markers placed on this genetic map have been evaluated in up to 18 other extant species of crocodilian, this map will be of intrinsic value to comparative mapping efforts aimed at understanding genome content and organization among crocodilians, as well as the molecular evolution of reptilian and other amniote genomes. As researchers continue to work towards elucidation of the crocodilian genome, this first generation map lays the groundwork for more detailed mapping investigations, as well as providing a valuable scaffold for future genome sequence assembly.</p

Non-LTE iron abundances in cool stars: The role of hydrogen collisions

In the aim of determining accurate iron abundances in stars, this work is meant to empirically calibrate H-collision cross-sections with iron, where no quantum mechanical calculations have been published yet. Thus, a new iron model atom has been developed, which includes hydrogen collisions for excitation, ionization and charge transfer processes. We show that collisions with hydrogen leading to charge transfer are important for an accurate non-LTE modeling. We apply our calculations on several benchmark stars including the Sun, the metal-rich star {\alpha} Cen A and the metal-poor star HD140283

Mg/O₂ Battery Based on the Magnesium-Aluminum Chloride Complex (MACC) Electrolyte

Mg/O₂ cells employing a MgCl₂/AlCl₃/DME (MACC/DME) electrolyte are cycled and compared to cells with modified Grignard electrolytes, showing that performance of magnesium/oxygen batteries depends strongly on electrolyte composition. Discharge capacity is far greater for MACC/DME-based cells, while rechargeability in these systems is severely limited. The Mg/O₂-MACC/DME discharge product comprises a mixture of Mg­(ClO₄)₂ and MgCl₂, with the latter likely formed from slow decomposition of the former. The presence of Cl in these compounds suggests that the electrolyte participates in the cell reaction or reacts readily with the initial electrochemical products. A rate study suggests that O₂ diffusion in the electrolyte limits discharge capacities at higher currents. Formation of an insulating product film on the positive electrodes of Mg/O₂-MACC/DME cells following deep discharge increases cell impedance substantially and likely explains the poor rechargeability. An additional impedance rise consistent with film formation on the Mg negative electrode suggests the presence of detrimental O₂ crossover. Minimizing O₂ crossover and bypassing charge transfer through the discharge product would improve battery performance

We’re All Infected: Legal Personhood, Bare Life and The Walking Dead

This article argues that greater theoretical attention should be paid to the figure of the zombie in the fields of law, cultural studies and philosophy. Using The Walking Dead as a point of critical departure concepts of legal personhood are interrogated in relation to permanent vegetative states, bare life and the notion of the third person. Ultimately, the paper recommends a rejection of personhood; instead favouring a legal and philosophical engagement with humanity and embodiment. Personhood, it is suggested, creates a barrier in law allowing individuals in certain contexts (and in certain embodied states) to be rendered non-persons and thus outside the scope of legal rights. An approach that rejects personhood in favour of embodiment would allow individuals to enjoy their rights without being subject to such discrimination. It is also suggested that the concept of the human, itself complicated by the figure of the zombie, allows for legal engagement with a greater number of putative rights claimants including admixed embryos, cyborgs and the zombie

Global Kidney Exchange: Analysis and Background Papers from the Perspective of Medical Anthropology

Global Kidney Exchange (GKE) is a program aimed at facilitating trans-national kidney donation. Although its proponents aim at reducing the unmet demand of kidneys in the United States through the trans-nationalization of kidney exchange programs, the World Health Organization (WHO) and The Transplantation Society (TTS) have expressed concerns about its potential effect on black markets of organs and transnational organ trafficking, as well as on low- or middle-income countries health systems. For GKE to be implemented, it would need to be permitted to operate in at least some low- or middle-income countries. Should a low- or middle-income country allow GKE’s implementation? With the aim of answering this question, the eighteen University of Denver students in the Medical Anthropology course I [Alejandro Cerón] taught in autumn 2017, identified and researched the different aspects that would affect this issue, and delved in a holistic analysis we present in this report. Based on our analysis, health authorities in low- or middle-income countries faced with decisions about GKE need to consider the following aspects: the country’s current and projected needs related to kidney transplant, as well as the capacity for addressing those needs; the country’s current situation related to organ trafficking, transplant tourism and black markets of organs; the current and projected legislation related to both organ donation and human trafficking; the prevailing ethical considerations that inform the practice of all professionals related to organ transplant in the country; analyze end-stage renal failure as a preventable disease needing public health measures; and the sociocultural aspects that surround organ donation in the country. We consider that the concrete configuration of these aspects would influence the effects of implementing GKE. Additionally, we identified some issues of concern that are beyond the level of influence of local authorities: the unmet demand of kidneys in high-income countries is a reality that incentivizes organ trade and transplant tourism, and this is a problem in need of solutions; transnational organ trafficking as well as human trafficking with the purpose of organ donation are problems that need more visibility; for a global exchange of organs to be implemented, it would need to rely on supranational or transnational regulation and oversight; and the global epidemic of chronic kidney disease needs to be addressed through a public health perspective that emphasizes prevention

Invasive species control: incorporating demographic data and seed dispersal into a management model for Rhododendron ponticum

Rhododendron ponticum is a serious invasive alien plant in the British Isles and is of significant conservation and economic concern. Here, we integrate information on both the life-history and spatial dynamics of this species within an individual-based, spatially-explicit model and investigate the effectiveness of different control strategies. Importantly, we simulate seed movement and dispersal using a mechanistic seed dispersal model. We investigate the effectiveness of initiating control at the edge versus the core of the infestation, with and without returning each year to remove seedlings. We compare these results to an age-dependent strategy whereby the oldest plants are removed each year. Age-dependent control, in which the oldest plants were removed first, was the most effective strategy investigated, both in terms of the probability of successful eradication and the number of years taken to control. We demonstrate that this is because the older (and taller) plants towards the core produce more seeds that, on average, travel further. Indeed, our results suggest that the expansion of the invading front is actually driven as much by seeds that disperse long distances from these larger plants as by the seed rain from recently matured plants located much closer to the front. Finally, we investigate the potential use of ‘quarantine lines’ - corridors of unsuitable habitat that are sufficiently wide to contain an infestation, preventing spread to vulnerable areas. This study has provided generic insights into best practice for management based on the current understanding of the biology and ecology of this pernicious, invasive plant

Science information literacy and the role of academic librarians

Teaching information literacy is a major responsibility for subject/liaison librarians, but advances in information-retrieval systems, such as improved natural language searching and Semantic Web, could significantly change the role librarians play in this area. This chapter examines the future of information literacy and how librarians could redefine their role by expanding it to include management of scientific information and research data, different instruction formats, and new approaches for assessing student learning. This will make library instruction a much more appealing, engaging, and useful experience for students and researchers. Responding to the needs of a generation born into a digital culture will require that librarians learn new skills and play new roles in supporting the educational and research goals of their institutions be redefined