682 research outputs found

    Climate Niche Evolution in C4+CAM Portulaca and Closely Related C3+CAM Lineages

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    With at least a hundred independent origins among land plants, the CAM and C4 photosynthetic pathways represent one of the most notable examples of global convergent evolution of a complex trait. While biochemically similar, CAM and C4 are generally understood to be two distinct ecological adaptations evolving along separate trajectories. However, the purslanes (Portulaca), a globally widespread clade of around 100 species of annual and perennial succulents, are able to operate both CAM and C4 cycles in the same leaf. Portulaca likely originated from a facultative CAM ancestor and then evolved a C4 system at least three times while maintaining its CAM capabilities. Here, we use a dataset of 55,000 specimen records curated from the Global Biodiversity Information Facility (GBIF) and the Australian Virtual Herbarium, combined with high-resolution environmental rasters, to investigate the climate niche of Portulaca. In comparison to its closest relatives (Anacampserotaceae, Talinaceae, Cactaceae, and Calandrinia)—which include facultative and constitutive CAM plants but no C4 plants—Portulaca is able to persist in areas experiencing much higher temperatures and precipitation levels. Ancestral character state reconstructions conducted on the best-supported phylogenies for Portulaca and Anacampserotaceae allow us to infer the ecological consequences of evolving the C4+CAM pathway as opposed to C3+CAM or strong CAM. Further research into Portulaca’s anomalous photosynthetic system will dramatically improve our understanding of which environmental selective pressures have driven land plants to repeatedly evolve CAM and C4 and how this diverse and ecologically important group of plants may respond to future climate change

    The geography of strain: organizational resilience as a function of intergroup relations

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    Organizational resilience is an organization’s ability to absorb strain and preserve or improve functioning, despite the presence of adversity. In existing scholarship there is the implicit assumption that organizations experience and respond holistically to acute forms of adversity. We challenge this assumption by theorizing about how adversity can create differential strain, affecting parts of an organization rather than the whole. We argue that relations among those parts fundamentally shape organizational resilience. We develop a theoretical model that maps how the differentiated emergence of strain in focal parts of an organization triggers the movements of adjoining parts to provide or withhold resources necessary for the focal parts to adapt effectively. Drawing on core principles of theories about intergroup relations, we theorize about three specific pathways—integration, disavowal, and reclamation—by which responses of adjoining parts to focal part strain shape organizational resilience. We further theorize about influences on whether and when adjoining parts are likely to select different pathways. The resulting theory reveals how the social processes among parts of organizations influence member responses to adversity and, ultimately, organizational resilience. We conclude by noting the implications for organizational resilience theory, research, and practice.Accepted manuscrip

    US Counterterrorism and the Human Rights of Foreigners Abroad: Putting the Gloves Back On?

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    This book examines why the United States has introduced safeguards that are designed to prevent their counterterrorism policies from causing harm to non-US citizens beyond US territory. It investigates what made US policymakers take steps to "put the gloves back on" through five case studies on the emergence of such safeguards related to the right not to be tortured, the right not to be arbitrarily detained, the right to life (in connection with targeted killing operations), the right to seek asylum (in connection with refugee resettlement), and the right to privacy (in connection with foreign mass surveillance). The book exposes two mechanisms – coercion and strategic learning – which explain why the United States has introduced what the authors refer to as "extraterritorial human rights safeguards", thus demonstrating that the emerging norm that states have human rights obligations towards foreigners beyond their borders constrains policy choices. This book will be of key interest to scholars and students of human rights, counterterrorism, US foreign policy, human rights law, and more broadly to political science and international relations. Institutions, Decisions and Collective Behaviou

    Recoding and reassignment in protists

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    During mRNA translation the ribosome reads each codon (nucleotide triplet) with a specific meaning. The standard genetic code comprises 61 sense-codons for specifying the 20 standard amino acids during elongation and three anti-sense codons which signal termination. While variations to the standard rules of genetic decoding are widely acknowledged, recent advances in next generation sequencing techniques have provided a wealth of new examples across many species. In this thesis, I provide evidence of novel decoding mechanisms in protists, as identified through bioinformatics analysis. To begin with I analysed the genomes of two ciliate species, Euplotes crassus and E. focardii. In combination with the analysis of E. crassus transcriptome using ribosome profiling, I determined over 1,700 cases of ribosomal frameshifting (22% of genes analysed) in E. crassus. I identified 47 codons upstream of a stop signal which directs the ribosome to either the +1 or +2 reading frames. Termination only occurs in the context of the poly-A tail. In addition I analysed the transcriptomes of over 200 diverse protist species for the protein ornithine decarboxylase antizyme, a key negative regulator of cellular polyamine synthesis. The synthesis of this protein usually requires a +1 ribosomal frameshift at the end of the first open reading frame. In this study I identified a novel mechanism of stop codon readthrough to regulate antizyme production in dinoflagellates and single ORF sequences from other protist phyla. Further I analysed transcriptomes of diverse ciliate organisms to characterize stop codon reassignments in their genetic codes. In addition to finding novel stop codon reassignments, I identified an organism, Condylostoma magnum where all three stop codons TAA, TAG & TGA have been reassigned to sense codons. All three stop codons are enriched at the expected positions of translation termination sites which occur at a short distance from the 3’ poly-A tail

    Around consensual non-monogamies – assessing attitudes toward non-exclusive relationships

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    Consensual non-monogamy is a term used to describe intimate romantic relationships which are sexually and/or emotionally non-exclusive. The present study examined the social norms which are violated by different forms of consensual nonmonogamy,and the negative judgements that result. We asked 375 participants to rate hypothetical vignettes of people involved in one of five relationship types (monogamy, polyamory, an open relationship, swinging, and cheating) on items related to relationship satisfaction, morality, and cognitive abilities. The monogamous couple was perceived most favourably, followed by the polyamorous couple, then the open and swinging couples who were rated equally. Participants judged the cheating couple most negatively. Although social norms of sexual and emotional monogamy are important, we conclude that the aspect that has the most effect on judgements is whether the relationship structure has been agreed to by all parties

    GWIPS-viz: development of a ribo-seq genome browser

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    We describe the development of GWIPS-viz (http://gwips.ucc.ie), an online genome browser for viewing ribosome profiling data. Ribosome profiling (ribo-seq) is a recently developed technique that provides genome-wide information on protein synthesis (GWIPS) in vivo. It is based on the deep sequencing of ribosome-protected messenger RNA (mRNA) fragments, which allows the ribosome density along all mRNA transcripts present in the cell to be quantified. Since its inception, ribo-seq has been carried out in a number of eukaryotic and prokaryotic organisms. Owing to the increasing interest in ribo-seq, there is a pertinent demand for a dedicated ribo-seq genome browser. GWIPS-viz is based on The University of California Santa Cruz (UCSC) Genome Browser. Ribo-seq tracks, coupled with mRNA-seq tracks, are currently available for several genomes: human, mouse, zebrafish, nematode, yeast, bacteria (Escherichia coli K12, Bacillus subtilis), human cytomegalovirus and bacteriophage lambda. Our objective is to continue incorporating published ribo-seq data sets so that the wider community can readily view ribosome profiling information from multiple studies without the need to carry out computational processing

    ‘A question of equality and choice’: same-sex couples’ attitudes towards civil partnership after the introduction of same-sex marriage

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    Since the introduction of same-sex marriage, there have been two parallel institutions (marriage and civil partnership) for the legal recognition of same-sex relationships in England, Wales and Scotland. The current study aimed to examine how those in a civil partnership or a same-sex marriage perceive civil partnership in the context of marriage equality. Eighty-two respondents completed a qualitative online survey, and their responses were analysed thematically. The respondents were divided between those who viewed civil partnership as: 1) a stepping stone to equality, and felt that civil partnerships should be discontinued; 2) a form of legal recognition free from cultural baggage, and argued the Government should make civil partnership available for all; or 3) those who displayed ambivalence and conflicting views. We conclude by discussing how the principle of formal equality underpinned opinions on all sides, and what implications this might have for how we understand discrimination

    Percent fluid overload for prediction of fluid de-escalation in critically ill patients in Saudi Arabia: a prospective observational study

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    Background Percent fluid overload greater than 5% is associated with increased mortality. The appropriate time for fluid deresuscitation depends on the patient's radiological and clinical findings. This study aimed to assess the applicability of percent fluid overload calculations for evaluating the need for fluid deresuscitation in critically ill patients. Methods This was a single-center, prospective, observational study of critically ill adult patients requiring intravenous fluid administration. The study's primary outcome was median percent fluid accumulation on the day of fluid deresuscitation or intensive care unit (ICU) discharge, whichever came first. Results A total of 388 patients was screened between August 1, 2021, and April 30, 2022. Of these, 100 with a mean age of 59.8±16.2 years were included for analysis. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 15.4±8.0. Sixty-one patients (61.0%) required fluid deresuscitation during their ICU stay, while 39 (39.0%) did not. Median percent fluid accumulation on the day of deresuscitation or ICU discharge was 4.5% (interquartile range [IQR], 1.7%–9.1%) and 5.2% (IQR, 2.9%–7.7%) in patients requiring deresuscitation and those who did not, respectively. Hospital mortality occurred in 25 (40.9%) of patients with deresuscitation and six (15.3%) patients who did not require it (P=0.007). Conclusions The percent fluid accumulation on the day of fluid deresuscitation or ICU discharge was not statistically different between patients who required fluid deresuscitation and those who did not. A larger sample size is needed to confirm these findings

    Alternative lengthening of telomeres, ATRX loss and H3â K27M mutations in histologically defined pilocytic astrocytoma with anaplasia

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    Anaplasia may be identified in a subset of tumors with a presumed pilocytic astrocytoma (PA) component or piloid features, which may be associated with aggressive behavior, but the biologic basis of this change remains unclear. Fiftyâ seven resections from 36 patients (23 M, 13 F, mean age 32 years, range 3â 75) were included. A clinical diagnosis of NF1 was present in 8 (22%). Alternative lengthening of telomeres (ALT) was assessed by telomereâ specific FISH and/or CISH. A combination of immunohistochemistry, DNA sequencing and FISH were used to study BRAF, ATRX, CDKN2A/p16, mutant IDH1 p.R132H and H3â K27M proteins. ALT was present in 25 (69%) cases and ATRX loss in 20 (57%), mostly in the expected association of ALT+/ATRXâ (20/24, 83%) or ALTâ /ATRX+ (11/11, 100%). BRAF duplication was present in 8 (of 26) (31%). H3â K27M was present in 5 of 32 (16%) cases, all with concurrent ATRX loss and ALT. ALT was also present in 9 (of 11) cases in the benign PA precursor, 7 of which also had ATRX loss in both the precursor and the anaplastic tumor. In a single pediatric case, ALT and ATRX loss developed in the anaplastic component only, and in another adult case, ALT was present in the PAâ A component only, but ATRX was not tested. Features associated with worse prognosis included subtotal resection, adult vs. pediatric, presence of a PA precursor preceding a diagnosis of anaplasia, necrosis, presence of ALT and ATRX expression loss. ALT and ATRX loss, as well as alterations involving the MAPK pathway, are frequent in PA with anaplasia at the time of development of anaplasia or in their precursors. Additionally, a small subset of PA with anaplasia have H3â K27M mutations. These findings further support the concept that PA with anaplasia is a neoplasm with heterogeneous genetic features and alterations typical of both PA and diffuse gliomas.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147190/1/bpa12646_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147190/2/bpa12646.pd

    A tale of two societies : The doing of qualitative comparative research in Hong Kong and Britain

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    This article explores the challenges and opportunities for methodological innovation arising from an exploratory, cross-national, qualitative study of women’s lives in Hong Kong and Britain. We begin by briefly outlining the aims of our study and its original research design, based on life history interviews with young adult women and their mothers in each location.We then turn to a discussion of how this was modified as we recruited participants and conducted the interviews, including the use of vignettes. We aim to be transparent about some of the problems of implementing a symmetrical approach to generating qualitative data in very different socio-cultural settings compounded by the practical difficulties of geographical distance between team members. We argue for a flexible approach that takes account of local cultural sensibilities rather than trying to follow rigidly identical procedures, recognising also that, in any qualitative research team, there will be differences in approach that affect the data produced. We highlight some of the insights yielded by the problems we encountered and, in particular, an accidental innovation that occurred through an ad hoc decision to conduct focus groups with the young women, which we call ‘cross-cultural data feedback’. This innovation involved our participants in contributing to cross cultural comparison and also brought taken-for-granted assumptions in each setting into sharp relief, as well as sensitising us to issues that proved important in analysing our data. This leads us to raise issues of interpreting and analysing data from differing socio-cultural locations and translating between cultures. We conclude with some recommendations including the potential for the future development of our method of cross-cultural data feedback
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