Nucleocytoplasmic transport: a thermodynamic mechanism

The nuclear pore supports molecular communication between cytoplasm and nucleus in eukaryotic cells. Selective transport of proteins is mediated by soluble receptors, whose regulation by the small GTPase Ran leads to cargo accumulation in, or depletion from the nucleus, i.e., nuclear import or nuclear export. We consider the operation of this transport system by a combined analytical and experimental approach. Provocative predictions of a simple model were tested using cell-free nuclei reconstituted in Xenopus egg extract, a system well suited to quantitative studies. We found that accumulation capacity is limited, so that introduction of one import cargo leads to egress of another. Clearly, the pore per se does not determine transport directionality. Moreover, different cargo reach a similar ratio of nuclear to cytoplasmic concentration in steady-state. The model shows that this ratio should in fact be independent of the receptor-cargo affinity, though kinetics may be strongly influenced. Numerical conservation of the system components highlights a conflict between the observations and the popular concept of transport cycles. We suggest that chemical partitioning provides a framework to understand the capacity to generate concentration gradients by equilibration of the receptor-cargo intermediary.Comment: in press at HFSP Journal, vol 3 16 text pages, 1 table, 4 figures, plus Supplementary Material include

Hominin reactions to herbivore distribution in the Lower Palaeolithic of the Southern Levant

We explore the relationship between the edaphic potential of soils and the mineral properties of the underlying geology as a means of mapping the differential productivity of different areas of the Pleistocene landscape for large herbivores. These factors strongly control the health of grazing animals irrespective of the particular types of vegetation growing on them, but they have generally been neglected in palaeoanthropological studies in favour of a more general emphasis on water and vegetation, which provide an incomplete picture. Taking the Carmel-Galilee-Golan region as an example, we show how an understanding of edaphic potential provides insight into how animals might have exploited the environment. In order to simplify the analysis, we concentrate on the Lower Palaeolithic period and the very large animals that dominate the archaeofaunal assemblages of this period. Topography and the ability of soils to retain water also contribute to the differential productivity and accessibility of different regions and to patterns of seasonal movements of the animals, which are essential to ensure a supply of healthy fodder throughout the year, especially for large animals such as elephants, which require substantial regions of good grazing and browsing. Other animals migrating in groups have similar needs. The complex topography of the Southern Levant with frequent sudden and severe changes in gradient, and a wide variety of landforms including rocky outcrops, cliffs, gorges, and ridges, places major limits on these patterns of seasonal movements. We develop methods of mapping these variables, based on the geology and our substantial field experience, in order to create a framework of landscape variation that can be compared with the locations and contents of archaeological sites to suggest ways in which early hominins used the variable features of the landscape to target animal prey, and we extend the analysis to the consideration of smaller mammals that were exploited more intensively after the disappearance of the elephants. We consider some of the ways in which this regional-scale approach can be further tested and refined, and advocate the development of such studies as an essential contribution to understanding the wider pattern of hominin dispersal

Revisiting Egyptian Foreign Policy towards Israel under Mubarak: From Cold Peace to Strategic Peace

This article is the first academic study of Egyptian foreign policy towards Israel under Hosni Mubarak (1981–2011). It challenges a deeply entrenched conventional wisdom that Egypt pursued a cold-peace foreign policy towards Israel throughout this period. We demonstrate that Egyptian foreign policy towards Israel was dynamic – comprising cold peace (1981–91), a hybrid foreign policy of cold peace and strategic peace (1991–2003), and a pure strategic peace posture (2003–11). We also use the case of Egyptian foreign policy towards Israel as a heuristic to develop a conception of a new type of peace, strategic peace, as an intermediary analytical category between cold and stable peace

Cognitive behavioral therapy of socially phobic children focusing on cognition: a randomised wait-list control study

BACKGROUND: Although literature provides support for cognitive behavioral therapy (CBT) as an efficacious intervention for social phobia, more research is needed to improve treatments for children. METHODS: Forty four Caucasian children (ages 8-14) meeting diagnostic criteria of social phobia according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; APA, 1994) were randomly allocated to either a newly developed CBT program focusing on cognition according to the model of Clark and Wells (n = 21) or a wait-list control group (n = 23). The primary outcome measure was clinical improvement. Secondary outcomes included improvements in anxiety coping, dysfunctional cognitions, interaction frequency and comorbid symptoms. Outcome measures included child report and clinican completed measures as well as a diagnostic interview. RESULTS: Significant differences between treatment participants (4 dropouts) and controls (2 dropouts) were observed at post test on the German version of the Social Phobia and Anxiety Inventory for Children. Furthermore, in the treatment group, significantly more children were free of diagnosis than in wait-list group at post-test. Additional child completed and clinician completed measures support the results. DISCUSSION: The study is a first step towards investigating whether CBT focusing on cognition is efficacious in treating children with social phobia. Future research will need to compare this treatment to an active treatment group. There remain the questions of whether the effect of the treatment is specific to the disorder and whether the underlying theoretical model is adequate. CONCLUSION: Preliminary support is provided for the efficacy of the cognitive behavioral treatment focusing on cognition in socially phobic children. Active comparators should be established with other evidence-based CBT programs for anxiety disorders, which differ significantly in their dosage and type of cognitive interventions from those of the manual under evaluation (e.g. Coping Cat)

Elevated creatine kinase activity in primary hepatocellular carcinoma

BACKGROUND: Inconsistent findings have been reported on the occurrence and relevance of creatine kinase (CK) isoenzymes in mammalian liver cells. Part of this confusion might be due to induction of CK expression during metabolic and energetic stress. METHODS: The specific activities and isoenzyme patterns of CK and adenylate kinase (AdK) were analysed in pathological liver tissue of patients undergoing orthotopic liver transplantation. RESULTS: The brain-type, cytosolic BB-CK isoenzyme was detected in all liver specimens analysed. Conversely, CK activity was strongly increased and a mitochondrial CK (Mi-CK) isoenzyme was detected only in tissue samples of two primary hepatocellular carcinomas (HCCs). CONCLUSION: The findings do not support significant expression of CK in normal liver and most liver pathologies. Instead, many of the previous misconceptions in this field can be explained by interference from AdK isoenzymes. Moreover, the data suggest a possible interplay between p53 mutations, HCC, CK expression, and the growth-inhibitory effects of cyclocreatine in HCC. These results, if confirmed, could provide important hints at improved therapies and cures for HCC

Aegilops sharonensis genome-assisted identification of stem rust resistance gene Sr62

The wild relatives and progenitors of wheat have been widely used as sources of disease resistance (R) genes. Molecular identification and characterization of these R genes facilitates their manipulation and tracking in breeding programmes. Here, we develop a reference-quality genome assembly of the wild diploid wheat relative Aegilops sharonensis and use positional mapping, mutagenesis, RNA-Seq and transgenesis to identify the stem rust resistance gene Sr62, which has also been transferred to common wheat. This gene encodes a tandem kinase, homologues of which exist across multiple taxa in the plant kingdom. Stable Sr62 transgenic wheat lines show high levels of resistance against diverse isolates of the stem rust pathogen, highlighting the utility of Sr62 for deployment as part of a polygenic stack to maximize the durability of stem rust resistance

Regulating E-Cigarettes: Why Policies Diverge

This paper, part of a festschrift in honor of Professor Malcolm Feeley, explores the landscape of e-cigarette policy globally by looking at three jurisdictions that have taken starkly different approaches to regulating e-cigarettes—the US, Japan, and China. Each of those countries has a robust tobacco industry, government agencies entrusted with protecting public health, an active and sophisticated scientific and medical community, and a regulatory structure for managing new pharmaceutical, tobacco, and consumer products. All three are signatories of the World Health Organization’s Framework Convention on Tobacco Control, all are signatories of the Agreement on Trade-Related Aspects of Intellectual Property Rights, and all are members of the World Trade Organization. Which legal, economic, social and political differences between the three countries explain their diverse approaches to regulating e-cigarettes? Why have they embraced such dramatically different postures toward e-cigarettes? In seeking to answer those questions, the paper builds on Feeley\u27s legacy of comparative scholarship, policy analysis, and focus on law in action

Shifting the limits in wheat research and breeding using a fully annotated reference genome

Introduction: Wheat (Triticum aestivum L.) is the most widely cultivated crop on Earth, contributing about a fifth of the total calories consumed by humans. Consequently, wheat yields and production affect the global economy, and failed harvests can lead to social unrest. Breeders continuously strive to develop improved varieties by fine-tuning genetically complex yield and end-use quality parameters while maintaining stable yields and adapting the crop to regionally specific biotic and abiotic stresses. Rationale: Breeding efforts are limited by insufficient knowledge and understanding of wheat biology and the molecular basis of central agronomic traits. To meet the demands of human population growth, there is an urgent need for wheat research and breeding to accelerate genetic gain as well as to increase and protect wheat yield and quality traits. In other plant and animal species, access to a fully annotated and ordered genome sequence, including regulatory sequences and genome-diversity information, has promoted the development of systematic and more time-efficient approaches for the selection and understanding of important traits. Wheat has lagged behind, primarily owing to the challenges of assembling a genome that is more than five times as large as the human genome, polyploid, and complex, containing more than 85% repetitive DNA. To provide a foundation for improvement through molecular breeding, in 2005, the International Wheat Genome Sequencing Consortium set out to deliver a high-quality annotated reference genome sequence of bread wheat. Results: An annotated reference sequence representing the hexaploid bread wheat genome in the form of 21 chromosome-like sequence assemblies has now been delivered, giving access to 107,891 high-confidence genes, including their genomic context of regulatory sequences. This assembly enabled the discovery of tissue- and developmental stage–related gene coexpression networks using a transcriptome atlas representing all stages of wheat development. The dynamics of change in complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. Aspects of the future value of the annotated assembly for molecular breeding and research were exemplarily illustrated by resolving the genetic basis of a quantitative trait locus conferring resistance to abiotic stress and insect damage as well as by serving as the basis for genome editing of the flowering-time trait. Conclusion: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding. Importantly, the bioinformatics capacity developed for model-organism genomes will facilitate a better understanding of the wheat genome as a result of the high-quality chromosome-based genome assembly. By necessity, breeders work with the genome at the whole chromosome level, as each new cross involves the modification of genome-wide gene networks that control the expression of complex traits such as yield. With the annotated and ordered reference genome sequence in place, researchers and breeders can now easily access sequence-level information to precisely define the necessary changes in the genomes for breeding programs. This will be realized through the implementation of new DNA marker platforms and targeted breeding technologies, including genome editing

Informing the NHS Outcomes Framework : evaluating meaningful health outcomes for children with neurodisability using multiple methods including systematic review, qualitative research, Delphi survey and consensus meeting

Background: The identification of suitable outcome measures will improve the evaluation of integrated NHS care for the large number of children affected by neurodisability, and has the potential to encourage the provision of more appropriate and effective health care. This research sought to appraise the potential of patient-reported outcome measures (PROMs) for children and young people with neurodisability. Aim: This research aimed (i) to identify key outcomes of health care for children with neurodisability, beyond morbidity and mortality, from the perspectives of children, parents and professionals, (ii) to critically appraise existing generic multidimensional PROMs, and (iii) to examine whether or not the key outcomes might be measured by existing PROMs. We also sought agreement on a definition of neurodisability. Methods: Data were gathered in three main ways, (i) a systematic review identified eligible generic multidimensional PROMs and peer-reviewed studies evaluating psychometric performance using English-language questionnaires. Studies were appraised for methodological quality and psychometric performance was appraised using standard criteria. (ii) Focus groups and interviews with children and young people with neurodisability, and separately with parents, sought to identify important outcomes of NHS care, and their feedback on example PROM questionnaires. (iii) An online Delphi survey was conducted with a multidisciplinary sample of health professionals to seek agreement on appropriate NHS outcomes. In addition, we convened a consensus meeting with a small nominal group of young people, parents and professionals, the group sought agreement on a core set of important health outcomes. Results: From the systematic review, we identified 126 papers that reported eligible evidence regarding the psychometric performance of 25 PROMs. Evidence of psychometric robustness was more favourable for a small number of PROMs: KIDSCREEN (generic), DISABKIDS (chronic-generic) and Child Health Utility 9D (preference-based measure). The Pediatric Quality of Life Inventory and KINDL offer both self-report and a proxy report version for a range of age bands, but evidence of their psychometric performance was weaker. Evidence was lacking in one or more respects for all candidate PROMs, in both general populations and those with neurodisability. Proxy reporting was found generally to be poorly correlated with self-report. Focus groups and interviews included 54 children and young people, and 53 parents. The more important health outcomes were felt to be communication, emotional well-being, pain, mobility, independence/self-care, worry/mental health, social activities and sleep. In addition, parents of children with intellectual impairment identified behaviour, toileting and safety as important outcomes. Participants suggested problems with the face validity of example PROM questionnaires for measuring NHS care. In the Delphi survey, 276 clinicians from a wide range of professions contributed to at least one of four rounds. Professionals rated pain, hearing, seeing, sleep, toileting, mobility and communication as key goals for the NHS but also identified treating neurological symptoms as important. Professionals in the Delphi survey and parents working with the research team agreed a proposed definition for neurodisability. The consensus meeting confirmed overlap between the outcomes identified as important by young people, parents and professionals, but not complete agreement. Conclusions: There was agreement between young people, parents and professionals regarding a core suite of more important health outcomes: communication, emotional well-being, pain, mobility, independence/self-care, worry/mental health, social activities and sleep. In addition, behaviour, toileting and safety were identified as important by parents. This research suggests that it would be appropriate to measure these constructs using PROMs to assess health care. None of the candidate PROMs in the review adequately captures all of the identified constructs, and there is inadequate evidence that candidate PROMs are psychometrically robust for use across children with neurodisability. Further consultation with young people, families and professionals is warranted to support the use of PROMs to measure NHS outcomes. Research to test potential PROMs with different age groups and conditions would be valuable