27 research outputs found
A novel mutation 5' to the HMG box of the SRY gene in a case of Swyer syndrome
We describe a novel mutation in the coding region of the SRY gene in a 46,XY female with Swyer syndrome. Analysis of SRY was carried out by direct sequencing of a 780-bp PCR product that included the SRY open reading frame (ORF). This revealed the presence of a point mutation, ins108A, in the coding region 50 to the HMG box which results in a frame shift and premature termination of the encoded protein. No other mutation was found in the SRY ORF. We infer that sex reversal in this individual is a result of this insertion. In none of the 13 other 46, XY females that were studied was a mutation detected in SRY, confirming earlier findings that most cases of XY femaleness are due to causes other than mutation in SRY. These observations and those of others are discussed in relation to the aetiology of XY sex reversal
Biological Contamination Prevention for Outer Solar System Moons of Astrobiological Interest: What Do We Need to Know?
To ensure that scientific investments in space exploration are not compromised by terrestrial contamination of celestial bodies, special care needs to be taken to preserve planetary conditions for future astrobiological exploration. Significant effort has been made and is being taken to address planetary protection in the context of inner Solar System exploration. In particular for missions to Mars, detailed internationally accepted guidelines have been established. For missions to the icy moons in the outer Solar System, Europa and Enceladus, the planetary protection requirements are so far based on a probabilistic approach and a conservative estimate of poorly known parameters. One objective of the European Commission-funded project, Planetary Protection of Outer Solar System, was to assess the existing planetary protection approach, to identify inherent knowledge gaps, and to recommend scientific investigations necessary to update the requirements for missions to the icy moons
Observation and integrated Earth-system science: a roadmap for 2016–2025
This report is the response to a request by the Committee on Space Research of the International Council for Science to prepare a roadmap on observation and integrated Earth-system science for the coming ten years. Its focus is on the combined use of observations and modelling to address the functioning, predictability and projected evolution of interacting components of the Earth system on timescales out to a century or so. It discusses how observations support integrated Earth-system science and its applications, and identifies planned enhancements to the contributing observing systems and other requirements for observations and their processing. All types of observation are considered, but emphasis is placed on those made from space.
The origins and development of the integrated view of the Earth system are outlined, noting the interactions between the main components that lead to requirements for integrated science and modelling, and for the observations that guide and support them. What constitutes an Earth-system model is discussed. Summaries are given of key cycles within the Earth system.
The nature of Earth observation and the arrangements for international coordination essential for effective operation of global observing systems are introduced. Instances are given of present types of observation, what is already on the roadmap for 2016–2025 and some of the issues to be faced. Observations that are organised on a systematic basis and observations that are made for process understanding and model development, or other research or demonstration purposes, are covered. Specific accounts are given for many of the variables of the Earth system.
The current status and prospects for Earth-system modelling are summarized. The evolution towards applying Earth-system models for environmental monitoring and prediction as well as for climate simulation and projection is outlined. General aspects of the improvement of models, whether through refining the representations of processes that are already incorporated or through adding new processes or components, are discussed. Some important elements of Earth-system models are considered more fully.
Data assimilation is discussed not only because it uses observations and models to generate datasets for monitoring the Earth system and for initiating and evaluating predictions, in particular through reanalysis, but also because of the feedback it provides on the quality of both the observations and the models employed. Inverse methods for surface-flux or model-parameter estimation are also covered. Reviews are given of the way observations and the processed datasets based on them are used for evaluating models, and of the combined use of observations and models for monitoring and interpreting the behaviour of the Earth system and for predicting and projecting its future.
A set of concluding discussions covers general developmental needs, requirements for continuity of space-based observing systems, further long-term requirements for observations and other data, technological advances and data challenges, and the importance of enhanced international co-operation
Dama Gazelle (Nanger dama) conservation strategy 2019-2028
Produced following the workshop hosted by Al Ain Zoo in Al Ain, United Arab Emirates, 11-13 December 2018. Compiled and edited by: David Mallon, Lisa Banfield, Helen Senn & Hessa Al Qahtani.Peer reviewe
STDP Allows Fast Rate-Modulated Coding with Poisson-Like Spike Trains
Spike timing-dependent plasticity (STDP) has been shown to enable single neurons to detect repeatedly presented spatiotemporal spike patterns. This holds even when such patterns are embedded in equally dense random spiking activity, that is, in the absence of external reference times such as a stimulus onset. Here we demonstrate, both analytically and numerically, that STDP can also learn repeating rate-modulated patterns, which have received more experimental evidence, for example, through post-stimulus time histograms (PSTHs). Each input spike train is generated from a rate function using a stochastic sampling mechanism, chosen to be an inhomogeneous Poisson process here. Learning is feasible provided significant covarying rate modulations occur within the typical timescale of STDP (∼10–20 ms) for sufficiently many inputs (∼100 among 1000 in our simulations), a condition that is met by many experimental PSTHs. Repeated pattern presentations induce spike-time correlations that are captured by STDP. Despite imprecise input spike times and even variable spike counts, a single trained neuron robustly detects the pattern just a few milliseconds after its presentation. Therefore, temporal imprecision and Poisson-like firing variability are not an obstacle to fast temporal coding. STDP provides an appealing mechanism to learn such rate patterns, which, beyond sensory processing, may also be involved in many cognitive tasks
Relating past and present diet to phenotypic and transcriptomic variation in the fruit fly
What Is Stochastic Resonance? Definitions, Misconceptions, Debates, and Its Relevance to Biology
Stochastic resonance is said to be observed when increases in levels of unpredictable fluctuations—e.g., random noise—cause an increase in a metric of the quality of signal transmission or detection performance, rather than a decrease. This counterintuitive effect relies on system nonlinearities and on some parameter ranges being “suboptimal”. Stochastic resonance has been observed, quantified, and described in a plethora of physical and biological systems, including neurons. Being a topic of widespread multidisciplinary interest, the definition of stochastic resonance has evolved significantly over the last decade or so, leading to a number of debates, misunderstandings, and controversies. Perhaps the most important debate is whether the brain has evolved to utilize random noise in vivo, as part of the “neural code”. Surprisingly, this debate has been for the most part ignored by neuroscientists, despite much indirect evidence of a positive role for noise in the brain. We explore some of the reasons for this and argue why it would be more surprising if the brain did not exploit randomness provided by noise—via stochastic resonance or otherwise—than if it did. We also challenge neuroscientists and biologists, both computational and experimental, to embrace a very broad definition of stochastic resonance in terms of signal-processing “noise benefits”, and to devise experiments aimed at verifying that random variability can play a functional role in the brain, nervous system, or other areas of biology
PPOSS - PLANETARY PROTECTION OF OUTER SOLAR SYSTEM EC H2020 PROJECT
The PPOSS (Planetary Protection of Outer Solar System bodies) project, coordinated by
the European Science Foundation was selected by the European Commission in August 2015
following the Horizon 2020 call `Space-Competitiveness of the European Space Sector-2015'.
In addition to the European Science Foundation, DLR, COSPAR, Imperial College London,
EUROSPACE, INAF and Space Technology Ireland Ltd. are also part of the project consortium
and PPOSS also has several international partners and observers.
PPOSS will run for three years (2016-2018) and has for main objectives to provide an interna-
tional forum to consider and approach the specificity of Planetary Protection (biological and
organic contamination) for outer Solar system bodies, including icy worlds and small bodies,
in the general context of Planetary Protection regulation.
While significant effort has been, and is being provided to address planetary protection in the
context of the exploration of inner Solar System bodies, and in particular Mars, PPOSS would
allow to tackle the scientific, technological and policy-making specificity of Planetary Protection
of outer solar system bodies. Project findings will be considered in the general context of the
international planetary protection landscape and presented to COSPAR PPP..
CONSIDERING PLANETARY PROTECTION OF OUTER SPACE BODIES - THE EUROPEAN PPOSS PROJECT
The PPOSS (Planetary Protection of Outer Solar System bodies) project, coordinated by the European
Science Foundation is supported by the European Commission Horizon 2020 programme. This project
kicked-off in January 2016 and will last for three years.
The PPOSS project intends to consider how planetary protection policy has been developed and is
being implemented, it will look at case studies, lessons learnt and good practices in order to produce a
Planetary Protection handbook that will be widely disseminated.
The project will also look forward and address the complex issues of organic and biological contamination
of outer solar system bodies, in particular small bodies and moons of gas giant planets. PPOSS
will identify knowledge gaps, propose scientific goals and suggest activities to overcome the main hurdles
to reach these goals.
Besides scientific issues, PPOSS will consider the European engineering landscape and the capacity of
the European industry to meet the challenges raised by planetary protection of outer solar system bodies,
an engineering roadmap will result from this effort.
As a one of the main outcomes, the PPOSS project will eventually review the international planetary
protection regulation structure, process and categorization related to outer solar system bodies, it will
suggest policy improvements to COSPAR Panel on Planetary Protection.
PPOSS is implemented by a consortium of seven European and international organisations (European
Science Foundation, DLR, COSPAR, Eurospace, INAF, Space Technology Ireland, Imperial College) as
well as by international partners, including the Chinese Academy of Sciences and China Academy of Space
Technology. The project intends to broaden its international footprint and allow a dedicated forum to
address the scientific, technical and policy challenges raised by planetary protection of outer solar system
bodies
Windows of opportunity: Ocean warming shapes temperature‐sensitive epigenetic reprogramming and gene expression across gametogenesis and embryogenesis in marine stickleback
Rapid climate change is placing many marine species at risk of local extinction. Recent studies show that epigenetic mechanisms (e.g. DNA methylation, histone modifications) can facilitate both within and transgenerational plasticity to cope with changing environments. However, epigenetic reprogramming (erasure and re-establishment of epigenetic marks) during gamete and early embryo development may hinder transgenerational epigenetic inheritance. Most of our knowledge about reprogramming stems from mammals and model organisms, whereas the prevalence and extent of reprogramming among non-model species from wild populations is rarely investigated. Moreover, whether reprogramming dynamics are sensitive to changing environmental conditions is not well known, representing a key knowledge gap in the pursuit to identify mechanisms underlying links between parental exposure to changing climate patterns and environmentally-adapted offspring phenotypes. Here, we investigated epigenetic reprogramming (DNA methylation/hydroxymethylation) and gene expression across gametogenesis and embryogenesis of marine stickleback (Gasterosteus aculeatus) under three ocean warming scenarios (ambient, + 1.5 °C and + 4 °C). We found that parental acclimation to ocean warming led to dynamic and temperature-sensitive reprogramming throughout offspring development. Both global methylation/hydroxymethylation and expression of genes involved in epigenetic modifications were strongly and differentially affected by the increased warming scenarios. Comparing transcriptomic profiles from gonads, mature gametes, and early embryonic stages showed sex-specific accumulation and temperature sensitivity of several epigenetic actors. DNA methyltransferase induction was primarily maternally inherited (suggesting maternal control of remethylation), whereas induction of several histone-modifying enzymes was shaped by both parents. Importantly, massive, temperature-specific changes to the epigenetic landscape occurred in blastula, a critical stage for successful embryo development, which could, thus, translate to substantial consequences for offspring phenotype resilience in warming environments. In summary, our study identified key stages during gamete and embryo development with temperature-sensitive reprogramming and epigenetic gene regulation, reflecting potential “windows of opportunity” for adaptive epigenetic responses under future climate change