542 research outputs found
Trends in the Discovery of New Marine Natural Products from Invertebrates over the Last Two Decades – Where and What Are We Bioprospecting?
It is acknowledged that marine invertebrates produce bioactive natural products that may be useful for developing new drugs. By exploring untapped geographical sources and/or novel groups of organisms one can maximize the search for new marine drugs to treat human diseases. The goal of this paper is to analyse the trends associated with the discovery of new marine natural products from invertebrates (NMNPI) over the last two decades. The analysis considers different taxonomical levels and geographical approaches of bioprospected species. Additionally, this research is also directed to provide new insights into less bioprospected taxa and world regions. In order to gather the information available on NMNPI, the yearly-published reviews of Marine Natural Products covering 1990–2009 were surveyed. Information on source organisms, specifically taxonomical information and collection sites, was assembled together with additional geographical information collected from the articles originally describing the new natural product. Almost 10000 NMNPI were discovered since 1990, with a pronounced increase between decades. Porifera and Cnidaria were the two dominant sources of NMNPI worldwide. The exception was polar regions where Echinodermata dominated. The majority of species that yielded the new natural products belong to only one class of each Porifera and Cnidaria phyla (Demospongiae and Anthozoa, respectively). Increased bioprospecting efforts were observed in the Pacific Ocean, particularly in Asian countries that are associated with the Japan Biodiversity Hotspot and the Kuroshio Current. Although results show comparably less NMNPI from polar regions, the number of new natural products per species is similar to that recorded for other regions. The present study provides information to future bioprospecting efforts addressing previously unexplored taxonomic groups and/or regions. We also highlight how marine invertebrates, which in some cases have no commercial value, may become highly valuable in the ongoing search for new drugs from the sea
Spectral performance of SKA log-periodic antennas I: Mitigating spectral artefacts in SKA1-LOW 21 cm cosmology experiments
This paper is the first in a series of papers describing the impact of
antenna instrumental artefacts on the 21-cm cosmology experiments to be carried
out by the low frequency instrument (SKA1-LOW) of the Square Kilometre Array
telescope (SKA), i.e., the Cosmic Dawn (CD) and the Epoch of Reionization
(EoR). The smoothness of the passband response of the current log-periodic
antenna being developed for the SKA1-LOW is analyzed using numerical
electromagnetic simulations. The amplitude variations over the frequency range
are characterized using low-order polynomials defined locally, in order to
study the impact of the passband smoothness in the instrument calibration and
CD/EoR Science. A solution is offered to correct a fast ripple found at 60~MHz
during a test campaign at the SKA site at the Murchison Radio-astronomy
Observatory, Western Australia in September 2015 with a minor impact on the
telescope's performance and design. A comparison with the Hydrogen Epoch of
Reionization Array antenna is also shown demonstrating the potential use of the
SKA1-LOW antenna for the Delay Spectrum technique to detect the EoR
Semi-local quantum liquids
Gauge/gravity duality applied to strongly interacting systems at finite
density predicts a universal intermediate energy phase to which we refer as a
semi-local quantum liquid. Such a phase is characterized by a finite spatial
correlation length, but an infinite correlation time and associated nontrivial
scaling behavior in the time direction, as well as a nonzero entropy density.
For a holographic system at a nonzero chemical potential, this unstable phase
sets in at an energy scale of order of the chemical potential, and orders at
lower energies into other phases; examples include superconductors and
antiferromagnetic-type states. In this paper we give examples in which it also
orders into Fermi liquids of "heavy" fermions. While the precise nature of the
lower energy state depends on the specific dynamics of the individual system,
we argue that the semi-local quantum liquid emerges universally at intermediate
energies through deconfinement (or equivalently fractionalization). We also
discuss the possible relevance of such a semi-local quantum liquid to heavy
electron systems and the strange metal phase of high temperature cuprate
superconductors.Comment: 31 pages, 7 figure
Strategic Planning for Local Tourism Destinations: An Analysis of Tourism
This paper reports on a study of the planning practices of local tourism destinations. The tourism plans of 30 local tourism destinations in Queensland, Australia were analyzed to determine the extent to which sustainability principles, namely strategic planning and stakeholder participation, were integrated into the planning process. Utilizing a tourism planning process evaluation instrument developed by Simpson (2001), it was found that local tourism destinations are not integrating sustainability principles in their planning processes
Combination disease-modifying treatment in spinal muscular atrophy: A proposed classification
We sought to devise a rational, systematic approach for defining/grouping survival motor neuron-targeted disease-modifying treatment (DMT) scenarios. The proposed classification is primarily based on a two-part differentiation: initial DMT, and persistence/discontinuation of subsequent DMT(s). Treatment categories were identified: monotherapy add-on, transient add-on, combination with onasemnogene abeparvovec, bridging to onasemnogene abeparvovec, and switching to onasemnogene abeparvovec. We validated this approach by applying the classification to the 443 patients currently in the RESTORE registry and explored the demographics of these different groups of patients. This work forms the basis to explore the safety and efficacy profile of the different combinations of DMT in SMA
Semi-Holographic Fermi Liquids
We show that the universal physics of recent holographic non-Fermi liquid
models is captured by a semi-holographic description, in which a dynamical
boundary field is coupled to a strongly coupled conformal sector having a
gravity dual. This allows various generalizations, such as a dynamical exponent
and lattice and impurity effects. We examine possible relevant deformations,
including multi-trace terms and spin-orbit effects. We discuss the matching
onto the UV theory of the earlier work, and an alternate description in which
the boundary field is integrated out.Comment: 26 pages, 4 figures; v2: typos corrected and report number adde
A spatial approach to combatting wildlife crime
Poaching can have devastating impacts on animal and plant numbers, and in many countries has reached crisis levels, with illegal hunters employing increasingly sophisticated techniques. We used data from an 8‐year study in Savé Valley Conservancy, Zimbabwe, to show how geographic profiling—a mathematical technique originally developed in criminology and recently applied to animal foraging and epidemiology—can be adapted for use in investigations of wildlife crime. The data set contained information on over 10,000 incidents of illegal hunting and the deaths of 6,454 wild animals. We used a subset of data for which the illegal hunters’ identities were known. Our model identified the illegal hunters’ home villages based on the spatial locations of the hunting incidences (e.g., snares). Identification of the villages was improved by manipulating the probability surface inside the conservancy to reflect the fact that although the illegal hunters mostly live outside the conservancy, the majority of hunting occurs inside the conservancy (in criminology terms, commuter crime). These results combined with rigorous simulations showed for the first time how geographic profiling can be combined with GIS data and applied to situations with more complex spatial patterns, for example, where landscape heterogeneity means some parts of the study area are less likely to be used (e.g., aquatic areas for terrestrial animals) or where landscape permeability differs (e.g., forest bats tend not to fly over open areas). More broadly, these results show how geographic profiling can be used to target antipoaching interventions more effectively and more efficiently and to develop management strategies and conservation plans in a range of conservation scenarios.TRAFFIC Southern and East Africa, the European Union, Wilderness Trust, Chicago Board of Trade, and the African Wildlife Conservation Fund.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1523-17392019-06-01hj2018Mammal Research InstituteZoology and Entomolog
Does sex influence the diagnostic evaluation of autism spectrum disorder in adults?
It is unknown whether sex influences the diagnostic evaluation of autism spectrum disorder, or whether male and female adults within the spectrum have different symptom profiles. This study reports sex differences in clinical outcomes for 1244 adults (935 males and 309 females) referred for autism spectrum disorder assessment. Significantly, more males (72%) than females (66%) were diagnosed with an autism spectrum disorder of any subtype (x2 = 4.09; p = 0.04). In high-functioning autism spectrum disorder adults (IQ > 70; N = 827), there were no significant sex differences in severity of socio-communicative domain symptoms. Males had significantly more repetitive behaviours/restricted interests than females (p = 0.001, d = 0.3). A multivariate analysis of variance indicated a significant interaction between autism spectrum disorder subtype (full-autism spectrum disorder/partial-autism spectrum disorder) and sex: in full-autism spectrum disorder, males had more severe socio-communicative symptoms than females; for partial-autism spectrum disorder, the reverse was true. There were no sex differences in prevalence of co-morbid psychopathologies. Sex influenced diagnostic evaluation in a clinical sample of adults with suspected autism spectrum disorder. The sexes may present with different manifestations of the autism spectrum disorder phenotype and differences vary by diagnostic subtype. Understanding and awareness of adult female repetitive behaviours/restricted interests warrant attention and sex-specific diagnostic assessment tools may need to be considered
Photoemission "experiments" on holographic superconductors
We study the effects of a superconducting condensate on holographic Fermi
surfaces. With a suitable coupling between the fermion and the condensate,
there are stable quasiparticles with a gap. We find some similarities with the
phenomenology of the cuprates: in systems whose normal state is a non-Fermi
liquid with no stable quasiparticles, a stable quasiparticle peak appears in
the condensed phase.Comment: 14 pages, 13 figures; v2: typos corrected and some clarification
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