17 research outputs found
TRY plant trait database â enhanced coverage and open access
Plant traitsâthe morphological, anatomical, physiological, biochemical and phenological characteristics of plantsâdetermine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traitsâalmost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Identification of in vitro and in vivo disconnects using transcriptomic data
Background: Integrating transcriptomic experiments within drug development is increasingly advocated for the early detection of toxicity. This is partly to reduce costs related to drug failures in the late, and expensive phases of clinical trials. Such an approach has proven useful both in the study of toxicology and carcinogenicity. However, general lack of translation of in vitro findings to in vivo systems remains one of the bottle necks in drug development. This paper proposes a method for identifying disconnected genes between in vitro and in vivo toxicogenomic rat experiments. The analytical framework is based on the joint modeling of dose-dependent in vitro and in vivo data using a fractional polynomial framework and biclustering algorithm. Results: Most disconnected genes identified belonged to known pathways, such as drug metabolism and oxidative stress due to reactive metabolites, bilirubin increase, glutathion depletion and phospholipidosis. We also identified compounds that were likely to induce disconnect in gene expression between in vitro and in vivotoxicogenomic rat experiments. These compounds include: sulindac and diclofenac (both linked to liver damage), naphtyl isothiocyanate (linked to hepatoxocity), indomethacin and naproxen (linked to gastrointestinal problem and damage of intestines). Conclusion: The results confirmed that there are important discrepancies between in vitro and in vivo toxicogenomic experiments. However, the contribution of this paper is to provide a tool to identify genes that are disconnected between the two systems. Pathway analysis of disconnected genes may improve our understanding of uncertainties in the mechanism of actions of drug candidates in humans, especially concerning the early detection of toxicity
Evidence for Parapatric Speciation in the Mormyrid Fish, Pollimyrus castelnaui (Boulenger, 1911), from the OkavangoâUpper Zambezi River Systems: P. marianne sp. nov., Defined by Electric Organ Discharges, Morphology and Genetics
We report on parapatric speciation in the mormyrid fish,Pollimyrus castelnaui (Boulenger, 1911), from the Okavango and the Upper Zambezi River systems. We recognise samples from the Zambezi River as a distinct species,
P. marianne, displaying an eastern phenotype of electric organ discharge (EOD) waveform (Type 3) that is distinct
from the western EOD phenotype (Type 1) observed in P. castelnaui samples from the neighbouring Okavango.
Samples from the geographically intermediate Kwando/Linyanti River (a tributary of the Zambezi that is also intermittently connected to the Okavango) presented a more variable third EOD phenotype (Type 2). In 13 out of 14
morphological characters studied, the Zambezi River samples differed significantly from P. castelnaui. Morphologically and in EOD characters, the Kwando/Linyanti fish are distinct from both P. castelnaui and P. marianne.
Sequence analysis of the mitochondrial cytochrome b gene unambiguously reveals that specimens from the Zambezi
River System form a well supported taxon which clearly differs from P. castelnaui from the Okavango (1.5â2.5%
sequence divergence).Within specimens from theKwandoâZambezi System some geographic differentiation can be
detected (nucleotide substitutions up to 0.6%); but groups cannot be resolved with certainty. Significant allozyme
differences were found between the Okavango and all other EOD types from the Upper Zambezi System, and, within the Zambezi System, between the Kwando (Type 2) and Zambezi (Type 3) individuals. The low Wrightâs fixation index values, the lack of fixed allele differences, and small genetic distances provide little evidence for speciation between groups within the Zambezi System, but moderate to great fixation index values and significant allele frequency differences were observed between the Okavango and the other fishes. It is concluded that within
the Zambezi System, differentiation between Kwando/Linyanti and Zambezi populations (as revealed by morphology and EOD waveform comparisons) is so recent that substantial genetic (allozyme and mitochondrial sequence)
differences could not have evolved, or were not detected
Effect of Skin Sensitizers on Inducible Nitric Oxide Synthase Expression and Nitric Oxide Production in Skin Dendritic Cells: Role of Different Immunosuppressive Drugs
Nitric oxide (NO) is involved in the pathogenesis of acute and chronic inflammatory
conditions, namely in allergic contact dermatitis (ACD). However, the mechanism by
which NO acts in ACD remains elusive. The present study focuses on the effects of different
contact sensitizers (2,4-dinitrofluorbenzene, 1,4-phenylenediamine, nickel sulfate),
the inactive analogue of DNFB, 2,4-dichloronitrobenzene, and two irritants
(sodium dodecyl sulphate and benzalkonium chloride) on the expression of the inducible
isoform of nitric oxide synthase (iNOS) and NO production in skin dendritic cells.
It was also studied the role of different immunosuppressive drugs on iNOS expression
and NO production. Only nickel sulfate increased the expression of iNOS and NO production
being these effects inhibited by dexamathasone. In contrast, cyclosporin A and
sirolimus, two other immunosuppressive drugs tested, did not affect iNOS expression
triggered by nickel
Amiodarone hydrochloride: enhancement of solubility and dissolution rate by solid dispersion technique
abstract Amiodarone HCl is an antiarrhythmic agent, which has low aqueous solubility and presents absorption problems. This study aimed to develop inclusion complexes containing hydrophilic carriers PEG 1500, 4000 and 6000 by fusion and kneading methods in order to evaluate the increase in solubility and dissolution rate of amiodarone HCl. The solid dispersion and physical mixtures were characterized by X-ray diffraction, FT-IR spectra, water solubility and dissolution profiles. Both methods and carriers increased the solubility of drug, however PEG 6000 enhanced the drug solubility in solid dispersion better than other carriers. Different media were evaluated for the solubility study, including distilled water, acid buffer pH 1.2, acetate buffer pH 4.5 and phosphate buffer pH 6.8 at 37 ÂșC. Based on the evaluation of the results obtained in the study phase solubility carriers PEG 4000 and PEG 6000 were selected for the preparation of the physical mixture and solid dispersion. All formulations were prepared at drug-carrier ratios of 1:1 to 1:10(w/w). The results of in vitro release studies indicated that the solid dispersion technique by fusion method in proportion of 1:10 (w/w) increased significantly the dissolution rate of the drug. X-ray diffraction studies showed reduced drug crystallinity in the solid dispersions. FT-IR demonstrated interactions between the drug and polymers
Avian palaeoneurology: Reflections on the eve of its 200th anniversary
In birds, the brain (especially the telencephalon) is remarkably developed, both in relative volume and complexity. Unlike in most early-branching sauropsids, the adults of birds and other archosaurs have a well-ossified neurocranium. In contrast to the situation in most of their reptilian relatives but similar to what can be seen in mammals, the brains of birds fit closely to the endocranial cavity so that their major external features are reflected in the endocasts. This makes birds a highly suitable group for palaeoneurological investigations. The first observation about the brain in a long-extinct bird was made in the first quarter of the 19th century. However, it was not until the 2000s and the application of modern imaging technologies that avian palaeoneurology really took off. Understanding how the mode of life is reflected in the external morphology of the brains of birds is but one of several future directions in which avian palaeoneurological research may extend. Although the number of fossil specimens suitable for palaeoneurological explorations is considerably smaller in birds than in mammals and will very likely remain so, the coming years will certainly witness a momentous strengthening of this rapidly growing field of research at the overlap between ornithology, palaeontology, evolutionary biology and neurosciences.This is a contribution to the research project CGL2017-89123-P funded by FEDER/Spanish Ministry of Science and Innovation State Research Agency. F. Knoll is an ARAID Senior Researcher and a member of the research group E04_17R FOCONTUR co-founded by the Government of Aragon Department of Innovation, Research and University and FEDER Aragon 2014-2020 âBuilding Europe from Aragonâ