4,303 research outputs found
First HighâResolution Benthic Habitat Map From the Greenland Shelf (Disko Bay Pilot Study)
A healthy ocean where marine habitats and ecosystems are mapped and protected is one of the UN's Sustainable Development Goals to sustainably use marine resources. Our study presents the first high-resolution benthic habitat map from Greenland integrating analyses of multibeam bathymetry and backscatter data, and ground-truth data including video sled, drop camera and day grab. The pilot area of 30 Ă 20 km is located on the continental shelf in central Disko Bay, West Greenland and all data were collected in a single, 10-day survey. Multibeam bathymetry data were gridded to a 10 Ă 10 m resolution, whereas backscatter mosaic was built from a 1 Ă 1 m grid cell to obtain higher resolution manifestation of seafloor properties. Ground-truth data consisted of 14 video transects, 17 drop camera deployments, and 17 sediment samples. Our results were verified with the published shallow seismic and vibrocore data from the Disko Bay region to link the geological background with the sedimentary environment. We distinguished five physical habitats in the area, based on the distribution of sediment types, water depth with general water masses and morphology. In addition, numerous gas seeps alongside pockmarks were observed in the area, as well as recent iceberg ploughmarks. The identified habitats were associated with two basic communities of benthic fauna, linked primarily to the distribution of sediments and representing hard bottom habitats (sessile fauna) and soft bottom habitats (shrimp/polychaetes). Our study is the first step toward mapping the entire seafloor of Disko Bay to provide a scientific context for the management of seafloor and marine resources
Regulation of caspase-3 processing by cIAP2 controls the switch between pro-inflammatory activation and cell death in microglia.
Cell Death and Disease is an open-access journal published by Nature Publishing Group. This work is licensed under a Creative Commons Attribution 4.0 International Licence. The images or other third party material in this article are included in the articleâs Creative Commons licence, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons licence, users will need to obtain permission from the licence holder to reproduce the material.The activation of microglia, resident immune cells of the central nervous system, and inflammation-mediated neurotoxicity are typical features of neurodegenerative diseases, for example, Alzheimer's and Parkinson's diseases. An unexpected role of caspase-3, commonly known to have executioner role for apoptosis, was uncovered in the microglia activation process. A central question emerging from this finding is what prevents caspase-3 during the microglia activation from killing those cells? Caspase-3 activation occurs as a two-step process, where the zymogen is first cleaved by upstream caspases, such as caspase-8, to form intermediate, yet still active, p19/p12 complex; thereafter, autocatalytic processing generates the fully mature p17/p12 form of the enzyme. Here, we show that the induction of cellular inhibitor of apoptosis protein 2 (cIAP2) expression upon microglia activation prevents the conversion of caspase-3 p19 subunit to p17 subunit and is responsible for restraining caspase-3 in terms of activity and subcellular localization. We demonstrate that counteracting the repressive effect of cIAP2 on caspase-3 activation, using small interfering RNA targeting cIAP2 or a SMAC mimetic such as the BV6 compound, reduced the pro-inflammatory activation of microglia cells and promoted their death. We propose that the different caspase-3 functions in microglia, and potentially other cell types, reside in the active caspase-3 complexes formed. These results also could indicate cIAP2 as a possible therapeutic target to modulate microglia pro-inflammatory activation and associated neurotoxicity observed in neurodegenerative disorders
Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions
Background
Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals.
Results
Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall.
Conclusions
The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions
Paleoclimate Implications for Human-Made Climate Change
Paleoclimate data help us assess climate sensitivity and potential human-made
climate effects. We conclude that Earth in the warmest interglacial periods of
the past million years was less than 1{\deg}C warmer than in the Holocene.
Polar warmth in these interglacials and in the Pliocene does not imply that a
substantial cushion remains between today's climate and dangerous warming, but
rather that Earth is poised to experience strong amplifying polar feedbacks in
response to moderate global warming. Thus goals to limit human-made warming to
2{\deg}C are not sufficient - they are prescriptions for disaster. Ice sheet
disintegration is nonlinear, spurred by amplifying feedbacks. We suggest that
ice sheet mass loss, if warming continues unabated, will be characterized
better by a doubling time for mass loss rate than by a linear trend. Satellite
gravity data, though too brief to be conclusive, are consistent with a doubling
time of 10 years or less, implying the possibility of multi-meter sea level
rise this century. Observed accelerating ice sheet mass loss supports our
conclusion that Earth's temperature now exceeds the mean Holocene value. Rapid
reduction of fossil fuel emissions is required for humanity to succeed in
preserving a planet resembling the one on which civilization developed.Comment: 32 pages, 9 figures; final version accepted for publication in
"Climate Change at the Eve of the Second Decade of the Century: Inferences
from Paleoclimate and Regional Aspects: Proceedings of Milutin Milankovitch
130th Anniversary Symposium" (eds. Berger, Mesinger and Sijaci
Identification of a Danish breast/ovarian cancer family double heterozygote for BRCA1 and BRCA2 mutations
Mutations in the two breast cancer susceptibility genes BRCA1 and BRCA2 are associated with increased risk of breast and ovarian cancer. Patients with mutations in both genes are rarely reported and often involve Ashkenazi founder mutations. Here we report the first identification of a Danish breast and ovarian cancer family heterozygote for mutations in the BRCA1 and BRCA2 genes. The BRCA1 nucleotide 5215GÂ >Â A/c.5096GÂ >Â A mutation results in the missense mutation Arg1699Gln, while the BRCA2 nucleotide 859Â +Â 4AÂ >Â G/c.631Â +Â 4AÂ >Â G is novel. Exon trapping experiments and reverse transcriptase (RT)âPCR analysis revealed that the BRCA2 mutation results in skipping of exon 7, thereby introducing a frameshift and a premature stop codon. We therefore classify the mutation as disease causing. Since the BRCA1 Arg1699Gln mutation is also suggested to be disease-causing, we consider this family double heterozygote for BRCA1 and BRCA2 mutations
Cross validation of bi-modal health-related stress assessment
This study explores the feasibility of objective and ubiquitous stress assessment. 25 post-traumatic stress disorder patients participated in a controlled storytelling (ST) study and an ecologically valid reliving (RL) study. The two studies were meant to represent an early and a late therapy session, and each consisted of a "happy" and a "stress triggering" part. Two instruments were chosen to assess the stress level of the patients at various point in time during therapy: (i) speech, used as an objective and ubiquitous stress indicator and (ii) the subjective unit of distress (SUD), a clinically validated Likert scale. In total, 13 statistical parameters were derived from each of five speech features: amplitude, zero-crossings, power, high-frequency power, and pitch. To model the emotional state of the patients, 28 parameters were selected from this set by means of a linear regression model and, subsequently, compressed into 11 principal components. The SUD and speech model were cross-validated, using 3 machine learning algorithms. Between 90% (2 SUD levels) and 39% (10 SUD levels) correct classification was achieved. The two sessions could be discriminated in 89% (for ST) and 77% (for RL) of the cases. This report fills a gap between laboratory and clinical studies, and its results emphasize the usefulness of Computer Aided Diagnostics (CAD) for mental health care
Smoking and health-related quality of life in English general population: Implications for economic evaluations
Copyright @ 2012 Vogl et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Little is known as to how health-related quality of life (HRQoL) when measured by generic instruments such as EQ-5D differ across smokers, ex-smokers and never-smokers in the general population; whether the overall pattern of this difference remain consistent in each domain of HRQoL; and what implications this variation, if any, would have for economic evaluations of tobacco control interventions. Methods: Using the 2006 round of Health Survey for England data (n = 13,241), this paper aims to examine the impact of smoking status on health-related quality of life in English population. Depending upon the nature of the EQ-5D data (i.e. tariff or domains), linear or logistic regression models were fitted to control for biology, clinical conditions, socio-economic background and lifestyle factors that an individual may have regardless of their smoking status. Age- and gender-specific predicted values according to smoking status are offered as the potential 'utility' values to be used in future economic evaluation models. Results: The observed difference of 0.1100 in EQ-5D scores between never-smokers (0.8839) and heavy-smokers (0.7739) reduced to 0.0516 after adjusting for biological, clinical, lifestyle and socioeconomic conditions. Heavy-smokers, when compared with never-smokers, were significantly more likely to report some/severe problems in all five domains - mobility (67%), self-care (70%), usual activity (42%), pain/discomfort (46%) and anxiety/depression (86%) -. 'Utility' values by age and gender for each category of smoking are provided to be used in the future economic evaluations. Conclusion: Smoking is significantly and negatively associated with health-related quality of life in English general population and the magnitude of this association is determined by the number of cigarettes smoked. The varying degree of this association, captured through instruments such as EQ-5D, may need to be fed into the design of future economic evaluations where the intervention being evaluated affects (e.g. tobacco control) or is affected (e.g. treatment for lung cancer) by individual's (or patients') smoking status
JLab Measurements of the 3He Form Factors at Large Momentum Transfers
The charge and magnetic form factors, FC and FM, of 3He have been extracted
in the kinematic range 25 fm-2 < Q2 < 61 fm-2 from elastic electron scattering
by detecting 3He recoil nuclei and electrons in coincidence with the High
Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The
measurements are indicative of a second diffraction minimum for the magnetic
form factor, which was predicted in the Q2 range of this experiment, and of a
continuing diffractive structure for the charge form factor. The data are in
qualitative agreement with theoretical calculations based on realistic
interactions and accurate methods to solve the three-body nuclear problem
Measurement of GEp/GMp in ep -> ep to Q2 = 5.6 GeV2
The ratio of the electric and magnetic form factors of the proton, GEp/GMp,
was measured at the Thomas Jefferson National Accelerator Facility (JLab) using
the recoil polarization technique. The ratio of the form factors is directly
proportional to the ratio of the transverse to longitudinal components of the
polarization of the recoil proton in the elastic
reaction. The new data presented in this article span the range 3.5 < Q2 < 5.6
GeV2 and are well described by a linear Q2 fit. Also, the ratio QF2p/F1p
reaches a constant value above Q2=2 GeV2.Comment: 6 pages, 4 figures Added two names to the main author lis
Cerebrospinal fluid HIV-1 RNA, intrathecal immunoactivation, and drug concentrations after treatment with a combination of saquinavir, nelfinavir, and two nucleoside analogues: the M61022 study
BACKGROUND: The way various antiretroviral drugs and drug combinations affect HIV-1 infection in the central nervous system is still largely unknown. The aim of this study was to determine the cerebrospinal fluid (CSF) steady-state concentrations of saquinavir and nelfinavir in relation to plasma concentrations, and to study their effect in combination with two nucleoside reverse transcriptase inhibitors (NRTIs) on CSF viral loads, intrathecal immunoactivation, and blood-brain barrier integrity. METHODS: Paired CSF and plasma samples from 8 antiretroviral-naĂŻve HIV-1 infected patients starting combination therapy with saquinavir, nelfinavir, and two nucleoside analogues were collected prior to treatment, and again after approximately 12 and 48 weeks of antiretroviral therapy. Additional plasma samples were taken at weeks 2, 4, 8, 24, and 36. The concentrations of protease inhibitors were analysed, as were levels of HIV-1 RNA, CD4+ T-cell count, ÎČ2-microglobulin, neopterin, albumin ratio, IgG index, and monocytic cell count. RESULTS: None of the patients in the study presented with HIV-1 RNA < 50 copies/mL in CSF or plasma prior to treatment, compared to 5/7 at the end of the study. Signs of cell-mediated intrathecal immunoactivation, measured by neopterin and ÎČ2-microglobulin, decreased significantly in both CSF and serum, although only 1/7 reached normal CSF neopterin levels after 48 weeks of treatment. There was no significant reduction of albumin ratio, IgG index or CSF monocytic cell count. Saquinavir median (range) concentrations were < 2.5 (< 2.5â96.0) nM unbound in plasma, and < 2.5 (< 2.5â9.0) nM total in CSF. Nelfinavir median (range) concentrations were 10.0 (< 2.0â31.0) nM unbound in plasma, and < 2.0 (< 2.0â23.0) nM total in CSF. Saquinavir and nelfinavir were detectable in 7/15 and 9/15 CSF samples, respectively. CONCLUSION: Saquinavir and nelfinavir, in combination with two NRTIs, decrease the CSF viral load and, to a lesser extent, intrathecal immunoactivation. We found reasonably high CSF concentrations of nelfinavir, but suboptimal concentrations of saquinavir
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