897 research outputs found
\u27Awakening the Sleeping Giant\u27: Re-Indigenization Principles for Transforming Biodiversity Conservation in Canada and Beyond
Precipitous declines in biodiversity threaten planetary boundaries, requiring transformative changes to conservation. Colonial systems have decimated species and ecosystems and dispossessed Indigenous Peoples of their rights, territories, and livelihoods. Despite these challenges, Indigenous governed lands retain a large proportion of biodiversity-rich landscapes. Indigenous Peoples have stewarded the land in ways that support people and nature in respectful relationship. Biodiversity conservation and resurgence of Indigenous autonomies are mutually compatible aims. To work towards these aims requires significant transformation in conservation and re-Indigenization. Key to both are systems that value people and nature in all their diversity and relationships. This paper introduces Indigenous principles for re-Indigenizing conservation: (i) embracing Indigenous worldviews of ecologies and Mâs-it Noâkmaq, (ii) learning from Indigenous languages of the land, (iii) Natural laws and Netukulimk, (iv) correct relationships, (v) total reflection and truth, (vi) Etuaptmumkââtwo-eyed seeing,â and âstrong like two peopleâ, and (vii) âstory-telling/ story-listeningâ. Although the principles derive primarily from a Miâkmaw worldview, many are common to diverse Indigenous ways of knowing. Achieving the massive effort required for biodiversity conservation in Canada will entail transformations in worldviews and ways of thinking and bold, proactive actions, not solely as means but as ongoing imperatives
Genesis and development of an interfluvial peatland in the central Congo Basin since the Late Pleistocene
The central Congo Basin contains the largest known peatland complex in the tropics. Here we present a detailed multi-proxy record from a peat core, CEN-17.4, from the centre of a 45 km wide interfluvial peatland (Ekolongouma), the first record of its kind from the central Congo peatlands. We use pollen, charcoal, sedimentological and geochemical data to reconstruct the site's history from the late Pleistocene to the present day. Peat began accumulating at the centre of the peatland âŒ19,600 cal BP (âŒ17,500â20,400 cal BP, 95% confidence interval), and between âŒ9500 (9430â9535 cal BP) and 10,500 (10,310â10,660 cal BP) cal BP towards the margins. Pollen data from the peatland centre show that an initial grass- and sedge-dominated vegetation, which burned frequently, was replaced by a Manilkara-type dominated flooded forest at âŒ12,640 cal BP, replaced in turn by a more mixed swamp forest at âŒ9670 cal BP. Mixed swamp forest vegetation has persisted to the present day, with variations in composition and canopy openness likely caused at least in part by changes in palaeo-precipitation. Stable isotope data (ÎŽDn-C29-v&icecorr) indicate a large reduction in precipitation beginning âŒ5000 and peaking âŒ2000 cal BP, associated with the near-complete mineralization of several metres of previously accumulated peat and with a transition to a drier, more heliophilic swamp forest assemblage, likely with a more open canopy. Although the peatland and associated vegetation recovered from this perturbation, the strong response to this climatic event underlines the ecosystem's sensitivity to changes in precipitation. We find no conclusive evidence for anthropogenic activity in our record; charcoal is abundant only in the Pleistocene part of the record and may reflect natural rather than anthropogenic fires. We conclude that autogenic succession and variation in the amount and seasonality of precipitation have been the most important drivers of ecological change in this peatland since the late Pleistocene
Surface free energy of polyurethane coatings with improved hydrophobicity
The polarity of polyurethane coats was studied on the basis of the goniometric method for determination of wetting angle values, on the basis of calculated surface free energy (SFE) values by the van OssâGood and OwensâWendt methods, and on the basis of polarity measurements with the use of the 1H NMR spectra. Test polyurethanes were synthesised in the reaction of methylene diphenyl 4,4âČ-diisocyanate (MDI) or 3-izocyanatomethyl â3,5,5- trimethylcyclohexyl isocyanate (IPDI) and polyoxyethylene glycols or polyesters poly(Δ-caprolactone) diols and poly(ethyleneadipate) diol with different molecular weights, and some diols as chain extenders, in dioxane. The type of raw material was found to significantly affect the phase structure of the obtained polyurethane elastomers and to control physical interactions within those structures, thus influencing the SFE values. Fundamental reduction in the SFE value of a coating below 28 mJ/m2 was achieved by the use of 2,2,3,3-tetrafluoro-1,4-butanediol as the urethane prepolymer chain extender
Chemopreventive potential of ÎČ-Sitosterol in experimental colon cancer model - an In vitro and In vivo study
<p>Abstract</p> <p>Background</p> <p><it>Asclepias curassavica </it>Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of ÎČ-sitosterol isolated from <it>A. curassavica </it>in colon cancer, using <it>in vitro </it>and <it>in vivo </it>models.</p> <p>Methods</p> <p>The active molecule was isolated, based upon bioassay guided fractionation, and identified as ÎČ-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its <it>in vitro </it>antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of ÎČ-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of ÎČ-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with ÎČ-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w.</p> <p>Results</p> <p>ÎČ-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC<sub>50 </sub>266.2 ÎŒM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of ÎČ-catenin and PCNA antigens in human colon cancer cells. ÎČ-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects.</p> <p>Conclusion</p> <p>We found doses of 10-20 mg/kg b.w. ÎČ-sitosterol to be effective for future <it>in vivo </it>studies. ÎČ-sitosterol had chemopreventive potential by virtue of its radical quenching ability <it>in vitro</it>, with minimal toxicity to normal cells. It also attenuated ÎČ-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis.</p
Simulating carbon accumulation and loss in the central Congo peatlands
Peatlands of the central Congo Basin have accumulated carbon over millennia. They currently store some 29 billion tonnes of carbon in peat. However, our understanding of the controls on peat carbon accumulation and loss and the vulnerability of this stored carbon to climate change is in its infancy. Here we present a new model of tropical peatland development, DigiBog_Congo, that we use to simulate peat carbon accumulation and loss in a rain-fed interfluvial peatland that began forming ~20,000 calendar years Before Present (cal. yr BP, where âpresentâ is 1950 CE). Overall, the simulated age-depth curve is in good agreement with palaeoenvironmental reconstructions derived from a peat core at the same location as our model simulation. We find two key controls on long-term peat accumulation: water at the peat surface (surface wetness) and the very slow anoxic decay of recalcitrant material. Our main simulation shows that between the Late Glacial and early Holocene there were several multidecadal periods where net peat and carbon gain alternated with net loss. Later, a climatic dry phase beginning ~5200 cal. yr BP caused the peatland to become a long-term carbon source from ~3975 to 900 cal. yr BP. Peat as old as ~7000 cal. yr BP was decomposed before the peatland's surface became wetter again, suggesting that changes in rainfall alone were sufficient to cause a catastrophic loss of peat carbon lasting thousands of years. During this time, 6.4 m of the column of peat was lost, resulting in 57% of the simulated carbon stock being released. Our study provides an approach to understanding the future impact of climate change and potential land-use change on this vulnerable store of carbon
Assessment of function and clinical utility of alcohol and other drug web sites: An observational, qualitative study
Background The increasing popularity and use of the internet makes it an attractive option for providing health information and treatment, including alcohol/other drug use. There is limited research examining how people identify and access information about alcohol or other drug (AOD) use online, or how they assess the usefulness of the information presented. This study examined the strategies that individuals used to identify and navigate a range of AOD websites, along with the attitudes concerning presentation and content. Methods Members of the general community in Brisbane and Roma (Queensland, Australia) were invited to participate in a 30-minute search of the internet for sites related to AOD use, followed by a focus group discussion. Fifty one subjects participated in the study across nine focus groups. Results Participants spent a maximum of 6.5 minutes on any one website, and less if the user was under 25 years of age. Time spent was as little as 2 minutes if the website was not the first accessed. Participants recommended that AOD-related websites should have an engaging home or index page, which quickly and accurately portrayed the siteâs objectives, and provided clear site navigation options. Website content should clearly match the title and description of the site that is used by internet search engines. Participants supported the development of a portal for AOD websites, suggesting that it would greatly facilitate access and navigation. Treatment programs delivered online were initially viewed with caution. This appeared to be due to limited understanding of what constituted online treatment, including its potential efficacy. Conclusions A range of recommendations arise from this study regarding the design and development of websites, particularly those related to AOD use. These include prudent use of text and information on any one webpage, the use of graphics and colours, and clear, uncluttered navigation options. Implications for future website development are discussed
Transition from children's to adult services for adolescents/young adults with life-limiting conditions : developing realist programme theory through an international comparison
Abstract
Background
Managing transition of adolescents/young adults with life-limiting conditions from childrenâs to adult services has become a global health and social care issue. Suboptimal transitions from childrenâs to adult services can lead to measurable adverse outcomes. Interventions are emerging but there is little theory to guide service developments aimed at improving transition. The Transition to Adult Services for Young Adults with Life-limiting conditions (TAYSL study) included development of the TASYL Transition Theory, which describes eight interventions which can help prepare services and adolescents/young adults with life-limiting conditions for a successful transition. We aimed to assess the usefulness of the TASYL Transition Theory in a Canadian context to identify interventions, mechanisms and contextual factors associated with a successful transition from childrenâs to adult services for adolescents/young adults; and to discover new theoretical elements that might modify the TASYL Theory.
Methods
A cross-sectional survey focused on organisational approaches to transition was distributed to three organisations providing services to adolescents with life-limiting conditions in Toronto, Canada. This data was mapped to the TASYL Transition Theory to identify corresponding and new theoretical elements.
Results
Invitations were sent to 411 potentially eligible health care professionals with 56 responses from across the three participating sites. The results validated three of the eight interventions: early start to the transition process; developing adolescent/young adult autonomy; and the role of parents/carers; with partial support for the remaining five. One new intervention was identified: effective communication between healthcare professionals and the adolescent/young adult and their parents/carers. There was also support for contextual factors including those related to staff knowledge and attitudes, and a lack of time to provide transition services centred on the adolescent/young adult. Some mechanisms were supported, including the adolescent/young adult gaining confidence in relationships with service providers and in decision-making.
Conclusions
The Transition Theory travelled well between Ireland and Toronto, indicating its potential to guide both service development and research in different contexts. Future research could include studies with adult service providers; qualitative work to further explicate mechanisms and contextual factors; and use the theory prospectively to develop and test new or modified interventions to improve transition
Structural and Spectroscopic Analysis of the Kinase Inhibitor Bosutinib and an Isomer of Bosutinib Binding to the Abl Tyrosine Kinase Domain
Chronic myeloid leukemia (CML) is caused by the kinase activity of the BCR-Abl fusion protein. The Abl inhibitors imatinib, nilotinib and dasatinib are currently used to treat CML, but resistance to these inhibitors is a significant clinical problem. The kinase inhibitor bosutinib has shown efficacy in clinical trials for imatinib-resistant CML, but its binding mode is unknown. We present the 2.4 Ă
structure of bosutinib bound to the kinase domain of Abl, which explains the inhibitor's activity against several imatinib-resistant mutants, and reveals that similar inhibitors that lack a nitrile moiety could be effective against the common T315I mutant. We also report that two distinct chemical compounds are currently being sold under the name âbosutinibâ, and report spectroscopic and structural characterizations of both. We show that the fluorescence properties of these compounds allow inhibitor binding to be measured quantitatively, and that the infrared absorption of the nitrile group reveals a different electrostatic environment in the conserved ATP-binding sites of Abl and Src kinases. Exploiting such differences could lead to inhibitors with improved selectivity
Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)
Using a sample of 122 million Upsilon(3S) events recorded with the BaBar
detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for
the spin-singlet partner of the P-wave chi_{bJ}(1P) states in the
sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We
observe an excess of events above background in the distribution of the recoil
mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width
of the observed signal is consistent with experimental resolution, and its
significance is 3.1sigma, including systematic uncertainties. We obtain the
value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching
fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).Comment: 8 pages, 4 postscript figures, submitted to Phys. Rev. D (Rapid
Communications
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