126 research outputs found

    Coherent Optical Spectroscopy Of Molecules And Molecular Beams

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    This paper presents our recent work on coherent optical spectroscopy of molecules and molecular beams. The theory for these nonlinear optical effects is summarized and related to the measurements in the gas phase and in the condensed phase. Finally, we discuss the importance of these methods, which disentangle the inhomogeneous optical resonances, in understanding nonradiative and optical dephasing processes

    Coherent Optical Spectroscopy Of Molecules And Molecular Beams

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    This paper presents our recent work on coherent optical spectroscopy of molecules and molecular beams. The theory for these nonlinear optical effects is summarized and related to the measurements in the gas phase and in the condensed phase. Finally, we discuss the importance of these methods, which disentangle the inhomogeneous optical resonances, in understanding nonradiative and optical dephasing processes

    Linking global drivers of agricultural trade to on-the-ground impacts on biodiversity.

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    Consumption of globally traded agricultural commodities like soy and palm oil is one of the primary causes of deforestation and biodiversity loss in some of the world's most species-rich ecosystems. However, the complexity of global supply chains has confounded efforts to reduce impacts. Companies and governments with sustainability commitments struggle to understand their own sourcing patterns, while the activities of more unscrupulous actors are conveniently masked by the opacity of global trade. We combine state-of-the-art material flow, economic trade, and biodiversity impact models to produce an innovative approach for understanding the impacts of trade on biodiversity loss and the roles of remote markets and actors. We do this for the production of soy in the Brazilian Cerrado, home to more than 5% of the world´s species. Distinct sourcing patterns of consumer countries and trading companies result in substantially different impacts on endemic species. Connections between individual buyers and specific hot spots explain the disproportionate impacts of some actors on endemic species and individual threatened species, such as the particular impact of European Union consumers on the recent habitat losses for the iconic giant anteater (Myrmecophaga tridactyla). In making these linkages explicit, our approach enables commodity buyers and investors to target their efforts much more closely to improve the sustainability of their supply chains in their sourcing regions while also transforming our ability to monitor the impact of such commitments over time.UK Global Food Security programme (Project 304 BB/N02060X/1

    Environmental Costs of Government-Sponsored Agrarian Settlements in Brazilian Amazonia

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    Brazil has presided over the most comprehensive agrarian reform frontier colonization program on Earth, in which ~1.2 million settlers have been translocated by successive governments since the 1970's, mostly into forested hinterlands of Brazilian Amazonia. These settlements encompass 5.3% of this ~5 million km2 region, but have contributed with 13.5% of all land conversion into agropastoral land uses. The Brazilian Federal Agrarian Agency (INCRA) has repeatedly claimed that deforestation in these areas largely predates the sanctioned arrival of new settlers. Here, we quantify rates of natural vegetation conversion across 1911 agrarian settlements allocated to 568 Amazonian counties and compare fire incidence and deforestation rates before and after the official occupation of settlements by migrant farmers. The timing and spatial distribution of deforestation and fires in our analysis provides irrefutable chronological and spatially explicit evidence of agropastoral conversion both inside and immediately outside agrarian settlements over the last decade. Deforestation rates are strongly related to local human population density and road access to regional markets. Agrarian settlements consistently accelerated rates of deforestation and fires, compared to neighboring areas outside settlements, but within the same counties. Relocated smallholders allocated to forest areas undoubtedly operate as pivotal agents of deforestation, and most of the forest clearance occurs in the aftermath of government-induced migration

    Skin color-specific and spectrally-selective naked-eye dosimetry of UVA, B and C radiations

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    Spectrally–selective monitoring of ultraviolet radiations (UVR) is of paramount importance across diverse fields, including effective monitoring of excessive solar exposure. Current UV sensors cannot differentiate between UVA, B, and C, each of which has a remarkably different impact on human health. Here we show spectrally selective colorimetric monitoring of UVR by developing a photoelectrochromic ink that consists of a multi-redox polyoxometalate and an e− donor. We combine this ink with simple components such as filter paper and transparency sheets to fabricate low-cost sensors that provide naked-eye monitoring of UVR, even at low doses typically encountered during solar exposure. Importantly, the diverse UV tolerance of different skin colors demands personalized sensors. In this spirit, we demonstrate the customized design of robust real-time solar UV dosimeters to meet the specific need of different skin phototypes. These spectrally–selective UV sensors offer remarkable potential in managing the impact of UVR in our day-to-day life

    Epigenetic regulation of CD44 in Hodgkin and non-Hodgkin lymphoma

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    <p>Abstract</p> <p>Background</p> <p>Epigenetic inactivation of tumor suppressor genes (TSG) by promoter CpG island hypermethylation is a hallmark of cancer. To assay its extent in human lymphoma, methylation of 24 TSG was analyzed in lymphoma-derived cell lines as well as in patient samples.</p> <p>Methods</p> <p>We screened for TSG methylation using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in 40 lymphoma-derived cell lines representing anaplastic large cell lymphoma, Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), Hodgkin lymphoma and mantle cell lymphoma (MCL) as well as in 50 primary lymphoma samples. The methylation status of differentially methylated <it>CD44 </it>was verified by methylation-specific PCR and bisulfite sequencing. Gene expression of <it>CD44 </it>and its reactivation by DNA demethylation was determined by quantitative real-time PCR and on the protein level by flow cytometry. Induction of apoptosis by anti-CD44 antibody was analyzed by annexin-V/PI staining and flow cytometry.</p> <p>Results</p> <p>On average 8 ± 2.8 of 24 TSG were methylated per lymphoma cell line and 2.4 ± 2 of 24 TSG in primary lymphomas, whereas 0/24 TSG were methylated in tonsils and blood mononuclear cells from healthy donors. Notably, we identified that <it>CD44 </it>was hypermethylated and transcriptionally silenced in all BL and most FL and DLBCL cell lines, but was usually unmethylated and expressed in MCL cell lines. Concordant results were obtained from primary lymphoma material: <it>CD44 </it>was not methylated in MCL patients (0/11) whereas <it>CD44 </it>was frequently hypermethylated in BL patients (18/29). In cell lines with <it>CD44 </it>hypermethylation, expression was re-inducible at mRNA and protein levels by treatment with the DNA demethylating agent 5-Aza-2'-deoxycytidine, confirming epigenetic regulation of <it>CD44</it>. CD44 ligation assays with a monoclonal anti-CD44 antibody showed that CD44 can mediate apoptosis in CD44<sup>+ </sup>lymphoma cells. <it>CD44 </it>hypermethylated, CD44<sup>- </sup>lymphoma cell lines were consistently resistant towards anti-CD44 induced apoptosis.</p> <p>Conclusion</p> <p>Our data show that <it>CD44 </it>is epigenetically regulated in lymphoma and undergoes <it>de novo </it>methylation in distinct lymphoma subtypes like BL. Thus <it>CD44 </it>may be a promising new epigenetic marker for diagnosis and a potential therapeutic target for the treatment of specific lymphoma subtypes.</p

    Spatial and temporal dimensions of landscape fragmentation across the Brazilian Amazon

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    The Brazilian Amazon in the past decades has been suffering severe landscape alteration, mainly due to anthropogenic activities, such as road building and land clearing for agriculture. Using a high-resolution time series of land cover maps (classified as mature forest, non-forest, secondary forest) spanning from 1984 through 2011, and four uncorrelated fragmentation metrics (edge density, clumpiness index, area-weighted mean patch size and shape index), we examined the temporal and spatial dynamics of forest fragmentation in three study areas across the Brazilian Amazon (Manaus, Santarém and Machadinho d’Oeste), inside and outside conservation units. Moreover, we compared the impacts on the landscape of: (1) different land uses (e.g. cattle ranching, crop production), (2) occupation processes (spontaneous vs. planned settlements) and (3) implementation of conservation units. By 2010/2011, municipalities located along the Arc of Deforestation had more than 55% of the remaining mature forest strictly confined to conservation units. Further, the planned settlement showed a higher rate of forest loss, a more persistent increase in deforested areas and a higher relative incidence of deforestation inside conservation units. Distinct agricultural activities did not lead to significantly different landscape structures; the accessibility of the municipality showed greater influence in the degree of degradation of the landscapes. Even with a high proportion of the landscapes covered by conservation units, which showed a strong inhibitory effect on forest fragmentation, we show that dynamic agriculturally driven economic activities, in municipalities with extensive road development, led to more regularly shaped, heavily fragmented landscapes, with higher densities of forest edge

    Strategies for tropical forest protection and sustainable supply chains: challenges and opportunities for alignment with the UN sustainable development goals

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    Governance for sustainable development increasingly involves diverse stakeholder groups, with the promise of enhanced legitimacy and effectiveness in decision-making and implementation. The UN sustainable development goals (SDGs) emphasise the important role of multiple (non-state) actors, including businesses and non-governmental organisations, including in efforts to ensure the sustainability of supply chains, and to reduce tropical deforestation and forest degradation. This paper critically analyses sustainability strategies to examine how the UN SDG agendas related to ‘sustainable supply chains’ and ‘tropical forest protection’ are framed and enacted by two contrasting non-state actors: (1) Instituto Centro de Vida (ICV), an NGO in Brazil working to address deforestation, including by supporting farmers to produce commodities, and (2) Unilever, a global consumer goods manufacturer and major buyer of such commodities. By identifying areas of variability in the discursive techniques used by ICV and Unilever, we unearth particular power dynamics that can shape the processes and outcomes of sustainability strategies. This paper finds that the two organisations use diverse strategies at different levels of governance, both participate actively in multi-stakeholder forums to advance their organisations’ goals, but have divergent framings of ‘sustainability’. Despite being considered ‘non-state’ actors, the strategies of the two organisations examined both reflect, and influence, the structural effects of the state in the implementation of non-state organisations’ strategies, and progress towards the SDGs. Although there is alignment of certain strategies related to tropical forest protection, in some cases, there is a risk that more sustainable, alternative approaches to governing forests and supply chains may be excluded

    Inhibition of the Nuclear Import of Cubitus Interruptus by Roadkill in the Presence of Strong Hedgehog Signal

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    Hedgehog (Hh) signalling plays an important role in various developmental processes by activating the Cubitus interruptus (Ci)/Glioblastoma (Gli) family of transcription factors. In the process of proper pattern formation, Ci activity is regulated by multiple mechanisms, including processing, trafficking, and degradation. However, it remains elusive how Ci distinctly recognizes the strong and moderate Hh signals. Roadkill (Rdx) induces Ci degradation in the anterior region of the Drosophila wing disc. Here, we report that Rdx inhibited Ci activity by two different mechanisms. In the region abutting the anterior/posterior boundary, which receives strong Hh signal, Rdx inhibited the nuclear import of Ci by releasing importin α3 from Ci. In this region, Rdx negatively regulated the expression of transcription factor Knot/Collier. In farther anterior regions receiving moderate levels of Hh signal, Rdx induced Ci degradation, as reported previously. Thus, two different mechanisms by which Rdx negatively regulates Ci may play an important role in the fine-tuning of Hh responses
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