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1.
Surv Geophys ; 40(4): 979-999, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31395994

RESUMO

Several upcoming satellite missions have core science requirements to produce data for accurate forest aboveground biomass mapping. Largely because of these mission datasets, the number of available biomass products is expected to greatly increase over the coming decade. Despite the recognized importance of biomass mapping for a wide range of science, policy and management applications, there remains no community accepted standard for satellite-based biomass map validation. The Committee on Earth Observing Satellites (CEOS) is developing a protocol to fill this need in advance of the next generation of biomass-relevant satellites, and this paper presents a review of biomass validation practices from a CEOS perspective. We outline the wide range of anticipated user requirements for product accuracy assessment and provide recommendations for the validation of biomass products. These recommendations include the collection of new, high-quality in situ data and the use of airborne lidar biomass maps as tools toward transparent multi-resolution validation. Adoption of community-vetted validation standards and practices will facilitate the uptake of the next generation of biomass products.

2.
J Phys Condens Matter ; 29(39): 395601, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28682301

RESUMO

The results of the magnetic, electron transport, heat capacity and heat conduction measurements on the new rhombohedral ternary compound Pr2Rh3Ge have been investigated. The synthesized polycrystalline compound was found to crystallize in the ternary ordered variant of the cubic Laves phase [Formula: see text]-type of structure with the space group R[Formula: see text]m, as previously reported. Pr2Rh3Ge exhibits a ferromagnetic behaviour below [Formula: see text] K, which was found to be unstable in low applied magnetic fields, revealing characteristics usually attributed to the long-range order. In the entire paramagnetic region electrical resistivity shows monotonous metallic conductivity character. We estimated that the Sommerfeld coefficient γ = 315 mJ/Pr-mol · [Formula: see text] of [Formula: see text] [Formula: see text]Ge is very large with comparison to ordinary metals which indicate the existence of heavy fermion behaviour of itinerant charge carriers at low temperatures or enhanced density of the quasi-particle state at the Fermi level. The crucial role of the crystalline electric field effects on the ground state properties of [Formula: see text] (J = 4) has been also observed. We think that the heavy fermion behaviour in [Formula: see text] [Formula: see text]Ge results from the dynamic low-lying crystal-field fluctuations, since there is no sign of Kondo effect in electrical resistivity and no enhancement of the slope S(T)/T in thermoelectric power data at low temperatures. It suggests that the conduction electrons at the Fermi level does not correlate with the 4f 2 states of [Formula: see text] atoms and hence there is no place for a typical spin Kondo effect, as it is commonly observed in Ce- and Yb-based heavy fermion systems.

3.
J Phys Condens Matter ; 27(39): 395601, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26381419

RESUMO

In this study we report the physical properties of the new ternary compound Ce2Rh3Ge that crystallizes in the rhombohedral, triple hexagonal MgCu2-type of structure. The electronic ground state properties of Ce2Rh3Ge were characterized by magnetic susceptibility, specific heat, electrical resistivity and thermal transport measurements. The results indicate the presence of short range magnetic interaction, probably of ferromagnetic origin below T(C) = 4 K. The shape of χ(-1)(T) deviates from the Curie-Weiss behavior with a broad minimum at about T(min)(χ(-1)) = 450 K reminiscent of valence fluctuating cerium systems. At T = 10 K, the magnetic part of the resistivity ρ(4 f) (T) exhibits a shallow minimum followed by increase of resistivity ρ(T) ∝ -lnT, which hints at a substantial Kondo screening effect. Ce2Rh3Ge belongs to a small group of strongly correlated cerium compounds in which the two competing effects of Kondo and RKKY interactions produce long-range magnetic order from strongly hybridized and intermediate-valent 4 f spins. At sufficiently low temperatures Ce2Rh3Ge scales well with the Kadowaki-Woods ratio A/γ(2) and the value of the Wilson ratio χ(T → 0)/γ found for this compound classifies it as a mixed-valence compound. The presence of valence fluctuation and magnetic order it is rare for these attributes to be found simultaneously in same compound, in same temperature range. In our opinion a novelty of presented results of Ce2Rh3Ge is that this compound adds a new member to a small but growing class of systems bearing a strongly mixed- or intermediate-valent 4 f magnetic moment, but in which the lattice of spins nevertheless end up finding it possible to order magnetically.

4.
J Pathol ; 209(1): 67-77, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16482496

RESUMO

Lymphangiogenesis is a novel prognostic parameter for several cancers that is preferentially quantified by immunohistochemistry of the lymphatic endothelium-specific hyaluronan receptor LYVE-1. Recently, the specificity of LYVE-1 was challenged by serendipitous observations of LYVE-1 expression in rare tissue macrophages. As expression of the hyaluronan receptor-like molecule stabilin-1 is shared by sinusoidal endothelium and macrophages, a thorough analysis of LYVE-1 expression was performed using macrophage-specific markers in vivo and in vitro. In murine tumour models and excisional wound healing, LYVE-1 expression occurred in a subset of CD11b(+), F4/80(+) tissue macrophages that preferentially co-expressed stabilin-1. Upon comparison of single- and double-labelling immunofluorescence, it became apparent that LYVE-1(+) macrophages mimic sprouting and collapsed lymphatic vessels. In vitro, LYVE-1 expression was induced in 25-40% of murine bone marrow-derived macrophages upon exposure to B16F1 melanoma-conditioned medium and IL-4/dexamethasone. By FACS analysis, 11.5% of bone marrow-derived macrophages were LYVE-1(+), stabilin-1(+) double-positive, while 9.9% were LYVE-1(+), stabilin-1(-) and 33.5% were LYVE-1(-), stabilin-1(+). Northern and western analyses confirmed expression of LYVE-1 mRNA and protein in bone marrow-derived macrophages. In the light of the current debate about true endothelial trans-differentiation versus endothelial mimicry of monocytes/macrophages, LYVE-1(+), stabilin-1(+) non-continuous endothelial-like macrophages will require further developmental and functional analyses. In conclusion, the findings imply that LYVE-1 staining must be supplemented by double labelling with macrophage markers in order to differentiate clearly between LYVE-1(+) lymphatics and LYVE-1(+) tumour-infiltrating macrophages. This improved approach will help to clarify the prognostic significance of lymphangiogenesis in malignant tumours.


Assuntos
Endotélio Linfático/metabolismo , Glicoproteínas/metabolismo , Linfangiogênese/fisiologia , Macrófagos/metabolismo , Melanoma/metabolismo , Animais , Antígenos de Diferenciação/análise , Células da Medula Óssea/metabolismo , Antígeno CD11b/análise , Moléculas de Adesão Celular Neuronais/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Feminino , Macrófagos/fisiologia , Melanoma/patologia , Melanoma/secundário , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Neoplasias/metabolismo , Células Tumorais Cultivadas , Proteínas de Transporte Vesicular , Cicatrização/fisiologia
5.
Anticancer Res ; 23(3B): 2303-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12894507

RESUMO

BACKGROUND: Cyclooxygenase-2 (Cox-2) has been found to be overexpressed in several types of human cancers and its role in tumorigenesis has been proposed. The aim of this study was to investigate the effects of the cyclooxygenase inhibitor diclofenac on the growth of murine C-26 colon carcinoma cells. MATERIALS AND METHODS: Expression of Cox-2 mRNA and protein was examined by RT-PCR analysis and immunohistochemistry, respectively. By using MTT-assay, we examined the effects of diclofenac at various concentrations on the growth of C-26 cells in vitro. The effect of diclofenac on the growth of the C-26 tumor in syngeneic mice was also investigated. RESULTS: By RT-PCR, Cox-2 mRNA was detected in C-26 cells. Cox-2 protein was localized to C-26 cells and treatment with diclofenac resulted in apoptotic cell death in a dose-dependent manner. Diclofenac administered in drinking water resulted in growth inhibition of C-26 tumor in mice and correlated with plasma levels of both PGE2 and TXB2. CONCLUSION: Our data show that diclofenac may be a potential agent for the prevention and treatment of human colon cancer.


Assuntos
Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Inibidores de Ciclo-Oxigenase/farmacologia , Diclofenaco/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Dinoprostona/antagonistas & inibidores , Dinoprostona/biossíntese , Feminino , Isoenzimas/biossíntese , Isoenzimas/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Prostaglandina-Endoperóxido Sintases/biossíntese , Prostaglandina-Endoperóxido Sintases/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
6.
J Mol Biol ; 294(2): 307-20, 1999 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-10610760

RESUMO

Rhodobacter sphaeroides rpoE encodes a 19.2 kDa protein, sigma(E), related to members of the extra-cytoplasmic function subfamily of eubacterial RNA polymerase sigma factors. We demonstrate that sigma(E) directs transcription from rpoE P1, the promoter for the rpoEchrR operon, and from cycA P3, a promoter for the cytochrome c2 structural gene. Comparison of these sigma(E)-dependent promoters reveals significant sequence conservation in their -35 and -10 regions; however, rpoE P1 is over 80-fold stronger than cycA P3. Both promoters contain identical -35 hexamers, (-36)TGATCC(-31), that appear to constitute the preferred sequence, since any single base mutation in this region of cycA P3 reduces promoter function. The higher activity of rpoE P1 appears to reflect a better -10 region, (-13)TAAGA(-9), as it contains four out of five of the nucleotides found to be important to sigma(E)-dependent transcription. We also propose that ChrR acts as an inhibitor of sigma(E), since these two proteins can form a complex, and DeltachrR mutations increase sigma(E)-dependent transcription. ChrR is believed to respond to a signal from tetrapyrrole biosynthesis because loss of function mutations in chrR lead to cohemin resistance. Based on our observations, we present a model in which cohemin resistance is conferred by increasing sigma(E) activity.


Assuntos
Proteínas de Bactérias/genética , Grupo dos Citocromos c/genética , Regiões Promotoras Genéticas , Rhodobacter sphaeroides/genética , Fator sigma/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Proteínas de Bactérias/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Sequência de Bases , Citoplasma/genética , Citoplasma/metabolismo , Análise Mutacional de DNA , Resistência Microbiana a Medicamentos/genética , Regulação Bacteriana da Expressão Gênica , Heme/farmacologia , Hemina , Histidina/genética , Dados de Sequência Molecular , Mutação Puntual , Sequências Reguladoras de Ácido Nucleico , Rhodobacter sphaeroides/efeitos dos fármacos , Fator sigma/efeitos dos fármacos , Fator sigma/metabolismo , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Transcrição Gênica
7.
Hybridoma ; 15(1): 55-68, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9064287

RESUMO

The TATA box-binding protein (TBP) is a key transcription factor required for transcription by all three eukaryotic RNA polymerases. It consists of a conserved carboxy-terminal DNA binding domain and a highly divergent amino terminal domain. TBP and different sets of TBP-associated factors (TAFs) constitute at least four multisubunit complexes referred to as SL1, TFIID, TFIIIB, and SNAPC. SL1, TFIID, and TFIIIB are required for transcription by RNA polymerases I, II, and III, respectively, while the SNAP complex is involved in transcription of the small nuclear RNA (snRNA) genes by RNA polymerases II and III. TBP also associates with a number of basal transcription factors such as TFIIA and TFIIB, and with several regulatory factors such as VP16, E1A, and p53. Here we describe the characterization of a panel of monoclonal antibodies (MAbs) directed against the amino-terminal domain of human TBP. These MAbs recognize different TBP epitopes, some of which have been precisely defined. Different MAbs recognize different TBP-containing complexes and several of them crossreact with TBP from other species. These antibodies can be used to purify TBP-containing complexes in a functional form and should be useful to identify new protein-protein interactions involving TBP.


Assuntos
Anticorpos Monoclonais/química , Proteínas de Ligação a DNA/imunologia , Mapeamento de Epitopos , Proteínas Pol1 do Complexo de Iniciação de Transcrição , Fatores de Transcrição/imunologia , Sequência de Aminoácidos , Animais , Sequência Conservada , Cricetinae , Reações Cruzadas , DNA/química , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/isolamento & purificação , Drosophila , Eletroforese em Gel de Poliacrilamida , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia , Ratos , Ouriços-do-Mar , Especificidade da Espécie , Proteína de Ligação a TATA-Box , Fatores de Transcrição/química , Fatores de Transcrição/isolamento & purificação
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