2,072 research outputs found
Sustainable supply chain management in developing countries: An analysis of the literature
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The purpose of this paper is to present an analysis of the academic literature addressing Sustainable Supply Chain Management (SSCM) practices in developing countries. A systematic literature review method was adopted; selected papers were reviewed from 2000 to 2016 that matched our inclusion criteria. Common themes across the literature were identified covering four factors regarding the adoption of SSCM: drivers, barriers, mechanisms and outcomes. A conceptual model integrating these factors and based on institutional theory was advanced to explain the adoption of sustainability practices along supply chains in developing countries. The paper concludes by identifying gaps in the literature that require further research on this topic, particularly for the context of developing countries. To the best of our knowledge this is the first paper reviewing the existing research on SSCM in developing countries that includes both social and environmental dimensions.We sincerely appreciate the financial support of Newton Caldas Institutional Link grant funded by British Council (grant no. 172727857). The paper is a result of the collaboration between University of Exeter, UK and University of Los Andes in Colombia
Estudio comparativo de la composición química del aceite esencial de Calycolpus moritzianus (Myrtaceae) proveniente de cinco regiones de Norte de Santander.Colombia
Los Aceites Esenciales (AEs) fueron obtenidos a partir de hojas de la especie Calycolpus moritzianus, recolectada en cinco egiones del departamento Norte de Santander: Chinácota, Ocaña, Pamplonita, Salazar y Toledo, por el método Destilación-Extracción con Solvente Simultánea (DES). El análisis cualitativo de los constituyentes volátiles mayoritarios del AE, se realizó por la técnica de Cromatografía de Gases de Alta Resolución (CGAR), utilizando el Detector de Ionización de Llama (FID) y el Detector Selectivo de Masas (MSD). Se logró la identificación de treinta y dos (32) compuestos, destacándose por su abundancia el Limoneno (17-38%), el 1,8-Cineol o Eucaliptol (12- 43.3%),el α-Pineno (2.3-5.6%), el β-Cariofileno (0.1-8.9%), α-Terpineol (0.2-5.5%) y el Guaiol (0.3- 20.2%), los cuales varían su concentración relativa según la región de procedencia. El análisis cuantitativo de los componentes volátiles mayoritarios se realizó empleando la técnica de normalización, estandarización externa e interna y finalmente, con los datos obtenidos se efectuó el respectivo análisis estadístico de los componentes principales (PCA)
Positive correlation between transcriptomic stemness and PI3K/AKT/mTOR signaling scores in breast cancer, and a counterintuitive relationship with PIK3CA genotype
A PI3Kα-selective inhibitor has recently been approved for use in breast tumors harboring mutations in PIK3CA, the gene encoding p110α. Preclinical studies have suggested that the PI3K/AKT/mTOR signaling pathway influences stemness, a dedifferentiation-related cellular phenotype associated with aggressive cancer. However, to date, no direct evidence for such a correlation has been demonstrated in human tumors. In two independent human breast cancer cohorts, encompassing nearly 3,000 tumor samples, transcriptional footprint-based analysis uncovered a positive linear association between transcriptionally-inferred PI3K/AKT/mTOR signaling scores and stemness scores. Unexpectedly, stratification of tumors according to PIK3CA genotype revealed a “biphasic” relationship of mutant PIK3CA allele dosage with these scores. Relative to tumor samples without PIK3CA mutations, the presence of a single copy of a hotspot PIK3CA variant was associated with lower PI3K/AKT/mTOR signaling and stemness scores, whereas the presence of multiple copies of PIK3CA hotspot mutations correlated with higher PI3K/AKT/mTOR signaling and stemness scores. This observation was recapitulated in a human cell model of heterozygous and homozygous PIK3CAH1047R expression. Collectively, our analysis (1) provides evidence for a signaling strength-dependent PI3K-stemness relationship in human breast cancer; (2) supports evaluation of the potential benefit of patient stratification based on a combination of conventional PI3K pathway genetic information with transcriptomic indices of PI3K signaling activation
Rad51 Paralogs Remodel Pre-synaptic Rad51 Filaments to Stimulate Homologous Recombination
SummaryRepair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which nucleates RAD-51-ssDNA filaments, RFS-1/RIP-1 binds and remodels pre-synaptic filaments to a stabilized, “open,” and flexible conformation, in which the ssDNA is more accessible to nuclease digestion and RAD-51 dissociation rate is reduced. Walker box mutations in RFS-1, which abolish filament remodeling, fail to stimulate RAD-51 strand exchange activity, demonstrating that remodeling is essential for RFS-1/RIP-1 function. We propose that Rad51 paralogs stimulate HR by remodeling the Rad51 filament, priming it for strand exchange with the template duplex
Design and simulation of an imaging neutral particle analyzer for the ASDEX Upgrade tokamak
An Imaging Neutral Particle Analyzer (INPA) diagnostic has been designed for the ASDEX Upgrade (AUG) tokamak. The AUG INPA diagnostic will measure fast neutrals escaping the plasma after charge exchange reactions. The neutrals will be ionized by a 20 nm carbon foil and deflected toward a scintillator by the local magnetic field. The use of a neutral beam injector (NBI) as an active source of neutrals will provide radially resolved measurements, while the use of a scintillator as an active component will allow us to cover the whole plasma along the NBI line with unprecedented phase-space resolution (<12 keV and 8 cm) and a fast temporal response (up to 1 kHz with the high resolution acquisition system and above 100 kHz with the low resolution one), making it suitable to study localized fast-ion redistributions in phase space.European Union’s Horizon 2020 (Grant Agreement No. 805162)Ministerio de Ciencia, Innovación y Universidades (Grant No. FPU19/02486
Correlación entre la act ividad antibacteriana y los componentes del aceite esencial de Calycolpus moritzianus
El aceite esencial (AE) de hojas de Calycolpus moritzianus, recolectado en las veredas de Pamplonita, Chinácota, Toledo, Salazar y Ocaña del departamento de Norte de Santander-Colombia fue obtenido por Arrastre con Vapor y analizado por Cromatografía de Gases de Alta Resolución acoplada a Espectrometría de Masas. Se identificaron 32 componentes, los cuales representaron el 98.7 % del total de constituyentes. Loscomponentes mayoritarios fueron el Limoneno (30.73 ± 11.13%) y el Eucaliptol (28.04 ± 10.81%), seguidos del -Pineno (6.80 ± 1.85%), -Cariofileno (6.73 ± 2.13%), Guaiol (3.46 ± 1.80%), -Terpineol (3.24 ± 1.26%), Oxido de Cariofileno (2.99 ± 3.04%), -Copaeno (1.39 ± 0.62%) y Germacreno-B (0.76 ± 0.60%).El aceite esencial fue efect ivo contra Bacillus subtilis ATCC 6633, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923 y Proteus mirabilis ATCC 4307, encontrándose como Concentraciones Mínimas Inhibitorias (CMI) 39 g/mL 106 g/mL 836.4 g/mL y 892.2 g/mL respectivamente. El análisis delcoeficiente de actividad antibacteriana de los componentes mayoritarios, demostró que el -Copaeno fue el más influyente en dicha actividad
A response to Yu et al. "A forward-backward fragment assembling algorithm for the identification of genomic amplification and deletion breakpoints using high-density single nucleotide polymorphism (SNP) array", BMC Bioinformatics 2007, 8: 145
<p>Abstract</p> <p>Background</p> <p>Yu et al. (BMC Bioinformatics 2007,8: 145+) have recently compared the performance of several methods for the detection of genomic amplification and deletion breakpoints using data from high-density single nucleotide polymorphism arrays. One of the methods compared is our non-homogenous Hidden Markov Model approach. Our approach uses Markov Chain Monte Carlo for inference, but Yu et al. ran the sampler for a severely insufficient number of iterations for a Markov Chain Monte Carlo-based method. Moreover, they did not use the appropriate reference level for the non-altered state.</p> <p>Methods</p> <p>We rerun the analysis in Yu et al. using appropriate settings for both the Markov Chain Monte Carlo iterations and the reference level. Additionally, to show how easy it is to obtain answers to additional specific questions, we have added a new analysis targeted specifically to the detection of breakpoints.</p> <p>Results</p> <p>The reanalysis shows that the performance of our method is comparable to that of the other methods analyzed. In addition, we can provide probabilities of a given spot being a breakpoint, something unique among the methods examined.</p> <p>Conclusion</p> <p>Markov Chain Monte Carlo methods require using a sufficient number of iterations before they can be assumed to yield samples from the distribution of interest. Running our method with too small a number of iterations cannot be representative of its performance. Moreover, our analysis shows how our original approach can be easily adapted to answer specific additional questions (e.g., identify edges).</p
On the Origin of Entropic Gravity and Inertia
It was recently suggested that quantum field theory is not fundamental but
emerges from the loss of phase space information about matter crossing causal
horizons. Possible connections between this formalism and Verlinde's entropic
gravity and Jacobson's thermodynamic gravity are proposed.
The holographic screen in Verlinde's formalism can be identified as local
Rindler horizons and its entropy as that of the bulk fields beyond the
horizons.
This naturally resolves some issues on entropic gravity.
The quantum fluctuation of the fields is the origin of the thermodynamic
nature of entropic gravity.
It is also suggested that inertia is related to dragging
Rindler horizons.Comment: 9 pages, revtex4-1, 3 figures, accepted for publication in
Foundations of Physic
Escherichia coli induces apoptosis and proliferation of mammary cells
Mammary cell apoptosis and proliferation were assessed after injection of Escherichia coli into the left mammary quarters of six cows. Bacteriological analysis of foremilk samples revealed coliform infection in the injected quarters of four cows. Milk somatic cell counts increased in these quarters and peaked at 24 h after bacterial injection. Body temperature also increased, peaking at 12 h postinjection, The number of apoptotic cells was significantly higher in the mastitic tissue than in the uninfected control. Expression of Bax and interleukin-1 beta converting enzyme increased in the mastitic tissue at 24 h and 72 h postinfection, whereas Bcl-2 expression decreased at 24 h but did not differ significantly from the control at 72 h postinfection, Induction of matrix metalloproteinase-g, stromelysin-1 and urokinase-type plasminogen activator was also observed in the mastitic tissue. Moreover, cell proliferation increased in the infected tissue, These results demonstrate that Escherichia coli-induced mastitis promotes apoptosis and cell proliferation
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