819 research outputs found
The emergent role of digital technologies in the context of humanitarian supply chains: a systematic literature review
The role of digital technologies (DTs) in humanitarian supply chains (HSC) has become an increasingly researched topic in the operations literature. While numerous publications have dealt with this convergence, most studies have focused on examining the implementation of individual DTs within the HSC context, leaving relevant literature, to date, dispersed and fragmented. This study, through a systematic literature review of 110 articles on HSC published between 2015 and 2020, provides a unified overview of the current state-of-the-art DTs adopted in HSC operations. The literature review findings substantiate the growing significance of DTs within HSC, identifying their main objectives and application domains, as well as their deployment with respect to the different HSC phases (i.e., Mitigation, Preparedness, Response, and Recovery). Furthermore, the findings also offer insight into how participant organizations might configure a technological portfolio aimed at overcoming operational difficulties in HSC endeavours. This work is novel as it differs from the existing traditional perspective on the role of individual technologies on HSC research by reviewing multiple DTs within the HSC domain
Hydroxamic acid-modified peptide microarrays for profiling isozyme-selective interactions and inhibition of histone deacetylases
Histones control gene expression by regulating chromatin structure and function. The posttranslational modifications (PTMs) on the side chains of histones form the epigenetic landscape, which is tightly controlled by epigenetic modulator enzymes and further recognized by so-called reader domains. Histone microarrays have been widely applied to investigate histone–reader interactions, but not the transient interactions of Zn-dependent histone deacetylase (HDAC) eraser enzymes. Here, we synthesize hydroxamic acid-modified histone peptides and use them in femtomolar microarrays for the direct capture and detection of the four class I HDAC isozymes. Follow-up functional assays in solution provide insights into their suitability to discover HDAC substrates and inhibitors with nanomolar potency and activity in cellular assays. We conclude that similar hydroxamic acid-modified histone peptide microarrays and libraries could find broad application to identify class I HDAC isozyme-specific substrates and facilitate the development of isozyme-selective HDAC inhibitors and probes
Childhood cancer in the south Asian population of England (1990–1992)
Cancer incidence in 1990–92 among English south Asian (residents with ethnic origins in India, Pakistan or Bangladesh) and non-south Asian children is compared. Standardized incidence ratios show significant overall excesses in south Asians (131), largely due to higher rates in south Asian boys, and specific excesses for leukaemia (141), lymphoid leukaemia (141), lymphoma (172) and hepatic tumours (375). Aetiological investigation is required. © 2001 Cancer Research Campaign http://www.bjcancer.co
Efficient Certified Resolution Proof Checking
We present a novel propositional proof tracing format that eliminates complex
processing, thus enabling efficient (formal) proof checking. The benefits of
this format are demonstrated by implementing a proof checker in C, which
outperforms a state-of-the-art checker by two orders of magnitude. We then
formalize the theory underlying propositional proof checking in Coq, and
extract a correct-by-construction proof checker for our format from the
formalization. An empirical evaluation using 280 unsatisfiable instances from
the 2015 and 2016 SAT competitions shows that this certified checker usually
performs comparably to a state-of-the-art non-certified proof checker. Using
this format, we formally verify the recent 200 TB proof of the Boolean
Pythagorean Triples conjecture
Longitudinal metabolic and gut bacterial profiling of pregnant women with previous bariatric surgery
Objective Due to the global increase in obesity rates and success of bariatric surgery in weight reduction, an increasing number of women now present pregnant with a previous bariatric procedure. This study investigates the extent of bariatric-associated metabolic and gut microbial alterations during pregnancy and their impact on fetal development.
Design A parallel metabonomic (molecular phenotyping based on proton nuclear magnetic resonance spectroscopy) and gut bacterial (16S ribosomal RNA gene amplicon sequencing) profiling approach was used to determine maternal longitudinal phenotypes associated with malabsorptive/mixed (n=25) or restrictive (n=16) procedures, compared with women with similar early pregnancy body mass index but without bariatric surgery (n=70). Metabolic profiles of offspring at birth were also analysed.
Results Previous malabsorptive, but not restrictive, procedures induced significant changes in maternal metabolic pathways involving branched-chain and aromatic amino acids with decreased circulation of leucine, isoleucine and isobutyrate, increased excretion of microbial-associated metabolites of protein putrefaction (phenylacetlyglutamine, p-cresol sulfate, indoxyl sulfate and p-hydroxyphenylacetate), and a shift in the gut microbiota. The urinary concentration of phenylacetylglutamine was significantly elevated in malabsorptive patients relative to controls (p=0.001) and was also elevated in urine of neonates born from these mothers (p=0.021). Furthermore, the maternal metabolic changes induced by malabsorptive surgery were associated with reduced maternal insulin resistance and fetal/birth weight.
Conclusion Metabolism is altered in pregnant women with a previous malabsorptive bariatric surgery. These alterations may be beneficial for maternal outcomes, but the effect of elevated levels of phenolic and indolic compounds on fetal and infant health should be investigated further
Longitudinal metabolic and gut bacterial profiling of pregnant women with previous bariatric surgery
Due to the global increase in obesity rates and success of bariatric surgery in weight reduction, an increasing number of women now present pregnant with a previous bariatric procedure. This study investigates the extent of bariatric-associated metabolic and gut microbial alterations during pregnancy and their impact on fetal development. Design A parallel metabonomic (1H NMR spectroscopy) and gut bacterial (16S rRNA gene amplicon sequencing) profiling approach was used to determine maternal longitudinal phenotypes associated with malabsorptive/mixed (n=25) or restrictive (n=16) procedures, compared to women with similar early pregnancy body mass index but without bariatric surgery (n=70). Metabolic profiles of offspring at birth were also analysed. Results Previous malabsorptive, but not restrictive, procedures induced significant changes in maternal metabolic pathways involving branched-chain and aromatic amino acids with decreased circulation of leucine, isoleucine and isobutyrate, increased excretion of microbial-associated metabolites of protein putrefaction (phenylacetlyglutamine, p-cresol sulfate, indoxyl sulfate and p-hydroxyphenylacetate), and a shift in the gut microbiota. Urinary concentration of phenylacetylglutamine was significantly elevated in malabsorptive patients relative to controls (P=0.001) and was also elevated in urine of neonates born from these mothers (P=0.021). Furthermore, the maternal metabolic changes induced by malabsorptive surgery were associated with reduced maternal insulin resistance and fetal/birth weight. Conclusion Metabolism is altered in pregnant women with a previous malabsorptive bariatric surgery. These alterations may be beneficial for maternal outcomes, but the effect of elevated levels of phenolic and indolic compounds on fetal and infant health should be investigated further
A conserved Polϵ binding module in Ctf18-RFC is required for S-phase checkpoint activation downstream of Mec1
Defects during chromosome replication in eukaryotes activate a signaling pathway called the S-phase checkpoint, which produces a multifaceted response that preserves genome integrity at stalled DNA replication forks. Work with budding yeast showed that the ‘alternative clamp loader’ known as Ctf18-RFC acts by an unknown mechanism to activate the checkpoint kinase Rad53, which then mediates much of the checkpoint response. Here we show that budding yeast Ctf18-RFC associates with DNA polymerase epsilon, via an evolutionarily conserved ‘Pol ϵ binding module’ in Ctf18-RFC that is produced by interaction of the carboxyl terminus of Ctf18 with the Ctf8 and Dcc1 subunits. Mutations at the end of Ctf18 disrupt the integrity of the Pol ϵ binding module and block the S-phase checkpoint pathway, downstream of the Mec1 kinase that is the budding yeast orthologue of mammalian ATR. Similar defects in checkpoint activation are produced by mutations that displace Pol ϵ from the replisome. These findings indicate that the association of Ctf18-RFC with Pol ϵ at defective replication forks is a key step in activation of the S-phase checkpoint
Perdeuteration of cholesterol for neutron scattering applications using recombinant Pichia pastoris
Deuteration of biomolecules has a great impact on both quality and scope of neutron scattering experiments. Cholesterol is a major component of mammalian cells, where it plays a critical role in membrane permeability, rigidity and dynamics, and contributes to specific membrane structures such as lipid rafts. Cholesterol is the main cargo in low and high-density lipoprotein complexes (i.e. LDL, HDL) and is directly implicated in several pathogenic conditions such as coronary artery disease which leads to 17 million deaths annually. Neutron scattering studies on membranes or lipid-protein complexes exploiting contrast variation have been limited by the lack of availability of fully deuterated biomolecules and especially perdeuterated cholesterol. The availability of perdeuterated cholesterol provides a unique way of probing the structural and dynamical properties of the lipoprotein complexes that underly many of these disease conditions. Here we describe a procedure for in vivo production of perdeuterated recombinant cholesterol in lipid-engineered Pichia pastoris. Using flask and fed-batch fermenter cultures in deuterated minimal medium perdeuteration of the purified cholesterol was verified by mass spectrometry and its use in a neutron scattering study was demonstrated using neutron reflectometry
Lack of neuroinflammation in the HIV-1 transgenic rat: An [18 F]-DPA714 PET imaging study
BACKGROUND: HIV-associated neuroinflammation is believed to be a major contributing factor in the development of HIV-associated neurocognitive disorders (HAND). In this study, we used micropositron emission tomography (PET) imaging to quantify neuroinflammation in HIV-1 transgenic rat (Tg), a small animal model of HIV, known to develop neurological and behavioral problems. METHODS: Dynamic [(18)F]DPA-714 PET imaging was performed in Tg and age-matched wild-type (WT) rats in three age groups: 3-, 9-, and 16-month-old animals. As a positive control for neuroinflammation, we performed unilateral intrastriatal injection of quinolinic acid (QA) in a separate group of WT rats. To confirm our findings, we performed multiplex immunofluorescent staining for Iba1 and we measured cytokine/chemokine levels in brain lysates of Tg and WT rats at different ages. RESULTS: [(18)F]DPA-714 uptake in HIV-1 Tg rat brains was generally higher than in age-matched WT rats but this was not statistically significant in any age group. [(18)F]DPA-714 uptake in the QA-lesioned rats was significantly higher ipsilateral to the lesion compared to contralateral side indicating neuroinflammatory changes. Iba1 immunofluorescence showed no significant differences in microglial activation between the Tg and WT rats, while the QA-lesioned rats showed significant activation. Finally, cytokine/chemokine levels in brain lysates of the Tg rats and WT rats were not significantly different. CONCLUSION: Microglial activation might not be the primary mechanism for neuropathology in the HIV-1 Tg rats. Although [(18)F]DPA-714 is a good biomarker of neuroinflammation, it cannot be reliably used as an in vivo biomarker of neurodegeneration in the HIV-1 Tg rat. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12974-015-0390-9) contains supplementary material, which is available to authorized users
GM-CSF/IL-3/IL-5 receptor common β chain (CD131) expression as a biomarker of antigen-stimulated CD8+ T cells
<p>Abstract</p> <p>Background</p> <p>Upon Ag-activation cytotoxic T cells (CTLs) produce IFN-γ GM-CSF and TNF-α, which deliver simultaneously pro-apoptotic and pro-inflammatory signals to the surrounding microenvironment. Whether this secretion affects in an autocrine loop the CTLs themselves is unknown.</p> <p>Methods</p> <p>Here, we compared the transcriptional profile of Ag-activated, Flu-specific CTL stimulated with the FLU M1:58-66 peptide to that of convivial CTLs expanded <it>in vitro </it>in the same culture. PBMCs from 6 HLA-A*0201 expressing donors were expanded for 7 days in culture following Flu M1:58-66 stimulation in the presence of 300 IU/ml of interleukin-2 and than sorted by high speed sorting to high purity CD8+ expressing T cells gated according to FluM1:58-66 tetrameric human leukocyte antigen complexes expression.</p> <p>Results</p> <p>Ag-activated CTLs displayed higher levels of IFN-γ, GM-CSF (CSF2) and GM-CSF/IL-3/IL-5 receptor common β- chain (CD131) but lacked completely expression of IFN-γ receptor-II and IFN-stimulated genes (ISGs). This observation suggested that Ag-activated CTLs in preparation for the release of IFN-γ and GM-CSF shield themselves from the potentially apoptotic effects of the former entrusting their survival to GM-SCF. <it>In vitro </it>phenotyping confirmed the selective surface expression of CD131 by Ag-activated CTLs and their increased proliferation upon exogenous administration of GM-CSF.</p> <p>Conclusion</p> <p>The selective responsiveness of Ag-activated CTLs to GM-CSF may provide an alternative explanation to the usefulness of this chemokine as an adjuvant for T cell aimed vaccines. Moreover, the selective expression of CD131 by Ag-activated CTLs proposes CD131 as a novel biomarker of Ag-dependent CTL activation.</p
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