170 research outputs found
Potential for a biogenic influence on cloud microphysics over the ocean: a correlation study with satellite-derived data
Aerosols have a large potential to influence climate through their effects on the microphysics and optical properties of clouds and, hence, on the Earth's radiation budget. Aerosol–cloud interactions have been intensively studied in polluted air, but the possibility that the marine biosphere plays an important role in regulating cloud brightness in the pristine oceanic atmosphere remains largely unexplored. We used 9 yr of global satellite data and ocean climatologies to derive parameterizations of the temporal variability of (a) production fluxes of sulfur aerosols formed by the oxidation of the biogenic gas dimethylsulfide emitted from the sea surface; (b) production fluxes of secondary organic aerosols from biogenic organic volatiles; (c) emission fluxes of biogenic primary organic aerosols ejected by wind action on sea surface; and (d) emission fluxes of sea salt also lifted by the wind upon bubble bursting. Series of global monthly estimates of these fluxes were correlated to series of potential cloud condensation nuclei (CCN) numbers derived from satellite (MODIS). More detailed comparisons among weekly series of estimated fluxes and satellite-derived cloud droplet effective radius (r[subscript e]) data were conducted at locations spread among polluted and clean regions of the oceanic atmosphere. The outcome of the statistical analysis was that positive correlation to CCN numbers and negative correlation to r[subscript e] were common at mid and high latitude for sulfur and organic secondary aerosols, indicating both might be important in seeding cloud droplet activation. Conversely, primary aerosols (organic and sea salt) showed widespread positive correlations to CCN only at low latitudes. Correlations to r[subscript e] were more variable, non-significant or positive, suggesting that, despite contributing to large shares of the marine aerosol mass, primary aerosols are not widespread major drivers of the variability of cloud microphysics. Validation against ground measurements pointed out that the parameterizations used captured fairly well the variability of aerosol production fluxes in most cases, yet some caution is warranted because there is room for further improvement, particularly for primary organic aerosol. Uncertainties and synergies are discussed, and recommendations of research needs are given
High involvement work systems, happiness at work (HAW) and absorptive capacity: a bathtub study
Purpose. The purpose of this research is to examine the impact of high-involvement work systems (HIWS) on absorptive capacity. In addition, the mediating effect of happiness at work in the relationship between high involvement work practices and absorptive capacity is analyzed. Design/methodology/approach. A2-1-2 bathtub multilevel mediation model was used to analyze a sample of 783 employees from 111 bank branches, gathering data at three different times. Findings. The results reveal that HIWS positively affect absorptive capacity. In addition, they show that happiness at work partially mediates the relationship between HIWS and absorptive capacity. Originality/value. Happiness at work is a fundamental element for knowledge absorption. The findings support the basic assumptions of the job demands-resources model, and demonstrate how HIWS, acting as a job resource, lead to positive attitudes (happiness at work) and, in turn, to positive outcomes (absorptive capacity). The proposed HIWS, based on the assumptions of the mutual gains model, reveal a positive employment relationship with effects on both HAW and organizational outcomes. If organizations expose their employees to management practices that have specific benefits for their HAW, employees are more likely to perform their jobs in ways that will promote their absorptive capacity
Artrosis postraumática en pacientes con fractura-luxacion de Lisfranc.
La artrosis postraumática es una de las complicaciones más frecuentes y más invalidantes de la
fractura-luxación de Lisfranc (FLL).
Objetivo
. Evaluar el grado de incidencia de artrosis postraumática como
complicación y secuela en pacientes con fractura-luxación de Lisfranc y valorar qué factores muestran relación
directa o influyen en su aparición y desarrollo.
Material y Método
. Se realizó un estudio de cohortes ambispectivo
transversal de 83 pacientes con diagnóstico de fractura-luxación de Lisfranc. Se utilizó un protocolo de recogida
de datos con variables relacionadas con la lesión, parámetros clínicos, terapéuticos, complicaciones y escalas de
valoración clínica. La valoración de artrosis se realiza mediante aparición de signos radiológicos de la clasifica
-
ción radiológica de Kellgren y Lawrence y su correlación clínica con presencia de dolor.
Resultados
. La artrosis
se mostró como un factor influyente en los resultados, puntuaciones regulares y malas presentan mayor tasa de
artrosis (p=0,001), y en cuanto al grado de artrosis, los casos más graves de artrosis se situaban en el grupo de
puntuaciones malas (p=0,025). Este grupo de pacientes presentaron peores puntuaciones porque referían más
dolor, mayor consumo de analgésicos, más limitación de las actividades de la vida diaria, de las actividades
deportivas y limitación de la distancia caminada.
Conclusiones
. La artrosis se mostró como un factor influyente
en los resultados (p=0,001). Los pacientes que desarrollaron artrosis tardaron más tiempo en reincorporarse a
su empleo o actividad laboral previa, tenían un tiempo más demorado desde la cirugía al alta y mayor número
total de incapacidades laborales y compensaciones económicas con respecto a los pacientes que no desarrollaron
artrosis, siendo todos estos valores estadísticamente significativos.The posttraumatic degenerative osteoarthritis is one of the most frequent complications and more
disabling of Lisfranc's fracture - luxation (FLL).
Objetive. Evaluate the degree of frequency of posttraumatic
degenerative osteoarthritis as complication and adverse effect in patients with Lisfranc's fracture - luxation and
value what factors show straight relation or influence in its appearance and development.
Material and Method.We have made a transversal prospective and retrospective study of cohorts on 83 patients with diagnosis of
Lisfranc's fracture - luxation. We have used a data collecting protocol of items related to the injury, clinical,
therapeutic parameters, complications and scales of clinical valuation. The assessment valuation of degenerative
osteoarthritis is made under radiological signs realized by means of appearance of radiological signs of Kellgren
and Lawrence classification and clinical correlation with presence of pain.
Results
. The degenerative osteoarthri
tis appeared as an influential factor in the results, regular and bad punctuations present major rate of degenerative
osteoarthritis (p=0,001), and as for the degree of degenerative osteoarthritis, the most serious cases of degenerative osteoarthritis were placing in the group of bad punctuations (p=0,025). This group of patients presented
worse punctuations because they were recounting more pain, major consumption of analgesics, more limitation
of the activities of the daily life, of the sports activities and limitation of the travelled distance.
Conclusions
. The
degenerative osteoarthritis appeared as an influential factor in the results (p=0,001). The patients who developed
degenerative osteoarthritis were late more time in coming back to his employment or labor previous activity;
they had a time more delayed from the surgery to the discharge and major total number of labor disabilities and
economic compensations with regard to the patients who did not develop degenerative osteoarthritis, being all
these statistically significant values
A novel pathway producing dimethylsulphide in bacteria is widespread in soil environments
The volatile compound dimethylsulphide (DMS) is important in climate regulation, the sulphur cycle and signalling to higher organisms. Microbial catabolism of the marine osmolyte dimethylsulphoniopropionate (DMSP) is thought to be the major biological process generating DMS. Here we report the discovery and characterisation of the first gene for DMSP-independent DMS production in any bacterium. This gene, mddA, encodes a methyltransferase that methylates methanethiol (MeSH) and generates DMS. MddA functions in many taxonomically diverse bacteria including sediment-dwelling pseudomonads, nitrogen-fixing bradyrhizobia and cyanobacteria, and mycobacteria, including the pathogen Mycobacterium tuberculosis. The mddA gene is present in metagenomes from varied environments, being particularly abundant in soil environments, where it is predicted to occur in up to 76% of bacteria. This novel pathway may significantly contribute to global DMS emissions, especially in terrestrial environments, and could represent a shift from the notion that DMSP is the only significant precursor of DMS
The correlation between immune subtypes and consensus molecular subtypes in colorectal cancer identifies novel tumour microenvironment profiles, with prognostic and therapeutic implications
Background
Solid tumour growth is the consequence of a complex interplay between cancer cells and their microenvironment. Recently, a new global transcriptomic immune classification of solid tumours has identified six immune subtypes (ISs) (C1–C6). Our aim was to specifically characterise ISs in colorectal cancer (CRC) and assess their interplay with the consensus molecular subtypes (CMSs).
Methods
Clinical and molecular information, including CMSs and ISs, were obtained from The Cancer Genome Atlas (TCGA) (N = 625). Immune cell populations, differential gene expression and gene set enrichment analysis were performed to characterise ISs in the global CRC population by using CMSs.
Results
Only 5 ISs were identified in CRC, predominantly C1 wound healing (77%) and C2 IFN-γ dominant (17%). CMS1 showed the highest proportion of C2 (53%), whereas C1 was particularly dominant in CMS2 (91%). CMS3 had the highest representation of C3 inflammatory (7%) and C4 lymphocyte depleted ISs (4%), whereas all C6 TGF-β dominant cases belonged to CMS4 (2.3%). Prognostic relevance of ISs in CRC substantially differed from that reported for the global TCGA, and ISs had a greater ability to stratify the prognosis of CRC patients than CMS classification. C2 had higher densities of CD8, CD4 activated, follicular helper T cells, regulatory T cells and neutrophils and the highest M1/M2 polarisation. C2 had a heightened activation of pathways related to the immune system, apoptosis and DNA repair, mTOR signalling and oxidative phosphorylation, whereas C1 was more dependent of metabolic pathways.
Conclusions
The correlation of IS and CMS allows a more precise categorisation of patients with relevant clinical and biological implications, which may be valuable tools to improve tailored therapeutic interventions in CRC patients.This work was funded by projects DTS15/00157 , PI16/01827 and CIBER-ONC CB16/12/00442 from the Instituto de Salud Carlos III ( Ministry of Economy, Industry and Competitiveness, Spain ) and cofunded by the European Regional Development Fund (ERDF, European Union), and approved by the Ethics Committee or our Institution. BS is funded by AECC (Spain). MCR is funded by Instituto de Salud Carlos III and SEOM (Spain) CCP and BRC are funded by CAM (Programa de Empleo Juvenil (YEI)
The Adblocking Tug-of-War
Online advertising subsidizes a majority of the “free” services on the Web. Yet many find this approach intrusive and annoying, resorting to adblockers to get rid of ads chasing them all over the Web. A majority of those using an adblocker tool are familiar with messages asking them to either disable their adblocker or to consider supporting the host Web site via a donation or subscription. This is a recent development in the ongoing adblocking arms race which we have explored in our recent report, “Adblocking and Counter Blocking: A Slice of the Arms Race”. For our study, we used popular adblockers, trawled the Web and analyzed some of the most popular sites to uncover how many are using anti-adblockers. Our preliminary analysis found that anti-adblockers come from a small number of providers, are widely used, and that adblockers also often block anti-adblockers
The Differential Impact of SRC Expression on the Prognosis of Patients with Head and Neck Squamous Cell Carcinoma
Aberrant SRC expression and activation is frequently detected in multiple cancers, and hence, targeting SRC has emerged as a promising therapeutic strategy. Different SRC inhibitors have demonstrated potent anti-tumor activity in preclinical models, although they largely lack clinical efficacy as monotherapy in late-stage solid tumors, including head and neck squamous cell carcinomas (HNSCC). Adequate selection and stratification of patients who may respond to and benefit from anti-SRC therapies is therefore needed to guide clinical trials and treatment efficacy. This study investigates the prognostic significance of active SRC expression in a homogeneous cohort of 122 human papillomavirus (HPV)-negative, surgically treated HNSCC patients. Immunohistochemical evaluation of the active form of SRC by means of anti-SRC Clone 28 monoclonal antibody was specifically performed and subsequently correlated with clinical data. The expression of p-SRC (Tyr419), total SRC, and downstream SRC effectors was also analyzed. Our results uncovered striking differences in the prognostic relevance of SRC expression in HNSCC patients depending on the tumor site. Active SRC expression was found to significantly associate with advanced disease stages, presence of lymph node metastasis, and tumor recurrences in patients with laryngeal tumors, but not in the pharyngeal subgroup. Multivariate Cox analysis further revealed active SRC expression as an independent predictor of cancer-specific mortality in patients with laryngeal carcinomas. Concordantly, expression of p-SRC (Tyr419) and the SRC substrates focal adhesion kinase (FAK) and the Arf GTPase-activating protein ASAP1 also showed specific associations with poor prognosis in the larynx. These findings could have important implications in ongoing Src family kinase (SFK)-based clinical trials, as these new criteria could help to improve patient selection and develop biomarker-stratified trials
A novel Carcinoembryonic Antigen (CEA)-Targeted Trimeric Immunotoxin shows signifcantly enhanced Antitumor Activity in Human Colorectal Cancer Xenografts
Immunotoxins are chimeric molecules, which combine antibody specifcity to recognize and bind with high-afnity tumor-associated antigens (TAA) with the potency of the enzymatic activity of a toxin, in order to induce the death of target cells. Current immunotoxins present some limitations for cancer therapy, driving the need to develop new prototypes with optimized properties. Herein we describe the production, purifcation and characterization of two new immunotoxins based on the gene fusion of the anti-carcinoembryonic antigen (CEA) single-chain variable fragment (scFv) antibody MFE23 to α-sarcin, a potent fungal ribotoxin. One construct corresponds to a conventional monomeric single-chain immunotoxin design (IMTXCEAαS), while the other one takes advantage of the trimerbody technology and exhibits a novel trimeric format (IMTXTRICEAαS) with enhanced properties compared with their monomeric counterparts, including size, functional afnity and biodistribution, which endow them with an improved tumor targeting capacity. Our results show the highly specifc cytotoxic activity of both immunotoxins in vitro, which was enhanced in the trimeric format compared to the monomeric version. Moreover, the trimeric immunotoxin also exhibited superior antitumor activity in vivo in mice bearing human colorectal cancer xenografts. Therefore, trimeric immunotoxins represent a further step in the development of next-generation therapeutic immunotoxins
Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles
Global ocean biogeochemistry models currently employed in climate change projections use highly simplified representations of pelagic food webs. These food webs do not necessarily include critical pathways by which ecosystems interact with ocean biogeochemistry and climate. Here we present a global biogeochemical model which incorporates ecosystem dynamics based on the representation of ten plankton functional types (PFTs); six types of phytoplankton, three types of zooplankton, and heterotrophic bacteria. We improved the representation of zooplankton dynamics in our model through (a) the explicit inclusion of large, slow-growing zooplankton, and (b) the introduction of trophic cascades among the three zooplankton types. We use the model to quantitatively assess the relative roles of iron vs. grazing in determining phytoplankton biomass in the Southern Ocean High Nutrient Low Chlorophyll (HNLC) region during summer. When model simulations do not represent crustacean macrozooplankton grazing, they systematically overestimate Southern Ocean chlorophyll biomass during the summer, even when there was no iron deposition from dust. When model simulations included the developments of the zooplankton component, the simulation of phytoplankton biomass improved and the high chlorophyll summer bias in the Southern Ocean HNLC region largely disappeared. Our model results suggest that the observed low phytoplankton biomass in the Southern Ocean during summer is primarily explained by the dynamics of the Southern Ocean zooplankton community rather than iron limitation. This result has implications for the representation of global biogeochemical cycles in models as zooplankton faecal pellets sink rapidly and partly control the carbon export to the intermediate and deep ocean
The abundant marine bacterium Pelagibacter simultaneously catabolizes dimethylsulfoniopropionate to the gases dimethyl sulfide and methanethiol
Marine phytoplankton produce ~109 tons of dimethylsulfoniopropionate (DMSP) per year1,2, an estimated 10% of which is catabolized by bacteria through the DMSP cleavage pathway to the climatically active gas dimethyl sulfide (DMS)3,4. SAR11 Alphaproteobacteria (order Pelagibacterales), the most abundant chemoorganotrophic bacteria in the oceans, have been shown to assimilate DMSP into biomass, thereby supplying this cell’s unusual requirement for reduced sulfur5,6. Here we report that Pelagibacter HTCC1062 produces the gas methanethiol (MeSH) and that simultaneously a second DMSP catabolic pathway, mediated by a cupin-like DMSP lyase, DddK, shunts as much as 59% of DMSP uptake to DMS production. We propose a model in which the allocation of DMSP between these pathways is kinetically controlled to release increasing amounts of DMS as the supply of DMSP exceeds cellular sulfur demands for biosynthesis
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