Spatial and temporal invasion dynamics of the 2014–2017 Zika and chikungunya epidemics in Colombia

Zika virus (ZIKV) and chikungunya virus (CHIKV) were recently introduced into the Americas resulting in significant disease burdens. Understanding their spatial and temporal dynamics at the subnational level is key to informing surveillance and preparedness for future epidemics. We analyzed anonymized line list data on approximately 105,000 Zika virus disease and 412,000 chikungunya fever suspected and laboratory-confirmed cases during the 2014–2017 epidemics. We first determined the week of invasion in each city. Out of 1,122, 288 cities met criteria for epidemic invasion by ZIKV and 338 cities by CHIKV. We analyzed risk factors for invasion using linear and logistic regression models. We also estimated that the geographic origin of both epidemics was located in Barranquilla, north Colombia. We assessed the spatial and temporal invasion dynamics of both viruses to analyze transmission between cities using a suite of (i) gravity models, (ii) Stouffer’s rank models, and (iii) radiation models with two types of distance metrics, geographic distance and travel time between cities. Invasion risk was best captured by a gravity model when accounting for geographic distance and intermediate levels of density dependence; Stouffer’s rank model with geographic distance performed similarly well. Although a few long-distance invasion events occurred at the beginning of the epidemics, an estimated distance power of 1.7 (95% CrI: 1.5–2.0) from the gravity models suggests that spatial spread was primarily driven by short-distance transmission. Similarities between the epidemics were highlighted by jointly fitted models, which were preferred over individual models when the transmission intensity was allowed to vary across arboviruses. However, ZIKV spread considerably faster than CHIKV.     

Biodeterioration of granite monuments by Ochrolechia parella (L.) mass: an FT Raman spectroscopic study

Ochrolechia parella is one of the most abundant lichens colonizing granite monuments in the region of Galicia (N.W. Spain). Its interaction with granite used in the construction of four ancient monuments was studied using FT Raman spectroscopy to evaluate the production of calcium oxalate by this lichen and the relationship of this production with different environmental conditions, particularly humidity. The results obtained showed that Ochrolechia parella is an aggressive colonizer, causing chemical disturbances to the granite through the formation of both calcium oxalate monohydrate and dihydrate. Apothecial development appears to be related to the production of calcium oxalate, and humidity determines the state of hydration of the calcium oxalate in the thallus.     

Degradation of phenol by Rhodococcus erythropolis UPV-1 immobilized on Biolite in a packed-bed reactor

A strain of Rhodococcus erythropolis has been isolated and identified by 16S rRNA sequencing. Cells acclimated to phenol can be adsorbed on the external surface of beads of the ceramic support Biolite where they grow forming a network of large filaments. Exponentially-growing cells were adsorbed faster than their stationary-phase counterparts. Immobilization resulted in a remarkable enhancement of the respiratory activity of cells and a shorter lag phase preceding the active phenol degradation. Under optimum operation conditions, the immobilized cells in a laboratory-scale column reactor packed with support beads were able to degrade completely phenol in defined mineral medium at a maximum rate of 18 kg phenol m(-3) per day. The performance of the bioreactor in long-term continuous operation was characterized by pumping defined mineral medium which contained different concentrations of phenol at different flow-rates. Once phenol biodegradation in defined mineral medium was well established, an industrial wastewater from a resin manufacturing company, which contained both phenol and formaldehyde, was tested. In this case, after wastewater conditioning (i.e. pH, nitrogen source and micronutrient amendments) the immobilized cells were able to remove completely formaldehyde and to partly biodegrade phenols at a rate of 1 kg phenol m(-3) per day.     

Effects of the Antiandrogen Flutamide on the Expression of Protein Kinase C Isoenzymes in LNCaP and PC3 Human Prostate Cancer Cells

Flutamide is a nonsteroidal antiandrogen that is frequently used for total androgen blockage in the treatment of advanced prostate cancer. We investigated the effect of this antiandrogen on the expression of protein kinase C (PKC) isoenzymes (alpha, beta1, epsilon, zeta) that are involved in cell growth, apoptosis and neoplastic transformation. Androgen-dependent (LNCaP) and independent (PC3) human prostate cancer cells were cultured in a medium that contained fetal bovine serum (FBS) or charcoal-stripped serum (CSS) and treated with 10 microM flutamide. The expression of PKC isoenzymes and the androgen receptor (AR) were analyzed by Western blot and RT-PCR, respectively. Serum steroids differentially regulate the expression of PKC isoenzymes in LNCaP and PC3 cells. Flutamide up-regulated the expression of alpha, beta1 and zeta, but not epsilon, PKC isoenzymes in CSS-LNCaP cells. These results were not homogeneously reproduced in the presence of androgens. We observed an opposite effect of flutamide, compared to CSS, on PKCbeta1 isoform expression in CSS-LNCaP suggesting that this antiandrogen exerts an agonistic effect. In PC3 cells flutamide potentiated the expression of the four PKC isoenzymes in almost all conditions tested (FBS- and CSS-cultured cells). Such effect of flutamide in PC3 cells is independent of AR since no expression of AR was detected. These results provide new evidence on antagonistic/agonistic responses of prostate cancer cells to antiandrogen drugs that are widely used in therapy and show that flutamide can elicit responses in prostate cancer cells that do not express AR.     

Effect of lindane upon the beta-adrenergic stimulation of cyclic AMP accumulation in rat renal cortical tubules caused by alterations in membrane fluidity.

The influence of lindane (gamma-hexachlorocyclohexane) on fluidity and lipid composition in rat renal cortical tubules has been investigated. Lindane increased membrane fluidity as measured by a fluorescence polarization technique using the probe diphenylhexatriene. This effect was dose-dependent and was accompanied by a 70% inhibition of the beta-adrenergic stimulatory activity upon cyclic AMP accumulation after 30 min of preincubation with lindane at 25 degrees C. Experiments with increasing concentrations of isoproterenol indicated that the efficacy, but not the potency, of the beta-adrenergic effect upon cyclic AMP accumulation was affected by lindane. Lindane toxicity could also be associated with variations in the incorporation of acetate into various lipid classes. Lindane increased acetate incorporation into phospholipids and decreased that into cholesterol.     

Two-stage continuous process development for the production of medium-chain-length poly(3-hydroxyalkanoates)

Pseudomonas oleovorans forms medium-chain-length poly(3-hydroxyalkanoate) (PHA) most effectively at growth rates below the maximum specific growth rate. Under adequate conditions, PHA accumulates in inclusion bodies in cells up to levels higher than half of the cell mass, which is a time-consuming process. For PHA production, a two-stage continuous cultivation system with two fermentors connected in series is a potentially useful system. It offers production of cells at a specific growth rate in a first compartment at conditions that lead cells to generate PHA at higher rates in a second compartment, with a relatively long residence time. In such a system, dilution rates of 0.21 h(-1) in the first fermentor (D(1)) and 0.16 h(-1) in the second fermentor (D(2)) were found to yield the highest volumetric PHA productivity. Transient-state experiments allowed investigation of D(1) and D(2) over a wide dilution rate range at high resolution in time-saving experiments. Furthermore, the influence of temperature, pH, nutrient limitation, and carbon source on PHA productivity was investigated and results similar to optimum conditions in single-stage chemostat cultivations of P. oleovorans were found. With all culture parameters optimized, a volumetric PHA productivity of 1.06 g L(-1) h(-1) was determined. Under these conditions, P. oleovorans cells contained 63% (dry weight) PHA in the effluent of the second fermentor. This is the highest PHA productivity and PHA content reported thus far for P. oleovorans cultures grown on alkanes.     

Effects of Planktonic Copepods on Transparent Exopolymeric Particles (TEP) Abundance and Size Spectra

Diatoms exude considerable quantities of polymers, mainly polysaccharides,that play an important role in the process of sestonic particleaggregation in the sea. We investigated the impact of copepodson transparent exopolymeric particles (TEP) generated by thediatom Thalassiosira weissflogii. Grazing experiments with ¹⁴C-labelledalgae exudates demonstrated that copepods typical of the BalticSea were not actively filtering TEP. Control experiments showedthat ‘uptake’ of radioactivity could be ascribedto passive uptake, such as adsorption of radioactively-labelledparticles to the body surface. Furthermore, we tested the effectof copepods on TEP size spectra. The abundance and size distributionof TEP (from 1.4 to 180 µm of Equivalent Spherical Diameter)were analysed in a 4 h incubation experiment. In the presenceof copepods, the proportion of larger TEP was higher. An increasein total volume of TEP in jars containing copepods (~2 x 10⁷µm ml^–1) compared with control jars without copepods(~0.5 x 10⁷ µm³ ml^–1) was also observed. The processof aggregation of TEP demonstrated in this work, whereby copepodsincrease downward particle flux without consuming carbon, canhave far-reaching consequences for carbon fluxes along the watercolumn and for copepods feeding dynamics.     

Accumulating behaviour of Lupinus albus L. growing in a normal and a decalcified calcic luvisol polluted with Zn

Lupinus albus L. is a leguminous plant that is starting to generate interest for the phytoremediation soils showing intermediate metal pollution. Among these metals, Zn causes major phytotoxicity problems and is common in polluted soils of central Spain. The purpose of this study was to explore the nutritional behaviour of this plant species towards increasing Zn concentrations in two calcic luvisol soils: a normal basic soil and a decalcified acid soil. For this purpose the effects of different Zn concentrations on mineral nutrition, growth, nodulation and nitrogenase activity of nodulated Lupinus albus cv. Multolupa plants has been investigated. A 12-week trial was performed in pots under greenhouse conditions. In each soil, four replicate pots were set up per treatment (100, 150, 300, 500 and 700 ppm Zn). Seeds were inoculated with a Bradyrhizobium sp. (Lupinus) strain ISLU-16.

Statistical analysis of data revealed significant effects of soil Zn on grown, plant mineral composition and nodulation. Lupin growth was better in acid soil than in basic soil with the low dose of Zn applied, although plant growth in acid soil was severely affected from 300 ppm Zn, where the pH of the soil was 4.7. Zn application produce nutritional imbalances, especially with the higher dose added. Most of Zn accumulation occurred in the roots in both types of soils. In acid soil, lupin absorbs high amounts of Zn in both root (4650 ppm) and aerial part (3605 ppm), when the doses of Zn applied was 300 ppm. This feature permits Lupinus albus cv. Multolupa to be considered as potential phytoremediator and also for the revegetation of degraded landfill areas with slightly acid or neutral soils polluted with Zn.     

A Versatile Vector for In Vivo Monitoring of Type I Interferon Induction and Signaling

Development of reporter systems for in vivo examination of IFN-β induction or signaling of type I interferon (IFN-I) pathways is of great interest in order to characterize biological responses to different inducers such as viral infections. Several reporter mice have been developed to monitor the induction of both pathways in response to different agonists. However, alternative strategies that do not require transgenic mice breeding have to date not been reported. In addition, detection of these pathways in vivo in animal species other than mice has not yet been addressed. Herein we describe a simple method based on the use of an adeno-associated viral vector (AAV8-3xIRF-ISRE-Luc) containing an IFN-β induction and signaling-sensitive promoter sequence controlling the expression of the reporter gene luciferase. This vector is valid for monitoring IFN-I responses in vivo elicited by diverse stimuli in different organs. Intravenous administration of the vector in C57BL/6 mice and Syrian hamsters was able to detect activation of the IFN pathway in the liver upon systemic treatment with different pro-inflammatory agents and infection with Newcastle disease virus (NDV). In addition, intranasal instillation of AAV8-3xIRF-ISRE-Luc showed a rapid and transient IFN-I response in the respiratory tract of mice infected with the influenza A/PR8/34 virus lacking the NS1 protein. In comparison, this response was delayed and exacerbated in mice infected with influenza A/PR/8 wild type virus. In conclusion, the AAV8-3xIRF-ISRE-Luc vector offers the possibility of detecting IFN-I activation in response to different stimuli and in different animal models with no need for reporter transgenic animals.