Role of Thiobacillus thioparus in the biodegradation of carbon disulfide in a biofilter packed with a recycled organic pelletized material

This study reports the biodegradation of carbon disulfide (CS₂) in air biofilters packed with a pelletized mixture of composted manure and sawdust. Experiments were carried out in two lab-scale (1.2 L) biofiltration units. Biofilter B was seeded with activated sludge enriched previously on CS₂-degrading biomass under batch conditions, while biofilter A was left as a negative inoculation control. This inoculum was characterized by an acidic pH and sulfate accumulation, and contained Achromobacter xylosoxidans as the main putative CS₂ biodegrading bacterium. Biofilter operation start-up was unsuccessfully attempted under xerophilic conditions and significant CS₂ elimination was only achieved in biofilter A upon the implementation of an intermittent irrigation regime. Sustained removal efficiencies of 90–100 % at an inlet load of up to 12 g CS₂ m^?3 h^?1 were reached. The CS₂ removal in this biofilter was linked to the presence of the chemolithoautotrophic bacterium Thiobacillus thioparus, known among the relatively small number of species with a reported capacity of growing on CS₂ as the sole energy source. DGGE molecular profiles confirmed that this microbe had become dominant in biofilter A while it was not detected in samples from biofilter B. Conventional biofilters packed with inexpensive organic materials are suited for the treatment of low-strength CS₂ polluted gases (IL <12 g CS₂ m^?3 h^?1), provided that the development of the adequate microorganisms is favored, either upon enrichment or by inoculation. The importance of applying culture-independent techniques for microbial community analysis as a diagnostic tool in the biofiltration of recalcitrant compounds has been highlighted.     

Seed dispersal by lizards on a continental‐shelf island: predicting interspecific variation in seed rain based on plant distribution and lizard movement patterns

Aim We estimated the patterns of seed deposition provided by the eyed lizard, Timon lepidus, and evaluated whether these patterns can be generalized across plant species with different traits (fruit and seed size) and spatial distributions. Location Monteagudo Island, Atlantic Islands National Park (north‐western Spain). Methods We radio‐tracked seven lizards for 14 days and estimated their home ranges using fixed kernels. We also geo‐referenced all fruit‐bearing individuals of four plant species dispersed by eyed lizards in the study area (Corema album, Osyris alba, Rubus ulmifolius and Tamus communis), measured the passage time of their seeds through the lizard gut, and estimated seed predation in four habitats (bare sand, grassland, shrub and gorse). Seed dispersal kernels were estimated using a combination of these data and were combined with seed predation probability maps to incorporate post‐dispersal seed fate (‘seed survival kernels’). Results Median seed gut‐passage times were around 52–98 h, with maximum values up to 250 h. Lizards achieved maximum displacement in their home ranges within 24–48 h. Seed predation was high (80–100% of seeds in 2 months), particularly under Corema shrub and gorse. Seed dispersal kernels showed a common pattern, with two areas of preferential seed deposition, but the importance of these varied among plant species. Interspecific differences among dispersal kernels were strongly reduced by post‐dispersal seed predation; hence, seed survival kernels of the different plant species showed high auto‐ and pairwise‐correlations at small distances (< 50 m). As a result, survival to post‐dispersal seed predation increased with dispersal distance for O. alba and T. communis, but not for C. album. Main conclusions Seed dispersal by lizards was determined primarily by the interaction between the dispersers’ home ranges and the position of the fruit‐bearing plants. As a result, seed rain shared a common template, but showed considerable variation among species, determined by their specific spatial context. Seed predation increased the spatial coherence of the seed rain of the different species, but also resulted in contrasting relationships between seed survival and dispersal distance, which may be of importance for the demographic and evolutionary processes of the plants.     

Early cognitive stimulation compensates for memory and pathological changes in Tg2576 mice

Education and cognitive occupations are commonly associated to reduce risk of Alzheimer's disease (AD) or dementia. Animal studies have demonstrated that cognitive stimulation (CS) achieved by social/physical activities and/or enriched environments compensates for memory decline. We have elaborated a novel paradigm of CS that is devoid of physical/social activity and enriched environments. 4 month-old Tg2576 mice were cognitively trained for 8 weeks and, after a break of 8 months, long-lasting effects of CS on cognitive abilities and AD-like pathology were measured. Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests showed that deficits in spatial and recognition memories were compensated by CS. These outcomes were accompanied by increased levels of hippocampal post-synaptic markers (PSD95 and NR1) and proteins involved in synaptic formation (Arc, β-catenin). CS softened amyloid pathology in terms of reduced levels of Aβ_1–42 and the dodecameric assembly, referred as Aβ*56. CS appeared to affect the APP processing since differences in levels of ADAM17, BACE1 and C99/C83 ratio were found. Tau hyper-phosphorylation and high activities of tau kinases were also reduced by CS. In contrast, CS did not induce any of these molecular changes in wild-type mice. The present findings suggest beneficial and long-lasting effects of CS early in life on cognitive decline and AD-like pathology.     

Dipeptidyl-Peptidase IV Activity Is Correlated with Colorectal Cancer Prognosis

Background

Dipeptidyl-peptidase IV (EC 3.4.14.5) (DPPIV) is a serine peptidase involved in cell differentiation, adhesion, immune modulation and apoptosis, functions that control neoplastic transformation. Previous studies have demonstrated altered expression and activity of tissue and circulating DPPIV in several cancers and proposed its potential usefulness for early diagnosis in colorectal cancer (CRC).

Methods and principal findings

The activity and mRNA and protein expression of DPPIV was prospectively analyzed in adenocarcinomas, adenomas, uninvolved colorectal mucosa and plasma from 116 CRC patients by fluorimetric, quantitative RT-PCR and immunohistochemical methods. Results were correlated with the most important classic pathological data related to aggressiveness and with 5-year survival rates. Results showed that: 1) mRNA levels and activity of DPPIV increased in colorectal neoplasms (Kruskal-Wallis test, p<0.01); 2) Both adenomas and CRCs displayed positive cytoplasmic immunostaining with luminal membrane reinforcement; 3) Plasmatic DPPIV activity was lower in CRC patients than in healthy subjects (Mann-U test, p<0.01); 4) Plasmatic DPPIV activity was associated with worse overall and disease-free survivals (log-rank p<0.01, Cox analysis p<0.01).

Conclusion/significance

1) Up-regulation of DPPIV in colorectal tumors suggests a role for this enzyme in the neoplastic transformation of colorectal tissues. This finding opens the possibility for new therapeutic targets in these patients. 2) Plasmatic DPPIV is an independent prognostic factor in survival of CRC patients. The determination of DPPIV activity levels in the plasma may be a safe, minimally invasive and inexpensive way to define the aggressiveness of CRC in daily practice.     

Are Nested Networks More Robust to Disturbance? A Test Using Epiphyte-Tree,Comensalistic Networks

Recent research on ecological networks suggests that mutualistic networks are more nested than antagonistic ones and, as a result, they are more robust against chains of extinctions caused by disturbances. We evaluate whether mutualistic networks are more nested than comensalistic and antagonistic networks, and whether highly nested, host-epiphyte comensalistic networks fit the prediction of high robustness against disturbance. A review of 59 networks including mutualistic, antagonistic and comensalistic relationships showed that comensalistic networks are significantly more nested than antagonistic and mutualistic networks, which did not differ between themselves. Epiphyte-host networks from old-growth forests differed from those from disturbed forest in several topological parameters based on both qualitative and quantitative matrices. Network robustness increased with network size, but the slope of this relationship varied with nestedness and connectance. Our results indicate that interaction networks show complex responses to disturbances, which influence their topology and indirectly affect their robustness against species extinctions.     

A customized pigmentation SNP array identifies a novel SNP associated with melanoma predisposition in the SLC45A2 gene

As the incidence of Malignant Melanoma (MM) reflects an interaction between skin colour and UV exposure, variations in genes implicated in pigmentation and tanning response to UV may be associated with susceptibility to MM. In this study, 363 SNPs in 65 gene regions belonging to the pigmentation pathway have been successfully genotyped using a SNP array. Five hundred and ninety MM cases and 507 controls were analyzed in a discovery phase I. Ten candidate SNPs based on a p-value threshold of 0.01 were identified. Two of them, rs35414 (SLC45A2) and rs2069398 (SILV/CKD2), were statistically significant after conservative Bonferroni correction. The best six SNPs were further tested in an independent Spanish series (624 MM cases and 789 controls). A novel SNP located on the SLC45A2 gene (rs35414) was found to be significantly associated with melanoma in both phase I and phase II (P<0.0001). None of the other five SNPs were replicated in this second phase of the study. However, three SNPs in TYR, SILV/CDK2 and ADAMTS20 genes (rs17793678, rs2069398 and rs1510521 respectively) had an overall p-value<0.05 when considering the whole DNA collection (1214 MM cases and 1296 controls). Both the SLC45A2 and the SILV/CDK2 variants behave as protective alleles, while the TYR and ADAMTS20 variants seem to function as risk alleles. Cumulative effects were detected when these four variants were considered together. Furthermore, individuals carrying two or more mutations in MC1R, a well-known low penetrance melanoma-predisposing gene, had a decreased MM risk if concurrently bearing the SLC45A2 protective variant. To our knowledge, this is the largest study on Spanish sporadic MM cases to date.     

The effect of antidepressant drugs on the ultradian rhythms of the locomotor activity in rats

Abstract

The effect of two antidepressant drugs (+)‐ and (‐)‐oxaprotiline hydrochloride (Ciba‐Geigy, OXA) on the exploration and the basal activity of rats in the light and dark phases of the diurnal cycle was investigated. (+)‐OXA is a selective noradrenaline (NA) uptake inhibitor, while its (‐)‐enantiomer is devoid of such an activity. Male Wistar rats housed individually on a 12:12 h light‐dark schedule (light on: 07.00 h) were treated with (+)‐ or (‐)‐OXA in a dose of 10 mg/kg twice daily, for 14 days. The rats received the last dose at the beginning of the light or dark phase and their movements were registered using Animex actometers for 12 h. The first 30 min of activity was regarded as the exploratory and the further period as the basal activity. In the light phase both (+)‐ and (‐)‐OXA decreased the exploration (80% and 70% of control, resp., p < 0.05) and potentiated it (180% and 190% of control, resp., p < 0.01) in the dark phase. The effect on the ultradian rhythm of the basal activity was phase‐dependent also. (+)‐OXA prolonged the period and did not change mesor, amplitude or acrophase of the rhythm in the light phase, and diminished mesor and amplitude, shifted acrophase and did not change period in the dark phase. (‐)‐OXA did not change parameters of the rhythm in the light phase and shortened period, diminished mesor and shifted acrophase of the rhythm in the dark phase. The results show that both (+)‐ and (‐)‐OXA given in the same dose change the same activity in opposite ways in the light and dark phases of the diurnal cycle. The NA uptake inhibition seems not to be a requisite of the light/dark phase differences.     

Impact of insect pollinators on yield and fruit quality of strawberry

Investigations were conducted to determine the insect pollinators visiting strawberry blossoms and their impact on fruit production. Various pollinators observed during the blooming period of strawberry were viz. Apis mellifera, Apis cerana, Apis florea. Apis dorsata, soil nesting solitary bees such as Andrena leana and A. ilerda, butterflies, houseflies, syrphid flies and some beetles. The percentage of fruit set was much higher in open pollinated plants than control. There was 11.20 per cent malformed fruit in open pollinated plots as compared to 17.44 per cent in controlled one. Further the fruits obtained from the open pollinated plants were of good quality and large as compared to the controlled plants. Growers are recommended to take advantage of the several pollinators, either the honey bee or the native pollinators (Syrphidae and native bees). The importance of diversifying pollination sources, avoiding the dependence on a single specific group is stressed. This study also suggests measures which envisage the conservation, establishment and increase of native pollinators’ populations in the typical agro-ecosystem of region.     

Exploring sub‐individual variability: role of ontogeny,abiotic environment and seed‐dispersing birds

• Within‐individual trait variation – otherwise known as sub‐individual variation – is an important component of phenotypic variation, with both a genetic and epigenetic basis. We explore its adaptive value and the effects of ontogeny and the environment on sub‐individual variability.
• We conducted a field study to analyse the effects of tree age, soil pH, soil water content and soil nutrients on sub‐individual variability in fruit size of hawthorn (Crataegus monogyna) in three sites in northwest Spain. Additionally, we examined how bird‐mediated selection influences average and sub‐individual variation in fruit size.
• Results show that average and sub‐individual variations in fruit size were related to fitness affecting seed dispersal. Older trees produced larger fruits, but tree age did not affect sub‐individual variation in fruit size. Abiotic environmental factors differently affected sub‐individual variation and average fruit size. Seed‐dispersing birds exerted correlated selection on average and variation in fruit size, favouring trees with larger and less variable fruit size at one site.
• Our work suggests that the fruit size variation within individual trees, the sub‐individual variation, is modified by abiotic environmental factors and, additionally, is an adaptive trait that responds to natural selection.

     

Monitoring implantable immunoisolation devices with intrinsic fluorescence of genipin

Imaging of implanted hydrogel‐based biosystems usually requires indirect labeling of the vehicle or cargo, adding complexity and potential risk of altering functionality. Here, for the first time, it is reported that incorporation of genipin into the design of immunoisolation devices can be harnessed for in vivo imaging. Using cell‐compatible in situ cross‐linking reactions, a fast, efficient and noncytotoxic procedure is shown to maximize fluorescence of microcapsules. Moreover, genipin is validated as a quantitative imaging probe by injecting increasing doses of microcapsules in the subcutaneous space of mice, obtaining strong, stable fluorescence with good linearity of signal to microcapsule dose over several weeks. This allows immediate assessment of the actual injected dose and monitoring of its position over time, thereby significantly enhancing the efficacy and biosafety of the therapy. These outcomes may facilitate clinical translation and optimize medical applications of multiple hydrogel‐based biotechnologies.