Biodeterioration of Mayan buildings at uxmal and tulum,Mexico

Uxmal and Tulum are two important Mayan sites in the Yucatan peninsula. The buildings are mainly composed of limestone and grey/black discoloration is seen on exposed walls and copious greenish biofilms on inner walls. The principal microorganisms detected on interior walls at both Uxmal and Tulum were cyanobacteria; heterotrophic bacteria and filamentous fungi were also present. A dark‐pigmented mitosporic fungus and Bacillus cereus, both isolated from Uxmal, were shown to be acidogenic in laboratory cultures. Cyanobacteria belonging to rock‐degrading genera Synechocystis and Gloeocapsa were identified at both sites. Surface analysis previously showed that calcium ions were present in the biofilms on buildings at Uxmal and Tulum, suggesting the deposition of biosolubilized stone. Apart from their potential to degrade the substrate, the coccoid cyanobacteria supply organic nutrients for bacteria and fungi, which can produce organic acids, further increasing stone degradation.     

Biocontrol agents promote growth of potato pathogens,depending on environmental conditions

There is a pressing need to understand and optimize biological control so as to avoid over‐reliance on the synthetic chemical pesticides that can damage environmental and human health. This study focused on interactions between a novel biocontrol‐strain, Bacillus sp. JC12GB43, and potato‐pathogenic Phytophthora and Fusarium species. In assays carried out in vitro and on the potato tuber, the bacterium was capable of near‐complete inhibition of pathogens. This Bacillus was sufficiently xerotolerant (water activity limit for growth = 0.928) to out‐perform Phytophthora infestans (~0.960) and challenge Fusarium coeruleum (~0.847) and Fusarium sambucinum (~0.860) towards the lower limits of their growth windows. Under some conditions, however, strain JC12GB43 stimulated proliferation of the pathogens: for instance, Fusarium coeruleum growth‐rate was increased under chaotropic conditions in vitro (132 mM urea) by >100% and on tubers (2‐M glycerol) by up to 570%. Culture‐based assays involving macromolecule‐stabilizing (kosmotropic) compatible solutes provided proof‐of‐principle that the Bacillus may provide kosmotropic metabolites to the plant pathogen under conditions that destabilize macromolecular systems of the fungal cell. Whilst unprecedented, this finding is consistent with earlier reports that fungi can utilize metabolites derived from bacterial cells. Unless the antimicrobial activities of candidate biocontrol strains are assayed over a full range of field‐relevant parameters, biocontrol agents may promote plant pathogen infections and thereby reduce crop yields. These findings indicate that biocontrol activity, therefore, ought to be regarded as a mode‐of‐behaviour (dependent on prevailing conditions) rather than an inherent property of a bacterial strain.     

Cecal Ligation and Puncture Results in Long-Term Central Nervous System Myeloid Inflammation

Survivors of sepsis often experience long-term cognitive and functional decline. Previous studies utilizing lipopolysaccharide injection and cecal ligation and puncture in rodent models of sepsis have demonstrated changes in depressive-like behavior and learning and memory after sepsis, as well as evidence of myeloid inflammation and cytokine expression in the brain, but the long-term course of neuroinflammation after sepsis remains unclear. Here, we utilize cecal ligation and puncture with greater than 80% survival as a model of sepsis. We found that sepsis survivor mice demonstrate deficits in extinction of conditioned fear, but no acquisition of fear conditioning, nearly two months after sepsis. These cognitive changes occur in the absence of neuronal loss or changes in synaptic density in the hippocampus. Sepsis also resulted in infiltration of monocytes and neutrophils into the CNS at least two weeks after sepsis in a CCR2 independent manner. Cellular inflammation is accompanied by long-term expression of pro-inflammatory cytokine and chemokine genes, including TNFα and CCR2 ligands, in whole brain homogenates. Gene expression analysis of microglia revealed that while microglia do express anti-microbial genes and damage-associated molecular pattern molecules of the S100A family of genes at least 2 weeks after sepsis, they do not express the cytokines observed in whole brain homogenates. Our results indicate that in a naturalistic model of infection, sepsis results in long-term neuroinflammation, and that this sustained inflammation is likely due to interactions among multiple cell types, including resident microglia and peripherally derived myeloid cells.     

Inhibition of Phosphoinositide 3-Kinase p110delta Does Not Affect T Cell Driven Development of Type 1 Diabetes Despite Significant Effects on Cytokine Production

Type 1 diabetes is caused by the destruction of insulin producing beta cells by the immune system. The p110δ isoform of PI3K is expressed primarily in cells of haematopoietic origin and the catalytic activity of p110δ is important for the activation of these cells. Targeting of this pathway offers an opportunity to reduce immune cell activity without unwanted side effects. We have explored the effects of a specific p110δ isoform inhibitor, IC87114, on diabetogenic T cells both in vitro and in vivo, and find that although pharmacological inhibition of p110δ has a considerable impact on the production of pro-inflammatory cytokines, it does not delay the onset of diabetes after adoptive transfer of diabetogenic cells. Further, we demonstrate that combination treatment with CTLA4-Ig does not improve the efficacy of treatment, but instead attenuates the protective effects seen with CTLA4-Ig treatment alone. Our results suggest that decreased IL-10 production by Foxp3⁺ CD4⁺ T cells in the presence of IC87114 negates individual anti-inflammatory effects of IC8114 and CTLA4-Ig.     

Epistatic Gene-Based Interaction Analyses for Glaucoma in eMERGE and NEIGHBOR Consortium

Primary open angle glaucoma (POAG) is a complex disease and is one of the major leading causes of blindness worldwide. Genome-wide association studies have successfully identified several common variants associated with glaucoma; however, most of these variants only explain a small proportion of the genetic risk. Apart from the standard approach to identify main effects of variants across the genome, it is believed that gene-gene interactions can help elucidate part of the missing heritability by allowing for the test of interactions between genetic variants to mimic the complex nature of biology. To explain the etiology of glaucoma, we first performed a genome-wide association study (GWAS) on glaucoma case-control samples obtained from electronic medical records (EMR) to establish the utility of EMR data in detecting non-spurious and relevant associations; this analysis was aimed at confirming already known associations with glaucoma and validating the EMR derived glaucoma phenotype. Our findings from GWAS suggest consistent evidence of several known associations in POAG. We then performed an interaction analysis for variants found to be marginally associated with glaucoma (SNPs with main effect p-value <0.01) and observed interesting findings in the electronic MEdical Records and GEnomics Network (eMERGE) network dataset. Genes from the top epistatic interactions from eMERGE data (Likelihood Ratio Test i.e. LRT p-value <1e-05) were then tested for replication in the NEIGHBOR consortium dataset. To replicate our findings, we performed a gene-based SNP-SNP interaction analysis in NEIGHBOR and observed significant gene-gene interactions (p-value <0.001) among the top 17 gene-gene models identified in the discovery phase. Variants from gene-gene interaction analysis that we found to be associated with POAG explain 3.5% of additional genetic variance in eMERGE dataset above what is explained by the SNPs in genes that are replicated from previous GWAS studies (which was only 2.1% variance explained in eMERGE dataset); in the NEIGHBOR dataset, adding replicated SNPs from gene-gene interaction analysis explain 3.4% of total variance whereas GWAS SNPs alone explain only 2.8% of variance. Exploring gene-gene interactions may provide additional insights into many complex traits when explored in properly designed and powered association studies.     

Length polymorphisms at two candidate genes explain variation of migratory behaviors in blackpoll warblers (Setophaga striata)

Migratory behaviors such as the timing and duration of migration are genetically inherited and can be under strong natural selection, yet we still know very little about the specific genes or molecular pathways that control these behaviors. Studies in candidate genes Clock and Adcyap1 have revealed that both of these loci can be significantly correlated with migratory behaviors in birds, though observed relationships appear to vary across species. We investigated geographic genetic structure of Clock and Adcyap1 in four populations of blackpoll warblers (Setophaga striata), a Neotropical–Nearctic migrant that exhibits geographic variation in migratory timing and duration across its boreal breeding distribution. Further, we used data on migratory timing and duration, obtained from light‐level geolocator trackers to investigate candidate genotype–phenotype relationships at the individual level. While we found no geographic structure in either candidate gene, we did find evidence that candidate gene lengths are correlated with five of the six migratory traits. Maximum Clock allele length was significantly and negatively associated with spring arrival date. Minimum Adcyap1 allele length was significantly and negatively associated with spring departure date and positively associated with fall arrival date at the wintering grounds. Additionally, we found a significant interaction between Clock and Adcyap1 allele lengths on both spring and fall migratory duration. Adcyap1 heterozygotes also had significantly shorter migration duration in both spring and fall compared to homozygotes. Our results support the growing body of evidence that Clock and Adcyap1 allele lengths are correlated with migratory behaviors in birds.     

The F box protein S phase kinase-associated protein 2 regulates adipose mass and adipocyte number in vivo

Objective: The etiology of some obesity may involve adipocyte hyperplasia. However, the role of adipocyte number in establishing adipose mass is unclear. Cyclin‐dependent kinase inhibitor p27 regulates activity of cyclin/cyclin‐dependent kinase complexes responsible for cell cycle progression. This protein is critical for establishing adult adipocyte number, and p27 knockout increases adult adipocyte number. The SCF (for Skp1‐Cullin‐F‐box protein) complex targets proteins such as p27 for ubiquitin‐proteosome degradation; the F box protein S phase kinase‐associated protein 2 (Skp2), a component of the SCF complex, specifically recognizes p27 for degradation. We used Skp2 knockout (Skp2^?/?) mice to test whether Skp2 loss decreased adipose mass and adipocyte number. Research Methods and Procedures: We measured body weight, adipose mass, adipocyte diameter and number, and glucose tolerance in wild‐type (WT), Skp2^?/?, and p27^?/?Skp2^?/? mice. Mouse embryo fibroblasts (MEFs) from WT and Skp2^?/? fetuses were differentiated to determine whether Skp2 directly affected adipogenesis. Results: Skp2^?/? mice had a 50% decrease in both subcutaneous and visceral fat pad mass and adipocyte number; these decreases exceeded those in body weight, kidney, or muscle. To test the hypothesis that Skp2 effects on adipocyte number involved p27 accumulation, we used p27^?/?Skp2^?/? double knockout mice. The Skp2^?/? decrements in adipocyte number and fat pad mass were totally reversed in p27^?/?Skp2^?/? mice. Adipogenesis was inhibited in MEFs from Skp2^?/? vs. WT mice, and this inhibition was absent in MEFs from p27^?/?Skp2^?/? mice. Discussion: Our results indicate that Skp2 regulates adipogenesis and ultimate adipocyte number in vivo; thus, Skp2 may contribute to obesity involving adipocyte hyperplasia.     

Does a High‐protein Diet Improve Weight Loss in Overweight and Obese Children?

Objective: To evaluate the effect of a high‐protein diet on anthropometry, body composition, subjective appetite, and mood sensations in overweight and obese children attending a residential weight‐loss camp. Research Methods and Procedures: Children (120; BMI, 33.1 ± 5.5 kg/m²; age, 14.2 ± 1.9 years) were randomly assigned to either a standard or high‐protein diet group (15% vs. 22.5% protein, respectively). All children were assessed at baseline and at the end of the camp for anthropometry, body composition, blood pressure, biochemical variables (n = 27), and subjective appetite and mood sensations (n = 50). Results: Attendance at the weight‐loss camp resulted in significant improvements in most measures. Campers lost 5.5 ± 2.9 kg in body weight (p < 0.001) and 3.8 ± 5.4 kg in fat mass (p < 0.001) and reduced their BMI standard deviation score by 0.27 ± 0.1 (p < 0.001) and their waist circumference by 6.6 ± 2.8 cm (p < 0.001). Subjective sensations of hunger increased significantly over the camp duration, but no other changes in appetite or mood were observed. There were no significant differences between the two diets on any physical or subjective measures. Discussion: Weight‐loss camps are effective in assisting children to lose weight and improve on a range of health outcomes, independently of the protein content of the diet. The implications of an increase in hunger associated with weight loss needs to be considered. Further work is warranted to investigate whether higher levels of dietary protein are feasible or effective in longer‐term weight‐loss interventions of this type.     

Coloured LED light as a potential behavioural guidance tool for age 0 and 2 year walleye Sander vitreus

Based on existing laboratory research on the visual physiology of walleye Sander vitreus, we tested colours of known spectral sensitivity (i.e., green and orange) using constant and strobing (5 Hz) illumination with an LED-based light guidance device (LGD). Hatchery-reared age 0 and 2 years S. vitreus were exposed to these four light combinations as well as an unilluminated control treatment during day and night trials. Age 2 years S. vitreus generally avoided the LGD when light was produced (negative phototaxis) compared with the control, with continuous illumination having a greater effect than strobing. The proportions of both age 0 and 2 year fish exiting illuminating zones of the trial arena did not differ with light colour or strobe rate, suggesting that phototactic behaviours in S. vitreus do not change with ontogeny in these age classes. Our findings confirm that typical behavioural responses of S. vitreus to light stimuli are characterised by avoidance and provide evidence that the use of light for behavioural guidance (deterrence) may be effective at reducing entrainment and impingement of this species on hydraulic barriers during migrations, independent of ontogenetic stage.     

Effects of predator exposure on baseline and stress-induced glucocorticoid hormone concentrations in pumpkinseed Lepomis gibbosus

We compared baseline and maximal cortisol concentrations between predator exposure and prey blood samples in pumpkinseed Lepomis gibbosus, captured using a standardised fishing event underneath osprey Pandion haliaetus nests and away from osprey nests. We did not detect differences in cortisol or glucose between sites. These findings suggest that predictable sources of predation risk may not confer stress-related costs in teleosts.