Structural collapse in kaolinite, montmorillonite and illite clay and its role in the ceramic rehydroxylation dating of low-fired earthenware

The rehydroxylation dating of ancient pottery estimates the age of ceramic manufacture based upon the total hydroxyl (OH) accumulation since initial firing. The diffusion of OH is impacted by the structural porosity of the ceramic that becomes progressively, or suddenly, closed with increasing temperature as the clay structure collapses. Changes in ceramic mineral structure along the temperature continuum occur at certain thermal set points. Infrared spectroscopic analysis of heat-treated kaolin, illite, and montmorillonite reveals that shifts in the Si-O band correlate with the extent of structural collapse occurring between 600 and 1000 degrees C. Accelerated rehydroxylation experiments reveal that the activation energy of rehydroxylation decreases with greater structural collapse and indicates that the rate of rehydroxylation will be faster for ceramics fired at more elevated temperatures. (C) 2016 Elsevier Ltd. All rights reserved

Plasmodium chabaudi AS Infection Induces CD4+ Th1 Cells and Foxp3+T-bet+ Regulatory T Cells That Express CXCR3 and Migrate to CXCR3 Ligands

Control and elimination of blood-stage Plasmodium chabaudi AS infection requires CD4+ Th1 cells that secrete IFN-γ and T follicular help (Tfh) cells together with B cell production of antibody. Foxp3+ regulatory T cells (Tregs) are also crucial to protect the host from immunopathology and severe disease, but these cells can suppress protective immune responses to malaria. The chemokine receptor CXCR3 expressed by activated T cells is important for trafficking of CD4+ Th1 cells to sites of inflammation and infection. Previous studies demonstrated CXCR3 is expressed on CD4+ T cells in the spleen during malaria, but the phenotype was not defined. We identified the phenotype of CD4+ T cells that expressed CXCR3 in C57BL/6 (B6) mice during acute P. chabaudi AS infection by analyzing expression of the transcription factors T-bet and Foxp3. We also investigated if CXCR3 contributes to control of parasite replication and survival. The frequency and number of CD4+CXCR3+ T cells increased dramatically in the spleen of infected B6 mice coincident with increased CD4+IFN-γ+ T cells. CXCR3 was up-regulated on effector CD4+Foxp3− T cells as well as Foxp3+ Tregs. Consistent with our previous observations, CD4+T-bet+Foxp3− T cells increased in B6 mice during acute infection. T-bet+Foxp3+ Tregs also increased significantly and a high frequency of these cells expressed CXCR3 supporting the notion that these cells may be Th1-like Tregs. Despite this, the percentage of CD4+Foxp3+ Tregs from infected B6 mice that migrated in vitro to the CXCR3 ligands CXCL9 and CXCL10 was significantly less than naïve mice. To investigate the in vivo contribution of CXCR3 to control of acute blood-stage malaria, we compared the course and outcome of P. chabaudi AS infection in wild-type (WT) B6 and CXCR3-deficient mice. Parasitemia levels were significantly higher around the time of peak parasitemia in CXCR3−/− compared to WT mice but survival was similar suggesting a role for CXCR3 in controlling parasite replication during acute P. chabaudi AS infection. Together, our findings indicate Th1-like CD4+T-bet+Foxp3+ Tregs that express CXCR3 are induced during acute blood-stage malaria and suggest CXCR3 expression on CD4+ Th1 cells may contribute to their migration to the spleen

Complex genetic control of susceptibility to malaria: positional cloning of the Char9 locus

Mouse strains AcB55 and AcB61 are resistant to malaria by virtue of a mutation in erythrocyte pyruvate kinase (PklrI90N). Linkage analysis in [AcB55 × A/J] F2 mice detected a second locus (Char9; logarithm of odds = 4.74) that regulates the blood-stage replication of Plasmodium chabaudi AS independently of Pklr. We characterized the 77 genes of the Char9 locus for tissue-specific expression, strain-specific alterations in gene expression, and polymorphic variants that are possibly associated with differential susceptibility. We identified Vnn1/Vnn3 as the likely candidates responsible for Char9. Vnn3/Vnn1 map within a conserved haplotype block and show expression levels that are strictly cis-regulated by this haplotype. The absence of Vnn messenger RNA expression and lack of pantetheinase protein activity in tissues are associated with susceptibility to malaria and are linked to a complex rearrangement in the Vnn3 promoter region. The A/J strain also carries a unique nonsense mutation that leads to a truncated protein. Vanin genes code for a pantetheinase involved in the production of cysteamine, a key regulator of host responses to inflammatory stimuli. Administration of cystamine in vivo partially corrects susceptibility to malaria in A/J mice, as measured by reduced blood parasitemia and decreased mortality. These studies suggest that pantetheinase is critical for the host response to malaria

Proteomic Analysis of Excretory-Secretory Products of Heligmosomoides polygyrus Assessed with Next-Generation Sequencing Transcriptomic Information

The murine parasite Heligmosomoides polygyrus is a convenient experimental model to study immune responses and pathology associated with gastrointestinal nematode infections. The excretory-secretory products (ESP) produced by this parasite have potent immunomodulatory activity, but the protein(s) responsible has not been defined. Identification of the protein composition of ESP derived from H. polygyrus and other relevant nematode species has been hampered by the lack of genomic sequence information required for proteomic analysis based on database searches. To overcome this, a transcriptome next generation sequencing (RNA-seq) de novo assembly containing 33,641 transcripts was generated, annotated, and used to interrogate mass spectrometry (MS) data derived from 1D-SDS PAGE and LC-MS/MS analysis of ESP. Using the database generated from the 6 open reading frames deduced from the RNA-seq assembly and conventional identification programs, 209 proteins were identified in ESP including homologues of vitellogenins, retinol- and fatty acid-binding proteins, globins, and the allergen V5/Tpx-1-related family of proteins. Several potential immunomodulators, such as macrophage migration inhibitory factor, cysteine protease inhibitors, galectins, C-type lectins, peroxiredoxin, and glutathione S-transferase, were also identified. Comparative analysis of protein annotations based on the RNA-seq assembly and proteomics revealed processes and proteins that may contribute to the functional specialization of ESP, including proteins involved in signalling pathways and in nutrient transport and/or uptake. Together, these findings provide important information that will help to illuminate molecular, biochemical, and in particular immunomodulatory aspects of host-H. polygyrus biology. In addition, the methods and analyses presented here are applicable to study biochemical and molecular aspects of the host-parasite relationship in species for which sequence information is not available

Three Week Hypergravity Training Intervention Decreases Ground Contact Time During Repeated Jumping and Improves Sprinting and Shuttle Running Performance

International Journal of Exercise Science 9(2): 149-158, 2016. This study examined the effects of a non-traditional training method, hypergravity training (HT), on anaerobic performance. Highly active men (n = 9) completed a 3 week HT protocol in which weighted vests were worn 8 h/day, 4+ days/week separate from training. Vest loads were 11.2 ± 0.6% of body mass during week one, and increased to 13.2 ± 0.7% (week 2), and 16.1 ± 0.4% (week 3). Performance testing included power clean 1-RM (PC), counter movement jumps, 4 continuous jumps, 36.6 m sprints (SP), a 137.2 m short shuttle run (SSR), and a 274.3 m long shuttle run (LSR). A 3 week non-hypergravity training period (NHT) proceeded HT. Baseline SP improved from 4.69 ± 0.29 s to 4.58 ± 0.22 s post-treatment, and regressed after NHT (4.69 ± 0.24 s) (p = 0.006, ES = 1.80). Improvements in SSR (p = 0.012, ES = 1.71) occurred from baseline (26.7 ± 1.5 s) to post-treatment (26.2 ± 1.4 s), followed by a return to near-baseline values (26.9 ± 1.8 s). Jumping tasks displayed similar trends, but no statistical differences and modest effect sizes (0.51 - 0.62) were found except for improved ground contact time during repeated jumps post-HT (ES = 2.26). PC and LSR performances did not improve. Three weeks of HT significantly enhanced short running task performances and decreased ground contact time between 4 continuous jumps. HT may be incorporated into training programs prior to key points in an athletic season without hindering the quality of regular training session activities

ESTimating plant phylogeny: lessons from partitioning

BACKGROUND: While Expressed Sequence Tags (ESTs) have proven a viable and efficient way to sample genomes, particularly those for which whole-genome sequencing is impractical, phylogenetic analysis using ESTs remains difficult. Sequencing errors and orthology determination are the major problems when using ESTs as a source of characters for systematics. Here we develop methods to incorporate EST sequence information in a simultaneous analysis framework to address controversial phylogenetic questions regarding the relationships among the major groups of seed plants. We use an automated, phylogenetically derived approach to orthology determination called OrthologID generate a phylogeny based on 43 process partitions, many of which are derived from ESTs, and examine several measures of support to assess the utility of EST data for phylogenies. RESULTS: A maximum parsimony (MP) analysis resulted in a single tree with relatively high support at all nodes in the tree despite rampant conflict among trees generated from the separate analysis of individual partitions. In a comparison of broader-scale groupings based on cellular compartment (ie: chloroplast, mitochondrial or nuclear) or function, only the nuclear partition tree (based largely on EST data) was found to be topologically identical to the tree based on the simultaneous analysis of all data. Despite topological conflict among the broader-scale groupings examined, only the tree based on morphological data showed statistically significant differences. CONCLUSION: Based on the amount of character support contributed by EST data which make up a majority of the nuclear data set, and the lack of conflict of the nuclear data set with the simultaneous analysis tree, we conclude that the inclusion of EST data does provide a viable and efficient approach to address phylogenetic questions within a parsimony framework on a genomic scale, if problems of orthology determination and potential sequencing errors can be overcome. In addition, approaches that examine conflict and support in a simultaneous analysis framework allow for a more precise understanding of the evolutionary history of individual process partitions and may be a novel way to understand functional aspects of different kinds of cellular classes of gene products

Performance and perceptual responses of collegiate female soccer players to a practical external and internal cooling protocol

International Journal of Exercise Science 8(4): 331-340, 2015. This study examined practical pre- and mid practice cooling interventions on running performance, perceived exertion (RPE), and thermal sensation (TS) during soccer. During two formal pre-season practices female, NCAA Division II soccer players participated in three, 15 min scrimmage bouts followed by a 4th 10 min bout. Following the 1st, 2nd, and 3rd bouts, 8 field position players completed competitive sets of two, 30 yard sprints against other team members with time recorded between 5 and 30 yards. After the 4th bout, players completed an indoor shuttle running beep test (BT). In the treatment group (COOL) ice towels (IT) were applied to the head and neck regions and draped across both legs for 10 min following a standardized warm-up and for 10 min during a 15 min break between the 2nd and 3rd scrimmage sessions. Sport beverage slurries (350 mL; -0.3 °C, ~6% carbohydrate) were also served during IT cooling for COOL; while the control (CON) received no IT and drank the same ,uncooled sport beverage. No main effect was found for sprint performance (COOL = 3.55 ± 0.16 s; CON = 3.51 ± 0.07 s; P = 0.51) or numbers of reps completed in the BT (COOL = 17.6 ± 5.6; CON = 17.3 ± 6.0; P = 0.88). RPE did not differ following any performance test, but TS was lower following the 3rd sprint bout (P = 0.04) and the BT (P = 0.005) for COOL. COOL promoted lower TS, but had no effect on performance

Mouse Intestine Selects Nonmotile \u3cem\u3eflhDC\u3c/em\u3e Mutants of \u3cem\u3eEscherichia coli\u3c/em\u3e MG1655 with Increased Colonizing Ability and Better Utilization of Carbon Sources

d-Gluconate which is primarily catabolized via the Entner-Doudoroff (ED) pathway, has been implicated as being important for colonization of the streptomycin-treated mouse large intestine by Escherichia coli MG1655, a human commensal strain. In the present study, we report that an MG1655 Δedd mutant defective in the ED pathway grows poorly not only on gluconate as a sole carbon source but on a number of other sugars previously implicated as being important for colonization, including l-fucose, d-gluconate, d-glucuronate, N-acetyl-d-glucosamine, d-mannose, and d-ribose. Furthermore, we show that the mouse intestine selects mutants of MG1655 Δedd and wild-type MG1655 that have improved mouse intestine-colonizing ability and grow 15 to 30% faster on the aforementioned sugars. The mutants of MG1655 Δedd and wild-type MG1655 selected by the intestine are shown to be nonmotile and to have deletions in the flhDC operon, which encodes the master regulator of flagellar biosynthesis. Finally, we show that ΔflhDC mutants of wild-type MG1655 and MG1655 Δedd constructed in the laboratory act identically to those selected by the intestine; i.e., they grow better than their respective parents on sugars as sole carbon sources and are better colonizers of the mouse intestine