bluuebunny/crossref_metadata_2025 huggingface dataset:
Emissions of Sulfur‐Containing Odorants, Ammonia, and Methane from Pig Slurry: Effects of Dietary Methionine and Benzoic Acid
Authors: Eriksen Jørgen , Adamsen Anders Peter S. , Nørgaard Jan V. , Poulsen Hanne D. , Jensen Bent Borg , Petersen Søren O.
Published: April 2010

Supplementation of benzoic acid to pig diets reduces the pH of urine and may thereby affect emissions of ammonia and other gases from slurry, including sulfur‐containing compounds that are expected to play a role in odor emission. Over a period of 112 d, we investigated hydrogen sulfide (H2S), methanethiol (MT), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), and dimethyl trisulfide (DMTS), as well as ammonia and methane emissions from stored pig slurry. The slurry was derived from a feeding experiment with four pig diets in a factorial design with 2% (w/w) benzoic acid and 1% (w/w) methionine supplementation as treatments. Benzoic acid reduced slurry pH by 1 to 1.5 units and ammonia emissions by 60 to 70% for up to 2 mo of storage, and a considerable, but transitory reduction of methane emissions was also observed after 4 to 5 wk. All five volatile sulfur (S) compounds were identified in gas emitted from the slurry of the control treatment, which came from pigs fed according to Danish recommendations for amino acids and minerals. The emission patterns of volatile S compounds suggested an intense cycling between pools of organic S in the slurries, with urinary sulfate as the main source. Diet supplementation with methionine significantly increased all S emissions. Diet supplementation with benzoic acid reduced emissions of H2S and DMTS compared with the control slurry and moderately increased the concentrations of MT. Sulfur gas emissions were influenced by a strong interaction between methionine and benzoic acid treatments, which caused a significant increase in emissions of especially MT, but also of DMDS. In conclusion, addition of 2% benzoic acid to pig diets effectively reduced ammonia volatilization, but interactions with dietary S may increase odor problems.
Effect of Road Salt Application on Seasonal Chloride Concentrations and Toxicity in South‐Central Indiana Streams
Authors: Gardner Kristin M. , Royer Todd V
Published: April 2010

Contemporary information on road salt runoff is needed for management of water resources in regions experiencing urbanization and increased road density. We investigated seasonal Cl− concentrations among five streams in south‐central Indiana that drained watersheds varying in degree of urbanization and ranging in size from 9.3 to 27 km2 We also conducted acute toxicity tests with Daphnia pulex to assess the potential effects of the observed Cl− concentrations on aquatic life. Periods of elevated Cl− concentrations were observed during the winters of 2007–08 and 2008–09 at all sites except the reference site. The highest Cl− concentration observed during the study was 2100 mg L−1 and occurred at the most urbanized site. The Cl− concentration at the reference site never exceeded 22 mg L−1 The application of road salt caused large increases in stream Cl− concentrations, but the elevated Cl− levels did not appear to be a significant threat to aquatic life based on our toxicity testing. Only the most urbanized site showed evidence of salt retention within the watershed, whereas the other sites exported the road salt relatively quickly after its application, suggesting storm drains and impervious surfaces minimized interaction between soils and salt‐laden runoff. During winter at these sites, the response in stream Cl− concentrations appeared to be controlled by the timing and intensity of road salt application, the magnitude of precipitation, and the occurrence of air temperatures that caused snowmelt and generated runoff.
Microbial Degradation of Plant Leachate Alters Lignin Phenols and Trihalomethane Precursors
Authors: Pellerin Brian A. , Hernes Peter J. , Saraceno JohnFranco , Spencer Robert G. M. , Bergamaschi Brian A.
Published: April 2010

Although the importance of vascular plant–derived dissolved organic carbon (DOC) in freshwater systems has been studied, the role of leached DOC as precursors of disinfection byproducts (DBPs) during drinking water treatment is not well known. Here we measured the propensity of leachates from four crops and four aquatic macrophytes to form trihalomethanes (THMs)—a regulated class of DBPs—before and after 21 d of microbial degradation. We also measured lignin phenol content and specific UV absorbance (SUVA254) to test the assumption that aromatic compounds from vascular plants are resistant to microbial degradation and readily form DBPs. Leaching solubilized 9 to 26% of total plant carbon, which formed 1.93 to 6.72 mmol THM mol C−1 However, leachate DOC concentrations decreased by 85 to 92% over the 21‐d incubation, with a concomitant decrease of 67 to 92% in total THM formation potential. Carbon‐normalized THM yields in the residual DOC pool increased by 2.5 times on average, consistent with the preferential uptake of nonprecursor material. Lignin phenol concentrations decreased by 64 to 96% over 21 d, but a lack of correlation between lignin content and THM yields or SUVA254 suggested that lignin‐derived compounds are not the source of increased THM precursor yields in the residual DOC pool. Our results indicate that microbial carbon utilization alters THM precursors in ecosystems with direct plant leaching, but more work is needed to identify the specific dissolved organic matter components with a greater propensity to form DBPs and affect watershed management, drinking water quality, and human health.
Study on degradation of acid orange II in aqueous solution using one-dimensional MnO2 nanorods
Authors: Sun Hongmei , Chen Hongyu , Shu Dong , Xie Zhengyi , He Chun , Peng Liangbo
Published: April 2010

MnO2 nanorods were prepared by the reaction of KMnO4 and MnSO4 in aqueous media and subsequently followed by hydrothermal methods. The structure and surface morphology of as-prepared powder were characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results indicated that the prepared MnO2 possessed α- and γ structure. SEM observations showed that the obtained MnO2 powder possessed a well-defined one-dimensional nanorod-like shape 100 nm wide and 700 nm long. The surface area of the MnO2 nanorods was 92 m2 g−1. The degradation efficiency of MnO2 nanorods towards the organic pollutants in aqueous solution was evaluated using acid orange II as a model dye. It was found that the degradation efficiency of MnO2 nanorods was a function of initial acid orange II concentration, MnO2 nanorods concentration, and the proton concentration. The apparent reaction orders for the initial acid orange II concentration, MnO2 nanorods concentration and the proton concentration were determined to be −0.76, 0.37 and 0.12, respectively. It was found that the degradation efficiency for 60 ppm acid orange II reached 99% with 0.5 g L−1 MnO2 nanorods concentration at pH 2.0 after 60 min, demonstrating its higher degradation efficiency in aqueous solution. The apparent activation energy of the degradation reaction of acid orange II was calculated to be 17.3 kJ mol−1. Furthermore, MnO2 nanorods were demonstrated to have superior durability during regeneration tests.
Comparative analysis of time-scaling properties about water pH in Poyang Lake Inlet and Outlet on the basis of fractal methods
Authors: Shi K. , Liu C. Q. , Huang Z. W. , Zhang B. , Su Y.
Published: April 2010

Detrended fluctuation analysis (DFA) and multifractal methods are applied to the time-scaling properties analysis of water pH series in Poyang Lake Inlet and Outlet in China. The results show that these pH series are characterised by long-term memory and multifractal scaling, and these characteristics have obvious differences between the Lake Inlet and Outlet. The comparison results suggest that monofractal and multifractal parameters can be quantitative dynamical indexes reflecting the capability of anti-acidification of Poyang Lake. Furthermore, we investigated the frequency-size distribution of pH series in Poyang Lake Inlet and Outlet. Our findings suggest that water pH is an example of a self-organised criticality (SOC) process. The results show that it is different SOC behaviours that result in the differences of power-law relations between pH series in Poyang Lake Inlet and Outlet. This work can be helpful to improvement of modelling of lake water quality.
Development and optimization of a sequencing batch reactor for nitrogen and phosphorus removal from abattoir wastewater to meet irrigation standards
Authors: Pijuan Maite , Yuan Zhiguo
Published: April 2010

A sequencing batch reactor (SBR) was used for the treatment of abattoir wastewater to produce effluent with desirable nitrogen and phosphorus levels for irrigation. The SBR cycle consisted of an anaerobic phase with wastewater feeding, a relatively short aerobic period (allowing full ammonium oxidation), a second anoxic period with feeding, followed by settling and decanting. This design of operation allowed biological nitrification and denitrification via nitrite, and therefore with reduced demand for aeration and COD for nitrogen removal. The design also allowed ammonium, rather than oxidized nitrogen, being the primary nitrogen species in the effluent. Biological phosphorus removal was also achieved, with an effluent level desirable for irrigation. A high-level of nitrite accumulation (40 mg N/L) in the reactor caused inhibition to the biological P uptake. This problem was solved through process optimization. The cycle time of the SBR was reduced, with the wastewater load per cycle also reduced, while the daily hydraulic loading maintained. This modification proved to be an effective method to ensure reliable N and P removal. N2O accumulation was measured in two experiments simulating the anoxic phase of the SBR and using nitrite and nitrate respectively as electron donors. The estimated N2O emissions for both experiments were very low.
The Effect of Proposition 2 on the Demand for Eggs in California
Authors: Lusk Jayson L
Published: April 2010

Californians recently passed Proposition 2, barring the use of cages in egg production in the state. Because most consumers are unknowledgeable of egg production practices, the appearance of Proposition 2 likely served as an information shock that potentially affected consumer demand. In this paper, we use scanner data to investigate the market effects of Proposition 2 by studying whether and how consumer demand for eggs changed in the months leading up to the vote in San Francisco and Oakland. Results indicate that demand for the types of eggs associated with higher animal welfare standards, cage free and organic, increased over time and in response to articles on the proposition whereas demand for other types of eggs fell. These results coupled with the finding that cage free and organic egg demand was virtually unchanged in a location unaffected by the vote, Dallas, suggests that Proposition 2 had a significant effect on consumer preferences for eggs  increasing demand for cage free and organic eggs by 180% and 20%, respectively.
Effects of acid treatment duration and sulfuric acid molarity on purification of multi-walled carbon nanotubes
Authors: Mortazavi Seyedeh , Novinrooz Abdul , Reyhani Ali , Mirershadi Soghra
Published: April 2010

Multi-walled carbon nanotubes were synthesized using a Fe-Ni bimetallic catalyst supported by MgO using thermal chemical vapor deposition. Purification processes to remove unwanted carbon structures and other metallic impurities were carried out by boiling in sulfuric acid solution. Various analytical techniques such as TGA/DSC, Raman spectroscopy, SEM, HRTEM and EDAX were employed to investigate the morphology, graphitization and quality of the carbon nanotubes. The obtained results reveal the molarity of sulfuric acid and immersed time of the carbon nanotubes in the acid solution is very effective at purifying multi-walled carbon nanotubes. It was also found that 5 M concentration of boiling sulfuric acid for a 3 h treatment duration led to the highest removal of the impurities with the least destructive effect. Moreover, it was observed that acid treatment results in decreasing of CNTs’ diameter.
Spinor model of a perfect fluid
Authors: Saha Bijan
Published: April 2010

Different characteristics of matter influencing the evolution of the uUniverse haves been simulated by means of a nonlinear spinor field. We have considered two cases where the spinor field nonlinearity occurs either as a result of self-action or due to the interaction with a scalar field.
Inoculation with a bacterial consortium alleviates the effect of cadmium overdose in soybean plants
Authors: Zaets Iryna , Kramarev Sergij , Kozyrovska Natalia
Published: April 2010

Inoculating plants that have inefficient antioxidant systems with plant-associated bacteria allows them to overcome heavy metal intoxication. We monitored protein oxidation, the activity of plant defense system enzymes, and the phenolics content in soybean (Glycine max L.) during a prolonged exposure to cadmium (Cd). The assistance of the bacterial consortium reduced the bioavailability of Cd in a soil containing 10 times the metal’s Standard Maximum Value (SMV). This reduced the accumulation of Cd in the soybeans’ roots and seeds. At 100 SMV, bacterial inoculation resulted in increased Cd bioavailability, which enhanced cadmium uptake by the soybean plants. At both Cd concentrations, oxidative stress was more prolonged in the soybean’s roots than its leaves. In cadmium-polluted soil, glutathion peroxidase activity changed more rapidly in the roots of plants when they had been inoculated. Inhibition of the peroxidases’ activities strengthened the activity of glutathione-S-transferase; increased the phenolics content in plant roots; and alleviated stress in inoculated soybean plants compared to untreated plants. The bacterial consortium may be recommended for a plant protection at 10 SMV Cd in the soil, and for phytostabilization at 100 SMV.
Synergy between Salvia officinalis L. and some preservatives
Authors: Stanojević Dragana , Čomić Ljiljana , Stefanović Olgica
Published: April 2010

The aim of the present study is to investigate the antibacterial activity of Salvia officinalis L. aqueous extracts and its synergistic action with preservatives sodium nitrite, sodium benzoate and potassium sorbate in vitro against selected food spoiling bacteria. Synergy was assessed by the checkerboard assay method and quantitatively represented by the FIC index. Synergistic action was established for aqueous extract/ sodium benzoate, aqueous extract/ potassium sorbate, aqueous extract/ sodium nitrite combinations. Synergy was detected in relation to: Agrobacterium tumefaciens, Bacillus subtilis and Proteus sp. Synergy was established at plant extract and preservative concentrations corresponding up to 1/8 MIC values.
µ-Conotoxins as Leads in the Development of New Analgesics
Authors: Norton Raymond S.
Published: April 2010

Voltage-gated sodium channels (VGSCs) contain a specific binding site for a family of cone shell toxins known as µ-conotoxins. As some VGSCs are involved in pain perception and µ-conotoxins are able to block these channels, µ-conotoxins show considerable potential as analgesics. Recent studies have advanced our understanding of the three-dimensional structures and structure-function relationships of the µ-conotoxins, including their interaction with VGSCs. Truncated peptide analogues of the native toxins have been created in which secondary structure elements are stabilized by non-native linkers such as lactam bridges. Ultimately, it would be desirable to capture the favourable analgesic properties of the native toxins, in particular their potency and channel sub-type selectivity, in non-peptide mimetics. Such mimetics would constitute lead compounds in the development of new therapeutics for the treatment of pain.
Calcium-Activated Pathways and Oxidative Burst Mediate Zymosan-Induced Signaling and IL-10 Production in Human Macrophages
Authors: Kelly Erin K. , Wang Lu , Ivashkiv Lionel B.
Published: April 2010

Outside of the TLR paradigm, there is little understanding of how pathogen recognition at the cell surface is linked to functional responses in cells of the innate immune system. Recent work in this area demonstrates that the yeast particle zymosan, by binding to the β-glucan receptor Dectin-1, activates an ITAM-Syk–dependent pathway in dendritic cells, which is required for optimal cytokine production and generation of an oxidative burst. It remains unclear how activation of Syk is coupled to effector mechanisms. In human macrophages, zymosan rapidly activated a calcium-dependent pathway downstream of Dectin-1 and Syk that led to activation of calmodulin-dependent kinase II and Pyk2. Calmodulin-dependent kinase and Pyk2 transduced calcium signals into activation of the ERK–MAPK pathway, CREB, and generation of an oxidative burst, leading to downstream production of IL-10. These observations identify a new calcium-mediated signaling pathway activated by zymosan and link this pathway to both inflammatory and anti-inflammatory responses in macrophages.
Murine Kupffer Cells Are Protective in Total Hepatic Ischemia/Reperfusion Injury with Bowel Congestion through IL-10
Authors: Ellett Justin D. , Atkinson Carl , Evans Zachary P. , Amani Zainab , Balish Edward , Schmidt Michael G. , van Rooijen Nico , Schnellmann Rick G. , Chavin Kenneth D.
Published: April 2010

Kupffer cells (KCs) are thought to mediate hepatocyte injury via their production of proinflammatory cytokines and reactive oxygen species in response to stress. In this study, we depleted KCs from the liver to examine their role in total warm hepatic ischemia/reperfusion (I/R) injury with bowel congestion. We injected 8-wk-old C57BL/10J mice with liposome-encapsulated clodronate 48 h before 35 min of hepatic ischemia with bowel congestion, followed by 6 or 24 h of reperfusion. KC-depleted animals had a higher mortality rate than diluent-treated animals and a 10-fold elevation in transaminase levels that correlated with increases in centrilobular necrosis. There was extensive LPS binding to the endothelial cells, which correlated with an upregulation of endothelial adhesion molecules in the KC-depleted animals versus diluent-treated animals. There was an increase in the levels of proinflammatory cytokines in KC-depleted animals, and a concomitant decrease in IL-10 levels. When KC-depleted mice were treated with recombinant IL-10, their liver damage profile in response to I/R was similar to diluent-treated animals, and endothelial cell adhesion molecules and proinflammatory cytokine levels decreased. KCs are protective in the liver subjected to total I/R with associated bowel congestion and are not deleterious as previously thought. This protection appears to be due to KC secretion of the potent anti-inflammatory cytokine IL-10.
TCR Stimulation Drives Cleavage and Shedding of the ITIM Receptor CD31
Authors: Fornasa Giulia , Groyer Emilie , Clement Marc , Dimitrov Jordan , Compain Caroline , Gaston Anh-Thu , Varthaman Aditi , Khallou-Laschet Jamila , Newman Debra K. , Graff-Dubois Stéphanie , Nicoletti Antonino , Caligiuri Giuseppina
Published: April 2010

CD31 is a transmembrane molecule endowed with T cell regulatory functions owing to the presence of 2 immunotyrosine-based inhibitory motifs. For reasons not understood, CD31 is lost by a portion of circulating T lymphocytes, which appear prone to uncontrolled activation. In this study, we show that extracellular T cell CD31 comprising Ig-like domains 1 to 5 is cleaved and shed from the surface of human T cells upon activation via their TCR. The shed CD31 can be specifically detected as a soluble, truncated protein in human plasma. CD31 shedding results in the loss of its inhibitory function because the necessary cis-homo–oligomerization of the molecule, triggered by the trans-homophilic engagement of the distal Ig-like domain 1, cannot be established by CD31shed cells. However, we show that a juxta-membrane extracellular sequence, comprising part of the domain 6, remains expressed at the surface of CD31shed T cells. We also show that the immunosuppressive CD31 peptide aa 551–574 is highly homophilic and possibly acts by homo-oligomerizing with the truncated CD31 remaining after its cleavage and shedding. This peptide is able to sustain phosphorylation of the CD31 ITIM686 and of SHP2 and to inhibit TCR-induced T cell activation. Finally, systemic administration of the peptide in BALB/c mice efficiently suppresses Ag-induced T cell-mediated immune responses in vivo. We conclude that the loss of T cell regulation caused by CD31 shedding driven by TCR stimulation can be rescued by molecular tools able to engage the truncated juxta-membrane extracellular molecule that remains exposed at the surface of CD31shed cells.
CD40 Signaling in CD8+CD40+ T Cells Turns On Contra-T Regulatory Cell Functions
Authors: Martin Sunil , Pahari Sushmita , Sudan Raki , Saha Bhaskar
Published: April 2010

CD4+ regulatory T cells (Treg cells) mediate immunosuppression, whereas CD8+ T cells confer resistance in many diseases. It is unknown whether CD8+ T cells confer protection by antagonizing the Treg cells. Using a model of stage-specific immune responses against Leishmania donovani infection in susceptible BALB/c mice, we report that CD3+CD8+CD40+ T cells executed CD40-dependent cytotoxicity on CD3+CD4+CD127dimGITR+CD25+ Treg cells during the initial phase of the infection but were later apoptosed by IL-10. CD40 signaled through Ras, PI3K, and protein kinase C, resulting in p38MAPK- or ERK-1/2–independent, but NF-κB–dependent, induction of the cytotoxic mediators granzyme and perforin. Adoptive transfer of CD3+CD8+CD40+ T cells reduced the L. donovani infection in BALB/c mice. These results identify CD3+CD8+CD40+ T cells as the contra-Treg cells and imply a novel immunotherapeutic principle.
Combination Therapy of Established Tumors by Antibodies Targeting Immune Activating and Suppressing Molecules
Authors: Takeda Kazuyoshi , Kojima Yuko , Uno Tomoyasu , Hayakawa Yoshihiro , Teng Michele W. L. , Yoshizawa Hirohisa , Yagita Hideo , Gejyo Fumitake , Okumura Ko , Smyth Mark J.
Published: April 2010

The blockade of immune suppression against antitumor responses is a particularly attractive strategy when combined with agents that promote tumor-specific CTLs. In this study, we have attempted to further improve the CTL induction and potent antitumor efficacy of a combination mAb-based therapy (termed “trimAb therapy”) that comprises tumor cell death-inducing anti-death receptor 5 mAb and immune activating anti-CD40 and anti-CD137 mAbs. Among trimAb-treated tumors, the infiltration of CD4+ Foxp3+ cells was greater in progressing tumors compared with stable tumors. Blockade of CTLA-4 (CD152)-mediated signals by an antagonistic mAb substantially increased the tumor rejection rate of trimAb therapy, although the immune responses of draining lymph node cells were not augmented. Interestingly, by comparison, additional treatment with agonistic anti-glucocorticoid-induced TNF receptor mAb, antagonistic anti-programmed death-1 (CD279) mAb, or agonistic anti-OX40 (CD134) mAb significantly augmented immune responses of draining lymph node cells, but did not augment the therapeutic effect of trimAb. CD4 T cell depletion reduced the antitumor effect of anti–CTLA-4 mAb treatment alone, but did not reduce the tumor rejection rate of trimAb in conjunction with anti–CTLA-4 mAb. Thus, the blockade of the CTLA-4–mediated inhibitory signal in tumor infiltrating CTL may be the most effective strategy to augment the effect of immune therapies that generate tumor-specific CTL.
CD4+ T Cells Elicit Host Immune Responses to MHC Class II− Ovarian Cancer through CCL5 Secretion and CD40-Mediated Licensing of Dendritic Cells
Authors: Nesbeth Yolanda C. , Martinez Diana G. , Toraya Seiko , Scarlett Uciane K. , Cubillos-Ruiz Juan R. , Rutkowski Melanie R. , Conejo-Garcia Jose R.
Published: April 2010

T cell adoptive transfer strategies that have produced clinical remissions against specific tumors have so far produced disappointing results against ovarian cancer. Recent evidence suggests that adoptively transferred CD4+ T cells can trigger endogenous immune responses in particular patients with ovarian cancer through unknown mechanisms. However, conflicting reports suggest that ovarian cancer-infiltrating CD4+ T cells are associated with negative outcomes. In this study, we elucidate the phenotypic attributes that enable polyclonal CD4+ T cells briefly primed against tumor Ags to induce therapeutically relevant endogenous antitumor immune responses. Our results unveil a therapeutic mechanism whereby tumor-primed CD4+ T cells transferred into ovarian cancer-bearing mice secrete high levels of CCL5, which recruits endogenous CCR5+ dendritic cells to tumor locations and activate them through CD40–CD40L interactions. These newly matured dendritic cells are then able to prime tumor-specific endogenous CD8+ T cells, which mediate long-term protection. Correspondingly, administration of tumor-primed CD4+ T cells significantly delayed progression of MHC class II− ovarian cancers, similarly to CD8+ T cells only, and directly activated wild-type but not CD40-deficient dendritic cells recruited to the tumor microenvironment. Our results unveil a CCL5- and CD40L-dependent mechanism of transferring immunity from exogenously activated CD4+ T cells to tumor-exposed host cells, resulting in sustained antitumor effects. Our data provide a mechanistic rationale for incorporating tumor-reactive CD4+ T cells in adoptive cell transfer immunotherapies against ovarian cancer and underscore the importance of optimizing immunotherapeutic strategies for the specific microenvironment of individual tumors.
The Mandatory Role of IL-10–Producing and OX40 Ligand-Expressing Mature Langerhans Cells in Local UVB-Induced Immunosuppression
Authors: Yoshiki Ryutaro , Kabashima Kenji , Sakabe Jun-ichi , Sugita Kazunari , Bito Toshinori , Nakamura Motonobu , Malissen Bernard , Tokura Yoshiki
Published: April 2010

The mechanism underlying the local UVB-induced immunosuppression is a central issue to be clarified in photoimmunology. There have been reported a considerable number of cells and factors that participate in the sensitization phase-dependent suppression, including Langerhans cells (LCs), regulatory T cells, IL-10, and TNF-α. The recent important finding that LC-depleted mice rather exhibit enhanced contact hypersensitivity responses urged us to re-evaluate the role of LCs along with dermal dendritic cells (dDCs) in the mechanism of UVB-induced immunosuppression. We studied the surface expression of OX40 ligand (OX40L) and the intracellular expression of IL-10 in LCs and dDCs from UVB-irradiated (300 mJ/cm2) skin of BALB/c mice and those migrating to the regional lymph nodes from UVB-irradiated, hapten-painted mice. In epidermal and dermal cell suspensions prepared from the UVB-irradiated skin, LCs expressed OX40L as well as CD86 and produced IL-10 at a higher level than Langerin‒ dDCs. The UVB-induced immunosuppression was attenuated by the administration of IL-10–neutralizing or OX40L-blocking Abs. In mice whose UVB-irradiated, hapten-painted skin was dissected 1 d after hapten application, the contact hypersensitivity response was restored, because this treatment allowed dDCs but not LCs to migrate to the draining lymph nodes. Moreover, LC-depleted mice by using Langerin-diphtheria toxin receptor–knocked-in mice showed impaired UVB-induced immunosuppression. These results suggest that IL-10–producing and OX40L-expressing LCs in the UVB-exposed skin are mandatory for the induction of Ag-specific regulatory T cells.
Prostaglandin I2–IP Signaling Promotes Th1 Differentiation in a Mouse Model of Contact Hypersensitivity
Authors: Nakajima Saeko , Honda Tetsuya , Sakata Daiji , Egawa Gyohei , Tanizaki Hideaki , Otsuka Atsushi , Moniaga Catharina Sagita , Watanabe Takeshi , Miyachi Yoshiki , Narumiya Shuh , Kabashima Kenji
Published: April 2010

PGI2, which exerts its actions via its specific Gs-coupled I prostanoid receptor (IP), is known to be present in the lymph nodes, but its roles in acquired cutaneous immune responses remain unclear. To investigate the role of PGI2–IP signaling in cutaneous immune responses, we applied IP-deficient (Ptgir−/−) mice to contact hypersensitivity as a model of acquired immune response and found that Ptgir−/− mice exhibited a significantly decreased contact hypersensitivity response. Lymph node cells from sensitized Ptgir−/− mice exhibited decreased IFN-γ production and a smaller T-bet+ subset compared with control mice. PGI synthase and IP expression were detected in dendritic cells and T cells, respectively, by quantitative real-time PCR analysis, suggesting that PGI2 produced by dendritic cells acts on IP in T cells. In fact, in vitro Th1 differentiation was enhanced by an IP agonist, and this enhancement was nullified by protein kinase A inhibitor. These results suggest that PGI2–IP signaling promotes Th1 differentiation through a cAMP-protein kinase A pathway and thereby initiates acquired cutaneous immune responses.
Resistance to Dengue Virus Infection in Mice Is Potentiated by CXCL10 and Is Independent of CXCL10-Mediated Leukocyte Recruitment
Authors: Ip Peng-Peng , Liao Fang
Published: April 2010

CXCL10 is an IFN-inducible chemokine ligand that binds CXCR3, a receptor that is expressed on lymphocytes; CXCL10 shares the CXCR3 receptor with another two ligands, CXCL9 and CXCL11. Previously, we found that CXCL10−/− mice were more susceptible than wild-type (WT) mice to dengue virus (DENV) infection. In this study, we explored the mechanisms underlying this enhanced susceptibility. We found that viral loads were higher in the brains of CXCL10−/− mice than in WT mice. Presuming a defect in effector lymphocyte migration, we investigated whether recruitment of effector T cells and Ab-secreting cells to the infected tissues were impaired in CXCL10−/− mice. Unexpectedly, compared with WT, CXCL10−/− mice had comparable numbers of total infiltrating T cells, higher numbers of CXCR3+ T cells, and higher numbers of Ab-secreting cells in the brain. Additionally, we found that CXCL10 was induced in neurons following DENV infection and that CXCL10 competed with DENV for binding to cell surface heparan sulfate, a coreceptor for DENV entry, thus inhibiting binding of DENV to neuronal cells. These results demonstrate that the enhanced susceptibility of CXCL10−/− mice to DENV infection is not due to a defect in recruitment of effector lymphocytes but rather to an antiviral activity that promotes viral clearance.
CpG Inhibits Pro-B Cell Expansion through a Cathepsin B-Dependent Mechanism
Authors: Lalanne Ana Inés , Moraga Ignacio , Hao Yi , Pereira João Pedro , Alves Nuno L. , Huntington Nicholas D. , Freitas Antonio A. , Cumano Ana , Vieira Paulo
Published: April 2010

TLR9 is expressed in cells of the innate immune system, as well as in B lymphocytes and their progenitors. We investigated the effect of the TLR9 ligand CpG DNA on the proliferation of pro-B cells. CpG DNA inhibits the proliferation of pro-B, but not pre-B, cells by inducing caspase-independent cell death through a pathway that requires the expression of cathepsin B. This pathway is operative in Rag-deficient mice carrying an SP6 transgene, in which B lymphopoiesis is compromised, to reduce the size of the B lymphocyte precursor compartments in the bone marrow. Thus, TLR9 signals can regulate B lymphopoiesis in vivo.
Retinoic Acid Determines the Precise Tissue Tropism of Inflammatory Th17 Cells in the Intestine
Authors: Wang Chuanwu , Kang Seung G. , HogenEsch Harm , Love Paul E. , Kim Chang H.
Published: April 2010

Th17 cells are major effector T cells in the intestine, but the regulation of their tissue tropism within the gut is poorly understood. We investigated the roles of vitamin A and retinoic acid in generation of inflammatory Th17 cells with distinct tissue tropisms within the intestine. We found that Th17 cells with distinct tissue tropisms and pathogenic activities are generated depending on the available concentration of retinoic acid (RA). In contrast to the widespread perception that RA would suppress the generation of Th17 cells, we provide evidence that RA is actually required for generation of Th17 cells with specific tissue tropisms within the gut. Th17 cells induced at suboptimal serum concentrations of RA migrated and induced moderate inflammation mainly in the large intestine, whereas the Th17 cells induced with optimal levels of exogenous RA (∼10 nM) migrated to the small intestine and induced more severe inflammation. The Th17 cells, induced in the presence or absence of RA, differentially expressed the trafficking receptors CCR9 and α4β7. CCR9 is required for Th17 cell migration to the small intestine, whereas α4β7 is required for the migration of Th17 cells throughout the whole intestine. Our results identified RA as a major signal that regulates the generation of gut Th17 cells with distinct capacities in migration and inflammatory activities. The results indicate also that specific gut tropism of Th17 cells is determined by the combination of trafficking receptors regulated by the RA signal.
Variation in the Cd3ζ (Cd247) Gene Correlates with Altered T Cell Activation and Is Associated with Autoimmune Diabetes
Authors: Lundholm Marie , Mayans Sofia , Motta Vinicius , Löfgren-Burström Anna , Danska Jayne , Holmberg Dan
Published: April 2010

Tuning of TCR-mediated activation was demonstrated to be critical for lineage fate in T cell development, as well as in the control of autoimmunity. In this study, we identify a novel diabetes susceptibility gene, Idd28, in the NOD mouse and provide evidence that Cd3ζ (Cd247) constitutes a prime candidate gene for this locus. Moreover, we show that the allele of the Cd3ζ gene expressed in NOD and DBA/2 mouse strains confers lower levels of T cell activation compared with the allele expressed by C57BL/6 (B6), BALB/c, and C3H/HeJ mice. These results support a model in which the development of autoimmune diabetes is dependent on a TCR signal mediated by a less-efficient NOD allele of the Cd3ζ gene.
ST2 Negatively Regulates TLR2 Signaling, but Is Not Required for Bacterial Lipoprotein-Induced Tolerance
Authors: Liu Jinghua , Buckley Julliette M. , Redmond H. Paul , Wang Jiang Huai
Published: April 2010

Activation of TLR signaling is critical for host innate immunity against bacterial infection. Previous studies reported that the ST2 receptor, a member of the Toll/IL-1 receptor superfamily, functions as a negative regulator of TLR4 signaling and maintains LPS tolerance. However, it is undetermined whether ST2 negatively regulates TLR2 signaling and furthermore, whether a TLR2 agonist, bacterial lipoprotein (BLP)-induced tolerance is dependent on ST2. In this study, we show that BLP stimulation-induced production of proinflammatory cytokines and immunocomplex formation of TLR2–MyD88 and MyD88–IL-1R–associated kinase (IRAK) were significantly enhanced in ST2-deficient macrophages compared with those in wild-type controls. Furthermore, overexpression of ST2 dose-dependently attenuated BLP-induced NF-κB activation, suggesting a negative regulatory role of ST2 in TLR2 signaling. A moderate but significantly attenuated production of TNF-α and IL-6 on a second BLP stimulation was observed in BLP-pretreated, ST2-deficient macrophages, which is associated with substantially reduced IRAK-1 protein expression and downregulated TLR2–MyD88 and MyD88–IRAK immunocomplex formation. ST2-deficient mice, when pretreated with a nonlethal dose of BLP, benefitted from an improved survival against a subsequent lethal BLP challenge, indicating BLP tolerance develops in the absence of the ST2 receptor. Taken together, our results demonstrate that ST2 acts as a negative regulator of TLR2 signaling, but is not required for BLP-induced tolerance.
Cutting Edge: PulmonaryLegionella pneumophilaIs Controlled by Plasmacytoid Dendritic Cells but Not Type I IFN
Authors: Ang Desmond K. Y. , Oates Clare V. L. , Schuelein Ralf , Kelly Michelle , Sansom Fiona M. , Bourges Dorothée , Boon Louis , Hertzog Paul J. , Hartland Elizabeth L. , van Driel Ian R.
Published: April 2010

Plasmacytoid dendritic cells (pDCs) are well known as the major cell type that secretes type I IFN in response to viral infections. Their role in combating other classes of infectious organisms, including bacteria, and their mechanisms of action are poorly understood. We have found that pDCs play a significant role in the acute response to the intracellular bacterial pathogen Legionella pneumophila. pDCs were rapidly recruited to the lungs of L. pneumophila-infected mice, and depletion of pDCs resulted in increased bacterial load. The ability of pDCs to combat infection did not require type I IFN. This study points to an unappreciated role for pDCs in combating bacterial infections and indicates a novel mechanism of action for this cell type.
Requirement for BAFF and APRIL during B Cell Development in GALT
Authors: Yeramilli Venkata A. , Knight Katherine L.
Published: April 2010

The effects of B cell-activating factor belonging to the TNF family (BAFF) on B cell maturation and survival in the mouse are relatively well understood. In contrast, little is known about the role of BAFF in B cell development in other mammals, such as rabbits, that use GALT to develop and maintain the B cell compartment. We examined the expression and requirement of BAFF and a proliferation-inducing ligand (APRIL) during peripheral B cell development in young rabbits. By neutralizing BAFF and APRIL in neonates with a soluble decoy receptor, transmembrane activator calcium modulator and cyclophilin ligand interactor-Fc, we found a marked reduction in the number of peripheral B cells, but found no change in the bone marrow (BM) compartment. In the appendix, the size and number of proliferating B cell follicles were greatly reduced, demonstrating that although BAFF/APRIL is dispensable for B cell development in BM, it is required for B cell development in GALT. We found that all rabbit B cells expressed BAFF receptor 3, but did not bind rBAFF, suggesting that the BAFF-binding receptors (BBRs) are bound by endogenous soluble BAFF. Further, we found that B cells themselves express BAFF, suggesting that the soluble BAFF bound to BBRs may be endogenously produced and stimulate B cells in an autocrine fashion. Additionally, we propose that this chronic occupancy of BBRs on B cells may provide a tonic and/or survival signal for the maintenance of peripheral B cells in adults after B lymphopoiesis is arrested in BM.
My Facebook Friends
Authors: Graham Donna L.
Published: April 2010

AAAE Distinguished Lecture,Charlotte, N.C., May 19, 2006
Influence Of The Relationship Between The Student Teacher And Cooperating Teacher On Student Teacher'S Decision To Enter Teaching
Authors: Kasperbauer Holly J. , Roberts T. Grady
Published: April 2010

The purpose of the study was to determine if student teachers' perceptions of the student teacher/cooperating teacher relationship were predictive of their decisions to enter the teaching profession. The target population of this study consisted of preservice agricultural education students atTexasA&MUniversity. The accessible sample consisted of student teachers in agricultural education atTexasA&MUniversity in fall 2004, a group of 33 student teachers. Multiple regression was used to build a model that explained the greatest amount of variability in the student teachers' decision to enter teaching, based on the student teachers' perceptions of the cooperating teacher and other suspected predictor variables. The typical student teacher in agricultural education was a 22 year old white female completing an undergraduate degree. The majority of student teachers had no full-time agricultural employment experience. The majority of student teachers had at least four semesters (two years) of high school agricultural science courses. It was concluded that the student teaching/cooperating teacher relationship is not predictive of decision to teach. However, semesters of high school agricultural sciences courses completed was predictive of one's decision to teach. The best model explained 18.3% of the variance.
A Model For The Study Of Reading In Agriscience
Authors: Park Travis D. , Osborne Ed
Published: April 2010

Agriscience is facing pressure to document and contribute to student achievement in math, science, and reading. Agriscience teachers may be able to foster student reading and comprehension through utilization of research-based reading strategies to further develop literacy in and about agriculture. Building on Dunkin and Biddle's (1974) model of the study of teaching, this synthesis of research proposes areas of inquiry regarding the teacher and context variables associated with reading. Teachers influence reading in agriscience through personal reading habits, expectations for reading, attitudes toward reading, and knowledge of and preparation in reading strategy use. Contextual variables include the student, environment, and text. Students enter agriscience classes with differing reading ability, interest, prior knowledge, prior reading, motivation, age, and experience. They encounter texts in the home, classroom, and school environments. Texts are comprised of varying readability, vocabulary, structure, content, and selection, all of which impact comprehension.
Changes In Student Teacher Perceptions Of The Student Teacher-Cooperating Teacher Relationship Throughout The Student Teaching Semester
Authors: Kasperbauer Holly J. , Roberts T. Grady
Published: April 2010

The purpose of the study was to explore student teacher perceptions of the student teacher/ cooperating teacher relationship throughout the student teaching experience. The target population of this study consisted of preservice agricultural education students atTexasA&MUniversity. The accessible sample consisted of student teachers in agricultural education in fall 2004, a group of 33 student teachers. Data were collected via paper instruments at four points during the student teaching semester: 1) the first day of the block; 2) the last day of the block; 3) the midpoint of the 11-week student teaching experience; and 4) the end of the 11-week student teaching experience. Two measures were examined: 1) the student teachers' perceptions of the importance of the relationship and 2) the student teachers' perceptions about the current level of relationship exhibited by their cooperating teachers. The typical student teacher in this study would be a 22 year old white female completing an undergraduate degree. The student teachers' perceptions of the importance of the relationship between student teacher/cooperating teacher did not change. However, the student teachers' perceptions of their cooperating teacher's current level decreased during the student teaching experience.
Biotechnology: An Assessment Of Agricultural Science Teachers' Knowledge And Attitudes
Authors: Mowen Diana L. , Roberts T. Grady , Wingenbach Gary J. , Harlin Julie F.
Published: April 2010

The purpose of this study was to explore agricultural science teachers' knowledge levels and attitudes toward biotechnology topics. The average agricultural science teacher in this study was a 37-year-old male who had taught for 12 years. He had a bachelor's degree and had lived or worked on a farm or ranch. He had not attended biotechnology-related workshops or classes since he graduated from college. Agricultural science teachers in the current study had some knowledge of biotechnology. However, great variation existed between specific topics. Teachers were most knowledgeable about animal reproduction and least knowledgeable about electrophoresis and bioremediation. Significant relationships were found between teachers' self-perceived knowledge levels of specific biotechnology topics and the likelihood that the topic was taught in the classroom. Agricultural science teachers had favorable attitudes toward biotechnology. A low positive relationship existed between agricultural science teachers' knowledge and attitudes toward biotechnology. When comparing teachers based on experience (those with less than 15 years versus those with 15 or more years) results indicated no differences in knowledge and attitudes.
Overcoming Gender Bias With Self-Efficacy: A Case Study Of Women Agricultural Education Teachers And Preservice Students
Authors: Kelsey Kathleen D.
Published: April 2010

Women have been traditionally underrepresented in secondary agricultural education as teachers and students. Using critical theory as the lens for interpreting findings, this case study sought to explore female teachers' and preservice students' experiences in secondary agricultural education to better understand their perceptions of barriers to entry into the profession. Two-thirds of the women reported that they experienced gender bias from school administrators, community members, and peers; however, they exhibited a high degree of self-efficacy for teaching agricultural education that allowed them to persist in spite of any barriers. However, all discriminatory experiences are more likely to discourage women in preservice education from entering the profession. It is recommended that agricultural teacher educators prepare female preservice students with the knowledge and skills necessary to face and overcome gender bias in a variety of formal and informal educational contexts, especially job-seeking interviews, to increase their chances of career entry into secondary agricultural education in this state.
Supervisory Behaviors Of Cooperating Agricultural Education Teachers
Authors: Thobega Moreetsi , Miller Greg
Published: April 2010

The purpose of this study was to determine the extent to which cooperating agricultural education teachers used selected supervision models. The relationships between maturity characteristics of the cooperating teachers and their choices of a supervision model were also examined. Results showed that cooperating teachers commonly used clinical, contextual, and conceptual supervision models. They also commonly used nondirective and directive informational styles from the developmental supervision model. Maturity of the cooperating teachers was not related to their choices of structured or unstructured models of supervision. Future studies should examine the relationship between cooperating teachers' use of supervision models and contextual factors like teaching load and administrative responsibilities. The importance of student teacher characteristics as factors in cooperating teachers' choices of supervision models should also be examined.
Barriers, Support, And Collaboration: A Comparison Of Science And Agriculture Teachers' Perceptions Regarding Integration Of Science Into The Agricultural Education Curriculum
Authors: Warnick Brian K. , Thompson Gregory W.
Published: April 2010

This study is part of a larger investigation which focused on determining and comparing the perceptions of agriculture teachers and science teachers on integrating science into agricultural education programs. Science and agriculture teachers' perceptions of barriers to integrating science, the support of stakeholders, and collaboration between science and agriculture teachers and programs were investigated.The majority of both science and agriculture teachers were in agreement that funding, equipment, and the science teachers' lack of an agricultural background were barriers to integration.However, they differed in their level of agreement about curriculum and teachers' philosophical differences as barriers.Both groups agreed their school has strong science and agriculture programs, that collaboration would benefit students, and that the two departments have something to offer each other. However, fewer than one-half of teachers in both groups reported they work in a collaborative effort with the other department.