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Combatting Clostridioides difficile infections, a dominant cause of hospital-associated infections with incidence and resulting deaths increasing worldwide, is complicated by the frequent emergence of new virulent strains. Here, we employ whole-genome sequencing, high-throughput phenotypic screenings, and genome-scale models of metabolism to evaluate the genetic diversity of 451 strains of C. difficile. Constructing the C. difficile pangenome based on this set revealed 9,924 distinct gene clusters, of which 2,899 (29%) are defined as core, 2,968 (30%) are defined as unique, and the remaining 4,057 (41%) are defined as accessory. We develop a strain typing method, sequence typing by accessory genome (STAG), that identifies 176 genetically distinct groups of strains and allows for explicit interrogation of accessory gene content. Thirty-five strains representative of the overall set were experimentally profiled on 95 different nutrient sources, revealing 26 distinct growth profiles and unique nutrient preferences; 451 strain-specific genome scale models of metabolism were constructed, allowing us to computationally probe phenotypic diversity in 28,864 unique conditions. The models create a mechanistic link between the observed phenotypes and strain-specific genetic differences and exhibit an ability to correctly predict growth in 76% of measured cases. The typing and model predictions are used to identify and contextualize discriminating genetic features and phenotypes that may contribute to the emergence of new problematic strains.

In contrast to a self-generated action, a human-to-human object handover represents a semi-predictable task, due to a lack of exact knowledge about the partner's future movement behavior. Thus far, it has not been determined which behavioral characteristics result from dealing with this prevailing uncertainty, although this distinction would enhance the understanding of underlying motor control strategies in such semi-predictable situations. Behavioral effects of mutual interaction during object handovers were therefore investigated in the current study, by comparing grip force profiles and kinematic data from predictable solo-handovers (between the two hands of one person) with data from semi-predictable partner-handovers. There were significant decreases in passers' mean release rates as well as corresponding increases in handover durations in partner-handovers compared to solo-handovers. Likewise, receivers in partner-handovers employed lower mean grip force rates to take the object, which speaks for feedback reliance of both partners in the load transfer process of partner-handovers. Increased vertical object displacement in this phase might represent timing deficits due to the prediction uncertainties in partner-handovers. The data also provided first evidence that left-handed people serving as receivers in partner-handovers exhibit an altered take-over strategy compared to right-handed receivers.

Background Specific IgE (sIgE) against the peanut component Arachis hypogaea (Ara h) 2 has been shown to be the most important allergen to discriminate between peanut allergy and peanut tolerance. Several studies determined sIgE cut off values for Ara h 2, determined by singleplex measurements. However, cut off values for Ara h 2 from multiplex arrays are less well defined. The aim of this study was to evaluate the correlation between Ara h 2 sIgE determined by singleplex versus multiplex measurements and to assess the diagnostic value of the different peanut components included in Immuno Solid-phase Allergen Chip (ISAC) multiplex analysis in children with a suspected peanut allergy. Methods In this retrospective study we analyzed Ara h 2 sIgE values with singleplex Fluorescence Enzyme Immunoassay (FEIA, ImmunoCap) and multiplex microarray (ISAC) measurements in 117 children with a suspected peanut allergy. Also, other peanut components measured by ISAC were analyzed. Double blinded placebo controlled oral food challenges were used as golden standard. Results Among all studied peanut components FEIA Ara h 2 sIgE showed the highest area under the curve (AUC, 0.922), followed by ISAC Ara h 6 and Ara h 2 sIgE with AUCs of respectively 0.906 and 0.902. Best cut off values to diagnose peanut allergy were 4.40 kU/l for FEIA Ara h 2 sIgE and, 7.43 ISU and 8.13 ISU for respectively Ara h 2 and Ara h 6 sIgE in ISAC microarray. Ara h 2 sIgE determined in FEIA and ISAC showed a good correlation (r = 0.88; p Conclusion Ara h 6 and Ara h 2 sIgE in multiplex ISAC are both good predictors of clinical peanut allergy in Dutch children, and their performance is comparable to the use of Ara h 2 in singleplex FEIA. The simultaneous measurement of different peanut components using ISAC is an advantage and clinically useful to detect peanut allergic children that are Ara h 2 negative but sensitized to other peanut proteins such as Ara h 6.

Forests are integral to sustaining clean water resources and healthy watersheds. It is critical, therefore, that managers fully understand the potential impacts of their actions on myriad ecosystem services provided by forested watersheds. While forest hydrologists have long used paired-watershed experiments to elucidate the complex interactions between forest management and watershed biogeochemical and ecohydrological processes, there is still much to learn from these studies. Here, we present an overview of the process for designing a paired-watershed study using a large harvesting experiment at the Caspar Creek Experimental Watersheds in coastal California as an example. We detail many considerations when designing such an experiment and highlight the wide range of scientific investigations that are part of the larger experiment. Paired watershed studies are a great example of community engaged scholarship and offer the unique opportunity to work with land managers to solve applied problems while simultaneously discovering new fundamental knowledge about how watersheds function.

The use of remote sensing data for burned area mapping hast led to unprecedented advances within the field in recent years. Although threshold and traditional machine learning based methods have successfully been applied to the task, they implicate drawbacks including the involvement of complex rule sets and requirement of previous feature engineering. In contrast, deep learning offers an end-to-end solution for image analysis and semantic segmentation. In this study, a variation of U-Net is investigated for mapping burned areas in mono-temporal Sentinel-2 imagery. The experimental setup is divided into two phases. The first one includes a performance evaluation based on test data, while the second serves as a use case simulation and spatial evaluation of training data quality. The former is especially designed to compare the results between two local (trained only with data from the respective research areas) and a global (trained with the whole dataset) variant of the model with research areas being Indonesia and Central Africa. The networks are trained from scratch with a manually generated customized training dataset. The application of the two variants per region revealed only slight superiority of the local model (macro-F1: 92%) over the global model (macro-F1: 91%) in Indonesia with no difference in overall accuracy (OA) at 94%. In Central Africa, the results of the global and local model are the same in both metrics (OA: 84%, macro-F1: 82%). Overall, the outcome demonstrates the global model’s ability to generalize despite high dissimilarities between the research areas.

Several studies have identified an increased abundance of Fusobacterium in the intestinal tracts of patients with colon cancer, liver cirrhosis, primary sclerosing cholangitis, gastroesophageal reflux disease, HIV infection, and alcoholism. However, the direct mechanism(s) of action of Fusobacterium on pathophysiological within the gastrointestinal tract is unclear., Multiple studies have implicated microbes in the development of inflammation, but the mechanisms remain unknown. Bacteria in the genus Fusobacterium have been identified in the intestinal mucosa of patients with digestive diseases; thus, we hypothesized that Fusobacterium nucleatum promotes intestinal inflammation. The addition of >50 kDa F. nucleatum conditioned media, which contain outer membrane vesicles (OMVs), to colonic epithelial cells stimulated secretion of the proinflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor (TNF). In addition, purified F. nucleatum OMVs, but not compounds 50-kDa compounds also stimulated TNF secretion, p-ERK, p-CREB, and NF-κB activation in human colonoid monolayers. In mice harboring a human microbiota, pretreatment with antibiotics and a single oral gavage of F. nucleatum resulted in inflammation. Compared to mice receiving vehicle control, mice treated with F. nucleatum showed disruption of the colonic architecture, with increased immune cell infiltration and depleted mucus layers. Analysis of mucosal gene expression revealed increased levels of proinflammatory cytokines (KC, TNF, IL-6, IFN-γ, and MCP-1) at day 3 and day 5 in F. nucleatum-treated mice compared to controls. These proinflammatory effects were absent in mice who received F. nucleatum without pretreatment with antibiotics, suggesting that an intact microbiome is protective against F. nucleatum-mediated immune responses. These data provide evidence that F. nucleatum promotes proinflammatory signaling cascades in the context of a depleted intestinal microbiome.

Hospital acquired Clostridioides (Clostridium) difficile infection is exacerbated by the continued evolution of C. difficile strains, a phenomenon studied by multiple laboratories using stock cultures specific to each laboratory. Intralaboratory evolution of strains contributes to interlaboratory variation in experimental results adding to the challenges of scientific rigor and reproducibility. To explore how microevolution of C. difficile within laboratories influences the metabolic capacity of an organism, three different laboratory stock isolates of the C. difficile 630 reference strain were whole-genome sequenced and profiled in over 180 nutrient environments using phenotypic microarrays. The results identified differences in growth dynamics for 32 carbon sources including trehalose, fructose, and mannose. An updated genome-scale model for C. difficile 630 was constructed and used to contextualize the 28 unique mutations observed between the stock cultures. The integration of phenotypic screens with model predictions identified pathways enabling catabolism of ethanolamine, salicin, arbutin, and N-acetyl-galactosamine that differentiated individual C. difficile 630 laboratory isolates. The reconstruction was used as a framework to analyze the core-genome of 415 publicly available C. difficile genomes and identify areas of metabolism prone to evolution within the species. Genes encoding enzymes and transporters involved in starch metabolism and iron acquisition were more variable while C. difficile distinct metabolic functions like Stickland fermentation were more consistent. A substitution in the trehalose PTS system was identified with potential implications in strain virulence. Thus, pairing genome-scale models with large-scale physiological and genomic data enables a mechanistic framework for studying the evolution of pathogens within microenvironments and will lead to predictive modeling to combat pathogen emergence.

Lewis acidic zeolites such as Sn-Beta catalyze glucose isomerization to fructose via an intramolecular 1,2-H-shift reaction, a key step for converting lignocellulosic biomass into renewable chemicals. Na-exchange of Sn-Beta titrates the neighboring SiOH group in the open Sn site and shifts catalyst selectivity to mannose formed by a 1,2-C-shift reaction. To probe structure/activity relationships in the zeolite, tin-containing silsesquioxanes with (1a) and without (1b) a neighboring SiOH group were recently synthesized and tested. These molecular catalysts are active for glucose conversion, and the presence (absence) of the SiOH favors fructose (mannose) selectivity by intramolecular H(C)-shift reactions. Using density functional theory, we investigated numerous H/C-shift pathways on these tin-silsesquioxane catalysts. On both 1a and 1b, the H-shift reaction occurs through a bidentate binding mode without participation of the SiOH, while the bidentate binding mode is not favored for the C-shift due to steric hindrance. Instead, the C-shift reaction occurs through different concerted reaction pathways, in which an acetylacetonate (acac) ligand interacts with the substrate in the transition state complexes. Favorable H-shift pathways without SiOH participation and acac ligand promotion of the C-shift pathway explain why 1a produces mannose from C-shift reactions instead of exclusively catalyzing H-shift reactions, as the Sn-Beta open site does.

Background Although the disabling effects of fibromyalgia (FM) are well recognised, there are no published data regarding the impact of FM on work ability in Australians. The impact of the development of FM symptoms on ability to work in Australians was explored in a pilot survey project. Method Members of the Fibromyalgia Support Network of Western Australia were invited to undertake an anonymous online survey. Information was gathered regarding demographics, symptom onset, the timing of diagnosis, employment status and changes in the ability to work. Results Two hundred and eighty-seven responses were analysed. Of the respondents, 90.6% were female, with a mean age of 51.1 ± 10.6 years and had experienced symptoms between 2 and 20 years; 52.8% were diagnosed less than 5 years previously. Of the participants, 54.2% were working full time and 21.5% working part time at symptom onset; however, only 15.6% were currently working full time, with 44.8% not currently working at all. Because of FM, 24.3% stopped and 32.6% reduced paid work directly within 5 years of symptom development, with 15.3% ceasing and an additional 17.4% reducing work because of symptoms before diagnosis. Due to FM symptoms, 35.1% currently received financial support because they were unable to work. While 24.3% reported FM medication increased their ability to work, 20.8% reported it reduced their ability to work. Conclusion A community pilot survey of Australians with FM indicates a high impact on work ability. This occurs from symptom onset and often before diagnosis. Early diagnosis and intervention may provide a window of opportunity to prevent work disability in FM.

RHO and KFI-type zeolites are synthesized in the absence of organic structure-directing agents (OSDAs), post-synthetically dealuminated via high temperature (600–800 °C) steam treatments, and evaluated as catalysts for converting methanol-to-light olefins (MTO). The proton forms of the as-made zeolites deactivate rapidly when tested for the MTO reaction (conducted at 400 °C and atmospheric pressure) due to their high aluminum content. Steam treatments lead to improvements in olefin selectivities and catalyst lifetimes with samples steamed at 600 °C giving the best combination of lifetime and olefin selectivity. Zeolite characterizations by ^(27)Al NMR, ^(29)Si NMR and argon physisorption indicate that the steam treatments extract framework aluminum, leading to reductions in the total number of Brønsted acid sites and the creation of mesopores that can facilitate transport of reactants. Poisoning of the acid sites external to the 8MR pores of the zeolites by treatments with trimethylphosphite results in longer catalyst lifetimes but do not affect the observed olefin selectivities, suggesting that olefins do not undergo secondary dimerization or methylation reactions at these sites.

Large-pore microporous materials are of great interest to process bulky hydrocarbon and biomass-derived molecules. ITQ-27 (IWV) has a two-dimensional pore system bounded by 12-membered rings (MRs) that lead to internal cross-sections containing 14 MRs. Investigations into the catalytic behavior of aluminosilicate (zeolite) materials with this framework structure have been limited until now due to barriers in synthesis. The facile synthesis of aluminosilicate IWV in both hydroxide and fluoride media is reported herein using simple, diquaternary organic structure-directing agents (OSDAs) that are based on tetramethylimidazole. In hydroxide media, a zeolite product with Si/Al=14.8–23.2 is obtained, while in fluoride media an aluminosilicate product with Si/Al up to 82 is synthesized. The material produced in hydroxide media is tested for the hydroisomerization of n-hexane, and results from this test reaction suggest that the effective pore size of zeolites with the IWV framework structure is similar to but slightly larger than that of ZSM-12 (MTW), in fairly good agreement with crystallographic data.

Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. Enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electron microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).

Equilibrium molecular dynamics simulations were performed to calculate self, corrected, and transport diffusivities of H2 in the metal–organic frameworks NU-100 and UiO-68 with varying numbers of Mg alkoxide functionalizations per organic linker at 243 K. Preferred hydrogen siting locations, as well as H2–H2 radial distribution functions were calculated. Increasing functionalization leads to a decrease in the diffusivity values, especially at low hydrogen loadings. Although the functionalization effects on the mobility of hydrogen molecules are appreciable, diffusivity values are still large in all cases.

Grand canonical Monte Carlo simulations were used to calculate hydrogen adsorption in IRMOF-16, NU-100, and UiO-68 functionalized with Mg or Fe catecholates on the linkers. We examined how altering the number of metal catecholate groups affects H2 uptake and deliverable capacity near ambient temperature. We find that large free volume and an isosteric heat of adsorption (Qst) of 20 kJ mol−1 at low loading will maximize gravimetric deliverable capacity while a small pore diameter will maximize volumetric deliverable capacity. This suggests a trade-off between the properties that lead to maximal gravimetric and volumetric capacities. For example, our calculations suggest that NU-100 functionalized with six Fe catecholate groups per linker takes up 5.5 wt.% deliverable H2 at 243 K and 100 bar, but only 24.2 g L−1 deliverable H2.

Tin-containing zeolite Beta (Sn-Beta) has been investigated as a catalyst for isomerizing aldohexoses into ketohexoses through a Lewis acid mediated hydride shift. Recent studies on the reactivities of Lewis base-doped and alkali-exchanged Sn-Beta samples have conclusively demonstrated that the “open” tin site performs the glucose isomerization reaction. With Lewis base doped Sn-Beta, glucose conversion is almost completely eliminated and product selectivity is shifted predominantly to mannose. These data suggest that glucose reactions may occur through pathways that do not involve the “open” site in Sn-Beta; albeit at significantly lower rates. To examine this possibility, reactions of glucose catalyzed by a homogeneous model of Sn-Beta that does not contain “open” sites, methyl-ligated tin silsesquioxane 1a, is experimentally and theoretically examined. 1a is an active glucose conversion catalyst selectively producing mannose, although the rates of reaction are far below those obtained from Sn-Beta. A hybrid quantum mechanical/molecular mechanics model is constructed, and the complete catalytic cycle is computationally examined, considering ring-opening, three distinct pathways for each hydride- and carbon-shift reaction, and ring-closing. The combined experimental and computational results suggest that there could be reaction pathways that involve Si–O–Sn cleavage that give much slower reaction rates than the open tin site in Sn-Beta.

Optically bright Galactic stars (V < 13 mag) having fv(24 um) > 1 mJy are identified in Spitzer mid-infrared surveys within 8.2 square degrees for the Bootes field of the NOAO Deep Wide-Field Survey and within 5.5 square degrees for the First Look Survey (FLS). 128 stars are identified in Bootes and 140 in the FLS, and their photometry is given. (K-[24]) colors are determined using K magnitudes from the 2MASS survey for all stars in order to search for excess 24 um luminosity compared to that arising from the stellar photosphere. Of the combined sample of 268 stars, 141 are of spectral types F, G, or K, and 17 of these 141 stars have 24 um excesses with (K-[24]) > 0.2 mag. Using limits on absolute magnitude derived from proper motions, at least 8 of the FGK stars with excesses are main sequence stars, and estimates derived from the distribution of apparent magnitudes indicate that all 17 are main sequence stars. These estimates lead to the conclusion that between 9% and 17% of the main sequence FGK field stars in these samples have 24 um infrared excesses. This result is statistically similar to the fraction of stars with debris disks found among previous Spitzer targeted observations of much brighter, main sequence field stars., Accepted for publication in The Astronomical Journal

Spitzer MIPS images in the Bootes field of the NOAO Deep Wide-Field Survey have revealed a class of extremely dust obscured galaxy (DOG) at z~2. The DOGs are defined by very red optical to mid-IR (observed-frame) colors, R - [24 um] > 14 mag, i.e. f_v (24 um) / f_v (R) > 1000. They are Ultra-Luminous Infrared Galaxies with L_8-1000 um > 10^12 -10^14 L_sun, but typically have very faint optical (rest-frame UV) fluxes. We imaged three DOGs with the Keck Laser Guide Star Adaptive Optics (LGSAO) system, obtaining ~0.06'' resolution in the K'-band. One system was dominated by a point source, while the other two were clearly resolved. Of the resolved sources, one can be modeled as a exponential disk system. The other is consistent with a de Vaucouleurs profile typical of elliptical galaxies. The non-parametric measures of their concentration and asymmetry, show the DOGs to be both compact and smooth. The AO images rule out double nuclei with separations of greater than 0.1'' (< 1 kpc at z=2), making it unlikely that ongoing major mergers (mass ratios of 1/3 and greater) are triggering the high IR luminosities. By contrast, high resolution images of z~2 SCUBA sources tend to show multiple components and a higher degree of asymmetry. We compare near-IR morphologies of the DOGs with a set of z=1 luminous infrared galaxies (LIRGs; L_IR ~ 10^11 L_sun) imaged with Keck LGSAO by the Center for Adaptive Optics Treasury Survey. The DOGs in our sample have significantly smaller effective radii, ~1/4 the size of the z=1 LIRGs, and tend towards higher concentrations. The small sizes and high concentrations may help explain the globally obscured rest-frame blue-to-UV emission of the DOGs., 9 pages, 7 figures, 2 tables, accepted for publication in the Astronomical Journal

The use of biomass as a resource to produce value-added products has garnered significant interest as a means of reducing reliance on fossil fuels. This task is complicated by the complex, highly functionalized nature of abundant biomass derivatives, such as glucose. Tin-containing zeolite Beta (Sn-Beta) can selectively isomerize glucose to fructose through a 1,2-intramolecular hydride shift (1,2-HS) or selectively produce mannose through a 1,2-intramolecular carbon shift (1,2-CS) by titration of the silanol groups with sodium (Na-Sn-Beta). To understand the structure–activity relationships between the conditions of the active sites in the zeolite, two molecular models (tin silsesquioxanes) of the tin sites in the zeolite were synthesized. Tin silsesquioxanes that contain an octahedral tin site with and without an adjacent silanol group selectively form fructose through a 1,2-HS and mannose through a 1,2-CS, respectively, and provide further evidence for the nature of the active sites in Sn-Beta.

We present near-infrared spectroscopic observations for a sample of ten optically faint luminous infrared galaxies (R-[24]> 14) using Keck NIRSPEC and Gemini NIRI. The sample is selected from a 24 micron Spitzer MIPS imaging survey of the NDWFS Bootes field. We measure accurate redshifts in the range 1.3 1900 km/s) Halpha or Hbeta emission lines; the remaining three are type II AGN. Given their large mid-IR luminosities and faint optical magnitudes, we might expect these sources to be heavily extincted quasars, and therefore only visible as type II AGN. The visibility of broad lines in 70% of the sources suggests that it is unlikely that these AGN are being viewed through the mid-plane of a dusty torus. For four of the sources we constrain the Halpha/Hbeta Balmer decrement and estimate the extinction to the emission line region to be large for both type I and type II AGN, with A_Halpha > 2.4-5 mag. Since the narrow-line region is also extincted and the UV continuum emission from the host galaxies is extremely faint, this suggests that much of the obscuration is contributed by dust on large (~kpc) scales within the host galaxies. These sources may be examples of "host-obscured" AGN which could have space densities comparable or greater to that of optically luminous type I AGN with similar bolometric luminosities.

Ozone has been proposed as an alternative oral antiseptic in dentistry, due to its antimicrobial power reported for gaseous and aqueous forms, the latter showing a high biocompatibility with mammalian cells. New therapeutic strategies for the treatment of periodontal disease and apical periodontitis should consider not only antibacterial effects, but also their influence on the host immune response. Therefore, our aim was to investigate the effect of aqueous ozone on the NF-kappaB system, a paradigm for inflammation-associated signaling/transcription. We showed that NF-kappaB activity in oral cells stimulated with TNF, and in periodontal ligament tissue from root surfaces of periodontally damaged teeth, was inhibited following incubation with ozonized medium. Under this treatment, IkappaBalpha proteolysis, cytokine expression, and kappaB-dependent transcription were prevented. Specific ozonized amino acids were shown to represent major inhibitory components of ozonized medium. In summary, our study establishes a condition under which aqueous ozone exerts inhibitory effects on the NF-kappaB system, suggesting that it has an anti-inflammatory capacity.

Zeolite A (LTA) has many large-scale uses in separations and ion exchange applications. Because of the high aluminum content and lack of high-temperature stability, applications in catalysis, while highly desired, have been extremely limited. Herein, we report a robust method to prepare pure-silica, aluminosilicate (product Si/Al = 12–42), and titanosilicate LTA in fluoride media using a simple, imidazolium-based organic structure-directing agent. The aluminosilicate material is an active catalyst for the methanol-to-olefins reaction with higher product selectivities to butenes as well as C_5 and C_6 products than the commercialized silicoalumniophosphate or zeolite analogue that both have the chabazite framework (SAPO-34 and SSZ-13, respectively). The crystal structures of the as-made and calcined pure-silica materials were solved using single-crystal X-ray diffraction, providing information about the occluded organics and fluoride as well as structural information.

Accurate photometric redshifts are calculated for nearly 200,000 galaxies to a 4.5 micron flux limit of ~13 uJy in the 8.5 deg^2 Spitzer/IRAC Shallow survey. Using a hybrid photometric redshift algorithm incorporating both neural-net and template-fitting techniques, calibrated with over 15,000 spectroscopic redshifts, a redshift accuracy of \sigma = 0.06(1+z) is achieved for 95% of galaxies at 01) galaxy clusters. We present one such spectroscopically confirmed cluster at =1.24, ISCS J1434.5+3427. Finally, we present a measurement of the 4.5 micron-selected galaxy redshift distribution., Comment: 14 pages, 9 Figures, 5 Tables. ApJ in press. For a version with full-resolution figures, please see http://www.astro.utoronto.ca/~brodwin/papers/0607450.pdf

We determine the contribution of AGN to the mid-IR emission of luminous infrared galaxies (LIRGs) at z>0.6 by measuring the mid-IR dust continuum slope of 20,039 mid-IR sources. The 24 micron sources are selected from a Spitzer/MIPS survey of the NOAO Deep Wide-Field Survey Bo\"otes field and have corresponding 8 micron data from the IRAC Shallow Survey. There is a clear bimodal distribution in the 24 micron to 8 micron flux ratio. The X-ray detected sources fall within the peak corresponding to a flat spectrum in nufnu, implying that it is populated by AGN-dominated LIRGs, whereas the peak corresponding to a higher 24 micron to 8 micron flux ratio is likely due to LIRGs whose infrared emission is powered by starbursts. The 24 micron emission is increasingly dominated by AGN at higher 24 micron flux densities (f_24): the AGN fraction of the z>0.6 sources increases from ~9% at f_24 ~ 0.35 mJy to 74+/-20% at f_24 ~ 3 mJy in good agreement with model predictions. Deep 24 micron, small area surveys, like GOODS, will be strongly dominated by starburst galaxies. AGN are responsible for ~ 3-7% of the total 24 micron background.

Infectious bronchitis is a respiratory disease of chickens that is caused by the coronavirus infectious bronchitis virus (IBV). Virtually all broiler and layer breeder flocks are routinely vaccinated against IBV. Two hatches of 1-day-old chicks from four lines were mistakenly vaccinated for infectious bronchitis using a moderately attenuated vaccine designed for chicks of an older age. The vaccination resulted in high mortality, and chicks from three of four lines died with signs typical of infectious bronchitis. The mortality that occurred using this less-attenuated vaccine was significantly influenced by the genetic line, and the MHC (B) haplotype in chickens of three B congenic lines. B congenic chickens possessing the B*15 haplotype were resistant in contrast to chickens possessing the B*13 or B*21 haplotypes. Chicks from two further hatches of the four lines were vaccinated appropriately with a more attenuated IBV vaccine, and only limited chick mortality was seen. These retrospective data from two repeated hatches confirm earlier data indicating chicken genes influence resistance to IBV, and indicate for the first time that genes tightly linked to the B haplotype are relevant in resistance to IBV. Due to extenuating circumstances it was not possible to verify results with chicks from F2 matings. Factors that may enhance definition of the role of the B haplotype in immune response to IBV, and the desirability for further analysis of a B haplotype-linked influence on immunity to IBV are discussed.

Local lifetime control by proton and alpha-particle irradiation with energies from 1.8 to 12.1 MeV and doses up to 5×10 12 cm −2 was faced with two types of electron irradiation giving the different profiles of carrier lifetime: the high-energy (4 MeV) resulting in a homogeneous lifetime distribution and the low-energy (500 and 460 keV) providing so-called sloping lifetime control. Deep and shallow levels introduced by irradiation were characterised by DLTS, HVCTS and C – V profiling and their effect on static and dynamic parameters of irradiated diodes was measured and simulated. The advantages and drawbacks of different lifetime control techniques are compared and their application aspects are discussed, as well.

Current transient spectroscopy (CTS) using high relaxation voltages up to 1 kV is shown to be an effective tool for non-destructive characterization of radiation defect profiles in silicon resulting from the MeV ion irradiation. The method was used for profiling of different defect centers produced in low-doped, float zone, n-type silicon by irradiation with 3, 4 and 5.3 MeV protons to a fluence of 5×10 9 and 1×10 10 cm −2 . The results were compared with those obtained from capacitance DLTS and reverse I – V profiling. Electronic properties and introduction rates of dominant defect centers were also established. It is shown that CTS is capable to trace full-depth profiles of dominant radiation defects and provide precise and more accurate data than previously presented by destructive profiling procedures. Measured distributions of vacancy related radiation defects agree well with the distribution of the primary damage received from Monte Carlo simulations with the exception of the peak broadening attributed to vacancy diffusion.

Application of radiation defects for adjustment of power diode parameters is demonstrated. Local lifetime control (LLC) by proton and alpha-particle irradiation with energies 1.8–12.1 MeV is compared with uniform lifetime killing by 4.5 MeV electrons. The influence of both the techniques on static and dynamic parameters of modified diodes is experimentally established and explained by means of state-of-the-art simulation system. Optimization means and limits of lifetime control by irradiation techniques are discussed, as well.

Perovskite multilayers built by thin layers of the half-metal La 0.7 Sr 0.3 MnO 3 (LSMO) and the insulator SrTiO 3 have been epitaxially grown by pulsed laser deposition. High quality superlattices have been obtained as indicated by the results of X-ray diffraction and transmission electron microscopy. Magnetization and in-plane electrical transport of multilayers with a manganite thickness of 10 nm > d LSMO > 1.9 nm have been studied. A systematic suppression of ferromagnetic order and metallic conductivity with decreasing d LSMO has been observed. The properties of the ultrathin manganite layers can be well understood assuming a phase separation into ferromagnetic metallic and insulating regions, as it has been established for other manganites recently. Within this regime, large magnetoresistance (MR) in a wide range of temperatures as well as anomalous MR effects, including positive MR and very large negative MR in dependence on d LSMO , have been observed.

Fibroblasts and myofibroblasts are known to secrete a wide spectrum of cytokines, but the individual spectrum is tissue-specific. We investigated the effect of cell activation on cytokine secretion of isolated human colonic fibroblasts/myofibroblasts from control patients and patients with mucosal inflammation.Primary cultures of human colonic submucosal fibroblasts/myofibroblasts were incubated with IL-1alpha (100 U/ml), IL-Ibeta (10 ng/ml), IL-10 (10 ng/ml), TNF (10 ng/ml), PMA (10 ng/ml), LPS (50 ng/ml), IL-4 (10 ng/ml), or a combination of IL-1 and TNF. Secreted cytokines were determined by ELISA. NF-kappaB activation was demonstrated by electrophoretic mobility-shift assays (EMSA).Incubation of colonic fibroblasts/myofibroblasts with IL-1, LPS, TNF and PMA induced secretion of IL-6, IL-8, M-CSF and GM-CSF. IL-8 and IL-6 secretion could be stimulated by IL-1alpha, IL-1beta, TNF, PMA and LPS within 6 h of incubation. IL-6 secretion was stimulated from 0.5 +/- 0.01 pg/h x microg fibroblast protein to 18.5 +/- 2.6 pg/h x microg fibroblast protein with IL-1beta (P0.01). IL-8 secretion was stimulated from 1.0 +/- 0.1 pg/h x microg fibroblast protein to 41.1 +/- 3.6 pg/h x microg (P0.005). IL-4 and IL-10 did not change cytokine secretion significantly. No significant differences between cultures from normal and inflamed mucosa were observed. TNF and IL-1 induced NF-kappaB activation. ALLN, a proteasome and NF-kappaB activation inhibitor, reduced TNF-mediated IL-8, GM-CSF and M-CSF induction significantly, whereas induction of IL-6 secretion remained unchanged.Human colonic myofibroblasts can secrete large amounts of IL-6, IL-8, M-CSF and GM-CSF upon stimulation. The induction of IL-8, M-CSF and GM-CSF, but not of IL-6 secretion, is mediated mainly by NF-kappaB activation. The cytokine profile and the total amounts of cytokines released suggest that colonic myofibroblasts can play a role in leukocyte recruitment and during mucosal inflammation. They therefore have to be regarded as an important part of the mucosal immune system.

Nanoscale cobalt-copper multilayers prepared by pulsed laser deposition on oxidized silicon substrate were investigated by means of transmission electron microscopic (TEM) methods combined with energy dispersive X-ray spectroscopy. The multilayers proved to be polycrystalline with grain sizes between some nanometers and the stack thickness. The topmost copper layer was incomplete with droplets up to 1 μm. For single layer thicknesses greater than 4 nm it could be shown that the structure of the layer stacks was face centred cubic with hexagonal close packed parts in the cobalt layers.

In the thermally immiscible Ag/Fe (5–20 nm)/Ag-(0 0 1)-multilayer-structure ion beam mixing of the layers induces a strong tetragonal distortion of the Fe-layer. The induced changes of the magnetic properties were determined by the ferromagnetic resonance (FMR) and Faraday magnetometry (FM) methods. For high dose irradiated samples of 10 16 cm −2 a tetragonal symmetry of the magnetic anisotropy fields was observed. An influence of the ion beam mixing on the saturation magnetisation of the Fe-layer was not detected. Annealing of the samples shows a recovery of the magnetic properties at 450–600 K indicating the influences on the magnetic properties are mainly caused by induced atomic intermixing of Ag in the Fe-layer and Fe in the Ag-layer.