Concentric bodies in two species of he loculoascomycetes

Concentric bodies were found in vegetative and pycnidial cells of Podoxythium tricothecium and in ascostromal paraphyses of Rhytidhysterium rufulum, two representatives of the Loculoascomycetes. They averages 185 nm in diameter in P. trichothecium and 255 nm in R. rufulum and consisted of three zones.     

Few electron double quantum dots in InAs/InP nanowire heterostructures

We report on fabrication of double quantum dots in catalytically grown InAs/InP nanowire heterostructures. In the few-electron regime, starting with both dots empty, our low-temperature transport measurements reveal a clear shell structure for sequential charging of the larger of the two dots with up to 12 electrons. The resonant current through the double dot is found to depend on the orbital coupling between states of different radial symmetry. The charging energies are well described by a capacitance model if next-neighbor capacitances are taken into account.     

Creep crack growth in welded components — a numerical study and comparison with the R5 procedures

In the present study, creep crack growth (CCG) in a circumferentially welded low alloyed pipe is numerically investigated for a number of different combinations of weldment constituent material properties. A creep ductility based damage model describes the accumulation of creep damage ahead of the crack tip where a constraint parameter and the creep strain rate perpendicular to the crack plane are used as characterising parameters. It is assumed that a fully circumferential creep crack, located in the heat affected zone with a depth of one quarter of the pipe thickness, is growing at a constant rate from the outer surface towards the inside. The numerical results reveal that not only the properties of the zone containing the crack, but also the deformation properties of the surrounding material influence the CCG behaviour. This influence can be noted on the characterising parameters used for the CCG rate predictions as well as on the CCG rate itself. The mismatch influence on corresponding C^* values is, however, marginal. This indicates that determination of the CCG rate in weldments, based on the C^* value only, may result in uncertain estimates.The numerically investigated cases are also assessed by use of the R5 procedures for the sake of comparison. Considering the stress re-distribution, due to the mismatch effect, the CCG rate is determined for the different weldment configurations. The comparison shows that the assumption of plane strain or plane stress conditions in the R5 analysis is essential for the agreement of the results between R5 and the two-parameter approach. Assuming plane stress conditions at the crack tip results in a relatively good agreement for the axial stress dominated cases investigated. However, for the hoop stress dominated cases, the R5 procedures predict higher CCG rates by an order of magnitude.     

ZIP8-Mediated Intestinal Dysbiosis Impairs Pulmonary Host Defense against Bacterial Pneumonia

Pneumococcal pneumonia is a leading cause of morbidity and mortality worldwide. An increased susceptibility is due, in part, to compromised immune function. Zinc is required for proper immune function, and an insufficient dietary intake increases the risk of pneumonia. Our group was the first to reveal that the Zn transporter, ZIP8, is required for host defense. Furthermore, the gut microbiota that is essential for lung immunity is adversely impacted by a commonly occurring defective ZIP8 allele in humans. Taken together, we hypothesized that loss of the ZIP8 function would lead to intestinal dysbiosis and impaired host defense against pneumonia. To test this, we utilized a novel myeloid-specific Zip8KO mouse model in our studies. The comparison of the cecal microbial composition of wild-type and Zip8KO mice revealed significant differences in microbial community structure. Most strikingly, upon a S. pneumoniae lung infection, mice recolonized with Zip8KO-derived microbiota exhibited an increase in weight loss, bacterial dissemination, and lung inflammation compared to mice recolonized with WT microbiota. For the first time, we reveal the critical role of myeloid-specific ZIP8 on the maintenance of the gut microbiome structure, and that loss of ZIP8 leads to intestinal dysbiosis and impaired host defense in the lung. Given the high incidence of dietary Zn deficiency and the ZIP8 variant allele in the human population, additional investigation is warranted to improve surveillance and treatment strategies.     

Exceedance Degree-Hours: A new method for assessing long-term thermal conditions

Several “discomfort indices” have been proposed and codified into building standards, with several needs usually reported for such indices. They should: express the severity of discomfort in time steps while incorporating all environmental and personal factors; be usable with any comfort model (and thus, a variety of interests, for example, traditional thermal comfort, sleep comfort), among other requirements. The existing indices, however, fall short of meeting all these goals, limiting their usefulness in many situations, such as assessing conditions in mixed-mode buildings, especially when used for building performance simulation and design optimization purposes. Here, a new discomfort index called “Exceedance Degree-Hours” is developed, which accounts for all six main environmental and personal factors. By using an equivalent temperature index, “Exceedance Degree-Hours” can capture variations in discomfort severity between different thermal conditions that other indices cannot. In contrast with other indices, “Exceedance Degree-Hours” can be paired with various comfort definitions from literature, and, importantly, it can be used to assess thermal comfort in mixed-mode buildings, providing a single value as a result. Here, the results of the proposed method are compared to those of existing discomfort indices suggested in standards, and the advantages and limitations of the proposed approach are discussed.     

Gate-induced fermi level tuning in InP nanowires at efficiency close to the thermal limit

As downscaling of semiconductor devices continues, one or a few randomly placed dopants may dominate the characteristics. Furthermore, due to the large surface-to-volume ratio of one-dimensional devices, the position of the Fermi level is often determined primarily by surface pinning, regardless of doping level. In this work, we investigate the possibility of tuning the Fermi level dynamically with wrap-around gates, instead of statically setting it using the impurity concentration. This is done using Ω-gated metal-oxide-semiconductor field-effect transistors with HfO(2)-capped InP nanowires as channel material. It is found that induced n-type devices exhibit an optimal inverse subthreshold slope of 68 mV/decade. By adjusting the growth and process parameters, it is possible to produce ambipolar devices, in which the Fermi level can be tuned across the entire band gap, making it possible to induce both n-type and p-type conduction.     

Effects of long-term herbicide use,irrigation and nitrogen fertiliser on soil fertility in an apple orchard

In 1972 an experiment was set up to investigate the long-term effects of herbicide, irrigation and two rates of nitrochalk fertiliser application on soil fertility in a Cox's Orange Pippin apple orchard. Samples taken in 1986 showed that uncultivated soil which had been maintained bare by herbicide had much lower organic C, total N and extractable K and Mg concentrations than soil which had been maintained under grass. Extractable P concentrations were lower in soil under grass than in soil under herbicide. In the absence of grass, soil pH was slightly lower than in its presence. All these effects were much greater at depths above 7·5 cm than below. Irrigation of the grass slightly increased organic C and total N levels at 0–7·5 cm compared with unirrigated grass but had no effect on extractable P, K and Mg. Increasing the fertiliser rate from 63 to 189 kg N ha^?1 had no effect on organic C, total N, extractable P and K. Yet, throughout the soil profile, extractable Mg concentrations were greater at the low than at the high N fertiliser rate. In a seedling growth test on soil taken from the orchard in 1988 (and confirmed to be free from residual herbicide), apple seedlings grown in soil which had previously been under grass grew significantly better than those in soil which had been bare. These differences were ascribed to a greater rate of N mineralisation in the soil formerly under grass. The results of this trial indicate that to safeguard soil fertility it is necessary to maintain a grass cover in the orchard. In addition, fertiliser application on newly planted trees should be adjusted to take account of the presence or absence of grass in the previous soil management treatment.     

Dissolution of Lignin from Kraft Pulp after Treatment with Nitrogen Oxides

Laboratory experiments show that pretreatment with NO₂ including heating and ripening at 5% consistency and 90°C for 3 hours in the presence of NO₃- and H⁺ led to a dissolution of approximately 50–60% of the lignin in unbleached kraft pulp. Only 5–15% were dissolved when the treatment was terminated after heating to 90°C. An extensive fragmentation of the lignin during the ripening explains the extensive delignification in acid medium.

Fractionated dissolution of the remaining lignin by alkaline extraction gave fractions with small variation in N-contents (2.9–3.4%) and hydrophilicity. The last fraction exhibited the highest sorption of water vapor. The delignification was related to the decrease in molecular size during the pretreatment and during the subsequent alkaline treatments.     

Cover Picture: Epitaxial Growth of Indium Arsenide Nanowires on Silicon Using Nucleation Templates Formed by Self‐Assembled Organic Coatings (Adv. Mater. 14/2007)

On p. 1801, Lars Samuelson and co‐workers report on InAs nanowires that are grown directly on Si substrates by employing self‐assembled organic coatings to create an oxide template which guides nanowire nucleation. The nanowires extend vertically from the Si(111) substrate (foreground). No metal catalysts are used, and the InAs crystal extends to the nanowire tip as shown in the atomically resolved transmission electron microscopy image (dome background). The reported method constitutes a promising approach to the integration of new components into existing Si technology.