Quantification of mycorrhizal limitation in beech spread

Establishment of Nothofagus spp. into grasslands can be limited by a lack of ectomycorrhizal inoculum, but the degree of mycorrhizal inoculum limitation and how far mycorrhizal inoculum spreads from forest edges has not been quantified. Further, it has been hypothesised, but not confirmed, that established Kunzea ericoides (a native Myrtaceae tree with both ectomycorrhizal and arbuscular mycorrhizal associations) could serve as an alternative host for ectomycorrhizal fungi and thus facilitate mycorrhizal infection of Nothofagus. To confirm and quantify these hypotheses, first we used an ex situ, intact-soil-core bioassay of soils collected near Nothofagus solandri var. cliffortioides forest, near established Kunzea, and in grassland distant from trees of either species. Second, we collected soils along transects of increasing distance from Nothofagus forest into adjacent grasslands. Mycorrhizal infection of Nothofagus solandri var. cliffortioides seedlings was high in soils from Near-Nothofagus and Near-Kunzea (74% and 67% of root tips, respectively) and lower in soils Distant from trees (28% of root tips). Seedlings in soils from Near-Nothofagus also had 3.4× greater biomass than those in soils Distant from trees. In the transects, mycorrhizal infection declined in a stepwise fashion at approximately 16 m distance from the forest edge, and seedling biomass was positively correlated with mycorrhizal infection. These data confirm that a lack of mycorrhizal inoculum can limit seedling establishment and show that Kunzea can provide an alternative host for Nothofagus-compatible mycorrhizal inoculum. Further, they provide quantitative data for spatially explicit models of woody establishment. Forty percent of seedlings in soils collected distant from trees had greater than 20% infection, suggesting that a lack of mycorrhizal inoculum is not a complete barrier to woody establishment, but instead may act as one of multiple environmental filters slowing beech spread. © New Zealand Ecological Society

A Study of Urinary Infection in Childhood, with Reference to Its Incidence as a Complication of Other Diseases

An investigation was made of 310 children admitted to hospital for treatment of a variety of conditions and the following facts were noted 1. The total incidence of urinary infection among these children was found to be 13.8%. 2. Urinary infection was found to occur four times more frequent in girls than boys, and the incidence was highest below the age of a year. 3. The condition frequently follows gastroenteritis, especially in infants. It is not a common complication of other diseases, and when it occurs, tends to run a mild course. 4. Normal urine, collected under aseptic conditions, contains not more than one leucocyte per high power field. During infection of the urinary tract this count is increased, but is not necessarily high. 5. The coliform bacillus is the infecting organism in the majority of cases. 6. Pyelitis is rare in children. The lesion most frequently present is bilateral suppurative interstitial pyelonephritis, 7. The pH of the urine shows no constant changes, either before the onset of urinary infection or during its course. 8. The symptoms of pyelonephritis vary according to the age of the child. 9. Important factors in the production of urinary infection are constipation, diarrhoea, purgation and a state of dehydration. 10. Chronic and recurrent cases may be due to congenital or acquired abnormalities of the urinary tract. 11. A moderate leucocytosis, due to an increase of the poly-nuclear neutrophils, was found to occur during the acute stage of the disease. 12. Haemolytic streptococci were isolated from the throat in a large number of cases of acute pyelonephritis. 13. The mortality rate from urinary infection was 16.2%. Where pyelonephritis was the primary condition the mortality was 10%. The largest number of deaths occurred in infants below the age of one year, and where the condition occurred as a complication of gastroenteritis. 14. The methods of prophylaxis and treatment are discussed

Blood–brain barrier water exchange measurements using contrast-enhanced ASL

A technique for quantifying regional blood–brain barrier (BBB) water exchange rates using contrast-enhanced arterial spin labelling (CE-ASL) is presented and evaluated in simulations and in vivo. The two-compartment ASL model describes the water exchange rate from blood to tissue, (Formula presented.), but to estimate (Formula presented.) in practice it is necessary to separate the intra- and extravascular signals. This is challenging in standard ASL data owing to the small difference in (Formula presented.) values. Here, a gadolinium-based contrast agent is used to increase this (Formula presented.) difference and enable the signal components to be disentangled. The optimal post-contrast blood (Formula presented.) ((Formula presented.)) at 3 T was determined in a sensitivity analysis, and the accuracy and precision of the method quantified using Monte Carlo simulations. Proof-of-concept data were acquired in six healthy volunteers (five female, age range 24–46 years). The sensitivity analysis identified the optimal (Formula presented.) at 3 T as 0.8 s. Simulations showed that (Formula presented.) could be estimated in individual cortical regions with a relative error (Formula presented.) % and coefficient of variation (Formula presented.) %; however, a high dependence on blood (Formula presented.) was also observed. In volunteer data, mean parameter values in grey matter were: arterial transit time (Formula presented.) s, cerebral blood flow (Formula presented.) mL blood/min/100 mL tissue and water exchange rate (Formula presented.) s−1. CE-ASL can provide regional BBB water exchange rate estimates; however, the clinical utility of the technique is dependent on the achievable accuracy of measured (Formula presented.) values

Is Oak Establishment in Old‐fields and Savanna Openings Context Dependent?

Multiple factors are known to influence tree seedling establishment, yet the degree to which these factors depend on each other and on spatial context is largely unknown. We examined the influence of herbaceous competition and water and nitrogen limitations on tree seedling establishment as functions of distance from trees (within‐site spatial context) and site history (between‐site spatial context; as old‐fields vs. savanna openings). We grew Quercus ellipsoidalis E.J. Hill (pin oak) and Q. macrocarpa Michx. (bur oak) seedlings for 3 years in abandoned agricultural fields and savannas in central Minnesota, USA, near and distant from adult oak trees, with and without water and nitrogen resource additions, and with and without clipping of herbaceous vegetation (reducing above‐ground competition). The strongest treatment effects were found in response to distance from trees and clipping herbaceous vegetation. Ectomycorrhizal infection, year 1 foliar N concentrations, and survival were greater in seedlings growing near vs. distant from adult trees, while clipping herbaceous vegetation increased above‐ground seedling biomass but reduced seedling heights, regardless of distance from adult trees. There were conflicting effects of resource addition, which were dependent on clipping of herbaceous vegetation and site (savanna vs. old‐field). Distance from adult trees and clipping herbaceous vegetation appear to have largely independent effects. Thus, while being near trees benefits seedlings, probably via increased mycorrhizal infection, competition from herbaceous vegetation limits seedlings regardless of distance from trees. In contrast, the effects of resource addition were more context dependent, interacting significantly with herbaceous context and site. The factors influencing seedling success can perhaps be best conceptualized as a series of largely independent environmental filters: seedlings near trees have increased mycorrhizal infection, nutrient uptake and survival, but face competition from herbaceous vegetation regardless of distance from trees. The slow encroachment of woody vegetation into old‐fields and savanna openings in this region is likely to be the result of the net cumulative effect of such filters

Method to Improve Indium Bump Bonding via Indium Oxide Removal Using a Multi-Step Plasma Process

A process for removing indium oxide from indium bumps in a flip-chip structure to reduce contact resistance, by a multi-step plasma treatment. A first plasma treatment of the indium bumps with an argon, methane and hydrogen plasma reduces indium oxide, and a second plasma treatment with an argon and hydrogen plasma removes residual organics. The multi-step plasma process for removing indium oxide from the indium bumps is more effective in reducing the oxide, and yet does not require the use of halogens, does not change the bump morphology, does not attack the bond pad material or under-bump metallization layers, and creates no new mechanisms for open circuits

Nickel(II) and nickel(0) complexes of bis(diisopropylphosphino)amine: Synthesis, structure, and electrochemical activity

In its neutral state, bis(diisopropylphosphino)amine HL reacts in equimolar amounts with the nickel halides NiCl2·6H2O, NiBr2, and NiI2in ethanol solutions to give the air- and moisture-stable P,P-chelated complexes (HL)NiX2(X = Cl, Br, I). Under similar conditions, complexes of the form (HL)2NiX2(X = BF4, NO3, ClO4) were prepared from 2:1 ligand-metal ratios of Ni(BF4)2{\textperiodcentered}6H2O, Ni(NO3)2{\textperiodcentered}6H2O, or Ni(ClO4)2{\textperiodcentered}6H2O. Deprotonation of the ligand with NaNH2followed by reaction with NiI2gives L2Ni when performed in Et2O, but leads to the co-crystal L2Ni{\textperiodcentered}2NCCHC(Me)NH2 when the solvent is acetonitrile. In addition to these Ni2+compounds, the Ni0complex (HL)2Ni can be prepared from a toluene solution of Ni(cod)2. Each complex has been characterized by a combination of IR and multi-nuclear NMR spectroscopies, as well as single-crystal X-ray diffraction. Electrochemical studies of the complexes revealed irreversible decomposition of the (HL)NiX2(X = Cl, Br, I) series, but electrocatalytic CO2reduction by the (HL)2NiX2(X = BF4, NO3, ClO4) compounds

Mediterranean-type diet and brain structural change from 73 to 76 years in a Scottish cohort

STUDY FUNDING The data were collected by a Research into Ageing programme grant; research continues as part of the Age UK–funded Disconnected Mind project. The work was undertaken by The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross-council Lifelong Health and Wellbeing Initiative (MR/K026992/1), with funding from the BBSRC and Medical Research Council. Imaging and image analysis was performed at the Brain Research Imaging Centre (sbirc.ed.ac.uk/), Edinburgh, supported by the Scottish Funding Council SINAPSE Collaboration. Derivation of mean cortical thickness measures was funded by the Scottish Funding Council’s Postdoctoral and Early Career Researchers Exchange Fund awarded by SINAPSE to David Alexander Dickie. L.C.A.C. acknowledges funding from the Scottish Government's Rural and Environment Science and Analytical Services (RESAS) division.Peer reviewedPublisher PD

Two-Step Plasma Process for Cleaning Indium Bonding Bumps

A two-step plasma process has been developed as a means of removing surface oxide layers from indium bumps used in flip-chip hybridization (bump bonding) of integrated circuits. The two-step plasma process makes it possible to remove surface indium oxide, without incurring the adverse effects of the acid etching process

Optimization of Indium Bump Morphology for Improved Flip Chip Devices

Flip-chip hybridization, also known as bump bonding, is a packaging technique for microelectronic devices that directly connects an active element or detector to a substrate readout face-to-face, eliminating the need for wire bonding. In order to make conductive links between the two parts, a solder material is used between the bond pads on each side. Solder bumps, composed of indium metal, are typically deposited by thermal evaporation onto the active regions of the device and substrate. While indium bump technology has been a part of the electronic interconnect process field for many years and has been extensively employed in the infrared imager industry, obtaining a reliable, high-yield process for high-density patterns of bumps can be quite difficult. Under the right conditions, a moderate hydrogen plasma exposure can raise the temperature of the indium bump to the point where it can flow. This flow can result in a desirable shape where indium will efficiently wet the metal contact pad to provide good electrical contact to the underlying readout or imager circuit. However, it is extremely important to carefully control this process as the intensity of the hydrogen plasma treatment dramatically affects the indium bump morphology. To ensure the fine-tuning of this reflow process, it is necessary to have realtime feedback on the status of the bumps. With an appropriately placed viewport in a plasma chamber, one can image a small field (a square of approximately 5 millimeters on each side) of the bumps (10-20 microns in size) during the hydrogen plasma reflow process. By monitoring the shape of the bumps in real time using a video camera mounted to a telescoping 12 magnifying zoom lens and associated optical elements, an engineer can precisely determine when the reflow of the bumps has occurred, and can shut off the plasma before evaporation or de-wetting takes place