Simulation of salinity effects on past, present, and future soil organic carbon stocks

Soil organic carbon (SOC) models are used to predict changes in SOC stocks and carbon dioxide (CO(2)) emissions from soils, and have been successfully validated for non-saline soils. However, SOC models have not been developed to simulate SOC turnover in saline soils. Due to the large extent of salt-affected areas in the world, it is important to correctly predict SOC dynamics in salt-affected soils. To close this knowledge gap, we modified the Rothamsted Carbon Model (RothC) to simulate SOC turnover in salt-affected soils, using data from non-salt-affected and salt-affected soils in two agricultural regions in India (120 soils) and in Australia (160 soils). Recently we developed a decomposition rate modifier based on an incubation study of a subset of these soils. In the present study, we introduce a new method to estimate the past losses of SOC due to salinity and show how salinity affects future SOC stocks on a regional scale. Because salinity decreases decomposition rates, simulations using the decomposition rate modifier for salinity suggest an accumulation of SOC. However, if the plant inputs are also adjusted to reflect reduced plant growth under saline conditions, the simulations show a significant loss of soil carbon in the past due to salinization, with a higher average loss of SOC in Australian soils (55 t C ha(-1)) than in Indian soils (31 t C ha(-1)). There was a significant negative correlation (p < 0.05) between SOC loss and osmotic potential. Simulations of future SOC stocks with the decomposition rate modifier and the plant input modifier indicate a greater decrease in SOC in saline than in non-saline soils under future climate. The simulations of past losses of SOC due to salinity were repeated using either measured charcoal-C or the inert organic matter predicted by the Falloon et al. equation to determine how much deviation from the Falloon et al. equation affects the amount of plant inputs generated by the model for the soils used in this study. Both sets of results suggest that saline soils have lost carbon and will continue to lose carbon under future climate. This demonstrates the importance of both reduced decomposition and reduced plant input in simulations of future changes in SOC stocks in saline soils.     

A cascode modulated class-E power amplifier for wireless communications

A cascode modulated CMOS class-E power amplifier (PA) is presented in this paper. It is shown that by applying a modulated signal to the gate of the cascode transistor the output power is modulated. The main advantage of the proposed technique is a high 35 dB output power dynamic range. The peak power added efficiency (PAE) is 35%. The concept of the cascode power control of class-E RF PA operating at 2.2 GHz with 18 dBm output power was implemented in a CMOS technology and the performance has been verified by measurements. The prototype CMOS PA is tested by single tone excitation and by enhanced data rates for GSM evolution (EDGE) modulated signal. Digital predistortion is used to linearize the transfer characteristic. The EDGE spectrum mask is met and the rms error vector magnitude (EVM) is less than 4° in the entire output power range.     

Modified-atmosphere retail packaging of discovery apples

An experimental modified-atmosphere packaging system was used to compare the atmospheric compositions that developed within sealed packs made from a range of films of different permeability properties. The effects of these conditions were then related to the primary quality attributes, i.e. background skin colour and flesh firmness, and the sensory quality of Discovery apples. Concentrations of CO₂ and O₂ within packs were dependent on the permeability of the film and the holding temperature. In packs sealed with low density polyethylene films and held at 20°C, equilibrated atmospheres containing 3-5% CO₂ and 5-6% O₂ developed within 1-2 days. Softening and yellowing of fruit was markedly retarded. In packs sealed with some less permeable films, atmospheres containing 12-20% CO₂ and 0.9-4% O₂ developed within 1-2 days, resulting in retarded softening and yellowing of the fruit but also a high incidence of tainting. Possible commercial applications, benefits and limitations of modified-atmosphere packaging are discussed.     

Characteristics of mammary mitochondria in lines of mice genetically divergent for milk production

The purpose of this study was to determine the relationship of mitochondrial proliferation and ATP production to milk production in two lines of mice that were genetically divergent for milk production. Milk production differed between high production and low production lines by .8 phenotypic standard deviations as determined by cross-fostered litter weight gain from 1 to 12 d postpartum. Mammary weight, mammary total DNA, and RNA:DNA ratio were greater in glands of high line mice. Mammary DNA and protein, expressed per gram mammary tissue, were similar between lines. Mammary mitochondrial mass per gland differed after six generations of divergent selection. Rates of succinate-supported ATP production and ADP:O of isolated mitochondria differed, but the rate of pyruvate-supported ATP production did not differ between lines. Differences between selection lines in mitochondrial mass and in the efficiency of succinate use for support of ATP production were probable consequences of selection for divergent milk production.     

Determination of carotenoids in salmonoids

Summary A routine method for quantitative analysis of carotenoid pigments in salmonoids has been developed, based on an extraction with acetone and subsequent cleaning on silicagel prior to identification by thin-layer chromatography (TLC). Quantitative determinations of astaxanthin and canthaxanthin were performed by high-pressure liquid chromatography (HPLC) on a C-18 column eluted with 20% ethyl acetate and 80% methanol/water (9+1) followed by spectrophotometric detection in the visible region. Other combinations of carotenoids could be separated by this system using isocratic or gradient elution. Carotenoid contents of examined fish meat were 2.3–8.1 mg astaxanthin/kg and 0.3–1.0 mg canthaxanthin/kg. Purified colour extracts from fish could be stored at –18 °C for a least 1 month before a final carotenoid analysis was carried out.

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Bestimmung von Carotenoiden in Salmoniden

Zusammenfassung Es wurde eine Routinemethode für die quantitative Analyse von Carotenoidpigmenten in Salmoniden entwickelt, die auf einer Extraktion der Farbstoffe mit Aceton und einem Reinigungsschritt auf Kieselgel vor der Identifizierung durch TLC beruht. Eine quantitative Bestimmung von Astaxanthin und Canthaxanthin konnte durch HPLC auf einer C-18 Säule und Elution mit Essigester/Methanol Wasser (9 + 1) (20:80) gefolgt von photometrischer Detektion im sichtbaren Bereich erzielt werden. Auch andere Kombinationen von Carotenoiden können mit diesem System getrennt werden, wenn isokratische oder Gradientenelution verwendet wird. Die Gehalte an Carotenoiden betrugen in den untersuchten Fischen 2,3–8,1 mg Astaxanthin/Kg und 0,3–1,0 mg Canthaxanthin/kg. Die gereinigten Farbstoffextrakte sind bei –18 °C mindestens 1 Monat lang lagerstabil.

     

Replacing fossil oil with fresh oil – with what and for what?

Industrial chemicals and materials are currently derived mainly from fossil‐based raw materials, which are declining in availability, increasing in price and are a major source of undesirable greenhouse gas emissions. Plant oils have the potential to provide functionally equivalent, renewable and environmentally friendly replacements for these finite fossil‐based raw materials, provided that their composition can be matched to end‐use requirements, and that they can be produced on sufficient scale to meet current and growing industrial demands. Replacement of 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met, will require a trebling of global plant oil production from current levels of around 139 MT to over 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (i) tailor plant oils to have high purity (preferably >90%) of single desirable fatty acids, (ii) introduce unusual fatty acids that have specialty end‐use functionalities and (iii) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. This review outlines recent progress and future challenges in each of these areas. Practical applications: The research reviewed in this paper aims to develop metabolic engineering technologies to radically increase the yield and alter the fatty acid composition of plant oils and enable the development of new and more productive oil crops that can serve as renewable sources of industrial feedstocks currently provided by non‐renewable and polluting fossil‐based resources. As a result of recent and anticipated research developments we can expect to see significant enhancements in quality and productivity of oil crops over the coming decades. This should generate the technologies needed to support increasing plant oil production into the future, hopefully of sufficient magnitude to provide a major supply of renewable plant oils for the industrial economy without encroaching on the higher priority demand for food oils. Achievement of this goal will make a significant contribution to moving to a sustainable carbon‐neutral industrial society with lower emissions of carbon dioxide to the atmosphere and reduced environmental impact as a result.     

Systematic Exploration of Natural and Synthetic Flavonoids for the Inhibition of Staphylococcus aureus Biofilms

When single-cell (or suspended) bacteria switch into the biofilm lifestyle, they become less susceptible to antimicrobials, imposing the need for anti-biofilms research. Flavonoids are among the most extensively studied natural compounds with an unprecedented amount of bioactivity claims. Most studies focus on the antibacterial effects against suspended cells; fewer reports have researched their anti-biofilm properties. Here, a high throughput phenotypic platform was utilized to screen for the inhibitory activity of 500 flavonoids, including natural and synthetic derivatives, against Staphylococcus aureus biofilms. Since discrepancies among results from earlier antibacterial studies on flavonoids had been noted, the current study aimed to minimize sources of variations. After the first screen, flavonoids were classified as inactive (443), moderately active (47) or highly active (10). Further, exclusion criteria combining bioactivity and selectivity identified two synthetic flavans as the most promising. The body of data reported here serves three main purposes. First, it offers an improved methodological workflow for anti-biofilm screens of chemical libraries taking into account the (many times ignored) connections between anti-biofilm and antibacterial properties. This is particularly relevant for the study of flavonoids and other natural products. Second, it provides a large and freely available anti-biofilm bioactivity dataset that expands the knowledge on flavonoids and paves the way for future structure-activity relationship studies and structural optimizations. Finally, it identifies two new flavans that can successfully act on biofilms, as well as on suspended bacteria and represent more feasible antibacterial candidates.     

Spatial analysis of diffusion tensor tractography statistics along the inferior fronto-occipital fasciculus with application in progressive supranuclear palsy

Background

The purpose of the study was to develop a method for analysis of diffusion parameters along white matter (WM) tracts, using spatial normalization based on anatomical landmarks, and to introduce the apparent area coefficient (AAC). The method’s applicability was tested in the inferior fronto-occipital fasciculus (IFO) in patients with progressive supranuclear palsy (PSP) and healthy controls (HCs).

Methods

A framework for analysis of diffusion parameters was developed. Spatial normalization of the tracts was performed using anatomical landmarks, to avoid deformations caused by cerebral atrophy. Initially, 38 HCs were used to optimize a threshold for the minimal size of regions that differ between groups. The fractional anisotropy, mean diffusivity, AAC, and the hemispheric asymmetry index (AI), were compared between 11 PSP patients and 15 HCs.

Results

The method was feasible for analysis of PSP patients and HCs. The AI showed that the observed hemispheric asymmetry of AAC was significantly larger in PSP patients compared with HCs in small regions of the IFO.

Conclusions

The method was successfully employed for analysis of diffusion parameters along the IFO in a patient group. This method can be potentially useful in studies of WM diseases, with or without cerebral atrophy.     

On the rate of growth and extent of the steady damage accumulation phase in repeated impact tests

In the paper, data of repeated impact tests performed on seven laminates of different lay-up and thickness are used to illustrate how the damage index (DI), a damage variable recently introduced by the authors to monitor the range of the penetration process in thick laminates, can be applied in case of repeated impact tests to get information on the rate of initial steady damage accumulation as well as on the onset of severe damage modes.Curves of the rate of growth of the DI in the steady phase (ΔDI/ΔN) vs. the normalised impact energy (ratio of the impact energy E_i and the laminate penetration threshold P_n) show no significant damage accumulation besides initial specimen indentation for impact energies below 0.2P_n. For intermediate levels of impact energy, repeated impact tests are characterised by an initial region of steady damage accumulation followed by an abrupt change in the rate of damage growth a few impacts before laminate perforation. For higher impact energies (E_i/P_n > 0.4–0.45), no phase of steady damage accumulation is present, suggesting that severe damage mechanisms take place from the very first impacts. Values of the DI at the end of the steady phase (DI_unsteady) are shown to be rather peculiar to each laminate regardless of the impact energy used in the tests and therefore may be used to get a first indication of the laminate performance to repeated impacts. The extent of the steady phase may also be used to compute the total energy absorbed by the laminate in the steady damage accumulation phase (E_aTOT__steady).     

All-over,over-all: biothing and emergent composition

In the last decade, the impact of the digital on form-finding in architecture has been conspicuous. Could working with computational algorithms as the primary generative material, however, have deeper, more far-reaching effects on the creative field? Here, Pia Ednie-Brown asserts that a new paradigm in composition is being articulated, as exemplified by the Invisibles installation, created by the New York-based practice biothing. Copyright © 2006 John Wiley & Sons, Ltd.