Fox Hunting in Wild Apples: Searching for Novel Genes in Malus Sieversii

Malus sieversii is considered the progenitor of modern apple (Malus pumila) cultivars and to represent a valuable source of genetic diversity. Despite the importance of M. sieversii as a source of disease resistance, stress tolerance, and novel fruit traits, little is known about gene function and diversity in M. sieversii. Notably, a publicly annotated genome sequence for this species is not available. In the current study, the FOX (Full-length cDNA OvereXpressing) gene hunting system was used to construct a library of transgenic lines of Arabidopsis in which each transgenic line overexpresses a full-length gene obtained from a cDNA library of the PI619283 accession of M. sieversii. The cDNA library was constructed from mRNA obtained from bark tissues collected in late fall–early winter, a time at which many abiotic stress-adaptative genes are expressed. Over 4000 apple FOX Arabidopsis lines have been established from the pool of transgenic seeds and cDNA inserts corresponding to various Gene Ontology (GO) categories have been identified. A total of 160 inserts appear to be novel, with no or limited homology to M. pumila, Arabidopsis, or poplar. Over 1300 lines have also been screened for freezing resistance. The constructed library of transgenic lines provides a valuable genetic resource for exploring gene function and diversity in Malus sieversii. Notably, no such library of t-DNA lines currently exists for any Malus species.     

Inhibition of Toll-Like Receptor 4 Signaling Mitigates Microvascular Loss but Not Fibrosis in a Model of Ischemic Acute Kidney Injury

The development of chronic kidney disease (CKD) following an episode of acute kidney injury (AKI) is an increasingly recognized clinical problem. Inhibition of toll-like receptor 4 (TLR4) protects renal function in animal models of AKI and has become a viable therapeutic strategy in AKI. However, the impact of TLR4 inhibition on the chronic sequelae of AKI is unknown. Consequently, we examined the chronic effects of TLR4 inhibition in a model of ischemic AKI. Mice with a TLR4-deletion on a C57BL/6 background and wild-type (WT) background control mice (C57BL/6) were subjected to bilateral renal artery clamping for 19 min and reperfusion for up to 6 weeks. Despite the acute protective effect of TLR4 inhibition on renal function (serum creatinine 1.6 ± 0.4 mg/dL TLR4-deletion vs. 2.8 ± 0.3 mg/dL·WT) and rates of tubular apoptosis following ischemic AKI, we found no difference in neutrophil or macrophage infiltration. Furthermore, we observed significant protection from microvascular rarefaction at six weeks following injury with TLR4-deletion, but this did not alter development of fibrosis. In conclusion, we validate the acute protective effect of TLR4 signal inhibition in AKI but demonstrate that this protective effect does not mitigate the sequential fibrogenic response in this model of ischemic AKI.     

Evaluation of a four-point sine wave frequency estimator for portable DSP based instrumentation

A recent frequency estimation method was proposed in a Measurement paper for use in portable DSP based instrumentation. This method is especially important due to its low computational effort making it suitable for fast and low cost instrumentation. It has been found that many parameters can affect the frequency estimation using the proposed method. In this paper, the performance of the method in the presence of additive noise is evaluated, and the influence of signal frequency, initial phase, additive noise and number of analog-to-digital converter bits on the estimator is studied. Some caveats of the practical use of the method are addressed. Detailed numerical simulations based on a Monte Carlo procedure are presented in order to highlight the range of applicability of the method and determine the estimation bias.     

PAHs in sediments of the Black River and the Ashtabula River, Ohio: source apportionment by factor analysis

Sources of polycyclic aromatic hydrocarbons (PAHs) in the Black River and Ashtabula River sediments were apportioned using a factor analysis (FA) model with nonnegative constraints. Source profiles, contributions (microg/g) and percent contributions are determined with no prior knowledge of sources. The FA model includes scaling and backscaling of data with average PAH concentrations, without sample normalization. The present work is a follow-up to studies that used a chemical mass balance model to apportion sources to the same data sets. Literature source profiles, modified based on gas/particle partitioning of individual PAHs, from nine PAH sources were considered for comparison. FA results for a three-source solution indicate traffic (58%), coke oven (26%), and wood burning/coal tar (16%) are the primary PAH sources to Black River sediments. The primary PAH sources to the Ashtabula River sediments are traffic (51%), coke oven (44%), and wood burning (5%). This work supports the previous studies of Black River and Ashtabula River PAHs by CMB model. In addition, FA provides a more realistic fit to Ashtabula River model data by eliminating 100% contributions from one source.     

Electrocatalytic properties of Ti/Pt–IrO2 anode for oxygen evolution in PEM water electrolysis

A novel Pt–IrO₂ electrocatalyst was prepared using the dip-coating/calcinations method on titanium substrates. Titanium electrodes coated with oxides were investigated for oxygen evolution. Experimental results showed that Ti/Pt–IrO₂ electrode containing 30 mol% Pt in the coating exhibited significantly higher electrocatalytic activity for oxygen evolution compared to Ti/IrO₂ prepared by the same method, which is also supported by the electrochemical impedance data. Stability tests demonstrated Pt–IrO₂ electrocatalyst had a service cycle of 10,000 times in 0.1 M H₂SO₄ solution. And the anode surface had hardly discovered cracks and had compact structures, which contributed to stable nature of the electrode together with good conductivity and specific interaction between Pt and IrO₂ formed during the calcination. Furthermore, the enhanced catalytic activity for O₂ evolution at Ti/Pt–IrO₂ electrode is preliminarily discussed using the Mott–Schottky analysis.     

Electrophoretic deposition of carbon nanotubes onto carbon-fiber fabric for production of carbon/epoxy composites with improved mechanical properties

Carbon nanotubes (CNTs) have been deposited onto carbon-fiber fabric using electrophoretic deposition (EPD) prior to the infusion of epoxy resin for the production of carbon/epoxy composites. The carbon-fiber fabric employed for EPD was used in the as-received condition, in which the proprietary epoxy sizing-agent was present. CNTs were functionalized prior to EPD using ozone treatment for oxidation, followed by chemical reaction with polyethyleneimine. The CNT oxidation used a novel recirculating system which enabled ozonolysis to be conducted on large-volume solutions of CNTs in the presence of high-powered sonication, facilitating preparation of stable dispersions suitable for EPD. Significant increases in the shear strength and fracture toughness of the carbon/epoxy composites with the CNT treatment have been measured relative to composites without the CNT treatment. Analysis of fracture surfaces revealed interlaminar regions with high levels of CNTs and evidence of good adhesion between the carbon nanotubes and sized carbon-fiber, which is believed to have contributed to the measured improvement in mechanical properties.     

Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual COD_organic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH₄ (80-90 vol.%), CO₂ (10-20 vol.%) and H₂S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H₂S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass.     

Elucidation of the formation of CO2 in culinary dry products

 The formation of CO₂ in tomato powder, chosen as an example of a dry culinary product, was investigated at room temperature and at low values of water activity (a _w). CO₂ formation correlated well with parameters that represent the beginning and progression of the Maillard reaction. In the absence of O₂, CO₂ formation decreased. Pectin and depolymerized pectin did not influence CO₂ formation while galacturonic acid (GalA) had a large effect. Determination of ¹³CO₂ in low-moisture model systems revealed that CO₂ was not formed by decarboxylation of GalA alone. Only a small proportion of [1-¹³C]glycine and GalA was degraded by the Strecker pathway; however, glucose reacted with the labelled amino acid forming ¹³CO₂ which amounted to over 90% of the total CO₂ formed. Therefore, CO₂ could be used as an early indicator for the beginning of the Maillard reaction in dry culinary products. Received: 28 October 1996     

The Falling Lake Victoria Water Level: GRACE,TRIMM and CHAMP Satellite Analysis of the Lake Basin

In the last 5 years, Lake Victoria water level has seen a dramatic fall that has caused alarm to water resource managers. Since the lake basin contributes about 20% of the lakes water in form of discharge, with 80% coming from direct rainfall, this study undertook a satellite analysis of the entire lake basin in an attempt to establish the cause of the decline. Gravity Recovery And Climate Experiment (GRACE), Tropical Rainfall Measuring Mission (TRMM) and CHAllenging Minisatellite Payload (CHAMP) satellites were employed in the analysis. Using 45 months of data spanning a period of 4 years (2002–2006), GRACE satellite data are used to analyse the variation of the geoid (equipotential surface approximating the mean sea level) triggered by variation in the stored waters within the lake basin. TRMM Level 3 monthly data for the same period of time are used to compute mean rainfall for a spatial coverage of .25°×.25° (25×25 km) and the rainfall trend over the same period analyzed. To assess the effect of evaporation, 59 CHAMP satellite’s occultation for the period 2001 to 2006 are analyzed for tropopause warming. GRACE results indicate an annual fall in the geoid by 1.574 mm/year during the study period 2002–2006. This fall clearly demonstrates the basin losing water over these period. TRMM results on the other hand indicate the rainfall over the basin (and directly over the lake) to have been stable during this period. The CHAMP satellite results indicate the tropopause temperature to have fallen in 2002 by about 3.9 K and increased by 2.2 K in 2003 and remained above the 189.5 K value of 2002. The tropopause heights have shown a steady increase from a height of 16.72 m in 2001 and has remained above this value reaching a maximum of 17.59 km in 2005, an increase in height by 0.87 m. Though the basin discharge contributes only 20%, its decline has contributed to the fall in the lake waters. Since rainfall over the period remained stable, and temperatures did not increase drastically to cause massive evaporation, the remaining major contributor is the discharge from the expanded Owen Falls dam.     

Effect of chitosan and Dysphania ambrosioides on the bone regeneration process: A randomized controlled trial in an animal model

The focus of this triple‐blind study was on evaluating the effect of chitosan combined with Dysphania ambrosioides (A) extract on the bone repair process in vivo. In total, 60 male Wistar rats (Rattus norvegicus albinus) weighing between 260 and 270 g were randomly selected for this study and distributed into four groups (n = 15). Group C (chitosan), Group CA5 (chitosan + 5% of D. ambrosioides), Group CA20 (chitosan + 20% of D. ambrosioides), and Group CO (Control‐Blood clot). In each animal, bone defects measuring 2 mm in diameter were performed in both tibias for placement of the substances. After 7, 15, and 30 days, the animals were sedated and sacrificed using the cervical dislocation technique and the tissues were analyzed under optical microscope relative to the following events: inflammatory infiltrate, necrosis, osteoclasts, osteoblasts, fibroblasts, periosteal, and endosteal bone formation. The data were evaluated to verify distribution using the Kolmogorov–Smirnov test, and variance, using the Levene test; as distribution was not normal, data were subjected to the Kruskal–Wallis and Dunn nonparametric tests (p < .05). A significant inflammatory infiltrate was observed in Group CA5 (p = .008) in the time interval of 7 days, and in Group C at 15 (p = .009) and 30 (p = .017) days. Osteoblastic activity was more significant in Group CA20 (p = .027) compared with CA5 in the time interval of 7 days. Group CA20 demonstrated a significantly higher endosteal and periosteal bone formation value in the time interval of 7 (p = .013), 15 (p = .004), and 30 days (p = .008) compared with the other groups. The null hypothesis was refuted, bone regeneration was faster in spheres with an association of chitosan and 20% extract, and complete bone repair occurred clinically at 15 days and histologically at 30 days. The spheres proved to be a promising method for the biostimulation of alveolar bone repair and bone fractures.