Effects of ca treatments and temperature on broccoli colour development

Broccoli combines high contents of vitamins, fibres and glucosinolates with a low calorie count and is sometimes referred to as the ‘crown jewel of nutrition’. Colour is one of the most important quality attributes of broccoli, and yellowing due to senescence of broccoli florets is the main external quality problem in the broccoli supply chain. Controlled Atmosphere (CA) is a very effective method to maintain broccoli quality but the effects of CA on colour retention have not been studied extensively. The aim of this paper is to characterise the colour behaviour (measured by RGB colour image analysis) of broccoli as affected by CA and temperature. Data on colour behaviour and gas exchange were gathered for broccoli heads that were stored in containers at three temperatures and subjected to four levels of O2 and three levels of CO2. Gas conditions and temperature have a clear effect on the colour change of broccoli especially at low O2 in combination with high CO2. An integrated colour model is proposed that combines a colour model with a standard gas exchange model. The colour model is based on three differential equations describing the formation of (blue/green) chlorophyllide from the colourless precursor, the bidirectional conversion of chlorophyllide into (blue/green) chlorophyll, and the decay of chlorophyllide. During the first step of building the integrated model, gas exchange data were analysed simultaneously using multi response regression analysis. No fermentation was encountered for this batch of broccoli. During the second step it was found that only one of the reactions of the colour model, the decay of chlorophyllide, is affected by the gas conditions. In the final step, a multi-response approach was applied where gas exchange parameters were estimated using the gas exchange model, the colour parameters were estimated using the colour model with both models linked via the reaction rate constant affected by the gas conditions. Such a calibrated, integrated, model could be used as a tool for predicting colour change in the postharvest chain

Combination therapy with tranilast and angiotensin-converting enzyme inhibition provides additional renoprotection in the remnant kidney model

Despite current therapy with agents that block the renin–angiotensin system, renal dysfunction continues to progress in a significant proportion of patients with kidney disease. Several pre-clinical studies have reported beneficial effects of tranilast, an inhibitor of transforming growth factor (TGF)-β's actions in a range of diseases that are characterized by fibrosis. However, whether such therapy provides additional benefits in renal disease, when added to angiotensin-converting enzyme (ACE) inhibition, has not been explored. We randomized subtotally (5/6) nephrectomized rats to receive vehicle, the ACE inhibitor, perindopril (6 mg/l), tranilast (400 mg/kg/day), or their combination for 12 weeks. When compared with sham-nephrectomized animals, subtotally nephrectomized animals had reduced creatinine clearance, proteinuria, glomerulosclerosis, interstitial fibrosis, tubular atrophy, and evidence of TGF-β activity, as indicated by the abundant nuclear staining of phosphorylated Smad2. These manifestations of injury and TGF-β activation were all attenuated by treatment with either tranilast or perindopril, with the latter also attenuating the animals’ hypertension. When compared with single-agent treatment, the combination of tranilast and perindopril provided additional, incremental improvements in creatinine clearance, proteinuria, and glomerulosclerosis, and a reduction in nuclear phsopho-Smad2 beyond single-agent treatment. These findings indicate that the combination of tranilast and perindopril was superior to single-agent treatment on kidney structure and function in the remnant kidney model, and suggests the potential for such dual therapy in kidney disease that continues to progress despite blockade of the renin–angiotensin system

Single measurement to predict potential mineralizable nitrogen

Non-Peer ReviewedAlthough soil nitrate nitrogen (N) has been used as a basis for N fertilizer recommendation in western Canada, potential mineralizable N should be (or is) a more accurate indicator of the N supplying power of the soil. Potential mineralizable N, analyzed by extraction with hot KCl, and organic matter content were determined on the AESA Soil Quality Benchmark Sites in Alberta. Using these results, we developed an approach to estimate Nt from soil organic matter, based on the equation Nt=No(1-e-kt)y, and validated the calculated Nt with the hot KCl extracted N. Results indicated that the potential mineralizable N released from soil differed among ecoregions and slope positions. Potential mineralizable N is lower in southern Alberta than central Alberta. The lower slopes released more N than higher slope positions. Nt released in soil over the growing season correlated well with hot KCl extracted N in three different slope positions. However, variability of Nt in the upper slope position was greater than middle and lower slopes due to a shallow A horizon and variable soil moisture during the growing season. After removal of outliers (9% of the total data set), the values of R2 (regression of hot KCl with calculated Nt) are 0.529, 0.576 and 0.627 for upper, middle and lower slope position, respectively. Using calculated Nt results, a potential mineralizable map in Alberta has been developed. This map will guide producers to manage soil as well as fertilizer N

Collapse of ρxx\rho_{xx} ringlike structures in 2DEGs under tilted magnetic fields

In the quantum Hall regime, the longitudinal resistivity $\rho_{xx}$ plotted as a density--magnetic-field ($n_{2D}-B$) diagram displays ringlike structures due to the crossings of two sets of spin split Landau levels from different subbands [e.g., Zhang \textit{et al.}, Phys. Rev. Lett. \textbf{95}, 216801 (2005)]. For tilted magnetic fields, some of these ringlike structures "shrink" as the tilt angle is increased and fully collapse at $\theta_c \approx 6^\circ$. Here we theoretically investigate the topology of these structures via a non-interacting model for the 2DEG. We account for the inter Landau-level coupling induced by the tilted magnetic field via perturbation theory. This coupling results in anti-crossings of Landau levels with parallel spins. With the new energy spectrum, we calculate the corresponding $n_{2D}-B$ diagram of the density of states (DOS) near the Fermi level. We argue that the DOS displays the same topology as $\rho_{xx}$ in the $n_{2D}-B$ diagram. For the ring with filling factor $\nu=4$, we find that the anti-crossings make it shrink for increasing tilt angles and collapse at a large enough angle. Using effective parameters to fit the $\theta = 0^\circ$ data, we find a collapsing angle $\theta_c \approx 3.6^\circ$. Despite this factor-of-two discrepancy with the experimental data, our model captures the essential mechanism underlying the ring collapse.Comment: 3 pages, 2 figures; Proceedings of the PASPS V Conference Held in August 2008 in Foz do Igua\c{c}u, Brazi

Secretoglobin and Transferrin Expression in Bronchoalveolar Lavage Fluid of Horses with Chronic Respiratory Disease

Background: Lower expression of secretoglobin and transferrin has been found in the bronchoalveolar lavage fluid (BALF) of a small number of horses with experimentally induced signs of recurrent airway obstruction (RAO) compared to healthy controls. Hypothesis/Objectives: Secretoglobin and transferrin BALF expression will be similarly decreased in horses with naturally occurring clinical signs of RAO and in horses with experimentally induced clinical signs of RAO as compared to healthy controls and intermediate in horses with inflammatory airway disease (IAD). Animals: Recurrent airway obstruction-affected and control horses were subjected to an experimental hay exposure trial to induce signs of RAO. Client-owned horses with a presumptive diagnosis of RAO and controls from the same stable environments were recruited. Methods: Pulmonary function and BALF were evaluated from control and RAO-affected research horses during an experimental hay exposure trial (n = 5 in each group) and from client-owned horses (RAO-affected horses, n = 17; IAD-affected horses, n = 19; healthy controls, n = 5). The concentrations of secretoglobin and transferrin in BALF were assessed using Western blots. Results: Naturally occurring and experimentally induced RAO horses had similar decreases in BALF transferrin expression, but secretoglobin expression was most decreased in naturally occurring RAO. Secretoglobin and transferrin expression were both lower in BALF of RAO-affected horses than in IAD-affected and control horses. Conclusions and Clinical Importance: Secretoglobin and transferrin expression is decreased in BALF of RAO-affected horses after both experimental and natural exposure. Secretoglobin and transferrin likely play clinically relevant roles in the pathophysiology of RAO, and may thus be used as biomarkers of the disease

The IBI1 receptor of β-aminobutyric acid interacts with VOZ transcription factors to regulate abscisic acid signaling and callose-associated defense

External and internal signals can prime the plant immune system for a faster and/or stronger response to pathogen attack. β-aminobutyric acid (BABA) is an endogenous stress metabolite that induces broad-spectrum disease resistance in plants. BABA perception in Arabidopsis is mediated by the aspartyl tRNA synthetase IBI1, which activates priming of multiple immune responses, including callose-associated cell wall defenses that are under control by abscisic acid (ABA). However, the immediate signaling components after BABA perception by IBI1, as well as the regulatory role of ABA therein, remain unknown. Here, we have studied the early signaling events controlling IBI1-dependent BABA-induced resistance (BABA-IR), using untargeted transcriptome and protein interaction analyses. Transcriptome analysis revealed that IBI1-dependent expression of BABA-IR against the biotrophic oomycete Hyaloperonospora arabidopsidis is associated with suppression of ABA-inducible abiotic stress genes. Protein interaction studies identified the VOZ1 and VOZ2 transcription factors (TFs) as IBI1-interacting partners, which are transcriptionally induced by ABA but suppress pathogen-induced expression of ABA-dependent genes. Furthermore, we show that VOZ TFs require nuclear localization for their contribution to BABA-IR by mediating augmented expression of callose-associated defense. Collectively, our study indicates that the IBI1-VOZ signaling module channels pathogen-induced ABA signaling toward cell wall defense while simultaneously suppressing abiotic stress-responsive genes

Dynamics and distribution of natural and human-caused hypoxia

Water masses can become undersaturated with oxygen when natural processes alone or in combination with anthropogenic processes produce enough organic carbon that is aerobically decomposed faster than the rate of oxygen re-aeration. The dominant natural processes usually involved are photosynthetic carbon production and microbial respiration. The re-supply rate is indirectly related to its isolation from the surface layer. Hypoxic water masses (\u3c 2 mg L-1, or approximately 30% saturation) can form, therefore, under \u27natural\u27 conditions, and are more likely to occur in marine systems when the water residence time is extended, water exchange and ventilation are minimal, stratification occurs, and where carbon production and export to the bottom layer are relatively high. Hypoxia has occurred through geological time and naturally occurs in oxygen minimum zones, deep basins, eastern boundary upwelling systems, and fjords. Hypoxia development and continuation in many areas of the world\u27s coastal ocean is accelerated by human activities, especially where nutrient loading increased in the Anthropocene. This higher loading set in motion a cascading set of events related to eutrophication. The formation of hypoxic areas has been exacerbated by any combination of interactions that increase primary production and accumulation of organic carbon leading to increased respiratory demand for oxygen below a seasonal or permanent pycnocline. Nutrient loading is likely to increase further as population growth and resource intensification rises, especially with increased dependency on crops using fertilizers, burning of fossil fuels, urbanization, and waste water generation. It is likely that the occurrence and persistence of hypoxia will be even more widespread and have more impacts than presently observed. Global climate change will further complicate the causative factors in both natural and human-caused hypoxia. The likelihood of strengthened stratification alone, from increased surface water temperature as the global climate warms, is sufficient to worsen hypoxia where it currently exists and facilitate its formation in additional waters. Increased precipitation that increases freshwater discharge and flux of nutrients will result in increased primary production in the receiving waters up to a point. The interplay of increased nutrients and stratification where they occur will aggravate and accelerate hypoxia. Changes in wind fields may expand oxygen minimum zones onto more continental shelf areas. On the other hand, not all regions will experience increased precipitation, some oceanic water temperatures may decrease as currents shift, and frequency and severity of tropical storms may increase and temporarily disrupt hypoxia more often. The consequences of global warming and climate change are effectively uncontrollable at least in the near term. On the other hand, the consequences of eutrophication-induced hypoxia can be reversed if long-term, broad-scale, and persistent efforts to reduce substantial nutrient loads are developed and implemented. In the face of globally expanding hypoxia, there is a need for water and resource managers to act now to reduce nutrient loads to maintain, at least, the current status

Coupling to haloform molecules in intercalated C60?

For field-effect-doped fullerenes it was reported that the superconducting transition temperature Tc is markedly larger for C60.2CHX_3 (X=Cl, Br) crystals, than for pure C60. Initially this was explained by the expansion of the volume per C60-molecule and the corresponding increase in the density of states at the Fermi level in the intercalated crystals. On closer examination it has, however, turned out to be unlikely that this is the mechanism behind the increase in Tc. An alternative explanation of the enhanced transition temperatures assumes that the conduction electrons not only couple to the vibrational modes of the C60-molecule, but also to the modes of the intercalated molecules. We investigate the possibility of such a coupling. We find that, assuming the ideal bulk structure of the intercalated crystal, both a coupling due to hybridization of the molecular levels, and a coupling via dipole moments should be very small. This suggests that the presence of the gate-oxide in the field-effect-devices strongly affects the structure of the fullerene crystal at the interface.Comment: 4 pages, 1 figure, to be published in PRB (rapid communication

Long term Mesenchymal stem cell culture on a defined synthetic substrate with enzyme free passaging

Mesenchymal stems cells (MSCs) are currently the focus of numerous therapeutic approaches in tissue engineering/repair because of their wide multi-lineage potential and their ability to modulate the immune system response following transplantation. Culturing these cells, while maintaining their multipotency in vitro, currently relies on biological substrates such as gelatin, collagen and fibronectin. In addition, harvesting cells from these substrates requires enzymatic or chemical treatment, a process that will remove a multitude of cellular surface proteins, clearly an undesirable process if cells are to be used therapeutically. Herein, we applied a high-throughput ‘hydrogel microarray’ screening approach to identify thermo-modulatable substrates which can support hES-MP and ADMSC growth, permit gentle reagent free passaging, whilst maintaining multi-lineage potential. In summary, the hydrogel substrate identified, poly(AEtMA-Cl-co-DEAA) cross-linked with MBA, permitted MSCs to be maintained over 10 passages (each time via thermo-modulation), with the cells retaining expression of MSC associated markers and lineage potency. This chemically defined system allowed the passaging and maintenance of cellular phenotype of this clinically important cell type, in the absence of harsh passaging and the need for biological substrates