Organophosphate levels in apple composites and individual apples from a treated Canadian orchard

Azinphos-methyl, phosalone, and phosmet were applied individually to separate rows of trees within a commercial apple orchard in Quebec, Canada, during the 2003 agricultural season. Apples were collected for residue analysis immediately prior to the harvesting of the remaining apples for market distribution and were prepared for analysis as both individual apples and as composites of eight individuals. Analysis of the three applied compounds, as well as five organophosphate insecticides that were not applied, was performed using gas chromatography-mass spectrometry. Azinphos-methyl, phosalone, and phosmet, which were applied, were detected in all samples analyzed at concentrations ranging from 0.004 ng/g to 2260 ng/g. Methidathion was not observed in any sample. Chlorpyrifos, diazinon, dimethoate, and malathion concentrations ranged from below method detection limits to 0.71 ng/g, and the detection frequency for these compounds ranged from 20% to 100%. Residues measured in this study were all below the Canadian maximum residue limit for apples. Variability factors ranged from 2 to 19 for all compounds observed in this study. Composite samples may not accurately reflect the extremes of exposure from consumption of single servings of apples.     

Clinical use of a low-dose medetomidine infusion in healthy dogs undergoing ovariohysterectomy

Eight healthy dogs undergoing elective ovariohysterectomy were anesthetized with a standard protocol and received a low-dose medetomidine constant rate infusion during surgery. Cardiorespiratory parameters, including non-invasive cardiac output, were measured at various times. This protocol resulted in acceptable and stable cardiovascular performance, allowed low isoflurane concentrations, and provided smooth recoveries.     

Optimum use of milk in traditionally managed cattle herds in the tropics

In traditional cattle systems in the tropics, the milk produced is generally shared between the calf and the cattle keeper. This literature review evaluates the socio-economic aspects related to milk production and milk use in traditional cattle systems and identifies the best strategies of milk allocation in order to improve food security and maximise income. The available literature indicates that milk, in terms of economic, social and subsistence value, is more valuable than meat. Thus, under the conditions that characterise traditional cattle systems in the tropics, it is appropriate to have a higher milk offtake at the expense of calf growth. This review also found that certain management practices, such as restricted suckling, can be useful to minimise mortality of calves, while improving milk offtake for human consumption.     

Ex vivo evaluation of imatinib mesylate for induction of cell death on canine neoplastic mast cells with mutations in c-Kit exon 11 via apoptosis

Several studies of canine spontaneous mast cell tumours have described mutations in the c-kit proto-oncogene. These mutations produce a constitutively activated product and have been suggested to play a role in the malignant transformation of mast cells. We hypothesize that the selective tyrosine kinase inhibitor imatinib mesylate inhibits signal transduction and induces apoptosis when tested in cutaneous canine mast cell tumour samples positive for mutation in c-kit exon 11. Three-dimensional ex vivo cultures of canine grade II mast cell tumour treated with STI-571 at 48, 72, and 96 h and tested for signal transduction and apoptosis using appropriate assays were used. There was a progressive and significant increase in caspase-3 and TUNEL-positive mast cells compared to the untreated cultures. Additionally, a concurrent reduced expression of Ki67 and BCL-2 was observed. Furthermore, the treated cultures showed a marked reduction of Kit expression. Our results demonstrate that STI-571 induces Caspase-dependent apoptosis in a canine neoplastic mast cells possessing mutations in c-kit exon 11.     

Translocation of nitrogen in the xylem of field-grown cherry and poplar trees during remobilization

Studies of small trees growing in pots have established that individual amino acids or amides are translocated in the xylem sap of a range of tree species following bud burst, as a consequence of nitrogen (N) remobilization from storage. This paper reports the first study of N translocation in the xylem of large, deciduous, field-grown trees during N remobilization in the spring. We applied 15N fertilizer to the soil around 10-year-old Prunus avium L. and Populus trichocharpa Torr. & Gray ex Hook var. Hastata (Dode) A. Henry x Populus balsamifera L. var. Michauxii (Dode) Farwell trees before bud burst to label N taken up by the roots. Recovery of unlabeled N in xylem sap and leaves was used to demonstrate that P. avium remobilizes N in both glutamine (Gln) and asparagine (Asn). Sap concentrations of both amides rose sharply after bud burst, peaking 14 days after bud burst for Gln, and remaining high some 45 days for Asn. There was no 15N enrichment of either amide until 21 days after bud burst. In the Populus trees, nearly all the N was translocated in the sap as Gln, the concentration of which peaked and then declined before the amide was enriched with 15N, 40 days after bud burst. Xylem sap of clonal P. avium trees was sampled at different positions in the crown to assess if the amino acid and amide composition of the sap varied within the crown. Sap was sampled during remobilization (when the concentration of Gln was maximal), at the end of remobilization and at the end of the experiment (68 days after bud burst). Although the date of sampling had a highly significant effect on sap composition, the effect of position of sampling was marginal. The results are discussed in relation to N translocation in adult trees and the possibility of measuring N remobilization by calculating the flux of N translocation in the xylem.     

Release of protein, lipid, and vitamin E from almond seeds during digestion

The evaluation of the bioaccessibility of almond nutrients is incomplete. However, it may have implications for the prevention and management of obesity and cardiovascular disease. This study quantified the release of lipid, protein, and vitamin E from almonds during digestion and determined the role played by cell walls in the bioaccessibility of intracellular nutrients. Natural almonds (NA), blanched almonds (BA), finely ground almonds (FG), and defatted finely ground almonds (DG) were digested in vitro under simulated gastric and gastric followed by duodenal conditions. FG were the most digestible with 39, 45, and 44% of lipid, vitamin E, and protein released after duodenal digestion, respectively. Consistent with longer residence time in the gut, preliminary in vivo studies showed higher percentages of nutrient release, and microscopic examination of digested almond tissue demonstrated cell wall swelling. Bioaccessibility is improved by increased residence time in the gut and is regulated by almond cell walls.     

Short-Term Response of Soil Microbial Biomass to Different Chabazite Zeolite Amendments

Zeolitites (ZTs) are rocks containing more than 50% of zeolite minerals and are known to be a suitable material for agricultural purposes by improving soil physicochemical properties and nitrogen (N) use efficiency. However, little is known about their effects on soil microbial biomass. This study aimed to evaluate short-term effects of different chabazite-rich ZT (CHAZT) amendments on soil microbial biomass and activity. A silty-clay agricultural soil was amended in three different ways, including the addition of natural (5% and 15%) and NH_4~+-enriched (10%) CHAZT. Soil dissolved organic carbon (C), total dissolved N, NH_4~+, NO_3~-, NO_2~-, microbial biomass C and N, and ergosterol were measured periodically over 16 d in a laboratory incubation. To verify the microbial immobilization of the N derived from NH_4~+-enriched CHAZT, a high15N source was used for enriching the mineral to measure the microbial biomass δ15N signature. An increase in the ergosterol content was observed in the soil amended with 5% natural CHAZT. However, no similar result was observed in the soil amended with 15% natural CHAZT, suggesting that the fungal biomass was favored at a lower CHAZT application rate. In the soil amended with NH+ 4-enriched CHAZT, microbial biomass N was related to NO_3~-production over time and inversely related to NH_4~+, suggesting high nitrification process. Isotopic measurements on microbial biomass confirmed immediate assimilation of N derived from NH_4~+-enriched CHAZT. These results suggested that the NH_4~+-enriched CHAZT used in this study supplied an immediately available N pool to the microbial biomass.     

Predatory ability of the ant <Emphasis Type="Italic">Crematogaster scutellaris</Emphasis> on the brown marmorated stink bug <Emphasis Type="Italic">Halyomorpha halys</Emphasis>

The pest Halyomorpha halys is a recent example of severe worldwide biological invasion. In Italy, after the first detection in 2012, it has rapidly spread and economic damage has already been reported in commercial fruit orchards, eliciting enormous concern for Italian agricultural production. As a long-term solution, biological control investigations are focusing on the potential of natural antagonists, such as generalist predators, in the invaded areas. Due to their biology, ecology and behavior, ants represent one such generalist predator potentially suitable for inflicting mortality on H. halys. In this research, Crematogaster scutellaris was used as a study model. Specifically, the effect of ant predatory behavior on the survival of all H. halys pre-imaginal stages was tested in the laboratory environment. The results suggest that C. scutellaris has a significant predatory impact on all H. halys pre-imaginal stages except for eggs. The reduction of survivorship is between 95 and 85% for instars 1 and 2 and between 38 and 52% for instars 3, 4 and 5. The different levels of predation success suggest that these ants could act as useful generalist predators when associated with other antagonists and/or other control strategies. Although further field investigations are needed, the potential of ants as biocontrol agents of invasive species in agroecosystems deserves consideration in integrated pest management programs.     

Chlorophyll a fluorescence analysis along a vertical gradient of the crown in a poplar (Oxford clone) subjected to ozone and water stress

An experiment in open-top chambers was carried out in summer 2008 at Curno (Northern Italy) in order to study the effects of ozone and mild water stress on poplar cuttings (Oxford clone). In this experiment direct fluorescence parameters (JIP-test) were measured in leaves from different sections of the crown (L: lower; M: medium; U: upper parts of the crown). The parameters considered were calculated at the different steps of the fluorescence transient, and include maximum quantum yield efficiency in the dark-adapted state (F(v)/F(M)); the L-band, at 100?∝?s, that expresses the stability of the tripartite system reaction centre-harvesting light complex-core antenna; the K-band, at 300?∝?s, that expresses the efficiency of the oxygen-evolving complex; the J-phase, at 2 ms, that expresses the efficiency with which a trapped exciton can move an electron into the electron transport chain from Q(A)(-) to the intersystem electron acceptors; the IP-phase, which expresses the efficiency of electron transport around the photosystem 1 (PSI) to reduce the final acceptors of the electron transport chain, i.e., ferredoxin and NADP; and finally the performance index total (PItot) for energy conservation from photons absorbed by PSII to the reduction flux of PSI end acceptors. The main results are: (i) different dynamics were observed between leaves in the lower section, whose PItot decreased over time, and those in the upper sections in which it increased, with a dynamic connected to the leaf age; (ii) ozone depressed all the considered fluorescence parameters in basal leaves of well-watered plants, while it had little or no damaging effect on medium-level or upper-section leaves; (iii) PItot and IP-phase increased in upper leaves of plants subjected to ozone stress, as well as the net photosynthesis; (iv) water stress increased PItot of leaves in all levels of the crown. The results suggest that ozone-damaged poplar plants compensate, at least partially, for the loss of photosynthesis with higher photosynthetic rates in young leaves (in the upper section of the crown), more efficient to fix carbon.     

Evaluation of the dynamic predictors of fluid responsiveness in dogs receiving goal-directed fluid therapy

Objectives

Goal-directed fluid therapy (GDFT) based on pulse pressure variation (PPV) was used in anaesthetized dogs undergoing abdominal surgeries. The aims were 1) to evaluate the success rate of the PPV ≥13% in detecting fluid responsiveness [delta stroke volume (ΔSV) ≥10%]; 2) to assess the correlation between PPV, systolic pressure variation (SPV), Plethysmograph Variability Index (PVI) and central venous pressure (CVP) and 3) to establish the threshold value for the PVI that would predict a PPV value of ≥13% and indirectly discriminate responders from nonresponders to fluid therapy.