Boron and zinc deficiencies and toxicities and their interactions with other nutrients in soybean roots,leaves, and seeds

In many parts of the world, soils deficient and/or toxic in micronutrients reduce potential soybean (Glycine max) yields. The objective of our study was to grow plants in low to high concentrations of boron (B) and zinc (Zn) to determine how B and Zn deficiencies and toxicities affect soybean growth and interact with other essential nutrients in roots, leaves, and seeds. We found that B significantly affected levels of all essential nutrients except manganese and iron, while Zn significantly affected all essential nutrients in at least one plant tissue tested. Some of the physiological responses and nutrient interactions were cultivar-dependent. This study showed how deficiencies and toxicities of B and Zn affect plant growth and how B and Zn fertility interacts with many of the other essential nutrients.     

School food in Mexican children

OBJECTIVE: To establish the school eating habits of Mexican children, who are prone to obesity and later to high rates of adult chronic diseases. DESIGN: Questionnaires for students and parents with staff questionnaires and interviews. SETTING: Randomly sampled schools in a socio-economically representative district of Mexico City. SUBJECTS: Subjects were 1504 adolescents aged 10-19 years attending schools in Mexico City, 27 teachers and seven headmasters, sampled from both public and private schools and from the full range of socio-economic groups. RESULTS: Foods brought from home were of a higher nutritional quality than those purchased at school, where purchases were dominated by crisps, soft drinks and other items with high energy density. Girls were more inclined to purchase inappropriately; those from poorer homes purchased less. Private-school students irrespective of socio-economic grade brought more food from home and purchased more expensive food at school. School policies allowed food and drink vendors to market any products within the schools, which benefited financially from these activities. CONCLUSIONS: Current school food policies are conducive to amplifying the current epidemic of obesity and related adult chronic diseases, and need to change.     

Analysis of chlorothalonil and three degradates in sediment and soil

A method has been developed for the simultaneous extraction of chlorothalonil and three of its degradates (4-hydroxy-2,5,6-trichloroisophthalonitrile, 1-carbamoyl-3-cyano-4-hydroxy-2,5,6-trichlorobenzene, and 1,3-dicarbamoyl-2,4,5,6-tetrachlorobenzene) from soils and sediments; the compounds were extracted using sonication with acetone and isolation of the parent compound and matrix interferences from the degradates by solid phase extraction (SPE). The chlorothalonil fraction underwent further coextracted matrix interference removal with Florisil. The degradates were derivatized with N, O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) and chlorotrimethylsilane (TMCS). All compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). Recoveries on a spiked (20 and 200 microg kg (-1)) sediment ranged from 80% to 91% with calculated limits of detection of 1-5 microg kg (-1) dry weight sediment. An additional 20 sediment samples were collected in watersheds from the Southeastern United States where chlorothalonil is used widely on peanuts and other crops. None of the target compounds were detected. Laboratory fortified recoveries of chlorothalonil and its degradates in these environmental sediment samples ranged from 75% to 89%.     

Dynamics in debris-flow activity on a forested cone — A case study using different dendroecological approaches

Dendrogeomorphological analyses of trees affected by debris flows have regularly been used to date past events. However, this method has always been limited to forested cones where trees registered the impact of previous events. The minimum age dating of trees growing in the debris deposits can, in contrast, provide information on the latest possible moment of past activity. In this paper, we report on results obtained from a combination of these two approaches on a forested cone in the Valais Alps (Switzerland). A detailed geomorphic map in a scale of 1:1000 served as a basis for the sampling strategy. Disturbed Larix decidua Mill. and Picea abies (L.) Karst. trees growing in the deposits allowed reconstruction of 49 events between AD 1782 and 2005 as well as the determination of the spatial extent of events. In the debris-flow channels where survivor trees are missing, we selected the oldest post-event trees and assessed their age by counting their growth rings. Missing rings due to lack of center as well as to sampling height were added so as to determine real tree age. The combination of the dendrogeomorphological event reconstruction with the assessment of germination dates of successor trees allowed realistic approximation of the minimum time elapsed since the last debris-flow activity in 23 of the 29 channels present on the current-day cone surface. In general, channels in the northern part of the cone and those close to the currently active channel generally show signs of (sub-) recent activity with one last overbank sedimentation event in the 1980s, whereas signs of debris-flow activity are absent from the channels in the outermost part since the late 19th century. As a consequence of the deeply incised channel and the stabilization measures undertaken along the banks, signs of debris flows are missing in the tree-ring record for the past two decades.     

Cherry picking by pseudomonads: After a century of research on canker,genomics provides insights into the evolution of pathogenicity towards stone fruits

Bacterial canker disease is a major limiting factor in the growing of cherry and other Prunus species worldwide. At least five distinct clades within the bacterial species complex Pseudomonas syringae are known to be causal agents of the disease. The different pathogens commonly coexist in the field. Reducing canker is a challenging prospect as the efficacy of chemical controls and host resistance may vary against each of the diverse clades involved. Genomic analysis has revealed that the pathogens use a variable repertoire of virulence factors to cause the disease. Significantly, strains of P. syringae pv. syringae possess more genes for toxin biosynthesis and fewer encoding type III effector proteins. There is also a shared pool of key effector genes present on mobile elements such as plasmids and prophages that may have roles in virulence. By contrast, there is evidence that absence or truncation of certain effector genes, such as hopAB, is characteristic of cherry pathogens. Here we highlight how recent research, underpinned by the earlier epidemiological studies, is allowing significant progress in our understanding of the canker pathogens. This fundamental knowledge, combined with emerging insights into host genetics, provides the groundwork for development of precise control measures and informed approaches to breed for disease resistance.     

Characterization of Mycobacterium avium subspecies paratuberculosis disseminated infection in dairy cattle and its association with antemortem test results

Mycobacterium avium subspecies paratuberculosis (MAP) disseminated infection in dairy cattle affects animal health and productivity and is also a potential public health concern. The study objectives were to characterize MAP disseminated infection in dairy cattle and to determine the role of antemortem tests in detecting cattle with disseminated infection. Forty culled dairy cows representing a variety of serum enzyme-linked immunosorbent assay (ELISA) results and body conditions were selected for the study. The physical condition of the cows was assessed via clinical examination prior to euthanasia and blood and feces were collected and tested by serum ELISA and fecal culture, respectively. Fifteen tissues were aseptically collected from each cow during necropsy and cultured for isolation of MAP. Disseminated infection was diagnosed when MAP was isolated in tissues other than the intestines or their associated lymph nodes (LNs) and was distinguished from infection found only in the gastrointestinal tissues and from absence of infection. Of the 40 cows in the study, 21 had MAP disseminated infection. Results showed that 57% (12/21) of cows with disseminated infection had average to heavy body condition and no diarrhea. Cows with disseminated infection had no to minimal gross pathologic evidence of infection in 37% (8/21) of cases. Only 76% (16/21) of cows with disseminated infection had positive historical ELISA results and only 62% (13/21) had a positive ELISA at slaughter. Thus, antemortem evidence of MAP infection was lacking in a high proportion of cows where MAP disseminated infection was confirmed.     

Molecular evaluation of five cardiac genes in Doberman Pinschers with dilated cardiomyopathy

OBJECTIVE: To sequence the exonic and splice site regions of 5 cardiac genes associated with the human form of familial dilated cardiomyopathy (DCM) in Doberman Pinschers with DCM and to identify a causative mutation. ANIMALS: 5 unrelated Doberman Pinschers with DCM and 2 unaffected Labrador Retrievers (control dogs). PROCEDURES: Exonic and splice site regions of the 5 genes encoding the cardiac proteins troponin C, lamin A/C, cysteine- and glycine-rich protein 3, cardiac troponin T, and the beta-myosin heavy chain were sequenced. Sequences were compared for nucleotide changes between affected dogs and the published canine sequences and 2 control dogs. Base pair changes were considered to be causative for DCM if they were present in an affected dog but not in the control dogs or published sequences and if they involved a conserved amino acid and changed that amino acid to a different polarity, acid-base status, or structure. RESULTS: A causative mutation for DCM in Doberman Pinschers was not identified, although single nucleotide polymorphisms were detected in some dogs in the cysteine- and glycine-rich protein 3, beta-myosin heavy chain, and troponin T genes. CONCLUSIONS AND CLINICAL RELEVANCE: Mutations in 5 of the cardiac genes associated with the development of DCM in humans did not appear to be causative for DCM in Doberman Pinschers. Continued evaluation of additional candidate genes or a focused approach with an association analysis is warranted to elucidate the molecular cause of this important cardiac disease in Doberman Pinschers.     

Pharmacokinetics of buprenorphine following intravenous administration in dogs

OBJECTIVE: To determine pharmacokinetics of buprenorphine in dogs after i.v. administration. ANIMALS: 6 healthy adult dogs. PROCEDURES: 6 dogs received buprenorphine at 0.015 mg/kg, i.v. Blood samples were collected at time 0 prior to drug administration and at 2, 5, 10, 15, 20, 30, 40, 60, 90, 120, 180, 240, 360, 540, 720, 1,080, and 1,440 minutes after drug administration. Serum buprenorphine concentrations were determined by use of double-antibody radioimmunoassay. Data were subjected to noncompartmental analysis with area under the time-concentration curve to infinity (AUC) and area under the first moment curve calculated to infinity by use of a log-linear trapezoidal model. Other kinetic variables included terminal rate constant (k(el)) and elimination half-life (t(1/2)), plasma clearance (Cl), volume of distribution at steady state (Vd(ss)), and mean residence time (MRT). Time to maximal concentration (T(max)) and maximal serum concentration (C(max)) were measured. RESULTS: Median (range) values for T(max) and MRT were 2 minutes (2 to 5 minutes) and 264 minutes (199 to 600 minutes), respectively. Harmonic mean and pseudo SD for t(1/2) were 270+/-130 minutes; mean +/- SD values for remaining pharmacokinetic variables were as follows: C(max), 14+/-2.6 ng/mL; AUC, 3,082+/-1,047 ng x min/mL; Vd(ss), 1.59+/-0.285 L/kg; Cl, 5.4+/-1.9 mL/min/kg; and, k(el), 0.0026+/-0.0,012. CONCLUSIONS AND CLINICAL RELEVANCE: Pharmacokinetic variables of buprenorphine reported here differed from those previously reported for dogs. Wide variations in individual t(1/2) values suggested that dosing intervals be based on assessment of pain status rather than prescribed dosing intervals.     

Levetiracetam as an adjunct to phenobarbital treatment in cats with suspected idiopathic epilepsy

OBJECTIVE: To assess pharmacokinetics, efficacy, and tolerability of oral levetiracetam administered as an adjunct to phenobarbital treatment in cats with poorly controlled suspected idiopathic epilepsy. DESIGN-Open-label, noncomparative clinical trial. ANIMALS: 12 cats suspected to have idiopathic epilepsy that was poorly controlled with phenobarbital or that had unacceptable adverse effects when treated with phenobarbital. PROCEDURES: Cats were treated with levetiracetam (20 mg/kg [9.1 mg/lb], PO, q 8 h). After a minimum of 1 week of treatment, serum levetiracetam concentrations were measured before and 2, 4, and 6 hours after drug administration, and maximum and minimum serum concentrations and elimination half-life were calculated. Seizure frequencies before and after initiation of levetiracetam treatment were compared, and adverse effects were recorded. RESULTS: Median maximum serum levetiracetam concentration was 25.5 microg/mL, median minimum serum levetiracetam concentration was 8.3 microg/mL, and median elimination half-life was 2.9 hours. Median seizure frequency prior to treatment with levetiracetam (2.1 seizures/mo) was significantly higher than median seizure frequency after initiation of levetiracetam treatment (0.42 seizures/mo), and 7 of 10 cats were classified as having responded to levetiracetam treatment (ie, reduction in seizure frequency of >or=50%). Two cats had transient lethargy and inappetence. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that levetiracetam is well tolerated in cats and may be useful as an adjunct to phenobarbital treatment in cats with idiopathic epilepsy.