Rapid phenotypic assessment of bird cherry-oat aphid resistance in winter wheat

Rhopalosiphum padi L. causes significant damage to winter wheat ( Triticum aestivum L.), even without obvious aboveground symptoms of injury. Our objectives were to develop a juvenile-plant bioassay for bird cherry-oat aphid (BCOA) resistance that allows rapid phenotypic differentiation. Central features of the bioassay include root and shoot weight measurements of 3-week-old seedlings produced in seed germination pouches, a 14-day aphid exposure period, and a non-infested control treatment to establish a baseline for expected biomass per genotype. Cultivars used in bioassay development were 'Illinois Rustproof' and 'Skala', which showed smaller BCOA-induced reductions in biomass than the more susceptible genotypes, 'Patrick' and 'Scout 66'. Mean reductions in root biomass were 48% for 'Patrick' and 'Scout 66', compared with 29% for 'Illinois Rustproof' and 'Skala'. This rapid and repeatable bioassay is extendable to large wheat collections and inbred line populations.     

Effect of Canine Hyperadrenocorticism on Coagulation Parameters

Background

Hyperadrenocorticism (HAC) has been associated with thrombotic disease in dogs.

Hypothesis

The purpose of this study was to use thromboelastography (TEG) and measurement of thrombin generation (TG) to characterize the hypercoagulable state in dogs with HAC. We hypothesized that dogs with HAC would have a hypercoagulable profile on TEG tracings and an increase in thrombin generation as measured by endogenous thrombin potential (ETP).

Animals

Sixteen dogs with HAC. Dogs were compared with a population of normal dogs used to obtain reference intervals.

Methods

TEG tracings on citrated whole blood were obtained from 15 dogs, and TG measurements on frozen‐thawed platelet‐poor plasma (PPP) were obtained from 15 dogs.

Results

For the TEG analysis, when results of individual dogs were compared with the reference interval, 12/15 dogs had at least 1 parameter associated with hypercoagulability. When the population of HAC dogs was compared with a population of healthy dogs, HAC dogs had decreases in R and K and increases in α and MA values. The ETP was increased when the HAC group was compared with a population of normal dogs. However, only 3/15 dogs had an ETP above reference interval, and 1/15 had a decreased lag time.

Conclusion and Clinical Importance

Of 16 dogs with HAC, 12/15 had evidence of hypercoagulability when evaluated by TEG, 4/15 when evaluated by TG, and 2 dogs had increases in ETP and MA.     

Probing single molecule dynamics

The room temperature dynamics of single sulforhodamine 101 molecules dispersed on a glass surface are investigated on two different time scales with near-field optics. On the 10(-2)- to 10(2)-second time scale, intensity fluctuations in the emission from single molecules are examined with polarization measurements, providing insight into their spectroscopic properties. On the nanosecond time scale, the fluorescence lifetimes of single molecules are measured, and their excited-state energy transfer to the aluminum coating of the near-field probe is characterized. A movie of the time-resolved emission demonstrates the feasibility of fluorescence lifetime imaging with single molecule sensitivity, picosecond temporal resolution, and a spatial resolving power beyond the diffraction limit.     

Chitin in sea anemone shells

Chitin, which is widely distributed among life forms, is well documented in the coelenterate class Hydrozoa and is contained in one member of class Scyphozoa. In class Anthozoa, hard corals synthesize it but soft corals do not. Chitin was identified by infrared spectrophotometry in the trochoid shell of the actinian Stylobates. It constitutes 1.7 percent of the shell by weight, the rest probably being protein. The ability of sea anemones to synthesize chitin is there by confirmed.     

Comparison of sevoflurane and isoflurane anesthetic index in unpremedicated dogs

Anesthetic respiratory effects of sevoflurane (SEVO) were compared with isoflurane (ISO) in unpremedicated dogs. Minimum alveolar concentration (MAC), apneic concentration (AC), and anesthetic index (AI) of SEVO and ISO were determined in eight 1‐year‐old healthy dogs, weighing 19 ± 3 kg (mean ± SEM) in a randomized complete block multiple cross‐over design. Dogs were mask‐induced with either SEVO or ISO in 100% oxygen. Following endotracheal intubation, dogs were instrumented, mechanically ventilated, and MAC was determined using a tail‐clamp method. Next, spontaneous ventilation was re‐established, and anesthetic concentration was increased to determine the AC. Throughout the anesthetic event, heart rate (HR), systolic blood pressure (SAP), mean blood pressure (MAP), diastolic blood pressure (DAP), respiratory rate (RR), end‐tidal carbon dioxide (Pe ′CO₂), and oxyhemoglobin saturation (SpO₂) were recorded at 3‐minute intervals. Following AC determination, AI was calculated as AC/MAC, and dogs were allowed to recover. Each dog was anesthetized four times (twice with ISO and SEVO each) at 1‐week intervals. All data were analyzed using the two‐way anova . Multiple comparisons were performed between ISO and SEVO treatments. Statistical significance was set at p < 0.05. Significant differences were noted between agents for MAC (SEVO, 2.13 ± 0.10%; ISO, 1.38 ± 0.14%; p < 0.0001), AC (SEVO, 7.34 ± 0.13%; ISO, 3.60 ± 0.13%; p < 0.0001), and AI (SEVO, 3.46 ± 0.22; ISO, 2.63 ± 0.14; p = 0.0002). Physiologic parameters were compared between SEVO and ISO at 1MAC, 2MAC, 3MAC, and AC. No differences were noted between SEVO and ISO treatments for cardiovascular parameters (HR, SAP, MAP, DAP). Significant differences were noted, favoring SEVO, for all respiratory parameters (RR, Pe ′CO₂, SpO₂) at increasing MAC multiples. Additionally, regression analysis was conducted for physiologic variable data points. Analysis of Pe ′CO₂ data points demonstrated a significant slope difference of ?6.47 ± 1.02 (B_SEVO ? B_ISO; p < 0.0001; r² = 0.6042) favoring SEVO. While expected dose‐related ventilatory depression was noted for both agents, all the respiratory parameters for SEVO demonstrated less respiratory depression than ISO at equipotent doses. These results indicated that SEVO caused less dose‐dependent ventilatory depression than ISO, having a significantly higher AI and causing less detrimental change in pulmonary parameters at increasing levels of MAC.     

Identification of genes associated with prophage-like gene transfer agents in the pathogenic intestinal spirochaetes Brachyspira hyodysenteriae, Brachyspira pilosicoli and Brachyspira intermedia

VSH-1 is an unusual prophage-like gene transfer agent (GTA) that has been described in the intestinal spirochaete Brachyspira hyodysenteriae. The GTA does not self-propagate, but it assembles into a virus-like particle and transfers random 7.5kb fragments of host DNA to other B. hyodysenteriae cells. To date the GTA VSH-1 has only been analysed in B. hyodysenteriae strain B204, in which 11 late function genes encoding prophage capsid, tail and lysis elements have been described. The aim of the current study was to look for these 11 genes in the near-complete genomes of B. hyodysenteriae WA1, B. pilosicoli 95/1000 and B. intermedia HB60. All 11 genes were found in the three new strains. The GTA genes in WA1 and 95/1000 were contiguous, whilst some of those in HB60 were not-although in all three strains some gene rearrangements were present. A new predicted open reading frame with potential functional importance was found in a consistent position associated with all four GTAs, located between the genes for head protein Hvp24 and tail protein Hvp53, overlapping with the hvp24 sequence. Differences in the nucleotide and predicted amino acid sequences of the GTA genes in the spirochaete strains were consistent with the overall genetic distances between the strains. Hence the GTAs in the two B. hyodysenteriae strains were considered to be strain specific variants, and were designated GTA/Bh-B204 and GTA/Bh-WA1 respectively. The GTAs in the strains of B. intermedia and B. pilosicoli were designated GTA/Bint-HB60 and GTA/Bp-95/1000 respectively. Further work is required to determine the extent to which these GTAs can transfer host genes between different Brachyspira species and strains.     

Comparison of femoral and auricular arterial blood pressure monitoring in pigs

Objective To compare arterial blood pressure measurements obtained from the femoral and auricular arteries in anaesthetized pigs. Study design Prospective experimental study. Animals Fifteen female Large White pigs were used weighing 21.3 ± 2.3 kg. Methods The pigs were anaesthetized with tiletamine/zolazepam and xylazine administered intramuscularly, and anaesthesia maintained with isoflurane delivered in oxygen/nitrogen. Arterial oxygen partial pressures were maintained between 11.3 and 13.3 kPa and PaCO₂ between 4.6 and 6.0 kPa. Monitoring included electrocardiogram, capnography and invasive blood pressure. The auricular and femoral arteries were catheterized for continuous systolic (SAP), diastolic (DAP) and mean arterial pressure (MAP) measurements. Measurements were recorded every 15 minutes. Statistical analysis involved a Bland–Altman plot analysis. Results The mean difference ± confidence intervals between the femoral and the auricular arterial diastolic, systolic and mean blood pressure measurements during hypotension were 2 ± 7, 2 ± 5 and 2 ± 5 mmHg respectively. In conditions of normotension mean difference ± confidence intervals, of femoral and auricular arterial blood pressure measurements of diastolic, systolic and mean blood pressure were 4 ± 5, 3 ± 7 and 4 ± 4 mmHg respectively. In conditions of increased arterial blood pressure, mean difference ± confidence intervals, of femoral and auricular arterial blood pressure measurements of diastolic, systolic and mean blood pressure were 4 ± 5, 3 ± 8 and 4 ± 4 mmHg respectively. Conclusion Auricular artery catheterization is easier and quicker to perform. Pressure measurements from the auricular artery compared well with the femoral artery. Clinical relevance We found that auricular arterial blood pressures were similar to femoral arterial values under the conditions of this experiment. We did not test extremes of blood pressure or significant alterations in body temperature.     

Stability of Native Folate and Added Folic Acid in Micronutrient‐Fortified Corn Masa and Tortillas

Degradation of added folic acid and native folates in micronutrient‐fortified corn masa and tortillas was evaluated using masa prepared from either nixtamalized corn flour or fresh nixtamal. Variations in masa pH, masa holding time at an elevated temperature, and iron source failed to show significant differences in folate loss in corn flour masa prepared in the laboratory. Masa was subsequently prepared from fresh nixtamal in a commercial mill in Mexico, and fortified with one of two different micronutrient premixes containing iron, zinc, B‐vitamins, and either unencapsulated or lipid‐encapsulated folic acid. Folate loss in commercial masa increased significantly with prebake masa holding time for both premixes. Unencapsulated folic acid showed a 73% loss after 4 hr of holding, compared to 60% loss for encapsulated. The difference was statistically significant, indicating a protective effect from the lipid coating. No significant differences in folate levels were found between prebake masa and baked tortillas. Holding baked tortillas for up to 12 hr also had no effect on folate levels. Native folate showed no significant losses throughout the process. Results from the commercial tortilla mill indicate that most of the loss in added folic acid occurs during prebake holding of masa, possibly from microbial degradation.