Effect of time of irrigation on the distribution of 1,2-dibromo-3-chloropropane in soil after shallow injection

The effect of irrigation time on the dispersion of 1,2-dibromo-3-chloroproparie (DBCP) in soil after a shallow injection treatment was determined for Yolo fine sandy loam. When injections equivalent to 23.5 litres of DBCP/ha at a depth of 7 to 8 cm were subsequently followed by 15 cm of irrigation water, adequate distribution of DBCP was obtained if the soil was irrigated within 5 days. However, the most rapid and deepest penetration of fumigant was obtained by irrigating 2 to 5 days after application. There was insufficient downward movement of DBCP in non-irrigated soil.     

The effect of autonomic manipulation on heart rate variability in dogs

Beat‐to‐beat variation of heart rate is reflective of autonomic balance and has been used to assess pain and stress in human beings. The purpose of this investigation was to pharmacologically manipulate the autonomic nervous system and to determine the effect of these manipulations on heart rate variability (HRV) in dogs. Four adult male hound dogs (27 ± 1 kg) were used in the investigation. Each dog was given five treatments: Parasympathetic blockade (glycopyrrolate; 0.01 mg kg^–1 IV and 0.01 mg kg^–1 IM), parasympathetic stimulation (phenylephrine; 0.005 mg kg^–1 IV + 0.05 mg kg^–1hour^–1), sympathetic blockade (propranolol; 0.11 mg kg^–1 IV), sympathetic stimulation propranolol; 0.01 μg kg^–1 minute^–1), and saline control. At least 48 hours were allowed between treatments. ECG recordings were obtained using an ambulatory ECG monitor. A 5‐minutes period of continuous recording obtained ~30 minutes after initiation of drug administration was used for data analysis. Changes in HRV were evaluated by time and frequency‐domain analysis. The standard deviation of normal R‐R intervals (SDNN), as well as the standard deviation of successive differences in RR intervals (SDSD) were assessed for each treatment. Low frequency (LFP; 0.05–0.15 Hz), high frequency (HFP; 0.15–0.35 Hz), and total (TP; 0.017–0.5 Hz) spectral power were also determined. The LFP:HFP ratio was also evaluated. A two‐way anova with a Tukey's test was used to detect differences (p < 0.05). Administration of glycopyrrolate or isoproterenol increased HR and decreased SDNN and SDSD below control levels. Phenylephrine or propranolol administration were without effect. LFP was diminished by glycopyrrolate and isoproterenol, but was unaffected by phenylephrine and propranolol. HFP, TP, and LFP:HFP were unaffected by treatment. Both branches of the autonomic nervous system influence SDNN and LFP. SDSD, in contrast, is altered primarily by parasympathetic activity. Thus, it appears that parasympathetic activity modulates HRV in the resting dog, as either withdrawal of parasympathetic influence or accentuated sympathetic activity led to significant changes in these measures of HRV. Conversely, augmentation of parasympathetic activity or withdrawal of sympathetic tone minimally affected HRV.     

Using the CERES-Maize model to estimate production for the U.S. Cornbelt

The ability of the CERES-Maize model to estimate annual fluctuations in maize (Zea mays L.) production for the U.S. Cornbelt was tested for the years 1982–1985. The model was run for 51 weather stations in the 14 states of the Cornbelt, which account for 85% of U.S. maize production. The model was calibrated for the region by deriving varietal coefficients for each station based on minimal growth stage data and yields for the 1982 season. Eight sets of varietal coefficients were derived for the 51 stations and should be interpreted as representing all the hybrids grown in an area, rather than a specific hybrid. For 1982 (the calibration year), 1983, 1984, and 1985, model production estimates were 92, 97, 98, and 101%, respectively, of the official U.S. government estimates. The results indicate that the model may be used for large area yield and production estimation in the U.S.A. with minimal regional calibration. The model has the potential for large area yield estimation in other parts of the world where daily maximum and minimum temperatures, precipitation, and solar radiation data are available.     

Comparison of proanthocyanidins in commercial antioxidants: grape seed and pine bark extracts

The major constituents in grape seed and pine bark extracts are proanthocyanidins. To evaluate material available to consumers, select lots were analyzed using high-performance liquid chromatography, gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), gel permeation chromatography (GPC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Atmospheric pressure chemical ionization (APCI) LC/MS was used to identify monomers, dimers, and trimers present. GC/MS analyses led to the identification of ethyl esters of hexadecanoic acid, linoleic acid, and oleic acid, as well as smaller phenolic and terpene components. The GPC molecular weight (MW) distribution indicated components ranging from approximately 162 to approximately 5500 MW (pine bark less than 1180 MW and grape seed approximately 1180 to approximately 5000 MW). MALDI-TOF MS analyses showed that pine bark did not contain oligomers with odd numbers of gallate units and grape seed contained oligomers with both odd and even numbers of gallate. Reflectron MALDI-TOF MS identified oligomers up to a pentamer and heptamer, and linear MALDI-TOF MS showed a mass range nearly double that of reflectron analyses.     

Culture, values and ethics of animal scientists

Ethnicity and culture are defined. Culture is recognized as the shared values and worldview of a race, nation, or professional group. Values are the objectives that matter most to a person or cultural group to which priority of interest is consistently given in time, energy, resources, wealth and education. Ethics defines the moral component of decisions reflecting self-interest or concern about the well-being of others. For professional agricultural scientists Culture, Values and Ethics are closely linked. Their role is evaluated as servants of society, seeking to fulfil the Inalienable Rights of each person as recognised by the Declaration of Independence: Life, Liberty and the pursuit of Happiness.

The cultural assumptions and commonly-held values of agricultural scientists are examined. Links between scientists and business interests mean that the culture and values of commerce inform and steer decisions by the former. The changing culture of Western society is now embracing values beyond cheap food. Radical changes in the culture, values and ethics of animal scientists are needed to match the Rights of all persons in society for their food supply. Disconnection of agricultural scientists from the culture and values of business interests in the food chain is advocated on the lines of the Declaration of Independence.