Bahman Shafii

Human Milk Oligosaccharides Promote the Growth of Staphylococci

ABSTRACT Human milk oligosaccharides (HMO), which constitute a major component of human milk, promote the growth of particular bacterial species in the infants gastrointestinal tract. We hypothesized that HMO also interact with the bacterial communities present in human milk. To test this hypothesis, two experiments were conducted. First, milk samples were collected from healthy women (n = 16); culture-independent analysis of the bacterial communities was performed, HMO content was analyzed, and the relation between these factors was investigated. A positive correlation was observed between the relative abundance of Staphylococcus and total HMO content (r = 0.66). In a follow-up study, we conducted a series of in vitro growth curve experiments utilizing Staphylococcus aureus or Staphylococcus epidermidis and HMO isolated from human milk. HMO exhibited stimulatory effects on bacterial growth under various nutritional conditions. Analysis of culture supernatants from these experiments revealed that HMO did not measurably disappear from the culture medium, indicating that the growth-enhancing effects were not a result of bacterial metabolism of the HMO. Instead, stimulation of growth caused greater utilization of amino acids in minimal medium. Collectively, the data provide evidence that HMO may promote the growth of Staphylococcus species in the lactating mammary gland.

Detecting Spotted Knapweed (Centaurea maculosa) with Hyperspectral Remote Sensing Technology1

Failure to detect noxious weeds with current survey methods prevents their control and has contributed to their ability to establish and spread in remote range and forest sites. Techniques used in remote sensing can classify plant occurrence on maps, offering a method for surveying invasive species in remote locations and across extensive areas. An imaging hyperspectral spectrometer recorded images on July 19, 1998 in Farragut State Park near Bayview, ID, in the reflected solar region of the electromagnetic spectrum ranging from 440 to 2,543 nm to detect spotted knapweed. The sensor records 128 spectral bands in 12- to 16-nm intervals at a spatial resolution of 5 m. A spectral angle mapper (SAM) algorithm was used to classify the data. Infestations in Idaho with 70 to 100% spotted knapweed cover that were 0.1 ha were detected regardless of the classification angle. However, narrow angles (2 to 8°) did not completely define the extent of the infestation, and the widest angle tested (20°) falsely classified some areas as infested. The overall image error for all classes was lowest (3%) when SAM angles ranged from 10 to 11°. Specific errors for the spotted knapweed class for the 10 to 11° angles showed that omissional and commissional errors were less than 3%. Areas with as little as 1 to 40% spotted knapweed cover were detected with an omissional error of 1% and a commissional error of 6%. Further verification sites were established on August 11, 1998 near Bozeman, MT, using the algorithms developed for Idaho. The omissional error for the Montana sites was 0%, and the commissional error was 10%. The hyperspectral sensor, Probe 1, proved an effective detection tool with the ability to detect spotted knapweed infestations. Nomenclature: Spotted knapweed, Centaurea maculosa Lam. #3 CENMA syn C. stoebe L. and C. biebersteinii DC. Additional index words: Hyperspectral sensor, imaging spectrometer, weed detection, whiskbroom scanner. Abbreviations: Ĉi, commissional error; DGPS, differentially corrected global positioning system; GPS, global positioning system without differential correction; L95, lower bounds expressed as 95% probability interval; Ôi, omissional error; SAM, spectral angle mapper; U95, upper bounds expressed as 95% probability interval.

Size Fractionation Of Soil Organo-mineral Complexes Using Ultrasonic Dispersion

Potential artifacts created by soil fractionation procedures are frequently ignored when studying the interaction of natural and synthetic organic compounds with clay-sized materials. Ultrasonic dispersion treatments of 0–7.66 kJ applied to soil in water were used in combination with centrifugation and sedimentation techniques to obtain sand, silt, coarse clay, and medium clay fractions from soils with 19.2 to 44.2 g organic C kg−1 soil. No more than 1.37 kJ of sonication energy was needed for maximum yields of silt-sized materials, whereas sand yields decreased monotonically and clay yields increased at a decreasing rate with energy inputs up to 7.66 kJ. Coulter counter analysis of silt-sized fractions showed that no redistribution in particle-size occurred within this fraction with increased sonication energy. Changes in total C and N concentrations in the silt-sized fractions showed no consistent trends with increased sonication energy. Total C and N concentrations increased in the coarse clay-sized fractions and decreased in the medium clay-sized fractions with a greater input of sonication energy. Diffuse reflectance Fourier transform infrared analysis did not reveal any qualitative changes in the coarse clay fractions, although changes in the medium clay fractions of the two soils highest in organic C occurred when energy was increased from 0.84 to 2.94 kJ. We conclude that excessive sonication energies may cause undesirable artifacts, especially in the medium clay-sized fraction. It is suggested that a standard sonication procedure to obtain adequate particle size yields and limit artifacts in the fractionated organomineral complexes include the application of no more than 3–5 kJ of energy to 10 g soil in 50 mL of water.

Fatty acids and monoacylglycerols inhibit growth of Staphylococcus aureus.

Staphylococcus aureus causes a variety of human infections including toxic shock syndrome, osteomyelitis, and mastitis. Mastitis is a common disease in the dairy cow, andS. aureus has been found to be a major infectious organism causing mastitis. The objectives of this research were to determine which FA and esterified forms of FA were inhibitory to growth ofS. aureus bacteria. FA as well as their mono-, di-, and triacylglycerol forms were tested for their ability to inhibit a human toxic shock syndrome clinical isolate (MN8) and twoS. aureus clinical bovine mastitis isolates (305 and Novel). The seven most potent inhibitors across all strains tested by minimum inhibitory concentration analysis included lauric acid, glycerol monolaurate, capric acid, myristic acid, linoleic acid,cis-9,trans-11 conjugated linoleic acid, andtrans-10,cis-12 conjugated linoleic acid. Some of these lipids were chosen for 48-h growth curve analysis with a bovine mastitisS. aureus isolate (Novel) at doses of 0, 20, 50, and 100 μg/mL except myristic acid, which was tested at 0, 50, 100, and 200 μg/mL. The saturated FA (lauric, capric, myristic) and glycerol monolaurate behaved similarly and reduced overall growth. In contrast, the polyunsaturated FA (linoleic andcis-9,trans-11 conjugated linoleic acid) delayed the time to initiation of exponential growth in a dose-dependent fashion. The results suggest that lipids may be important in the control ofS. aureus during an infection.

Effect of clinical mastitis and other diseases on reproductive performance of Holstein cows.

The objective of this study was to evaluate the effect of clinical mastitis and (or) other diseases on reproductive performance in lactating Holstein cows. Cows (n=967) from a commercial dairy farm were divided into four groups retrospectively: cows with clinical mastitis and other diseases (MD, n=54), clinical mastitis only (M, n=154), other diseases only (D, n=187), and cows with no record of clinical mastitis or other diseases (H, n=572). Days in milk at first service (DIMFS), services per conception (S/C), days not pregnant (DNP), the rate at which animals became pregnant over time and the proportion of cows that remained non-pregnant during 224 days of lactation were evaluated. Groups MD and M had greater (P<0.05) DNP compared with H (155+/-15 and 140+/-5 vs. 88+/-2, respectively). Moreover, MD and M had greater (P<0.05) S/C compared with H (3.0+/-0.4 and 2.1+/-0.1 vs. 1.6+/-0.1, respectively). The rate at which animals became pregnant over time was less (P<0.05) for MD and M and tended (P=0.1) to be less for D when compared with H. In addition, proportion of cows that remained non-pregnant by 224 days of lactation was greater (P<0.05) in MD, M, and D compared with H. Cows with mastitis were also divided into three groups according to the day of occurrence of the first case of clinical mastitis: (1) clinical mastitis occurred before 56 days postpartum (MP1); (2) clinical mastitis occurred between 56 and 105 days after parturition (MP2); and (3) clinical mastitis occurred after 105 days postpartum (MP3) Regardless of the time of occurrence, DNP was greater (P<0.05) for cows with mastitis compared with H. Time of mastitis occurrence affected S/C in that cows in MP2 and MP3 had a greater S/C compared with H cows (P<0.05). Reproductive efficiency was decreased by the presence of clinical mastitis alone because a greater proportion of cows with mastitis remained non-pregnant over time. Moreover, a greater proportion of cows with mastitis or diseases remained non-pregnant by 224 postpartum. Furthermore, the negative effects on reproduction were exacerbated when cows experienced both clinical mastitis and other diseases.

PP-604 rate and Avena fatua density effects on seed production and viability in Hordeum vulgare

Abstract High Avena fatua control costs have caused some Hordeum vulgare growers to use reduced rates of herbicides without fully understanding the consequences. Field studies near Moscow and Genesee, ID, were conducted to determine the effect of A. fatua density and PP-604 rate on A. fatua seed production in H. vulgare and on H. vulgare yield. PP-604 treatments were 25, 50, 100, 150, and 200 (minimum labeled rate) g ha−1, and five A. fatua densities ranged from 0 to 386 plants m−2. Visual A. fatua control was greater than 85% with 100 g ha−1 PP-604 at all locations. Data from 1998 were used to construct nonlinear exponential decay and parabolic models to describe the effect of reduced herbicide rates on viable A. fatua seed production and relative H. vulgare grain yield, respectively. At A. fatua densities of 42 to 138 plants m−2, 46 to 71% of the minimum labeled rate of PP-604 reduced seed production 95%. However, an estimated 140 to 235 seeds m−2 were produced at this level of control, which may not ensure a decline in the A. fatua population over the long-term. Hordeum vulgare grain yield was maximum when 70 to 85% of the minimum labeled rate was applied to A. fatua densities of 42 to 138 plants m−2. A higher rate of PP-604 likely will be required to ensure a decline in A. fatua populations over the long-term than needed to obtain maximum H. vulgare grain yield in a single growing season. Nomenclature: PP-604 (proposed common name, tralkoxydim), 2-[1-(ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-trimethylphenyl)-2-cyclohexene-1-one; Avena fatua L. AVEFA, wild oat; Hordeum vulgare L. ‘Baronesse’, spring barley.

Use of the Average and Fluctuating Velocity Components for Estimation of Volitional Rainbow Trout Density

Abstract The relationship between discharge and fish density in streams is commonly accepted to be curvilinear, progressing from low discharge and low fish density to a peak and then declining to high discharge and low fish density. Discharge is related to water velocity; in general, as discharge increases velocity increases. Habitat complexity is an important aspect of salmonid ecology; more complex habitats support higher fish densities. Habitat complexity also influences the flow of water through the process of flow separation and turbulence production. More complex habitats generally exhibit higher levels of turbulence even though both may have similar average velocities. We tested whether the physical link between habitat complexity and turbulence was correlated with fish density. Turbulent kinetic energy and average velocity for three different levels of discharge and habitat complexity were measured in a flume. Turbulent kinetic energy was found to predict fish density, whereas average velocity did...

CHARACTERIZATION OF PASTEURELLA MULTOCIDA ASSOCIATED WITH PNEUMONIA IN BIGHORN SHEEP

Pasteurella multocida is a highly diverse group of bacteria recognized as important pathogens. Although P. multocida is not ordinarily associated with disease in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), numerous isolates were cultured in high numbers from free-ranging bighorn sheep in the Hells Canyon area of Idaho, Washington, and Oregon (USA) during the winter of 1995–96. Animals captured in Hells Canyon and held in captivity, and their offspring, also harbored P. multocida. Biochemical utilization tests on 90 isolates identified three subspecies: P. multocida multocida a (n=54); P. multocida multocida b (n=13); and P. multocida gallicida (n=15); and a non-speciated biotype, U6 (n=8). Genomic DNA digestion with restriction endonuclease Hha I separated the isolates into 62 unique restriction fragment length polymorphism profiles. Capsular type A was predominant (72% of isolates). Only one isolate type, which may have been transmitted from a feral goat, was capsular type D, possessed the structural gene, toxA, for dermonecrotoxin detected by polymerase chain reaction, and produced toxin as determined by monoclonal antibody immunoblot. In conclusion, bighorn sheep in this study carried diverse types of generally non-toxigenic P. multocida associated with epizootic pneumonia.

Interspecific hybridization : Potential for movement of herbicide resistance from wheat to jointed goatgrass (Aegilops cylindrica)

The transfer of herbicide resistance genes from crops to related species is one of the greatest risks of growing herbicide-resistant crops. The recent introductions of imidazolinone-resistant wheat in the Great Plains and Pacific Northwest regions of the United States and research on transgenic glyphosate-resistant wheat have raised concerns about the transfer of herbicide resistance from wheat to jointed goatgrass via introgressive hybridization. Field experiments were conducted from 2000 to 2003 at three locations in Washington and Idaho to determine the frequency and distance that imidazolinone-resistant wheat can pollinate jointed goatgrass and produce resistant F1 hybrids. Each experiment was designed as a Nelder wheel with 16 equally spaced rays extending away from a central pollen source of ‘Fidel-FS4’ imidazolinone-resistant wheat. Each ray was 46 m long and contained three rows of jointed goatgrass. Spikelets were collected at maturity at 1.8-m intervals along each ray and subjected to an imazamox screening test. The majority of all jointed goatgrass seeds tested were not resistant to imazamox; however, 5 and 15 resistant hybrids were found at the Pullman, WA, and Lewiston, ID, locations, respectively. The resistant plants were identified at a maximum distance of 40.2 m from the pollen source. The overall frequency of imazamox-resistant hybrids was similar to the predicted frequency of naturally occurring acetolactate synthase resistance in weeds; however, traits with a lower frequency of spontaneous mutations may have a relatively greater risk for gene escape via introgressive hybridization. Nomenclature: Imazamox; jointed goatgrass, Aegilops cylindrica Host. #3 AEGCY; wheat, Triticum aestivum L. Additional index words: Herbicide-resistant wheat, hybridization, imidazolinone resistant, interspecific hybrids, introgression, outcrossing, pollen-mediated gene flow. Abbreviations: ALS, acetolactate synthase; BC, backcross generation; DAP, days after planting; PNW, Pacific Northwest.

Analysis of Genotype-by-Environment Interaction Using the Additive Main Effects and Multiplicative Interaction Model and Stability Estimates

Understanding the implication of genotype-by-environment (GE) interaction structure is an important consideration in plant breeding programs. A significant GE interaction for a quantitative trait such as yield can seriously limit efforts in selecting superior genotypes for both new crop introduction and improved cultivar development. Traditional statistical analyses of yield trials provide little or no insight into the particular pattern or structure of the GE interaction. The Additive Main Effects and Multiplicative Interaction (AMMI) statistical model incorporates both additive and multiplicative components of the two-way data structure which can account more effectively for the underlying interaction patterns. Integrating results obtained from biplot graphic displays with those of the genotypic stability analysis enables clustering of genotypes based on similarity of response and the degree of stability in performance across diverse environments. The AMMI model is presented, and its usage in diagnosing the GE interaction structure is discussed. Tais regression-based stability statistics are employed to determine the stability of genotypes tested. Empirical applications are demonstrated using data from a national winter rapeseed variety trial.