Neuroanatomy: the thalamus     

Kruger L 《Science (New York, N.Y.)》1986,232(4753):1028-1029

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Differential effects of -mannose and 2-deoxy- -glucose on attempted powdery mildew fungal infection of inappropriate and appropriate ramineae     

R. J. Zeyen  W. M. Kruger  M. F. Lyngkjr  T. L. W. Carver 《Physiological and Molecular Plant Pathology》2002,61(6)

Barley, oat and wheat were used as both inappropriate hosts (IH) and appropriate hosts (AH) for three formae speciales of the fungus Blumeria graminis, the causal agent of powdery mildew disease. Treatment with either the glucose analog 2-deoxy- -glucose (DDG) or with -mannose dramatically suppressed penetration resistance in IH and to a much lesser extent in AH combinations. Other effects of DDG and -mannose were strikingly dissimilar. DDG greatly reduced localized autofluorescence at fungal attack sites on epidermal cells, and prevented hypersensitive epidermal cell death (HR). -mannose had little effect on autofluorescence or HR. DDG arrested the development of fungal haustoria and apparently prohibited biotrophy leading to secondary hyphae. -mannose allowed haustorial development and functional biotrophy leading to the production of elongating secondary hyphae. This suggests that B. graminis is in some way capable of utilizing -mannose as a carbon substrate. Results with IH combinations paralleled those of known mlo -barley responses to DDG and -mannose. Results are discussed in relation to specific physiological processes known to be influenced by either DDG or by -mannose, or by both compounds.  相似文献   

Do public attitudes affect conservation effort? Using a questionnaire-based survey to assess perceptions,beliefs and superstitions associated with frogs in South Africa     

Jeanne Tarrant  Donnavan Kruger  Louis H du Preez 《African Zoology》2016,51(1):13-20

Globally, amphibians are among the least appreciated vertebrates and are often negatively perceived by the general public. Such attitudes are particularly prevalent in South Africa, where fear, superstitions and myths associated with frogs are pervasive in some cultures. These attitudes could have harmful consequences both for the animals concerned and conservation efforts. This study aimed to investigate attitudes to frogs throughout South Africa across multiple age and ethnic groups. We used a multi-language survey in both hard-copy and online versions. Respondents (n = 2 295) comprised both genders across six age groups and five ethnic groups. A functionalist approach using structural equation modelling was used to assess how liking of frogs and cultural beliefs varied with socio-demographic factors. Attitudes varied significantly between groups, with males more likely to like frogs than females and age and level of education also significantly linked to liking. The influence of cultural beliefs and lack of knowledge also directly influenced negative attitudes towards frogs. More than 60% of respondents expressed an interest in learning more about frogs, indicating an opportunity for improving attitudes through educational outreach. The findings of this study can be used to inform current efforts to protect amphibians in South Africa through social interventions.  相似文献   

Genetic characterization of 2 novel feline caliciviruses isolated from cats with idiopathic lower urinary tract disease     

Rice CC  Kruger JM  Venta PJ  Vilnis A  Maas KA  Dulin JA  Maes RK 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(3):293-302

Feline caliciviruses (FCVs) are potential etiologic agents in feline idiopathic lower urinary tract disease (I-LUTD). By means of a modified virus isolation method, we examined urine obtained from 28 male and female cats with nonobstructive I-LUTD, 12 male cats with obstructive I-LUTD, and 18 clinically healthy male and female cats. All cats had been routinely vaccinated for FCV. Two FCVs were isolated; I (FCV-U1) from a female cat with nonobstructive I-LUTD, and another (FCV-U2) from a male cat with obstructive I-LUTD. To determine the genetic relationship of FCV-U1 and FCV-U2 to other FCVs. capsid protein gene RNA was reverse transcribed into cDNA, amplified, and sequenced. Multiple amino acid sequence alignments and phylogenetic trees were constructed for the entire capsid protein, hypervariable region E, and the more conserved (nonhypervariable) regions A, B, D, and F. When compared to 23 other FCV isolates with known biotypes, the overall amino acid sequence identity of the capsid protein of FCV-U1 and FCV-U2 ranged from 83 to 96%; identity of hypervariable regions C and E ranged from 58 to 85%. Phylogenetically, FCV-U1 clearly separated from other FCV strains in phenograms based on nonhypervariable regions. In contrast, FCV-U2 consistently segregated with the Urbana strain in all phenograms. Clustering of isolates by geographic origin was most apparent in phenograms based on nonhypervariable regions. No clustering of isolates by biotype was apparent in any phenograms. Our results indicate that FCV-UI and FCV-U2 are genetically distinct from other known vaccine and field strains of FCV.  相似文献   

Prevalence of bovine herpesvirus-4 infection in cats in Central Michigan     

Kruger JM  Venta PJ  Swenson CL  Syring R  Gibbons-Burgener SN  Richter M  Maes RK 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2000,14(6):593-597

The gammaherpesvirus bovine herpesvirus-4 (BHV-4) has been isolated from a wide variety of animals, including lions and domestic cats. Although BHV-4 antibodies have been detected in normal cats and cats with urinary disorders, the epidemiology and pathogenic role of BHV-4 in cats is unknown. The purpose of this study was to determine the prevalence of BHV-4 antibodies and viral nucleic acid in a population of free-roaming cats. Plasma and peripheral blood leukocyte samples were collected from 52 male and 52 female free-roaming cats impounded at a regional animal control facility in Central Michigan. Plasma concentrations of BHV-4 antibodies were measured with an indirect fluorescent antibody test. Peripheral blood leukocyte DNA was isolated, and a 2-stage polymerase chain reaction with heminested primers delineating a conserved portion of the BHV-4 glycoprotein B gene homologue was used to amplify BHV-4-specific DNA sequences. BHV-4 antibodies were detected in 38 (73%) male and 23 (44%) female cats. Seropositive cats were significantly more likely to be male than female (odds ratio = 3.22; P = .007). Cell-associated viremia was detected in 17 (33%) male and 11 (21%) female cats. Of the 61 seropositive cats, 23 (38%) had a detectable viremia; only 5 (12%) seronegative cats had detectable viremia. Seropositive cats were significantly more likely to be viremic than seronegative cats (OR = 4.30: P = .009). Our results suggest that BHV-4 infection may be more widespread in certain cat populations than previously reported. Furthermore, many cats seropositive for BHV-4 antibodies have a concurrent cell-associated viremia.  相似文献   

Systemic calicivirus epidemic in captive exotic felids.     

Tara M Harrison  James Sikarskie  John Kruger  Annabel Wise  Thomas P Mullaney  Matti Kiupel  Roger K Maes 《Journal of zoo and wildlife medicine》2007,38(2):292-299

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Leaf respiratory acclimation to climate: comparisons among boreal and temperate tree species along a latitudinal transect     

Dillaway DN  Kruger EL 《Tree physiology》2011,31(10):1114-1127

In common gardens along an ～900 km latitudinal transect through Wisconsin and Illinois, U.S.A., tree species typical of boreal and temperate forests were compared with respect to the nature and magnitude of leaf respiratory acclimation to contrasting climates. The boreal representatives were trembling aspen (Populus tremuloides Michx.) and paper birch (Betula papyrifera Marsh.), while the temperate species were eastern cottonwood (Populus deltoides Bartr ex. Marsh var. deltoides) and sweetgum (Liquidambar styraciflua L.). Assessments were conducted on seedlings grown from seed sources collected near southern and northern range boundaries, respectively. Nighttime rates of leaf dark respiration (R(d)) at common temperatures, as well as R(d)'s short-term temperature sensitivity (energy of activation, E(o)), were assessed for all species and gardens twice during a growing season. Little evidence of R(d) thermal acclimation was observed, despite a 12 °C range in average air temperature across gardens. Instead, R(d) variation at warm temperatures was linked most closely with prior leaf photosynthetic performance, while R(d) variation at cooler temperatures was most strongly related to leaf nitrogen concentration. Moreover, E(o) differences across species and gardens appeared to stem from the somewhat independent limitations on warm versus cool R(d). Based on this construct, an empirical model relying on R(d) estimates from leaf photosynthesis and nitrogen concentration explained 55% of the observed E(o) variation.  相似文献   

The nutritional status of asymptomatic HIV-infected Africans: directions for dietary intervention?     

Vorster HH  Kruger A  Margetts BM  Venter CS  Kruger HS  Veldman FJ  Macintyre UE 《Public health nutrition》2004,7(8):1055-1064

OBJECTIVE: To compare the relationships between food (nutrient) intakes and biochemical markers of nutritional status of asymptomatic HIV-infected with HIV-uninfected subjects, to gain more information on the appropriate diet for HIV-infected persons at an early stage of infection. DESIGN: Cross-sectional population-based survey. SETTING: North West Province, South Africa. SUBJECTS: Two hundred and sixteen asymptomatic HIV-infected and 1550 HIV-uninfected men and women volunteers aged 15 years and older, recruited as 'apparently healthy' subjects from 37 randomly selected sites. OUTCOME MEASURES: Food and nutrient intakes, measured with a validated food-frequency questionnaire, and nutritional status indicated by anthropometric and biochemical variables, measured by a standardised methodology. RESULTS: The prevalence of HIV infection in the study population was 11.9%. The anthropometric indices and nutrient intakes of HIV-infected and uninfected subjects did not differ significantly, indicating that these 216 HIV-infected subjects were at an early stage of infection. Of the biochemical nutritional status variables, high-density lipoprotein cholesterol and total cholesterol, haemoglobin, albumin and triglycerides were significantly lower in infected subjects. They also had higher globulin and liver enzyme levels than uninfected subjects. In infected subjects, serum albumin correlated significantly with serum lipids, serum vitamin A, serum vitamin E, serum iron, total iron-binding capacity and haemoglobin. The significant positive correlations of the liver enzymes with serum lipids, albumin, vitamin A and iron, observed in HIV-uninfected subjects, disappeared in the infected subjects. Polyunsaturated fat intake showed significant positive correlations with the increased liver enzymes in infected subjects. A principal components analysis indicated that, in infected subjects, increased liver enzymes correlated with higher consumption of maize meal and lower consumption of meat and vegetables. CONCLUSIONS AND RECOMMENDATIONS: This survey indicated that asymptomatic HIV-infected subjects who followed a diet rich in animal foods had smaller decreases in serum albumin, haemoglobin and lipid variables, and smaller increases in liver enzymes, than those who consumed a diet based on staple foods. This suggests that animal foods are associated with improved nutritional status in HIV-infected persons. These results should be confirmed with intervention studies before dietary recommendations for asymptomatic HIV-infected individuals can be made.  相似文献   

Boundary layer profiles in plasma chemical vapor deposition     

Green DS  Owano TG  Williams S  Goodwin DG  Zare RN  Kruger CH 《Science (New York, N.Y.)》1993,259(5102):1726-1729

A nonlinear optical spectroscopy based on degenerate four-wave mixing has made possible direct measurements of species temperature and concentration profiles through the boundary layer of a reactive plasma at atmospheric pressure. Spectra were obtained for CH and C(2) radicals over a range of conditions including those for the plasma chemical vapor deposition of diamond films. Numerical simulations based on a one-dimensional stagnation-point flow model are in good agreement with the measurements. The CH mole fraction is shown to rise and fall as a function of distance from the substrate, which is compelling experimental evidence for the complex chemistry that is occurring in the plasma boundary layer.  相似文献   

Tumor DNA structure in plant cells transformed by A. tumefaciens   总被引：25，自引：0，他引：25  

P Zambryski  M Holsters  K Kruger  A Depicker  J Schell  M Van Montagu  H M Goodman 《Science (New York, N.Y.)》1980,209(4463):1385-1391

Crown gall tumors are induced in plants by infection with the soil bacterium Agrobacterium tumefaciens. Because the tumor induction involves transfer of a portion of the tumor-inducing (Ti) plasmid DNA from the bacterium to the plant cells, this system is of interest for the study of genetic exchange as well as tumor induction. The boundaries of the transferred DNA (T-DNA) have been cloned from transformed plant cells of tobacco. Detailed mapping with restriction enzymes and nucleotide sequence analysis of two independent clones were used to study the molecular structure of the ends of the T-DNA. One clone contains the two ends of the T-DNA joined together; the other contains one end of the T-DNA joined to repetitive plant DNA sequences. These studies provide direct evidence that the T-DNA can be integrated into the plant genome. In addition, the data suggest that in the plant, T-DNA can be tandemly repeated. Sequence analysis of the junction of crown gall clone 1 reveals several direct repeats as well as an inverted repeat; these structures may be involved in the transfer of the DNA from Agrobacterium to plant cells.  相似文献