Morphological characterization of the interaction between Diplocarpon rosae and various rose species

Blackspot, caused by Diplocarpon rosae , is the most severe and ubiquitous disease of garden roses, but information is lacking about genotype-specific forms of resistance and susceptibility of the host. Macro- and microscopic analyses of 34 rose genotypes with a defined monoconidial culture black spot inoculum identified susceptible and resistant rose genotypes and further genotype-specific subdivisions, indicating the presence of partial forms of resistance and different resistance mechanisms. In total, eight interaction types were characterized, five representing compatible (types 1–5) and three representing incompatible interactions (types 6–8). The incompatible interactions were characterized by the lack of any visible fungal structures beneath the cuticle (type 8), single-cell necroses (type 7) or necroses of larger cell clusters (type 6), the latter two types with penetration hyphae and haustoria in epidermal cells.     

Relationship between blood iron parameters and trichinellosis in swine

Reduced levels of total iron binding capacity and unsaturated iron binding capacity were observed in the blood of trichinous and iron-injected trichinous pigs. No change was observed in their serum iron and saturation concentration levels. Also, reduced iron concentration levels were observed in the livers of trichinous pigs, while increased iron concentration levels were observed in the spleens of trichinous pigs and the livers and spleens of iron-injected pigs. No difference was found with regard to weight gains, number of larvae per gram of tissues, or histologic characteristics of 'nurse cells'.     

Effect of various plant factors on the expression of creeping-rootedness in lucerne (Medicago sativa L. complex)

Although agronomically interesting, selection of creeping-rootedness inlucerne, that is, the ability to form adventitious shoots on horizontal,spreading roots, remains difficult because of the complex and still unclear geneticcontrol of this character, coupled with the possible occurrence of external factorsthat affect unpredictably its expression. Two experiments were undertaken onprogenies of creeping-rooted plants, to verify previous findings and inferences,and test novel hypotheses, concerning the effect of various plant factors on theexpression of creeping-rootedness. The ultimate aim was to provide information onthe most appropriate germplasm, procedures, or indirect selection criteria, that wouldimprove the efficiency of breeding for this character. The factors here examinedincluded genotype, age, kind of progeny, vigour, spreading ability, and undergroundmorphology. Some genotypes appeared to be good donors of the character, whereasothers did not. The proportion of creeping-rooted plants increased in allcases with the plant age. Selfing consistently depressed the expression ofthe character compared with clonal propagation or crossing. It is suggestedthat the effect of age and selfing on the penetrance of creeping-rootedness ismediated through their effect on plant vigour. Both aerial and root vigour showedindeed an effect per se on the presence of the character. Beside thevigour, possible indirect selection criteria were identified in the frequenciesof swollen zones and latent stem primordia on horizontal roots. Proportion ofcreeping-rooted plants in progenies after one year of growth appeared as a simple anduseful criterion to predict future trends. Consistent with previous conclusions, theresults provided evidence that a combination of family and individualselection may enhance the character expression.     

Aerosol transmission of arthropathic and amyloidogenic Enterococcus faecalis.

One-day-old brown layer chicks were exposed to an aerosol of an arthropathic and amyloidogenic Enterococcus faecalis strain alone or after being subjected to treatment with formaldehyde gas (100-200 ppm). Four-day-old chicks were also treated with the same aerosol but after treatment with a Newcastle disease vaccine virus (NDVV) aerosol or intramuscular injection with methylprednisolon at day 1. The same E. faecalis strain was inoculated intramuscularly in day-old chicks as positive control. Bacteremia with time showed that 24 hr after the aerosol the day-old exposed chicks had the highest rate of positive blood cultures (70%-80%). Lower numbers of bacteremic birds at this point in time were found in the chicks treated with E. faecalis aerosol at day 4 (3/10 in the methylprednisolon-treated group and 0/10 in the NDVV-treated group) and the E. faecalis intramuscular-injected group at day 1 (2/10). Formaldehyde gas treatment did not favor the occurrence of bacteremia. NDVV aerosol exposure or injection with corticosteroids did not favor the occurrence of bacteremia 24 hr after E. faecalis aerosol exposure at day 4 either, although 66 days after aerosol, one bird (1/14) treated with NDVV showed bacteremia. A few bacteremic birds were found 10 days after aerosol in the NDVV- and methylprednisolon-treated groups, whereas at 14 days after aerosol, one bacteremic bird was seen in the group subjected to E. faecalis aerosol at day 1, indicating the occurrence of chronic bacteremia. In contrast to the E. faecalis intramuscular-inoculated birds, no joint pathology was seen in the aerosol-exposed groups in spite of the occurrence of chronic bacteremia.     

Effects of Carbon Dioxide Exposure on Intensively Cultured Rainbow Trout Oncorhynchus mykiss: Physiological Responses and Fillet Attributes

Rainbow trout Oncorhynchus mykiss (261.6 × 24.7 g initial weight, mean × SEM) at 13.1 × 0.2 C were exposed for 94 d to one of three CO₂ treatments: control (22.1 × 2.8 mg/L), medium (34.5 × 3.8 mg/L), or high (48.7 × 4.4 mg/L). Trout were checked daily for survival, and fish were sampled at 0, 28, 56, and 84 d for physiological responses, growth, and fillet quality assessments. Trout were also challenged to a 15-min crowding stress at 93 d to assess their ability to initiate a stress response during hypercapnia. Chronically exposed trout showed nearly 100% survival through 84 d exposure (1 of 1,500 fish died). Growth and physiological results showed that increasing elevated CO₂, concentrations result in corresponding decreased growth rates and CO₂specific physiological parameters: The medium and high CO₂ treatments had significantly slower growth and subsequently smaller fish by 84 d. Exposed trout also showed significantly ( P < 0.05) decreased plasma chloride for medium and high CO₂ treatments compared to the control from 28 through 84 d. Decreased growth and smaller fish in the medium and high CO₂ treatments resulted in correspondingly smaller fresh and smoked fillet weights. Chronic CO₂ exposure did not result in notable changes in ultimate muscle pH. Exposure to 15-min crowding stress at 93 d resulted in significant changes in hematocrit, plasma cortisoI, glucose, and chloride for all treatment groups. CO₂-specific changes were detected in hematocrit, plasma cortisoI, and plasma chloride responses following the 15-min crowding stress.     

Patterns of silver eel (Anguilla anguilla L.) sex ratio in a catchment

Abstract –  Changes in the numbers and size-class structure of European silver eels, Anguilla anguilla , in the River Frémur (France) were examined over a 9-year period after installation of downstream eel passes. The number of silver eels migrating downstream peaked in 1999, then decreased strongly and steadily after 2000, reaching relatively low levels. At the same time, a gradual shift in the silver eel sex ratio from a dominance of males (size from 270 to 442 mm, age from 3 to 6 years) to females (size from 366 to 1112 mm, age from 4 to 9 years) was recorded. Possible explanations for the escapement patterns observed are environmental sex determination and the installation of eel passes on the main hydraulic engineering structures in 1992 and 1996.     

Sequence of the canine c-yes proto-oncogene

Cloning of the canine yes oncogene was attempted from a c library derived from a healthy canine spleen using a human c-yes-1 probe. The nucleotide and amino acid sequences revealed that the canine yes gene contained an open reading frame consisting of 539 amino acids. Its product had a molecular mass of 60,368 Daltons and showed 95·9 per cent and 90·4 per cent homology with human and chick p61^c-yes, respectively. Moreover, the product had a myristylation signal, src homology region (SH) 3, SH2, and tyrosine kinase domains showing 98·8 per cent and 96·0 per cent homology with those of human beings and chickens, respectively. These findings indicate that the products of the canine yes gene may have non-receptor-type tyrosine kinase activity on the cell membrane, as is the case in human and chick p61^c-yes