Competition between Ridolfia segetum and sunflower

Studies on competition between Ridolfia segetum Maris, and sunflower (Helianthemum annuus L.) were conducted at eight locations in southern Spain in 1990 and 1991. in order to define competition models and to estimate from these economic thresholds as affected by crop inputs and potential yields. Competition losses in sunflower crops ranged from 19% to 56% of weed–free yields. There were slightly better correlations between percentage sunflower reduction and weed density than with weed dry weight, (?0.66 and ?0.59, respectively). The weed competitive index, or sunflower crop dry weight reduction per unit dry weight of R. segetum, was 1.09. The percentage yield losses due to weed density (NPR_t) were fitted to multiple linear, quadratic, exponential and hyperbolic models. The hyperbolic equation, %RSY=100 (1+1/b*NPR_t)^?1, where b=0.14 and is the R. segetum competitive ability index, had the lowest error sum of squares (SSE), and gave the best biological explanation for the competition response. Early emergence (before mid–March) made weeds about 1.5 times more competitive than late emergence. The economic threshold to offset the cost of a shallow post–emergence tillage, assuming 70% control efficiency, ranged from about 2.5 plants m ^?2 for low–yielding crops(1200kgha^?1) to less than one plant m^?2 for higher–yielding crops (2800 kg ha^?1).     

Seed bank and other demographic parameters of broomrape (Orobanche crenata Forsk.) populations in faba bean (Vicia faba L.)

A study on the population dynamics of broom-rape (Orobanche crenata Forskal) in faba bean (Viciafaba L.) was conducted in two locations for 8 years. The O. crenata seed bank increased every year in the 20-cm depth arable layer until it reached approximately 4 million (M) seeds m^?2. Seed viability ranged between 53% and 68%, approximately half of the seeds remaining dormant. About 3 × 10^?3% of the seed bank became attached to the root system of the faba beans. Only 9% of the attached broomrapes developed and emerged from the soil, possibly reflecting high levels of intraspecific competition. Maximum broomrape seed production for a population of 53 emerged broomrapes per m² was approximately 4 M seeds m^?2. About 43% of the seeds produced were not incorporated into the soil, most probably as a result of their degradation, decomposition or dispersion. Stock semencier et autres paramètres démographiques de I'orobanche crénelée (Orobanche crenata Forsk.) dans des cultures de féverolle (Vicia faba L.) Une étude de la dynamique de populations d'orobanche crénelée (Orobanche crenata Forsk.) dans des cultures de féverolle (Viciafaba L.) a été menée pendant 8 années sur deux sites. Le stock semencier de O. crenata a augmenteéchaque année dans la couche (20 cm) arable du sol jusqu'à atteindre 4 millions (M) de graines m^?2. La viabilité des graines était comprise entre 53 et 68%, approximativement la moitié d'entre elles présentaient une dormance. Environ 3 × 10^?3% du stock semencier adhérait au système racinaire de la féverolle. Seulement 9% des orobanches adhérantes se développaient et levaient, ce qui pourrait refléter une compétition intraspécifique importante. La production maxi-male de graines par une population de 53 orobanches levées au m²était d'environ 4 M graines m^?2. Environ 43% des graines produites n'étaient pas incorporées au sol, très prob-ablement en raison de leur dégradation, de leur décomposition ou de leur dispersion. Bodensamenbank und andere populationsde-mographische Parameter der Sommerwurz Orobanche crenata Forsk. in Bestanden der Acker-Bohne (Vicia faba L.) Bei einer Untersuchung der Populationsdy-namik der Sommerwurz Orobanche crenata Forsk. in Beständen der Acker-Bohne (Vicia faba L.) an 2 Orten über 8 Jahre hin nahm die Bodensamenbank in der Pflugzone von 20 cm Tiefe jedes Jahr zu, bis sie rund 4 Millionen Samen m^?2 erreichte. Die Lebensfähigkeit der Samen lag bei 53 bis 68%, etwa die Hälfte war dormant. Ungefähr 3 × 10^?3% kamen mit den Bohnenwurzeln in Berührung. Nur 9% davon entwickelten sich und wuchsen heran, worin vielleicht der hohe Grad intraspezifischer Konkurrenz zum Ausdruck kommt. Die höchste Zahl gebildeter Samen eines Sommer-wurzbestands von 53 Pflanzen m^?2 war rund 4 Millionen. Etwa 43% der gebildeten Samen gelangten nicht in den Boden, wahrscheinlich weil sie zerstört oder verweht wurden.     

Synovial Hemangioma in a Dog

Objective— To report arthroscopic diagnosis and treatment of synovial hemangioma in a dog.
Study Design— Case report.
Animal— Standard Poodle (8-year-old neutered male).
Methods— A soft tissue density mass observed radiographically in the left stifle joint of a dog with a 2-month history of recurrent lameness, hemarthrosis, and a slight cranial drawer sign, was located by diagnostic arthroscopy and surgically excised via arthrotomy.
Results— Histologic evaluation revealed tissue composed of variably sized cavernous vascular spaces filled with erythrocytes that were considered compatible with synovial hemangioma.
Conclusions— In this dog, synovial hemangioma evident as a soft tissue mass on radiographs was associated with chronic lameness and hemarthrosis, and resolved with surgical excision.
Clinical Relevance— Synovial hemangioma, although seemingly rare in dogs, should be considered in the differential diagnosis for nontraumatic, recurrent lameness, and unresponsive to anti-inflammatory therapy when there is a circumscribed intracapsular soft tissue mass evident radiographically together with hemarthrosis.     

Optimum dietary soybean meal level for maximizing growth and nutrient utilization of on-growing gilthead sea bream (Sparus aurata)

Six isonitrogenous [450 g kg⁻¹ crude protein (CP)] and isoenergetic diets (23 kJ g⁻¹) with six levels of defatted soybean meal inclusion (0, 132, 263, 395, 526 and 658 g kg⁻¹) in substitution of fish meal were evaluated in gilthead sea bream of 242 g initial weight for 134 days. Fish fed diets S0, S13, S26 and S39 had a similar live weight (422, 422, 438 and 422 g, respectively) but fish fed diets S53 and S66 obtained the lowest final weight (385 and 333g, respectively), and similar results were presented in specific growth rate (SGR). Fish fed diets S53 and S66 also obtained the highest feed conversion ratio (FCR). Quadratic multiple regression equations were developed for SGR and FCR which were closely related to dietary soybean level. The optimum dietary soybean levels were 205 g kg⁻¹ for maximum SGR and 10 g kg⁻¹ for minimum FCR. Sensorial differences were appreciated by judges between fish fed S0 and S39 soybean level, but after a re-feeding period of 28 days with diet S0, these differences disappeared.     

Plasmids and antibiotic resistance in Aeromonas hydrophila isolated in Malaysia from healthy and diseased fish

Abstract. Thirty-four A. hydrophila strains isolated from various fish species and several geographical locations in Malaysia were examined for their antibiotic resistance pattern and plasmid carriage. All strains were found to possess multiple resisitance, most commonly to ampicillin and carbenicillin. Six different antibiogroups representing 18 different antibiotic patterns were obtained. There were no differences in the resistance patterns of A. hydrophila isolates from healthy and diseased fish with ulcerative syndrome. Rifampicin was found to be the most active antibiotic against these strains. Isolation of plasmid DNA have a plasmid occurrence rate of only 14·7%. The molecular sizes of these plasmids ranged from 2·6 to 6Mda. Multiple carriage of plasmid is more likely with strains having three of four plasmids.     

Gap colonization by weeds in a wheat crop grown under different cultivation regimes

The effects of tillage systems (mouldboard plough, chisel, disk and non-tillage, over 3 years) and gap openings during August and October of 0, 0.30 m × 0.30 m and 0.45 m × 0.45 m on the weed community were investigated in a wheat (Triticumaestivum L.) crop. Weed flora composition and species abundance were recorded in August, September and November and the data analysed with MULVA programs and non-parametric tests. The tillage system was more important than the timing or gap size on the weed floristic composition, and the changes in weed communities were evident within a 3-year period in spite of herbicide use. Less disturbing tillage systems (non-tillage and chisel plough) allowed the build-up of a more diverse community, whereas the most disturbing one (mouldboard plough) prevented high diversity in the weed community.     

The effect of different tillage systems on the composition of the seedbank

The soil seedbank of a wheat crop grown with four tillage systems (mouldboard plough, disk, chisel and no-tillage) for 3 years was analysed. Density and composition of seedbanks varied according to tillage system and depth. The mouidboard plough crop had seedbanks with the lowest seed density and there was no difference in density or composition at 0-5 cm and 5-10 cm depth whereas no—tillage had a more dense seed bank, especially in the upper part of the soil profile. Diversity of seedbanks also increased from mouidboard plough, to disk, to chisel, to no-titlage, which had the most diverse bank. Therefore, the data strongly support the hypothesis that the systems causing less disturbance allow the build-up of a larger and more diverse soil seed bank.     

Root proliferation in native perennial grasses of arid Patagonia,Argentina

Pappophorum vaginatum is the most abundant C4perennial grass desirable to livestock in rangelands of northeastern Patagonia,Argentina.We hypothesized that(1)defoliation reduce net primary productivity,and root length density and weight in the native species,and(2)root net primary productivity,and root length density and weight,are greater in P.vaginatum than in the other,less desirable,native species(i.e.,Aristida spegazzinii,A.subulata and Sporobolus cryptandrus).Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons.Root proliferation was measured using the cylinder method.Cylindrical,iron structures,wrapped up using nylon mesh,were buried diagonally from the periphery to the center on individual plants.These structures,initially filled with soil without any organic residue,were dug up from the soil on 25April 2008,after two successive defoliations in mid-spring 2007.During the second growing season(2008–2009),cylinders were destructively harvested on 4 April 2009,after one or two defoliations in midand/or late-spring,respectively.Roots grown into the cylinders were obtained after washing the soil manually.Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice,which supported the first hypothesis.The greater root net primary productivity,root length density and weight in P.vaginatum than in the other native species,in support of the second hypothesis,could help to explain its greater abundance in rangelands of Argentina.     

Detection and genetic characterisation of vanA‐containing Enterococcus strains in healthy Lusitano horses

Lusitano horses were investigated in order to detect the presence of vancomycin‐resistant enterococci. vanA isolates showed high level vancomycin (Minimum inhibitory concentration; MIC ≥128 mg/l) and teicoplanin resistance (MIC 64 mg/l), as well as resistance to ciprofloxacin, erythromycin and tetracycline. The tet(L) and erm(B) genes, associated with tetracycline and erythromycin resistance, respectively, were found in all vanA isolates. The intestinal tract of Lusitano horses can be a potential reservoir for vanA‐containing enterococci.     

Successful Cementless Cup Reimplantation Using Cortical Bone Graft Augmentation after an Acetabular Fracture and Cup Displacement

Objective— To report repair of a periprosthetic acetabular fracture with concurrent component displacement after cementless total hip arthroplasty (THA).
Study Design— Clinical case report.
Animals— Dog (n=1) with an acetabular fracture after THA.
Methods— Acetabular repair was performed on a highly comminuted periprosthetic acetabular fracture after cementless THA. A bulk, structural corticocancellous autograft from the ipsilateral ilial wing was used for repair and reconstruction of the dorsal acetabular wall before reimplantation of a cementless acetabular component.
Results— Repair of a periprosthetic acetabular fracture with a bulk structural autograft was successful in reconstruction of the dorsal acetabular wall and in reestablishing a stable, functional cementless THA acetabular prosthesis.
Conclusions— Structural corticocancellous autografts from the ilium can be successfully used in repair of periprosthetic acetabular fractures after THA.
Clinical Relevance— Structural corticocancellous grafting from the ilium can be considered as a treatment option for repair of periprosthetic acetabular fractures after THA.