Altersentwicklung der langen Röhrenknochen bei Weißen Neuseeländer Fleischkaninchen und Chinchilla-Bastard-Versuchskaninchen

The age dependent development of the long bones' diaphyses (humerus, os femoris and os tibiofibulare) was examined macroscopically, morphometrically and histologically using 15 White New Zealand Rabbits (WN) and 15 Chinchilla-Bastard-Experimental-Rabbits (Chbb) in 5 different age groups. The main growth of bone occurs in the first three months of life. The remodelling from juvenile to adult bone began in the period from the 4th-12th week. The different bones show various characteristic remodelling zones for each localization. Until the 12th week the resorption of juvenile bundled bone predominates. Afterwards an increasing bone formation by osteal bone can be observed. The bone growth is terminated between the 17th and 33rd week. The os tibiofibulare in both breeds represents the major part of the compact bone area on the whole cross-section area. Principally the bone-remodelling process proceeds equally in both breeds. Breed dependent differences in the adult bone are seen in the construction of the circumferential lamellae. These are formed considerably more irregularly by the Chbb-rabbits than by the WN-rabbits.     

Predator–prey interaction in soil food web: functional response, size-dependent foraging efficiency, and the influence of soil texture

In a series of laboratory experiments, we presented carnivorous Macrobiotus richtersi (Tardigrada, Macrobiotidae) with nematode prey to assess their importance as predator. We investigated consumption rate for (a) different prey densities (10–400 prey individuals), (b) different prey biomasses (22–80 ng), (c) different prey species (Pelodera teres, Rhabditidae, versus Acrobeloides nanus, Cephalobidae) and (d) different environments (2-D agar surface versus 3-D sand fractions of three different textures). M. richtersi consumed up to 4.6 g nematode prey in 4 h, that is, 43% of the tardigrades body mass. Predation rate was positively correlated with prey density. The optimal prey in the present investigation was the biggest prey because it yielded the highest biomass uptake per time. In addition, the size of M. richtersi played an important role in consumption rate. Bacterivorous nematodes reacted differently to attack. Even in a water film on stiff agar where nematode agility was limited, a vigorous undulation reaction of P. teres led to a measurable reduction in consumption rate. A. nanus, in contrast, showed little response to attack. Microcosm experiments with sands of different particle size demonstrated that M. richtersi is able to chase and consume small bacterivorous nematodes in a 3-D soil matrix. However, consumption rate in sand microcosms was significantly reduced compared with pure agar. The sand matrix improved nematode agility and possibly provided small pores as refuge for the nematodes. The lowest consumption rate was observed in fine sand. Effects of predatory tardigrades on nematode numbers in the field are discussed.     

Improving dynamic treatment unit forest planning with cellular automata heuristics

We present a model for conducting dynamic treatment unit (DTU) forest planning using a heuristic cellular automata (CA) approach. The clustering of DTUs is driven by entry costs associated with treatments, thus we directly model the economic incentive to cluster. The model is based on the work presented in the literature but enhanced by adding a third phase to the CA algorithm where DTUs are mapped in high detail. The model allows separate but nearby forest areas to be included in the same DTU and shares the entry cost if they are within a defined distance. The model is applied to a typical long-term forest planning problem for a 1 182 ha landscape in northern Sweden, represented by 4 218 microsegments with an average size of 0.28 ha. The added phase increased the utility by 1.5–32.2%. The model produced consistent solutions—more than half of all microsegments were managed with the same treatment program in 95% of all solutions when multiple solutions were found.

     

Glycosylation restores survival of chilled blood platelets

Cooling of blood platelets clusters the von Willebrand factor receptor complex. Macrophage alphaMbeta2 integrins bind to the GPIbalpha subunit of the clustered complex, resulting in rapid clearance of transfused, cooled platelets. This precludes refrigeration of platelets for transfusion, but the current practice of room temperature storage has major drawbacks. We document that alphaMbeta2 is a lectin that recognizes exposed beta-N-acetylglucosamine residues of N-linked glycans on GPIbalpha. Enzymatic galactosylation of chilled platelets blocks alphaMbeta2 recognition, prolonging the circulation of functional cooled platelets. Platelet-associated galactosyltransferase produces efficient galactosylation when uridine diphosphate-galactose is added, affording a potentially simple method for storing platelets in the cold.     

Superinfection occurs in Anaplasma phagocytophilum infected sheep irrespective of infection phase and protection status

Background

Anaplasma phagocytophilum infection in domestic ruminants is widespread in the coastal areas of southern Norway. The bacteria may persist in mammalian hosts. Several genetic variants of A. phagocytophilum exist. In the present study, we investigate whether superinfection occurs in the acute and persistent phase of the infection.

Methods

Five-month-old lambs of the Norwegian Dala breed were experimentally infected with two 16S rRNA gene variants of A. phagocytophilum, i.e. A. phagocytophilum variant 1 (GenBank accession number {"type":"entrez-nucleotide","attrs":{"text":"M73220","term_id":"148293","term_text":"M73220"}}M73220) and variant 2 (GenBank acc. no. {"type":"entrez-nucleotide","attrs":{"text":"AF336220","term_id":"13325085","term_text":"AF336220"}}AF336220). Eighteen lambs were used, two lambs in each group. Eight groups were experimentally inoculated with either variant 1 or 2 on day 0. Six of these groups were then challenged with the other variant on either days 7, 42 or 84, respectively. One group was left uninfected. The occurrence of A. phagocytophilum in blood samples was determined using semi-nested PCR analysis and gene sequencing. Specific antibodies were measured by an indirect immunofluorescence antibody assay (IFA).

Results

A. phagocytophilum variant 1 and 2 differed significantly with regards to clinical reaction and cross-immunity in infected lambs. Both variants were found in the blood after challenge. However, variant 1 was detected most frequently.

Conclusion

The present experiment indicates that superinfection of different genotypes occurs during the acute as well as the persistent phase of an A. phagocytophilum infection, even in lambs protected against the challenged infection.     

Effect of a biocontrol agent (<Emphasis Type="Italic">Bacillus subtilis</Emphasis>) and modified atmosphere packaging on postharvest decay control and quality retention of litchi during storage

The efficacy of biological control and two types of modified atmosphere packaging (MAP) alone and in combinations was evaluated under cold storage as well as simulated market-shelf conditions to control decay and pericarp browning on litchi cv. ‘McLean’s Red’. Fruits were dipped for 2 min at 15°C inBacillus subtilis or prochloraz separately, packed in MAP [low density polyethylene (LDPE) or polypropylene (PP)], heat sealed and stored at 2°C and 90% r.h. for 18 days followed by 2 days at 14°C and 75% r.h. to simulate market-shelf conditions. A commercially adopted sulfur dioxide treatment was included as a comparative control. Fruits treated withB. subtilis + PP or prochloraz + PP and stand-alone PP treatment did not show decay or browning at 2°C. Decay and browning were controlled significantly after 2 days at 14°C inB. subtilis + PP or prochloraz + PP treatments. However, the prochloraz + PP affected the natural pinkish-red color of the pericarp and gave higher h° (hue angle) values. The stand-alone PP treatment (∼14% O₂, ∼5% CO₂) showed 11.3% decay due mainly toAlternaria alternata andCladosporium spp. at 14°C. The effectiveness of the MAP was improved at 14°C whenB. subtilis was combined with PP, controlling decay and pericarp browning and retaining the fruit color and quality.B. subtilis survived in PP at 2° and 14°C, but not in LDPE. Stand-alone LDPE (∼3% O₂, ∼10% CO₂) and combination treatmentsB. subtilis + LDPE or prochloraz + LDPE failed to control decay and pericarp browning. Higher yeast populations were observed in LDPE orB. subtilis + LDPE at both 2° and 14°C.Candida, Cryptococcus andZygosaccharomyces spp. were the predominant yeasts in all LDPE treatments. Reprints ofS. Afr. Litchi Growers’ Assoc. Yearb. references can be obtained from D. Sivakumar.     

Plasminogen activation in the bovine udder

Plasmin is a serin protease with a broad substrate specificity which might cause disintegration of basal membranes, epithelium and surrounding matrix. Plasmin might also elicit degradation of tissue (Mullins & Rohrlich 1983).     

The first nosocomial outbreak of methicillin-resistant Staphylococcus aureus in horses in Sweden

Background

Methicillin-resistant Staphylococcus aureus (MRSA) in animals is a rare finding in Sweden. In horses, MRSA was first detected in a screening survey in 2007. In 2008, six clinical cases occurred in an equine hospital, indicating an outbreak.

Method

All MRSA isolates detected, 11 spa-type t011 and one t064 (n = 12), in infected horses (n = 10) and screening of horses (n = 2) in Sweden from December 2007 to March 2010 were retrospectively analysed with pulsed-field gel electrophoresis (PFGE) using Cfr9I and ApaI restriction enzymes, to study relationship between the isolates. Medical records of infected horses and outbreak investigation notes were scrutinised to monitor the clinical outcome and other aspects of the outbreak.

Results

Eight of the 10 infected horses were linked to one equine hospital and two to another hospital in the same region. The six horses infected with MRSA in 2008 underwent surgery during the period 22 May-7 July in one of the hospitals. Four more infections linked to the two hospitals were notified between 2009 and March 2010.Nine of the 11 spa-type t011 isolates had identical Cfr9I and ApaI PFGE pattern. All six infected horses from 2008 presented with this MRSA. Two t011 isolates differed in one and two bands, respectively, in PFGE.Nine horses suffered from surgical site infections (SSI). No antimicrobials were used following the MRSA diagnosis and the infections cleared. The time from surgery to MRSA diagnosis differed greatly between the horses (range 15-52 days).

Conclusions

Association in time and space of six horses infected with an identical MRSA strain of spa-type t011 confirmed an outbreak. Two isolates found in 2009 and 2010 in the outbreak hospital were closely related to the outbreak strain, indicating one circulating strain. Both spa-type t011 and t064 have been reported in horses in Europe prior to these findings. The observation that the infections cleared although antimicrobials were not used is encouraging for future prudent use of antimicrobials. The time from surgery to bacteriological diagnosis was not acceptable in most cases, as contagious spread was a risk. Sampling when symptoms of infection are noticed and accurate analysis are thus important.     

Influence of Oat β‐Glucan Preparations on the Perception of Mouthfeel and on Rheological Properties in Beverage Prototypes

The aim was to study the effect of concentration and molecular weight of four different β‐glucan preparations on the perceived sensory quality of a beverage prototype. The correlations between sensory and instrumental measures were investigated. Two of the preparations were brantype containing high molecular weight β‐glucan, two were more‐processed low molecular weight β‐glucan preparations. Twelve beverage samples containing 0.25–2% β‐glucan and one reference sample thickened with carboxymethyl cellulose (CMC) were profiled by a sensory panel and analyzed by instrumental measurements (viscosity and molecular weight). Sensory profiles of the beverages varied at the same concentration of β‐glucan, depending on β‐glucan preparation. Beverages made with the bran‐type preparations were more viscous and had higher perceived thickness than beverages made with more‐processed, low molecular weight preparations. Moderate correlations were obtained between perceived thickness and sliminess and instrumental viscosity at all shear rates between 26 and 100/sec (r = 0.63–0.78; P ≤ 0.001). Technologically, more‐processed β‐glucan preparations are easier to add into a beverage in amounts sufficient for achieving a physiologically functional amount of β‐glucan in a product.