A general model of temporary aquatic habitat use: Water phenology as a life history filter

Temporary aquatic habitats are not widely appreciated fish habitat. However, fish navigate the transient waters of intertidal zones, floodplains, intermittent and ephemeral streams, lake margins, seasonally frozen lakes and streams, and anthropogenic aquatic habitats across the globe to access important resources. The selective pressures imposed by water impermanence (i.e., freezing, drying, tidal fluctuations), however, operate similarly across taxa and ecosystems. These similarities are formalized into a conceptual model relating habitat use to surface water phenology. Whereas all necessary life history functions (spawning, foraging, refuge, and dispersal) can be accomplished in temporary habitats, the timing, duration, and predictability of water act as a “life history filter” to which habitats can be used and for what purpose. Habitats wet from minutes to months may all be important—albeit in different ways, for different species. If life history needs co‐occur with accessibility, temporary habitats can contribute substantially to individual fitness, overall production and important metapopulation processes. This heuristic is intended to promote research, recognition and conservation of these frequently overlooked habitats that can be disproportionately important relative to their size or brevity of existence. There is a pressing need to quantify how use of temporary aquatic habitats translates to individual fitness benefits, population size and temporal stability, and ecosystem‐level consequences. Temporary aquatic habitats are being impacted at an alarming rate by anthropogenic activities altering their existence, phenology, and connectivity. It is timely that scientists, managers and policymakers consider the role these habitats play in global fish production.     

Genome expansion and gene loss in powdery mildew fungi reveal tradeoffs in extreme parasitism

Powdery mildews are phytopathogens whose growth and reproduction are entirely dependent on living plant cells. The molecular basis of this life-style, obligate biotrophy, remains unknown. We present the genome analysis of barley powdery mildew, Blumeria graminis f.sp. hordei (Blumeria), as well as a comparison with the analysis of two powdery mildews pathogenic on dicotyledonous plants. These genomes display massive retrotransposon proliferation, genome-size expansion, and gene losses. The missing genes encode enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, probably reflecting their redundancy in an exclusively biotrophic life-style. Among the 248 candidate effectors of pathogenesis identified in the Blumeria genome, very few (less than 10) define a core set conserved in all three mildews, suggesting that most effectors represent species-specific adaptations.     

Waldverbreitung und Waldeigentum im deutschen Raumplanungsrecht

European Journal of Forest Research -     

Growth of sablefish (Anoplopoma fimbria) in marine net-pens

Sablefish (Anoplopoma fimbria) were reared in 1.6 × 2.0 × 1.2 m deep net-pens for 36 months using low-cost, locally available diets (frozen salmon and herring). Post-capture mortality, wound repair, and adaptability to floating net-pens were investigated. Results showed no mortality directly related to capture and rapid healing of wounds resulting from capture. All fish adapted to captivity without apparent difficulty.For grow-out trials, 36 age 1+ fish were tagged for individual identification. Male and female fish were identified using an immunodiffusion technique. Net-pen adaptability studies tested three diets. Maximum observed mean weight gains were 0.10 kg per fish per month. After 2 years, there was no significant difference in growth (length or weight) between any of the diets. A different weight gain was recorded between male and female fish fed the salmon diet.     

Spatial dispersal of porcine reproductive and respiratory syndrome virus-contaminated flies after contact with experimentally infected pigs

OBJECTIVE: To determine whether flies can acquire porcine reproductive and respiratory syndrome virus (PRRSV) and disperse the virus throughout a designated area. ANIMALS: 60 four-month-old pigs. PROCEDURE: On day 0, 28 of 60 pigs were inoculated with PRRSV MN 30-100 (index variant). On the same day, 100,000 pupae of ochre-eyed houseflies and 100,000 pupae of red-eyed (wild-type) houseflies were placed in the swine facility for a release-recapture study. Flies were recaptured at 2 locations within the swine facility, 6 locations immediately outside the facility, and 30 locations 0.4, 0.8, 1.3, 1.7, 1.9, and 2.3 km from the facility. Traps were emptied on days 2, 7, 8, 10, and 14. Samples derived from flies were tested by use of a polymerase chain reaction assay, virus DNA was sequenced, and viruses were tested for infectivity by means of a swine bioassay. RESULTS: PRRSV RNA homologous to the index PRRSV was detected in trapped flies collected inside and immediately outside the facility and from 9 of 48 samples collected at 0.4 km, 8 of 24 samples collected at 0.8 km, 5 of 24 samples collected at 1.3 km, and 3 of 84 samples collected at > 1.7 km from the facility. Two samples collected at 0.8 km contained genetically diverse variants of PRRSV. Swine bioassays revealed the virus in flies was infectious. CONCLUSIONS AND CLINICAL RELEVANCE: Flies appeared to become contaminated with PRRSV from infected pigs and transported the virus > or = 1.7 km. Fly-born transmission may explain how PRRSV is seasonally transported between farms.     

Morphology,cytochemical staining and ultrastructural characteristics of reindeer (Rangifer tarandus) leukocytes

Peripheral blood smears from four adult reindeer (Rangifer tarandus) were examined after staining with Romanowsky's stain and cytochemical stains, including alpha-napthyl butyrate esterase (alpha-NBE), Sudan black B (SBB), chloroacetate esterase (CAE) and alkaline phosphatase (ALP). Romanowsky-stained eosinophils, neutrophils, lymphocytes and monocytes resembled those of cattle, sheep and goats. Basophils had two different staining patterns with Romanowsky's stain. Basophils that we termed "grey basophils" were similar in appearance to grey eosinophils in Greyhound dogs, with medium blue-grey to lavender-grey cytoplasm containing varying numbers of clear vacuoles or granules and variable numbers of small, intensely basophilic, perinuclear granules. The second basophil staining pattern was more typical of ruminant basophils, with uniform, pale to dark basophilic cytoplasmic granules. Basophils stained positive for alpha-NBE, SBB, CAE, and ALP. Eosinophils stained positive for SBB, and were negative for alpha-NBE, CAE, and ALP. Neutrophils were negative for SBB, CAE, and ALP. Monocytes stained positive for alpha-NBE, were rarely positive for CAE and SBB, and were negative for ALP. Transmission electron microscopy revealed matrix within all granulocytes granules, including those of basophils.     

A study on the seasonal epidemiology of Anoplocephala spp.-infection in horses and the appropriate treatment using a praziquantel gel (Droncit 9% oral gel)

In a study on the seasonal dynamics of the gastro-intestinal nematode egg production in horses, one breeding farm also revealed a particularly high prevalence of Anoplocephala spp. infection. Consequently, this farm was chosen for analysing the seasonal pattern of the tapeworm egg excretion over a one year period in order to establish the most favourable periods for an appropriate and successful cestocidal treatment. The seasonal analysis showed a significantly higher (p < 0.05) Anoplocephala spp. egg excretion between July and October, i.e. during the second part of the grazing period. This result clearly underlines the importance of a cestocidal treatment during that period of the year. Subsequently, horses of this farm and of a second farm with a high prevalence of Anoplocephala spp. were used to evaluate the efficacy of praziquantel in a specific oral gel formulation for horses under field conditions. The efficacy of praziquantel was tested in a total of 33 horses from the two farms harbouring a coproscopically detected Anoplocephala spp. infection prior to treatment. Praziquantel (Droncit 9%, oral gel, 1 mg/kg bodyweight) was administered to the horses according to their body weight. The efficacy of the drug was evaluated ten days after treatment by a double faecal analysis. Thereby, no Anoplocephala spp. eggs were found in the faeces of 32 horses (97%). The single horse remaining positive for Anoplocephala spp. eggs did not completely swallow the anthelmintic gel and consequently, did not receive the appropriate dose of the drug.     

Hyalopterus amygdali Blanch., die Mehiige Pfirsichblattlaus,als Schädling am Pfirsich

Ohne Zusammenfassung     

Biomechanical comparison of orthofix pins and cortical bone screws in a canine humeral condylar fracture model

OBJECTIVE: To compare shear stability of simulated humeral lateral condylar fractures reduced with either a self-compressing pin or cortical bone screw. STUDY DESIGN: In vitro biomechanical tests. SAMPLE POPULATION: Bilateral cadaveric canine humeri (n=18) without evidence of elbow disease. METHODS: Lateral condylar fracture was simulated by standardized osteotomy. Bone fragments were stabilized with a self-compressing pin or a cortical bone screw (2.7 or 3.5 mm) inserted in lag fashion. Specimens were mounted in a materials testing system and the condylar fragment displaced in a proximal direction until failure. Mechanical testing variables derived from load-deformation curves were compared between stabilization methods using a Student's paired t-test. RESULTS: There were no statistically significant differences for mechanical testing variables between pin and screw stabilized specimens at expected walk and trot loads. Three yield points subjectively coincided with yield of the interfragmentary interface (Y1), bone at the implant interface (Y2), and implant deformation (Y3). Displacements at Y1 were 48-156% greater for pin than screw stabilized specimens. Y2 and Y3 loads were higher for screw than pin stabilized specimens, but likely supraphysiologic for dogs convalescing after surgical repair. CONCLUSIONS: A self-compressing pin or a cortical bone screw inserted in lag fashion both provided adequate strength in applied shear to sustain expected physiologic loads through the repaired canine elbow during postoperative convalescence. CLINICAL RELEVANCE: Because self-compressing pins were easy to implant and mechanical properties were not significantly different than cortical screws at expected physiologic loads, pins should be considered for the repair of traumatic humeral condylar fractures.