Reproductive interference and Satyrisation: mechanisms,outcomes and potential use for insect control

Journal of Pest Science - Reproductive Interference occurs when interactions between individuals from different species disrupt reproductive processes, resulting in a fitness cost to one or both...     

COMPUTED TOMOGRAPHIC CHARACTERISTICS OF ODONTOGENIC NEOPLASMS IN DOGS

Odontogenic neoplasms are locally invasive oral tumors in dogs. The purpose of this retrospective study was to describe CT characteristics for varying histopathologic types of canine odontogenic neoplasms. A board‐certified veterinary radiologist who was unaware of histologic findings reviewed and scored imaging studies. A total of 29 dogs were included in the study. Twenty‐three of these dogs had concurrent dental radiographs. The most common CT characteristics for all tumor types were a direct association with or in the region of multiple teeth in 96.4% (27/28), contrast enhancement in 96.3% (26/27), alveolar bone lysis in 93.1% (27/29), and mass‐associated tooth displacement in 85.2% (23/27). Mass‐associated cyst‐like structures were identified in 53.6% (15/28) and were only present in tumors containing odontogenic epithelium. Canine acanthomatous ameloblastomas (n = 15) appeared as extra‐osseous (10/15) or intra‐osseous (5/15) masses. Intra‐osseous canine acanthomatous ameloblastomas were more likely to have mass‐associated cyst‐like structures and were subjectively more aggressive when compared with extra‐osseous canine acanthomatous ameloblastomas. Amyloid‐producing odontogenic tumors (n = 3) had subjectively uniform CT imaging characteristics and consisted of round soft tissue and mineral attenuating masses with multiple associated cyst‐like structures. Fibromatous epulides of periodontal ligament origin (n = 4) were contrast enhancing extra‐osseous masses that were rarely referred for CT examinations and 25% (1/4) were not visible with CT. Other odontogenic tumors were less represented or had more variable CT imaging characteristics. Mass‐associated tooth destruction was appreciated more often with dental radiographs and extra‐oral tumor extension was identified more often with CT.     

MAGNETIC RESONANCE IMAGING FINDINGS ASSOCIATED WITH LATERAL CEREBRAL VENTRICULOMEGALY IN ENGLISH BULLDOGS

Multiple congenital or developmental anomalies associated with the central nervous system have been reported in English Bulldogs. The purpose of this retrospective study was to identify and describe the prevalence and MRI characteristics of these anomalies and their association with presence and degree of cerebral ventriculomegaly. Magnetic resonance imaging studies of 50 English Bulldogs were evaluated. Forty‐eight dogs had some degree of cerebral ventriculomegaly, 27 of which had an otherwise normal brain. Presence of lateral ventriculomegaly was not significantly associated with presence of another intracranial lesion. Appearance of the septum pellucidum was variable, ranging from intact to incomplete or completely absent. The corpus callosum was subjectively thinned in all but three dogs, two of which had normal lateral ventricles. Fusion of the rostral colliculi was not found in any dog. A persistent craniopharyngeal canal was identified in one dog. Aqueductal stenosis caused by fusion of the rostral colliculi was not identified in any dog. Findings indicated that cerebral ventriculomegaly is a common finding in English Bulldogs with or without other intracranial lesions, aqueductal stenosis caused by fusion of the rostral colliculi is unlikely to be a common etiology leading to obstructive hydrocephalus, and a large craniopharyngeal canal is a rare finding that has unknown clinical significance at this time.     

The epidemiology of Staphylococcus aureus infections from subclinical mastitis in dairy cows during a control programme

The objective was to investigate the spread of S. aureus in seven dairy herds. Milk samples were taken to determine mastitis pathogens and somatic cell count. An approved hygiene programme was established to control the spread of S. aureus from quarter to quarter. S. aureus isolates were differentiated by geno- and phenotyping to trace their spread within a herd.In two herds S. aureus showed a high prevalence, but were eliminated from the herds by the control programme. In these herds and a third herd typing results identified a particular type that was found much more frequently than all other types. The frequent types were repeatedly detectable during the study. In three other herds with a lower S. aureus prevalence and also in one herd with a long history of S. aureus and high prevalence subclinical mastitis was caused by several distinguishable S. aureus types. These types occurred simultaneously in the particular herd and showed little or no tendency to spread from quarter to quarter. They seemed to circumvent the control procedures resulting in a relatively high rate of new infected animals and therefore were hardly eliminated. The typing results and the clinical observations indicated that strains differed in their tendency to spread and their ability to infect udder quarters. In three herds typing methods identified a predominant type with the common epidemiological features of a contagious mastitis pathogen, while in the other herds the S. aureus type patterns were similar to that of environmental pathogens.     

Dynamics of total suspended matter and phytoplankton loads in the river Elbe

Purpose

Identifying sources and fluxes of suspended matter within the catchment is vitally important for the water quality of rivers and for establishing sediment management plans. Constituents of suspended particles are of abiotic and biotic origin. In the Elbe, the biotic fraction of suspended particles is mainly composed of phytoplankton biomass. In this study, total seston and phytoplankton are analyzed for their seasonality, their interdependence and temporal trends over three or five decades, respectively.

Materials and methods

The biotic load was separated from the total suspended matter load, and time series of total suspended substances (seston) (1964 to 2015) and chlorophyll a values (1985 to 2015) were analyzed. Our analyses focused on the seasonal dynamics, long-term trends, and the correlation to hydrological events.

Results and discussion

The mean share of phytoplankton in total seston accounted for 24% in summer months (April–September), with a negative correlation between discharge and total seston, and 11% in winter months (October–March), with a weak positive correlation between discharge and total seston. The long-term trend of seston load was decreasing, while phytoplankton load did not show a significant trend.

Conclusions

Autochthonous biogenic portions should not be neglected in the budget of total suspended matter loads in the Elbe catchment. Our results indicate that land-use and industrial changes subsequent to the German reunification mainly caused the observed trend. Phytoplankton growth superimposes the seasonal dynamics of seston in summer, whereas in the long term, decreasing mineral fraction dominates the significantly decreasing trend.

     

Genetic Diversity for RFLPs in European Maize Inbreds

Restriction fragment length polymorphisms (RFLPs) have been proposed for predicting the yield potential of different types of cross. Their has been evaluated in 15 flint and 12 dent inbreds from the European maize (Zea mays L.) germplasm as well as in 68 F₁ crosses (21 flint × flint, 14 dent × dent, and 33 flint × dent) produced between them. The materials were evaluated for F₁ performance and midparent heterosis of grain yield, dry matter content (DMC) and plant height in two environments in Germany. Genetic distances (GDs) between parental lines, calculated from RFLP data of 194 clone-enzyme combinations, showed greater means for flint × dent (0.67) than dent × dent (0.62) and flint × flint (0.55) crosses. Cluster analysis based on GDs resulted in a clear separation of flint and dent lines and agreed well with pedigree information. For the complete set of 64 crosses analyzed (excluding 4 crosses between closely related lines) correlations of GD with F₁ performance and heterosis were significant for all traits except F₁ performance of DMC. When separate calculations were performed for individual subjets of crosses, correlations of GD with Fl performance and heterosis were significantly positive (0.48 ≤ r ≤ 0.80) for all traits in the flint × flint crosses, but not significant for the subsets of flint × dent and dent × dent crosses. Our results confirm those of previous investigations in that the predictive value of RFLP data is restricted to crosses between lines from the same heterotic group, and cannot be applied to crosses between lines from genetically divergent heterotic groups.     

A diallel analysis of various traits in winter triticale

In triticale, preharvest sprouting tolerance is important for yield stability and quality of the grain. Therefore, an experiment was conducted to estimate quantitative genetic parameters of preharvest sprouting tolerance in triticale using a diallel of eight modern triticale cultivars and breeding lines. The 28 F₁‐hybrids and the parents were planted in the breeding nurseries in 2001 and 2002 at four locations. Heading, plant height, falling numbers of two harvest dates, thousand kernel weight (TKW) and preharvest sprouting (Spr) were measured. The heritabilities for plant height and TKW were the highest with 0.91 and 0.85, respectively. Falling number and sprouting showed heritabilities between 0.66 and 0.83. Mid‐parent heterosis (MPHET) was negative for heading, indicating a non‐significant earlier heading of the F₁‐hybrids. In plant height and TKW the heterosis was positive with 4.7% and 6.3% MPHET. Both falling numbers displayed a negative MPHET of nearly −15%. In contrast to falling numbers, the preharvest sprouting of hybrids was slightly reduced in comparison with the parents. In all traits analysed, general combining ability (GCA)‐variances were greater than specific combining ability (SCA)‐variances.     

Predicting optimal combinations of by‐catch reduction devices in trawl gears: A meta‐analytical approach

Global efforts to reduce unwanted catches have led to the development of a vast array of by‐catch reduction devices (BRDs), in particular for mixed trawl fisheries. Some of these BRDs could likely benefit from being combined. However, the number of possible combinations would be prohibitive to be tested experimentally. Therefore, in this study we propose a meta‐analytical approach that combines the data available on BRDs tested independently in a fishery and predict the theoretical selectivity of all possible combinations of those devices. This allows to identify promising BRD combinations, worth experimental investigation and flexible trawl configurations, where the selectivity can be substantially modified by adding or removing one BRD, thus aiding fishermen in adapting to high variability in catch composition and quota availability. To illustrate the approach, we used BRDs developed for the well‐studied Nephrops (Nephrops norvegicus, Nephropidae) directed mixed trawl fishery in the Skagerrak and Kattegat seas. We predicted the selectivity of 100 BRD combinations for Nephrops, cod (Gadus morhua, Gadidae) and haddock (Melanogrammus aeglefinus, Gadidae), compared them in terms of absolute selectivity and performance under realistic catch scenarios, from both single‐ and multispecies perspectives, and identified 15 BRD combinations that could be worth future experimental investigation. The meta‐analytical approach makes best use of existing knowledge and leads to new insights about the potential for improvement and flexibility in trawl selectivity. This could benefit a variety of mixed trawl fisheries and help developing a new generation of more flexible gears, with multiple BRDs integrated in their structure.