Climate and Dirofilaria infection in Europe

Climatic changes, together with an increase in the movement of cats and dogs across Europe, have caused an increase in the geographical range of several vector borne parasites like Dirofilaria, and in the risk of infection for animals and humans. The present paper reviews the effects of climate and other global drivers on Dirofilaria immitis and Dirofilaria repens infections in Europe and the possible implications on the transmission and control of these mosquito-borne nematodes. In the last several years, growing degree day (GDD)-based forecast models, which use wide or local scale temperature data, have been developed to predict the occurrence and seasonality of Dirofilaria in different parts of the world. All these models are based on the fact that: there is a threshold of 14 °C below which Dirofilaria development will not proceed; and there is a requirement of 130 GDD for larvae to reach infectivity and a maximum life expectancy of 30 days for a vector mosquito. The output of these models predicts that the summer temperatures (with peaks in July) are sufficient to facilitate extrinsic incubation of Dirofilaria even at high latitudes. The global warming projected by the Intergovernmental Panel on Climate Change suggests that warm summers suitable for Dirofilaria transmission in Europe will be the rule in the future decades and if the actual trend of temperature increase continues, filarial infection should spread into previously infection-free areas. These factors not only favour incubation of Dirofilaria, but also impact on mosquito species. Recent findings have also demonstrated that Aedes albopictus is now considered to be an important, competent vector of Dirofilaria infections. This mosquito species could spread from southern to northern European countries in the near future, changing the epidemiological patterns of dirofilariosis both in humans and animals.     

Assessment of oak forest condition based on leaf biochemical variables and chlorophyll fluorescence

Pedunculate oak forests (Quercus robur L.) in the Ticino Regional Park, Italy, are declining as a result of insect attacks, summer droughts and air pollution. The assessment and monitoring of forest condition can provide a basis for managing and conserving forest ecosystems and thereby avoid loss of valuable natural resources. Currently, most forest assessments are limited to ground-based visual evaluations that are local and subjective. It is therefore difficult to compare data collected by different crews or to define reliable trends over years. We examined vegetation variables that can be quantitatively estimated by remote observations and, thus, are suitable for objective monitoring over extended forested areas. We found that total chlorophyll (Chl) concentration is the most suitable variable for assessing pedunculate oak decline. It is highly correlated with visual assessments of discoloration. Furthermore, Chl concentration can be accurately estimated from leaf optical properties, making it feasible to map Chl concentration at the canopy level from satellite and airborne remote observations.     

Annual survival probabilities of juvenile loggerhead sea turtles indicate high anthropogenic impact on Mediterranean populations

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Resilience of European larch (<Emphasis Type="Italic">Larix decidua</Emphasis> Mill.) forests to wildfires in the western Alps

European larch is a dominant species in the subalpine belt of the western Alps. Despite recent increases in wildfire activity in this region, fire ecology of European larch is poorly understood compared to other larch species around the world. This study aims to assess whether European larch forests are resilient to fires, and to find out the factors that drive such resilience. We assessed the recovery of larch forests along a gradient of fire severity (low, moderate, high) based on the abundance and dominance of post-fire larch regeneration. We established 200 plots distributed among burned larch forests in nine wildfires that occurred between 1973 and 2007 in the western Alps. We included variables regarding topography, climate, fire severity, fire legacies, ground cover, grazing intensity, and time since fire. To evaluate potential drivers of larch recruitment, we applied generalized linear mixed models (GLMM) and random forests (RF). Larch regeneration was much more abundant and dominant in the moderate- and high-severity fire classes than in the low-severity class. More than half of the plots in the moderate- and high-severity classes were classified as resilient, i.e., post-fire larch regeneration was enough to recover a larch stand. GLMM and RF produced complementary results: fire severity and legacies, such as snags, canopy cover and distance to seed source, were crucial factors explaining post-fire larch recruitment. This study shows that fire has a positive effect on larch regeneration, and we conclude that European larch forests are highly resilient to mixed-severity fires in the western Alps.     

Lack of acute toxicity of an anthraquinone bird repellent to non-target crayfish (Procambarus clarkii) associated with rice-crayfish crop rotations

Aeroz™ (9,10-anthraquinone (AQ)), a chemical rice seed treatment that effectively deters birds from depredating newly planted fields, could be an important management tool that enables rice producers to plant earlier in the season and increase yields. This bird repellent, while non-lethal to birds, has unknown toxicity to crayfish that often are closely integrated with rice production in southern regions of the USA. This study was conducted to assess if AQ, the active ingredient in Aeroz™, could be acutely toxic to the red swamp crayfish Procambarus clarkii (Girard), the crayfish species most often associated with rice cultivation, via seed ingestion and/or through their contact with chemical in pond water. Mortality data from a 96 h feeding study indicate that AQ-treated (1.76% by wt) rice seed was not acutely toxic to juvenile (∼3 mo.) crayfish through the ingestion exposure route. In addition, a 96 h aquatic acute toxicity test showed that the LC₅₀ of AQ in juvenile crayfish is >85 μg L⁻¹ and above the water solubility limit of AQ. These results indicate that very minimal, if any, acute toxicity would be observed in juvenile crayfish if exposed to AQ via ingestion or dissolved or suspended in the water column.     

Managing faba bean residues to enhance the fruit quality of the melon (Cucumis melo L.) crop

Mulching and/or topsoil incorporation of plant residues from green manure legumes can increase cropping system sustainability, and can supply and retain nutrients. Two field experiments were conducted in Italy over the period of 2006–2007, to investigate the effect of faba bean grown in a temperate environment to fruit morphology, quality and chemical composition of the subsequent melon (Cucumis melo L.) crop. Flowering faba bean plants were managed as mulch on the melon plant rows and cut and incorporated into the soil, in comparison with cultivated soil (control) and black plastic mulch.     

Treatment of a malignant pheochromocytoma in a dog using 131I metaiodobenzylguanidine

A 12 yr old castrated male Yorkshire terrier was presented with a history of an inoperable pheochromocytoma. Physical examination revealed a large, midabdominal mass. Neurologic examination was normal at presentation. An abdominal computed tomography scan revealed a 215 cm(3) mass in the region of the right kidney. Forty-eight hours after IV injection of 370 megabecquerels (MBq, equivalent to10 millicuries [mCi]) of metaiodobenzylguanidine labeled with radioactive iodine ([(131)I]MIBG), standard planar scintigraphy was performed. A diffuse area of moderate uptake was noted in the midabdominal region. The dog experienced stable disease for 1.5 mo after injection based on a follow-up computed tomography (CT) scan; however, 5 mo after injection, repeat CT imaging revealed progression of the tumor, and a second IV injection of 370 MBq (10 mCi) of [(131)I]MIBG was administered. The dog died 3 wk after the second injection as a result of gastrointestinal blood loss that was believed to be caused by compression-induced bowel ischemia by the mass. A full necropsy was not performed, but the mass was removed for histologic evaluation, which confirmed the diagnosis of pheochromocytoma. This report is the first to document the treatment of canine pheochromocytoma using [(131)I]MIBG.     

Magnetic resonance and computed tomographic features of 4 cases of canine congenital thoracic vertebral anomalies

Magnetic resonance and computed tomography features of 4 cases of canine congenital vertebral anomalies (CVAs) are discussed. Two of the cases represent unusual presentations for such anomalies that commonly affect screw-tail or toy breeds. Moreover, the combination of CVAs and a congenital peritoneo-pericardial diaphragmatic hernia has never before been imaged.