Planktonic foraminifera abundances and isotopes of Late Quaternary sediments off New Zealand

A series of cores from east of New Zealand have been examined to determine the paleoceanographic history of the late Quaternary in the SW Pacific using planktonic foraminiferal data. Distinct shifts of species can be seen between glacial and interglacial times especially south of Chatham Rise east of South Island. Foraminiferal fragmentation ratios and benthic/planktonic foraminiferal ratios both show increased dissolution during glacials, especially isotope stage 2 to the south of Chatham Rise. The present-day Subtropical Convergence appears to be tied to the Chatham Rise at 44°S, but during glacial times this rise separated cold water to the south from much warmer water to the north, with an associated strong thermal gradient across the rise. We estimate that this gradient could have presented as much as an 8°C temperature change across 4° of latitude during the maximum of the last ice age. There is only weak evidence of the Younger Dryas cool event, but there is a clear climatic optimum between 8 and 6.4 ka with temperatures 1°-2°C higher than the present day. The marine changes compare well with vegetational changes on both South and North Island.

Planktic foraminifera abundances and winter SST reconstruction for sediment core SO90-39KG

The Indian winter monsoon (IWM) is a key component of the seasonally changing monsoon system that affects the densely populated regions of South Asia. Cold winds originating in high northern latitudes provide a link of continental-scale Northern Hemisphere climate to the tropics. Western Disturbances (WD) associated with the IWM play a critical role for the climate and hydrology in northern India and the western Himalaya region. It is vital to understand the mechanisms and teleconnections that influence IWM variability to better predict changes in future climate. Here we present a study of regionally calibrated winter (January) temperatures and according IWM intensities, based on a planktic foraminiferal record with biennial (2.55 years) resolution. Over the last ~250 years, IWM intensities gradually weakened, based on the long-term trend of reconstructed January temperatures. Furthermore, the results indicate that IWM is connected on interannual- to decadal time scales to climate variability of the tropical and extratropical Pacific, via El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). However, our findings suggest that this relationship appeared to begin to decouple since the beginning of the 20th century. Cross-spectral analysis revealed that several distinct decadal-scale phases of colder climate and accordingly more intense winter monsoon centered at the years ~1800, ~1890 and ~1930 can be linked to changes of the North Atlantic Oscillation (NAO).

High-resolution electrophoretic procedures for the identification of five Eimeria species from chickens, and detection of population variation

To overcome limitations of conventional approaches for the identification of Eimeria species of chickens, we have established high resolution electrophoretic procedures using genetic markers in ribosomal DNA. The first and second internal transcribed spacer (ITS-1 and ITS-2) regions of ribosomal DNA were amplified by polymerase chain reaction (PCR) from genomic DNA samples representing five species of Eimeria (E. acervulina, E. brunetti, E. maxima, E. necatrix and E. tenella), denatured and then subjected to denaturing polyacrylamide gel electrophoresis (D-PAGE) or single-strand conformation polymorphism (SSCP) analysis. Differences in D-PAGE profiles for both the ITS-1 and ITS-2 fragments (combined with an apparent lack of variation within individual species) enabled the unequivocal identification of the five species, and SSCP allowed the detection of population variation between some isolates representing E. acervulina, which remained undetected by D-PAGE. The establishment of these approaches has important implications for controlling the purity of laboratory lines of Eimeria, for diagnosis and for studying the epidemiology of coccidiosis.

Hospedabilidade de plantas daninhas a Meloidogyne enterolobii.

O objetivo deste trabalho foi avaliar a hospedabilidade de dezesseis espécies de plantas daninhas, Acanthospermum australe, Ageratum conyzoides, Alternanthera tenella, Amaranthus hybridus, A. viridis, Bidens pilosa, Digitaria horizontalis, Eleusine indica, Euphorbia heerophylla, Hyptis sauaveolens, Ipomoea grandifolia, I. nil, Portulaca oleracea, Solanum americanum, Sida cordifolia e tagetes sp. ao nematoide-das-galhas, Meloidogyne enterolobil.

Epidemiological studies on toxoplasma gondii infection in a one health perspective

The objective of the present Ph.D. thesis was to investigate with a One Health approach the epidemiological patterns of T. gondii infection in Italy, to better understand the transmission dynamics of the parasite, following different research lines. The results of a retrospective analysis in animals and human showed the widespread distribution of T. gondii in the study area, with specific antibodies found in various animal species and human populations, indicating its constant presence across diverse environments. The environment plays a significant role in T. gondii's epidemiology. Migratory aquatic birds, rodents, wolves, and wild boars were investigated as sentinels of their spread, highlighting the potential transmission across geographic areas and infection risks for wildlife in natural settings. The study also provided insights into seroprevalence in wolves. Dogs, subjected to serological investigations exhibited risk factors for T. gondii infection, such as cohabitation with cats, coprophagy behaviours, and continuous outdoor. Correlation between serological evidence of exposure to T. gondii and pathological anxiety in large-size dogs was observed, and the consumption of raw meat was associated with a higher risk of infection in these animals. Results of the investigations conducted in this thesis, demonstrate the dynamic nature of T. gondii infection in cattle, characterized by new infections and declining antibody levels over the production cycle. The study also describes a co-infection between T. gondii and Sarcocystis hominis in bovine eosinophilic myositis. In the final part of the Thesis, a comprehensive genotyping of T. gondii in Italy reveals the predominance of Type II strains, particularly in cases of ovine abortion and fatal toxoplasmosis among captive Lemur catta. This approach enhances our understanding of the parasite's genetic diversity and transmission patterns, vital for effective management of its impact on human and animal health in Italy.