641 research outputs found
Impact of urbanization on predator and parasitoid insects at multiple spatial scales
Landscapes are becoming increasingly urbanized, causing loss and fragmentation of natural habitats, with potentially negative effects on biodiversity. Insects are among the organisms with the largest diversity in urbanized environments. Here, we sampled predator (Ampulicidae, Sphecidae and Crabronidae) and parasitoid (Tachinidae) flower-visiting insects in 36 sites in the city of Rome (Italy). Although the diversity of herbivorous insects in urban areas mostly depends on the availability of flowering plants and nesting sites, predators and parasitoids generally require a larger number of resources during their life cycle, and are expected to be particularly influenced by urbanization. As flower-visitors can easily move between habitat patches, the effect of urbanization was tested at multiple spatial scales (local, landscape and sub-regional). We found that urbanization influenced predator and parasitoid flower-visitors at all three spatial scales. At the local scale, streets and buildings negatively influenced evenness of predators and species richness and abundance of parasitoids probably acting as dispersal barrier. At the landscape scale, higher percentage of urban decreased predator abundance, while increasing their evenness, suggesting an increase in generalist and highly mobile species. Area and compactness (i.e. Contiguity index) of urban green interactively influenced predator communities, whereas evenness of parasitoids increased with increasing Contiguity index. At the sub-regional scale, species richness and abundance of predators increased with increasing distance from the city center. Compared to previous studies testing the effect of urbanization, we found little variation in species richness, abundance and evenness along our urbanization gradient. The current insect fauna has been probably selected for its tolerance to habitat loss and fragmentation, being the result of the intensive anthropogenic alteration occurred in the area in the last centuries. Conservation strategies aimed at predator and parasitoid flying insects have to take in account variables at multiple spatial-scales, as well as the complementarity of resources across the landscape
Nuovi approcci basati su TRAIL ed MSC per la terapia delle malattie oncoematologiche
TNF-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily
of cytokines, including 18 genes which code 19 transmembrane proteins,
strictly correlated, and playing important roles in: cell death regulation, immune
response and inflammation. In humans at least 5 different TRAIL receptors have been
described belonging to the TNF-R family, each one expressed in different cellular lines.
TRAIL-R1 (DR4) and TRAIL-R2 (DR5) transduce apoptotic signals, while TRAIL-R3
(DcR1), TRAIL-R4 (DcR2) and osteoprotegerina (OPG) are decoy receptors unable to
induce cellular death.
Significant levels of TRAIL have been detected in many human tissues, including
spleen, prostate, lungs, thymus, kidney, intestine, ovary and, at lower levels, heart,
skeletal muscle cells, pancreas, liver, brain and testicle. One of the primary functions
of TRAIL is to induce apoptosis in numerous transformed cell lines and cancer cells in
vivo, without significant cytotoxicity on normal cells or tissues.
With the aim to identify antitumor agents, we have focused our attention on the
therapeutic potential of TRAIL. During the last three years, we tested new strategies
based on TRAIL in order to induce death selectively in neoplastic cells which have
developed resistance to conventional treatment. For this purpose we conducted a set
of studies in vitro and in vivo employing recombinant TRAIL.
Furthermore our research has concentrated on the therapeutic efficacy of human
bone marrow (BM) mesenchymal stem cells (MSC), which are considered the stromal
progenitor stem cells within the bone marrow. Our objective was to explore the
antitumor activity of these cells and to describe the mechanisms causing this effect.
The development of an animal model in SCID (Severe Combined
Immunodeficiency) mice of Non-Hodgkin lymphoma (NHL) was necessary in order to
investigate the in vivo dissemination of cancer cells and to assess the therapeutic
efficacy of recombinant TRAIL and BM-MSC. These models were established by intraperitoneal
(i.p.) injection of EBV- Burkitt-type BJAB and EBV+ B lymphoblastoid
SKW6.4 cell lines. Xenografts mice were then i.p. injected on the opposite site with
either human recombinant TRAIL or BM-MSC at a lymphoma:MSC assessing mice
survival after the treatment.
The results reported in this paper demonstrate that both treatments reduce the
growth of the tumoral masses, with a consequent significantly higher rate of mice
survival.
Furthermore, similar results were obtained when mesenchimal stem cells,
previously embedded in hyaluronan scaffolds to avoid the integration of mesenchymal
cells in the fibrovascular cancer network, were implanted in mice. Interestingly, this
hyaluronan-embedded MSC exert anti-lymphoma activity by ameliorating hepatic
functionality, as demonstrated by measurement of serum ALT/AST levels.
In conclusion, our research suggests that both strategies, i.e. rTRAIL and
mesenchymal stem cells can exert antitumoral activity and are good candidate for
development of new therapies
Noise fingerprints in quantum computers: Machine learning software tools
In this paper we present the high-level functionalities of a
quantum-classical machine learning software, whose purpose is to learn the main
features (the fingerprint) of quantum noise sources affecting a quantum device,
as a quantum computer. Specifically, the software architecture is designed to
classify successfully (more than 99% of accuracy) the noise fingerprints in
different quantum devices with similar technical specifications, or distinct
time-dependences of a noise fingerprint in single quantum machines.Comment: 9 pages, 2 figure
Role of Solar Irradiance Fluctuations on Optimal Solar Sail Trajectories
The aim of this work is to provide a systematic analysis for quantifying the impact of TSI fluctuations on minimum-time solar sail trajectories, in order to investigate the actual need of a control law able to counteract the environmental uncertainties
Physical Exercise and Appetite Regulation: New Insights
Physical exercise is considered an important physiological intervention able to prevent cardiovascular diseases, obesity, and obesity-related cardiometabolic imbalance. Nevertheless, basic molecular mechanisms that govern the metabolic benefits of physical exercise are poorly understood. Recent data unveil new mechanisms that potentially explain the link between exercise, feeding suppression, and obesity
Fungal diversity and specificity in Cephalanthera damasonium and C. longifolia (Orchidaceae) mycorrhizas
Serum levels of total IgE and soluble CD23 in bronchial asthma
The aim of the present study was to compare, during the pollen season, serum levels of total IgE and soluble CD23 (sCD23) from patients with allergic bronchial asthma, with those from healthy subjects. Significantly higher levels of total IgE and sCD23 were found in patients with asthma compared to the control group. Both in normal controls and in asthmatic patients, a significant correlation was shown between the levels of these two molecules. In asthmatic patients, significant correlations were found for both total IgE and sCD23, with lung function measured as bronchial responsiveness to inhaled methacholine. These results suggest that in asthmatic patients, in addition to the study of total serum IgE levels, the assessment of sCD23 serum levels may be helpful in the evaluation of disease activity
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