249 research outputs found
Le api svelano il mistero delle fonti di emissione di particolato inquinante
Si tratta di una ricerca che è durata due anni, ed è stata pubblicata sul numero di luglio 2015 della Rivista scientifica internazionale Plos One. Gli autori: Ilaria Negri, Marco Pellecchia (Koiné - Consulenze Ambientali S.n.c., Parma, Italy), Christian Mavris (Department of Earth Sciences, Natural History Museum, London, United Kingdom), Gennaro Di Prisco, Emilio Caprio (Dipartimento di Agraria, Laboratorio di Entomologia E. Tremblay, Università degli Studi di Napoli Federico II, Portici - Napoli). Nello studio scientifico i ricercatori dimostrano che le api si comportano anche come “campionatori” attivi di particolato atmosferico, i cosiddetti
PM (dall’inglese “Particulate Matter”), di cui sono ricche le nostre città come troppo spesso avvertono i dati dell’Agenzia Regionale di Protezione dell’Ambiente (ARPA). Dice che l’Iglesiente (Iglesias, Sardegna) è inquinato, fortemente contaminato da metalli pesanti come il piombo e il bario. E svela poi che la salute di chi ci vive potrebbe essere compromessa, se non lo è già, anche dall’alta concentrazione di ferro, silicio e alluminio. Rivela ancora, con scientifica precisione, da dove provengono le micro particelle di queste impercettibilissime polveri: dalle miniere dell’Iglesiente e dalle industrie di Portovesm
Honeybees' physiological and behavioural immunity deficit induced by DW Viruses
Item does not contain fulltextThe purpose of the present study was to determine the effect of a spinal cord injury (SCI) on resting vascular resistance in paralyzed legs in humans. To accomplish this goal, we measured blood pressure and resting flow above and below the lesion (by using venous occlusion plethysmography) in 11 patients with SCI and in 10 healthy controls (C). Relative vascular resistance was calculated as mean arterial pressure in millimeters of mercury divided by the arterial blood flow in milliliters per minute per 100 milliliters of tissue. Arterial blood flow in the sympathetically deprived and paralyzed legs of SCI was significantly lower than leg blood flow in C. Because mean arterial pressure showed no differences between both groups, leg vascular resistance in SCI was significantly higher than in C. Within the SCI group, arterial blood flow was significantly higher and vascular resistance significantly lower in the arms than in the legs. To distinguish between the effect of loss of central neural control vs. deconditioning, a group of nine SCI patients was trained for 6 wk and showed a 30% increase in leg blood flow with unchanged blood pressure levels, indicating a marked reduction in vascular resistance. In conclusion, vascular resistance is increased in the paralyzed legs of individuals with SCI and is reversible by training
Varroa destructor is an effective vector of Israeli acute paralysis virus in the honeybee, Apis mellifera.
The Israeli acute paralysis virus (IAPV) is a significant marker of honeybee colony collapse disorder (CCD). In the present work, we provide the first evidence that Varroa destructor is IAPV replication-competent and capable of vectoring IAPV in honeybees. The honeybees became infected with IAPV after exposure to Varroa mites that carried the virus. The copy number of IAPV in bees was positively correlated with the density of Varroa mites and time period of exposure to Varroa mites. Further, we showed that the mite-virus association could possibly reduce host immunity and therefore promote elevated levels of virus replication. This study defines an active role of Varroa mites in IAPV transmission and sheds light on the epidemiology of IAPV infection in honeybees
Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation
The neonicotinoid Clothianidin has a negative impact on NF-\u3baB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees
Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation
The neonicotinoid Clothianidin has a negative impact on NF-κB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees
Pan-european assessment, monitoring, and mitigation of stressors on the health of bees
As part of the activities foreseen by the POSHBEE project, we performed experiments to verify the
toxicokinetics of three pesticides (the insecticide sulfoxaflor, the fungicide azoxystrobin and the
herbicide glyphosate) in the bodies of social bees (Apis mellifera and Bombus terrestris) and solitary
bees (Osmia bicornis). For each species all castes and sexes were studied. Based on the results from
dose-response assays, sublethal doses were used to treat individuals, which were exposed to the
chosen pesticides orally and by contact. Bees were then sampled at multiple time points post-
exposure, to capture the breakdown of the active ingredients in the bodies of the organisms. Results
of the chemical analyses on bee samples were used for the evaluation of the dynamics of the oral
and contact acute exposure in the three species. Overall, the active ingredients sulfoxaflor, azoxystrobin and glyphosate degrade in all species, sex or
caste. Nevertheless, there were some exceptions: in honey bee workers, glyphosate administered
topically and azoxystrobin administered via the oral route seemed to remain stable in the bees’
bodies even 10 days after exposure (11% and 13% of degradation rate, respectively). We also
observed a low degradation of sulfoxaflor following topical exposure in bumble bee queens (26% of
degradation rate) and in Osmia bee females (22% of degradation rate). In bumble bees exposed
topically to glyphosate degradation was lower than 50% for all sexes and castes. These results
deserve further attention by researchers to understand the destiny of these molecules in the bee
body and their effects therein.Prepared under contract from the European Commission; Grant agreement No. 773921; EU Horizon 2020 Research and Innovation action.Prepared under contract from the European Commission; Grant agreement No. 773921; EU Horizon 2020 Research and Innovation actio
MWCNT/rGO/natural rubber latex dispersions for innovative, piezo‐resistive and cement‐based composite sensors
The present study is focused on the development and characterization of innovative cementitious-based composite sensors. In particular, multifunctional cement mortars with enhanced piezoresistive properties are realized by exploiting the concept of confinement of Multiwall Carbon Nanotubes (MWCNTs) and reduced Graphene Oxide (rGO) in a three-dimensional percolated network through the use of a natural-rubber latex aqueous dispersion. The manufactured cement-based composites were characterized by means of Inelastic Neutron Scattering to assess the hydration reactions and the interactions between natural rubber and the hydrated-cement phases and by Scanning Electron Microscopy and X-Ray diffraction to evaluate the morphological and mineralogical structure, respectively. Piezo-resistive properties to assess electro-mechanical behavior in strain condition are also measured. The results show that the presence of natural rubber latex allows to obtain a three-dimensional rGO/MWCNTs segregate structure which catalyzes the formation of hydrated phases of the cement and increases the piezo-resistive sensitivity of mortar composites, representing a reliable approach in developing innovative mortar-based piezoresistive strain sensors
is 18f fluorodeoxyglucose uptake by the primary tumor a prognostic factor in breast cancer
Abstract Background We retrospectively investigated 18F-FDG uptake by the primary breast tumor as a predictor for relapse and survival. Patients and methods We studied 203 patients with cT1-T3N0 breast cancer. Standardized uptake value (SUVmax), was measured on the primary tumor. After a median follow-up of 68 months (range 22–80), the relation between SUVmax and tumor factors, disease free-survival (DFS) and overall survival (OS) was investigated. Results In the PET-positive patients, the median FDG uptake by the tumor was 4.7. FDG uptake was significantly related to tumor size, number of involved axillary nodes, grade, negative ER, high Ki-67 and HER2 overexpression. No distant metastases or deaths occurred in the PET-negative group. Five-year DFS was 97% and 83%, respectively in the PET-negative and PET-positive groups (P = 0.096). At univariate analysis, DFS was significantly lower in patients with SUVmax >4.7 compared to the patients with negative PET (P = 0.042), but not to the patients with SUVmax ≤4.7 (P = 0.106). At multivariable analysis, among PET-positive patients, SUVmax was not an independent prognostic factor for DFS (HR>4.7 vs ≤4.7: 1.02 (95% CI 0.45–2.31)). Five-year OS was 100% and 93%, respectively, in the PET-negative and PET-positive groups (P = 0.126). Conclusion FDG uptake by the primary lesion was significantly associated with several prognostic variables, but it was not an independent prognostic factor
Influence of chronic exposure to thiamethoxam and chronic bee paralysis virus on winter honey bees.
Co-exposure to pesticides and viruses is likely to occur in honey bee colonies. Pesticides can be present in pollen, nectar, and persist in stored food (honey and bee bread), and viruses can be highly prevalent in honey bee colonies. Therefore, the present study describes the influence of chronic co-exposure to thiamethoxam and Chronic bee paralysis virus (CBPV) on bee survival, virus loads, expression level of immune and detoxication genes, and pesticide metabolism Experiments were performed on honey bees collected from a winter apiary with reduced viral contaminations. No synergistic effect of co-exposure was observed on bee survival, nor on the ability of bees to metabolise the pesticide into clothianidin. However, we found that co-exposure caused an increase in CBPV loads that reached the viral levels usually found in overt infections. The effect of co-exposure on CBPV replication was associated with down-regulation of vitellogenin and dorsal-1a gene transcription. Nevertheless, the observed effects might be different to those occurring in spring or summer bees, which are more likelyco-exposed to thiamethoxam and CBPV and exhibit a different physiology
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