585 research outputs found
Osservazione e modellazione del deflusso sottosuperficiale laterale saturo in un ripido versante naturale
I versanti sono unità morfologiche fondamentali che governano la risposta idrologica
dei bacini idrografici durante le precipitazioni più intense. Nonostante la loro
riconosciuta importanza idrologica, è ancora necessario condurre approfonditi studi,
sia a carattere sperimentale che teoretico, per meglio comprendere i meccanismi di
generazione e trasporto del deflusso sottosuperficiale laterale saturo nei versanti. In
questo contributo sono presentati i risultati di un monitoraggio di lungo periodo del
flusso laterale di falda intercettato per mezzo di una trincea drenante installata su
d’un ripido versante naturale nel bacino del Lago di Baratz, Sardegna. I dati raccolti
vengono utilizzati per sviluppare una relazione di tipo esponenziale tra la conducibilitÃ
idraulica laterale satura (KS) e lo spessore della falda (T), valida alla scala di
versante. I flussi osservati e i livelli di falda sono simulati con un modello numerico
orizzontale 1D, basato sulla soluzione simultanea della legge del moto e dell’equazione
di bilancio idrico, e implementato tramite uno schema risolutivo alle differenza
finite. Le principali assunzioni del modello sono che nel suolo il flusso sottosuperficiale
saturo sia regolato dalla legge di Darcy, e che si verifichi sempre l’istantaneo
raggiungimento di un profilo di equilibrio idrostatico del carico di suzione nella
zona vadosa. Il modello richiede la specifica della curva di ritenzione idrica del
suolo e della relazione KS(T) ottenute sperimentalmente. I risultati della simulazione
indicano che il modello è in grado di riprodurre in modo adeguato i dati osservati. Il
flusso di falda è ben riprodotto, sia in termini di tempi di risposta che di portate drenate.
Pertanto, il modello sviluppato può essere un utile strumento di previsione
della risposta idrologica in versanti naturali a forte pendenza
Large-scale lateral saturated soil hydraulic conductivity as a metric for the connectivity of subsurface flow paths at hillslope scale
Lateral saturated soil hydraulic conductivity, Ks,l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes at the hillslope and catchment scales. Likewise, the hydrological connectivity of the lateral flow paths plays a significant role in determining the rate of the subsurface flow at various spatial scales. This study investigates the relationship between Ks,l and hydrological connectivity at the hillslope spatial scale. Ks,l was determined by the subsurface flow rates intercepted by drains and water table depths observed in a well network. The hydrological connectivity was evaluated by the synchronicity among water table peaks, and between these and the peaks of the drained flow. Rainfall and soil moisture were used to investigate the influence of the transient hydrological soil condition on connectivity and Ks,l. As the synchronicity of the water table response between wells increased, the lag times between the peaks of water levels and those of the drained subsurface flow decreased. Moreover, the most synchronic water table rises determined the highest drainage rates. The relationships between Ks,l and water table depths were highly non-linear, with a sharp increase in the values for water table levels close to the soil surface. Estimated Ks,l values for the full saturated soil were in the order of thousands of mm h−1, suggesting the activation of macropores in the root zone. The Ks,l values determined at the peak of the drainage events were correlated with the indicators of synchronicity. The sum of cumulative rainfall and antecedent soil moisture was correlated with the connectivity indicators and Ks,l. We suggest that, for simulating realistic processes at the hillslope scale, the hydrological connectivity could be implicitly considered in hydrological modelling through an evaluation of Ks,l at the same spatial scale
SCHEMA SPERIMENTALE PER LA STIMA DELLA CONDUCIBILITÀ IDRAULICA LATERALE ALLA SCALA DI VERSANTE
La conducibilità idraulica alla saturazione, KS, è un parametro fondamentale per
la simulazione del flusso idrico nel suolo. La memoria illustra un approccio sperimentale
per la stima della KS laterale alla scala di versante. La metodologia proposta
è stata applicata in due aree contigue ricoperte, rispettivamente, da macchia mediterranea
e prato. Sono stati registrati i livelli di falda e i deflussi idrici sottosuperficiali,
e queste misure sono state usate per il calcolo della KS del suolo tramite l’equazione
di Darcy. Il monitoraggio è stato effettuato durante il periodo piovoso compreso tra
gennaio e giugno 2014. In aprile, inoltre, sono state eseguite prove di pioggia artificiale
con intensità di 30 e 70 mm h-1. Durante le precipitazioni naturali, il valore massimo
di KS stimato nel prato è stato di 2870 mm h-1, mentre è stato pari a 2400 mm h-1
nel corso delle prove di saturazione artificiale. Il valore massimo di KS pari 4000 mm
h-1 è stato ottenuto, nella macchia, durante le prove di pioggia artificiale. Per contro,
valori minori di KS sono stati ottenuti durante le piogge naturali a causa delle basse
portate sottosuperficiali registrate. La metodologia proposta è risultata idonea per la
stima di valori della conducibilità idraulica rappresentativi per le aree di interesse.
Tali informazioni potranno garantire una maggiore attendibilità della modellizzazione
dei processi idrologici a scala di versante e di bacino
FOOD SAFETY AND PROCESS HYGIENE CRITERIONS ON SHEEP CARCASSES
The hygienic status and the presence of some pathogens (Staphylococcus aureus, Listeria monocytogenes e Salmonella spp.) at slaughterhouses was evaluated in different matrix of sheep and lambs (carcass surface, faeces, fleeces and mesenteric lymph nodes) according to the Com. Reg. (EC) No 2073/2005. The 48% of sheep and 68.9% of lamb sampled carcasses resulted allocated into the marginal category for Aerobic colony count, while the 28% and 42.2% respectively were allocated into unacceptable category for Enterobacteriaceae. S.aureus was isolated more frequently in fleeces (11.5%), carcasses (12.6%) of lambs than sheep. L. monocytogenes was found in fleeces and carcass of two sheep and in faeces of four lambs, while Salmonella spp. was detected only in sheep carcasses of a single plant
Impaired sense of smell in a Drosophila Parkinson's model.
Parkinson’s disease (PD) is one of the most common neurodegenerative disease characterized by the clinical triad: tremor, akinesia and rigidity. Several studies have suggested that PD patients show disturbances in olfaction at the earliest onset of the disease. The fruit fly Drosophila melanogaster 32 is becoming a powerful model organism to study neurodegenerative diseases. We sought to use this system to explore olfactory dysfunction, if any, in PINK1 mutants, which is a model for PD. PINK1 mutants display many important diagnostic symptoms of the disease such as akinetic motor behavior. In the present study, we describe for the first time, to the best of our knowledge, neurophysiological and neuroanatomical results concerning the olfactory function in PINK1 mutant flies. Electroantennograms were recorded in response to synthetic and natural volatiles (essential oils) from groups of PINK1 mutant adults at three different time points in their life cycle: one from 3-5 day-old flies, from 15-20 and from 27-30 days. The results obtained were compared with the same age-groups of wild type flies. We found that mutant adults showed a decrease in the olfactory response to 1-hexanol, α-pinene and essential oil volatiles. This olfactory response in mutant adults decreased even more as the flies aged. Immunohistological analysis of the antennal lobes in these mutants revealed structural abnormalities, especially in the expression of Bruchpilot protein, a marker for synaptic active zones. The combination of electrophysiological and morphological results suggests that the altered synaptic organization may be due to a neurodegenerative process. Our results indicate that this model can be used as a tool for understanding PD pathogensis and pathophysiology. These results help to explore the potential of using olfaction as a means of monitoring PD progression and developing new treatments
Mucuna pruriens (Velvet bean) Rescues Motor, Olfactory, Mitochondrial and Synaptic Impairment in PINK1(B9) Drosophila melanogaster Genetic Model of Parkinson's Disease
The fruit fly Drosophila melanogaster (Dm) mutant for PTEN-induced putative kinase 1 (PINK1B9) gene is a powerful tool to investigate physiopathology of Parkinson's disease (PD). Using PINK1B9 mutant Dm we sought to explore the effects of Mucuna pruriens methanolic extract (Mpe), a L-Dopa-containing herbal remedy of PD. The effects of Mpe on PINK1B9 mutants, supplied with standard diet to larvae and adults, were assayed on 3–6 (I), 10–15 (II) and 20–25 (III) days old flies. Mpe 0.1% significantly extended lifespan of PINK1B9 and fully rescued olfactory response to 1-hexanol and improved climbing behavior of PINK1B9 of all ages; in contrast, L-Dopa (0.01%, percentage at which it is present in Mpe 0.1%) ameliorated climbing of only PINK1B9 flies of age step II. Transmission electron microscopy analysis of antennal lobes and thoracic ganglia of PINK1B9 revealed that Mpe restored to wild type (WT) levels both T-bars and damaged mitochondria. Western blot analysis of whole brain showed that Mpe, but not L-Dopa on its own, restored bruchpilot (BRP) and tyrosine hydroxylase (TH) expression to age-matched WT control levels. These results highlight multiple sites of action of Mpe, suggesting that its effects cannot only depend upon its L-Dopa content and support the clinical observation of Mpe as an effective medication with intrinsic ability of delaying the onset of chronic L-Dopa-induced long-term motor complications. Overall, this study strengthens the relevance of using PINK1B9 Dm as a translational model to study the properties of Mucuna pruriens for PD treatment
(1)H-NMR analysis provides a metabolomic profile of patients with multiple sclerosis
OBJECTIVE: To investigate the metabolomic profiles of patients with multiple sclerosis (MS) and to define the metabolic pathways potentially related to MS pathogenesis.
METHODS: Plasma samples from 73 patients with MS (therapy-free for at least 90 days) and 88 healthy controls (HC) were analyzed by (1)H-NMR spectroscopy. Data analysis was conducted with principal components analysis followed by a supervised analysis (orthogonal partial least squares discriminant analysis [OPLS-DA]). The metabolites were identified and quantified using Chenomx software, and the receiver operating characteristic (ROC) curves were calculated.
RESULTS: The model obtained with the OPLS-DA identified predictive metabolic differences between the patients with MS and HC (R2X = 0.615, R2Y = 0.619, Q2 = 0.476; p < 0.001). The differential metabolites included glucose, 5-OH-tryptophan, and tryptophan, which were lower in the MS group, and 3-OH-butyrate, acetoacetate, acetone, alanine, and choline, which were higher in the MS group. The suitability of the model was evaluated using an external set of samples. The values returned by the model were used to build the corresponding ROC curve (area under the curve of 0.98).
CONCLUSION: NMR metabolomic analysis was able to discriminate different metabolic profiles in patients with MS compared with HC. With the exception of choline, the main metabolic changes could be connected to 2 different metabolic pathways: tryptophan metabolism and energy metabolism. Metabolomics appears to represent a promising noninvasive approach for the study of M
Differential effects of phytotherapic preparations in the hSOD1 Drosophila melanogaster model of ALS
The present study was aimed at characterizing the effects of Withania somnifera (Wse) and Mucuna pruriens (Mpe) on a Drosophila melanogaster model for Amyotrophic Lateral Sclerosis (ALS). In particular, the effects of Wse and Mpe were assessed following feeding the flies selectively overexpressing the wild human copper, zinc-superoxide dismutase (hSOD1-gain-of-function) in Drosophila motoneurons. Although ALS-hSOD1 mutants showed no impairment in life span, with respect to GAL4 controls, the results revealed impairment of climbing behaviour, muscle electrophysiological parameters (latency and amplitude of ePSPs) as well as thoracic ganglia mitochondrial functions. Interestingly, Wse treatment significantly increased lifespan of hSDO1 while Mpe had not effect. Conversely, both Wse and Mpe significantly rescued climbing impairment, and also latency and amplitude of ePSPs as well as failure responses to high frequency DLM stimulation. Finally, mitochondrial alterations were any more present in Wse-but not in Mpe-Treated hSOD1 mutants. Hence, given the role of inflammation in the development of ALS, the high translational impact of the model, the known anti-inflammatory properties of these extracts, and the viability of their clinical use, these results suggest that the application of Wse and Mpe might represent a valuable pharmacological strategy to counteract the progression of ALS and related symptom
Functional and morphological correlates in the drosophila LRRK2 loss-of-function model of Parkinson's disease: drug effects of Withania somnifera (Dunal) administration
The common fruit fly Drosophila melanogaster (Dm) is a simple animal species that contributed significantly to the development of neurobiology whose leucine-rich repeat kinase 2 mutants (LRRK2) loss-of-function in the WD40 domain represent a very interesting tool to look into physiopathology of Parkinson's disease (PD). Accordingly, LRRK2 Dm have also the potential to contribute to reveal innovative therapeutic approaches to its treatment. Withania somnifera Dunal, a plant that grows spontaneously also in Mediterranean regions, is known in folk medicine for its anti-inflammatory and protective properties against neurodegeneration. The aim of this study was to evaluate the neuroprotective effects of its standardized root methanolic extract (Wse) on the LRRK2 loss-of-function Dm model of PD. To this end mutant and wild type (WT) flies were administered Wse, through diet, at different concentrations as larvae and adults (L+/A+) or as adults (L-/A+) only. LRRK2 mutants have a significantly reduced lifespan and compromised motor function and mitochondrial morphology compared toWT flies 1% Wse-enriched diet, administered to Dm LRRK2 as L-/A+and improved a) locomotor activity b) muscle electrophysiological response to stimuli and also c) protected against mitochondria degeneration. In contrast, the administration of Wse to Dm LRRK2 as L+/A+, no matter at which concentration, worsened lifespan and determined the appearance of increased endosomal activity in the thoracic ganglia. These results, while confirming that the LRRK2 loss-of-function in the WD40 domain represents a valid model of PD, reveal that under appropriate concentrations Wse can be usefully employed to counteract some deficits associated with the disease. However, a careful assessment of the risks, likely related to the impaired endosomal activity, is require
The Wikiplantbase project: the role of amateur botanists in building up large online floristic databases
The Wikiplantbase project, started in 2013, provides a framework where the full set of georeferenced floristic records of Tuscany and Sardinia can be entered, stored, updated and freely
accessed through the Internet. Mainly thanks to the collaboration of amateur botanists, data
have accumulated quickly. All records entered by collaborators are submitted to the project
coordinators, who are enabled to accept, modify, or reject them. As of 22 November 2016,
Wikiplantbase #Toscana holds 116,402 verified floristic records (90% based on published literature, 5% on unpublished herbarium specimens, 5% on field observations), and Wikiplantbase
#Sardegna 40,043 (77% published literature, 18% unpublished herbarium specimens, 5% on
field observations ). The records include over 90% of the specific and subspecific taxa known
for Tuscany and about 70% – but rapidly growing – of those known for Sardinia. The most
recorded species are Quercus ilex L. (Fagaceae) for Tuscany and Pistacia lentiscus L.
(Anacardiaceae) for Sardinia. With minor software tweaking, the online platform
Wikiplantbase might be adopted in other contexts, resulting in a well connected network of
regional floristic databases suited to exploit the involvement – still largely untapped – of nonacademic collaborators, as advocated by citizen science
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