The influence of landslide shape and continental shelf on landslide generated tsunamis along a plane beach

This work proposes an advancement in analytical modelling of landslide tsunamis propagating along a plane beach. It is divided into two parts. In the first one, the analytical two-horizontal-dimension model of Sammarco and Renzi (2008) for tsunamis generated by a Gaussian-shaped landslide on a plane beach is revised and extended to realistic landslide shapes. The influence of finiteness and shape of the slide on the propagating waves is investigated and discussed. In the second part, a new model of landslide tsunamis propagating along a semi-plane beach is devised to analyse the role of the continental platform in attenuating the wave amplitude along the shoreline. With these parameters taken into account, the fit with available experimental data is enhanced and the model completed

Validation of a microwave radar system for the monitoring of locomotor activity in mice

BACKGROUND: The general or spontaneous motor activity of animals is a useful parameter in chronobiology. Modified motion detectors can be used to monitor locomotor activity rhythms. We modified a commercial microwave-based detection device and validated the device by recording circadian and ultradian rhythms. METHODS: Movements were detected by microwave radar based on the Doppler effect. The equipment was designed to detect and record simultaneously 12 animals in separate cages. Radars were positioned at the bottom of aluminium bulkheads. Animal cages were positioned above the bulkheads. The radars were connected to a computer through a digital I/O board. RESULTS: The apparatus was evaluated by several tests. The first test showed the ability of the apparatus to detect the exact frequency of the standard moving object. The second test demonstrated the stability over time of the sensitivity of the radars. The third was performed by simultaneous observations of video-recording of a mouse and radar signals. We found that the radars are particularly sensitive to activities that involve a displacement of the whole body, as compared to movement of only a part of the body. In the fourth test, we recorded the locomotor activity of Balb/c mice. The results were in agreement with published studies. CONCLUSION: Radar detectors can provide automatic monitoring of an animal's locomotor activity in its home cage without perturbing the pattern of its normal behaviour or initiating the spurt of exploration occasioned by transfer to a novel environment. Recording inside breeding cages enables long-term studies with uninterrupted monitoring. The use of electromagnetic waves allows contactless detection and freedom from interference of external stimuli

Circadian and ultradian rhythms in locomotory activity of inbred strains of mice

In this study we recorded locomotor activity of two inbred of mice (B6 and C) in two photoperiod conditions (LD 12:12 and DD) to characterize behavioural parameters of the endogenous rhythms of locomotor activity with particular attention to the ultradian rhythms. Literature reveals discordant data for these parameters, both for animals belonging to the same strain and to those in the same laboratory or monitored in the same conditions. Our results show that C strain has a shorter and unstable endogenous circadian period, while B6 strain has a longer and stable endogenous rhythm. In our study, B6 showed a longer and stable period than C, so we can confirm the presence of a genetic component underlying this trait. Ultradian rhythms are expressed independently of either the photoperiod or the circadian rhythm. There are no strain-dependent differences in the periods of 12, 8 and 4 h. The situation was different for the length of the ultradian period in the range 1-8 h and for the weighted power in the ranges 480-300 and 300-100 min, for which there were differences between photoperiods and strains

Recent advances on the mechanisms regulating cholangiocyte proliferation and the significance of the neuroendocrine regulation of cholangiocyte pathophysiology

Cholangiocytes are epithelial cells lining the biliary epithelium. Cholangiocytes play several key roles in the modification of ductal bile and are also the target cells in chronic cholestatic liver diseases (i.e., cholangiopathies) such as PSC, PBC, polycystic liver disease (PCLD) and cholangiocarcinoma (CCA). During these pathologies, cholangiocytes (which in normal condition are in a quiescent state) begin to proliferate acquiring phenotypes of neuroendocrine cells, and start secreting different cytokines, growth factors, neuropeptides, and hormones to modulate cholangiocytes proliferation and interaction with the surrounding environment, trying to reestablish the balance between proliferation/loss of cholangiocytes for the maintenance of biliary homeostasis. The purpose of this review is to summarize the recent findings on the mechanisms regulating cholangiocyte proliferation and the significance of the neuroendocrine regulation of cholangiocyte pathophysiology. To clarify the mechanisms of action of these factors we will provide new potential strategies for the management of chronic liver diseases

Ecotoxicity of marine sediments: Sampling and laboratory artifacts and their impacts on risk classification

Assessing the ecotoxicological risk of marine sediments is now a critical factor in deciding how to treat dredged material in harbor and coastal areas. Although ecotoxicological analyses are routinely required by some regu-latory agencies in Europe, laboratory skills necessary to perform them are often underestimated. According to the Italian Ministerial decree No. 173/2016, ecotoxicological tests are performed on the solid phase and elutriates, and the classification of sediment quality is defined using the "Weight of Evidence" (WOE) approach. However, the decree does not provide adequate information regarding the preparation techniques and laboratory skills. As result, a wide variability among laboratories occurs. An error in the classification of ecotoxicological risk has a negative impact on the whole environmental quality and/or the economy and management of the interested area. Thus, the main aim of this study was to determine if such variability can affect the ecotoxicological out-comes of tested species and WOE associated classification, producing different options for the management of dredged sediments. Four different sediment types were selected to assess the ecotoxicological responses and their changes as a function of variability of the following factors: a) the storage time laps (STL) for both the solid phase and the elutriates; b) the methods used to prepare the elutriates (centrifugation vs. filtration), and the conser-vation method used for the elutriates (freshly prepared vs. freezing). Results suggest a wide variability of eco-toxicological responses among the four sediment samples here considered, differentiated according to chemical pollution, grain-size texture, and macronutrient contents. The storage time laps significantly affect the physi-cochemical parameters and the ecotoxicity of both the solid phase test and elutriates. For the elutriates prepa-ration, centrifugation is preferred to filtration to preserve a better representation of sediment heterogeneity. Freezing of elutriates does not seem to show any significant effects on the toxicity. Findings allow to define a weighted schedule of the storage time of sediments and elutriates useful for laboratories to scale analytical priority and strategies related to different sediment types

An infra-red beam device for the study of the motor activity rhythms on groundwater mysidacea

ItL’attività motoria o locomotoria è un parametro utile per comprendere il funzionamento degli orologi biologici. Gli animali cavernicoli rappresentano un eccellente modello per gli studi cronobiologici oltre che per comprendere l’evoluzione e l’adattamento alla vita sotterranea.Le ricerche in ambito cronobiologico richiedono spesso monitoraggi molto lunghi per i quali è necessario ricorrere all’utilizzo di sistemi automatici. L’obbiettivo primario del presente lavoro consiste nel testare, con animali vivi, il prototipo di un apparato elettronico ad infrarossi appositamente costruito per il monitoraggio dell’attività motoria di animali acquatici di piccole dimensioni. La specie utilizzata in questa ricerca è un misidaceo, Spelaeomysis bottazzii Caroli 1924, proveniente dalla Grotta di San Isidoro (Nardò – LE, Pu/507). La registrazione dell’attività motoria ha riguardato animali mantenuti singolarmente in celle di coltura da 30 ml (5x3x2 cm). L’attività motoria è stata rilevata con un sistema di 9 barriere a luce infrorossa (ciascuna barriera composta da una sorgente e un sensore alle sue estremità). I sensori erano collegati ad un circuito elettronico che inviava i segnali ad un personal computer che a sua volta li archiviava. È stata eseguita un’analisi qualitativa dell’attività motoria dei singoli animali, rappresentandola graficamente per mezzo di attogrammi. Inoltre è stata eseguita un’ analisi quantitativa esplorativa di questi primi dati sull’attività motoria dei misidacei. A tal fine tutte le serie temporali sono state analizzate applicando la trasformata discreta di Fourier (DFT). Sono state eseguite registrazioni per un totale di 20 giorni, 24 ore su 24 (12 gg il primo animale, 4 gg il secondo ed il terzo animale). Durante tale periodo non sono stati riportati problemi di eccessivo surriscaldamento dell’acqua, la componente elettronica (in particolare quella optoelettronica) si è rivelata altamente sensibile e non ha mostrato segni di usura dovuti alle condizioni di utilizzo. Gli animali sono rimasti vivi sino alla conclusione dell’esperimento. L’ispezione visiva degli attogrammi ha evidenziato una continua e costante rilevazione dell’attività locomotoria dei misidacei. L’analisi cronobiologia si è concentrata sul calcolo della lunghezza del periodo circadiano in free-running, trovando un periodo medio di 24,7 h. La DFT ha rilevato la presenza di un picco a circa 24 h in tutte le registrazioni esaminate, evidenziando inoltre una bassa potenza spettrale.Oltre al ritmo circadiano, in tutte le registrazioni ricorrevano ritmi ultradiani nell’attività motoria. Nonostante le repliche sperimentali non siano sufficienti a giustificare conclusioni circa i ritmi dell’attività motoria di Speleomysis bottazzii, i ritmi individuati e la loro differente intensità, testimoniano di un incoraggiante funzionamento dell’apparato progettato.EnLocomotor activity and cave animals represent excellent models for study of biological clocks. An infrared-based detection device for recording motor activity has been tested on the stigobitic Spelaeomysis bottazzii Caroli, 1924 (Crustacea: Mysidacea). The individual activity of mysidaceans was monitored in continuous darkness. Data were analyzed by a DFT and chi-square periodogram. The apparatus was able to read rhythms of activity, in particular a lower circadian rhythm and some ultradian ones

A second-order theory for wave energy converters with curved geometry

A second-order theory for wave energy converters with curved geometr

The development of postural strategies in children: a factorial design study

BACKGROUND: The present study investigates balance control mechanisms, their variations with the absence of visual input, and their development in children from 7 to 11 years old, in order to provide insights on the development of balance control in the pediatric population. METHODS: Posturographic data were recorded during 60 s trials administered on a sample population of 148 primary school children while stepping and then quietly standing on a force plate in two different vision conditions: eyes closed and eyes open. The extraction of posturographic parameters on the quiet standing phase of the experiment was preceded by the implementation of an algorithm to identify the settling time after stepping on the force plate. The effect of different conditions on posturographic parameters was tested with a two-way ANOVA (Age × Vision), and the corresponding eyes-closed/eyes-open (Romberg) Ratios underwent a one-way ANOVA. RESULTS: Several posturographic measures were found to be sensitive to testing condition (eyes closed vs. eyes open) and some of them to age and anthropometric parameters. The latter relationship did not explain all the data variability with age. An evident modification of postural strategy was observed between 7 and 11 years old children. CONCLUSION: Simple measures extracted from posturographic signals resulted sensitive to vision and age: data acquired from force plate made it possible to confirm the hypothesis of the development of postural strategies in children as a more mature selection and re-weighting of proprioceptive inputs to postural control in absence of visual input

Pressures and impacts on structure, functioning and services in marine, terrestrial, and transitional ecosystems

Goal of the special issue - Given this premise, the special issue will gather theoretical, methodological, and applied papers focusing on the assessment of pressures and impacts on structure, functioning and services in marine, terrestrial, and transitional ecosystem