Vittorio Pasquali

Temporal Variations of Coagulation Factor VII Activity in Mice Are Influenced by Lighting Regime

It was recently reported that the circadian clock machinery controls plasma levels of factor (F) VII, the serine protease triggering blood coagulation. Here, by exploiting the mouse model, this study showed that variations of photoperiod (i.e., winter or summer conditions or simulated chronic jetlag conditions) have a strong impact on plasma FVII activity levels. Under conditions mimicking summer or winter photoperiods, FVII activity showed a clear 24 h rhythmicity. Interestingly, mean daily FVII activity levels were significantly reduced in mice exposed to summer photoperiods. Behavioral activity rhythms under both photoperiods were synchronized to LD cycles, and the amount of activity per 24 h was comparable. The authors also investigated the influence of chronic jetlag (CJL) on the FVII activity rhythms, which can be easily mimicked in mice through continuous abrupt shifts in the lighting schedule. The exposure of mice to simulated CJL of either consecutive westward or consecutive westward and eastward flights for 15 days did not abolish the behavioral activity rhythms but was associated with a period significantly different from 24 h. Intriguingly, both types of CJL exerted a strong influence on FVII activity rhythms, which were virtually suppressed. Moreover, the mean daily FVII activity was significantly lower in the CJL than in the winter photoperiod condition. Taken together, these findings in mice provide novel insights into the modulation of FVII activity levels, which might have implications for human pathophysiology.

On the use of microwave radar devices in chronobiology studies: an application with Periplaneta americana.

Modified motion detectors can be used to monitor locomotor activity and measure endogenous rhythms. Although these devices can help monitor insects in their home cages, the small size of the animals requires a very short wavelength detector. We modified a commercial microwave-based detection device, connected the detector’s output to the digital input of a computer, and validated the device by recording circadian and ultradian rhythms.Periplaneta americana were housed in individual cages, and their activity was monitored at 18°C and subsequently at 28°C in constant darkness. Time series were analyzed by a discrete Fourier transform and a chi-square periodogram. Q10 values and the circadian free-running period confirmed the data reported in the literature, validating the apparatus. Moreover, the spectral analysis and periodogram revealed the presence of ultradian rhythmicity in the range of 1–8 h.

Being positive despite illness: The contribution of positivity to the quality of life of cancer patients.

Objective: The purpose of this study was to examine the longitudinal relationship between Positivity (POS), defined as a stable disposition to view at experience under a positive outlook, and physical and psychological functioning in a sample of cancer patients immediately after diagnosis and one year later. Methods: A total of 110 patients (40% males) with pulmonary, colorectal and breast cancer, aged 30–75 (M age = 59.62; SD = 10.33), have been prospectively enrolled between 2012 and 2013, at the S. Andrea Hospital in Rome. All patients were previously aware of their diagnosis. A follow-up one year after diagnosis was conducted. We used structural equation modeling in order to analyse the specific effects of POS on functioning impairment from diagnosis to follow up. Results: POS was associated with less functioning impairment both at diagnosis and follow-up assessments. Furthermore, POS level at diagnosis continued to be associated with less functioning impairment one year later, after controlling for its stability. Conclusions: Patients with higher level of POS tended to report less symptoms associated with negative affect such as anxiety and despondency and to preserve their habitual relationships and social roles. POS may act as a basic disposition that sustains patients’ efforts to deal efficaciously with severe illness, by complying with medical treatment and using cognitive strategies that enable individuals to cope with concurrent and prospective challenges of illness.

High variability in the expression of circadian rhythms in a cave beetle population

Cave-dwelling organisms belong to widely different evolutionary lineages but they show parallel or convergent evolution in several morphological and physiological traits such as elongated appendages, lower metabolism, specialized sensory systems, loss of eye and pigmentation. Circadian rhythms in locomotor activity have already been documented in hypogean insects but ultradian rhythmicity in cave-dwelling organisms has been reported only by recent authors. We selected Laemostenus latialis as a good candidate to investigate the biological clock functioning in a species thought to be at its beginning of the process of cave evolution in the darkness. We based our analysis on inferential methods used here to obtain the quantitative resolution of the rhythm features. An automatic electronic device was developed to this purpose so to continuously monitoring the general locomotor activity of individual cave-dwelling beetles. We found significant locomotor rhythms to be present and that Laemostenus maintained a 24-h circadian rhythm but with a different amplitude. We observed two different and opposite behavioural patterns: the “Rhythmic group” showed a typical circadian rhythmicity of surface-dwelling animals with a surprisingly and extremely stable circadian period and with a restricted variance and a high amplitude. Differently, within the “arrhythmic group” we have observed an evanescent circadian period with high variability in tau, a larger variance and a lower amplitude. DFT spectral analysis showed the presence of ultradian rhythms with several significant peaks in the range 1–10 h and a main peak at 12 h, similar to those found in mysid crustaceans, cockroaches and mice. Ultradian rhythm looked independent from the circadian one and we did not observe any regularity. Further experimental studies are still needed to track the variation of this trait along the process of adaptation to cave life, particularly in closely related populations and species of troglophilic animals.

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.

Stable isotopes and digital elevation models to study nutrient inputs in high-arctic lakes

Five major factors control nutrient and organic matter inputs in high-Arctic lakes, all potentially affected by climate change: ice cover; run-off from the watershed; aquatic and terrestrial primary productivity; guano deposition from birds. Quantifying these controls is a key first step to understand what combination of factors underlies the biological productivity in Arctic lakes and drives their ecological response to climate change. Based on C and N elemental content and stable isotope analysis in sediments belonging to three lakes in North Spitsbergen (Svalbard), Digital Elevation Models and drainage maps, we propose an integrated approach for the analysis of nutrient and organic matter inputs in lakes and the role of catchment hydro-geomorphology in determining inter-lake differences in the isotopic composition of sediments. Given its high run-off and large catchment, organic deposits in Tvillingvatnet were dominated by terrestrial inputs, whereas inputs were mainly of aquatic origin in Storvatnet, a lowland lake characterised by low potential run-off. In Kolhamna, organic deposits seemed to be dominated by inputs from birds. Isotopic signatures were similar between samples within each lake, representing precise tracers for studies on the effect of climate change on biogeochemical cycles in lakes. The presented approach proved to be an effective research pathway for the identification of factors underlying nutrient and organic matter inputs within each water body, as well as for the modelling of expected changes in nutrient content associated with changes in isotopic composition of sediments.

Locomotor activity rhythms in high arctic freshwater crustacean: Lepidurus arcticus (Branchiopoda; Notostraca)

All living organisms have “biological clocks” that regulate physiological and behavioural functions by means of rhythms similar to the geophysical rhythms of the earth; these rhythms have an evident adaptive value to enable organisms to anticipate and, hence, to prepare for predictable changes in their environment (King & Takahashi 2000). This occurs as interaction between the clocks and exogenous time cues (Zeitgebers), the most prominent of which is the 24-h light–dark (LD) cycle. However, in polar environments, the strength of this Zeitgebers is greatly reduced around the summer and winter solstices, when the sun never sets or never rises. The presence of circadian clocks is independent of the environmental conditions. There are recent evidences that when daily transitions of dusk and dawn are not present, reindeer and ptarmigan that live in the Arctic do not exhibit circadian rhythms in their behaviour and physiology. Free-ranging reindeer do not exhibit 24-h locomotor activity rhythms in summer and winter (continuous light and continuous darkness). Differently, during the equinoxes, animals express a circadian regulation of locomotor activity (van Oort et al. 2005, 2007). Seasonal absence of circadian rhythmicity has been recorded also in the daily activity of the Svalbard ptarmigan (Stokkan et al. 1986; Reierth & Stokkan 1998). New molecular and hormonal evidence suggest that reindeer living at high latitudes in the Arctic lack the underlying biological clock necessary for generating circadian rhythmicity (Stokkan et al. 2007; Lu et al. 2010). The diversity of behavioural responses, even within the limited number of species tested, is surprising and suggests that several factors may be involved in regulating circadian variability. It has been proposed that circadian clocks can be adaptively modified to enable species-specific time-keeping under polar conditions (Daan & Aschoff 1975; van Oort et al. 2007; Lu et al. 2010; Bloch et al. 2013). Thereby, clocks would be “fitted” to specific aspects of the ecology and behaviour of an organism. Animals everywhere are confronted by environments that demand specialized behavioural and metabolic responses; for those of us intent on understanding the adaptive significance of clocks and rhythms, arctic organisms represent an excellent model in chronobiological studies.

Circadian and ultradian motor activity rhythms under 21h and 28h lighting cycles

Numerous works show a circadian rhythm of activity in several species of animals; the ultradian rhythms have not received much interest. This study investigated whether the circadian motor activity rhythm would be synchronized to two non-24 h light cycles and explored the effects of these light–dark cycles on different ultradian rhythms. We used a radar-doppler detection system. Inbred strains of mice BALB/C and C57BL/6 were exposed to a 24LD cycle and then to a shorter (10.5:10.5 LD) or longer (14:14 LD) cycle. Time series corresponding to observation periods of seven days were analysed by Discrete Fourier Transform and Chi-Square periodogram. BALB/C synchronized to T21 and T28 cycles, whereas C57BL/6 did not. In both strains the motor activity showed ultradian components. Some ultradian rhythm was affected from the synchronization of the circadian rhythm to the non-24 h light cycles. The relation of the compound structure of the circadian and ultradian rhythms is discussed.

Body size-related constraints on the movement behaviour of the arctic notostracan Lepidurus arcticus (Pallas, 1973) under laboratory conditions

The movement behaviour of individuals has long been acknowledged as a key determinant of species distribution in space and time. Information on benthic macroinvertebrates from aquatic habitats are still scant, however, and for polar species are virtually nonexistent. Here, the influence of body size on the movement behaviour of the arctic notostracan Lepidurus arcticus (Pallas) was examined under resource-free laboratory conditions. The mean step length, total path length and average speed were determined for specimens varying in body dry mass by six orders of magnitude. The scale-independent fractal dimension D was used to quantify movement path tortuosity. Among the different movement metrics considered, the body size of specimens scaled significantly only with path tortuosity; specifically, a negative relationship with a breakpoint was observed between individual body masses and the D values of the respective movement paths. The results are discussed considering similar results obtained for benthic crustaceans from temperate habitats. Additionally, their implications for future investigations explicitly considering temperature effects on movement behaviour are briefly considered.

Ingested microplastic as a two-way transporter for PBDEs in Talitrus saltator

ABSTRACT The presence and accumulation of plastic waste into the marine environment are well known environmental issues. Microplastics (MPs) end up in sea waters and, due to their hydrophobicity and high surface/volume ratio, POPs tend to sorb and accumulate to their surface. The supralittoral amphipod Talitrus saltator (T. saltator) was selected to study the role of MPs in the transfer of organic pollutants and to investigate if ingested MPs could either transfer contaminants to biota or clean it adsorbing pollutants taken from the diet. T. saltator is an established POPs (Persistent Organic Pollutants) biomonitor in coastal environments and it is able to swallow microplastics in natural condition. Two laboratory experiments were performed and T. saltator was exposed to a labelled polybrominated diphenyl ether (13C‐labelled BDE‐47) to investigate the opposite gradient role of MPs. X Ray Micro‐CT (Micro‐Computed Tomography) analyses were also performed on sandhopper samples to evaluate the uptake of MPs via digestive tract. The results showed that MPs ingestion could whether transfer and remove contaminants from T. saltator, indicating a partial balance among positive and negative effects. This study has underlined MP potential double role demonstrating that MP can act both as a carrier and scavenger for the bioaccumulation of organic pollutants (i.e. PBDEs), suggesting that chemicals leaching from MPs could have a limited impact to biota. Graphical abstract Figure. No Caption available. HighlightsIngestion of contaminated MP by T. saltator moves organic pollutants to its tissues.Uncontaminated MP ingested by contaminated T. saltator removes organic pollutants.MP double role as carrier and scavenger of chemicals is demonstrated.