Exploring priming strategies to improve stress resilience of Posidonia oceanica seedlings.

Seagrasses' ability to store information after exposure to stress (i.e. stress memory) and to better respond to further stress (i.e. priming) have recently been observed, although the temporal persistence of the memory and the mechanisms for priming induction remain to be defined. Here, we explored three priming strategies in Posidonia oceanica seedlings, each inducing a different level of stress, for temperature and salinity. We investigated changes in morphometry, growth rate and biomass between primed and non-primed seedlings. The results showed similar behaviour of seedlings when exposed to an acute stress event, regardless of whether they had been primed or not and of the priming strategy received. This opens the debate on the level of stress necessary for inducing a priming status and the persistence of the stress memory in P. oceanica seedlings. Although no priming-induced stress resistance was observed, seedlings showed unexpectedly high resilience to extreme levels of both abiotic stressors.

Prevalence of depressive symptomatology among nursing students during the COVID-19 pandemic.

BACKGROUND: COVID-19 and the policies to contain it have been a social problem and public health emer-gency for people in Italy in 2020. The aim of the study is assessing the prevalence of depression symptoms among nursing students from the University of Palermo during the COVID-19 pandemic. MATERIALS AND METHODS: The study employed a cross-sectional study design. On April 2020, a survey was performed including all the nursing students of the University of Palermo. The survey was structured into two parts. The first part consisted in the collection of socio-demographic information, the second in the administration of the QIDS-SR16 questionnaire. A multivariable logistic regression model was used to elaborate the results and adjusted Odds Ratios are presented. RESULTS: The sample consisted of 525 students (70.3% female). The probability to have a moderate/severe/very severe depressive symptomatology is significantly associated with the following variables: "Female gender" (aOR 1.96), "Low perceived economic status" (aOR 2.32), "Low perceived health status" (aOR 2.30) and "To be a smoker" (aOR 2.24). CONCLUSIONS: The global pandemic and the efforts to contain it represent a unique event and offer the oppor-tunity to advance our understanding of how to provide mental health care focused on online psychoeducation and psychotherapy programs for young students.

Biological adhesion in seagrasses: The role of substrate roughness in Posidonia oceanica (L.) Delile seedling anchorage via adhesive root hairs.

Seagrasses are marine flowering plants that developed several adaptive traits for living in submerged waters. Among this group, Posidonia oceanica (L.) Delile is the dominant species of the Mediterranean Sea, forming persistent meadows that provide valuable ecosystem services to human communities. P. oceanica seedlings can anchor to rocky substrates through adhesive root hairs. Here we investigate, for the first time, the bioadhesion process in seagrasses. Seedlings were grown on substrates provided with different roughness in order to identify mechanisms involved in the adhesion process. Root anchorage strength was measured through a peel test and hair morphology at different micro-roughness was analysed by electron and fluorescence microscopy. Maximum anchorage strength was recorded at roughness levels between 3 and 26 µm, while on finer (0.3) and coarser (52, 162 µm) roughness attachment was weaker. No attachment was obtained on smooth surfaces. Accordingly, root hair tip morphology strongly responded to the substrate. Morphological adaptation of the root hairs to surface topography and mechanical interlocking into the micro-roughness of the substrate appear the main mechanisms responsible for bioadhesion in the system under study. Substrate roughness at the scale of microns and tens of microns is pivotal for P. oceanica seedling attachment to take place. These findings contribute to identification of features of optimal microsite for P. oceanica seedling settlement and to the development of novel approaches to seagrass restoration that take advantage of species' key life history traits.

Gambling in nursing students of the University of Palermo.

INTRODUCTION: Gambling disorder is recognized as a psychiatric disorder. It is shown that the prevalence of pathological gambling is on the rise among university students, especially involving students attending the nursing degree course. The aim of the study was to estimate the prevalence of gambling's problem and to analyze the associated factors in the population of nursing students at the University of Palermo. MATERIAL AND METHODS: It's a cross-sectional study. In April 2019, a self-administered, anonymous and voluntary questionnaire was provided to students who attend daily lessons of the 3-years nursing degree course of University of Palermo, after they gave informed consent. The questionnaire investigates on socio-demographic information, year of study, the perception of the economic and health status, alcohol use disorders and gambling problems. RESULTS: The average age of the sample is 22.0 years (standard deviation ±4.3), 67.6% of the interviewees are women. The analysis shows that the risk to be "Player at risk/Moderate gambling problems/Serious game problems" is significantly associated with the following independent variables: male gender (aOR 5.15); "Do you live with your family? No" (aOR 2.98); "perceived health status: low" (aOR 2.51); "Risky consumption of alcohol: At Risk" (aOR 3.40). CONCLUSIONS: It is important to develop an effective gambling prevention program that will reduce the risk that youths will develop gambling problems. Participation in the prevention program significantly improves youths' attitudes and knowledge regarding gambling activities.

Why nursing students have sex without condom? A study in the university of Palermo.

AIMS: Evaluation of the knowledge and behavioral risks related to sexually transmitted infections (STIs) among the student population of the degree course in nursing at the University of Palermo. MATERIAL AND METHODS: An anonymous online a survey was provided to students that investigate to socio-demographic information, sexual habits and the level of knowledge of the STIs. Multivariable logistic regression was performed, considering it as a dependent variable "Do you permanently have unprotected sex (without a condom)? Yes", in order to evaluate the role of the variables of the questionnaire. Results are expressed as adjusted Odds Ratio (aOR). RESULTS: The sample size consists of 405. The average age of the sample is 21.65 years (standard deviation±3.24). The analysis shows that the risk of having permanently unprotected sex (without condom) is significantly associated with the following variables: "Are you engaged or single? Engaged" (aOR 3.24, 95% CI 1.66 - 6.33); "Sexual orientation. Homosexual or Bisexual (aOR 4.45, 95% CI 1.30 - 15.29); "Have you occasionally had unprotected sex (without a condom)? Yes" (aOR 5.09, 95% CI 2.69 - 9.62); "How would you define your knowledge of sexually transmitted diseases? Good" (aOR 2.07, 95% CI 1.05 - 4.08); "How would you define your knowledge about contraceptive methods? Good" (aOR 2.51, 95% CI 1.23 - 5.15); "Have you or have you ever had a sexually transmitted disease? Yes (aOR 4.43, 95% CI 1.71 - 11.53); "Do you know that men can also undergo HPV vaccination? Yes" (aOR 2.57, 95% CI 1.03 - 6.40); "Age. As the unit increase" (aOR 1.14, 95% CI 1.02 - 1.26). CONCLUSIONS: These results highlight the importance of involving university students in programs aimed at improving the knowledge in terms of STIs and increase of Sexual and reproductive health. Further, because STIs prevention is based mainly on human behavior, tailored intervention is needed especially because behavior change remains a complex challenge.

The Continued Rise in Professional Use of Social Media at Scientific Meetings: An Analysis of Twitter Use during the ASNR 2018 Annual Meeting.

Professional use of social media continues to increase. We analyzed Twitter use of our own American Society of Neuroradiology (ASNR) 2018 annual meeting, reviewing all Twitter posts (3020 tweets from 523 participants) containing the hashtag #ASNR18 from May 21, 2018, to June 12, 2018, extracting the transcripts from Symplur. Then, each tweet was categorized by the role of user, type of tweet, and topic. The dominant user category was neuroradiologist/radiologist (63%). The keynote address, "The Radiology Renaissance: Shaping the Future of Healthcare," presented by Andy DeLao @Cancergeek was the most frequently tweeted topic (10%). Comment on a session was the major type of tweet. When we compared the data with a similar analysis in 2014, our data analysis showed a growth in the use of Twitter in only 4 years.

Spatial variability of soft-bottom macrobenthic communities in northern Sicily (Western Mediterranean): Contrasting trawled vs. untrawled areas.

This study examines the impact of bottom trawl fishing on the macrobenthic communities inhabiting the coastal terrigenous mud off the northern coast of Sicily (Western Mediterranean). Two intensely trawled gulfs were compared with two gulfs from which trawling has been excluded for 15 years. The results show a significant effect of trawling on the faunal assemblage and when comparing the mean biomass and the whole isotopic composition of the benthic communities. A similar pattern, although not significant, was found for total abundance, biomass, production/biomass ratio and diversity. Higher abundance and lower biomass were found in the untrawled areas, attributable to the presence of more numerous yet smaller individuals, possibly a consequence of more abundant larger predators that are not removed by trawling, and consequent higher predatory pressure on the benthic macrofauna. The SIMPER analysis evidenced a dominance of burrowing deposit feeding worms (Paraonidae and Cossuridae) in trawled areas, as a result of increased mechanical alteration and hence more organic matter available as food. In contrast, the response to trawling as drawn by the use of trophic markers (i.e., stable isotopes) was less clear. While δ15N of benthic taxa did not vary significantly between untrawled and trawled areas, δ13C was higher in trawled areas possibly due to high sediment resuspension and consequent intense microbial activity. Mixing models confirmed higher reliance to a detritus-based food web for benthic organisms in the trawled areas. Standard Ellipse Areas (SEAc) as a measure of community niche width were slightly larger in trawled areas, likely due to higher generalism triggered by alteration/removal of the original benthic community.

Imaging of cervical extradural en-plaque meningioma. A case report.

Meningioma is one of the most common spinal extramedullary tumors, largely intradural. An extradural localization is possible but less frequent. There are two morphologically different types of meningioma: one is round, and the other is the "en-plaque" form, that grows along the dura mater like a sheet. The "en-plaque" form, is unusual. We report on an unusual case of epidural and extraspinal "en-plaque" meningioma, describing the MRI and CT features and discussing the possible principal differential diagnosis (neurolymphomatosis, plexiform neurofibromas/schwannomas and metastasis).

Food partitioning and diet temporal variation in two coexisting sparids, Pagellus erythrinus and Pagellus acarne.

Resource partitioning in two congeneric sparids, pandora Pagellus erythrinus and axillary seabream Pagellus acarne, was investigated using stomach content analysis integrated with data on stable isotopes (δ(15) N and δ(13) C). The study was carried out on coastal muddy bottoms in the Gulf of Castellammare (southern Tyrrhenian Sea, western Mediterranean Sea) in seasons (autumn, November 2004; winter, March 2005; spring, early June 2005), at depths between 50 and 100 m. Stomach content analysis suggested low trophic niche overlap between the two species. Pagellus erythrinus mainly preyed on strictly benthic organisms (polychaetes, brachyuran crabs and benthic crustaceans). Although it consumed benthic prey, P. acarne preferred suprabenthic prey such as peracarid crustaceans from the benthic boundary layer a few metres above the bottom. The two species showed different isotopic values, with P. erythrinus exhibiting higher δ(15) N and more enriched δ(13) C than P. acarne, in accordance with its marked benthic behaviour and high predation on carnivore polychaetes. Significant temporal variability in both diet and isotopic values caused trophic differences between the two species. The autumn and winter diet differed from the spring diet and the trophic levels of both species increased from autumn and winter to spring, in accordance with variations in food availability and changes in prey δ(15) N and δ(13) C. These temporal variations may be linked to an increase in energy requirements for reproduction, together with the differing availability of preferred prey throughout the year. Significantly, lower δ(13) C was recorded in fishes collected in winter (March), suggesting the influence of river inputs as a source of particulate organic matter in this zone after the flooding season. In conclusion, these sympatric congeneric fish species displayed clear food partitioning throughout the temporal scale analysed.

Observing brownian motion in vibration-fluidized granular matter.

Observation of the rotational brownian motion of a very fine wire immersed in a gas led to one of the most important ideas of equilibrium statistical mechanics. Namely, the many-particle problem of a large number of molecules colliding with the wire can be represented by just two macroscopic parameters: viscosity and temperature. Interest has arisen in the question of whether this idea (mathematically developed in the Langevin model and the fluctuation-dissipation theorem) can also be used to describe systems that are far from equilibrium. Here we report an experimental investigation of an archetypal non-equilibrium system, involving a sensitive torsion oscillator immersed in a granular system of millimetre-size grains that are fluidized by strong external vibrations. The vibro-fluidized granular medium is a driven environment, with continuous injection and dissipation of energy, and the immersed oscillator can be seen as analogous to an elastically bound brownian particle. By measuring the noise and the susceptibility, we show that the experiment can be treated (to a first approximation) with the equilibrium formalism. This gives experimental access to a granular viscosity and an effective temperature; however, these quantities are anisotropic and inhomogeneous. Surprisingly, the vibro-fluidized granular matter behaves as a 'thermal' bath satisfying a fluctuation-dissipation relation.

Vogel-Fulcher-Tammann-type diffusive slowdown in weakly perturbed granular media.

We study the process by which a perturbed granular medium of millimetric-size particles reaches a "frozen" static configuration by decreasing perturbation intensity. The granular system is perturbed by isolated taps or by continuous vibrations. The granular process is observed by an immersed oscillator, which is used as a low-frequency "thermometer." A diffusive noise is seen until well below the fluidization limit, and the approach to the frozen configuration arises according to a modified Vogel-Fulcher-Tammann (VFT) behavior. As a function of an empirical control parameter with unit of time one recovers a standard VFT form.

The jamming route to the glass state in weakly perturbed granular media.

It has been suggested that a common conceptual framework known as 'jamming' (refs 1 and 2) may be used to classify a wide variety of physical systems; these include granular media, colloidal suspensions and glass-forming liquids, all of which display a critical slowdown in their dynamics before a sudden transition to an amorphous rigid state. Decreasing the relevant control parameter (such as temperature, drive or inverse density) may cause geometrical constraints to build up progressively and thus restrict the accessible part of the system's phase space. In glass-forming liquids (thermal molecular systems), jamming is provided by the classical vitrification process of supercooling, characterized by a rapidly increasing and apparently diverging viscosity at sufficiently low temperatures. In driven (athermal) macroscopic systems, a similar slowdown has been predicted to occur, notably in sheared foam or vibrated granular media. Here we report experimental evidence for dynamic behaviour, qualitatively analogous to supercooling, in a driven granular system of macroscopic millimetre-size particles. The granular medium is perturbed by isolated tapping or continuous vibration, with the perturbation intensity serving as a control parameter. We observe the random deflection of an immersed torsion oscillator that moves each time the grains rearrange, like a 'thermometer' sensing the granular noise. We caution that our granular analogy to supercooling is based on similarities in the dynamical behaviour, rather than quantitative theory.

Vibration-induced jamming transition in granular media.

The quasistatic frequency response of a granular medium is measured by a forced torsion oscillator method, with forcing frequency f(p) in the range 10(-4) Hz to 5 Hz, while weak vibrations at high-frequency f(s), in the range 50 Hz to 200 Hz, are generated by an external shaker. The intensity of vibration Gamma is below the fluidization limit. A loss factor peak is observed in the oscillator response as a function of Gamma or f(p). In a plot of ln f(p) against 1/Gamma, the position of the peak follows an Arrhenius-like behavior over four orders of magnitude in f(p). The data can be described as a stochastic hopping process involving a probability factor exp(-Gamma(j)/Gamma) with Gamma(j) a f(s)-dependent characteristic vibration intensity. An f(s)-independent description is given by exp(-tau(j)/tau), with tau(j) an intrinsic characteristic time, and tau=Gamma(n)/2pif(s), n=0.5-0.6, an empirical control parameter with unit of time. tau is seen as the effective average time during which the perturbed grains can undergo structural rearrangement. The loss factor peak appears as a crossover in the dynamic behavior of the vibrated granular system, which, at the time scale 1/f(p), is solid-like at low Gamma, and the oscillator is jammed into the granular material, and is fluid-like at high Gamma, where the oscillator can slide viscously.

Mechanical properties of granular media, including snow, investigated by a low-frequency forced torsion pendulum

The oscillating probe of a low-frequency forced torsion pendulum is immersed into various granular media, such as natural sand, glass beads, and granular snow. A first layer of particles is in general solidly bound to the probe surface. The principle of operation and a rheological model are presented. The measured dynamic moduli systematically show a peak of the loss factor and a step in the absolute modulus. The effect of moisture-induced aging in glass beads of small size and the effect of sintering of ice grains in snow are investigated. The response of the pendulum is determined by the long-range statistical properties of force chains opposing the rotation of the pendulum, and by the tribological processes that take place at the grain contacts.

Critical dynamics of burst instabilities in the Portevin-Le Ch atelier effect.

We investigate the Portevin-Le Châtelier effect (PLC), by compressing Al-Mg alloys in a very large deformation range, and interpret the results from the viewpoint of phase transitions and critical phenomena. The system undergoes two dynamical phase transitions between intermittent (or "jerky") and "laminar" plastic dynamic phases. Near these two dynamic critical points, the order parameter 1/tau of the PLC effect exhibits large fluctuations, and "critical slowing down" (i.e., the number tau of bursts, or plastic instabilities, per unit time slows down considerably).