Growing up with nature photography

I took up nature photography at a very young age. I embarked on this path first to satisfy the need to slow down and, somehow, stop the constant flow of emotions and experiences lived observing animals and exploring natural environments since my childhood. The images I took then offered me the opportunity to store those emotions forever, to relive them from time to time and to be even able to share them with others. In addition, I began to like the slow pace required by the photographic technique, which imposed patience, attention, empathy. A discipline that, compared to mere contemplation, urged me to look at things more in depth, teaching me to appreciate the constant variations of light, to look at animals in the eyes and to identify form and patterns in the apparent chaos that surrounds us. On the other hand, in the fleeting moment when you take a photograph, what is framed in the viewfinder becomes the most important thing in the world. This forced slowness then turned into a kind of initiation to the secrets of the subjects at the center of my photographic research. A very personal cultural journey that greatly increased my knowledge of nature things and gradually also the sense of belonging to something greater. With this baggage of awareness, I quickly went from a purely documentary photography to a more representative and, in some way, introspective one. What began as a moment of aesthetic contemplation soon became an inner dialogue, between the self and the world, regardless of the object or location. Even portraying a small insect, in fact, you notice your own image reflected in its eyes. Once I finished my university studies and with a degree in Biological Sciences in the bag, I chose to abandon a possible scientific career and instead undertake the profession of nature photographer. This is because, compared to the rigour and the greater depth required by scientific research, photography granted me instead the freedom to span between different topics, get to know very different realities and enter a deeper communication with the subjects of my work. It was then that, in order to overcome the apparent superficiality of the photographic approach and also to be able to build up a more robust professional portfolio, I chose to work exclusively on projects and not to seek the sensationalism of a single shot. Since then, all my photographic work has been carried out solely as a result of thorough research and meticulous planning and with a long-term approach. This allowed me eventually to turn the photo shoot into a research and the subsequent sharing of images into a process of dissemination and education. In this way, I discovered the fundamental role that photography can play in the conversation on our relationship with nature and in supporting the battle for the conservation of species and natural habitats. On the other hand, photography is a universal and very powerful language, that allows to overcome cultural, geographical and age barriers. Images can convey messages, arouse emotions and, therefore, become a useful communication tool to increase people's awareness toward certain issues. Despite the common perception, photography is not truth but can become "true" exclusively in the intentions of the photographer. It is at the end of the path taken by the photographer, in the honesty of this person, in the ethical sense and in the empathy with which she approaches her subjects that a photographic work can become truthful. Only a respectful and sincere photograph, both with regard to the well-being of the subject and the correctness of the message, can become a mirror of reality. I chose to share this personal experience with photography with fellow scientific researchers during the seminar “In Cammino al tempo dell'ecologia” organised by the LTER network at Feudozzo in 2019, in order to possibly offer a different perspective on ecology and invite them to use photography as a tool for discovery and education

Cryptococcus gattii sero-mating type allelic pattern determined by multiplex PCR

AbstractMolecular methods to differentiate serotypes, mating types and molecular types of Cryptococcus neoformans and C. gattii are important tools to understand epidemiology and pathogenesis of these pathogens. In this study, a multiplex polymerase chain reaction (PCR) approach was applied to sero-mating typing of C. gattii strains. Four pairs of primers were designed to target 4 allele-specific genes located in the mating-type locus. Twenty-three C. gattii strains, presenting different mating types and serotypes, were tested to validate the method. The method was able to identify all sero-mating allelic patterns including hybrid combinations, and therefore, it represents a simple one-step PCR for sero-mating typing of C. gattii strains

Observations of IMF coherent structures and their relationship to SEP dropout events

Abstract. The solar energetic particle (SEP) events from impulsive solar flares are often characterized by short-timescale modulations affecting, at the same time, particles with different energies. Several models and simulations suggest that these modulations are observed when SEPs propagate through magnetic structures with a different connection with the flare site. However, in situ observations rarely showed clear magnetic signatures associated with these modulations. In this paper we used the Grad–Shafranov reconstruction to perform a detailed analysis of the local magnetic field topology during the SEP event of 9–10 January 1999, characterized by several SEP dropouts. An optimization procedure is used to identify, during this SEP event, the magnetic structures which better satisfy the Grad–Shafranov assumptions and to evaluate the direction of their invariant axis. We found that these two-dimensional structures, which are flux ropes or current sheets with a more complex field topology, are generally associated with the maxima in the SEP counts. This association suggests that the SEPs propagate within these structures and, since their gyration radii is much smaller than the transverse dimension of these structure, cannot escape from them

On the Origin of Highly Alfvénic Slow Solar Wind

Alfvénic fluctuations are a common feature in the solar wind and are found especially in the trailing edges of fast wind streams. The slow wind usually has a lower degree of Alfvénicity, being more strongly intermixed with structures of non-Alfvénic nature. In the present paper we show the first evidence in the interplanetary space of two different kinds of slow solar wind: one coming from coronal streamers or active regions and characterized by non-Alfvénic structures and the other one being highly Alfvénic and originating from the boundary of coronal holes. The Alfvénic character of fluctuations, either outward or inward, can be studied by means of the normalized cross-helicity, {{σ }C}, which is an indicator of the {\boldsymbol{v}} -{\boldsymbol{b}} alignment. The evolution of {{σ }C} toward lower values with increasing radial distance is interpreted both as a decrease of the presence of the outward modes and as a continuous production of inward modes within those regions such as stream shears where some plasma instability is active. On the other hand, the decrease of {{σ }C} is often related also to magnetic field and/or density enhancements which specifically act on the destruction of the {\boldsymbol{v}} -{\boldsymbol{b}} alignment. In the present analysis we study the role of compressibility presenting both case studies and a statistical analysis over different phases of solar cycle 23. Our findings indicate that the presence of regions of magnetic field compression generally play a major role in the depletion of {{σ }C} and thus in the destruction of the {\boldsymbol{v}} -{\boldsymbol{b}} alignment

Helios 2 observations of solar wind turbulence decay in the inner heliosphere

The linear scaling of the mixed third-order moment of the magnetohydrodynamic fluctuations is used to estimate the energy transfer rate of the turbulent cascade in the expanding solar wind. In 1976 the Helios 2 spacecraft measured three samples of fast solar wind originating from the same coronal hole, at different distance from the sun. Along with the adjacent slow solar wind streams, these represent a unique database for studying the radial evolution of turbulence in samples of undisturbed solar wind. A set of direct numerical simulations of the MHD equations performed with the Lattice-Boltzmann code FLAME is also used for interpretation. We show that the turbulence energy transfer rate decays approximately as a power law of the distance, and that both the amplitude and decay law correspond to the observed radial temperature profile in the fast wind case. Results from magnetohydrodynamic numerical simulations of decaying magnetohydrodynamic turbulence show a similar trend for the total dissipation, suggesting an interpretation of the observed dynamics in terms of decaying turbulence, and that multi-spacecraft studies of the solar wind radial evolution may help clarifying the nature of the evolution of the turbulent fluctuations in the ecliptic solar wind.Comment: In press on Astron. Astrophy

PERSISTENT AND SELF-SIMILAR LARGE-SCALE DENSITY FLUCTUATIONS IN THE SOLAR CORONA

Density fluctuations of the low and midlatitude solar corona plasma are analyzed during the recent solar minimum period. Long time series of the intensity of the neutral hydrogen Lyα, 1216 A, line have been observed with the UltraViolet Coronagraph Spectrometer/Solar and Heliospheric Observatory at 1.7 R ☉, in low-latitude streamers and in regions where the slow solar wind is accelerated. Their frequency composition is investigated by using three different techniques, namely the Fourier, the Hurst, and the phase coherence analyses. The Fourier analysis reveals the existence of low-frequency f –α power spectra in the range from ~3 × 10–6 Hz to ~10–4 Hz, corresponding to periods from a few hours to a few days. The coronal density fluctuations are dominated by discontinuities separating structures with a minimum characteristic timescale of about 3 hr and a corresponding spatial scale of about 3 × 104 km. The nonlinear analysis technique based on the structure functions shows that for large timescales the coronal density fluctuations are statistically self-affine and give rise to an average Hurst exponent H = 0.654 ± 0.008. This indicates that the process underlying the variability of the corona and the slow wind at coronal level is a persistent mechanism, generating correlations among the plasma density fluctuations. Finally, the analysis based on the phase coherence index shows a high degree of phase synchronization of the coronal density variations for large timescales, which shows that the solar corona is dominated by phase coherent structures. The results of the analysis suggest a coupling of the variability of the solar corona and the photospheric dynamics induced by the convection at supergranular scale

STATISTICS OF DENSITY FLUCTUATIONS DURING THE TRANSITION FROM THE OUTER SOLAR CORONA TO THE INTERPLANETARY SPACE

This paper investigates the evolution of the plasma density fluctuations of the fast and slow solar wind from the solar corona into the interplanetary space. The study is performed by comparing the low-frequency spectra and the phase correlation of the proton density oscillations, measured in the inner heliosphere with the Helios 2 in situ instrumentation, with those due to the large-scale density perturbations observed with UVCS/SOHO in the outer corona. We find that the characteristics of density fluctuations of the fast solar wind are maintained in the transition from the outer corona to the inner heliosphere, thus suggesting a coronal imprint for the heliospheric large-scale 1/f 2 noise spectrum. In contrast, a quick dynamical evolution is observed in the slow wind, which, starting from large-scale fluctuations with strong phase correlations in the outer corona, gives rise to a Kolmogorov-like spectrum and an accumulation of density structures at small scales at 0.3 AU. This can be explained in the framework of nearly incompressible turbulence

First analysis of in-situ observation of surface Alfv\'en waves in ICME flux rope

Alfv\'en waves (AWs) are inevitable in space and astrophysical plasma. Their crucial role in various physical processes, occurring in plasma, has triggered intense research in solar-terrestrial physics. Simulation studies have proposed the generation of AWs along the surface of a cylindrical flux rope, referred to as Surface AWs (SAWs); however the observational verification of this distinct wave has been elusive to date. We report the first \textit{in-situ} observation of SAWs in an interplanetary coronal mass ejection flux rope. We apply the Wal\'en test to identify them. The Elsa\"sser variables are used to estimate the characterization of these SAWs. They may be excited by the movement of the flux rope's foot points or by instabilities along the plasma magnetic cloud's boundaries. Here, the change in plasma density or field strength in the surface-aligned magnetic field may trigger SAWs

The origin of slow Alfvenic solar wind at solar minimum

Although the origins of slow solar wind are unclear, there is increasing evidence that at least some of it is released in a steady state on overexpanded coronal hole magnetic field lines. This type of slow wind has similar properties to the fast solar wind, including strongly Alfvénic fluctuations. In this study, a combination of proton, alpha particle, and electron measurements are used to investigate the kinetic properties of a single interval of slow Alfvénic wind at 0.35 au. It is shown that this slow Alfvénic interval is characterized by high alpha particle abundances, pronounced alpha–proton differential streaming, strong proton beams, and large alpha-to-proton temperature ratios. These are all features observed consistently in the fast solar wind, adding evidence that at least some Alfvénic slow solar wind also originates in coronal holes. Observed differences between speed, mass flux, and electron temperature between slow Alfvénic and fast winds are explained by differing magnetic field geometry in the lower corona