A special class of solutions in F(R)F(R)-gravity

We consider a special class of vacuum $F(R)$-modified gravity models. The form of their Lagrangian is such that the field equations are trivially satisfied when the Ricci scalar is constant. There are many interesting $F(R)$-models for inflation and dark energy that fall in this class. However, little is known outside the domain of cosmology therefore we aim to explore the class of solutions that are static and spherically symmetric. After some general considerations, we investigate in more detail black hole solutions, traversable wormhole metrics and, finally, configurations that can match the anomalous rotation curves of galaxies.Comment: Minor typos corrected, references added. Version accepted for publication in the European Physical Journal

GPGPU for track finding in High Energy Physics

The LHC experiments are designed to detect large amount of physics events produced with a very high rate. Considering the future upgrades, the data acquisition rate will become even higher and new computing paradigms must be adopted for fast data-processing: General Purpose Graphics Processing Units (GPGPU) is a novel approach based on massive parallel computing. The intense computation power provided by Graphics Processing Units (GPU) is expected to reduce the computation time and to speed-up the low-latency applications used for fast decision taking. In particular, this approach could be hence used for high-level triggering in very complex environments, like the typical inner tracking systems of the multi-purpose experiments at LHC, where a large number of charged particle tracks will be produced with the luminosity upgrade. In this article we discuss a track pattern recognition algorithm based on the Hough Transform, where a parallel approach is expected to reduce dramatically the execution time.Comment: 6 pages, 4 figures, proceedings prepared for GPU-HEP 2014 conference, submitted to DESY-PROC-201

Blocking Temperature Engineering in Exchange-Biased CoFeB/IrMn Bilayer

In this paper, we report on the magnetic and chemical characterization of the exchange-biased CoFeB/IrMn bilayers, grown by magnetron sputtering on a Si-based platform and capped by either a Ru or MgO/Ru overlayer. For Ru capping, the locking temperature monotonously increases with the IrMn thickness within the investigated range (3.5–8 nm). On the contrary, for MgO/Ru capping, the exchange bias is inhibited below 6 nm, whereas above 6 nm, the magnetic behavior is the same of Ru-capped films. The chemical analysis reveals a significant dependence of the Mn content from the capping layer for thin IrMn films (2.5 nm), whereas the difference disappears when IrMn becomes thick (7 nm). Our work suggests that a non-uniform composition of the IrMn films directly affects the exchange coupling at the IrMn/CoFeB interface

New Insights on Eggplant/Tomato/Pepper Synteny and Identification of Eggplant and Pepper Orthologous QTL

Eggplant, pepper and tomato are the most exploited berry-producing vegetables within the Solanaceae family. Their genomes differ in size, but each has 12 chromosomes which have undergone rearrangements causing a redistribution of loci. The genome sequences of all three species are available but differ in coverage, assembly quality and percentage of anchorage.Determining their syntenic relationship and QTL orthology will contribute to exploit genomic resources and genetic data for key agronomic traits.The syntenic analysis between tomato and pepper based on the alignment of 34,727 tomato CDS to the pepper genome sequence, identified 19,734 unique hits. The resulting synteny map confirmed the 14 inversions and 10 translocations previously documented, but also highlighted 3 new translocations and 4 major new inversions. Furthermore, each of the 12 chromosomes exhibited a number of rearrangements involving small regions of 0.5-0.7 Mbp.Due to high fragmentation of the publicly available eggplant genome sequence, physical localization of most eggplant QTL was not possible, thus, we compared the organization of the eggplant genetic map with the genome sequence of both tomato and pepper. The eggplant/tomato syntenic map confirmed all the 10 translocations but only 9 of the 14 known inversions; on the other hand, a newly detected inversion was recognized while another one was not confirmed. The eggplant/pepper syntenic map confirmed 10 translocations and 8 inversions already detected and suggested a putative new translocation.In order to perform the assessment of eggplant and pepper QTL orthology, the eggplant and pepper sequence-based markers located in their respective genetic map were aligned onto the pepper genome. GBrowse in pepper was used as reference platform for QTL positioning. A set of 151 pepper QTL were located as well as 212 eggplant QTL, including 76 major QTL (PVE ≥ 10%) affecting key agronomic traits. Most were confirmed to cluster in orthologous chromosomal regions.Our results highlight that the availability of genome sequences for an increasing number of crop species and the development of ultra-dense physical maps provide new and key tools for detailed syntenic and orthology studies between related plant species

Very late-onset friedreich ataxia with laryngeal dystonia

Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder characterized by progressive gait and limb ataxia, cerebellar, pyramidal and dorsal column involvement, visual defects, scoliosis, pes cavus and cardiomyopathy. It is caused by a homozygous guanine-adenine-adenine (GAA) trinucleotide repeat expansion in intron 1 of the frataxin gene (FXN) on chromosome 9q13-q21.1. Onset is usually in the first or second decade of life; however, late-onset cases of Freidreich ataxia (LOFA), after the age of 25 years, and very late-onset cases of Freidreich ataxia (VLOFA), after the age of 40 years, have been reported. VLOFA is quite rare and usually presents a milder progression of the disease. We report the case of a 64-year-old woman affected with VLOFA whose first symptoms (balance and gait disturbances) occurred at the age of 44 years. At the age of 62 years, she started complaining of a slowly progressive dysphonia showing the clinical aspects of laryngeal dystonia. Molecular analysis showed a 210- and 230-trinucleotide GAA repeat expansion in the two alleles of the FXN gene. Laryngeal dystonia has been reported only in very few cases of ataxia syndrome and never before in FRDA patients. It may represent a rare clinical manifestation of VLOFA thus confirming the high variability of the clinical spectrum of FRDA

The divine spirit of bees. A note on honey and the origins of yeast-driven fermentation

One of the earliest domesticated organisms is perhaps the eukaryote microorganism known as Saccharomyces cerevisiae, or more simply “the yeast”. Its decisive role in triggering fermentation as a process useful for agricultural products preservation and transformation into consumable food, though known from the Palaeolithic in the ancient Near East, became decisive in the Neolithic Period. The earliest agriculturalists of the Fertile Crescent accidentally triggered fermentation with the addition of honey to fruits juices, as attested to in the archaeological record. The yeast, that lives inside the guts of bees and wasps, is responsible for this fermentation process. Honey contains both yeast and sugar that facilitates its growth generating fermentation. The creative capability of the bees let these insects to be credited of a divine skill

Mimicking dark matter and dark energy in a mimetic model compatible with GW170817

The recent observation of the the gravitational wave event GW170817 and of its electromagnetic counterpart GRB170817A, from a binary neutron star merger, has established that the speed of gravitational waves deviates from the speed of light by less than one part in $10^{15}$. As a consequence, many extensions of General Relativity are inevitably ruled out. Among these we find the most relevant sectors of Horndeski gravity. In its original formulation, mimetic gravity is able to mimic cosmological dark matter, has tensorial perturbations that travel exactly at the speed of light but has vanishing scalar perturbations and this fact persists if we combine mimetic with Horndeski gravity. In this work, we show that implementing the mimetic gravity action with higher-order terms that break the Horndeski structure yields a cosmological model that satisfies the constraint on the speed of gravitational waves and mimics both dark energy and dark matter with a non-vanishing speed of sound. In this way, we are able to reproduce the $\Lambda$CDM cosmological model without introducing particle cold dark matter.Comment: 29 pages, 2 figures. Version accepted for publication in Phys. Dark Uni

Alive and well: mimetic gravity and a higher-order extension in light of GW170817

The near-simultaneous multi-messenger detection of the gravitational wave (GW) event GW170817 and its optical counterpart, the short $\gamma$-ray burst GRB170817A, implies that deviations of the GW speed from the speed of light are restricted to being of ${\cal O}(10^{-15})$. In this note, we study the implications of this bound for mimetic gravity and confirm that in the original setting of the theory, GWs propagate at the speed of light, hence ensuring agreement with the recent multi-messenger detection. A higher-order extension of the original mimetic theory, appearing in the low-energy limit of projectable Ho\v{r}ava-Lifshitz gravity, is then considered. Performing a Bayesian statistical analysis where we compare the predictions of the higher-order mimetic model for the speed of GWs against the observational bound from GW170817/GRB170817A, we derive constraints on the three free parameters of the theory. Imposing the absence of both ghost instabilities and superluminal propagation of scalar and tensor perturbations, we find very stringent 95\% confidence level upper limits of $\sim 7 \times 10^{-15}$ and $\sim 4 \times 10^{-15}$ on the coupling strengths of Lagrangian terms of the form $\nabla^{\mu}\nabla^{\nu}\phi\nabla_{\mu}\nabla_{\nu}\phi$ and $(\Box \phi)^2$ respectively, with $\phi$ the mimetic field. We discuss implications of the obtained bounds for mimetic theories. This work presents the first ever robust comparison of a mimetic theory to observational data.Comment: 9 pages, 3 figures. Accepted for publication in Class. Quant. Gra

The Supply and Use Framework Can Be Exploited for Comparing Technologies Serving Similar Needs: The Case of the Italian Heavy-Duty Road Sector

In Italy, the transport sector contributes significantly to carbon dioxide (CO2) emissions, accounting for 30.7% of the total emissions, with road freight transport alone responsible for 25% of this figure. This situation demands urgent emissions reductions to meet the country’s national commitment to achieving net-zero by mid-century. The growing affordability of electric vehicles (EVs) due to improved energy densities and reduced lithium storage system costs is extending to heavy transport, promising emissions reductions. Additionally, short-term alternatives like hydrogen and liquefied natural gas (LNG) are being considered. To evaluate the carbon footprint of emerging transportation technologies, including internal combustion engine vehicles (ICEVs), fuel cell electric vehicles (FCEVs), LNG vehicles, and battery electric vehicles (BEVs), a detailed life cycle analysis (LCA) is essential. This research aims to inform decision-making processes, investment initiatives, and regulatory compliance by assessing emissions per kilometer within future scenarios. The study employs an LCA model integrating global supply chain contributions, offering regional context and scenario analysis. Findings indicate higher GHG emissions per kilometer for FCEVs and diesel vehicles, with BEVs emerging as promising alternatives. Moreover, the study highlights significant Scope 3 emissions associated with FCEV supply chains, emphasizing the broader environmental impacts of different vehicle types