Regulation of globin gene expression: boxes and borders

The experimental work presented in this thesis pertains to the regulation of gene expression and focuses on the regulation of the B globin genes. The expression of the globin genes is restricted to the erythropoietic tissue and is regulated during development. Therefore the study of globin gene expression can yield valuable insights in how organisms regulate their genes in a coordinated tissue and developmental manner. Two main issues will be addressed in the chapters of this thesis. The first concerns the mechanism by which a transcriptionally competent domain is formed in the chromosomal environment. This topic is the subject of Chapter 2. Once transcriptionally competent domains are formed, gene transcription can take place and it is orchestrated by factors that interact specifically with the regulatory elements of the gene itself. This interaction determines tissue specificity and developmental regulation of a gene. The second issue addressed concerns the transcriptional regulation of the ~ globin gene via their CCAAT boxes studied through NFE6, a factor that binds to these elements (Chapters 3 and 4). NF-E6 interaction with its target sequence participates in the change in globin gene expression concomitant with the progressive changes that occur during the development of an embryo to a fetus

Analysis of an Integrated Agro-waste Gasification and 120 kW SOFC CHP System: Modeling and Experimental Investigation

Abstract Renewable sources of hydrogen are of major interest in the context of energy production through fuel cells. The technical feasibility of CHP system composed by orange peels steam/air gasification unit coupled with a solid oxide fuel cell (SOFC) was investigated in this study. To this purpose, a zero-dimensional process simulation model of the CHP system using Aspen Plus was developed. Mathematical model was experimentally validated in a lab scale apparatus. Moreover, optimal operative conditions and integration options were investigated, as well as the system maximum theoretical overall efficiency. Results showed that in order to obtain 120 kW of DC power from the specific SOFC, 65 kg/h of biomass with 20% of moisture and 173 kg/h of raw biomass with 70% of water needed to be fed in the CHP system. It was theoretically proved that 120 kW of DC power and 135 kW of heat could be produced from SOFC unit at the selected operative conditions, with a net CHP maximum efficiency equal to 74%

The Red-throated pipit Anthus cervinus is a regular wintering in Sicily

We present a review of the phenology of the Red-throated Pipit Anthus cervinus and its wintering status in Sicily. We collected and analysed 91 different records related to a total of 280 indi-viduals. Data were collected both through direct observations on the field and by consulting recent literature and ornithological databases. The species has been regularly found overwintering during the last 11 winters (December 2012-January 2023), with the only exception of the winter of 2014/2015, likely due to the lack of coverage and targeted research, with an estimated population of 180-190 individuals. The average value is 3.07 individuals/records observed in 18 different loca-tions related to four Sicilian provinces (Caltanissetta, Catania, Sira-cusa, Trapani), mainly near wetlands and, more specifically, in Medi-terranean and thermo-Atlantic halophytic meadows and Mediterranean salt meadows. The number of wintering sites in the recent years appears to be increasing

Erythroid overexpression of C/EBPγ in transgenic mice affects γ-globin expression and fetal liver erythropoiesis

The CCAAT boxes of the β-like globin genes interact with three proteins: NF-Y, GATA-1 and NFE-6. We demonstrate that NFE-6 contains C/EBPγ, and address its role in globin gene regulation by erythroid overexpression of C/EBPγ, and a dominant-negative form C/EBPγΔB, in mice. Elevated levels of C/EBPγ, but not C/EBPγΔB, increase expression of the (fetal) γ-globin relative to the (adult) β-globin gene. Interestingly, fetal liver erythropoiesis is ablated when the C/EBPγ and C/EBPγΔB levels are further increased in homozygous transgenics. We suggest that targeted expression of dominant-negative leucine zipper proteins is a generally applicable approach to ablate specific tissues in mice.</p

Erythroid overexpression of C/EBPγ in transgenic mice affects γ-globin expression and fetal liver erythropoiesis

The CCAAT boxes of the β-like globin genes interact with three proteins: NF-Y, GATA-1 and NFE-6. We demonstrate that NFE-6 contains C/EBPγ, and address its role in globin gene regulation by erythroid overexpression of C/EBPγ, and a dominant-negative form C/EBPγΔB, in mice. Elevated levels of C/EBPγ, but not C/EBPγΔB, increase expression of the (fetal) γ-globin relative to the (adult) β-globin gene. Interestingly, fetal liver erythropoiesis is ablated when the C/EBPγ and C/EBPγΔB levels are further increased in homozygous transgenics. We suggest that targeted expression of dominant-negative leucine zipper proteins is a generally applicable approach to ablate specific tissues in mice.</p

Visual perceptual learning is effective in the illusory far but not in the near space

Visual shape discrimination is faster for objects close to the body, in the peripersonal space (PPS), compared to objects far from the body. Visual processing enhancement in PPS occurs also when perceived depth is based on 2D pictorial cues. This advantage has been observed from relatively low-level (detection, size, orientation) to high-level visual features (face processing). While multisensory association also displays proximal advantages, whether PPS influences visual perceptual learning remains unclear. Here, we investigated whether perceptual learning effects vary according to the distance of visual stimuli (near or far) from the observer, illusorily induced by leveraging the Ponzo illusion. Participants performed a visual search task in which they reported whether a specific target object orientation (e.g., triangle pointing downward) was present among distractors. Performance was assessed before and after practising the visual search task (30 minutes/day for 5 days) at either the close (near group) or far (far group) distance. Results showed that participants that performed the training in the near space did not improve. By contrast, participants that performed the training in the far space showed an improvement in the visual search task in both the far and near spaces. We suggest that such improvement following the far training is due to a greater deployment of attention in the far space, which could make the learning more effective and generalize across spaces

Visual perceptual learning is enhanced by training in the illusory far space (abstract only)

Objects’ shape discrimination is faster for objects closer to the body (peripersonal space, PPS) compared to objects far from it. The closeness advantage has been observed for both low-level (size, orientation) and high-level (face identification) visual features, recent evidence supporting body centred perception of multisensory stimulation in PPS, namely a better performance when stimuli are near the body. However, it is unclear how PPS influences visual learning. In a series of studies, we investigated whether visual perceptual learning differs according to the depth dimension (near or far from the observer). Depth perspective was created using the “Ponzo Illusion”, the effect of the illusion on learning was also examined. Participants performed a visual search task in which they reported whether a specific target object orientation (e.g., triangle pointing downward) was present amongst distractors. The task was performed before and after a training phase. This phase consisted in a visual search task in the near (half of the participants) or far space and lasted about 3 (Study 1) or 1.5 (Study 2) hours. Results showed that the learning was specific for the orientation of the target and position (near or far) in space with a more prominent improvement for the far space. These findings suggest that different learning processes may be specifically associated to different sectors of space