Pulse-duration dependence of the isotopic effect in simple molecular ions driven by strong laser fields

In this paper we discuss isotopic effects in simple molecular ions subjected to strong laser fields. We show that the intensity of the emitted spectra strongly depends upon both the nuclear mass of the molecular ions and the laser pulse duration. In particular, for short pulse duration [up to 8 optical cycles (o.c.)], we confirm the trend described in the most studied case in which the high-order harmonic generation is more efficient for heavier isotopes; in contrast, an interesting physical phenomenon is predicted for pulses longer than 16 o.c. characterized by an inverse effect in which lighter molecular species are responsible for higher-order harmonic emission

Laser induced ultrafast H2+ dinamic and attosecond generation

We examine the possibility that a H2+ molecular ion driven by a linearly polarized laser field can be considered as a source of attosecond pulses. The emisseion is investigated taking into account the role of the internuclear distance and by changing the angle between the laser field and the molecular axis. We find that the attosecond pulses emission happens when the electron cloud is over one nucleus; on the contrary, when the elctron is travelling between the two nuclei the attosecond emission do not take place

Angular harmonic dependence from a 3D-H2+ Molecular Ion

The time-dependent Schroedinger equation of a H2+ molecular ion in the presence of a linearly polarized laser field is numerically solved by means of a split-operator parallel code. The electron, driven by the laser electric field, emits electromagnetic radiation whose HHG spectrum (shown in Figure 1) can be finely controlled by changing the angle between the laser electric field and the molecular axis. The numerical results confirm that the structure of the spectra strongly depends on this angle. In particular the correlation between the laser orientation (with respect to the molecular axis) and the intensity of various harmonic peaks are displayed in Figure 2

EFFECT OF WIND LOADS ON NON REGULARLY SHAPED HIGH-RISE BUILDINGS

Wind loads have historically been recognized as one of the most important issue in high-rise buildings analysis and design. In particular, in regions of low seismic intensity, a high-rise building lateral design is controlled by wind loads. In wind analysis, Computational Fluid Dynamics (CFD) and/or wind tunnel testing are required to calculate the external pressures acting on a building. In this paper, two case studies are presented to show how the wind loads are calculated and applied in design. The first case study is based on the CFD results for the New Marina Casablanca Tower in Casablanca, Morocco. The second case study considers the results from the wind tunnel test studies conducted for the Al- Hamra tower, in Kuwait City, Kuwait. The New Marina Casablanca tower is a 167m tall concrete building, with a unique twisting shape generated from the relative rotation of two adjacent floors. Sloped columns are introduced in the perimeter to follow the tower outer geometry and to support the concrete slabs spanning between the central core and the perimeter frame. The effects of wind loads on the twisted geometry has been studied in details since the pressure coefficients are not easily identified for such a complex form. In addition, the effect of the wind loads on the structure presented unique challenges that required innovative structural solutions. The Al-Hamra tower is a 412m tall concrete building with a sculpted twisting form which optimizes the views to the Arabian Gulf while minimizing the solar heat gain. The complex form is realized using sloped walls and vertical columns on the perimeter and a central concrete core. The unique shape of the tower presented several design challenges related to the wind loads on the structure. This paper will discuss the unique challenges and solutions associated with wind loads effect on buildings of unique form

Dalla Strada della Real Favorita alla Villa Deliella : la misura della qualità nella prima espansione settentrionale di Palermo

Le città, sovente, finiscono per essere identificate con alcune delle proprie componenti salienti; piazze, strade, quartieri, comparti edilizi o interi settori urbani. Nella gamma di profili dei loro abitanti spesso si distinguono coloro i quali appartengono a questi luoghi, in quanto residenti, e quelli che eleggono tali contesti a proprio patrimonio civico, a volte con un maggiore coinvolgimento emotivo. Anche le vedute o i panorami possono spesso attribuire ad una città un valore. Ma proprio per questo sia le variabili delle componenti salienti sia le diverse angolazioni di confronto con il territorio e il paesaggio circostante sono inequivocabilmente soggette alle oscillazioni del sentire nelle varie epoche. Non fa eccezione il caso di via della Libertà a Palermo (detta «Strada della Real Favorita» nelle fasi iniziali della sua genesi) e del suo ruolo di agente significativo nei processi di trasformazione della forma della città e del suo territorio suburbano, come pure dei modi e delle forme della cultura dell’abitare della classe egemone nella sua rinnovata qualità di vertice e, al tempo stesso, compagine “quadro” del “sogno” di Palermo come città imprenditoriale, soprattutto nel suo primo secolo di sviluppo a partire dai moti liberali del 1848. Alle varie periodizzazioni di crescita dei settori urbani ad essa attestati corrispondono altrettante variabili delle tipologie ed espressioni della produzione architettonica, sia abitativa che d’uso collettivo, realizzata nei comparti di isolati su di essa bilanciati; la convergenza di cultura del progetto e di cultura artistica (cui si deve il corredo visuale di qualità di gran parte degli interni o delle definizioni figurali delle opere architettoniche) avrebbe, poi, garantito la formazione di uno dei più qualificati contesti urbani italiani d’Età Contemporanea. Si tratta di un fenomeno che nel Giardino Inglese di Giovan Battista Filippo Basile, nel Politeama Garibaldi di Giuseppe Damiani Almeyda e nella Villa Deliella di Ernesto Basile ha i suoi punti di maggiore eccellenza, innegabilmente rivelatori di una società con una precisa consapevolezza e volontà identitaria, sia nel pubblico che nel privato. Allo stesso modo però, a partire dalla fine degli anni Cinquanta del XX secolo, il venir meno di quei valori civici che avevano sostanziato la formazione di una nuova Palermo sull’asse di via della Libertà avrebbe comportato un inesorabile, quanto imprevedibile ed insolito per la sua incidenza (persino per la realtà italiana successiva al secondo dopoguerra), processo di trasfigurazione con deplorevoli azioni di manipolazione del patrimonio architettonico e con rapace furia demolitrice. La “cancellazione” di Villa Deliella sarebbe stato il primo e più eclatante segnale, ma purtroppo non l’ultimo, del raggiungimento del punto di non ritorno nell’inarrestabile cammino verso lo snaturamento dell’identità urbana avviato dai vincenti portatori delle nuove logiche di mercificazione applicate ad alcune strategiche porzioni di qualità del patrimonio architettonico palermitano

Time makes histone H3 modifications drift in mouse liver

To detect the epigenetic drift of time passing, we determined the genome-wide distributions of mono- and tri-methylated lysine 4 and acetylated and tri-methylated lysine 27 of histone H3 in the livers of healthy 3, 6 and 12 months old C57BL/6 mice. The comparison of different age profiles of histone H3 marks revealed global redistribution of histone H3 modifications with time, in particular in intergenic regions and near transcription start sites, as well as altered correlation between the profiles of different histone modifications. Moreover, feeding mice with caloric restriction diet, a treatment known to retard aging, reduced the extent of changes occurring during the first year of life in these genomic regions

Towards an operative use of remote sensing for exploring the past using satellite data: The case study of Hierapolis (Turkey)

This paper is focused on the presentation and discussion of an object oriented approach, applied to the Hierapolis (Turkey) site, to automatically detect the subtle features linked to buried archaeological remains. The data processing is applied twice: (i) first, globally at the whole image and, (ii) second, at the significant subsets identified by global analysis, in order to refine the previously obtained categorization. Object oriented approaches are usually based on two main steps: i) first the segmentation, ii) then the classification. Herein, we first performed the unsupervised classification step and, then, the segmentation. This choice is given by the specificity of archaeological issue, in particular: (i) the subtle features/targets to be identified are partially or totally unknown and characterized by a very small spectral separability from the background, and therefore (ii) the discrimination between archaeological class and substrates likely suffers significant confusion. To cope with these issues, the first step is based on an unsupervised classification, which provides a first ‘rough’ categorization of pixels; the second step, based on the segmentation, enables us to extract the geometric shape, and, in turn, to only categorize as archaeological class those pixels belonging to geometrically (rectangular and linear) shaped clusters. Outputs from this classification identify rectangular and linear features of archaeological interest whose size suggested that they may be a farm and some sectors of an aqueduct, respectively. Results from satellite based analysis were successfully evaluated by georadar and geomagnetic prospection along with field survey. From georadar and geomagnetic prospection we were able i) to confirm the presence of buried remains and ii) to detail and characterize these archaeological features at the subsoil level as well as to define the local stratigraphy. From field surveywe dated the detected buried remains to a period spanning from Imperial Roman to early Byzantine historical times

Effects of Fifty-Hertz Electromagnetic Fields on Granulocytic Differentiation of ATRA-Treated Acute Promyelocytic Leukemia NB4 Cells

Background/Aims: Life on Earth is constantly exposed to electromagnetic fields (EMFs) and the effects induced by EMFs on biological systems have been extensively studied producing different and sometimes contradictory results. Extremely low-frequency electromagnetic fields (ELF-EMFs) have shown to play a role in regulating cell proliferation and differentiation, although how EMFs influence these processes remains unclear. Human acute promyelocytic leukemia (APL) cells are characterized by the arrest of differentiation at the promyelocytic stage due to epigenetic perturbations induced by PML/RARα fusion protein (Promyelocytic Leukemia protein - PML/Retinoic Acid Receptor alpha - RARα). Therapeutic administration of all-trans retinoic acid (ATRA) re-establishes the leukemogenic mechanism re-inducing the normal differentiation processes. Methods: We studied the effects of ELF-EMFs (50 Hz, 2 mT) on the ATRA-mediated granulocytic differentiation process of APL NB4 cells (a cell line established from the bone marrow of a patient affected by the acute promyelocytic leukemia) by monitoring cellular proliferation and morphology, nitrob lue tetrazolium (NBT) reduction and the expression of differentiation surface markers. Finally, we investigated mechanisms focusing on reactive oxygen species (ROS) generation and related molecular pathways. Results: ELF-EMF exposure decreases cellular proliferation potential and helps ATRA-treated NB4 cells to mature. Furthermore, the analysis of ROS production and the consequent extracellular signal regulated kinases (ERK1/2) phosphorylation suggest that a changed intracellular oxidative balance may influence the biological effects of ELF-EMFs. Conclusions: These results indicate that the exposure to ELF-EMF promotes ATRA-induced granulocytic differentiation of APL cells

Histone H3 Lysine 4 and 27 Trimethylation Landscape of Human Alzheimer's Disease

none9sìBackground: Epigenetic remodeling is emerging as a critical process for both the onset and progression of Alzheimer's disease (AD), the most common form of neurodegenerative dementia. However, it is not clear to what extent the distribution of histone modifications is involved in AD. Methods: To investigate histone H3 modifications in AD, we compared the genome-wide distributions of H3K4me3 and H3K27me3 in entorhinal cortices from severe sporadic AD patients and from age-matched healthy individuals of both sexes. Results: AD samples were characterized by typical average levels and distributions of the H3K4me3 and H3K27me3 signals. However, AD patients showed a lower H3K4me3 and higher H3K27me3 signal, particularly in males. Interestingly, the genomic sites found differentially trimethylated at the H3K4 between healthy and AD samples involve promoter regions of genes belonging to AD-related pathways such as glutamate receptor signaling. Conclusions: The signatures of H3K4me3 and H3K27me3 identified in AD patients validate the role of epigenetic chromatin remodeling in neurodegenerative disease and shed light on the genomic adaptive mechanisms involved in AD.openPersico, Giuseppe; Casciaro, Francesca; Amatori, Stefano; Rusin, Martina; Cantatore, Francesco; Perna, Amalia; Auber, Lavinia Alberi; Fanelli, Mirco; Giorgio, MarcoPersico, Giuseppe; Casciaro, Francesca; Amatori, Stefano; Rusin, Martina; Cantatore, Francesco; Perna, Amalia; Auber, Lavinia Alberi; Fanelli, Mirco; Giorgio, Marc