Improved transverse (e,e') response function of 3He at intermediate momentum transfers

The transverse electron scattering response function of 3He is studied in the quasi-elastic peak region for momentum transfers between 500 and 700 MeV/c. A conventional description of the process leads to results at a substantial variation with experiment. To improve the results, the present calculation is done in a reference frame (the ANB or Active Nucleon Breit frame) which diminishes the influence of relativistic effects on nuclear states. The laboratory frame response function is then obtained via a kinematics transformation. In addition, a one-body nuclear current operator is employed that includes all leading order relativistic corrections. Multipoles of this operator are listed. It is shown that the use of the ANB frame leads to a sizable shift of the quasi-elastic peak to lower energy and, contrary to the relativistic current, also to an increase of the peak height. The additionally considered meson exchange current contribution is quite small in the peak region. In comparison with experiment one finds an excellent agreement of the peak positions. The peak height agrees well with experiment for the lowest considered momentum transfer (500 MeV/c), but tends to be too high for higher momentum transfer (10% at 700 MeV/c).Comment: 19 pages, 5 figure

A new look at Spitzer primary transit observations of the exoplanet HD189733b

Blind source separation techniques are used to reanalyse two exoplanetary transit lightcurves of the exoplanet HD189733b recorded with the IR camera IRAC on board the Spitzer Space Telescope at 3.6$\mu$m during the "cold" era. These observations, together with observations at other IR wavelengths, are crucial to characterise the atmosphere of the planet HD189733b. Previous analyses of the same datasets reported discrepant results, hence the necessity of the reanalyses. The method we used here is based on the Independent Component Analysis (ICA) statistical technique, which ensures a high degree of objectivity. The use of ICA to detrend single photometric observations in a self-consistent way is novel in the literature. The advantage of our reanalyses over previous work is that we do not have to make any assumptions on the structure of the unknown instrumental systematics. Such "admission of ignorance" may result in larger error bars than reported in the literature, up to a factor $1.6$. This is a worthwhile trade-off for much higher objectivity, necessary for trustworthy claims. Our main results are (1) improved and robust values of orbital and stellar parameters, (2) new measurements of the transit depths at 3.6$\mu$m, (3) consistency between the parameters estimated from the two observations, (4) repeatability of the measurement within the photometric level of $\sim 2 \times 10^{-4}$ in the IR, (5) no evidence of stellar variability at the same photometric level within 1 year.Comment: 43 pages, 18 figure

Improved (e,e') response functions at intermediate momentum transfers: the 3He case

A possibility of extending the applicability range of non-relativistic calculations of electronuclear response functions in the quasielasic peak region is studied. We show that adopting a particular model for determining the kinematical inputs of the non-relativistic calculations can extend this range considerably, almost eliminating the reference frame dependence of the results. We also show that there exists one reference frame, where essentially the same result can be obtained with no need of adopting the particular kinematical model. The calculation is carried out with the Argonne V18 potential and the Urbana IX three-nucleon interaction. A comparison of these improved calculations with experimental data shows a very good agreement for the quasielastic peak positions at $q=500,$ 600, 700 MeV/c and for the peak heights at the two lower $q$--values, while for the peak height at $q=700$ MeV/c one finds differences of about 20%.Comment: 10 pages, 4 figure

Incorporation of three-nucleon force in the effective interaction hyperspherical harmonic approach

It is shown how a bare three-nucleon force is incorporated into the formalism of the effective interaction approach for hyperspherical harmonics. As a practical example we calculate the ground state properties of 3H and 3He using the Argonne V18 nucleon-nucleon potential and the Urbana IX three-nucleon force. A very good convergence of binding energies and matter radii is obtained. We also find a very good agreement of our results compared to other high precision calculations.Comment: 17 pages, 3 figure

Coherent electronic and nuclear dynamics in a rhodamine heterodimer-DNA supramolecular complex

Elucidating the role of quantum coherences in energy migration within biological and artificial multichromophoric antenna systems is the subject of an intense debate. It is also a practical matter because of the decisive implications for understanding the biological processes and engineering artificial materials for solar energy harvesting. A supramolecular rhodamine heterodimer on a DNA scaffold was suitably engineered to mimic the basic donor-acceptor unit of light-harvesting antennas. Ultrafast 2D electronic spectroscopic measurements allowed identifying clear features attributable to a coherent superposition of dimer electronic and vibrational states contributing to the coherent electronic charge beating between the donor and the acceptor. The frequency of electronic charge beating is found to be 970 cm-1 (34 fs) and can be observed for 150 fs. Through the support of high level ab initio TD-DFT computations of the entire dimer, we established that the vibrational modes preferentially optically accessed do not drive subsequent coupling between the electronic states on the 600 fs of the experiment. It was thereby possible to characterize the time scales of the early time femtosecond dynamics of the electronic coherence built by the optical excitation in a large rigid supramolecular system at a room temperature in solution. © 2017 the Owner Societies.Multi valued and parallel molecular logi

HLA and KIR Frequencies in Sicilian Centenarians

Several studies suggest that human longevity appears to be linked inextricably with optimal functioning of the immune system, suggesting that specific genetic determinants may reside in loci that regulate the immune response, as human leukocyte antigen (HLA) and killer cell immunoglobulin-like receptor (KIR) genes. It has been suggested that longevity is associated with positive selection of alleles (i.e., HLA-DR11) or haplotypes (i.e., HLAB8, DR3) that confer resistance to infectious disease(s). On the other hand, the cytolytic activity of natural killer (NK) cells is controlled by activating and inhibitory cell-surface receptors, including KIR. The genetic diversity of the KIR loci with respect to successful aging has been analyzed only in one study performed in the Irish population. Although two KIR genes (2DS3, 2DL5) displayed an initial increased frequency in the aged group, the significance of this association was lost when repeated in a second cohort.We have evaluated by polymerase chain reaction–sequence-specific primers (PCR-SSP) HLA-DRB1 and KIR receptors=HLA ligands frequencies in centenarians and controls from Sicily. Our results demonstrate an increase of the HLA DRB1*18 allele in male centenarians ( p¼0.0266, after Bonferroni correction). Concerning KIR, no significant difference was observed after Bonferroni correction. However, our findings suggest that HLA=KIR=longevity associations are population specific, being heavily affected by the population-specific genetic and environmental history. This kind of study is important to better understand aging and longevity, hence enhancing the planning of antiaging strategies

Test of J-matrix inverse scattering potentials on electromagnetic reactions of few-nucleon systems

The J-matrix inverse scattering nucleon-nucleon potentials (JISP), describing both two-nucleon data and bound and resonant states of light nuclei to high accuracy, are tested on the total photoabsorption cross sections of Deuteron, Triton, 3He and 4He. The calculations in the three- and four-body systems are carried out via the Lorentz integral transform method and the hyperspherical harmonics (HH) technique. To this end the HH formalism has been adapted to accommodate non-local potentials. The cross sections calculated with the JISP are compared to those obtained with more traditional realistic interactions, which include two- and three-nucleon forces. While the results of the two kinds of potential models do not differ significantly at lower energies, beyond the resonance peak they show fairly large discrepancies, which increase with the nuclear mass. We argue that these discrepancies may be due to a probably incorrect long range behavior of the JISP, since the one pion exchange is not manifestly implemented there.Comment: 18 pages, 4 figures, 1 tabl

Oral amelanotic melanoma: a case report

Objectives. Primary oral melanoma is a very rare malignancy, representing about 0.5% of all melanomas, characterized by a wide clinical-histological variability and a very aggressive behavior. Aim of the present study is to describe a case of oral amelanotic melanoma, an infrequent variant with a poorer prognosis than that of pigmented melanomas for a more aggressive biological behavior and frequent delays for the correct diagnosis and for starting the treatment. Case report. A 53-year-old white man referred at the Department Surgical, Oncological and Oral Sciences for a macular, scarsely pigmented lesion with irregular margins, located on anterior region of hard palate. The lesion, completely asymptomatic and without any history of trauma or injury, was observed by his dentist some months ago. The patient was a smoker (about 20 cigarettes a day for 30 years) and his anamnesis was negative for any systemic diseases and drug assumption. Histological examination, following the incisional biopsy, showed the hyperplasia of the junctional melanocytes with occasionally dendritic appearance and light atypia; on the recommendation of pathologist, a second incisional biopsy was performed, and a definitive diagnosis of “amelanotic melanoma in situ” was confirmed. After diagnosis, the patient was referred to the unit of Head and Neck Surgery for staging and surgical approach of the lesion. Conclusions. This case report underlines the importance to perform biopsy of all lesions of the oral cavity to rule out malignancy, even when slightly colored, asymptomatic and with a clinically harmless presentation. Besides benign diseases (e.g melanotic macules, nevi, extravasation of blood pigments, amalgam tattoos and deposition of other exogenous/endogenous pigments), rare variant of non-pigmented melanoma should be considered in order to avoid a dangerous diagnostic and therapeutic delay

Minimally invasive approach to eliminate pyogenic granuloma using Er, Cr: YSGG laser

Backgroung. PG or granuloma pyogenicum is a common tumor like growth of the oral cavity that is considered to be of non-neoplastic nature, arising commonly as a result of constant low grade trauma and poor oral hygiene and in few instances because of hormonal disturbances. Since it is a benign lesion, choice of treatment is surgical excision with removal of underlying cause if any. A newer treatment modality using laser has been reported. Case report. A 16-year-old male patient reported to our sector of oral medicine with the chief complaint of intra-oral painless growth since four months. Past history and medical history did not reveal any relevant information. He was taking no medication and had no history of known drug allergy. On intra-oral examination smooth surfaced and lobulated growth of approximately 1.5 × 1 × 0.5 cm in size was present in the palate. The lesion was pedunculated and was freely movable over peduncle. The surface of the lesion showed non-omogenous red color whereas in certain area was covered by yellowish plaque like material. On palpation, growth was non-tender, nonfluctuant, hard and fibrous in consistency. Treatment plan comprising of excisional biopsy of the lesion using an Er, Cr: YSGG laser. An elliptical incision was made around the peduncle, the lesion was lifted along with the underlying periosteum from the bone surface and removed. Hemostasis was achieved with the same laser and healing was obtained for second intention. Excised specimen was preserved and sent for histopathological examination. At 7 days recall, the gingival tissues were healthy with successful healing. Conclusion. Excisional surgery is the treatment of choice for PG. The use of laser may be a valid approach for the excision of this lesion, as it is minimally invasive and offers many clinical advantages (minimal intra-operative bleeding,hemostasis, reduced times of healing)