New twist field couplings from the partition function for multiply wrapped D-branes

We consider toroidal compactifications of bosonic string theory with particular regard to the phases (cocycles) necessary for a consistent definition of the vertex operators, the boundary states and the T-duality rules. We use these ingredients to compute the planar multi-loop partition function describing the interaction among magnetized or intersecting D-branes, also in presence of open string moduli. It turns out that unitarity in the open string channel crucially depends on the presence of the cocycles. We then focus on the 2-loop case and study the degeneration limit where this partition function is directly related to the tree-level 3-point correlators between twist fields. These correlators represent the main ingredient in the computation of Yukawa couplings and other terms in the effective action for D-brane phenomenological models. By factorizing the 2-loop partition function we are able to compute the 3-point couplings for abelian twist fields on generic non-factorized tori, thus generalizing previous expressions valid for the 2-torus.Comment: 36 pages, 1 figure; v2: typos corrected, proof in the Appendix improve

Neurophysiological Profile of Antismoking Campaigns

Over the past few decades, antismoking public service announcements (PSAs) have been used by governments to promote healthy behaviours in citizens, for instance, against drinking before the drive and against smoke. Effectiveness of such PSAs has been suggested especially for young persons. By now, PSAs efficacy is still mainly assessed through traditional methods (questionnaires and metrics) and could be performed only after the PSAs broadcasting, leading to waste of economic resources and time in the case of Ineffective PSAs. One possible countermeasure to such ineffective use of PSAs could be promoted by the evaluation of the cerebral reaction to the PSA of particular segments of population (e.g., old, young, and heavy smokers). In addition, it is crucial to gather such cerebral activity in front of PSAs that have been assessed to be effective against smoke (Effective PSAs), comparing results to the cerebral reactions to PSAs that have been certified to be not effective (Ineffective PSAs). &e eventual differences between the cerebral responses toward the two PSA groups will provide crucial information about the possible outcome of new PSAs before to its broadcasting. &is study focused on adult population, by investigating the cerebral reaction to the vision of different PSA images, which have already been shown to be Effective and Ineffective for the promotion of an antismoking behaviour. Results showed how variables as gender and smoking habits can influence the perception of PSA images, and how different communication styles of the antismoking campaigns could facilitate the comprehension of PSA’s message and then enhance the related impac

Critical role for prokineticin 2 in CNS autoimmunity

Objective: To investigate the potential role of prokineticin 2 (PK2), a bioactive peptide involved in multiple biological functions including immune modulation, in CNS autoimmune demyelinating disease. Methods: We investigated the expression of PK2 in mice with experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS), and in patients with relapsing-remitting MS. We evaluated the biological effects of PK2 on expression of EAE and on development of T-cell response against myelin by blocking PK2 in vivo with PK2 receptor antagonists. We treated with PK2 immune cells activated against myelin antigen to explore the immune-modulating effects of this peptide in vitro. Results: Pk2 messenger RNA was upregulated in spinal cord and lymph node cells (LNCs) of mice with EAE. PK2 protein was expressed in EAE inflammatory infiltrates and was increased in sera during EAE. In patients with relapsing-remitting MS, transcripts for PK2 were significantly increased in peripheral blood mononuclear cells compared with healthy controls, and PK2 serum concentrations were significantly higher. A PK2 receptor antagonist prevented or attenuated established EAE in chronic and relapsing-remitting models, reduced CNS inflammation and demyelination, and decreased the production of interferon (IFN)-γ and interleukin (IL)-17A cytokines in LNCs while increasing IL-10. PK2 in vitro increased IFN-γ and IL-17A and reduced IL-10 in splenocytes activated against myelin antigen. Conclusion: These data suggest that PK2 is a critical immune regulator in CNS autoimmune demyelination and may represent a new target for therapy

Simplifying one-loop amplitudes in superstring theory

We show that 4-point vector boson one-loop amplitudes, computed in ref.[1] in the RNS formalism, around vacuum configurations with open unoriented strings, preserving at least N=1 SUSY in D=4, satisfy the correct supersymmetry Ward identities, in that they vanish for non MHV configurations (++++) and (-+++). In the MHV case (--++) we drastically simplify their expressions. We then study factorisation and the limiting IR and UV behaviour and find some unexpected results. In particular no massless poles are exposed at generic values of the modular parameter. Relying on the supersymmetric properties of our bosonic amplitudes, we extend them to manifestly supersymmetric super-amplitudes and compare our results with those obtained in the D=4 hybrid formalism, pointing out difficulties in reconciling the two approaches for contributions from N=1,2 sectors.Comment: 38 pages plus appendice

A magnetic internal mechanism for precise orientation of the camera in wireless endoluminal applications

Background and study aims: The use of magnetic fields to control operative devices has been recently described in endoluminal and transluminal surgical applications. The exponential decrease of magnetic field strength with distance has major implications for precision of the remote control. We aimed to assess the feasibility and functionality of a novel wireless miniaturized mechanism, based on magnetic forces, for precise orientation of the camera. Materials and methods: A remotely controllable endoscopic capsule was developed as proof of concept. Two intracapsular moveable permanent magnets allow fine positioning, and an externally applied magnetic field permits gross movement and stabilization. Performance was assessed in ex vivo and in vivo bench tests, using porcine upper and lower gastrointestinal tracts. Results: Fine control of capsule navigation and rotation was achieved in all tests with an external magnet held steadily about 15 cm from the capsule. The camera could be rotated in steps of 1.8°. This was confirmed by ex vivo tests; the mechanism could adjust the capsule view at 40 different locations in a gastrointestinal tract phantom model. Full 360° viewing was possible in the gastric cavity, while the maximal steering in the colonwas 45° in total. In vivo, a similar performance was verified, where the mechanism was successfully operated every 5 cm for 40 cm in the colon, visually sweeping from side to side of the lumen; 360° views were obtained in the gastric fundus and body, while antrally the luminal walls prevented full rotation. Conclusions: We report the feasibility and effectiveness of the combined use of external static magnetic fields and internal actuation to move small permanent intracapsular magnets to achieve wirelessly controllable and precise camera steering. The concept is applicable to capsule endoscopy as to other instrumentation for laparoscopic, endoluminal, or transluminal procedures

Relic Backgrounds of Gravitational Waves from Cosmic Turbulence

Turbulence may have been produced in the early universe during several kind of non-equilibrium processes. Periods of cosmic turbulence may have left a detectable relic in the form of stochastic backgrounds of gravitational waves. In this paper we derive general expressions for the power spectrum of the expected signal. Extending previous works on the subject, we take into account the effects of a continuous energy injection power and of magnetic fields. Both effects lead to considerable deviations from the Kolmogorov turbulence spectrum. We applied our results to determine the spectrum of gravity waves which may have been produced by neutrino inhomogeneous diffusion and by a first order phase transition. We show that in both cases the expected signal may be in the sensitivity range of LISA.Comment: 25 pages, 1 figur

Rotational dynamics of optically trapped polymeric nanofibers

The optical trapping of polymeric nanofibers and the characterization of the rotational dynamics are reported. A strategy to apply a torque to a polymer nanofiber, by tilting the trapped fibers using a symmetrical linear polarized Gaussian beam is demonstrated. Rotation frequencies up to 10 Hz are measured, depending on the trapping power, the fiber length and the tilt angle. A comparison of the experimental rotation frequencies in the different trapping configurations with calculations based on optical trapping and rotation of linear nanostructures through a T-Matrix formalism, accurately reproduce the measured data, providing a comprehensive description of the trapping and rotation dynamics.Comment: (21 pages, 5 figures

Changes in anthropometric, biochemical, hematological, hormonal and cardiac markers in a group of late-adult amateur cyclist, afet continuous and prolonged exercise on an uncontrolled diet

Abstract: Purpose: to describe and compare the main biochemical and hematological parameters, markers of cardiac and stress suffering (cortisol), in an amateur group of 8 late-adult cyclists (average age 60.9 years s.d. 4.1 years) before and after a continuous bicycle course of 9 days with an actual duration of 7 days and a daily average of 103.5 Km (total of 725 km) on an uncontrolled diet. Results: body weight, BMI, systolic and diastolic pressure did not vary significantly in pre- and post-cycling performance (p> 0.05). There was no significant change in the pre- and post-red blood cell count in the hemochromocytometric hematological parameters (p = 0.57), while hemoglobin values decreased significantly after pedaling (p = 0.03), as did the average cellular hemoglobin values and the average cell concentration of hemoglobin (p = 0.002 and p = 0.0006, respectively). The number of platelets, white blood cells, the absolute number of neutrophils, lymphocytes, eosinophils, basophils and monocytes, and the percentage of neutrophils, eosinophilic lymphocytes, basophils and monocytes did not change significantly (p> 0.05). With regard to basic biochemistry, there was no significant variation in the values of glucose, urea, creatinine, alanine amino transferase, alkaline phosphatase, cholinesterase and creatinine kinase (p> 0.05). Aspartate amino transferase was found to be significantly greater after pedaling (p = 0.03). The values of albumin, total proteins, lactate dehydrogenase, total calcium, inorganic phosphorus, total magnesium, total iron, sodium and potassium were statistically non-significant between pre and post phases. The lipid profile, total cholesterol, triglycerides, lipases, HDL and LDL were also statistically non-significant even if HDL values increased on average after cycling performance (before 48.9 \ub1 9.5 and after 53.8 \ub1 12.4) while LDL values decreased on average (before 118.5 \ub1 28.8 and after 101.6 \ub1 10.3). In the hormone-labeling and vitamin group, ferritin was statistically non-significant. Pre and post changes in the stress hormone cortisol, PSA, vitamin B12 and natriuretic B-type NT-proBNP peptide were statistically non-significant. Instead, folate decreased significantly following the cycling performance (p = 0.017). In protein biochemistry, apolipoprotein A1 was statistically significant (p = 0.038) increasing after pedaling, while apolipoprotein B, C-reactive protein and transferrin were statistically non-significant. CK MB mass and troponin I in the cardiac markers did not undergo significant changes between pre and post phases. Conclusions: despite the small size of the chosen sample, parameters analyzed between pre and post continuous physical effort lead to the conclusion and confirmation of many data in the literature and, that is, that sporting activity conducted in an important way can improve the biochemical/functional state and, therefore, the health of practising subjects even in late adults and/or the elderly. This could postpone physical psychic decline caused by the natural progression of years