3,132 research outputs found

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

    Full text link
    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

    Get PDF
    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

    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

    Get PDF
    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

    A LOW-COST ICT SOLUTION TO SUPPORT VISITORS IN TOURISTIC CAVES

    Get PDF
    This study aims to examine innovative solutions to enhance the tourist experience and visitor localization within the Bossea Cave, one of the most important karstic caves in Italy, located in the municipality of Frabosa Soprana. The lack of advanced technological tools for managing cave structures and modernizing visitor tours creates a significant opportunity for the integration of new technologies. The researchers propose a low-cost and modular hardware infrastructure, consisting of a series of single-board computers distributed throughout the cave, acting as local web servers to provide visitors with customizable multimedia content, accessible through a web application on their personal devices via a local Wi-Fi network. This infrastructure also enables visitor localization based on their connection point within the cave, with the additional goal of testing the ultra-wideband (UWB) wireless technology in this complex and humid environment. The UWB technology offers high-precision localization, even in indoor environments and caves, where GNSS signals are not available. Overall, the study provides a promising solution to enhance the visitor experience and offers opportunities for cave management and research

    Critical role for prokineticin 2 in CNS autoimmunity

    Get PDF
    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

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

    Get PDF
    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

    Engraulis anchoita

    Get PDF
    This coastal to mid-continental shelf, pelagic species is widely distributed from Brazil to Argentina. It is a short-lived species with an estimated generation length of 2-4 years. Biomass fluctuates naturally with environmental conditions. It is currently commercially exploited only in Argentina. The global population is comprised of three stocks (1. southeast Brazil north of 28°S, 2. Brazil south of 28°S, Uruguay and Argentina to 41°S and 3. Argentine Patagonia between 41°S and 48°S). Abundance of the species in Brazil is stable. According to fishery independent scientific surveys, the Buenos Aires stock has a high biomass close to historical levels and it is underexploited. The Argentine population is regularly monitored and there are stringent fishing regulations in place. Fishing activity is not expected to be driving global-level declines approaching a Near Threatened or threatened level at this time. It is listed as Least Concern with a recommendation to continue to conduct research cruises to improve stock assessments. Research is also needed to better understand the observed changes in body size structure of the southern stocks.Fil: Buratti, C.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Díaz de Astarloa, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Hüne, M.. Universidad Austral de Chile; ChileFil: Irigoyen, A.. No especifíca;Fil: Landaeta, M.. Universidad de Valparaíso; ChileFil: Riestra, C.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Vieira, J.P.. Universidade Federal Do Rio Grande.; BrasilFil: Di Dario F.. Universidade Federal do Rio de Janeiro; Brasi

    Empowering Executive Functions in 5- and 6-Year-Old Typically Developing Children Through Educational Robotics: An RCT Study

    Get PDF
    Educational Robotics (ER) is a new learning approach that is known mainly for its effects on scientific academic subjects such as science, technology, engineering, and mathematics. Recent studies indicate that ER can also affect cognitive development by improving critical reasoning and planning skills. This study aimed to quantify the ability of ER to empower Executive Functions (EF), including the ability to control, update, and program information, in 5- and 6-year-old children attending first grade, a crucial evolutionary window for the development of such abilities. A total of 187 typically developing children were enrolled and randomly allocated into two experimental conditions: A, for immediate ER training, and B, for waitlist. ER-Laboratories (ER-Lab) for small groups were organized at schools, using a child-friendly, bee-shaped robot called Bee-Bot® (Campus Store). Activities were intensive, enjoyable, and progressively more challenging over the 20 twice-weekly sessions. Outcome measures, based on standardized tests, were used to quantify the effects of ER on EF. Compared to the control group, the ER-Lab group showed significantly better ability to actively manipulate information in short-term memory and suppress automatic responses in favor of goal-appropriate actions. This RCT study provides the first quantitative evidence of the positive effects of ER activities for improving working memory and inhibition in the early school years

    Light-emitting nanocomposite cds-polymer electrospun fibres via in-situ nanoparticle generation

    Get PDF
    We report on the simple, in situ generation of CdS nanocrystals inside electrospun polymer fibres by thermal decomposition of a cadmium thiolate precursor, leading to nanocomposite light-emitting fibres. The modifications induced in the precursor by the thermal decomposition are investigated by a morphological, structural and spectroscopic analysis of the resulting nanocomposite fibres. This approach allows us to overcome nanofabrication difficulties related to disfavoured micro- or nanofluidic molecular flow as given by the direct incorporation of particles in the electrospinning solution. This method therefore enables the synthesis of luminescent, CdS-based composite fibres with emission peaked in the visible range, suitable as building blocks for nanophotonic devices based on light-emitting nanomaterials
    corecore