Effective Lagrangian for Heavy and Light Mesons: Semileptonic Decays

We introduce an effective lagrangian including negative and positive parity heavy mesons containing a heavy quark, light pseudoscalars, and light vector resonances, with their allowed interactions, using heavy quark spin-flavour symmetry, chiral symmetry, and the hidden symmetry approach for light vector resonances. On the basis of such a lagrangian, by considering the allowed weak currents and by including the contributions from the nearest unitarity poles we calculate the form factors for semileptonic decays of $B$ and $D$ mesons into light pseudoscalars and light vector resonances. The available data, together with some additional assumptions, allow for a set of predictions in the different semileptonic channels, which can be compared with those following {}from different approaches. A discussion of non-dominant terms in our approach, which attempts at including a rather complete dynamics, will however have to wait till more abundant data become available.Comment: LaTeX (style article), 19 pages, UGVA-DPT 1992/11-790, BARI-TH/92-12

Environmental parameters monitoring in show caves: some examples from NW Italian show caves

Natural cavities are characterized by particular environmental conditions such as no light and the remarkable stability of the air temperature. These distinctive environmental factors have been able to maintain and preserve speleothems, paleontological and archaeological remains, and particular habitats rich in specialized fauna over the centuries (Balestra et al., 2021). The development of a cave into a show cave requires different modification to create the necessary facilities for tourist use and the passage of several hundred visitors a day can irreversibly damage speleothems and ecosystems (Cigna, 2016; Cigna & Forti, 2013), therefore, it is necessary to pay special attentions and monitor environmental parameters over time. The data should be collected before the construction of the tourist facilities, followed by a constant monitoring of the parameters during the tourist use to examine and verify any possible impacts over time affecting the cavity. In general, there is a lack of data about the studies on cave environmental conditions before and during the tourist use, especially because there are no reference protocols regarding the main environmental parameters to monitor and how these monitoring must be carried out. In this work, the main environmental parameters of three different show caves in NW Italy (Bossea Cave, Piedmont, Toirano and Borgio Verezzi caves, Liguria) were monitored. These parameters are the main factors characterizing the delicate cave environment balance and they can be significantly modified by the lighting systems and the tourist passage. A series of instruments with high precision probes were installed in every cave, aiming at environmental monitoring, especially hydrogeology, hypogeal meteorology (temperature and air circulation) and air carbon dioxide concentrations. These instruments must be able to operate in particularly difficult conditions, such as high relative humidity (usually close to 100% in caves) and to detect even very small parameters variations, such as air velocity variations. The probes must be correctly located in different part of the cavities, especially considering the significant air stratifications that often occur in caves, with consequent vertical variations in air temperature and CO₂ content. The data recording time is a fundamental parameter too, allowing to examine with precision the possible impacts related to the tourist passages in some areas of the show cave

Development of a sustainable water management for the su Gologone karst spring (Sardinia, Italy)

Drought climate change hot spots, Su Gologone, Sardinia, water pumping management

Detecting Molecular Rotational Dynamics Complementing the Low-Frequency Terahertz Vibrations in a Zirconium-Based Metal-Organic Framework

We show clear experimental evidence of co-operative terahertz (THz) dynamics observed below 3 THz (~100 cm-1), for a low-symmetry Zr-based metal-organic framework (MOF) structure, termed MIL-140A [ZrO(O2C-C6H4-CO2)]. Utilizing a combination of high-resolution inelastic neutron scattering and synchrotron radiation far-infrared spectroscopy, we measured low-energy vibrations originating from the hindered rotations of organic linkers, whose energy barriers and detailed dynamics have been elucidated via ab initio density functional theory (DFT) calculations. For completeness, we obtained Raman spectra and characterized the alterations to the complex pore architecture caused by the THz rotations. We discovered an array of soft modes with trampoline-like motions, which could potentially be the source of anomalous mechanical phenomena, such as negative linear compressibility and negative thermal expansion. Our results also demonstrate coordinated shear dynamics (~2.5 THz), a mechanism which we have shown to destabilize MOF crystals, in the exact crystallographic direction of the minimum shear modulus (Gmin).Comment: 10 pages, 6 figure

FRATTURE DA STRESS NEI TERSICOREI: PREVENZIONE E ITER DIAGNOSTICO TERAPEUTICO. ANALISI DEI FATTORI DI RISCHIO MEDIANTE QUESTIONARIO 'SELF REPORTED INJURY' E DATABASE CLINICO

STRESS FRACTURES IN BALLET DANCERS: OUR PREVENTION AND DIAGNOSTIC PROTOCOL. RISK FACTORS EVALUATION USING A SELF REPORTED INJURY QUESTIONNAIRE AND CLINICAL HISTORY DATA BASE. STUDY DESIGN: RETROSPECTIVE DESCRIPTIVE STUDY OBJECTIVE: WE PERFORMED A STUDY TO DESCRIBE OUR DIAGNOSTIC AND CLINICAL APPROACH TO STRESS FRACTURES IN ELITE YOUNG BALLET DANCERS. THE STUDY LASTED ONE DANCE ACADEMIC YEAR. MATERIAL AND METHODS: OUR POPULATION CONSISTED OF 180 BALLET DANCERS BUT ONLY 111 DANCERS WERE FINALLY ENROLLED TO THE STUDY. AT THE END OF THE ACCADEMIC YEAR EACH DANCER FILLED IN A SELF REPORTED INJURIES QUESTIONNAIRE, AND ALL CLINICAL DATA OF DANCERS MEDICAL HISTORY DURING THE SAME YEAR WERE COLLECTED. IF A STRESS FRACTURE WAS SUPPOSED DURING CLINICAL EVALUATION, A SPECIFIC PROTOCOL WAS APPLIED. THIS WAS BASED ON MRI EVALUATION AND EXTERNAL SHOCK WAVE THERAPY (ESWT) APPLICATIONS. SUSPICIOUS FACTORS OF STRESS FRACTURES WERE IDENTIFIED AND USED TO DECIDE THE TREATMENT OPTIONS. RESULTS: DESCRIPTIVE DATA REGARDING AGE, SEX, AND ANTHROPOMETRIC MEAUSEREMENTS WERE PUBLISHED IN THE ORIOGINAL WORK. 19 STRESS FRACTURES WERE OCCURRED AT METATARSAL AND TIBIAL REGION. ALL DANCERS UNDERWENT TO THREE APPLICATIONS OF ESWT. DISCUSSION: USING THE CLINICAL DATA OF THE MEDICAL HISTORY, WE IDENTIFIED SEVERAL SUSPICIOUS FACTORS FOR STRESS FRATURES. POSITIVE SIGNS DURING THE CLINICAL EVALUATION AND AT LEAST TWO SUSPICIOUS FACTORS WERE PEREMPTORY TO DECIDE TO FOLLOW THE TREATMENT WITH ESWT. ALL DANCERS WITH STRESS FRACTURES RECEIVED THREE CONSECUTIVE APPLICATIONS OF ESWT WITH GOOD RESULTS. THEN THESE DANCERS FOLLOWED A PERIOD OF ABSOLUTE REST OF 3 WEEKS (MEAN) AND A PERIOD OF RELATIVE REST OF 4 WEEKS (MEAN). DANCERS NEVER USED CASTS AND CONTINUED TO PRACTISE EXERCISE FOR ELASTICITY IN NON-WEIGHT BEARING DURING ALL THESE PERIODS. AFTER THIS, DANCERS STARTED AGAIN DANCING PROGRESSIVELY WITH A RESTORATION OF A COMPLETE DANCING ACTIVITY AFTER 1 MONTH. WE THINK THAT ESWT AND THE CORRECTION OF ANY PREDISPOSING FACTORS WERE AND ARE ACTUALLY THE GOLD STANDARD IN THE TREATMENT OF STRESS FRACTURES IN ELITE DANCERS. THE PROMPT DIAGNOSIS FOLLOWED A METICULOUS CLINICAL AND ANAMNESTIC EVALUATION. MRI IMAGES CAN HIGHLIGHT STRESS FRACTURES AND THEY SCHOULD BE PERFOMED AT THE BEGINNING OF SYMPTOMS TO START TREATMENT IN TIME. CONCLUSION: OUR DIAGNOSTIC AND TREATMENT PROTOCOL FOR STRESS FRACTURE PERMITTED A GOOD HEALING OF STRESS FRATURES IN ALL YOUNG ELITE BALLET DANCERS OF OUR STUDY GROUP

An evolutionary model for the V404 Cyg system

V404 Cyg is a low mass X-Ray binary (LMXB) system that has undergone outbursts in 1938, 1989, and 2015. During these events, it has been possible to make determinations for the relevant data of the system. This data include the mass of the compact object (i.e., a black hole; BH) and its companion, the orbital period, the companion spectral type, and luminosity class. Remarkably, the companion star has a metallicity value that is appreciably higher than solar. All these data allow for the construction of theoretical models to account for its structure, determine its initial configuration, and predict its fate. Assuming that the BH is already formed when the primary star reaches the zero age main sequence, we used our binary evolution code for this purpose. We find that the current characteristics of the system are nicely accounted for by a model with initial masses of 9 M· for the BH, 1.5 M· for the companion star and an initial orbital period of 1.5 d, while also considering that at most 30% of the mass transferred by the donor is accreted by the BH. The metallicity of the donor for our best fit is Z=0.028 (twice solar metallicity). We also studied the evolution of the BH spin parameter, assuming that is not rotating initially. Remarkably, the spin of the BHs in our models is far from reaching the available observational determination. This may indicate that the BH in V404 Cyg was initially spinning, a result that may be relevant for understanding the formation BHs in the context of LMXB systems.Fil: Bartolomeo Koninckx, Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: de Vito, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Benvenuto, Omar Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

Local probing of the field emission stability of vertically aligned multiwalled carbon nanotubes

Metallic cantilever in high vacuum atomic force microscope has been used as anode for field emission experiments from densely packed vertically aligned multi-walled carbon nanotubes. The high spatial resolution provided by the scanning probe technique allowed precise setting of the tip-sample distance in the submicron region. The dimension of the probe (curvature radius below 50nm) allowed to measure current contribution from sample areas smaller than 1um^2. The study of long-term stability evidenced that on these small areas the field emission current remains stable (within 10% fluctuations) several hours (at least up to 72 hours) at current intensities between 10-5A and 10-8A. Improvement of the current stability has been observed after performing long-time Joule heating conditioning to completely remove possible adsorbates on the nanotubes.Comment: 15 pages, 7 figure

The impact of aging on human brain network target controllability

Understanding how few distributed areas can steer large-scale brain activity is a fundamental question that has practical implications, which range from inducing specific patterns of behavior to counteracting disease. Recent endeavors based on network controllability provided fresh insights into the potential ability of single regions to influence whole brain dynamics through the underlying structural connectome. However, controlling the entire brain activity is often unfeasible and might not always be necessary. The question whether single areas can control specific target subsystems remains crucial, albeit still poorly explored. Furthermore, the structure of the brain network exhibits progressive changes across the lifespan, but little is known about the possible consequences in the controllability properties. To address these questions, we adopted a novel target controllability approach that quantifies the centrality of brain nodes in controlling specific target anatomo-functional systems. We then studied such target control centrality in human connectomes obtained from healthy individuals aged from 5 to 85. Main results showed that the sensorimotor system has a high influencing capacity, but it is difficult for other areas to influence it. Furthermore, we reported that target control centrality varies with age and that temporal-parietal regions, whose cortical thinning is crucial in dementia-related diseases, exhibit lower values in older people. By simulating targeted attacks, such as those 19 occurring in focal stroke, we showed that the ipsilesional hemisphere is the most affected one regardless of the damaged area. Notably, such degradation in target control centrality was more evident in younger people, thus supporting early-vulnerability hypotheses after stroke

Spermatogonial kinetics in humans

The human spermatogonial compartment is essential for daily production of millions of sperm. Despite this crucial role, the molecular signature, kinetic behavior and regulation of human spermatogonia are poorly understood. Using human testis biopsies with normal spermatogenesis and by studying marker protein expression, we have identified for the first time different subpopulations of spermatogonia. MAGE-A4marks all spermatogonia, KITmarks all Bspermatogonia and UCLH1 all Apale-dark (Ap-d) spermatogonia. We suggest that at the start of the spermatogenic lineage there are Ap-d spermatogonia that are GFRA1High, likely including the spermatogonial stem cells. Next, UTF1 becomes expressed, cells become quiescent and GFRA1 expression decreases. Finally, GFRA1 expression is lost and subsequently cells differentiate into B spermatogonia, losing UTF1 and acquiring KIT expression. Strikingly, most human Ap-d spermatogonia are out of the cell cycle and even differentiating type B spermatogonial proliferation is restricted. A novel scheme for human spermatogonial development is proposed that will facilitate further research in this field, the understanding of cases of infertility and the development of methods to increase sperm output