197,814 research outputs found
Introduction: Working Stars
No full textThis chapter describes the rationale of the edited collection, connecting it to the Italian research project it stems from. Building on previous theoretical understandings of actorship and on literature on Italian actors, and showcasing the main methods to survey the subject, i.e., performance studies, celebrity studies, and production studies. It shows describes how the subject of Italian contemporary film and media performers is investigated: by looking at the training and the early steps of actors, by following multifaceted careers across different projects, audiences, and media, and by tracing the design of personas and their recognition through press, PR, awards, and social media. Both the agency of actors and the role of intermediaries are highlighted, scrutinizing the background of a changing landscape, with the aim of providing our readership with a thorough account of the individual Italian case histories
Autoecologia e valore indicatore di diverse specie del genere Orthocladius van der Wulp (Diptera, Chironomidae)
No full textHarnessing radiation to improve immunotherapy: better with particles?
No full textThe combination of radiotherapy and immunotherapy is one of the most promising strategies for cancer treatment. Recent clinical results support the pre-clinical experiments pointing to a benefit for the combined treatment in metastatic patients. Charged particle therapy (using protons or heavier ions) is considered one of the most advanced radiotherapy techniques, but its cost remains higher than conventional X-ray therapy. The most important question to be addressed to justify a more widespread use of particle therapy is whether they can be more effective than X-rays in combination with immunotherapy. Protons and heavy ions have physical advantages compared to X-rays that lead to a reduced damage to the immune cells, that are required for an effective immune response. Moreover, densely ionizing radiation may have biological advantages, due to different cell death pathways and release of cytokine mediators of inflammation. We will discuss results in esophageal cancer patients showing that charged particles can reduce the damage to blood lymphocytes compared to X-rays, and preliminary in vitro studies pointing to an increased release of immune-stimulating cytokines after heavy ion exposure. Pre-clinical and clinical studies are ongoing to test these hypotheses
Comparison between unilateral and bilateral lower limb strength trainings
No full textAim: Back Squat (BS) is an exercise traditionally used to increase lower limb strength and power (Hoffman et al., 2009). Unilateral training such as Bulgarian Split Squat (BSS) could be an alternative method (McCurdy et al., 2005). The aim of this study was to compare the effects of unilateral and bilateral strength training on lower limb strength and power.
Methods: Ten healthy males (age=28.8±5.1yrs; BMI=23.37±2.10 kg m-2) were recruited in this study and split into two groups: Bilateral group (BG, n=5) that performed BS high-intensity resistance training (HIRT, 4x5repetitions, ~80% of 1RM); Unilateral group (UG, n=5) that performed BSS HIRT (4x5repetitions,~80% of 1RM) on both left and right leg. Before and after 9 weeks of training (2 times per week), they were tested on: 1RM on back squat (1RMBS) and 1RM on BSS using left and right leg (1RMBSS-L and 1RMBSS-R, respectively). Two-way ANOVA was used to identify group difference pre and post training periods.
Results: Both groups improved 1RMBS of 12.34±4.25% between pre and post training periods (within-subjects differences: p<0.001). UG improved 1RMBSS-L of 9.86% (interaction: p=0.002) and 1RMBSS-R of 9.36% (interaction: p=0.002) with respect than BG.
Conclusion: Although UG obtained greater improvement in unilateral lower limb strength than BG, UG was not able to transfer this improvement on bilateral movement. Thus, both trainings seemed to be similarly useful to improve bilateral strength and power.
Reference
Hoffman JR, Ratamess NA, Klatt M, Faigenbaum AD ... Kraemer WJ (2009) Comparison between different off-season resistance training programs in Division III American college football players. J Strength Cond Res 23:11–19.
McCurdy KW, Langford GA, Doscher MW, Wiley LP, Mallard KG (2005) The effects of short-term unilateral and bilateral lower-body resistance training on measures of strength and power J Strength Cond Res 19:9–15
Radiation-Induced Chromosomal Aberrations and Immunotherapy: Micronuclei, Cytosolic DNA, and Interferon-Production Pathway
No full textRadiation-induced chromosomal aberrations represent an early marker of late effects, including cell killing and transformation. The measurement of cytogenetic damage in tissues, generally in blood lymphocytes, from patients treated with radiotherapy has been studied for many years to predict individual sensitivity and late morbidity. Acentric fragments are lost during mitosis and create micronuclei (MN), which are well correlated to cell killing. Immunotherapy is rapidly becoming a most promising new strategy for metastatic tumors, and combination with radiotherapy is explored in several pre-clinical studies and clinical trials. Recent evidence has shown that the presence of cytosolic DNA activates immune response via the cyclic GMP–AMP synthase/stimulator of interferon genes pathway, which induces type I interferon transcription. Cytosolic DNA can be found after exposure to ionizing radiation either as MN or as small fragments leaking through nuclear envelope ruptures. The study of the dependence of cytosolic DNA and MN on dose and radiation quality can guide the optimal combination of radiotherapy and immunotherapy. The role of densely ionizing charged particles is under active investigation to define their impact on the activation of the interferon pathway
Inhibitory action of acetylcholine, baclofen and GTP-gamma-S on calcium channels in adult rat sensory neurons
No full textHigh- and low-voltage activated calcium channel currents (HVA and LVA) were inhibited by acetylcholine (10-100-mu-M) and baclofen (10-mu-M) in adult rat sensory neurons. This modulatory effect was present on dihydropyridine (nifedipine 1-mu-M) and/or omega-conotoxin (3.2-mu-M, 2-5 h incubation) insensitive components and was insensitive to holding potentials (V(h) -50 to -90 mV). GTP-gamma-S (100-mu-M) prolonged calcium channel current activation in a time- and voltage-dependent manner. On the other hand, the current amplitude reduction induced by muscarinic and GABA(B) receptor activation, was not relieved by a 50-ms conditioning prepulse to +50 mV. This suggests the possibility of an alternative voltage-independent modulation mechanism
SOMATOSENSORY TRANSMISSION THROUGH THE VENTROPOSTEROLATERAL THALAMIC NUCLEUS DURING SLEEP AND WAKEFULNESS
No full textThe first humans travelling on ice: an energy-saving strategy?
No full textEconomy of locomotion is a constant challenge for animals, particularly when related to migrations and travelling. The present study focuses on human locomotion and particularly on the development of ice skating. The aim of our research was to understand whether an environmental feature such as a strong presence of lakes (frozen in winter) could force humans to develop ice skates in order to limit the energy cost of travelling. We hypothesized that the energy-saving principle was a determinant factor in the development of human locomotion on ice. Five healthy adult participants took part in the experiments, during which we recorded the speed (1.2 ± 0.3 m s−1) and metabolic energy cost (4.6 ± 0.9 J kg−1 m−1) associated with travelling on bone skates. Simulations were also performed to demonstrate whether the benefit given by the use of skates was different in the areas where ice skating appears to have evolved originally. The gain reachable by using bone skates could lead to an extremely high energy saving (equal to 10% of the energy needed to survive during the cold season) and differs significantly between the regions considered in the present study. An analysis of the geometrical shape of lakes associated with fractal analysis of their distribution suggests that, in order to better adapt to the severe conditions imposed by the long lasting winters, Finnish populations could benefit more than others from developing this ingenious locomotion tool. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 1–7
Skin temperature modifications during physical exercise measured by infrared thermography
No full textHeat dissipation during sport exercise is an important physiological mechanism that may affect athletic performance. It depends on skin temperature (ST) and on cutaneous blood flow (CBF). ST, as an indicator of CBF, can be measured by infrared thermography (IRT). ST modifications during different kinds of exercise have been studied by few researchers using IRT.
Global endurance exercise, such as graded load running, was characterized by a decrease in the ST of the all body (Merla et al., 2010); similar results was also found in incremental cycling exercise where the ST of the trunk (Torii et al., 1992) and of the finger of the hand (Zontak et al., 1998) begun to fall immediately on starting to exercise.
Different ST trend was found in exercise involving only small muscle groups. In a localized resistance physical exercise it was observed a little increase in ST of the posterior thigh (Ferreira et al., 2008) and of the deltoid after static exertion until exhaustion (Bertmaring et al., 2008).
Also breathing exercises were evaluated using IRT: it was found a different dynamics of ST changes in diaphragmatic and thoracic respiration. In diaphragmatic exercise, which mainly uses internal musculature, as compared to thoracic one, temperature did not increase in trunk areas. This is probably due to a lesser use of superficial muscle (Ludwig et al., 2012).
A recent study put in evidence that trained subjects responded more quickly than untrained controls in standing calf raise exercise (Formenti et al., 2013). A possible explanation may be found in the different grade of vasoconstriction in trained and untrained subjects that occur in the beginning of the exercise.
In a new study that we are performing, we would to test the hypothesis that differences in ST trend exist in two modalities of squat exercise: normal velocity of movement (1 sec. eccentric/1 sec. concentric phase) and slow velocity of movement (5 sec. eccentric/5 sec. concentric phase) that should cause more vasoconstriction in the quadriceps.
Medical thermal images are captured in several modes that can be classified according to the temporal rate of shooting. Single state image enhance areas of the body with hot and cold spots. Temporal sequences of thermal images can be helpful to detect thermal anomalies linked to different pathologies and during exercise. With very fast image shooting (100 hz.) it is possible to detect variations in temperature arise from hemodynamic or neural control. Because of the difficult in recording and analyzing thermal images, the methods by researchers are not similar with the others. Thus, further studies are necessary to standardize the methods both in thermal images analysis and protocol procedure, as well as applying IRT to other kind of physical exercises and subjects.
Bibliography
Bertmaring et al., Ergonomics. 2008, 51, 1606-1619.
Ferreira et al., Ann. Biomed. Eng. 2008, 37, 1420-1427.
Formenti et al., Ann. Biomed. Eng. 2013, 41, 863-871.
Ludwig et al., Acta Bioeng. Biomech. 2012, 14, 41-47.
Merla et al., Ann. Biomed. Eng. 2010, 38, 158-63.
Torii et al., Br. J. Sports. Med. 1992, 26, 29-32.
Zontak et al., Ann. Biomed. Eng. 1998, 26, 988-993
Modeling and simulations of ultra-intense laser-driven bremsstrahlung with double-layer targets
No full textHigh-energy bremsstrahlung emission can occur owing to electron scattering in the nuclei or ions Coulomb field following the relativistic-electron generation in high-intensity laser interaction with plasmas. Such emission of photons in the keV–MeV energy range is of interest to characterize the relativistic-electron populations and develop laser-based photons sources. Even if it is a well-established and widely studied emission process, its modeling in laser-plasma scenarios needs further investigation. Moreover, advanced near-critical double-layer targets (DLTs), consisting in a low-density foam deposited on a thin solid substrate, have never been explored extensively for bremsstrahlung photon emission. Therefore, in this paper, we show the rationale, advantages, limitations, application regime, and complementarity of different modeling approaches and apply them to the unconventional configuration based on DLTs. We use multi-dimensional particle-in-cell (PIC) simulations coupled with a Monte Carlo strategy to simulate bremsstrahlung in two ways: integrated into the PIC loop itself or after the simulation with two separate codes. We also use simplified semi-analytical relations to retrieve the photon properties starting only from information on the relativistic electrons. With these tools, we investigate bremsstrahlung emission when an ultra-intense laser (0.8 μm wavelength, 30 fs duration, a0 = 20 and 3 μm waist) interacts with DLTs having different properties. Despite some limitations of the numerical tools, we find that all approaches significantly agree on the characteristics of ~1–100 MeV photon emission. This points to the possibility of adopting the different modeling approaches in a complementary way while at the same time identifying the best suited for a specific scenario. Regardless, DLTs appear to overall boost the high energy photon emission while at the same time enabling control of the emission itself
- …
