1,721,197 research outputs found
Subwavelength quantum imaging with noisy detectors
No full textIt has been recently shown that an interferometric measurement may allow for subwavelength resolution of incoherent light. Whereas this holds for noiseless detectors, one could expect that the resolution is in practice limited by the signal-to-noise ratio. Here I present a qualitative assessment of the ultimate resolution limits that can be achieved using noisy detectors. My analysis indeed indicates that the signal-to-noise ratio represents a fundamental limit to quantum imaging, and the reduced resolution scales with the square root of the signal-to-noise ratio. For example, a signal-to-ratio of 20dB is needed to resolve one order of magnitude below the wavelength
Differential effects of exercise on sex hormone-binding globulin and non-sex hormone-binding globulin-bound testosterone
No full textThe response of total testosterone (T), free testosterone (fT), sex hormone-binding globulin (SHBG) and non-SHBG-bound testosterone (NST) to the same exercise protocol was evaluated in two different experiments on long distance runners. The first experiment was performed in the morning at 0900 hours with nine athletes, while the second was carried out in the afternoon at 1500 hours with seven athletes. During each experiment, each athlete ran for 1 h at the previously determined speed corresponding to 2 mmol.l-1 blood lactate concentration. Three venous blood samples were collected in each experiment: before exercise, at the end of running and after 1 h of recovery. Total T and SHBG showed similar responses: in the first experiment they had decreased after exercise, while in the second they had increased at the end of running. A positive correlation between total T and SHBG concentrations was found at the end of exercise. In both experiments, NST and fT had increased after exercise and decreased to initial concentrations during recovery. The results would suggest the existence of a compensatory mechanism which maintains adequate concentrations of biologically active T when total T concentrations decrease
Notational analysis of elite men’s water polo related to specific margins of victory
No full textThe present study aimed to analyze the water polo matches of the men's World Championships, comparing technical and tactical aspects of winning and losing teams, during closed (≤ 3 goals of margin of victory at the end of the 4(th) quarter; winning, W; losing, L) and unbalanced (>3 goals; winning, MW; losing, ML) games. Therefore, 42 of the 48 (6 were draw at end of the 4(th) quarter) matches were considered. According to each game situation (i.e., even, counterattack, power-play, transition), a notational analysis was performed in relation to the following aspects: occurrence of actions, action outcome, execution and origin of shots, and mean duration. In addition, the occurrence of the offensive (and role) and defensive arrangements of even and power-play were analyzed. To show differences (p < 0.05) in terms of margin of victory, an analysis of variance was applied. Although ML (74 ± 11%) performed more even actions than W (68 ± 7%) and MW (69 ± 6%), the latter teams (W = 9 ± 6%; MW = 13 ± 6%) performed more counterattacks than L (3 ± 2%) and ML (5 ± 5%). Power-play is more played during closed (W = 20 ± 3%; L = 22 ± 3%) than unbalanced games (MW = 17 ± 4%; ML = 16 ± 7%). Moreover, differences in terms of margin of victory emerged for mean duration (even, power-play, transition), action outcome (even, power-play), zone origin (even, counterattack, power-play) and technical execution (even, power-play) of shots, and even and power-play offensive (and role) and defensive arrangements. Divergences mainly emerged between closed and unbalanced games, highlighting that the water polo matches of the men's World Championships need to be analyzed either considering the winning and losing outcome of match and specific margins of victory. Thus, coaches can advance their knowledge, considering that closed and unbalanced games are largely characterized by the opponent's exclusion fouls to perform power-play actions, and by a divergent grade of defensive skills regardless of game situation, respectively. Key pointsThe water polo matches of the men's World Championships need to be analyzed considering successful/unsuccessful teams as well as specific margins of victory.Closed matches are mainly characterized by a high occurrence of the opponent's exclusion fouls to perform the power-play actions.For the unbalanced matches, a divergent grade of defensive skills between teams has been highlighted.Coaches can improve their training, considering the opponent's exclusion fouls to perform the power-play actions towards a closed match, and caring the defensive skills of each game situation towards an unbalanced match
Dynamic monitoring of the Temple of Neptune in Paestum (Italy) - Preliminary results
No full textThis paper focuses on an experimental monitoring system developed for the Temple of Neptune in Paestum within a joint research project carried out by the Department of Civil Engineering (DICIV) at the University of Salerno and the Archaeological Park of Paestum and Velia (PAEVE).This monitoring system is an innovative seismometric network consisting of mechanical and electronic components of high sensitivity and precision, allowing the assessment of the static and dynamic response of the structure in order to monitor its evolution over time and support proactive maintenance activities. In particular, the paper presents the monitoring network and discusses the preliminary results highlighting the contribution that such an innovative system can provide to a broader maintenance process. The results confirm the high level of accuracy and stability of the overall system, as well as preliminary correlations between the temple's daily response and weather changes such as temperature
Erratum: The random field XY model on sparse random graphs shows replica symmetry breaking and marginally stable ferromagnetism (Journal of Physics A: Mathematical and Theoretical (2019) 52 (284001)
No full textAfter the publication, the authors have discovered an error made in the analysis of the large C limit: namely equation (A5) in the appendix was solved only perturbatively around the trivial solution. In fact, a non-trivial solution can also appear discontinuously at low enough temperatures, corresponding to a first-order thermodynamical transition. The discovery of such a first-order transition makes necessary to reformulate the paragraph where the data in figure 4 are discussed and to amend the appendix with the right computation and the appropriate phase diagram. The last paragraph of section 3.5 after the sentence ‘the non-monotonicity of the critical line between the paramagnetic and the ferromagnetic line’ should read: ‘As discussed in detail in appendix A, the curve we are drawing in figure 4 is actually the spinodal curve of the paramagnetic phase. In the large C limit it becomes non-monotonic as a consequence of the phase transition becoming first order at low enough temperatures. In appendix A we show the exact location of the coexistence phase in the C = 8limit. For finite C values we have just checked that the saddle point equations admit a unique solution, i.e. (Figure Presented) (Formula Presented)
Preparatory versus main competitions: differences in performances, lactate responses, and pre-competitions plasma cortisol concentrations in elite male swimmers
No full textTwo groups of elite male swimmers were studied with a similar protocol during the winter training seasons of two consecutive years. In the first season (September 1997-January 1998), eight male swimmers (age 19-25 years) of the Italian National Team participated, after 12 weeks of increased training volume, in a preparatory national competition (PWC) and then, after a further 6 weeks of specific training, in the World Championships (WC, both competitions in a 50-m pool), which represented the main competition at the end of the 18 week-long winter season. In the second season (September 1998-December 1998), a group of ten high-level male swimmers (18-22 years) participated, after 8 weeks of increased training volume, in a preparatory national competition (PNC) and then, after a further 6 weeks of specific training, in the Italian Championships (IC, both competitions in a 25-m pool), the the main competition at the end of the 14 week-long winter season. A tapering period lasting 1-3 weeks was observed before the main competition in both seasons. All swimmers were competing in distances up to 400 m; two of them participated in the study in both seasons. The swimming velocities and post-competition blood lactate concentrations were higher in the main competitions than in the preparatory competitions in both seasons. Pre-competition cortisol (CORT) plasma concentrations were higher than the initial values at the beginning of the season, reaching maximal values at the preparatory competitions and then decreasing before the main competitions in both seasons. The percentage increase in individual swimming velocity from the preparatory to the main competition was positively correlated with the corresponding increase in post-competition blood lactate (r=0.63, p=0.046) in the 1997 season (WC) and negatively correlated with the corresponding decrease in pre-competition CORT concentration (r=-0.66, p=0.019) in the 1998 season (IC). Our results indicate that a decrease in pre-competition CORT could be a prerequisite for an improvement in swimming performance
Effects of formalin-induced pain on behaviour in rabbits
No full textWe have used formalin to assess the long-term behavioural and hormonal effects of persistent pain in rabbits. Behaviour has been recorded over 10 min sessions both before and after 10 min, 4 and 24 hours after injection of formalin. A low dose of formalin (0.1 ml at 5%) elicited licking of the injected paw which lasted only a few minutes. Exploratory behaviour was greater than in the control (sham-injected) animals in all post-injection sessions. Following a larger dose of formalin (0.5 ml at 8%) licking occurred in all post-injection sessions, while exploration was lower than the controls only immediately after injection. Twenty-four hours after the formalin injection, testosterone levels were unaffected. Corticosterone levels increased over the course of the experiment but this increase was equal for the experimental and the control groups. Results suggest that different pain intensities and durations have opposite effects on exploratory behaviour in rabbits
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