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We review the derivation and design of digital waveguides from physical models of stiff systems, useful for the synthesis of sounds from strings, rods, and similar objects. A transform method approach is proposed to solve the classic fourth-order equations of stiff systems in order to reduce it to two second-order equations. By introducing scattering boundary matrices, the eigenfrequencies are determined and their dependency is discussed for the clamped, hinged, and intermediate cases. On the basis of the frequency-domain physical model, the numerical discretization is carried out, showing how the insertion of an all-pass delay line generalizes the Karplus-Strong algorithm for the synthesis of ideally flexible vibrating strings. Knowing the physical parameters, the synthesis can proceed using the generalized structure. Another point of view is offered by Laguerre expansions and frequency warping, which are introduced in order to show that a stiff system can be treated as a nonstiff one, provided that the solutions are warped. A method to compute the all-pass chain coefficients and the optimum warping curves from sound samples is discussed. Once the optimum warping characteristic is found, the length of the dispersive delay line to be employed in the simulation is simply determined from the requirement of matching the desired fundamental frequency. The regularization of the dispersion curves by means of optimum unwarping is experimentally evaluated.

The "Urbino Charter" is a document aimed at promoting the wellbeing of the working person that the Olympus Observatory of the University of Urbino Carlo Bo and the Rubes Triva National Foundation, a joint body in the field of environmental hygiene, presented in Bilbao at a public conference in March 2023. The Charter has the objective of stimulating reflection on the issues related to prevention while drawing attention to the essential values for the effective protection of workers' health, safety and well-being. This commentary has the aim of presenting the 10 statements of the Chart, from a perspective of Occupational health and safety. [ABSTRACT FROM AUTHOR]

Older heart donors (D) are associated to decreased survival after heart transplant (HT) both in older and younger recipients (R). However, the effect of age mismatched D-R pair on late-term survival is still a matter of debate. The aim of this study is to analyze late outcomes after HT in age mismatched D-R pairs compared to equal age matched pairs. We retrospectively analyzed all patients who underwent HT at our center between November 1985-September 2022. Long-term survival was compared among 4 subgroups matched according to their D-R age (D<50years-R>50years, Group 1; D>50years-R>50years, Group 2; D<50years-R<50years, Group 3; D>50years-R<50years, Group 4). Of 1058 patients enrolled during the study period, Group 1,2,3 and 4 included 417 (male D/R 65%/83%, median age D/R 35/58 years), 245 (male D/R 47%/82%, mean age D/R 58/62 years), 356 (male D/R 66%/80%, mean age D/R 22/38 years) and 40 (male D/R 38%/62%, mean age D/R 56/42 years) patients, respectively. 30-day mortality was not different among the 4 groups (p=0.487). At 37-year follow-up, Group 4 showed similar overall survival compared to Group 3 (p=0.324); Group 1 showed better survival compared to Group 2 (p=0.018). Regardless of recipient age, older donors were associated to similar late outcomes (Group 2 vs 4, p=0.676), whereas younger donors showed better late outcomes in younger recipients (Group 3 vs 1, p<0.001) (Figure 1). Severe cardiac allograft vasculopathy did not differ among the 4 groups (p=0.270) at the same follow-up time. Our experience suggests that D-R age mismatch does not affect early survival. At long-term follow-up, regardless of donor age, young recipients show similar long-term survival, whereas older recipients show better survival when receiving young donors. This study highlights the concept that additional unknown biological aging-related D-R factors might influence donor graft durability. [ABSTRACT FROM AUTHOR]

DCD heart procurement is an emerging strategy to expand cardiac donor pool, but the effect of prolonged warm ischemia times on heart transplant (HT) late outcomes is not clearly known. Uncontrolled cardiac arrest of the cardiac graft before DBD might be a useful model to assess post-transplant outcomes after prolonged warm ischemia. Aim of this study is to evaluate the impact of cardiac arrest before DBD on late clinical outcomes in HT recipients. We retrospectively analyzed and compared early and late outcomes of all subjects ≥18 years of age who underwent HT at our Center between November 1985-September 2022 and with cardiac arrest before DBD (Group 1) or without (Group 2). Of 990 enrolled HT within the study period, 104 (10.5%) (male 65, X age 36±2 years) were included in Group 1 (mean time of cardiac arrest 15.0±14.0 minutes, range 0.5-90.0 minutes, cardiac arrest >20 minutes in 19 cases). Group 1 was associated to donor age <50 years (p=0.023), h/o tobacco (p=0.006), alcohol (p=0.007) or substance abuse (p<0.001), suicide or multiple trauma-related death (p<0.001). It was not associated to EF <55% (p=0.367), coronary disease (p=0.922), valve disease (p=0.327) or a specific recipient gender or age. Cardiac arrest <20 and >20 minutes were not associated to increased 30-day mortality compared to Group 2 (8.7% vs 8.5%, p=0.613, and 5.3% vs 8.5%, p=0.816, respectively). At 37-year follow-up, we did not find any significant difference in terms of overall survival (p=0.259) or severe CAV (p=0.54) between the two groups (Figure 1). Cardiac arrest of the donor heart does not affect early and late mortality neither the risk of severe CAV. According to these data, cardiocirculatory arrest of the donor graft might not be a contraindication to its use for HT also at longer warm ischemia times before donation, confirming DCD HT as a potential source of donor hearts, with similar results to DBD also in the long-term. [ABSTRACT FROM AUTHOR]

The article focuses on a study on the effect of active protein phosphatase-1inhibitor-1(I-1) on basal cardiac function and schemia/reperfusion injury through a mouse model. It states that I-1 activity has enhanced contractile function and sarcoplasmic reticulum Ca 2+ transport. Further, a phosphoproteomic analysis reveals that I-1 activity has contracted the recovery of ischemia/reperfusion injury. It suggests that I-1 activity can be a therapeutic strategy in myocardial infarction.

In this article, we outlined time-frequency techniques that, when brought together, form the basis for FAS. The method is based on an exact orthogonal transform, the HBWT. The FAS model can be seen as an intelligent spectrogram, i.e., as a spectrogram where the frequency bins (the HBWT subbands) are adapted to the spectrum of the analyzed sound by tuning the number of channels P to the period of the sound. Local cosines replace the classical windowed complex exponentials, whose main property is that the basis elements form sidebands of the harmonics rather than being centered on the harmonics themselves. The wavelet transform nonuniform frequency subdivision characteristic is exploited to synthesize each sideband of the harmonic peaks by means of colored noise, generating an approximate pseudoperiodic 1/f behavior. The pseudoharmonics are modeled by narrow sidebands whose weights can be generated by means of amplitude envelopes and phase functions in a complexified HBWT domain. We also showed how perceptual criteria can be employed to reduce the number of synthesis parameters. The possibility of independently controlling the noisy components and the harmonic terms and the definition of parameters such as volumes and envelopes for all of the components independently provide powerful tools for processing voiced-sound for sound design purposes [ABSTRACT FROM PUBLISHER]

We illustrate the mathematical background and musical use of a class of audio effects based on frequency warping. These effects alter the frequency content of a signal via spectral mapping. They can be implemented in dispersive tapped delay lines based on a chain of all-pass filters. In a homogeneous line with first-order all-pass sections, the signal formed by the output samples at a given time is related to the input via the Laguerre transform. However, most musical signals require a time-varying frequency modification in order to be properly processed. Vibrato in musical instruments or voice intonation in the case of vocal sounds may be modeled as small and slow pitch variations. Simulation of these effects requires techniques for time-varying pitch and/or brightness modification that are very useful for sound processing. The basis for time-varying frequency warping is a time-varying version of the Laguerre transformation. The corresponding implementation structure is obtained as a dispersive tapped delay line, where each of the frequency dependent delay element has its own phase response. Thus, time-varying warping results in a space-varying, inhomogeneous, propagation structure. We show that time-varying frequency warping is associated to an expansion over biorthogonal sets generalizing the discrete Laguerre basis. Slow time-varying characteristics lead to slowly varying parameter sequences. The corresponding sound transformation does not suffer from discontinuities typical of delay lines based on unit delays.