Thinking beyond organism energy use: A trait-based bioenergetic mechanistic approach for predictions of life history traits in marine organisms

The functional trait-based bioenergetic approach is emergent in many ecological spectra, from the conservation of natural resources to mitigation and adaptation strategies in a global climate change context. Such an approach relies on being able to exploit mechanistic rules to connect environmental human-induced variability to functional traits (i.e. all those specific traits defining species in terms of their ecological roles) and use these to provide estimates of species life history traits (LH; e.g. body size, fecundity per life span, number of reproductive events). LHs are species-specific and proximate determinants of population characteristics in a certain habitat. They represent the most valuable quantitative information to investigate how broad potential distributional boundaries of a species are, and to feed predictive population models. There is much to be found in the current literature that describes mechanistic functional trait-based bioenergetics models, using them to test ecological hypotheses, but a mathematical framework often renders interpretation and use complicated. Here, we wanted to present a simpler interpretation and description of one of the most important recent mechanistic bioenergetic theories: the dynamic energy budget theory by Kooijman (Dynamic Energy Budget Theory for Metabolic Organisation, 2010, Cambridge University Press, Cambridge). Our main aim was to disentangle those aspects that at first reading may seem too mathematically challenging to many marine biologists, ecologists and environmental scientists, and present them for use in mechanistic applications

Nanoscaled Piezoelectric Aluminum Nitride Contour- Mode Resonant Sensors

This paper reports on a new class of nanoscaled piezoelectric aluminum nitride contour-mode resonant sensors (CMR-S) that have been developed for the gravimetric detection of volatile organic chemicals (VOC). The use of the CMR-S and its scaling for the making of large arrays of detectors is justified in terms of the superior sensitivity and limit of detection (LOD ~ zg/μm2) that this technology attains with respect to any other available acoustic device. The choice of a novel functionalization layer based on ss-DNA is introduced as an effective way to selectively detect multiple VOCs without altering the electromechanical characteristics of the resonator. Experimental results confirming the advantages of scaling the device dimensions and its frequency of operation in terms of improved LOD and measurement speed are presented. Furthermore, preliminary data showing selective detection of dymethyl-methylphosphonate (DMMP) and dinitroluene (DNT) (with LOD in the order of ppt) are reported

Ultra-Thin-Film AlN Contour-Mode Resonators for Sensing Applications

This paper reports on the design and experimental verification of a new class of ultra-thin-film (250 nm) aluminum nitride (AlN) microelectromechanical system (MEMS) contour mode resonators (CMRs) suitable for the fabrication of ultra-sensitive gravimetric sensors. The device thickness was opportunely scaled in order to increase the mass sensitivity, while keeping a constant frequency of operation. In this first demonstration the resonance frequency of the device was set to 178 MHz and a mass sensitivity as high as 38.96 KHz⋅μm2/fg was attained. This device demonstrates the unique capability of the CMR-S technology to decouple resonance frequency from mass sensitivity

5-10 GHz AlN Contour-Mode Nanoelectromechanical Resonators

This paper reports on the design and experimental verification of Super High Frequency (SHF) laterally vibrating NanoElctroMechanical (NEMS) resonators. For the first time, AlN piezoelectric nanoresonators with multiple frequencies of operation ranging between 5 and 10 GHz have been fabricated on the same chip and attained the highest f-Q product (4.6E12 Hz) ever reported in AlN contour-mode devices. These piezoelectric NEMS resonators are the first of their class to demonstrate on-chip sensing and actuation of nanostructures without the need of cumbersome or power consuming excitation and readout systems. Effective piezoelectric activity has been demonstrated in thin AlN films having vertical and lateral features in the range of 250 nm

High Frequency Piezoelectric Resonant Nanochannel for Bio-Sensing Applications in Liquid Environment

This paper reports on the first demonstration of a 457 MHz AlN Piezolectric Resonant Nanochannel (PRN) for biosensing applications in liquid environment. A novel process consisting of 7 lithographic steps was developed to fabricate the PRN. The new resonant device shows an unchanged value of the electromechanical coupling, kt 2 (about 0.8 %), whether the channel is filled with air or water and a quality factor, Q, in liquid of approximately 170. The value of kt 2 and Q are respectively about 2.7 and 2 times the ones recorded for conventional laterally vibrating AlN Contour Mode Resonant Sensors (CMR-Ss) submerged in water. Overall, these results translate in a ~ 5 fold enhancement in the figure of merit (kt 2 - Q product) of the resonant device when operated in liquid and simultaneously permit the efficient delivery of ultra-low concentrations of fluid samples directly on the surface of the sensor

Power Handling and Related Frequency Scaling Advantages in Piezoelectric AlN Contour-Mode MEMS Resonators

This paper reports on the analytical modeling and experimental verification of the mechanically-limited power handling and nonlinearity in piezoelectric aluminum nitride (AlN) contour-mode resonators (CMR) having different electrode configurations (thickness field excitation, lateral field excitation, one-port and two-port configurations) and operating at different frequencies (177-3047 MHz). Despite its simplicity, the one-dimensional analytical model fits the experimental behavior of AlN CMRs in terms of power handling capabilities. The model and experiment also confirm the advantage of scaling (i.e. miniaturizing) the AlN CMRs to higher frequencies at which higher critical power density can be more easily attained up to values in excess of 10 μW/μm3

Two sides of the same coin: educational and professional pathway for surgical residents

Aim: To provide a review of medical malpractice cases ruled by the Italian Supreme Court with the aims at identifying lawsuits targeting involved with surgical residents. Material and methods: Legal cases ruled by the Italian Supreme Court, from September 2020 to October 2020, pertaining to medical claims involving surgical residents were examined, using the main online databases. Results: Of a total of eleven (n=11; 100%) cases identified, four (n= 4; 36,4%) cases addressed the standard of care pertaining to the surgical residents' medical activity. The legal reasoning of the Italian Supreme Court does not focus on the manual skill in the resident's medical performance, but rather on the choice to accept to treat the patient, regardless of the participation of the tutor. Conclusions: The performance of the surgical residents is made more difficult due to their peculiar nature, characterized by the complex interactions between the directives given by the tutor and the need to guarantee patients' needs

AlN Contour-Mode Resonators for Narrow-Band Filters above 3 GHz

This paper reports on the design and experimental verification of a new class of thin-film (250 nm) super high frequency (SHF) laterally-vibrating piezoelectric microelectromechanical (MEMS) resonators suitable for the fabrication of narrow-band MEMS filters operating at frequencies above 3 GHz. The device dimensions have been opportunely scaled both in the lateral and vertical dimensions in order to excite a contour-extensional mode of vibration in nano features of an ultra-thin (250 nm) aluminum nitride (AlN) film. In this first demonstration two-port resonators vibrating up to 4.5 GHz were fabricated on the same die and attained electromechanical coupling, kt^2, in excess of 1.5 %. These devices were employed to synthesize the highest frequency ever reported MEMS filter (3.7 GHz) based on AlN contour-mode resonator (CMR) technology

GHz Range Nanoscaled AlN Contour-Mode Resonant Sensors (CMR-S) with Self-Sustained CMOS Oscillator

This paper reports on the design and experimental verification of a new class of nanoscaled AlN Contour-Mode Resonant Sensors (CMR-S) for the detection of volatile organic chemicals (VOC) operating at frequencies above 1 GHz and connected to a chip-based CMOS oscillator circuit for direct frequency read-out. This work shows that by scaling the CMR-S to 250 nm in thickness and by operating at high frequencies (1 GHz) a limit of detection of ~35 zg/µm2 and a fast response time (\u3c1 \u3ems) can be attained. In addition, the capability to detect concentrations of volatile organic compounds such as 2,6 dinitroluene (DNT) as low as 1.5 ppb (4.7 ag/µm2) is experimentally verified

Ultra-Thin Super High Frequency Two-Port ALN Contour-Mode Resonators and Filters

This paper reports on the demonstration of a new class of ultra-thin (250 nm thick) super high frequency (SHF) AlN piezoelectric two-port resonators and filters. A thickness field excitation scheme was employed to excite a higher order contour extensional mode of vibration in an AlN nano plate (250 nm thick) above 3 GHz and synthesize a 1.96 GHz narrow-bandwidth channel-select filter. The devices of this work are able to operate over a frequency range from 1.9 to 3.5 GHz and are employed to synthesize the highest frequency MEMS filter based on electrically self-coupled AlN contour-mode resonators. Very narrow bandwidth (~ 0.35%) and high off-band rejection (~ 35 dB) were achieved at an operating frequency of 1.96 GHz. This first prototype showed insertion loss of 11 dB, which can be improved to few dB if parasitic elements are eliminated or device capacitance is increased