This work presents a detailed review of the development of distributed acoustic sensors (DAS) and their newest scientific applications. It covers most areas of human activities, such as the engineering, material, and humanitarian sciences, geophysics, culture, biology, and applied mechanics. It also provides the theoretical basis for most well-known DAS techniques and unveils the features that characterize each particular group of applications. After providing a summary of research achievements, the paper develops an initial perspective of the future work and determines the most promising DAS technologies that should be improved. The development of modern science is inconceivable without the constant improvement of research equipment and the design of novel tools providing new knowledge about the world around us. One of the most critical issues in this development process is the implementation of existing modern research equipment and methods in those areas of science where they have not yet been exploited. One of the most modern families of measuring instruments are fiber-based sensors, intelligibly presented by Fang et al. . The conFor example, the work of distributed fiber sensors applying the Brillouin scattering is based on the fact that the Brillouin frequency shift (BFS) (peak frequency shift of the Brillouin gain spectrum (BGS) or Brillouin loss spectrum (BLS)) linearly depends on the distributed information (temperature or strain) . These sDistributed fiber sensors are used to measure the distribution of temperature ,19,20,21There are lots of essential reviews devoted to the technical applications of DAS systems ,55,56. IA group of purely scientific or “exotic” DAS applications have also been studied in the scientific literature of various disciplines. This is due to the fact that sound plays an important role in nature and acoustic data provide a wealth of information about the environment and what is happening in it. Such data may result from geophysical studies, the sound image of processes in a mine or borehole, the sound of forests, marine fauna, the acoustic snapshot of highways, etc. The literature review covers all the application areas mentioned above with an outline of the most relevant outcomes as well as an assessment of the prospects of research directions. The fundamentals of distributed acoustic sensing and the advantages and limitations are also provided in the theoretical background section.The study of acoustic vibration, its effect on the characteristics of the medium, and how the light propagates in it has been carried out by many scientists since the early 20th century .The first acoustic sensors based on Rayleigh backscattering in optical fibers appeared in the literature after the sufficiently low-loss optical fiber was demonstrated . These sNowadays, such sensors are also widely used in geophysics and traffic control. Applications in natural sciences and culture have begun to develop. The new applications have emerged due to the ability of such sensors to meet some unique needs and the more economical total cost of such systems.The distributed phase-sensitive time–domain sensing employs the coherent light backscattered from the sensing fiber for the detection and analysis of perturbations induced by an external physical field on the sensing fiber. Probe pulses emitted from a highly coherent laser source (the coherence length is much longer than the pulse width) are injected into the sensing fiber one by one and backscattering signals induced by each of them are recorded at the fiber input and then compared to localize and evaluate the external forces applied to the sensing fiber during such monitoring. In this section, we present the mathematical formalism underlying the basic principles of ϕ-OTDR sensing.Let the probe pulse be injected into the sensing fiber with low linear losses ngth See . At the The backscattering events satisfying this criterion occur in time between The probe pulse is assumed to be a piece of a monochromatic optical wave at the frequency Substituting Equation (2) into Equation (1) gives an expression for the backscattered signal amplitude:The backscattered light intensity formed at the pulse trailing edge point is transmitted then by the fiber to the fiber input point In terms of the registration time Using new variables Finally, Equation (6) is reduced to the following set:Although Equations (9) and (10) describe Rayleigh backscattering in a non-perturbated sensing fiber, they allow specific features important for an advanced understanding of the ϕ-OTDR sensing operation to be highlighted. 1. A low fluctuated contribution to the detected signal It is an incoherent part of the backscattered signal that is commonly employed with a traditional optical time domain reflectometer (OTDR) based on a low coherent laser source. In such systems, the recorded signal reproduces the distribution of loss coefficient Equation (11) is valid as well if the distribution of reflection centers is strongly del-ta-correlated and uniformly distributed over the fiber length :The function 3. Equations (9) and (10) have been derived for a non-perturbated sensing fiber interrogated by a single coherent pulse. However, they can be easily extended on a perturbated fiber periodically interrogated by coherent pulses one by one with the period 4. The response of the signal modulation 5. By the way, several advanced techniques for absolute measurements of the external physical fields with the ϕ-OTDR sensing have been demonstrated. In particular, for very slow changing or steady-state external fields (such as temperature heating) such measurements could be performed with the described simple setup equipped by a frequency tunable probe laser source. The procedure of the measurement is reduced to the laser frequency scanning with the aim to find for different fiber points In conclusion, for this section, we have given a simplified insight into the physical mechanisms underlying the operation of a ϕ-OTDR setup for sensor applications. The key system parameters responsible for the distributed sensor performance are listed and their interconnects are highlighted. A number of effects associated with the ϕ-OTDR sensing are demonstrated and explained, in order to support a better understanding of the ϕ-OTDR techniques outlined in the rest of the review.DAS have experienced a steadily expanding transition into commercialization due to the enormous potential of DAS implementations in a wide range of application areas cf. . Still, quasi-distributed manner . In this subsection, the specific group of quasi-distributed configurations that are based on weak fiber Bragg gratings (acting as scattering centers with known reflection coefficients and positions) is handled  from a narrow-linewidth laser source is injected into the sensing fiber and under the condition that W is greater than twice the separation L between two successive FBGs, the signals reflected from both FBGs overlap on the ϕ-OTDR trace in a so-called interference zone (IF). FBG-assisted fiber-optic DAS techniques embrace various interrogation approaches ,71. WithN and FBGN+1). Three zones can be observed: two zones of length L corresponding to the parts of the signals reflected by FBGN and FBGN+1 that do not overlap and a zone of length W/2-L corresponding to interference zone IFNN+1&. This interference zone is created by the superposition of the electric fields EN and EN+1 . The complex reflection coefficient, rN, and the complex transmission coefficient tN for FBGN are determined as a function of the known parameters ), N and FBGN+1. This phase component (N and FBGN+1 ). This additional delay allows extra data on the ϕ-OTDR trace to be obtained: the signals reflected independently by each FBG (NP and N+P1) can also be measured (not only their interference), and Equation (17) can be used to suppress the spectral shadowing. The spectral shadowing for the double pulse interrogation technique is less obvious since, in that case, only the interference zone is present on the ϕ-OTDR trace. posed in  to overcThe distributed time–domain acoustic sensors including the quasi-distributed FBG-based DAS-systems discussed above have passed from scientific setups in labs to become powerful measurement instruments. All recent advances improving the performance and accuracy of DAS systems  have resulted in the technical requirements for various engineering problems being met. Unsurprisingly, systems created by engineers have found widespread use in the technical sciences. The next section of our review is devoted to the application of DAS systems in the engineering sciences.Among the applications in engineering science, the following main areas can be distinguished: pipelines, railways, highways, and structures, including composite ones. These areas can be combined into two large groups: objects of great length  and medium-range structures requiring permanent monitoring activity . For the latter, DAS have replaced a large number of electrical point sensors that are difficult to implement due to the huge number of required electrical wires ,79. The Pipeline monitoring has been one of the most common applications for distributed fiber optic systems . This isThe development of fiber drawing technologies has led to the development of using fibers with enhanced scattering points (dots) induced by a femtosecond laser or with reflective centers (weak FBGs) ,82 Figu. For exaIn the work of a group from IRE RAS  , an optiThe authors of  have preA pipeline integrity threat detection system was demonstrated in , where t−8 to 10−4 s. As a continuation of this work, a fiber Mach–Zehnder interferometer with a path difference of 100 km with an acoustic optical modulator (AOM) located in one of the interferometer arms was used. This approach is easier to implement than the heterodyning configuration with a reference laser, where the optical frequency difference between the laser under test and the reference laser must be maintained within the acquisition bandwidth over the whole measurement time. The modified setup proposed in [−8 to 10−1 s. At the same time, the result was not affected by the low-frequency beatings of laser couples, which was manifested in [When the wFBG array is implemented in the fiber, the reflection level is increased to a level at least two orders of magnitude higher than that of Rayleigh scattering, resulting in an increased SNR, even in the absence of a preamplifier. In this case, it becomes important to study the phase noise of the laser source, which remains as the main noise contribution of the system . The stuposed in  allowed ested in .The detection of leaks from holes of various shapes and the determination of the leakage volume using wFBGs has also been studied. The relationship between vibration frequency and pressure in the pipeline for holes of different shapes is presented in . In thisIn  a neuralIn  a combinRailways are particularly well suited for fiber sensing monitoring as a relatively high signal level is guaranteed by the enormous mass of the train. Fiber sensors can be applied to the entire infrastructure: tracks, bridges, adjacent territory (security), and trains. Commercially available fiber sensing solutions in this area already exist and provide a number of implementations on the railways, e.g., Frauscher Sensonic . HoweverThe work in  is a gooOne of the leading teams working on fiber-optic sensors for railway monitoring are from the Technical University of Graz, where an introductory feasibility study , followeBased on the abovementioned papers, the main difficulties of DAS-based railway monitoring systems can be defined as the limitations imposed by the railway construction requirements and the proper installation of optical cables. There might be situations when the cable is not laid in parallel to the tracks or too far from it. Such situations will lead to errors and blind spots. Nowadays DAS for railway applications remain a perspective technology that may replace many sensors such as axle counters by processing signals such as the ones demonstrated in Issues dealt with in relation to highways are quite similar to those of railways, but they have a higher complexity due to the random nature of the traffic. On highways, there is a variety of moving vehicles  and more noise, including the activity of pedestrians. Sensor systems can be extremely relevant  when creating “smart cities”. The cable position with respect to the road and the dependencies of the system quality on the cable laying options are considered in . The resWith the help of DAS, it was possible to observe global changes in traffic congestion associated with the COVID-19 pandemic , as presented in a cooperation work of scientific groups from Stanford University and Royal Observatory of Belgium . MoreoveIn , based oIn , the appIn addition to highway monitoring, the possibilities of more detailed tracking that includes the movement of people using fiber sensors are also being explored. As an example, a sensor with directed scattering centers recorded the movement of one and two people walking and running in different shoes in work by Z. Peng et al. . MachineIn addition to the abovementioned ultra-long-distance systems, in which distributed acoustic sensors are used all along the available sensor length before a critical signal decrease (amplification methods can increase the maximum length), DAS are also used in systems with a total fiber length of less than 10 km, especially when the compactness or explosion safety features of the sensor are important.Applications related to the composite materials are particularly important as the sensing fibers without additional coatings can be inserted between the layers during the piece’s construction without additional fixing. Such sensors allow material delamination to be registered at the early stages, before the entire structure is brought to a dangerous state. The critical issue of such implementations is the complexity of assembling a structure with built-in fibers . There aAnother application is the tracking of aircraft movements at airports. The test results were realized on an 8.1 km sensor, which was buried orthogonal to the runway of aircrafts at a distance of 4.2 km. The registration of a flying aircraft was reported by a scientific group from Beijing Jiaotong University in . The 5 HStructural inspection is not limited to composite materials. For example, in , the plaAn overview of structural health monitoring using DAS was carried out in , which dAnother application is related to wind generators where a φ-OTDR makes it possible to measure the natural frequencies of the tower oscillations. Based on their amplitude, it is possible to draw conclusions about the reliability of the fastening (losses and breakages of bolts are possible) . In addition to the listed and more common applications of the distributed sensors, there are some original applications. For example, in the work of researchers from Huazhong University of Science and Technology , the levAn interesting part of the study of DAS is the analysis of the behavior of the sensor according to the used fiber optic cables. Increasing the acoustic sensitivity of the cable is a new direction which is particularly important for novel DAS development. Research about the SNR of DAS for cables in a tank with a propagation medium of various cross-sections is presented in . IndividAnother research group from Corning Inc. and OptaSense carried out field trials involving the cables buried at the test site . In thisResearch data show that the cross-sectional configuration ,116,117 This section has presented some of the applications of DAS systems in the engineering sciences. However, the review would be incomplete without mentioning one of the most outstanding DAS engineering applications: geophysical measurements. These studies cover such a significant number of scientific works that this required the creation of an individual chapter. So, the next section is devoted to the application of distributed acoustic sensing systems in geophysics.The unique properties of DAS attracted the attention of geophysicists shortly after the development of measurement systems with a good enough spatial resolution and sensitivity level while having the ability to reconstruct the phase and amplitude of acoustic signals. The first application was related to vertical seismic profiling (VSP). The sensing optical cable is placed in the exploration well in the same way as the seismic cable in traditional technology. This eliminates the presence of electronics in the well, which must operate at high temperatures and pressures, often in an aggressive environment. These conditions determine the high cost of traditional seismic instruments and entail significant operational expenses.The advantage of the new technology is that the well is explored along its full depth in a single measurement. There is therefore no need for the sequential movement of the seismic sensors’ streamer along with the depth of the well, which necessitates the precise positioning of the streamer, ensuring reliable mechanical contact with the environment, accurate synchronization of all processes in time and, ultimately, a significant waste of time to carry out the research. When using DAS, it is enough to run the cable into the well, ensure its connection with the studied environment , implement the appropriate seismic action , and record seismic waves for a short time . The resulting recording of seismic signals allows P-S-, reflected, and converted waves to be identified and generally replaces traditional VSP surveys. At the same time, an optical cable is cheap and can be considered a consumable material; there is usually no need to remove it for reuse.The first mention of the use of DAS for VSP in the literature appeared about ten years ago . In thisThe excitation of seismic waves can be carried out both by impulse sources and vibrators, with the help of which it is possible to generate mainly P- or S-waves, which provides additional information when interpreting the research results.2(θ) response of the fiber to the incident angle of the seismic wavefield for P-waves and sin 2θ for S-waves  axis sensitivity. Directional patterns are described as a cos S-waves . In thisThis work also compared seismic data obtained using DAS with similar data recorded using traditional geophones. There was a good coincidence of both the kinematic parameters (the velocity pattern of propagation of various waves) and the dynamic (amplitude relationships). The reliability of the resulting DAS VSP data sets makes DAS technology an essential VSP acquisition tool.However, in most cases, the signal-to-noise ratio for DAS at a comparable spatial resolution is lower than for traditional geophones. This is due to the small optical power of Rayleigh light scattering in low-loss fibers intended for optical communication. The use of special engineered optical fibers can significantly increase the magnitude of the backscattered signals, which leads to a noticeable improvement in DAS performance. For example, the authors of  demonstrIn addition to increasing the signal-to-noise ratio, engineered fibers can improve the fidelity of seismic results, since in ordinary fibers, due to the randomness of Rayleigh scattering processes, distortions of both kinematic and dynamic parameters appear . ThAn example of the use of specialty fibers with an increased Rayleigh scattering efficiency in DAS is given in , which sOptical cables already installed in the wells for distributed thermometry can be used for monitoring. In most cases, they contain multimode fibers, while DASs typically work with single-mode fibers. It was however shown in  that theDozens of works have already been devoted to vertical seismic profiling, and it can be considered that this technology has already gained a foothold in industrial applications. Surface seismic is no less promising. At present, it is performed using discrete seismic sensors with relatively high characteristics. However, obtaining relevant data requires a very dense network of such sensors, which conflicts with economic considerations.DAS technology provides an unprecedented opportunity for very dense coverage of the surveyed area with independent seismic recording channels at a meager price, determined by the lower price of the optical cable which can be considered as a consumable. Unlike borehole geophysics, the cable is located on the ground surface or at very shallow depths, replacing thousands of traditional sensors. Of course, the interrogators for DAS are quite expensive now, but they have a very long service life and a specific cost for any survey can be acceptable. As a result, seismic exploration can be performed quickly and economically . In , the speIn , a studyWhile discussing surface seismic technology, it should be noted that the ordinary optical cables provide only one-dimensional sensitivity which is not always convenient. At the same time, a spiral cable option ensuring omnidirectional sensitivity was proposed . Such a As already noted, the surface location of the optical cable makes it possible to register technogenic microseisms, and local and teleseismic earthquakes, including extremely low-frequency ones. In recent years, many researchers have been engaged in registering earthquakes using DAS ,138,139.The study in  is quiteThe best surface seismic results are usually obtained with the underwater location of the sensitive cable using dark fibers in the seafloor communication lines ,144,145 In addition to studying the processes in the earth’s crust, including those associated with volcanic activity , DAS havDAS technology can be used to study active faults on the seabed in addition to static measurements using Brillouin reflectometry .Recently, works have appeared , where aThus, the use of distributed fiber-optic sensors can be considered as a new branch in geophysics . In addition to research tasks, DAS is used to control hydraulic fracturing in hydrocarbon production . It is pAt the end of this section, it should be noted that the tasks of geophysics have become a powerful accelerator for the development of distributed acoustic sensors and for performance improvements. The high popularity of such studies has allowed researchers from related fields to draw attention to the unique features of DAS they can use in their own work. The next two sections of the review will describe such applications thoroughly. So, the following chapter will focus on the use of DAS in biology and other natural sciences.The previous sections have demonstrated the various successful applications of DAS in geophysics, engineering, and material sciences. Many other fields of science and industry require efficient and highly specialized distributed acoustic sensors. Biology is one of them. Currently, the number of existing bio-acoustical sensors based on the DAS principle is very low compared to the number of potential applications.A research group from China and Saudi Arabia reported a successful red palm weevil detection with DAS . The timFirstly, the authors recorded a set of reference sounds produced by 12-day old weevil larvae using a high-quality pointwise recorder to train the neural network designed to detect the activity of these insects. The FFTs of two these recordings made in a row are presented in In such applications, distinguishing the signals from the perturbation source  from noises such as bird sounds and wind can be realized with the help of machine learning algorithms. The DAS system presented in  providesStudies ,155 haveBiologists often need to detect, locate, and identify various animals in relatively large areas, as Browning et al. highlighted . Due to simulated natural conditions (the polar bear intrusion was mimicked by people). Despite the fact that a human’s weight is less than that of a bear, human footstep pressure is practically equal to that of a small bear because the foot area of the latter is bigger. In addition, it was found that the external noise affecting the signal quality decreases with the decreasing temperature, so the SNR of the sensor working at temperatures below 0 degrees Celsius was better than the sensor functioning in normal SNR conditions. The ability to detect footstep pressures of different values was studied, making it possible to classify polar bears of different kinds or distinguish them from other animals or humans. The sensor system was tested at the laboratory under The authors of  have claAs a severe consequence of global warming (melting glaciers), ice calving monitoring has recently drawn the attention of ecologists. Ice disruptions are usually detected accidentally by sailors or satellites, and their monitoring is a challenging task to perform due to the severe Arctic and Antarctic weather conditions. DAS are good candidates to implement in such an application. Anthropogenic factors and species invasion also affect various sea animals that also require specific monitoring systems. The existing systems still implement single or multiple electronic underwater microphones (hydrophones) ,160. Fiber optic underwater DAS were introduced about three decades ago and have gained popularity as a detector of intrusions, including ships, submarines, and divers. In 2021, Sandia researchers reported the first successful application of Silixa underwater DAS in the severe conditions of the Arctic Sea . AlthougBatelle states that DAS based on a standard optical cable are suitable for tracking animals  to better understand their behavior and needs. The ability of the proposed sensor to monitor weather conditions  was left for further investigations .In terms of measuring weather conditions and seismic activity detection, one of the most efficient utilizations of DAS was presented by scientists from Pennsylvania State University , where aIt was believed for a long time that mechanical vibrations had no significant effect on flora. However, the studies carried out since the early 20th century and especially in the past few years have demonstrated that acoustic vibrations can have a negative  or positPlants from the test group bore fruit for 20–30 days longer than the plants from the control group, which led to a yield increase of 30–40%. Further development of such techniques in the future would ensure the formation of a well-developed, flat, horizontal root system in plants instead of a vertical one, which will allow them to absorb fertilizers, nutrients, and pesticides more efficiently, reducing the residue of harmful substances in fruits. The effect of the signal frequency ranging from 50 to 500 Hz on the plants, callus, and seeds was studied by Hassanien et al. . The devIn summary, the application of DAS in biology and vibration ecology are expected to rapidly increase as more researchers will become aware of the fiber optic-based distributed sensing, its operation principles, and advantages. The perspectives of distributed acoustic sensors not only in biology and natural sciences, but also in arts, humanitarian sciences and culture are subjects of interest. In the next section, we will discuss how realistic and close these prospects are.In the 20th and 21st centuries, the cultural industry experienced an ever-growing demand for the development of audio information recording, storage, and distribution means. Despite the conservatism of the sound and music community, optical sensing technologies have also found their way into this industry. A good example is the successful commercial application of the simple optical sensors built on the principle of recording the intensity of the light beam emitted by the diode and reflected from the membranes placed at strings of guitars and bass guitars  by ChrisFiber optic technology has made its way into the audio industry. Back in 2009, fiber Bragg gratings were placed in solid and hollow-body guitar bridges and their signal was digitized and studied for processing suitability and musical aesthetics . Loock eThe following instrument by Avino et al.  has FabrAmong the pointwise sensitive elements, it is also appropriate to mention an amplitude fiber-optic microphone for concert and studio sound engineering , which aThe unique design of the sensing element allows the frequencies required by the sound engineer to be transmitted, and the completely passive and non-metallic design opens up many other possible applications.The examples of point-wise sensors given above were presented as a history reference. We believe that the positive experience of using single FBGs and other elements could give a reason for testing them as parts of a weak-FBGs-assisted DAS-system in the nearest future.The mentioned sources sufficiently demonstrate the ability of certain sensitive elements to perceive oscillations of acoustic frequencies emitted by musical instruments. Since the publication of references ,168,169,Traditional setups of coherent OTDR require significant modifications of both the interrogator, that is, the reflectometer itself, and the sensitive element (sensor) for use in detecting the sound of musical instruments and speech (singing). In a paper by Wu et al. , the autThe joint group from different institutions   recordedSubsequent signal processing made it possible to read the word “Bonjour” from the local area of the distributed sensor with the upper recorded frequency of the order of 1.5 kHz . The resf = 3 kHz was applied through a PZT at position z = 2 m of a 3 m long fiber. L. Marcon, A. Galtarossa, and L. Palmieri  found anIn modern digital sound engineering, recording such a signal and its digitization at such frequencies is quite essential—this excludes or makes controllable the appearance of various artifacts during further processing of the signal. The operating range of such systems is usually tens of meters, which would provide a high-quality recording of chamber ensembles or complex musical instruments, such as an organ relatively quickly. The group of Dr. Franciscangelis from the University of Campina, Brazil  reportedAmong other things, direct detection helps to simplify the signal-receiving part of the setup and decreases polarization fading. The records of music and human voice made with the proposed sensor are attached to the electronic version of the article. With proper development, this system can be used for concert sound engineering, as the outputs of such circuits can be switched with the inputs of mixing consoles.DAS based on ϕ-OTDR setups helps overcome the disadvantages of more simple sensors, measuring the intensity of Rayleigh backscattering . The microphone, presented in , cannot As seen in this section, the performance of distributed fiber optic sensors designed for recording vibrations of acoustic frequencies in the air and human speech, or musical instruments is getting better every year. In many ways, this rapid development is driven by the requirements in other areas, mainly oil, gas, geophysics, etc. It is safe to assume that in 7–10 years, an efficient distributed fiber optic sensor system for multi-track high-quality audio recording will be available on the market. The high price of this system will certainly be offset by its flexible and seemingly fantastic capabilities. To accelerate this moment, the sensory giants must cast their eyes on the hi-end audio market; and researchers working in the field of optoelectronics, even poorly experienced in music and sound production, must look at their daily scientific activities from a new creative angle. It is worth remembering that the existing distributed and quasi-distributed systems can already solve individual creative problems, and the issues and obstacles described above, in some cases, are not even challenging for them. For example, the highest notes of some instruments, even taking into account overtones, can be significantly lower than the required 20 kHz, which will effectively record a whole group of such instruments with a distributed acoustic pickup; in addition, not all musical instruments need to be recorded from a distance: for example, guitar resonators, cabinets, combo amplifiers, various string instruments, etc., which means that the distributed sensor has close contact with the vibrating surface, and there is no need to modify the coating or develop the membrane significantly. Finally, the dream of every sound engineer is to obtain an unlimited number of microphones covering as many spectral ranges as possible, becomes more realistic with the constant improvement of DAS technology. It could provide an amazing source data for DAWs, containing waves with different phases and spectra. The modern DAS systems have a significant number of the parameters desired by most sound engineers, but they still need to improve their spectral response linearity and signal processing time. The acquiring, processing, and the transmission of a single trace to the DAW within 20 ms will make possible DAS applications for live shows outside the studio.In conclusion, there is another one thing certainly worth noting. Even though DAS systems, as just noted, are not yet perfect for live sound engineering, the recording of a rather big open-air music event using a distributed acoustic sensor has already taken place. This is evidenced by the work , alreadyThis literature review showed that distributed acoustic sensors, which are known to be efficient at intrusion sensing, structural health monitoring and railway supervision, are also being actively used for scientific research in geophysics, materials science, and other engineering disciplines. In addition, quite exotic applications of distributed acoustic sensors were investigated in relation to biology, urban studies, culture, and the media industry. Let us determine the main factors describing all mentioned scientific fields where DAS systems could be applied: 1. The number of scientific papers related to the application of distributed acoustic sensors in this area;2. The availability of technology for the given scientific industry;3. The readiness of the technology for the given scientific field. It is determined by technical requirements in area of interest see ;4. Assessment of development prospects , it can be found that there is much less work using DAS technology than in geophysics. Despite the sufficiently high readiness of the technology for solving a whole class of research problems in engineering sciences, its availability for researchers is relatively not high. This can be explained, among other things, by the difficulties in acquiring a rather expensive system using grants from scientific funding. Nevertheless, since the technology is in demand, there is a task to reduce the system’s total cost by using less expensive components, so the prospects for DAS in this scientific direction are quite promising. Referring to In biology and other natural sciences, the application of distributed optical sensors is just emerging. The first works of this kind are mentioned in our review; there are relatively few of them. The question of the readiness of DAS technology for this scientific industry is controversial since many different tasks can be set. For example, in the case of monitoring forest or marine flora and fauna, the method becomes difficult to implement from the point of view of data interpretation, which can be partially compensated by using quasi-distributed systems with weak reflectors in the line. However, it should be admitted that, according to the authors, there is not a single commercially available system, let alone inexpensive, for use in this scientific field. The life sciences industry does not yet have a clearly defined frequency range that DAS manufacturers should focus on. The researchers are currently using typical commercial systems available on the world market. Due to the variety of tasks and not yet high interest of biologists, it is rather difficult to determine the other parameters as well.Nevertheless, the described sensors created for biological purposes turn out to be the cheapest opportunity for the monitoring demands they satisfy. Readiness and availability of technology are also not so high. With a decrease in the cost of systems, the prospects are also quite good.The use of DAS in music, particularly in sound engineering and recording, is quite interesting. While there is almost no scientific information on the use of distributed acoustic sensors for this purpose, the review presents some works describing the studies of individual structural elements of quasi-distributed sensors—fiber Bragg gratings. Since the distributed acoustic sensors with a satisfactory amplitude-frequency response can record the desired frequencies from 20 Hz to 20 kHz and given the successful start of the research on single FBGs, the readiness of the technology for use in this industry is relatively high, which cannot be said about the accessibility. We will also evaluate the prospects provided that the cost of the system decreases as quite attractive. If we look at To be applied in different areas, many of DAS-system parameters require significant improvement in performance, which can be achieved by decreasing phase noise , polarizSumming up, it should be noted that such a powerful and flexible scientific instrument as a distributed acoustic sensor can and should be used more often in various branches of science, not only technical ones. The main obstacle in integration of this technology into various scientific fields is the high cost. In some cases, the DAS systems need the improvement of some parameters. If the world’s leading manufacturers make efforts to reduce the cost of the element base of their products and to improve custom parameters, this will help making an essential step towards expanding the range of DAS applications and obtaining scientifically exceptional knowledge about the world around us.


The Education and Training Centre for Public Healthcare of the National Medical Centre plays a key role in providing continuing professional development (CPD) to 221 public health and medical institutions in South Korea. To assess the realization of the Centre’s core value and the intended changes, program evaluations are required. The context, input, process, and product (CIPP) model is particularly suitable for evaluating CPD in the public sector, as it allows for recognizing the dynamic nature of the program environment.This research applied the CIPP model to the evaluation of CPD programs, particularly abdominal and thoracic ultrasound programs implemented in 2017 and 2018. Data were collected from 2017 to 2019. The program and its feedback were reviewed in the context evaluation. Based on this, a subsequent program strategy was established for the input evaluation. Observing the program in real time and recording its progress was followed in process evaluation. Finally, the outcomes and impacts of the program were reviewed and compared with baseline data in the product evaluation.In context evaluation, the educational needs of the Centre’s CPD program recipients, impediments that inhibit participation in education, and resources that the Centre can utilize were identified through an online survey, focus group interviews and expert consultation. Through input evaluation, we identified the best alternative that satisfied all pre-selected criteria, which were responsiveness to priority system needs, potential effectiveness, fit with existing services, affordability, and administrative feasibility. Observing the program in real time and recording its progress were conducted in process evaluation, demonstrating that the augmented program went as planned, and even had to be expanded due to increased demand. The impact of the program was measured, interpreted, and assessed in the product evaluation. The review committee decided that the intended change had been occurred, thus the Centre decided to maintain the program.A thorough evaluation is necessary to determine the potential benefits of CPD. The CIPP methodology is valuable for executing formative and summative evaluations. The CIPP model is particularly useful for securing accountability data for large-scale nationwide educational programs supplied by public funds.The online version contains supplementary material available at 10.1186/s12909-022-03271-4. Continuing professional development (CPD) for physicians is important to achieve safe, effective, and improved clinical care . HoweverThe Education and Training Centre for Public Healthcare at the National Medical Centre (NMC), hereafter referred to as the Centre, plays a key role in providing CPD to 221 public health and medical institutions (PHMIs) in South Korea. PHMIs are established and operated by the state, local governments, and public institutions . The CenThe Centre’s core values are to focus on enhancing publicness in healthcare and improving the quality of medical services . EnhanciProgram evaluations should assess how well the Centre’s core values are realized and whether the intended changes have occurred. Educational programs are fundamentally focused on change; therefore, program evaluations should assess whether the desired changes occur as a result of educational initiatives . The CPDAmong the diverse methodologies –11, the Informed by the complexity theory , 15, theWe applied the CIPP model to evaluate CPD programs implemented by the Centre in 2017 and 2018. The Centre offered 17 programs in 2017 and 10 programs in 2018. Among these programs, we evaluated abdominal and thoracic ultrasound programs because major changes were made to these programs, in terms of strategy, educational goals, content, and methodology in 2018, following a needs assessment in 2017, which showed the strongest demand for change among other programs. Educational evaluation is useful for examining the effectiveness of a program after changes are made and for determining whether to continue the changes.To answer the evaluation questions in each phase of the CIPP model, data were collected from learners, instructors, operators, stakeholders, and external experts between May 2017 and January 2019  from December 5, 2017, to March 8, 2018, to achieve in-depth interpretations of the survey results. A total of 106 valid responses were received from the 111 participants.The FGIs targeting learners followed a democratic view of educational needs assessment approaches . This apIn the input evaluation, the most cost-effective and feasible strategy was selected to best satisfy the needs identified through context evaluation. Our online survey responses and FGI-based needs assessment indicated that the ultrasound program was most in need of improvement. Therefore, we performed an input evaluation for the ultrasound program. A literature review, expert consultation, and stakeholder workshops were conducted to identify the strategy selection criteria . Upon coProcess evaluation was conducted by providing an ongoing assessment of the plan implementation, followed by documentation of the process . Acting The goal of product evaluation is to measure, interpret, and assess the outcomes and impacts of a program . Upon thIn the context evaluation, the educational needs of the recipients of the Centre’s CPD program, impediments inhibiting participation in education, and resources that the Centre can utilize were identified. Our online survey results were analyzed for educational needs assessment Table . Due to Similar results were derived using FGIs, which were conducted to achieve an in-depth interpretation of the online survey results . Many reThe ultrasound educational program was the course that respondents most wished to take because it was the most applicable in primary medical care. However, the ultrasound program was cancelled several times in 2017 because of a lack of enrolment. This indicates that the content and delivery of education can prevent learners from enrolling in a program, despite high awareness of its utility, which is problematic.Whether it is applicable in the practical field is also a key factor prominent in FGIs. The groups, who responded to the overall curriculum in 2017 were good but not well-applied, pointed out that they could not use their learning in the practical field due to differences between the environment of a hospital in Seoul and a remote local hospital. The environment, human resources, facilities, and even patient groups are vastly different from that of a university hospital in Seoul and a local hospital in remote areas. In addition, interest and practical applications are prominent factors in promoting learners’ participation. Therefore, to recruit physicians as potential learners and draw good responses, educational content that can be applied in the environment where they work must be developed.In consultation with experts, expanding accessibility and providing educational content tailored to the roles played by public health institutions in the community were highlighted. In particular, significant gaps were observed in the actual clinical environment and patient groups between the learners and university hospital where the educational program was outsourced.In the literature review, two goals for PHMIs were revealed as immediate challenges: ameliorating the financial independence of hospitals by securing sufficient profits and pursuing public interest in improving the health of the local community –21. The In addition, labor productivity was found to greatly influence public hospital profits. Among them, the labor productivity of physicians accounted for a significant part of PHMI’s labor productivity . Due to The abdominal and thoracic ultrasonography program was determined to require the most changes in needs assessment due to the largest gap between willingness to attend the program and actual participation rate. Moreover, the Centre can potentially be held accountable for cancelled programs if poorly planned during inspections by the government administration. Therefore, we reviewed records from the 2017 educational program. Initially, the Centre planned to deliver three ultrasonography courses for a total of 10 classes. However, only six classes were completed, which leads to a potential accountability issue. Financial support from the Ministry of Health and Education and administrative support from the Centre were secured for the program.en bloc to a single contractor. While the Centre provided administrative support, it selected one academic society in a related field that best fulfilled the criteria.Through input evaluation, we identified the best alternative that satisfied all preselected criteria. After consultation with external experts and workshops with stakeholders, responsiveness to priority system needs, potential effectiveness, fit with existing services, affordability, and administrative feasibility were selected as criteria. The abdominal and thoracic ultrasound program was maintained in 2018 because it fulfilled the priority system needs, thereby enabling the quick screening of emergency patients. However, it was clear that the program required improvement. We selected educational materials and providers through open competitive bidding by using a targeted outsourcing strategy for the abdominal and thoracic ultrasound course only. This strategy was determined to be superior to the outsourcing strategy used in 2017 when a total of 17 CPD programs were outsourced One academic society fulfilled the criteria of responsiveness to priority system needs and fit with existing services by setting the educational goal as differentiation of emergency diseases and achievement of skills required for quick referral in primary care. It also fulfills the criteria for potential effectiveness by establishing a practice-centric educational method. By shortening the educational period from four nights and 5 days in 2017 to one night and 2 days, we satisfied the criteria of potential effectiveness and fit with existing services. The educational program described in the initial proposal was affordable and administratively feasible. For these reasons, the academic society was selected as the provider of educational content. In addition, considering the demand for improved geographical accessibility, we decided to provide education not only in Seoul, but also in other areas.After adopting these changes, the revised abdominal and thoracic ultrasound program was introduced in 2018. This program proceeded as planned and even had to be expanded due to increased demand. The initial goal was to educate 24 clinicians in two sessions with 12 students each. However, due to the increased accessibility of the program, compared with the 2017 program in terms of time and location, more students signed up than expected. More sessions were scheduled, thus bringing the program operation rate to 150% and the education recipient rate to 187%, with both being higher than those in 2017 Table .Table 3PTwo of the authors observed the sessions in real-time and recorded progress. The learners, instructors, and operators were requested to complete the free-answer questionnaires. The data obtained were then analyzed during a meeting at the Centre, where concerns were raised that the necessary capabilities may not have been sufficiently trained due to the shortened education period. However, the responses from learners during the sessions indicated that they were not only satisfied but also quite confident about their learning. The instructors believed that the learners had demonstrated the required level of competence. Freely-answered questionnaire responses were collected from all instructors, learners, and operators. The instructors said that the program was highly effective, citing intense concentration and enthusiasm among the learners. The learners were satisfied with the learning content that could be applied in daily clinical practice and the diverse case studies they were provided. Many learners left comments thanking the instructors and operators. The operators described the vibrant interactions between the instructors and learners.Goal attainment was assessed by examining post-education improvements in academic achievement. When comparing pre- and post-education academic achievements, the scores for abdominal ultrasound course and thoracic ultrasound course increased from 3.04 to 7.75 and from 3.07 to 8.06, respectively. Academic achievement, measured based on self-efficacy, increased from an average of 3.06 out of 10 to an average of 7.9 post-education. The educational satisfaction levels for the 2017 and 2018 programs , as well as higher levels of participant satisfaction and cost-effectiveness.This study has limitations because it analyzed only one program provided by the Centre  over a short span of time. Educational programs are constantly affected by factors within and outside the program. Therefore, it is clear that numerous programs provided by the Centre must have mutually affected each other. Needs assessment was carried out through surveys and FGIs, with the subject being the entire educational program provided by the Centre.The scope of this study was limited to an ultrasound educational program that was identified as a high priority through needs assessment. Selecting one course for the program cannot expand its positive effects to the entire program (10 courses in 2018). In addition, this narrow scope may have made it impossible to analyze the complexity and interrelations between programs. Moreover, the FGIs conducted in 2017 were based on voluntary participation, thus only 10% learners participated in the FGIs. Therefore, we cannot dismiss the possibility of bias toward the inclusion of enthusiastic learners. Long-term outcomes, such as the impact on patient treatment, were not evaluated. The study was based on data collected May 2017 to January 2019, when the 2017 program was initiated to when the applications of practical skills were surveyed for the 2018 program. Therefore, the long-term outcomes or impacts of the program have not been fully examined. Nonetheless, one obstetrician-gynecologist reported improvements in the diagnosis and survival rates of emergency patients after receiving ultrasound education.Despite the limitations mentioned above, the study has strengths in being comprehensive, having conducted evaluations at all phases beginning with the previous educational program, improvement and implementation of the revised program, and evaluation of the revised program after implementation. In addition, ongoing program evaluation is carried out based on a shared understanding, thus determining whether year-long education is being provided as planned can be reviewed later. We assessed not only whether the intended outcomes were achieved, but also how and why they were achieved, thus the process can be reproduced in the future, and accountability data can be secured in the future as well.The CIPP approach is suitable for the evaluation and improvement of CPD in public health. It enables the analysis of interactions between internal and external factors affecting educational programs, as well as the context in which the program is provided. Therefore, the CIPP approach helps to produce desired changes in educational programs and evaluate and improve programs funded by taxpayer money because accountability data are generated while simultaneously executing formative and summative evaluations. CPD programs administered by the Centre have the potential to improve quality of care provided by physicians in Korean PHMIs, and eventually to enhance public health. The educational program we examined exhibited notable improvement after the application of the CIPP approach, thus we were successful in realizing our goals.Additional file 1.


Goal 17 of the sustainable development goals (SDGs) attracted attention to the importance of partnerships between governments, the private sector, and nonprofit organizations (NPOs) for sustainable development. This paper aims to analyze the processes of establishing and operating the partnerships between NPOs and other actors in terms of governance. The best practices for partnership governance were examined according to the partnering life cycle framework. A simple random sample of 184 NPOs in six regions of Saudi Arabia was selected for data collection. These organizations were analyzed according to their governance practices in 937 partnerships established during 2016–2018. The findings showed that the organizations had strongly implemented the phases of building and scoping and managing and maintaining, while their governance practices regarding phases of reviewing and revising and sustaining outcomes ranged between moderate and low levels. The results also revealed significant differences between the overall implementation of the partnering life cycle practices and the NPO’s year of establishment. It was concluded that analyzing the current situation of implementing the best practices of partnership governance is useful to explore the efficiency and effectiveness of partnerships between NPOs and other actors, as well as the existing policy gaps, so as to create and implement sustainable-oriented partnerships. In 2015, the General Assembly of the United Nations (UN) formally provided a framework for "peace and prosperity for people and the planet, now and into the future", as formulated in the Global Sustainable Development Agenda , 4. The Globally, NPOs are a growing feature of societies and have become a key player as service providers of sustainable development concerns , 11. ThePartnership is a powerful tool for collaboration between various parties, both public and private , 30. A pPartnerships between NPOs and other actors can operate at two levels: intra-sector (nonprofit–nonprofit) and inter-sector  , 41. ByiTo develop successful collaborations between NPOs and other actors, building an effective collaborative governance structure for the partnerships is essential . AccordiIn Saudi Arabia, the nonprofit sector comprises organizations and entities that provide services in nine main fields: culture and entertainment, education and research, health, social services, environment, development and housing, advocacy, charity, and religious education . Over thDespite the growing interest in analyzing the various aspects of partnerships in the literature, limited evidence has been observed regarding the interactions of formal and informal governance processes and structures throughout the lifetime of a partnership, specifically in the context of Saudi Arabia. Accordingly, there is a need for more comprehensive empirical research to understand the governance practices and mechanisms that facilitate successful partnerships. The objectives of this study were to identify current NPOs’ implementation levels of governance practices during the life cycle of their partnerships and determine the differences in implementing these practices based on the NPOs’ characteristics.Building successful partnerships between organizations is one of the most essential good corporate governance practices . Good goThe governance of cross-sector partnerships has received growing academic interest due to the differences between partners in their configurations and objectives . These pTo understand how tensions are addressed through governance, informal and formal governing mechanisms and their interactions throughout the partnership’s lifetime should be identified . Formal This phase consists of four steps: scoping, identifying, building, and planning. In the scoping step, partners define the area of interest by identifying geographic, thematic, and strategic priorities. Furthermore, partners assess the partnership’s viability through a contextual analysis and map the stakeholders (step #2) . In the This phase includes three steps: structuring, mobilizing, and delivering. In the structuring step, actors establish the communication protocols, decision-making mechanisms, governance structures, and accountability procedures . The parIn this phase, partners judge the “health” of the partnering relationship. In other words, they measure the outcomes of the partnership to determine its performance (step #8) . In stepIn the final phase, depending upon the partnership’s outcomes, partners might decide to end the partnership  or continue it . If the A quantitative research methodology using a survey design was adopted as the overarching research strategy for the present study. Quantitative research generally investigates why and how phenomena happen or exist in social life . This stThe present study considered one NPO that provides social services in Saudi Arabia and meets all the inclusion and exclusion criteria as a unit of analysis. These criteria included organizations being a registered charity under the Saudi charities regulation of 1990 or the modified regulation of civil organizations of 2015, having an operating age of at least three years as of 31 December 2015, and being engaged in three partnerships during the period of 2016–2018. Even though the research design may also apply to other types of NPOs, they were not considered the unit of analysis in this study. This study identified these criteria to achieve its objectives for the valid and reliable measurement of the phenomena under investigation according to the scale adopted. While the survey was addressed among the organizations’ managers, these managers were not a unit of analysis even though they provided information regarding their organizations’ governance practices, as this study describes an NPO’s governance in a partnership throughout the partnership’s life cycle, not each manager’s characteristics or practices.This study’s population was the total number of social service NPOs in Saudi Arabia that are registered charities under the charities regulation of 1990 or the civil organization regulation of 2015 and whose details were available in the database of the Ministry of Human Resources and Social Development. In 2020, there were 1335 total social service organizations, including charities . HoweverThe questionnaire comprised two sections as presented in To ensure the reliability of the instrument, this research adopted internal consistency as its reliability measure by calculating the Cronbach’s alpha coefficient. The value of the Cronbach’s alpha of the scale was 0.82 (>0.7), indicating good internal consistency and high reliability. In terms of content validity, each item included in the scale was measured and operationalized based on the definitions and explanations provided in previous studies that highlighted the partnership life cycle , 105–108Data were collected by face-to-face interviews and by online survey during the period from June to October 2020. An information sheet explaining the purpose of the study and the contact details of the researchers was provided with the questionnaire. The e-questionnaires were shared with the managers of the organizations who were selected through a sampling process via e-mail and WhatsApp. The questionnaires were addressed to the managers of the surveyed NPOs  who manage the day-to-day affairs and partnership affairs in these organizations, as revealed during the pre-test.The sample NPOs were given four weeks to fill in the questionnaire, and 43 questionnaires were received back in this period without any reminders. A reminder was then sent to all non-responding NPOs after four weeks. A further two weeks were given to complete the questionnaires after this reminder. Another 54 questionnaires were then received. A final reminder was sent to the sample with another two weeks given to complete the questionnaires, and 29 responses were delivered within this period. This provided a total of 126 responses. The rest of the sample (58 responses) was collected through personal interviews.The collected data were analyzed using the Statistical Package for Social Sciences . Percentages, means, and standard deviations were used as descriptive statistics to describe the data. Inferential statistics of variance analysis (ANOVA) were employed to find the differences between groups. Moreover, the least significant difference test (LSD) was performed to determine which specific means were significant from the others.The NPOs’ implementation of the partnering life cycle framework in the scoping and building phase is presented in In terms of the identifying step, however, the importance of making initial contact with potential partners to explore the partnership idea had a moderate level of implementation. The results shown in In the planning step, for all five items being assessed , the impThe implementation of managing and maintaining practices as the second phase of the partnering life cycle is highlighted in In the delivering step, the assessment of the two statements pertaining to this step  demonstrIn the measuring step, all items were considered to have a moderate level of implementation . The iteFor all three items being assessed , the impA low level of implementation of the revising step among NPOs was observed in all items . The aveAll seven statements assessed for scaling and moving the steps involved in this phase were considered to have low implementation for sustaining outcomes . As showThe overall mean of each step of the partnering life cycle framework is presented in p < 0.05. This result demonstrates that the NPOs differed in their implementation of governance practices based on their establishment date. According to the results of the LSD test, the mean value of the "6–10 years" category significantly differed from that of the "fewer than six years" category at the 0.05 level. Moreover, the mean value of the "more than 10 years" category significantly differed from the "fewer than six years" category at the 0.01 level. This indicates that the organizations with a longer period of establishment scored higher in the items related to implementing governance practices included in the partnering life cycle. The findings also showed no significant differences in the overall implementation of governance practices regarding the region, field of practice, or number of partnerships.In this article, we examined the formal and informal processes of partnerships through which NPOs and other actors frame and prioritize issues, articulate their interests, and make, implement, monitor, and enforce decisions. The insights from this exploration will enrich existing literature on the governance of partnerships, which is mainly based on qualitative research. From a theoretical point of view, partnerships with strong internal governance are more likely to leave a social footprint in society and encourage partners to engage in sustainable collaboration with NPOs. This study assessed how partnerships between NPOs and other actors in Saudi Arabia should be practically managed for sustainability by adopting the partnering life cycle framework. This approach provides a series of valuable guidelines to analyze the phases and steps necessary to form a partnership. Furthermore, it gives a complementary vision to design healthy relationships between partners to increase the transformation potential of a partnership. Our results about the current situation of applying the steps included in the partnering life cycle framework complement existing knowledge and offer insights into how we can increase the efficiency and impact of working in partnerships.Our findings highlight the increasing linkages between NPOs and the development of cooperating actors. The number of partnerships signed during 2016–2018 was promising and indicates a substantial transformation of collaboration to meet mutual interests and solve complex issues. This transformation reflects the Saudi government’s significant role through Vision 2030 in supporting partnerships between NPOs and other actors . After aPrior to signing a partnering agreement, the results showed that NPOs professionally undertake the needed steps to form a partnership. These steps relate to four areas: identifying the issue to be addressed, identifying appropriate partners, suggesting ground rules for building successful partner relationships, and outlining a planning and resource mapping framework. These results confirm the availability of an environment conducive to partnering. In this context, Sterne, Heaney  indicateSome difficulties were observed during the implementation of the partnerships. Meeting stakeholders’ needs and mapping stakeholders’ priorities are two of the challenges that NPOs face in the delivering step. Furthermore, the findings revealed that NPOs’ implementation of the reviewing and revising steps ranged from low to moderate levels. These results show that some governance practices still need to be enhanced to minimize their impacts on a partnership’s effectiveness and achieve social innovation. Practically, some NPOs could face such problems due to a lack of required competencies, the nature of the issue to be addressed, and the level of engagement with partners in performing activities . In thisSustaining outcomes was the least commonly implemented phase by NPOs. As evidenced from the results, the activities included in the steps of scaling and moving on were rarely implemented by NPOs throughout the life cycle of partnerships. This result may be because most of the partnerships signed were characterized as philanthropic, rather than strategic. This would reduce the willingness of partners to develop long-term mechanisms for sustaining outcomes with NPOs. Furthermore, most partnerships, as shown in The extent to which the NPOs followed governance practices varied among these organizations in Saudi Arabia based on their year of establishment. Kuruvila  argued tThis study had some limitations that should be acknowledged. First, this study focused only on social service organizations registered as charities under the charities’ regulation of 1990 or the civic organizations regulation of 2015. Although our results provide some insights into the partnership governance of NPOs in general and may assist other types of NPOs, these results are mainly limited to social service organizations. While the study results may be useful to NPOs in other countries, this research’s generalization is limited to Saudi Arabia’s NPOs. Second, the data collection tool included close-ended questions to identify the implementation level of governance practices. The responses may have been influenced by social desirability biases, and the method of data collection could have prevented the researchers from obtaining additional comments. Third, data were collected from NPOs as partners in collaborations without obtaining the opinions of other actors that engage with these organizations in the partnerships. This approach is not sufficient to accurately describe the nature of the partnerships’ governance in formal and informal structures or in the processes implemented during collaboration. Fourth, the level of analysis involved only organizations. Highlighting governance practices according to each partnership could give a fuller picture of how these practices differ according to partnerships’ configuration and the types of actors involved in the partnership. Finally, the profiles of the NPOs included only some general characteristics of these organizations and the partnerships that they were involved in with other actors. Other indicators of organizational capacity, such as the board, service delivery, staff, volunteers, and finances, are also important to identify the management of NPOs. Therefore, such variables should be included in future research to explain and interpret the differences—if they exist—among organizations in partnership governance practices.This study attempted to develop an understanding of NPOs’ governance of partnerships in Saudi Arabia. This aim was achieved by examining the NPOs’ implementation of the partnering life cycle framework. The story of the NPOs’ implementation of the phases and steps included in this framework could be described as an "hourglass", with promising beginnings and incomplete or non-hopeful endings. As evident in the partnering life cycle analysis, partnership governance is a complex issue that requires the management of internal organizational processes and the organization’s interactions with the external environment. The findings concluded that NPOs still need to enhance their monitoring and evaluation practices to improve their partnerships’ value for society and the partners. Additionally, how NPOs can scale their successful partnerships up and develop long-term mechanisms to sustain their partnerships remains questionable. The practices of governance over the life cycle of the partnership developed in this study have implications in both theory and practice. This paper offers a relatively simple view of NPO governance without losing its complexity. This framework conceptualizes the interactions between partners in both internal and external environments in easily understandable steps and offers a practical guide with a tested and reliable rating scale to assist future researchers who want to research the governance of partnerships. Practically, this study provides insights into the gaps that need to be filled by NPOs during the life cycle of a partnership, particularly during the steps of measuring, reviewing, revising, scaling, and moving on. One of the needs expressed by NPOs is the concern to reach an agreement on how the achievement of outcomes will be measured and assessed and what needs to be changed, hence the importance of dialogue along the life-cycle of the partnership process. Co-developing performance indicators are essential to evaluate not only of the collaboration between parties itself, but also of the partnership’s outcomes. Therefore, the assessment of results should consider three main areas: the partnership’s value for each of the partners involved, the true costs and benefits of the partnership approach, and impacts on the target group in particular and society in general. External third parties are urgently needed as brokers between partners to enhance collaboration practices. Brokers can act as allies to complement the partners’ roles during the entire life cycle of a partnership to enable NPOs to achieve more significant social innovation. Also, the study recommends using social media as a part of organizational strategy of the partnership. The main purpose of such platforms is to enhance NPO’s visibility, publicize the results, and connect with other NPOs for sharing of lessons learned of the partnership. From a policy perspective, as most of the participant NPOs rely on government and private sector contracts for their functioning, new collaborations should consider the capacity-building needs of NPOs in terms of governance practices along a partnership’s life cycle. Due to the scarcity of research on partnership governance in Saudi Arabia’s nonprofit sector, more research in this area is needed to bring more diverse perspectives to the discussion of partnership governance. This study highlights the need for more comprehensive empirical research on the impact of external environmental barriers on partnership governance. Moreover, how the governance of these partnerships may be influenced by the type and number of partners and the organizational capacity of NPOs would be an interesting topic to investigate.S1 Data(XLSX)Click here for additional data file.S1 File(PDF)Click here for additional data file.


The implication is of a unidirectional flow from “the bench to bedside”. The rapidly emergent field of additive manufacturing (3D printing) is contributing to a major shift in translational medical research. This includes the concept of bidirectional or reverse translation, early collaboration between clinicians, bio-engineers and basic scientists, and an increasingly entrepreneurial mindset. This coincides with, and is strongly complemented by, the rise of systems biology. The rapid pace at which this type of translational research can occur brings a variety of potential pitfalls and ethical concerns. Regulation surrounding implantable medical devices is struggling to keep up. 3D printing has opened the way for personalization which can make clinical outcomes hard to assess and risks putting the individual before the community. In some instances, novelty and hype has led to loss of transparency of outcomes with dire consequence. Collaboration with commercial partners has potential for conflict of interest. Nevertheless, 3D printing has dramatically changed the landscape of translational research. With early recognition and management of the potential risks, the benefits of reshaping the approach to translational research are enormous. This impact will extend into many other areas of biomedical research, re-establishing that science is more than a body of research. It is a way of thinking. The impModern healthcare demands for innovative, faster and more personalized solutions have seen the convergence of engineering and biomedical research, leading to emergence of the rapidly growing field of bioengineering, driven to a large extent through the application of additive manufacturing. . Additiv3D printing has not only been instrumental to the development of new fields of study, it has brought together multidisciplinary teams from across the spectrum of engineering, medicine, biomedical research, information technology with other stakeholders, including consumers and commercial funders. The result is reframing of multiple aspects of translational research, ranging from how translational research is defined, to the role of multidisciplinary teams, to tools that better replicate human biology, to the fundamental philosophies that drive it and, ultimately, to the pace at which it occurs.Appreciating the impact of 3D printing on translational research starts with defining what “translational research” means. The term was originally used sporadically during the 1990s in cancer research to describe research that spanned different types or different disciplines of research, such as basic and clinical research, or immunology and molecular genetics. . The turIn June 2000 the initial meeting of the Clinical Research Roundtable of the Institute of Medicine , a body Over time the “T” has changed from representing a translational block to representing a translational phase. Currently there is general consensus on the definitions of T1 through to T4 . Fort e Additionan interdisciplinary branch of the biomedical field supported by three main pillars: benchside, bedside and community.  is a systematic approach to finding a solution to a problem. The starting point is identifying and researching the problem, followed by ideation of a solution, planning, development of proof of concept and/or prototyping, testing and re-iterations, then implementation. . The engThe application of 3D technologies to human biology and medicine in order to improve healthcare and healthcare outcomes has contributed to the rise of the new field of biomedical engineering. . Use of Complex systems exist everywhere in nature, including the human body. . They arIronically, whilst the engineering field adopted systems thinking generating the fields of cybernetics and system dynamics , biomediSystems thinking allows biomedical research and engineering to dovetail into translatable solutions  and 3D pAvailability of 3D printers to the wider public has seen the rise of the “prosumer”, a person who is involved in the co-creation and innovation of the product they use. . In healThe Covid-19 pandemic has also driven prosumers to the fore with 3D printing used widely to fill the need for low-cost, rapid fabrication of medical devices and personal protective equipment as the world faced a short fall from more established production lines. Frontline healthcare workers became actively involved in designing items for personal and peer use. Not only was 3D printing used to crucially help with this shortfall, it demonstrated, in real time, how fast translation can be when problem and outcome focused. .Public awareness of the ability to use 3D printing to customize prothesis, implants and other devices is increasing demand for such products. In turn, this drives innovation and translation. There has been an explosion in prosumer driven custom-made prosthetics, such as Free 3D Hands and Art4Leg, allowing patients to be involved in designing their own limb or casts with an increasing focus on developing better functionality at lower cost. . SurgeonEntrepreneurialism seeks creation or extraction of value through creativity and innovation. . The hisThe impact is that the foundations of good business  , need to3D printing is an exciting technology. It fires the imagination, bringing with it the biggest risk: exposing scientific research to public hype. The Gartner Hype Cycle is a graphic representation of the maturity and adoption of technologies and applications, and how they are potentially relevant to solving real world problems. . Whilst Complex regulatory requirements are seen as a major barrier. . New req3D printing highlights the need for increased and early multidisciplinary collaboration in translational research. . Whilst Commercial partnerships and funding arrangements can generate conflict of interest and pitfalls, through looking for faster, more expedient ways to bring devices or technologies to market, or creating prestige to advance further funding opportunities without paying attention to the way this is achieved. . The disFinally, measuring and evaluating progress is unstandardized. Personalization makes outcome measures harder to determine and standardize and risks putting the need of the individual before the community. Many academic organizations reward work based on individual output primarily through publications and grants, rather than team outputs, patents, trade secrets, and impact on health outcomes. This can dissuade collaboration and translation..3D printing has demonstrated that when healthcare needs, such as prosthetic limbs, are the driver, real world outcomes can be achieved at a faster pace with less waste and lower costs. As the cost of 3D printers and materials reduce, these technologies will become more widely available. Use of 3D printed organoids is already seeing the cost of pharmaceutical development being reduced and has potential to reduce, if not eliminate, use of animal experimentation. . ProsumeThe temptation may be to either overregulate or forgo proper safety assessment. Jurisdictions that are agile in adapting their regulations to ensure a balance of safety whilst not stifling progress will be the big winners.Those countries or groups who can connect and engage with the end-users, build functioning multi-disciplinary teams across a myriad of disciplines, and maintain focus on meeting the desired healthcare outcomes will achieve faster translation and better return on research, government and commercial funding. Finally, those who are able to grasp how 3D printing technologies can be used in understanding complex systems will be the ones to tap into the wealth of knowledge that has yet to produce healthcare impact.In this century, 3D printing has moved from the realm of fiction to generating impact on health outcomes and healthcare across the spectrum. 3D printing has been pivotal in the merging of engineering and biomedical fields. In this way, it has helped shape how translational research is defined, understood and pursued.


Klosterth century and still functions today as a church and convent. The abbey , or due to stochastic triggers . The risk of an event becoming manifest can be modified through surveillance and prevention strategies, designed for each hazard. Should an event occur, the kinetic energy expended upon a population is termed impact. In the case of modern firearms, both the kinetic energy and the resulting impact are highly lethal.ulnerability of the population to the impact determines the damage to that population. After impact occurs, damage to the vulnerable population may be only be modified by timely active response and resources termed resilience. In the best case, the prevention of a hazard removes or disables its potential energy, rendering it harmless. If an event is allowed to impact a vulnerable population, the damage is mitigated by the resilience of the community. The Utstein style is an analytical heuristic, similar to the Haddon matrix,In Utstein style analysis, any potential disaster may be characterized as a hazard in the Utstein framework. Along with Mexico and Guatemala, the United States (US) is one of three nations on earth that designates firearm possession as a Constitutional right and not a privilege. Therefore, the hazard of firearm violence cannot be prevented without amending the US Constitution. For this reason, our collective challenge is to find a better way to modify the risk of civilian misuse of firearms. State and local firearm ordinances represent an attempt at risk modification through a patchwork of restrictive and permissive strategies in which uniform enforcement is not possible. A wide variety of socioeconomic and cultural communities are overlaid on that patchwork of laws making the application of “gun control laws” confusing and contradictory. One law does not work in all places.With respect to firearm violence, the citizen misuse of firearms would be the hazard) and low rate of firearm violence , such as Hawaii, Idaho, Montana, Wyoming, or Switzerland. In contradiction, there are cities with both a high level of firearm regulation  and a paradoxically high level of firearm violence  such as the District of Columbia or Chicago. The risk of firearm violence in the US resembles an archipelago of high-risk firearm violence islands with interspersed large zones of minimal risk oceans. One strategy does not fit all locations.There are states, and in fact nations, that have high firearm ownership  and more about the factors involved in motivating a citizen to misuse firearms. Because Second Amendment arguments lend themselves to primal emotions on both sides, too much energy is expended on the right of firearm possession vs dispossession  and not enough on identifying and intervening in the factors leading up to the shooting or risk modification.One possible explanation for these conflicting examples is perhaps that the problem is less about the firearm  is not included in this analysis, the issue of intentional firearm violence has at least four key categories:Suicide or self-harmIntimate partner, family, or business partner violenceCriminal activityMass shootings and assassinationsrisk of firearm violence becoming an event. Further, the target population has different vulnerabilities, with many different mitigation strategies. Like motor vehicle speed limits, one strategy does not fit all problem sets.In each category, there are different factors that determine the risk of a firearm-assisted suicide event in this category.Suicide by firearm represents over one third of total firearm deaths in the US,risk individuals may be evaluated for short-term firearm dispossession and crisis counseling.Intimate partner violence, family conflict, or revenge on business associates are significant subcategories for children and adults. Each of these subcategories involves some level of conflict or rejection, combined with a malign adjustment reaction. Similar to child abuse, or domestic abuse not involving firearms, there are higher risk individuals and precipitating events  that are surveillable. Individuals undergoing these precipitating events may be screened and have data-driven resources provided such as personal, legal, and/or financial counselling. Higher risk of segments of our population to criminal behavior and associated firearm violence at a great cost in both lives and dollars.Given the cost of the judicial and prison systems in the US, criminal activity with firearm violence has perhaps the largest total resource allocation of the subsets. Great efforts have been made to predict criminal activity by better understanding the spatial, temporal, and perpetrator-victim associations of specific crimes. The risk modification of criminal behavior has received much less attention. If we assume that all people are born with more or less the same inclination to crime, then poor schools, gang activity, and systemic racial bias that produce disparate justice system outcomes are specific risk factors associated with poor and minority communities. These structural factors contribute to a loss of legitimate academic and/or economic opportunities and are a driver of criminal behavior. Consider, the US has 5% of the world’s population yet 25% of the world’s incarcerated population. Blacks and Hispanics represent 32% of the US population but 56% of the incarcerated population. While Blacks comprise 13% of the US population, 35% of those executed in the past 40 years are Black. Approximately half of those incarcerated will return to prison and 75% of formerly incarcerated people are unemployed.While the category of mass shootings and assassinations is the most newsworthy and consistently evokes public outcry, it is actually 1–2% of the total firearm violence.For too long the US has avoided an injury control perspective, largely due to the Dickey Amendment of 1996,risk. Informed with data, gun violence policy may improve, and firearm injuries may be reduced.A notional system to modify the issue of firearm violence is depicted in