Test-Bench for the Characterization of Flexion Sensors Used in Biomechanics

The design, prototyping and validation of an innovative test bench for the characterization and the hysteresis measurement of flexion sensors are presented in this paper. The device, especially designed to test sensors employed in the biomedical field, can be effectively used to characterize also sensors intended for other applications, such as wearable devices. Flexion sensors are widely adopted in devices for biomedical purposes and in this context are commonly used in two main ways: to measure movements (i) with fixed radius of curvature and (ii) with variable radius of curvature. The test bench has been conceived and designed with reference to both of these needs of use. The technological choices have been oriented towards simplicity of manufacture and assembly, configuration flexibility and low cost of realization. For this purpose, 3D printing technology was chosen for most of the structural components of the device. To verify the test bench performances, a test campaign was carried out on five commercial bending sensors. To characterize each sensor, the acquired measurements were analysed by assessing repeatability and linearity of the sensors and hysteresis of the system sensor/test bench. A statistical analysis was performed to study the positioning repeatability and the hysteresis of the device. The results demonstrate good repeatability and low hysteresis.

Wildlife Trade Influencing Natural Parrot Populations on a Biodiverse Indonesian Island

Indonesia has been identified as the highest priority country for parrot conservation based on the number of species, endemics, and threats (trapping and smuggling). It is crucial to understand the current population status of parrots in the wild in relation to the illegal wildlife trade but the ecology and population dynamics of most parrot species in this region remain poorly understood. We conducted a parrot survey around an area of high biodiversity in the Manusela National Park, in Seram Island, Indonesia. We used a combination of fixed-radius point counts and fixed-width line transects to count multiple species of parrots. We recorded nearly 530 wild parrots from 10 species in and around Manusela National Park. The dominant parrot species were Eos bornea, Trichoglosus haematodus, and Geoffroyus geoffroyi. We applied the Savage selectivity index to evaluate poaching of parrot species in proportion to their abundance and which species had higher than expected poaching pressure. This study has important implications for the conservation status of endemic parrots (Cacatua moluccensis, Lorius domicella, and Eos semilarvata) and shows that parrots in the Manusela NP are largely threatened by poaching.

The Comparison Between Different Hospital Market Definition Approaches: An Empirical Analysis of 11 Representative Diseases in Sichuan Province, China

Objective: This study aims to provide empirical evidence for the controversy about whether the inference is consistent if alternative hospital market definition methods are employed, and for which definition method is the best alternative to the predicted patient flow approach.Data sources: Collecting data from the discharge data of inpatients and hospital administrative data of Sichuan province in China in the fourth quarter of 2018.Study Design: We employed Herfindahl–Hirschman Index (HHI) as the proxy of market competition used as an example to measure the hospital market structure. Correlation coefficients of HHIs based on different definition methods were assessed. The corresponding coefficient of each HHI estimated in identical regression models was then compared. In addition, since the predicted patient flow method has been argued by the literature of its advantages compared with the previous approaches, we took the predicted patient flow as a reference to compare with the other approaches.Data Extraction Methods: We selected the common diseases with a significant burden, and 11 diseases were included (902,767 hospitalizations).Principal Findings: The correlation coefficients of HHIs based on different market definition methods are all significantly greater than 0, and the coefficients of HHIs are different in identical regression models. Taking the predicted patient flow approach as a reference, we found that the correlation coefficients between HHIs based on fixed radius and predicted patient flow approach is larger than others, and their parameter estimates are all consistent.Conclusion: Although the HHIs based on different definition methods are significantly and positively correlated, the inferences about the effectiveness of market structure would be inconsistent when alternative market definition methods are employed. The fixed radius would be the best alternative when researchers want to use the predicted patient flow method to define the hospital market but are hindered by the data limitations and computational complexity.

Tackling the SDC in AdS with CFTs

We study the Swampland Distance Conjecture for supersymmetric theories with AdS5 backgrounds and fixed radius through their $$ \mathcal{N} $$ N = 2 SCFT holographic duals. By the Maldacena-Zhiboedov theorem, around a large class of infinite-distance points there must exist a tower of exponentially massless higher-spin fields in the bulk, for which we find bounds on the decay rate in terms of the conformal data. We discuss the origin of this tower in the gravity side for type IIB compactification on S5 and its orbifolds, and comment about more general cases.

Migratory Seasonality and Phenology by Birds in a Temperate Forest with Two Disturbance Conditions

Objective: The objective was to infer the effect of the variables phenology (migration-non-migration), seasonal (rainfall-dry season), sex and forest condition on the abundances of birds (resident-migratory) in a semi-preserved and disturbed oak pine forest. Design/methodology/approach: It was carried out in Monte Tlaloc, State of Mexico, under two conditions of apparent disturbance, semi-preserved oak pine forest and disturbed oak pine forest. Ten bird samplings were carried out with "count on point" with a fixed radius of 25 m, covering the 4 seasons of the year and migratory periods. With the previous data, the Relative Abundance Index (RAI) was estimated. To infer the effect of the variables phenology, seasonality, sex and forest condition on the abundances of birds, generalized linear models were elaborated. Results: The IAR of the birds registered in the semi-considered pine forest indicates that the species with the lowest presence was Aphelocoma ultramarina (0.002) and with the highest frequency Empidonax sp. (0.13), unlike to that found in the disturbed pine forest where the lowest IAR corresponded to Colaptes auratus (0.003) and with the highest appearance was Ptiliogonys cinereus (0.23). The Generalized Linear Model suggested that forest condition and phenology are significantly related to the frequency of species. Limitations on study/implications: In this study it was found that the abundance of birds was affected by the condition of the forest and that the phenology (migration-non-migration), seasonal (rain-dry season), sex and condition of the forest were related to the abundance of birds. Four species classified as under Special Protection and two Threatened according to NOM-059 were registered as well as the presence of four endemic species which highlights the importance of conserving these ecosystems. Findings/conclusions: The fauna communities present in Monte Tláloc highlight the importance of conserving the pine-oak forests since this site is part of the Eje Neovolcanico Transversal.

Birds in Wetland Ecosystems of Ayodhya District, Uttar Pradesh

This study was carried out in the wetlands across Ayodhya District, Uttar Pradesh using fixed radius point counts, to understand the diversity and distribution of birds in these ecosystems. A total of 102 bird species belonging to 35 families and 12 orders were recorded from the study area. Amongst the order, Passeriformes (24 and 12) had the maximum number of species and families. The highest number of species recorded were Carnivores (44 species, 43%). A total of 61 bird species (60%) were resident, 41 bird species (40%) were winter visitors and ten species were in the threatened category of IUCN Red List (2021) which highlights the conservation value of wetland ecosystems in Ayodhya District, Uttar Pradesh.

STABILITYANALYSIS OF SCHWARZSCHILD-DAMOUR-SOLODUKHIN WORMHOLE

The equations of general relativity are nonlinear second-order partial differential equations, and, as a consequence, obtaining the exact solutions is a difficult problem. One of the solutions to this problem is to obtain models with a thin self-gravitating shell. This method is used to study most of the phenomena in the theory of gravity, where the reverse effect of matter on the geometry of space-time is a key factor. Another interesting problem that can be studied using the thin shell method is the «simulation» of a black hole. Consider a system consisting of a spherically symmetric Schwarzschild black hole and a thin shell surrounding it, located at a certain fixed distance from the black hole. From the viewpoint of gravitational physics, an observer at infinity is unable to distinguish a real black hole from a wormhole with a thin shell, in which the simulation condition is satisfied. Simulation of a black hole is possible only under sufficiently stringent conditions for the parameters of the model. In particular, the shell needs to be held at a fixed radius. In the general case, such a movement of the shell is non-geodesic, and external forces are required to hold it. The radius of the shell is also a parameter that determines the possibility / impossibility of simulation. In this paper, the radius is found for the case of a Schwarzschild black hole. In particular, the paper considers a model of a wormhole obtained as a result of gluing two space-times: a Schwarzschild black hole and a Damour-Solodukhin wormhole. The latter solution differs from the Schwarzschild black hole in the parameter of the dimensionless real deviation λ and is a twice asymptotically flat regular space-time. It is shown that they can be glued along a given radius. As a result, a thin shell is formed between two glued manifolds consisting of exotic matter. Cases are considered when the thin shell is stable. It turns out that zones corresponding to the «force» constraint are more restrictive than those corresponding to the «mass» constraint.

Tail asymptotics of an infinitely divisible space-time model with convolution equivalent Lévy measure

We consider a space-time random field on ${{\mathbb{R}^d} \times {\mathbb{R}}}$ given as an integral of a kernel function with respect to a Lévy basis with a convolution equivalent Lévy measure. The field obeys causality in time and is thereby not continuous along the time axis. For a large class of such random fields we study the tail behaviour of certain functionals of the field. It turns out that the tail is asymptotically equivalent to the right tail of the underlying Lévy measure. Particular examples are the asymptotic probability that there is a time point and a rotation of a spatial object with fixed radius, in which the field exceeds the level x, and that there is a time interval and a rotation of a spatial object with fixed radius, in which the average of the field exceeds the level x.

A comparison of the accuracy of different types of samples for spatial structure indices determination in beech forests in Serbia

In this paper we compared the accuracy of different samples (minus the sample with the NN1 edge correction and buffer zone, plus sample and modified cluster sample) to determine indices of spatial structure in beech forests in Serbia, which can be used in regular forest inventory. The research was conducted in 11 forest stands of different structure at the territory of Central Serbia. Field data used for the assessment of spatial structure indices were collected across the examined stands on the sample plots of different sizes, using systematic grid, with the square layout of sample plots (100x100 meters). The study was conducted on 242 sample plots. For accuracy comparison of different sample types, five indices were used: Uniform angle index, Mean directional index, Species mingling index, DBH differentiation and DBH dominance indices. One-way ANOVA showed that at the stand level there were no statistically significant differences between mean values of indices obtained by different sample types. However, Simple linear correlations confirmed for most indices that if the spatial structure is to be determined with accuracy at the level of sample plots (in this case, a circular fixed radius plot of 5 acres) it is necessary to use a plus sample during data collection. For species mingling and DBH differentiation indices, Simple linear correlations show that both minus sampling with edge correction buffer zone and modified cluster sampling with somewhat less accuracy can be used to a certain extent. Minus sampling with NN1 edge correction is not practical for use on sample plots of this size in beech forests in Serbia.