Evaluating the instability of injuries according to the AOSpine Subaxial Cervical Spine Injury Classification System

Background. The main criteria for determining surgery strategy in patients with traumatic subaxial cervical injury are as follows: the type and degree of damage to the osteo-ligamentous structures of cervical spine that determines the level of instability; the value of spinal cord compression; the state of the sagittal profile. The aim of this study was to assess the degree of instability in different types of cervical spine injuries according to AOSpine Subaxial Cervical Spine Injury Classification System. Materials and methods. We performed a retrospective analysis of Х-ray, computed tomography and magnetic resonance imaging data of 168 patients with traumatic injury of subaxial cervical spine. All of them were hospitalized at the Department of Spinal Cord Pathology of the Romodanov Neurosurgery Institute of National Academy of Medical Sciences of Ukraine 2008–2018. We assessed the degree of instability using the Cervical Spine Injury Severity Score and determined the type of damage according to the AOSpine Subaxial Cervical Spine Injury Classification System. Results. We found that the median rate of instability increases progressively with increasing severity of injury type. The widest range of instability values is observed in the compression damage: from 6 points (95% confidence interval (CI): 4.76–6.84) in A1 type to 11 points (95% CI: 9.48–11.81) in A4. For A2 and A3 types, we registered 7 (95% CI: 6.68–7.53) and 8 points (95% CI: 7.97–9.01), respectively. A smaller range of values characterizes flexion-extension injuries. The median progressively increases from B1 type — 13 points (95% CI: 12.4–13.92) to B3 type — 15.5 points (95% CI: 14.5–16.35). The value for B2 is intermediate and is 15 points (95% CI: 13.59–15.52). We registered maximum values in flexion-extension injuries — 18 points, for both B2 and B3 types. C type has the highest level of instability — 17 points (95% CI: 16.58–17.86) and a quite wide range of estimated values: from 13 to 20 points. Conclusions. The general trend is an increase in the level of instability in the range from A1 to C injury subtypes, but even A1 type in some cases are quite unstable and require surgery. In contrast to the classical views, type A injuries are often accompanied by da-mage to the facet joints, which must also be taken into account when determining the individual treatment.

THE RESEARCH OF STABILITY OF STATIONARY ROTATION A ROTOR SYSTEM WITH A LIQUID, THE AXLE OF WHICH IS LOCATED IN ANISOTROPIC FIXINGS

Earlier, one of the authors proposed and developed (together with coworkers) an original method to study the stability of stationary rotation of rotary systems containing a viscous liquid and having a drive that maintains the angular velocity of rotation constant. It was assumed that the rotor has axial symmetry, the anchors of its axis are isotropic. The method is based on two theorems, according to which a change in the degree of instability is associated with the possibility of a perturbed motion of the circular precession type. This motion has a remarkable property: the velocity field and the shape of the liquid surface do not depend on time in a specially selected non-inertial reference frame associated with the line of centers. Finding the conditions for the feasibility of circular precession makes it possible to effectively construct the boundaries of the stability regions of the stationary rotation regime in the space of problem parameters. In addition, the study of the occurrence of circular precession allows us to find the conditions under which a subcritical (supercritical) Andronov-Hopf bifurcation takes place in the rotor system and to identify "dangerous" (“safe”) sections of the boundaries of the stability regions. In this paper, the previously proposed method of stability research applies to systems in which the rotor axis is located in anisotropic Laval type anchors. In the study of rotary systems of this type, it is possible to link the change in the degree of instability with the feasibility of perturbed movements of the elliptical precession type. It can be shown that the imaginary characteristic numbers of the equations in deviations from the stationary rotation mode are possible only in the case when there is a perturbed motion in the form of an elliptical precession. An example of a study of the stability of stationary rotation of a typical rotary system is given. Mechanical effects caused by the fact that gyroscopic stabilization becomes impossible with anisotropic fixing of the rotor axis are noted.

Особенности истечения в вакуум микроструй невязкой жидкости

Experimental results of the outflow of ethanol microjets from the capillary (vertical flow in the direction of gravity) and from the hole in the wall (in the horizontal direction) are presented. It is shown that a long-term flow of a microjet of a liquid in a vacuum exhibits a high degree of instability with sudden changes in direction, structure, observed density and differs significantly from the well-studied modes of outflow into the atmosphere, as well as from short-term modes of outflow into vacuum. The main features of the flow and the conditions for the onset of instability are described. A probable explanation of the reasons for the destruction of the microjet is given.

Growth and Instability Analysis of Pearl Millet Cultivation in India

The present study was undertaken to analyze growth and instability in terms of area, production and yield in a major pearl millet growing states of India. The study has employed the secondary time series data of the area, production and yield of pearl millet crop collected from 1997-1998 to 2016-17 for the major pearl millet crop-growing states of India. The results revealed that area under cultivation registered declined growth in all states and India except Uttar Pradesh. Gujarat showed overall negative growth in terms of area, production and yield. Rajasthan and Uttar Pradesh found increased production and yield. High level of instability in terms of yield recorded in Rajasthan while, Gujarat, Haryana, Rajasthan and India witnessed a high degree of instability in terms of production during the entire period.

Governing Illiberal Democracies: Democratic Backsliding and the Political Appointment of Top Officials in Hungary

This paper examines the impact of democratic backsliding on the management of top officials in Hungary. Based on a unique data set of more than 1,600 top officials the article shows that the number of appointments to top positions increased in 2010 and subsequent years, during which Hungary experienced democratic back-sliding. Moreover, the data shows that turnover in top official positions was higher in 2010 and in subsequent years than in the period between 1990 and 2010. The paper concludes that the politicisation and high degree of instability in top official positions may be characteristic of governance in illiberal democracies.

Predicting collapse of complex ecological systems: quantifying the stability–complexity continuum

Dynamical shifts between the extremes of stability and collapse are hallmarks of ecological systems. These shifts are limited by and change with biodiversity, complexity, and the topology and hierarchy of interactions. Most ecological research has focused on identifying conditions for a system to shift from stability to any degree of instability—species abundances do not return to exact same values after perturbation. Real ecosystems likely have a continuum of shifting between stability and collapse that depends on the specifics of how the interactions are structured, as well as the type and degree of disturbance due to environmental change. Here we map boundaries for the extremes of strict stability and collapse. In between these boundaries, we find an intermediate regime that consists of single-species extinctions, which we call the extinction continuum. We also develop a metric that locates the position of the system within the extinction continuum—thus quantifying proximity to stability or collapse—in terms of ecologically measurable quantities such as growth rates and interaction strengths. Furthermore, we provide analytical and numerical techniques for estimating our new metric. We show that our metric does an excellent job of capturing the system's behaviour in comparison with other existing methods—such as May’s stability criteria or critical slowdown. Our metric should thus enable deeper insights about how to classify real systems in terms of their overall dynamics and their limits of stability and collapse.

What Will Robot Laws Look Like? The Code of AI and Human Laws

The author aims to present in the course of this study the possible future interactions between laws and the behaviour of artificial intelligence. Firstly, the theory of code is presented as well as the debate regarding the aptitude of laws to represent a means for the control of machine behaviour either directly or, as is more likely, when embedded in code. Secondly, the author analyses the consequences of the emergence of ‘robot law’, the ways in which a mixed, two-, or possibly three-tiered normative system is arising. In such a system, human-readable law and robot law are likely to diverge and even possess different characteristics such as an added degree of instability in the case of robot law. The author analyses the difficulties posed by transitioning between these systems and those of endowing machines with behavioural concepts such as ethics and unbiased action, problems compounded by the inherent opaqueness of the processes which underpin artificial intelligence. Finally, the author raises the possibility that codes designed to regulate human–machine interrelationships in and of themselves may constitute the beginning of a new, supranational legal system, with the platforms employing such codes transformed into quasi-sovereign entities.

Predicting Collapse of Complex Ecological Systems: Quantifying the Stability-Complexity Continuum

Dynamical shifts between the extremes of stability and collapse are hallmarks of ecological systems. These shifts are limited by and change with biodiversity, complexity, and the topology and hierarchy of interactions. Most ecological research has focused on identifying conditions for a system to shift from stability to any degree of instability—species abundances do not return to exact same values after perturbation. Real ecosystems likely have a continuum of shifting between stability and collapse that depends on the specifics of how the interactions are structured, as well as the type and degree of disturbance due to environmental change. Here we map boundaries for the extremes of strict stability and collapse. In between these boundaries, we find an intermediate regime that consists of single-species extinctions, which we call the Extinction Continuum. We also develop a metric that locates the position of the system within the Extinction Continuum—thus quantifying proximity to stability or collapse—in terms of ecologically measurable quantities such as growth rates and interaction strengths. Furthermore, we provide analytical and numerical techniques for estimating our new metric. We show that our metric does an excellent job of capturing the system behaviour in comparison with other existing methods—such as May’s stability criteria or critical slowdown. Our metric should thus enable deeper insights about how to classify real systems in terms of their overall dynamics and their limits of stability and collapse.

A Study on the Productivity of Potato in Hugli District, West Bengal, India

In spite of its industrial importance, Hugli is one of the leading potato producing districts of West Bengal with momentous productivity. But the productivity has shown considerable variation in its quantity, yield per unit of land and area under the crop over the last few decades. The present study strives to assess the spatio-temporal dynamics, emphasizing on trend, growth and variability as well as inter-Block variations in potato productivity of Hugli District from 1990-91 to 2013-14. The study was primarily based on the secondary data obtained from various sources. Time series analysis (3 year moving average curve), Coppock’s Instability Index and Sahu’s Simple Achieved Variation have been used to analyze the trend, instability and sustainability of the productivity, whereas, Crop Yield and Concentration Indices Ranking Coefficient is employed to identify productivity regions of potato. The result has revealed a unique oscillating nature in area, yield and output over the study period. The area and the output of the crop have been increased almost 51.70% [Exponential R2= 0.751] and 32.75% [Exponential R2= 0.381] respectively, whereas the yield rate has shown an insignificant positive trend of growth [Exponential R2= 0.014] during the same period. The Blocks have also revealed wide inter-disparity in productivity during the phase with considerable degree of instability and sustainability.