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Many people with stroke (PwS) demonstrate reduced balance and increased postural sway afterwards, which may ultimately lead to falls and injury. In this study, we aimed to better understand postural sway behavior and the mechanisms of balance control by examining balance in upright standing among PwS using methods from statistical mechanics i.e., the Stabilogram diffusion analysis (SDA). Center-of-pressure displacements while standing still were measured in 25 PwS and 11 healthy subjects. The traditional postural sway parameters were measured, and the SDA was used to characterize balance control in eyes-open and eyes-closed conditions. We found that PwS demonstrated significantly greater postural sway in the mediolateral and anterior–posterior directions and significantly higher SDA short-term diffusion coefficients and critical displacement in both eyes-open and eyes-closed conditions. There was also a significant group-by-condition interaction, whereas PwS demonstrated more sway in the eyes-closed condition. The SDA analysis revealed unstable behavior during short-term intervals, interpreted as larger distance of sway until closed-loop control took place. This significant group-by-condition interaction suggests that PwS have a significantly greater reliance on visual input compared with healthy subjects.

Bacterial infections are significant causes of serious human health problems. Different bacterial pathogens might have similar symptoms, and it is important to detect the cause of the infection early in order to enable effective treatment. In many infections, a mixture of different bacteria might exist in the same tested sample. To treat such infections effectively, it is very important to identify the various types of infecting bacteria in the sample. In this pioneering study, we examined the potential of Fourier transform infrared (FTIR) microscopy for accurate identification and differentiation between different bacteria in experimentally mixed samples of bacteria in the genus level in time span of about 30 min. We have measured the FTIR spectra of bacteria in pure form as well as in various mixtures. Principal components analysis (PCA) was applied on the spectra of various classes, followed by linear discriminant analysis (LDA) as a linear classifier. Our results show that it is possible to differentiate between mixed categories of bacteria with high rates of success. The classification rate was higher when the mixed samples included Gram-positive and Gram-negative types. When the mixing range was comparable ([0.5,0.5] and [0.6,0.4]), a classification success rate > 95% was achieved using only the first 20 PCs.

Pseudomonas (P.) aeruginosa is a bacterium responsible for severe infections that have become a real concern in hospital environments. Nosocomial infections caused by P. aeruginosa are often hard to treat because of its intrinsic resistance and remarkable ability to acquire further resistance mechanisms to multiple groups of antimicrobial agents. Thus, rapid determination of the susceptibility of P. aeruginosa isolates to antibiotics is crucial for effective treatment. The current methods used for susceptibility determination are time-consuming; hence the importance of developing a new method. Fourier-transform infra-red (FTIR) spectroscopy is known as a rapid and sensitive diagnostic tool, with the ability to detect minor abnormal molecular changes including those associated with the development of antibiotic- resistant bacteria. The main goal of this study is to evaluate the potential of FTIR spectroscopy together with machine learning algorithms, to determine the susceptibility of P. aeruginosa to different antibiotics in a time span of ∼20 min after the first culture. For this goal, 590 isolates of P. aeruginosa, obtained from different infection sites of various patients, were measured by FTIR spectroscopy and analyzed by machine learning algorithms. We have successfully determined the susceptibility of P. aeruginosa to various antibiotics with an accuracy of 82-90%.

Speaker diarization is a problem of separating unknown speakers in a conversation into homogeneous parts in the speaker sense. State-of-the-art diarization systems are based on i-vector methodologies. However, these approaches require large quantities of training data, which must be obtained from an environment that is similar to that of the conversation being diarized. In this paper we present a diarization system that does not require such training data but instead can suffice with some development data for parameter-tuning. This system is a generalization of the well-known hidden Markov model (HMM), a popular clustering algorithm trained by Viterbi statistics. Our proposed model, referred to as a hidden distortion model (HDM), is based on state distortion models and transition costs, for which probabilistic calculations are not mandatory, in contrast to the case of HMM. We provide a mathematical basis for our approach, and we demonstrate that Viterbi-based HMM can be seen as a special case of HDM. This proximity allows us to apply similar approaches for state-model training when the new paradigm is used to learn sequence dependencies. We carry out diarizations of two-speaker telephone conversations in order to evaluate the performance of HDM. When applied to conversations from the LDC CALLHOME database, HDM improves on the performance of a baseline HMM system by about 26% (relative improvement). Moreover, when applied to the NIST 2005 database, it yields a small improvement over the HMM system.

Use of PLDA as a criterion to choose the best i-vectors for the new mean.Replacing the constant threshold for as the i-vector's neighborhood by the kNN which dramatically increased the stability of the system. This paper extends upon a previous work using Mean Shift algorithm to perform speaker clustering on i-vectors generated from short speech segments. In this paper we examine the effectiveness of probabilistic linear discriminant analysis (PLDA) scoring as the metric of the mean shift clustering algorithm in the presence of different numbers of speakers. Our proposed method, combined with k-nearest neighbors (kNN) for bandwidth estimation, yields better and more robust results in comparison to the cosine similarity with fixed neighborhood bandwidth for clustering segments of large numbers of speakers. In the case of 30 speakers, we achieved significant improvement in cluster and speaker purity with the PLDA-based mean shift algorithm compared to the cosine-based baseline system.

Specific patterns of pelvic and thorax motions are required to maintain stability during walking. This cross-sectional study explored older-adults' gait kinematics and their kinematic adaptations to different walking speeds, with the purpose of identifying mechanisms that might be related to increased risk for falls. Fifty-eight older adults from self-care residential facilities walked on a treadmill, whose velocity was systematically increased with increments of 0.1meters/second (m/s) from 0.5 to 0.9m/s, and then similarly decreased. Thorax, pelvis, trunk, arms, and legs angular total range of motion (tROM), stride time, stride length, and step width were measured. Twenty-one of the subjects reported falling, and 37 didn't fall. No significant effect of a fall history was found for any of the dependent variables. A marginally significant interaction effect of fall history and walking speed was found for arms' tROM (p=0.098). Speed had an effect on many of the measures for both groups. As the treadmill's velocity increased, the non-fallers increased their arm (15.9±8.6° to 26.6±12.7°) and trunk rotations (4.7±1.9° to 7.2±2.8°) tROM, whereas for the fallers the change of arm (14.7±14.8° to 20.8±13°) and trunk (5.5±2.9° to 7.3±2.3°) rotations tROM were moderate between the different walking speeds. We conclude that walking speed manipulation exposed different flexibility trends. Only non-fallers demonstrated the ability to adapt trunk and arm ROM to treadmill speed i.e., had a more flexible pattern of behavior for arm and trunk motions, supporting the upper-body's importance for stability while walking.

This paper focuses on estimating the quality of a clustering process. The task is to cluster short speech segments that belong to different speakers. A variety of statistical parameters are estimated from the output of the clustering process. These parameters are used to train a logistic regression to serve as a clustering quality estimation system. In this paper, mean-shift clustering with either a cosine distance or probabilistic linear discriminant analysis (PLDA) score as the similarity measure, as well as stochastic vector quantization (VQ) with cosine distance, are applied in order to cluster the short speaker segments, which are represented by i-vectors. The quality of the clustering is measured using the average cluster purity (ACP), average speaker purity (ASP) and K, which is the geometric mean of ASP and ACP. We show that these measures can be estimated fairly well by applying logistic regression. Moreover, clustering quality may be well estimated even if the logistic regression was trained using parameters derived from a different clustering algorithm. This is very important, as it allows the use of a single quality estimation system, without the need for retraining when the clustering method is changed. Additionally, we showed how the clustering quality estimator could be served as an estimator of the number of clusters. For VQ-based clustering the number of clusters has to be predefined. We perform the clustering with different number of clusters. The best number of clusters is estimated as the clustering that achieved the higher estimation of the K value. We will show that this approach estimate the best number of clusters accurately.

This study aimed to explore the ability to overcome unannounced surface perturbations of different magnitudes during standing and walking under single-task and dual-task conditions. Balance recovery abilities during perturbed walking and concurrently performing cognitive tasks has rarely been investigated although it provides more ecological information in regard to real-life situations than perturbations during single-task conditions (i.e., just walking). Thirteen young adults were asked to perform: 1) a cognitive task while sitting; 2) perturbed standing; 3) a concurrent cognitive task during perturbed standing; 4) perturbed walking; and 5) a concurrent cognitive task during perturbed walking. The cognitive task was to perform number subtractions by seven. The participants were instructed to "try to avoid a fall" during the perturbation trials. Step threshold, cognitive task performance, and 3D kinematic analysis of the first recovery step, i.e., the spatiotemporal characteristics, were compared between all conditions. Step threshold and the spatiotemporal parameters of the first recovery stepping responses were similar between all task conditions. Cognitive performance was also unaffected by the postural challenges in all task conditions. These results suggest that the first balance recovery stepping response among young adults is automatic. Furthermore, young adults seem to have sufficient motor-cognitive resources to perform concurrently both balance recovery and cognitive tasks with no interference effects.

We present a novel method for aqueous effective disaggregation, dispersion, and stabilization of detonation nanodiamonds (NDs) that also allows easy further second-step nanodiamond (ND) functionalization/surface engineering through lanthanide-based coordination chemistry. This method includes ultrasonic irradiation of NDs in the presence of a strong mono-electronic ceric ammonium nitrate (CAN, [Ce(IV)(NH4)2(NO3)6]) oxidant. The resulting CAN-treated NDs are positively charged with lanthanide [CeLn]3/4+ complexes/cations, enabling an anti-aggregation effect together with the ability to be further surface-modified through [CeLn]3/4+ ligand exchange (lanthanide coordinative chemistry). Therefore, this method produces ~10 nm-sized CAN-modified nanoparticles (NDs-CAN NPs) that are highly positively charged (ξ potential maximal value: +45.7 mV & average zeta potential: +34.6 mV). The obtained ND surface modification by [CeLn]3/4+ complexes/cations enabled an organic-type coordination attachment of various different organic molecules. This innovative way of dealing with the well-known ND aggregation phenomenon enables a novel way for the development of a wide range of biomedical, imaging, and diagnostic-related ND-based applications.

Introduction Falling during walking is a common problem among the older population. Hence, the challenge facing clinicians is identifying who is at risk of falling during walking, for providing an effective intervention to reduce that risk. We aimed to assess whether the clinical version of the narrow path walking test (NPWT) could identify older adults who are reported falls. Materials and methods A total of 160 older adults were recruited and asked to recall fall events during the past year. Subjects were instructed to walk in the laboratory at a comfortable pace within a 6 meter long narrow path, 3 trials under single task (ST) and 3 trials dual task (DT) conditions without stepping outside the path (i.e., step errors). The average trial time , number of steps, trial velocity , number of step errors, and number of cognitive task errors were calculated for ST and DT. Fear of falling, performance oriented mobility assessment (POMA) and mini-metal state examination (MMSE) were measured as well. Results Sixty-one subjects reported that they had fallen during the past year and 99 did not. Fallers performed more steps, and were slower than non-fallers. There were no significant differences, however, in the number of steps errors, the cognitive task errors in ST and DT in POMA and MMSE. Conclusion Our data demonstrates slower gait speed and more steps during the NPWT in ST and DT in fallers. There is no added value of DT over the ST for identification of faller’s older adults.

Objective Older adults who have recently fallen demonstrate increased postural sway compared with non-fallers. However, the differences in postural control between older adults who were seriously injured (SI) as a result of a fall, compared with those who fell but were not injured (NSI) and non-fallers (NFs), has not been investigated. The objective of the present study was to investigate the underlying postural control mechanisms related to injuries resulting from a fall. Methods Both traditional postural sway measures of foot center-of-pressure (CoP) displacements and fractal measures, the Stabilogram-Diffusion Analysis (SDA), were used to characterize the postural control. One hundred older adults aged 65–91years were tested during narrow base upright stance in eyes closed condition; falls were monitored over a 1-year period. Results Forty-nine older adults fell during the 1-year follow-up, 13 were seriously injured as a result of a fall (SI), 36 were not injured (NSI), and 49 were non-fallers (NFs); two passed away. The SDA showed significantly higher short-term diffusion coefficients and critical displacements in SI in the anterior–posterior direction compared with both NSI and NF. However, in the medio-lateral direction there were no statistically significant differences between groups. For the traditional measures of sway, the average anterior–posterior CoP range was also larger in SI individuals. Conclusions This work suggests that older fallers with a deterioration of anterior–posterior postural control may be at higher risk of serious injury following fall events.

The vestibulo-ocular response (VOR) may not be fully developed in children with an intellectual and developmental disability (IDD). This study aimed to identify the presence of VOR deficit in children and young adults with unspecified mild-to-moderate intellectual and developmental disability and its effect on balance control. Twenty-one children and young adults with IDD ranging in age from 8 to 22 years (mean 17.5 ± 3.9 years) were included in the study. The VOR was evaluated with the Head Impulse Test and the Static and Dynamic Visual Acuity Test (SD-VAT). Postural stability was measured in an upright standing position by the Clinical Test for Sensory Interaction in Balance (CTSIB), single leg stance (SLS) during eyes open and eyes closed, and Romberg stance under eyes open and eyes closed conditions using a force platform. Reduced vestibulo-ocular responses were found in 13 of 21 (62%) participants who were able to complete testing. In the fifth condition of the CTSIB (standing on foam with eyes closed), those without VOR deficit were able to maintain balance longer than those with VOR deficit (29 s [median 30] vs. 12s [median 7.3], respectively; p=0.03). The study demonstrates potential effects of VOR deficit in children and young adults with IDD and some significant differences in balance control between those with and without a VOR deficit. VOR function in children and young adults with IDD should be routinely tested to enable early detection of deficits.

A B S T R A C T This study evaluated the effects of a water exercise training program that includes perturbation exercises (WEP) to improve the speed of voluntary stepping reaction in older adults. Speed of voluntary stepping considered as an important skill to prevent a fall when balance is lost. In a single-blinded randomized controlled trial with a crossover design thirty-six independent old adults (64–88 years old) were divided into two groups. Group A received WEP for the first 12 weeks, followed by no intervention for the second 12 weeks. Group B did not receive intervention for the first 12 weeks and received WEP for the second 12 weeks. Voluntary Step Execution Test and postural stability in upright standing (eyes open and closed conditions) were measured at baseline, 12 weeks, and 24 weeks. A significant interaction effect between group and time was found for the step execution, due to improvement in initiation phase and swing phase durations in the WEP group. Also significant improvement in postural stability parameters in eyes open and closed conditions is noted. The present results indicate that the primary benefit of WEP that include perturbations to induce stepping, was a reduction in voluntary stepping times. The WEP generalized to a better control of balance in up-right standing.

Protocols for real-time collaboration of multiple agents for supply chain security tasks utilizing RFID information with real-time sensor tracking and monitoring are presented. The proposed system provides a structured framework and a set of interaction services by controlling a network of agents; each of the agents has a set of skills and resources that they contribute to the system. Optimal control through task administration protocols of agents' collaboration is developed. Simulation analysis indicated improved performance of 11% by optimal task assignment and agent's collaboration, with improved time management flexibility.

Objective Previous studies have demonstrated that ankle muscle fatigue alters postural sway. Our aim was to better understand postural control mechanisms during upright stance following plantar flexor fatigue. Method Ten healthy young volunteers, 25.7±2.2years old, were recruited. Foot center-of-pressure (CoP) displacement data were collected during narrow base upright stance and eyes closed (i.e. blindfolded) conditions. Subjects were instructed to stand upright and as still as possible on a force platform under five test conditions: (1) non-fatigue standing on firm surface; (2) non-fatigue standing on foam; (3) ankle plantar flexor fatigue, standing on firm surface; (4) ankle plantar flexor fatigue, standing on foam; and (5) upper limb fatigue, standing on firm surface. An average of the ten 30-s trials in each of five test conditions was calculated to assess the mean differences between the trials. Traditional measures of postural stability and stabilogram-diffusion analysis (SDA) parameters were analyzed. Results Traditional center of pressure parameters were affected by plantar flexor fatigue, especially in the AP direction. For the SDA parameters, plantar flexor fatigue caused significantly higher short-term diffusion coefficients, and critical displacement in both mediolateral (ML) and anteroposterior (AP) directions. Long-term postural sway was different only in the AP direction. Conclusions Localized plantar flexor fatigue caused impairment to postural control mainly in the Sagittal plane. The findings indicate that postural corrections, on average, occurred at a higher threshold of sway during plantar flexor fatigue compared to non-fatigue conditions.

BACKGROUND: In order to evaluate the effect of an auditory-memory attention-demanding task on balance control, nine blind adults were compared to nine age-gender-matched sighted controls. This issue is particularly relevant for the blind population in which functional assessment of postural control has to be revealed through "real life" motor and cognitive function. The study aimed to explore whether an auditory-memory attention-demanding cognitive task would influence postural control in blind persons and compare this with blindfolded sighted persons. METHODS: Subjects were instructed to minimize body sway during narrow base upright standing on a single force platform under two conditions: 1) standing still (single task); 2) as in 1) while performing an auditory-memory attention-demanding cognitive task (dual task). Subjects in both groups were required to stand blindfolded with their eyes closed. Center of Pressure displacement data were collected and analyzed using summary statistics and stabilogram-diffusion analysis. FINDINGS: Blind and sighted subjects had similar postural sway in eyes closed condition. However, for dual compared to single task, sighted subjects show significant decrease in postural sway while blind subjects did not. INTERPRETATION: The auditory-memory attention-demanding cognitive task had no interference effect on balance control on blind subjects. It seems that sighted individuals used auditory cues to compensate for momentary loss of vision, whereas blind subjects did not. This may suggest that blind and sighted people use different sensorimotor strategies to achieve stability. Language: en

Background This study investigated the force–time relationship during the push-off stage of a rapid voluntary step in young and older healthy adults, to study the assumption that when balance is lost a quick step may preserve stability. The ability to achieve peak propulsive force within a short time is critical for the performance of such a quick powerful step. We hypothesized that older adults would achieve peak force and power in significantly longer times compared to young people, particularly during the push-off preparatory phase. Methods Fifteen young and 15 older volunteers performed rapid forward steps while standing on a force platform. Absolute anteroposterior and body weight normalized vertical forces during the push-off in the preparation and swing phases were used to determine time to peak and peak force, and step power. Two-way analyses of variance (‘Group’ [young–older] by ‘Phase’ [preparation-swing]) were used to assess our hypothesis (P ≤ 0.05). Findings Older people exerted lower peak forces (anteroposterior and vertical) than young adults, but not necessarily lower peak power. More significantly, they showed a longer time to peak force, particularly in the vertical direction during the preparation phase. Interpretations Older adults generate propulsive forces slowly and reach lower magnitudes, mainly during step preparation. The time to achieve a peak force and power, rather than its actual magnitude, may account for failures in quickly performing a preventive action. Such delay may be associated with the inability to react and recruit muscles quickly. Thus, training elderly to step fast in response to relevant cues may be beneficial in the prevention of falls.

Background A cross-sectional retrospective study of parameters reflecting balance function in elderly fallers and non-fallers was conducted to better understand postural control mechanisms in individuals prone to falls. Methods Ninety-nine old adults (65–91 years, mean age 78.4 (SD 5.7)) from two self-care residential facilities participated in the study. Foot center-of-pressure (CoP) displacement data were collected during narrow base upright stance eyes closed conditions and analyzed using summary statistics and Stabilogram-Diffusion Analysis (SDA) for mediolateral (ML) and anteroposterior (AP) directions. Subjects were instructed to minimize body sway. Findings Twenty-nine of the subjects reported at least one fall and 69 subjects reported no falls in the past six months. The SDA showed significantly higher short-term diffusion coefficients and critical displacements in fallers in the ML but not the AP direction. Mean sway area and ML-CoP sway range were also larger in fallers. Interpretation The greater ML critical displacement seen in fallers suggests that balance corrections on average occurred at higher sway amplitudes in this population. This is consistent with an ML decrease in the sensitivity of their postural control system. A higher short-term diffusion coefficient is consistent with increased muscle stiffness, a possible compensation for lost control sensitivity. Testing balance function under narrow stance conditions provides a modest increase in task difficulty that may help reveal pre-conditions of the balance control system that could increase the risk of falls.

Objective If balance is lost, quick step execution can prevent falls. Research has shown that speed of voluntary stepping was able to predict future falls in old adults. The aim of the study was to investigate voluntary stepping behavior, as well as to compare timing and leg push-off force–time relation parameters of involved and uninvolved legs in stroke survivors during single- and dual-task conditions. We also aimed to compare timing and leg push-off force–time relation parameters between stroke survivors and healthy individuals in both task conditions. Methods Ten stroke survivors performed a voluntary step execution test with their involved and uninvolved legs under two conditions: while focusing only on the stepping task and while a separate attention-demanding task was performed simultaneously. Temporal parameters related to the step time were measured including the duration of the step initiation phase, the preparatory phase, the swing phase, and the total step time. In addition, force–time parameters representing the push-off power during stepping were calculated from ground reaction data and compared with 10 healthy controls. Results The involved legs of stroke survivors had a significantly slower stepping time than uninvolved legs due to increased swing phase duration during both single- and dual-task conditions. For dual compared to single task, the stepping time increased significantly due to a significant increase in the duration of step initiation. In general, the force time parameters were significantly different in both legs of stroke survivors as compared to healthy controls, with no significant effect of dual compared with single-task conditions in both groups. Conclusions The inability of stroke survivors to swing the involved leg quickly may be the most significant factor contributing to the large number of falls to the paretic side. The results suggest that stroke survivors were unable to rapidly produce muscle force in fast actions. This may be the mechanism of delayed execution of a fast step when balance is lost, thus increasing the likelihood of falls in stroke survivors.

Introduction/Background Falls after stroke are a major health concern, as they are one of the most frequent complications. An important and effective strategy to avoid falling is the “change of support” strategy, which is characterized by rapid compensatory stepping and/or grasping that increase the base of support, and by so, stability is regained. Using the arms may also be an effective way to avoid falling when balance is lost due to balance perturbations. Here we aimed to characterize the arm responses to perturbations in stroke patients. Material and method Fifteen post-stroke subjects and 15 age and gender matched healthy controls were exposed to unexpected surface translations while standing on a movable platform (Balance Tutor, MediTouch, Israel). Perturbation intensity increased in six levels of difficulty. Kinematic parameters were collected using the Ariel Performance 3D motion Analysis System (APAS) and the data was analyzed by MatLab algorithms written especially for the study. Results Post-stroke subjects and healthy controls had a symmetric response with two arms. Stroke group had a few reactions with one arm mostly with the paretic arm. We found a significant difference in the overall arm displacement and overall arm velocity between the right arm of control group and the paretic arm of stroke group. When we compared between the paretic and non-paretic arms of stroke survivors we found that the non-paretic arm had a faster reaction time, larger displacement and the paretic arm has a higher velocity. Arm reaction time was faster than leg reaction time. Conclusion Our results show that hemiparetic stroke patients have the ability to respond with both arms, similar to healthy control subjects, but stroke survivors’ responses seems to have reflexive and spastic movement patterns, not as effective as the movement patterns observed in healthy controls.

This paper presents a set of algorithms developed for real-time dynamic switching between collaboration levels in a human-robot target recognition system. The algorithms were developed for a closed-loop controller to maximize system performance despite deviations in the parameter values and were evaluated by conducting a thorough simulation analysis. These developments enable smooth real-time adaptation of the combined human-robot system to many possible changes of the environment, human operator and robot performance. System performance was analyzed in simulations for a variety of target probabilities distributions. Improvements that can be achieved by each algorithm were calculated as a mean value for 200 independent simulations for each target probability distribution. The numerical analysis results indicated that the developed algorithms for dynamic switching achieved improved system performance.

Selective targeting of cells engaged in pathological activities is a major challenge for medical research. We generated monoclonal antibodies (mAbs) that exclusively bind, at concentrations ranging from 2 to 100 microg/ml, to a modified CD44 variant (designated CD44vRA) expressed on synovial fluid cells from joints of rheumatoid arthritis (RA) patients. These mAbs cross-reacted with keratinocytes expressing wild type CD44vRA (CD44v3-v10) only at a relatively high concentration (200 microg/ml). Sequence analysis of CD44vRA cDNA revealed, in 33 out of 43 RA and psoriatic arthritis patients, an extra intron-derived trinucleotide, CAG, which allows translation of an extra alanine. This insertion imposes a configurational change on the cell surface CD44 of RA synovial fluid cells, creating an immunogenic epitope and potentiating the ability to produce disease-specific antibodies. Indeed, the anti-CD44vRA mAbs (designated F8:33) were able to induce apoptosis in synovial fluid cells from RA patients, but not in peripheral blood leukocytes from the same patients, in keratinocytes from normal donors or in synovial fluid cells from osteoarthritis patients. Furthermore, injection of anti-CD44vRA mAbs reduced joint inflammation in DBA/1 mice with collagen-induced arthritis. These findings show that anti-CD44vRA mAbs are both bioactive and RA-specific.

We present an analysis of cancer based on the synthesis of physical and social models of life as the stability-variability conflict (SVC). We showed that the intensity of the SVC increases with an increase in the rate of evolution or progress of species and populations. The probability of oncogenesis depends on this intensity and on the gray zone in the host's homeostasis. An organism and its cells are two interdependent systems which in extreme situations become antagonistic and competitive. The hierarchy of the biosystems (cell, organism, population) does not resolve the SVC and does not decrease the gray zone of this conflict. Cancer develops mainly due to external effects and results in some internal, including genomic, alterations which result in cell death (apoptosis), or cause cells to begin a new stage in their lives, possibly leading to tumors. In this respect, cancer is a rescuer of the cells, although it brings about the death of the host. An increase in the production of tumor-associated proteins in cancer patients is an example of such changes. Cancer can also be analysed in terms of entropy and information. In the context of the SVC, cancer is irreversible deviations from the "golden mean" solution. The golden mean and cancer deviation are considered universal categories of physical and social reflections of the SVC as the quintessence of life.