Global parental leave in surgical careers: differences according to gender, geographical regions and surgical career stages.

BACKGROUND: There is a lack of information regarding the provision of parental leave for surgical careers. This survey study aims to evaluate the experience of maternity/paternity leave and views on work-life balance globally. METHODS: A 55-item online survey in 24 languages was distributed via social media as per CHERRIES guideline from February to March 2020. It explored parental leave entitlements, attitude towards leave taking, financial impact, time spent with children and compatibility of parenthood with surgical career. RESULTS: Of the 1393 (male : female, 514 : 829) respondents from 65 countries, there were 479 medical students, 349 surgical trainees and 513 consultants. Consultants had less than the recommended duration of maternity leave (43.8 versus 29.1 per cent), no paid maternity (8.3 versus 3.2 per cent) or paternity leave (19.3 versus 11.0 per cent) compared with trainees. Females were less likely to have children than males (36.8 versus 45.6 per cent, P = 0.010) and were more often told surgery is incompatible with parenthood (80.2 versus 59.5 per cent, P < 0.001). Males spent less than 20 per cent of their salary on childcare and fewer than 30 hours/week with their children. More than half (59.2 per cent) of medical students did not believe a surgical career allowed work-life balance. CONCLUSION: Surgeons across the globe had inadequate parental leave. Significant gender disparity was seen in multiple aspects.

An assessment of patient-reported long-term outcomes following surgery for cauda equina syndrome.

BACKGROUND: Data regarding long-term outcomes following surgery for cauda equina syndrome (CES) is scarce. In addition, these studies rely on patient descriptions of the presence or absence of symptoms, with no gradation of severity. This study aimed to assess long-term bladder, bowel, sexual and physical function using validated questionnaires in a CES cohort. METHODS: A pre-existing ethically approved database was used to identify patients who had undergone surgery for CES between August 2013 and November 2014. Patients were contacted over a 1-month period between August and September 2017 and completed validated questionnaires via telephone, assessing bladder (Urinary Symptom Profile), bowel (Neurogenic Bowel Dysfunction Score), sexual dysfunction (Arizona Sexual Experiences Scale) and physical function (Physical Component Summary of SF-12 Questionnaire), with scores compared between those presenting with incomplete CES (CES-I) and CES with retention (CES-R). Patients were also asked which of their symptoms currently they would most value treatment for and what healthcare services they had accessed post-operatively. RESULTS: Forty-six of 77 patients (response rate 72%, inclusion rate 60%) with a mean age of 45 years (21-83) and mean time since admission of 43 months (range 36-60) took part in the follow-up study. The prevalence of bladder dysfunction was 76%, bowel dysfunction 13%, sexual dysfunction 39% and physical dysfunction 48%. Patients presenting with CES-R had significantly worse long-term outcomes in bladder (stream domain), bowel and sexual function in compared to those with CES-I. Pain was chosen as the symptom patients would most value treatment for by 57%, but only 7% reported post-operative pain management referral. CONCLUSIONS: With a mean follow-up time of 43 months, these findings confirm the high prevalence of long-term bladder, sexual and physical dysfunction in CES patients and that a diagnosis of CES-R confers poorer outcomes. This study provides useful, objective data to guide the expectations of patients and clinicians.

[STUDYING THE INTERACTION OF RHESUS MONKEYS WITH THE TACTILE MONITOR DURING THEIR OBSERVATION OF LOW-FREQUENCY VISUAL TEST IMAGES].

In behavioral experiments rhesus macaque monkeys were trained to interact with the computer using a tactile display. We used grayscale Gabor patches of low spatial frequency as stimuli. Monkeys' task was to touch the screen with his hand in the area of the target stimulus, followed by automatic food or juice reinforcement. After two successive correct answers, stimulus contrast gradually decreased. Using a two-alternative forced choice method the contrast threshold was measured within which monkeys can detect the appearance of low-frequency images. It was shown that the contrast sensitivity decreased with the decrease of stimulus spatial frequency, while the reaction time increased. The findings extend our knowledge of the primates' activity in the virtual environment and open new possibilities for modeling and studying various human diseases.

[Latency of Evoked Potentials in the Tasks Involving Classification of Images after Wavelet Filtration.]

We studied the characteristics of evoked potentials recorded during the recognition test based on four types of series of images subjected to the wavelet filtration: images of living objects containing either low frequency or high frequency portion of the spatial frequency spectrum, and imaging of non-living objects in the same two spatial frequency bands. Each subject had to classify the image either by its semantic feature (live-not live), or by its physical feature (low-high frequency). The purpose of this study was to compare the time characteristics of evoked potentials in these two types of tasks, which provides information on the time characteristics of categorization mechanisms of visual images. Analysis of the latent periods and amplitudes of the components of evoked potentials enabled to detect the occipital areas of the leads where the early components (up to 170 ms) are associated with spatial and frequency characteristics of the image, the frontal and temporal areas where the components of 170-200 ms correspond with the process of categorization, and the later frontal, central and parietal areas (300-500 ms) correspond with the process of error detection and the organization of motor response.

[Visual Priming and Perception of the Small Pictures in Scene with Multiscale Objects.]

Biederman and co-authors [1, 2], have shown that the priming effect in the long-tirn priming paradigm does not depend on the difference between the angular sizes of the test stimulus and the primer. However, these two and other similar works (both with long-time and short-fime priming paradigms) studied a small range of the angular sizes of stimuli. In Vakhrameeva et al. [3], it has been shown that there exist two perceptionally different size ranges: perception of the objects with angular size varying from 1-1.5 to 50 deg was found to be invariant, but for the objects which angular size is less than 1-1.5 deg (depending on object class and task) their perception is no longer invariant. In this work we have investigated the presence of priming effect in match-to-sample task with such a difference in the angular sizes of a primer and a test stimuli, when the sizes of the primer (about 4 deg) and the test stimulus (about 0.5 deg) belong to those different physiological size ranges. The sample stimulus was presented with and without the noise superposition. It has been shown that the priming effect is suppressed when the size difference between the primer and the test stimulus is large. A congruent primer can give a positive impact on the recognition of the test objects, but this takes place under viewing conditions complicated by the noise superposition.

[Intravascular leiomyomatosis].

Intravenous leiomyomatosis is a rare disease from a group of tumors with the indefinite grading potential. The paper describes two cases of intravenous leiomyomatosis with its detailed morphological pattern, molecular genetic findings, and a brief literature review. Losses of heterozygosity of microsatellite repeats thatwere located on chromosome 10 in 10q22.1 and common in uterine leiomyosarcomas were found in both cases. Investigations of the morphological and biological characteristics of leimyomatosis are important to clarify the key molecular mechanisms underlying the development of this nosological entity and to determine etiopathogenetic relationships between intravenous leiomyomatosis and other uterine smooth muscle neoplasms.

[The Effect of the Disease Duration on the Changes of the Visual Evoked Potentials and Contrast Sensitivity in Multiple Sclerosis].

The most sensitive methods to detect pathological changes in the visual system are the method of recording visual evoked potentials and the psychophysical method of measuring contrast sensitivity. Described in the literature features of functional disorders of the visual system in patients with multiple sclerosis are controversial. The results of the study allowed us to make an assumption about the depen-dence of the nature and severity of changes of the evoked potentials and contrast sensitivity and the duration of disease in patients with multiple sclerosis. In some patients with disease duration from 3 to 10 years there are irregularities in the magno-channels (reduced amplitude component P1), in others-- parvo-channels (amplitude reduction N 1) without increasing the latency, in patients with a disease duration of 10 to 14 years--both channels dysfunction (decreased amplitude components P1 and N1) with an increase of latency. The data indicate heterogeneity of pathophysiological changes upon increase of the degree of demyelination and damage of optic nerve fibers in multiple sclerosis.

[Hormone therapy alone for pre-cancerous conditions and early endometrial cancer: pros and cons].

The results of conservative treatment of 121 patients with endometrial atypical hyperplasia (EAH) and early endometrial cancer (EC) with preservation of fertility are presented. In EAH (n = 56) for 6 months the intrauterine spiral Mirena was used. The effectiveness was 91%, the recurrence rate 16%, pregnancies occurred in 16% of patients. In EC (n = 65) hormone therapy was conducted for 6 months using the intrauterine spiral Mirena and zoladex. The effectiveness was 79%, recurrence rate 22%, pregnancies occurred in 24% of patients. Based on our data and on the results of other studies, the benefits and risks of hormone therapy alone for EAH and EC are discussed in women of reproductive age.

[Study of parvocellular and magnocellular visual channels in normal subjects and in patients with psychopathology].

We measured susceptibility to the Müller-Lyer illusion in schizophrenic patients and normal observers. The images of the Müller-Lyer figure were digitally filtered in a high-frequency and low-frequency band by wavelet filter. Patients with schizophrenia are more susceptible to Müller-Lyer illusion, than mentally healthy examinees. The images of the Müller-Lyer figure with low spatial frequency were perceived in a similar way by the schizophrenic patients on the initial stage of disease and the control subjects. Patients with schizophrenia were more sensitive to the Müller-Lyer illusion when the image contained only high or medium spatial frequency. Schizophrenic patients in advanced stage were more susceptible to the illusion while presented with all types of images of the Müller-Lyer figure than the control group. It is hypothesized that those differences arise from the mismatch work of the magnocellular and parvocellular systems. It is known that images with the high spatial frequencies are most relevant for the parvocellular visual channels. The magnocellular visual channels are most sensitive to the images with the low spatial frequencies. Thus these findings demonstrate a significant impairment in parvocellular pathway function in patients on initial stage of schizophrenia. The patients on advanced stage of schizophrenia demonstrate impairment of both the parvocellular and magnocellular systems.

[Features of perception of length of segments under conditions of ponzo and Müller-Lyer illusions in schizophrenia].

In order to better appreciate the neurophysiologic mechanisms of perception of length under conditions of geometrical visual illusions, we studied sensitivity of mentally healthy subjects and schizophrenic patients to Ponzo and Müller-Lyer illusion. Patients with schizophrenia estimated length of segments of Müller-Lyer figure less precisely. Accuracy of perception of length of segments in Ponzo figure was ambiguously connected with the duration of the disease. Persons suffering from schizophrenia for a short time were less inclined to Ponzo illusion than mentally healthy subjects. On the contrary, patients who suffered from schizophrenia for a long time were more sensitive to this illusion. Ponzo illusion can be used as a marker of schizophrenia which is found out during the specific period of development of the disease. High sensitivity of patients with schizophrenia to Müller-Lyer and Ponzo illusions supports a hypothesis about the role of the global analysis of an image during processing of its low-frequency component in formation of the illusions under study.

Studies of the perception of incomplete outline images of different sizes.

The aim of the present work was to assess the range of angular sizes of fragmented images of objects at which perception of the images was scale-independent. Measurements were made of human subjects' recognition thresholds for the shapes of the objects over a wide range of angular sizes (0.19-50 degrees). The experiments used the Gollin test--a method for studying the recognition of fragmented outline images of objects with which the observer is familiar. The results obtained demonstrated that there is a wide range of angular sizes, from 1.0 degrees to 50 degrees, over which the perception thresholds of incomplete outline images do not change with changes in size, along with a narrow range of stimulus sizes, 0.19-1.0 degrees, over which there is a significant size dependence. We suggest that the increase in thresholds and the failure to recognize images of small size occur as a result of an increased contribution of sampling noise at the level of the human retina.

[Investigation of the perception of incomplete contour figures of the various size].

The purpose of the current research was to estimate the range of angular sizes of incomplete images across which the perception of the given images does not depend on scale. We have measured thresholds of recognition of the identities of objects across a wide range of angular sizes from 0.19 to 50 degrees of visual angle. The methodology derived from the Gollin-test which has been used as a method for studying the perception of objects presented as incomplete contour and pattern recognition. Results demonstrated that there is a wide range of angular sizes (from 1 .0 up to 50 degrees of visual angle) across which thresholds perception of incomplete images does not depend on object size. However, there was found a narrow range of small sizes of stimulus (0.19-1.0 degrees of visual angle) at which there was found dependence of performance on object size. We assume that increase of thresholds and occurrence of undistinguished images (when they have small size) depends on increase of the contribution of sampling noise at the observer's eye retina.

Localization of human cortical areas activated on perception of ordered and chaotic images.

The aims of this study were to identify the locations of areas in the human cortex responsible for describing fragmented test images of different degrees of ordering and to identify the areas taking decisions regarding stimuli of this type. The locations of higher visual functions were determined by functional magnetic resonance imaging (fMRI) using a scanner fitted with a superconducting magnet and a field strength of 1.5 T. The blood oxygen level-dependent (BOLD) method was based on measurements of the level of hemoglobin oxygenation in the blood supplied to the brain. This level was taken to be proportional to the extent of neuron activation in the corresponding part of the gray matter. Stimuli were matrixes consisting of Gabor elements of different orientations. The measure of matrix ordering was the ratio of the number of Gabor elements with identical orientations to the total number of elements in the image. Brain neurons were activated by simultaneous changes in the orientations of all the elements, leading to substitution of one matrix by another. Substitution of the orientation was perceived by observers as rotation of the elements in the matrix. Stimulation by matrixes with a high level of ordering was found to activate the occipital areas of the cortex, V1 and V2 (BA17-BA18), while presentation of matrixes with random element orientations also activated the parietal-temporal cortex, V3, V4, V5 (BA19), and the parietal area (BA7). Brain zones responsible for taking decisions regarding the level of order or chaos in the organization of the stimuli are located in different but close areas of the prefrontal and frontal cortex of the brain, including BA6, BA9, and BA10. The results are assessed in terms of concepts of the roles and interactions of different areas of the human brain during recognition of fragmented images of different degrees of complexity.

Electrophysiological studies of texture recognition mechanisms.

We report here our electrophysiological and psychophysiological studies of the mechanisms by which the visual system recognizes structured images with different levels of ordering. Visual stimuli consisted of textures, i.e., a set of matrixes consisting of Gabor grids. Matrixes differed in terms of the degree of ordering resulting from changes in the probability that grids with the same orientation would appear. The subject's task was to identify the dominant orientation in the stimulus. The relationship between response accuracy, reaction time, and the main characteristics of evoked potentials on the one hand, and the number of identical grids in the matrix on the other was identified. The proportion of correct responses increased and the reaction time decreased as the degree of ordering of stimuli increased. Visual evoked potentials recorded in the occipital areas showed a relationship between the amplitudes of the N2, P2, and P3 waves, with latent periods of 180, 260, and 400 msec, respectively, and matrix parameters. The amplitudes of the P3 component and the positive component recorded in the frontal leads, with a latent period of 250 msec, increased gradually as the task became simpler. The amplitude of the N2 wave also increased with increases in the number of identically oriented elements in the matrix, though this relationship was S-shaped. The magnitude of the P2 component, conversely, was maximal in response to presentation of those matrixes which were most complex to recognize and gradually decreased as the content of identically oriented grids in the matrix increased. These relationships were compared with the statistical characteristics of the stimuli and assessed in terms of the view that the visual system contains two mechanisms, i.e., local and integral image descriptions.

[Localization of human brain areas activated for chaotic and ordered pattern perception].

The aim of our work was to localize cortical areas involved in the processing of incomplete figures using functional MRI (fMRI) for 8 healthy volunteers (18-30 year old) with the did of anatomical and fMRI fast imaging technique: echo planar imaging (EPI), whole brain scan (36 slices) matrix 64 x 64, 3.7 second. We used 1.5 T MR-scanner and BOLD-method (Blood Oxygenation Level Dependent), based on distinctions of magnetic properties of hemoglobin. Fast imaging technique on modern MR-scanners with > or = 1.5 T provides precise statistical maps of oxygenation increase with high spatial resolution. For test stimuli we used matrix of Gabor grating. We used two types of 10 x 10 matrices with chaotic and ordered orientation of Gabor gratings. The size, brightness and contrast of the stimuli were identical. The chaotic and ordered patterns activated different brain areas. We establish that ordered patterns activated only primary visual cortex - V1 and V2, (BA17-18), wheareas chaotic patterns activated in addition primary visual cortex, the V3,V4,V5 (BA19) of the occipital cortex and the area 7 of parietal area (BA7) classification. Decision making for that task is localized in prefrontal and frontal cortex, including (BA 6, 9, 10).

Objective measurement of human visual acuity by visual evoked potentials.

Electrophysiological studies were performed to measure the threshold (upper end of range) spatial frequency using visual evoked potentials and comparison with visual acuity neuron 26 healthy subjects. The aim of the present work was to create a method for objective measurement of visual acuity. This was addressed by initial measurements using a universally accepted method of visual stimulation and processing of electroencephalograms, which allows errors due to individual differences in visual system function to be minimized. These experiments yielded a strong correlation between the threshold spatial frequency of the test grid yielding an evoked potential on presentation and visual acuity, in degrees, expressed as the resolving ability of the visual system for this optotype. A logarithmic relationship was found between these values and an equation allowing automated calculation of visual acuity (resolving ability) from electrophysiological data was derived. The results were independent of the subject's responses and therefore provides a maximally objective assessment of visual acuity.

The threshold signal:noise ratio in the perception of fragmented figures.

Perception thresholds were measured for fragmented outline figures (the Gollin test). A new approach to the question of the perception of incomplete images was developed. In this approach, figure fragmentation consisted of masking with multiplicative texture-like noise--this interference was termed "invisible" masking. The first series of studies established that the "similarity" between the amplitude-frequency spectra of test figures and "invisible" masks, expressed as a linear correlation coefficient, had significant effects on the recognition thresholds of these figures. The second series of experiments showed that progressing formation of the figures was accompanied by increases in the correlation between their spatial-frequency characteristics and the corresponding characteristics of the incomplete figure, while the correlation with the "invisible" mask decreased. It is suggested that the ratio of the correlation coefficients, characterizing the "similarity" of the fragmented figure with the intact figure and the "invisible" mask, corresponds to the signal:noise ratio. The psychophysical recognition threshold for figures for naive subjects not familiar with the test image alphabet was reached after the particular level of fragmentation at which this ratio was unity.

[Objective measurements of visual acuity by visual evoked potentials].

Electrophysiological measurements of the threshold spatial frequency were conducted in 26 healthy subjects by using visual evoked potentials with the purpose of objective determination of the visual acuity. For that we proposed a universal method of the visual stimulation and EEG processing (using ICA decomposition in particular) to minimize errors arising on account of individual differences in the visual system functioning. As a result, a correlation of 0.74 and a logarithmic dependence were obtained between spatial resolution measured by electrophysiological and psychophysical methods. The proposed methods of objective measurement of visual resolution has a high effectiveness, does not depend on specificity of individual EEG and domination of different channels in the visual system. Therefore it is possible to determinate objectively the visual acuity in humans independently of their responses.

The optical-geometrical characteristics and thresholds of perception of fragmented outline figures.

Measurements were made of the threshold of recognition of cumulatively forming line figures. The threshold value of the outline, expressed in pixels, depended on the length of the outline of the whole unfragmented figure. Relative threshold values were constant, and for the measures of figure fragments used in the present study, averaged 12.5%. A spatial frequency analysis of the test images was performed. Variation of the amplitude-frequency parameters of the spectra of the images of various figures with threshold fragmentation was minimal as compared with the variation of these parameters in figures with subthreshold or suprathreshold levels of fragmentation.