The kinaesthetic perception of Euclidean distance: a study of the detour effect

An experiment investigated the mechanisms by which humans estimate Euclidean distances on the basis of kinaesthetic cues. Blindfolded participants followed straight and curvilinear paths with a hand-held stylus (encoding phase). Then, with a straight movement, they estimated the Euclidean distance between the start- and end-points of the path (response phase). The experiment contrasted an On-axis condition, in which encoding and response movements were spatially aligned, and an Off-axis condition, in which they were displaced laterally. Performances were slightly more accurate in the On-axis condition than in the Off-axis condition. In both conditions, however, errors were consistently smaller when the path covered a larger surface. The results showed that small paths yielded an overestimation of the Euclidean distance, the relative errors increasing with the length of curvilinear paths. The findings are compared with results of other studies in which distances were estimated on the basis of haptic cues.     

Factors affecting the perception of low-level vibration

Summary The level at which vibration becomes a nuisance is low, well below the vibration intensity discussed with regard to the health of industrial workers in the International Standard ISO-2631 draft. The relationships between the various factors and the human response to low-level vibration generated by vehicular traffic, are discussed from the results obtained from questionnaires.A female may respond to a lower level than a male. There is no difference in response to low-level vibration between standing and sitting postures. Accompanying noise distracts the perception of low-level vibration, however at high levels, the effect of distraction is reduced.     

The perception of movements elicited by magnetic cortex stimulation depends on the site of stimulation

Previous reports suggest that magnetic cortical stimulation (MCS) of the motor cortex can elicit a sensation of movement (kinaesthesia) in paralysed limbs. To assess this sensory effect of MCS, we examined the accuracy of kinaesthetic perception of stimulus-induced right elbow flexion in six blindfolded, healthy subjects. Matching of movements elicited by MCS was compared with matching of passive elbow movements. Small flexion movements between 1.5 and 5° of angle were regularly overestimated by 50–100% when induced by MCS over the parietal cortex, whereas movements elicited by MCS over the frontal cortex or by passive elbow flexion were accurately estimated. Our results provide data compatible with the hypothesis of the existence of a central sense of movement. Activation of collateral branches projecting from the motor cortex to the sensory could be the underlying mechanism to this phenomenon.     

The energy cost of running increases with the distance covered

Summary The net energy cost of running per unit of body mass and distance (C_r, ml O₂·kg^–1·km^–1) was determined on ten amateur runners before and immediately after running 15, 32 or 42 km on an indoor track at a constant speed. The C_r was determined on a treadmill at the same speed and each run was performed twice. The average value of C_r, as determined before the runs, amounted to 174.9 ml O₂·kg^–1·km^–1 SD 13.7. After 15 km, C_r was not significantly different, whereas it had increased significantly after 32 or 42 km, the increase ranging from 0.20 to 0.31 ml O₂·kg^–1·km^–1 per km of distance (D). However, C_r before the runs decreased, albeit at a progressively smaller rate, with the number of trials (N), indicating an habituation effect (H) to treadmill running. The effects of D alone were determined assuming that C_r increased linearly with D, whereas H decreased exponentially with increasing N, i.e.C _r =C _r0+aD+He^–bN. The C_ro, the true energy cost of running in nonfatigued subjects accustomed to treadmill running, was assumed to be equal to the average value of C_r before the run for N equal to or greater than 7 (171.1 ml O₂·kg^–1·km^–1, SD 12.7;n = 30). A multiple regression of C_r on N and D in the form of the above equation showed firstly that Cr increased with the D covered by 0.123%·km^–1, SEM 0.006 (i.e. about 0.22 ml O₂·kg^–1·km^–1 per km,P<0.001); secondly, that in terms of energy consumption (obtained from oxygen consumption and the respiratory quotient), the increase of C_r with D was smaller, amounting on average to 0.08%·km^–1 (0.0029 J·kg^–1·m^–1,P<0.001) and thirdly that the effects of H amounted to about 16% of C_r0 for the first trial and became negligible after three to four trials.     

The effects of landmarks on the performance of delayed and real-time pointing movements

Converging lines of evidence suggest that the presence of non-target landmarks affects the performance of delayed target-directed movements (e.g., Diedrichsen et al. 2004; Sheth and Shimojo 2004). In the present experiment, we examined the effects of non-target landmarks on the accuracy and precision of delayed and immediate target-directed pointing movements. In our experiment, the landmarks were present just prior to and during the presentation of the target; they were never present during the execution of the movement. Absolute errors were significantly reduced when the landmarks were available during target presentation for both delayed and immediate action conditions. In contrast, the presence of landmarks improved the precision of delayed but not immediate movements (as indexed by the variable error). The locus of this “landmark benefit” appears to be in the encoding of target position since landmarks were never available after target offset. We suggest that, when available, information provided by landmarks is used to improve the accuracy of the estimation of target location. Since the targets were presented for only 100 ms, it is apparent that the spatial information available from landmarks can be quite rapidly used to estimate target position. Further, with respect to the precision of movements, we suggest that the presence of landmarks serves to improve the stability of the estimation of target position. This particular reliance on landmark information becomes more critical as the movement is delayed.     

Ultrastructural localization of calcyon in the primate cortico-basal ganglia-thalamocortical loop

Recent observations suggest that calcyon, a novel single transmembrane protein implicated in schizophrenia and attention-deficit/hyperactivity disorder, regulates clathrin-mediated endocytosis in brain. To explore the role of calcyon in neurotransmission, we investigated its distribution in the neuropil of the primate prefrontal cortex (PFC), striatum (STR) and mediodorsal thalamic nucleus (MD), three brain regions implicated in these neuropsychiatric disorders. Calcyonimmunoreactivity revealed by immunoperoxidase technique, was localized in both pre- and postsynaptic structures including axons, spines and dendrites, as well as myelinated fibers and astroglial processes in all the three brain regions. The morphological diversity of immunopositive boutons suggest that in addition to glutamatergic, calcyon could regulate GABAergic as well as monoaminergic neurotransmission. Consistent with the role of calcyon in endocytosis, calcyon-immunoreactivity was rarely found at the synaptic membrane specializations proper, although it was present in distal compartments of neuronal processes establishing synapses. Given the widespread upregulation of calcyon in schizophrenic brain, these findings underscore a potential association with deficits in a range of neurotransmitter systems in the cortico-basal ganglia-thalamic loop.     

The effect of altered gravity states on the perception of orientation

We measured the effect of the orientation of the visual background on the perceptual upright (PU) under different levels of gravity. Brief periods of micro- and hypergravity conditions were created using two series of parabolic flights. Control measures were taken in the laboratory under normal gravity with subjects upright, right side down and supine. Participants viewed a polarized, natural scene presented at various orientations on a laptop viewed through a hood which occluded all other visual cues. Superimposed on the screen was a character the identity of which depended on its orientation. The orientations at which the character was maximally ambiguous were measured and the perceptual upright was defined as half way between these orientations. The visual background affected the orientation of the PU less when in microgravity than when upright in normal gravity and more when supine than when upright in normal gravity. A weighted vector sum model was used to quantify the relative influence of the orientations of gravity, vision and the body in determining the perceptual upright.

Factors affecting the measurement of bone impedance

Factors which affect the measurement of the electrical properties of bone were examined. Environmental conditions such as the pH of the preserving solution and time of exposure of the sample to air, which controls the moisture content of the specimen, significantly affected the bone impedance. A change in pH of ×2 from the neutral solution (pH=7) caused a change in the resistance R. conductance β and capacitance C values of 70 per cent, 125 per cent and 190 per cent respectively. A 5 min exposure to air increased the resistance by 92 per cent and reduced the capacitance by 35 per cent of their original values. A loss of 8 per cent moisture content by weight resulted in 400 per cent increase in R and 65 per cent decrease in C. Significant errors were introduced in the measurement of bone impedance owing to stray and wiring capacitances; these were avoided by using a differential impedance measurement technique. Further, it is shown that it is essential to measure the phase angle while measuring the bone impedance. Finally, it is illustrated that when normalising for different sized bone specimens, both the resistive component and capacitive component have to be considered while computing the impedance per unit volume.     

Brain activity during emotion perception: the role of attachment representation

To examine emotional face processing in mothers of different attachment representations, event-related potentials were recorded from 16 mothers during presentation of infant emotion faces with positive, negative or neutral emotional expressions within a three-stimulus oddball paradigm, and frontal asymmetries were assessed. Insecure mothers, as compared to secure ones, showed a more pronounced negativity in the face-sensitive N170 component and a smaller N200 amplitude. Regarding the P300 component, secure mothers showed a stronger response to face stimuli than insecure mothers. No differences were found for frontal asymmetry scores. The results indicate that attachment differences may be related to neuropsychological functioning.     

Factors in the dose-response effect of testosterone in the male ring dove

The dose-response effect of testosterone propionate on six behavioral patterns was examined in the castrated male ring dove. There was no dose-response effect when all behaviors were compared on the 13th day, the last day of systemic injection. However, a discernible dose-response effect in two behavioral patterns (Bow-coos and Nest-coos) was found on the day when maximal response was manifested. The latency (days) of maximal response differs from one behavioral pattern to the next, but is generally constant for each behavioral pattern at all dose levels.     

Factors affecting quality of life in cancer patients undergoing chemotherapy

Background

Cancer can produce many different symptoms, some subtle and some not at all subtle. An increasingly important issue in oncology is to evaluate quality of life (QoL) in cancer patients. The cancer-specific QoL is related to all stages of this disease.

Objective

The aim of this study was to evaluate the QoL in cancer patients with solid tumors and at the different chemotherapy cycles (CT).

Methods

This was a cross-sectional study. A total of 200 cancer patients were included. With some modification, the European Organization for Research and Treatment of Cancer QoL Questionnaire (EORTC QLQ-C30) was used to measure QoL in the patients. The QoL in most subjects (66%) was fairly favorable.

Results

A significant relationship between the cancer type, pain intensity, and fatigue was found. However, none of the demographic variables (age, education, marital status, income) were significantly related to QoL. Nevertheless, significant difference was found between the level of QoL in patients with ≤ 2 CT cycles and/or with 3–5 cycles (p< 0.001).

Conclusion

Cancer is an important health issue influencing QoL. An appropriate treatment which may provide care to the cancer patients is CT. A CT cycle may improve QoL in patients with solid tumors.     

Auditory-visual speech integration by prelinguistic infants: perception of an emergent consonant in the McGurk effect

The McGurk effect, in which auditory [ba] dubbed onto [ga] lip movements is perceived as "da" or "tha," was employed in a real-time task to investigate auditory-visual speech perception in prelingual infants. Experiments 1A and 1B established the validity of real-time dubbing for producing the effect. In Experiment 2, 4 1/2-month-olds were tested in a habituation-test paradigm, in which an auditory-visual stimulus was presented contingent upon visual fixation of a live face. The experimental group was habituated to a McGurk stimulus (auditory [ba] visual [ga]), and the control group to matching auditory-visual [ba]. Each group was then presented with three auditory-only test trials, [ba], [da], and [(delta)a] (as in then). Visual-fixation durations in test trials showed that the experimental group treated the emergent percept in the McGurk effect, [da] or [(delta)a], as familiar (even though they had not heard these sounds previously) and [ba] as novel. For control group infants [da] and [(delta)a] were no more familiar than [ba]. These results are consistent with infants' perception of the McGurk effect, and support the conclusion that prelinguistic infants integrate auditory and visual speech information.     

Factors affecting size and swelling of poly(ethylene glycol) microspheres formed in aqueous sodium sulfate solutions without surfactants

The LCST behavior of poly(ethylene glycol) (PEG) in aqueous sodium sulfate solutions was exploited to fabricate microspheres without the use of other monomers, polymers, surfactants or organic solvents. Reactive PEG derivatives underwent thermally induced phase separation to produce spherical PEG-rich domains that coarsened in size pending gelation, resulting in stable hydrogel microspheres between ≈1 and 100 microns in size. The time required to reach the gel point during the coarsening process and the extent of crosslinking after gelation both affected the final microsphere size and swelling ratio. The gel point could be varied by pre-reaction of the PEG derivatives below the cloud point, or by controlling pH and temperature above the cloud point. Pre-reaction brought the PEG derivatives closer to the gel point prior to phase separation, while the pH and temperature influenced the rate of reaction. Dynamic light scattering indicated a percolation-to-cluster transition about 3–5 min following phase separation. The mean radius of PEG-rich droplets subsequently increased with time to the 1/4th power until gelation. PEG microspheres produced by these methods with controlled sizes and densities may be useful for the production of modular scaffolds for tissue engineering.     

Factors affecting the designation of cerebrovascular diseases as work-related in administrative litigation

The purpose of this study was to identify factors that could be used as standardized criteria for evaluating occupational diseases in initial assessments or requests for examination. Using 100 administrative litigation cases on the work-relatedness of cerebrovascular diseases (CVDs) by the Seoul Branch of the Korea Labor Welfare Corporation (KLWC) from 1997 to 2002, we estimated the relationship between the investigated variables and designation of the work-relatedness of the CVD. As for the age, the odds ratio of the acceptance rate of a case as work-related in subjects over 60 yr of age was 0.08 (95% CI, 0.01-0.75), which was compared to subjects under 30 yr of age. Regarding working hours, the odds ratio of the acceptance rate of a case as work-related in CVDs in those over 56 hr was 9.50 (95% CI, 1.92-47.10) when compared to those less than 56 hr. As for the benefit type, the odds ratio of the acceptance rate of a case as work-related in medical benefits was 5.74 (95% CI, 1.29-25.54), compared to survivor benefits. As for the criteria for defining situations as work overload, the odds ratio of the acceptance rate of a case as work-related in injured workers was 12.06 (95% CI, 3.12-46.62), compared to that in non-injured workers. Our findings show that the criteria for defining situations of work overload played an important role in assessing the work-relatedness of CVDs in administrative litigation, and it is necessary to make the scientific evidence on judgement of work-relatedness on overwork.     

Factors affecting the variation in the adult temporomandibular joint of archaeological human populations

To elucidate factors that may affect the variation in the bony components of temporomandibular joint (TMJ), a preliminary study was conducted on the temporal articular surface of the TMJ of 30 skulls from Iron Age and medieval populations from Lithuania and a mixed Neolithic and Bronze Age population from the Central Elbe-Saale region (CESR). Using three-dimensional (3D) photos of the skulls, length and width measurements of the TMJ were obtained and compared with external skull measurements. Distinct, random variation between the TMJ values from opposite sides of the cranium were identified as fluctuating asymmetry. ANOVA results suggest significant differences in the length of the TMJ between the population of the CESR and the two Lithuanian populations, but not between the two Lithuanian populations. Environmental factors, including geography, may be responsible for the variation in the TMJ form.     

Comparison of the family history method to direct interview: Factors affecting the diagnosis of depression

This study compares information on the diagnosis of depression obtained by family history reports with the information obtained by direct interview. Reports were obtained from family memebers on the psychiatric status of 696 individuals for whom direct SADS-L interviews were also available. The effects on family history reports of subjects characteristics, treatment status, age of onset of depression, and endogenous symptoms were examined. Sensitivity and specificity for family history reports on the specific symptoms of depression are also reported. The specificity of family history reports for the diagnosis of depression was consistently high but sensitivity varied as a function of subject and illness characteristics. Sensitivity was somewhat higher for females than males and appreciably higher for probands than for their first-degree relatives and spouses. Sensitivity was increased whenever treatment, hospitalization or endogenous symptoms were present in the subject, indicating that family history reports are most accurate for detecting the cases of depression. Finally, the symptoms of depression that are least accurately reported by relatives are identified and suggestions for modifying the family history criteria for depression are proposed.     

电场对肿瘤的治疗作用及机制研究进展

电场治疗肿瘤是将电工技术应用于肿瘤治疗的一项多学科交叉综合性的应用研究,具有安全、适用性强、参数容易控制的特点,近年来倍受关注.目前研究或应用的电场类型主要有脉冲电场和直流电场,均通过改变肿瘤生长的内环境,使之产生病理性变化而死亡.中频交变电场是一种新型的肿瘤治疗电场,应用前景广阔.综述了3种电场的抗癌效应及作用机制在国内外的研究进展.     

Effect of noise on the contrast detection threshold in visual perception

It has recently been shown that noise can improve the detection of stimuli in several sensory modalities. We herein investigated whether visual contrast detection sensitivity can be improved by adding a certain amount of noise. The contrast detection thresholds of a light changing brightness periodically were measured either with or without overlapping noise in 22 normal participants. Sinusoidal modulating light at 1 or 15 Hz was used as a signal. White noise was used to produce random flickering light as the noise. Participants were required to detect any changes in the brightness of the signal with or without noise. The contrast detection threshold, which was measured using a psychophysical method, decreased at around the threshold level of the noise intensity. The maximum facilitatory effect was obtained at a noise intensity of 5 dB. This effect was consistently observed regardless of the frequency of the signal (1 and 15 Hz). These findings indicate that noise can improve the signal detection in human visual perception.     

Factors affecting quality of life in patients with systemic lupus erythematosus: important considerations and potential interventions

ABSTRACT

Introduction: Patients with systemic lupus erythematosus (SLE) have a better survival than decades ago; nevertheless, they still experience a low health-related (HR) quality of life (QoL).

Areas covered: After defining QoL and HRQoL, we review the need to assess it, its elements, how to measure it, its predictors, and its impact and potential interventions to improve it.

Expert commentary: Physicians assessments of disease activity and damage do not capture the patients’ perspective of their health, and these differences could lead to nonadherence to therapy. Based on that, a comprehensive evaluation of SLE should include the assessment of HRQoL or the sum of the physical, psychological, and social perception of wellbeing, influenced by the patient’s illness. The most consistent predictors of low HRQoL are older age, poverty, lower educational level, behavioral issues, some clinical manifestations, and comorbidities. HRQoL impacts negatively on dealing with stress, intimal relationship, home and job-related activities, and treatment adherence. At the present, there are no successful specific therapeutic strategies aimed at improving it.