Upward-directed exit-site of the swan-neck catheter and "Easy-to-disinfect the backside area of exit-site" may prevent PD complications

BACKGROUND

Upward-directed exit-site has been believed to be the worst for frequent ESI by an old retrospective study using straight catheters. No comparison study of 3 exit-site directions using swan-neck catheter has been performed regarding which direction is the best for our endpoints, Easy-to-see the backside area of exit-site: ESBE, Easy-to-disinfect the backside area of exit-site: EDBE, reduction of both exit-site infection (ESI), symptomatic catheter dislocation and peritonitis.

METHODS

We assessed the relationship of exit-site direction with our endpoints in a quantitative cross-sectional, multicentered questionnaire survey. Patients who received either non-surgical catheter implantation or exit-site surgery were excluded.

RESULTS

The numbers (percentage) of exit-site directions in included 291 patients were upward 79 (26.0), lateralward 108 (37.5) and downward 105 (36.5). Cochran-Armitage analysis showed a significant step-ladder increase in the prevalence of ESI as the direction changed from upward to lateralward to downward (0.15 ± 0.41, 0.25 ± 0.54, 0.38 ± 0.69 episodes/patient-year, p = 0.03). Multivariable regression analysis revealed the upward exit-site independently associates with both higher frequency of ESBE (OR 5.55, 95% CI 2.23-16.45, p < 0.01) and reduction of prevalence of ESI (OR 0.55, 95%CI 0.27-0.98, p = 0.04). Positive association between the prevalence of symptomatic catheter dislocation and ESI (OR 2.84, 95% CI 1.27-7.82, p = 0.01), and inverse association between EDBE and either prevalence of symptomatic catheter dislocation (OR 0.27, 95% CI 0.11-0.72) or peritonitis (OR 0.48, 95% CI 0.23-0.99) observed.

CONCLUSION

Upward-directed swan-neck catheter exit-site may be the best for both ESBE and prevention of ESI. EDBE may reduce catheter dislocation and peritonitis. Symptomatic catheter dislocation may predict ESI.

Distinct patterns of fracture propagation in distal radial fractures and the relationship to the ulnar head

BACKGROUND

The aim was to assess the direction of distal radius fractures and their relationship to the ulnar head.

METHODS

We reviewed the 160 wrist radiographs. The fracture line was measured on the postero-anterior and lateral radiographs relative to the long axis of the forearm and the relationship to the ulnar head.

FINDINGS

PA radiographs: the fracture line ran distal ulnar to proximal radial (ulnar to radial) in 11%, transverse in 74% and distal radial to proximal ulnar (radial to ulnar) in 16%. Lateral radiographs: the fracture line ran distal volar to proximal dorsal in 88%, transverse in two 1% and dorsal to volar in 11%. Radial shift (7.5%) only occurred with ulnar to radial or transverse fractures. The ulnar to radial fracture line started at the proximal end of the ulnar head/distal radio-ulnar joint in 88%. The radial to ulnar fracture line started ended a mean of 2.5 mm proximal to the distal radio-ulnar joint (p < 0.01). The transverse fracture line started at the base of the distal radio-ulnar joint in 53% and proximally in 47%.

INTERPRETATION

There are two distinct coronal patterns: radial to ulnar ending c. 2 mm proximal to the distal radio-ulnar joint; ulnar to radial starting at the proximal distal radio-ulnar joint. There may be third pattern - transverse fractures; these may be variants of the above. Sagittally the main direction is volar to dorsal but 11% are obverse. This is the first description of distinct fracture patterns in extra-articular distal radius fractures. In addition the fracture patterns appear to correlate with different directions of force transmission which fit with our understanding of falling and the relatively uncontrolled impact of the wrist/hand with the ground. These patterns of fracture propagation help understand how the biomechanics of wrist fractures and may enable prediction of collapse.

Direction and distance information in memory for location relative to landmarks

An object's location is often remembered relative to one or more landmarks. An object has a certain direction and distance relative to a landmark. When multiple landmarks are available the information from the different landmarks is integrated. In the prevailing view direction and distance are equally influential in the integration process. We present evidence that direction and distance are not always equally influential in landmark-based memory. During the study phase of our task, participants viewed a set of layouts, each comprising a target and two landmarks. During the test phase participants attempted to place each target in the correct location relative to the two landmarks. Our measure of direction deviation indexed the degree to which the targets were placed on the basis of distance rather than solely on the basis of direction. Our measure of distance deviation indexed the degree to which the targets were placed on the basis of direction rather than solely on the basis of distance. Direction deviation was smaller than distance deviation. The results suggest that direction is more influential than distance in memory for the locations of objects relative to landmarks.

THE EFFECT DIRECTION SHOULD BE TAKEN INTO ACCOUNT WHEN ASSESSING SMALL-STUDY EFFECTS

OBJECTIVE

Studies with statistically significant results are frequently more likely to be published than those with non-significant results. This phenomenon leads to publication bias or small-study effects and can seriously affect the validity of the conclusion from systematic reviews and meta-analyses. Small-study effects typically appear in a specific direction, depending on whether the outcome of interest is beneficial or harmful, but this direction is rarely taken into account in conventional methods.

METHODS

We propose to use directional tests to assess potential small-study effects. The tests are built on a one-sided testing framework based on the existing Egger's regression test. We performed simulation studies to compare the proposed one-sided regression tests, conventional two-sided regression tests, as well as two other competitive methods (Begg's rank test and the trim-and-fill method). Their performance was measured by type I error rates and statistical power. Three real-world meta-analyses on measurements of infrabony periodontal defects were also used to examine the various methods' performance.

RESULTS

Based on simulation studies, the one-sided tests could have considerably higher statistical power than competing methods, particularly their two-sided counterparts. Their type I error rates were generally controlled well. In the case study of the three real-world meta-analyses, by accounting for the favored direction of effects, the one-sided tests could rule out potential false-positive conclusions about small-study effects. They also are more powerful in assessing small-study effects than the conventional two-sided tests when true small-study effects likely exist.

CONCLUSION

We recommend researchers incorporate the potential favored direction of effects into the assessment of small-study effects.

Direction and distance information in memory for locations of objects relative to landmarks and boundaries

An observer often remembers an object's location on the basis of its direction and distance from reference objects. Two kinds of reference object are of particular interest: landmarks and boundaries. We compared how well observers remembered the direction and distance of target objects from a landmark and a boundary. Patterns of variable error implied that the landmark was more effective than the boundary in supporting memory for target object direction. When the predictions of the landmark and the boundary were placed in conflict, patterns of constant error implied that the boundary was more effective than the landmark in supporting memory for target object distance. These results suggest affinities between direction information and landmarks and between distance information and boundaries. They raise the possibility that, rather than collapsing across direction and distance error, theoretical analyses should distinguish the two kinds of error in assessing the reliability of landmarks and boundaries.

Processing directional information in stimuli inhibits the spatial association of luminance levels

Previous studies have found that the spatial-numerical association of the response codes (SNARC) effect automatically occurred when processing both numbers and non-symbolic magnitudes. However, this conclusion was challenged by several recent studies that found no SNARC effect when processing non-symbolic magnitudes with a directional cue. In the present study, we hypothesized that automatic spatial association of non-symbolic magnitudes would be inhibited by directional cues; thus, we utilized left and right arrow stimuli with different luminance levels to systematically investigate the spatial association of luminance. To ensure that participants could effectively discriminate the luminance stimuli, we first replicated the SNARC effect in Experiment 1, by presenting rectangles with different luminance levels. Then, arrows with the same luminance levels as the rectangles were randomly presented to participants on the centre of a screen; participants completed direction classification (Experiment 2), colour classification (Experiment 3), or luminance classification (Experiment 4) tasks with these arrow stimuli. We found that (1) the SNARC effect was present when processing rectangles with different luminance levels (Experiment 1); however, (2) the Simon-like effect rather than the spatial association of luminance was observed when processing arrows with different luminance levels in the luminance-irrelevant classification tasks (Experiments 2 and 3) and the luminance-relevant classification task (Experiment 4). These results indicate that processing of a directional cue inhibited the spatial association of luminance in both luminance-relevant and luminance-irrelevant classification tasks.

Drop-out in dual VET: why we should consider the drop-out direction when analysing drop-out

Despite high drop-out rates from vocational education and training (VET) throughout most countries and a long research tradition on potential drop-out reasons, little is known about the effects exerted on drop-out intentions by the quality of training. Furthermore, only rarely do scholars distinguish between different drop-out directions, and systematic insights on possibly differing causes are scarce. This study explores the factors influencing four directions of drop-out intention ('upwards', 'downwards', 'company change', 'occupation change'). Linear regression modelling is used to analyse survey data on the motivation, socio-demographic aspects and competency of 562 trainees as industrial management assistants in Germany and on how they perceived the training quality. The results show that different directions of drop-out intention stem from various factors, with training quality in general having the largest effect. Additionally, the findings indicate a two-tier-scheme of influence factors, 'core' and 'direction-typical' factors.

Unilateral or Bilateral Standing Broad Jumps: Which Jump Type Provides Inter-Limb Asymmetries with a Higher Reliability?

This study aimed to compare the between-session reliability of performance and asymmetry variables between unilateral and bilateral standing broad jumps (SBJ). Twenty-four amateur basketball players (12 males and females) completed two identical sessions which consisted of four unilateral SBJs (two with each leg) and two bilateral SBJs. Mean and peak values of force, velocity and power, and impulse were obtained separately for each leg using a dual force platform. Inter-limb asymmetries were computed using the standard percentage difference for the unilateral SBJ, and the bilateral asymmetry index-1 for the bilateral SBJ. All performance variables generally presented an acceptable absolute reliability for both SBJs (CV range = 3.65-9.81%) with some exceptions for mean force, mean power, and peak power obtained with both legs (CV range = 10.00-15.46%). Three out of 14 variables were obtained with higher reliability during the unilateral SBJ (CVratio ≥ 1.18), and 5 out of 14 during the bilateral SBJ (CVratio ≥ 1.27). Asymmetry variables always showed unacceptable reliability (ICCrange = -0.40 to 0.58), and slight to fair levels of agreement in their direction (Kappa range = -0.12 to 0.40) except for unilateral SBJ peak velocity [Kappa = 0.52] and bilateral SBJ peak power [Kappa = 0.51]) that showed moderate agreement for both SBJs. These results highlight that single-leg performance variables can be generally obtained with acceptable reliability regardless of the SBJ variant, but the reliability of the inter-limb asymmetries in the conditions examined in the present study is unacceptable to track individual changes in performance.

The optomotor response of aging zebrafish reveals a complex relationship between visual motion characteristics and cholinergic system

Understanding the principles underlying age-related changes in motion perception is paramount for improving the quality of life and health of older adults. However, the mechanisms underlying age-related alterations in this aspect of vision, which is essential for survival in a dynamic world, still remain unclear. Using optomotor responses to drifting gratings, we investigated age-related changes in motion detection of adult zebrafish (wild-type/AB-strain and ache^sb55/+ mutants with decreased levels of acetylcholinesterase). Our results pointed out negative optomotor responses that significantly depend on the spatial frequency and contrast level of stimulation, providing supporting evidence for the visual motion-driven aspect of this behavior mainly exhibited by adult zebrafish. Although there were no significant main effects of age and genotype, we found a significant three-way interaction between contrast level, age, and genotype. In the contrast domain, the changes in optomotor responses and thus in the detection of motion direction were age- and genotype-specific. Accordingly, these behavioral findings suggest a strong but complicated relationship between visual motion characteristics and the cholinergic system during neural aging.

Phenotypic variation of floral organs in Malus using frequency distribution functions

BACKGROUND

Phenotypic diversity of floral organs plays an important role in plant systematic taxonomy and genetic variation studies. Previous research have focused on the direction of variation but disregarded its degree. Phenotypic variation (including directions and degrees) of 17 floral traits from wild to cultivated crabapples were explored by comparing their distributions and deviations in three different dimensions: floral organ number, size, and the shape.

RESULTS

Except for petal number, petal length / petal width, and sepal length / sepal width, the analyzed floral traits of cultivated crabapples all showed downward distributed box bodies in box plot analysis and left deviations of fitted curves in frequency distribution function analysis when compared to the wild, which revealed consistent variation directions of petaloid conversion (pistils or stamens → petals), size miniaturization (large → small), and shape narrowness (petal shape: circular → elliptic; sepal shape: triangular → lanceolate). However, only seven floral traits exhibited significant differences in box plot analysis, while all of the traits in frequency distribution function analysis were obviously offset. The variation degrees were quantitatively characterized by sizing traits > shaping traits > numbering traits and by horizontal dimensions > radial dimensions.

CONCLUSIONS

Frequency distribution function analysis was more sensitive than the box plot analysis, which constructed a theoretical basis for Malus flower type breeding and would provide a new quantitative method for future evaluation of floral variation among different groups of angiosperms at large.

Optimal suture anchor direction in arthroscopic lateral ankle ligament repair

PURPOSE

In this study, the distance between the insertion point of the suture anchors and posterior surface of the fibula during arthroscopic lateral ankle ligament repair was investigated on computed tomography (CT) images. The hypothesis of this study was that there is an optimal insertional direction of the suture anchor to avoid anchor-related complications.

METHODS

One hundred eleven ankles of 98 patients who had undergone three-dimensional CT scans for foot or ankle disorders without deformity of the fibula were assessed (59 males, 52 females; median age 25.5 years; age range 12-78 years). The shortest distance from the insertion point of the suture anchor to the deepest point of the fossa/top of the convex aspect of the fibula was measured on the axial plane, tilting from the longitudinal axis of the fibula at 90°, 75°, 60°, and 45°. The distance from the insertion point of the suture anchor to the posterior surface of the fibula was also measured in a direction parallel to the sagittal plane of the lateral surface of the talus on the axial plane, tilting from the longitudinal axis of the fibula at 90°, 75°, 60°, and 45°.

RESULTS

The posterior fossa was observed in all cases on the 90° and 75° images. The distance from the insertion point to the posterior surface of the fibula in the parallel direction was 15.0 ± 3.4 mm at 90°, 17.5 ± 3.2 mm at 75°, 21.7 ± 3.3 mm at 60°, and 25.7 ± 3.6 mm at 45°. The posterior points in the parallel direction were located on the posterior fossa in 36.0% of cases at 90°, in 12.6% at 75°, and in 0.0% at 60° and 45°.

CONCLUSIONS

The suture anchor should be directed from anterior to posterior at an angle of <45° to the longitudinal axis of the fibula, parallel to the lateral surface of the talus, to avoid passing through the fibula.

LEVEL OF EVIDENCE

Cohort study, Level III.

Uterine EMG activity in the non-pregnant sow during estrous cycle

BACKGROUND

Uterine myoactivity is crucial for successful reproductive performance of the sow. Spontaneous contractions of the uterus are strictly controlled and coordinated. Uterine electromyographic (EMG) activity undergoes hormonal regulation with rapid and long-term effects. What is more, interstitial Cajal-like Cells (ICLC) appear essential for smooth muscle contractility in the reproductive tract where they are suspected to be playing a major role in generating, coordinating, modulating and synchronizing slow triggering waves. The aim of this study was to investigate the myoelectrical activity of sow's uterus during estrus cycle.

RESULTS

Study was conducted on 10 Polish Landrace sows. Propagation mechanisms and their connection with the uterine EMG activity were considered in correlation with expression of c-kit, progesterone and oxytocin receptors of the non-pregnant sow. ICLC were labeled with antibody directed against c-kit receptor and visualized by confocal microscopy and scanning cytometer for positive cells percentage assessment. EMG signal was recorded directly from the myometrium with telemetry transmitters and electrodes located in different topographic regions of reproductive tracts. The stages of estrus cycle were determined by monitoring levels of luteinizing hormone, progesterone and estrogen with radioimmunoassays. Significant differences of the EMG signal parameters between diestrus and estrus and the correlations with density of labelled receptors were demonstrated. Moreover, the electrophysiological studies indicated that ICLC in the myometrium in the tip of uterine horn may participate in the regulation of slow waves duration and frequency.

CONCLUSIONS

The pattern of EMG signal propagation in the wall of the non-pregnant porcine uterus occurs in an orderly, bidirectional fashion and at distinctive speed, with no differences between diestrus and estrus.

Knee Muscular Control During Jump Landing in Multidirections

BACKGROUND

Jump landing is a complex movement in sports. While competing and practicing, athletes frequently perform multi-planar jump landing. Anticipatory muscle activity could influence the amount of knee flexion and prepare the knee for dynamic weight bearing such as landing tasks.

OBJECTIVES

The aim of the present study was to examine knee muscle function and knee flexion excursion as athletes naturally performed multi-direction jump landing.

MATERIALS AND METHODS

Eighteen male athletes performed the jump-landing test in four directions: forward (0°), 30° diagonal, 60° diagonal, and lateral (90°). Muscles tested were vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), semitendinosus (ST), and biceps femoris (BF). A Vicon(TM) 612 workstation collected the kinematic data. An electromyography was synchronized with the Vicon(TM) Motion system to quantify dynamic muscle function. Repeated measure ANOVA was used to analyze the data.

RESULTS

Jump-landing direction significantly influenced (P < 0.05) muscle activities of VL, RF, and ST and knee flexion excursion. Jumpers landed with a trend of decreasing knee flexion excursion and ST muscle activity 100 ms before foot contact progressively from forward to lateral directions of jump landing.

CONCLUSIONS

A higher risk of knee injury might occur during lateral jump landing than forward and diagonal directions. Athletes should have more practice in jump landing in lateral direction to avoid injury. Landing technique with high knee flexion in multi-directions should be taught to jumpers for knee injury prevention.

The extent of altered digit force direction correlates with clinical upper extremity impairment in chronic stroke survivors

Many stroke survivors suffer from impaired hand function. Biomechanics of hand grip suggests that abnormally directed grip force can hamper gripping abilities and hand function. This study examined the relation between the ability to precisely direct fingertip force and clinical hand function scores among individuals affected by stroke. Specifically, clinical hand function tests of the Fugl-Meyer, Chedoke McMaster, and Box and Block Test were used, since they involve various hand movements required for activities of daily living. Digit force direction during static grip was recorded using multiaxial load cells. Data for 59 chronic stroke survivors were analyzed. We found that larger angular deviation of digit force from the normal direction was significantly associated with lower hand functional levels (p<.001 for all three clinical tests). Particularly, stroke survivors whose digit force deviated more than 21° from the normal direction could not achieve the normal level of Fugl-Meyer or Chedoke or move more than 4 blocks in a minute. The biomechanics of the way digit force direction affects hand grip function is described. In addition, underlying mechanisms for altered digit force direction post stroke are postulated, including impaired somatosensation and abnormal neural input to muscles. In summary, this study identifies a new biomechanical marker for hand functional level and recovery. Future interventions may focus on correcting digit force direction to improve hand functional outcome.

Why do lesions in the rodent anterior thalamic nuclei cause such severe spatial deficits?

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A dual hypothesis is introduced to explain the importance of these thalamic nuclei.

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ATN are vital for multiple spatial functions.

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ATN damage disrupts processing across distal limbic sites.

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Distal pathology caused by ATN damage disrupts plasticity and metabolic activity.

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ATN lesion effects reflect both their intrinsic importance and distal dysfunctions.

Lesions of the rodent anterior thalamic nuclei cause severe deficits to multiple spatial learning tasks. Possible explanations for these effects are examined, with particular reference to T-maze alternation. Anterior thalamic lesions not only impair allocentric place learning but also disrupt other spatial processes, including direction learning, path integration, and relative length discriminations, as well as aspects of nonspatial learning, e.g., temporal discriminations. Working memory tasks, such as T-maze alternation, appear particularly sensitive as they combine an array of these spatial and nonspatial demands. This sensitivity partly reflects the different functions supported by individual anterior thalamic nuclei, though it is argued that anterior thalamic lesion effects also arise from covert pathology in sites distal to the thalamus, most critically in the retrosplenial cortex and hippocampus. This two-level account, involving both local and distal lesion effects, explains the range and severity of the spatial deficits following anterior thalamic lesions. These findings highlight how the anterior thalamic nuclei form a key component in a series of interdependent systems that support multiple spatial functions.

Evaluation of Phase Locking and Cross Correlation Methods for Estimating the Time Lag between Brain Sites: A Simulation Approach

INTRODUCTION

Direction and latency of electrical connectivity between different sites of brain explains brain neural functionality. We compared efficiency of cross correlation and phase locking methods in time lag estimation which are based on local field potential (LFP) and LFP-spike signals, respectively.

METHODS

Signals recorded from MT area of a macaque's brain was used in a simulation approach. The first signal was real brain activity and the second was identical to the first one, but with two kinds of delayed and not delayed forms. Time lag between two signals was estimated by cross correlation and phase locking methods.

RESULTS

Both methods estimated the time lags with no errors. Phase locking was not as time efficient as correlation. In addition, phase locking suffered from temporal self bias.

DISCUSSION

Correlation was a more efficient method. Phase locking was not considered as a proper method to estimate the time lags between brain sites due to time inefficiency and self bias, the problems which are reported for the first time about this method.

Effects of age and lean direction on the threshold of single-step balance recovery in younger, middle-aged and older adults

Several studies have quantified and compared balance recovery between healthy younger and older adults, using a variety of large postural perturbations and loss of balance directions. However, to the best of our knowledge, no studies at the threshold of balance recovery, where avoiding a fall is not always possible, have included middle-aged adults. We thus determined the maximum lean angle from which 20 younger, 16 middle-aged and 16 older healthy adults could be suddenly released and still recover balance using a single step for forward, sideways and backward leans. Results showed that the maximum lean angles of younger adults were 23% greater than middle-aged adults and 48% greater than older adults. The maximum lean angles for forward leans were 23% greater than sideways leans and 22% greater than backward leans. These declines with age and lean direction were associated with declines in response initiation, execution and geometry. Finally exponential regressions showed that the critical ages at which the ability to recover balance and avoid a fall significantly decreases were 51.0, 60.6 and 69.9 yrs for forward, sideways and backward leans, respectively. Therefore, we have demonstrated that age affects the ability to recover balance nearly a decade earlier than the rate of falls. Future studies should thus not only include older adults over 65 yrs, but also middle-aged adults under 65 yrs, or recruit all ages from 18 to 85 yrs. Finally, the critical ages identified in this study may justify an earlier screening of aging adults to prevent future falls, especially the first fall.

Navigational range lights: effect of stimulus configuration on alignment accuracy

The use of range lights in nautical navigation involves the visual determination of the vertical alignment of two points of light, in order to indicate the centre of the channel. In two experiments it is shown that this vernier alignment task is more accurate if illuminated linear stimuli are used as range lights. Experiment 1 involved a laboratory simulation and experiment 2 involved a field test with full sized range lights. The average reduction of error through the use of linear stimuli over the standard point stimuli, for navigational alignments at a distance of one-half nautical mile from the range lights, was 69-4%. This suggests that a marked safety advantage might accrue from the use of linear range lights for nautical navigation purposes.