Effects of microcystin-producing and non-microcystin-producing Microcystis on the behavior and life history traits of Chironomus pallidivittatus.

Species of the genus Microcystis are among the most notorious cyanobacteria in eutrophic lakes worldwide, with ability present adverse effects on many aquatic organisms. In the surface sediments, Microcystis can be ingested by benthic macroinvertebrates such as Chironomus. However, the potential negative effects of Microcystis on Chironomus life history traits remain unclear. In the present study, we investigated the effect of different Microcystis diets on specific behaviors (burrowing activity, locomotion ability) and life history traits of Chironomus pallidivittatus (Diptera, Chironomidae). We also studied the interactive effects of microcystin-producing M. aeruginosa and temperature (15, 20, and 25 °C) stress on chironomid larvae. The results showed that the inhibitory effect on the cumulative emergence and burrowing activity of larvae was more severe when they were fed M. aeruginosa among the three Microcystis diets groups. Locomotion ability (i.e., locomotor distance and velocity) and adult dry weight decreased significantly in the group fed M. aeruginosa. Locomotion was significantly inhibited and mortality increased when the larvae were fed a mixture of M. aeruginosa and M. wesenbergii, which may have been the result of additive or synergistic effect of the toxins. Under the stress of lower temperature, C. pallidivittatus larvae exhibited weaker locomotion and growth ability, and the emerging adults were mostly male. At both the lower and higher temperature conditions, M. aeruginosa cause cumulative emergence decreased, and sex ratio imbalance, which inhibited the reproduction of larvae from the population perspective. The fourth-instar larvae showed better adaption to Microcystis than did the other instars. This study thus highlights the adverse effects of microcystin-producing M. aeruginosa on Chironomus. It also provides a novel perspective on how environmental factors may influence the behavior and life history traits of chironomid larvae, and how they may respond to cyanobacterial blooms and global warming.

Visual Cues Promote Head First Strategies During Walking Turns in Individuals With Parkinson's Disease.

Anticipatory eye movement promotes cranio-caudal sequencing during walking turns. Clinical groups, such as Parkinson's disease (PD), do not produce anticipatory eye movements, leading to increased risk of falls. Visual cues may promote anticipatory eye movement by guiding the eyes into the turn. This study examined if visual cues could train anticipatory eye movement. Ten neurotypical young adults and 6 adults with PD completed three blocks of walking trials. Trials were blocked by visual condition: non-cued baseline turns (5 trials), visually cued turns (10 trials), and non-cued post turns (5 trials). A Delsys Trigno (Delsys, Boston, MA) recorded horizontal saccades at 1024 Hz via electrooculography (EOG). Two Optotrak cameras (Northern Digital Inc., ON, Canada) captured body segment kinematics at 120 Hz. Initiation of segment rotation with respect to ipsilateral foot contact (IFC1) prior to the turn was calculated. Neurotypical young adults (NYA) produced typical cranio-caudal rotation sequences during walking turns. Eyes led (407 ms prior to IFC1), followed by the head (50 ms prior to IFC1), then trunk and pelvis. In contrast, PD produced no anticipatory eye or segment movement at baseline. During pre-trials the eyes moved 96 ms after IFC1 and segment movement was initiated by the pelvis followed by trunk and head segments. After visual cue training however, PD produced anticipatory eye movements 161 ms prior to IFC1, followed by the head 88 ms following IFC1 but ahead of trunk and pelvis onset. These results suggest visual cues assist in producing cranio-caudal control during walking turns in PD.

Behavioural and biochemical alterations by chlorpyrifos in aquatic insects: an emerging environmental concern for pristine Alpine habitats.

This study aimed to assess how different concentrations of the insecticide chlorpyrifos (1.1, 5.24, 11, 52.4, 110, 262, 524 and 1100 ng L-1) affect the swimming behaviour of Diamesa zernyi larvae following exposure. A video tracking system was employed to analyse two swimming traits (total distance moved and average speed) of the larvae simultaneously after 3 days of exposure to the pesticide at 2 °C. The behavioural results were also interpreted according to biochemical responses to oxidative stress (OS) induced by chlorpyrifos, based on malondialdehyde (MDA) and protein carbonyl (PCC) content. Both distance and speed significantly decreased after 72 h of exposure to chlorpyrifos concentrations of ≥ 110 ng L-1, under which significant OS was detected as lipid peroxidation (level of MDA) and protein carbonylation (level of carbonyl). Analysis of altered swimming behaviour, along with MDA and carbonyl content, indicated that ≥ 110 ng L-1 contamination levels of the insecticide cause the organism to reallocate energy normally used for locomotor activity to repair cell damage, which might explain the strong impairment to locomotor performance. Locomotor performance is an ecologically relevant trait for elucidating the population dynamics of key species, with disturbance to this trait having long-term negative impacts on population and community structure. Therefore, chlorpyrifos insecticides represent a serious ecological risk for mountain aquatic species based on the detrimental effects observed in the current study, as the tested concentrations were those at which the insecticide is found in many Alpine rivers of Italy.

Cross-cultural validity of the ABILOCO questionnaire for individuals with stroke, based on Rasch analysis.

PURPOSE: The purpose of this study was to evaluate the cross-cultural validity of the Brazilian version of the ABILOCO questionnaire for stroke subjects. MATERIALS AND METHODS: Cross-cultural adaptation of the original English version of the ABILOCO to the Brazilian-Portuguese language followed standardized procedures. The adapted version was administered to 136 stroke subjects and its measurement properties were assessed using Rash analysis. Cross-cultural validity was based on cultural invariance analyses. RESULTS: Goodness-of-fit analysis revealed one misfitting item. The principal component analysis of the residuals showed that the first dimension explained 45% of the variance in locomotion ability; however, the eigenvalue was 1.92. The ABILOCO-Brazil divided the sample into two levels of ability and the items into about seven levels of difficulty. The item-person map showed some ceiling effect. Cultural invariance analyses revealed that although there were differences in the item calibrations between the ABILOCO-original and ABILOCO-Brazil, they did not impact the measures of locomotion ability. CONCLUSIONS: The ABILOCO-Brazil demonstrated satisfactory measurement properties to be used within both clinical and research contexts in Brazil, as well cross-cultural validity to be used in international/multicentric studies. However, the presence of ceiling effect suggests that it may not be appropriate for the assessment of individuals with high levels of locomotion ability. Implications for rehabilitation Self-report measures of locomotion ability are clinically important, since they describe the abilities of the individuals within real life contexts. The ABILOCO questionnaire, specific for stroke survivors, demonstrated satisfactory measurement properties, but may not be most appropriate to assess individuals with high levels of locomotion ability The results of the cross-cultural validity showed that the ABILOCO-Original and the ABILOCO-Brazil calibrations may be used interchangeable.

Application of a paraplegic gait orthosis in thoracolumbar spinal cord injury.

Paraplegic gait orthosis has been shown to help paraplegic patients stand and walk, although this method cannot be individualized for patients with different spinal cord injuries and functional recovery of the lower extremities. There is, however, a great need to develop individualized paraplegic orthosis to improve overall quality of life for paraplegic patients. In the present study, 36 spinal cord (below T4) injury patients were equally and randomly divided into control and observation groups. The control group received systematic rehabilitation training, including maintenance of joint range of motion, residual muscle strength training, standing training, balance training, and functional electrical stimulation. The observation group received an individualized paraplegic locomotion brace and functional training according to the various spinal cord injury levels and muscle strength based on comprehensive systematic rehabilitation training. After 3 months of rehabilitation training, the observation group achieved therapeutic locomotion in 8 cases, family-based locomotion in 7 cases, and community-based locomotion in 3 cases. However, locomotion was not achieved in any of the control group patients. These findings suggest that individualized paraplegic braces significantly improve activity of daily living and locomotion in patients with thoracolumbar spinal cord injury.