Significant Differences In Movement Research Articles

Physical demands of collegiate basketball practice: a preliminary report on novel methods and metrics

Knowing the specific physical demands of basketball players can provide useful information for clinical decision making when rehabilitating athletes following injury. The purpose of this observational study was to describe the physical demands of basketball play at the Division I collegiate level using video-based time-motion analysis and introduce a time-efficient alternative method of quantifying demands. Eleven NCAA Division I basketball players (6M, 5F; 4 guards, 4 centers, 3 forwards) participated in the study. Video footage was collected from four practices (2 men's, 2 women's) and used to quantify the types and frequencies of player movements based on definitions from seminal work. A second and simpler method was also used to classify movement. A two-way ANOVA was used to assess significant differences in movement by team (men's, women's) and position (guard, forward, center). There were significant differences in counts of stand/walk (p < 0.001), jog (p = 0.012), run (p = 0.001), stride/sprint (p = 0.04), and medium-intensity shuffling (p < 0.001) per minute and proportion of practice time spent in bodyweight (p < 0.001) or above-bodyweight (p < 0.001) loading between teams. There were significant differences for jog (p = 0.001) and transition (p = 0.07) rates across positions. Position and team are important considerations for rehabilitation and return-to-sport clearance. Quantification of these demands can be reliably acquired through video analysis using a simplified method (estimated foot load) or using traditional methods of movement classification and counts, particularly when applying descriptors that better capture the current style of play.

The effects of COVID-19 restrictions on gross motor function of children with cerebral palsy

Purpose. COVID-19 is an extremely infectious, life-threatening viral illness that has constituted a global public health emergency. Rehabilitation programs of children with cerebral palsy were interrupted during the COVID-19 pandemic. The aim of the study was to assess the effects of COVID-19 restrictions on gross motor function of children with cerebral palsy.
 Material and Methods. In this study, a survey of fifty eight cerebral palsied children of both genders who received physical therapy recruited from three hospitals in Cairo, Egypt (October 6 university hospital -6th of October general hospital- El Hosary hospital- Zaid general hospital- Zaid specialled hospital- Private physical therapy centers). It was done through paediatrics Quality of life inventory (cerebral therapy module) to compare between the level of the children’s quality of life before and after frequent stopping of physical therapy sessions due to covid-19 pandemic.
 Results. The result of this study shows that there was a significant difference in movement and balance before and after the lockdown (p <0.001). The mean value was decreased from 54.1% to 33.3%. Also, there was a significant decrease in Pain and hurt (p<0.001) from 68.2% to 37.1% and in fatigue (p<0.001) from 58.8% to 37.8%. Regarding age there was a significant difference between different age groups regarding daily activities (p<0.001), pain (p<0.010) and fatigue (p<0.030), while after lockdown, there was a significant difference between different age groups regarding daily activities (p<0.001) and fatigue (p<0.001).
 Conclusion. Children with cerebral palsy were protected from COVID-19 exposure by staying at home, but their rehabilitation activities were disrupted. Therefore, during pandemics, caregivers must develop effective homecare therapy procedures, and healthcare professionals must routinely reassess the state of the child and caregiver. Additionally, caregivers of children with CP should experience less stress and anxiety. Children with CP can get multidisciplinary support, effective communication, and contact between medical professionals and families.

Evaluation of three different 99mTc-based mock-venom agents for lymphoscintigraphy studies in preclinical models of peripheral snakebite envenomation

Snakebite envenomation is one of the major public health concerns across many countries; with the WHO designating it as a ‘priority neglected tropical disease’ and stressing for a need to develop novel therapeutic strategies to reduce death and disability rate by end of 2030. Since a major component of venom; the high molecular weight (HMw) toxins enter the bloodstream through lymphatic system, research is focusing on modulating the lymphatic flow rate after topical application of suitable drug candidates. Present study compared the suitability of three radiopharmaceutical agents, namely 99mTc-Sulfur colloid (SC), 99mTc-Phytate (Phy) and 99mTc-Human serum albumin (HSA), to be used as mock-venom agent in studying modulation in lymphatic flow rate in preclinical models of peripheral snakebite envenomation using lymphoscintigraphy studies. The study was performed in 72 Sprague Dawley rats; divided into six groups of 12 rats each. Control groups were given intradermal injection (1.29–1.48 MBq in 100 μl normal saline) of either 99mTc-Phy/ 99mTc-SC/ 99mTc-HSA into the tail as ‘mock-venom’. In respective test groups, commercially available topical formulation (Anobliss® Cream) containing Nifedipine (Nif; 0.3% w/w) and Lidocaine (Lid; 1.5% w/w) was applied topically over the animals' lower body (tail and hind limbs) immediately within 20s of administering intradermal injection of the radiopharmaceutical. Any modulation in lymph transit time from periphery to systemic circulation was assessed using lymphoscintigraphy by taking dynamic gamma-scintigraphy images of 60s each till 1 h post-injection of the test radiopharmaceuticals. Significant difference in movement of the three radiopharmaceuticals was noted in terms of their lymphatic movement. 99mTc-Phy did not show significant travel through the lymphatics and the liver was faintly visualized in control as well as test intervention groups. In case of 99mTc-SC, significant changes in movement of the radiotracer after topical application of Nif/Lid in the test intervention groups were clearly noted in comparison to control (P < 0.05). Multiple numbers of lymph nodes (LNs) could be clearly visualized in control (5 ± 1 LNs) and test intervention groups (3 ± 1 LNs). Liver uptake was more prominent in control animals and it reduced significantly in test intervention groups. On the other hand, 99mTc-HSA showed lesser number of lymph nodes and higher accumulation in liver as compared to 99mTc-SC, suggesting very fast movement of this radiopharmaceutical. Results indicates that 99mTc-SC could be used as a suitable agent to mimic lymphatic transit behavior of HMw toxin components of snake venom and could therefore be used as a model in studying the effect of any test pharmacological intervention in modulating lymphatic transit rate. Additional advantage could be a significant reduction in the need for sacrificing large number of animals, particularly during initial screening phase of drug development cycle.

P33: “Digital Dance”: Analyzing and Quantifying Signatures of a Demi Plié via Stretchable Electronic Wearable Sensors for Dance Movement Therapy

Background: Dance, an artistic movement, has utility in dance/movement therapy (DMT) when performed accurately and safely. Dance movements consist of exercises promoting muscle building, flexibility, and enhancing longevity as well as providing psychological benefits. Here we evaluated the foundational ballet exercise, the demi plié, and the associated movements of the knees and pelvis. We hypothesized that deviations in motion signatures are identifiable between dancers performing correct vs. incorrect demi pliés, as well as between collegiate level dancers and non-dancers. Methods: Motion sensors (BioStamps) were placed on the left tibialis anterior and sacrum of seven classically trained, injury-free, collegiate-level dancers, who then performed: 1) correct demi pliés, 2) incorrect demi pliés with anterior pelvic tilt, and 3) incorrect demi pliés with posterior pelvic tilt. Then, six non-dancers of similar age, performed correct demi pliés to the best of their ability after brief instruction. For all conditions, acceleration and gyroscope data was collected (X, Y, and Z axes). Results: The dancers movement of the sacrum differed between Conditions 1 and 2 (p=0.00018) and Conditions 1 and 3 (p=0.00178). No significant difference in movement of the sacrum was found between Condition 1 in the dancer group and the non-dancer group (p=0.30952). In addition, no statistically significant difference was found between the depth of plié in the dancers between Conditions 1 and 2 (p=0.50162) and Conditions 1 and 3 (p=0.84254) and in the non-dancer group compared to Condition 1 in the dancers (p=0.26011). No consistent patterns were found regarding medial and lateral motion of the tibialis anterior in both the dancer and non-dancer groups. Conclusions: The BioStamps technology accurately tracked the movements of the tibialis anterior and sacrum during correct and incorrect classical demi pliés in both the “Dancer” and “Non-dancer” groups. This knowledge when applied could promote correct ballet technique and be used in injury prevention, as well as for dance/movement therapy (DMT).

Comparison of maxillary anterior tooth movement between Invisalign and fixed appliances

This research project aimed to compare the number of maxillary incisors and canine movement between Invisalign and fixed orthodontic appliances using artificial intelligence and identify any limitations of Invisalign. Sixty patients (Invisalign, n= 30; braces, n= 30) were randomly selected from the Ohio State University Graduate Orthodontic Clinic archive. Peer Assessment Rating (PAR) analysis was used to indicate the severity of the patients in both groups. To analyze the incisors and canine movement, specific landmarks were identified on incisors and canines using an artificial intelligence framework, two-stage mesh deep learning. Total average tooth movement in the maxilla and individual (incisors and canine) tooth movement in 6 directions (buccolingual, mesiodistal, vertical, tipping, torque, rotation) were then analyzed at a significance level of α= 0.05. Based on the posttreatment Peer Assessment Rating scores, the quality of finished patients in both groups was similar. In maxillary incisors and canines, there was a significant difference in movement between Invisalign and conventional appliances for all 6 movement directions (P<0.05). The greatest differences were with rotation and tipping of the maxillary canine, along with incisor and canine torque. The smallest statistical differences observed for incisors and canines were crown translational tooth movement in the mesiodistal and buccolingual directions. When comparing fixed orthodontic appliances to Invisalign, patients treated with fixed appliances were found to have significantly more maxillary tooth movement in all directions, especially with rotation and tipping of the maxillary canine.

Effects of SmartWater, a fluorescent mark, on the dispersal, behavior, and biocontrol efficacy of Phytoseiulus persimilis.

New marking methods for studying small biocontrol agents (especially predatory mites) are needed because many current techniques are expensive, ineffective or not applicable to small organisms. The objective of this study was to determine whether SmartWater, a liquid and permanent fluorescent dye, can be used to mark Phytoseiulus persimilis for experimentation without any deleterious effects on its dispersal, behavior, reproduction, and biocontrol efficacy. Our results show that there were no significant differences in movement, inter-plant dispersal, feeding behavior, survivability, and reproduction between marked P. persimilis and control individuals sprayed with water. We also found that the SmartWater mark lasted for the duration of the mites' life, indicating strong durability over time. Marking efficacy may be reduced, due to a trade-off between batch marking efficacy and the possibility of drowning study organisms. However, we feel future research could improve liquid marking techniques that would reduce this risk. Overall, this study concludes that SmartWater could be a useful marking tool for predatory mites in both laboratory and field studies.

Superior-segment Bilateral Facet Violation in Lumbar Transpedicular Fixation, Part III: A Biomechanical Study of Severe Violation.

This is an in vitro biomechanical study. This study aimed to investigate the biomechanical variations of lumbar spine motor units after bilateral facet joint severe violation in cadaver specimens and analyze the biomechanics under different moments. The incidence of facet joint violation (FJV) is highly variable, and one of the most important factors is the lack of awareness of protection. Until now, the biomechanical effects of FJV remain unclear. Biomechanical testing was performed on 12 human cadaveric spines under flexion-extension, lateral bending, and axial rotation loading. After intact analysis, pedicle screws were inserted at L5, and the biomechanical testing was repeated. Full range of motion (ROM) at the proximal adjacent levels under different moments was recorded and normalized to the intact (100%) noninstrumented spine. The relative ROM changes were compared between the control and severe violation groups. The adjacent-level ROM (flexion-extension, lateral bending, axial rotation) did not change significantly in the control group at each moment (7.5, 6.0, 4.5 Nm) compared with the intact noninstrumented spine. In the severe violation group, the supradjacent-level ROM decreased significantly under all moments relative to the intact noninstrumented spine (P < 0.05) except for the ROM of lateral bending at moments of 7.5 and 6.0 Nm. When comparing the ROM between the two groups, there were significant differences in all movements except lateral bending at 7.5 Nm. When superior-segment bilateral facet joints are severely violated by screws, the flexion-extension and axial rotation ROM of adjacent vertebrae decreases at each moment (7.5, 6.0, 4.5 Nm), and the lateral bending ROM decreases at 4.5 Nm. N/A.

RESPONSES OF JUVENILE AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) TO CONTACT CALLS

Abstract Crocodylians are known for their ability to vocalize throughout their lives in a variety of social and ecological contexts, particularly during their vulnerable juvenile life stage. However, few studies have analyzed juvenile calls in laboratory settings, fewer still have analyzed them across large sample sizes or with respect to sex and body size, and no studies to date have analyzed crocodylian vocalizations with respect to human conditioning in captivity or animal personality profiles. This study tests juvenile American alligators' (Alligator mississippiensis) ability to respond via movement and callback vocalizations to pre-recorded conspecific contact calls across a large sample size (n=36), and tests for relationships between response rates and juvenile body size and sex. Seventeen and sixteen individuals out of a total of thirty-six responded via movement toward the source of pre-recorded vocalizations across the first and second experimental trials, respectively, whereas none responded through movement toward control sounds; 75% of juveniles who vocalized did so only in response to contact calls rather than controls (though the latter difference was not significant given that only four vocalized in Trial 1, and only a single animal vocalized in Trial 2); there was also no significant difference in movement toward recorded vocalizations across size or sex. However, one particularly vocal individual whose upbringing in captivity was known was identified as a possible unique personality profile given its propensity for callback vocalizations in comparison to its fellow study subjects.

Impact of Single Gene and Pyramided Aphid-Resistant Soybean on Movement and Spatial Pattern of Soybean Aphid (Hemiptera: Aphididae).

Host plant resistance may be an effective option to manage soybean aphid, Aphis glycines (Matsumura) (Hemiptera: Aphididae), an important pest on soybean (Glycine max (L.) Merr.) in the U.S. Movement of soybean aphid may be altered by the presence of resistance (i.e., Rag [Resistance to Aphis glycines]) genes in soybean and changes in movement may affect the spatial pattern of a species. This study aims to assess the effects of Rag1 and pyramided Rag1+Rag2 aphid-resistant varieties on movement of soybean aphid under laboratory conditions and to evaluate potential impacts of this movement on spatial pattern of soybean aphid under field conditions. Results from the greenhouse study showed more movement of soybean aphid on both aphid-resistant varieties than the susceptible variety when aphids were placed on unifoliate leaves and no statistically significant difference in movement between Rag1 and pyramided Rag1+Rag2 varieties. When aphids were placed on new growth, movement was greater on pyramided Rag1+Rag2 than the Rag1 and susceptible variety. However, under field conditions, the spatial patterns of soybean aphid in plots with susceptible, Rag1 or pyramided Rag1+Rag2 varieties were aggregated and did not differ among varieties in vegetative and reproductive growth stages. These results are of relevance because they suggest that aspects of soybean aphid management that may be sensitive to changes in spatial pattern of the pest (e.g., natural enemy efficacy and sampling plans) may not be impacted by implementation of varieties with these resistance genes for host plant resistance.

Changes in spontaneous movement in response to silent gaps are not robust enough to indicate the perception of tinnitus in mice.

Approaches to identify the perception of tinnitus in various animal models have been difficult to apply to mouse. As a result, mice have been underutilized to investigate the cellular, molecular, and genetic mechanisms underlying tinnitus. A recent study in guinea pigs identified a novel spontaneous behavior (unconditioned response), changes in movement during silent gaps, that identified a subgroup of animals presumably with tinnitus. Guinea pigs identified with tinnitus failed to “freeze” in response to silent gaps in sound. In the hope of developing a rapid and reliable assay for mice, we used a similar approach. C57BL/6J mice underwent three trials in which spontaneous movement was video recorded in the presence of white noise interrupted with six silent gaps. Movement metrics included velocity and body movement. Before the third trial, mice underwent either sham or noise exposure to induce hearing loss and tinnitus. Auditory brainstem responses before and after noise trauma confirmed normal hearing in sham-treated animals and hearing loss in the noise-exposed cohort. No differences in the various movement metrics were detected during the silent gaps either before or after sham/noise exposure. Variability in spontaneous movement both before and after sham/noise exposure was substantially greater in mice compared to guinea pigs. Thus, this assay is not sufficiently statistically powerful to identify changes in movement that might indicate tinnitus perception in mice. Previous observations also reported increased movement overall in guinea pigs identified as suffering tinnitus. In contrast, mice showed no statistically significant differences in movement between the three trials. Despite our results, other unconditioned (as well as conditioned) behaviors should be examined in mice to test their utility to detect changes that indicate the perception of tinnitus. Such assays are essential to accelerate the use of mouse models in tinnitus research.

Predictive factors of uterine movement during definitive radiotherapy for cervical cancer.

To determine the predictive factors affecting uterine movement during radiotherapy (RT), we quantified interfraction uterine movement using computed tomography (CT) and cone-beam CT (CBCT). A total of 38 patients who underwent definitive RT for cervical cancer were retrospectively analyzed. We compared pre-RT planning CT (n = 38) and intratreatment CBCT (n = 315), measuring cervical and corporal movement in each direction. Correlations between uterine movement and volume changes of the bladder and rectum on all CBCT scans were analyzed using Spearman rank correlation analysis. Relationships between the mean uterine movement and patient factors were analyzed using the Mann–Whitney test. The mean corpus movement was: superior margin (cranio–caudal direction), 7.6 ± 5.9 mm; anterior margin (anteroposterior direction), 8.3 ± 6.3 mm; left margin (lateral direction), 3.3 ± 2.9 mm; and right margin (lateral direction), 3.0 ± 2.3 mm. Generally, the mean values for cervical movement were smaller than those for the corpus. There was a significant, weak correlation between changes in bladder volume and the movement of the superior margin of the corpus (ρ = 0.364, P < 0.001). There was a significant difference in movement of the superior margin of the corpus between the subgroups with and without a history of previous pelvic surgery (P = 0.007). In conclusion, change in bladder volume and a history of previous surgery were significantly related to intrafractional corpus movement; however, our observations suggest that the accurate prediction of uterine movement remains challenging.

EP 110. Phase-locking as a neurophysiological marker of movement execution in young and elderly subjects

Motor actions are generated by complex interactions of various brain regions. The same brain regions can build various functional networks depending on the action. Identifying the neural signals that encode an action’s component (selection, preparation, execution) remains a difficult task. In the current study, EEG data were recorded continuously from 18 young (22–35 years) and 16 elderly (60–71 years) right-handed healthy subjects as they performed a simple motor task. The task required participants to execute a left or right index finger tapping triggered by a visual cue or by an uncued voluntary choice. We found that voluntary and visually triggered movements exhibit significant phase locking in the delta-theta frequency band (2–7 Hz) around movement onset both in young and old subjects. However, significant differences in movement and processing time between the two groups of subjects were observed as well. Moreover, there was a negative correlation between the movement time and the maximal value of the phase-locking index (PLI) in young subjects. This indicates that the aforementioned changes in behavioral performance result from a decrease of PLI in the respective motor regions. In summary, we suggest that this enhanced intra-regional synchrony, which seems to be impaired in the elderly, helps the simultaneously active pathways of distinct cortical networks that initiate voluntary and stimulus-triggered movements, converge to a common motor output and activate the appropriate muscles to perform the movement. This mechanism may thus be regarded as a prototype for organizing more complex motor activities.

Yoga Training in Junior Primary School-Aged Children Has an Impact on Physical Self-Perceptions and Problem-Related Behavior.

The present pilot study investigated the effects of yoga training, as compared to physical skill training, on motor and executive function, physical self-concept, and anxiety-related behavior in junior primary school-aged children. Twenty-four participants with a mean age of 8.4 (±1.4) years completed either yoga or physical skill training twice a week for 6 weeks outside of regular school class time. Both forms of training were delivered in an individualized and child-oriented manner. The type of training did not result in any significant differences in movement and executive function outcomes. In terms of physical self-concept, significant group differences were revealed only for perceived movement speed such that yoga training resulted in perceptions of being slower while physical skill training resulted in perceptions of moving faster. Analysis of anxiety related outcomes revealed significant group effects only for avoidance behavior and coping strategies. Avoidance behavior increased following yoga training, but decreased following physical skill training. In addition, following yoga training, children showed an increased use of divergent coping strategies when facing problematic situations while after physical skill training children demonstrated a decrease in use of divergent coping strategies. Changes in overall physical self-concept scores were not significantly correlated with changes in avoidance behavior following yoga training. In contrast, following physical skill training increased physical self-concept was significantly correlated with decreases in avoidance behavior. In sum, exposure to yoga or physical skill training appears to result in distinct effects for specific domains of physical self-concept and anxiety-related behavior. Further studies with larger samples and more rigorous methodologies are required to further investigate the effects reported here. With respect to future studies, we address potential research questions and specific features associated with the investigation of the effects of yoga in a sample of school-aged children.

Movement and habitat selection patterns of smallmouth bass Micropterus dolomieu in an Ozark river

Limited information exists on 24-hr movement and habitat selection patterns of stream dwelling smallmouth bass, Micropterus dolomieu. We monitored the 24-hr movement patterns of smallmouth bass in an Ozark river during three seasons: summer, autumn, and winter. During each season, fish were located every two hours throughout a 24-hr period; habitat data and water depth were collected at each fish location. Four random points representing available locations around each fish location were generated in ArcGIS. Habitat and depth data were collected at each of these points, and discrete choice models were fit to the data to predict habitat and depth selection by smallmouth bass. No significant differences in movement across seasons or time of day were evident, although the greatest observed displacement within a 2-hr tracking period occurred during the winter, with one bass moving over 630 m. Across all three seasons, water depth and habitat type were strong predictors of bass locations. Throughout our study, water depths used by smallmouth bass ranged from 0.6 to 3.7 m. Although depth of water used by fish did not differ by time of day, fish used the deeper waters of Big Spring during the winter and intermediate depths during the summer and autumn. Smallmouth bass utilized several habitat types; however, bass selected boulders more frequently in all seasons than any other available habitat type. Our work provides additional insight into smallmouth bass behavior that will help guide future management.

Is dexmedetomidine really superior to propofol?

1. Sriganesh K, Reddy M, Jena S, Mittal M, Umamaheswara Rao GS. A comparative study of dexmedetomidine and propofol as sole sedative agents for patients with aneurysmal subarachnoid hemorrhage undergoing diagnostic cerebral angiography. J Anesth. 2014. doi:10.1007/s00540-014-1952-1. To the Editor: We read the article by Sriganesh et al. published ahead of print in your journal [1]. Based on a study conducted in 60 patients, the authors concluded that “dexmedetomidine appears to be superior to propofol as a sole sedative agent for sedation during cerebral angiography in patients with subarachnoid hemorrhage.” We noticed that the sample size calculation by Sriganesh et al. is based on the onset time for sedation in pediatric patients undergoing magnetic resonance imaging. The validity of this extrapolation to cerebral angiography (CA) needs to be confirmed. We feel that the authors should have conducted a pilot study and then calculated the sample size. In an ongoing trial in our center, on a similar patient population with similar intervention drugs, we conducted a pilot study. We calculated the necessary sample size to be as large as 92 patients in each group in order to show significant differences in movement during CA. Sedation for diagnostic CA needs to be evaluated further in patients of different grades of subarachnoid hemorrhage, as the sensorium of the patients will significantly influence the choice of drug and its dosages.

Quantitative Gait Analysis Detects Significant Differences in Movement between Osteoarthritic and Nonosteoarthritic Guinea Pig Strains before and after Treatment with Flunixin Meglumine.

A computer-aided gait analysis system was used to contrast two guinea pig strains with differing propensity for osteoarthritis (OA), with/without administration of a nonsteroidal anti-inflammatory drug. Walking speed and static/dynamic gait parameters were determined at baseline. Flunixin meglumine was given and animals were evaluated 4, 24, and 72 hours after treatment. Body weight was compared using unpaired t-tests. Knee joints were histologically evaluated using species-specific criteria; indices were analyzed using one-way ANOVA, Kruskal-Wallis test, followed by Dunn's multiple comparisons. A generalized linear model followed by Tukey's posttests juxtaposed gait parameters; walking speed was a covariate for other outcome measures. Body weight was not different between strains; OA-prone animals demonstrated more progressive chondropathy. At baseline, OA-prone animals had slower walking speeds, narrower hind limb bases of support, shorter stride lengths, and slower limb swing speeds relative to OA-resistant animals. These differences were not detected 4 or 24 hours after treatment. By 72 hours, OA-prone animals had returned to baseline values. These findings indicate a distinct voluntary gait pattern in a rodent model of bilateral primary OA, modification of which may allow rapid screening of novel therapies. Flunixin meglumine temporarily permitted OA-prone animals to move in a manner that was analogous to OA-resistant animals.

Can off-river water and shade provision reduce cattle intrusion into drinking water catchment riparian zones?

Cattle defecation into rivers and overgrazing of riparian zones, are major concerns for drinking water catchment managers. Behaviour modification has been proposed instead of fencing for managing impacts, but reported success varies. Our study aimed to resolve whether provision of off-stream water and shade on real working farms could reduce the likelihood of cattle entering watercourses feeding Sydney, Australia's primary water supply, Lake Burragorang (34°S, 150°E). Cattle herds (1.4 and 11 Animal Unitsha−1) at two sites were fitted with Global Positioning System (GPS) collars (n=12). Cattle movements were tracked following installation of industry-recommended off-stream water and shade (twelve 2 week duration control+treatment experiments). Some statistically significant differences in movement (Mann–Whitney U Prob.<0.0001) were observed, as judged by comparisons of riparian, water trough and shade NEAR distances, and riparian zone visit number, duration and frequency. But effect magnitudes were small, inconsistent between different experiments, and insufficient to justify widespread water and shade provision. These findings contrast with the marked reductions in riparian impacts reported for rangeland pastured (>≈1km2) cattle, but were not inconsistent with smaller scale grazing studies. Statistically significant correlations (Spearman R) were, however, observed (Goulburn_1, Robertson_2 experiments respectively) between the movement of cattle within the same herd (0.94, 0.85), cattle in adjacent fields (0.7, 0.64), and heat stress related factors (temperature, light, humidity, wind) (0.1–0.5) indicating GPS tracking was sound and other factors more strongly influenced animal location. We hypothesize that our off-stream water and shade did not markedly influence cattle movement because our paddocks were relatively small (1.5 and 20ha) compared to rangeland pastures. The study's main limitation was that GPS error prevented differentiation of riparian zone interaction from full stream contact. We recommend in future using direct video to overcome this, and differential quantification of these impacts.

Differential Migration between Discrete Populations of Juvenile Red-tailed Hawks (Buteo jamaicensis)

Migratory species are of increased conservation concern because of their reliance on multiple, geographically disjunct habitats. An understanding of how long-term ecological processes and contemporary population genetic patterns are related is critical for effective management and conservation of such species. Combining traditional long-term census and mark-recapture data with temporally focused molecular genetic data can help inform these efforts. We used 24 years of banding data, 15 years of migration counts, and molecular genetic data from 17 microsatellite loci to describe the migration phenology, direction, and population connectivity of Red-tailed Hawks (Buteo jamaicensis) migrating through the Marin Peninsula, California. Count data indicated two distinct peak periods of movement across years: 15 August-30 September and 1 October-30 November. Band-encounter data from these two periods revealed a significant difference in movement: individuals in the early period of migration (15 August-30 September) displayed little net movement, whereas individuals from the second period (1 October-30 November) showed directional, southward movement. Finally, molecular genetic data suggest that the early-season period primarily involves a population from central California, whereas the second period includes both individuals from central California and individuals from desert regions of the Intermountain West. These analyses provide important information for interpreting long-term Red-tailed Hawk count and banding data and offer an example of how traditional population-monitoring methods can be combined with molecular genetic markers.

Detecting broken struts of a BjÖrk-Shiley heart valve using ultrasound: A feasibility study

The Björk-Shiley (BScc) mechanical heart valve has extensively been used in surgery from 1979 to 1986. There is, compared with equivalent valve types, increased occurrence of unexpected mechanical failure of the outlet strut of the valve, with a high incidence of mortality, when it occurs. Many approaches have been attempted to noninvasively determine BScc valve integrity. None of the approaches resulted in adequate assessment, mostly due to a lack of either sensitivity or specificity demonstrated in in vitro and/or in vivo studies. In our study we analyze leg movement of the BScc valves outlet strut during the cardiac cycle with ultrasound. For a broken strut, the movement of both legs will be significantly different, whereas the difference will be negligible for an intact strut. BScc valves were mounted in the mitral position in an in vitro pulse duplicator system. A focused single-element transducer was used to direct ultrasound on a leg of the outlet strut. Correlation-based time delay estimation was used to estimate differences in time of flight of the outlet strut echoes to determine outlet strut leg movement. The movement of an intact valve and a valve with a single-leg fracture with both ends grating against each other (SLF), the most difficult fracture to diagnose, has been studied. The results showed no significant difference in movement between both legs of the outlet strut of the intact BScc valve (amplitude of movement 9.2 μm ± 0.1 μm). Whereas for the defective valve, the amplitude of movement of the broken leg of the SLF valve was 12 μm ± 1.6 μm vs. 8.6 μm ± 0.1 μm for the intact leg. In conclusion, the proposed method has shown to be feasible in vitro and has potentials for in vivo detection of BScc valve outlet strut fracture. (E-mail: n.dejong@erasmusmc.nl)

Home range of greater and lesser rhea in Argentina : relevance to conservation

In this work we report results of radiotracking studies on the movements and home range sizes of two near-threatened species, the greater rhea (Rhea americana) and the lesser rhea (Pterocnemia pennata pennata) in relation to different land use regimes. We radiomonitored greater and lesser rheas for 3 years in their respective habitats: the Pampas and the Patagonia regions. We chose two study areas in each habitat with similar agricultural activities and different hunting control. We did not find significant differences in movements and home range size between study areas of each species. This suggests that disturbance caused by human presence in the areas did not affect rhea spacing behaviors. Moreover, lesser rheas showed larger home range and movements than greater rheas, showing that the home range size is not an immutable property of body mass, and that abundance and distribution of food appears to be the main factor that influences the movements and home range size of these birds.