Influence of natal habitat preference on habitat selection during extra-home range movements in a large ungulate

Natal habitat preference induction (NHPI) occurs when animals exhibit a preference for new habitat that is similar to that which they experienced in their natal environment, potentially leading to post-dispersal success. While the study of NHPI is typically focused on post-settlement home ranges, we investigated how this behavior may manifest during extra-home range movements (EHRMs), both to identify exploratory prospecting behavior and assess how natal habitat cues may influence path selection before settlement. We analyzed GPS collar relocation data collected during 79 EHRMs made by 34 juvenile and subadult white-tailed deer (Odocoileus virginianus) across an agricultural landscape with highly fragmented forests in Illinois, USA. We developed a workflow to measure multidimensional natal habitat dissimilarity for each EHRM relocation and fit step-selection functions to evaluate whether natal habitat similarity explained habitat selection along movement paths. Across seasons, selection for natal habitat similarity was generally weak during excursive movements, but strong during dispersals, indicating that NHPI is manifested in dispersal habitat selection in this study system and bolstering the hypothesis that excursive movements differ functionally from dispersal. Our approach for extending the NHPI hypothesis to behavior during EHRMs can be applied to a variety of taxa and can expand our understanding of how individual behavioral variation and early life experience may shape connectivity and resistance across landscapes.

Emotional impacts of excursions on parents of children with medical complexity

BACKGROUND

Parents of children with medical complexity (CMC) have extra child-raising responsibilities because of the time commitments necessary for care, and their social participation is often compromised. Experiencing leisure excursions with such children may be a solution to some of these problems but the first-hand experience of excursions in regard to their psychological impact on the caregivers of CMC remains to be appraised.

METHODS

Semi-structured interviews were conducted, via video conference, with eight informal and eight formal caregivers of CMC who attended an excursion to Tokyo Disney Land (TDL). We investigated the psychological changes that they had experienced through the excursion, performing inductive thematic analysis.

RESULTS

Three themes were identified among parents and five were identified among medical professionals. Themes reported by the parents were: Increased trust in the public and society (Theme 1); confidence for other challenges (Theme 2), and connection with other parents in the non-medical settings (Theme 3). Themes reported by medical professionals were: Expanding the initiative to other CMC (Theme 1); feeling bonded with other caregivers within the working group (Theme 2); information exchange across different working groups (Theme 3), positive responses from CMC (Theme 4); families' confidence to go out (Theme 5).

CONCLUSIONS

This study showed that the excursion to TDL led to positive psychological changes in both medical professionals and parents of CMC, enhancing trust, connection, and confidence. The promising results of this study suggest a need for further research about the impact of an excursion on caregivers of CMC.

Efficacy of insulin dosing algorithms for high-fat high-protein mixed meals to control postprandial glycemic excursions in people living with type 1 diabetes: A systematic review and meta-analysis

Optimizing postprandial blood glucose (PPG) levels after mixed meals that contain high fat and protein remains a challenge in the treatment of type 1 diabetes. This study evaluated the efficacy of different algorithms used for dosing insulin based on counting units of high fat and high protein (HFHP) meals with the current conventional method of counting carbohydrates alone to control PPG excursions. The MEDLINE, EMBASE, and Cochrane electronic databases were searched, with the analysis restricted to randomized control trials (RCTs). The primary outcome was the PPG (mean and standard deviation) at 240 min. The pooled final estimate was the mean difference (MD) of the PPGs at 240 min using random effect models to account for heterogeneity. In total, 15 studies were identified and included in the systemic review, of which 12 were RCTs, and three studies were non-randomized trials. The pooled MD of the PPG at 240 min was in favor of additional insulin doses in HFHP meals compared to the carbohydrate counting alone. The statistically significant results favored the combined bolus (30:70) that split over 2 h in insulin pump therapy with pooled MD of the PPG, 240 min of -24.65; 95% CI: -36.59, -8.41; and heterogeneity, 0%. Other statistically significant results favored the additional insulin added to insulin to carb ratio (ICR) of meal bolus (25-60% ICR) in multiple daily injections therapy with the pooled MD of PPG at 240 min, -21.71; 95% CI: -38.45, -4.73; and heterogeneity, 18%. Insulin treatment based on fat and protein content, in addition to carbohydrate counting, is more effective than the carbohydrate counting method alone; however, further research is warranted to determine the best equation for fat and protein counting, particularly in people with multiple daily injections.

Changes in tendon length and excursion following extensor tendon grafting at the distal radioulnar joint

IV.

Diaphragm thickness, thickness change, and excursion in subjects with and without nonspecific low back pain using B-mode and M-mode ultrasonography

Background: Previous studies have demonstrated that respiratory dysfunction has a potential association with low back pain (LBP). Despite the role of the diaphragm for respiration and spinal stability, knowledge of the function of both sides of the diaphragm in subjects with LBP is still limited.Objective: This study aimed to compare the structural integrity and function of the right and left hemidiaphragm by ultrasonography (USG) in subjects with and without nonspecific chronic low back pain (NS-CLBP).Methods: A total of 37 subjects with NS-CLBP and 34 healthy subjects participated in this case-control study. The thickness, thickness change, and excursion of the right and left hemidiaphragm were compared within and between the groups during quiet breathing (QB) and deep breathing (DB) through B-mode and M-mode ultrasound imaging.Results: The LBP group had a significantly smaller degree of right hemidiaphragm thickness change (P = .001) compared with the healthy control group, with a strong effect size. Nevertheless, there was no significant change for diaphragm thickness and excursion between the two groups. The result showed that, in the healthy group, the right hemidiaphragm had a significantly smaller thickness at expiration and larger thickness change compared with the left hemidiaphragm, with a moderate effect size. Based on the multivariate prediction analysis, the right hemidiaphragm thickness change might significantly predict LBP.Conclusion: We found that participants with LBP had a smaller degree of right hemidiaphragm thickness change. Also, the right hemidiaphragm thickness change might significantly predict LBP.

Partial range of motion training elicits favorable improvements in muscular adaptations when carried out at long muscle lengths

The study compared changes in strength and regional muscle hypertrophy between different ranges of motion (ROM) in the knee extension exercise. Forty-five untrained women were randomized to either a control group or to perform the exercise in one of the following 4 groups (0°=extended knee): Full ROM (FULL_ROM: 100°-30° of knee flexion); Initial Partial ROM (INITIAL_ROM: 100°-65°); Final Partial ROM (FINAL_ROM: 65°-30°); Varied ROM (VAR_ROM: daily alternation between the ROM of INITIAL_ROM and FINAL_ROM). Pre- and post-training assessments included one repetition maximum (1RM) testing in the ROM corresponding to the initial, final and full ROM, and measurement of cross-sectional areas of the rectus femoris and vastus lateralis muscles at 40%, 50%, 60% and 70% of femur length in regard to regional muscle hypertrophy. Results showed that the INITIAL_ROM group presented a greater relative increase than all groups at 70%, and at 50% and 60% the increases were greater than FINAL_ROM, FULL_ROM, and non-training control (CON) groups. Moreover, FINAL_ROM group presented similar changes compared to the CON group at 60% and 70%. In regard to 1RM, FINAL_ROM and INITIAL_ROM groups presented greater relative increases at the ROM trained, and no group showed greater increases than VAR_ROM or INITIAL_ROM, regardless the ROM tested. In conclusion, partial ROM training in the initial phase of the knee extension exercise promoted greater relative hypertrophy in certain muscle regions than training in other ROM configurations, and no group promoted a greater 1RM increase than VAR_ROM group, which showed similar 1RM increases in the different ROMs tested.

Lesion Sequence and Catheter Spatial Stability Affect Lesion Quality Markers in Atrial Fibrillation Ablation

OBJECTIVES

This study sought to analyze high-frequency catheter excursion in relation to lesion quality markers in 20 consecutive patients undergoing first-time radiofrequency (RF) ablation for paroxysmal atrial fibrillation (AF).

BACKGROUND

Ablation therapy for AF requires the delivery of durable lesions. The extent to which lesion sequence, catheter spatial stability, and anatomic location influence lesion formation during RF ablation of AF is not well understood.

METHODS

Three-dimensional spatial excursion of the ablation catheter sampled at 60 Hz during pre-specified pairs of RF lesions was extracted from the CARTO3 System (Biosense Webster Inc., Irvine, California) and analyzed by using custom-developed MATLAB software (MathWorks, Natick, Massachusetts) to define precise catheter spatial stability during RF ablation. Ablation parameters including bipolar electrogram amplitude reduction, impedance decline and transmurality-associated unipolar electrogram (TUE) as evidence of lesion transmurality during lesion placement were recorded and analyzed.

RESULTS

We collected 437,760 position data points during lesion placement. Ablation catheter spatial stability and lesion formation parameters varied considerably by anatomic location. Lesions placed immediately had similar bipolar electrogram amplitude reduction, smaller impedance decline, but higher likelihood of achieving TUE compared to delayed lesions. Greater catheter spatial stability correlated with lesser impedance decline.

CONCLUSIONS

Lesion sequence, ablation catheter spatial stability, and anatomic location are important modifiers of RF lesion formation. Lesions placed immediately are more likely to exhibit TUE. Greater ablation catheter stability is associated with lesser impedance decline but greater likelihood of TUE.

Short-term effect of the demonstration of human dissection and excursion on students´ ideas about the human organ systems: a Slovak experience

BACKGROUND

Excursions in natural sciences education are justified in the current school system and within the scope of subject focus. The research aimed to observe the immediate impact of demonstration of the human dissection and excursion on the formation of ideas of students about the human body systems.

METHODS

The experiment involved the first Slovak demonstration of a real human autopsy for students of the Biology Teaching Department (PdF TU in Trnava). Concepts of the structure of the human body were analyzed before and after experimental impact by a projective technique. The evaluation included the representation, description, and abundance of organs in the view of various systems. The subject of the research were also the questions focused on the use of illustrative procedures and tools in the educational process.

RESULTS

Significant statistical differences were found in the group affected by human autopsy in understanding of the digestive, urinary, and locomotor systems. Conversely, the skin, endocrine glands, and lymphatic system were the least represented by the experimental groups.

CONCLUSION

Considering the presented results, using different organizational forms and aids (real and virtual) is essential for bringing a positive educational effect on the studied problem (Tab. 1, Fig. 5, Ref. 20).

Musculotendon excursion potential, tendon slack and muscle fibre length: the interaction of the canine gastrocnemius muscle and tendon

Although the form-function relation of muscles and tendons has been studied extensively, little in vivo data exist on the musculotendon properties of the gastrocnemius complex in dogs. Using a combination of ultrasound and 3D motion tracking, musculotendon parameters were obtained in vivo from the lateral gastrocnemius muscle and the gastrocnemius tendon in nine healthy Labrador Retrievers. These parameters include musculotendon length and excursion potential, tendon slack length, muscle belly length, muscle fibre length, pennation angle and architectural index. This study also examined the variation of muscle and tendon length contributions to musculotendon length, as well as the relation between musculotendon excursion potential and muscle fibre length or tendon length. To facilitate comparison between dog breeds, the femur length as a potential scaling parameter was examined. In the Labrador gastrocnemius musculotendon complex, the tendon contributes 41% (± 9%) of musculotendon length. In longer musculotendon complexes, the contribution of the muscle belly increases while the tendon contribution decreases. Longer muscle belly and musculotendon complexes were, however, associated with shorter muscle fibres. No significant relations were found between musculotendon excursion potential and muscle fibre length or tendon slack length, and femur length did not prove to be a reliable scale factor for the length-related musculotendon parameters examined in this study. Longer musculotendon complexes exhibit relatively longer muscle bellies, which are in turn associated with shorter muscle fibre lengths. This trade-off between gastrocnemius muscle belly length and muscle fibre length might have the advantage that muscle volume stays constant regardless of the length of the limbs.

In vivo effects of limb movement on nerve stretch, strain, and tension: A systematic review

BACKROUND

The mechanical behavior of the peripheral nervous system under elongation and tension has not been adequately established in vivo.

OBJECTIVE

The purpose of this review is to investigate the mechanical behavior of the peripheral nervous system in vivo.

METHODS

In vivo studies which evaluated the effects of limb movement and neurodynamic tests on peripheral nerve biomechanics were systematically searched in PubMed (Medline), the Cochrane Database, CINAHL, PEDro, Embase and Web of Science. Studies fulfilling the search criteria were assessed for methodological quality with a modified version of the Down & Blacks scale by two reviewers.

RESULTS

This review includes the results of 22 studies, of which 15 examined limb movement influencing the median nerve, four the sciatic nerve, two the tibial nerve; and one each the ulnar and peroneal nerves respectively. Substantial nerve longitudinal and transverse excursion and changes in diameter were reported. Despite this, increased nerve strain was not a major finding.

CONCLUSION

The heterogeneity of included studies, including wide variety of nerves tested, measurement location and joint position prevented comparisons between studies and also amalgamation of data. Limb movement induces complex biomechanical effects of which nerve elongation plays only a minor role.

Methods to infer the compliance status with interval-averaged and with instantaneous occupational exposure limits from the results of longer-duration, integrated air sampling

The duration of integrated air sampling for a substance may exceed the time frame of a substance's occupational exposure limit. Nonetheless, the compliance status of a limit may be inferred, under some circumstances, by the application of certain methods to the results of longer-duration samples. The purpose of this article is to define the inference methods and to illustrate their utility with actual and hypothetical examples. A review of articles and reports in U.S.-based Industrial Hygiene publications and databases revealed that the methods often were not but arguably should have been applied. Also revealed were inappropriate conclusions about the compliance status with exposure limits. Among the benefits of employing the inference methods is gaining information on exposures that might otherwise be overlooked. This article discusses the potential limitations of using the methods, and highlights some of the challenges of using integrated air sampling for assessing compliance with shorter-term exposure limits.

Impaired Quadriceps Rate of Torque Development and Knee Mechanics After Anterior Cruciate Ligament Reconstruction With Patellar Tendon Autograft

BACKGROUND

Rate of torque development (RTD) measures the ability of a muscle to produce torque quickly. Decreased quadriceps RTD may impair performance of sporting tasks after surgery. Currently, little is known about variations in quadriceps RTD between anterior cruciate ligament (ACL)-reconstructed and noninjured limbs.

PURPOSE

To determine the differences in RTD of the quadriceps, the rate and timing of knee extensor moment (KEM) development, and knee flexion excursion during running after ACL reconstruction with patellar tendon autograft.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

This study involved 21 patients (11 female) 6 months after ACL reconstruction with patellar tendon autograft (median [IQR]: age, 18 [16-20] years; mass, 68.18 [61.34-75] kg; height, 1.74 [1.66-1.78] m). Patients performed four 5-second maximal voluntary isometric strength trials of both limbs on an isokinetic dynamometer. RTD was calculated as the mean slope of the torque-time curve between 20% and 80% of total time to peak torque. Then, patients underwent 3-dimensional motion analysis while running on an instrumented treadmill at a self-selected running speed (mean ± SD, 2.68 ± 0.28 m/s). The rate of knee extensor moment (RKEM) was calculated as the mean slope of the moment curve between 10% and 30% of stance phase. Between-limb comparisons were determined with a paired t test for peak KEM, RKEM, knee flexion excursion during 10% to 30% of stance, and time to generate KEM.

RESULTS

In the reconstructed limb, deficits in the peak rate of quadriceps torque development compared with the noninjured limb existed both isometrically (RTD, 257.56 vs 569.11 Nm/s; P < .001) and dynamically (RKEM, 16.47 vs 22.38 Nm/kg·m·s; P < .001). The reconstructed limb also generated a KEM later in the stance phase compared with the noninjured limb (11.37% vs 9.61% stance; P < .001) and underwent less knee flexion excursion (15.5° vs 19.8°; P < .001).

CONCLUSION

After ACL reconstruction with patellar tendon autograft, patients have lower RTD and RKEM in the reconstructed limb. Deviations in RTD and the timing of the KEM can change the way the knee is loaded and can potentially increase injury risk and future development of posttraumatic osteoarthritis. Rehabilitation should consider exercises designed to improve RTD and prepare the limb for the demands of sport performance.

Effects of knee flexion angle and loading conditions on the end-to-end distance of the posterior cruciate ligament: a comparison of the roles of the anterolateral and posteromedial bundles

BACKGROUND

It is commonly accepted that the anterolateral (AL) bundle of the posterior cruciate ligament (PCL) is tight in flexion and that the posteromedial (PM) bundle is tight in extension. However, a recent in vivo study showed that both bundles were tight in extension.

PURPOSE

To investigate the effects of knee flexion angle, rotational torque, and anterior/posterior translational force on the end-to-end distance between the femoral and tibial insertion sites of each bundle of the PCL.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Cadaveric knees (10 specimens) were mounted on a robotic system, and the relative positional data between the femur and tibia were acquired during passive flexion/extension, with an applied 5-N·m rotational torque and an applied 89-N translational force. The bony surface and PCL insertion data were acquired with a 3-dimensional scanner after gross dissection and were superimposed onto the positional data. The end-to-end distance between the 2 PCL insertion sites of the femur and tibia was measured.

RESULTS

The end-to-end distance increased from full extension to 90° for both the AL (9.2 ± 1.8 mm; from 30.0 to 39.2 mm) and PM bundles (5.8 ± 2.2 mm; from 32.0 to 37.7 mm). With an internal rotational torque, the end-to-end distance of the PM bundle increased significantly (P < .05) at 0°, 30°, and 60° of knee flexion. Under a posterior translational force at 90° of knee flexion, the length of both bundles increased to their longest measurements (AM bundle: 40.6 ± 4.2 mm; PM bundle: 38.4 ± 3.8 mm).

CONCLUSION

The end-to-end distance of the AL and PM bundles of the PCL increased in flexion, and this pattern was maintained during tests with posterior translational force. The PM bundle was more affected by the rotational torque than was the AL bundle.

CLINICAL RELEVANCE

Both bundles of the PCL may serve a greater functional role in flexion than in extension. The PM bundle might be more important for the control of rotation than the AL bundle. Posterior translation at 90° of knee flexion could be the most stressful condition for both bundles of the PCL, which may have implications for an injury mechanism.

Altered tibial nerve biomechanics in patients with diabetes mellitus

INTRODUCTION

Hyperglycemia associated with diabetes mellitus (DM) has adverse impacts on peripheral nerve connective tissue structure, and there is preliminary evidence that nerve biomechanics may be altered.

METHODS

Ultrasound imaging was utilized to quantify the magnitude and timing of tibial nerve excursion during ankle dorsiflexion in patients with DM and matched healthy controls.

RESULTS

Tibial nerve longitudinal excursion at the ankle and knee was reduced, and timing was delayed at the ankle in the DM group. Severity of neuropathy was correlated with larger reductions in longitudinal excursion. Nerve cross-sectional area was increased at the ankle in the DM group.

CONCLUSIONS

Larger tibial nerve size within the tarsal tunnel in patients with DM may restrict longitudinal excursion, which was most evident with more severe neuropathy. It is hypothesized that these alterations may be related to painful symptoms during functional activities that utilize similar physiological motions through various biomechanical and physiological mechanisms.

Ulnar nerve strain at the elbow in patients with cubital tunnel syndrome: effect of simple decompression

Simple decompression of the ulnar nerve at the elbow has not been shown to reduce nerve strain in cadavers. In this study, ulnar nerve strain at the elbow was measured intraoperatively in 11 patients with cubital tunnel syndrome, before and after simple decompression. Statistical analysis was performed using a paired Student's t-test. Mean ulnar nerve strain before and after simple decompression was 30.5% (range 9% to 69%) and 5.5% (range -2% to 11%), respectively; this difference was statistically significant (p < 0.01) with a statistical power of 96%. Simple decompression reduced ulnar nerve strain in all patients by an average of 24.5%. Our results suggest that the pathophysiology of cubital tunnel syndrome may be multifactorial, being neither a simple compression neuropathy nor a simple traction neuropathy, and simple decompression may be a favourable surgical procedure for cubital tunnel syndrome in terms of decompression and reduction of strain in the ulnar nerve.

Excursion of the flexor digitorum profundus tendon: a kinematic study of the human and canine digits

The most common problem following primary flexor tendon repair is the failure of the tendon apparatus to glide, secondary to the formation of adhesions. Early motion following tendon repair has been shown to be effective in reducing adhesions between the tendon and the surrounding sheath. Therefore, it is important to determine the amount of flexor tendon excursion along the digit during joint motion. In this study, the excursion between the flexor digitorum profundus (FDP) tendon and the sheath was examined in both human and canine digits. Based on roentgenographic measurements and joint kinematic analysis, the motion of the bones, the FDP tendon, and the sheath were measured with respect to joint rotations. It was found that the canine flexor tendon apparatus behaved similarly to that of the human for the motions studied. The amount of tendon excursion was very small in regions distal to the joint in motion (approximately 0.1 mm/10 degrees of joint rotation). There was little displacement of the sheath (0.2-0.3 mm), except at the metacarpal joint region during metacarpophalangeal (MCP) joint motion and at the proximal interphalangeal (PIP) joint region during PIP joint motion. Tendon excursion relative to the tendon sheath was the largest in zone II during PIP joint rotation (1.7 mm/10 degrees of joint rotation). These results suggest that PIP joint motion may be most effective in reducing adhesions following tendon repair in zone II.