Mechanical constraints during vertical climbing reveals limited deviation from theoretical minimums.

Center of mass (COM) mechanics, often used as an energetic proxy during locomotion, has primarily focused on level movement and hardly explores climbing scenarios. This study examines three-dimensional COM movements across five phylogenetically-distinct species (0.008 kg - 84 kg) to test theoretical expectations of climbing costs, explore how interspecific variation (different limb numbers, adhesion mechanisms, body masses, limb postures) affects COM mechanics, and determine the impact of out-of-plane COM movements on climbing costs. A parallel experiment with rosy-faced lovebirds explores how inclination angle affects COM mechanical energy and how these empirical data align with theoretical expectations. Results indicate that irrespective of anatomical differences, total mechanical costs of climbing are primarily driven by potential energy, outweighing contributions from total kinetic energy. Despite species exhibiting significant out-of-plane kinematics, these movements have minimal impact on overall locomotor costs. Inclination angle changes have minimal effects, as potential energy accumulation dominates quickly as steepness increases, suggesting climbing occurs even on acutely angled substrates from a center of mass perspective. The study challenges prior assumptions about factors influencing climbing costs, such as body mass, speed, or posture, indicating a lack of evident anatomical or behavioral adaptations for climbing efficiency across species. The research sheds light on the universal challenges posed by the mechanical demands of scaling vertical substrates, offering valuable insights for functional morphologists studying climbing behaviors in extant and fossilized species.

Genotype-phenotype assessment in autosomal recessive arrhythmogenic right ventricular cardiomyopathy (Naxos disease) caused by a deletion in plakoglobin.

OBJECTIVES: The purpose of this study was to examine the genotype-phenotype relation with respect to penetrance, age and severity of expression, disease progression and prognosis in a recessively inherited arrhythmogenic right ventricular cardiomyopathy (ARVC). BACKGROUND: Naxos disease is a recessively inherited ARVC caused by a mutation in the gene encoding plakoglobin (cell adhesion protein) in which the cardiac phenotype is associated with palmoplantar keratoderma and woolly hair. METHODS: Twelve families with Naxos disease underwent cardiac and molecular genetic investigation. Serial cardiac assessment with annual resting 12-lead and 24-h ambulatory electrocardiogram (ECG) and two-dimensional echocardiography was performed during 1 to 16 years, median 7 +/- 6 years in all 78 surviving members. RESULTS: Twenty-eight surviving members were homozygous and 40 were heterozygous for the mutation. All adults who were homozygous (n = 26) fulfilled the diagnostic criteria for ARVC, the youngest by the age of 13 years. In eight who were heterozygous, minor ECG or echocardiographic abnormalities were observed. Of the 26 subjects who were affected homozygotes, 92% showed ECG abnormalities, 92% ventricular arrhythmias, 100% right ventricular structural alterations and 27% left ventricular involvement. During follow-up (10 +/- 6 years), 16 (62%) developed structural progression, 12 (46%) arrhythmic events and 7 (27%) heart failure. The annual disease-related and sudden death mortality was 3% and 2.3%, respectively. CONCLUSIONS: Autosomal recessive ARVC caused by a mutation in plakoglobin was 100% penetrant by adolescence. Affected subjects who were homozygous experienced progressive disease with adverse prognosis. A minority of subjects who were heterozygous showed minor ECG/echocardiographic changes, but clinically significant disease did not develop.

Coronary artery ectasia, aneurysm of the basilar artery and varicose veins: common presentation or generalized defect of the vessel wall? A case report.

A young man who suffered from an acute myocardial infarction is presented. He presented coronary artery ectasia along with coronary artery disease. Further evaluation revealed the presence of both a saccular aneurysm of the basilar artery as well as varicose veins of the lower limbs. A common pathogenic mechanism is discussed since all these findings are characterized by similar histologic substrate with the most profound defect being destruction of the myoelastic elements of the media.

Quality assurance in a neurophysiology laboratory.

In order to assess patient satisfaction with the Neurophysiology Services within our department, we undertook a pilot study using a simple questionnaire designed by staff members (MAHB and ABB). Patients were approached after their tests (nerve conduction tests (NCTs), electromyography (EMG) and electroencephalography (EEG)) were completed, by staff not involved in the testing. 31 patients were approached and all completed the questionnaire. None reported being inconvenienced by an undue waiting time. All felt that adequate information about the test had been provided, that their personal comfort and feelings were considered, and that they were adequately informed of the time and place at which the test results would be available. 61% considered their overall treatment excellent, the remainder good. To date, increased departmental awareness has resulted in staff participation in program evaluation, design of an outcomes hierarchy for the department, redesigning the patients' waiting area and, overall, a more active participation in quality assurance. We see this pilot study as a baseline for future more in-depth client and staff evaluations thereby promoting quality performance improvement.