Universal Ontogenetic Growth without Fitting Parameters: Implications for Life History Invariants & Population Growth

Since the work of Von Bertalanffy (1957), several models have been proposed that relate the ontogenetic scaling of energy assimilation and metabolism to growth, being able to describe ontogenetic growth trajectories for living organisms and collapse them onto a single universal curve (West et al. 2001; Barnavar et al. 2002). Nevertheless, all these ontogenetic growth models critically depends on fitting parameters and on the allometric scaling of the metabolic rate. Using a new metabolic rate relation (Escala 2019) applied to a Bertalanffy-type ontogenetic growth equation, we find that ontogenetic growth can also be described by an universal growth curve for all studied species, but without the aid of any fitting parameters. We find that the inverse of the heart frequency fH, rescaled by the ratio of the specific energies for biomass creation and metabolism, defines the characteristic timescale for ontogenetic growth. Moreover, our model also predicts a generation time and lifespan that explains the origin of several 'Life History Invariants' (Charnov 1993) and predicts that the Mathusian Parameter should be inversely proportional to both the generation time and lifespan, in agreement with the data in the literature (Duncan et al. 1997; Dillingham et. al 2016; Hatton et al 2019). In our formalism, several critical timescales and rates (lifespan, generation time & intrinsic population growth rate) are all proportional to the heart frequency fH, thus their allometric scaling relations comes directly from the allometry of the heart frequency, which is typically fH ∝ M-0.25 under basal conditions.

Bradycardia in Accidental Severe Hypothermia in a Newborn: Treat or Don’t Touch? A case report

BackgroundHypothermia significantly affects mortality and morbidity of newborns. Literature about severe accidental hypothermia in neonates is limited. We present a case of a neonate suffering from severe accidental hypothermia. An understanding of the physiology of neonatal thermoregulation and hypothermia is important to decide on treatment.Case presentationWe report a case of severe accidental hypothermia (rectal temperature 25.7°C) in a hypothropic newborn due to prolonged exposure to low ambient temperature. The newborn presented bradycardic, bradypneic, lethargic, pale and cold. Bradycardia, bradypnea and consciousness were interpreted in the context of the measured body temperature. Therefore, no reanimation or intubation was initiated. The newborn was closely monitored and successfully treated only with active and passive rewarming. ConclusionClinical parameters such as heart frequency, blood pressure, respiration and consciousness must be interpreted in light of the measured body temperature. Medical treatment should be adapted to the clinical presentation. External rewarming can be a safe and effective measure in neonatal patients.

Analysis of aerobic testing in basketball referees and heart rate recovery time

The study analyzed the physical conditioning and the time of recovery of the maximum heart rate of 12 international referees being used the test of 20 meters with beep to evaluate the cardiorespiratory conditioning, with the frequency to control the recovery time of the maximum cardiac post test. The majority of the referees obtained a recovery of heart rate greater than 50% in 3 minutes, were those that reached the levels of good to excellent in the table of maximum Vo2. Even with some factors influencing their physical performance most of the referees were able to complete the aerobic test and obtained a good recovery of the heart rate, the others that failed to reach the test goal had the HR recovery in 3 minutes much lower than expected, thus highlighting the association of the maximum VO2 level between good and excellent with the recovery of the heart frequency.

Evidence-Based BIODANZA Programmes for Children (TANZPRO-Biodanza) in Schools and Kindergartens

Biodanza for children was developed in Chile by Cecilia Luzzi, from the model of the BIODANZA method, created by Rolando Toro. Stück and Villegas developed evidence-based and structured Biodanza programmes in conjunction with the Ministry of Health in Germany for children in schools and kindergartens. These programmes—TANZPRO-Biodanza—were introduced in twenty-two locations with around 500 children. Each ten-session programme included dance, movement, encounter, and non-verbal communication with music, aimed at two age groups of 4–6 years and 7–12 years. In this chapter, scientific results are shared about the effects of TANZPRO-Biodanza on cortisol, testosterone, Immunoglobulin A (IgA), change in heart frequency, hypersensitivity of the skin, implications for psychology, and autoregulation in children. The results indicate the potential of the programme to reduce stress and enhance social skills in children, providing a first insight into the effects of dance on the responses and modulation of neurohormones in children.

Efeitos da Ingestão Alcoólica na Frequência Cardíaca, Potência e Tempo no Esforço Máximo

O consumo de bebidas alcoólicas entre desportistas é frequente e sabe-se que o álcool é usado como fonte de energia, porém em atividades físicas intensas, que exigem uma grande disponibilidade calórica, o uso pode ser prejudicial para o rendimento. Este estudo teve como objetivo verificar os efeitos da ingestão alcoólica na frequência cardíaca, potência e tempo no esforço máximo de indivíduos jovens não sedentários. Uma amostra de 10 voluntários foi selecionada e foram submetidos ao teste ergométrico inicialmente sem ingestão de álcool. Após o primeiro teste os sujeitos foram instruídos a ficarem sete dias sem ingerir álcool, assim, no dia do segundo teste ergométrico, eles ingeriram 0,5 ml de etanol por quilograma de massa magra, 30 minutos antes do teste. Os resultados demonstraram uma diferença estatística p = 0,0058 no tempo de teste de esforço máximo e p = 0,015 na potência máxima atingida, contudo não houve diferenças estatisticamente significativas (p = 0,1) ao avaliar a frequência cardíaca nos dois testes. Logo, o estudo demonstrou que a ingestão alcoólica interferiu negativamente no desempenho físico. Effects of Alcoholic Beverages on Heart Frequency, Potency and Maximum Effort Time ABSTRACT. The intake of alcoholic beverages among sportsmen is frequent. Although alcohol is an important energy source, its use may bring liabilities in performance in intense physical activities which require great caloric availability. Current study analyzes the effects of alcohol intake on heart frequency, potency and maximum effort time in exercising young people. Ten volunteers were selected and they underwent the ergometric test without any alcohol intake. After the first test, the volunteers were asked to remain seven days without ingesting alcohol beverages. On the second ergometric test they took 0.5 mL ethanol per kg of mass, 30 min prior to test. Results revealed a statistical difference, p = 0.0058, in maximum effort test and p = 0.015 in maximum potency, with no significantly statistical difference (p = 0.1) when heart frequency was evaluated for the two tests. Analysis demonstrated that alcohol intake interfered negatively on physical performance.