RESUMO
The mechanical forces experienced during movement and the time constants of muscle activation are important determinants of the durations of behaviours, which may both be affected by size-dependent scaling. The mechanics of slow movements in small animals are dominated by elastic forces and are thus quasistatic (i.e. always near mechanical equilibrium). Muscular forces producing movement and elastic forces resisting movement should scale identically (proportional to mass2/3), leaving the scaling of the time constant of muscle activation to play a critical role in determining behavioural duration. We tested this hypothesis by measuring the duration of feeding behaviours in the marine mollusc Aplysia californica whose body sizes spanned three orders of magnitude. The duration of muscle activation was determined by measuring the time it took for muscles to produce maximum force as A. californica attempted to feed on tethered inedible seaweed, which provided an in vivo approximation of an isometric contraction. The timing of muscle activation scaled with mass0.3. The total duration of biting behaviours scaled identically, with mass0.3, indicating a lack of additional mechanical effects. The duration of swallowing behaviour, however, exhibited a shallower scaling of mass0.17. We suggest that this was due to the allometric growth of the anterior retractor muscle during development, as measured by micro-computed tomography (micro-CT) scans of buccal masses. Consequently, larger A. californica did not need to activate their muscles as fully to produce equivalent forces. These results indicate that muscle activation may be an important determinant of the scaling of behavioural durations in quasistatic systems.
Assuntos
Aplysia , Músculos , Animais , Aplysia/fisiologia , Microtomografia por Raio-X , Músculos/fisiologia , Comportamento Alimentar/fisiologia , Deglutição/fisiologiaRESUMO
Over the past two decades, China has become a distinctive and increasingly important donor of development assistance for health (DAH). However, little is known about what factors influence China's priority-setting for DAH. In this study, we provide an updated analysis of trends in the priorities of Chinese DAH and compare them to comparable trends among OECD Development Assistance Committee (DAC) donors using data from the AidData's Global Chinese Development Finance Dataset (2000-2017, version 2.0) and the Creditor Reporting System (CRS) database (2000-2017). We also analyse Chinese medical aid exports before and after the start of the COVID-19 pandemic using a Chinese Aid Exports Database. We further explore the potential factors influencing China's shifting priority-setting processes by reviewing Chinese official documents following Walt and Gilson's policy analysis framework (context-actors-process-content) and by testing our conjectures empirically. We find that China has become an important DAH donor to most regions if measured using project value, including but not limited to Africa. China has prioritized aid to African and Asian countries as well as to CRS subsectors that are not prioritized by DAC donors, such as medical services and basic health infrastructure. Chinese quarterly medical aid exports almost quintupled after the start of the COVID-19 pandemic. Noticeably, China has allocated more attention to Asia, eye diseases and infectious disease outbreaks over time. In contrast, the priority given to malaria has declined over the same period. Regarding factors affecting priority shifts, the outbreaks of SARS and Ebola, the launch of the Belt and Road Initiative and the COVID-19 pandemic appear to be important milestones in the timeline of Chinese DAH. Unlike stereotypes of China as a 'lone wolf' donor, our analysis suggests multilateral processes are influential in informing and setting Chinese DAH priorities.
Assuntos
COVID-19 , Pandemias , Humanos , Ásia , China , África , COVID-19/epidemiologiaRESUMO
In the pursuit of universal health coverage, countries are invariably confronted with questions about which services to pay with public funds, to whom, and at what cost. Such priority-setting processes have major ramifications for the costs and benefits of care delivered. These processes are not just technical, but also highly political and organizational in nature and expressions of social values. This special issue focuses on building institutions for priority setting in health. These institutions serve a public purpose and are primarily concerned with conducting or using health technology assessment (HTA) to inform resource allocation decisions. We first define the concept of institutions for priority setting in health and the methodological considerations of assessing and evaluating these institutions. Next, we present key common themes and summarize key messages across the articles, including lessons learned and future challenges in building these institutions.
Assuntos
Prioridades em Saúde , Prioridades em Saúde/tendências , Humanos , Avaliação da Tecnologia Biomédica/métodosRESUMO
Countries pursuing universal health coverage must set priorities to determine which benefits to add to a national health program, but the roles that organizations play are less understood. This article investigates the case of the formation of an organization with a mandate for choice of technology for public health interventions and priorities, the Health Technology Assessment India. First, we narrate a chronology of agenda setting and adoption of national policy for organizational formation drawing on historical documentation, publicly available literature, and lived experiences from coauthors. Next, we conduct a thematic analysis that examines windows of opportunity, enabling factors, barriers and conditions, roles of stakeholders, messaging and framing, and specific administrative and bureaucratic tools that facilitated organization formation. This case study shows that organizational formation relied on the identification of multiple champions with sufficient seniority and political authority across a wide group of organizations, forming a coalition of broad base support, who were keen to advance health technology assessment policy development and organizational placement or formation. The champions in turn could use their roles for policy decisions that used private and public events to raise priority and commitment to the decisions, carefully considered organizational placement and formation, and developed the network of organizations for the generation of technical evidence and capacity building for health technology assessment, strengthened by international networks and organizations with financing, expertise, and policymaker relationships.
Assuntos
Prioridades em Saúde , Avaliação da Tecnologia Biomédica , Índia , Avaliação da Tecnologia Biomédica/métodos , Humanos , Prioridades em Saúde/tendências , Política de Saúde , Formulação de Políticas , História do Século XX , História do Século XXIRESUMO
All health systems must set priorities. Evidence-informed priority-setting (EIPS) is a specific form of systematic priority-setting which involves explicit consideration of evidence to determine the healthcare interventions to be provided. The international Decision Support Initiative (iDSI) was established in 2013 as a collaborative platform to catalyze faster progress on EIPS, particularly in low- and middle-income countries. This article summarizes the successes, challenges, and lessons learned from ten years of iDSI partnering with countries to develop EIPS institutions and processes. This is a thematic documentary analysis, structured by iDSI's theory of change, extracting successes, challenges, and lessons from three external evaluations and 19 internal reports to funders. We identified three phases of iDSI's work-inception (2013-15), scale-up (2016-2019), and focus on Africa (2019-2023). iDSI has established a global platform for coordinating EIPS, advanced the field, and supported regional networks in Asia and Africa. It has facilitated progress in securing high-level commitment to EIPS, strengthened EIPS institutions, and developed capacity for health technology assessments. This has resulted in improved decisions on service provision, procurement, and clinical care. Major lessons learned include the importance of sustained political will to develop EIPS; a clear EIPS mandate; inclusive governance structures appropriate to health financing context; politically sensitive and country-led support to EIPS, taking advantage of policy windows for EIPS reforms; regional networks for peer support and long-term sustainability; utilization of context appropriate methods such as adaptive HTA; and crucially, donor-funded global health initiatives supporting and integrating with national EIPS systems, not undermining them.