scholarly journals Repetitive Head Impact Exposure

Concussion ◽  
2019 ◽  
pp. 169-172
Author(s):  
Brian Hainline ◽  
Lindsey J. Gurin ◽  
Daniel M. Torres
Keyword(s):  
Clinical Manifestation ◽  
Structural Changes ◽  
Head Impact ◽  
Causal Connection ◽  
Neurologic Diseases ◽  
The Public ◽  
The Brain ◽  
Safety First ◽  
Over Time

Repetitive head impact exposure refers to a head impact that does not lead to the clinical manifestation of concussion. There is emerging information that repetitive head impact exposure may lead to structural changes in the brain, but it is not clear if these changes normalize, remain static, or worsen over time. Currently there is no known causal connection between repetitive head impact exposure and long-term neurologic diseases, although such a connection is often assumed by the public. A safety-first approach should always be taken in sport, and this includes steps to mitigate head impact exposure.

Institutions, Investment, and Growth in Developing Countries

2020 ◽  
pp. 220-237
Author(s):  
Giovanni Andrea Cornia
Keyword(s):  
Developing Countries ◽  
Economic Development ◽  
Political Stability ◽  
Informal Institutions ◽  
Economic Institutions ◽  
Formal Institutions ◽  
The Public ◽  
Over Time ◽  
Macroeconomic Stability

Many analyses of long-term development neglect the importance of formal and informal political and economic institutions in developing countries. This chapter discusses the nature of such institutions, their endogeneity and persistence over time as well as their impact on growth, inequality, and political stability. The chapter places particular attention on the institutions that build the market and facilitate economic exchange, and on the public organizations mandated with their enforcement. It then discusses their impact on growth and macroeconomic stability as well as the role played by informal institutions in developing countries where formal institutions are often perceived as a costly obstacle to economic development.

Autoimmune Neurologic Diseases in Children

2018 ◽  
Vol 38 (03) ◽  
pp. 355-370
Author(s):  
Michael Sweeney
Keyword(s):  
Nervous System ◽  
Autoimmune Diseases ◽  
Peripheral Nerves ◽  
Autoimmune Process ◽  
Rare Disorders ◽  
Nerve Roots ◽  
Neurologic Diseases ◽  
Neurologic Outcomes ◽  
The Brain

AbstractAutoimmune diseases of the nervous system in children are composed of a heterogeneous group of rare disorders that can affect the central or peripheral nervous system at any level. Presentations may occur in children of any age and are typically acute or subacute in onset. Consideration of an autoimmune process as the etiology of neurologic diseases in children is important, as it may lead to early initiation of immunotherapy and an improvement in long-term neurologic outcomes. The developing nervous and immune systems in children create unique challenges in diagnosis and treatment of these rare diseases. In this review, autoimmune diseases affecting the brain, spinal cord, nerve roots, peripheral nerves, neuromuscular junction, and muscle in children are described.

Practical Challenges in Collecting Head Impact Biomechanics Data in Real-World Scenarios via a Helmet-Based Accelerometer System

2013 ◽  
Author(s):  
Mari A. Allison ◽  
Yun Seok Kang ◽  
Matthew R. Maltese ◽  
John H. Bolte ◽  
Kristy B. Arbogast
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Real World ◽  
Head Impact ◽  
Permanent Damage ◽  
Head Impact Biomechanics ◽  
Impact Biomechanics ◽  
The Brain

Recent studies have shown that mild traumatic brain injury (mTBI) can have long-term neurological consequences and may cause permanent damage to the brain [1,2]. Given estimates that millions of these injuries occur each year [3], this knowledge has created a demand for countermeasures to prevent mTBI. In order to create countermeasures, the biomechanical inputs leading to mTBI, which are still a matter of debate, must be better understood in both children and adults.

Role of the GABAA receptors in the long-term cognitive impairments caused by neonatal sevoflurane exposure

2019 ◽  
Vol 30 (8) ◽  
pp. 869-879 ◽  
Author(s):  
Tao Li ◽  
Zeyi Huang ◽  
Xianwen Wang ◽  
Ju Zou ◽  
Sijie Tan
Keyword(s):  
Structural Changes ◽  
Cognitive Impairments ◽  
Elevated Serum ◽  
Developmental Abnormalities ◽  
Inhalational Anesthetic ◽  
Excitatory Gaba ◽  
Hpa Axis Activity ◽  
The Brain

Abstract Sevoflurane is a widely used inhalational anesthetic in pediatric surgeries, which is considered reasonably safe and reversible upon withdrawal. However, recent preclinical studies suggested that peri-neonatal sevoflurane exposure may cause developmental abnormalities in the brain. The present review aimed to present and discuss the accumulating experimental data regarding the undesirable effects of sevoflurane on brain development as revealed by the laboratory studies. First, we summarized the long-lasting side effects of neonatal sevoflurane exposure on cognitive functions. Subsequently, we presented the structural changes, namely, neuroapoptosis, neurogenesis and synaptogenesis, following sevoflurane exposure in the immature brain. Finally, we also discussed the potential mechanisms underlying subsequent cognitive impairments later in life, which are induced by neonatal sevoflurane exposure and pointed out potential strategies for mitigating sevoflurane-induced long-term cognitive impairments. The type A gamma-amino butyric acid (GABAA) receptor, the main targets of sevoflurane, is excitatory rather than inhibitory in the immature neurons. The excitatory effects of the GABAA receptors have been linked to increased neuroapoptosis, elevated serum corticosterone levels and epigenetic modifications following neonatal sevoflurane exposure in rodents, which might contribute to sevoflurane-induced long-term cognitive abnormalities. We proposed that the excitatory GABAA receptor-mediated HPA axis activity might be a novel mechanism underlying sevoflurane-induced long-term cognitive impairments. More studies are needed to investigate the effectiveness and mechanisms by targeting the excitatory GABAA receptor as a prevention strategy to alleviate cognitive deficits induced by neonatal sevoflurane exposure in future.

scholarly journals Residual Pituitary Function after Brain Injury-Induced Hypopituitarism: A Prospective 12-Month Study

2005 ◽  
Vol 90 (11) ◽  
pp. 6085-6092 ◽  
Author(s):  
Gianluca Aimaretti ◽  
Maria Rosaria Ambrosio ◽  
Carolina Di Somma ◽  
Maurizio Gasperi ◽  
Salvatore Cannavò ◽  
...  
Keyword(s):  
Brain Injury ◽  
High Risk ◽  
Gh Deficiency ◽  
Pituitary Function ◽  
Brain Injured ◽  
Injured Patients ◽  
The Brain ◽  
Over Time

Abstract Context: Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are conditions at high risk for the development of hypopituitarism. Objective: The objective of the study was to clarify whether pituitary deficiencies and normal pituitary function recorded at 3 months would improve or worsen at 12 months after the brain injury. Design and Patients: Pituitary function was tested at 3 and 12 months in patients who had TBI (n = 70) or SAH (n = 32). Results: In TBI, the 3-month evaluation had shown hypopituitarism (H) in 32.8%. Panhypopituitarism (PH), multiple (MH), and isolated (IH) hypopituitarism had been demonstrated in 5.7, 5.7, and 21.4%, respectively. The retesting demonstrated some degree of H in 22.7%. PH, MH, and IH were present in 5.7, 4.2, and 12.8%, respectively. PH was always confirmed at 12 months, whereas MH and IH were confirmed in 25% only. In 5.5% of TBI with no deficit at 3 months, IH was recorded at retesting. In 13.3% of TBI with IH at 3 months, MH was demonstrated at 12-month retesting. In SAH, the 3-month evaluation had shown H in 46.8%. MH and IH had been demonstrated in 6.2 and 40.6%, respectively. The retesting demonstrated H in 37.5%. MH and IH were present in 6.2 and 31.3%, respectively. Although no MH was confirmed at 12 months, two patients with IH at 3 months showed MH at retesting; 30.7% of SAH with IH at 3 months displayed normal pituitary function at retesting. In SAH, normal pituitary function was always confirmed. In TBI and SAH, the most common deficit was always severe GH deficiency. Conclusion: There is high risk for H in TBI and SAH patients. Early diagnosis of PH is always confirmed in the long term. Pituitary function in brain-injured patients may improve over time but, although rarely, may also worsen. Thus, brain-injured patients must undergo neuroendocrine follow-up over time.

scholarly journals Climate change will cause non-analog vegetation states in Africa and commit vegetation to long-term change

2020 ◽  
Vol 17 (22) ◽  
pp. 5829-5847
Author(s):  
Mirjam Pfeiffer ◽  
Dushyant Kumar ◽  
Carola Martens ◽  
Simon Scheiter
Keyword(s):  
Vegetation Change ◽  
Structural Changes ◽  
Equilibrium States ◽  
Tree Cover ◽  
Environmental Drivers ◽  
Vegetation Model ◽  
Dynamic Global Vegetation Model ◽  
Lag Times ◽  
Over Time

Abstract. Vegetation responses to changes in environmental drivers can be subject to temporal lags. This implies that vegetation is committed to future changes once environmental drivers stabilize; e.g., changes in physiological processes, structural changes, and changes in vegetation composition and disturbance regimes may happen with substantial delay after a change in forcing has occurred. Understanding the trajectories of such committed changes is important as they affect future carbon storage, vegetation structure, and community composition and therefore need consideration in conservation management. In this study, we investigate whether transient vegetation states can be represented by a time-shifted trajectory of equilibrium vegetation states or whether they are vegetation states without analog in conceivable equilibrium states. We use a dynamic vegetation model, the aDGVM (adaptive Dynamic Global Vegetation Model), to assess deviations between simulated transient and equilibrium vegetation states in Africa between 1970 and 2099 for the RCP4.5 and 8.5 scenarios using regionally downscaled climatology based on the MPI-ESM output for CMIP5. We determined lag times and dissimilarity between simulated equilibrium and transient vegetation states based on the combined difference of nine selected state variables using Euclidean distance as a measure for that difference. We found that transient vegetation states over time increasingly deviated from equilibrium states in both RCP scenarios but that the deviation was more pronounced in RCP8.5 during the second half of the 21st century. Trajectories of transient vegetation change did not follow a “virtual trajectory” of equilibrium states but represented non-analog composite states resulting from multiple lags with respect to vegetation processes and composition. Lag times between transient and most similar equilibrium vegetation states increased over time and were most pronounced in savanna and woodland areas, where disequilibrium in savanna tree cover frequently acted as the main driver of dissimilarities. Fire additionally enhanced lag times and dissimilarity between transient and equilibrium vegetation states due to its restraining effect on vegetation succession. Long lag times can be indicative of high rates of change in environmental drivers, of meta-stability and non-analog vegetation states, and of augmented risk for future tipping points. For long-term planning, conservation managers should therefore strongly focus on areas where such long lag times and high residual dissimilarity between most similar transient and equilibrium vegetation states have been simulated. Particularly in such areas, conservation efforts need to consider that observed vegetation may continue to change substantially after stabilization of external environmental drivers.

Automated long-term two-photon imaging in head-fixed walking Drosophila

2021 ◽  
Author(s):  
Andres Flores Valle ◽  
Rolf Honnef ◽  
Johannes D. Seelig
Keyword(s):  
Structural Changes ◽  
Long Term Memory ◽  
Head Direction ◽  
Multiple Timescales ◽  
Two Photon ◽  
Photon Imaging ◽  
Two Photon Imaging ◽  
Millisecond Range ◽  
The Brain

The brain of Drosophila shows dynamics at multiple timescales, from the millisecond range of fast voltage or calcium transients to functional and structural changes occurring over multiple days. To relate such dynamics to behavior requires monitoring neural circuits across these multiple timescales in behaving animals. Here, we develop a technique for automated long-term two-photon imaging in fruit flies, during wakefulness and sleep, navigating in virtual reality over up to seven days. The method is enabled by laser surgery, a microrobotic arm for controlling forceps for dissection assistance, an automated feeding robot, as well as volumetric, simultaneous multiplane imaging. The approach is validated in the fly's head direction system. Imaging in behaving flies over multiple timescales will be useful for understanding circadian activity, learning and long-term memory, or sleep.

Granting Immunity: Authorisation and “Public Benefit”

2020 ◽  
pp. 231-263
Author(s):  
Rex Ahdar
Keyword(s):  
New Zealand ◽  
Cost Benefit ◽  
The Public ◽  
Public Benefits ◽  
Local Companies ◽  
Court Of Appeal ◽  
Total Welfare ◽  
Term Benefit ◽  
Over Time

This chapter analyses the authorisation mechanism—a demanding cost-benefit test for those applicants who seek advance approval of their potentially contravening conduct. The “public benefits” and detriments the Commission can assess under this test are very broad. The potentially relevant matters go well beyond economic efficiencies to intangible and unquantified gains or harms. A thorny issue has been the distributional question. Does the Act have an implicit bias in favour of consumers when it comes to weighing benefits and detriments? Must benefits be passed on to consumers? The Chicagoan thinking came to dominate and the Commission pronounced it was “neutral” regarding wealth transfers from consumers to producers. The 2001 Amendment, which altered the purpose of the Act to clarify that competition operated for the long-term benefit of New Zealand consumers, did not initially alter the Chicagoan stance. Over time, however, the purely neutral stance towards wealth transfers has been eroded. The Court of Appeal decided that private gains, redounding solely to the companies alone, were not sufficient. “Modified total welfare” arrived as a new term in the New Zealand antitrust lexicon. The chapter also analyses the non-neutral stance where the benefits go to foreign owners of local companies.

Structural Changes in the Receiving Country and Future Labor Migration –The Case of Kuwait

1995 ◽  
Vol 29 (4) ◽  
pp. 1000-1022
Author(s):  
Nasra M. Shah
Keyword(s):  
Labor Force ◽  
Migrant Workers ◽  
Labor Migration ◽  
Structural Changes ◽  
Foreign Workers ◽  
The Public ◽  
Domestic Servants ◽  
Personal Services ◽  
Age And Sex

Structural changes in the labor force of the receiving country can provide some important clues to the speed and nature of replacement of migrant workers by indigenous ones. This article analyzes changes in the national labor force with regard to volume, age and sex composition, retention in the labor force, productivity, type of occupation, and sector of activity. Changes in the above features during the last two decades indicate that the median age of the national male labor force remains low, its concentration in the public sector has increased, and its participation in production and manual work has declined further. The labor force participation of females has increased substantially, and they comprised 31 percent of the national labor force in 1993. Kuwaiti females participate mainly in the professional or technical and clerical occupations. The number of non-Kuwaiti females in the labor force has increased, with domestic servants as a major category. The above structural changes suggest that the national labor force is growing in a manner that implies a continued long-term dependence on foreign workers. Dependence on expatriates is likely to be greatest for occupations involving maintenance of infrastructures and personal services.

scholarly journals Analyzing complexities in the Brazilian soybean supply chain: a systems thinking and modeling approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Monique Filassi ◽  
Andréa Leda Ramos de Oliveira ◽  
Arun Abraham Elias ◽  
Karina Braga Marsola
Keyword(s):  
Supply Chain ◽  
Public Sector ◽  
Systems Thinking ◽  
Structural Changes ◽  
Transport Infrastructure ◽  
Transport Systems ◽  
Loop Modeling ◽  
Content Type ◽  
The Public

Purpose This study aims to analyze the complexities of the Brazilian soybean supply chain (SSC) and develop strategic interventions to improve the origin system’s performance. Design/methodology/approach This study used stakeholder interviews to identify the SSC bottlenecks and determine and assess drivers of competitiveness. A methodological framework based on the systems thinking approach for developing long-term structural changes was used. The problem was structured using behavior over time graph and causal loop modeling to propose three investment strategies to solve the logistics problem in SSC. Findings This study highlights the gaps in coordination between stakeholders and the public sector regarding the public policy for infrastructure investment. Three strategic interventions were developed to address the agro-industrial logistical problem, namely, investment in storage, multimodal transport systems and improvements in existing transport infrastructure. To overcome transport and storage logistics limitations, the authors suggest different forms of partnerships, including public-private partnerships. Research limitations/implications This research is limited to evaluating an agricultural commodity (soybean) and does not include its by-products. The sample of stakeholders was limited and the boundary of analysis was Brazil. Nevertheless, the study showed how strategic interventions could be developed following a holistic analysis. Practical implications The proposed integrated approach illustrates the development of three strategic initiatives. It can be implemented by stakeholders, including the public sector, which is the basis for providing assertive long-term investments in Brazilian logistics. Social implications The SSC analysis could promote the implementation of systemically determined interventions and strategies. It could significantly improve the performance of agricultural systems and help the formulation of public policies aimed at rural development. Originality/value The use of system dynamics to identify intervention points is an essential contribution to mitigating the SSC’s hindrances. Moreover, the combining methodologies resulted in comprehensive intervention strategies.

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