Causal effects of education on cognition : how do we generate evidence?

Background: Education is a key institution in our societies, and should prepare us for future by improving cognition and teaching us needed life skills. Education is associated with many aspects of life, including health. For example, there is hope that improved education may help to reduce the burden of dementia, which is a large public health challenge for which treatment is missing. However, such hopes assume causality of the relationship between education and dementia. Aim: The primary aim of this doctoral thesis was to examine the relationship between formal education and cognition (i.e. early-life cognition, cognitive decline and neuropathological disturbances to cognition in form of dementia) during the life-course. The secondary aim was to discuss how we can generate evidence on causal relationships and infer causation in epidemiology. Methods: This thesis adopted a plurality and triangulation of evidence approach with regards to arriving at causal conclusions. The individual studies employed diverse designs in the exploration of links between education, cognition and dementia. Study I described thirty-year trends in the burden of dementia in inpatient records according to educational level. In Study II, we exploited a quasi-experimental comprehensive school reform in order to ascertain causal relationship between education and intelligence in men at military conscription. Further, we explored the heterogeneity of the effect according to childhood socioeconomic position. Study III focused on dementia. In order to investigate the causal effect of education on dementia diagnosis in Swedish registers, we used a primary schooling reform as a natural experiment. The reform had minimal spill-over effects on adult socioeconomic factors. The last study (Study IV) was a systematic review and meta-analysis summarizing the evidence from population-based studies of healthy adults. It examined the association between education and change in episodic memory, a cognitive domain with strong links to dementia. Results: The burden of dementia in Swedish inpatient records began to decline during the last half a decade. Educational inequalities in dementia incidence remained stable and those with the highest educational attainment had the lowest dementia incidence rates. The comprehensive school reform increased intelligence and reduced socioeconomic disparities in cognition. However, in Study III we did not discover any substantial effect of the primary schooling reform on dementia risk. Similarly, the meta-analytic estimate indicated that the association between education and age-related decline in episodic memory is negligible. Conclusions: Education is associated with level of cognition, but not decline - at least not in the episodic memory domain. Further, prolonged education cannot be uncritically assumed to reduce dementia burden, especially in absence of spillover effects to adult socioeconomic factors. However, education fulfils one of its many aims by increasing early-life cognition, and also has the potential to reduce socioeconomic inequalities in cognitive ability

Qualitative Research of Violent Incidents Toward Young Paramedics in the Czech Republic

Introduction: Prehospital and emergency medical services (EMS) providers are usually the first to respond to an individual’s urgent health needs, sometimes in emotionally charged circumstances. Because violence toward EMS providers in the Czech Republic is often overlooked and under-reported, we do not have a complete understanding of the extent of such violence, nor do we have recommendations from EMS professional organizations on how to resolve this problem in prehospital emergency medicine.Methods: We conducted this study to explore the process of violence against EMS providers, using the Strauss/Corbin systematic approach of grounded theory to create a paradigm model. The participants in this research included personnel who had at least two years experience in the EMS systems of the city of Prague and the Central Bohemian Region, and who had been victims of violence. Our sample included 10 registered paramedics and 10 emergency medical technicians ages 23–33 (mean ± standard deviation: 27.7). The impact of communication during EMS delivery, in the context of violence from patients or their relatives, emerged as the core category and the main focus of our study. The five main groups of the paradigm model of violence against EMS personnel included causal, contextual and intervening conditions, strategies, and consequences.Results: Of the 20 study participants, 18 reported experiencing an attack during the night shift. Ten participants experienced violence on the street, and 10 inside an ambulance. The perpetrators in all 18 cases were men. The behavior of EMS personnel plays a crucial role in how violent confrontations play out: nonprofessional behavior with drunken or addict patients increases the possibility of violence in 70% of cases.Conclusion: We found that paramedics and EMTs were exposed to verbal abuse and physical violence. However, in 10 of the violent encounters reported by our 20 participants, the attack was perpetrated by otherwise-ordinary people (ie, individuals with strong family support and good jobs) who found themselves in a very stressful situation. Thanks to grounded theory we learned that for all 20 participants there was a potential opportunity to prevent the conflict

Experimental Transmission of Leishmania infantum by Two Major Vectors: A Comparison between a Viscerotropic and a Dermotropic Strain

We quantified Leishmania infantum parasites transmitted by natural vectors for the first time. Both L. infantum strains studied, dermotropic CUK3 and viscerotropic IMT373, developed well in Phlebotomus perniciosus and Lutzomyia longipalpis. They produced heavy late-stage infection and colonized the stomodeal valve, which is a prerequisite for successful transmission. Infected sand fly females, and especially those that transmit parasites, feed significantly longer on the host (1.5–1.8 times) than non-transmitting females. Quantitative PCR revealed that P. perniciosus harboured more CUK3 strain parasites, while in L. longipalpis the intensity of infection was higher for the IMT373 strain. However, in both sand fly species the parasite load transmitted was higher for the strain with dermal tropism (CUK3). All but one sand fly female infected by the IMT373 strain transmitted less than 600 promastigotes; in contrast, 29% of L. longipalpis and 14% of P. perniciosus infected with the CUK3 strain transmitted more than 1000 parasites. The parasite number transmitted by individual sand flies ranged from 4 up to 4.19×104 promastigotes; thus, the maximal natural dose found was still about 250 times lower than the experimental challenge dose used in previous studies. This finding emphasizes the importance of determining the natural infective dose for the development of an accurate experimental model useful for the evaluation of new drugs and vaccines

The biting midge Culicoides sonorensis (Diptera Ceratopogonidae) is capable of developing late stage infections of Leishmania enriettii

BACKGROUND: Despite their importance in animal and human health, the epidemiology of species of the Leishmania enriettii complex remains poorly understood, including the identity of their biological vectors. Biting midges of the genus Forcipomyia (Lasiohelea) have been implicated in the transmission of a member of the L. enriettii complex in Australia, but the far larger and more widespread genus Culicoides has not been investigated for the potential to include vectors to date. METHODOLOGY/PRINCIPAL FINDINGS: Females from colonies of the midges Culicoides nubeculosus Meigen and C. sonorensis Wirth & Jones and the sand fly Lutzomyia longipalpis Lutz & Nevia (Diptera: Psychodidae) were experimentally infected with two different species of Leishmania, originating from Australia (Leishmania sp. AM-2004) and Brazil (Leishmania enriettii). In addition, the infectivity of L. enriettii infections generated in guinea pigs and golden hamsters for Lu. longipalpis and C. sonorensis was tested by xenodiagnosis. Development of L. enriettii in Lu. longipalpis was relatively poor compared to other Leishmania species in this permissive vector. Culicoides nubeculosus was not susceptible to infection by parasites from the L. enriettii complex. In contrast, C. sonorensis developed late stage infections with colonization of the thoracic midgut and the stomodeal valve. In hamsters, experimental infection with L. enriettii led only to mild symptoms, while in guinea pigs L. enriettii grew aggressively, producing large, ulcerated, tumour-like lesions. A high proportion of C. sonorensis (up to 80%) feeding on the ears and nose of these guinea pigs became infected. CONCLUSIONS/SIGNIFICANCE: We demonstrate that L. enriettii can develop late stage infections in the biting midge Culicoides sonorensis. This midge was found to be susceptible to L. enriettii to a similar degree as Lutzomyia longipalpis, the vector of Leishmania infantum in South America. Our results support the hypothesis that some biting midges could be natural vectors of the L. enriettii complex because of their vector competence, although not Culicoides sonorensis itself, which is not sympatric, and midges should be assessed in the field while searching for vectors of related Leishmania species including L. martiniquensis and "L. siamensis"

High School Quality is Associated with Cognition 58 Years Later

We leveraged a unique school-based longitudinal cohort—the Project Talent Aging Study—to examine whether attending higher quality schools is associated with cognitive performance among older adults in the United States (mean age = 74.8). Participants (n = 2,289) completed telephone neurocognitive testing. Six indicators of high school quality, reported by principals at the time of schooling, were predictors of respondents’ cognitive function 58 years later. To account for school-clustering, multilevel linear and logistic models were applied. We found that attending schools with a higher number of teachers with graduate training was the clearest predictor of later-life cognition, and school quality mattered especially for language abilities. Importantly, Black respondents (n = 239; 10.5 percentage) were disproportionately exposed to low quality high schools. Therefore, increased investment in schools, especially those that serve Black children, could be a powerful strategy to improve later life cognitive health among older adults in the United States

Visualisation of Leishmania donovani Fluorescent Hybrids during Early Stage Development in the Sand Fly Vector

hybrids were produced by co-infecting sand flies with two strains carrying different drug resistance markers. However, the location and timing of hybridisation events in sand flies has not been described. strains carrying hygromycin or neomycin resistance genes and red or green fluorescent markers. Fed females were dissected at different times post bloodmeal (PBM) and examined by fluorescent microscopy or fluorescent activated cell sorting (FACS) followed by confocal microscopy. In mixed infections strains LEM3804 and Gebre-1 reached the cardia and stomodeal valves more rapidly than strains LEM4265 and LV9. Hybrids unequivocally expressing both red and green fluorescence were seen in single flies of both vectors tested, co-infected with LEM4265 and Gebre-1. The hybrids were present as short (procyclic) promastigotes 2 days PBM in the semi-digested blood in the endoperitrophic space. Recovery of a clearly co-expressing hybrid was also achieved by FACS. However, hybrids could not sustain growth in vitro. has profound epidemiological significance, because it facilitates the emergence and spread of new phenotypic traits

Risk factors of visceral leishmaniasis: a case control study in north-western Ethiopia

Background Visceral leishmaniasis (VL, also called “kala-azar”), is a life threatening neglected tropical infectious disease which mainly affects the poorest of the poor. VL is prevalent in Ethiopia particularly in the northwest of the country. Understanding the risk factors of VL infection helps in its prevention and control. The aim of the present study was to identify the factors associated with VL. Methods A case–control study was carried out during the period of January-July 2013 in northwest Ethiopia. Cases and controls were diagnosed using clinical presentation, the rk39 rapid diagnostic test and Direct Agglutination Test (DAT). A total of 283 (84.8% males versus 15.2% females) participants were interviewed. 90 cases and 193 controls were involved, matched by age, sex and geographical location with a ratio of 1:2 (case: controls). Univariate and backward multivariate conditional logistic regression were used to identify risk factors of VL. Results Elevated odds of VL was associated with goat ownership (OR = 6.4; 95%: confidence interval [Cl]: 1.5-28.4), living in houses with cracked wall (OR = 6.4; 95% Cl: 1.6-25.6), increased family size (OR = 1.3; 95% Cl: 1.0-1.8) and the number of days spent in the farm field (OR = 1.1; 95% Cl: 1.0-1.2). However, daily individual activities around the home and farm fields, mainly sleeping on a bed (OR = 0.2; 95%: Cl 0.03-0.9), sleeping outside the house under a bed net (OR = 0.1; 95% Cl: 0.02-0.36)] and smoking plant parts in the house during the night time (OR = 0.1; 95% Cl: 0.01-0.6) were associated with decreased odds of being VL case. Conclusion Our findings showed that use of bed net and smoke could be helpful for the prevention of VL in the area particularly among individuals who spend most of their time in the farm. VL control effort could be focused on improving housing conditions, such as sealing cracks and crevices inside and outside houses. Further research is warranted to elucidate the role of goats in the transmission of L. donovani, assess the impact of bed nets and the role of the traditional practice of smoking plants

The impact of the COVID-19 pandemic on the mental health of healthcare workers:study protocol for the COVID-19 HEalth caRe wOrkErS (HEROES) study

BACKGROUND: Preliminary country-specific reports suggest that the COVID-19 pandemic has a negative impact on the mental health of the healthcare workforce. In this paper, we summarize the protocol of the COVID-19 HEalth caRe wOrkErS (HEROES) study, an ongoing, global initiative, aimed to describe and track longitudinal trajectories of mental health symptoms and disorders among health care workers at different phases of the pandemic across a wide range of countries in Latin America, Europe, Africa, Middle-East, and Asia. METHODS: Participants from various settings, including primary care clinics, hospitals, nursing homes, and mental health facilities, are being enrolled. In 26 countries, we are using a similar study design with harmonized measures to capture data on COVID-19 related exposures and variables of interest during two years of follow-up. Exposures include potential stressors related to working in healthcare during the COVID-19 pandemic, as well as sociodemographic and clinical factors. Primary outcomes of interest include mental health variables such as psychological distress, depressive symptoms, and posttraumatic stress disorders. Other domains of interest include potentially mediating or moderating influences such as workplace conditions, trust in the government, and the country’s income level. RESULTS: As of August 2021, ~ 34,000 health workers have been recruited. A general characterization of the recruited samples by sociodemographic and workplace variables is presented. Most participating countries have identified several health facilities where they can identify denominators and attain acceptable response rates. Of the 26 countries, 22 are collecting data and 2 plan to start shortly. CONCLUSIONS: This is one of the most extensive global studies on the mental health of healthcare workers during the COVID-19 pandemic, including a variety of countries with diverse economic realities and different levels of severity of pandemic and management. Moreover, unlike most previous studies, we included workers (clinical and non-clinical staff) in a wide range of settings. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00127-021-02211-9