Malaria Parasites in the Asymptomatic: Looking for the Hay in the Haystack

With malaria elimination back on the international agenda, programs face the challenge of targeting all Plasmodium infections, not only symptomatic cases. As asymptomatic individuals are unlikely to seek treatment, they are missed by passive surveillance while remaining infectious to mosquitoes, thus acting as silent reservoirs of transmission. To estimate the risk of asymptomatic infections in various phases of malaria elimination, we need a deeper understanding of the underlying mechanisms favoring carriage over disease, which may involve both pathogen and host factors. Here we review our current knowledge on the determinants leading to Plasmodium falciparum symptomless infections. Understanding the host-pathogen interactions that are most likely to affect transitions between malaria disease states could guide the development of tools to tackle asymptomatic carriers in elimination settings

Ανάπτυξη Εκπαιδευτικού Παιγνίου: Κληρονομικότητα

Η παρούσα εργασία έχει ως στόχο την δημιουργία μιας οικογένειας εκπαιδευτικών υπολογιστικών παιχνιδιών για τη διδασκαλία βασικών εννοιών και αρχών γενετικής και κληρονομικότητας. Η υλοποίηση έχει τη μορφή διαδικτυακής εφαρμογής, έχοντας ως κύριο στόχο τη μεθοδική και απλουστευμένη εφαρμογή της σε εκπαιδευτικά ιδρύματα δεύτερης βαθμίδας, απαιτώντας παράλληλα ελάχιστες υποδομές. Συνολικά, η εφαρμογή αποτελείται από 4 παιχνίδια, τα οποία αποσκοπούν στο να εισαγάγουν τους μαθητές σε απλές έννοιες κλασικής γενετικής, πιο συγκεκριμένα στη βάση της Μεντελικής κληρονομικότητας, της μεταβίβασης του γενετικού υλικού από έναν οργανισμό στους απογόνους του, στον καθορισμό του φύλου και στη δημιουργία του καρυοτύπου.The goal of this thesis is the creation of a group of educational computer games for the purpose of teaching the basic elements of Inheritance. The implementation is in the form of a web application, the main objective being its methodical and simplified application to second-tier educational institutions, i.e. the simple distribution to systems with minimal infrastructure. In total, the application consists of 4 games designed to introduce students to classical genetics concepts: Mendelian Inheritance, transmission of genetic material from parent to offspring, sex differentiation and karyotype analysis

Extent and structure of treatment of substance abusers in multiservice mental-health agencies : a work behavior analysis

This study investigated factors which contribute to the global self-esteem of professional women assumed to be competent. Special interest was directed toward exploration of the extent to which these successful women had high self-efficacy yet low self-worth. Participants were mainly white middle class college-educated professional women between the ages of 32-46. Each of the 184 participants completed a questionnaire regarding dimensions of self-esteem and gender identity. The questionnaire on self-esteem included measures of global self-esteem, self-efficacy, and self-worth. Independent variables included gender identity status, traditional versus non-traditional fields of work, mother's encouragement of independence, and mother's employment. The effect of these factors was examined through a MANOVA, a series of ANOVAs, t-tests, and a regression analysis

Additive manufactured sandwich composite/ABS parts for unmanned aerial vehicle applications

Fused deposition modelling (FDM) is one of most popular 3D printing techniques of thermoplastic polymers. Nonetheless, the poor mechanical strength of FDM parts restricts the use of this technology in functional parts of many applications such as unmanned aerial vehicles (UAVs) where lightweight, high strength, and stiffness are required. In the present paper, the fabrication process of low-density acrylonitrile butadiene styrenecarbon (ABS) with carbon fibre reinforced polymer (CFRP) sandwich layers for UAV structure is proposed to improve the poor mechanical strength and elastic modulus of printed ABS. The composite sandwich structures retains FDM advantages for rapid making of complex geometries, while only requires simple post-processing steps to improve the mechanical properties. Artificial neural network (ANN) was used to investigate the influence of the core density and number of CFRP layers on the mechanical properties. The results showed an improvement of specific strength and elastic modulus with increasing the number of CFRP. The specific strength of the samples improved from 20 to 145 KN·m/kg while the Young’s modulus increased from 0.63 to 10.1 GPa when laminating the samples with CFRP layers. On the other hand, the core density had no significant effect on both specific strength and elastic modulus. A case study was undertaken by applying the CFRP/ABS/CFRP sandwich structure using the proposed method to manufacture improved dual-tilting clamps of a quadcopter UAV

Members' views and practices concerning the Association for Assessment in Counseling

This article reports the results of a survey of 391 Association for Assessment in Counseling (AAC) members concerning the organization's activities; its journal, Measurement and Evaluation in Counseling Development; AAC Newsnotes; strategic planning goals; and convention activities

A prospective cohort study to assess the micro-epidemiology of Plasmodium falciparum clinical malaria in Ilha Josina Machel (Manhiça, Mozambique)

Background: After the decrease in clinical malaria incidence observed in Mozambique until 2009, a steady resurgence of cases per year has been reported nationally, reaching alarming levels in 2014. However, little is known about the clinical profile of the cases presented, or the possible epidemiological factors contributing to the resurgence of cases. Methods: An analysis of surveillance data collected between July 2003 and June 2013 in the high malaria-transmission area of Ilha Josina Machel (Southern Mozambique) through a paediatric outpatient morbidity surveillance system was conducted to calculate hospital-based clinical malaria rates, slide-positivity rates, and minimum community-based incidence rates (MCBIRs) and incidence rate ratios per malaria season in children younger than 15 years of age. Clinical malaria was defined as a fever ≥37.5 °C or a reported fever in the previous 24 h with a positive blood smear. Yearly mean age, geometric mean parasitaemia (GMP) and mean packed cell volume (PCV) were also described for all clinical malaria cases and compared between seasons using DID analysis or ANOVA tests. Results: During the study period, the percentage of outpatient visits presenting with confirmed clinical malaria decreased from 51 % in the 2003–2004 season to 23 % in 2008–2009, followed by an increase back to 51 % in 2012–2013. The yearly mean age of cases significantly increased from 2.9 (95 % CI 2.8–3.0) in 2003–2004 to 5.7 (95 % CI 5.6–5.7) in 2012–2013, compared to non-malaria cases. An increase in mean PCV levels was also observed (p < 0.001), as well as in GMPs: from 5778 parasites/µL in 2002–2003 to 17,316 parasites/µL in 2012–2013 (p < 0.001) mainly driven by an increase in GMP in children older than 1 year of age. MCBIRs in infants decreased by 70 % (RR = 0.3, p < 0.001) between 2003–2004 and 2012–2013. Incidence diminished by a third among children 1- to 4-years between 2003 and 2007, although such drop was unsustained as observed in 2012–2013 (RR = 1.0, 95 % CI 0.9–1.0). Finally, the incidence among children 5–14 years was 3.8 (95 % CI 3.4–4.3) times higher in 2012–2013 compared to 2003–2004. Conclusion: Since 2003, Ilha Josina Machel observed a significant reduction of clinical malaria cases which was followed by an upsurge, following the national trend. A shift in the age distribution towards older children was observed, indicating that the changes in the transmission intensity patterns resulted in a slower acquisition of the naturally acquired immunity to malaria in children

Long-Lasting Immune Protection and Other Epidemiological Findings after Chikungunya Emergence in a Cambodian Rural Community, April 2012.

The East/Central/South African genotype of Chikungunya virus with the E1-A226V mutation emerged in 2011 in Cambodia and spread in 2012. An outbreak of 190 cases was documented in Trapeang Roka, a rural village. We surveyed 425 village residents within 3-4 weeks after the outbreak, and determined the sensitivity and specificity of case definitions and factors associated with infection by CHIKV. Self-reported clinical presentation consisted mostly of fever, rash and arthralgia. The presence of all three clinical signs or symptoms was identified as the most sensitive (67%) and specific (84%) self-reported diagnostic clinical indicator compared to biological confirmation by MAC-ELISA or RT-PCR used as a reference. Having an indoor occupation was associated with lower odds of infection compared with people who remained at home (adjOR 0.32, 95%CI 0.12-0.82). In contrast with findings from outbreaks in other settings, persons aged above 40 years were less at risk of CHIKV infection, likely reflecting immune protection acquired when Chikungunya circulated in Cambodia before the Khmer Rouge regime in 1975. In view of the very particular history of Cambodia, our epidemiological data from Trapeang Roka are the first to support the persistence of CHIKV antibodies over a period of 40 years

Changing plasma cytokine, chemokine and growth factor profiles upon differing malaria transmission intensities

Background: Malaria epidemiological and immunological data suggest that parasite tolerance wanes in the absence of continuous exposure to the parasite, potentially enhancing pathogenesis. The expansion of control interventions and elimination campaigns raises the necessity to better understand the host factors leading to susceptibility or tolerance that are afected by rapid changes in malaria transmission intensity (MTI). Mediators of cellular immune responses are responsible for the symptoms and pathological alterations during disease and are expected to change rapidly upon malaria exposure or cessation. Methods: The plasma concentrations of 30 cytokine, chemokine and growth factors in individuals of all ages from a malaria endemic area of southern Mozambique were compared between 2 years of diferent MTI: 2010 (lower, n=234) and 2013 (higher, n=143). The efect of the year on the correlations between cytokines, chemokines and growth factors and IgGs to Plasmodium falciparum (markers of exposure) was explored. The efects of age, sex, neighbourhood and parasitaemia on analyte levels and their interactions with year were also assessed. Results: An inverse correlation of several cellular immune mediators with malarial antibodies in 2013, and a lack of correlation or even a positive correlation in 2010 were observed. Most cytokines, chemokines and growth factors, regardless of their immune function, had higher concentrations in 2010 compared with 2013 in P. falciparum-infected and uninfected subjects. Age and neighbourhood showed an efect on analyte concentrations. Conclusions: The results show a diferent regulation of the cellular immune response in 2010 vs 2013 which could be related to a loss of immune-tolerance after a decline in MTI in 2010 and previous years, and a rapid re-establishment of tolerance as a consequence of more continuous exposure as MTI began increasing in 2012. Cellular immune mediators warrant further investigation as possible surrogates of MTI-associated host susceptibility or tolerance

Molecular surveillance of pfhrp2 and pfhrp3 deletions in Plasmodium falciparum isolates from Mozambique

BACKGROUND: Malaria programmes use Plasmodium falciparum histidine-rich protein-2 (PfHRP2) based rapid diagnostic tests (RDTs) for malaria diagnosis. The deletion of this target antigen could potentially lead to misdiagnosis, delayed treatment and continuation of active transmission. METHODS: Plasmodium falciparum isolates (n = 1162) collected in Southern Mozambique were assessed by RDTs, microscopy and/or 18SrRNA qPCR. pfhrp2 and pfhrp3 deletions were investigated in isolates from individuals who were negative by RDT but positive by microscopy and/or qPCR (n = 69) using gene-specific PCRs, with kelch13 PCR as the parasite DNA control. RESULTS: Lack of pfhrp2 PCR amplification was observed in one of the 69 isolates subjected to molecular analysis [1.45% (95% CI 0.3-7.8%)]. CONCLUSIONS: The low prevalence of pfhrp2 deletions suggests that RDTs will detect the vast majority of the P. falciparum infections. Nevertheless, active surveillance for changing deletion frequencies is required