Exploration and categorization of pre-service physics teachers' alternative conceptions in superconductivity and nanotechnology

An exploratory case study research design was followed to explore and categorize 23 pre-service physics teachers’ understanding in the fields of superconductivity and nanotechnology at the Sultan Qaboos University in Oman. To elicit their responses, a five-stage categorical framework analysis was used. The five stages included identification of the thematic framework, familiarization, coding, placing the categories on a chart and finally, interpretation. A conceptual survey test (Conceptual Survey of Superconductivity and Nanotechnology) was administered to the pre-service physics teachers to form four independently homogenous ability focus groups. This was followed by focus group discussions whose data were analyzed to group their conceptions in both the epistemological as well as ontological categories. From the focus group discussions, six categories were considered from previous studies, namely; lateral alternative conceptions, ontological conceptions, naïve physics, Ohm’s p-primes, mixed conceptions and loose ideas. Since this was a pre-instructional study, naïve physics ideas and lateral alternative conceptions were dominant. Naïve physics refers to the untrained student or human perception of various physical phenomena while lateral alternative conception refers the misconceptions individuals have on ideas that may be inconsistent with scientifically acceptable facts. Findings indicate that the pre-service teachers’ conceptions deviated from canonical scientific concepts, are diversified and inconsistent. The knowledge on pre-instructional conceptions will influence the development of evidence-based pedagogy, which is fundamental to the development of an effective physics education curriculum.Institute for Science and Technology Education (ISTE)M. Sc. (Physics Education

Effect of Maternally Derived Anti-protein and Anticapsular IgG Antibodies on the Rate of Acquisition of Nasopharyngeal Carriage of Pneumococcus in Newborns

BACKGROUND: In developing countries, introduction of pneumococcal conjugate vaccine has not eliminated circulation of vaccine serotypes. Vaccinating pregnant mothers to increase antibody concentrations in their newborn infants may reduce the acquisition of pneumococcal carriage and subsequent risk of disease. We explored the efficacy of passive immunity, attributable to anti-protein and anticapsular pneumococcal antibodies, against acquisition of carriage. METHODS: We examined the rate of nasopharyngeal acquisition of pneumococci in the first 90 days of life associated with varying anticapsular and anti-protein antibody concentrations in infant cord/maternal venous blood in Kilifi, Kenya. We used multivariable Cox proportional hazard models to estimate continuous functions relating acquisition of nasopharyngeal carriage to the concentration of maternally derived antibody. RESULTS: Cord blood or maternal venous samples were collected from 976 mother-infant pairs. Pneumococci were acquired 561 times during 33,905 person-days of follow-up. Increasing concentrations of anti-protein antibodies were associated with either a reduction (PhtD1, PspAFam2, Spr0096, StkP) or, paradoxically, an increase (CbpA, LytC, PcpA, PiaA, PspAFam1, RrgBT4) in acquisition rate. We observed a nonsignificant reduction in the incidence of homologous carriage acquisition with high concentrations of maternally derived anticapsular antibodies to 5 serotypes (6A, 6B, 14, 19F, and 23F). CONCLUSION: The protective efficacy of several anti-protein antibodies supports the strategy of maternal vaccination to protect young infants from carriage and invasive disease. We were not able to demonstrate that passive anticapsular antibodies were protective against carriage acquisition at naturally occurring concentrations though it remains possible they may do so at the higher concentrations elicited by vaccination

Pneumococcal conjugate vaccine given shortly after birth stimulates effective antibody concentrations and primes immunological memory for sustained infant protection.

BACKGROUND: In developing countries, newborn immunization with pneumococcal conjugate vaccines (PCVs) could protect young infants who are at high risk of invasive pneumococcal disease (IPD) but might lead to immune tolerance. METHODS: In a randomized trial, young infants received 7-valent PCV at 6, 10, and 14 weeks (Expanded Programme on Immunization [EPI] group) or 0, 10, and 14 weeks (newborn group). Safety was monitored actively at 2-7 days and then passively. Serum samples obtained at birth and 6, 10, 14, 18, 36, and 37 weeks were assayed by enzyme-linked immunosorbent assay for anticapsular immunoglobulin G concentration and avidity. Infants were boosted with either 7-valent PCV or one-fifth dose of pneumococcal polysaccharide vaccine at 36 weeks. Nasopharyngeal swab samples were obtained at 18 and 36 weeks. RESULTS: Three-hundred neonates and young infants were enrolled. Newborn vaccination was well tolerated. Adverse events occurred equally in each group; none was related to immunization. One infant, immunized at birth, died of unrelated neonatal sepsis. At 18 weeks, protective concentrations (≥0.35 μg/mL) were achieved against each serotype by ≥87% of infants with no significant differences between groups. Geometric mean concentrations were higher in the EPI group for serotypes 4, 9V, 18C, and 19F at 18 weeks and for serotype 4 at 36 weeks. Avidity was greater in the newborn group for serotypes 4, 6B, and 19F at 18 weeks and for serotype 19F at 36 weeks. Booster responses and vaccine-type/nonvaccine-type carriage prevalence did not differ between groups. CONCLUSIONS: PCV was safe, immunogenic, and primed for memory when given at birth. There was no evidence of immune tolerance. Vaccination beginning at birth offers an alternative to control IPD in vulnerable young infants

Long-term population effects of pneumococcal vaccines on carriage of pneumococcal serotypes and subsequent disease in Kenya

Many African counties, like Kenya, have introduced pneumococcal conjugate vaccines (PCVs) with financial support from Gavi, the Vaccine Alliance. However, in the near future, they are expected to transition and take up the full costs. Kenya introduced the ten-valent PCV (PCV10) in 2011 and enters the accelerated transition phase in 2022. This work aimed to study the effects of PCV10 vaccination on pneumococcal carriage and disease in the pre- and the immediate post-vaccination period, predict the long-term vaccination impact on carriage of pneumococcus and subsequent invasive pneumococcal disease, evaluate immune factors that may influence that impact and, ultimately, investigate the cost-effectiveness of potential policy options in order to guide Kenya’s decision-making. A dynamic transmission model was fitted to pre-vaccination carriage data and its predictions were validated against post-vaccination carriage data. In order to evaluate immune factors that may influence vaccination impact and thus warrant consideration in the mathematical model, statistical modelling of the association between pre-existing pneumococcal carriage and vaccine responsiveness, and between maternally-derived anti-protein and anti-capsular antibodies and the rate pneumococcal acquisition in newborns, was undertaken. A cost-effectiveness analysis was done based on the disease incidence predictions from the transmission model. The dynamic transmission model was shown be useful as it closely predicted the observed magnitude and timing of serotype replacement. Maternal anti-capsular antibodies were estimated to have a limited role while impaired immune responses were observed among vaccine serotype carriers at the point of vaccination. These two immune factors were evaluated within the decision making structure and considered to have negligible impact on the performance of the model. In the conclusion, I estimated that sustaining PCV10 vaccination in Kenya will be cost-effective but will present a significant challenge to affordability by the Kenyan Government

Estimating the contribution of different age strata to vaccine serotype pneumococcal transmission in the pre vaccine era: a modelling study.

BACKGROUND: Herd protection through interruption of transmission has contributed greatly to the impact of pneumococcal conjugate vaccines (PCVs) and may enable the use of cost-saving reduced dose schedules. To aid PCV age targeting to achieve herd protection, we estimated which population age groups contribute most to vaccine serotype (VT) pneumococcal transmission. METHODS: We used transmission dynamic models to mirror pre-PCV epidemiology in England and Wales, Finland, Kilifi in Kenya and Nha Trang in Vietnam where data on carriage prevalence in infants, pre-school and school-aged children and adults as well as social contact patterns was available. We used Markov Chain Monte Carlo methods to fit the models and then extracted the per capita and population-based contribution of different age groups to VT transmission. RESULTS: We estimated that in all settings, < 1-year-old infants cause very frequent secondary vaccine type pneumococcal infections per capita. However, 1-5-year-old children have the much higher contribution to the force of infection at 51% (28, 73), 40% (27, 59), 37% (28, 48) and 67% (41, 86) of the total infection pressure in E&W, Finland, Kilifi and Nha Trang, respectively. Unlike the other settings, school-aged children in Kilifi were the dominant source for VT infections with 42% (29, 54) of all infections caused. Similarly, we estimated that the main source of VT infections in infants are pre-school children and that in Kilifi 39% (28, 51) of VT infant infections stem from school-aged children whereas this was below 15% in the other settings. CONCLUSION: Vaccine protection of pre-school children is key for PCV herd immunity. However, in high transmission settings, school-aged children may substantially contribute to transmission and likely have waned much of their PCV protection under currently recommended schedules

Dysmenorrhoea during the COVID-19 lockdown: a study of women in the age group 18-45 years in Goa, India

Background: Dysmenorrhea can be incapacitating and affect a woman’s quality of life and productivity. Our aim was to ascertain the prevalence and attributes of dysmenorrhea among women aged 18-45 years in the state of Goa, India; the attitude towards dysmenorrhea and management methods; and to also understand the impact of the COVID-19 lockdown on women experiencing dysmenorrhea.Methods: A self-administered Google form was circulated and analysed using STATA-statistical software version 16. The study was conducted under the observation of Goa Medical College, in the months of May and June of 2020.Results: 87.7% (664) of participants experienced dysmenorrhea of which 72% had moderate-severe pain during menses. The pain lasted for 1-4 days in 98.6% of the respondents. A total of 69.25% women took some measures to relieve the pain; however only 27% of them sought professional medical help. During the lockdown 17% participants noticed a change in their periods. A change in the method of pain management was reported in 12.05% of the women. It was noted that the younger age group reported more changes in their periods during the lockdown.Conclusions: Dysmenorrhea impacted the lives of a large proportion of women. Even though some experienced incapacitating pain, many women did not seek medical advice. The lockdown due to the COVID-19 pandemic affected the menstrual cycle including dysmenorrhoea and its management. The high prevalence of dysmenorrhea coupled with inadequate utilisation of health services, makes it all the more important to utilise the results of this study in order to educate women about the effective methods of treatment.

Pneumococcal conjugate vaccine induced IgG and nasopharyngeal carriage of pneumococci: Hyporesponsiveness and immune correlates of protection for carriage

BACKGROUND: Prior studies have demonstrated hyporesponsiveness to pneumococcal conjugate vaccines (PCVs) when administered in the presence of homologous carriage. This may be substantially more important in Africa where carriage prevalence is high. Deriving a correlate of protection (CoP) for carriage is important in guiding the future use of extended PCVs as population control of pneumococcal disease by vaccination is now focused principally on its indirect effect. We therefore explored the complex relationship between existing carriage and vaccine responsiveness, and between serum IgG levels and risk of acquisition. METHODS: We undertook secondary analyses of data from two previously published clinical trials of the safety and immunogenicity of PCV in Kenya. We compared responses to vaccination between serotype-specific carriers and non-carriers at vaccination. We assessed the risk of carriage acquisition in relation to PCV-induced serum IgG levels using either a step- or continuous-risk function. RESULTS: For newborns, the immune response among carriers was 51–82% lower than that among non-carriers, depending on serotype. Among toddlers, for serotypes 6B, 14 and 19F the post-vaccination response among carriers was lower by between 29 and 70%. The estimated CoP against acquisition ranged from 0.26 to 1.93 μg/mL across serotypes, however, these thresholds could not be distinguished statistically from a model with constant probability of carriage independent of assay value. CONCLUSION: We have confirmed hyporesponsiveness in an equatorial African setting in both infants and toddlers. Population responses to vaccination are likely to improve with time as carriage prevalence of vaccine serotypes is reduced. We have not found clear correlates of protection against carriage acquisition among toddlers in this population. Assessing the potential of new vaccines through the use of CoP against carriage is still difficult as there are no clear-cut serotype specific correlates

Effect of Maternally Derived Anti-protein and Anticapsular IgG Antibodies on the Rate of Acquisition of Nasopharyngeal Carriage of Pneumococcus in Newborns.

Background: In developing countries, introduction of pneumococcal conjugate vaccine has not eliminated circulation of vaccine serotypes. Vaccinating pregnant mothers to increase antibody concentrations in their newborn infants may reduce the acquisition of pneumococcal carriage and subsequent risk of disease. We explored the efficacy of passive immunity, attributable to anti-protein and anticapsular pneumococcal antibodies, against acquisition of carriage. Methods: We examined the rate of nasopharyngeal acquisition of pneumococci in the first 90 days of life associated with varying anticapsular and anti-protein antibody concentrations in infant cord/maternal venous blood in Kilifi, Kenya. We used multivariable Cox proportional hazard models to estimate continuous functions relating acquisition of nasopharyngeal carriage to the concentration of maternally derived antibody. Results: Cord blood or maternal venous samples were collected from 976 mother-infant pairs. Pneumococci were acquired 561 times during 33,905 person-days of follow-up. Increasing concentrations of anti-protein antibodies were associated with either a reduction (PhtD1, PspAFam2, Spr0096, StkP) or, paradoxically, an increase (CbpA, LytC, PcpA, PiaA, PspAFam1, RrgBT4) in acquisition rate. We observed a nonsignificant reduction in the incidence of homologous carriage acquisition with high concentrations of maternally derived anticapsular antibodies to 5 serotypes (6A, 6B, 14, 19F, and 23F). Conclusion: The protective efficacy of several anti-protein antibodies supports the strategy of maternal vaccination to protect young infants from carriage and invasive disease. We were not able to demonstrate that passive anticapsular antibodies were protective against carriage acquisition at naturally occurring concentrations though it remains possible they may do so at the higher concentrations elicited by vaccination

Pneumococcal conjugate vaccine induced IgG and nasopharyngeal carriage of pneumococci: Hyporesponsiveness and immune correlates of protection for carriage.

BACKGROUND: Prior studies have demonstrated hyporesponsiveness to pneumococcal conjugate vaccines (PCVs) when administered in the presence of homologous carriage. This may be substantially more important in Africa where carriage prevalence is high. Deriving a correlate of protection (CoP) for carriage is important in guiding the future use of extended PCVs as population control of pneumococcal disease by vaccination is now focused principally on its indirect effect. We therefore explored the complex relationship between existing carriage and vaccine responsiveness, and between serum IgG levels and risk of acquisition. METHODS: We undertook secondary analyses of data from two previously published clinical trials of the safety and immunogenicity of PCV in Kenya. We compared responses to vaccination between serotype-specific carriers and non-carriers at vaccination. We assessed the risk of carriage acquisition in relation to PCV-induced serum IgG levels using either a step- or continuous-risk function. RESULTS: For newborns, the immune response among carriers was 51-82% lower than that among non-carriers, depending on serotype. Among toddlers, for serotypes 6B, 14 and 19F the post-vaccination response among carriers was lower by between 29 and 70%. The estimated CoP against acquisition ranged from 0.26 to 1.93?g/mL across serotypes, however, these thresholds could not be distinguished statistically from a model with constant probability of carriage independent of assay value. CONCLUSION: We have confirmed hyporesponsiveness in an equatorial African setting in both infants and toddlers. Population responses to vaccination are likely to improve with time as carriage prevalence of vaccine serotypes is reduced. We have not found clear correlates of protection against carriage acquisition among toddlers in this population. Assessing the potential of new vaccines through the use of CoP against carriage is still difficult as there are no clear-cut serotype specific correlates

Strong Gradients in Forest Sensitivity to Climate Change Revealed by Dynamics of Forest Fire Cycles in the Post Little Ice Age Era

The length of the fire cycle is a critical factor affecting the vegetation cover in boreal and temperate regions. However, its responses to climate change remain poorly understood. We reanalyzed data from earlier studies of forest age structures at the landscape level, in order to map the evolution of regional fire cycles across Eastern North American boreal and temperate forests, following the termination of the Little Ice Age (LIA). We demonstrated a well-defined spatial pattern of post-LIA changes in the length of fire cycles toward lower fire activity during the 1800s and 1900s. The western section of Eastern North America (west of 77°W) experienced a decline in fire activity as early as the first half of the 1800s. By contrast, the eastern section showed these declines as late as the early 1900s. During a regionally fire-prone period of the 1910s–1920s, forests in the western section of Eastern boreal North America burned more than forests in the eastern section. The climate appeared to dominate over vegetation composition and human impacts in shaping the geographical pattern of the post-LIA change in fire activity. Changes in the atmospheric circulation patterns following the termination of the LIA, specifically changes in Arctic Oscillation and the strengthening of the Continental Polar Trough, were likely drivers of the regional fire dynamics