Elucidation of the Tetraterpene Hydrocarbon Biosynthetic Pathway in the Green Microalga Botryococcus braunii Race L

The colony-forming green microalga Botryococcus braunii is a potential source of biofuel feedstocks as it produces large amount of liquid hydrocarbon oils that can be converted into combustion engine fuels. There are three different races of B. braunii based on the hydrocarbons it synthesizes. Race A produces fatty acid derived alkadienes and alkatrienes, race B produces the triterpenoid The colony-forming green microalga Botryococcus braunii is a potential source of biofuel feedstocks as it produces large amount of liquid hydrocarbon oils that can be converted into combustion engine fuels. There are three different races of B. braunii based on the hydrocarbons it synthesizes. Race A produces fatty acid derived alkadienes and alkatrienes, race B produces the triterpenoid hydrocarbons tetramethylsqualene and botryococcenes, and race L, the focus of this study, produces the C₄₀ tetraterpenoid hydrocarbon lycopadiene via a previously uncharacterized biosynthetic pathway. Structural similarities suggest this pathway follows a biosynthetic mechanism analogous to that of C₃₀ squalene. Confirming this hypothesis, the studies presented here identified C₂₀ geranylgeranyl diphosphate (GGPP) as a precursor for lycopaoctaene biosynthesis, the first committed intermediate in the production of lycopadiene. Two squalene synthase (SS)-like cDNAs were identified in race L with one encoding a true SS, and the other an enzyme with lycopaoctaene synthase (LOS) activity. Interestingly, LOS utilizes alternative C₁₅ and C₂₀ prenyl diphosphate substrates to produce combinatorial hybrid hydrocarbons, but almost exclusively utilizes GGPP in vivo. This discovery highlights how SS enzyme diversification resulted in the production of specialized tetraterpenoid oils in race L of B. braunii. To understand LOS substrate and product specificity, rational mutagenesis experiments were conducted based on sequence alignments with several SS proteins as well as a structural comparison with the human SS (HSS) crystal structure. Characterization of the LOS mutants in vitro identified Ser276 and Ala288 in the LOS active site as key amino acids responsible for controlling substrate binding, and thus the promiscuity of this enzyme. Mutating these residues to those found in HSS largely converted LOS from lycopaoctaene production to C₃₀ squalene production. Furthermore, these studies were confirmed in vivo by expressing LOS in E. coli cells metabolically engineered to produce high FPP and GGPP levels. These studies also offer insights into tetraterpenoid hydrocarbon metabolism in B. braunii and provide a foundation for engineering LOS for robust production of specific hydrocarbons of a desired chain length

Parental School Involvement on Physical Activity and Screen Time Among Middle and High School Students

Background: High levels of sedentary activity and low levels of physical activity have led to an increase in childhood obesity. A reduction of sedentary behavior and the promotion of an active lifestyle positively impacts weight status of children. A child may modify their behavior through direct interventions from their parents, such as enforcement of rules or guided activities, or through broad interventions, by expressing their values and modeling behavior. Current research does not establish if broad or specific parental involvement has a greater effect on healthy behavior. Our group sought to support existing evidence that parental involvement directly impacts behavior that reduces the likelihood of childhood obesity and determines if broad or specific parental involvement had a greater impact on healthy behavior. Methods: The study population included all children grades 6-12 who completed the Georgia Student Health Survey 2.0. Survey questions from 674,354 students in Georgia were used for the analysis. Exploratory factor analysis (EFA) was conducted to derive a composite measure. Two factors were generated, broad parental involvement and specific parental involvement. Mixed-effects logistic regression was run using physical activity as the dependent variable and the two composite measures of parental involvement as predictors. The same mixed-effects logistic regression was performed using screen time as the dependent variable. Results: Both measures of parental involvement showed a statistically significant positive relationship with physical activity. Both measures of parental involvement were significantly associated with screen time. Conclusion: Results suggest that specific parental involvement leads to an increase in weekly physical activity and a decrease in daily screen time. Increasing physical activity and reducing screen time have demonstrated clear reductions in the rate of obesity amongst children. To improve healthy behavior and reduce the likelihood of childhood obesity, parents should be directly involved in their child’s school behavior

Counting crocodiles from the sky: Monitoring the critically endangered gharial (Gavialis gangeticus) population with an Unmanned Aerial Vehicle (UAV).

Technology is rapidly changing the methods in the field of wildlife monitoring. Unmanned aerial vehicle (UAV) is an example of a new technology that allows biologists to take to the air to monitor wildlife. Fixed Wing UAV was used to monitor critically endangered gharial population along 46 km of the Babai River in Bardia National Park. The UAV was flown at an altitude of 80 m along 12 pre-designed missions with a search effort of 2.72 hours of flight time acquired a total of 11,799 images covering an effective surface area of 8.2 km2 of river bank habitat. The images taken from the UAV could differentiate between gharial and muggers. A total count of 33 gharials and 31 muggers with observed density (per km2) of 4.64 and 4.0 for gharial and mugger respectively. Comparison of count data between one-time UAV and multiple conventional visual encounter rate surveys data showed no significant difference in the mean. Basking season and turbidity were important factors for monitoring crocodiles along the river bank habitat. Efficacy of monitoring crocodiles by UAV at the given altitude can be replicated in high priority areas with less operating cost and acquisition of high resolution data

Prevalence of Postpartum Family Planning Service Coverage in Selected Referral Facilities of Nepal

Introduction: Nepal Society of Obstetricians and Gynecologists jointly with the Nepalese government and with the support from the International Federation of Obstetrics and Gynecology has implemented an initiative to institutionalize postpartum family planning services in selected major referral facilities of Nepal to address the gap of low uptake of postpartum family planning in Nepal. The aim of the study is to find the prevalence of the service coverage of postpartum contraception in the selected facilities. Methods: A descriptive cross-sectional study was conducted in seven major referral facilities across Nepal. Data were collected from the hospital records of all women who delivered in these facilities between October 2018 and March 2019. Ethical approval for this study was obtained from Nepal Health Research Council. Data analysis was done with SPSS version 23. Results: Among the 29,072 deliveries from all the facilities, postpartum family planning counseling coverage was 27,301 (93.9%). The prevalence of uptake of Postpartum Intrauterine Device is 1581 (5.4%) and female sterilization is 1830 (6.3%). In total 11387 mothers (52.2%) had the intention to choose a postpartum family planning method. However, 36% of mothers neither used nor had the intention to choose a postpartum family planning method. Conclusions: The coverage of Postpartum Intrauterine Device counseling service coverage in Nepal is higher in 2018 as compared to 2016-2017 and in other countries implementing Postpartum Intrauterine Device initiatives. However, the prevalence of service coverage of immediate Postpartum Family Planning methods, mainly Postpartum Intrauterine Device in 2018 is lower in Nepal as compared to 2016-2017, and other countries implementing Postpartum Intrauterine Device initiative. More efforts are needed to encourage mothers delivering in the facilities to use the postpartum family planning method