The characteristics and effectiveness of pregnancy yoga interventions: a systematic review and meta-analysis.

BACKGROUND: Yoga is a popular mind-body medicine frequently recommended to pregnant women. Gaps remain in our understanding of the core components of effective pregnancy yoga programmes. This systematic review and meta-analysis examined the characteristics and effectiveness of pregnancy yoga interventions, incorporating the FITT (frequency, intensity, time/duration and type) principle of exercise prescription. METHODS: Nine electronic databases were searched: MEDLINE, PsycINFO, EMBASE, CINAHL, WHOLiS, AMED, ScieLo, ASSIA and Web of Science. Randomised control trials and quasi-experimental studies examining pregnancy yoga interventions were eligible. Covidence was used to screen titles, abstracts, and full-text articles. Outcomes of interest were stress, anxiety, depression, quality of life, labour duration, pain management in labour and mode of birth. The Cochrane Collaboration's Risk of Bias Assessment tool was used to assess methodological quality of studies and GRADE criteria (GRADEpro) evaluated quality of the evidence. Meta-analysis was performed using RevMan 5.3. RESULTS: Of 862 citations retrieved, 31 studies met inclusion criteria. Twenty-nine studies with 2217 pregnant women were included for meta-analysis. Pregnancy yoga interventions reduced anxiety (SMD: -0.91; 95% CI: - 1.49 to - 0.33; p = 0.002), depression (SMD: -0.47; 95% CI: - 0.9 to - 0.04, P = 0.03) and perceived stress (SMD: -1.03; 95% CI: - 1.55 to - 0.52; p < 0.001). Yoga interventions also reduced duration of labour (MD = - 117.75; 95% CI - 153.80 to - 81.71, p < 0.001) and, increased odds of normal vaginal birth (OR 2.58; 95% CI 1.46-4.56, p < 0.001) and tolerance for pain. The quality of evidence (GRADE criteria) was low to very low for all outcomes. Twelve or more yoga sessions delivered weekly/bi-weekly had a statistically significant impact on mode of birth, while 12 or more yoga sessions of long duration (> 60 min) had a statistically significant impact on perceived stress. CONCLUSION: The evidence highlights positive effects of pregnancy yoga on anxiety, depression, perceived stress, mode of birth and duration of labour. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42019119916. Registered on 11th January 2019.

Behavioral responses of gravid Culex quinquefasciatus, Aedes aegypti, and Anopheles quadrimaculatus mosquitoes to aquatic macrophyte volatiles.

Mosquitoes use many cues to assess whether a habitat is conducive for reproduction, possibly including the presence of stimuli from aquatic macrophytes. The effect of water infusions of water hyacinth (Eichhornia crassipes), water lettuce (Pista stratioles), parrotfeather (Myriophyllum aquaticum), and water pennywort (Hydrocotyle umbellata) on mosquito oviposition and attraction was investigated. Gravid Culex quinquefasciatus deposited significantly more egg rafts in water hyacinth, water lettuce, or Bermuda hay (positive control) infusions compared to water, while water pennywort and parrotfeather infusions did not differ from water. In-flight attraction responses of Cx. quinquefasciatus, Aedes aegypti, and Anopheles quadrimaculatus were evaluated. The strongest attraction of gravid Cx. quinquefasciatus and Ae. aegypti occurred in the presence of volatiles from infusions of water hyacinth and water lettuce, which were equal in attractiveness to hay infusion. Water pennywort and parrotfeather infusions were not attractive. Gravid An. quadrimaculatus were not attracted to aquatic plant volatiles. The results suggest that water hyacinth and water lettuce emit volatile chemicals that attract two of three mosquito species tested and stimulate oviposition by Cx. quinquefasciatus, demonstrating that the level of attraction of aquatic plant volatiles varies among species in ways that may have relevance to bait-based detection and control methods.

The relative influence of nutrients and habitat on stream metabolism in agricultural streams.

Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration (CR-24). In conjunction with the stream metabolism estimates, water quality and algal biomass samples were collected, as was an assessment of habitat in the sampling reach. When data for all study areas were combined, there were no statistically significant relations between gross primary production or community respiration and any of the independent variables. However, significant regression models were developed for three study areas for GPP (r(2) = 0.79-0.91) and CR-24 (r(2) = 0.76-0.77). Various forms of nutrients (total phosphorus and area-weighted total nitrogen loading) were significant for predicting GPP in two study areas, with habitat variables important in seven significant models. Important physical variables included light availability, precipitation, basin area, and in-stream habitat cover. Both benthic and seston chlorophyll were not found to be important explanatory variables in any of the models; however, benthic ash-free dry weight was important in two models for GPP.

Effects of drought stressed cotton, Gossypium hirsutum L., on beet armyworm, Spodoptera exigua (Hübner), oviposition, and larval feeding preferences and growth.

The beet armyworm, Spodoptera exigua (Hübner), has been anecdotally reported to oviposit more on drought stressed than on nonstressed cotton plants. Using potted cotton plants in cages, this study demonstrated that beet armyworms deposited 3.3, 4.6, and 2.3 times more (P < or = 0.05) eggs on cotton plants that were grown on 1500, 1000, and 750 ml water/wk, respectively, than on cotton plants grown in well watered (4000 ml water/wk) soil. Third instars, however, showed no preference for stressed cotton foliage over nonstressed foliage. Third instar beet armyworms raised on well watered cotton plants were 1.5, 2.3, and 2.6 times heavier than those reared on cotton grown in the 1500, 1000, and 750 ml water/wk plants (P < or = 0.05), respectively. Physiochemical analyses showed that drought stressed leaves had significantly greater accumulations of free amino acids that are essential for insect growth and development. Soluble protein and soluble carbohydrates were also more abundant in stressed leaves compared to nonstressed leaves. Despite the apparent increase in nutritional quality in drought stressed plants, larval survival was reduced, probably because the limiting factor became water. Greater amounts of cotton leaf area were consumed from drought stressed leaves (P < or = 0.05) than from nonstressed leaves, probably because the larvae had to metabolize greater portions of assimilated energy to supplement body water with metabolic water derived from respiration. The association of greater host plant nutritional quality to oviposition preference, and conversely, to reduced survivorship, is discussed.