RESUMEN
Female ticks deposit large egg clusters that range in size from hundreds to thousands. These clusters are restricted to a deposition site, usually under leaf litter and other debris. These sites can be exposed to periodic flooding, where the cluster of tick eggs can float to the surface or remain underneath organic debris entirely underwater. Here, we examined the viability of egg clusters from winter ticks, Dermacentor albipictus , and lone star ticks, Amblyomma americanum , when partially submerged or fully submerged in water in relation to the developmental stages of the eggs. In general, egg clusters that were older and partially submerged had a higher viability than fully submerged, young eggs in water. A. americanum was much more resistant to water exposure between the two species. These studies highlight that egg clusters for specific tick species can remain viable when exposed to water for at least two weeks, where eggs float on the surface. These studies also suggest that water-based distribution of egg clusters could occur for some species, and flooding will differentially impact tick egg survival based on the specific developmental stage of exposure and species.
RESUMEN
BACKGROUND: Bariatric surgery is effective for patients with severe obesity, but relatively little is known about long-term functional outcomes. OBJECTIVE: To describe physical fitness and activity changes among bariatric surgery patients in a clinical trial of physical activity interventions through 5 years postoperatively. SETTING: Large bariatric center in the midwestern United States. METHODS: Preoperatively, 6 months, and 5 years after surgery, 42 bariatric surgery patients wore an accelerometer to track activity and completed strength and cardiovascular endurance testing via treadmill, where estimated metabolic equivalents (METs) and ratings of perceived exertion (RPEs) were obtained. RESULTS: Preoperatively, 25% of patients reported exertion of <3 METs (equivalent to walking 2.5 mi/hr) as an RPE of 16 ("hard to very hard"). This decreased significantly to approximately 5% of patients 6 months and 5 years after surgery. Before surgery, 7.5% achieved ≥6 METs (vigorous activity) at an RPE of 16. This increased significantly to 36.6% at 6 months and 42.1% at 5 years after surgery. Body mass index and age, but no physical activity measure, predicted functional ability over time. The steps/d and exercise bout min/wk increased significantly from before surgery to 6 months postoperatively (4886.5 to 5948.5 steps and 23.8 to 66.6 bout min), but increases were not maintained at 5 years (5677.7 steps and 41.4 bout min). Conversely, moderate to vigorous min/ d increased progressively from before surgery (17.4) to 6 months (32.3) and 5 years (48.1) postoperatively. CONCLUSIONS: Functional abilities of bariatric surgery patients increased postoperatively and were maintained over 5 years. However, treadmill testing suggests that most patients are still unable to perform sustained activities of 6 METs (vigorous) or greater. Research is needed on bariatric patients' long-term function- and intervention- optimizing outcomes.
RESUMEN
The mosquito midgut is an important site for bloodmeal regulation while also acting as a primary site for pathogen exposure within the mosquito. Recent studies show that exposure to dehydrating conditions alters mosquito bloodfeeding behaviors as well as post-feeding regulation, likely altering how pathogens interact with the mosquito. Unfortunately, few studies have explored the underlying dynamics between dehydration and bloodmeal utilization, and the overall impact on disease transmission dynamics remains veiled. In this study, we find that dehydration-based feeding in the yellow fever mosquito, Aedes aegypti, prompts alterations to midgut gene expression, as well as subsequent physiological factors involving water control and post-bloodfeeding (pbf) regulation. Altered expression of ion transporter genes and aquaporin 2 (AQP2) in the midgut of dehydrated mosquitoes as well as the rapid reequilibration of hemolymph osmolality after a bloodmeal indicate an ability to expedite fluid and ion processing. These alterations ultimately indicate that female A. aegypti employ mechanisms to ameliorate the detriments of dehydration by imbibing a bloodmeal, providing an effective avenue for rehydration. Continued research into bloodmeal utilization and the resulting effects on arthropod-borne transmission dynamics becomes increasingly important as drought prevalence is increased by climate change.