Seed Bank and Seasonal Patterns of the Eukaryotic SAR (Stramenopila, Alveolata and Rhizaria) Clade in a New England Vernal Pool

Vernal pools are dynamic freshwater ecosystems that dry during the summer. These unique habitats are vital to a number of well-studied animal species but there is little documentation of the diversity of the SAR—Stramenopila, Alveolata and Rhizaria—clade in vernal pools. Here, we characterize the protist community over a portion of the hydroperiod as the vernal pool transitions from its winter stage through its drying out in late summer. Our study focuses on the SAR clade, which encompasses a broad range of morphological diversity and a variety of trophic modes within the microbial food web. Using high-throughput sequencing, we investigate the total community (DNA) and the active (RNA) members on a temporal scale. These molecular data reveal seasonality within microbial communities, suggesting a larger community of autotrophs in the winter followed by an increase in heterotrophs in the summer. Our analysis also suggests the presence of a microbial seed bank, a collection of encysted protists, in the sediments below the pool. We hypothesize the seed bank allows for community turnover: taxa encyst in the sediment in poor environmental conditions and exit their cysts when favorable conditions occur. We also observe seasonal preference and partitioning of the environment within clades of close relatives, including taxa closely related to the ciliate Halteria and the oomycete Haptoglossa. These data provide insights into the seasonal patterns of a frequently overlooked group of organisms in this unusual environment

Results of the ICTuS 2 Trial (Intravascular Cooling in the Treatment of Stroke 2)

Background and purposeTherapeutic hypothermia is a potent neuroprotectant approved for cerebral protection after neonatal hypoxia-ischemia and cardiac arrest. Therapeutic hypothermia for acute ischemic stroke is safe and feasible in pilot trials. We designed a study protocol to provide safer, faster therapeutic hypothermia in stroke patients.MethodsSafety procedures and 4°C saline infusions for faster cooling were added to the ICTuS trial (Intravascular Cooling in the Treatment of Stroke) protocol. A femoral venous intravascular cooling catheter after intravenous recombinant tissue-type plasminogen activator in eligible patients provided 24 hours cooling followed by a 12-hour rewarm. Serial safety assessments and imaging were performed. The primary end point was 3-month modified Rankin score 0,1.ResultsOf the intended 1600 subjects, 120 were enrolled before the study was stopped. Randomly, 63 were to receive hypothermia plus antishivering treatment and 57 normothermia. Compared with previous studies, cooling rates were improved with a cold saline bolus, without fluid overload. The intention-to-treat primary outcome of 90-day modified Rankin Score 0,1 occurred in 33% hypothermia and 38% normothermia subjects, odds ratio (95% confidence interval) of 0.81 (0.36-1.85). Serious adverse events occurred equally. Mortality was 15.9% hypothermia and 8.8% normothermia subjects, odds ratio (95% confidence interval) of 1.95 (0.56-7.79). Pneumonia occurred in 19% hypothermia versus 10.5% in normothermia subjects, odds ratio (95% confidence interval) of 1.99 (0.63-6.98).ConclusionsIntravascular therapeutic hypothermia was confirmed to be safe and feasible in recombinant tissue-type plasminogen activator-treated acute ischemic stroke patients. Protocol changes designed to reduce pneumonia risk appeared to fail, although the sample is small.Clinical trial registrationURL: http://www.clinicaltrials.gov. Unique identifier: NCT01123161