Interpreting an Archaean paleoenvironment through 3D imagery of microbialites

While stromatolites, and to a lesser extent thrombolites, have been extensively studied in order to unravel Precambrian (>539 Ma) biological evolution, studies of clastic-dominated microbially induced sedimentary structures (MISS) are relatively scarce. The lack of a consolidated record of clastic microbialites creates questions about how much (and what) information on depositional and taphonomic settings can be gleaned from these fossils. We used μCT scanning, a non-destructive X-ray-based 3D imaging method, to reconstruct morphologies of ancient MISS and mat textures in two previously described coastal Archaean samples from the ~3.48 Ga Dresser Formation, Pilbara, Western Australia. The aim of this study was to test the ability of μCT scanning to visualize and make 3D measurements that can be used to interpret the biotic–environmental interactions. Fossil MISS including mat laminae with carpet-like textures in one sample and mat rip-up chips in the second sample were investigated. Compiled δ¹³C and δ³⁴S analyses of specimens from the Dresser Fm. are consistent with a taxonomically diverse community that could be capable of forming such MISS. 3D measurements of fossil microbial mat chips indicate significant biostabilization and suggest formation in flow velocities >25 cm s⁻¹. Given the stratigraphic location of these chips in a low-flow lagoonal layer, we conclude that these chips formed due to tidal influence, as these assumed velocities are consistent with recent modeling of Archaean tides. The success of μCT scanning in documenting these microbialite features validates this technique both as a first step analysis for rare samples prior to the use of more destructive techniques and as a valuable tool for gaining insight into microbialite taphonomy.     

Moths complement bumblebee pollination of red clover: a case for day-and-night insect surveillance

Recent decades have seen a surge in awareness about insect pollinator declines. Social bees receive the most attention, but most flower-visiting species are lesser known, non-bee insects. Nocturnal flower visitors, e.g. moths, are especially difficult to observe and largely ignored in pollination studies. Clearly, achieving balanced monitoring of all pollinator taxa represents a major scientific challenge. Here, we use time-lapse cameras for season-wide, day-and-night pollinator surveillance of Trifolium pratense (L.; red clover) in an alpine grassland. We reveal the first evidence to suggest that moths, mainly Noctua pronuba (L.; large yellow underwing), pollinate this important wildflower and forage crop, providing 34% of visits (bumblebees: 61%). This is a remarkable finding; moths have received no recognition throughout a century of T. pratense pollinator research. We conclude that despite a non-negligible frequency and duration of nocturnal flower visits, nocturnal pollinators of T. pratense have been systematically overlooked. We further show how the relationship between visitation and seed set may only become clear after accounting for moth visits. As such, population trends in moths, as well as bees, could profoundly affect T. pratense seed yield. Ultimately, camera surveillance gives fair representation to non-bee pollinators and lays a foundation for automated monitoring of species interactions in future.     

ROENTGEN THERAPY OF RHEUMATOID SPONDYLITIS

Based on the pathological processes involved in rheumatoid spondylitis, comparison is made between the physical qualities of certain techniques of roentgen therapy. Graphic representation of the isodose curves and the homogeneous distribution of radiation pertaining to the method herein advocated is shown.Results obtained in the treatment of 125 cases illustrative of the evolution of technique experienced at the University of California Hospital are tabulated. The indications, contraindications, and complications of the method are discussed.Practically every patient with rheumatoid spondylitis, regardless of the stage of the disease, was benefited, with the best results having been obtained when the radiation was given in three courses, separated by rest periods, and homogeneously distributed along the spine.     

Intrathecal Morphine Use in Adolescent Idiopathic Scoliosis Surgery is Associated with Decreased Opioid Use and Decreased Length of Stay

BackgroundLength of stay (LOS) in the hospital following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) has decreased over the past decade due to well-defined postoperative clinical pathways, earlier mobilization, and improved pain control methods. Historically, liberal use of parenteral and oral opioids for pain control caused side effects, resulting in delayed discharge. Intraoperative intrathecal morphine (ITM) has been posited to reduce the need for postoperative opioids and to expedite the discharge process. This study examines the relationship between the use of ITM with average required postoperative opioid usage and with average LOS.MethodsThis IRB-approved retrospective cohort study examined 105 patients with AIS who received PSF with instrumentation split into two cohorts. One cohort underwent PSF via standard surgical protocol (n=40) while the other cohort received intraoperative ITM with the standard surgical protocol (n=65). Power analysis demonstrated a study power of 0.8. LOS and total postoperative opioid analgesic medication (morphine milligram equivalent, MME) data were collected. Age at surgery, gender, number of spinal levels fused, estimated intraoperative blood loss (EBL), preoperative Cobb angle, and any complications related to the use of ITM were also recorded. Continuous variables were analyzed with Student’s t-test and categorical variables were analyzed with chi-square independent-sample tests using SAS 9.4 (α = 0.05).ResultsPatients who were treated with ITM displayed shorter LOS (p<0.0001) and reduced postoperative analgesic requirement (p<0.0001). Patients who received ITM spent an average of 1.8 fewer midnights in the hospital and received an average of 221.2 MME less than patients who received standard protocol (57% decrease). There were no significant differences between the two groups for any other variable.ConclusionIntraoperative ITM is a simple and effective treatment for scoliosis surgeons to better control postoperative pain in patients, reduce the risk of dependency, and achieve earlier discharge from the hospital. Shortened LOS reduces the overall cost of care, benefitting patients, hospitals, and insurance companies. Based on the results of this study and several earlier studies, the authors recommended that scoliosis surgeons consider incorporating use of ITM into their standard operative protocols. Level of Evidence: IV