Deep-water first occurrences of Ediacara biota prior to the Shuram carbon isotope excursion in the Wernecke Mountains, Yukon, Canada.

Ediacara-type macrofossils appear as early as ~575 Ma in deep-water facies of the Drook Formation of the Avalon Peninsula, Newfoundland, and the Nadaleen Formation of Yukon and Northwest Territories, Canada. Our ability to assess whether a deep-water origination of the Ediacara biota is a genuine reflection of evolutionary succession, an artifact of an incomplete stratigraphic record, or a bathymetrically controlled biotope is limited by a lack of geochronological constraints and detailed shelf-to-slope transects of Ediacaran continental margins. The Ediacaran Rackla Group of the Wernecke Mountains, NW Canada, represents an ideal shelf-to-slope depositional system to understand the spatiotemporal and environmental context of Ediacara-type organisms' stratigraphic occurrence. New sedimentological and paleontological data presented herein from the Wernecke Mountains establish a stratigraphic framework relating shelfal strata in the Goz/Corn Creek area to lower slope deposits in the Nadaleen River area. We report new discoveries of numerous Aspidella hold-fast discs, indicative of frondose Ediacara organisms, from deep-water slope deposits of the Nadaleen Formation stratigraphically below the Shuram carbon isotope excursion (CIE) in the Nadaleen River area. Such fossils are notably absent in coeval shallow-water strata in the Goz/Corn Creek region despite appropriate facies for potential preservation. The presence of pre-Shuram CIE Ediacara-type fossils occurring only in deep-water facies within a basin that has equivalent well-preserved shallow-water facies provides the first stratigraphic paleobiological support for a deep-water origination of the Ediacara biota. In contrast, new occurrences of Ediacara-type fossils (including juvenile fronds, Beltanelliformis, Aspidella, annulated tubes, and multiple ichnotaxa) are found above the Shuram CIE in both deep- and shallow-water deposits of the Blueflower Formation. Given existing age constraints on the Shuram CIE, it appears that Ediacaran organisms may have originated in the deeper ocean and lived there for up to ~15 million years before migrating into shelfal environments in the terminal Ediacaran. This indicates unique ecophysiological constraints likely shaped the initial habitat preference and later environmental expansion of the Ediacara biota.

Coral Gardens Reef, Belize: A refugium in the face of Caribbean-wide Acropora spp. coral decline.

Caribbean Acropora spp. corals have undergone a decline in cover since the second half of the twentieth century. Loss of these architecturally complex and fast-growing corals has resulted in significant, cascading changes to the character, diversity, and available eco-spaces of Caribbean reefs. Few thriving Acropora spp. populations exist today in the Caribbean and western North Atlantic seas, and our limited ability to access data from reefs assessed via long-term monitoring efforts means that reef scientists are challenged to determine resilience and longevity of existing Acropora spp. reefs. Here we used multiple dating methods to measure reef longevity and determine whether Coral Gardens Reef, Belize, is a refuge for Acropora cervicornis against the backdrop of wider Caribbean decline. We used a new genetic-aging technique to identify sample sites, and radiocarbon and high-precision uranium-thorium (U-Th) dating techniques to test whether one of the largest populations of extant A. cervicornis in the western Caribbean is newly established after the 1980s, or represents a longer-lived, stable population. We did so with respect for ethical sampling of a threatened species. Our data show corals ranging in age from 1910 (14C) or 1915 (230Th) to at least November 2019. While we cannot exclude the possibility of short gaps in the residence of A. cervicornis earlier in the record, the data show consistent and sustained living coral throughout the 1980s and up to at least 2019. We suggest that Coral Gardens has served as a refuge for A. cervicornis and that identifying other, similar sites may be critical to efforts to grow, preserve, conserve, and seed besieged Caribbean reefs.

Calibrating the coevolution of Ediacaran life and environment.

The rise of animals occurred during an interval of Earth history that witnessed dynamic marine redox conditions, potentially rapid plate motions, and uniquely large perturbations to global biogeochemical cycles. The largest of these perturbations, the Shuram carbon isotope excursion, has been invoked as a driving mechanism for Ediacaran environmental change, possibly linked with evolutionary innovation or extinction. However, there are a number of controversies surrounding the Shuram, including its timing, duration, and role in the concomitant biological and biogeochemical upheavals. Here we present radioisotopic dates bracketing the Shuram on two separate paleocontinents; our results are consistent with a global and synchronous event between 574.0 ± 4.7 and 567.3 ± 3.0 Ma. These dates support the interpretation that the Shuram is a primary and synchronous event postdating the Gaskiers glaciation. In addition, our Re-Os ages suggest that the appearance of Ediacaran macrofossils in northwestern Canada is identical, within uncertainty, to similar macrofossils from the Conception Group of Newfoundland, highlighting the coeval appearance of macroscopic metazoans across two paleocontinents. Our temporal framework for the terminal Proterozoic is a critical step for testing hypotheses related to extreme carbon isotope excursions and their role in the evolution of complex life.

Tailored e-mails in the workplace.

Employee wellness programs can potentially contribute to a stronger and healthier work force, with increased dexterity and positive mental health. Programs that keep the work force physically active can reduce heart disease, type 2 diabetes, hypertension, hyperlipidemia, cerebrovascular accident, and workplace injury. The occupational health nurse provides information to motivate employees to take the first step toward an active lifestyle. The purpose of this article is to present the qualitative evaluation results of an intervention study that tested the effectiveness of tailored e-mail communications designed to increase intentional physical activity in a group of manufacturing workers. The increase in overall physical activity demonstrates the effectiveness of the workplace interventions. Research will now strengthen theoretical concepts, refine messages, and increase both the dose and the power of the interventions.

Medroxyprogesterone acetate inhibits CD8+ T cell viral-specific effector function and induces herpes simplex virus type 1 reactivation.

Clinical research suggests hormonal contraceptive use is associated with increased frequencies of HSV reactivation and shedding. We examined the effects of medroxyprogesterone acetate (MPA), the compound most commonly used for injectable hormonal contraception, on HSV type 1 (HSV-1) reactivation and CD8(+) T cell function in murine trigeminal ganglia (TG). In ex vivo TG cultures, MPA dramatically inhibited canonical CD8(+) T cell effector functions, including IFN-gamma production and lytic granule release, and increased HSV-1 reactivation from latency. In vivo, MPA treatment of latently infected ovariectomized mice inhibited IFN-gamma production and lytic granule release by TG resident CD8(+) T cells stimulated directly ex vivo. RNA specific for the essential immediate early viral gene ICP4 as well as viral genome DNA copy number were increased in mice that received MPA during latency, suggesting that treatment increased in vivo reactivation. The increase in HSV-1 copy number appeared to be the result of a two-tine effect, as MPA induced higher reactivation frequencies from latently infected explanted TG neurons in the presence or absence of CD45(+) cells. Our data suggest hormonal contraceptives that contain MPA may promote increased frequency of HSV reactivation from latency through the combinatory effects of inhibiting protective CD8(+) T cell responses and by a leukocyte-independent effect on infected neurons.

A delicate balance: risk factors for acquisition of bacterial vaginosis include sexual activity, absence of hydrogen peroxide-producing lactobacilli, black race, and positive herpes simplex virus type 2 serology.

BACKGROUND: The etiology of bacterial vaginosis (BV) is poorly understood, but better definition of the risk factors associated with its acquisition should improve our understanding of this complex disease entity. METHODS: A longitudinal cohort study of young sexually active women was conducted to identify variables associated with BV acquisition. Seven hundred seventy-three women without BV at enrollment were followed at 4-month intervals for 1 year. At each visit, demographic and behavioral interview data, a vaginal smear for the Gram stain diagnosis of BV, and a serum sample for detection of herpes simplex virus type 1 (HSV-1) and HSV-2 type-specific antibodies were collected. RESULTS: The overall incidence of BV acquisition was 36 cases/100 woman-years (223 acquisitions of BV during 619 woman-years of follow-up). Acquisition of BV was independently associated with black race, cigarette smoking, vaginal intercourse, receptive anal sex before vaginal intercourse, sex with an uncircumcised male partner, lack of vaginal H2O2-producing lactobacilli, and the detection of HSV-2 serum antibodies at the visit before BV acquisition. Longitudinal analyses revealed that HSV-2 serum antibodies were independently associated with loss of H2O2-producing lactobacilli. CONCLUSIONS: Our findings suggest that multiple and diverse risk factors can contribute to BV acquisition. They also illustrate why a more complete understanding of BV pathogenesis and the formulation of effective BV prevention strategies have been elusive. Further work will be needed to determine the specific effects of HSV-2 infection on vaginal flora composition and the acquisition of BV.

Photolytically driven generation of dissolved oxygen and increased oxyhemoglobin in whole blood.

The severely debilitating nature of chronic lung disease has long provided the impetus for the development of technologies to supplement the respiratory capacity of the human lung. Although conventional artificial lung technologies function by delivering pressurized oxygen to the blood through a system of hollow fibers or tubes, our approach uses photolytic energy to generate dissolved oxygen (DO) from the water already present in blood, thus eliminating the need for gas delivery. We have previously demonstrated that it is feasible to generate dissolved oxygen from water based on UVA illumination of a highly absorbent TiO2 thin film. In the current study, we extend this work by using photolytic energy to generate DO from whole blood, thus resulting in an increase of oxyhemoglobin as a function of back side TiO2 surface film illumination. Initial experiments, performed with Locke's Ringer solution, demonstrated effective film thickness and material selection for the conductive layer. The application of a small bias voltage was used to conduct photogenerated electrons from the aqueous phase to minimize electron recombination with the DO.Mixed arterial-venous bovine blood was flowed in a recirculating loop over TiO2 nanocrystalline films illuminated on the side opposite the blood (or "back side") to eliminate the possibility of any direct exposure of blood to light. After light exposure of the TiO2 film, the fraction of oxyhemoglobin in the blood rapidly increased to near saturation and remained stable throughout the trial period. Last, we evaluated potential biofouling of the DO generating surface by scanning electron microscopy, after photolytically energized DO generation in whole blood, and observed no white or red blood cell surface deposition, nor the accumulation of any other material at this magnification. We conclude that it is feasible to photolytically oxygenate the hemoglobin contained in whole blood with oxygen derived from the blood's own water content without involving a gaseous phase.

Use of personal digital assistants in diagnostic radiology resident education.

RATIONALE AND OBJECTIVES: Personal digital assistants (PDAs) are gaining widespread use in the medical community. We introduced a PDA-based mobile system that provides departmental and educational information with a seamless connection to the intranet. The objective of this study is to determine the impact a PDA has on educational resources (learning or data reference) brought to work and used at home by a radiology resident based on user surveys. MATERIALS AND METHODS: Survey was performed on 32 radiology residents in our department before and 6 months after the release of the PDA-based system. We assessed the changes in (1) sources of learning at home and at work, and in (2) data reference. The second survey also evaluated the usefulness of each component of the system. RESULTS: After the release of the PDA-based mobile system, the use of "digital books and references" as data references and educational resources that were brought to work every day significantly increased (P = .016, P < .0001, respectively). "Traditional books and references" remained the "most useful source in learning radiology"; however, "digital books and references" increased as the residents' first choice from 0% to 16% within 6 months of introducing the package (P = .125). CONCLUSION: The introduction of a PDA-based system consisting of educational and departmental information had a statistically significant impact in increasing the use of digitized information in radiology resident education.

A mobile solution: PDA-based platform for radiology information management.

OBJECTIVE: We describe how our radiology department set up, integrated, and deployed a personal digital assistant-based mobile platform to deliver updated critical departmental and educational material to our residents. CONCLUSION: We have implemented and described a robust mobile solution that maintains a seamless connection with the departmental intranet. Resident feedback regarding the use of the mobile solution program has confirmed our belief that using this mobile technology is a feasible and clinically practical alternative for accessing time-sensitive and educational materials. Furthermore, our description can help others deploy such digital products and facilitate the transition to soft copy that is already occurring in radiology education.

Development of a photolytic artificial lung: preliminary concept validation.

There is an established need for pulmonary technology capable of facilitated gas exchange in the blood, thereby bypassing the alveolar-capillary interface. To address this need, we emulated one of the best-known photolytic reactions in nature, photosynthesis, in which green plants use sunlight to drive the exchange of oxygen for carbon dioxide. Our goal in the current study was to demonstrate the feasibility of direct photolytic conversion of water to liquid phase oxygen (dissolved oxygen [DO]) in synthetic serum. To this end, we constructed a test flow cell consisting of a conductive coating of vacuum-deposited titanium (Ti) metal, adherent TiO2 (anatase), and MnO2, applied as a laminate to a glass substrate, and then immersed the device in Locke's-Ringer solution (synthetic blood serum). Long wavelength (low energy) ultraviolet A laser light, directed to the transparent glass slide, reproducibly resulted in the generation of an active form of oxygen (AO), which was subsequently converted directly by the catalytic action of MnO2 to DO. The absence of light activation provided an entirely null response. We conclude that the photolytic production of DO from water in a blood serum surrogate, with commensurate CO2 clearance, is feasible. A prototype photolytic module is proposed, which uses multiple parallel photolytic surfaces to improve system production capacity and CO2 clearance through selective gas-liquid separation from the oxygen-enriched fluid.