Asynchronous division by non-ring FtsZ in the gammaproteobacterial symbiont of <em>Robbea hypermnestra</em>

The reproduction mode of uncultivable microorganisms deserves investigation as it can largely diverge from conventional transverse binary fission. Here, we show that the rod-shaped gammaproteobacterium thriving on the surface of the Robbea hypermnestra nematode divides by FtsZ-based, non-synchronous invagination of its poles-that is, the host-attached and fimbriae-rich pole invaginates earlier than the distal one. We conclude that, in a naturally occurring animal symbiont, binary fission is host-oriented and does not require native FtsZ to polymerize into a ring at any septation stage

The role of interparticle heterogeneities in the selenization pathway of Cu Zn Sn S nanoparticle thin films a real time study

Real time energy dispersive X ray diffraction EDXRD analysis has been utilized to observe the selenization of Cu Zn Sn S nanoparticle films coated from three nanoparticle populations Cu and Sn rich particles roughly 5 nm in size, Zn rich nanoparticles ranging from 10 to 20 nm in diameter, and a mixture of both types of nanoparticles roughly 1 1 by mass , which corresponds to a synthesis recipe yielding CZTSSe solar cells with reported total area efficiencies as high as 7.9 . The EDXRD studies presented herein show that the formation of copper selenide intermediates during the selenization of mixed particle films can be primarily attributed to the small, Cu and Sn rich particles. Moreover, the formation of these copper selenide phases represents the first stage of the CZTSSe grain growth mechanism. The large, Zn rich particles subsequently contribute their composition to form micrometer sized CZTSSe grains. These findings enable further development of a previously proposed selenization pathway to account for the roles of interparticle heterogeneities, which in turn provides a valuable guide for future optimization of processes to synthesize high quality CZTSSe absorber layer

Enhanced superconductivity of YBCO interfaces: origin of high critical temperature in layered superconductors

Superconducting transition temperatures Tc of the YBCO film surface and of the YBCO film/substrate interface were measured inductively. It was observed that the interface- Tc is always higher then the surface - Tc. However deposition of silver over-layer enhances the superconducting transition temperatures. This observation was confirmed by four-point resistance measurements. In the annealed YBCO/Ag bilayers magnetic properties of the interface were observed. We believe that such phenomena are a common feature of layered systems. This two dimensional structure reminds the layered microstructure of the high-temperature superconductors and one can suppose that covering of the superconducting layer by non-superconducting layer is a condition for obtaining high critical temperatures in general.Comment: 13 pages, 9 figures, submited to Natur

Healthcare Provider N95 Respirator Contamination Worn Behind Face Shields With SARS-CoV-2 During Routine Clinical Care of Patients With COVID-19

N95 respirator contamination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during clinical care of patients with coronavirus disease 2019 is poorly understood. We performed a prospective observational study on healthcare provider's (HCP's) N95 respirators' and face shields' SARS-CoV-2 contamination during aerosol-generating procedures on SARS-CoV-2- positive patients housed in a COVID-19-specific unit. Medical masks worn on top of HCP's N95 respirators, and under face shields, during study aerosol-generating procedures were used as surrogates to detect contamination to avoid waste. Thirtythree HCPs were studied, and a total of 33 mask and 27 face shields were sampled. Masks were cut into 9 pieces and face shields were sampled twice, front and back, to determine locality of contamination; however, no positive samples were identified using standard polymerase chain reaction techniques with a CT value up to 40. All 9 mask piece samples were then pooled, as were face shield samples, using centrifugal concentration with polyethersulfone membranes. Once pooled and concentrated, overall, 9 (15%) samples were positive via real-time polymerase chain reaction: 5 from masks (15.2%) and 4 from face shields (14.8%)

From VAP to VAE: Implications of the new CDC definitions on a burn intensive care unit population

Ventilator-associated pneumonia (VAP) is a frequent complication of severe burn injury. Comparing the current ventilator-associated event-possible VAP definition to the pre-2013 VAP definition, we identified considerably fewer VAP cases in our burn ICU. The new definition does not capture many VAP cases that would have been reported using the pre-2013 definition

The rate of colonization by macro-invertebrates on artificial substrate samplers

The influence of exposure time upon macro-invertebrate colonization on modified Hester-Dendy substrate samplers was investigated over a 60-day period. The duration of exposure affected the number of individuals, taxa and community diversity. The numbers of individuals colonizing the samplers reached a maximum after 39 days and then began to decrease, due to the emergence of adult insects. Coefficients of variation for the four replicate samples retrieved each sampling day fluctuated extensively throughout the study. No tendencies toward increasing or decreasing coefficients of variation were noted with increasing time of sampler exposure. The number of taxa colonizing the samplers increased throughout the study period. The community diversity index was calculated for each sampling day and this function tended to increase throughout the same period. This supports the hypothesis that an exposure period of 6 weeks, as recommended by the United States Environmental Protection Agency, may not always provide adequate opportunity for a truly representative community of macro-invertebrates to colonize multiplate samplers. Many of the taxa were collected in quite substantial proportions after periods of absence or extreme sparseness. This is attributed to the growth of periphyton and the collection of other materials that created food and new habitats suitable for the colonization of new taxa. Investigation of the relationship between ‘equitability’ and length of exposure revealed that equitability did not vary like diversity with increased time of exposure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72073/1/j.1365-2427.1979.tb01522.x.pd

Improving Research Enrollment of Severe Burn Patients

Enrolling severely burn injured patients into prospective research studies poses specific challenges to investigators. The authors describe their experience of recruiting adults with ≥20% TBSA burns or inhalation injury admitted to a single academic burn unit into observational research with minimally invasive specimen collection. The authors outline iterative changes that they made to their recruitment processes in response to perceived weaknesses leading to delays in enrollment. The primary outcome was the change in days to consent for enrolled patients or cessation of recruitment for nonenrolled patients before and after the interventional modifications. The authors assessed change in overall enrollment as a secondary outcome. Study enrollment was approximately 70% in both 4-month study periods before and after the intervention. Following the intervention, time to consent by surrogate decision maker decreased from a median of 26.5 days (interquartile range [IQR] 14-41) to 3 days (IQR 3-6) (P =.004). Time to initial consent by patient changed from a median of 15 days (IQR 2-30) to 3 days (IQR 2-6) (P =.27). Time to decline for nonenrolled patients decreased from a median of 12 days (IQR 6.5-27) to 1.5 days (IQR 1-3.5) (P =.026). Both the findings of the study and a brief literature review suggest that careful design of the recruitment protocol, increased experience of the study team, and broad time windows for both approach and enrollment improve the efficiency of recruiting critically injured burn patients into research

Electric current circuits in astrophysics

Cosmic magnetic structures have in common that they are anchored in a dynamo, that an external driver converts kinetic energy into internal magnetic energy, that this magnetic energy is transported as Poynting fl ux across the magnetically dominated structure, and that the magnetic energy is released in the form of particle acceleration, heating, bulk motion, MHD waves, and radiation. The investigation of the electric current system is particularly illuminating as to the course of events and the physics involved. We demonstrate this for the radio pulsar wind, the solar flare, and terrestrial magnetic storms

Self-monitoring by Environmental Services May Not Accurately Measure Thoroughness of Hospital Room Cleaning

The hospital environment and environmental contamination are increasingly emphasized in the prevention of healthcare-associated infection.1 Appropriate cleaning and disinfection of the hospital environment has emerged as a key infection prevention strategy, yet environmental services (EVS) personnel often fail to clean and disinfect all surfaces in hospital rooms.2 Consequently, the Centers for Disease Control and Prevention (CDC) recommends that all hospitals perform objective monitoring of environmental cleaning and disinfection.3 More specifically, the CDC tool kit emphasizes that monitoring should be performed by hospital epidemiologists or infection preventionists who are not part of EVS to reduce the likelihood of surveillance bias and to assure the validity of results. To date, however, few if any studies have compared monitoring results of EVS and non-EVS personnel