Implementation of a drive cylinder for low collisional experiments on magnetic reconnection.

For most laboratory plasma experiments, Coulomb collisions between the particle species are sufficiently frequent that the particle distribution functions are relaxed to a near-Maxwellian form. This hampers the applicability of such experiments to phenomena observed in tenuous and near-collisionless space plasma. The Terrestrial Reconnection EXperiment (TREX) at the Wisconsin Plasma Physics Laboratory aims to study collisionless reconnection for parameters relevant to the Earth's magnetosphere. To reduce the role of collisional effects, a reconnection Drive Cylinder has been developed, which increases both the effective system size of the TREX configuration and the rate at which reconnection can be driven. These two effects now permit TREX to reach a kinetic reconnection regime where collisional effects are minimized. The Drive Cylinder is comprised of 12 single loop drive-coils connected in parallel to a 10 kV capacitor bank. Insulated sheets of aluminum are applied to smooth the magnetic fields and enhance the drive efficiency. Following is a description of the technical details and performance of the Drive Cylinder.

The inside scoop: Comparative genomics of two intranuclear bacteria, "Candidatus Berkiella cookevillensis" and "Candidatus Berkiella aquae".

"Candidatus Berkiella cookevillensis" (strain CC99) and "Candidatus Berkiella aquae" (strain HT99), belonging to the Coxiellaceae family, are gram-negative bacteria isolated from amoebae in biofilms present in human-constructed water systems. Both bacteria are obligately intracellular, requiring host cells for growth and replication. The intracellular bacteria-containing vacuoles of both bacteria closely associate with or enter the nuclei of their host cells. In this study, we analyzed the genome sequences of CC99 and HT99 to better understand their biology and intracellular lifestyles. The CC99 genome has a size of 2.9Mb (37.9% GC) and contains 2,651 protein-encoding genes (PEGs) while the HT99 genome has a size of 3.6Mb (39.4% GC) and contains 3,238 PEGs. Both bacteria encode high proportions of hypothetical proteins (CC99: 46.5%; HT99: 51.3%). The central metabolic pathways of both bacteria appear largely intact. Genes for enzymes involved in the glycolytic pathway, the non-oxidative branch of the phosphate pathway, the tricarboxylic acid pathway, and the respiratory chain were present. Both bacteria, however, are missing genes for the synthesis of several amino acids, suggesting reliance on their host for amino acids and intermediates. Genes for type I and type IV (dot/icm) secretion systems as well as type IV pili were identified in both bacteria. Moreover, both bacteria contain genes encoding large numbers of putative effector proteins, including several with eukaryotic-like domains such as, ankyrin repeats, tetratricopeptide repeats, and leucine-rich repeats, characteristic of other intracellular bacteria.

Individual participant data meta-analysis of trials comparing frozen versus fresh embryo transfer strategy (INFORM): a protocol.

INTRODUCTION: Existing randomised controlled trials (RCTs) comparing a freeze-all embryo transfer strategy and a fresh embryo transfer strategy have shown conflicting results. A freeze-all or a fresh transfer policy may be preferable for some couples undergoing in-vitro fertilisation (IVF), but it is unclear which couples would benefit most from each policy, how and under which protocols. Therefore, we plan a systematic review and individual participant data meta-analysis of RCTs comparing a freeze-all and a fresh transfer policy. METHODS AND ANALYSIS: We will search electronic databases (Medline, Embase, PsycINFO and CENTRAL) and trial registries (ClinicalTrials.gov and the International Clinical Trials Registry Platform) from their inception to present to identify eligible RCTs. We will also check reference lists of relevant papers. The search was performed on 23 September 2020 and will be updated. We will include RCTs comparing a freeze-all embryo transfer strategy and a fresh embryo transfer strategy in couples undergoing IVF. The primary outcome will be live birth resulting from the first embryo transfer. All outcomes listed in the core outcome set for infertility research will be reported. We will invite the lead investigators of eligible trials to join the Individual participant data meta-analysis of trials comparing frozen versus fresh embryo transfer strategy (INFORM) collaboration and share the deidentified individual participant data (IPD) of their trials. We will harmonise the IPD and perform a two-stage meta-analysis and examine treatment-covariate interactions for important baseline characteristics. ETHICS AND DISSEMINATION: The study ethics have been granted by the Monash University Human Research Ethics Committee (Project ID: 30391). The findings will be disseminated via presentations at international conferences and publication in peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42021296566.

The effect of ovarian follicle size on oocyte and embryology outcomes.

OBJECTIVE: To identify relationships between the size of punctured ovarian follicles and subsequent embryology outcomes. DESIGN: Prospective observational cohort study. SETTING: Private fertility center. PATIENTS: One hundred fifty-seven oocyte retrievals performed during the study period. INTERVENTIONS: The diameter of punctured follicles was ultrasonically measured during routine oocyte collection. The resulting embryos were group-cultured to the blastocyst stage and classified into 8 groups according to follicle size (≤9.5, 10-12.5, 13-15.5, 16-18.5, 19-21.5, 22-24.5, 25-27.5, and ≥28 mm). MAIN OUTCOME MEASURE: Rate of good-quality blastocysts per follicle puncture. RESULTS: This study included 4,539 follicle punctures, 2,348 oocytes, 1,772 mature oocytes, 1,258 bipronuclear (2pn) oocytes, and 571 good-quality blastocysts derived from 157 oocyte retrievals. The per-puncture yields of oocytes, mature oocytes, 2pn oocytes, and good-quality blastocysts were associated with the size of the punctured follicle. The rates of good-quality blastocysts per punctured follicle were 2.2% (≤9.5 mm), 6.2% (10-12.5 mm), 11.9% (13-15.5 mm), 14.5% (16-18.5 mm), 18.9% (19-21.5 mm), 17.5% (22-24.5 mm), 15.9% (25-27.5 mm), and 16.0% (≥28 mm). When compared with the overall average, punctures of follicles in groups ≤12.5 mm in diameter had significantly inferior yields of good-quality blastocysts, whereas punctures of follicles in groups 19-24.5 mm in diameter were associated with significantly greater than average yields of good-quality blastocysts. Other groups did not differ significantly from average. No correlation was observed between follicle diameter and ploidy of biopsied blastocysts. CONCLUSIONS: Punctures of follicles ≤12.5 mm in diameter rarely result in good-quality blastocysts. The yield of good-quality blastocysts progressively increases with follicle size up to approximately 19 mm in diameter, with no substantial decline above that size. The ploidy of the blastocysts that form appears to be unaffected by follicle size.

The change in endometrial thickness following progesterone exposure correlates with in vitro fertilization outcome after transfer of vitrified-warmed blastocysts.

PURPOSE: To determine if the change in endometrial thickness following exogenous progesterone (P) initiation correlates with outcome following autologous transfer of a single thawed blastocyst. METHODS: The study is a retrospective observational cohort study conducted at a private fertility center. Patients scheduled for thawed blastocyst transfer received artificial endometrial preparation (artificial cycle FET) and underwent serial ultrasonography. The main outcomes were the rate of ongoing pregnancy (fetal heart motion at 12 weeks of gestation) and early pregnancy loss. Logistic regression was used to test for correlations between these outcomes and the change in endometrial thickness while adjusting for potential confounders (patient age, embryo quality, and the use of genetic testing). RESULTS: There were 232 qualifying autologous single-blastocyst transfers in the 20-month study period ending 31 December 2019. Mean endometrial thicknesses were 3.8 mm, 10.0 mm, and 11.2 mm at baseline, P initiation, and at transfer, respectively. The change in endometrial thickness after exogenous P exposure ranged from - 5 to + 9 mm and negatively correlated with ongoing pregnancy in logistic regression analyses. Specifically, ongoing pregnancy rates per transfer were 63.2% in 19 cases where endometria compacted by 10% or more, 64.2% in 95 cases where there was unchanged endometrial thickness, and 52.5% in 118 cases where endometria expanded. CONCLUSIONS: The change in endometrial thickness after P initiation was associated with the probability of ongoing pregnancy but not with early pregnancy loss. Ongoing pregnancy rates were greater in endometria with negative growth (compaction) when compared to endometria that grew (expanded) after P exposure.

Ion Heating and Flow Driven by an Instability Found in Plasma Couette Flow.

We present the first observation of instability in weakly magnetized, pressure dominated plasma Couette flow firmly in the Hall regime. Strong Hall currents couple to a low frequency electromagnetic mode that is driven by high-ß (>1) pressure profiles. Spectroscopic measurements show heating (factor of 3) of the cold, unmagnetized ions via a resonant Landau damping process. A linear theory of this instability is derived that predicts positive growth rates at finite ß and shows the stabilizing effect of very large ß, in line with observations.

Laboratory Resolved Structure of Supercritical Perpendicular Shocks.

Supermagnetosonic perpendicular flows are magnetically driven by a large radius theta-pinch experiment. Fine spatial resolution and macroscopic coverage allow the full structure of the plasma-piston coupling to be resolved in laboratory experiment for the first time. A moving ambipolar potential is observed to reflect unmagnetized ions to twice the piston speed. Magnetized electrons balance the radial potential via Hall currents and generate signature quadrupolar magnetic fields. Electron heating in the reflected ion foot is adiabatic.

Weakly Magnetized, Hall Dominated Plasma Couette Flow.

A novel plasma equilibrium in the high-ß, Hall regime that produces centrally peaked, high Mach number Couette flow is described. Flow is driven using a weak, uniform magnetic field and large, cross field currents. Large magnetic field amplification (factor 20) due to the Hall effect is observed when electrons are flowing radially inward, and near perfect field expulsion is observed when the flow is reversed. A dynamic equilibrium is reached between the amplified (removed) field and extended density gradients.

A spectrometer for high-precision ion temperature and velocity measurements in low-temperature plasmas.

We have developed a low-cost spectrometer with simple optical design that achieves unprecedented precision measurements of ion temperature (±0.01 eV) and velocity (±20 m/s). A Fabry-Pérot étalon provides the simultaneous high resolving power and high throughput needed for the light levels available in singly ionized helium and argon plasmas. Reducing the systematic uncertainty in the absolute wavelength calibration needed for the specified velocity precision motivates a Bayesian analysis method called Nested Sampling to address the nontrivial uncertainty in the diffraction order. An initial emission measurement of a singly charged stationary argon plasma yields a temperature of 0.339 ± 0.007 eV and a velocity of -3 ± 4 m/s with a systematic uncertainty of 20 m/s.

Laboratory evidence of dynamo amplification of magnetic fields in a turbulent plasma.

Magnetic fields are ubiquitous in the Universe. The energy density of these fields is typically comparable to the energy density of the fluid motions of the plasma in which they are embedded, making magnetic fields essential players in the dynamics of the luminous matter. The standard theoretical model for the origin of these strong magnetic fields is through the amplification of tiny seed fields via turbulent dynamo to the level consistent with current observations. However, experimental demonstration of the turbulent dynamo mechanism has remained elusive, since it requires plasma conditions that are extremely hard to re-create in terrestrial laboratories. Here we demonstrate, using laser-produced colliding plasma flows, that turbulence is indeed capable of rapidly amplifying seed fields to near equipartition with the turbulent fluid motions. These results support the notion that turbulent dynamo is a viable mechanism responsible for the observed present-day magnetization.

Observation of Electron Bernstein Wave Heating in a Reversed Field Pinch.

The first observation of rf heating in a reversed field pinch (RFP) using the electron Bernstein wave (EBW) is demonstrated on the Madison Symmetric Torus. Propagation across and heating in a stochastic magnetic field is observed. Novel techniques are required to measure the suprathermal electron tail generated by EBW heating in the presence of intense Ohmic heating. rf-heated electrons directly probe the edge transport properties in the RFP; measured loss rates imply a large noncollisional radial diffusivity.

[Cryptosporidiosis, a cause of acute diarrhea: A review and retrospective study of cases in Rouen university hospital's pediatrics department]. / La cryptosporidiose, une cause de diarrhée aiguë : revue de la littérature et étude rétrospective des cas dans le département de pédiatrie du CHU de Rouen.

Cryptosporidium is the most important diarrhea-causing protozoan parasite, with severe health consequences for very young, malnourished children living in endemic areas and for immunocompromised individuals. Cryptosporidium is widely distributed and disease transmission can occur through person-to-person or animal-to-person contact, or contaminated food or water (drinking or swimming), leading to large outbreaks. The zoonotic Cryptosporidium parvum and the anthroponotic Cryptosporidium hominis are responsible for the majority of human cases. Specific therapy, primarily nitazoxanide, has some effect in healthy individuals, but drugs effectively preventing or controlling this disease in all clinical situations are not yet available. In France, as elsewhere in Europe, little epidemiological and molecular information is available regarding the burden of cryptosporidiosis in children. Cryptosporidium is usually not tested in all fecal samples submitted for routine parasitological examination and only tested on special request, primarily in immunocompromised patients. Between January 2007 and October 2014, out of a total of 5337 immunocompetent children with diarrhea in Rouen university hospital's pediatrics department, the prevalence of Cryptosporidium infection was 0.97 % (52 infected children). The median age of infected children was 3 years (range, 5 months to 11 years) and 80 % of the cases occurred between July and November. Thirty-six (69.2 %) and 16 (30.8 %) infections were due to C. parvum and C. hominis, respectively. The fact that the species C. parvum, mainly the IIaA15G2R1 subtype, was detected in most locally infected children suggests that cryptosporidiosis must primarily be considered as a zoonotic disease in Upper Normandy.

Porous monolith microfluidics for bacterial cell-to-cell communication assays.

Genetically engineered bacteria can be used for a wide range of applications, from monitoring environmental toxins to studying complex communication networks in the human digestive system. Although great strides have been made in studying single strains of bacteria in well-controlled microfluidic environments, there remains a need for tools to reliably control and measure communication between multiple discrete bacterial populations. Stable long-term experiments (e.g., days) with controlled population sizes and regulated input (e.g., concentration) and output measurements can reveal fundamental limits of cell-to-cell communication. In this work, we developed a microfluidic platform that utilizes a porous monolith to reliably and stably partition adjacent strains of bacteria while allowing molecular communication between them for several days. We measured small molecule production by the bacterial populations in response to stimuli using analytical chemistry methods and measured fluorescent output. The results are compared with communication and diffusion delay models. This porous monolith microfluidic system enables bacterial cell-to-cell communication assays with dynamic control of inputs, relatively long-term experimentation with no cross contamination, and stable bacterial population size. This system can serve as a valuable tool in understanding bacterial communication and improving biosensor design capabilities.

Robotic navigation to subcortical neural tissue for intracellular electrophysiology in vivo.

In vivo studies of neurophysiology using the whole cell patch-clamp technique enable exquisite access to both intracellular dynamics and cytosol of cells in the living brain but are underrepresented in deep subcortical nuclei because of fouling of the sensitive electrode tip. We have developed an autonomous method to navigate electrodes around obstacles such as blood vessels after identifying them as a source of contamination during regional pipette localization (RPL) in vivo. In mice, robotic navigation prevented fouling of the electrode tip, increasing RPL success probability 3 mm below the pial surface to 82% (n = 72/88) over traditional, linear localization (25%, n = 24/95), and resulted in high-quality thalamic whole cell recordings with average access resistance (32.0 MΩ) and resting membrane potential (-62.9 mV) similar to cortical recordings in isoflurane-anesthetized mice. Whole cell yield improved from 1% (n = 1/95) to 10% (n = 9/88) when robotic navigation was used during RPL. This method opens the door to whole cell studies in deep subcortical nuclei, including multimodal cell typing and studies of long-range circuits.NEW & NOTEWORTHY This work represents an automated method for accessing subcortical neural tissue for intracellular electrophysiology in vivo. We have implemented a novel algorithm to detect obstructions during regional pipette localization and move around them while minimizing lateral displacement within brain tissue. This approach leverages computer control of pressure, manipulator position, and impedance measurements to create a closed-loop platform for pipette navigation in vivo. This technique enables whole cell patching studies to be performed throughout the living brain.

X-ray analysis of electron Bernstein wave heating in MST.

A pulse height analyzing x-ray tomography system has been developed to detect x-rays from electron Bernstein wave heated electrons in the Madison symmetric torus reversed field pinch (RFP). Cadmium zinc telluride detectors are arranged in a parallel beam array with two orthogonal multi-chord detectors that may be used for tomography. In addition a repositionable 16 channel fan beam camera with a 55° field of view is used to augment data collected with the Hard X-ray array. The chord integrated signals identify target emission from RF heated electrons striking a limiter located 12° toroidally away from the RF injection port. This provides information on heated electron spectrum, transport, and diffusion. RF induced x-ray emission from absorption on harmonic electron cyclotron resonances in low current (<250 kA) RFP discharges has been observed.

Cleaning patch-clamp pipettes for immediate reuse.

Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manually replacing patch-clamp pipettes after each recording. To circumvent this limitation, we developed a simple, fast, and automated method for cleaning glass pipette electrodes that enables their reuse within one minute. By immersing pipette tips into Alconox, a commercially-available detergent, followed by rinsing, we were able to reuse pipettes 10 times with no degradation in signal fidelity, in experimental preparations ranging from human embryonic kidney cells to neurons in culture, slices, and in vivo. Undetectable trace amounts of Alconox remaining in the pipette after cleaning did not affect ion channel pharmacology. We demonstrate the utility of pipette cleaning by developing the first robot to perform sequential patch-clamp recordings in cell culture and in vivo without a human operator.