Paternal imprinting in Marchantia polymorpha.

We are becoming aware of a growing number of organisms that do not express genetic information equally from both parents as a result of an epigenetic phenomenon called genomic imprinting. Recently, it was shown that the entire paternal genome is repressed during the diploid phase of the life cycle of the liverwort Marchantia polymorpha. The deposition of the repressive epigenetic mark H3K27me3 on the male pronucleus is responsible for the imprinted state, which is reset by the end of meiosis. Here, we put these recent reports in perspective of other forms of imprinting and discuss the potential mechanisms of imprinting in bryophytes and the causes of its evolution.

Firearm Ownership: A Key Factor to Consider in Firearm Suicide Deaths in Children, Despite State Gun Laws.

INTRODUCTION: Firearm-related suicides among children present a significant public health concern and a tragic loss of young lives. This study explores the relationship between firearm-related suicides, gun ownership, and state-specific gun laws. METHODS: This retrospective cohort study collected data from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research on children under 18 who died by firearm-related suicides between 2009 and 2016 in all 50 states and D.C. It also utilized data from the RAND State-Level Estimates of Household Firearm Ownership. The study focused on the rate of child firearm suicide deaths per 100,000 individuals. The key variable of interest was the percentage of guns owned per household in each state. Univariable analysis was conducted to examine the association between individual gun laws and child firearm suicide mortalities, while multivariable regression, adjusting for household gun ownership and significant firearm legislation, was employed to assess connection to child firearm suicide mortality. RESULTS: From 2009 to 2016, 3903 children died from firearm-related suicides in the United States. In our analysis, 15 out of 44 firearm laws were found to be associated with reducing the rates of firearm suicides among children (P < 0.05). However, multivariable regression showed that higher state gun ownership rates were the primary predictor of increased child fatalities from firearms, with children in such states being 325% more likely to die when analyzing handgun laws and 337% more likely when analyzing long gun laws, as indicated by coefficients of 4.25 and 4.37, respectively. No state laws alone notably improved death rates. CONCLUSIONS: Gun ownership has a stronger association with child suicide rates than state-specific gun laws. Given the weight of gun ownership, future research should prioritize comprehensive public health initiatives to prevent child firearm-related suicides.

The evolution and functional divergence of the histone H2B family in plants.

Chromatin regulation of eukaryotic genomes depends on the formation of nucleosome complexes between histone proteins and DNA. Histone variants, which are diversified by sequence or expression pattern, can profoundly alter chromatin properties. While variants in histone H2A and H3 families are well characterized, the extent of diversification of histone H2B proteins is less understood. Here, we report a systematic analysis of the histone H2B family in plants, which have undergone substantial divergence during the evolution of each major group in the plant kingdom. By characterising Arabidopsis H2Bs, we substantiate this diversification and reveal potential functional specialization that parallels the phylogenetic structure of emergent clades in eudicots. In addition, we identify a new class of highly divergent H2B variants, H2B.S, that specifically accumulate during chromatin compaction of dry seed embryos in multiple species of flowering plants. Our findings thus identify unsuspected diverse properties among histone H2B proteins in plants that has manifested into potentially novel groups of histone variants.

"I'm Leaving": Factors That Impact Against Medical Advice Disposition Post-Trauma.

BACKGROUND: Discharge against medical advice (AMA) is an important, yet understudied, aspect of health care-particularly in trauma populations. AMA discharges result in increased mortality, increased readmission rates, and higher health care costs. OBJECTIVE: The goal of this analysis was to determine what factors impact a patient's odds of leaving the hospital prior to treatment. METHODS: We performed a retrospective analysis of the National Trauma Data Bank on adult trauma patients (older than 14 years) from 2013 to 2015. Of the 1,770,570 patients with known disposition, excluding mortality, 24,191 patients (1.4%) left AMA. We ascertained patient characteristics including age, sex, race, ethnicity, insurance status, ETOH, drug use, geographic location, Injury Severity Score (ISS), injury mechanism, and anatomic injury location. Multivariate logistic regression models were used to determine which patient factors were associated with AMA status. RESULTS: Uninsured (odds ratio [OR] 2.72; 95% confidence interval [CI] 2.58-2.86) or Medicaid-insured (OR 2.50; 95% CI 2.37-2.63) trauma patients were significantly more likely to leave AMA than patients with private insurance. Compared to white patients, African-American patients (OR 1.06; 95% CI 1.02-1.11) were more likely, and Native-American (OR 0.62; 95% CI 0.52-0.75), Asian (OR 0.59; 95% CI 0.49-0.69), and Hispanic (OR 0.80; 95% CI 0.75-0.85) patients were less likely, to leave AMA when controlling for age, sex, ISS, and type of injury. CONCLUSIONS: Insurance status, race, and ethnicity are associated with a patient's decision to leave AMA. Uninsured and Medicaid patients have more than twice the odds of leaving AMA. These findings demonstrate that racial and socioeconomic disparities are important targets for future efforts to reduce AMA rates and improve outcomes from blunt and penetrating trauma.

A comparison of a homemade central line simulator to commercial models.

BACKGROUND: Simulation is quickly becoming vital to resident education, but commercially available central line models are costly and little information exists to evaluate their realism. This study compared an inexpensive homemade simulator to three commercially available simulators and rated model characteristics. MATERIALS AND METHODS: Seventeen physicians, all having placed >50 lines in their lifetime, completed blinded central line insertions on three commercial and one homemade model (made of silicone, tubing, and a pressurized pump system). Participants rated each model on the realism of its ultrasound image, cannulation feel, manometry, and overall. They then ranked the models based on the same variables. Rankings were assessed with Friedman's and post hoc Conover's tests, using alphas 0.05 and 0.008 (Bonferroni corrected), respectively. RESULTS: The models significantly differed (P < 0.0004) in rankings across all dimensions. The homemade model was ranked best on ultrasound image, manometry measurement, cannulation feel, and overall quality by 71%, 67%, 53%, and 77% of raters, respectively. It was found to be statistically superior to the second rated model in all (P < 0.003) except cannulation feel (P = 0.134). Ultrasound image and manometry measurement received the lowest ratings across all models, indicating less realistic simulation. The cost of the homemade model was $400 compared to $1000-$8000 for commercial models. CONCLUSIONS: Our data suggest that an inexpensive, homemade central line model is as good or better than commercially available models. Areas for potential improvement within models include the ultrasound image and ability to appropriately measure manometry of accessed vessels.

Supplementing dietary sugar promotes endoplasmic reticulum stress-independent insulin resistance and fatty liver in goose.

It is known that endoplasmic reticulum stress (ERS) contributes to insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) in mammals. However, we recently demonstrated that overfeeding with a traditional diet (mainly consisting of cooked maize) does not induce ERS in goose. As cellular studies show that high glucose and palmitate can trigger ERS in mammalian cells, we hypothesized that supplementing sugar to the traditional diet could induce ERS, thus promoting insulin resistance and fatty liver. To test the hypothesis, we first treated goose primary hepatocytes with high glucose (25 mM and 50 mM) and palmitate (0.5 mM) supplemented with or without 0.25 mM oleate. Data indicated that, as in mammalian cells, high glucose and palmitate indeed induced ERS in goose primary hepatocytes, and palmitate-induced ERS was suppressed by supplemental 0.25 mM oleate. We then tested the hypothesis with an in vivo study, in which Landes geese overfed with traditional or novel diets (i.e., the traditional diet supplemented with sugar) were compared with control geese (normally fed with cooked maize) for ERS, IR and fatty liver. The differences in glucose tolerance, insulin tolerance and postprandial blood glucose between the geese overfed with traditional and novel diets suggested that supplementing dietary sugar promoted IR. This promotion was accompanied with an increasing trend of liver weight and abdominal fat weight relative to body weight. Surprisingly, compared to overfeeding with the traditional diet, overfeeding with the novel diet did not induce ERS, even further suppressed ERS in goose fatty liver. Together, our findings suggest that supplementing dietary sugar promotes ERS-independent IR and fatty liver in goose. It is intriguing to discover the factor(s) protecting goose liver from ERS as well as the non-ERS mechanism underlying IR.

Transcriptome-derived evidence supports recent polyploidization and a major phylogeographic division in Trithuria submersa (Hydatellaceae, Nymphaeales).

Relatively little is known about species-level genetic diversity in flowering plants outside the eudicots and monocots, and it is often unclear how to interpret genetic patterns in lineages with whole-genome duplications. We addressed these issues in a polyploid representative of Hydatellaceae, part of the water-lily order Nymphaeales. We examined a transcriptome of Trithuria submersa for evidence of recent whole-genome duplication, and applied transcriptome-derived microsatellite (expressed-sequence tag simple-sequence repeat (EST-SSR)) primers to survey genetic variation in populations across its range in mainland Australia. A transcriptome-based Ks plot revealed at least one recent polyploidization event, consistent with fixed heterozygous genotypes representing underlying sets of homeologous loci. A strong genetic division coincides with a trans-Nullarbor biogeographic boundary. Patterns of 'allelic' variation (no more than two variants per EST-SSR genotype) and recently published chromosomal evidence are consistent with the predicted polyploidization event and substantial homozygosity underlying fixed heterozygote SSR genotypes, which in turn reflect a selfing mating system. The Nullarbor Plain is a barrier to gene flow between two deep lineages of T. submersa that may represent cryptic species. The markers developed here should also be useful for further disentangling species relationships, and provide a first step towards future genomic studies in Trithuria.

The role of endoplasmic reticulum stress and insulin resistance in the occurrence of goose fatty liver.

In mammals, insulin resistance (IR) is required for the occurrence of non-alcoholic fatty liver disease, and endoplasmic reticulum stress (ERS) contributes to IR. As geese have physiological and metabolic characteristics different from mammals, it is unclear whether these mechanisms also underlie the occurrence of goose fatty liver. To address this, 70-day-old geese were treated with an ERS inducer or overfed, and variables associated with ERS or IR were subsequently determined. The data indicated that the group of geese treated with the ERS inducer for 20d appeared to be more intolerant to blood glucose than the control group, and their livers showed features of hepatic steatosis, suggesting ERS can induce IR and hepatic steatosis in geese. In contrast, overfeeding did not induce ERS, probably due to the upregulated expression of fatty acid desaturases, but induced higher fasting/postprandial blood glucose as well as glucose intolerance in geese, which was accompanied by a dramatic increase of liver weight. Taken together, these findings delineated the role of ERS and IR in the occurrence of goose fatty liver.

Velocity changes in femoral vessel ultrasound with Doppler in Porcine hemorrhagic shock.

Objective: Physician-directed point-of-care ultrasound (PoCUS) is routinely used to identify the etiology of shock and guide therapy in the ICU. We performed a preclinical study to determine what changes are manifested in the femoral vessels during hemorrhagic shock on Duplex imaging and to generate a femoral vessel sonographic profile over the time course of shock. Design & setting: A preclinical study in swine was performed using a convenience sample of animals that were being used in a Trauma Surgery training lab. The animals developed progressive unregulated hemorrhage during the lab. Subjects: Six anesthetized swine underwent Duplex studies of the femoral vessels prior to any hemorrhage and at two time points after the start of hemorrhage. Interventions: N/A. Measurements: Femoral vessel imaging was performed using a portable ultrasound (Sonosite and Clarius). Main results: Femoral arterial peak systolic velocity decreased in all animals with hemorrhage, from a mean (SD) of 77 (27) cm/s pre-hemorrhage to 42 (17) and 32 (16) cm/s at the two post-hemorrhage time points. There were also changes to the arterial waveform morphology. Mean venous velocities also decreased with hemorrhage (20, 11, 7 cm/s). Animals with severe hemorrhage had a cessation of venous flow during positive pressure ventilation. Conclusion: In this preclinical study, both femoral peak systolic velocity and venous velocity decreased with hemorrhage. Femoral vessels represent an easily accessible target for non-invasive hemodynamic monitoring. Changes in femoral vessel Duplex waveforms and velocities should be studied both in a larger sample of animals with controlled hemorrhage and in human trauma patients to determine whether changes appear in early hemorrhage, before the onset of clinically evident hemorrhagic shock.

Effect of traditional roughage-based or limit-fed, high-energy diets on growth performance and digestion in newly received growing cattle and subsequent implications on feedlot growth performance and carcass characteristics.

The objective was to determine the effects of ad libitum-fed roughage-based diets or limit-fed high-energy diets on growth performance, behavior, health, and digestion in newly received growing cattle and subsequent implications on feedlot growth performance and carcass characteristics. In experiment 1, 409 crossbred heifers (initial body weight [BW] = 279 ±â€…24 kg) in 32 pens were used in a randomized block design. Heifers were fed one of two dietary treatments: a total mixed ration with 0.99 Mcal net energy for gain (NEg)/kg dry matter (DM) fed ad libitum (0.99AL) or 1.32 Mcal NEg/kg DM limit-fed at 85% of intake of heifers fed 0.99AL (1.32LF85%). Both diets contained 40% DM as a branded wet corn gluten feed. In experiment 2, 370 crossbred heifers (initial BW = 225 ±â€…20 kg) were used in a randomized block design and were fed a diet formulated to contain 0.99 Mcal of NEg/kg DM for ad libitum intake or a diet formulated to contain 1.32 Mcal of NEg/kg DM and fed at 2.2% of BW daily (DM basis; 1.32LF2.2). For experiments 1 and 2, treatment integrity was maintained through the finishing phase where cattle were fed a common diet. Cattle were sorted by BW into heavy and light groups prior to finishing, with light cattle fed longer than heavy cattle to reach similar harvest BW. In experiment 3, eight ruminally cannulated heifers (average BW = 305 ±â€…23 kg) were used in a 2-period cross-over design and fed treatments from experiment 1 to assess digestibility and ruminal fermentation characteristics. Gain:feed was 47% and 35% greater (P < 0.01) in experiments 1 and 2, respectively, for limit-fed heifers compared with 0.99AL heifers. Rumination time was greater (P < 0.01) for 0.99AL compared with limit-fed treatments in experiments 1 and 2. Activity was greater (P < 0.01) for 1.32LF2.2 than for 0.99AL in experiment 2. In experiment 1, more (P = 0.03) carcasses from light-sort heifers than carcasses from heavy-sort heifers had livers with large, active abscesses. In experiment 2, finishing phase morbidity was greater (P < 0.01) for 1.32LF2.2 than for 0.99AL. Light-sort groups had fewer (P < 0.01) edible livers than heavy-sort groups, suggesting that greater number of days on feed may increase the risk of liver abscess prevalence and condemnation. In experiment 3, apparent total-tract DM and organic matter digestibilities were greater (P < 0.01) for 1.32LF85% than for 0.99AL. Overall, dietary treatments during the growing phase had little carryover effect on feedlot growth performance, carcass characteristics, or liver abscesses prevalence at harvest.

Optic Nerve Sheath Point of Care Ultrasound: Image Acquisition.

The goal of this protocol is to develop a standardized method for acquiring images of the optic nerve sheath and measuring the optic nerve sheath diameter (ONSD). Diagnostic ultrasound of the ONSD to detect intracranial hypertension has traditionally faced many problems because of methodologic discrepancies. Due to inconsistencies in the measuring techniques, the potential for ONSD to become a non-invasive bedside monitoring tool for ICP has been hampered. However, establishing a transparent, consistent methodology for measuring the ONSD would support its use as a valid and reliable method of identifying intracranial hypertension. This is important as it has both high sensitivity and specificity in acute care settings. This narrative review describes ONSD POCUS image acquisition, including patient positioning, transducer selection, probe placement, the acquisition sequence, and image optimization. Further, visual aids are provided to assist in real-time during image acquisition. This method should be considered for patients for whom there are concerns regarding intracranial hypertension but who do not have an intracranial monitor in place.

Image Acquisition Method for the Sonographic Assessment of the Inferior Vena Cava.

Over the past several decades, clinicians have incorporated several applications of diagnostic point-of-care ultrasound (POCUS) into medical decision-making. Among the applications of POCUS, imaging the inferior vena cava (IVC) is practiced by a wide variety of specialties, such as nephrology, emergency medicine, internal medicine, critical care, anesthesiology, pulmonology, and cardiology. Although each specialty uses IVC data in slightly different ways, most medical specialties, at minimum, attempt to use IVC data to make predictions about intravascular volume status. While the relationship between IVC sonographic data and intravascular volume status is complex and highly context-dependent, all clinicians should collect the sonographic data in standardized ways to ensure repeatability. This paper describes standardized IVC image acquisition including patient positioning, transducer selection, probe placement, image optimization, and the pitfalls and limitations of IVC sonographic imaging. This paper also describes the commonly performed anterior IVC long-axis view and three other views of the IVC that can each provide helpful diagnostic information when the anterior long-axis view is difficult to obtain or interpret.

Detection of pneumothorax on ultrasound using artificial intelligence.

BACKGROUND: Ultrasound (US) for the detection of pneumothorax shows excellent sensitivity in the hands of skilled providers. Artificial intelligence may facilitate the movement of US for pneumothorax into the prehospital setting. The large amount of training data required for conventional neural network methodologies has limited their use in US so far. METHODS: A limited training database was supplied by Defense Advanced Research Projects Agency of 30 patients, 15 cases with pneumothorax and 15 cases without. There were two US videos per patient, of which we were allowed to choose one to train on, so that a limited set of 30 videos were used. Images were annotated for ribs and pleural interface. The software performed anatomic reconstruction to identify the region of interest bounding the pleura. Three neural networks were created to analyze images on a pixel-by-pixel fashion with direct voting determining the outcome. Independent verification and validation was performed on a data set gathered by the Department of Defense. RESULTS: Anatomic reconstruction with the identification of ribs and pleura was able to be accomplished on all images. On independent verification and validation against the Department of Defense testing data, our program concurred with the SME 80% of the time and achieved a 86% sensitivity (18/21) for pneumothorax and a 75% specificity for the absence of pneumothorax (18/24). Some of the mistakes by our artificial intelligence can be explained by chest wall motion, hepatization of the underlying lung, or being equivocal cases. CONCLUSION: Using learning with limited labeling techniques, pneumothorax was identified on US with an accuracy of 80%. Several potential improvements are controlling for chest wall motion and the use of longer videos. LEVEL OF EVIDENCE: Diagnostic Tests; Level III.

Evaluation of commercially available point-of-care ultrasound for automated optic nerve sheath measurement.

BACKGROUND: Measurement of the optic nerve sheath diameter (ONSD) via ultrasonography has been proposed as a non-invasive metric of intracranial pressure that may be employed during in-field patient triage. However, first responders are not typically trained to conduct sonographic exams and/or do not have access to an expensive ultrasound device. Therefore, for successful deployment of ONSD measurement in-field, we believe that first responders must have access to low-cost, portable ultrasound and be assisted by artificial intelligence (AI) systems that can automatically interpret the optic nerve sheath ultrasound scan. We examine the suitability of five commercially available, low-cost, portable ultrasound devices that can be combined with future artificial intelligence algorithms to reduce the training required for and cost of in-field optic nerve sheath diameter measurement. This paper is focused on the quality of the images generated by these low-cost probes. We report results of a clinician preference survey and compare with a lab analysis of three quantitative image quality metrics across devices. We also examine the suitability of the devices in a hypothetical far-forward deployment using operators unskilled in ultrasound, with the assumption of a future onboard AI video interpreter. RESULTS: We find statistically significant differences in clinician ranking of the devices in the following categories: "Image Quality", "Ease of Acquisition", "Software", and "Overall ONSD". We show differences in signal-to-noise ratio, generalized contrast-to-noise ratio, point-spread function across the devices. These differences in image quality result in a statistically significant difference in manual ONSD measurement. Finally, we show that sufficiently wide transducers can capture the optic nerve sheath during blind (no visible B-mode) scans performed by operators unskilled in sonography. CONCLUSIONS: Ultrasound of the optic nerve sheath has the potential to be a convenient, non-invasive, point-of-injury or triage measure for elevated intracranial pressure in cases of traumatic brain injury. When transducer width is sufficient, briefly trained operators may obtain video sequences of the optic nerve sheath without guidance. This data suggest that unskilled operators are able to achieve the images needed for AI interpretation. However, we also show that image quality differences between ultrasound probes may influence manual ONSD measurements.

Point-of-Care Lung Ultrasound in Adults: Image Acquisition.

Consultative ultrasound performed by radiologists has traditionally not been used for imaging the lungs, as the lungs' air-filled nature normally prevents direct visualization of the lung parenchyma. When showing the lung parenchyma, ultrasound typically generates a number of non-anatomic artifacts. However, over the past several decades, these artifacts have been studied by diagnostic point-of-care ultrasound (POCUS) practitioners, who have identified findings that have value in narrowing the differential diagnoses of cardiopulmonary dysfunction. For instance, in patients presenting with dyspnea, lung POCUS is superior to chest radiography (CXR) for the diagnosis of pneumothorax, pulmonary edema, lung consolidations, and pleural effusions. Despite its known diagnostic value, the utilization of lung POCUS in clinical medicine remains variable, in part because training in this modality across hospitals remains inconsistent. To address this educational gap, this narrative review describes lung POCUS image acquisition in adults, including patient positioning, transducer selection, probe placement, acquisition sequence, and image optimization.

Focused Assessment with Sonography for Trauma (FAST) Exam: Image Acquisition.

Over the past twenty years, the Focused Assessment with Sonography for Trauma (FAST) exam has transformed the care of patients presenting with a combination of trauma (blunt or penetrating) and hypotension. In these hemodynamically unstable trauma patients, the FAST exam permits rapid and noninvasive screening for free pericardial or peritoneal fluid, the latter of which implicates intra-abdominal injury as a likely contributor to the hypotension and justifies emergent abdominal surgical exploration. Further, the abdominal portion of the FAST exam can also be used outside of the trauma setting to screen for free peritoneal fluid in patients who become hemodynamically unstable in any context, including after procedures that may inadvertently injure abdominal organs. These "non-trauma" situations of hemodynamic instability are often triaged by providers from specialties other than emergency medicine or trauma surgery who are not familiar with the FAST exam. Therefore, there is a need to promulgate knowledge about the FAST exam to all clinicians caring for critically ill patients. Toward this end, this article describes FAST exam image acquisition: patient positioning, transducer selection, image optimization, and exam limitations. Since the free fluid is likely to be found in specific anatomic locations that are unique for each canonical FAST exam view, this work centers on the unique image acquisition considerations for each window: subcostal, right upper quadrant, left upper quadrant, and pelvis.

The Polycomb repressive complex 2 deposits H3K27me3 and represses transposable elements in a broad range of eukaryotes.

The mobility of transposable elements (TEs) contributes to evolution of genomes. Their uncontrolled activity causes genomic instability; therefore, expression of TEs is silenced by host genomes. TEs are marked with DNA and H3K9 methylation, which are associated with silencing in flowering plants, animals, and fungi. However, in distantly related groups of eukaryotes, TEs are marked by H3K27me3 deposited by the Polycomb repressive complex 2 (PRC2), an epigenetic mark associated with gene silencing in flowering plants and animals. The direct silencing of TEs by PRC2 has so far only been shown in one species of ciliates. To test if PRC2 silences TEs in a broader range of eukaryotes, we generated mutants with reduced PRC2 activity and analyzed the role of PRC2 in extant species along the lineage of Archaeplastida and in the diatom P. tricornutum. In this diatom and the red alga C. merolae, a greater proportion of TEs than genes were repressed by PRC2, whereas a greater proportion of genes than TEs were repressed by PRC2 in bryophytes. In flowering plants, TEs contained potential cis-elements recognized by transcription factors and associated with neighbor genes as transcriptional units repressed by PRC2. Thus, silencing of TEs by PRC2 is observed not only in Archaeplastida but also in diatoms and ciliates, suggesting that PRC2 deposited H3K27me3 to silence TEs in the last common ancestor of eukaryotes. We hypothesize that during the evolution of Archaeplastida, TE fragments marked with H3K27me3 were selected to shape transcriptional regulation, controlling networks of genes regulated by PRC2.

Relationships between hippocampal sharp waves, ripples, and fast gamma oscillation: influence of dentate and entorhinal cortical activity.

Hippocampal sharp waves (SPWs) and associated fast ("ripple") oscillations (SPW-Rs) in the CA1 region are among the most synchronous physiological patterns in the mammalian brain. Using two-dimensional arrays of electrodes for recording local field potentials and unit discharges in freely moving rats, we studied the emergence of ripple oscillations (140-220 Hz) and compared their origin and cellular-synaptic mechanisms with fast gamma oscillations (90-140 Hz). We show that (1) hippocampal SPW-Rs and fast gamma oscillations are quantitatively distinct patterns but involve the same networks and share similar mechanisms; (2) both the frequency and magnitude of fast oscillations are positively correlated with the magnitude of SPWs; (3) during both ripples and fast gamma oscillations the frequency of network oscillation is higher in CA1 than in CA3; and (4) the emergence of CA3 population bursts, a prerequisite for SPW-Rs, is biased by activity patterns in the dentate gyrus and entorhinal cortex, with the highest probability of ripples associated with an "optimum" level of dentate gamma power. We hypothesize that each hippocampal subnetwork possesses distinct resonant properties, tuned by the magnitude of the excitatory drive.

A Portable Negative Pressure Isolation System as a Solution to Minimize Exposure of Health Care Providers to Infectious Pathogens.

The COVID-19 pandemic has resulted in the exposure of many surgeons and healthcare providers (HCPs) to disease given high patient loads and limited availability of negative pressure rooms. For these reasons we pursued the development of a portable patient isolation system (COVIAGE™ by iSolace, Inc.) that can be used to contain patients with respiratory illness and minimize the exposure of HCPs. COVIAGE™ is comprised of a reusable aluminum frame, a disposable thermoplastic polyurethane tent and a HEPA filtration/ventilation system (HVAC) utilizing two inline filters. The efficacy of filtration was tested by comparing particulate concentration inside and outside of the device by an independent third party. Additionally, physician, nursing, and respiratory tasks were performed initially on simulated patients and then on intubated patients in the ICU. The system attained a verified filtration efficiency greater than 99.999% for an average 0.3-µm size particulates. Simulation testing revealed that most common physician, nursing, and respiratory tasks could be completed in the device, including endotracheal intubation. Emergency removal of the device can be accomplished in 8.8 ± 2.8 seconds. The reusable aluminum frame allows for simple attachment to the bed, and adaptability to different types and sizes of beds/stretchers. An emergency use authorization was granted by the FDA. The device created results in a portable negative pressure isolation system that can be placed over the patient's bed to contain aerosols during high aerosol generating procedures, transportation of patients or for total patient care in environments where negative pressure rooms are not available.