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1.
Phys Rev Lett ; 130(26): 265101, 2023 Jun 30.
Article in English | MEDLINE | ID: mdl-37450828

ABSTRACT

The propagation and energy coupling of intense laser beams in plasmas are critical issues in inertial confinement fusion. Applying magnetic fields to such a setup has been shown to enhance fuel confinement and heating. Here we report on experimental measurements demonstrating improved transmission and increased smoothing of a high-power laser beam propagating in a magnetized underdense plasma. We also measure enhanced backscattering, which our kinetic simulations show is due to magnetic confinement of hot electrons, thus leading to reduced target preheating.


Subject(s)
Electrons , Heating , Heart Rate , Kinetics , Lasers
2.
BMC Bioinformatics ; 23(1): 156, 2022 May 02.
Article in English | MEDLINE | ID: mdl-35501696

ABSTRACT

BACKGROUND: Quantification of gene expression from RNA-seq data is a prerequisite for transcriptome analysis such as differential gene expression analysis and gene co-expression network construction. Individual RNA-seq experiments are larger and combining multiple experiments from sequence repositories can result in datasets with thousands of samples. Processing hundreds to thousands of RNA-seq data can result in challenges related to data management, access to sufficient computational resources, navigation of high-performance computing (HPC) systems, installation of required software dependencies, and reproducibility. Processing of larger and deeper RNA-seq experiments will become more common as sequencing technology matures. RESULTS: GEMmaker, is a nf-core compliant, Nextflow workflow, that quantifies gene expression from small to massive RNA-seq datasets. GEMmaker ensures results are highly reproducible through the use of versioned containerized software that can be executed on a single workstation, institutional compute cluster, Kubernetes platform or the cloud. GEMmaker supports popular alignment and quantification tools providing results in raw and normalized formats. GEMmaker is unique in that it can scale to process thousands of local or remote stored samples without exceeding available data storage. CONCLUSIONS: Workflows that quantify gene expression are not new, and many already address issues of portability, reusability, and scale in terms of access to CPUs. GEMmaker provides these benefits and adds the ability to scale despite low data storage infrastructure. This allows users to process hundreds to thousands of RNA-seq samples even when data storage resources are limited. GEMmaker is freely available and fully documented with step-by-step setup and execution instructions.


Subject(s)
High-Throughput Nucleotide Sequencing , Software , High-Throughput Nucleotide Sequencing/methods , RNA-Seq , Reproducibility of Results , Sequence Analysis, RNA/methods
3.
Ultrasound Obstet Gynecol ; 58(5): 744-749, 2021 Nov.
Article in English | MEDLINE | ID: mdl-33724570

ABSTRACT

OBJECTIVE: To evaluate the influence of stomach position on postnatal outcome in cases of left congenital diaphragmatic hernia (CDH) without liver herniation, diagnosed and characterized on prenatal ultrasound (US), by comparing those with ('stomach-up' CDH) to those without ('stomach-down' CDH) intrathoracic stomach herniation. METHODS: Infants with left CDH who underwent prenatal US and postnatal repair at our institution between January 2008 and March 2017 were eligible for inclusion in this retrospective study. Detailed prenatal US examinations, fetal magnetic resonance imaging (MRI) studies, operative reports and medical records of infants enrolled in the pulmonary hypoplasia program at our institution were reviewed. Cases with liver herniation and those with an additional anomaly were excluded. Cases in which bowel loops were identified within the fetal chest on US while the stomach was intra-abdominal were categorized as having stomach-down CDH. Cases in which bowel loops and the stomach were visualized within the fetal chest on US were categorized as having stomach-up CDH. Prenatal imaging findings and postnatal outcomes were compared between the two groups. RESULTS: In total, 152 patients with left CDH were initially eligible for inclusion. Seventy-eight patients had surgically confirmed liver herniation and were excluded. Of the 74 included CDH cases without liver herniation, 28 (37.8%) had stomach-down CDH and 46 (62.2%) had stomach-up CDH. Of the 28 stomach-down CDH cases, 10 (35.7%) were referred for a suspected lung lesion. Sixty-eight (91.9%) cases had postnatal outcome data available for analysis. There was no significant difference in median observed-to-expected (o/e) lung-area-to-head-circumference ratio (LHR) between cases with stomach-down CDH and those with stomach-up CDH (41.5% vs 38.4%; P = 0.41). Furthermore, there was no difference in median MRI o/e total lung volume (TLV) between the two groups (49.5% vs 44.0%; P = 0.22). Compared with stomach-up CDH patients, stomach-down CDH patients demonstrated lower median duration of intubation (18 days vs 9.5 days; P < 0.01), median duration of extracorporeal membrane oxygenation (495 h vs 223.5 h; P < 0.05), rate of supplemental oxygen requirement at 30 days of age (20/42 (47.6%) vs 3/26 (11.5%); P < 0.01) and rate of pulmonary hypertension at initial postnatal echocardiography (28/42 (66.7%) vs 9/26 (34.6%); P = 0.01). No neonatal death occurred in stomach-down CDH patients and one neonatal death was seen in a patient with intrathoracic stomach herniation. CONCLUSIONS: In infants with left CDH without liver herniation, despite similar o/e-LHR and o/e-TLV, those with stomach-down CDH have decreased neonatal morbidity compared to those with stomach herniation. Progressive or variable physiological distension of the stomach over the course of gestation may explain these findings. Stomach-down left CDH is mistaken for a lung mass in a substantial proportion of cases. Accurate prenatal US characterization of CDH is crucial for appropriate prenatal counseling and patient management. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Subject(s)
Hernias, Diaphragmatic, Congenital/pathology , Infant, Newborn, Diseases/pathology , Magnetic Resonance Imaging , Stomach/pathology , Ultrasonography, Prenatal , Adult , Cephalometry , Female , Fetus/diagnostic imaging , Fetus/pathology , Head/diagnostic imaging , Head/pathology , Hernias, Diaphragmatic, Congenital/diagnostic imaging , Hernias, Diaphragmatic, Congenital/embryology , Humans , Infant, Newborn , Infant, Newborn, Diseases/diagnostic imaging , Infant, Newborn, Diseases/embryology , Lung/diagnostic imaging , Lung/embryology , Lung/pathology , Male , Morbidity , Pregnancy , Retrospective Studies , Stomach/diagnostic imaging , Stomach/embryology
4.
Ultrasound Obstet Gynecol ; 55(6): 740-746, 2020 06.
Article in English | MEDLINE | ID: mdl-31613408

ABSTRACT

OBJECTIVE: To determine whether the presence of a myelomeningocele (MMC) sac and sac size correlate with compromised lower-extremity function in fetuses with open spinal dysraphism. METHODS: A radiology database search was performed to identify cases of MMC and myeloschisis (MS) diagnosed prenatally in a single center from 2013 to 2017. All cases were evaluated between 18 and 25 weeks. Ultrasound reports were reviewed for talipes and impaired lower-extremity motion. In MMC cases, sac volume was calculated from ultrasound measurements. Magnetic resonance imaging reports were reviewed for hindbrain herniation. The association of presence of a MMC sac and sac size with talipes and impaired lower-extremity motion was assessed. Post-hoc analysis of data from the multicenter Management of Myelomeningocele Study (MOMS) randomized controlled trial was performed to confirm the study findings. RESULTS: In total, 283 MMC and 121 MS cases were identified. MMC was associated with a lower incidence of hindbrain herniation than was MS (80.9% vs 100%; P < 0.001). Compared with MS cases, MMC cases with hindbrain herniation had a higher rate of talipes (28.4% vs 16.5%, P = 0.02) and of talipes or lower-extremity impairment (34.9% vs 19.0%, P = 0.002). Although there was a higher rate of impaired lower-extremity motion alone in MMC cases with hindbrain herniation than in MS cases, the difference was not statistically significant (6.6% vs 2.5%; P = 0.13). Among MMC cases with hindbrain herniation, mean sac volume was higher in those associated with talipes compared with those without talipes (4.7 ± 4.2 vs 3.0 ± 2.6 mL; P = 0.002). Review of the MOMS data demonstrated similar findings; cases with a sac on baseline imaging had a higher incidence of talipes than did those without a sac (28.2% vs 7.5%; P = 0.007). CONCLUSIONS: In fetuses with open spinal dysraphism, the presence of a MMC sac was associated with fetal talipes, and this effect was correlated with sac size. The presence of a larger sac in fetuses with open spinal dysraphism may result in additional injury through mechanical stretching of the nerves, suggesting another acquired mechanism of injury to the exposed spinal tissue. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Subject(s)
Lower Extremity Deformities, Congenital/embryology , Meningomyelocele/embryology , Prenatal Injuries/etiology , Spinal Dysraphism/embryology , Talipes/embryology , Databases, Factual , Female , Gestational Age , Humans , Lower Extremity Deformities, Congenital/diagnostic imaging , Meningomyelocele/complications , Meningomyelocele/diagnostic imaging , Pregnancy , Prenatal Injuries/diagnostic imaging , Spinal Dysraphism/complications , Spinal Dysraphism/diagnostic imaging , Talipes/congenital , Talipes/diagnostic imaging , Ultrasonography, Prenatal
5.
J Neurochem ; 145(3): 232-244, 2018 05.
Article in English | MEDLINE | ID: mdl-29250792

ABSTRACT

Orexin/hypocretin neurons of the lateral hypothalamus and perifornical area are integrators of physiological function. Previous work from our laboratory and others has shown the importance of orexin transmission in cognition. Age-related reductions in markers of orexin function further suggest that this neuropeptide may be a useful target for the treatment of age-related cognitive dysfunction. Intranasal administration of orexin-A (OxA) has shown promise as a therapeutic option for cognitive dysfunction. However, the neurochemical mechanisms of intranasal OxA administration are not fully understood. Here, we use immunohistochemistry and in vivo microdialysis to define the effects of acute intranasal OxA administration on: (i) activation of neuronal populations in the cortex, basal forebrain, and brainstem and (ii) acetylcholine (ACh) and glutamate efflux in the prefrontal cortex (PFC) of Fischer 344/Brown Norway F1 rats. Acute intranasal administration of OxA significantly increased c-Fos expression, a marker for neuronal activation, in the PFC and in subpopulations of basal forebrain cholinergic neurons. Subsequently, we investigated the effects of acute intranasal OxA on neurotransmitter efflux in the PFC and found that intranasal OxA significantly increased both ACh and glutamate efflux in this region. These findings were independent from any changes in c-Fos expression in orexin neurons, suggesting that these effects are not resultant from direct activation of orexin neurons. In total, these data indicate that intranasal OxA may enhance cognition through activation of distinct neuronal populations in the cortex and basal forebrain and through increased neurotransmission of ACh and glutamate in the PFC.


Subject(s)
Acetylcholine/metabolism , Glutamic Acid/metabolism , Neurons/drug effects , Orexins/pharmacology , Prefrontal Cortex/drug effects , Administration, Intranasal , Animals , Male , Neurons/metabolism , Prefrontal Cortex/metabolism , Rats , Synaptic Transmission/drug effects , Synaptic Transmission/physiology
7.
Euro Surveill ; 20(29): 21189, 2015 Jul 23.
Article in English | MEDLINE | ID: mdl-26227369

ABSTRACT

In 2011 and 2012, a nationwide Canadian vaccine safety surveillance network rapidly collected safety data from healthcare workers (HCW) during the first weeks of the annual influenza vaccination campaign. This network provided the first available post-marketing safety data on seasonal influenza vaccines with information on background rates as a comparator. In 2012, these data were used to investigate a possible safety concern regarding a particular vaccine. An online questionnaire was provided to participating HCW two weeks before the annual influenza vaccination campaign for controls, and eight days after influenza vaccination for vaccinees. Control and vaccinees were requested to report health events occurring in the seven days prior to receiving the questionnaire. Control data were used to calculate background rates. HCW reporting a severe event were followed-up by telephone within 48 hours of the online report to validate the report and check on their health status. More than 22,000 vaccinated HCW were enrolled and surveyed over two seasons and > 90% reported no severe event following vaccination. Validated severe event rates were similar in vaccinated HCW and unvaccinated HCW (2.2% vs 2.3%; p < 0.70). The questionnaire was accurately completed for most reported symptoms, matched the validated report and was able to detect events of interest. Prior to the safety concern, the implicated vaccine was in use at one centre. Reassuring safety data were provided to public health authorities 48 hours after the vaccine was temporarily suspended. Data from this and similar networks can be used for rapid evaluation of vaccine safety and for safety assessment as required by the European Medicines Agency in 2015.


Subject(s)
Adverse Drug Reaction Reporting Systems , Immunization/adverse effects , Influenza Vaccines/adverse effects , Influenza, Human/prevention & control , Population Surveillance/methods , Vaccination/methods , Adult , Aged , Canada/epidemiology , Case-Control Studies , Epidemiological Monitoring , Female , Health Personnel , Humans , Influenza A Virus, H1N1 Subtype/immunology , Influenza Vaccines/administration & dosage , Influenza, Human/epidemiology , Male , Middle Aged , Program Evaluation , Surveys and Questionnaires
8.
Curr Oncol ; 21(1): e52-61, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24523621

ABSTRACT

BACKGROUND: Delays in chemotherapy because of neutropenia may be associated with poorer outcomes. The purpose of the present study was to examine the effect that granulocyte colony-stimulating factors (g-csfs) have on survival. METHODS: We conducted a chart review of all outpatients diagnosed with metastatic colorectal cancer and treated with folfiri chemotherapy (irinotecan, 5-fluorouracil, leucovorin) with or without bevacizumab at Mount Sinai Hospital between 2007 and 2012. Multivariable Cox proportional hazards models were used to compare survival in neutropenic patients treated with g-csf, in neutropenic patients not so treated, and in patients without neutropenia. RESULTS: The review identified 93 patients, 31 of whom did not experience a neutropenic event. Of the 62 who experienced neutropenia, 18 were managed with g-csf support, and 44, with reductions or delays in dose. Compared with patients experiencing a neutropenic episode not treated with g-csf, those treated with g-csf experienced a nonsignificant increase in time to event [progression or death: hazard ratio (hr): 1.37; 95% confidence limits (cl): 0.72, 2.61], but compared with patients not having a neutropenic episode, the same patients experienced a significant increase in time to event (hr: 2.07; 95% cl: 1.03, 4.15). CONCLUSIONS: In patients who experienced neutropenia, g-csf did not have a statistically significant impact on survival. Time to event was prolonged in g-csf-treated patients compared with patients who did not experience neutropenia.

9.
J Hosp Infect ; 148: 77-86, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38554807

ABSTRACT

BACKGROUND: Pseudomonas aeruginosa (PA) is a common cause of healthcare-associated infection (PA-HAI) in the intensive care unit (ICU). AIM: To describe the epidemiology of PA-HAI in ICUs in Ontario, Canada, and to identify episodes of sink-to-patient PA transmission. METHODS: This was a prospective cohort study of patients in six ICUs from 2018 to 2019, with retrieval of PA clinical isolates, and PA-screening of antimicrobial-resistant organism surveillance rectal swabs, and of sink drain, air, and faucet samples. All PA isolates underwent whole-genome sequencing. PA-HAI was defined using US National Healthcare Safety Network criteria. ICU-acquired PA was defined as PA isolated from specimens obtained ≥48 h after ICU admission in those with prior negative rectal swabs. Sink-to-patient PA transmission was defined as ICU-acquired PA with close genomic relationship to isolate(s) previously recovered from sinks in a room/bedspace occupied 3-14 days prior to collection date of the relevant patient specimen. FINDINGS: Over ten months, 72 PA-HAIs occurred among 60/4263 admissions. The rate of PA-HAI was 2.40 per 1000 patient-ICU-days; higher in patients who were PA-colonized on admission. PA-HAI was associated with longer stay (median: 26 vs 3 days uninfected; P < 0.001) and contributed to death in 22/60 cases (36.7%). Fifty-eight admissions with ICU-acquired PA were identified, contributing 35/72 (48.6%) PA-HAIs. Four patients with five PA-HAIs (6.9%) had closely related isolates previously recovered from their room/bedspace sinks. CONCLUSION: Nearly half of PA causing HAI appeared to be acquired in ICUs, and 7% of PA-HAIs were associated with sink-to-patient transmission. Sinks may be an under-recognized reservoir for HAIs.


Subject(s)
Cross Infection , Intensive Care Units , Pseudomonas Infections , Pseudomonas aeruginosa , Humans , Intensive Care Units/statistics & numerical data , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/isolation & purification , Pseudomonas aeruginosa/classification , Cross Infection/epidemiology , Cross Infection/microbiology , Cross Infection/transmission , Pseudomonas Infections/epidemiology , Pseudomonas Infections/transmission , Pseudomonas Infections/microbiology , Prospective Studies , Ontario/epidemiology , Male , Middle Aged , Female , Aged , Adult , Aged, 80 and over , Whole Genome Sequencing
10.
Eur J Clin Microbiol Infect Dis ; 31(4): 591-7, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21796343

ABSTRACT

We aimed to assess the immunogenicity of a single half-dose of AS03-adjuvanted monovalent 2009 pandemic H1N1 vaccine in healthy adults. Healthy subjects age 20-60 years were prospectively enrolled in a cohort receiving intramuscular administration of a single half-dose (1.875 µg of hemagglutinin [HA]) of adjuvanted 2009 pandemic H1N1 influenza vaccine. Data from participants enrolled in a concomitant study of immunogenicity following a full-dose (3.75 µg of HA) are presented concurrently. Sera for assessment of hemagglutination-inhibiting (HAI) antibody to the vaccine strain were obtained before and 14 or 21 days after vaccination. Ninety-seven participants received a half-dose and 50 received a full-dose of vaccine. In the half-dose cohort, Food and Drug Administration criteria for immunogenicity regarding seroprotection and seroconversion rates were met for subjects aged 20-45 years, but not for those aged 46-60 years. There was no statistically significant difference in the proportion of individuals achieving a post-vaccination HAI titre of ≥1:40, the geometric mean titres of post-vaccination antibody, or the proportion of individuals with a four-fold or greater increase in antibody levels between the two cohorts. Participants 46-60 years of age were significantly less likely to be seroprotected at day 21 than those 20-45 years old in both cohorts. Immunogenicity of a half dose of adjuvanted pH1N1 influenza vaccine was adequate in subjects aged 20-45 years. Dose reduction is a possible strategy for expanding the availability in the event of vaccine shortage in this age group.


Subject(s)
Influenza A Virus, H1N1 Subtype/immunology , Influenza Vaccines/administration & dosage , Influenza Vaccines/immunology , Influenza, Human/prevention & control , Adjuvants, Immunologic/administration & dosage , Adult , Age Factors , Antibodies, Viral/blood , Cohort Studies , Female , Hemagglutination Inhibition Tests , Humans , Injections, Intramuscular , Male , Middle Aged , Prospective Studies
11.
Epidemiol Infect ; 140(4): 633-42, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21733246

ABSTRACT

To determine whether drinking water contaminated with antimicrobial-resistant E. coli is associated with the carriage of resistant E. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005-2006 were asked to participate in a cross-sectional study. Household members aged ≥12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain of E. coli and 28% carried a multidrug-resistant strain. The risk of carriage of resistant E. coli was 1·26 times higher for users of water contaminated with resistant E. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance in E. coli.


Subject(s)
Drinking Water/microbiology , Escherichia coli Infections/transmission , Escherichia coli , Adolescent , Adult , Aged , Aged, 80 and over , Alberta/epidemiology , Child , Cross-Sectional Studies , Drug Resistance, Bacterial , Escherichia coli/drug effects , Escherichia coli Infections/epidemiology , Escherichia coli Infections/etiology , Family Characteristics , Feces/microbiology , Female , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Ontario/epidemiology , Prevalence , Young Adult
12.
Prog Neurobiol ; 212: 102252, 2022 05.
Article in English | MEDLINE | ID: mdl-35227866

ABSTRACT

Reinforcement learning and goal-seeking behavior are thought to be mediated by midbrain dopamine neurons. However, little is known about neural substrates of curiosity and exploratory behavior, which occur in the absence of clear goal or reward. This is despite behavioral scientists having long suggested that curiosity and exploratory behaviors are regulated by an innate drive. We refer to such behavior as information-seeking behavior and propose 1) key neural substrates and 2) the concept of environment prediction error as a framework to understand information-seeking processes. The cognitive aspect of information-seeking behavior, including the perception of salience and uncertainty, involves, in part, the pathways from the posterior hypothalamic supramammillary region to the hippocampal formation. The vigor of such behavior is modulated by the following: supramammillary glutamatergic neurons; their projections to medial septal glutamatergic neurons; and the projections of medial septal glutamatergic neurons to ventral tegmental dopaminergic neurons. Phasic responses of dopaminergic neurons are characterized as signaling potentially important stimuli rather than rewards. This paper describes how novel stimuli and uncertainty trigger seeking motivation and how these neural substrates modulate information-seeking behavior.


Subject(s)
Dopamine , Motivation , Dopaminergic Neurons , Hippocampus , Humans , Reward
13.
Nat Commun ; 13(1): 1386, 2022 03 16.
Article in English | MEDLINE | ID: mdl-35296648

ABSTRACT

The prefrontal cortex is involved in goal-directed behavior. Here, we investigate circuits of the PFC regulating motivation, reinforcement, and its relationship to dopamine neuron activity. Stimulation of medial PFC (mPFC) neurons in mice activated many downstream regions, as shown by fMRI. Axonal terminal stimulation of mPFC neurons in downstream regions, including the anteromedial thalamic nucleus (AM), reinforced behavior and activated midbrain dopaminergic neurons. The stimulation of AM neurons projecting to the mPFC also reinforced behavior and activated dopamine neurons, and mPFC and AM showed a positive-feedback loop organization. We also found using fMRI in human participants watching reinforcing video clips that there is reciprocal excitatory functional connectivity, as well as co-activation of the two regions. Our results suggest that this cortico-thalamic loop regulates motivation, reinforcement, and dopaminergic neuron activity.


Subject(s)
Dopaminergic Neurons , Goals , Animals , Axons , Dopaminergic Neurons/physiology , Humans , Mice , Neural Pathways/physiology , Prefrontal Cortex/physiology , Thalamus
14.
Physiol Behav ; 234: 113370, 2021 05 15.
Article in English | MEDLINE | ID: mdl-33621561

ABSTRACT

The intranasal (IN) administration of neuropeptides, such as insulin and orexins, has been suggested as a treatment strategy for age-related cognitive decline (ARCD). Because dysfunctional neuropeptide signaling is an observed characteristic of ARCD, it has been suggested that IN delivery of insulin and/or orexins may restore endogenous peptide signaling and thereby preserve cognition. IN administration is particularly alluring as it is a relatively non-invasive method that directly targets peptides to the brain. Several laboratories have examined the behavioral effects of IN insulin in young, aged, and cognitively impaired rodents and humans. These studies demonstrated improved performance on various cognitive tasks following IN insulin administration. Fewer laboratories have assessed the effects of IN orexins; however, this peptide also holds promise as an effective treatment for ARCD through the activation of the cholinergic system and/or the reduction of neuroinflammation. Here, we provide a brief overview of the advantages of IN administration and the delivery pathway, then summarize the current literature on IN insulin and orexins. Additional preclinical studies will be useful to ultimately uncover the mechanisms underlying the pro-cognitive effects of IN insulin and orexins, whereas future clinical studies will aid in the determination of the most efficacious dose and dosing paradigm. Eventually, IN insulin and/or orexin administration may be a widely used treatment strategy in the clinic for ARCD.


Subject(s)
Cognitive Dysfunction , Neuropeptides , Administration, Intranasal , Aged , Humans , Insulin , Orexin Receptors , Orexins
15.
Nat Commun ; 12(1): 334, 2021 Jan 12.
Article in English | MEDLINE | ID: mdl-33436570

ABSTRACT

Magnetized plasma interactions are ubiquitous in astrophysical and laboratory plasmas. Various physical effects have been shown to be important within colliding plasma flows influenced by opposing magnetic fields, however, experimental verification of the mechanisms within the interaction region has remained elusive. Here we discuss a laser-plasma experiment whereby experimental results verify that Biermann battery generated magnetic fields are advected by Nernst flows and anisotropic pressure effects dominate these flows in a reconnection region. These fields are mapped using time-resolved proton probing in multiple directions. Various experimental, modelling and analytical techniques demonstrate the importance of anisotropic pressure in semi-collisional, high-ß plasmas, causing a reduction in the magnitude of the reconnecting fields when compared to resistive processes. Anisotropic pressure dynamics are crucial in collisionless plasmas, but are often neglected in collisional plasmas. We show pressure anisotropy to be essential in maintaining the interaction layer, redistributing magnetic fields even for semi-collisional, high energy density physics (HEDP) regimes.

16.
Nat Commun ; 12(1): 2811, 2021 05 14.
Article in English | MEDLINE | ID: mdl-33990558

ABSTRACT

The supramammillary region (SuM) is a posterior hypothalamic structure, known to regulate hippocampal theta oscillations and arousal. However, recent studies reported that the stimulation of SuM neurons with neuroactive chemicals, including substances of abuse, is reinforcing. We conducted experiments to elucidate how SuM neurons mediate such effects. Using optogenetics, we found that the excitation of SuM glutamatergic (GLU) neurons was reinforcing in mice; this effect was relayed by their projections to septal GLU neurons. SuM neurons were active during exploration and approach behavior and diminished activity during sucrose consumption. Consistently, inhibition of SuM neurons disrupted approach responses, but not sucrose consumption. Such functions are similar to those of mesolimbic dopamine neurons. Indeed, the stimulation of SuM-to-septum GLU neurons and septum-to-ventral tegmental area (VTA) GLU neurons activated mesolimbic dopamine neurons. We propose that the supramammillo-septo-VTA pathway regulates arousal that reinforces and energizes behavioral interaction with the environment.


Subject(s)
Dopaminergic Neurons/physiology , Hypothalamus, Posterior/cytology , Hypothalamus, Posterior/physiology , Animals , Behavior, Animal/drug effects , Behavior, Animal/physiology , Consummatory Behavior/drug effects , Consummatory Behavior/physiology , Dopamine/physiology , Female , Glutamic Acid/physiology , Magnetic Resonance Imaging , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Models, Neurological , Neural Pathways/cytology , Neural Pathways/physiology , Optogenetics , Rats , Rats, Wistar , Reinforcement, Psychology , Septum of Brain/cytology , Septum of Brain/drug effects , Septum of Brain/physiology , Ventral Tegmental Area/cytology , Ventral Tegmental Area/physiology , alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/administration & dosage
17.
Indoor Air ; 20(1): 61-71, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20028435

ABSTRACT

UNLABELLED: The reaction of ozone with permethrin can potentially form phosgene. Published evidence on ozone levels and permethrin surface concentrations in aircraft cabins indicated that significant phosgene formation might occur in this setting. A derivatization technique was developed to detect phosgene with a lower limit of detection of 2 ppb. Chamber experiments were conducted with permethrin-coated materials (glass, carpet, seat fabric, and plastic) exposed to ozone under cabin-relevant conditions (150 ppb O(3), 4.5/h air exchange rate, <1% relative humidity, 1700 ng/cm(2) of permethrin). Phosgene was not detected in these experiments. Reaction of ozone with permethrin appears to be hindered by the electron-withdrawing chlorine atoms adjacent to the double bond in permethrin. Experimental results indicate that the upper limit on the reaction probability of ozone with surface-bound permethrin is approximately 10(-7). Extrapolation by means of material-balance modeling indicates that the upper limit on the phosgene level in aircraft cabins resulting from this chemistry is approximately 1 microg/m(3) or approximately 0.3 ppb. It was thus determined that phosgene formation, if it occurs in aircraft cabins, is not likely to exceed relevant, health-based phosgene exposure guidelines. PRACTICAL IMPLICATIONS: Phosgene formation from ozone-initiated oxidation of permethrin in the aircraft cabin environment, if it occurs, is estimated to generate levels below the California Office of Environmental Health Hazard Assessment acute reference exposure level of 4 microg/m(3) or approximately 1 ppb.


Subject(s)
Air Pollution, Indoor/analysis , Aviation , Ozone/chemistry , Permethrin/chemistry , Phosgene/chemical synthesis , California , Inhalation Exposure , Phosgene/analysis , Phosgene/chemistry
18.
Brain Res ; 1731: 145921, 2020 03 15.
Article in English | MEDLINE | ID: mdl-30148983

ABSTRACT

Cognitive impairment is a core feature of several neuropsychiatric and neurological disorders, including narcolepsy and age-related dementias. Current pharmacotherapeutic approaches to cognitive enhancement are few in number and limited in efficacy. Thus, novel treatment strategies are needed. The hypothalamic orexin (hypocretin) system, a central integrator of physiological function, plays an important role in modulating cognition. Several single- and dual-orexin receptor antagonists are available for various clinical and preclinical applications, but the paucity of orexin agonists has limited the ability to research their therapeutic potential. To circumvent this hurdle, direct intranasal administration of orexin peptides is being investigated as a prospective treatment for cognitive dysfunction, narcolepsy or other disorders in which deficient orexin signaling has been implicated. Here, we describe the possible mechanisms and therapeutic potential of intranasal orexin delivery. Combined with the behavioral evidence that intranasal orexin-A administration improves cognitive function in narcoleptic and sleep-deprived subjects, our neurochemical studies in young and aged animals highlights the capacity for intranasal orexin administration to improve age-related deficits in neurotransmission. In summary, we highlight prior and original work from our lab and from others that provides a framework for the use of intranasal orexin peptides in treating cognitive dysfunction, especially as it relates to age-related cognitive disorders.


Subject(s)
Aging/physiology , Aging/psychology , Brain/drug effects , Brain/physiology , Cognitive Dysfunction/prevention & control , Cognitive Dysfunction/physiopathology , Orexins/administration & dosage , Orexins/physiology , Administration, Intranasal , Animals , Basal Forebrain/drug effects , Basal Forebrain/physiology , Cholinergic Neurons/drug effects , Cholinergic Neurons/physiology , Humans , Neurons/drug effects , Neurons/physiology
19.
J Hosp Infect ; 106(3): 454-464, 2020 11.
Article in English | MEDLINE | ID: mdl-32898614

ABSTRACT

BACKGROUND: Decades of studies document an association between Gammaproteobacteria in sink drains and hospital-acquired infections, but the evidence for causality is unclear. AIM: We aimed to develop a tool to assess the quality of evidence for causality in research studies that implicate sink drains as reservoirs for hospital-acquired Gammaproteobacterial infections. METHODS: We used a modified Delphi process with recruited experts in hospital epidemiology to develop this tool from a pre-existing causal assessment application. FINDINGS: Through four rounds of feedback and revision we developed the 'Modified CADDIS Tool for Causality Assessment of Sink Drains as a Reservoir for Hospital-Acquired Gammaproteobacterial Infection or Colonization'. In tests of tool application to published literature during development, mean percent agreement ranged from 46.7% to 87.5%, and the Gwet's AC1 statistic (adjusting for chance agreement) ranged from 0.13 to 1.0 (median 68.1). Areas of disagreement were felt to result from lack of a priori knowledge of causal pathways from sink drains to patients and uncertain influence of co-interventions to prevent organism acquisition. Modifications were made until consensus was achieved that further iterations would not improve the tool. When the tool was applied to 44 articles by two independent reviewers in an ongoing systematic review, percent agreement ranged from 93% to 98%, and the Gwet's AC1 statistic was 0.91-0.97. CONCLUSION: The modified causality tool was useful for evaluating studies that implicate sink drains as reservoirs for hospital-acquired infections and may help guide the conduct and reporting of future research.


Subject(s)
Cross Infection/prevention & control , Disease Reservoirs/microbiology , Equipment Contamination/prevention & control , Equipment and Supplies, Hospital/microbiology , Gram-Negative Bacterial Infections/prevention & control , Software , Causality , Cross Infection/microbiology , Equipment Contamination/statistics & numerical data , Gammaproteobacteria , Gram-Negative Bacterial Infections/transmission , Hospitals/statistics & numerical data , Humans , Infection Control/methods
20.
AJNR Am J Neuroradiol ; 41(10): 1923-1929, 2020 10.
Article in English | MEDLINE | ID: mdl-32943419

ABSTRACT

BACKGROUND AND PURPOSE: Fetal imaging is crucial in the evaluation of open neural tube defects. The identification of intraventricular hemorrhage prenatally has unclear clinical implications. We aimed to explore fetal imaging findings in open neural tube defects and evaluate associations between intraventricular hemorrhage with prenatal and postnatal hindbrain herniation, postnatal intraventricular hemorrhage, and ventricular shunt placement. MATERIALS AND METHODS: After institutional review board approval, open neural tube defect cases evaluated by prenatal sonography between January 1, 2013 and April 24, 2018 were enrolled (n = 504). The presence of intraventricular hemorrhage and gray matter heterotopia by both prenatal sonography and MR imaging studies was used for classification. Cases of intraventricular hemorrhage had intraventricular hemorrhage without gray matter heterotopia (n = 33) and controls had neither intraventricular hemorrhage nor gray matter heterotopia (n = 229). A total of 135 subjects with findings of gray matter heterotopia were excluded. Outcomes were compared with regression analyses. RESULTS: Prenatal and postnatal hindbrain herniation and postnatal intraventricular hemorrhage were more frequent in cases of prenatal intraventricular hemorrhage compared with controls (97% versus 79%, 50% versus 25%, and 63% versus 12%, respectively). Increased third ventricular diameter, specifically >1 mm, predicted hindbrain herniation (OR = 3.7 [95% CI, 1.5-11]) independent of lateral ventricular size and prenatal intraventricular hemorrhage. Fetal closure (n = 86) was independently protective against postnatal hindbrain herniation (OR = 0.04 [95% CI, 0.01-0.15]) and postnatal intraventricular hemorrhage (OR = 0.2 [95% CI, 0.02-0.98]). Prenatal intraventricular hemorrhage was not associated with ventricular shunt placement. CONCLUSIONS: Intraventricular hemorrhage is relatively common in the prenatal evaluation of open neural tube defects. Hindbrain herniation is more common in cases of intraventricular hemorrhage, but in association with increased third ventricular size. Fetal closure reverses hindbrain herniation and decreases the rate of intraventricular hemorrhage postnatally, regardless of the presence of prenatal intraventricular hemorrhage.


Subject(s)
Cerebral Hemorrhage/diagnostic imaging , Fetal Diseases/diagnostic imaging , Neural Tube Defects/diagnostic imaging , Cerebral Hemorrhage/epidemiology , Cerebral Hemorrhage/etiology , Female , Fetus , Humans , Magnetic Resonance Imaging/methods , Male , Neural Tube Defects/complications , Pregnancy , Rhombencephalon/diagnostic imaging , Third Ventricle/diagnostic imaging , Ultrasonography, Prenatal/methods
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