Search

Hydrogen (H2) is considered a promising fuel to contribute to net-zero carbon emission goals. While hydrogen itself is not a greenhouse gas, leakage of hydrogen fuels causes indirect warming due to hydrogen’s influence on methane, tropospheric ozone, and stratospheric water vapor, with the methane term dominating the impact. Some studies consider a simple four-equation box model to explore the climate consequences of leakage from hydrogen fuel use relative to methane, while others have employed much more detailed global photochemical models. Here we use a comprehensive photochemical box model including 66 reactions to show and quantify how the analogous four-equation system is missing a critical OH feedback, leading it to overestimate the time-integrated methane response to a pulse of hydrogen by over 100%. We estimate a hydrogen global warming potential (GWP) relative to carbon dioxide of 28−11+18 on the 20-year time horizon and 10−4+7 on the 100-year time horizon based on the 66-reaction model and information from the literature. GWPs provide a measure of the relative global warming impact of emission of one gas compared to a selected reference gas per unit mass emitted. While CO2 is generally chosen for the reference, any gas can be used. We present the GWP of H2 using CH4 as the reference, as this choice cancels out some uncertainties that are common to both H2 and CH4. The GWP for H2 relative to CH4 from fossil fuel sources is 0.35−0.06+0.13 on time horizons beyond 15 years; put differently, we find that relative to an equivalent mass of emission of fossil CH4, hydrogen emission has a climate impact about three times smaller. These global warming potentials underscore that hydrogen leakage does contribute to climate change, emphasizing the importance of limiting both hydrogen and methane leakage if global net-zero greenhouse gas emissions are to be achieved by 2050.

Abstract Following the Hunga Tonga–Hunga Ha'apai (HTHH) eruption in January 2022, significant reductions in stratospheric hydrochloric acid (HCl) were observed in the Southern Hemisphere mid‐latitudes during the latter half of 2022, suggesting potential chlorine activation. The objective of this study is to comprehensively understand the loss of HCl in the aftermath of HTHH. Satellite measurements and a global chemistry‐climate model are employed for the analysis. We find strong agreement of 2022 anomalies between the modeled and the measured data. The observed tracer‐tracer relations between nitrous oxide (N2O) and HCl indicate a significant role of chemical processing in the observed HCl reduction, especially during the austral winter of 2022. Further examining the roles of chlorine gas‐phase and heterogeneous chemistry, we find that heterogeneous chemistry emerges as the primary driver for the chemical loss of HCl, and the reaction between hypobromous acid (HOBr) and HCl on sulfate aerosols is the dominant loss process.

Therapists’ responses to challenging therapy situations on the Facilitative Interpersonal Skills (FIS) performance task are a significant predictor of therapists’ differences in treatment outcomes. The aim of this study was to assess whether the complexity of the therapy situation influenced the facilitative interpersonal skills of trainees. Trainee therapists (n=46) participated in an experiment in which they responded to a set of challenging and benign (i.e., non-challenging) video vignettes of therapy situations of the FIS performance task. Their responses were video recorded and coded by four independent raters. Results showed that trainees scored significantly higher on the FIS performance task responding to benign therapy situations than responding to challenging situations. This is the first study to investigate difficulty of therapy situations as a potential predictor or trainees interpersonal skills. Further research is needed to replicate these results in a larger sample.

Following international agreements, the use of chlorofluorocarbons in production is supposed to be phased out. Here, the authors present a new estimate of these products already in use and their emissions and show that they are larger than expected and that not recovering these banks leads to a substantial delay in the polar ozone hole recovery.

The ideal ophthalmic anti-infective exhibits broad-spectrum activity against gram-positive, gram-negative, and atypical bacterial species. These pathogens can cause potentially blinding infections such as keratitis and endophthalmitis, both of which are associated with ophthalmic surgery or traumatic injury. These infections often require aggressive antibacterial therapy, preferably with newer generations of antibiotics. In this study, minimal inhibitory concentration (MIC) values for gatifloxacin and moxifloxacin were determined in vitro against bacterial strains that were isolated from suspected cases of bacterial keratitis and endophthalmitis. The ocular isolates included 7 gram-positive, 4 gram-negative, and 3 atypical bacterial species. Gatifloxacin and moxifloxacin exhibited similar activity against 6 gram-positive organisms: Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Bacillus cereus, and Enterococcus faecalis. MIC90 values for the drugs against these isolates ranged from 0.08 mg/mL to 0.57 mg/mL and were comparable to previously published values against isolates from patients with systemic infections. The MIC90 for gatifloxacin against Streptococcus viridans was 0.22 mg/mL compared with 0.73 mg/mL for moxifloxacin (P = .011). Among the gram-negative isolates, the mean MIC90 for gatifloxacin against Pseudomonas aeruginosa was 1.28 mg/mL compared with 2.60 mg/ mL for moxifloxacin (P = .023). MIC90 values for gatifloxacin against Klebsiella pneumoniae and Enterobacter aerogenes were one fourth to one fifth the values for moxifloxacin. For the atypicals, the MIC90 values for gatifloxacin against Nocardia asteroides and Mycobacterium chelonae were one fourth the corresponding values for moxifloxacin. Gatifloxacin demonstrated a broad spectrum of activity against several key ocular pathogens tested in this study and was at least as effective as moxifloxacin against these pathogens. [ABSTRACT FROM AUTHOR]

The Southern Hemisphere (SH) zonal-mean circulation change in response to Antarctic ozone depletion is re-visited by examining a set of the latest model simulations archived for the Chemistry-Climate Model Initiative (CCMI) project. All models reasonably well reproduce Antarctic ozone depletion in the late 20th century. The related SH-summer circulation changes, such as a poleward intensification of westerly jet and a poleward expansion of the Hadley cell, are also well captured. All experiments exhibit quantitatively the same multi-model mean trend, irrespective of whether the ocean is coupled or prescribed. Results are also quantitatively similar to those derived from the Coupled Model Intercomparison Project phase 5 (CMIP5) high-top model simulations in which the stratospheric ozone is mostly prescribed with monthly- and zonally-averaged values. These results suggest that the ozone-hole-induced SH-summer circulation changes are robust across the models irrespective of the specific chemistry-atmosphere-ocean coupling.

Abstract The increasing popularity of systems-based approaches to plant research has resulted in a demand for high throughput (HTP) methods to be developed. RNA extraction from multiple samples in an experiment is a significant bottleneck in performing systems-level genomic studies. Therefore we have established a high throughput method of RNA extraction from Arabidopsis thaliana to facilitate gene expression studies in this widely used plant model. We present optimised manual and automated protocols for the extraction of total RNA from 9-day-old Arabidopsis seedlings in a 96 well plate format using silica membrane-based methodology. Consistent and reproducible yields of high quality RNA are isolated averaging 8.9 μg total RNA per sample (~20 mg plant tissue). The purified RNA is suitable for subsequent qPCR analysis of the expression of over 500 genes in triplicate from each sample. Using the automated procedure, 192 samples (2 × 96 well plates) can easily be fully processed (samples homogenised, RNA purified and quantified) in less than half a day. Additionally we demonstrate that plant samples can be stored in RNAlater at -20°C (but not 4°C) for 10 months prior to extraction with no significant effect on RNA yield or quality. Additionally, disrupted samples can be stored in the lysis buffer at -20°C for at least 6 months prior to completion of the extraction procedure providing a flexible sampling and storage scheme to facilitate complex time series experiments.

Abstract Background Safe and effective treatment for chronic inflammatory and neuropathic pain remains a key unmet medical need for many patients. The recent discovery and description of the transient receptor potential family of receptors including TRPV1 and TRPA1 has provided a number of potential new therapeutic targets for treating chronic pain. Recent reports have suggested that TRPA1 may play an important role in acute formalin and CFA induced pain. The current study was designed to further explore the therapeutic potential of pharmacological TRPA1 antagonism to treat inflammatory and neuropathic pain. Results The in vitro potencies of HC-030031 versus cinnamaldehyde or allyl isothiocyanate (AITC or Mustard oil)-induced TRPA1 activation were 4.9 ± 0.1 and 7.5 ± 0.2 μM respectively (IC50). These findings were similar to the previously reported IC50 of 6.2 μM against AITC activation of TRPA1 1. In the rat, oral administration of HC-030031 reduced AITC-induced nocifensive behaviors at a dose of 100 mg/kg. Moreover, oral HC-030031 (100 mg/kg) significantly reversed mechanical hypersensitivity in the more chronic models of Complete Freunds Adjuvant (CFA)-induced inflammatory pain and the spinal nerve ligation model of neuropathic pain. Conclusion Using oral administration of the selective TRPA1 antagonist HC-030031, our results demonstrated that TRPA1 plays an important role in the mechanisms responsible for mechanical hypersensitivity observed in inflammatory and neuropathic pain models. These findings suggested that TRPA1 antagonism may be a suitable new approach for the development of a potent and selective therapeutic agent to treat both inflammatory and neuropathic pain.

Self-determination (SD) is linked to autonomy and better adult outcomes. Adults with autism spectrum disorder (ASD) are often less independent than cognitively matched peers. Given the frequency with which depression co-occurs in ASD and the established association between depression and SD, we sought to evaluate the influence of both ASD severity and depression on SD among cognitively able emerging adults with ASD. Emerging adults (n = 59) with ASD completed measures of SD, ASD severity, and depression. Both ASD severity and depression were moderately correlated with SD (r = - 0.473; - 0.423, respectively) and with each other (r = 0.625). After controlling for ASD severity, depression did not significantly predict SD. Strengthening SD should be considered in programming to promote independence., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Aims: Endovascular coiling is a common modality for treating intracranial aneurysms; however, recanalization occurs in approximately 1 in 5 cases, with downstream consequences of regrowth and rupture. Aneurysm packing density >24% reduces recanalization risk; packing density can be increased by inserting additional coils or by using coils with larger volumetric filling. Coil volume depends on length and primary wind diameter (PWD). This study evaluated the influence of PWD on packing density and total case costs., Materials and Methods: Two hypothetical scenarios and one case study were analyzed. In scenario one, the number of coils required to achieve packing density >24% in a hypothetical aneurysm was determined for 0.012″ vs. 0.010″ PWD coils. In scenario two, the total length of 0.010″ vs. 0.012″ PWD coils required to achieve a packing density >24% was analyzed relative to aneurysm volume. In the case study, packing densities with one 0.012″ PWD coil (actual scenario) and one 0.010″ PWD coil (theoretical scenario) were compared., Results: In scenario one, cost savings would be realized by using four 0.012″ PWD coils vs. seven 0.010″ PWD coils to achieve packing density >24%. In scenario two, greater volumetric filling of 0.012″ vs. 0.010″ PWD coils was correlated with lower total length of coil required. In the case study, a 0.012″ PWD coil achieved packing density >24%, whereas an equivalent length 0.010″ PWD coil would not., Limitations: Theoretical modeling was used to explore the impact of coil PWD on aneurysm packing density. In clinical practice, packing density depends not only on PWD but on its length, shape, distribution within an aneurysm, and other recanalization risk factors., Conclusions: Coil PWD influences packing density, the number of coils required to achieve a specific packing density, and total case costs. Using 0.012″ PWD coils may provide cost and procedural efficiencies.

Identification of effective consultation models could inform implementation efforts. This study examined the effects of a fidelity-focused consultation model among community-based clinicians implementing Attachment and Biobehavioral Catch-up. Fidelity data from 1217 sessions from 7 clinicians were examined in a multiple baseline design. In fidelity-focused consultation, clinicians received feedback from consultants' fidelity coding, and also coded their own fidelity. Clinicians' fidelity increased after fidelity-focused consultation began, but did not increase during other training periods. Fidelity was sustained for 30 months after consultation ended. Findings suggest that consultation procedures involving fidelity coding feedback and self-monitoring of fidelity may promote implementation outcomes.

Aims: This study aimed to determine whether host-adapted lactobacilli exhibit superior survival during intestinal transit relative to nomadic and free-living organisms, and to characterize the impact of probiotic lactobacilli on autochthonous lactobacilli., Methods and Results: Mixed cultures of Lactobacillus casei K9-1 and Lactobacillus fermentum K9-2, or reutericyclin producing Lactobacillus reuteri and its isogenic mutant were fed to piglets as freeze-dried culture, or as part of fermented feed. Lactobacilli in digesta and faecal samples were quantified by strain-specific quantitative PCR (qPCR), high-resolution-melting curve qPCR, and high-throughput sequencing of 16S rRNA gene sequence tags. The abundance of the host adapted L. reuteri in digesta and faeces was higher (P < 0·05) when compared to L. casei or L. fermentum. Feed fermentation or chemical acidification of feed reduced (P < 0·05) cell counts of Lactobacillus salivarius in colonic digesta. The reutericyclin producing L. reuteri TMW1.656 transiently reduced (P < 0·05) the faecal abundance of lactobacilli. However, the overall impact of probiotic intervention on autochthonous lactobacilli was minor., Conclusions: The vertebrate host-adapted L. reuteri survives better during intestinal transit of piglets compared to L. casei and L. fermentum., Significance and Impact of the Study: Ecology and lifestyle of Lactobacillus strains may be suitable criteria for selection of probiotic strains for use in swine production., (© 2018 The Society for Applied Microbiology.)

This article describes the development and validation of the Learning Difficulties Assessment (LDA), a normed and web-based survey that assesses perceived difficulties with reading, writing, spelling, mathematics, listening, concentration, memory, organizational skills, sense of control, and anxiety in college students. The LDA is designed to (a) map individual learning strengths and weaknesses, (b) provide users with a comparative sense of their academic skills, (c) integrate research in user-interface design to assist those with reading and learning challenges, and (d) identify individuals who may be at risk for learning disabilities and attention-deficit/hyperactivity disorder (ADHD) and who should thus be further assessed. Data from a large-scale 5-year study describing the instrument's validity as a screening tool for learning disabilities and ADHD are presented. This article also describes unique characteristics of the LDA including its user-interface design, normative characteristics, and use as a no-cost screening tool for identifying college students at risk for learning disorders and ADHD.

Bacillus causes one of the most rapidly blinding intraocular infections: endophthalmitis. In this study, Bacillus spp. were isolated from ocular infection cases, taxonomically characterized by riboprint analysis, and screened for the presence of putative virulence factors. The ability of these isolates to kill retinal and corneal cells was examined, as were antibiotic susceptibility profiles. The majority of isolates belonged to the B. cereus taxonomic group of microorganisms and were identified as B. cereus (53%) or B. thuringiensis (26%). Toxins were identified in most B. thuringiensis and B. cereus isolates. Most B. cereus and B. thuringiensis killed corneal and retinal cells within 6 h. All isolates were susceptible to most antibiotics tested, with quinolones and vancomycin being the most potent. These findings represent the first report of B. thuringiensis as an important ocular pathogen, demonstrates the potential ocular toxicity of B. cereus and B. thuringiensis isolates, and identifies antibiotics whose efficacy against Bacillus were superior to those used clinically.

Purpose: Bacillus endophthalmitis is a highly explosive infection of the eye that commonly results in rapid inflammation and vision loss, if not loss of the eye itself, within a few days. Quorum-sensing-controlled toxins are essential to virulence during infection. Another unique characteristic of this disease is the ability of Bacillus to replicate rapidly and migrate to all parts of the eye. This study was conducted to determine the combined roles of toxins and motility during Bacillus endophthalmitis., Methods: Rabbit eyes were injected intravitreally with approximately 100 cfu of wild type, nonmotile, or nonmotile/quorum-sensing-deficient Bacillus thuringiensis. Infection courses were analyzed by biomicroscopy, histology, electroretinography, and quantitation of bacteria and inflammatory cells., Results: Infection with wild type B. thuringiensis resulted in complete retinal function loss by 18 hours after infection, whereas nonmotile B. thuringiensis infections required 30 hours to achieve a reduction of >90% in retinal function. Further attenuation of infection resulted from infection with the nonmotile/quorum-sensing-deficient B. thuringiensis strain, with approximately 90% retinal function loss occurring at 36 hours. Overall, the nonmotile and nonmotile/quorum-sensing-deficient mutants were significantly less virulent than wild-type B. thuringiensis., Conclusions: The results demonstrate that, in addition to quorum-sensing-controlled toxin production, bacterial migration within the eye contributed to the rapidly fulminant and destructive course of Bacillus endophthalmitis. Motility and quorum-sensing may therefore represent possible targets for the development of therapies designed to attenuate the devastating effects of Bacillus in the eye during endophthalmitis.

The explosive, destructive course of Bacillus endophthalmitis has been attributed to the production of toxins during infection. In this study we analyzed the contribution of toxins controlled by the global regulator plcR to the pathogenesis of experimental Bacillus endophthalmitis. Isogenic plcR-deficient mutants of Bacillus cereus and Bacillus thuringiensis were constructed by insertional inactivation of plcR by the kanamycin resistance cassette, aphA3. Rabbit eyes were injected intravitreally with approximately 100 CFU of wild-type B. cereus or B. thuringiensis or a plcR-deficient mutant. The evolution of endophthalmitis resulting from each plcR-deficient mutant was considerably slower than that caused by each wild-type strain. Retinal function was not eliminated until 42 h postinfection in rabbits with endophthalmitis caused by the plcR-deficient mutants, whereas wild-type infections resulted in a complete loss of retinal function within 18 h. The intraocular inflammatory cell influx and retinal destruction in plcR-deficient endophthalmitis approached the severity observed in wild-ype infections, but not until 36 h postinfection. Gross and histological examinations of eyes infected with plcR mutants demonstrated that the anterior and posterior segment changes were muted compared to the changes observed in eyes infected with the wild types. The loss of plcR-regulated factors significantly attenuated the severity of Bacillus endophthalmitis. The results therefore suggest that plcR may represent a target for which adjunct therapies could be designed for the prevention of blindness during Bacillus endophthalmitis.

Membrane-damaging toxins are thought to be responsible for the explosive clinical course of Bacillus endophthalmitis. This study analyzed the contribution of phosphatidylinositol-specific phospholipase C (PI-PLC) and phosphatidylcholine-specific phospholipase C (PC-PLC) to the pathogenesis of experimental Bacillus endophthalmitis. Isogenic mutants were constructed by insertion of lacZ into Bacillus thuringiensis genes encoding PI-PLC (plcA) and PC-PLC (plcB). Rabbit eyes were injected intravitreally with 2 log(10) CFU of strain BT407 (wild type), the PI-PLC mutant (BTplcA::lacZ), or the PC-PLC mutant (BTplcB::lacZ). The rates of decrease in retinal responses of eyes infected with the isogenic mutants were similar to that of wild type, with all infections resulting in elimination of retinal function by 18 h. Strain BT407 caused a significant increase in the latency of retinal responses at 6 h, but strains BTplcA::lacZ and BTplcB::lacZ did not. All strains elicited significant inflammatory cell influx into the anterior chamber by 12 h. Histologically, eyes infected with each strain were indistinguishable throughout the infection course. In this model, neither PI-PLC nor PC-PLC had an effect on the course or severity of experimental Bacillus endophthalmitis. Alterations in retinal responses early in infection may mark the beginnings of specific photoreceptor or glial cell dysfunction.

Bacillus endophthalmitis is one of the most devastating intraocular infections, frequently resulting in significant vision loss, if not loss of the eye itself, in only a few days. This review summarizes recent research focused on characterizing the interactions between Bacillus and the host response during endophthalmitis. Analyses of the contribution of Bacillus toxins and cell wall components, and the behavior of the organism during progressive disease are discussed. A better understanding of the host/pathogen interactions occurring during endophthalmitis is critical for the development of novel therapeutic agents designed to impede the progression of infection and protect vision.