Aims
We aimed to elucidate whether the DNA extraction kit and bacteria therein affect the characterization of bacterial communities associated with butterfly samples harbouring different bacterial ...abundancies.
Methods and Results
We analysed bacteria associated with eggs of Pieris brassicae and with adults of this butterfly, which were either untreated or treated with antibiotics (ABs). Three DNA extraction kits were used. Regardless of the extraction kit used, PCR amplification of the bacterial 16S rRNA gene detected very low bacterial presence in eggs and AB‐treated butterflies. In untreated butterflies, bacterial signal intensity varied according to the kit and primers used. Sequencing (MiSeq) of the bacterial communities in untreated and AB‐treated butterflies revealed a low alpha diversity in untreated butterflies because of the dominance of few bacteria genera, which were detectable regardless of the kit. However, a significantly greater alpha diversity was found in AB‐treated butterflies, evidencing a true bias of the results due to bacterial contaminants in the kit.
Conclusions
The so‐called ‘kitome’ can impact the profiling of Lepidoptera‐associated bacteria in samples with low bacterial biomass.
Significance and Impact of the Study
Our study highlights the necessity of method testing and analysis of negative controls when investigating Lepidoptera‐associated bacterial communities.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
We present an overview of the Large Program, “Early Planet Formation in Embedded Disks (eDisk),” conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). The ubiquitous ...detections of substructures, particularly rings and gaps, in protoplanetary disks around T Tauri stars raise the possibility that at least some planet formation may have already started during the embedded stages of star formation. In order to address exactly how and when planet formation is initiated, the program focuses on searching for substructures in disks around 12 Class 0 and 7 Class I protostars in nearby (<200 pc) star-forming regions through 1.3 mm continuum observations at a resolution of ∼7 au (0.″04). The initial results show that the continuum emission, mostly arising from dust disks around the sample protostars, has relatively few distinctive substructures, such as rings and spirals, in marked contrast to Class II disks. The dramatic difference may suggest that substructures quickly develop in disks when the systems evolve from protostars to Class II sources, or alternatively that high optical depth of the continuum emission could obscure internal structures. Kinematic information obtained through CO isotopologue lines and other lines reveals the presence of Keplerian disks around protostars, providing us with crucial physical parameters, in particular, the dynamical mass of the central protostars. We describe the background of the eDisk program, the sample selection and their ALMA observations, and the data reduction, and we also highlight representative first-look results.
Simultaneous observations from Defense Meteorological Satellite Program, Swarm, Resolute Bay all‐sky imagers, GPS Total Electron Content and Super Dual Auroral Radar Network, are used to investigate ...the evolution and key characteristics of the Tongue of Ionization (TOI) being restructured into a polar cap patch. Six satellites crossed the TOI of patch as it moved from the dayside to the nightside. It was initially hot, then a mix of both cold and hot, and finally it became a cold patch. This suggests that cold patch is not only a result of solar extreme ultraviolet radiation, but may also develop when a hot patch cools down. Soft‐electron precipitation and flow shears both contribute to the TOI restructuring and the appearance of polar cap patch. The plasma density of patch at ∼500 km was at least 4 times higher than at ∼800 km. The plasma density enhancement gradually decreased as the patch evolved due to decreased production and transport of cold nightside low‐density plasma. Moreover, the duskward motion of the patch was influenced by changes in the ionospheric convection pattern.
Plain Language Summary
The appearance of high‐density plasma is a common phenomenon in the polar ionosphere. High‐density polar cap patches usually form near the dayside sunlit region, and then move from the dayside to the nightside with the ionospheric flow. In the paper, we use multiple instruments including six satellites and ground‐based observations to carefully investigate an event that started out on the dayside. It was initially a hot tongue of ionization (TOI) of high density and high electron temperature, followed by a mix of hot and cold (high vs. low electron temperature), before it finally became a cold patch. Soft‐electron precipitation and flow shears both influenced the dayside high‐density TOI plasma restructuring and the appearance of polar cap patch. The enhanced plasma density gradually weakened as the plasma migrated toward the nightside due to decreased production and transport of cold nightside low‐density plasma. Moreover, the duskward motion of the patch was influenced by changes in the ionospheric convection pattern.
Key Points
Cold dense plasma in the polar cap can appear either via transport of solar extreme ultraviolet plasma or after a hot patch cools down
Soft‐electron precipitation and flow shears both influence the Tongue of Ionization restructuring and the appearance of polar cap patches
The enhanced plasma density is reduced due to decreased production and transport of cold nightside low‐density plasma
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Mucosal damage, barrier breach, inflammation, and iron-deficiency anemia (IDA) typify ulcerative colitis (UC) in humans. The anemia in UC appears to mainly relate to systemic inflammation. The ...pathogenesis of this ‘anemia of inflammation’ (AI) involves cytokine-mediated transactivation of hepatic
Hamp
(encoding the iron-regulatory hormone, hepcidin). In AI, high hepcidin represses iron absorption (and iron release from stores), thus lowering serum iron, and restricting iron for erythropoiesis (causing anemia). In less-severe disease states, inflammation may be limited to the intestine, but whether this perturbs iron homeostasis is uncertain. We hypothesized that localized gut inflammation will increase overall iron demand (to support the immune response and tissue repair), and that hepatic
Hamp
expression will decrease in response, thus derepressing (i.e., enhancing) iron absorption. Accordingly, we developed a rat model of mild, acute colitis, and studied iron absorption and homeostasis. Rats exposed (orally) to DSS (4%) for 7 days had intestinal (but not systemic) inflammation, and biomarker analyses demonstrated that iron utilization was elevated. Iron absorption was enhanced (by 2-3-fold) in DSS-treated, WT rats of both sexes, but unexpectedly, hepatic
Hamp
expression was not suppressed. Therefore, to gain a better understanding of regulation of iron absorption during acute colitis,
Hamp
KO rats were used for further experimentation. The severity of DSS-colitis was similar in
Hamp
KOs as in WT controls. In the KOs, increased iron requirements associated with the physiological response to colitis were satisfied by mobilizing hepatic storage iron, rather than by increasing absorption of enteral iron (as occurred in WT rats). In conclusion then, in both sexes and genotypes of rats, iron absorption was appropriately modulated to match physiological demand for dietary iron during acute intestinal inflammation, but regulatory mechanisms may not involve hepcidin.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
We present the first results from the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter Array Large Program toward Oph IRS43, a binary system of solar mass ...protostars. The 1.3 mm dust continuum observations resolve a compact disk, ∼6 au radius, around the northern component and show that the disk around the southern component is even smaller, ≲3 au. CO,
13
CO, and C
18
O maps reveal a large cavity in a low-mass envelope that shows kinematic signatures of rotation and infall extending out to ∼2000 au. An expanding CO bubble centered on the extrapolated location of the source ∼130 yr ago suggests a recent outburst. Despite the small size of the disks, the overall picture is of a remarkably large and dynamically active region.
Summary
Background
Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC) worldwide. It remains incompletely understood in the real world how anti‐viral therapy affects ...survival after HCC diagnosis.
Methods
This was an international multicentre cohort study of 2518 HBV‐related HCC cases diagnosed between 2000 and 2015. Cox proportional hazards models were utilised to estimate hazard ratios (HR) with 95% (CI) for anti‐viral therapy and cirrhosis on patients' risk of death.
Results
Approximately, 48% of patients received anti‐viral therapy at any time, but only 17% were on therapy at HCC diagnosis (38% at US centres, 11% at Asian centres). Anti‐viral therapy would have been indicated for >60% of the patients not on anti‐viral therapy based on American criteria. Patients with cirrhosis had lower 5‐year survival (34% vs 46%; P < 0.001) while patients receiving anti‐viral therapy had increased 5‐year survival compared to untreated patients (42% vs 25% with cirrhosis and 58% vs 36% without cirrhosis; P < 0.001 for both). Similar findings were seen for other patient subgroups by cancer stages and cancer treatment types. Anti‐viral therapy was associated with a decrease in risk of death, whether started before or after HCC diagnosis (adjusted HR 0.62 and 0.79, respectively; P < 0.001).
Conclusions
Anti‐viral therapy improved overall survival in patients with HBV‐related HCC across cancer stages and treatment types but was underutilised at both US and Asia centres. Expanded use of anti‐viral therapy in HBV‐related HCC and better linkage‐to‐care for HBV patients are needed.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Determining physiological mechanisms and thresholds for climate-driven tree die-off could help improve global predictions of future terrestrial carbon sinks. We directly tested for the lethal ...threshold in hydraulic failure – an inability to move water due to drought-induced xylem embolism – in a pine sapling experiment.
In a glasshouse experiment, we exposed loblolly pine (Pinus taeda) saplings (n = 83) to drought-induced water stress ranging from mild to lethal. Before rewatering to relieve drought stress, we measured native hydraulic conductivity and foliar color change. We monitored all measured individuals for survival or mortality.
We found a lethal threshold at 80% loss of hydraulic conductivity – a point of hydraulic failure beyond which it is more likely trees will die, than survive, and describe mortality risk across all levels of water stress. Foliar color changes lagged behind hydraulic failure – best predicting when trees had been dead for some time, rather than when they were dying.
Our direct measurement of native conductivity, while monitoring the same individuals for survival or mortality, quantifies a continuous probability of mortality risk from hydraulic failure. Predicting tree die-off events and understanding the mechanism involved requires knowledge not only of when trees are dead, but when they begin dying – having passed the point of no return.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
.
Background. Klebsiella pneumoniae, a Gram‐negative bacillus usually forming glistening mucoid colonies with viscid consistency on the culture plate, is a common pathogen causing various clinical ...infection patterns. However, little is known about the clinical implications of this mucoid character.
Objective. The purposes of this study, therefore, were to investigate the frequency of hypermucoviscosity (HV) in bacteraemic isolates of K. pneumoniae, and determine the significance of any association between HV and various clinical manifestations.
Design. Retrospective observational study.
Patients. Patients diagnosed with K. pneumoniae bacteraemia at a community‐based university hospital between June 1999 and June 2001 were enrolled in this analysis.
Measurements. Clinical data concerning comorbid diseases and infection patterns was collected. K. pneumoniae bacteraemic isolates were examined for the presence of HV using a modified string test. The clinical impact of HV and risk factors for the invasive syndrome were assessed using statistical analysis. Polymerase chain reaction (PCR) was performed to detect magA, a gene related to HV phenotype.
Results. Overall, 200 (64.9%) of the 308 cases of K. pneumoniae bacteraemia were community‐acquired infections. Compared with hospital‐acquired K. pneumoniae bacteraemia (HA‐KpB), community‐acquired K. pneumoniae bacteraemia (CA‐KpB) was more likely to be monomicrobial in nature (83.5% vs. 64.8%; P < 0.001) and caused by HV strains (41.5% vs. 14.8%; P < 0.001). The prevalence rate of magA among HV phenotypical K. pneumoniae strains was 24.1%. Patients infected with HV‐positive strains were more likely to have the distinctive invasive syndrome (i.e. liver abscess, meningitis, pleural empyaema or endophthalmitis) than those infected with HV‐negative variants (37.3% vs. 6.8%; P < 0.001). Multivariate logistic regression analysis, adjusted for age, showed that HV phenotype in K. pneumoniae strains (OR 8.86; 95% CI, 3.70–21.25; P < 0.001) was positively associated with the development of the invasive syndrome in CA‐KpB cases.
Conclusions. The HV phenotype of K. pneumoniae bacteraemic isolates was associated with the development of a distinctive invasive syndrome. Identification of the HV phenotype should prompt clinicians to initiate aggressive investigations for invasive diseases.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
A statistical study of ion upflow and field‐aligned currents (FACs) has been performed in the topside ionosphere of both hemispheres for magnetic quiet and disturbed times by using DMSP satellite ...observations from 2010–2013. Distributions in MLT/MLat reveal that ion upflow occurrence shows a dawn‐dusk asymmetry distribution that matches well with the Region 1 FACs. In addition, there are highest occurrence regions near noon and within the midnight auroral disturbance area, corresponding to dayside cusp and nightside auroral disturbance regions, respectively. Both the ion upflow occurrence and FAC regions expand equatorward to a wider area during disturbed times.
Key Points
Ionospheric ion upflow occurrence exhibits a dawn‐dusk asymmetry, consistent to that of the Region 1 field‐aligned currents
The ion upflow occurrence expands to a wider area in disturbed times than in quiet times
In both hemispheres, maximum ion upflow occurrence is consistent with cusp and nightside auroral disturbance regions
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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