bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effectiveness of Rlm7 resistance against Leptosphaeria maculans (phoma stem canker) in UK winter oilseed rape cultivars
Authors: Mitrousia G. K. , Huang Y. J. , Qi A. , Sidique S. N. M. , Fitt B. D. L. 
Published: February 2018

The Rlm7 gene in Brassica napus is an important source of resistance for control of phoma stem canker on oilseed rape caused by the fungus Leptosphaeria maculans. This study shows the first report of L. maculans isolates virulent against Rlm7 in the UK. Leptosphaeria maculans isolates virulent against Rlm7 represented 3% of the pathogen population when cultivars with the Rlm7 gene represented 5% of the UK oilseed rape area in 2012/13. However, the Rlm7 gene has been widely used since then, representing >15% of the UK oilseed rape area in 2015/16. Winter oilseed rape field experiments included cultivars with the Rlm7 gene, with the Rlm4 gene or without Rlm genes and took place at five sites in the UK over four cropping seasons. An increase in phoma leaf spotting severity on Rlm7 cultivars in successive seasons was observed. Major resistance genes played a role in preventing severe phoma leaf spotting at the beginning of the cropping season and, in addition, quantitative resistance (QR) in the cultivars examined made an important contribution to control of phoma stem canker development at the end of the cropping season. Deployment of the Rlm7 resistance gene against L. maculans in cultivars with QR in combination with sustainable disease management practices will prolong the use of this gene for effective control of phoma stem canker epidemics.
Event‐related potentials of emotional and neutral memories: The role of encoding position and delayed testing
Authors: Wirkner Janine , Ventura‐Bort Carlos , Schulz Paul , Hamm Alfons O. , Weymar Mathias 
Published: February 2018

AbstractPrevious research found that memory is not only better for emotional information but also for neutral information that has been encoded in the context of an emotional event. In the present ERP study, we investigated two factors that may influence memory for neutral and emotional items: temporal proximity between emotional and neutral items during encoding, and retention interval (immediate vs. delayed). Forty‐nine female participants incidentally encoded 36 unpleasant and 108 neutral pictures (36 neutral pictures preceded an unpleasant picture, 36 followed an unpleasant picture, and 36 neutral pictures were preceded and followed by neutral pictures) and participated in a recognition memory task either immediately (N = 24) or 1 week (N = 25) after encoding. Results showed better memory for emotional pictures relative to neutral pictures. In accordance, enhanced centroparietal old/new differences (500–900 ms) during recognition were observed for unpleasant compared to neutral pictures, most pronounced for the 1‐week interval. Picture position effects, however, were only subtle. During encoding, late positive potentials for neutral pictures were slightly lower for neutral pictures following unpleasant ones, but only at trend level. To summarize, we could replicate and extend previous ERP findings showing that emotionally arousing events are better recollected than neutral events, particularly when memory is tested after longer retention intervals. Picture position during encoding, however, had only small effects on elaborative processing and no effects on memory retrieval.
Nutrition education in the care of patients with chronic kidney disease and end‐stage renal disease
Authors: Anderson Cheryl A. M. , Nguyen Hoang Anh 
Published: February 2018

AbstractDiet counseling and nutrition education are recommended in the prevention and management of chronic kidney disease (CKD) and end‐stage renal disease (ESRD). The importance of effectively addressing nutrition with patients has grown given the increasing prevalence of obesity, hypertension, and diabetes; conditions which influence CKD/ESRD. Dietary advice for individuals with CKD/ESRD can be seen as complex; and successful dietary management requires careful planning, periodic assessment of nutritional status, as well as monitoring of dietary compliance. In spite of recommendations and pressing need, formal training in nutrition and adequate preparation for providers is limited; and for physicians the lack of nutrition education has been acknowledged, repeatedly, as an area for improvement in medical training curricula. It has also been suggested that dietitians have an essential role in management of CKD in the primary care setting; however, dietitians who do not practice renal education daily may need training on the specific challenges in CKD/ESRD. The objectives of this chapter were to: characterize select nutrition education resources for providers who care for patients with CKD/ESRD; summarize key dietary components emphasized in the care of patients with CKD/ESRD; and address practical considerations in educational efforts focused on nutrition and CKD/ESRD.
Oxidative capacity varies along the length of healthy human tibialis anterior
Authors: Boss Andreas , Heskamp Linda , Breukels Vincent , Bains Lauren J , van Uden Mark J. , Heerschap Arend 
Published: February 2018

Key points
During exercise skeletal muscles use the energy buffer phosphocreatine.
The post‐exercise recovery of phosphocreatine is a measure of the oxidative capacity of muscles and is traditionally assessed by 31P magnetic resonance spectroscopy of a large tissue region, assuming homogeneous energy metabolism.
To test this assumption, we collected spatially resolved spectra along the length of human tibialis anterior using a home‐built array of 31P detection coils, and observed a striking gradient in the recovery rate of phosphocreatine, decreasing along the proximo‐distal axis of the muscle.
A similar gradient along this muscle was observed in signal changes recorded by 1H muscle functional MRI.
These findings identify intra‐muscular variation in the physiology of muscles in action and highlight the importance of localized sampling for any methodology investigating oxidative metabolism of this, and potentially other muscles.
AbstractThe rate of phosphocreatine (PCr) recovery (kPCr) after exercise, characterizing muscle oxidative capacity, is traditionally assessed with unlocalized 31P magnetic resonance spectroscopy (MRS) using a single surface coil. However, because of intramuscular variation in fibre type and oxygen supply, kPCr may be non‐uniform within muscles. We tested this along the length of the tibialis anterior (TA) muscle in 10 male volunteers. For this purpose, we employed a 3T MR system with a 31P/1H volume transmit coil combined with a home‐built 31P phased‐array receive probe, consisting of five coil elements covering the TA muscle length. Mono‐exponential kPCr was determined for all coil elements after 40 s of submaximal isometric dorsiflexion (SUBMAX) and incremental exercise to exhaustion (EXH). In addition, muscle functional MRI (1H mfMRI) was performed using the volume coil after another 40 s of SUBMAX. A strong gradient in kPCr was observed along the TA (P < 0.001), being two times higher proximally vs. distally during SUBMAX and EXH. Statistical analysis showed that this gradient cannot be explained by pH variations. A similar gradient was seen in the slope of the initial post‐exercise 1H mfMRI signal change, which was higher proximally than distally in both the TA and the extensor digitorum longus (P < 0.001) and strongly correlated with kPCr. The pronounced differences along the TA in functional oxidative capacity identify regional variation in the physiological demand of this muscle during everyday activities and have implications for the bio‐energetic assessment of interventions to modify its performance and of neuromuscular disorders involving the TA.
Verapamil Targets Membrane Energetics in Mycobacterium tuberculosis
Authors: Chen Chao , Gardete Susana , Jansen Robert Sander , Shetty Annanya , Dick Thomas , Rhee Kyu Y. , Dartois Véronique 
Published: February 2018

ABSTRACT

Mycobacterium tuberculosis
kills more people than any other bacterial pathogen and is becoming increasingly untreatable due to the emergence of resistance. Verapamil, an FDA-approved calcium channel blocker, potentiates the effect of several antituberculosis (anti-TB) drugs
in vitro
and
in vivo
. This potentiation is widely attributed to inhibition of the efflux pumps of
M. tuberculosis
, resulting in intrabacterial drug accumulation. Here, we confirmed and quantified verapamil's synergy with several anti-TB drugs, including bedaquiline (BDQ) and clofazimine (CFZ), but found that the effect is not due to increased intrabacterial drug accumulation. We show that, consistent with its
in vitro
potentiating effects on anti-TB drugs that target or require oxidative phosphorylation, the cationic amphiphile verapamil disrupts membrane function and induces a membrane stress response similar to those seen with other membrane-active agents. We recapitulated these activities
in vitro
using inverted mycobacterial membrane vesicles, indicating a direct effect of verapamil on membrane energetics. We observed bactericidal activity against nonreplicating “persister”
M. tuberculosis
that was consistent with such a mechanism of action. In addition, we demonstrated a pharmacokinetic interaction whereby human-equivalent doses of verapamil caused a boost of rifampin exposure in mice, providing a potential explanation for the observed treatment-shortening effect of verapamil in mice receiving first-line drugs. Our findings thus elucidate the mechanistic basis for verapamil's potentiation of anti-TB drugs
in vitro
and
in vivo
and highlight a previously unrecognized role for the membrane of
M. tuberculosis
as a pharmacologic target.
The Gills of Reef Fish Support a Distinct Microbiome Influenced by Host-Specific Factors
Authors: Pratte Zoe A. , Besson Marc , Hollman Rebecca D. , Stewart Frank J. 
Published: February 2018

ABSTRACT

Teleost fish represent the most diverse of the vertebrate groups and play important roles in food webs, as ecosystem engineers, and as vectors for microorganisms. However, the microbial ecology of fishes remains underexplored for most host taxa and for certain niches on the fish body. This is particularly true for the gills, the key sites of respiration and waste exchange in fishes. Here we provide a comprehensive analysis of the gill microbiome. We focus on ecologically diverse taxa from coral reefs around Moorea, sampling the gills and intestines of adults and juveniles representing 15 families. The gill microbiome composition differed significantly from that of the gut for both adults and juveniles, with fish-associated niches having lower alpha diversity values and higher beta diversity values than those for seawater, sediment, and alga-associated microbiomes. Of ∼45,000 operational taxonomic units (OTUs) detected across all samples, 11% and 13% were detected only in the gill and the intestine, respectively. OTUs most enriched in the gill included members of the gammaproteobacterial genus
Shewanella
and the family
Endozoicimonaceae
. In adult fish, both gill and intestinal microbiomes varied significantly among host species grouped by diet category. Gill and intestinal microbiomes from the same individual were more similar to one another than to gill and intestinal microbiomes from different individuals. These results demonstrate that distinct body sites are jointly influenced by host-specific organizing factors operating at the level of the host individual. The results also identify taxonomic signatures unique to the gill and the intestine, confirming fish-associated niches as distinct reservoirs of marine microbial diversity.

IMPORTANCE
Fish breathe and excrete waste through their gills. The gills are also potential sites of pathogen invasion and colonization by other microbes. However, we know little about the microbial communities that live on the gill and the factors shaping their diversity. Focusing on ecologically distinct types of coral reef fish, we provide a comprehensive analysis of the fish gill microbiome. By comparison to microbiomes of the gut and the surrounding environment, we identify microbes unique to the gill niche. These microbes may be targets for further studies to determine the contribution of the microbiome to waste exchange or host immunity. We also show that despite exhibiting a unique taxonomic signature, the gill microbiome is influenced by factors that also influence the gut microbiome. These factors include the specific identity of the host individual. These results suggest basic principles describing how association with fishes structures the composition of microbial communities.
Integrated Metabolomics and Morphogenesis Reveal Volatile Signaling of the Nematode-Trapping Fungus Arthrobotrys oligospora
Authors: Wang Bai-Le , Chen Yong-Hong , He Jia-Ning , Xue Hua-Xi , Yan Ni , Zeng Zhi-Jun , Bennett Joan W. , Zhang Ke-Qin , Niu Xue-Mei 
Published: February 2018

ABSTRACT

The adjustment of metabolic patterns is fundamental to fungal biology and plays vital roles in adaptation to diverse ecological challenges. Nematode-trapping fungi can switch their lifestyle from saprophytic to pathogenic by developing specific trapping devices induced by nematodes to infect their prey as a response to nutrient depletion in nature. However, the chemical identity of the specific fungal metabolites used during the switch remains poorly understood. We hypothesized that these important signal molecules might be volatile in nature. Gas chromatography-mass spectrometry was used to carry out comparative analysis of fungal metabolomics during the saprophytic and pathogenic lifestyles of the model species
Arthrobotrys oligospora
. Two media commonly used in research on this species, cornmeal agar (CMA) and potato dextrose agar (PDA), were chosen for use in this study. The fungus produced a small group of volatile furanone and pyrone metabolites that were associated with the switch from the saprophytic to the pathogenic stage.
A. oligospora
fungi grown on CMA tended to produce more traps and employ attractive furanones to improve the utilization of traps, while fungi grown on PDA developed fewer traps and used nematode-toxic furanone metabolites to compensate for insufficient traps. Another volatile pyrone metabolite, maltol, was identified as a morphological regulator for enhancing trap formation. Deletion of the gene
AOL_s00079g496
in
A. oligospora
led to increased amounts of the furanone attractant (2-fold) in mutants and enhanced the attractive activity (1.5-fold) of the fungus, while it resulted in decreased trap formation. This investigation provides new insights regarding the comprehensive tactics of fungal adaptation to environmental stress, integrating both morphological and metabolomic mechanisms.

IMPORTANCE
Nematode-trapping fungi are a unique group of soil-living fungi that can switch from the saprophytic to the pathogenic lifestyle once they come into contact with nematodes as a response to nutrient depletion. In this study, we investigated the metabolic response during the switch and the key types of metabolites involved in the interaction between fungi and nematodes. Our findings indicate that
A. oligospora
develops multiple and flexible metabolic tactics corresponding to different morphological responses to nematodes.
A. oligospora
can use similar volatile furanone and pyrone metabolites with different ecological functions to help capture nematodes in the fungal switch from the saprophytic to the pathogenic lifestyle. Furthermore, studies with
A. oligospora
mutants with increased furanone and pyrone metabolites confirmed the results. This investigation reveals the importance of volatile signaling in the comprehensive tactics used by nematode-trapping fungi, integrating both morphological and metabolomic mechanisms.
Plant-Microbe and Abiotic Factors Influencing Salmonella Survival and Growth on Alfalfa Sprouts and Swiss Chard Microgreens
Authors: Reed Elizabeth , Ferreira Christina M. , Bell Rebecca , Brown Eric W. , Zheng Jie 
Published: February 2018

ABSTRACT

Microgreens, like sprouts, are relatively fast-growing products and are generally consumed raw. Moreover, as observed for sprouts, microbial contamination from preharvest sources may also be present in the production of microgreens. In this study, two
Salmonella enterica
serovars (Hartford and Cubana), applied at multiple inoculation levels, were evaluated for survival and growth on alfalfa sprouts and Swiss chard microgreens by using the most-probable-number (MPN) method. Various abiotic factors were also examined for their effects on
Salmonella
survival and growth on sprouts and microgreens. Community-level physiological profiles (CLPPs) of sprout/microgreen rhizospheres with different levels of
S. enterica
inoculation at different growth stages were characterized by use of Biolog EcoPlates. In the seed contamination group, the ability of
S. enterica
to grow on sprouting alfalfa seeds was affected by both seed storage time and inoculation level but not by serovar. However, the growth of
S. enterica
on Swiss chard microgreens was affected by serovar and inoculation level. Seed storage time had little effect on the average level of
Salmonella
populations in microgreens. In the irrigation water contamination group, the growth of
Salmonella
on both alfalfa sprouts and microgreens was largely affected by inoculation level. Surprisingly, the growth medium was found to play an important role in
Salmonella
survival and growth on microgreens. CLPP analysis showed significant changes in the microbial community metabolic diversity during sprouting for alfalfa sprouts, but few temporal changes were seen with microgreens. The data suggest that the change in rhizosphere bacterial functional diversity was dependent on the host but independent of
Salmonella
contamination.

IMPORTANCE
Sprouts and microgreens are considered “functional foods,” i.e., foods containing health-promoting or disease-preventing properties in addition to normal nutritional values. However, the microbial risk associated with microgreens has not been well studied. This study evaluated
Salmonella
survival and growth on microgreens compared to those on sprouts, as well as other abiotic factors that could affect
Salmonella
survival and growth on microgreens. This work provides baseline data for risk assessment of microbial contamination of sprouts and microgreens. Understanding the risks of
Salmonella
contamination and its effects on rhizosphere microbial communities enables a better understanding of host-pathogen dynamics in sprouts and microgreens. The data also contribute to innovative preventive control strategies for
Salmonella
contamination of sprouts and microgreens.
Phenazines Regulate Nap-Dependent Denitrification in Pseudomonas aeruginosa Biofilms
Authors: Lin Yu-Cheng , Sekedat Matthew D. , Cornell William Cole , Silva Gustavo M. , Okegbe Chinweike , Price-Whelan Alexa , Vogel Christine , Dietrich Lars E. P. 
Published: February 2018

ABSTRACTMicrobes in biofilms face the challenge of substrate limitation. In particular, oxygen often becomes limited for cells inPseudomonas aeruginosabiofilms growing in the laboratory or during host colonization. Previously we found that phenazines, antibiotics produced byP. aeruginosa, balance the intracellular redox state of cells in biofilms. Here, we show that genes involved in denitrification are induced in phenazine-null (Δphz) mutant biofilms grown under an aerobic atmosphere, even in the absence of nitrate. This finding suggests that resident cells employ a bet-hedging strategy to anticipate the potential availability of nitrate and counterbalance their highly reduced redox state. Consistent with our previous characterization of aerobically grown colonies supplemented with nitrate, we found that the pathway that is induced in Δphzmutant colonies combines the nitrate reductase activity of the periplasmic enzyme Nap with the downstream reduction of nitrite to nitrogen gas catalyzed by the enzymes Nir, Nor, and Nos. This regulatory relationship differs from the denitrification pathway that functions under anaerobic growth, with nitrate as the terminal electron acceptor, which depends on the membrane-associated nitrate reductase Nar. We identified the sequences in the promoter regions of thenapandniroperons that are required for the effects of phenazines on expression. We also show that specific phenazines have differential effects onnapgene expression. Finally, we provide evidence that individual steps of the denitrification pathway are catalyzed at different depths within aerobically grown biofilms, suggesting metabolic cross-feeding between community subpopulations.IMPORTANCEAn understanding of the unique physiology of cells in biofilms is critical to our ability to treat fungal and bacterial infections. Colony biofilms of the opportunistic pathogenPseudomonas aeruginosagrown under an aerobic atmosphere but without nitrate express a denitrification pathway that differs from that used for anaerobic growth. We report that the components of this pathway are induced by electron acceptor limitation and that they are differentially expressed over the biofilm depth. These observations suggest that (i)P. aeruginosaexhibits “bet hedging,” in that it expends energy and resources to prepare for nitrate availability when other electron acceptors are absent, and (ii) cells in distinct biofilm microniches may be able to exchange substrates to catalyze full denitrification.