1,098 research outputs found
Description of a strain from an atypical population of Aspergillus parasiticus that produces aflatoxins B only, and the impact of temperature on fungal growth and mycotoxin production
In this study, an atypical strain of Aspergillus parasiticus is described. This strain, reported from Portuguese almonds, was named Aspergillus parasiticus B strain. The strain is herein characterised at the morphological and physiological levels, and compared with the typical A. parasiticus strain and other similar species in section Flavi. Previously published morphological and molecular data support that the B strain is very closely related to the A. parasiticus type strain. However, while A. parasiticus typically produces aflatoxins B and G, B strain produces aflatoxins B only. Furthermore, this atypical strain showed to differ from the typical strain in the fact that higher growth (colony diameter) and strain. This strain can become a major food safety concern in colder regions where the typical A. parasiticus strains are not well adapted.NORTE-07-0124-FEDER-000028PEst-OE/EQB/LA0023/2013PEst-OE/AGR/UI0690/201
Exploring the measurement of markedness and its relationship with other linguistic variables
Antonym pair members can be differentiated by each word's markedness-that distinction attributable to the presence or absence of features at morphological or semantic levels. Morphologically marked words incorporate their unmarked counterpart with additional morphs (e.g., "unlucky" vs. "lucky"); properties used to determine semantically marked words (e.g., "short" vs. "long") are less clearly defined. Despite extensive theoretical scrutiny, the lexical properties of markedness have received scant empirical study. The current paper employs an antonym sequencing approach to measure markedness: establishing markedness probabilities for individual words and evaluating their relationship with other lexical properties (e.g., length, frequency, valence). Regression analyses reveal that markedness probability is, as predicted, related to affixation and also strongly related to valence. Our results support the suggestion that antonym sequence is reflected in discourse, and further analysis demonstrates that markedness probabilities, derived from the antonym sequencing task, reflect the ordering of antonyms within natural language. In line with the Pollyanna Hypothesis, we argue that markedness is closely related to valence; language users demonstrate a tendency to present words evaluated positively ahead of those evaluated negatively if given the choice. Future research should consider the relationship of markedness and valence, and the influence of contextual information in determining which member of an antonym pair is marked or unmarked within discourse
Environmental factors influencing red knot (Calidris canutus islandica) departure times of relocation flights within the non-breeding period
Deciding when to depart on long-distance, sometimes global, movements can be especially important for flying species. Adverse weather conditions can affect energetic flight costs and navigational ability. While departure timings and conditions have been well-studied for migratory flights to and from the breeding range, few studies have focussed on flights within the non-breeding season. Yet in some cases, overwintering ranges can be large enough that ecological barriers, and a lack of resting sites en route, may resist movement, especially in unfavorable environmental conditions. Understanding the conditions that will enable or prohibit flights within an overwintering range is particularly relevant in light of climate change, whereby increases in extreme weather events may reduce the connectivity of sites. We tracked 495 (n = 251 in 2019; n = 244 in 2020) overwintering red knots (Calidris canutus islandica) in the Dutch Wadden Sea and investigated how many departed towards the UK (on westward relocation flights), which requires flying over the North Sea. For those that departed, we used a resource selection model to determine the effect of environmental conditions on the timing of relocation flights. Specifically, we investigated the effects of wind, rain, atmospheric pressure, cloud cover, and migratory timing relative to sunset and tidal cycle, which have all been shown to be crucial to migratory departure conditions. Approximately 37% (2019) and 36% (2020) of tagged red knots departed on westward relocation flights, indicating differences between individuals' space use within the overwintering range. Red knots selected for departures between 1 and 2.5 h after sunset, approximately 4 h before high tide, with tailwinds and little cloud cover. However, rainfall and changes in atmospheric pressure appear unimportant. Our study reveals environmental conditions that are important for relocation flights across an ecological barrier, indicating potential consequences of climate change on connectivity
Standardised assessment of personality – a study of validity and reliability in substance abusers
<p>Abstract</p> <p>Background</p> <p>Brief screening instruments for co-morbid personality disorders could potentially have great value in substance abuse treatment settings.</p> <p>Methods</p> <p>We assessed the psychometric properties of the 8-item Standardised Assessment of Personality – Abbreviated Scale (SAPAS) in a sample of 58 methadone maintenance patients.</p> <p>Results</p> <p>Internal consistency was modest, but similar to the original value (alpha = 0.62), and test-retest correlation at four months follow-up was moderately encouraging for a short instrument such as this (n = 31, test retest intraclass correlation = 0.58), and change at the mean level was minimal, but marginally significant (from an average of 3.3 to 3.8, p = 0.06). Analyses of nurse ratings of patients' behaviour at the clinic showed that SAPAS was significantly correlated with nurse ratings of externalizing behaviour (r = 0.42, p = 0.001), and Global Assessment of Functioning (r = -0.36, p = 0.006), but unrelated to intoxication (r = 0.02, NS), or withdrawal (r = 0.20, NS).</p> <p>Conclusion</p> <p>There is evidence that the SAPAS is a modestly valid and relatively reliable brief screening measure of personality disorders in patients with ongoing substance abuse undergoing methadone maintenance. It can be used in situations where limited resources are available, and researchers or others wish to get an impression of the degree of personality pathology in a clinical population, as well as for screening purposes.</p
Inside the guts of wood-eating catfishes: can they digest wood?
To better understand the structure and function of the gastrointestinal (GI) tracts of wood-eating catfishes, the gross morphology, length, and microvilli surface area (MVSA) of the intestines of wild-caught Panaque nocturnus, P. cf. nigrolineatus “Marañon”, and Hypostomus pyrineusi were measured, and contrasted against these same metrics of a closely related detritivore, Pterygoplichthys disjunctivus. All four species had anatomically unspecialized intestines with no kinks, valves, or ceca of any kind. The wood-eating catfishes had body size-corrected intestinal lengths that were 35% shorter than the detritivore. The MVSA of all four species decreased distally in the intestine, indicating that nutrient absorption preferentially takes place in the proximal and mid-intestine, consistent with digestive enzyme activity and luminal carbohydrate profiles for these same species. Wild-caught Pt. disjunctivus, and P. nigrolineatus obtained via the aquarium trade, poorly digested wood cellulose (<33% digestibility) in laboratory feeding trials, lost weight when consuming wood, and passed stained wood through their digestive tracts in less than 4 h. Furthermore, no selective retention of small particles was observed in either species in any region of the gut. Collectively, these results corroborate digestive enzyme activity profiles and gastrointestinal fermentation levels in the fishes’ GI tracts, suggesting that the wood-eating catfishes are not true xylivores such as beavers and termites, but rather, are detritivores like so many other fishes from the family Loricariidae
Simulations of events for the LUX-ZEPLIN (LZ) dark matter experiment
The LUX-ZEPLIN dark matter search aims to achieve a sensitivity to the WIMP-nucleon spin-independent cross-section down to (1–2)×10−12 pb at a WIMP mass of 40 GeV/c2. This paper describes the simulations framework that, along with radioactivity measurements, was used to support this projection, and also to provide mock data for validating reconstruction and analysis software. Of particular note are the event generators, which allow us to model the background radiation, and the detector response physics used in the production of raw signals, which can be converted into digitized waveforms similar to data from the operational detector. Inclusion of the detector response allows us to process simulated data using the same analysis routines as developed to process the experimental data
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Projected sensitivity of the LUX-ZEPLIN experiment to the 0νββ decay of Xe 136
The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double β decay search in parallel to the main science goal of discovering dark matter particle interactions. We report the expected LZ sensitivity to Xe136 neutrinoless double β decay, taking advantage of the significant (>600 kg) Xe136 mass contained within the active volume of LZ without isotopic enrichment. After 1000 live-days, the median exclusion sensitivity to the half-life of Xe136 is projected to be 1.06×1026 years (90% confidence level), similar to existing constraints. We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with Xe136 at 1.06×1027 years
Inducible high-efficiency CRISPR-Cas9-targeted gene editing and precision base editing in African trypanosomes
A PATO-compliant zebrafish screening database (MODB): management of morpholino knockdown screen information
<p>Abstract</p> <p>Background</p> <p>The zebrafish is a powerful model vertebrate amenable to high throughput <it>in vivo </it>genetic analyses. Examples include reverse genetic screens using morpholino knockdown, expression-based screening using enhancer trapping and forward genetic screening using transposon insertional mutagenesis. We have created a database to facilitate web-based distribution of data from such genetic studies.</p> <p>Description</p> <p>The MOrpholino DataBase is a MySQL relational database with an online, PHP interface. Multiple quality control levels allow differential access to data in raw and finished formats. MODBv1 includes sequence information relating to almost 800 morpholinos and their targets and phenotypic data regarding the dose effect of each morpholino (mortality, toxicity and defects). To improve the searchability of this database, we have incorporated a fixed-vocabulary defect ontology that allows for the organization of morpholino affects based on anatomical structure affected and defect produced. This also allows comparison between species utilizing Phenotypic Attribute Trait Ontology (PATO) designated terminology. MODB is also cross-linked with ZFIN, allowing full searches between the two databases. MODB offers users the ability to retrieve morpholino data by sequence of morpholino or target, name of target, anatomical structure affected and defect produced.</p> <p>Conclusion</p> <p>MODB data can be used for functional genomic analysis of morpholino design to maximize efficacy and minimize toxicity. MODB also serves as a template for future sequence-based functional genetic screen databases, and it is currently being used as a model for the creation of a mutagenic insertional transposon database.</p
The Effect of Diet and Opponent Size on Aggressive Interactions Involving Caribbean Crazy Ants (Nylanderia fulva)
Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition
between introduced and native species can strongly influence the distribution and spread of exotic species and in some
cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently
introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with
the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the
potential of interspecific competition among these two introduced ants by measuring interspecific aggression between
Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on
individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter
interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in
antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in
aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire
ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than
fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an
individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome
by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants
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