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Reactor-based models are well-suited Turbulence-Chemistry Interactions, Sub-Grid Scale closures for Large Eddy Simulation (LES) due to their ability to account for finite-rate kinetics. The Partially Stirred Reactor (PaSR) model relies on the estimation of characteristic time scales to define the reacting fraction of each computational cell. However, chemistry develops a spectrum of intrinsic chemical time scales, leaving no clear consensus on the definition of a single representative scale. Nevertheless, in numerical codes, a single chemical time scale formulation is used on the whole physical domain despite local and complex phenomena. Through an a priori assessment on Direct Numerical Simulation (DNS) data of turbulent non-premixed combustion, the present work proposes a numerical method to locally select an optimal chemical time scale formulation that minimises the model error. Data points are grouped into clusters via supervised partitioning algorithms where the optimal formulation is attributed to each cluster by means of distances minimisation. Using a combination of partitioning procedures can further improve the reconstruction quality of the clustered solutions, up to 35% global errors reductions with respect to standard solutions. Existing data partitions are then tested on unseen data points, yielding great prediction capabilities. DNS data of a turbulent premixed flame are used to demonstrate that the methodology is also robust across combustion regimes. The present proof of concept shows suitable features to introduce systematic improvements for the PaSR combustion closure in LES. [ABSTRACT FROM AUTHOR]

Marine reserves (MRs) are implemented worldwide to protect, restore, and manage marine ecosystems and species. However, it is important to document the positive effects those marine reserves have on slow-growth, temperate invertebrates such as abalone. Abalone, Haliotis spp., are marine gastropods of high economic value extracted worldwide for decades, which has led to fisheries-driven population decreases. In this work, we focused on a case study and assessed the short-term (1–2 years) effects of marine reserves established and managed by a local fishing cooperative at Guadalupe Island, Mexico. We evaluated the population status of green abalone, H. fulgens, by conducting (1) an assessment of the green abalone population around Guadalupe Island through subtidal monitoring and (2) an evaluation of the effect of two recently established marine reserves on population parameters such as the increase in density (individuals·m2), biomass, number of aggregated abalone, egg production, and proportion of individuals bigger than 150 mm (minimum harvest size) compared to fished areas. To assess the population around Guadalupe Island, we surveyed 11,160 m2 during 2020 and 2021. We recorded 2327 green abalones with a mean ± SE shell length of 135.978 ± 0.83 mm and a mean density of 0.21 ± 0.02 individuals·m2. All variables were statistically higher at the MRs except for shell length in 2021. In this work, we report for the first time the green abalone population status at Guadalupe Island and a positive short-term biological response to community-based marine reserves. This study suggests that a network of MRs combined with good management could help abalone populations in the short term in Guadalupe Island, potentially leading to more sustainable fishing practices and social-ecological resilience. [ABSTRACT FROM AUTHOR]

Context: Tropical dry forests (TDFs) are one of the richest and also one of the most threatened ecosystems in the world due to anthropization. In Mexico, only a minimal proportion of TDF is conserved in protected areas, typically surrounded by human-modified landscapes. Habitat modification can impact gene flow, affecting the populations' genetic structure, and ultimately, the long-term persistence of natural populations. Objectives: We examined the influence of landscape features on the genetic connectivity of Thryophilus sinaloa, a common and highly territorial TDF-associated bird species. We conducted our study in a Mexican landscape along the Pacific coast characterized by a protected area surrounded by a heterogenous human-modified landscape. Methods: We genotyped 90 individuals from 20 localities at 24,549 SNPs derived from 3RADseq and de novo assembling techniques to examine the relationship between population genetic patterns and landscape features using a resistance surface optimization framework. Results: Populations were genetically structured in two groups across the landscape. An open-areas resistance surface, along with geographic distance, reduced genetic connectivity. This finding suggests that protected areas are partially isolated from TDF fragments and other non-protected areas. Conclusions: Our research highlights the impact of TDF landscape modification by human-induced activities on the genetic connectivity of a common bird. Our study reveals that the only TDF reserve in the region is mostly disconnected from other remnants of non-protected areas of continuous TDF. The increasing deterioration of the habitat could eventually cause a decrease in genetic diversity and effective population size. Moreover, genetic differentiation could be enhanced as habitat patches are more isolated, increasing the likelihood of local extinctions. [ABSTRACT FROM AUTHOR]

Implementing new and effective control strategies to reduce populations of invasive species is needed to offset their negative impacts worldwide. The spread of Indo-Pacific lionfish (Pterois sp.) through much of the western Atlantic has been one of the most publicized marine invasions globally, and is considered a major biodiversity threat whose longer-term impacts are still uncertain. Marine managers have explored several strategies to control lionfish, such as fishing tournaments (derbies) and commercial fisheries. Commercial fisheries for invasive species are controversial because they could create perverse incentives to maintain these populations, and they have never been demonstrated to successfully control target populations. We analyzed the development and impacts of an opportunistic fishing operation aimed at commercializing invasive lionfish in the Mexican Caribbean. We examined official lionfish landings and compared them to catches from lionfish derbies and lionfish densities from locations in the state of Quintana Roo, Mexico. We found that commercial fishers, particularly from one fishing cooperative on Cozumel Island, were effective at catching lionfish, with landings peaking at 20,000 individuals in 2014. This number is comparable to the number of lionfish caught in derbies across the entire Caribbean in the same year. Ecological survey data suggest a ~ 60% reduction in lionfish density on Cozumel reefs over two years (2013–2015), matching the peak landings in the lionfish fishing operation. However, the fishery's apparent success as a control tool during the time window analyzed seemed to trigger its own demise: a decline in landings was followed by evaporating market interest and loss of economic viability. If fisheries are to be established and used as management strategies to control future invasions, managers must develop strategic collaboration plans with commercial fishing partners. [ABSTRACT FROM AUTHOR]

Functional studies aimed at confirming the negative prognostic impact played by BCL-W expression in PTCL-NOS observed in this study are warranted, while functional dependence on BCL-W for PTCL-NOS has yet to be proven [[14]]. Among the 27 patients included in this study, 24 (89%) received treatment after tissue biopsy collection, including chemotherapy in 17 (63%) and biological therapy in 7 (16%), for a median of 2 cycles (range, 1-6); 3 (11%) did not receive any further treatment. Serum levels of Th1 and Th2-type effector cells-related cytokines (IL2, IFN , IL4, IL10, IL5, IL6, IL1 , TNF , IL8) and soluble receptors (sIL2R, sIL6R) and BCL-2 proteins levels have been previously measured in a group of healthy subjects, showing an association between GATA3/Th2 phenotype and higher levels of BCL-2 [[13]]. This is a retrospective analysis of patients with PTCL-NOS receiving either frontline or salvage therapy at the MD Anderson Cancer Center between 09/2000 and 09/2019, and for whom pre-treatment tissue biopsy samples were available for correlative analysis. [Extracted from the article]

The effects of swirled inflows on the evaporation of dilute acetone droplets dispersed in turbulent jets are investigated by means of direct numerical simulation. The numerical framework is based on a hybrid Eulerian–Lagrangian approach and the point-droplet approximation. Phenomenological and statistical analyses of both phases are presented. An enhancement of the droplet vaporization rate with increasing swirl velocities is observed and discussed. The key physical drivers of this augmented evaporation, namely dry air entrainment and swirl-induced centrifugal forces acting on the droplets, are isolated with the aid of additional simulations in which the inertial properties of the droplets are neglected. The correlation between swirl and dry air entrainment rate is found to be responsible for the increase of the global evaporation rate and the spray penetration length reduction, while swirl-induced centrifugal forces are found to be effective only in the jet shear layer, close to the injection orifice, for the analyzed cases. [ABSTRACT FROM AUTHOR]

Polyamines (PAs), such as spermidine (SPD) and spermine (SPM), are essential to promote cell growth, survival, proliferation, and longevity. In the adult central nervous system (CNS), SPD and SPM are accumulated predominantly in healthy adult glial cells where PA synthesis is not present. To date, the accumulation and biosynthesis of PAs in developing astrocytes are not well understood. The purpose of the present study was to determine the contribution of uptake and/or synthesis of PAs using proliferation of neonatal astrocytes as an endpoint. We inhibited synthesis of PAs using α-difluoromethylornithine (DFMO; an inhibitor of the PA biosynthetic enzyme ornithine decarboxylase (ODC)) and inhibited uptake of PAs using trimer44NMe (PTI; a novel polyamine transport inhibitor). DFMO, but not PTI alone, blocked proliferation, suggesting that PA biosynthesis was present. Furthermore, exogenous administration of SPD rescued cell proliferation when PA synthesis was blocked by DFMO. When both synthesis and uptake of PAs were inhibited (DFMO + PTI), exogenous SPD no longer supported proliferation. These data indicate that neonatal astrocytes synthesize sufficient quantities of PAs de novo to support cell proliferation, but are also able to import exogenous PAs. This suggests that the PA uptake mechanism is present in both neonates as well as in adults and can support cell proliferation in neonatal astrocytes when ODC is blocked. [ABSTRACT FROM AUTHOR]

We report an auditory effect of visual performance degradation in a virtual reality (VR) setting, where the viewing conditions are significantly different from previous studies. With the presentation of temporally congruent but spatially incongruent sound, we can degrade visual performance significantly at detection and recognition levels. We further show that this effect is robust to different types and locations of both auditory and visual stimuli. We also analyze participants behavior with an eye tracker to study the underlying cause of the degradation effect. We find that the performance degradation occurs even in the absence of saccades towards the sound source, during normal gaze behavior. This suggests that this effect is not caused by oculomotor phenomena, but rather by neural interactions or attentional shifts. [ABSTRACT FROM AUTHOR]

With the proliferation of low-cost, consumer level, head-mounted displays (HMDs) we are witnessing a reappearance of virtual reality. However, there are still important stumbling blocks that hinder the achievable visual quality of the results. Knowledge of human perception in virtual environments can help overcome these limitations. In this work, within the much-studied area of perception in virtual environments, we look into the less explored area of crossmodal perception, that is, the interaction of different senses when perceiving the environment. In particular, we look at the influence of sound on visual perception in a virtual reality scenario. First, we assert the existence of a crossmodal visuo-auditory effect in a VR scenario through two experiments, and find that, similar to what has been reported in conventional displays, our visual perception is affected by auditory stimuli in a VR setup. The crossmodal effect in VR is, however, lower than that present in a conventional display counterpart. Having asserted the effect, a third experiment looks at visuo-auditory crossmodality in the context of material appearance perception. We test different rendering qualities, together with the presence of sound, for a series of materials. The goal of the third experiment is twofold: testing whether known interactions in traditional displays hold in VR, and finding insights that can have practical applications in VR content generation (e.g., by reducing rendering costs). [ABSTRACT FROM AUTHOR]

Orobanche spp. (broomrape) is an obligate root parasite that can attack a wide spectrum of plants, including tobacco. It has been responsible for economic losses in Europe since 2002 and its incidence in many tobacco-growing countries is increasing. Preventive and curative methods exist, including the use of agrochemicals, however efficacy is limited and pest dissemination remains important due to a high rate of multiplication of the parasite and very small long lasting seeds. The tobacco variety 'Wika' induces lower or delayed germination of Orobanche seeds. This seems to be conditioned by a single recessive gene (Cailleteau et al. in: CORESTA Congress, Paris, 2006). Artificial testing in Petri dishes was developed to evaluate the ability of tobacco plantlets to stimulate seed germination. Different lines derived from 'Wika', with susceptible control lines, were tested and studied by RNA-Seq. Candidate markers including SNPs or genes differentially expressed between susceptible and resistant lines were identified. An F2 population segregating for 'Wika' recessive tolerance was then used for marker validation and mapping. All candidates were situated on chromosome 14 of the tobacco genetic map. The Nicotiana variety collection from Imperial Brands was also tested for these markers, highlighting or confirming other potential tolerant lines. KASP™ genotyping or markers for conventional gel electrophoresis are now available to drive the transfer of 'Wika' recessive tolerance into elite lines. RNA-Seq technology combined with sound experimental testing has again proven its high efficiency to identify useful markers for tobacco breeding. [ABSTRACT FROM AUTHOR]

Many successful invasive species have generalist diets, but the extent to which they can track changing resources has seldom been documented. Stable isotope analysis was used to measure dietary shifts with ontogeny and over time in relation to changes in prey availability for Indo-Pacific lionfish (Pterois sp.). These are invasive predators that are well established throughout the western North Atlantic and Caribbean where they have caused significant decreases in native reef fish populations in some areas. Samples and observations were made off New Providence Island, Bahamas during the summers of 2008 and 2010. Lionfish δ15N and δ13C values increased only weakly with body length, suggesting that processes other than growth also contribute to stable isotope variability. The trophic niche of lionfish changed significantly between years, concomitant with large changes in native fish prey abundance and community structure. The trophic niche of large lionfish expanded, increasing in trophic diversity at the population level and showing lower individual trophic similarity, while that of small lionfish remained similar in size but shifted towards more 15N-enriched and 13C-depleted prey sources. The ability of lionfish to modify their diet over time may have facilitated their expansion and persistence at high densities in some areas despite local prey depletion. [ABSTRACT FROM AUTHOR]

The G-Scheme is a well established framework for multi-scale adaptive model reduction, whose effectiveness was demonstrated with reference to a number of test models, together with an identification of the critical areas that were in need of further theoretical and computational refinement. In this communication, we report on how we enhanced the solver performance. Two new features involving (i) the criteria to identify the fast and slow subspace dimensions, and (ii) a criterion to decide if and when the reuse of the CSP Basis is feasible without deteriorating the overall performance of the solver, have been proved able to increase significantly the computational efficiency of the solver without sacrificing its accuracy. [ABSTRACT FROM AUTHOR]

The synthesis of patient data of a certain medical image modality by applying an image processing pipeline starting from other modality is receiving a lot of interest recently, as it allows to save acquisition time and sometimes avoid radiation to the patient. An example of this is the creation of computerized tomography volumes from magnetic resonance imaging data, which can be useful for several applications such as electromagnetic simulations, cranial morphometry and attenuation correction in PET/MR systems. We present a fast patch-based algorithm for this purpose, implemented using graphics processing unit computing techniques and gaining up to $$\times$$ 15.9 of speedup against a multicore CPU solution and up to about $$\times$$ 75 against a single core CPU solution. [ABSTRACT FROM AUTHOR]

Objectives: To analyze the prognostic value of microsatellite instability (MSI) in a population-based study of FIGO stage 1-4 endometrial endometrioid adenocarcinomas. Study Design: Survival analysis in 273 patients of MSI status and clinico-pathologic features. Using a highly sensitive pentaplex polymerase chain reaction to establish MSI status, cases were divided into microsatellite stable (MSS), MSI-low (MSI-L, 1 marker positive) and MSI-high (MSI-H, 2-5 markers positive). Results: After 61 months median follow-up (1-209), 34 (12.5%) of the patients developed metastases but only 6.4% of the FIGO-1. MSI (especially as MSI-H versus MSS/MSI-Lcombined) was prognostic in FIGO-1 but not in FIGO2-4. The 5 and10 year recurrence-free survival rates were 98% and 95% in the MSS/MSI-L versus 85% and 73% in the MSI-H patients ( P = 0.005). Conclusions: MSI-H status assessed by pentaplex polymerase chain reaction is an indicator of poor prognosis in FIGO 1, but not in FIGO 2-4 endometrial endometrioid adenocarcinomas. [ABSTRACT FROM AUTHOR]

Background: Cervical intraepithelial neoplasia (CIN), a frequently encountered disease caused by Human Papilloma Virus (HPV) is often diagnosed in formaldehyde-fixed paraffin embedded (FFPE) punch biopsies. Since it is known that this procedure strongly affects the water-soluble proteins contained in the cervical tissue we decided to investigate whether a water-soluble protein-saving biopsy processing method can be used to support the diagnosis of normal and CIN. Methods: Cervical punch biopsies from 55 women were incubated for 24 h at 4°C in RPMI1640 medium for protein analysis prior to usual FFPE processing and p16 and Ki67-supported histologic consensus diagnosis was assessed. The biopsy supernatants were subjected to surface-enhanced laser desorption-ionization time of flight mass spectrometry (SELDI-TOF MS) for identifying differentially expressed proteins. Binary logistic regression and classification and regression trees (CART) were used to develop a classification model. Results: The age of the patients ranged from 26 to 40 years (median 29.7). The consensus diagnoses were normal cervical tissue ( n = 10) and CIN2-3 ( n = 45). The mean protein concentration was 1.00 and 1.09 mg/ml in the normal and CIN2-3 group, respectively. The peak detection and clustering process resulted in 40 protein peaks. Many of these peaks differed between the two groups, but only three had independent discriminating power. The overall classification results were 88%. Conclusions: Water-soluble proteins sampled from punch biopsies are promising to assist the diagnosis of normal and CIN2-3. [ABSTRACT FROM AUTHOR]

To test for an association with risk for restenosis after coronary stent placement, the TNF-α and IL-10 polymorphisms were analyzed by 5′ exonuclease TaqMan assays in 162 patients who initially underwent coronary stenting. Analysis of basal and procedure coronary angiographies revealed a higher proportion of restenosis in lesions treated with bare metal stents compared with those treated with drug-eluting stents ( P < 0.001). Distribution of TNF-α genotypes was similar in patients with and without restenosis. The IL-10 polymorphisms showed a moderate protective trend of the − 819 TT genotype against restenosis when the lesions were analyzed ( P = 0.071, OR = 0.471). Multivariate analysis confirmed a protective role for drug-eluting stents ( P < 0.001, OR = 0.199) and the − 819 TT genotype ( P = 0.037, OR = 0.391). These results suggest the IL-10 −819 TT genotype has a protective role against in-stent restenosis. [ABSTRACT FROM AUTHOR]

We report a case of transmural florid cystic endosalpingiosis of the colon with tumor-like obstruction in a 90-year-old woman with abdominal distention and obstruction. Colonoscopy examination revealed an obstructive luminal mass. Pathologic examination of the sigmoid colectomy specimen revealed a transmural, florid proliferation of mostly cystically dilated glands that were lined by epithelium that varied from flattened to ciliated tubal-type cells typical of endosalpingiosis. The pathologic diagnosis of florid cystic endosalpingiosis of the colon was made based on characteristic microscopic features and the immunoprofile. To our knowledge, this is only the second reported case in the English literature of this entity presenting as an obstructive colon mass. [ABSTRACT FROM AUTHOR]

Summary. The assembly of Tobacco etch potyvirus (TEV) coat protein (CP) and truncated mutants in Escherichia coli was studied. CP from which 28, 63 or 112 amino acids were deleted from the N-terminus polymerized into potyvirus-like particles (PVLPs). These structures were more rigid and progressively smaller in diameter than those produced by full length TEV-CP. CP from which 175 N-terminal amino acids were removed, failed to polymerize. A fragment containing amino acids 131 to 206 of TEV-CP is sufficient for PVLP assembly in E. coli. To determine the function of the highly conserved amino acids Ser152, Arg154, and Asp198 point mutants were generated. The mutant CP?63(Asp198Glu) exhibited different spectral properties following circular dichroism analysis showing a lower amount of a-helix compared to the wild type molecule. No differences were observed in spectra obtained from fluorescence spectroscopy. The point mutants bind RNA in vitro to the same degree as the wild type protein. However, while the wild type and the Arg154Gln mutant CP were each able to form PVLPs in E. coli, the Asp198Glu and the double mutant Ser152Pro/Arg154Gln mutants did not. These results suggest that the Asp198Glu mutation has an altered secondary structure which affects the capacity of the protein to polymerize but did not affect in vitro protein-RNA interactions. [ABSTRACT FROM AUTHOR]

Summertime urban PM2.5 was collected on cellulose filters in downtown Toronto, using a customized air sampler (635 l/min). Mass concentrations for up to 19 trace elements/ions were measured by ICP-AES, INAA and IC. Source apportionment was performed on these results including additional carbon and total mass concentrations using positive matrix factorization (PMF). PMF factors exhibited trends that indicated soil (18%), stationary (19%), secondary (48%), and vehicle (15%) sources. Potential source contribution function (PSCF) analysis identified probable sources of the stationary and secondary PM2.5 as originating from the south and southwest of Toronto. [ABSTRACT FROM AUTHOR]

Virtual reality (VR) has the potential to become a revolutionary technology with a significant impact on our daily lives. The immersive experience provided by VR equipment, where the user’s body and senses are used to interact with the surrounding content, accompanied by the feeling of presence elicits a realistic behavioral response. In this work, we leverage the full control of audiovisual cues provided by VR to study an audiovisual suppression effect (ASE) where auditory stimuli degrade visual performance. In particular, we explore if barely audible sounds (in the range of the limits of hearing frequencies) generated following a specific spatiotemporal setup can still trigger the ASE while participants are experiencing high cognitive loads. A first study is carried out to find out how sound volume and frequency can impact this suppression effect, while the second study includes higher cognitive load scenarios closer to real applications. Our results show that the ASE is robust to variations in frequency, volume and cognitive load, achieving a reduction of visual perception with the proposed hardly audible sounds. Using such auditory cues means that this effect could be used in real applications, from entertaining to VR techniques like redirected walking. [ABSTRACT FROM AUTHOR]

Prolonged stimulation of newborn mice by intraperitoneal injections with inactivated staphylococci induces a chronic neonatal inflammatory reaction and an associated oxidative-stress response. The chronically stimulated animals exhibit anorexy. show a reduction in their body weight and undergo a depression in both antibody synthesis andin vitro proliferativc response of Con A-stimulated splenic T-lymphocytes. These stressed animals also develop adrenal hyperplasia, hypozincamia and thymic hypoplasia. Despite this stress-mediated thymic involution, Con-A stimulated T-lymphocytes from thymus displayed increased theirin vitro proliferative response. Results of the present work show that intramuscular injections of zinc acetate in stressed mice, one single dose (5 μg) every other day for two weeks, reduce both the zinc concentration in the thymus gland and thein vitro proliferative response of their Con A-stimulated T-lymphocytes. The results suggest that prophylactic administration of zinc can have benefical consequences on the immunity of chronically stressed mice. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined the ability of a prophylactic zinc treatment to modulate the zinc turnover into the thymic gland from stressed newborn mice and influence the response of their thymic T-lymphocytes. Materials and methods used in the study; Results; Discussion.

Reports on the genetic variability and evolution of natural populations of DNA viruses are scarce in comparison with the abundant information on the variability of RNA viruses. Geminiviruses are plant viruses with circular ssDNA genomes that are replicated by the host plant DNA polymerases. Whitefly-transmitted geminiviruses (WTG) are the agents of important diseases of crop plants and best exemplify emerging plant viruses. In this report we have analyzed the genetic diversity of cotton leaf curl geminivirus (CLCuV), a typical emerging WTG. No genetic differentiation was observed between isolates from different host plant species or geographic regions. Thus, the analyzed isolates represented a unique, undifferentiated population. Genetic variability, estimated as nucleotide diversities at synonymous positions in open reading frames (ORFs) for the AC1 (=replication) protein and coat protein (CP = AV1), was very high, exceeding the values reported for different genes in several plant and animal RNA viruses. This was unexpected in a virus that uses the DNA replication machinery of its eukaryotic host. Diversities at nonsynonymous positions, on the other hand, indicated that variability may be constrained in the genome of CLCuV. The ratio of nonsynonymous-to-synonymous substitutions varied for the different ORFs: they were higher for CP than for AC1 and lower still for the AC4 and AV2 ORFs, which overlap AC1 and CP ORFs, respectively. Analysis of nucleotide diversities at synonymous and nonsynonymous positions of the AC4 and AV2 ORFs suggest that their evolution is constrained by AC1 and CP, respectively. Data suggest that AC4 and AV2 are new genes that may have originated by overprinting on the preexistent AC1 and CP genes. Evidence for recombination was found for the AC1 and CP ORFs and for the noncoding intergenic region (IR). Data indicate that the origin of replication is a major recombination point in the IR, but not the only one. Analyses of the IR also suggest that recombinants may be frequent in the population and that recombination may have an important role in the generation of CLCuV variability. [ABSTRACT FROM AUTHOR]

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The ribonuclease (RNase) protection assay (RPA) was evaluated as a method to estimate genetic distances among sequence variants of RNA viruses. The patterns of fragments generated, under different RPA conditions, by three sets of RNA sequence variants of known nucleotide sequence, were analyzed. Both the effectiveness of cleavage (i.e. the probability of cleavage in a certain heteroduplex) and its degree (i.e. in all the molecules in the assay or in a part of them) varied largely according to the nature of the mismatch. Probability and degree of cleavage were also dependent on distant sequence context effects. No correlation could be established between context and cleavage, so that the pattern of fragments in RPA cannot be unequivocally predicted from sequence information. Accordingly, nucleotide sequence differences between two sequence variants cannot be directly derived from RPA data. For all three sequence sets linear relationships were found between the number of non-shared fragments in the RPAs of two variants and their nucleotide sequence differences. Nevertheless, both linearity and the linear regression parameters varied largely according to the sequence set and according to RPA conditions, in a non-predictable way. Thus, under experimental conditions, RPA may not be as appropriate a method to estimate genetic distances between RNA sequences as simulation under an ideal model suggested. Possible ways to diminish the gap between the ideal model and the experimental procedure are proposed. [ABSTRACT FROM AUTHOR]

Salt extracts from seeds of 36 lines of Einkorn wheats were analyzed for their inhibitory activity towards two insect ( Tenebrio molitor, Coleoptera, and Ephestia kuehniella, Lepidoptera) and one mammalian (human salivary) α-amylases. Whereas all ten T. monococcum accessions tested were active towards the lepidopteran enzyme, they had no effect on the coleopteran or the mammalian ones. More variability was found among the 21 lines of T. boeticum analyzed, although none of them inhibited human α-amylase. The five accessions of T. urartu showed even greater diversity. Among all Einkorn accessions tested, only two urartu lines affected the three α-amylases. These lines displayed inhibition patterns similar to those of T. aestivum and T. turgidum cultivars. Since several breadwheat α-amylase inhibitors are major allergens associated with baker's asthma, we also studied the in vitro allergenic activity of salt extracts from the Einkorn wheats under study. No significant differences in IgE-binding were found between these accessions and the T. aestivum or T. turgidum cultivars. Furthermore, putative allergens with molecular sizes in the range of 20-60 kDa were detected in these Einkorn wheats. [ABSTRACT FROM AUTHOR]

The nucleotide sequence of 17 variants of the satellite RNA of cucumber mosaic virus (CMV-satRNA) isolated from field-infected tomato plants in the springs of 1989, 1990, and 1991 was determined. The sequence of each of the 17 satRNAs was unique and was between 334 and 340 nucleotides in length; 57 positions were polymorphic. There was much genetic divergence, ranging from 0.006 to 0.141 nucleotide substitutions per site for pairwise comparisons, and averaging 0.074 for any pair. When the polymorphic positions were analyzed relative to a secondary structure model proposed for CMV-satRNAs, it was found that there were significantly different numbers of changes in base-paired and non-base-paired positions, and that mutations that did not disrupt base pairing were preferred at the putatively paired sites. This supports the concept that the need to maintain a functional structure may limit genetic divergence of CMV-satRNA. Phylogenetic analyses showed that the 17 CMV-satRNA variants clustered into two subgroups, I and II, and evolutionary lines proceeding by the sequential accumulation of mutations were apparent. Three satRNA variants were outliers for these two phylogenetic groups. They were shown to be recombinants of subgroup I and II satRNAs by calculating phylogenies for different molecular regions and by using Sawyer's test for gene conversion. At least two recombination events were required to produce these three recombinant satRNAs. Thus, recombinants were found to be frequent (∼17%) in natural populations of CMV-satRNA, and recombination may make an important contribution to the generation of new variants. To our knowledge this is the first report of data allowing the frequency of recombinant isolates in natural populations of an RNA replicon to be estimated. [ABSTRACT FROM AUTHOR]

Some equilibrium properties of a two loci deterministic system subject to a postulated viability matrix are given. Two conclusions are reached: i) linkage can not stabilize additive equally contributing two-loci systems under optimizing selection. ii) Hybrid protein superiority can not be invoked for the maintenance of polymorphisms shared by duplicated structural loci. [ABSTRACT FROM AUTHOR]

The metabolic effects of dopamine have been investigated by its infusion in normal man with and without simultaneous somatostatin administration. Dopamine was infused into overnight fasted men at 1.5 µg/kg/min ( n=6) and 3.0 µg/kg/min ( n=5) for 120 min. Plasma dopamine concentrations at 120 min were 78±9 nmol/l and 117±17 nmol/l respectively, associated with a marginal rise in plasma noradrenaline. Dopamine (1.5 µg/kg/min) induced an early and sustained rise in plasma glucagon (48±9 pg/ml versus 19±6 pg/ml in saline controls at 10 min, p<0.01)and a transient elevation in serum growth hormone which peaked to 17.7 (range 4.5-71.8)mU/l at 60 min (7.2 (range 0.6-37.7) mU/l with saline, p<0.05), but did not alter serum insulin, blood glucose or other metabolite levels. At 3.0 µg/kg/min, dopamine in addition provoked mild and transient elevations in blood glucose and serum insulin. Somatostatin (250 µg/h) suppressed circulating insulin, glucagon, and growth hormone levels and abolished the small hyperglycaemic effect seen with the higher dopamine dose. Somatostatin alone induced a progressive rise in circulating non-esterified fatty acid and 3-hydroxybutyrate levels reflecting insulin deficiency. This rise in NEFA and 3-hydroxybutyrate was increased by dopamine particularly at the higher dosage (plasma NEFA; somatostatin alone, 1.08±0.13 mmol/l; somatostatin plus dopamine 3 µg/kg/min, 1.44±0.17 mmol/l at 120 min, p<0.01: blood 3-hydroxybutyrate; somatostatin alone, 0.32±0.04 mmol/l; somatostatin plus dopamine 3 µg/kg/min, 0.56±0.12 mmol/l at 120 min, p<0.05). Thus: 1) dopamine at pharmacological dosage has minor effects when other endocrine mechanisms are intact, 2) it enhances lipolysis and ketogenesis during somatostatin-induced insulin deficiency, 3) the hyperglycaemic effect of the higher dopamine dose is probably mediated through stimulated glucagon secretion. [ABSTRACT FROM AUTHOR]

How different KRAS variants impact tumor initiation and progression in vivo has not been thoroughly examined. We hypothesize that the ability of either KRASG12D or KRASG12V mutations to initiate tumor formation is context dependent. Amhr2-Cre mice express Cre recombinase in tissues that develop into the fallopian tubes, uterus, and ovaries. We used these mice to conditionally express either the KRASG12V/+or KRASG12D/+ mutation. Mice with the genotype Amhr2-Cre Pten(fl/fl) KrasG12D/+(G12D mice) had abnormal follicle structures and developed low-grade serous ovarian carcinomas with 100% penetrance within 18 weeks. In contrast, mice with the genotype Amhr2-Cre Pten(fl/fl) KrasG12V/+ (G12V mice) had normal follicle structures, and about 90% of them developed uterine tumors with diverse histological features resembling those of leiomyoma and leiomyosarcoma. Granulosa cell tumors also developed in G12V mice. Differences in cell-signaling pathways in the uterine tissues of G12D and G12V mice were identified using RNA sequencing and reverse-phase protein array analyses. We found that CTNNB1, IL1A, IL1B, TNF, TGFB1, APP, and IL6 had the higher activity in G12V mice than in G12D mice. These mouse models will be useful for studying the differences in signaling pathways driven by KrasG12V/+ or KrasG12D/+ mutations to aid development of targeted therapies for specific KRAS mutant variants. Our leiomyoma model driven by the KrasG12V/+ mutation will also be useful in deciphering the malignant progression from leiomyoma to leiomyosarcoma. [ABSTRACT FROM AUTHOR]