Miracle-dz/UniFAR-FTUs huggingface dataset:
Pre‐ and post‐landing response of the parasitoid Encarsia formosa to whitefly hosts on Gerbera jamesonii

One of the factors that may complicate biological control of the greenhouse whitefly on Gerbera jamesonii by Encarsia formosa is the rosette shape of this ornamental, which differs from the vertical shape of most vegetable plants (cucumber, egg plant, tomato, etc.). Therefore, host‐habitat location and the behaviour prior to landing on uninfested and infested leaves was studied. Attraction of E. formosa from a short distance by infested leaves could not be detected: the parasitoid females landed at random on uninfested and infested leaves. After the first landing, a redistribution of the wasps occurred on the leaves. After 24 h three times as many wasps were found on the infested leaves than on uninfested ones. In a dispersal experiment with four plants, E. formosa appeared to have no preference for landing on leaves of the medium age class, which is the age class on which most of the whiteflies in a suitable stage for parasitism occur. Twenty percent of the parasitoids were found on the plants 20 min after releasing them. These results were independent of the plant cultivar and the host density on the plants. In the course of 8 h, the number of E. formosa females recovered from plants increased linearly, and this increase was greater on plants where hosts were present and also greater on the plant cultivar with the lowest trichome density. After 24 h, the percentage of females was highest (56%) on plants with the highest host density. E. formosa females were arrested on leaves where hosts were present. Contrary to our expectation, the results from the two G. jamesonii cultivars that differed strongly in leaf hairiness were not significantly different in most experiments. Only at the high host density was parasitism found to be lower on the cultivar with the higher hair density. Parasitoids may walk on top of the ‘hair coverlet’ of cultivars with high trichome density and, therefore, be hampered less than expected.
Predators, parasites, and the social behaviour of the guppy Poecilia reticulata

Predators can have both direct and indirect effects on how their prey interact with parasites. This thesis explores these effects using observational and experimental approaches. A behavioural experiment suggested that the direct effects of predators are size- and sex-biased, with small and male guppies, Poecilia reticulata Peters 1859, more prone to Gyrodactylus turnbulli Harris 1986 parasite-induced vulnerability to predation (Chapter 2). Trait-mediated indirect effects of predators also appear important to this host-parasite interaction, as revealed by surveys of natural Trinidadian populations under different predation regimes. First, predator-driven life history evolution predicts an apparent population divergence in parasite tolerance (Chapter 3). Similar divergence in a second trait, social behaviour, may drive sex- and age-biased parasitism: the guppies most liable to shoal have the highest infection probability (Chapter 4). Social behaviour is thus an important driver of parasite transmission, but how parasites affect social interactions remains poorly understood. The second part of this thesis investigates how guppies may use sensory information to mitigate this cost of sociality. Many fishes rely on chemical and visual information and the interaction between sensory modalities to behave appropriately; for example, chemical cues change how guppies respond to visual cues (Chapter 5). In a social context, guppies use both chemical and visual cues to detect infection in conspecifics, but only avoid those in the later stages of infection (Chapter 6). Infection avoidance behaviour is not innate, but likely results from juvenile guppies imprinting on cues of conspecifics, and associating with these cues in adulthood (Chapter 7). This imprinting-mediated avoidance appears to be adaptive: a transmission experiment showed that the onset of avoidance behaviour coincides with the stage of infection at which conspecifics are most infectious (Chapter 8). The sensory ecology of the host and the community in which it lives therefore have important implications for disease dynamics.
Ecological communities: conceptual problems and definitions

Abstract Three major problems with respect to ecological communities are tackled. The first is the problem of ambiguity, i.e. the fact that the term “community” is being used for various kinds of objects at different levels of organisation. We argue that this problem can be resolved by restricting use of the term “community” to sets of co-occurring organisms belonging to a single taxonomic phylum or class (plants, birds, insects, etc.) and by using the term “biocoenosis” for sets of organisms belonging to multiple phyla or classes and comprising the biotic components of ecosystems. We also argue that interaction between organisms is neither a necessary nor a sufficient condition for community membership, or, in other words, that communities may consist of both interacting and non-interacting organisms. The second and third problems are the boundary problem and the problem of heterogeneity, i.e. the fact that communities, as currently defined, most often do not have discrete boundaries and are quite heterogeneous with respect to species composition. We argue that both problems result from the fact that communities are seen as groups of co-occurring populations of species, whereas actually populations of different species rarely if ever co-occur in exactly the same area. These problems can be resolved by redefining communities as particular sets of individuals occurring in the intersection of the areas occupied by different populations of species. In the final section we defend our definition against some potential objections, viz. (1) that it would lead to an excessive number of small communities, especially in species-rich situations, and (2) that, because population boundaries may change all the time, such communities would be very unstable.
Isolation, characterization and analysis of TGFβ gene expression in adipose-derived precursor cells cultured in diff erent growth media

Human adult (autologous) stem cells which are capable of self-renewal and diff erentiation into other cell types, can be isolated from various tissue and are a promising source for cell therapy, since there are no ethical and rejection problems as in the case of embryonic stem cells. Th e human body contains a great amount of adipose tissue which consists also of several mezenchymal stem cell populations. According to the existing data Transforming Growth Factor β (TGFβ) is one of the molecules involved in MSC diff erentiation. Th e aim of this work was to study the capablility of human adipose-derived precursor cells to diff erentiate into other cell types and to study the eff ect of various cell media on the expression of TGFβ in adipoze-derived precursor cells. Here we show that in serum-free medium the morphology of cells diff ers and the expression level of TGFβ is signifi cantly higher than in serum-supplemented media. Our work also shows that cell populations isolated from human adipose tissue can diff erentiate not only into mezenchymal lineage cells but also into neuronal lineage cells, prooving the plasticity of adipose derived cells. We conclude that cell populations isolated from human adipose tissue contain a number of precursor cells with characteristic features of stem cells – ability to diff erentiate into more than one cell type. Cell cultivation medium aff ects population growth and morphology. Cells in serum-containing medium grow faster and develop a monolayer, while cells in serum-free medium grow slower and tend to form spheres. TGFβ expression is signifi cantly higher in cells grown in serum-free medium which is more suitable for maintenance of cells than for promoting rapid growth.
Species Limits Based on mtDNA and Morphological Data in the Polytypic Species Plestiodon brevirostris (Squamata: Scincidae)

Abstract The Mexican Plestiodon brevirostris species group (Squamata: Scincidae) is composed of seven nominal species. The wide-ranging P. brevirostris is a polytypic species composed of five subspecies: P. b. brevirostris, P. b. bilineatus, P. b. dicei, P. b. indubitus, and P. b. pineus. A tree-based approach for species delimitation with mtDNA data was used to test the traditional species-level taxonomy of P. brevirostris preliminarily. A haplotype phylogeny for all of the species and subspecies in the P. brevirostris group, except P. colimensis, was inferred. The mtDNA data consisted of sequences encompassing the genes encoding 16S rRNA (part), ND1, and associated tRNAs (1355 base pairs), which were analyzed with Bayesian methods. Then, a search for diagnostic morphological characters for the putative species delimited by this approach was performed. The results indicate that the P. brevirostris group is paraphyletic with respect to P. lynxe, and that P. brevirostris actually is composed of at least five distinct lineages disguised by traditional taxonomy: P. b. brevirostris, P. b. bilineatus, P. b. dicei, and the eastern populations of P. b indubitus (from Morelos, Guerrero, and México) represent distinct species, whereas the western populations of P. b. indubitus (from Colima and Jalisco) represent an undescribed species. The data cannot resolve whether P. b. pineus is conspecific with P. b. dicei or P. b. dicei is a paraphyletic ( = nonexclusive) species relative to an exclusive P. b. pineus. Thus, the status of P. b. pineus remains uncertain. The haplotype phylogeny also suggests that P. b. brevirostris may represent more than one species.
Tackling SARS-CoV-2: proposed targets and repurposed drugs

The SARS-CoV-2 pandemic, declared as a global health emergency by the WHO in February 2020, has currently infected more than 6 million people with fatalities near 371,000 and increasing exponentially, in absence of vaccines and drugs. The pathogenesis of SARS-CoV-2 is still being elucidated. Identifying potential targets and repurposing drugs as therapeutic options is the need of the hour. In this review, we focus on potential druggable targets and suitable therapeutics, currently being explored in clinical trials, to treat SARS-CoV-2 infection. A brief understanding of the complex interactions of both viral as well as host targets, and the possible repurposed drug candidates are described with an emphasis on understanding the mechanisms at the molecular level.
Isolation, Sequence Analysis, and Linkage Mapping of Nucleotide Binding Site–Leucine-rich Repeat Disease Resistance Gene Analogs in Watermelon

ADDITIONAL INDEX WORDS. Citrullus lanatus, TIR, degenerate primers, Cucurbitaceae, STS ABSTRACT. Sixty-six watermelon (Citrullus lanatus var. lanatus) disease resistance gene analogs were cloned from 'Calhoun Gray', PI 296341, and PI 595203 using degenerate primers to select for the nucleotide binding sites (NBS) from the NBS-leucine-rich repeat (LRR) resistance gene family. After contig assembly, watermelon resistance gene analogs (WRGA) were identified and amino acid sequence alignment revealed that these groups contained motifs characteristic of NBS-LRR resistance genes. Using cluster analysis, eight groups of WRGA were identified and further characterized as having homology to Drosophila Toll and mammalian interleukin-1 receptor (TIR) and non- TIR domains. Three of these WRGA as well as three disease-related watermelon expressed sequence tag homologs were placed on a test-cross map. Linkage mapping placed the WRGA on linkage group XIII, an area on the watermelon map where resistance gene analogs cluster. In addition, these WRGA sequence-tagged sites (STS) were amplified from various genera of the Cucurbitaceae indicating that conservation of resistance gene analogs exists among cucurbits. These WRGA-STS markers may be useful in marker-assisted selection for the improvement for disease resistance in watermelon.
Value at Risk with Time Varying Variance, Skewness and Kurtosisthe NIG-ACD Model

A new model for financial returns with time varying variance, skewness and kurtosis based on the Normal Inverse Gaussian (NIG) distribution is proposed. The new model and two previously suggested NIG models are evaluated by their Value at Risk (VaR) forecasts on a long series of daily Standard and Poor's 500 returns. All three models perform very well compared with extant models and clearly outperform a Gaussian GARCH model. Moreover, the results show that only the new model cannot be rejected as providing correct conditional VaR forecasts.
Spatial Distributions and Temporal Trends in Sediment Contamination in Lake St. Clair

ABSTRACT The sediments of Lake St. Clair were surveyed in 2001 for a range of compound classes including metals (such as total mercury and lead), polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, organochlorine pesticides, polycyclic aromatic hydrocarbons, and short- and medium-chain chlorinated paraffins, in order to evaluate the spatial distribution and temporal trends of contamination. Concentrations of contaminants were generally low compared to the lower Great Lakes (Erie and Ontario), and were typically below the Canadian Sediment Quality Probable Effect Level (PEL) guidelines. The only exceptions were for mercury and DDE, where concentrations exceeded their respective PEL at one of the thirty-four sites sampled. With the exception of mercury, it was difficult to interpret spatial trends in contaminant concentrations due to these low levels, although relatively elevated concentrations of several contaminants were found in L'Anse Creuse Bay and at the outflow of the Thames River. In the case of mercury, historically-contaminated sediments in the St. Clair River associated with chloralkali production appeared to contribute to loadings to Lake St. Clair. There have been substantial reductions in sediment contamination in Lake St. Clair over the past three decades, as determined through sediment core profiles as well as through comparison of current data to those from historical surveys conducted in the early 1970s. These results indicate that management actions to reduce contaminant loadings to Lake St. Clair have been generally successful.
Studies on rainbow trout fry syndrome (RTFS)

A comprehensive survey of representative rainbow trout (Oncorhynchus mykiss) hatcheries revealed that the Gram negative, yellow-pigmented, filamentous bacterium Cytophaga psychrophila was implicated in a single disease in the U.K. and other European states. The involvement of C. psychrophila as the aetiological agent of the syndrome was substantiated by the fulfilment of Koch's postulates. Infectivity studies with isolates of C. psychrophila, carried out under natural and laboratory conditions successfully reproduced clinical signs and gross pathological changes analogous to those observed during field outbreaks of the condition. Histopathological examination of artificially and naturally infected fish tissues demonstrated several features that were considered to be pathognomonic for RTFS. Preliminary electron microscopic studies described the ultra-structure of C. psychrophila and partially elucidated the cellular response to the pathogen. Environmental sampling across selected hatchery sites demonstrated that members of the family Cytophagaceae formed a substantial element of the bacterial flora from natural waters, although recovery of C. psychrophila was restricted to areas where the substantial mortalities in fry attributable to RTFS had occurred. C. psychrophila was isolated from the sexual fluids of broodstock and additionally the bacterium was demonstrated associated with surfaces of eyed ova following various disinfection regimes. The minimum inhibitory concentrations of a range of antimicrobial agents both existing in, and novel to, aquaculture were examined, revealing compounds which would potentially mitigate losses attributable to RTFS during field outbreaks. The emergence of bacterial resistance to chemotherapeutants was discussed. The minimum inhibitory and bactericidal concentrations and required exposure times to a number of disinfecting agents were demonstrated. The efficacy of these agents as disinfectants of egg surfaces and equipment associated with fish production was assessed. The potential of a number of serodiagnostic techniques were evaluated as a means of rapid detection of C. psychrophila in diseased fish.
Forecasting fish stock dynamics under climate change: Baltic herring (Clupea harengus) as a case study

Climate change and anthropogenic disturbances may affect marine populations and ecosystems through multiple pathways. In this study we present a framework in which we integrate existing models and knowledge on basic regulatory processes to investigate the potential impact of future scenarios of fisheries exploitation and climate change on the temporal dynamics of the central Baltic herring stock. Alternative scenarios of increasing sea surface temperature and decreasing salinity of the Baltic Sea from a global climate model were combined with two alternative fishing scenarios, and their direct and ecosystem-mediated effects (i.e., through predation by cod and competition with sprat) on the herring population were evaluated for the period 2010-2050. Gradual increase in temperature has a positive impact on the long-term productivity of the herring stock, but it has the potential to enhance the recovery of the herring stock only in combination with sustainable fisheries management (i.e., F-msy). Conversely, projections of herring spawning stock biomass (SSB) were generally low under elevated fishing mortality levels (F-high), comparable with those experienced by the stock during the 1990s. Under the combined effects of long-term warming and high fishing mortality uncertainty in herring SSB projections was higher and increasing for the duration of the forecasts, suggesting a synergistic effect of fishery exploitation and climate forcing on fish populations dynamics. Our study shows that simulations of long-term fish dynamics can be an informative tool to derive expectations of the potential long-term impact of alternative future scenarios of exploitation and climate change. (Less)
Effects of dietary yeast autolysate (Saccharomyces cerevisiae) on performance, carcass and gut characteristics, blood profile, and antibody production to sheep red blood cells in broilers

SUMMARY This study was conducted to determine the effects of dietary yeast autolysate on performance, carcass and gut traits, blood parameters, and humoral immune response of broilers. A total of 175 day-old Ross 308 male broiler chicks were allocated into one control group and 4 treatment groups each containing 5 replicate groups of 7 chicks. A basal diet was supplemented with 0, 1, 2, 3, and 4 g/kg of yeast autolysate (Saccharomyces cerevisiae, InteWall) to generate dietary treatments. The experimental period lasted 42 d. Supplemental yeast autolysate improved live weight gain (P
Restrictions on Managers’ Outside Employment Opportunities and Asymmetric Disclosure of Bad versus Good News

This study examines the effect of restrictions on managers’ outside employment opportunities on voluntary corporate disclosure. The recognition of the Inevitable Disclosure Doctrine (IDD) by courts in the U.S. states in which the firms are headquartered place greater restrictions on their managers from joining or forming a rival company. We find that on average the IDD adoption increases the asymmetric withholding of bad news. We further show that the IDD adoption increases the asymmetric withholding of bad news relative to good news for firms whose managers are mainly concerned about losing their current job. However, an opposite effect is observed for firms whose managers are mainly interested in seeking promotion elsewhere. Furthermore, these effects are less pronounced for firms subject to greater monitoring of their disclosure policy. These results suggest that managers’ career concerns affect corporate disclosure policy and the effect varies with the type of career concerns.
Ingratiation and Favoritism: Experimental Evidence

We provide experimental evidence of workers' ingratiation by opinion conformity and of managers' discrimination in favor of workers with whom they share similar opinions. In our Baseline, managers can observe both workers' performance at a task and opinions before assigning unequal payoffs. In the Ingratiation treatment, workers can change their opinion after learning that held by the manager. In the Random treatment, workers can also change opinion but payoffs are assigned randomly, which gives a measure of non-strategic opinion conformism. We find evidence of high ingratiation indices, as overall, ingratiation is effective. Indeed, managers reward opinion conformity, and even more so when opinions cannot be manipulated. Additional treatments reveal that ingratiation is cost sensitive and that the introduction of performance pay for managers as well as a less noisy measure of performance increase the role of relative performance in the assignment of payoffs, without eliminating the reward of opinion conformity.
The hosts of Nemeritis canescens a problem in the host specificity of insect parasitoids

1 Published records of the hosts of N.canescens have been collected and critically examined. 2 It is accepted that canescens has developed on twenty‐three species; on one of them perhaps accidentally, on two with some doubt. 3 Twelve species were parasitized in nature; nine species in the laboratory. Two species served as hosts when artificially infected. 4 The natural hosts belong in the Pyralidae, Tinaeidae and Yponomeutidae; the laboratory hosts in the Pyralidae, Oecophoridae and Gelechiidae. One individual was reared from a Tortricid, perhaps accidentally. 5 The host specificity of N.canescens is not easily explained on either a systematic or an ecological basis. It offers interesting problems for research.
Economic Benefits of Firms' Government Sale Dependency

In this paper, using a new channel of political connections, firm dependency on government sales, I study the value of political connections for firms. I find an economically and statistically significant relation between firm dependency on government entities in terms of revenues and the cross-section of future stock returns. Firms experience significantly higher profit margins post government dependency. In addition, past government sales significantly predict future government sales. The atypical features of government contracts and the information asymmetry between the contractor and contractee are likely to be behind the firms' higher profit margins. Further tests based on attention and uncertainty proxies suggest that investors' limited attention and greater valuation uncertainty contribute to abnormal returns. Furthermore, I find evidence suggesting that firms gain the wealth effects of political connections found by Cooper, Gulen, and Ovtchinnikov (2010) by winning material government contracts; however, the wealth effects of government dependency stay strong even after controlling for such connections.