Miracle-dz/UniFAR-FTUs huggingface dataset:
Role of the anterior endoderm in cardiac specification

The heart is the first functional organ of embryogenesis in many vertebrates, however little is known about the early specification events of cardiogenesis. Evidence in the chick and amphibian suggests a requirement for the anterior endoderm in cardiac induction to direct mesoderm toward a cardiac fate. Furthermore, the signals responsible for specification and their mode of action are unknown. Several signalling pathways, including FGF, Nodal, BMP and Wnt have been implicated. However, as these pathways have other roles in early embryogenesis a specific role in cardiac induction has been difficult to define. We have devised a model testing the cardiac-inducing activity of the anterior endoderm addressing its ability to re-specify pluripotent embryonic ectoderm upon conjugation. We have shown that the anterior endoderm is sufficient to induce robust expression of cardiac markers and formation of contractile tissue in the responder. Characterisation of the model showed the anterior endoderm produces a specific signal skeletal muscle is not induced, distinguishing it from general mesoderm induction. The cardiac-inducing capacity of the anterior endoderm was not uniform as it was restricted to the most anterior regions of the anterior endoderm, correlating with expression of Hex. The cardiac-inducing signal requires two hours of interaction with the responding tissue during gastrulation to produce an effect. Further involvement of the anterior endoderm beyond specification of cardiac precursors was not required. The model provided the basis to investigate the early signalling events of specification. Whereas BMP signalling was not necessary for cardiac induction by the endoderm, an essential requirement for FGF and Nodal pathways was shown. Timed inhibition revealed both were required during the first hour of conjugation, while sustained ERK activation was needed for at least four hours. In addition it was shown that elevated Wnt/p-catenin signalling during specification had no effect, while sustained activation antagonised cardiogenesis. Further analysis revealed Wnt/p-catenin has no direct role in specification, but suppression or low activity was required prior to the onset of cardiac differentiation. Therefore, this work established a simple and experimentally amenable assay for elucidating the mechanisms of cardiac specification.
Regulatory signals influencing expression of the PDA1 gene of Nectria haematococca MPVI in culture and during pathogenesis of pea

The PDA1 gene of the filamentous fungus Nectria haematococca MPVI (anamorph: Fusarium solani) encodes a cytochrome P450 monooxygenase that detoxifies pisatin, the isoflavonoid phytoalexin produced by its host, garden pea (Pisum sativum). PDA1 is regulated by several signals in culture that may control its expression during pathogenesis of pea. It is induced by pisatin and repressed by glucose and amino acids. Deletion analysis was performed on the PDA1 promoter to define regulatory regions, using a β-glucuronidase (GUS) reporter gene fusion. The results identified a region between -287 and -429, relative to the start of transcription, that mediated repression by either glucose or amino acids in culture, independent from pisatin induction. Transformants bearing PDA1 promoter constructs displaying altered regulation in response to the different signals were used to infect pea epicotyls in order to correlate regulation in culture with that observed during pathogenesis of the host. Removal of the nutritional .
Modelling the effect of size on the aerial dispersal of microorganisms

Aim We investigate the long‐standing question of whether the small size of microbes allows most microbial species to colonize all suitable sites around the globe or whether their ranges are limited by opportunities for dispersal. In this study we use a modelling approach to investigate the effect of size on the probability of between‐continent dispersal using virtual microorganisms in a global model of the Earth’s atmosphere.
Dual alterations in casein kinase I-ε and GSK-3β modulate β-catenin stability in hyperproliferating colonic epithelia

Casein kinase I (CKI)-e and GSK-3β phosphorylate β-catenin at Ser45 (β-cat45) and Thr41/Ser37,33 (β-cat33,37,41) residues, thereby facilitating its ubiquitination and proteasomal degradation. We us.
Practice and Song Development in Zebra Finches

Male zebra finches reared by both parents were placed in isolation from day 35 to day 70 of life, the sensitive phase for song learning, and exposed to a singing adult male thereafter. Half the birds were stimulated to practice by a tape of birdroom noise during their period in isolation, and the practice of all birds was monitored. Those that were stimulated did practice more during the period when the tape was on, but the overall amount of practice in both groups was very high, rising to occur in 60-80% of all 10 min monitoring sessions after 50 days of age. Individual differences were considerable. In the unstimulated group, there was some suggestion that birds which practised more had achieved greater song stereotypy on one measure by day 70. However, the hypothesis that birds which practised more would be more likely to develop copies of their fathers' songs was not supported. Instead, the final song of birds in both groups was clearly based on that of the tutor introduced at 70 days. While the results point to a great deal of practice by young zebra finches, they do not suggest that greater practice leads to earlier crystallisation of song or increases the likelihood of copying songs heard earlier.
Contrasting responses of bee communities to coffee flowering at different spatial scales

While investigating biodiversity patterns on different spatial scales, ecological processes determining these patterns have been rarely analysed. Flower visitation by bees is an important ecological process that is related to floral resource availability. However, little is known about whether responses of bee communities to floral resource availability change at different spatial scales. We studied density and species richness of flower-visiting bees in relation to floral resource availability, provided by coffee, in traditional agroforestry systems on a field, shrub, and branch scale. On a field scale, mean bee density per shrub increased with decreasing proportion of flowering coffee shrubs per site, showing a dilution effect. Conversely, on shrub and branch scales bee density per shrub, or shrub part, increased with increasing number of inflorescences, showing a concentration effect. Additionally, bee density per shrub was higher on those that were only partly, rather than totally surrounded by other flowering coffee shrubs. Species richness of flower-visiting bees was positively affected by high resource availability on a shrub and a branch scale, expressed by a high number of inflorescences, but at the field scale the proportion of flowering shrubs per site did not have any effect on species richness. Our results show contrasting responses of the community of flower-visiting bees to floral resource availability, depending on the spatial scale considered. We conclude that patterns of flower-visiting bee communities of only one spatial scale can not be generalized, since the number of pollinators may be limited on a field scale, but not on smaller scales.
Estimating the Dependence of Spawning Frequency on Size and Age in Gulf of Mexico Red Snapper

Abstract In 2011, a large multivessel survey was conducted to provide nearly synoptic sampling of Red Snapper Lutjanus campechanus throughout their reproductive season in the U.S. Gulf of Mexico. A total of 2,487 Red Snapper were caught with a female : male ratio that was approximately 1:1. The ovaries of 1,002 females were histologically examined. Females (n = 391) were found with spawning markers (postovulatory follicles and hydrated oocytes) throughout the study area, but primarily in outer shelf waters. Statistical models were developed to quantify and test the dependence of the proportion of females bearing spawning markers (spawning fraction) on female length and age, time of year, depth, gear type (vertical line or longline), or region (east or west of the Mississippi River). Most of the variance in spawning fraction was explained by the time of year; spawning fractions were generally low in spring, peaked in midsummer, and declined by fall. There was also strong statistical evidence of a positive relationship between spawning fraction and either age or length. The effects of region and gear type were not significant once time of year and size or age were accounted for. These results demonstrate the need to account for differences in the time of year and age structure of the population when the productivity of populations of Red Snapper are compared. For example, productivity has been hypothesized to be greater in the western Gulf than in the eastern Gulf, as evidenced by regional patterns of egg and larval abundance. Our results suggest that this regional difference is not due to any intrinsic difference in the biology of the fish, but simply a consequence of there being more large, old Red Snapper in the western Gulf. Recent stock assessments have indicated that Red Snapper are increasing in abundance and there is a need to continue monitoring to detect any possible compensation in reproduction.
Importance of maternal size on the reproductive success of perch, Perca fluviatilis, in small forest lakes: implications for fisheries management

Abundance, sex ratio and size structure of perch, Perca fluviatilis L. , populations were studied in two forest lakes. The influence of maternal size on the amount and quality of eggs and larvae was investigated, and the effect of the spawning stock’s length structure on population egg and fry production was evaluated. The importance of large females was essential for the reproduction of perch. Large perch spawned more and bigger eggs that had higher hatching percentage resulting in considerably higher fry production. Larvae of large females were heavier and survived longer with bare yolk sac reserves. The relation between egg dry weight and female length differed between the study lakes suggesting varying maternal influence in different environments. Decrease in the share of large individuals in a perch population can substantially reduce the amount and quality of larvae produced. The results can be applied to improve the sustainability of perch fisheries.
Population genetic structure of parthenogenetic flatworm populations with occasional sex

Summary 1. Sexual populations are expected to perform better in fluctuating environments than asexuals because recombination provides the potential to adapt to changing environments due to increased genetic variation. Nevertheless, some asexual species show comparably high levels of genotypic diversity. Such diversity might be achieved through gene flow between coexisting sexual and asexual populations or through sexual events within asexual populations. 2. Evidence for occasional sex in the flatworm Schmidtea polychroa was previously found at one specific site that is inhabited by parthenogenetic forms. There, varying rates of sex between subpopulations, reaching up to 12%, were observed. Past recurrent sexual processes left a significant genetic signature in the population genetic structure of this population. In the present study, we examined the population genetic structure of six independent metapopulations (lakes) of the freshwater planarian flatworm S. polychroa, to confirm the presence of occasional sex and that its population genetic consequences can be generalised. 3. Using microsatellites, we found varying rates of occasional sex among subpopulations. Metapopulations showed medium to high levels of genotypic diversity that correlated with the rate of sex. 4. We conclude that occasional sex has considerable consequences for population genetic structure of parthenogenetic species and promotes diversity that might allow response to the particular type of selection that is usually predicted to favour sexual reproduction. This reproductive strategy provides genetic characteristics required for selection to act on, and might, therefore, explain the success of this parthenogenetic species.
Effect of artificial diet media, glucose, protein hydrolyzates, and other factors on oviposition in wax eggs by Trichogramma pretiosum

Artificial diet media were clearly inferior to dilute KCl–MgSO4 solutions as ovipositional stimulants for Trichogramma pretiosum. Depending on their concentrations, glucose, protein hydrolyzates, and free amino acids either had no effect on or were inhibitors of oviposition when they were mixed with KCl–MgSO4 solutions. Oviposition into artificial eggs containing salt solutions formulated to correspond to the concentration of potassium, magnesium, and sodium in insect components revealed that the hemolymph mimic and the mimic of Sitotroga cerealella eggs were poor, and that the mimic of whole Heliothis spp. larvae, which was similar to the concentration of these cations in Heliothis virescens eggs, was the most active in eliciting oviposition.
Separate cytotoxic T lymphocyte subsets recognize the different H-2 specificities

Using a monolayer adsorption technique, the fine specificity of cytotoxic effector T lymphocytes (CTL) generated against allogeneic or semi-allogeneic H-2 haplotypes was investigated. The results show that: (a) CTL reacting with the private specificity expressed on an H-2.K molecule can be separated from those reacting with the public specificities expressed on the same molecule and (b) the CTL that recognize cross-reacting H-2 determinants (public specificities) can also be separated into several subpopulations. These data support the hypothesis that an allogeneic stimulation induces a large number of independent T cell clones that react with H-2 determinants.
Feeding habits of the crab-eating fox, Cerdocyon thous (Carnivora: Canidae), in a mosaic area with native and exotic vegetation in Southern Brazil

Cerdocyon thous (Linnaeus, 1766) is the most widespread neotropical canid, most commonly inhabiting forested areas. This animal is a generalist omnivore that is able to use environments disturbed by human activities. The aim of this study was to describe its diet through the stomach content analysis of 30 samples obtained from specimens that were run over in a mosaic composed by Araucaria Pine Forest, Semidecidual Seasonal Forest, natural grasslands, and exotic vegetation. The items were quantified by frequency of occurrence (F.O.) and percentage of occurrence (P.O.). A total of 64 food items were found among 171 occurrences. According to F.O. method, plant items corresponded to 93.3% of the occurrences, followed by animal items (86.7%) and human rejects (16.6%). Among plants, fruits accounted for 92.9% of the occurrences, followed by leaves (53.6%) and flowers (10.7%). Syagrus romanzoffianum (Cham.) Glassman, 1968 and the exotic Hovenia dulcis Thunberg were the most consumed fruits (30% each), and the most consumed leaves were Poaceae. Among preyed animals, the F.O. was 73.3% for invertebrates (mostly Orthoptera and Coleoptera, 36.7% each) and 63.3% for vertebrates (mostly mammals, 33.3%). Regarding the P.O. method, there was an overestimation of invertebrates (98.1%) due to the presence of ants and termites in the stomach of a single individual. In general, C. thous presented its usual diet. Its generalistic feeding habits can positively influence its survival in altered environments. This study also compares different methods for dietary analysis and discusses some opportunistic behaviors of C. thous, such as the consumption of exotic species and the use of silviculture areas as hunting sites.
Description and Phylogenetic Relationships of a New Genus and Species of Lizard (Squamata, Gymnophthalmidae) from the Amazonian Rainforest of Northern Brazil

ABSTRACT Marinussaurus curupira, a new genus and species of Gymnophthalmidae lizard is described from Iranduba, state of Amazonas, Brazil. The genus is characterized by an elongate body; short and stout pentadactyl limbs; all digits clawed; single frontonasal; two prefrontals; absence of frontoparietals; interparietal and parietals forming a straight posterior margin, with interparietal shorter than parietals; distinctive ear opening and eyelid; few temporals; three pairs of chin shields; nasal divided; a distinct collar; smooth, mainly hexagonal, dorsal scales; smooth quadrangular ventral scales; two precloacal and three femoral pores on each side in males; pores between three or four scales. Parsimony (PAR) and partitioned Bayesian (BA) phylogenetic analyses with morphological and molecular data recovered the new genus as a member of the Ecpleopodini radiation of the Cercosaurinae. A close relationship of the new genus with Arthrosaura is postulated.
THE STRUCTURE AND WEAR OF THE MANDIBLES IN SOME AFRICAN GRASSHOPPERS

The form and arrangement of the incisor and molar cusps on the mandibles of grasshoppers varies according to the typo of food they eat and is largely independent of the taxonomic position of the species. As the grasshoppers get older their mandibles become worn and the original cusps may be completely worn away. It is possible that this may have some effect on the ability of the grasshoppers to feed, but laboratory experiments suggest that the effect is not sufficiently great to be a significant factor causing mortality.
Aspectos da biologia de Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) em quatro cultivares dealgodoeiro, em laboratório

Objetivou-se estudar alguns aspectos biologicos de Aphis gossypii Glover alimentado nas cultivares de algodoeiro Allen, IPEACO-SL 21-61131, JPM 781-88-3 e Auburn SM 310, em experimentos conduzidos a 25 ± 2oC, 60 ± 10% UR e foto-fase de 12 horas, em delineamento inteiramente casualizado. Femeas adultas obtidas apos a ultima ecdise foram individualizadas em discos foliares dessas cultivares durante 24 horas e das ninfas produzidas, uma foi escolhida ao acaso para conducao do experimento. Avaliaram-se tambem a densidade e os tipos de tricomas em cada cultivar. A JPM 781-88-3 permitiu o melhor desenvolvimento do pulgao, com uma producao diaria de 4,2 ± 0,1 ninfas/femea e um total de 69,2 ± 2,1. Na cultivar IPEACO-SL 2261131, ocorreram um prolongamento da fase ninfal e reducao na fecundidade, com uma media diaria de 3,0 ± 0,3 ninfas/femea e um total de 54,9 ± 2,2 ninfas/femea. A cultivar Auburn SM 310 afetou o ciclo biologico desse afideo, reduzindo a sua duracao em relacao as demais cultivares. Com relacao aos tipos de tricomas, foram identificadas estruturas nao glandulares de formas estreladas e glandulares, com predominância do primeiro tipo. As maiores densidades de tricomas nao glandulares foram observadas nas cultivares Allen e IPEACO-SL 21-61131, enquanto os glandulares ocorreram em maior numero nas cultivares JPM 78188-3 e Allen. Na Auburn SM 310, nao foi encontrado nenhum tipo de tricoma.
Benthos of an acid lake

Data on composition and distribution of the bottom fauna in a very acid lake (pH 3.9-4.6) in western Sweden are reported. In comparison with three other lakes with higher pH values the fauna is low in abundance with few taxa represented. The benthos is most similar to that of a typically polyhumic reference lake. Molluscs and large crustaceans are missing but many chironomid species show little or no reduction in their distribution.
Family Pseudolividae (Caenogastropoda, Muricoidea): A polyphyletic taxon*

A detailed morphological study was performed on the following taxa normally considered to belong to the family Pseudolividae: (1) Zemira australis (Sowerby, 1833) from Australia; (2) Fulmentum ancilla (Hanley, 1859) from South Africa; and (3) Melapium lineatum (Lamarck, 1822) from South Africa. Two additional species of pseudolivids, Benthobia atafona Simone, 2003 and B. complexirhyna Simone, 2003, from Brazil and New Zealand respectively, are considered. Two other muricoideans are included in this study: (1) Nassodonta dorri (Watteblet, 1886) [Nassariidae] from Vietnam (morphological study also included) and (2) Siratus senegalensis (Gmelin, 1791) (Muricidae) from Brazil (published elsewhere). Both species are outgroups, but operationally included as part of the ingroup in order to test the monophyly of the Pseudolividae. In particular, N. dorri has a shell very similar to a pseudolivid. A complete taxonomical and morphological treatment of each species is included, as a scenario of a formal phylogenetic analysis. Additional outgroups considered include a pool of Tonnoidea (the root) and Conoidea. The cladogram is: (Tonnoidea (Conoidea ((Benthobia atafona–B. complexirhyna) (Nassodonta dorri (Zemira australis (Fulmentum ancilla (Siratus senegalensis–Melapium lineatum))))))). Analyses of each important character and of the cladogram were performed. Some of the conclusions include that the family Pseudolividae, as presently understood, is polyphyletic, as it would include a nassariid (N. dorri) and a muricid (S. senegalensis).
Digestible lysine levels obtained by two methods of formulation of diets for 22-to-42-day-old broilers

The objective of this study was to evaluate the effect of digestible lysine levels in diets with or without supplementation of industrial amino acids on performance, carcass characteristics and nitrogen excretion in broilers of 22 to 42 days of age. Birds were distributed in a completely randomized experimental design in a 4 × 2 factorial arrangement, with four digestible lysine levels (9.0, 10.0, 11.0 and 12.0 g/kg) and two methods to obtain the lysine levels (variation in the proportion of corn and soybean meal, without supplementation; or supplementation of industrial amino acids), eight replicates and 20 birds per replicate. There was an interaction effect on the performance characteristics and on the weights and yields of prime cuts. In both diets, feed conversion improved linearly as the lysine levels were increased. Feed intake; weight gain; carcass, thigh and drumstick weights; and boneless breast yield increased and abdominal fat reduced linearly as the lysine levels were increased in the unsupplemented diet. The lysine levels of the supplemented diets linearly reduced the yield of drumstick and quadratically reduced the yields of bone-in and boneless breast up to the estimated levels of 10.4 and 10.7 g/kg, respectively. Diets without supplementation increased the excretion and retention of nitrogen. The levels of 9.0 and 12.0 g/kg digestible lysine obtained with supplementation of industrial amino acids and without it, respectively, provide the best performance and yield of prime cuts in the birds. Diets in which the digestible lysine levels are obtained without supplementation provide better performance responses and carcass characteristics compared with supplemented diets.
Signal Transduction and Transcriptional Regulation of Plant Defence Responses

Plant defence responses are regulated by a complex network of signal molecules and transcriptional regulators. Resistance (R) genes play a role in specific recognition of a pathogen and initiate defence responses. Three key signal molecules, namely salicylic acid (SA), jasmonate (JA) and ethylene (ET) mediate expression of both specific (R gene-mediated) as well as basal defence responses. The signalling pathways involving these molecules have been studied using mutants showing enhanced susceptibility or resistance to pathogens, or those showing insensitivity to exogenously applied SA, JA or ET. Crosstalk between the different signalling pathways leads to fine-tuning of the expression of defence-related genes. Complex regulatory networks modulated by at least eight different families of transcription factors play a role in defence gene expression. The transcription factors bind to cis-elements present in the promoters of the defence genes and are specific for different transcription factors. Several cis-elements often lie within the same promoter indicating that different transcription factors may lead to induction of the same defence gene. The redundancy observed in defence signalling and gene expression enables a plant to successfully combat a wide range of pathogens.