Miracle-dz/UniFAR-FTUs huggingface dataset:
An assessment of the in vitro toxicology of Clostri di urn perfringens type D ε-toxin in human and animal cells

The epithelial Madin Darby canine kidney (MDCK) cell line and 17 human cell lines were examined for sensitivity to Clostridium perfringens type D a-toxin. MDCK cells were confirmed as being sensitive to the toxin. In addition, the Caucasian renal leiomyoblastoma (G-402) human cell line was identified as being ε-toxin sensitive. Using the MTS/PMS assay system the concentration of toxin reducing cell culture viability by 50% (LC50) was found to be 2 ug/ml in MDCK cells. The LC50 for G-402 cells was 280,ug/ml. a-Toxin was found to be rapid acting in MDCK cells exposed to a maximum lethal dose of the toxin (40% loss of viability after a 0.5 h exposure), but slower acting in G-402 cells (40% loss of viability after 1.7 h exposure). Photomicrography of toxin exposed cultures indicated necrotic cell death on exposure to a-toxin. Investigations using an antibody probe indicated that ε-toxin could bind to many cell surface proteins in both MDCK, G-402 and a toxin insensitive human cell line (CAKI-2). It has previously been found that the toxin may bind to the cell surface via glycosylated moieties. However, exposing MDCK and G-402 cells to a-toxin in the presence of sialic acid and several different sugars did not reduce the lethal effects of the toxin.
The Three Brothers' Problem: Kin Selection with More than One Potential Helper. 1. The Case of Immediate Help

In situations involving a single relative in distress and several potential helpers, the advantage of leaving the risky job of aiding the relative in need to any of the other potential helpers is quite obvious. Hence, even if Hamilton's condition for altruism in the one-to-one situation is satisfied, it might seem that altruistic behavior would not evolve if there is more than one potential helper. In this paper we investigate the evolutionarily stable strategy (ESS) of helping behavior in situations involving several potential helpers and a necessarily instantaneous response. The main result is that if Hamilton's condition is met, the ESS is usually a mixed strategy of altruism and selfishness, with a decreasing (yet positive) probability of helping as the number of potential helpers increases.
Online Preparation Resources Help First Year Students to Benefit from Practical Classes

Practical skills are important for the employability of biosciences graduates; however, first year science undergraduates often struggle to adapt to university practical classes, affecting skills development and decreasing their enthusiasm for laboratory work. This study describes the effects of introducing online multimedia practical support resources on biochemistry and biological sciences on first year student performance, and investigates student usage and student opinion of the value of these resources. In total, 391 students used these resources over a three-period. Information was collated on their completion of preparation tasks and module performance. Student opinion was sought using questionnaires with opportunity for free comment. Engagement with preparation tasks affected student performance in practical modules. Student’s t-tests showed a significant difference between the performances of highly engaged, engaged and poorly engaged students, with higher engagement leading to improved performance. Student opinion was sought twice, in 2010–11 and 2012–13. Resources were well used, and students found the resources helpful in understanding the theoretical basis of practical work and how to undertake experiments; they enjoyed practical classes and felt that the preparation resources increased their confidence. Multimedia practical preparation resources are valuable in helping students to manage the transition from school to university practical work in biosciences.
Relative significance of nursery infections and orchard inoculum in the development and spread of apple canker (Nectria galligena) in young orchards

Three nurseries produced apple rootstocks (M9) and budwood (cv. Royal Gala), which they exchanged at the end of the first year. Each nursery then budded its own budwood onto the rootstocks it had produced and that from the other two nurseries. Budded trees were grown on for a further year before being planted at HRI, East Malling in southern England; NIHPBS, Loughgall in Northern Ireland; and ADAS, Rosemaund in the West Midlands of England. Canker development was monitored twice a year. The position of the infected trees within the orchard was recorded, as was the position of the canker on each tree (main-stem or peripheral). Nectria galligena was isolated from representative cankers and analysed using molecular techniques. At the sites in Northern Ireland and HRI there was a strong positional effect, especially of peripheral cankers, indicating that most of the inoculum was external and had been spread from neighbouring orchards. There was little or no positional effect on main-stem cankers at any of the three sites. The proportions of different isolates taken from peripheral cankers was different in Northern Ireland from that in England, suggesting different populations associated with the geographic areas. In contrast, the populations of N. galligena obtained from main-stem cankers were very similar in England and Northern Ireland. It was concluded that a small proportion of trees developing canker were infected during propagation, with no symptom development until after planting. In a second trial it was demonstrated that trees infected during the propagation phase, and particularly at budding and heading back, could develop canker up to 3 years later. While it is clear that some canker developing in the orchard can be associated with the nursery of production, in climatic conditions conducive to the formation and dissemination of conidia, inoculum from surrounding infected orchards is the primary source of the pathogen. Aerial spread is therefore an essential element of the epidemiology of N. galligena, and its control is a crucial part of any canker-control programme.
Ecology and Distribution of Pocket Gophers (Geomyidae) in Colorado

The general distribution of the family geomyidae in North America is limited only by suitable soils, although a particular species may be also be limited by climatic or other factors associated with altitude and latitude and by interspecies competition. A study was made of the factors affecting the distributions of the pocket gophers Thomomys bottae, T. talpoides, Geomys bursarius, and Cratogeomys castanops in Colorado. The most critical factors in the relationships among pocket gophers are soil tolerance and competition. All four species in Colorado prefer deep light soils,but their ranges of tolerance vary, with the result that interspecies competition consists of the fundamental niche of one species being a proper subset of another. In each combination of competitive and is able to displace the other speices to less favorable habitats. The relationship among the four species in competitive ability is G. bursarius > C. castanops > T. bottae > T. talpoides. Possible mechanisms of competition are discussed in relation to body size, territory, aggression, and dispersal.
Rapid Quantification of Phototrophic Microorganisms and their Physiological State through their Colour

Quantification of phototrophic organisms on solid substrata together with their metabolic activity can be assessed easily, reliably and quickly through measurement of the organisms' colour. For that purpose only a chroma meter for solid substrata able to quantify the three components of colour is needed. A correlation between these three components and the number of organisms and their physiological state was demonstrated. The methodology developed here makes it possible to save time and materials in comparison with traditional microbiological methods. Moreover, it is a non-destructive method which can be used directly on site and in site. This characteristic is important when microbial environmental monitoring of cultural heritage is involved.
Vegetation recovery following fire in two Waikato peatlands at Whangamarino and Moanatuatua, New Zealand

Abstract After fires in 1984 and 1989 at Whangamarino wetland, and in 1972 at Moanatuatua Bog, peatland flora and vegetation were monitored to determine rates and patterns of recovery. Species with rhizomes that survived the fires were able to resprout and grow rapidly in the initial post-fire period. Species that were eliminated had to re-establish from seed and so recovered more slowly. The vegetation at Moanatuatua took almost 12 years to recover to pre-fire condition, twice as long as at Whangamarino. Adventive and early colonising native species were prominent only in the first 1-2 post-fire years, probably because of temporarily increased availability of nutrients and/or open habitat. Ordination techniques arranged the plots and species in a sequence from shrub-sedgeland (Whangamarino), through Empodisma minus restiad rushland (Whangamarino), to Sporadanthus traversii/ Empodisma restiad rushland (Moanatuatua) following a gradient of decreasing fertility with time. Fires reset the bog development pro.
Plant introduction trials: genotype-environment analysis of plant introductions for the high country

Abstract The relative productivity, adaptability, and persistence rankings of 168 lines of grasses, legumes, and herbs were determined from a spaced plant trial in the Mackenzie Country at 3 contrasting sites and 2 fertility levels. Plants were visually assessed in spring, summer, and autumn in the 1st, 2nd, and 5th year. The species groups, in approximate descending order of productivity within legumes and grasses, together with the number of lines ranked within each group, were: white and alsike clover 4, lucerne 3, red clover 10, Lotus 31, other perennial legumes 15, Melilotus 4, Vicia 10, annual legumes and grasses 14, Dactylis 18, other perennial grasses 8, Bromus 5, wheat grasses 13, Poa pratensis 24, native grasses 5, and herbs 5. Within each group, lines are ranked according to productivity and persistence.
Status of Crested Penguin (Eudyptes spp.) populations on three islands in Southern Chile

Abstract We surveyed the coast of Chile between Isla Terhalten (54° 20′ S) and Islote Leonard (55° 44′ S) by boat during November–December 2005 to document breeding locations of Rockhopper (Eudyptes chrysocome chrysocome) and Macaroni (E. chrysolophus) penguins, and to count the number of nests during the early incubation period. A yacht-based observation recorded 1,000 Rockhopper Penguin nests at Isla Terhalten. Ground-based counts at Isla Noir estimated a total of 158,200 Rockhopper and 3,470 Macaroni penguin nests in 17 mixed colonies and one Macaroni Penguin breeding colony. The Rockhopper population on Isla Noir increased significantly from the previous estimate of 70,000 pairs, making this island the most important breeding site for the southern subspecies of Rockhopper Penguin. The new estimate for Rockhopper Penguins suggests a population increase over the last 20 years, consistent with recent data for the main colony in Argentina. Conservation status of the species and the factors potentially responsible for population declines elsewhere may need to be re-evaluated.
Mimicry in coral reef fishes: ecological and behavioural responses of a mimic to its model

Mimicry is a widely documented phenomenon in coral reef fishes, but the underlying relationships between mimics and models are poorly understood. Juveniles of the surgeonfish Acanthurus pyroferus mimic the coloration of different pygmy angelfish Centropyge spp. at different locations throughout the geographic range of the surgeonfish, while adopting a common species-specific coloration as adults. This study examines the ecological and behavioural relationships between A. pyroferus and one of its models, Centropyge vroliki, in Papua New Guinea. Surgeonfish underwent a transition from the juvenile (mimetic) coloration to the adult (non-mimetic) coloration when they reached the maximum size of the angelfish. As typical of mimic-model relationships, mimic surgeonfish were always less abundant than their model. Spatial variation in the abundance of mimics was correlated with models, while the abundance of adults was not. We show that juvenile surgeonfish gain a foraging advantage by mimicking the angelfish. Mimic surgeonfish were always found within 1-2 m of a similar-sized individual of C. vroliki with which they spent c. 10% of their time in close association. When in association with angelfish, juvenile surgeonfish exhibited an increase of c. 10% in the amount of time spent feeding compared to when they were alone. This foraging benefit seems to be explained by reduced aggression by the territorial damselfish Plectroglyphidon lacrymatus, which dominates the reef crest habitat. While adult A. pyroferus and all other surgeonfish were aggressively displaced from damselfish territories, mimic surgeonfish and their models were attacked less frequently and were not always displaced. Stomach contents analysis showed that the diet of C. vroliki differed substantially from P. lacrymatus, while that of A. pyroferus was more similar to the damselfish. We hypothesize that mimics deceive damselfish as to their diet in order to gain access to food supplies in defended areas.
ULTRASTRUCTURE OF A CHAIN‐FORMING DIATOM PHAEODACTYLUM TRICORNUTUM 1

The ultrastructure of a chain‐forming clone of the polymorphic diatom Phaeodactylum tricornutum Bohlin has been studied by scanning and transmission electron microscopy. Both fusiform and tri‐radiate cells are capable of forming chains. The cells, lacking any silica shell, are attached to each other at the central region of the theca, leaving the arms free. Neither homogenization nor sonication completely disrupts the chains. The attachment is due to fusion of the cell wall in the central region of the cell during cell wall deposition. This fusion results from failure of the cytoplasmic cleavage furrow to separate the plasma membranes of the two daughter cells sufficiently so that a single wall is deposited instead of two separate walls. Possible explanations for this are discussed.
Ultrastructural and molecular delineation of the Chytridiaceae (Chytridiales)

The Chytridiomycota is in need of taxonomic revision, especially the largest order, the Chytridiales. We analyzed 25 isolates in, or allied to, the Chytridium clade of this order. Isolates were selected based on one or more of the following criteria: (i) having a large subunit molecular sequence similar to that of the type of the genus Chytriomyces, (ii) having specific zoospore morphology, and (iii) currently classified as a species in the genus Chytriomyces. We examined ultrastructural characters and partial sequences of large subunit and small subunit rDNA and generated a phylogenetic hypothesis using maximum parsimony and Bayesian analyses. The sequence analyses strongly supported the Chytridiaceae, Phlyctochytrium, and Chytriomyces angularis clades, and each clade had a specific zoospore type. Developmental morphology of the thallus did not mirror the DNA-based phylogeny. Based on the results of phylogenetic analyses of sequences and ultrastructural characters, we emend the Chytridiaceae by including.
Helix periodicity, topology, and dynamics of membrane‐associated α‐Synuclein

The protein α‐Synuclein (aS) is a synaptic vesicle‐associated regulator of synaptic strength and dopamine homeostasis with a pathological role in Parkinson's disease. The normal function of aS depends on a membrane‐associated conformation that is adopted upon binding to negatively charged lipid surfaces. Previously we found that the membrane‐binding domain of aS is helical and suggested that it may exhibit an unusual structural periodicity. Here we present a study of the periodicity, topology, and dynamics of detergent micelle‐bound aS using paramagnetic spin labels embedded in the micelle or attached to the protein. We show that the helical region of aS completes three full turns every 11 residues, demonstrating the proposed 11/3 periodicity. We also find that the membrane‐binding domain is partially buried in the micelle surface and bends toward the hydrophobic interior, but does not traverse the micelle. Deeper submersion of certain regions within the micelle, including the unique lysine‐free sixth 11‐residue repeat, is observed and may be functionally important. There are no long‐range tertiary contacts within this domain, indicating a highly extended configuration. The backbone dynamics of the micelle‐bound region are relatively uniform with a slight decrease in flexibility observed toward the C‐terminal end. These results clarify the topological features of aS bound to membrane‐mimicking detergent micelles, with implications for aS function and pathology.
Body Weight Prediction Using Digital Image Analysis for Slaughtered Beef Cattle

Abstract Bozkurt, Y. , Aktan, S. and Ozkaya, S. 2007. Body weight prediction using digital image analysis for slaughtered beef cattle. J. Appl. Anim. Res., 32: 195–198. To predict body weight of beef cattle using traditional methods and digital image analysis system, 140 animals were used and prediction models were developed. The R2 values of prediction equations were 52.1, 63.6, 53.2, 47.1, 43.1 and 49.8% for body area, body length, wither height, hip height, hip width and chest depth, respectively. The regression equations which included only body area, body length or wither height showed that the prediction ability of digital image analysis system was better than the equations including other body traits. The results showed that the prediction ability of digital image analysis system was very promising to predict body weight.
Genetic Analysis of Cucumber Mosaic, Peanut Stunt and Chrysanthemum Mild Mottle Viruses

Four strains of cucumber mosaic virus (CMV-Y, CMV-L, CMV-E and CMV-P), Peanut stunt virus (PSV) and chrysanthemum mild mottle virus (CMMV) had a tripartite genome. Molecular weights of RNA's of CMV, PSV, and CMMV in aqueous gels were determined by polyacrylamide gel electrophoresis under non-denaturing conditions. Analysis utilizing pseudorecombinants constructed by RNA3 exchange between CMV strains or between GMV-L and CMMV revealed that serotypes were determined by RNA3, while symptoms on cucumber and cowpea plants depended on RNA1+2. Furthermore when RNA 1 and RNA 2 were exchanged between CMV strains, symptoms on cowpea depended on RNA2.
Between the Nile and the Ocean The bead assemblage from Shenshef in the Eastern Desert (4th–6th centuries AD)

PAM 26/1: Research Abstract: More than 200 beads and pendants were found in seven trash middens excavated at the 4th/5th to the 6th century AD settlement site in Shenshef in the Eastern Desert of Egypt. The site lies close to the Sudanese border and the Red Sea coast, and about 20 km to the southwest of the ancient port of Berenike. Although the purpose of the settlement has not been established, excavations provided a wide range of imports from the Mediterranean region and the Indian Ocean. An overview of the materials and manufacturing techniques applied in the production of the beads and pendants confirms the shortand long-distance contacts of Shenshef inhabitants. In addition to the many bead parallels that link the site with the Red Sea ports and the Nile Valley region up to the First Cataract, the presence of South Indian/Sri Lankan beads at Shenshef is especially meaningful. They may be proof of the intermediary role played by the Shenshef inhabitants in trading overseas imports into the Nubian Nile Valley region.
Exigências líquidas de proteína e energia para crescimento de tourinhos santa gertrudis em dietas de alto teor de concentrado

Thirty two Santa Gertrudis bulls with ten months of age and 245 kg average live weight were fed 88% concentrate diets with corn silage or sugarcane bagasse and dry corn or high moisture corn. Four animals were slaughtered in the beginning of the experiment for initial body composition determination. Other 28 animals were distributed on four treatments. The experimental design was randomized blocks in 2 X 2 factorial (two roughage X two corn sources) with seven replicates. Regression equation of log body energy content as a function of log empty body weight (EBW) provided estimation of body energy content at any EBW range included in this research: for weight gain of 1 kg, an animal of 300 kg requires 3.64 Mcal/day of energy and 129.5 g of protein.
Demography of lions in relation to prey and habitat in the Maasai Mara National Reserve, Kenya

We studied lion demography in the Maasai Mara National Reserve between September 1990 and April 1992, with a special emphasis on the spatial and seasonal variation in demographic characteristics. Lion density (0.2–0.4 lions km−2) and pride size (range 8–48) were high because of a high resident prey biomass (10 335 kg km−2) augmented by migrant prey to 26 092 kg km−2 in the dry season. Overall, their sex ratio was almost at parity and varied neither spatially nor seasonally. Sex ratio was even among subadults but skewed toward males and females among cubs and adults, respectively. This implies an increasing differential mortality of males with age through subadulthood. The age ratio varied seasonally because of a birth peak in March–June and an influx of subadults into the reserve during July–August, coincident with increases in migrant prey. The birth peak was apparently preceded by another peak in mating activity falling between November and May. Further research should investigate the precise causes of the biased cub sex ratio, low lion density in the Mara Triangle and the higher ratio of subadults in Musiara than in the Mara Triangle or Sekenani. Resume Nous avons etudie la demographie des lions dans la Reserve Nationale de Masai Mara entre septembre 1990 et avril 1992, en insistant particulierement sur les variations spatiales et saisonnieres des caracteristiques demographiques. La densite des lions (0.2–;0.4 lions/km2) et la taille des troupes (de 8 a 48) etaient elevees en raison de la forte biomasse des proies residentes (10 335 kg/km2), portee a 26 092 kg/km2 en saison seche par les proies migratrices. En general, le sex-ratio etait a peu pres egal et ne variait ni selon les saisons, ni selon les endroits. Les sex-ratio etait egal parmi les sub-adultes, mais il deviait en faveur des mâles et des femelles chez les petits et les adultes, respectivement. Ceci implique une mortalite de plus en plus differentielle des mâles a l'âge sub-adulte. L'âge-ratio variait avec les saisons en raison d'un pic de natalite de mars a juin et d'une arrivee de sub-adultes dans la reserve en juillet-aout, coincidant avec l'augmentation des proies migratrices. Le pic des naissances etait apparemment precede par un autre pic des activites d'accouplement, entre novembre et mai. De nouvelles recherches devraient etudier les raisons precises du sex-ratio biaise chez les lionceaux, de la faible densite des lions dans le Mara Triangle et du taux de sub-adultes plus elevea Musiara que dans le Mara Triangle ou a Sekenani.
Optimal time for remote sensing to relate to crop grain yield on the Canadian prairies

The optimal time to acquire remote sensing imagery to relate to grain yield has not been thoroughly investigated for the Canadian prairies. Remotely sensed data collected when there is the best relationship with yield should provide useful information on the in-field spatial variability of biophysical factors affecting crop productivity relevant to site-specific management. The correlations of normalized difference vegetation index (NDVI) with grain yield for three dates in 2000 at Indian Head and Swift Current, SK, for field pea, canola, and spring wheat were compared. No single date consistently had the highest NDVI-yield correlation for all crops. The period between Jul. 10 to 30 was optimal to obtain NDVI to relate to grain yield for springseeded crops that typically mature in August. Significant NDVI-yield correlations for this period were confirmed in three additional site-years. In a further site-year, however, NDVI-yield correlation was significant for wheat and pea, but not for canola. Occasional.