Miracle-dz/UniFAR-FTUs huggingface dataset:
An allometric model of home range formation explains the structuring of animal communities exploiting heterogeneous resources

Understanding and predicting the composition and spatial structure of communities is a central challenge in ecology. An important structural property of animal communities is the distribution of individual home ranges. Home range formation is controlled by resource heterogeneity, the physiology and behaviour of individual animals, and their intra- and interspecific interactions. However, a quantitative mechanistic understanding of how home range formation influences community composition is still lacking. To explore the link between home range formation and community composition in heterogeneous landscapes we combine allometric relationships for physiological properties with an algorithm that selects optimal home ranges given locomotion costs, resource depletion and competition in a spatially-explicit individual-based modelling framework. From a spatial distribution of resources and an input distribution of animal body mass, our model predicts the size and location of individual home ranges as well as the individual size distribution (ISD) in an animal community. For a broad range of body mass input distributions, including empirical body mass distributions of North American and Australian mammals, our model predictions agree with independent data on the body mass scaling of home range size and individual abundance in terrestrial mammals. Model predictions are also robust against variation in habitat productivity and landscape heterogeneity. The combination of allometric relationships for locomotion costs and resource needs with resource competition in an optimal foraging framework enables us to scale from individual properties to the structure of animal communities in heterogeneous landscapes. The proposed spatially-explicit modelling concept not only allows for detailed investigation of landscape effects on animal communities, but also provides novel insights into the mechanisms by which resource competition in space shapes animal communities.
The Use of Geological and Paleontological Evidence in Evaluating Plant Phylogeographic Hypotheses in the Northern Hemisphere Tertiary

Phylogeography posits that the sequence of speciation events within a clade should parallel the geographic migration and isolation of members of the clade through time. The primary historical features that govern migration and allopatry in land plants are changes in physical geography (e.g., oceans, mountains, and deserts) and in climate (e.g., moisture, temperature, and day length), features that are often interrelated. If we assume that living genera retain physiological stability through time, much as they retain the morphological features that allow their identification, then these environmental features of the geologic past may be used to test phylogeographic hypotheses of living genera based on phylogenetic analysis. The history of the climatic and geographic features of the Tertiary of the Northern Hemisphere agrees with many phylogenetically based phylogeographic hypotheses of living angiosperm genera but indicates that some hypotheses require reanalysis. While the parallel comparison of phylogenetic hypotheses and historical biogeographic evidence is in its infancy, the reciprocal illumination of the two approaches shows great promise for future application.
Component of Plant Competition Along an Experimental Gradient of Nitrogen Availability

We tested for variation in the intensity of above— and belowground competition along a 5—yr—old experimental gradient of nitrogen availability in a Minnesota old field. Standing crop increased, species richness decreased, and species composition varied significantly as nitrogen availability increased. Transplants of the three grasses that were dominants at the three levels of the nitrogen gradient (low; Schizachyrium scoparium, intermediate: Poa pratensis, high: Agropyron repens) were grown along the gradient with no neighbors present, with only the roots of neighbors present, or with both the roots and shoots of neighbors present. Resource measurements indicated that the treatment with only neighbor roots present provided at light regime similar to that in which all neighbors had been removed but a nitrogen regime similar to that in which all neighbors were present. At low nitrogen availability, transplants grown with only neighbor roots generally did not differ significantly in biomass or growth rate from those grown with both neighbor roots and shoots, suggesting that the bulk of neighbor effects at low nitrogen were belowground. At high nitrogen availability, plants grown with only neighbor roots generally grew significantly larger than those grown with both roots and shoots of neighbors, but not as large as plants grown with no neighbors, suggesting that both above— and belowground competition occurred. At low nitrogen availability, plants grown with neighbors weighed 3—12% as much as those grown without; at the highest rate of nitrogen addition, plants grown with neighbors weighed 12—58% as much as those grown without, indicating that competition occurred on both poor and rich soils. The intensity of competition, measured as the suppression of transplants by neighbors, did not vary significantly with nitrogen availability. Further, the per—gram effect of neighbors, measured as the slope of the relationship between transplant performance and neighbor biomass, did not vary significantly with nitrogen supply rate. In total, competition was an important force at all points along the experimental productivity gradient, but competition shifted from being mainly belowground in the least productive vegetation to both above— and belowground in fertilized plots.
Analysis of Cell Patterns in Developing Maize Leaves: Dark‐Induced Cell Expansion Restores Normal Division Orientation in the Mutant tangled

Cells in a Zea mays L. (maize) leaf retain an oriented axial relationship during normal development. Mutant analyses demonstrate, however, that cellular order is not required for normal leaf development. For example, the tangled (tan) mutation disrupts longitudinally oriented cross walls preferentially with little impact on overall leaf development. One hypothesis to explain how tan leaves acquire normal dimensions is that expanding cells adjust for division defects, resulting in net normal cell growth. Plant cells could self‐adjust by a combination of molecular and biophysical factors. To evaluate self‐adjustment, the relationship between division and expansion was analyzed in a unique meristematic predifferentiation zone (PDZ) that is retained at the base of elongating leaf blades. The results show that the tan mutation disrupts cell expansion in addition to the previously described division defect. Mutant cells of altered wall lengths still have net normal cell area, supporting the idea that the overall growth of mutant cells is unaffected. We propose that mutant cellular defects are mitigated by later stages of expansion during periods when cells have surpassed the mitotic cycling found in the PDZ. These observations support the idea that molecular control of cell expansion varies with stage of growth: rapidly cycling cells require TAN for the cell expansion that intervenes between mitotic cycles but not for the expansion that occurs during cellular differentiation. We use dark growing conditions to alter the cell cycle in the PDZ and show that dark growth ameliorates both division and expansion defects in the mutant. Cell divisions in the tan mutant were restored to near‐normal orientations in response to the dark‐induced cell expansion.
Antioxidant Activity of Some Furanocoumarins Isolated from Heracleum persicum

Antioxidants are important substances that possess the abil-ity to protect the body from damage caused by free radical-induced oxidative stress. A variety of free-radical scavenging antioxidants exist within the body, many of which are derived from dietry sources such as fruits, vegetables, and teas. This paper describes a search for bioactive components in fruits of Heracleum persicum Desf. ex Fisher, which led to isolation of four furanocoumarins that exhibit antioxidant activity. The structure of the constituents were identified by ultraviolet, infrared, nuclear magnetic resonance, and mass spectrometry analyses in comparison with literature data. The isolated constituents were tested by linoleic acid peroxidation for their antioxidant activities and were found to be moderately active. Antioxidant activity of crude ethyl acetate extract was stronger than single isolated constituents.
Ecological Life Table of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

An ecological life table was constructed, aiming to determine the critical stages and key mortality factors of Tuta absoluta (Lepidoptera: Gelechiidae). The total population mortality of this tomato leafminer was 92.3%. During the egg stage the mortality was 58.7%, mainly due to egg inviability. A total of 8.6% egg parasitism by Trichogramma pretiosum (Riley) (Hymenoptera: Trichogrammatidae) and 5.0% egg predation by Xylocoris sp. (Heteroptera: Anthocoridae), Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) and members of the family Phlaeothripidae (Thysanoptera) was observed. The mortality of the larval stage was 33.0%. This was considered to be the critical stage as it showed the highest apparent mortality (79.8%). Larval parasitism was low (0.1%), and was only found with Goniozus nigrifemur Ashmead (Hymenoptera: Bethylidae). Predators were responsible for 79.4% of larval mortality. Therefore, their attraction to and maintenance in the target area are important management tactics to be considered fo.
Nitrogen Uptake and Leaching under Annual Bluegrass Ecotypes and Bentgrass Species: A Lysimeter Experiment

Nitrate (NO; ) can leach from golf greens, potentially causing the degradation of surface and ground water quality. A greenhouse experiment was conducted with 11 annual bluegrass (Poa annua var. reptans Hausskn.) ecotypes from eastern Canada (Quebec and Ontario) and the USA, and three bentgrass (Agrostis spp.) species to compare N uptake and potential for N leaching. Two-month-old grasses were established for a 6-wk period in lysimeter columns simulating a golf-green profile. An unplanted root zone control was included. Water-soluble fertilizer was applied at 25 kg N ha -1 (NH 4 NO 3 ) every 14 d for 57 d. Leachate samples were collected every second day and analyzed for NO 3 -N and ammonium N (NH 4 -N) content. Dry weight and N concentration were determined on clippings, shoots, and roots. Ammonium N leaching was negligible for all grasses. Less NO 3 -N leaching losses occurred under bentgrasses (6-11% of applied N) than under annual bluegrasses (28-71% of applied N). Differences in NO 3 -N leaching were also found within annual bluegrasses; Quebec P. annua > Ontario P. annua > USA P. annua. Grasses with a greater aboveground biomass developed a larger and deeper root system and were associated with a greater N uptake (r = 0.94) and, therefore, a lower NO 3 -N leaching (r = -0.94). Breeding programs and management practices to improve turfgrass root development appear to be critical to reduce fertilizer N leaching under sand-based putting greens.
Inhibition of FcRI-mediated Activation of Rat Basophilic Leukemia Cells by Clostridium difficile Toxin B (Monoglucosyltransferase) (*)

Treatment of rat basophilic leukemia (RBL) 2H3-hm1 cells with Clostridium difficile toxin B (2 ng/ml), which reportedly depolymerizes the actin cytoskeleton, blocked [3H]serotonin release induced by 2,4-dinitrophenyl-bovine serum albumin, carbachol, mastoparan, and reduced ionophore A23187-stimulated degranulation by about 55-60%. In lysates of RBL cells, toxin B 14C-glucosylated two major and one minor protein. By using two-dimensional gel electrophoresis and immunoblotting, RhoA and Cdc42 were identified as protein substrates of toxin B. In contrast to toxin B, Clostridium botulinum transferase C3 that selectively inactivates RhoA by ADP-ribosylation did not inhibit degranulation up to a concentration of 150 μg/ml. Antigen-stimulated tyrosine phosphorylation of a 110-kDa protein was inhibited by toxin B as well as by the phosphatidylinositol 3-kinase inhibitor wortmannin. Depolymerization of the microfilament cytoskeleton of RBL cells by C. botulinum C2 toxin or cytochalasin D resulted in an increased [3H]serotonin release induced by antigen, carbachol, mastoparan, or by calcium ionophore A23187, but without affecting toxin B-induced inhibition of degranulation. The data indicate that toxin B inhibits activation of RBL cells by glucosylation of low molecular mass GTP-binding proteins of the Rho subfamily (most likely Cdc42) by a mechanism not involving the actin cytoskeleton.
β- and γ-Crystallin Synthesis in Rat Lens Epithelium Explanted with Neural Retina

The main aim of this study was to determine whether the neural retina brought about the qualitative changes in protein synthesis associated with lens fibre differentiation. Explants of lens epithelium from newborn rats which only contain alpha-crystallin in detectable amounts were cultured alone or on pieces of neural retina. In the latter case the explants increased in size and contained alpha-, beta-, and gamma-crystallins. This size increase and change in crystallin composition is characteristic of lens fibre differentiation from epithelial cells. To determine if this was a specific property of the neural retina the epithelium was grown on other tissues. Corneal stroma and cartilage brought about some differentiation in the presence of foetal calf serum but were not as effective as the neural retina. Dermis had no effect on differentiation of the lens epithelium. One interpretation of these results is that the neural retina simply provides a good substratum on which the epithelium can grow and differentiate. However, epithelial explants grown in retina-conditioned medium also differentiate. Therefore the explant response must be a result of the modification of the medium by the neural retina.
Muzika wa Dzikhwairi: An essay on the history of Venda choral music

Abstract There has been notable growth in the production of indigenous South African choral music repertoire. However, little effort has been made in the collection, documentation, preservation and promotion of the repertoire of Venda choral music. This article traces the foundations and historical development of choral music as an art form among Vhavenda. It seeks to identify and describe the factors that shaped Venda choral music by providing a description of the socio-political circumstances that shaped the music, and traces and places the existing Venda choral tradition within the context of Venda history, culture, tradition and language. The article aims to explore the place and significance of Venda choral music within South Africa, and to determine whether Venda composers such as Stephen Maimela Dzivhani, Derrick Nephawe, Khorommbi Joseph Nonge, Thinawanga Israel Ramabannda and Fhatuwani Hamilton Sumbana succeeded in gaining recognition within the indigenous South African choral fraternity. In essence, the article accounts for the slow growth of repertoire and respect for Venda choral music, and the possible reasons for the misperceptions and marginalisation of the music in national competitions. Finally, the article advocates the promotion of Venda choral music in order to motivate and encourage present and future composers of the language group, Vhavenda.
Comparison of extracellular proteases produced by Aeromonas salmonicida strains, isolated from various fish species.

Extracellular products (ECPs) of five typical and 25 atypical Aeromonas salmonicida isolates from various fish species and geographical locations were analysed by substrate specificity, inhibition of proteolytic activity and substrate SDS-PAGE. The type strains of Aer. salmonicida subsp. salmonicida and Aer. salmonicida subsp. achromogenes were included for comparison. The results indicated that the strains formed six protease groups. The proteases produced by the two type strains were of a different nature. All the typical strains belonged to one group and showed proteolytic activities comparable to P1 and P2 proteases. Three atypical (oxidase-negative) strains secreted a protease comparable to P1. With the exception of these three, all strains produced metallo-gelatinases. A metallo-caseinase (AsaP1) was detected in the ECP of subsp. achromogenes type strain and 10 of the atypical strains. A number of proteolytic components with different apparent molecular weights (AMWs) were identified. These include caseinases with AMWs of > 100, 80, 60 and 30 kDa and gelatinolytic components with different AMWs, including some with AMW higher than P1 and lower than P2. The protease production of the isolates was not found to be host specific.
Where River Meets Sea

Recent genetic research suggests an expansion along the tropical coastline of the Indian Ocean, between 75,000 and 60,000 years ago, of the population which included the ancestors of all of the non‐African human mitochondrial DNA lineages known today. In view of the arid sections along this coastal stretch, irregularly punctuated by resource‐rich estuaries, and the crossings over open sea during the last leg to Australia/New Guinea, this expansion would necessarily have involved the features of watercraft, portage of potable water, and adaptation to estuaries. These features could well have been the cultural basis for the rapid tropical dispersal of Homo sapiens out of Africa to Australia/New Guinea.
Optimized Method To Obtain Stable Food-Safe Recombinant Wine Yeast Strains

Pure Saccharomyces cerevisiae cultures are commonly used to inoculate fresh musts. The added active dry yeasts dominate the fermentation and produce wine of more reproducible quality. This microbiological simplification of the vinification process opens the way for the genetic modification of active dry yeasts. Industrial yeast strains have been successfully transformed, selecting for G418 resistance. The use of this method for integrative transformation facilitates the construction of food-safe recombinant yeast strains with high efficiency. To demonstrate the potential of the method, the two URA3 alleles of the wine yeast T73 strain were disrupted in two consecutive steps, obtaining a stable recombinant strain that retains all of its useful wine-making properties. Keywords: Yeast; wine; genetic transformation; food-safe
Effects of growth path and post-slaughter chilling regime on carcass composition and meat quality of ewe lambs

Sixty-five Poll Dorset x (Border Leicester/Merino) ewe lambs. were grown at pasture on one of four growth paths commencing at mean age of 24 weeks and a mean liveweight of 37-5 kg. These were, continuous growth between 24 and 34 weeks (HH), maximum possible growth for 6 weeks followed by weight loss for 4 weeks (HL), no gain for 6 weeks followed by rapid gain for 4 weeks (LH) and weight maintenance (LL). Lambs were slaughtered as soon as possible after LH and HL lambs were the same full weight. There were significant differences between treatments in average growth rate, liveweight, hot carcass weight (HCW) and dressing percentage. After adjustment for HCW, LH had significantly (P < 0.05) less omental and kidney fat than HH, and there was a strong tendency for less subcutaneous fat, intermuscular fat and a lower tissue depth over the twelfth rib (at the GR site). Eye muscle area was significantly larger in LH than HH, but this did not translate to a significant difference in dissectible 'soft tissue' measurement. The Warner Bratzler shear value for LL in the M. longissimus dorsi was significantly higher than LH and HH. There were no differences between treatments for pH, Warner Bratzler shear values of the M. semimembranosus, cooking loss, or the colour measurements using a Minolta chromameter of L* (lightness) or b* (yellowness). The difference in a* (redness) between HL and LH was significant. Warner Bratzler shear values for M. longissimus dorsi and M.semimembranosus were significantly higher at 4¦C than 10¦C. The a* was significantly higher at 10¦C, but there were no differences between L* and b*. There were no interactions between the post-slaughter chilling regime and the pre-slaughter nutritional management. It was concluded that the growth path had little effect on meat quality unless the lamb had been continuously on a restricted diet. Therefore there was some potential for the use of growth paths to manipulate carcass composition, and further research into management systems at pasture is recommended.
Distinct functional stoichiometry of potassium channel β subunits

Shaker-type potassium channels play important roles in determining the electrical excitability of cells. The native channel complex is thought to be formed by four pore-forming α subunits that provide four interaction sites for auxiliary modulatory Kvβ subunits. Because Kvβ subunits possess diverse modulatory activities including either up-regulation or down-regulation of potassium currents, differential assembly of the α–β complex could give rise to diverse current properties. However, the detailed physical and functional stoichiometry of the α–β complex remains unknown. Kvβ1 subunits reduce potassium currents through inactivation, whereas Kvβ2 subunits enhance potassium currents by inhibiting the Kvβ1-mediated inactivation and at the same time by promoting the surface expression of certain potassium channels. In this report we show that Kvβ1 and Kvβ2 of the Shaker-type potassium channels display distinct functional stoichiometry to interact with the Kv1 α subunits, a subfamily of Shaker-type potassium channels. The interaction of Kvβ1 subunits with α subunits is consistent with the α4βn model, where n equals 0, 1, 2, 3, or 4, depending upon the relative concentration of α and β subunits. The α4βn stoichiometry allows for gradual changes of the Kvβ1-mediated inactivation. In contrast, Kvβ2 subunits self-associate to form oligomers and interact with the α subunits via α4β4 stoichiometry, which permits effective multivalent associations with α subunits. Such distinct functional stoichiometry of Kvβ1 and Kvβ2 provides a molecular mechanism that is well suited to their contrasting activities of up-regulation or down-regulation of potassium currents.
Cytological study of palisade development in the seed coat of Candle canola

The differentiation of the palisade layer in the developing seed of Brassica campestris L. cv. Candle canola was studied from pollination to maturity. The palisade was derived from the innermost cell layer of the outer integument and was sandwiched between several layers of crushed parenchyma. The secondary thickening of the radial and inner tangential walls of all palisade cells was initiated about 5 days after pollination and continued for about 20 days. Vesicles and similar-sized invaginations of the plasmalemma were present in the cytoplasm. An increased number of dictyosomes and endoplasmic reticulum associated with paracrystalline bodies were also observed. The palisade cytoplasm appeared normal in unfertilized ovules and seeds 5 days after pollination but degenerated as seeds neared maturity. Outer portions of the radial walls had no secondary thickening and collapsed to form characteristic folds when seen in radial section. Lamellations were visible in areas where secondary thickening was heavily .