Miracle-dz/UniFAR-FTUs huggingface dataset:
Summer Food Limitation Reduces Brook and Rainbow Trout Biomass in a Southern Appalachian Stream

Abstract We assessed salmonid production in summer in a second- and third-order montane stream in eastern Tennessee in 1987. We sampled three stream sections, one containing exclusively brook trout Salvelinus fontinalis, one containing exclusively rainbow trout Oncorhynchus mykiss, and a third with a mixture of both species. Population estimates for July and October 1987 revealed reductions in biomass over the 4-month period that ranged from 31 to 49%, whereas population densities declined by 32–46% during the same period. Total net production during the 4-month period was low and ranged from 0.38 to 0.45 g/m2. From June through September, the mean number of prey items per stomach ranged from 4.2 to 29.9, whereas the mean relative weight of stomach contents ranged from 0.12 to 1.34 mg dry weight per gram wet weight offish flesh. There was a strong positive correlation between the mean relative weight of stomach contents and the mean condition factor for a given date. Calculated energy intake was below the.
Fractal dimension of a coral reef at ecological scales

Conventional analytical techniques do not cope adequately with multiscale processes. Mandelbrot's concept of fractal dimension, a novel approach to multiscale phenomena, is applied to the problem of coral reef topography. A fractal dimension D = 1.9-2.0 for a contour on the reef slope is obtained. This contrasts strongly with the well established value of D = 1.2-1.3 for coastlines. We speculate that in common with the human lung, another living surface with a high D value, the coral reef slope is maximizing its contact with the surrounding medium.
Homo in the middle pleistocene: Hypodigms, variation, and species recognition

It is generally accepted that modern humans evolved in Africa. This consensus has emerged in the last two decades, as molecular evidence has been coupled with findings from paleontology and prehistory. Patterns of DNA variation in living populations, morphology of fossils, and archeological traces can all be read to show that our species has deep roots in Africa and began to disperse into other regions only late in the Pleistocene. There are still questions about the timing of these dispersals and the extent to which modern people replaced or exchanged genes with other, more archaic groups, but new problems are now coming more clearly into focus. These relate to the ancestry of Homo sapiens in the Middle Pleistocene. In this essay, I emphasize the evidence available from Middle Pleistocene localities in Africa and Europe, exploring variation among individuals, composition of hypodigms, species‐level taxonomy, and evolutionary relationships of the hominin populations. One obvious difficulty is that the fossils are scarce. For the most part, only incomplete crania are available from African localities. The record is more comprehensive for the Sima de los Huesos in Spain, but principally crania and jaws are known from other European sites. This means that skull traits and measurements must provide the basis for sorting individuals to groups and building differential diagnoses. For much of the material, dating is still poorly controlled, although a few of the most important assemblages can now be placed more securely within a Middle Pleistocene chronological framework. Despite these constraints, it is possible to point toward tentative solutions.
REMOVAL OF LISTERIA SPP. IN A CHEESE FACTORY

A total of 311 samples of 10 mL for liquids and 400-cm2 for surfaces were analyzed in a cheese plant in Galicia (Spain) within a period of 10 months (Feb.-Nov. 1996). Forty-six samples were positive for Listeria spp. , 36 of which corresponded to L. innocua, 8 to L. monocytogenes and 2 to L. welshimeri. Twenty percent of raw milk samples were Listeria-positive. Listeria was initially detected on some surfaces of production and ripening rooms, but was never detected after replacing old iron machinery with stainless steel machinery, avoiding the movement of the plant equipment outside the factory building, eliminating wooden boards in the ripening chambers and modifying the disinfection system. ; Accepted for Publication May 23, 1997
IMMUNE RESPONSES IN VITRO

The mixed leukocyte reaction stimulatory M-locus product of DBA/2 spleen cells was absent from thymus cells. The absence of stimulation was not a result of suppressor T cells. These findings are discussed in relation to the divergent specificity found for the inductive and effector phases of cell-mediated responses.
Spatial and Temporal Induction of Cell Death, Defense Genes, and Accumulation of Salicylic Acid in Tobacco Leaves Reacting Hypersensitively to a Fungal Glycoprotein Elicitor

We have analyzed the spatial and temporal expression of defense responses induced in attached tobacco leaves treated with a Phytophthora megasperma glycoprotein that was previously shown to be an efficient elicitor of the hypersensitive reaction. The infiltrated tissue (zone 1), the surrounding tissue (zone 2), which is 5 mm in width, and tissue at a distance >2 cm from zone 2 (zone 3) were analyzed separately. Cell death occurred only in zone 1 and was completed by 14 h. Defense gene expression was induced in zones 1 and 2 with striking differential patterns, but not in zone 3. There was a rapid (1 to 4 h) induction of genes of the phenylpropanoid, salicylic acid, and ses-quiterpenoid pathways in zones 1 and 2. However, it was strong and transient in the former and of lesser extent but sustained in the latter. High amounts of scopoletin, a phenylpropanoid metabolite, were found synthesized in zone 2. Pathogenesis-related (PR) transcripts and the corresponding PR proteins accumulated in high amounts in zo.
Bacterial stem and peduncle canker of greenhouse pepper

Disease losses to Erwinia carotovora subsp. carotovora were 12 and 20% in 1996 and 1998, respectively, in greenhouse peppers (Capsicum annuum) at St. David's, Ontario. The disease was also observed on field peppers near Harrow in 1996–1997. Symptoms consisted of dark brown to black cankers on the stem nodes and fruit peduncles, dark discolouration of the internal stem tissue, and internal breakdown of the pith with stem hollowness in some cases. Extensive physiological and biochemical tests were conducted on all isolates recovered to verify identity. Reactions of greenhouse and field strains were generally similar with a few exceptions. Spraying, spraying + wounding or rubbing, and stem inoculation were conducted with selected isolates. 'Early California Wonder' pepper plants that were wounded and then sprayed with a bacterial suspension consistently showed extensive collapse of stems and death of plants 4 days later regardless of isolate used. 'Trust' tomato plants (Lycopersicon esculentum) showed a similar response or, in some cases, developed an internal brown stem discolouration and hollowness. Spraying or spraying + rubbing of leaves with isolates also caused extensive disease development but fewer plants were affected. Greenhouse and field isolates caused similar symptoms on both tomatoes and peppers. This is the first report of bacterial stem canker on greenhouse peppers in Canada.
Comparison of Alewife Young-of-the-Year and Adult Respiration and Swimming Speed Bioenergetics Model Parameters: Implications of Extrapolation

Abstract Parameters derived from laboratory experiments that separately measured the routine metabolic rates (respiration) and swimming speeds of young-of-the-year (age-0) alewives Alosa pseudoharengus were compared with values published for a bioenergetics model for adults. Respiration rates of age-0 alewives were significantly influenced by water temperature and scaled isometrically with weight (range, 0.0001–1 g). Swimming speed was strongly related to fish weight and, unlike for adult alewives, water temperature significantly influenced the swimming speeds of age-0 fish. Temperature coefficients, along with the slopes for the weight dependence of age-0 alewife respiration rates and swimming speeds, significantly differed by 51–709% from published parameters for adults. Using adult parameters, the standard respiration rates at 15–25°C of age-0 alewives weighing less than 0.02 g were overestimated by 7–88% and the swimming speeds for fish weighing less than 1.0 g were overestimated by 130–4,270%. Applic.
Microhabitat Selection in Diet and Trophic Ecology of a Spiny‐Tailed Iguana Ctenosaura hemilopha

Annual variation in the diet of adult spiny‐tailed iguanas was studied by analyzing feces collected at 38 known iguana refuges in the desert of the southern Baja California peninsula. Iguanas consumed mostly plants, a small percentage of arthropods, their own skin, and remains from conspecifics. They consumed at least 22 of 83 plant species known to be present in the area. Leaves of three perennial Leguminosae species formed the year‐round basis of their diet. Iguanas ate flowers and fruit when available. We propose that iguanas could be efficient seed dispersers for Cactaceae, but that they crush many of the seeds of leafy tree species. No significant differences in food consumption pattern were found between dry and rainy seasons. Iguanas apparently moved to neighboring trees only when searching for food. We propose that predation risk could have more influence than the nutritional value of plants on the species' foraging behavior and microhabitat selection in this area.
Brain Size and Its Relation to the Rate of Metabolism in Mammals

In mammals, brain size corrected for the influence of body mass appears to be independent of the basal rate of metabolism corrected for the influence of body mass. Brain size depends on the habits of a mammal: it is larger in arboreal species and in species that feed on vertebrates, seeds, or fruit, and it is smaller in terrestrial species that feed on grass or the leaves of woody plants. Some factors that are associated with a relatively high rate of metabolism, such as a small mass, a large surface-to-volume ratio, and life in a cold environment, have no direct effect on brain size. Caution should be used when using a similarity of scaling in two organic characters as sole evidence of their functional interrelatedness.
Diversity, Floristic Richness, and Species Evenness During a Secondary (Post‐Fire) Succession

Diversity, species richness, and species evenness were analyzed in II boreal forest areas that had been burned from 0 to 44 years previously. The values of the information measure of diversity, H'. and Hurlbert's probability of interspecific encounter. Delta_1, obtained here are highly correlated. Both show a long—term declining successional trend, but exhibit relatively high values for the period 4 to 11 years after burning. Fluctuations in both appear to be attributable to variations in richness rather than evenness, supporting Pielou and Hurlbert's contentions that the two components of diversity should be analyzed separately. Delta_1 is preferred to H' because, if used in conjunction with a knowledge of spatial heterogeneity, it can provide information about the levels of competition in a community. The results indicate a slight increase in the amount of intraspecific competition during the course of succession, contrary to what might be expected as the outcome of evolution. It is argued that the species present are adapted to the occurrence of frequent catastrophes, particularly fires, so that prevailing evolutionary pressures and their outcome differ from those in more stable environments.
Methods for Identifying a Default Cross-Species Scaling Factor

ABSTRACT The need to identify “toxicologically equivalent” doses across different species is a major issue in toxicology and risk assessment. In this article, we describe an approach for establishing default cross-species extrapolation factors used to scale oral doses across species for non-carcinogenic endpoints. This work represents part of an on-going effort to harmonize the way animal data are evaluated for carcinogenic and non-carcinogenic endpoints. In addition to considering default scaling factors, we also discuss how chemical-specific data (e.g., metabolic or mechanistic data) can be incorporated into the dose extrapolation process. After first examining the required properties of a default scaling methodology, we consider scaling approaches based on empirical relationships observed for particular classes of compounds and also more theoretical approaches based on general physiological principles (i.e, allometry). The available data suggest that the empirical and allometric approaches each provide support for the idea that toxicological risks are approximately equal when daily oral doses are proportional to body weight raised to the 3/4-power. We also discuss specific challenges for dose scaling related to different routes of exposure, acute versus chronic toxicity, and extrapolations related to particular life stages (e.g., childhood).
Nutritional research to meet future challenges

Nutrition is a mature science with well established principles for energy, protein and mineral metabolism based on known metabolic pathways. The quantitative requirements are summarised within various international feeding standards and models. However, when these are applied to specific circumstances, especially in northern Australia, the response of the animal to nutrient supply does not always agree with that predicted from the feeding standards or the error of prediction is not sufficiently accurate for practical use. There is a need for the continual testing of these relationships within production systems. Molecular methods have the potential to discover new metabolic relationships within tissues and characterise the microbial ecology and its relationship to rumen function. Suitable problem models based on growth, meat quality, reproduction, milk and fibre production, and environmental consequences need to be identified. We suggest that production systems designed to meet market weight for age specifications, growth paths and compensatory growth, skeletal growth, parasites, fatty acid isomers, adaptation to low crude protein diets, rumen microbial ecology, epigenetics, remote data acquisition and animal management, greenhouse gas emission, and C balance of various production systems are important problem models, the research of which will benefit the future of the livestock industries in Australia.
The diet of strap‐toothed whales (Mesoplodon layardii)

The food habits of strap-toothed whales (Mesoplodon layardii) were examined in detail using stomach contents from 14 stranded whales found on South African and New Zealand coasts. Although a few unidentified fish otoliths and crustacean remains were found in two of these stomachs, 24 species of oceanic squids (some of which occur at a great depth) accounted for 94.8% of counted prey items (n= 232). Histioteuthis sp. and Taonius pavo were the predominant prey species (25.0 and 17.2% by number, 21.4 and 19.9% by mass, respectively). The presence of sub-Antarctic squid species suggested a northward migration to South African waters in late summer/autumn. Prey sizes were compared between males with fully grown strap-teeth and females/immature males without erupted teeth, using dorsal mantle lengths (DML) and weights of squids estimated from beak measurements. Although females/immature males ate longer squids than males, there was no significant difference in the estimated weights of squids eaten by the two groups. The presence of fully-erupted teeth in adult males, therefore, did not seem to influence the size of prey ingested, even though an adult male could only open its jaws about half as wide as a female. In general, the sizes of cephalopods eaten by strap-toothed whales were not significantly different from those eaten by smaller odontocetes, such as spotted dolphins and dwarf sperm whales, but were significantly smaller than those eaten by larger odontocetes, such as false killer, long-finned pilot, Cuvier's beaked, and southern bottlenose whales.
Using Team-Based Learning to Teach Grade 7 Biology: Student satisfaction and improved performance

Team-based learning (TBL) is an innovative form of collaborative learning. The purpose of this study was to evaluate TBL’s effect on the performance and satisfaction of grade 7 students in biology in a private school in Lebanon, as well as teachers’ willingness to implement this new methodology. An exploratory study was performed whereby two biology units were taught to two groups of students using either TBL (60 students) or traditional lecture-based instruction (30 students). Later, a summative test was administered to evaluate students’ performance. Students’ attitudes were evaluated using a questionnaire and teachers’ classroom observations. Finally, science teachers’ willingness to try TBL in their classes was assessed using a questionnaire (14 teachers). Results showed that underachievers taught according to TBL did better than underachievers taught with the lecture-based approach. The majority of students enjoyed TBL and found it useful and fun. Finally, science teachers agreed that TBL is a good alternative to the traditional lecture-based method.
Paleobotany and the Evolution of Plants

and that evolution of and how and The represent a broad paleoenvironmental of and visits to rich geological Eras and events discussed include, not limited the much varied Quaternary environments, the evolution of plants and animals during the Cenozoic, the rise of angiosperms, vertebrate evolution and ecosystems in the Mesozoic, the Permian mass extinction, the late Paleozoic glaciation, and the origin of the first trees and land plants in the Devonian-Ordovician. With state-of-the art expert scientific instruction on these topics and up-to-date and scientifically accurate illustrations, this book can serve as an international course for students, teachers, and other interested individuals.
Effect of Vegetation Matrix on Animal Dispersal: Genetic Evidence from a Study of Endangered Skinks

Abstract: Maintaining connectivity in fragmented landscapes is a key principle of biological conservation. Although corridors are a widely accepted approach to connecting populations, their merits are still debated, and they may be impractical in many situations. A focus on management of the vegetation matrix between populations has been advocated as an alternative way to deal with habitat fragmentation and has theoretical support. We combined microsatellite DNA and demographic data to provide an empirical account of how two forms of agricultural land use affect the connectivity of insular populations of an endangered skink in southern New Zealand. The grand skink (Oligosoma grande) lives in small populations (approximately 20 individuals) on rock outcrops separated from one another by 50–150 m of inhospitable matrix vegetation (either native tussock grassland or exotic pasture). Skinks typically dispersed short distances, and the nature of the matrix both quantitatively and qualitatively affected dispersal dynamics. Skink populations in pasture were significantly more genetically structured and had less genetic variation than similar populations in tussock, implying less dispersal between populations in pasture than tussock. Furthermore, although female‐biased dispersal was a feature of populations in tussock, no sex bias was evident in pasture. In addition, Bayesian individual‐based genetic assignment tests that incorporated prior mark‐recapture information revealed that some populations produced many emigrants but received few immigrants, whereas other populations were relatively insular. Patterns of dispersal and response to matrix vegetation were complex, and the causes of these patterns deserve attention in future studies of habitat fragmentation. Managing the vegetation matrix may be a practical way to connect animal populations in some situations.
The vegetative body of Metasequoia milleri from the Middle Eocene of southern British Columbia

Anatomically preserved vegetative remains of Metasequoia milleri Rothwell and Basinger are common in the Princeton chert of the Allenby Formation in southern British Columbia. Deposition of the Allenby Formation and associated volcanics occurred during Middle Eocene time. The Princeton chert locality is in the upper strata of the Allenby Formation and is of late Middle Eocene age. The Princeton chert was formed by siliceous permineralization of marsh soil. Dissolved silicates were probably introduced by periodic influx of water from mineral springs or geysers.Anatomical features of stems, wood, and leaves are well preserved. Mature wood of the fossil resembles that of Metasequoia glyptostroboides in having traumatic resin cysts; opposite pitting on radial walls of tracheids; taxodioid cross-field pitting; tall, uniseriate rays; smooth-walled ray parenchyma; and diffuse, resinous, smooth-walled wood parenchyma. Leaves are linear, hypostomatic, and borne decussately, and have one or three resin ducts and sl.
Destruction without extinction: long‐term impacts of an invasive tree species on Galápagos highland vegetation

1. A common belief in invasion ecology is that invasive species are a major threat to biodiversity, but there is little evidence yet that competition from an exotic plant species has led to the extinction of any native plant species at the landscape scale. However, effects of invasive species at community and ecosystem levels can severely compromise conservation goals.
Highly polymorphic genetic markers in meadow voles microtus pennsylvanicus revealed by a murine major histocompatibility complex mhc probe

We performed cross-species hybridization at the major histocompatibility complex (MHC) to evaluate the ability of murine probes to reveal polymorphism in wild meadow vole populations. Genomic hybridization of a mouse MHC class II I-Aα cDNA revealed extensive restriction fragment length polymorphisms when meadow vole genomic DNA was cleaved with BamHI EcoRI, HindIII, or HincII. The polymorphisms were interpreted by analyzing 10 half-sib families, comprising 6 sires, 10 dams, and 34 offspring. At least 26 different alleles were found with HincII in the family material, and the estimated heterozygosity at those sites is 96%. Several other alleles were found in a population sample. The high degree of genetic variation revealed by this system indicates that it is a viable alternative to multilocus "genetic fingerprinting" probes for the analysis of small mammal pedigrees or strains. Several mouse MHC probes are readily available and they provide a quick route to screening populations and remove the need to ext.
Responses of wild type and abscisic acid mutants ofArabidopsis thaliana to cadmium

Summary Heavy metal-induced inhibitory effects are reported to be concomitant with an increase in endogenous abscisic acid (ABA) levels in plant tissues indicating the possibility of this phytohormone mediating a part of the metal-imposed phytotoxicity. We examined this possibility by comparing the seed germination and seedling growth responses of ABA-deficient (aba-1, aba-3 and aba-4) and ABA-insensitive (abi2-1 and abi3-1) mutants of Arabidopsis thaliana to Cd with those of the wild type (Landsberg erecta, Ler). Assuming that Cd imposed a part of its toxic influence via affecting a rise in endogenous ABA level, all ABA mutants studied could be predicted to exhibit reduced responsiveness to Cd exposure in comparison to the wild type. However, the data obtained both in germination and growth assays were not consistent with this prediction. In germination assays, all ABA mutants proved consistently more sensitive than the wild type to Cd. In case of growth (root length and seedling fresh weight), the magnitude of Cd-induced inhibition in ABA mutants (aba-1, abi2-1 and abi3-1) was generally comparable to that in the wild type. Based on these observations a direct mediatory role of ABA in Cd-imposed phytotoxic effects on early growth could be excluded. The possible significance of heavy metal-dependent increase in endogenous ABA levels in plant tissues is discussed.