Miracle-dz/UniFAR-FTUs huggingface dataset:
Nitrogen dynamics in perennial- and annual-dominated arid rangeland

Abstract It is often assumed that displacement of native perennial vegetation by exotic annuals will alter nutrient cycling. Nitrogen dynamics of native bunchgrass vegetation and adjacent stands of the exotic annual grass Bromus tectorum were compared on three sites in south-eastern Washington, U.S.A. The stands of B. tectorum had dominated the sites for at least 40 years. It should be emphasized that these sites were not prone to frequent wildfires as can be the case in some B. tectorum -dominated ecosystems. Over a 2-year period very few consistent differences were found between the two vegetation types in above-ground standing crop, root mass, in situ N mineralization, extractable soil N, or total soil C or N. Bromus tectorum above-ground plant mass and litter tended to have lower C/N ratios than did the native vegetation, but the results were not consistent over time or site. It appears that the exotic annual adapted to the resources on the site and, at least at the fairly gross level measured, had little impact on soil nitrogen. These results suggest that caution must be taken when assuming that a change in vegetation type and growth form will necessarily alter soil N levels.
Variance Effective Population Size under Mixed Self and Random Mating with Applications to Genetic Conservation of Species

When collecting and regenerating genetic resources, genetic drift affects the representation of a population and occurs at two stages: when sampling the parents and when gametes are sampled from these parents. The variance effective population size [Nₑ ₍ ᵥ ₎] quantifies genetic drift. In this study, a model for calculating Nₑ ₍ ᵥ ₎, that considers the two-stage sampling of mixed self and random mating species, is developed. For germplasm collection, as the rate of natural or artificial self-fertilization (s) increases, Nₑ ₍ ᵥ ₎ is reduced and becomes increasingly dependent on the number of seed parents (P) and is less influenced by the number of seeds sampled per parent (n/P). Female gametic control (GC) leads to higher Nₑ ₍ ᵥ ₎ than with random sampling of seeds (RS), but its effect is tangible only when n/P is small. For accession regeneration, maintaining accession integrity (the proportion of functional parents, u) at an adequately high level and adopting GC are required for assuring Nₑ ₍ ᵥ ₎ equal to or greater than the actual size of the accession (Nₑ ₍ ᵥ ₎ ≥ n). The importance of these two factors is enhanced as s increases. For arbitrary rates of selfing (0 ≤ s ≤ 1), under inbreeding equilibrium (IE) and with constant population size (n = N), Nₑ ₍ ᵥ ₎ can be adequately maintained through GC with a loss of ≤20% within accessions. For large sample size (n → ∞), an accession loss of ≤33% can be recovered. For maintaining adequate Nₑ ₍ ᵥ ₎, artificial selfing followed by GC is more efficient than accession regeneration by natural reproduction. For achieving appropriate Nₑ ₍ ᵥ ₎s, increasing the rate of self-fertilization in polymorphic materials makes collection more difficult but regeneration easier for minimal loss (≤20%) within accessions.
The Identity of Derocheilocaris Remanei Katesae (Mystacocarida) From South Africa

Derocheilocaris remanei katesae was described from Durban on the east coast of South Africa by Noodt (1954). He distinguished this subspecies on the basis of the shape of the anterior portion of the cephalon, the spines and seta of the anal operculum and the body shape. The work of Hessler ( 1972 ) on African mystacoca rids brought to light the extreme conservativeness of this subclass and the minute nature of differences sufficient to warrant species status. Forms from Angola and South West Africa, considered by Noodt to be D. remanei, were shown by Hessler to be distinct species and named D. angolensis and D. delamarei respectively. D. r. katesae thus became separated from the type D. remanei by at least two species and nearly 1000 km of coastline. A further species was then recorded from Algoa Bay on the south-eastern corner of Africa (McLachlan & Grindley, 1974) and named D. algoensis. At the time it was not certain whether D. r. katesae and D. algoensis were the same species or whether D. r. katesae was distinct and warranted species status. Noodt's (1954) description of D. r. katesae was not sufficiently detailed to decide this. Now as the result of a series of collections along the east coast of South Africa both north and south of Durban it is possible to clarify this. All specimens examined from these east coast collections are identical to D. algoensis. Three points of difference between Noodt's (1954) description and D. algoensis, namely (1) the antero-medial notch of antennulary portion of cephalon, (2) the constriction separating antennulary portion of cephalon from the rest of the cephalon and (3) the acute process on the supra anal process (anal operculum), were checked. In all cases these appeared as described for D. algoensis, namely (1) a U-shaped anteromedial notch in the cephalon, (2) the constriction in the cephalon had a distinct notch and (3) the supra anal process had two acute processes, a short stout vertral one and a slender, longer dorsal one. It must thus be concluded that D. r. katesae and D. algoensis are conspecific and the small differences in Noodt's description were due to distorted specimens. It is therefore suggested that D. r. katesae Noodt, 1954 be considered a senior synonym of D. algoensis McLachlan & Grindley, 1974. The recorded range of D. katesae is now extended from Algoa Bay up the east coast of South Africa to Sordwana Bay near the Mozambique border. REFERENCES
Light microscopic observation of nuclei and mitotic chromosomes of Botrytis species.

The mean number of nuclei in a conidium of B. allii (seven isolates), B. byssoidea (three isolates), and B. cinerea (five isolates) was 1.3-1.5, 5.0-5.1, and 4.0-5.1; respectively, whereas that of B. squamosa (one isolate) was 18.4. The chromosome number was found to be 16 in B. byssoidea, B. cinerea, B. squamosa, and B. tulipae. Seven isolates of B. allii were divided into two groups according to the chromosome number: three isolates had 32 chromosomes, whereas the other four had 16
Diversity and population dynamics of Penicillium spp. on apples in pre‐ and postharvest environments: consequences for decay development

Isolates of Penicillium spp. were collected regularly from 2001 to 2003 from the surfaces of apple fruit pre- and postharvest, and from the atmosphere of orchards and storage rooms in France. Penicillium spp. were not detected from the atmosphere of conventional orchards, while their density did not exceed 50 spores m−3 in the atmosphere of organically managed orchards. Penicillium spp. were seldom detected on apple surfaces in the orchard. The density of Penicillium on apples increased from 10 to 50 spores cm−2 after 1 month in storage to 300–400 spores cm−2 after 6 months. The level of airborne Penicillium increased by up to 2 × 104 and 2·5 × 103 spores m−3 within nondisinfected and previously disinfected warehouses, respectively. Penicillium expansum (30–62%) and P. solitum (6–45%) were the most prevalent species on apple or in storage rooms. Other species of Penicillium isolated included P. commune, P. verrucosum, P. chrysogenum, P. rugulosum and P. digitatum. Apple fruit were also surveyed for wounds and the number of open lenticels using the sulphur dioxide test. The incidence of wounding at harvest varied from 12 to 36%, depending on cultivar and locality. When apples were inoculated at harvest by either aqueous or aerial inoculum of P. expansum, the decay incidence was constantly higher than the incidence of wounding. The number of open lenticels per cm2 of apple surface varied from 0·5 on cv. Boskoop to 4·4 on cv. Golden Delicious. An average of 13 and 2·1% of lenticels, respectively, were infected when they were inoculated by P. expansum and P. verrucosum. Cultivars of apple fruit that showed a greater number of open lenticels, combined with a large diameter varying from 100 to 200 µm, were more susceptible to P. expansum.
Reassessment of the pits and antipits in soybean seeds

A soybean (Glycine max (L.) Merr. ) cotyledon has a concave region on its abaxial center called a pit, and the seed coat has a corresponding convex region on its inner surface called an antipit. While it is clear that the pit is lined with large epidermal cells, the anatomical identity of the antipit has been a subject of confusion. The inner surface of the seed coat consists of a compressed endosperm tissue that is subtended by an aleurone layer. In the antipit region of the seed coat, additional endosperm cells are situated between the aleurone layer and the compressed endosperm tissue. These endosperm cells, called cone cells, are similar to ordinary aleurone cells in basic structure. In the present study, it is demonstrated that the surface ornamentations of the antipit are a print of the pit on the compressed endosperm tissue. The functional aspects of the antipitpit complex are not known. It was previously postulated that the antipitpit region has an enhanced capability of nutrient translocation to.
Improved Puchtler's Congo Red Method for Demonstrating Amyloid

Abstract This paper describes a modification of Puchtler'sa lkaline Congo red method for demonstrating amyloid in human tissues. Special emphasis is given to the stability of the new staining solution, which has much greater stability than the one reported by Puchtler. This was accomplished by reducing the amount of sodium chloride and alcohol in the solution. The method is less time consuming than Puchtler's method because we found it unnecessary to pretreat tissue with alkaline sodium chloride in alcohol. Tissue sections are stained with a modified Weigert iron hematoxylin and placed into the alkaline Congo red solution for 20 min. They are then dehydrated rapidly in alcohol, cleared in xylene, and mounted with synthetic resin. Staining results obtained with this method are consistent and reliable. (The J Histotechnol 23:139, 2000)
Fotossíntese, condutância estomática e potencial hídrico foliar em árvores jovens de andiroba (Carapa guianensis)

Leaf water potential is one of the most important factors affecting stomatal functioning. The aim of this study was to assess the effect of variation in diurnal irradiance and vapour pressure deficit on photosynthesis (A), stomatal conductance (gs) and leaf water potential (Y) in Carapa guianensis (Aubl.). Data were collected from 07:00 to 17:00 h. Photosynthetic rates reached a maximum (2.5 µmol m-2 s-1) at 10:00 h, thereafter declined to a minimum of 1 µmol m-2 s-1 at 16:00 h. Stomatal conductance oscillated during the day, from 0.04 mol m-2 s-1 (at midday) to 0.02. mol.m-2.s-1 at the end of the afternoon. Leaf water potential was higher early in the morning (-0.3 MPa) and lower (-0.75 MPa) at mid-afternoon (14:30 -15:00 h). After reaching a minimum, Y increased up to -0.64 MPa at sunset. Photosynthetic rates increased linearly as a function of gs (P < 0.01). Also there was a positive relationship between Y and gs (P< 0.01). Photosynthetic rates declined during the day after reaching a peak early in the morning, which makes clear that environmental factors that influence Y greatly affect carbon assimilation of C. guianensis.
AMNIOTE PHYLOGENY AND THE IMPORTANCE OF FOSSILS

Abstract— Several prominent cladists have questioned the importance of fossils in phylogenctic inference, and it is becoming increasingly popular to simply fit extinct forms, if they are considered at all, to a cladogram of Recent taxa. Gardiner's (1982) and Løvtrup's (1985) study of amniote phylogeny exemplifies this differential treatment, and we focused on that group of organisms to test the proposition that fossils cannot overturn a theory of relationships based only on the Recent biota. Our parsimony analysis of amniote phylogeny, special knowledge contributed by fossils being scrupulously avoided, led to the following best fitting classification, which is similar to the novel hypothesis Gardiner published: (lepidosaurs (turtles (mammals (birds, crocodiles)))). However, adding fossils resulted in a markedly different most parsimonious cladogram of the extant taxa: (mammals (turtles (lepidosaurs (birds, crocodiles)))). That classification is like the traditional hypothesis, and it provides a better fit to the stratigraphic record. To isolate the extinct taxa responsible for the latter classification, the data were successively partitioned with each phylogenetic analysis, and we concluded that: (1) the ingroup, not the outgroup, fossils were important; (2) synapsid, not reptile, fossils were pivotal; (3) certain synapsid fossils, not the earliest or latest, were responsible. The critical nature of the synapsid fossils seemed to lie in the particular combination of primitive and derived character slates they exhibited. Classifying those fossils, along with mammals, as the sister group to the lineage consisting of birds and crocodiles resulted in a relatively poor fit to data; one involving a 2—4 fold increase in evolutionary reversals! Thus, the importance of the critical fossils, collectively or individually, seems to reside in their relative primitive‐ness, and the simplest explanation for their more conservative nature is that they have had less time to evolve. While fossils may be important in phylogenetic inference only under certain conditions, there is no compelling reason to prejudge their contribution. We urge systematists to evaluate fairly all of the available evidence.
How Many Kingdoms? Current Views of Biological Classification.

S CHEMES FOR CLASSIFICATION have always been of great importance in biology. They are vital as means of communication among biologists, but also are functional as tools for developing generalizations, making predictions, and guiding experimentation. Early biologists grouped all living organisms into two huge kingdoms: one for plants and one for animals. When microscopic organisms were discovered, taxonomists tried to make all of them "fit" into either the plant or animal categories. When this didn't seem to work, a third kingdom was invented for bacteria. Traditions developed over many decades, with taxonomic "lumpers" favoring a two-kingdom scheme and "splitters" espousing three kingdoms. During the last few decades, advances in cytological techniques and in general understanding of evolutionary biology have raised serious questions about the traditional twoor three-kingdom schemes. First proposed by Professor R.H. Whittaker in 1959, a five-kingdom classification scheme is rapidly being embraced by many pro fessional biologists (fig. 1). Whittaker suggested the following kingdoms: Monera, Protista, Animalia, Fungi, and Plantae. This approach seemed to be biological
Chromatin condensation and morphometry of the bovine sperm head after in vitro sperm selection and capacitation

Methods of sperm selection and concentration are used to improve efficiency in obtaining viable embryos from in vitro fertilization procedures. Eighteen semen samples were submitted for selection with Percoll gradient and swim-up methods, followed by in vitro sperm capacitation with heparin, to assess the effect of selection method on chromatin condensation and sperm head morphometry. Smears were made at each stage of the process and stained with toluidine blue (TB). Digital images were analysed using computer algorithms developed with Scilab environment. After selection with either the Percoll gradient method sperm had less condensed chromatin. The swim-up method selected for smaller, more symmetrical heads with less variation in size when compared to semen samples that underwent no selection or were selected with the Percoll gradient method. The sperm also exhibited less condensed chromatin and more uniform head shape after heparin-induced capacitation.
Potential impact of some abiotic parameters on a phytoplankton community in a confined bay of the Eastern Mediterranean Sea: Eastern Harbour of Alexandria, Egypt

The Eastern Harbour (E.H.) is sheltered from the sea by a breakwater with two main entrances through which exchange with the netitic Mediterranean water takes place. Some physico-chemical parameters of the study area showed that dissolved oxygen ranged from 6.57 to 11.4 mg l-1 at the open sea station and 5.08 to 11.71 mg l-1 for the E.H. stations. Higher nutrient concentrations were recorded in the E.H. than that at the open sea station, except for ammonia and nitrate. The phytoplankton flora of the E. H. stations was much richer in species than the adjacent open sea station, attaining 96 and 74 species, respectively. As well as the average phytoplankton density, it was higher in the surface water than near the bottom water layer. With regard to the total phytoplankton community, Bacillariophyceae dominated at all sites, whereas Dinophyceae, Chlorophyceae, Cyanophyceae and Euglenophyceae were rarely recorded. The highest average density of phytoplankton abundance was recorded during March, both at the surface. Correlation coefficient of biological factors with some physico-chemical parameters and a series of stepwise multiple regression equations describing the dependence of phytoplankton density on the changes of most abiotic prevailing conditions are provided and discussed.
Proportionality of Body to Scale Growth: Validation of Two Back-Calculation Models with Individually Tagged and Recaptured Smallmouth Bass and Walleyes

Abstract We compared the proportionality of scale to body growth and length estimates produced by the Fraser–Lee and Weisberg back-calculation models using individually tagged smallmouth bass Micropterus dolomieu and walleyes Stizostedion vitreum marked and recaptured in spring. Individual fish were tagged and later recaptured, providing multiple intervals of known growth to compare with back-calculated lengths (BCLs). There was no significant difference between total radii of scales collected when fish were younger and radii measured to the same annulus for scales collected from the same fish at final capture. Scale increment lengths remained constant and accrediting an annulus to the scale edge for fish caught in spring was valid. Known scale growth was not proportional to known body growth for smallmouth bass or walleyes; the body generally grew at a faster rate than the scales. Multiple regression analyses found that known scale growth described the most variance in known body growth, age was not alwa.
Soybean genetic resources and crop improvement

The soybean (Glycine max (L.) Merr. ) is an economically important leguminous crop for feed, oil, and soyfood products. It contains about 40% protein and 20% oil in the seed and, in the international trade markets, is ranked number one in oil production (48%) among the major oil seed crops. Despite its economic importance, the genetic base of soybean cultivars is extremely narrow. The indigenous cultivars and landraces in East Asia are on the verge of extinction, because farmers are now growing high yielding soybean cultivars. The exotic germplasm, enriched with genes for abiotic and biotic stresses, has not been fully exploited by soybean breeders. Mutation breeding has improved the fatty acids of the soybeans and has produced soybeans tolerant to herbicides. By using recombinant DNA technology, Monsanto has produced stable glyphosate tolerant soybean lines known as 'Round Up Ready' soybean. DuPont is producing transgenic soybean lines with improved fatty acids content. The feasibility of developing hybri.
Length Changes in Silver Hake (Merluccius bilinearis) Larvae: Effects of Formalin, Ethanol, and Freezing

Silver hake (Merluccius bilinearis) larvae preserved in either formalin or ethanol decreased in length over time, most shrinkage being achieved in the first 15 d. The magnitude and variability of the length reduction was greater for smaller larvae. Rate and magnitude of shrinkage for ethanol-preserved larvae exceeded those of formalin-preserved larvae. Frozen specimens were extremely variable in length change response, and we noted a transition from shrinkage to expansion with increasing larval length.
DNA-content variation in mouse spermatozoa arising from irregular meiotic segregation

Abstract We have examined the DNA content of spermatozoa from house mouse hybrids between ST 40 chromosome karyotype and Apennine populations with 22 chromosomes, as well as from hybrids between CD and CB strains both possessing 22 chromosomes, but characterized by dissimilar Robertsonian fusions. In the spermatozoa from 22 × ST 40 strains the variations in DNA content were found to fit the variability in gamete ploidy as estimated in spermatids by scoring second meiotic metaphase chromosomes. This demonstrates that during spermiohistogenesis aneuploid spermatids are not eliminated. The rare spermatozoa produced by CD×CB hybrids display a wide variability in their DNA content, with a low percentage of values referable to haploid cells.
The physicochemical approach to drug design and discovery (QSAR)

The study of physicochemical parameters to correlate mathematically chemical structure with biological activity induced by sets of congeneric drugs is now generally referred to as QSAR (quantitative structure‐activity relationships). The ways in which the QSAR paradigm are developing are becoming more varied and complex. Many kinds of parameters are under study in many different groups; various types of mathematical models have been proposed and are being evaluated. Drug researchers are turning more to enzyme modulation to control various biological processes. It is the study of enzyme‐ligand reactions of enzymes whose x‐ray crystallographic structure is known that affords us the means for developing a deeper understanding of QSAR and, at the same time, enhancing our ability to make drugs more selective for various forms of a given enzyme. The union of x‐ray crystallography, moleculargraphics, and QSAR is one of the most exciting new areas of drug development. This report is an introduction to how QSAR is being used to gain insight into the interaction of drugs with macromolecules and macromolecular systems.
A quantitative analysis of temperature-dependent dormancy changes in Polygonum aviculare seeds.

Mathematical models that predict emergence of weed seedbanks could be useful tools for determining the most suitable time for weed seedling control and, consequently, should result in a higher efficacy of applied control methods. To achieve this goal in dormant weed species, functional relationships should be established between environmental factors regulating dormancy and dormancy changes of seed populations. In the present work, we used a simple model and an optimisation procedure to quantify the effect of temperature on Polygonum aviculare seed dormancy release and induction, based on germination data. Dormancy release rate was inversely related to temperature, showing a decreasing logistic trend that results in no dormancy release for seeds exposed to 20 and 25 degrees C. In contrast, dormancy induction rates in absolute values were positively associated with temperature, showing a logistic trend in which dormancy induction was almost zero at low temperatures and maximal at 25 degrees C. Derived model parameters were used to simulate dormancy changes of P. aviculare seeds stored under controlled and field conditions. These results suggest that similar model structures could be used to quantify temperature effects on seed dormancy status of other weed species and to develop predictive models of weed emergence.