Miracle-dz/UniFAR-FTUs huggingface dataset:
Quantitative Determination of Oxytetracycline Uptake and Release by Juvenile Sockeye Salmon

Abstract A fluorometric procedure has been designed to quantify the uptake and release of submicrogram quantities of the antibiotic oxytetracycline (OTC) by young sockeye salmon Oncorhynchus nerka. Juveniles and smolts were homogenized in 5% trichloroacetic acid, the solute containing OTC was extracted with ethylacetate, and the OTC within the ethylacetate phase was shaken with calcium to form a fluorescent complex. Fluorescence intensity was linearly related to OTC concentration for both OTC standard solutions and samples extracted from fish. Efficiencies of OTC extraction averaged 36% for standard solutions and 32% for spiked biological material and were independent of OTC concentration for sample spikes ranging from 0.47 to 9.4 μg OTC; the minimum quantity that could be detected against background was 0.17 μg OTC. The method allowed OTC to be detected in 100% of test fish when they were 33 mm long (0.4 g) after 29 d feeding on treated food; usual standard methods allowed 100% detection only after 54 d .
Physiological and endocrinological mechanisms associated with ovulatory cycle and induced-moulting in the domestic chicken – a Review

The ovulatory cycle and moulting are associated with physiological and endocrinological mechanisms involving a complex interplay of light stimulus, hypothalamus, pituitary, gonads, thyroid and adrenal glands. During ovulation, the LH surge triggers the release of a mature follicle. With advance in the age of a laying hen, egg production decreases coinciding with decrease in ovarian steroids and gonadotropins. Moulting occurs when oestrogen, progesterone and luteinizing hormone are low while thyroid hormones and corticosterone are high. The physiological processes observed during induced moulting are common to those found in natural moulting. Moulting results in the rejuvenation of reproductive tissues of old laying hens, preparing them for another laying cycle. Vitellogenin provides the two proteins (lipovitellin and phosvitin) to the developing yolk, at the same time serving as their transport protein through the blood stream. Low levels of vitellogenin in the plasma of moulting hens are attributable to decrease in oestrogen during moulting since production of vitellogenin from the liver is stimulated by oestrogen.
Parameterization of the Phenological Development of Select Annual Weeds Under Noncropped Field Conditions

Abstract Barnyardgrass, common lambsquarters, redroot pigweed, and wild mustard are among the most common weeds in cropping systems throughout North America. Crop and weed competition models that predict phenological development across environments are useful research tools for advancing our knowledge of population dynamics or crop and weed competition. Phenological parameter estimates for such models require verification under field conditions. Field studies were conducted in 1999 and 2000 to determine growth and phenological development of these species under noncropped conditions to compare parameters developed previously from controlled environment studies. Weeds were planted on three separate planting dates in each year. Growth and phenological development were recorded. Number of leaves on the mainstem of all weed species, except common lambsquarters, was not affected by planting dates. Rate of leaf appearance described as a function of days after emergence ranged from 0.48 to 0.89, 0.10 to 0.31, 0.33 to 0.65, and 0.24 to 0.29 leaves d−1 for common lambsquarters, barnyardgrass, redroot pigweed, and wild mustard, respectively. When expressed as a function of growing degree days (GDD), rate of leaf appearance for these species ranged from 0.04 to 0.05, 0.01 to 0.02, 0.04 to 0.07, and 0.02 to 0.03 leaves GDD−1, respectively. Planting date had differential effects on the rate of stem elongation and final plant height of each species in the 2 yr. Final plant biomass was also influenced by the time of planting; in general, weeds planted by mid-May had more biomass than those planted later. Parameters developed to describe phenological development under field conditions were comparable to those reported previously from controlled environment studies. We conclude that phenological parameters quantified under controlled environmental studies were comparable to those developed under field conditions for these weed species. Thus, either experimental method can be used to parameterize weed phenological development to initialize crop and weed competition models with reasonable confidence. Nomenclature: Barnyardgrass, Echinochloa crus-galli (L.) Beauv. ECHCG; common lambsquarters, Chenopodium album L. CHEAL; redroot pigweed, Amaranthus retroflexus L. AMARE; wild mustard, Sinapis arvensis L. SINAR
Does social complexity lead to sex-biased dispersal in polygynous mammals? A test on ground-dwelling sciurids

Mating systems are well known to influence the dispersing sex, but the magnitude of the sex-biased dispersal has not actually been measured, whereas many theoretical predictions have been made. In this study, we tested a new prediction about the coevolution between natal dispersal and sociality from a recent evolutionarily stable strategy (ESS) approach. From a comparative approach, we showed that, in agreement with the model, the male-biased dispersal increases with increasing level of sociality in polygynous ground-dwelling sciurids. In addition, the increase in male-biased dispersal with increasing sociality results from an increase in male dispersal rates, whereas female dispersal rates remain constant, contrary to what is expected from the ESS model. Although the mating system through the level of polygyny could act as a confounding factor, our results strengthen previous work that states that inbreeding avoidance plays a major role in the evolution of dispersal for the most social mammalian species. Copyright 2004.
Tree Selection and Landscape Analysis of Eastern Red Bat Day Roosts

Abstract Declining bat populations and increasing demands on forest resources have prompted researchers to investigate tree roost selection of forest bats. Few studies, however, have investigated different spatial scales and landscape pattern as criteria for selection of tree roosts. In 1999 and 2000, we radiotracked 23 eastern red bats (Lasiurus borealis) to 64 day roosts. Using univariate and multivariate comparisons, we tested roost tree variables with random tree data at 3 circular spatial scales: roost tree, plot, and landscape. We found 15 variables that were entered in a stepwise discriminant analysis to best differentiate between the roost and random samples; 11 (73.3%) were landscape variables measured with a geographic information system. On average (𝑥̄ ± SE), red bats roosted in deciduous trees (42.0 ± 2.1 cm dbh) that were located in plots with more (3.1 ± 0.1 m2) basal area, higher (84.0 ± 1.3) percentage of canopy closure, and lower (27.2 ± 2.2) percentage of groundcover than random plots. At the landscape scale (by percent magnitude), red bat buffers (1,000-m-radius circle) had significantly less development (81.6%), less feeding operations (70.4%), more deciduous (52.9%) and pine forest (63.8%), and fewer local roads (5.4%) but more trails (94.1%), open water (61.4%), wetland areas (80.4%), and stream areas (63.1%) than random buffers. Red bat roost trees were significantly closer (χ2 = 22.0088, df = 1, P ≤ 0.001) to trails (106.2 ± 13.3 m) than to streams (279.4 ± 28.5 m). Our results suggest that red bats in our study area select roosts in mature riparian forests near trails, open water, and wetlands. The high percentage of landscape values in the discriminant analysis lends support to using landscape metrics as an investigative technique of resource selection. We recommend that managers consider landscape factors when protecting red bat day-roost habitat.
Exigência nutricional de lisina digestível para galinhas poedeiras de 54 a 70 semanas de idade

An experiment was performed to determine the dietary digestible lysine requirement of hens (Lohman LSL and Lohman Brown) from 54 to 70 weeks of age. Three hundred and sixty hens were randomly assigned to 5 × 2 factorial arrangement (Lys levels by hen strain), according to the dietary treatments withj six replicates (groups) of 6 birds. An experimental diet was formulated to contain deficient digestible lysine levels in order to be supplemented with lysine (L-Lys-HCL,78%) originating the five dietary treatments (0.555; 0.605; 0.655; 0.705 and 0.755% of digestible lysine). The parameters analyzed were egg production, egg weight, egg mass, feed intake, lysine intake, feed conversion, albumen weight, yolk weight and shell weight, Haugh unit, albumen index and yolk index, percentage of non-commercial eggs and body weight gain. There was linear effect of lysine levels to light laying hens on feed intake, lysine intake, yolk index, albumen weight, yolk weight and quadratic effect on egg production, egg weight, egg mass, feed conversion and shell weight. For brown-type laying hens, there was linear effect of lysine levels on lysine intake and egg weight and quadratic effect on egg production, egg mass, feed conversion and shell weight. The digestible lysine requirements were estimated through polynomial regression models. Estimates of digestible lysine requirements were calculated as 0.724 and 0.692% for light laying hens and brown-type laying hens, respectively, which corresponds to 784 and 748 mg/hen/day and 14.9 and 14.5 g of digestible lysine/g egg mass produced, in the period from 54 to 70 weeks of age.
In Vitro Development of Inflorescences from Switchgrass Nodal Segments

Immature inflorescences are an important explant source for initiating in vitro cultures in gramineous species. The objective of this study with switchgrass (Panicum virgatum L.) cv. Alamo was to produce axenic inflorescences from nodes cultured in vitro. The top nodal segments from tillers in the two to four node stage of greenhouse grown plants were surface sterilized, split longitudinally, and plated with the cut surface in contact with Murashige and Skoog (MS) medium containing 30 g L-' maltose. 6-Benzylaminopurine (BAP) was added in concentrations of 0.0, 5.0, 12.5, or 25.0 μM. After 2 to 5 wk culture, panicles were produced with fully developed spikelets and perfect terminal florets. Panicles produced on medium without BAP were between 5 and 9 cm long and the number of spikelets ranged between 50 and 200. Panicles produced on medium with 5.0 to 25.0 μM BAP had a shorter rachis (2-5 cm) and branches, but contained more spikelets (200-700). Young spikelets obtained after 20- to 30-d culture of nodes, were used as explants for regeneration experiments. Calli were initiated from spikelets plated on MS solid medium with 30 g L -1 maltose, 22.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 5.0 μM BAP. They were later transferred to MS medium without growth regulators, where thousands of regenerants developed through somatic embryogenesis and organogenesis. The procedure is highly efficient for producing multiple sterile explants from a single genotype for use in various in vitro culture experiments.
OBSERVATION OF SAND‐DWELLING TOXIC DINOFLAGELLATES (DINOPHYCEAE) FROM WIDELY DIFFERING SITES, INCLUDING TWO NEW SPECIES

Dinoflagellate associations, including toxic and potentially toxic benthic species, were examined in sand from South Water Cay and Carrie Bow Cay, Belize. The inshore sand habitat in localized areas of warm shallow lagoonal waters supported blooms of toxic assemblages of dinoflagellates. In the sand, the dominant microalgae were dinoflagellates; cyanobacteria were a minor component and diatoms were absent. Ciliates and nematodes were present. Assemblages of microorganisms in colored sand were examined for 4 consecutive days after which a storm washed away the patch. The sand‐dwelling dinoflagellate assemblage included 16 species where densities ranged from as low as 1.3% to 15% of total cell densities. The dominant species was Scrippsiella subsalsa, having 1.8 × 105 to 2.6 × 105 cells g‐1 sand. Toxic dinoflagellates identified in the sand were Gambierdiscus toxicus, Ostreopsis lenticularis, Prorocentrum lima, Prorocentrum mexicanum, and Amphidinium carteri. The potentially toxic Ostreopsis labens, Gambierdiscus belizeanussp. nov., and Coolia tropicalis sp. nov. were also identified. Toxic and potentially toxic species represented 36% to 60% of total microalgal cell assemblage.
Hereditary differences in social behaviour of male mice (Mus musculus L.)

Abstract Pairs of sibling male mice, laboratory reared offspring of feral parents, were studied in one enclosure consisting of two boxes connected by a long runway. Two different patterns of social structure and spatial dispersion were observed: some males were highly intolerant of each other and established individual territories; other pairs peacefully shared the territory and its defence from intruders. From the analysis of their progeny, the behavioural differences proved to have a hereditary basis.
İnek ve Düvelerde Ovsynch Öncesi Uygulanan Pgf2α ve Gnrh Enjeksiyonlarının Gebelik Oranlarına Etkisi

The objective of the study was to investigate the effect of PGF2α and GnRH injections applied before Ovsynch protocol (G6G) on pregnancy rates in cows and heifers. Totally, 196 Holstein cows in postpartum 50-100 days and 169 Holstein heifers were used. Animals in group 1 (Control: 40 cows, 40 heifers) were inseminated artificially in their standing heat without hormonal treatment. In group 2 (Ovsynch: 37 cows, 80 heifers), Ovsynch protocol (day 0, 10 μg buserelin acetate, intramuscular (IM); day 7, 500 μg cloprostenol, IM; day 9, 10 μg buserelin acetate, IM; 16 h later following last injection, artificial insemination) was applied. In group 3 (G6G: 119 cows, 49 heifers), 500 μg cloprostenol on day 0 and 10 μg buserelin acetate on day 2 were injected and Ovsynch protocol was performed 6 days later following last injection. Pregnancy rates in cows and heifers were detected 57.50-60.00%; 37.83-32.50% and 53.78-59.18% in 1st, 2nd and 3rd groups, respectively. The pregnancy rate in G6G protocol was significantly higher than those of Ovsynch protocol, in heifers (P<0.05). In conclusion, it is suggested that G6G protocol is an important approach in control of reproduction in heifers and lactating dairy cows instead of Ovsynch protocol which causes low pregnancy rates. Moreover, the present study provides evidence that G6G protocol has higher pregnancy rates in Holstein heifers.
Persistence and production of perennial grasses under water deficits and extreme temperatures: importance of intraspecific vs. interspecific variability

Extreme climatic events are expected to increase in frequency and magnitude as a consequence of global warming. Grasslands cover a large proportion of the European continent and contribute to both agricultural production and ecosystem services through inter and intraspecific genetic variability. This study analysed the effects of summer droughts and heat waves on the persistence and production of perennial forage grasses. Mediterranean and temperate populations of Dactylis glomerata L. and Festuca arundinacea (Schreb.) were compared at both Mediterranean and temperate sites in France. By manipulating canopy temperatures and water availability, grass swards in the field were subjected to cumulative summer and spring water deficits (CSSWD) ranging from 329 to 707 mm to test different projected climatic conditions and extreme summer events. Under controlled summer heat waves (6–21 days at a mean daily canopy temperature higher than 30–35 °C), there was no increase in membrane damage to surviving aerial tissues. Plant stress was thus mainly generated through greater soil water deficit. Under the greatest CSSWD, annual biomass production was reduced on average by 60% and 30% with temperate and Mediterranean populations, respectively. Thresholds for a significant increase in summer tiller mortality were seen at CSSWD higher than 450 mm for temperate populations and 550 mm for Mediterranean populations. The latter displayed lower predawn leaf water potentials in summer and recovered through intense tillering in the subsequent seasons. Under the most extreme CSSWD, fewer than 20% of tillers of temperate populations survived and their nitrogen uptake ability was drastically altered. The higher potential productivity of Mediterranean populations in winter was associated with greater frost sensitivity. The identification of thresholds for vulnerability and the determination of the role of genetic diversity will improve the management of plant resilience and the design of new plant material to cope with climate change.
Structure of the C-terminal sterile α-motif (SAM) domain of human p73α

p73 is a homologue of the tumour suppressor p53 and contains all three functional domains of p53. The α-splice variant of p73 (p73α) contains near its C-terminus an additional structural domain known as the sterile α-motif (SAM) that is probably responsible for regulating p53-like functions of p73. Here, the 2.54 A resolution crystal structure of this protein domain is reported. The crystal structure and the published solution structure have the same five-helix bundle fold that is characteristic of all SAM-domain structures, with an overall r.m.s.d. of 1.5 A for main-chain atoms. The hydrophobic core residues are well conserved, yet some large local differences are observed. The crystal structure reveals a dimeric organization, with the interface residues forming a mini four-helix bundle. However, analysis of solvation free energies and the surface area buried upon dimer formation indicated that this arrangement is more likely to be an effect of crystal packing rather than reflecting a physiological state. This is consistent with the solution structure being a monomer. The p73α SAM domain also contains several interesting structural features: a Cys-X-X-Cys motif, a 310-helix and a loop that have elevated B factors, and short tight inter-helical loops including two β-turns; these elements are probably important in the normal function of this domain.
Anomalous Diversity of Tropical Parasitoids: A General Phenomenon?

Turner, F. B. 1960. Population structure and dynamics of the western spotted frog, Rana pretiosa pretiosa in Yellowstone Park, Wyoming. Ecol. Monogr. 30:251-278. Twitty, V. C. , D. Grant, and 0. Anderson. 1964. Long distance homing in the newt Taricha rivularis. Proc. Natl. Acad. Sci. U.S.A. 50:51-58. Vial, J. L. 1968. The ecology of the tropical salamander, Bolitoglossa subpalmata in Costa Rica. Rev. Biol. Trop. 15:13-115. Vilter, V. , and A. Vilter. 1963. Mise en evidence d'un cycle reproducteur biennal chez le Triton alpestre de montagne. C. R. Soc. Biol. 157:464-469. Wharton, C. H. 1966. Reproduction and growth in the cottonmouth Agkistrodon piscivortis Lacepede, of Cedar Keys, Florida. Copeia 1966:149-161. Wilson, F. H. 1942. The cycle of egg and sperm production in Amphiuma tridactyla Cuvier. Anat. Rec. Sunnl. 84:532.
Produtividade e composição de uva e de vinho de videiras consorciadas com plantas de cobertura

The objective of this work was to evaluate the influence of green cover crops on vine productivity and on grape and wine composition. For two growing seasons, evaluations were done for three intercrops, two managements of the cover crops, and for a control treatment with weeds controlled by herbicides and mowing. A vineyard of 'Cabernet Sauvignon', located at 1,130 m altitude in a Haplumbrept soil, in Sao Joaquim, SC, Brazil was used. Intercropping was done with a succession of the cover crops moha (Setaria italica) with annual ryegrass (Lolium multiflorum), and buckwheat (Fagopyrum esculentum) with oat (Avena sativa), and with perennial fescue (Fetusca sp.). Cover crop managements consisted of transferring or not crop residues from the row to the between rows. Grape yield were higher in vines intercropped with the annual plants, in comparison to the control treatment or to fescue. The management of the cover crops did not affect the evaluated variables. Intercropping did not consistently influence N contents of grapes and wine composition; however, soluble solid contents of must were greater with intercropping treatments compared to control, in the last season. Moreover, vines intercropped with fescue can enable wine with greater content of anthocyanins and total polyphenols.
In-line recording of PAM fluorescence of phytoplankton cultures as a new tool for studying effects of fluctuating nutrient supply on photosynthesis

Turbidostat cultures of Dunaliella salina (Chlorophyceae) and Thalassiosira weissflogii (Bacillariophyceae) were grown at fluctuating concentrations of nitrate, phosphate and silicate. In-line measurements of PAM fluorescence were used to monitor the effects of fluctuating nutrient supply on the photochemical efficiency of photosystem II reaction centres of light-adapted cells (ΔF/F′m). Besides the maximal photochemical efficiency of photosystem II reaction centres of dark-adapted cells (F v/F m), chlorophyll a, particulate organic carbon, nitrogen and phosphorus, and the cell number were measured frequently during the experiments. Following nutrient-replete growth, the cells were supplied with medium from which either nitrate, phosphate or silicate was omitted. When significant effects of nutrient starvation were indicated by the fluorescence parameters, a pulse of the deficient nutrient was added to the cultures. Our experimental set-up for in-line fluorescence measurements provided sensitive and reproducible detection of the various fluorescence signals, revealing strong influences of nutrient supply on the photochemical efficiency of photosystem II. In general the fluorescence values changed substantially within 1–30 min after re-addition of the deficient nutrient. Addition of phosphate and silicate induced an immediate characteristic decrease in fluorescence, whereas nitrate addition was characterized by a strong, delayed increase in fluorescence. Complete recovery to pre-starvation fluorescence values took about 48 h in all experiments. The physiological background of nutrient uptake is used to explain the observed tight couplings between fluorescence responses and nutrient re-addition. Our study clearly demonstrates that in-line fluorescence measurements provide a new tool for the investigation of phytoplankton reactions to fluctuating nutrients and offer the possibility to detect nutrient starvation in the field.