Miracle-dz/UniFAR-FTUs huggingface dataset:
Sulphur stable isotopes can distinguish trophic dependence on sediments and plankton in boreal lakes

Summary 1. Stable isotopes of carbon are useful for differentiating between freshwater food chains based on planktonic algae or benthic algae, but are reported to be of limited use for identifying food chains based on sedimentary detritus. Because data from marine systems suggest that stable isotopes of sulphur (δ34S values) have potential in this regard, we tested their utility in freshwater lakes. 2. We found that sulphate in the water column of four boreal lakes was enriched in 34S compared to the sulphur in bulk sediments from these lakes. Furthermore, within a given lake, insects known to feed on sediment (directly or via predation) had δ34S values similar to those of sediment, whereas planktonic and benthic invertebrates known to feed on suspended particles had δ34S values similar to those of sulphate in the water column. 3. Using the stable S isotope values of invertebrates that obtain their S from either the sediment or the water column as end members in a two-source mixing model, we show that two fish species obtain their food from both planktonic and sedimentary sources. Furthermore, model results suggest that, as expected, the more benthic-feeding fish species obtains more of its S from the sediment compartment than does the species that feeds in the water-column. 4. Our results suggest that measurements of stable sulphur isotopes provide a means of distinguishing between members of food chains that are based in the water column from those based on sedimentary detritus. As such, they would be a useful complement to stable C isotopes that are used to distinguish between food chains based on planktonic or benthic algae.
EFFECT OF SOIL MOISTURE AND SIMULATED RAINFALL ON PUPAL SURVIVAL AND MOTH EMERGENCE OF HELICOVERPA PUNCTIGERA (WALLENGREN) AND H. ARMIGERA (HÜBNER) (LEPIDOPTERA: NOCTUIDAE)

Prepupae of Helicoverpa punctigera (Wallengren) and H. armigera (Hübner) were allowed to pupate in a black cracking‐clay soil at different moisture levels. No differences in pupal survival and moth emergence were recorded where soil moisture ranged from dry to very wet when prepupae tunnelled into the soil. In a second experiment, simulated rainfall after pupation, but before moth emergence, reduced survival by disrupting emergence tunnels and trapping moths in their tunnels. This effect was greater where prepupae had tunnelled into dry soil than where they had tunnelled into wet soil.
Drumming signals of Danish Plecoptera

Abstract The drumming signals of 4 species of Plecoptera collected in Denmark are reported. Danish Capnia bifrons drum about 15 times longer and more slowly than specimens from the Taunus Mountains, central Germany (d= 1.4 sec, as compared to 0.09 sec; f=6 and 80 knocks/sec, respectively). The drumming signals of Danish Isoperla grammatica differ only in duration (d = 0.5 sec.) from signals of German specimens (d = 1.0 sec). Drumming of Amphinemura sulcicollis was analyzed for the first time. Its signal is divided into two compounds lasting 0.1 and 0.4 sec, respectively. Frequency decreases from 49 to 31 knocks/sec. At 20°C, Taeniopteryx nebulosa drums for 1.6 sec, with a frequency of 5.5 knocks/sec. However, their drumming pattern varies largely with temperature.
Assimilation of trace elements ingested by the mussel Mytilus edulis: Effects of algal food abundance

Pulse-chase feeding and multi-labeled radiotracer techniques were employed to measure the assimilation of 6 trace elements ( l l O m ~ g , 2 4 1 ~ m , '09Cd, 5 7 ~ o , '$Se and " ~ n ) from ingested diatoms in the mussel Mytilus edu l~s feeding at different rates (0.1, 0.49 and 1.5 mg dry wt h-'). Uniformly radiolabeled diatoms Thalassiosira pseudonana were fed to mussels for 0.5 h, and the behavior of the radiotracers in individual mussels was followed for 96 h in a depuration seawater system. Assimilation efficiency (AE) of each element declined with increasing ingestion rate and increased with gut passage time. The importance of extracellular digestion relative to intracellular digestion increased with ingestion activity, which, when coupled with a decline in AE, suggested that extracellular digestion is less efficient in metal absorption. Zn assimilation was most affected by ingestion rate, suggesting that AE may play a role in the physiological regulation of this metal in M. edulis. In an experiment to simulate the effects of an acidic gut, lowered pH (5.5) enhanced the release of elements from intact diatom cells, especially at low particle concentration. These results indicate that both feeding components of the mussel (i.e. gut passage time, digestive partitioning) and metal chemistry (i.e. metal release at lowered pH within the bivalve gut) are responsible for the difference in the assimilation of trace metals at different food quantities observed in mussels.
Hygromycin A and Methoxyhygromycin, Novel Inhibitors of K88 Antigen Synthesis of Enterotoxic Escherichia coli Strain

During the screening for inhibitors of K88 antigen synthesis that suppress hemagglutination by E. coli E68 NIH 457-71, we found Streptomyces sp. No. 207 produced two active substances, one of which was identified as hygromycin A. Another new compound, named methoxyhygromycin, was very similar to hygromycin A but methoxyhygromycin had a methoxy group on the neoinosamine-2 moiety instead of the methylene dioxy group found in hygromycin A. Although hygromycin A and methoxyhygromycin had almost no effect on the growth of E. coli E68 NIH 457-71, they inactivated the hemagglutination activity of E. coli at low concentrations of 12.5 μg/ml and 25 μg/ml, respectively.
A review of harvest theory and applications of optimal control theory in fisheries management

Optimal control theory is a useful tool for analysis of general mathematical models of fisheries and harvest strategies. It provides a framework for management decisions, but is too general for direct application to many specific management problems. A review of applications of optimal control theory to fisheries management is presented, with a general audience in mind. Advantages and shortcomings of optimal control theory in the context of fisheries management are discussed with some specific examples.
Factors Associated with Arrival Densities of Grasshopper Sparrow (Ammodramus savannarum) and Baird's Sparrow (A. Bairdii) in the Upper Great Plains

ABSTRACT. Although critical to habitat and population management, the proximate cues that birds use to establish territories are largely unknown. Understanding these cues is important for birds, such as many grassland birds, that exhibit high annual variability in population density and make new habitat-selection decisions annually. Identifying the actual cues used is difficult in the field, but the factors associated with the arrival densities of birds can help uncover variables that are involved in or correlated with cues used for selection. During the summers of 2002–2004, we investigated how weather and local vegetation factors were related to arrival densities of Grasshopper Sparrows (Ammodramus savannarum) and Baird's Sparrows (A. bairdii) at three locations across North Dakota and Saskatchewan. Spring densities of Grasshopper Sparrows were positively correlated with concurrent May precipitation, whereas densities of Baird's Sparrows were negatively correlated with the previous winter's snowfall. We used a model-selection approach to evaluate the vegetation characteristics associated with arrival densities of birds. Grasshopper Sparrow densities showed a strong negative relationship to woody cover, and Baird's Sparrow densities showed a negative relationship to vegetation height and vegetation density near the ground. Our results provide a first detailed look at habitat and weather associations immediately after arrival in spring and an important first step in uncovering factors that may be involved in habitat selection in two grassland species.
Foraging Location and Site Fidelity of the Double-crested Cormorant on Oneida Lake, New York

Abstract We studied the foraging behavior of the Double-crested Cormorant (Phalacrocorax auritus) on Oneida Lake, New York, by monitoring the activities of 27 radio-tagged birds in July and August of 1999 and 2000. A total of 224 locations were obtained of cormorants actively diving, and presumed foraging, at the time of detection. A geographic information system was used to examine foraging distances from the nesting island, the water depth and type of substrate at preferred foraging sites, and to estimate kernel home ranges for analysis of individual foraging site fidelity. An explanatory model was developed to determine parameters affecting the distance to cormorant foraging sites. The mean distance to foraging locations of tagged cormorants from the colony site was 2,920 m (SE ± 180 m, max = 14,190 m), and 52% of the locations were within 2,000 m of the nesting island. No cormorant was observed making daily foraging trips to outside water bodies. Mean foraging distance was greater during morning than in the afternoon, and there was a significant effect of the time of day on distance. There was no significant effect of sex date, a seasonal measure on distance to foraging location. Individual cormorants exhibited fidelity to specific foraging sites. Most cormorants foraged in close proximity to the nesting island much of the time, while those detected further from the island tended to return repeatedly to the same locations. Ninety percent of the foraging locations were in water depths ≤7.5 m, and most were in water 2.5-5 m deep. Compositional analysis of habitat use revealed a preference for these depths, along with substrates of cobble with rubble, and silt with clay.
Genetic variation in the endemic plant Cycas debaoensis on the basis of ISSR analysis

Cycas debaoensis Y.C. Zhong et C.J.Chen is a rare and endangered cycad species that is endemic to South China. It has divided pinnae. Genetic variation in the species was investigated by using an intersimple sequence repeat (ISSR) marker. The species exhibits a moderate level of genetic diversity (at population level P = 34.7%, H = 0.141, I = 0.204; at species level P = 57.4%, H = 0.215, I = 0.315) and a high level of genetic differentiation among populations (Gst = 0.342). Thus, the indirect estimate of gene flow on the basis of Gst was low (Nm = 0.481). The narrow colonisation area and island pattern of distribution, combined with limited gene flow among populations and genetic drift, may play an important role in shaping the genetic structure of C. debaoensis. On the basis of these findings, strategies are suggested for the conservation and management of the species.
Effects of lipid extraction on stable carbon and nitrogen isotope analyses of fish tissues: potential consequences for food web studies

– We examined whether solvent-based lipid extractions, commonly used for stable isotope analysis (SIA) of biota, alters δ15N or δ13C values of fish muscle tissue or whole juvenile fish. Lipid extraction from muscle tissue led to only small (<1‰) isotope shifts in δ13C and δ15N values. By contrast, ecologically significant shifts (+3.4‰ for δ13C and +2.8‰ for δ15N) were observed for whole juvenile fish. Sample variance was not affected by lipid extraction. For tissue-specific SIA, two sample aliquots may be required: a lipid-extracted aliquot for stable carbon isotope analysis when differing lipid content among tissues is a concern, and a nonextracted aliquot for δ15N determination. Whole organism SIA is not recommended because of the mix of tissues having different turnover times; for very small fish, we recommend that fish be eviscerated, decapitated, and skinned to minimise differences with samples of muscle tissue. Resumen 1. Cada vez con mayor frecuencia, los ecologos de peces utilizan analisis de isotopos estables. Por ello, se hace cada vez mas importante comprender las fuentes de variacion, - debido a diferencias inherentes entre muestreos biologicos o como resultado de tecnicas de procesamiento de muestreo - tanto como identificar estrategias para tratar tales fuentes. Examinamos si la extraccion de lipidos basada en disolventes, comunmente utilizada en analisis de isotopos de carbono estable, altera negativamente los valores de δ15N y δ13C de tejido muscular de tres peces de tamano pequeno y de peces juveniles completos. 2. La extraccion de lipidos de musculo de pez llevo a pequenos cambios isotopicos de + +0.4 a +1.0‰ y de +0.3 a +0.5‰ para δ13C y δ15N, respectivamente. Por el contrario, la extraccion de lipidos de peces juveniles completos vario marcadamente en +3.4‰ para δ13C y +2.8‰ para δ15N - ambos cambios ecologicamente importantes. La varianza de los valores de muestreos de δ13C y de δ15N tanto para tejido muscular como para los peces completos no difirieron entre los muestreos de lipidos extraidos y muestreos sin tratamiento. 3. Nuestros resultados recomiendan el analisis de isotopos estables de tejidos especificos. Cuando ello no es posible o deseable, dos alicuotas de muestreo pueden ser requeridas: una alicuota de lipidos extraidos para el analisis de isotopos de carbono estable cuando la varianza de δ13C, debida a diferencias en el contenido de lipidos de diferentes tejidos, y una alicuota de no-extraccion para determinaciones de δ15N. 4. Dada la mezcla de tejidos, el analisis de isotopos de un organismo completo no es recomendable – en el caso de peces muy pequenos, recomendamos que los peces sean eviscerados, decapitados, y despellejados para minimizar las diferencias de muestreos de tejido muscular.
CALORIMETRIC DETERMINATION OF AVERAGE BODY TEMPERATURE OF SMALL MAMMALS AND ITS VARIATION WITH ENVIRONMENTAL CONDITIONS

A method is described for determining average body temperature of mice by placing them immediately after killing in a Dewar flask containing water and recording the temperature rise. Evidence is presented to show that postmortem heat production does not contribute appreciably to the results. Average body temperatures are usually about 2 °C. lower than colonic temperatures except during lethal chilling when average temperatures are frequently higher than colonic. The rise in average body temperature produced by activity increases with environmental temperature. Body temperatures may be lower during activity than during rest at cold air temperatures.
Evolução de indicadores do ponto de colheita em manga 'Tommy Atkins' durante o crescimento e a maturação, nas condições do vale do São Francisco, Brasil

Objetivou-se, neste trabalho, caracterizar a evolucao dos principais indicadores do ponto de colheita sugeridos para a manga (Mangifera indica L.), durante o crescimento e a maturacao de frutos da cultivar Tommy Atkins, nas condicoes do Vale do Sao Francisco. Por ocasiao da frutificacao, foram selecionadas quarenta e oito plantas, distribuidas uniformemente em quatro fileiras de plantio de um pomar comercial. Nessas plantas, foram marcados seiscentos frutos, no estadio de desenvolvimento denominado "ovo" (40 mm de diâmetro), o que foi verificado aos 52 dias apos a frutificacao (daf). Periodicamente, ate o completo amadurecimento na planta, foram coletadas amostras desses frutos, correspondentes a idade, aos 52, 64, 72, 83, 92, 99, 106, 113, 120, 125, 128, 133 e 139 daf. O delineamento experimental foi inteiramente casualizado, com 13 tratamentos (idade dos frutos) e quatro repeticoes constituidas por dez frutos. As mudancas ocorridas na coloracao a partir de 99 daf e na firmeza da polpa foram os indicadores que melhor delimitaram o inicio da maturacao das mangas, devendo ser acompanhados por meio de amostragem da area. As mudancas na acidez titulavel e nos teores de solidos soluveis (SS) e de carotenoides totais da polpa tambem foram indicativas da evolucao da maturacao. A polpa da manga madura apresentou o maximo teor de SS e teores de acido ascorbico e de carotenoides totais inferiores aos dos frutos no inicio da maturacao.
Two new protist species, Trypanoplasma ojedae sp. n. (Mastigophora: Kinetoplastida) and Trichodina lascrucensis sp. n. (Ciliophora: Peritrichida) in a blenniid fish, Scartichthys viridis, from the coast of Chile

Two new protistan species were observed in a blenniid fish, Scartichthys viridis, inhabiting tide pools at Las Cruces, central Chile. Trypanoplasma ojedae sp. n. (Mastigophora: Kinetoplastida) in the blood is characterized by its small size (29.8 ± 5.0 x 5.1 +1.2 im), short anterior flagellum (4.9 ± 0.6 im), anterior located kinetoplast (2.4 ± 0.2) and a prominent undulating membrane. All of 18 fish were infected and 67% were parasitized on the gills by an unidentified piscicolid leech that harbored developing and infective biflagellated stages. Trichodina lascrucensis sp. n. (Ciliophora: Peritrichida) parasitized the gill fillaments of all fish. The ciliate is characterized by its body size (70.8 ± 8.4 im), adhesive disc (53 ± 5.4 im), denticular ring (33 ± 3.1 im), mean number of denticles (32.8 ± 3.0), mean number of denticular pins (9.5 ± 1.0) and ovoid micronucleus located near to one of the macronuclear arms. Since none of the two parasites was similar to any species described from marine tide pool habitats as well as from the Pacific Ocean, both are considered new species with the characteristics described herein.
Fungi from Canadian coniferous forest soils

The fungus flora from four pine forest soils was investigated. Qualitative studies used a soil-washing method, whereas quantitative investigations were performed using a direct observation technique. Results indicate that the fungus populations on litter and humus from all four forest soils are fairly similar, with Cladosporium herbarum, Aureobasidium pullulans, Alternaria sp. , and various members of the order Sphaeropsidales being common in the litter, and Trichoderma and Penicillium species increasing in frequency in the F and H layers. The fungi isolated from the mineral soil horizons were more varied in nature, but certain genera seemed to be found frequently; these included Mortierella, Chrysosporium, Oidiodendron, Paecilomyces, Cylindrocarpon, Torulomyces, and sterile dark fungi.A detailed investigation of a Pinus strobus forest at St. Williams, Ontario, revealed no distinct seasonal patterns in the relative frequencies of the species of fungi.Quantitative studies showed that, in all soils, mycelial.
SDZ 200–110 Induces Leydig Cell Tumors By Increasing Gonadotropins in Rats

The administration of 62.5 mg/kg/day of SDZ 200–110, a calcium channel blocker, for 2 years increased the incidence of Leydig cell tumors while decreasing pituitary tumors in Sprague-Dawley rats. Lower doses did not change the incidence of these tumors. No other endocrine tumors were seen in rats or mice of either sex. A single gavage dose of 62.5 mg/kg/day decreased serum testosterone levels by 90% 4 hr after dosing. In vitro testosterone production by Leydig cells from these animals was minimally decreased, which suggests that a direct inhibition of steroid synthesis was removed during cell isolation. Dietary administration of the drug for 10 weeks did not significantly alter levels of serum hormones or testicular luteinizing hormone (LH) and gonadotropin-releasing hormone (GnRH) receptors, although a significant elevation of testicular testosterone levels was seen. Increased serum levels of LH and follicle-stimulating hormone (FSH) were seen after 52 and 66 weeks, respectively, of dietary feeding of 62.5 mg/kg/day. The increase in serum LH was observed to week 104, while FSH levels returned to control levels by week 94. No effect on gonadotropin receptors was seen at the 6.25 mg/kg/day dosage. The age-related increase in serum prolactin was markedly reduced by 62.5 mg/kg/day of SDZ 200–110 in weeks 66 to 104 and to a lesser extent at the 6.25 mg/kg/day dosage. Testicular LH receptors were decreased by the high dose in animals sacrificed after 90–104 weeks. In conclusion, SDZ 200–110 increases the incidence of Leydig cell tumors by elevating levels of serum gonadotropins. The suggested mechanism for this increase in gonadotropins is a result of the effects of SDZ 200–110 on serum hormones and testicular LH receptors. The drug was judged not to pose a risk to humans since no change in gonadotropin levels was observed after chronic treatment.
NEGATIVE GOLD STAINING FOR ELECTROPHORETIC PROTEIN PROFILE INTERPRETATIONS

A simple method was described for negative gold staining of ultrathin-layer polyacrylamide gels. The protein bands were clear (unstained) and sharp while the gel matrix was pink-purple. Negative gold staining was up to five-fold more sensitive than coomassie blue, but an order of magnitude less sensitive than silver staining for protein detection. However, there were examples where negative gold staining was able to detect particular proteins not effectively stained by coomassie blue or silver.
Serratia marcescens: a potential pathogen for fish

Abstract. Characterization of a red pigmented enterobacterium isolated from natural population of white perch, Morone americanus (Gmelin), during the course of a bacteriological survey in the Back River (Baltimore, Maryland, USA) indicated that the bacterium belonged to the species Serratia marcescents. The virulence properties of this isolate (RB 469), studied in comparison with the reference strain of S. marcescens ATCC 1800 and S. plymuthica K1R, revealed that all the strains were highly pathogenic for fish with LD50s raging from 5 × 103 to 1 × 105. Similarly, te extracellular products (ECP) from the three isolates were lethal for fish (LD50 ranging from 0·22 to 4·8 μg protein g-1 fish). However, only ECP from strains with strong proteolytic activity (the white perch isolate and S. plymuthica) were cytotoxic for both in fish and homoiothermic cell cultures and both activities were completely destroyed by heating at 100°C for 10min. In contrast, only the two S. marcescens strains which possessed phospholipase active were pathogenic for mice and produced enterotoxins. None of the Serratia strains displayed dermonecrotic factor in rabbits. All these lindings indicate that a direct relationship between eytotoxicity and virulence cannot be established.
Local extinction of British farmland birds and the prediction of further loss

1. The populations of many UK farmland birds declined between 1970 and 1990, frequently accompanied by contractions in breeding ranges. Ornithological atlas data, land use data and environmental data at the scale of 10-km squares were used to investigate the relationship between local extinctions and habitat suitability for six species, and to predict where future losses are most likely. 2. For each species we tested the hypothesis that local extinctions were concentrated in environments that were inherently less suitable. We also tested the hypothesis that spatial patterns of loss were not independent between species due to their concurrence in the same habitats. 3. Multivariate analyses (PCA) showed that areas where each species became extinct between 1970 and 1990 were more similar in land use type, climate and topography to areas where a species was never present than those where it was retained; local extinction was more likely in less suitable environments. Multiple logistic regression showed that for five of the six species the environmental gradient best predicting presence or absence in 1970 was also that best predicting loss between 1970 and 1990. For the six species studied, local extinctions were least likely in lowland arable areas. 4. For any pair of species, local extinctions were more frequent outside the area of overlap of the two species' ranges than inside. Within the area of overlap, species tended to be lost from the same squares. For each species, likelihood of local extinction declined with increasing number of the other five species present. 5. We used model parameters to map the probability of future local extinctions of the six species considered, allowing the identification of key areas for conservation management at a spatial scale appropriate to agri-economic incentives.