Miracle-dz/UniFAR-FTUs huggingface dataset:
Mathematical description of competition between two and three bacterial species under dual substrate limitation in the chemostat: A comparison with experimental data

A mathematical model is presented which describes the growth of two bacterial species in mixed chemostat cultures under dual substrate limitation. Competition experiments between a facultatively chemolithotrophic Thiobacillus and either a heterotroph or an obligately chemolithotrophic Thiobacillus served as an experimental model system [Gottschal, de Vries, and Kuenen, Archives of Microbiology, 121, 241-249 (1979)]. Furthermore, the introduction of Monod-type growth kinetics in the model allowed an assessment of the relative importance of the growth parameters for the outcome of the competition. In addition, it is shown how the results of the mathematical description of the two-membered mixed cultures can be used to predict the outcome of the competition between the three species competing for the two growth-limiting substrates acetate and thiosulfate in a three-membered mixed culture. In contrast to the experimental data of Gottschal, de Vries, and Kuenen it is predicted that two of the three species or only one of them (the "mixotroph") will survive in the culture. Within the framework of the proposed mathematical model, two possible explanations for the experimentally observed coexistence of three species are suggested: either the very slow dynamics of the system did not allow the attainment of a true steady state within the time scale of the present experiments or some parameters describing the mixed culture were extremely sensitive towards minor fluctuations in dilution rate. The results of the present mathematical model support the view that facultatively chemolithotrophic bacteria are able to survive under appropriate limiting mixed substrate conditions in the presence of more "specialized" heterotrophs and obligately chemolitotrophs, in spite of their relatively low specific growth rate.
Evaluating Spatial and Temporal Overlap Between Larval Alosines and Potential Zooplankton Prey in Lower Roanoke River and Albemarle Sound, North Carolina

Spatial and temporal overlap between zooplankton and larval American shad (Alosa sapidissima) river herring (alewife A. pseudoharengus and blueback herring A. aestivalis) and hickory shad (A. mediocris) was evaluated in lower Roanoke River and Albemarle Sound North Carolina. Zooplankton abundances in this system have historically been lower than those found in other coastal river systems. It was hypothesized food limitation during the early life history of alosines was contributing to recruitment failure. Zooplankton and ichthyoplankton samples were collected concurrently March through June 2008-09 at 19 stations within three areas: River Delta and Sound. Significant spatial and temporal differences were observed for alosine abundances. Abundances (number/100m[superscript]3 Â± SD) were significantly higher in 2009 (30.8 Â± 149.8) than in 2008 (4.1 Â± 20.9). Across both years River (21.0 Â± 127.6) alosine abundances were significantly higher than those in Delta (7.4 Â± 35.4) and Sound (4.6 Â± 24.8). Zooplankton abundances were higher than observed in previous studies and did not differ significantly between years. Zooplankton abundances exhibited the opposite spatial trend of alosines with significantly higher abundances (number/m[superscript]3 Â± SD) observed in the Sound (16 547 Â± 14 678) than in the River (4 934 Â± 3 806) and Delta (4 647 Â± 2 846). Differences in zooplankton composition were evaluated using analysis of similarity. Composition in the Sound significantly differed from the River and Delta. Canonical correspondence analysis explored the relationship between zooplankton and the environment and found that some differences in composition could be explained by salinity preferences of zooplankton taxa. Zooplankton size distribution was evaluated and the most common taxa segregated into two groups based on size. Rotifers and copepod nauplii comprised the small size group and Daphniidae Bosminidae calanoid copepods and cyclopoid copepods composed the larger size class. Mouth gape models were developed for each alosine species and used to estimate maximum prey size at first feeding. At first feeding alewives blueback herring and hickory shad are primarily able to consume copepod nauplii and rotifers. Larval American shad are larger and have a wider potential prey breadth including Bosminidae cyclopoid copepods copepod nauplii and rotifers at first feeding. During both years there was a high amount of overlap between larval alosines and size-appropriate zooplankton suggesting larval alosines in this system are not food limited.
A fibre‐optic scalar irradiance microsensor: application for spectral light measurements in sediments

The manufacturing of a new spherical fibre-optic microsensor is described. The microsensor measures scalar irradiance, i.e. the spherically integrated light at a point in space. The light collector of the probe was a 70-μm diffusing sphere cast on the tip of a 125-μm wide optical fibre tapered down to 15–20 μm diametre. The microsensor had an isotropic (±10%) response from −160° to +160° over the whole spectral range from 400–900 nm in air as well as in water. The microsensor was coupled to a sensitive spectroradiometre and the spectral distribution of scalar irradiance in sediments was measured at 100 μm spatial resolution. Light was available for photosynthesis near the sediment surface at a higher intensity and a different spectral composition than could be expected from the illumination. By the combination of oxygen microelectrodes and the present fibre-optic microsensor it is now possible to study the depth distribution of microbenthic photosynthesis in relation to the available photosynthetically active radiation at ≤ 100 μm resolution.
Climate change and livestock parasites: integrated management of sheep blowfly strike in a warmer environment

The incidence of parasite‐mediated livestock disease is the result of a complex interaction of factors such as parasite and host abundance, host susceptibility, climate and, critically, farmer husbandry and intervention strategies, all of which change seasonally in space and time. Given the complexity of the interacting factors, the effects of environment changes on disease incidence are hard to predict, as accordingly are the optimal husbandry responses required to ameliorate any effects. Here a model system is used to explore these issues. Cutaneous myiasis (blowfly strike) is common disease of livestock and would be expected to be highly sensitive to even small changes in climate; it provides a good model for highlighting the problems inherent in attempting to predict the effect of climate change on livestock disease incidence. For this, a stochastic simulation model is used to examine the changes in the seasonal incidence of ovine cutaneous myiasis on farms in the United Kingdom and the likely effects of changes in husbandry and control strategies. The simulations show that the range of elevated temperatures predicted by current climate change scenarios result in an elongated blowfly season with earlier spring emergence and a higher cumulative incidence of strike. Overall, higher temperatures increased strike incidence disproportionately in ewes in early summer, but had relatively less direct effect on the pattern of lamb strike incidence; a +3 °C increase in average temperature approximately doubles the cumulative incidence of strike in lambs but results in four times more strikes in ewes. A range of strike management options is examined and the models show that changes in husbandry practices are also likely to have an important effect in reducing early season ewe strike incidences. The simulations suggest that integrated changes in husbandry practices are likely to be able to manage expected increases in strike, given the range of climate changes currently predicted.
An IFN-γ-dependent pathway plays a critical role in the pathogenesis of murine immunodeficiency syndrome induced by LP-BM5 murine leukemia virus

: The murine acquired immunodeficiency syndrome (MAIDS) caused by a defective murine leukemia virus produces severe immunodeficiency with abnormal lymphoproliferation and hypergammaglobulinemia. The presence of both CD4+ T cells and B cells is critical for the development of this disease. Remarkably elevated mRNA expression for IFN-gamma and IL-10 was observed in spleen cells of C57BL/6 mice starting from the early phase of viral infection. IFN-gamma production was induced by spleen cells from virus-infected mice upon stimulation with concanavalin A or lipopolysaccharide in both the early and late phases of MAIDS progression. When mice that had been passively administered anti-IFN-gamma mAb were infected with the virus, the development and progression of lymphadenopathy, immunodeficiency and elevated levels of serum IgG2a associated with MAIDS were delayed. Treatment with anti-IL-4 or anti-IL-10 mAb in place of anti-IFN-gamma mAb did not induce the delayed progression of MAIDS. These data support the concept that IFN-gamma-dependent pathway may be involved in the development of MAIDS.
Digestible lysine requirement of broilers based on practical diet

The aim of this study was to estimate the requirement for digestible lysine for broilers from 35 to 49 days of age. Two hundred and forty chicks with a mean weight of 44±1 g were used in a completely randomized design, made up of male and female chicks and 6 digestible lysine levels. Experimental diets were formulated to be isoenergetic and isonitrogenous. Fitted broken lines on different responses indicated break points at 0.93, 0.93 (for body weight), 0.98, and 0.92 for feed conversion ratio for male and female, respectively. The results showed that the digestible lysine requirement of male broilers for maximum breast yield percentage, plasma free lysine and antibody titer against Newcastle disease virus exceeded the range of lysine levels tested. Dietary lysine had a significant effect in increasing the plasma free lysine, albumin, total protein, immunoglobulin, antibody titer against sheep red blood cell, Newcastle disease virus and heterophil to lymphocyte ratio. In conclusion, lysine requirements of broilers for performance were lower than breast yield percentage and immune responses. Broken-line analysis showed that the concentrations of plasma free lysine were useful physiological indicators for determining the digestible lysine requirement of male and female broilers. Our results suggest that the estimated requirements based on exponential response curves were higher than estimated requirements obtained using a broken-line model.
The stability of milk protein to heat: I. Subjective measurement of heat stability of milk

Summary A subjective test for the determination of the stability of milk protein to heat is described. In the test, the time required for particles of coagulated protein to become visible throughout a 2·5-ml sample of separated milk maintained at 135°C in a glass tube rocking at 8 c/min is taken as a measure of stability. The precision of the test was such that single determinations were generally adequate. Coagulation time decreased by about 12% as rocking speed was increased over the range 4–12 c/min and increased by a factor of about 3 for a decrease in heating temperature of 10 degC over the range 140–105 °C; with some milks the Q10 °C value increased to 5–8 a temperature decreased. As sample volume was increased over the range 1–3 ml coagulation time increased, especially With milks whose coagulation was poor (initial clots small). This volume effect appeared to be a consequence of the accompanying decrease in the proportion of headspace oxygen to volume of milk.
Changes in rheological and viscoelastic properties and protein breakdown during the ripening of ‘Port Salut Argentino’ cheese

Summary Changes in the rheological behaviour and viscoelastic properties during ripening at 10°C of a soft cheese (Port Salut Argentino) packaged in a plastic film (EVA-EVA) were analysed. Casein degradation was measured by electrophoresis slab gels; αs1 casein degradation was rapid and striking compared with that of β casein. Rheological parameters obtained from uniaxial compression tests changed during ripening: hardness decreased, adhesiveness and cohesiveness increased. An exponential decay equation with two maxwellian elements and one elastic in parallel was fitted to characterize stress relaxation curves. Viscoelastic parameters (elastic moduli and relaxation times) were obtained using non-linear regression analysis. The elastic equilibrium modulus decreased 80% during the ripening period and the viscosity of the element with the highest relaxation time decreased 20%. These parameters represented the changes observed in cheese hardness and elasticity during ageing time and were related to the extent of casein breakdown.
The Role of Endangered Species Reintroduction in Ecosystem Restoration: Tortoise–Cactus Interactions on Española Island, Galápagos

We evaluated the role that endangered species reintroduction efforts can play in the larger context of ecosystem restoration. To do so, we examined interactions between endangered giant tortoises (Geochelone nigra hoodensis), currently being reintroduced to Isla Española, Galápagos, and an arboreal cactus (Opuntia megasperma var. megasperma), which is itself endangered and a keystone resource for many animals on the island. We collected information on spatial patterns of occurrence of cacti, tortoises, and woody vegetation and compared recruitment of juvenile cacti in areas occupied versus unoccupied by tortoises. Reintroduced tortoises appeared to suppress cactus recruitment near the few remaining adult cacti at the study site, but facilitate it at longer distances, with tortoise–cactus interactions mediated by the presence of woody vegetation, which likely alters tortoise movements and thereby patterns of cactus seed dispersal. The net effect of tortoises on cacti appeared to be positive insofar as tortoise presence was associated with greater recruitment of juveniles into cactus populations. Our study provides support for reintroducing endangered reptiles and other animals to aid ecosystem restoration in areas where they might once have played an important role in grazing upon and dispersing plants.
Effects of nitrogenous fertilizer on the growth, grain yield and grain protein concentration of wheat

The responses of wheat to applications of nitrogenous fertilizer were examined between 1988 and 1990 at 10 sites in South Australia which were considered to be marginally deficient in N. Nitrogen rates ranged from 0 kg N/ha to 150 kg N/ha and the experiments were sown after a range of crops and pastures. Nitrogen often increased early crop vigour and subsequent vegetative growth but significant increases in grain yield occurred at three of the 10 sites only; at the remaining sites there was no significant response or there was a reduction in yield at the highest rates of N. Kernel weights fell and grain protein concentration increased at most sites as the rate of N increased. The total amount of N per kernel was relatively constant across the N treatments at each site and across the 10 sites it varied less than the starch content per kernel. Grain protein concentration therefore was affected more by the amount of starch deposited in the grain than by the total amount of nitrogen. The amount of dry matter remobilized post-anthesis, calculated from changes in dry weight, was high and at the majority of sites was increased with applications of nitrogenous fertilizer. Despite the generally large amount of dry matter remobilized, this appeared to be used inefficiently during grain filling and there was little evidence that it greatly contributed to grain growth and grain protein concentration. The relationship between starch content per kernel and N content per kernel varied between sites: in some cases starch and N were negatively correlated, while in other instances there was a positive correlation or no correlation. The data suggest that high grain protein concentration at high levels of N are not a direct consequence of increased mobilization of dry matter and greater translocation of N to the grain. Dry matter production at anthesis was correlated with the amount of growth after 10 weeks but generally this increased dry matter production was of no benefit to yield. It is concluded that in the medium rainfall areas of the state, there is no advantage to be gained from improved early vigour, except perhaps where poor early growth is due to inadequate management.
Evaluation of market value: comparison between different techniques applied on pork carcasses (short communication)

Abstract. The market value of a carcass in the whole should be represented by the sum of values of all Single cuts dissected from a carcass. These values of the single cuts are defined by their tissue composition and meat quality characteristics (pH, etc.)respectively. The ftxing of market value at the slaughter line requires very quick methods that base on instrumental measurements and electronic data management. Nowadays four technically different types of instruments are available for the determination of market value in Germany. Following instrumental devices are compared and valuated. Opto-electronic devices, Ultrasonic Scanners, Autoform (SFK Company, DK), The video imaging System VCS 2000. These four technical Systems presented in this study give equally good results in predicting the market value of pork carcass. It can State, that the fully automatic devices represent a new stage of development. They are calculating the market value on a great number of measurements and in most aspects with a high reliability.
Volatility Clustering, Fat Tails and Bitcoin Exchange Rate Returns

In the era of diminishing power from US dollar and increasing competition among world currencies, Bitcoin, as a completely new concept as a medium of exchange, has received increasing attentions over the world. Nowadays, Bitcoin also becomes an investment vehicle, which carries attractive opportunities but also significant risks for the investment community. In this paper, we have compared the empirical performance of a newly-developed heavy-tailed distribution, the normal reciprocal inverse Gaussian (NRIG), with the most popular heavy-tailed distribution, the Student’s t distribution, under the GARCH framework in fitting the daily Bitcoin exchange rate returns. Our results indicate the heavy-tailed distribution has better performance in capture the daily Bitcoin exchange rate returns dynamics than the standard normal distribution. Our results also show the older fashioned Student’s t distribution still performs better than the new heavy-tailed distribution.
New crystal form of β-lactoglobulin

Summary The milk whey protein β-lactoglobulin has been isolated from ovine milk, purified and crystallized in a form suitable for X-ray crystallography. The crystals, which diffract to 1·9 Å resolution, belong to the trigonal space group P3121 with unit cell lengths a = b = 99·8 Å, c = 67·7 Å and unique angle γ = 120·0°. Although there have been many crystal forms reported for bovine β-lactoglobulin, none has been reported with these unit cell parameters. A preliminary native data set has been collected and a molecular replacement solution obtained, using the structure of dimeric bovine β-lactoglobulin as the search model. The importance of the ovine structure in relation to that of the bovine is discussed.
The intriguing structure of non‐geometric frames in string theory

Non‐geometric frames in string theory are related to the geometric ones by certain local O(D,D) transformations, the so‐called β‐transforms. For each such transformation, we show that there exists both a natural field redefinition of the metric and the Kalb‐Ramond two‐form as well as an associated Lie algebroid. We furthermore prove that the all‐order low‐energy effective action of the superstring, written in terms of the redefined fields, can be expressed through differential‐geometric objects of the corresponding Lie algebroid. Thus, the latter provides a natural framework for effective superstring actions in non‐geometric frames. Relations of this new formalism to double field theory and to the description of non‐geometric backgrounds such as T‐folds are discussed as well.
An overview of formation and roles of acetaldehyde in winemaking with emphasis on microbiological implications

Summary Acetaldehyde is an important aroma compound in wine. This article first reviews the microbial and chemical formation of acetaldehyde, then the effects of sulphur dioxide on acetaldehyde and effects of acetaldehyde on wine colour and physical stability are described briefly. Finally, the microbiological implications of acetaldehyde are emphasized with respect to practical significance in wine fermentation.
STRATIGRAPHY AND POLLEN ANALYSIS OF BROMFIELD SWAMP, NORTH EASTERN QUEENSLAND, AUSTRALIA

SUMMARY The sequence of vegetation changes evidenced in the Bromfield Swamp pollen diagram is similar to those derived from previous studies at Lake Euramoo and Quincan Crater. It is established that the initial presence of sclerophyll vegetation around the sites was a regional feature of the Atherton Tableland, determined by low precipitation. Throughout the succeeding rain forest phase, precipitation was higher at Bromfield Swamp than at the other sites suggesting that the rainfall gradient across the Tableland has remained constant. The contrast between the relatively simple stratigraphic sequence of deposits in the swamp and the present complex mosaic of vegetation types and depositional environments implies that there has been a great deal of recent interference with the swamp and the surrounding crater slopes.
Supplementation to improve the production of yearling steers grazing poor quality forage 1. The effects of forage type and a cottonseed meal supplement

Yearling Hereford steers grazed on either oat stubble or dry annual pasture and were supplemented with daily rations of 0, 200, 400, 600, 800 or 1000 g/steer of pelleted cottonseed meal. Steer growth rates increased with increasing level of supplement from 500 to 961 g/steer.day on the oat stubble and from 128 to 613 g/steer.day on the dry pasture. The growth responses appeared to be not only due to the metabolizable energy ofthe supplement, but also due to greater forage consumption. Compensatory growth during the 3 months after cessation of supplementation reduced the advantage of the supplementary feeding only slightly. The cottonseed meal supplement was chosen after a preliminary experiment which compared the influence of four protein supplements on the ad libitum intake of a low-quality roughage by weaner lambs. The supplements (pelleted cottonseed meal, pelleted lupins, soybean meal, and rolled lupins) improved consumption of roughage by 67, 49, 46 and 35%, respectively. An in vitro determination of ammonia and amino acid production from these supplements showed that pelleted cottonseed meal and soybean meal are most resistant to degradation.