On the dual interpretation of zero-curvature Friedmann-Robertson-Walker models

Two possible interpretations of FRW cosmologies (perfect fluid or dissipative fluid)are considered as consecutive phases of the system. Necessary conditions are found, for the transition from perfect fluid to dissipative regime to occur, bringing out the conspicuous role played by a particular state of the system (the ''critical point '').Comment: 13 pages Latex, to appear in Class.Quantum Gra

Longevity of Dayglo Fluorescent Particle Marker Used to Mark Birds in Flight Pen and Field

Spray application of fluorescent particles is a widely used and very valuable technique for marking birds. This remains one of the few practical means to mark large numbers of birds for monitoring movement, despite recent availability of a variety of more technologically advanced options. We monitored the longevity of the DayGlo fluorescent particle marker on red-winged blackbirds under simulated field conditions in a flight pen, and in an observational field experiment. In the pen study we banded 52 red-winged blackbirds with individually numbered leg bands, and sprayed them with DayGlo fluorescent particle marker from a distance of ~50 cm, on 1 December 2004. These birds were recaptured and DayGlo fluorescent particle marks assessed 11 times until 10 August 2005. All 31 surviving birds at the conclusion of the study (i.e. after 254 days) retained at least some DayGlo fluorescent particle marker on one or more body regions. Wings retained DayGlo fluorescent particle marks longer than other body regions and thus could be used to identify marks in large-scale collections. Roosting wild blackbirds aerially marked in September and October 2005 retained marks through June 2006, 263 days after marking. The formulation used is inexpensive (US$4.00 L-1), easy-to-apply at many scales and practical for many species (e.g. starlings, blackbirds, sparrows, gulls and shorebirds)

Laboratory Efficacy of Chemical Repellents for Reducing Blackbird Damage in Rice and Sunflower Crops

Nonlethal alternatives are needed to manage blackbird (Icterids) damage to rice and sunflower production in the United States. We evaluated 4 registered fungicides on rice seeds (i.e., Allegiance® FL, Thiram 42-S, Trilex®, and Vitavax® 200 preplant seed treatments) and 2 foliar pesticides on sunflower seeds (CobaltTM insecticide and Flock Buster bird repellent) as candidate blackbird repellents. Red-winged blackbirds (Agelaius phoeniceus) preferred untreated rice relative to rice treated with Thiram (P \u3c 0.001) and Vitavax (P \u3c 0.001), and untreated sunflower relative to sunflower treated with Cobalt (P \u3c 0.001). Blackbirds preferred untreated sunflower relative to sunflower treated with Flock Buster repellent on day 1 of a 4-day preference test (P \u3c 0.001). We observed no difference in consumption of treated versus untreated rice during the Allegiance preference test (P = 0.928), and blackbirds preferred rice treated with Trilex relative to untreated rice (P = 0.003). Although repellency was positively related to tested concentrations of Thiram (P = 0.010), Trilex (P = 0.026), and Vitavax (P \u3c 0.001), maximum repellency was \u3c50% during our concentration-response tests of these seed treatments. Repellency was also positively related to tested concentrations of Cobalt (P \u3c 0.001), and we observed \u3e80% repellency of sunflower treated with Cobalt at ≥50% of the label rate. We observed no concentration-response relationship for the Allegiance seed treatment (P = 0.341) and Flock Buster repellent (P = 0.952). We recommend implementation of supplemental field studies to compare laboratory efficacy, repellency, and chemical residues of effective avian repellents throughout periods of needed crop protection

Evaluation of an Electronic Device for Reducing Damage by Pileated Woodpeckers to Wooden Utility Poles

Woodpecker damage to utility poles results in significant economic losses to utility companies. Pileated woodpeckers (Dryocopus pileatus), one of the largest woodpeckers in North America, can severely damage utility poles. Many types of repellent techniques have been evaluated for managing pileated woodpecker damage to utility poles. However, each technique has short-comings including cost, difficulty of installation, longevity of the product, or defeat by the woodpeckers. The Sonic Dissuader, a deterrent device, has shown some promise in field testing. We further evaluated the effectiveness of the device for deterring pileated woodpeckers from damaging utility poles in controlled flight pens at the National Wildlife Research Center, Fort Collins, Colorado. Birds spent similar time (F1.7 = 0.00, P = 0.9621) on poles with Sonic Dissuaders (6956.3 ± 1421.4 sec), and poles with the control device (8358.6 ± 1004.2 sec). Woodpeckers spent less time pecking on poles with the Sonic Dissuader (385.9 ± 69.1 sec) compared to control poles (1877.6 ± 494.2 sec) although the difference was not significant (F1.7 = 1.40, P = 0.2751). Weight of woodchips removed did not vary (t = -0.89, df= 14, P = 0.3887) between poles equipped with the Sonic Dissuader (54.7 ± 21.3 g) and poles equipped with the control device (101.0 ± 47.4 g), but weight of woodchips removed varied considerably by bird. We were also unable to detect a difference among times to departure after the 7 types of calls were emitted by the Sonic Dissuader (F6.8 = 1.14, P = 0.4216). Efficacy of the Sonic Dissuader might be improved by programming to broadcast whenever pecking occurs and by utilizing calls or sounds which have been evaluated for deterring woodpeckers from utility poles

DDFT calibration and investigation of an anisotropic phase-field crystal model

The anisotropic phase-field crystal model recently proposed and used by Prieler et al. [J. Phys.: Condens. Matter 21, 464110 (2009)] is derived from microscopic density functional theory for anisotropic particles with fixed orientation. Further its morphology diagram is explored. In particular we investigated the influence of anisotropy and undercooling on the process of nucleation and microstructure formation from atomic to the microscale. To that end numerical simulations were performed varying those dimensionless parameters which represent anisotropy and undercooling in our anisotropic phase-field crystal (APFC) model. The results from these numerical simulations are summarized in terms of a morphology diagram of the stable state phase. These stable phases are also investigated with respect to their kinetics and characteristic morphological features.Comment: It contain 13 pages and total of 7 figure

The Effect of European Starlings and Ambient Air Temperature on \u3cem\u3eSalmonella enterica\u3c/em\u3e Contamination within Cattle Feed Bunks

European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings

The effect of European starlings and ambient air temperature on \u3ci\u3eSalmonella enterica\u3c/i\u3e contamination within cattle feed bunks

European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings

Field Method for Analyzing Birds for Avicide 3-Chloro-P-Toluidine Hydrochloride

We developed a fast and simple method to detect presence or absence of DRC-1339 (CPTH: 3-Chloro-p-toluidine Hydrochloride) in birds that fed on DRC-1339 bait sites. We compared the effectiveness of the colorimetric method to the previously published analytical method using birds collected from DRC-1339 bait sites in Louisiana and Texas. We also conducted tests with caged red-winged blackbirds (Agelaius phoeniceus) to determine if time from consumption of DRC-1339-treated bait to death and time from death to colorimetric analysis affected test results. The colorimetric assay was effective in detecting the presence or absence of DRC-1339 in birds collected from bait sites. In the tests with caged birds, the method resulted in the detection of four grains of treated rice consumed up to 120 minutes post consumption, but failed to detect 1 grain of treated rice consumed at 120 minutes. Frozen samples of 4 treated consumed rice grains could be detected up to 90 days post collection

The effect of European starlings and ambient air temperature on \u3ci\u3eSalmonella enterica\u3c/i\u3e contamination within cattle feed bunks

European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings