The construction and evaluation of an instrument to determine the sports knowledge of boys from grades five through eight

Thesis (Ed.M.)--Boston Universit

Four-fold structure of vortex core states in Bi2Sr2CaCu2O8 (Bi2212)

We present a detailed study of vortex core spectroscopy in slightly overdoped Bi2Sr2CaCu2O8 using a low temperature scanning tunneling microscope. Inside the vortex core we observe a four-fold symmetric modulation of the local density of states with an energy-independent period of (4.3\pm 0.3)a0. Furthermore we demonstrate that this square modulation is related to the vortex core states which are located at ~6 meV. Since the core-state energy is proportional to the superconducting gap magnitude, our results strongly suggest the existence of a direct relation between the superconducting state and the local electronic modulations in the vortex core.Comment: 5 pages, 4 figures. Submitted to Physical Review Letter

Fiskevelfærd i økologisk ørred opdræt Er der forskel på EU-regelsættet og RSPCA standarden?

Opdræt af regnbueørred, især økologisk ørred, er kritisk udfordret på grund af relativt mange hud/gælle infektioner forårsaget af forskellige patogener, især parasitten Costia (Ichthyobodo necator), som ultimativt er dødelig for yngel/mindre fisk. Dette kan være en trussel mod tilstrækkelig udbud af økologisk yngel til videre produktion, da regelsættet for økologisk akvakultur kræver 100% økologisk yngel. Endvidere forårsager en såkaldt ny ”Rickettsia-lignende" bakterie “rødpletsyge” (RMS), dvs. røde pletter i huden, som medfører ned-klassificering/kassation af op til 30% af fiskene ved slagtning. Behandling ved brug af antibiotika/hjælpestoffer er kun muligt i begrænset omfang i økologisk ørred produktion. Løsninger til forebyggelse og/eller behandling af Costia og RMS er derfor strengt påkrævet – ikke kun for blot at sikre produktion af økologisk ørred i Danmark, men også for at styrke grundlaget for en større produktion af robuste økologiske fisk. ShelterFish vil fokusere på løsninger i krydsfeltet: Fisk - Patogener – Opdrætssystem/miljø og vandkvalitet; omfattende 1) Test af skjul/skygge med henblik på at skabe bedre og robust opdrætsmiljø; 2) Test af urte ekstrakter og et nyt bakterielt overfladeaktivt stof til behandling af gæller/hud parasit infektioner; 3) Test af induceret immunitet mod ”rødpletsyge” og 4) Test af metoder til reduktion af belastning med organisk stof i økologiske dambrug og herved forbedre vandkvalitet/miljø, fiske sundhed og velfærd. Fiskevelfærd har høj fokus i såvel det fælles EU regelsæt for økologisk akvakultur som i den engelske dyreværnsorganisations RSPCA standard. Økologisk ørred opdræt sker i dag efter fælles EU-regler. Fiskevelfærd er væsentlig for enhver akvakultur produktion og er særligt fremtrædende i det økologiske EU-regelsæt. Men der findes også andre regelsæt, der har primær fokus på fiskevelfærd som f. eks. den engelske RSPCA standard. RSPCA er forkortelsen for: Royal Society for the Prevention of Cruelty to Animals, der er en non-profit engelsk dyreværnsorganisation med sit eget “RSPCA Assured” mærke. Men tager det ene regelsæt mere hensyn til fiskevelfærd end det andet? Dette søges belyst i denne artikel i forhold til EU-regelsættet og RSPCA standarden

Stress-resilience differences related to emergence time in rainbow trout

In wild salmonid fish, individual behavioural traits have been suggested to be coupled with the timing of fry emergence form gravel spawning nests, in such a way that early emerging fish have shown to be more aggressive and to have a higher probability to become socially dominant than those fish emerging at a later stage. Besides aggression and dominance, other behavioural and metabolic traits such as boldness, metabolic rate or growth had also been coupled to emergence time. Altogether, early- and late-emerging fish have traits resembling those of proactive and reactive stress coping styles, respectively. Proactive fish are considered to be more resilient to stress. However, it is currently unclear if that coupling is maintained in farmed fish populations, which showed no consistent evidence of a clear relation between emergence time and stress coping style. In this study, fish were hatched and larvae were fractionated according their emergence time (Early fraction: first 20 % of fish to emerge; Intermediate fraction: mid 20 %; Late fraction: last 20 %). Several months later, the resilience against a mild stressor (30 min of high stocking density), along with the stress habituation ability was investigated in 5 g fish from the different fractions. Results showed that fish from different fractions di played a similar neuroendocrine response to a novel stressor. Interestingly, the capacity of habituation to stress was however better in the fish from the early emergence fraction, which showed no cortisol response to the stressor after being exposed daily for 15 days to another mild acute stressor (1.5 min of air exposure). These results demonstrate that at least some behavioural differences related to emergence time exist in a domesticated trout population. The aquaculture related implications of these stress resilience differences are currently under study

Evaluation of yeast single cell protein (SCP) diets on growth performance, feed conversion and carcass composition of Tilapia Oreochromis niloticus (L.) fingerlings

An investigation was carried out on the possibility of replacing fishmeal with graded levels of yeast single cell protein (SCP; 10, 20, 30, 40 and 50%) in isonitrogenous feed formulations (30% protein) in the diet of Oreochromis niloticus fingerlings for a period of 12 weeks. The control diet had fishmeal as the primary protein source. There were six treatments and four replicates. The result indicates that the 50% yeast SCP diet gave the best in growth response with percentage weight gain (PWG) of 6.04, specific growth rate (SGR) of 0041, daily growth rate (DRG) of (0.0088) and feed conversion ratio (FCR) of 1.94. There was however no significant difference in growth parameters and feed conversion ratio between treatment (p > 0.05). The proximate examination of the carcass composition of the whole fish body showed that the 50% yeast SCP fed fish had the highest percentage of body protein (55.35%), but with a lower amount of fat at the end of the feeding trial compared to the control. There was however no significant difference in carcass protein and fat content between treatments (p > 0.05). It could therefore be concluded that yeast SCP can successfully replace fishmeal up to 50% level with 0.25% dietary methionine supplementation in a 30% protein diet for O. niloticus fingerlings with no significant difference in fish performance (p > 0.05).Key words: Tilapia, yeast single cell protein, growth, carcass composition, feeding trials

Emergence time and skin melanin spot patterns do not correlate with growth performance, social competitive ability or stress response in farmed rainbow trout

In wild salmonid fish, specific individual behavioral traits have been correlated with the timing of fry emergence from their gravel spawning nests; Early emerging fish display more aggressive behavior and have a higher probability of becoming socially dominant, compared to fish that emerge at a later stage. Apart from aggression and dominance, other behavioral and metabolic traits, such as boldness, metabolic rate, or growth, have also been linked to emergence time. Altogether, the traits of early- and late-emerging fish resemble those of the proactive and reactive stress-coping style, respectively. As proactive fish are considered more resilient to stress, it may be desirable to select these for aquaculture production. However, it is currently unclear to what extent the link between emergence time and stress-coping styles is maintained in the selective breeding of farmed fish. In the present study, eyed eggs from a commercial supplier were hatched, and larvae fractionated according to their emergence time. Later on, juvenile fish from different emergence fractions were subjected to a stress challenge and also tested to evaluate their competitive ability for food. Beyond some slight dissimilarities in the acute stress responses, emergence fraction displayed no correlation with growth rates, or the ability to compete for feed. Within the whole group of fish utilized in the experiments, no relationship between skin melanin spot pattern and growth performance, stress response intensity, or competitive ability was found. Altogether, the differences in physiological traits related to emergence time were not as strong as those found in earlier studies. It is hypothesized, that the origin and degree of domestication of the fish might be partly responsible for this. The predictive value of skin spots or emergence time to infer the fish stress coping style in farmed fish is also discussed

Influence of the impaction angle on the triboelectric charging of aerosol nanoparticles

A low pressure impactor is used to measure triboelectric charging behavior of metallic nanoparticles. Ag nanoparticles, produced by spark discharge, were impacted onto Pt sputtered targets. The influence of the impaction angle and impaction velocity on the triboelectric charging was investigated. While for perpendicular impaction the charge transfer behavior of previous work was confirmed, the oblique impaction revealed new phenomena. Additional charge transfer was observable, which increases with obliqueness. The possibility of mass transfer between particle and target due to the high-energy collisions was also investigated. SEM characterization and Auger spectroscopy indicate mass transfer from the particle to the target surface

Modell zum Einfluß erhöhter CO2-Konzentrationen und Temperatur auf den Wasserumsatz von Buchenbeständen

Seit Beginn der kontinuierlichen Messungen der CO2-Konzentration auf dem Mauna-Loa 1958 ist die Konzentration bis 1997 von 315,83 µmol mol-1 auf 363,82 µmol mol-1 angestiegen. Mit großer Wahrscheinlichkeit ist die Erwärmung der Erde auf die anthropogene Erhöhung der atmosphärischen CO2-Konzentration zurückzuführen. Anhand eines im Rahmen dieser Arbeit entwickelten Modells werden mögliche Auswirkungen der Erhöhung der atmosphärischen CO2-Konzentration und erwarteter Temperaturerhöhungen auf den Wasserumsatz und das Wachstum von Buchenbeständen untersucht. Die im Modell verwendeten Wetterdaten werden generiert. Zwei Verfahren zur Generierung von Wetterdaten (Wettergenerator WGEN und FOURIER-Reihen) werden gegenübergestellt. Die Biomassen werden basierend auf dem Farquhar Modell (der Stickstoffgehalt in den Blattschichten beeinflußt in der verwendeten Variante VCmax und Jmax) und empirischen Verteilungsfunktionen berechnet. Die Evapotranspiration wird auf Basis eines von JARVIS modifizierten PENMAN-MONTEITH Ansatz berechnet, bei dem der Einfluß der Bestandesrauhigkeit auf den Grenzschichtwiderstand zwischen Bestand und angrenzender Atmosphäre berücksichtigt wird. Für die Darstellung des Bodenwasserhaushaltes wird ein Modell von VANDENBERG verwendet. In einigen Modelläufen wird zum Berechnen des Beginns der Vegetationsperiode ein Modell von KRAMER verwendet. Das Modell errechnet bei erhöhter CO2-Konzentration eine deutlich höhere Biomasse und einen höheren LAI. Die Transpiration sinkt bezogen auf die Biomasse um 14%. Bezogen auf die Grundfläche gibt es kaum eine Änderung. Die Interzeption nimmt deutlich (36%) ab. Die Evaporation von der Bodenoberfläche nimmt um 9% und die Versickerungsrate um 16% zu. Eine konstante Temperaturerhöhung um 2 °C über den Simulationszeitraum von 150 Jahren führt bei Verwendung des Modells von KRAMER nicht zu einer verlängerten Vegetationsperiode. Daher konnten Effekte, die durch eine erhöhten Temperatur erwarteten längeren Vegetationsperiode auftreten, im Modell nicht nachgebildet werden

Dynamics, Operator Theory, and Infinite Holomorphy

The works on linear dynamics in the last two decades show that many, even quite natural, linear dynamical systems exhibit wild behaviour. Linear chaos and hypercyclicity have been at the crossroads of several areas of mathematics. More recently, fascinating new connections have started to be explored: operators on spaces of analytic functions, semigroups and applications to partial differential equations, complex dynamics, and ergodic theory. Related aspects of functional analysis are the study of linear operators on Banach spaces by using geometric, topological, and algebraic techniques, the works on the geometry of Banach spaces and Banach algebras, and the study of the geometry of a Banach space via the behaviour of some of its operators. In recent years some aspects of the theory of infinite-dimensional complex analysis have attracted the attention of several researchers. One is in the general field of Banach and Fréchet algebras and Banach spaces of polynomial and holomorphic functions. Another is in a deep connection with the theory of one and several complex variables as Dirichlet series in one variable, Bohr radii in several variables, Bohnenblust-Hille constants, Sidon constants, domains of convergence, and so forth. This special issue shows some new advances in the topics shortly described above