IDENTIFYING AN EFFICIENT FEED DISTRIBUTION SYSTEM IN THE MIDWEST

Livestock Production/Industries,

ON THE APPLICATION OF SEMI-CLASSICAL CONCEPTS TO HEAVY ION SCATTERING

Semi-classical methods work quite well usually for heavy-ion collisions. However counter examples exist and one of them is discussed here

DIFFUSION AVANT ET ARRIÈRE D'IONS LOURDS ET MOMENTS ANGULAIRES COMPLEXES

L'amplitude de diffusion élastique d'ions lourds a été calculée par la formule de sommation de Poisson. Celle-ci nécessite l'évaluation d'intégrales I±m(θ), où θ est l'angle de diffusion et m = 0, ± 1, ± 2, ... A l'approximation semi-classique I±m(θ) = 0 pour m 0, bien que non nulles sont négligeables. En appliquant la méthode du col (déjà utilisée par Knoll et Schaeffer dans un problème similaire) pour les intégrales restantes, on vérifie que seule I-0 contribue aux petits angles. Elle comporte deux parties l'une liée à un col sous l'axe réel, dépendant de l'angle de diffusion, l'autre à un pôle ou à un col très localisé dans le premier quadrant du plan complexe. Les oscillations de la section efficace élastique aux angles avant résultent de l'interférence de ces deux contributions de I-0. Vers l'arrière d'autres oscillations apparaissent dues à un col de I-0 et I+-1. Si le premier terme est bien connu, le second n'existe pas a l'approximation semi-classique, car la fonction de déflexion ne peut être supérieure à 180°. La présence de I+-1, est cependant indispensable pour reproduire l'effet glory. Ces résultats ne dépendent pratiquement pas de la paramétrisation choisie. Ils ne sont fonction que des caractéristiques de la coupure des ondes partielles les plus basses, en particulier du moment angulaire d'affleurement

Modalités spatio-temporelles de la dispersion d'alevins de saumon atlantique (Salmo salar L.) à l'émergence

Nous avons étudié la dispersion (vitesse, durée, distance) d'alevins de saumon atlantique à l'émergence dans un ruisseau expérimental.Le rythme journalier de dévalaison suit étroitement le rythme d'émergence des alevins, ce qui montre une bonne corrélation entre les deux activités, tout au moins en début de période. Les histogrammes de capture des alevins échantillonnés tous les 10 m présentent des caractéristiques de forme similaires (durée, asymétrie et aplatissement). Jusqu'au pic des captures, près de 50 % des alevins dévalent en 5 jours. Ils se dispersent à partir de la frayère sur 50 m en 3 ou 4 nuits et forment une cohorte homogène d'après leur rythme de dévalaison et leur taille. Après le mode, les captures sont plus étalées dans le temps (environ 10 jours) et montrent plus de variabilité en fonction de la distance. Les alevins résidents ne sont pas distribués uniformément dans les cinq biefs : les densités, de même que les poids moyens, tendent à augmenter vers l'aval. Plus de 50 % de la population d'alevins survivants s'est établi dans les 50 m en aval de la frayère. Les résultats révèlent deux vagues de dévalants. La première vague de dispersion, aussitôt après l'émergence, est rapide et importante. Elle ne dépendrait pas directement de la compétition territoriale et de la densité, mais permettrait d'éviter des densités localement trop élevées et d'utiliser plus efficacement les zones productives situées en aval de la frayère. La deuxième vague d'alevins dévalants correspondrait aux émergents tardifs et aux poissons soumis aux effets de la compétition territoriale.We have analysed the dispersal patterns (rate, duration, extent) of Atlantic salmon fry at emergence. The rate and duration of movement, and the distance travelled were measured in an experimental stream, located near S-Pée-sur-Nivelle, in SW France. A batch of 8 850 eyed eggs, from the grilse wild stock of the Nivelle River, was buried in the gravel substrate at the upstream end of a series of 5 sections, each 10 m long by 3 m wide. Shortly before emergence, drift nets equipped with fry traps were installed at the downstream end of each section. The nets sampled about 1/10 of the flow, except for those nets at the downstream end of the last section which collected all downstream moving fry. The traps were visited every morning and the fry enumerated. At the time of peak movements, samples were collected for length-weight measurements. At the end of the dispersal period, fry which had settled in the different sections (residents) were captured with electro-fishing gear and measured.The pattern of downstream movement of fry in a set of drift nets was closely related to the pattern of emergence from an artificial redd upstream of the nets. Hence, emergence and downstream dispersion were well synchronized, at least during the first part of the dispersal from the redd. The time-frequency histograms of fry sampled every 10 m showed the same pattern and general shape (duration, skewness and kurtosis). Until the peak of captures, nearly 50 % of all downstream moving fry were caught within 5 days in each section. Dispersion from the redd over 50 m occurred within 3-4 nights. During this first period, the fry exhibited similar characteristics with respect to activity patterns and sizes. After the modal day of capture, catches were more evenly spread over time (about 10 days) and showed greater variability in relation to the distance travelled from the redd.Resident fry were not uniformly distributed in the 5 sections : densities, as well as average weights, increased from upstream to downstream. Over 50 % of the surviving fry (75.3 % of planted eggs) settled within 50 m downstream from the redd.Our results showed two waves of downstream dispersion. The first dispersal wave, occurring soon after emergence, was swift and implied large numbers of fry. It was not the result of territorial competition or density, since it occurred before the onset of aggressive behaviour. Rather, this first wave appeared as process to avoid the formation of clumps and allow for a more efficient use of the more productive zones, generally located downstream from the redd. The second wave of downstream moving fry corresponded to late emerging fry and to those fry which, 10-12 days after emergence, were displaced by territorial competition

The Transformative and Healing Powers of Compassion, Forgiveness, and Wonder

Since time immemorial, humankind has struggled to coexist peacefully together. As human beings, we strive on our relationships with each other and, yet, with actions of hatred and prejudice, we seem to consistently destroy those very relationships we value so deeply. Our current society is plagued by fear, which seems to run more rampant now – more than ever – with assistance of our rapidly evolving communication technology. The question must be asked, “How can we end this madness and heal ourselves into a kinder and more fulfilling future?” By providing up-to-date scientific research on the human emotions of compassion, forgiveness, wonder and awe, I will show how the existence and awareness of these emotions can positively impact our current global society and substantially lessen the hold that fear so often has on humanity. I will also provide current examples of existing smaller societies that have adopted this behavioral model and have begun to flourish. Lastly, I will explore some of the teachings from various renowned spiritual leaders who espouse the crucial importance of these emotions in our world today

The X-ray nebula of the filled center supernova remnant 3C58 and its interaction with the environment

An \xmm observation of the plerionic supernova remnant 3C58 has allowed us to study the X-ray nebula with unprecedented detail. A spatially resolved spectral analysis with a resolution of 8\arcsec has yielded a precise determination of the relation between the spectral index and the distance from the center. We do not see any evidence for bright thermal emission from the central core. In contrast with previous ASCA and {\em Einstein} results, we derive an upper limit to the black-body 0.5-10 keV luminosity and emitting area of $1.8\times 10^{32}$ \ergsec and $1.3\times 10^{10}$ cm$^2$, respectively, ruling out emission from the hot surface of the putative neutron star and also excluding the "outer-gap" model for hot polar caps. We have performed for the first time a spectral analysis of the outer regions of the X-ray nebula, where most of the emission is still non-thermal, but where the addition of a soft (kT=0.2-0.3 keV) optically thin plasma component is required to fit the spectrum at $E<1$ keV. This component provides 6% of the whole remnant observed flux in the 0.5-10.0 keV band. We show that a Sedov interpretation is incompatible with the SN1181-3C58 association, unless there is a strong deviation from electron-ion energy equipartition, and that an origin of this thermal emission in terms of the expansion of the nebula into the ejecta core nicely fits all the radio and X-ray observations.Comment: 10 pages, 7 figures, accepted for publication in A&

Hydrological changes in the Ligurian Sea (NW Mediterranean, DYFAMED site) during 1995–2007 and biogeochemical consequences

Data obtained during the monthly cruises of the DYFAMED time-series study (northwestern Mediterranean Sea) in the period 1995–2007 were compiled to examine the hydrological changes and the linked variation of some biogeochemical characteristics (nutrients and pigments). A regular increase of temperature and salinity (0.005 °C y&lt;sup&gt;−1&lt;/sup&gt;, 0.0022 psu y&lt;sup&gt;−1&lt;/sup&gt;) was recorded in deep waters of the NW Mediterranean Sea (2000 m depth) during 1995–2005. In February 2006 an abrupt increase in &lt;i&gt;T&lt;/i&gt; (+0.1 °C) and &lt;i&gt;S&lt;/i&gt; (+0.03 psu) was measured at 2000 m depth as the result of successive intense winter mixing events during the 3 previous years. The February 2006 event led to the mixing of the whole water column (0 to &gt;2000 m) and increased salt and heat content of the Western Mediterranean Deep Water by mixing with saltier and warmer Levantine Intermediate Water. The deficit in fresh water inputs to the western Mediterranean basin in three successive years (2003–2005) was suspected to be the major cause of this event since an increase of salinity in surface waters was monitored during these years. The measured phytoplankton biomass was specifically high after the periods of intense mixing. Chlorophyll &lt;i&gt;a&lt;/i&gt; integrated biomass reached 230 mg m&lt;sup&gt;−2&lt;/sup&gt; in 1999, 175 mg m&lt;sup&gt;−2&lt;/sup&gt; in 2003, and 206 mg m&lt;sup&gt;−2&lt;/sup&gt; in 2006. The high levels of biomass were related to the particularly high increases in nutrients content in surface layers following the intense water column mixing and the subsequent development of a diatom bloom (as seen by fucoxanthin content). The occurrence of extreme events (high mixing, high nutrients, and high biomass) increased in recent drought years (2003 to 2006). Our results indicated that the NW Mediterranean Sea productivity is increasing