Alien Registration- Crone, Roy E. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/24221/thumbnail.jp

Alien Registration- Crone, Roy E. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/24221/thumbnail.jp

Alien Registration- Crone, Roy E. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/24221/thumbnail.jp

Alien Registration- Crone, Roy E. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/24221/thumbnail.jp

Rare plants are common where you find them

Broad patterns in distribution and abundance can elucidate processes of evolution. A positive association between local abundance and the size of the geographic range has been demonstrated for closely related species across many taxa. This pattern is usually explained by assuming that species with smaller ranges are ecologically inferior (e.g., poor competitors or dispersers). Many areas of high endemism support local species that have evolved recently. The distribution of these neoendemics may reflect historical processes not accounted for by ecological, equilibrium hypotheses. We asked whether such traditional macroecological hypotheses also applied to the local abundance of seven narrowly endemic species and ecologically similar widespread congeners in the northern Rocky Mountains. For each of the 14 species, we estimated abundance of five randomly chosen populations by counting plants in 10 randomly located plots. The association between range size and local abundance was not positive. Instead, all seven narrow endemics were more abundant than their widespread congeners. Ecological specialization or differences in dispersal ability are not likely explanations for our results. We believe the local abundance of narrowly endemic species may be a sign of recent speciation. Most or all of our narrowly distributed species have probably not yet had time to spread to their full potential. Furthermore, theory predicts that speciation is more likely to occur in locally abundant populations. Our results suggest that strictly ecological mechanisms cannot explain abundance and distribution in regions with high neoendemism

Disappearing Plants: Why They Hide and How They Return

Prolonged dormancy is a life-history stage in which mature plants fail to resprout for one or more growing seasons and instead remain alive belowground. Prolonged dormancy is relatively common, but the proximate causes and consequences of this intriguing strategy have remained elusive. In this study we tested whether stored resources are associated with remaining belowground, and investigated the resource costs of remaining belowground during the growing season. We measured stored resources at the beginning and end of the growing season in Astragalus scaphoides, an herbaceous perennial in southwest Montana, USA. At the beginning of the growing season, dormant plants had lower concentrations of stored mobile carbon (nonstructural carbohydrates, NSC) than did emergent plants. Surprisingly, during the growing season, dormant plants gained as much NSC as photosynthetically active plants, an increase most likely due to remobilization of structural carbon. Thus, low levels of stored NSC were associated with remaining belowground, and remobilization of structural carbon may allow for dormant plants to emerge in later seasons. The dynamics of NSC in relation to dormancy highlights the ability of plants to change their own resource status somewhat independently of resource assimilation, as well as the importance of considering stored resources in understanding plant responses to the environment

Het zieke kind: een zorg voor huisarts en kinderarts

[s er een reden tot zorg over de wijze waarop de medische zorg voor kinderen in het Nederlandse gezondheidszorgsysteem is verankerd? Ogenschijnlijk niet! Vrijwel nergens ter wereld zijn de cijfers die een maat vormen voor de gezondheidstoestand van kinderen gunstiger. Zou het toch nog beter kunnen2 De zorg voor het zieke kind is in ons land primair de taak van de huisarts, dit in tegenstelling tot de situatie in veel andere landen waar zowel de curatieve als de preventieve zorg veelal door de kinderarts wordt verleend. Specialistische zorg, ook die van de kinderarts, wordt gegeven na verwijzing en de preventieve zorg is in handen van de jeugdgezondheidszorg. Zijn er punten waarop de zorg door de huisarts te kort schiet, op welke wijze zou de kinderarts kunnen bijdragen aan een verbetering van de zorg en is de wisselwerking tussen de circuits waarin de zorg wordt verleend optimaal? Voor de afdelingen huisartsgeneeskunde en kindergeneeskunde van de Erasmus Universiteit Rotterdam was dit begin jaren tachtig een discussiepunt. In 1986 werden door het Ministerie van Onderwijs en Wetenschappen gelden beschikbaar gesteld voor projecten, gericht op onderzoek dat een bijdrage levert aan de versterking van de extramurale gezondheidszorg. Uit het Vernieuwingsfonds Extramurale Vakken/Toponderzoek Eerstelijn werden gelden toegekend aan de afdelingen Huisartsgeneeskunde en Kindergeneeskunde van de Erasmus Universiteit Rotterdam om onderzoek te verrichten naar de samen~ werking tussen huisarts en kinderarts. De doelstelling van het onderzoek was na te gaan of er knelpunten zijn in de wiize waarop de zorg voor zieke kinderen door huisarts en kinderarts wordt gerealiseerd en op welke punten de samenwerking tussen huisarts en kinderarts niet optimaal is. Indien problemen gesignaleerd werden zou worden nagegaan of de werkwijze van en de interacties tussen huisarts en kinderarts door interventies verbeterd konden worden, er van uitgaande dat dit zou bijdragen tot de verbetering van de zorg voor het zieke kind

The Cosmological Dependence of Cluster Density Profiles

We use N-body simulations to study the shape of mean cluster density and velocity profiles formed via gravitational instability. The dependence of the final structure on both cosmology and initial density field is examined, using a grid of cosmologies and scale-free initial power spectra P\propto k^n. For each model, we stack clusters to define an average density profile in the non-linear regime. The profiles are well fit by a power law over 99% of the cluster volume, with a clear trend toward steeper slopes with both increasing n and decreasing Omega_o. For models with a Omega_o = 0.2, the profile slopes are consistently higher than those for Omega-1.0. Cluster density profiles are thus potentially useful cosmological diagnostics. We find no evidence for a constant density core in any of the models, although the density profiles do tend to flatten at small radii. Much of the flattening is due to the force softening required by the simulations, and an attempt is made to recover the unsoftened profiles assuming angular momentum invariance. The recovered profiles in the Omega=1 cosmologies are consistent with a pure power law up to the highest density contrasts (10^6) accessible with our resolution. The low density models show significant deviations from a power law above density contrasts \sim 10^5. We interpret this curvature as reflecting the non scale-invariant nature of the background cosmology in these models.Comment: uuencoded, 22 pages + 13 figs. Astrophysical Journal, in pres