자연주의적 탐구조사(Naturalistic Inquiry)

Thank you for downloading using multivariate statistics. As you may know, people have look hundreds times for their favorite novels like this using multivariate statistics, but end up in infectious downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they juggled with some harmful bugs inside their laptop. using multivariate statistics is available in our digital library an online access to it is set as public so you can download it instantly. Our books collection saves in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the using multivariate statistics is universally compatible with any devices to read.

Using Multivariate Statistics

Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

We review recent determinations of the present-day mass function (PDMF) and initial mass function (IMF) in various components of the Galaxy—disk, spheroid, young, and globular clusters—and in conditions characteristic of early star formation. As a general feature, the IMF is found to depend weakly on the environment and to be well described by a power-law form forM , and a lognormal form below, except possibly for m!1 early star formation conditions. The disk IMF for single objects has a characteristic mass around M , m!0.08 c and a variance in logarithmic mass , whereas the IMF for multiple systems hasM , and . j!0.7 m!0.2 j!0.6 c The extension of the single MF into the brown dwarf regime is in good agreement with present estimates of L- and T-dwarf densities and yields a disk brown dwarf number density comparable to the stellar one, n!n! BD " pc !3 .T he IMF of young clusters is found to be consistent with the disk fi eld IMF, providing the same correction 0.1 for unresolved binaries, confirming the fact that young star clusters and disk field stars represent the same stellar population. Dynamical effects, yielding depletion of the lowest mass objects, are found to become consequential for ages!130 Myr. The spheroid IMF relies on much less robust grounds. The large metallicity spread in the local subdwarf photometric sample, in particular, remains puzzling. Recent observations suggest that there is a continuous kinematic shear between the thick-disk population, present in local samples, and the genuine spheroid one. This enables us to derive only an upper limit for the spheroid mass density and IMF. Within all the uncertainties, the latter is found to be similar to the one derived for globular clusters and is well represented also by a lognormal form with a characteristic mass slightly larger than for the disk, M , ,e xcluding as ignif icant population of m!0.2-0.3 c brown dwarfs in globular clusters and in the spheroid. The IMF characteristic of early star formation at large redshift remains undetermined, but different observational constraints suggest that it does not extend below!1M , .T hese results suggest a characteristic mass for star formation that decreases with time, from conditions prevailing at large redshift to conditions characteristic of the spheroid (or thick disk) to present-day conditions.Theseconclusions,however, remain speculative, given the large uncertainties in the spheroid and early star IMF determinations. These IMFs allow a reasonably robust determination of the Galactic present-day and initial stellar and brown dwarf contents. They also have important galactic implications beyond the Milky Way in yielding more accurate mass-to-light ratio determinations. The mass-to-light ratios obtained with the disk and the spheroid IMF yield values 1.8-1.4 times smaller than for a Salpeter IMF, respectively, in agreement with various recent dynamical determinations. This general IMF determination is examined in the context of star formation theory. None of the theories based on a Jeans-type mechanism, where fragmentation is due only to gravity, can fulfill all the observational constraints on star formation and predict a large number of substellar objects. On the other hand, recent numerical simulations of compressible turbulence, in particular in super-Alfvenic conditions, seem to reproduce both qualitatively and quantitatively the stellar and substellar IMF and thus provide an appealing theoretical foundation. In this picture, star formation is induced by the dissipation of large-scale turbulence to smaller scales through radiative MHD shocks, producing filamentary structures. These shocks produce local nonequilibrium structures with large density contrasts, which collapse eventually in gravitationally bound objects under the combined influence of turbulence and gravity. The concept of a single Jeans mass is replaced by a distribution of local Jeans masses, representative of the lognormal probability density function of the turbulent gas. Objects below the mean thermal Jeans mass still have a possibility to collapse, although with a decreasing probability.

/pdf/galactic-stellar-and-substellar-initial-mass-function-1fntlgtk9q.pdf

Galactic stellar and substellar initial mass function

In the 1980s, exosomes were described as vesicles of endosomal origin secreted from reticulocytes. Interest increased around these extracellular vesicles, as they appeared to participate in several cellular processes. Exosomes bear proteins, lipids, and RNAs, mediating intercellular communication between different cell types in the body, and thus affecting normal and pathological conditions. Only recently, scientists acknowledged the difficulty of separating exosomes from other types of extracellular vesicles, which precludes a clear attribution of a particular function to the different types of secreted vesicles. To shed light into this complex but expanding field of science, this review focuses on the definition of exosomes and other secreted extracellular vesicles. Their biogenesis, their secretion, and their subsequent fate are discussed, as their functions rely on these important processes.

/pdf/biogenesis-secretion-and-intercellular-interactions-of-4pskmvujl3.pdf

Biogenesis, Secretion, and Intercellular Interactions of Exosomes and Other Extracellular Vesicles

Until now, all the clouds imaged in Titan's troposphere have been found at far southern latitudes (60°-90° south). The occurrence and location of these clouds is thought to be the result of convection driven by the maximum annual solar heating of Titan's surface, which occurs at summer solstice (2002 October) in this south polar region. We report the first observations of a new recurring type of tropospheric cloud feature, confined narrowly to ~40° south latitude, which cannot be explained by this simple insolation hypothesis. We propose two classes of formation scenario, one linked to surface geography and the other to seasonally evolving circulation, which will be easily distinguished with continued observations over the next few years.

Discovery of Temperate Latitude Clouds on Titan

A 6-month-long monitoring campaign of the Io plasma torus and neutral cloud was conducted to determine the characteristics of their interaction. During the observations, a large outburst of material from Io—inferred to be caused by the eruption of a volcanic plume on Io—caused a transient increase in the neutral cloud and plasma torus masses. The response of the plasma torus to this outburst shows that the interaction between Io and Jupiter's magnetosphere is stabilized by a feedback mechanism in which increases in the plasma torus mass cause a nonlinear increase in loss from the plasma torus, limiting plasma buildup.

http://science.sciencemag.org/content/sci/278/5336/268.full.pdf

The response of Jupiter's magnetosphere to an outburst on Io.

The first phase of the Caltech Wide Area Sky Survey occurred from late November 2001 through mid-April 2003 We present preliminary results from this survey which has detected 28 bright Kuiper Belt Objects (KBOs) and 4 Centaurs, 19 of which were discovered in our survey including Quaoar, the largest KBO, as well as 6 of the 10 intrinsically brightest KBOs We have surveyed 5108 square degrees of the sky nearest the invariable plane to a limiting red magnitude of 207 Correcting for the overabundance of objects near the invariable plane, this represents 27% completeness in terms of KBO numbers Thus, approximately 100 KBOs and Centaurs brighter than m R = 207 exist, about 3/4 of which remain undiscovered The bright KBOs are consistent with the canonical q = 4 size distribution, suggesting that about ten 1000 km diameter KBOs and about one 2000 km diameter KBO exist Additionally, we observe only 3 KBOs with low inclination (i 3σ level This suggests that the bright KBOs have a fundamentally different maximum size than the fainter KBOs A better characterization of the survey limiting magnitude and a more thorough modeling of observational bias effects of different classes of KBOs will be made in a future work

The Caltech Wide Area Sky Survey

We report the detection of H{$\alpha$} emission in the T dwarf (methane brown dwarf) 2MASSW J1237392+652615 over three days using the Keck Low Resolution Imaging Spectrograph. The measured line flux, log(L$_{H{\alpha}}$/L$_{bol}$) = $-$4.3, is roughly consistent with early M dwarf activity levels and inconsistent with decreasing activity trends in late M and L dwarfs. Similar emission is not seen in two other T dwarfs. We speculate on several mechanisms that may be responsible for emission, including a strong magnetic field, continuous flaring, acoustic heat generation, and a close ($a$ $\sim$ 4 - 20 R$_{Jup}$) interacting binary, with the cooler component overflowing its Roche lobe. We suggest that the M9.5Ve PC 0025+0447 could be a warm analogue to 2MASS J1237+65, and may be powered by the latter mechanism.

/pdf/detection-of-h-alpha-emission-in-a-methane-t-type-brown-3ph0wlo370.pdf

Detection of H Alpha Emission in a Methane (T-Type) Brown Dwarf

Ground‐based high‐resolution spectra of emission from the Io plasma torus obtained during 53 nights of observation over a seven month period are used to measure the torus rotation speed and discern regions of the torus that are slowed by mass loading of newly ionized materials. The amount of torus slowing implies that between 2000 and 3000 kg sec^(−1) are being ionized by the torus. The slowing is spread azimuthally throughout the orbit of Io, suggesting that neutral materials emanating from Io are distributed around Jupiter much more uniformly than currently believed.

/pdf/observation-of-mass-loading-in-the-io-plasma-torus-2xqmyoymzh.pdf

Michael E. Brown

Papers

Discovery of Temperate Latitude Clouds on Titan

The response of Jupiter's magnetosphere to an outburst on Io.

The Caltech Wide Area Sky Survey

Detection of H Alpha Emission in a Methane (T-Type) Brown Dwarf

Observation of mass loading in the Io plasma torus