Within The City Gates : Theme Varie

https://digitalcommons.library.umaine.edu/mmb-ps/1721/thumbnail.jp

Correspondence from C. Ripley

Correspondence from C. Ripley regarding absent soldiers from Oxford Count

Strains From The Rocky Mountains : Reverie

https://digitalcommons.library.umaine.edu/mmb-ps/1901/thumbnail.jp

Comments on the avifauna of Tanzania, II

Buccanodon olivaceum ulugurensis and Viridubucco leucomystax meridionalis (both Capitonidae), new subspecies, are described on the basis of morphological characters. Evidence is presented that Dendropicos fuscescens (Vieillot) and Dendropicos lafresnayi Malherbe ( = D. f. lafresnayi Malherbe) are distinct taxa. The distribution of Smithornis capensis (Smith) is redefined based on an examination of a large series of specimens from eastern Africa. Smithornis capensis meinertzhageni van Someren, S. c. suahelicus Grote, S. c. shimba van Someren, and S. c. chyulu van Someren are reinstated as valid subspecies and a key to their identification is given. Macrodipteryx longipennis (Shaw) is recorded as new to Tanzania. New records of Modulatrix stictigula stictigula (Reichenow) from the Uzungwa Plateau show that this subspecies has a disjunct range in south-central Tanzania. Species and subspecies representing extensions of geographic range in Tanzania are Caprimulgus poliocephalus Ruppell, Tricholaema lacrymosum lacrymosum Cabanis and T. I. ruahae Neumann. Field data from specimens of Alethe fulleborni (Reichenow) reveal that the breeding season coincides with the rainy season, October to March. Call notes and behavior of this species, based on field observations, are also recorded

Additions to the avifauna of northern Angola II

The present publication is a continuation of the report published in Postilla no. 47, 1960. It refers to the same collection, procured by Mr. and Mrs. Heinrich for the Peabody Museum during the course of their expedition to Angola in 1957-1958…

Additions to the avifauna of northern Angola I.

During the course of a year\u27s visit to Angola for the Peabody Museum in 1957-58 by one of us (Heinrich) a number of interesting new records were made…

Comments on the avifauna of Tanzania I

In 1961-63 Gerd H. Heinrich and his wife, accompanied during the first year by their son Bernd Heinrich, carried out an ornithological expedition through Tanzania…

Likelihood informed dimension reduction for inverse problems in remote sensing of atmospheric constituent profiles

We use likelihood informed dimension reduction (LIS) (T. Cui et al. 2014) for inverting vertical profile information of atmospheric methane from ground based Fourier transform infrared (FTIR) measurements at Sodankyl\"a, Northern Finland. The measurements belong to the word wide TCCON network for greenhouse gas measurements and, in addition to providing accurate greenhouse gas measurements, they are important for validating satellite observations. LIS allows construction of an efficient Markov chain Monte Carlo sampling algorithm that explores only a reduced dimensional space but still produces a good approximation of the original full dimensional Bayesian posterior distribution. This in effect makes the statistical estimation problem independent of the discretization of the inverse problem. In addition, we compare LIS to a dimension reduction method based on prior covariance matrix truncation used earlier (S. Tukiainen et al. 2016)

Ecophysiological traits of grasses: resolving the effects of photosynthetic pathway and phylogeny

C4 photosynthesis is an important example of convergent evolution in plants, having arisen in eudicots, monocots and diatoms. Comparisons between such diverse groups are confounded by phylogenetic and ecological differences, so that only broad generalisations can be made about the role of C4 photosynthesis in
determining ecophysiological traits. However, 60% of C4 species occur in the grasses (Poaceae) and molecular phylogenetic techniques confirm that there are between 8 and 17 independent origins of C4 photosynthesis in the Poaceae. In a screening experiment, we compared leaf physiology and growth traits across several major
independent C3 & C4 groups within the Poaceae, asking 1) which traits differ consistently between photosynthetic
types and 2) which traits differ consistently between clades within each photosynthetic type

Phase transitions in optimal unsupervised learning

We determine the optimal performance of learning the orientation of the symmetry axis of a set of P = alpha N points that are uniformly distributed in all the directions but one on the N-dimensional sphere. The components along the symmetry breaking direction, of unitary vector B, are sampled from a mixture of two gaussians of variable separation and width. The typical optimal performance is measured through the overlap Ropt=B.J* where J* is the optimal guess of the symmetry breaking direction. Within this general scenario, the learning curves Ropt(alpha) may present first order transitions if the clusters are narrow enough. Close to these transitions, high performance states can be obtained through the minimization of the corresponding optimal potential, although these solutions are metastable, and therefore not learnable, within the usual bayesian scenario.Comment: 9 pages, 8 figures, submitted to PRE, This new version of the paper contains one new section, Bayesian versus optimal solutions, where we explain in detail the results supporting our claim that bayesian learning may not be optimal. Figures 4 of the first submission was difficult to understand. We replaced it by two new figures (Figs. 4 and 5 in this new version) containing more detail