A simple permutation test for clusteredness

Hierarchical clustering is a popular method for finding structure in multivariate data,resulting in a binary tree constructed on the particular objects of the study, usually samplingunits. The user faces the decision where to cut the binary tree in order to determine the numberof clusters to interpret and there are various ad hoc rules for arriving at a decision. A simplepermutation test is presented that diagnoses whether non-random levels of clustering are presentin the set of objects and, if so, indicates the specific level at which the tree can be cut. The test isvalidated against random matrices to verify the type I error probability and a power study isperformed on data sets with known clusteredness to study the type II error.

Identification of three Sorex species with microsatellite markers

Three sibling species of shrews, the common shrew (Sorex araneus), the Valais shrew (S. antinorii) and the Jersey shrew (S. coronatus) are morphologically similar. Different techniques based on karyorypes, morphology, biochemistry and genetic markers have been developed to identify individuals from these taxa. In this paper, we have used multiple microsatellite markers (L13, L14 and L99) to identify 55 dead animals coming from the Tarentaise Valley in France. As some individuals showed an unclear pattern with loci previously thought to be diagnostic (Lugon-Moulin et al. 2000), we have used morphologic measurements (Hausser et al. 1991) to confirm the status of these animals. This analysis clearly showed the limitations of the use of genetic diagnostic markers that have been designed in local populations and then applied to a wider scale. Even if these markers have great advantages over other techniques (i.e. simple to use and do not require samples from living animals), they should always be used with caution. There is always a risk of a locus not being diagnostic in the sampling region or in finding individuals with hybrid genotypes. Additional genetic markers should then be used, simultaneously with other identification techniques, to be sure of the status of the individuals.

Senior Living Program State Fiscal Year 2004 Report, July 1, 2003-June 30, 2004

This report shows the number of older low-income and moderate-income Iowans who received service from the Senior Living Program (SLP) and the number of units by service category. Additionally, it shows the number of persons served across services. In other words, if you add the total number of clients from all services it is higher than the actual number of persons served across all services, because some people need and receive more than one service. (Please note: this is preliminary data, and may be subject to change.)

Senior Living Program State Fiscal Year 2003 Report (July 1, 2002-June 30, 2003)

This report shows the number of older low-income and moderate-income Iowans who received service from the Senior Living Program (SLP) and the number of units by service category. Additionally, it shows the number of persons served across services. In other words, if you add the total number of clients from all services it is higher than the actual number of persons served across all services, because some people need and receive more than one service. (Please note: this is preliminary data, and may be subject to change.)

Senior Living Program Report, July 1, 2007-July 31, 2007 Senior Living Program Report, July 1, 2007-August 31, 2007

This report shows the number of older low-income and moderate-income Iowans who received service from the Senior Living Program (SLP) and the number of units by service category. Additionally, it shows the number of persons served across services. In other words, if you add the total number of clients from all services it is higher than the actual number of persons served across all services, because some people need and receive more than one service. (Please note: this is preliminary data, and may be subject to change.)

Senior Living Program Report, July 1, 2007-August 31, 2007

This report shows the number of older low-income and moderate-income Iowans who received service from the Senior Living Program (SLP) and the number of units by service category. Additionally, it shows the number of persons served across services. In other words, if you add the total number of clients from all services it is higher than the actual number of persons served across all services, because some people need and receive more than one service. (Please note: this is preliminary data, and may be subject to change.)

Independent Living Program, Vol. 3, 2007

The Iowa Department for the Blind is the state agency that serves Iowans with vision loss. Services are free, confidential and available statewide. "There are no limitations to what you can do with training and a positive attitude." (All quotes in this newsletter are from former training participants). At the Iowa Department for the Blind, we believe in a positive approach to blindness. Vision loss alone should not prevent anyone from being independent. For this reason, we offer a wide variety of opportunities to obtain the skills necessary for independence.

Simple models for multi-attribute choice with many alternatives: When it does and does not pay to face tradeoffs with binary attributes

Working Paper no longer available. Please contact the author.

Breeding sites of Neotropical Drosophilidae (Diptera): IV. living and fallen flowers of Sessea brasiliensis and Cestrum spp. (Solanaceae)

The flowering phenologies of Sessea brasiliensis and three species of Cestrum (C. amictum, C. schlechtendalii and C. sendtnerianum), all belonging to the Solanaceae, were monitored in a fragment of the montane Atlantic rain forest within São Paulo city from July 1993 through June 1995. A total of 11,021 flies belonging to five species of the flavopilosa group of Drosophila (D. cestri, D. cordeiroi, D. hollisae, D. incompta and D. mariaehelenae), plus 1,244 flies belonging to four species of Zygothrica (Z. dispar, Z. vittimaculosa, Z. vittinubila and Z. aff. vittipunctata) emerged from 33,955 sampled flowers. Cestrum amictum, C. sendtnerianum and Sessea brasiliensis are recorded for the first time as host plants for the species of the Neotropical flavopilosa group ofDrosophila. Additionally, at least ten less abundant taxa belonging also to the Drosophilidae, plus 1,073 microhymenopteran parasitoids (Braconidae, Eucoilidae, and Pteromalidae), emerged from the sampled flowers of S. brasiliensis e Cestrum spp. The present study raised from nine to eleven the number of species of Cestrum previously recorded as breeding sites for these flies. A comprehensive list of species of Solanaceae known to host six species of Drosophila and four species of Zygothrica in southeastern and southern Brazil is included.

Aleo Vera living barriers - Cape Verde - Barreiras Vivas de Aleo vera (Portuguese)

Projecto DESIRE - Cabo Verde

A simple adaptive procedure leading to correlated equilibrium

We propose a simple adaptive procedure for playing a game. In thisprocedure, players depart from their current play with probabilities thatare proportional to measures of regret for not having used other strategies(these measures are updated every period). It is shown that our adaptiveprocedure guaranties that with probability one, the sample distributionsof play converge to the set of correlated equilibria of the game. Tocompute these regret measures, a player needs to know his payoff functionand the history of play. We also offer a variation where every playerknows only his own realized payoff history (but not his payoff function).

Take-the-best and other simple strategies: Why and when they work 'well' in binary choice

The effectiveness of decision rules depends on characteristics of bothrules and environments. A theoretical analysis of environments specifiesthe relative predictive accuracies of the lexicographic rule 'take-the-best'(TTB) and other simple strategies for binary choice. We identify threefactors: how the environment weights variables; characteristics of choicesets; and error. For cases involving from three to five binary cues, TTBis effective across many environments. However, hybrids of equal weights(EW) and TTB models are more effective as environments become morecompensatory. In the presence of error, TTB and similar models do not predictmuch better than a naïve model that exploits dominance. We emphasizepsychological implications and the need for more complete theories of theenvironment that include the role of error.