Marguerite

https://digitalcommons.library.umaine.edu/mmb-vp/6080/thumbnail.jp

The Sinking Ship

https://digitalcommons.library.umaine.edu/mmb-vp/6636/thumbnail.jp

Predation Risk and Elk-Aspen Foraging Patterns

Elk-aspen foraging patterns may be influenced by cover type, distance from roads or trails, the type of user on road or trail (park visitor, human hunter, or predator), and two general states of aspen condition (open-grown or thicket). Pellet group and browse utilization transects in the Canadian Rockies showed that elk were attracted to roads used by park visitors and avoided by wolves, and that elk possibly avoided aspen and conifer patches near backcountry trails used by wolves. In high predation risk landscapes, aspen stands were dense, lightly browsed, and rarely entered by elk. As risk decreased, elk density and aspen browsing increased proportionally faster on edges of aspen stands compared to the interior of aspen stands. In low risk landscapes, edge and interior plots were intensively used, and stands had a low density of heavily browsed stems. Regeneration of aspen stands likely requires low densities of risk-sensitive elk

A Bosonic Model of Hole Pairs

We numerically investigate a bosonic representation for hole pairs on a two-leg t-J ladder where hard core bosons on a chain represent the hole pairs on the ladder. The interaction between hole pairs is obtained by fitting the density profile obtained with the effective model to the one obtained with the \tj model, taking into account the inner structure of the hole pair given by the hole-hole correlation function. For these interactions we calculate the Luttinger liquid parameter, which takes the universal value $K_{\rho}=1$ as half filling is approached, for values of the rung exchange $J'$ between strong coupling and the isotropic case. The long distance behavior of the hole-hole correlation function is also investigated. Starting from large $J'$, the correlation length first increases as expected, but diminishes significantly as $J'$ is reduced and bound holes sit mainly on adjacent rungs. As the isotropic case is approached, the correlation length increases again. This effect is related to the different kind of bonds in the region between the two holes of a hole pair when they move apart.Comment: 11 page

Approximate solutions in space mission design

In this paper, we address multi-objective space mission design problems. From a practical point of view, it is often the case that,during the preliminary phase of the design of a space mission, the solutions that are actually considered are not 'optimal' (in the Pareto sense)but belong to the basin of attraction of optimal ones (i.e. they are nearly optimal). This choice is motivated either by additional requirements that the decision maker has to take into account or, more often, by robustness considerations. For this, we suggest a novel MOEA which is a modification of the well-known NSGA-II algorithm equipped with a recently proposed archiving strategy which aims at storing the set of approximate solutions of a given MOP. Using this algorithm we will examine some space trajectory design problems and demonstrate the benefit of the novel approach

Embodied Experiences of Trans Pregnancy

Drawing on interview data from the international project Trans Pregnancy: An International Exploration of Transmasculine Practices of Reproduction this article explores embodied experiences of male, trans/masculine and non-binary pregnancy. Moving beyond the spectacle of the ‘pregnant’ man, our analysis builds on existing literature on trans health and embodiment in order to develop a deeper understanding of the lived, bodily complexities of trans pregnancy. We consider the strategies men, trans/masculine and non-binary folks engage in to manage gender presentation during pregnancy and the degree to which pregnancy disrupts the ability to control the presentation of gender. Our analysis contributes to the deconstruction of normative readings of the relationship between gender and the body and highlights the need for improvements in trans and non-binary reproductive healthcare

Modelling the effect of temperature on the seasonal population dynamics of temperate mosquitoes

Mosquito-borne diseases cause substantial mortality and morbidity worldwide. These impacts are widely predicted to increase as temperatures warm and extreme precipitation events become more frequent, since mosquito biology and disease ecology are strongly linked to environmental conditions. However, direct evidence linking environmental change to changes in mosquito-borne disease is rare, and the ecological mechanisms that may underpin such changes are poorly understood. Environmental drivers, such as temperature, can have non-linear, opposing impacts on the demographic rates of different mosquito life cycle stages. As such, model frameworks that can deal with fluctuations in temperature explicitly are required to predict seasonal mosquito abundance, on which the intensity and persistence of disease transmission under different environmental scenarios depends. We present a novel, temperature-dependent, delay-differential equation model, which incorporates diapause and the differential effects of temperature on the duration and mortality of each life stage and demonstrates the sensitivity of seasonal abundance patterns to inter- and intra-annual changes in temperature. Likely changes in seasonal abundance and exposure to mosquitoes under projected changes in UK temperatures are presented, showing an increase in peak vector abundance with warming that potentially increases the risk of disease outbreaks

Transnormativity in the psy disciplines: Constructing pathology in the Diagnostic and Statistical Manual and Standards of Care

The psy disciplines (i.e., psychiatry, psychology, psychoanalysis, and psychotherapy) have played a significant role in shaping understandings of transgender people’s lives in ways that are transnormative (i.e., by emphasizing one particular account of what it means to be transgender). This paper documents 1) how the rise of the psy disciplines created opportunities for transgender people to access treatment (but that such access often required tacit acceptance of transnormativity), and 2) how transgender people have resisted transnormative accounts within the psy disciplines. More specifically, this paper explores how both the American Psychiatric Association’s Diagnostic and Statistical Manual, and what is now the World Professional Association for Transgender Health’s Standards of Care, have often enshrined highly regulatory accounts of transgender people’s lives, while also changing over time, in part due to the contributions of transgender people. The paper concludes by considering recent contributions by transgender people in terms of the use of informed consent models of care and clinical research, and highlights the ongoing marginalization of transgender people in terms of access to ethical, trans-competent care

Phase separation in t-J ladders

The phase separation boundary of isotropic t-J ladders is analyzed using density matrix renormalization group techniques. The complete boundary to phase separation as a function of J/t and doping is determined for a chain and for ladders with two, three and four legs. Six-chain ladders have been analyzed at low hole doping. We use a direct approach in which the phase separation boundary is determined by measuring the hole density in the part of the system which contains both electrons and holes. In addition we examine the binding energy of multi-hole clusters. An extrapolation in the number of legs suggests that the lowest J/t for phase separation to occur in the two dimensional t-J model is J/t~1.Comment: 8 pages in revtex format including 13 embedded figures, one reference adde

Charge density correlations in t-J ladders investigated by the CORE method

Using 4-site plaquette or rung basis decomposition, the CORE method is applied to 2-leg and 4-leg t-J ladders and cylinders. Resulting range-2 effective hamiltonians are studied numerically on periodic rings taking full advantage of the translation symmetry as well as the drastic reduction of the Hilbert space. We investigate the role of magnetic and fermionic degrees of freedom to obtain the most reliable representation of the underlying model. Spin gaps, pair binding energies and charge correlations are computed and compared to available ED and DMRG data for the full Hamiltonian. Strong evidences for short-range diagonal stripe correlations are found in periodic 4-leg t-J ladders.Comment: Computation of Luttinger liquid parameters (charge velocity and charge correlation exponent) adde