43 research outputs found
A review of the relationship between eggshell colour and water vapour conductance
This review brings together the available literature that examines the effect of variations in pigmentation on the gas conductance of avian eggshells. Pheasant and Houbara bustard eggs provide some evidence that shell abnormalities can impact upon colour and conductance. By contrast, data from wild birds suggest that neither the degree of maculation or intensity of ground colour impact upon gas conductance. Those studies that purport to show variation in rates of water loss in eggs with different degrees of pigmentation may have been confounded by variation in nest humidity. This emerging field of research remains very much in its infancy
New, Highly Accurate Propagator for the Linear and Nonlinear Schr\"odinger Equation
A propagation method for the time dependent Schr\"odinger equation was
studied leading to a general scheme of solving ode type equations. Standard
space discretization of time-dependent pde's usually results in system of ode's
of the form u_t -Gu = s where G is a operator (matrix) and u is a
time-dependent solution vector. Highly accurate methods, based on polynomial
approximation of a modified exponential evolution operator, had been developed
already for this type of problems where G is a linear, time independent matrix
and s is a constant vector. In this paper we will describe a new algorithm for
the more general case where s is a time-dependent r.h.s vector. An iterative
version of the new algorithm can be applied to the general case where G depends
on t or u. Numerical results for Schr\"odinger equation with time-dependent
potential and to non-linear Schr\"odinger equation will be presented.Comment: 14 page
White shark comparison reveals a slender body for the extinct megatooth shark, Otodus megalodon (Lamniformes: Otodontidae)
The extinct megatooth shark, †Otodus megalodon, which likely reached at least
15 m in total length, is an iconic extinct shark represented primarily by its gigantic teeth
in the Neogene fossil record. As one of the largest marine carnivores to ever exist,
understanding the biology, evolution, and extinction of †O. megalodon is important
because it had a significant impact on the ecology and evolution of marine ecosystems
that shaped the present-day oceans. Some attempts inferring the body form of †O.
megalodon have been carried out, but they are all speculative due to the lack of any
complete skeleton. Here we highlight the fact that the previous total body length estimated from vertebral diameters of the extant white shark for an †O. megalodon individual represented by an incomplete vertebral column is much shorter than the sum of
anteroposterior lengths of those fossil vertebrae. This factual evidence indicates that
†O. megalodon had an elongated body relative to the body of the modern white shark
(Carcharodon carcharias). Although its exact body form remains unknown, this proposition represents the most parsimonious empirical evidence, which is a significant step
towards deciphering the much-debated body form of †O. megalodon
Estudo endócrino reprodutivo e do comportamento sócio-sexual de sagui-de-tufo-preto (Callithrix penicillata) mantido em cativeiro
Editorial: Changes and Clarifications to the Policies of the International Journal of Primatology to Promote Transparency and Open Communication.
The joint meeting of the International Primatological Society and the American Society of Primatologists in Chicago 2016 provided an opportunity to discuss and update the policies of the International Journal of Primatology, the official journal of the International Primatological Society. As a result, we have made several changes and clarifications to journal policy. Most of these are to improve transparency. Scientific progress requires transparency and open communication among scientists. However, an emphasis on innovation combined with insufficient and selective reporting of methods and results impede progress. In this editorial we clarify our policies on replication, reproducibility, null results, statistical reporting, and methods validation. We have updated the Instructions for Authors and introduced badges to acknowledge open science. We also take this opportunity to summarize other changes to the International Journal of Primatology
Crop-raiding and commensalism in olive baboons::The costs and benefits of living with humans
Crop-raiding and Commensalism in Olive Baboons: The Costs and Benefits of Living with Humans
Assessing adaptability and reactive scope: Introducing a new measure and illustrating its use through a case study of environmental stress in forest-living baboons
In order to maintain regulatory processes, animals are expected to be adapted to the range of environmental stressors usually encountered in their environmental niche. The available capacity of their stress responses is termed their reactive scope, which is utilised to a greater or lesser extent to deal with different stressors. Typically, non-invasive hormone assessment is used to measure the physiological stress responses of wild animals, but, for methodological reasons, such measurements are not directly comparable across studies, limiting interpretation. To overcome this constraint, we propose a new measure of the relative strength of stress responses, ‘demonstrated reactive scope’, and illustrate its use in a study of ecological correlates (climate, food availability) of faecal glucocorticoid (fGC) levels in two forest-living troops of baboons. Results suggest the wild-feeding troop experiences both thermoregulatory and nutritional stress, while the crop-raiding troop experiences only thermoregulatory stress. This difference, together with the crop-raiding troop’s lower overall physiological stress levels and lower demonstrated fGC reactive scope, may reflect nutritional stress-buffering in this troop. The relatively high demonstrated fGC reactive scope levels of both troops compared with other baboons and primate species, may reflect their extreme habitat, on the edge of the geographic range for baboons. Demonstrated reactive scope provides a means of gauging the relative strengths of stress responses of individuals, populations, or species under different conditions, enhancing the interpretive capacity of non-invasive studies of stress hormone levels in wild populations, e.g. in terms of animals’ adaptive flexibility, the magnitude of their response to anthropogenic change, or the severity of impact of environmental conditions