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Purpose: To assess the ability of a new posterior pole protocol to detect areas with significant differences in retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness in patients with multiple sclerosis versus healthy control subjects; in addition, to assess the correlation between RNFL and GCL thickness, disease duration, and the Expanded Disability Status Scale (EDSS). Methods: We analyzed 66 eyes of healthy control subjects and 100 eyes of remitting-relapsing multiple sclerosis (RR-MS) patients. Double analysis based on first clinical symptom onset (CSO) and conversion to clinically definite MS (CDMS) was performed. The RR-MS group was divided into subgroups by CSO and CDMS year: CSO-1 (≤ 5 years) and CSO-2 (≥ 6 years), and CDMS-1 (≤ 5 years) and CDMS-2 (≥ 6 years). Results: Significant differences in RNFL and GCL thickness were found between the RR-MS group and the healthy controls and between the CSO and CDMS subgroups and in both layers. Moderate to strong correlations were found between RNFL and GCL thickness and CSO and CDMS. Furthermore, we observed a strong correlation with EDSS 1 year after the OCT examination. Conclusions: The posterior pole protocol is a useful tool for assessing MS and can reveal differences even in early stages of the disease. RNFL thickness shows a strong correlation with disability status, while GCL thickness correlates better with disease duration. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2009.02.004 Byline: Jose Martin (a), Pilar Lopez (a), Vicente Polo (b) Abstract: Prey experience a broad range of temporal patterns of predation risk and may face different problems when assessing risk level and deciding how to allocate costly antipredator behaviour across time. We simulated in the laboratory repeated predatory attacks of different intensity (low versus high risk) to Iberian rock lizards, Iberolacerta cyreni, with similar numbers of low- and high-risk attacks across a trial, but with different temporal patterns of presentation (i.e. a series of low-risk and then a series of high risk, or vice versa, or successive attacks where risk changed randomly). We measured activity levels, time hidden in refuges after each predatory attack, and propensity to hide in refuges when the predator is close but not actually attacking ('false alarm' flights). Antipredator responses were of higher intensity when risk was high, but responses also depended on temporal patterns of risk. When previous attacks were of low-risk or when risk was random, prey activity did not change between risk levels. False alarm flights in the low-risk situation were more frequent when risk was random or immediately after a series of high-risk attacks. When successive attacks were of similar risk level, lizards seemed able to predict risk level in the next attack and modified their antipredator behaviour accurately. However, when risk level was random, lizards did not seem able to predict risk level and adopted a conservative strategy, overestimating risk even though costs of the antipredator responses increased. Author Affiliation: (a) Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Spain (b) Area de Biodiversidad & Conservacion, Escuela Superior de Ciencias Experimentales y Tecnologia (ESCET), Universidad Rey Juan Carlos, Madrid, Spain Article History: Received 23 October 2008; Revised 22 November 2008; Accepted 8 February 2009 Article Note: (miscellaneous) MS. number: 08-00693R

Optimal life‐history theory predicts that individuals should adjust both the number and the sex of their offspring to maximize fitness in response to environmental and social factors such as breeding density. While reductions in optimal clutch size are well‐studied in birds, the evidence for sex ratio adjustments is still equivocal and, so far, we lack a thorough understanding of how these strategies interact to maximize fitness. Here, we investigate how breeding density simultaneously affects brood sex ratio and clutch size in a sexually dimorphic and polygynous bird. We tested the prediction that mothers breeding at a higher density lay smaller clutches and overproduce daughters, the sex with less variable fitness returns and that disperses further away from their natal territory. We distributed nest boxes at either a high (HD) or a low density (LD) and monitored clutch sizes and sex ratios during five years in a wild breeding colony of spotless starlings. While mothers breeding in HD nests produced more daughters than those breeding in LD nests, the density dependence of clutch size varied among years, with a tendency to lay smaller clutches in HD nests. Our results suggest that mothers consistently adjust offspring sex ratio in response to breeding density, whereas adjustments in clutch size varied in a more complex way. These results support the role of sex allocation strategies in response to density and show that further theoretical and empirical research is required to understand the interaction between clutch size and sex ratio adjustments in animals. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2007.10.006 Byline: Juan Carranza, Vicente Polo, Juliana Valencia, Concha Mateos, Carlos de la Cruz Abstract: In cooperatively breeding systems, breeders may reduce their provisioning to the brood when aided by helpers. However, this is found in only some species, and the reasons for the different reactions of breeders are far from clear. Recently, a paradoxical case of breeders in the azure-winged magpie, Cyanopica cyanus, increasing their contribution when aided by helpers has further complicated the issue. Existing models on the response of breeders consider only whether helpers contribute to increase the amount of food delivered to the brood. Helpers, however, can also contribute with other types of help that may increase the value of the whole brood for parents, such as reducing predation rate. Here we present a deterministic decision-making model to predict how parents should reduce or increase their parental effort on the basis of the relative role of both types of helpers' contributions: delivering food and/or dispensing protection against predation. The model can be used by field workers to make qualitative and quantitative predictions with their data. As an example, we show how data for the azure-winged magpie predicts the observed increase of parental contribution in the presence of helpers. Author Affiliation: (a) Biology & Ethology Research Group, University of Extremadura, Spain (a ) Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Spain Article History: Received 21 February 2007; Revised 23 April 2007; Accepted 5 October 2007 Article Note: (miscellaneous) MS. number: 9276

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2005.11.027 Byline: Luis M. Carrascal, Vicente Polo Abstract: Theoretical and experimental evidence suggests that an increase in flight costs will decrease flight performance, and that birds should trade-off the benefits of body reserves to minimize these costs. Alternatively, birds could avoid starvation by increasing food intake, thereby maintaining body reserves, and/or decreasing flight activity to compensate for the greater per unit flight costs. To test the effect of increased flight costs on body mass regulation and on flying and feeding activity, we experimentally manipulated wing area in a free-ranging wintering population of coal tits, Periparus ater, and in captive birds living in a less restrictive environment (large outdoor aviaries). In the field, body mass decreased when wing area was reduced, but heavier birds lost more weight than lighter birds as a consequence of an allometric increase in flying costs. However, wing area reduction had no effect on body mass in the aviaries. Birds also flew less when wing area was reduced and those with higher wing loadings decreased flying frequency more markedly. We suggest that the goal of small resident birds living in a Mediterranean montane climate would be to maintain daily fat reserves within narrow limits during autumn and winter, even under contrasting ecological conditions. Author Affiliation: Museo Nacional de Ciencias Naturales, CSIC, Spain Article History: Received 26 October 2004; Revised 14 February 2005; Accepted 25 November 2005 Article Note: (miscellaneous) MS. number: 8316R