Relative Impacts of Adult Movement, Larval Dispersal and Harvester Movement on the Effectiveness of Reserve Networks

Movement of individuals is a critical factor determining the effectiveness of reserve networks. Marine reserves have historically been used for the management of species that are sedentary as adults, and, therefore, larval dispersal has been a major focus of marine-reserve research. The push to use marine reserves for managing pelagic and demersal species poses significant questions regarding their utility for highly-mobile species. Here, a simple conceptual metapopulation model is developed to provide a rigorous comparison of the functioning of reserve networks for populations with different admixtures of larval dispersal and adult movement in a home range. We find that adult movement produces significantly lower persistence than larval dispersal, all other factors being equal. Furthermore, redistribution of harvest effort previously in reserves to remaining fished areas (‘fishery squeeze’) and fishing along reserve borders (‘fishing-the-line’) considerably reduce persistence and harvests for populations mobile as adults, while they only marginally changes results for populations with dispersing larvae. Our results also indicate that adult home-range movement and larval dispersal are not simply additive processes, but rather that populations possessing both modes of movement have lower persistence than equivalent populations having the same amount of ‘total movement’ (sum of larval and adult movement spatial scales) in either larval dispersal or adult movement alone

Dementia and mild cognitive impairment in patients with Parkinson's disease Demência e transtorno cognitivo leve em pacientes com doença de Parkinson

The objective of this research was to assess the occurrence of cognitive impairment in 32 individuals (average age: 67.2 years old) with Parkinson' disease (PD). Procedures: clinical-neurological assessment; modified Hoehn and Yahr staging scale (HYS); standard neuropsychological battery of CERAD (Consortium to Establish a Registry for Alzheimer' Disease); Pfeffer questionnaire; and Clinical Dementia Rating. A comparison was made with a control group (CG), consisting of 26 individuals with similar age and educational level but without cognitive impairment. The PD patients showed an inferior performance in the CERAD battery when compared to the CG. Three PD sub-groups were characterised according to cognition: no cognitive impairment - 15 cases; mild cognitive impairment - 10; dementia - 7 cases. There was a significant association between motor disability (HYS) and the occurrence of dementia. Dementia and mild cognitive impairment frequently occur in PD patients and should be investigated in a routine way.<br>O objetivo desta pesquisa foi avaliar a ocorrência de déficits cognitivos em 32 indivíduos (idade média: 67,2 anos) com doença de Parkinson (DP). Procedimentos: avaliação clínico-neurológica, escala de Hoehn and Yahr modificada (EHY), bateria neurospicológica do CERAD (Consortium to Establish a Registry for Alzheimer' Disease), questionário de Pfeffer e escore clínico da demência (Clinical Dementia Rating). Foi feita comparação com grupo controle (GC) de 26 indivíduos sem declínio cognitivo, com idade e nível educacional similares. Os pacientes com DP tiveram desempenho inferior na bateria CERAD, quando comparados ao do GC. Foram caracterizados 3 subgrupos com PD segundo a cognição: sem déficits cognitivos - 15 casos; transtorno cognitivo leve - 10; demência - 7 casos. Houve associação entre comprometimento motor e ocorrência de demência. Demência e transtorno cognitivo leve são freqüentes em pacientes com DP e devem ser investigados de modo rotineiro

Wild mallards have more ‘‘goose-like’’ bills than their ancestors : a case of anthropogenic influence?

Wild populations of the world’s most common dabbling duck, the mallard (Anas platyrhynchos), run the risk of genetic introgression by farmed conspecifics released for hunting purposes. We tested whether bill morphology of free-living birds has changed since large-scale releases of farmed mallards started. Three groups of mallards from Sweden, Norway and Finland were compared: historical wild (before large-scale releases started), present-day wild, and present-day farmed. Higher density of bill lamellae was observed in historical wild mallards (only males). Farmed mallards had wider bills than present-day and historical wild ones. Present-day wild and farmed mallards also had higher and shorter bills than historical wild mallards. Present-day mallards thus tend to have more “goose-like” bills (wider, higher, and shorter) than their ancestors. Our study suggests that surviving released mallards affect morphological traits in wild population by introgression. We discuss how such anthropogenic impact may lead to a maladapted and genetically compromised wild mallard population. Our study system has bearing on other taxa where large-scale releases of conspecifics with ‘alien genes’ may cause a cryptic invasive process that nevertheless has fitness consequences for individual birds