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Introduction The hippocampus uniquely supports the acquisition and retention of spatial information, and sleep supports the consolidation of hippocampal-dependent memories. However, support for the role of sleep in spatial memory and navigation is mixed. We developed and tested a novel Minecraft Memory and Navigation (MMN) task in adults which showed that sleep uniquely supports the memory for spatial locations, but navigation improved regardless of delay condition (Simon et al., submitted). Here, we tested participants during the developmental transition from childhood to adolescence, a time known for structural and functional hippocampal maturation. Methods Thirty-one youth (Mage = 10.6, SD = 1.56, 9-13 years, grouped: child, early adolescent, adolescent) were administered the MNN task. Training included two free-explorations trials to learn 12 unique object-locations associations in an open-field Minecraft environment. At test, participants were cued to place objects from randomly teleported locations. They were tested twice, immediately and 12-hours later, after a period of sleep or wake. Conditions and environments were counterbalanced in a within-subject design. Each step-by-step movement was recorded for navigation analyses including path length, orientation angle, and search behaviors. Results We found a significant benefit of sleep, compared to wake, on the spatial location accuracy when accounting for age group (F(1,27) = 6.153, p = .02), such that similar to young adults, youth’s metric accuracy of spatial locations improved. We found no change in navigation performances from Test 1 to Test 2 in either condition. Between the start and target locations, youth initiated and maintained similar trajectory angles with similar total path lengths (p’s > .068). Spatial location memory did not correlate with any navigation metrics (p’s > .361). Navigation metrics correlated among themselves, which withstood correction (p’s < .005). Conclusion Youth demonstrated similar sleep-dependent benefits for the metric accuracy of the spatial locations. In contrast to adults, youth’s navigation performance did not improve over delay, regardless condition. Our findings are in line with sleep’s promotion of hippocampal-dependent information, with retention of the spatial locations. Our data are consistent with the hypothesis that sleep does not facilitate navigation, and points to potential developmental maturation required to support navigation behaviors. Support (If Any)

Understanding the remarkably high species diversity and levels of endemism found among Madagascar’s flora and fauna has been the focus of many studies. One hypothesis that has received much attention proposes that Quaternary climate fluctuations spurred diversification. While spatial patterns of distribution and phylogenetic relationships can provide support for biogeographic predictions, temporal estimates of divergence are required to determine the fit of these geospatial patterns to climatic or biogeographic mechanisms. We use multilocus DNA sequence data to test whether divergence times among Malagasy iguanid lizards of the subfamily Oplurinae are compatible with a hypotheses of Pliocene‐Pleistocene diversification. We estimate the oplurine species tree and associated divergence times under a relaxed-clock model. In addition, we examine the phylogeographic structure and population divergence times within two sister species of Oplurus primarily distributed in the north-west and south-west of Madagascar (Oplurus cuvieriandOpluruscyclurus,respectively).Wefindthatdivergenceeventsamongoplurine lineages occurred in the Oligocene and Miocene and are thus far older and incompatible with the hypothesis that recent climate fluctuations are related to current species diversity. However,thetimingofintraspecificdivergencesandspatialpatternsofpopulationgenetic structure within O. cuvieri and O. cyclurus suggest a role for both intrinsic barriers and recentclimate fluctuationsat population-leveldivergences.Integratinginformationacross spatial and temporal scales allows us to identify and better understand the mechanisms generating patterns diversity.

Objective Inflammatory progressive multifocal leukoencephalopathy (iPML) with enhancing magnetic resonance imaging (MRI) lesions and leukocyte infiltration occurs in human immunodeficiency virus (HIV)–infected individuals after highly active antiretroviral therapy (HAART) treatment. MRI diagnostic criteria for PML suggest that iPML does not occur in HIV-negative individuals. Methods We studied pathologically proved PML (12 by biopsy, 9 with MRI, 32 at autopsy). Results HIV-negative (2/5) and -positive (2/4) PML patients had enhancing MRI lesions, correlated with CD3+ lymphocyte infiltration. Inflammatory infiltrates occurred in the majority of HIV-negative (7/8) and HIV-positive/HAART (17/20) cases (p > 0.2), but in only 2 of 16 HIV-positive/non-HAART cases (p < 0.001). Interpretation iPML showed radiographic and pathological similarity in HIV-positive/HAART and HIV-negative patients. HIV-negative iPML necessitates further consideration of MRI criteria for PML. Ann Neurol 2007

Understanding the remarkably high species diversity and levels of endemism found among Madagascar's flora and fauna has been the focus of many studies. One hypothesis that has received much attention proposes that Quaternary climate fluctuations spurred diversification. While spatial patterns of distribution and phylogenetic relationships can provide support for biogeographic predictions, temporal estimates of divergence are required to determine the fit of these geospatial patterns to climatic or biogeographic mechanisms. We use multilocus DNA sequence data to test whether divergence times among Malagasy iguanid lizards of the subfamily Oplurinae are compatible with a hypotheses of Pliocene-Pleistocene diversification. We estimate the oplurine species tree and associated divergence times under a relaxed-clock model. In addition, we examine the phylogeographic structure and population divergence times within two sister species of Oplurus primarily distributed in the north-west and south-west of Madagascar (Oplurus cuvieri and Oplurus cyclurus, respectively). We find that divergence events among oplurine lineages occurred in the Oligocene and Miocene and are thus far older and incompatible with the hypothesis that recent climate fluctuations are related to current species diversity. However, the timing of intraspecific divergences and spatial patterns of population genetic structure within O. cuvieri and O. cyclurus suggest a role for both intrinsic barriers and recent climate fluctuations at population-level divergences. Integrating information across spatial and temporal scales allows us to identify and better understand the mechanisms generating patterns diversity.