Downregulation of CCR5 on brain perivascular macrophages in simian immunodeficiency virus-infected rhesus macaques.

Background: C-C chemokine receptor 5 (CCR5) is a major coreceptor for Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) cell entry; however, its role in brain pathogenesis is largely understudied. Thus, we sought to examine cell type-specific protein expression of CCR5 during SIV infection of the brain.

Methods: We examined occipital cortical tissue from uninfected rhesus macaques and SIV-infected animals with or without encephalitis using immunohistochemistry and immunofluorescence microscopy to determine the number and distribution of CCR5-positive cells.

Ecosystem response persists after a prolonged marine heatwave.

Some of the longest and most comprehensive marine ecosystem monitoring programs were established in the Gulf of Alaska following the environmental disaster of the Exxon Valdez oil spill over 30 years ago. These monitoring programs have been successful in assessing recovery from oil spill impacts, and their continuation decades later has now provided an unparalleled assessment of ecosystem responses to another newly emerging global threat, marine heatwaves. The 2014-2016 northeast Pacific marine heatwave (PMH) in the Gulf of Alaska was the longest lasting heatwave globally over the past decade, with some cooling, but also continued warm conditions through 2019.

Increased summer food supply decreases non-breeding movement in black-legged kittiwakes.

Individual condition at one stage of the annual cycle is expected to influence behaviour during subsequent stages, yet experimental evidence of food-mediated carry-over effects is scarce. We used a food supplementation experiment to test the effects of food supply during the breeding season on migration phenology and non-breeding behaviour. We provided an unlimited supply of fish to black-legged kittiwakes () during their breeding season on Middleton Island, Alaska, monitored reproductive phenology and breeding success, and used light-level geolocation to observe non-breeding behaviour.

Diverging phenological responses of Arctic seabirds to an earlier spring.

The timing of annual events such as reproduction is a critical component of how free-living organisms respond to ongoing climate change. This may be especially true in the Arctic, which is disproportionally impacted by climate warming. Here, we show that Arctic seabirds responded to climate change by moving the start of their reproduction earlier, coincident with an advancing onset of spring and that their response is phylogenetically and spatially structured.

Lack of susceptibility in neonatally infected rhesus macaques to simian immunodeficiency virus-induced encephalitis.

Despite combination antiretroviral therapies making HIV a chronic rather than terminal condition for many people, the prevalence of HIV-associated neurocognitive disorders (HAND) is increasing. This is especially problematic for children living with HIV. Children diagnosed HAND rarely display the hallmark pathology of HIV encephalitis in adults, namely infected macrophages and multinucleated giant cells in the brain.

Overexpression and activation of colony-stimulating factor 1 receptor in the SIV/macaque model of HIV infection and neuroHIV.

In the present study, we investigated whether colony-stimulating factor 1 receptor (CSF1R) is expressed on brain macrophages and microglia in the human and macaque brain and whether it is upregulated and activated after lentivirus infection in vivo and contributes to development of encephalitic lesions. We examined, using multi-label and semi-quantitative immunofluorescence microscopy, the protein expression level and cellular localization of CSF1R in brain tissues from uninfected controls and SIV-infected adult macaques with or without encephalitis and also from uninfected controls, HIV-infected encephalitic subjects and virally suppressed subjects. In the normal uninfected brain, CSF1R protein was detected only on microglia and brain macrophages but not on neurons, astrocytes or oligodendrocytes.

Are Alcohol Trajectories a Useful Way of Identifying At-Risk Youth? A Multiwave Longitudinal-Epidemiologic Study.

Objective: Trajectory approaches are a popular way of identifying subgroups of children and adolescents at high risk for developing alcohol use problems. However, mounting evidence challenges the meaning and utility of these putatively discrete alcohol trajectories, which can be analytically derived even in the absence of real subgroups. This study tests the hypothesis that alcohol trajectories may not reflect discrete groups-that the development of alcohol use is continuous rather than categorical.

Circumpolar dynamics of a marine top-predator track ocean warming rates.

Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of organisms to abrupt warming and associated regime shifts can be unlike responses to periods of slow or moderate change.

Genome-wide association study of lifetime cannabis use based on a large meta-analytic sample of 32 330 subjects from the International Cannabis Consortium.

Cannabis is the most widely produced and consumed illicit psychoactive substance worldwide. Occasional cannabis use can progress to frequent use, abuse and dependence with all known adverse physical, psychological and social consequences. Individual differences in cannabis initiation are heritable (40-48%).

Impact of adolescent marijuana use on intelligence: Results from two longitudinal twin studies.

Marijuana is one of the most commonly used drugs in the United States, and use during adolescence--when the brain is still developing--has been proposed as a cause of poorer neurocognitive outcome. Nonetheless, research on this topic is scarce and often shows conflicting results, with some studies showing detrimental effects of marijuana use on cognitive functioning and others showing no significant long-term effects. The purpose of the present study was to examine the associations of marijuana use with changes in intellectual performance in two longitudinal studies of adolescent twins (n = 789 and n = 2,277).

Wintering North Pacific black-legged kittiwakes balance spatial flexibility and consistency.

Background: Marine environments are inherently dynamic, yet marine predators are often long-lived and employ strategies where consistency, individual specialization, routine migrations, and spatial memory are key components to their foraging and life-history strategies. Intrinsic determinates of animal movements are linked to physiological and life-history traits (e.g.

Body size affects individual winter foraging strategies of thick-billed murres in the Bering Sea.

Foraging and migration often require different energetic and movement strategies. Though not readily apparent, constraints during one phase might influence the foraging strategies observed in another. For marine birds that fly and dive, body size constraints likely present a trade-off between foraging ability and migration as smaller bodies reduce flight costs, whereas larger bodies are advantageous for diving deeper.

Genetic relationship between the addiction diagnosis in adults and their childhood measure of addiction liability.

Transmissible liability index (TLI), developed employing a high-risk design and item response theory, enables quantification of the latent trait of liability to drug use disorders (DUD) in children. TLI has been shown to have high heritability and predict DUD in young adulthood. This study extends prior research and determines the genetic contribution of DUD liability measured by TLI to adult liability as indexed by DUD diagnosis.

In search of rare variants: preliminary results from whole genome sequencing of 1,325 individuals with psychophysiological endophenotypes.

Whole genome sequencing was completed on 1,325 individuals from 602 families, identifying 27 million autosomal variants. Genetic association tests were conducted for those individuals who had been assessed for one or more of 17 endophenotypes (N range = 802-1,185). No significant associations were found.

The adolescent origins of substance use disorders: a behavioral genetic perspective.

Over the past twenty years there has been an increasing recognition within the substance abuse research field that (SUDs) are usefully conceptualized within a developmental framework. That is, initiation of substance use in adolescence and escalation to substance abuse in early adulthood are strongly age-graded, with the relevant behavioral risk and protective factors manifesting early in development, often prior to substance use onset. In this chapter we review a program of research that seeks to provide a behavioral genetic perspective on the development of SUDs.

Tests of the effects of adolescent early alcohol exposures on adult outcomes.

Aims: To determine whether early adolescent alcohol use contributes to adult alcohol use, misuse and other adult substance-related and social outcomes.

Design: In a longitudinal study of twins assessed at target ages 11, 14 and 24 years, two techniques adjusted for confounding factors: a propensity score (PS) adjusting for the effects of measured background covariates and co-twin control (CTC) adjusting for confounding by unmeasured (including genetic) factors shared within early alcohol exposure-discordant pairs.

Setting: The community-based Minnesota Twin Family Study.

Gamma-aminobutyric acid system genes--no evidence for a role in alcohol use and abuse in a community-based sample.

Background: While twin and adoption studies point to substantial genetic influence upon alcohol use, dependence, and other alcohol-related phenotypes, few of the genes underlying variation in these phenotypes have been identified. Markers in genes related to GABAergic activity-a system integral to many of alcohol's biological effects-have been implicated in alcohol use and alcohol-related psychopathology in linkage and association studies.

Methods: Using multiple methods, we conducted a comprehensive examination of the effects of markers in γ-aminobutyric acid (GABA) system genes in a community-based sample of 7,224 individuals assessed in early and middle adulthood.

Prey patch patterns predict habitat use by top marine predators with diverse foraging strategies.

Spatial coherence between predators and prey has rarely been observed in pelagic marine ecosystems. We used measures of the environment, prey abundance, prey quality, and prey distribution to explain the observed distributions of three co-occurring predator species breeding on islands in the southeastern Bering Sea: black-legged kittiwakes (Rissa tridactyla), thick-billed murres (Uria lomvia), and northern fur seals (Callorhinus ursinus). Predictions of statistical models were tested using movement patterns obtained from satellite-tracked individual animals.

The inheritance of process: a dynamical systems approach.

A central unresolved problem of evolutionary biology concerns the way in which evolution at the genotypic level relates to the evolution of phenotypes. This genotype-phenotype map involves developmental and physiological processes, which are complex and not well understood. These processes co-determine the rate and direction of adaptive change by shaping the distribution of phenotypic variability on which selection can act.

Developmental trajectory and environmental moderation of the effect of ALDH2 polymorphism on alcohol use.

Background: In the aldehyde dehydrogenase 2 (ALDH2) gene, the ALDH2*2 allele, prevalent in East Asian populations, encodes an enzyme with severely reduced activity, thereby disrupting the normal metabolism of alcohol. Possession of the ALDH2*2 allele has been repeatedly shown to be associated with lower risk for alcohol dependence and reduced alcohol use. However, relatively few studies have considered whether the magnitude of the effect of ALDH2 polymorphism upon drinking is related to developmental stage or varies by environmental context.

Synergistic toxic effect of nano-TiO and As(V) on Ceriodaphnia dubia.

Due to the active development and application of nanotechnology, engineered nanomaterials (ENMs) are becoming a new class of environmental pollutants that may significantly impact the environment and human health. While many toxicity investigations have been conducted, there is little information about the synergistic effect of ENMs and other toxic compounds in the environment. In order to extend this knowledge, the combined effect of TiO₂ nanoparticles (n-TiO₂) and As(V) were investigated.

Transmission and reassortment of avian influenza viruses at the Asian-North American interface.

Twenty avian influenza viruses were isolated from seven wild migratory bird species sampled at St. Lawrence Island, Alaska. We tested predictions based on previous phylogenetic analyses of avian influenza viruses that support spatially dependent trans-hemispheric gene flow and frequent interspecies transmission at a location situated at the Asian-North American interface.

Harsh discipline, childhood sexual assault, and MAOA genotype: an investigation of main and interactive effects on diverse clinical externalizing outcomes.

We studied the impact of MAOA genotype, childhood sexual assault, and harsh discipline on clinical externalizing symptoms (substance problems, adult antisocial behavior, and conduct disorder). Participants were 841 individual twins from the Minnesota Twin Family Study assessed through age 25. MAOA genotype was not associated with differences in any phenotype, nor was there a significant interaction between MAOA and harsh discipline for any phenotype or a significant interaction between MAOA and childhood sexual assault for substance problems.

Robustness of positional specification by the Hedgehog morphogen gradient.

Spatial gradients of Hedgehog signalling play a central role in many patterning events during animal development, regulating cell fate determination and tissue growth in a variety of tissues and developmental stages. Experimental evidence suggests that many of the proteins responsible for regulating Hedgehog signalling and transport are themselves targets of Hedgehog signalling, leading to multiple levels of feedback within the system. We use mathematical modelling to analyse how these overlapping feedbacks combine to regulate patterning and potentially enhance robustness in the Drosophila wing imaginal disc.