Formation of sinuous ridges by inversion of river-channel belts in Utah, USA, with implications for Mars

Sinuous ridges are important landforms on the surface of Mars that show promise for quantifying ancient martian surface hydrology. Morphological similarity of these ridges to river channels in planform led to a hypothesis that ridges are topographically inverted river channels, or “inverted channels”, formed due to an erosion-resistant channel-filling material that preserved a snapshot of the channel geometry in inverted relief due to differential erosion. An alternative deposit-inversion hypothesis proposes that ridges represent exhumed river-channel belts, with geometries that reflect the lateral migration and vertical aggradation of rivers over significant geologic time, rather than the original channel geometry. To investigate these hypotheses we studied sinuous ridges within the Cretaceous Cedar Mountain Formation near Green River, Utah, USA. Ridges in Utah extend for hundreds of meters, are up to 120 m wide, and stand up to 39 m above the surrounding plain. Ridges are capped by sandstone bodies 3–10 m thick that contain dune- and bar-scale inclined stratification, which we interpret as eroded remnants of channel belts that record the migration and aggradation of single-thread, sand-bedded rivers, rather than channel fills that can preserve the original channel geometry. Caprocks overlie mudstones and thinner sandstone beds that are interpreted as floodplain deposits, and in cases additional channel-belt sandstones are present lower in the ridge stratigraphy. Apparent networks from branching ridges typically represent discrete sandstone bodies that cross at different stratigraphic levels rather than a coeval river network. Ridge-forming sandstone bodies also have been narrowed during exhumation by cliff retreat and bisected by fluvial erosion. Using a large compilation of channel-belt geometries on Earth and our measurements of ridges in Utah, we propose that caprock thickness is the most reliable indicator of paleo-channel geometry, and can be used to reconstruct river depth and discharge. In contrast, channel lateral migration and caprock erosion during exhumation make ridge breadth an uncertain proxy for channel width. An example in Aeolis Dorsa, Mars, illustrates that river discharge estimates based solely on caprock width may differ significantly from estimates based on caprock thickness. Overall, our study suggests that sinuous ridges are not inverted channel fills, but rather reflect exhumation of a thick stratigraphic package of stacked channel belts and overbank deposits formed from depositional rivers over significant geologic time

Formation of sinuous ridges by inversion of river-channel belts in Utah, USA, with implications for Mars

Sinuous ridges are important landforms on the surface of Mars that show promise for quantifying ancient martian surface hydrology. Morphological similarity of these ridges to river channels in planform led to a hypothesis that ridges are topographically inverted river channels, or “inverted channels”, formed due to an erosion-resistant channel-filling material that preserved a snapshot of the channel geometry in inverted relief due to differential erosion. An alternative deposit-inversion hypothesis proposes that ridges represent exhumed river-channel belts, with geometries that reflect the lateral migration and vertical aggradation of rivers over significant geologic time, rather than the original channel geometry. To investigate these hypotheses we studied sinuous ridges within the Cretaceous Cedar Mountain Formation near Green River, Utah, USA. Ridges in Utah extend for hundreds of meters, are up to 120 m wide, and stand up to 39 m above the surrounding plain. Ridges are capped by sandstone bodies 3–10 m thick that contain dune- and bar-scale inclined stratification, which we interpret as eroded remnants of channel belts that record the migration and aggradation of single-thread, sand-bedded rivers, rather than channel fills that can preserve the original channel geometry. Caprocks overlie mudstones and thinner sandstone beds that are interpreted as floodplain deposits, and in cases additional channel-belt sandstones are present lower in the ridge stratigraphy. Apparent networks from branching ridges typically represent discrete sandstone bodies that cross at different stratigraphic levels rather than a coeval river network. Ridge-forming sandstone bodies also have been narrowed during exhumation by cliff retreat and bisected by fluvial erosion. Using a large compilation of channel-belt geometries on Earth and our measurements of ridges in Utah, we propose that caprock thickness is the most reliable indicator of paleo-channel geometry, and can be used to reconstruct river depth and discharge. In contrast, channel lateral migration and caprock erosion during exhumation make ridge breadth an uncertain proxy for channel width. An example in Aeolis Dorsa, Mars, illustrates that river discharge estimates based solely on caprock width may differ significantly from estimates based on caprock thickness. Overall, our study suggests that sinuous ridges are not inverted channel fills, but rather reflect exhumation of a thick stratigraphic package of stacked channel belts and overbank deposits formed from depositional rivers over significant geologic time

Depression, Stressful Life Events, and the Impact of Variation in the Serotonin Transporter: Findings from the National Longitudinal Study of Adolescent to Adult Health (Add Health)

BackgroundThe low transcriptionally efficient short-allele of the 5HTTLPR serotonin transporter polymorphism has been implicated to moderate the relationship between the experience of stressful life events (SLEs) and depression. Despite numerous attempts at replicating this observation, results remain inconclusive.MethodsWe examined this relationship in young-adult Non-Hispanic white males and females between the ages of 22 and 26 (n = 4724) participating in the National Longitudinal Study of Adolescent to Adult Health (Add Health) with follow-up information every six years since 1995.ResultsLinear and logistic regression models, corrected for multiple testing, indicated that carriers of one or more of the S-alleles were more sensitive to stress than those with two L-alleles and at a higher risk for depression. This relationship behaved in a dose-response manner such that the risk for depression was greatest among those who reported experiencing higher numbers of SLEs. In post-hoc analyses we were not able to replicate an interaction effect for suicide ideation but did find suggestive evidence that the effects of SLEs and 5HTTLPR on suicide ideation differed for males and females. There were no effects of childhood maltreatment.DiscussionOur results provide partial support for the original hypothesis that 5-HTTLPR genotype interacts with the experience of stressful life events in the etiology of depression during young adulthood. However, even with this large sample, and a carefully constructed a priori analysis plan, the results were still not definitive. For the purposes of replication, characterizing the 5HTTLPR in other large data sets with extensive environmental and depression measures is needed

APOΕ4 Lowers Energy Expenditure in Females and Impairs Glucose Oxidation by Increasing Flux through Aerobic Glycolysis

BACKGROUND: Cerebral glucose hypometabolism is consistently observed in individuals with Alzheimer\u27s disease (AD), as well as in young cognitively normal carriers of the Ε4 allele of Apolipoprotein E (APOE), the strongest genetic predictor of late-onset AD. While this clinical feature has been described for over two decades, the mechanism underlying these changes in cerebral glucose metabolism remains a critical knowledge gap in the field. METHODS: Here, we undertook a multi-omic approach by combining single-cell RNA sequencing (scRNAseq) and stable isotope resolved metabolomics (SIRM) to define a metabolic rewiring across astrocytes, brain tissue, mice, and human subjects expressing APOE4. RESULTS: Single-cell analysis of brain tissue from mice expressing human APOE revealed E4-associated decreases in genes related to oxidative phosphorylation, particularly in astrocytes. This shift was confirmed on a metabolic level with isotopic tracing of 13C-glucose in E4 mice and astrocytes, which showed decreased pyruvate entry into the TCA cycle and increased lactate synthesis. Metabolic phenotyping of E4 astrocytes showed elevated glycolytic activity, decreased oxygen consumption, blunted oxidative flexibility, and a lower rate of glucose oxidation in the presence of lactate. Together, these cellular findings suggest an E4-associated increase in aerobic glycolysis (i.e. the Warburg effect). To test whether this phenomenon translated to APOE4 humans, we analyzed the plasma metabolome of young and middle-aged human participants with and without the Ε4 allele, and used indirect calorimetry to measure whole body oxygen consumption and energy expenditure. In line with data from E4-expressing female mice, a subgroup analysis revealed that young female E4 carriers showed a striking decrease in energy expenditure compared to non-carriers. This decrease in energy expenditure was primarily driven by a lower rate of oxygen consumption, and was exaggerated following a dietary glucose challenge. Further, the stunted oxygen consumption was accompanied by markedly increased lactate in the plasma of E4 carriers, and a pathway analysis of the plasma metabolome suggested an increase in aerobic glycolysis. CONCLUSIONS: Together, these results suggest astrocyte, brain and system-level metabolic reprogramming in the presence of APOE4, a \u27Warburg like\u27 endophenotype that is observable in young females decades prior to clinically manifest AD

Practical Guidance for Integrating Data Management into Long-Term Ecological Monitoring Projects

Long-term monitoring and research projects are essential to understand ecological change and the effectiveness of management activities. An inherent characteristic of long-term projects is the need for consistent data collection over time, requiring rigorous attention to data management and quality assurance. Recent papers have provided broad recommendations for data management; however, practitioners need more detailed guidance and examples. We present general yet detailed guidance for the development of comprehensive, concise, and effective data management for monitoring projects. The guidance is presented as a graded approach, matching the scale of data management to the needs of the organization and the complexity of the project. We address the following topics: roles and responsibilities; consistent and precise data collection; calibration of field crews and instrumentation; management of tabular, photographic, video, and sound data; data completeness and quality; development of metadata; archiving data; and evaluation of existing data from other sources. This guidance will help practitioners execute effective data management, thereby, improving the quality and usability of data for meeting project objectives as well as broader meta-analysis and macrosystem ecology research

Coronaridine congeners attenuate fentanyl seeking during prolonged abstinence

Background: The prevalence of opioid use disorder (OUD) has reached epidemic proportions with a record-breaking number of overdose deaths. Over 70% of the record-breaking number of overdose deaths are caused by synthetic opioids, including fentanyl. Fentanyl is commonly administered intravenously or by inhalation (smoking/vaping), which results in rapid drug bioavailability in the brain. There is a current need to identify a novel pharmacologic therapy to treat OUD, and there is increasing evidence to support the use of novel compounds referred to as coronaridine congeners to treat OUD and other psychiatric illnesses. In preclinical models, coronaridine congeners have been shown to decrease self-administration of drugs of abuse and induce antidepressant and anxiolytic effects. Here we used a preclinical fentanyl vapor self-administration model and fast-scan cyclic voltammetry (FSCV) to study the anti-addictive effects of two coronaridine congeners, 18-methoxycoronaridine (18-MC) and catharanthine (Cath).Methods: C57BL/6J mice were trained to self-administer vaporized fentanyl (5 mg/mL) or vehicle in airtight operant chambers. Mice self-administered vapor for 1 hour per day for 10 days (sessions were conducted for 5 consecutive days, followed by 2 days off). Chambers were equipped with two nosepokes, one active and one inactive. A successful response in the active nosepoke resulted in a vapor delivery that coincided with the presentation of a cue light, followed by a 1-minute timeout period. Mice learned to self-administer vapor with 3-second vapor deliveries for the first 3 days of training, which was then reduced to 1.5-second vapor deliveries the remaining 7 days. After training, mice were returned to their home cages for a forced abstinence period. Cue-induced drug seeking tests were conducted on abstinence days (AD) 20 and 25. During cue-induced seeking tests, successful responses in the active nosepoke resulted in presentation of the drug-associated cue, but no vapor was delivered (i.e. extinction conditions). Cue-induced drug seeking tests were conducted using a crossover design where half of subjects received coronaridine treatment (18-MC or Cath), while the other half received vehicle (ddH2O), on AD20. On AD25, subjects received the opposite treatment compared to AD20. Mice were injected (i.p.) with either vehicle or coronaridine treatment 1 hour before seeking tests. To examine the molecular mechanism of coronaridine congeners, FSCV was conducted on dopaminergic pre-synaptic terminals in the nucleus accumbens (NAc) neurons to measure dopamine (DA) release in the presence of 18-MC and Cath with or without nicotinic acetylcholine receptor antagonists.Results: We found that both 18-MC and Cath significantly reduced fentanylseeking during prolonged abstinence with no effect on mice that had previously self-administered vehicle. Furthermore, FSCV revealed that 18-MC and Cath significantly reduced DA release onto NAc neurons.Conclusion: In this study, we report that both 18-MC and Cath decrease fentanyl seeking during prolonged abstinence. DA release is important for opioid-related behaviors, and we found that 18-MC and Cath reduce DA release in the NAc, a mechanism that may underlie the effect of coronaridine congeners on fentanyl seeking. Together, these results provide evidence that coronaridine congeners may be promising novel compounds for the pharmacotherapeutic treatment of OUD

'Me and my bump': an interpretative phenomenological analysis of the experiences of pregnancy for vulnerable women

Eight pregnant women, considered to be ‘vulnerable’ due to exposure to a number of underlying risk factors, participated in semi-structured interviews regarding their experiences of pregnancy and of Mellow Bumps, a 6-week targeted antenatal intervention. Interview transcripts were explored using interpretative phenomenological analysis. The analysis revealed five superordinate themes: pregnancy as a time of reflection; the body being taken over; pregnancy as an emotional rollercoaster; relationships as important; separating identities. Pre- and post-natal attachment theories were found to be useful in interpreting the data. Findings suggest that pregnancy may be ‘normalising’ and provide an important opportunity for building more positive representations of the self. Findings also provide clinical support for the assertion that the attachment relationship begins before birth. The Mellow Bumps intervention was uniformly seen as helpful. It appeared to nurture prenatal attachment relationships, playing a potentially protective role, by helping to establish the foundations for secure mother–infant relationships in the future. Meeting similar women and engaging in ordinary, supportive conversation during Mellow Bumps seemed to reduce feelings of isolation and stigma. Implications for clinical practice are considered

Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development.

BACKGROUND: We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. RESULTS: The genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. CONCLUSIONS: Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution

The Impact of Digital Storytelling on Social Agency: Early Experience at an Online University

Digital Storytelling\u27 is a term often used to refer to a number of different types of digital narrative including web-based stories, hypertexts, videoblogs and computer games. This emergent form of creative work has found an outlet in a wide variety of different domains ranging from community social history, to cookbooks, to the classroom. It is the latter domain that provides the focus for this paper, specifically the online classroom at the tertiary level...Early feedback from students suggests that listening to and telling \u27true stories\u27 was a compelling and emotionally-engaging experience, providing an opportunity for \u27transformative reflection\u27 (Lambert 2000). By including multimedia, learners were able to build upon the fundamentals, presenting content in an easy-to-absorb and compelling way. In terms of team assignments students learned to become more effective actors in collaborative work environments

New Directions in the Development of Population Estimates in the United States?

The advent of a continuously updated Master Area File (MAF) following the 2000 census represents an information resource that can be tapped for purposes of developing timely, cost-effective, and precise population estimates for even the smallest of geographical units (e.g., census blocks). We argue that the MAF can be enhanced (EMAF) for these purposes. In support of our argument we describe a set of activities needed to develop EMAF, each of which is well within the current capabilities of the U.S. Census Bureau and discuss various costs and benefits of each. We also describe how EMAF would provide population estimates containing a wide range of demographic (e.g., age, race, and sex) and socio-economic characteristics (e.g., educational attainment, income, and employment). As such, it could largely negate and eliminate the need for many of the traditional demographic methods of population estimation and possibly reduce the number of sample surveys. We identify important challenges that must be surmounted in order to realize EMAF and make suggestions for doing so. We conclude by noting that the idea of the EMAF could be of interest to other countries with MAF files and strong administrative records systems that, like the United States, are facing the challenge of producing good population information in the face of increasing census costs