Modelling and interpretation of venusian channels

The Magellan high resolution radar mapping of Venus discovered several different types of channels on the surface of the planet. Some closely resemble the sinuous rilles on the moon whilst the most spectacular type of channel, referred to as 'canali', are simple channels, up to several thousand kilometres long. One of the most remarkable features of the canali is that they often appear to have undergone erosional processes during their formation. Ambient conditions on Venus make any association with water unlikely, and point to a volcanic origin. A preliminary study of the venusian surface indicated an unusually high density of canali type channels in a region roughly 30° latitude by 30° longitude to the south east of Aphrodite Terra and to the east of Artemis Chasma. Twelve channels were found and a detailed study of them undertaken. This included measurements of length and present day slope as well as determination of cross-sectional profile. Part of this study involved consideration of their origin with particular reference to erosion by lava. As lava erosion is uncommon on Earth it was decided to consider under what conditions lava might be able to erode, either thermally or mechanically, on Venus. A numerical model is derived to investigate the sensitivity of the erosion process to various thermal and physical parameters of the lava and substrate, placing constraints on the physical characteristics required to obtain a suitably rapid erosion rate. The model allows for the effects of latent heat and also considers the presence of a liquid substrate boundary layer between the lava and solid substrate. In the model, the higher initial substrate temperature results in a calculated venusian erosion rate approximately 1.5 times greater than the equivalent terrestrial one

The Mars Desert Research Station - ERAU Crew 160 Expedition

The Mars Desert Research Station (MDRS) is a research program which is owned and operated by the Mars Society. The MDRS is located in Hanksville, Utah which hosts simulations that are typically two weeks long for professional scientists and engineers as well as college students of all levels, in training for human operations specifically on Mars. This space analog facility is in isolation, allowing for rigorous field studies regarding research that represents a true mission as if the crew members are conducting a real expedition on Mars. Participants are assigned specific roles and tasks that are typically aligned with their research topics as well as their educational backgrounds. Six students were selected from Embry-Riddle Aeronautical University to attend in December of 2015. Two main studies were conducted at the station which included memory tracking in isolated environments and the monitoring of solar radiation levels with the corresponding consequences on personality/characteristic traits. The results showed that the isolated environment as well as social factors may have attributed to the data obtained, including induced stress that may have occurred from daily tasks

Simulation on Mars - Mars Desert Research Station ERAU Crew 160 Rotation

The Mars Desert Research Station (MDRS) is a research program which is owned and operated by the Mars Society. MDRS is a space analog facility located in Hanksville, Utah that hosts field seasons that are two weeks long where professional scientists as well as undergraduate students may attend. The relative isolation of the facility allowed for rigorous field studies for research in a two week simulation that acts as if the crew members are conducting a real expedition on Mars. Participants are assigned specific roles and tasks that are typically aligned with their research topics as well as their educational backgrounds. Six students were selected from Embry-Riddle Aeronautical University to attend in December of 2015. Two main studies were conducted at the station which included memory tracking in isolated environments which included survey questions as well as timed puzzles to observe any consequences, and monitoring solar radiation levels and the corresponding consequences on personality/characteristic

Gender differences in financial socialisation in the home – an exploratory study

Recent literature has stressed the need for research examining the causes of females in general having lower levels of financial literacy than males. This paper uses social cognitive theory of gender development as a framework to propose differing financial socialisation of children in the home by gender as a possible cause of gender differences later in life. Evidence is found of gender based differences in the financial socialisation of eleven to fourteen year olds. Findings include more frequent parent-child discussions being correlated to more positive financial attitudes, but not to saving behaviour. Saving behaviour of children is influenced by attitudes to money along with the presence of parents when spending, which is subject to a same sex gender bias for girls, with large effect sizes. Girls are over 200% more likely to state they save some of their pocket money if their mother is present when they spend their pocket money, compared to having no parent present. This difference does not exist for male children. When a boy is with both parents when spending, they are 245% more likely to report saving some of their pocket money then when neither parent is present. Having a father present when spending does not yield significantly different results to when no parent is present. These findings of gender biased financial socialisation in the home are important considerations for the design of school-based financial literacy programmes. Specifically, these programmes should consider a goal of encouraging discussion and questioning gender based attitudes and roles in the home. They are also important findings in terms of going some way to explaining the existence of a gender difference in financial knowledge in adulthood

Functionally dissociating aspects of event memory: The effects of combined perirhinal and postrhinal lesions on object and place memory in the rat

Reciprocal interactions between the hippocampus and the perirhinal and parahippocampal cortices form core components of a proposed temporal lobe memory system. For this reason, the involvement of the hippocampus in event memory is thought to depend on its connections with these cortical areas. Contrary to these predictions, we found that NMDA-induced lesions of the putative rat homologs of these cortical areas (perirhinal plus postrhinal cortices) did not impair performance on two allocentric spatial tasks highly sensitive to hippocampal dysfunction. Remarkably, for one of the tasks there was evidence of a facilitation of performance. The same cortical lesions did, however, disrupt spontaneous object recognition and object discrimination reversal learning but spared initial acquisition of the discrimination. This pattern of results reveals important dissociations between different aspects of memory within the temporal lobe. Furthermore, it shows that the perirhinal–postrhinal cortex is not a necessary route for spatial information reaching the hippocampus and that object familiarity–novelty detection depends on different neural substrates than do other aspects of event memory

Accumbal Cholinergic Interneurons Differentially Influence Motivation Related to Satiety Signaling

Satiety, rather than all or none, can instead be viewed as a cumulative decrease in the drive to eat that develops over the course of a meal. The nucleus accumbens (NAc) is known to play a critical role in this type of value reappraisal, but the underlying circuits that influence such processes are unclear. Although NAc cholinergic interneurons (CINs) comprise only a small proportion of NAc neurons, their local impact on reward-based processes provides a candidate cell population for investigating the neural underpinnings of satiety. The present research therefore aimed to determine the role of NAc-CINs in motivation for food reinforcers in relation to satiety signaling. Through bidirectional control of CIN activity in mice, we show that when motivated by food restriction, increasing CIN activity led to a reduction in palatable food consumption while reducing CIN excitability enhanced food intake. These activity-dependent changes developed only late in the session and were unlikely to be driven by the innate reinforcer strength, suggesting that CIN modulation was instead impacting the cumulative change in motivation underlying satiety signaling. We propose that on a circuit level, an overall increase in inhibitory tone onto NAc output neurons played a role in the behavioral results, as activating NAc-CINs led to an inhibition of medium spiny neurons that was dependent on nicotinic receptor activation. Our results reveal an important role for NAc-CINs in controlling motivation for food intake and additionally provide a circuit-level framework for investigating the endogenous cholinergic circuits that signal satiety.Peer reviewe

Fornix lesions can facilitate acquisition of the transverse patterning task: a challenge for "configural" theories of hippocampal function

Configural theories of hippocampal function predict that hippocampal dysfunction should impair acquisition of the transverse patterning task, which involves the concurrent solution of three discrimination problems: A+ versus B−; B+ versus C−; and C+ versus A−. The present study tested this prediction in rats using computer-graphic stimuli presented on a touchscreen. Experiment 1 assessed the effects of fornix lesions when the three problems were introduced sequentially (phase 1: A+ vs B−; phase 2: A+ vs B−, B+ vs C−; phase 3: A+ vs B−, B+ vs C−, C+ vs A−). Fornix lesions significantly facilitated acquisition of the complete transverse patterning task (phase 3) but had no effect on the number of sessions or errors required to attain criterion during phase 1 or phase 2. In experiment 2, in which all three problems were presented concurrently from the outset of training, fornix-lesioned animals outperformed control animals during the seventh block of acquisition trials and were not impaired during any stage of acquisition. Importantly, these same animals were significantly impaired on two allocentric spatial tasks: T-maze alternation (experiments 1 and 2) and the Morris Swim Task (experiment 1). These results contradict the predictions of configural theories of hippocampal function and cast doubt on the popular notion that spatial learning is a special case of configural learning

Genome-Wide Fitness Test and Mechanism-of-Action Studies of Inhibitory Compounds in Candida albicans

Candida albicans is a prevalent fungal pathogen amongst the immunocompromised population, causing both superficial and life-threatening infections. Since C. albicans is diploid, classical transmission genetics can not be performed to study specific aspects of its biology and pathogenesis. Here, we exploit the diploid status of C. albicans by constructing a library of 2,868 heterozygous deletion mutants and screening this collection using 35 known or novel compounds to survey chemically induced haploinsufficiency in the pathogen. In this reverse genetic assay termed the fitness test, genes related to the mechanism of action of the probe compounds are clearly identified, supporting their functional roles and genetic interactions. In this report, chemical–genetic relationships are provided for multiple FDA-approved antifungal drugs (fluconazole, voriconazole, caspofungin, 5-fluorocytosine, and amphotericin B) as well as additional compounds targeting ergosterol, fatty acid and sphingolipid biosynthesis, microtubules, actin, secretion, rRNA processing, translation, glycosylation, and protein folding mechanisms. We also demonstrate how chemically induced haploinsufficiency profiles can be used to identify the mechanism of action of novel antifungal agents, thereby illustrating the potential utility of this approach to antifungal drug discovery

Community Readiness for Environmental Change: A Pilot Study in a Minnesota Forest-Associated Community

1 electronic resource (PDF; 38 pages)This project was supported by funding from the USDA Forest Service Northern Research Station