Automated Identification and Differentiation of Spectrally Similar Hydrothermal Minerals on Mars

Early telescopic observations corroborated hydration related absorptions on Mars in the infrared. Images from the Viking missions led to speculation of hydrothermal alteration and were followed by two missions which mapped the spatial variability of the ~ 3 m hydration feature. Since then, the Compact Reconnaissance Imager for Mars (CRISM) has provided high spatial resolution (up to 18m) spectral identification of a suite of hydrothermal and diagenetic minerals which have illuminated a range of formation mechanisms. Presence/absence and spatial segregation or mixing of minerals like prehnite, epidote, chlorite amphiboles, and mixed-layer Fe/Mg smectite-chlorite provide valuable evidence for the geologic setting of deposits on Earth, and these phases are often used as temperature and aqueous chemistry indicators in terrestrial systems. Mapping the distribution of these phases will help to answer whether Mars had widespread conditions favorable for low-grade metamorphism and diagenesis, or only focused hydrothermal systems in areas of high heat flow. Further characterizing the chemistry and structure of these phases will then help to answer how most of the widespread Fe/Mg phyllosilicates formed, further defining early geochemical cycling and climate. A fully automated approach for accurate mapping of important hydrothermal mineral phases on Mars has been a challenge. Due to overlapping features in the M-OH region (~2.2-2.4 m), the strongest absorption features of chlorite, prehnite, and epidote in the short-wave infrared are difficult to distinguish from one another and from the most commonly occurring hydrated silicates on Mars, Fe/Mg smectites. Weaker absorptions are present in both prehnite and epidote which help to distinguish them from chlorite and smectites, but their relative strength in the presence of noise and spatial mixing is often too low to confidently identify them without the noise suppression and feature enhancement methods described here. The spectral signatures of mixed-layer Fe/Mg smectite-chlorite and partially chloritized Fe/Mg smectites have not yet been adequately assessed. Here we evaluate the effectiveness of two empirical and statistical methods for identifying and differentiating these phases using CRISM data

Post-training depletions of basolateral amygdala serotonin fail to disrupt discrimination, retention, or reversal learning.

In goal-directed pursuits, the basolateral amygdala (BLA) is critical in learning about changes in the value of rewards. BLA-lesioned rats show enhanced reversal learning, a task employed to measure the flexibility of response to changes in reward. Similarly, there is a trend for enhanced discrimination learning, suggesting that BLA may modulate formation of stimulus-reward associations. There is a parallel literature on the importance of serotonin (5HT) in new stimulus-reward and reversal learning. Recent postulations implicate 5HT in learning from punishment. Whereas, dopaminergic involvement is critical in behavioral activation and reinforcement, 5HT may be most critical for aversive processing and behavioral inhibition, complementary cognitive processes. Given these findings, a 5HT-mediated mechanism in BLA may mediate the facilitated learning observed previously. The present study investigated the effects of selective 5HT lesions in BLA using 5,7-dihydroxytryptamine (5,7-DHT) vs. infusions of saline (Sham) on discrimination, retention, and deterministic reversal learning. Rats were required to reach an 85% correct pairwise discrimination and single reversal criterion prior to surgery. Postoperatively, rats were then tested on the (1) retention of the pretreatment discrimination pair, (2) discrimination of a novel pair, and (3) reversal learning performance. We found statistically comparable preoperative learning rates between groups, intact postoperative retention, and unaltered novel discrimination and reversal learning in 5,7-DHT rats. These findings suggest that 5HT in BLA is not required for formation and flexible adjustment of new stimulus-reward associations when the strategy to efficiently solve the task has already been learned. Given the complementary role of orbitofrontal cortex in reward learning and its interconnectivity with BLA, these findings add to the list of dissociable mechanisms for BLA and orbitofrontal cortex in reward learning

Growth, Mortality, Sexual Maturity and Exploitation Level of the Golden African Snapper (Lutjanus fulgens, Lutjanidae) in Ghanaian Waters

The golden African snapper, Lutjanus fulgens, is one of the most commercially important demersal species exploited by commercial fishers along the coast of Ghana. Growth and mortality as well as aspects of reproduction of L. fulgens were studied to contribute to the paucity of biological information on the species in Ghanaian waters. Samples were collected along the coast of Ghana from September 2018 to August 2019. Total lengths of L. fulgens sampled ranged between 16.2 and 45.6 cm. Length-weight relationship of the species showed isometric growth pattern. The asymptotic length (L∞), growth coefficient (K) and age at zero length (to) for L. fulgens were estimated as 51.09 cm, 0.47 yr-1 and -0.301yr respectively. Total (Z), fishing (F) and natural (M) mortality rates of L. fulgens were estimated at 2.69 yr-1, 1.91 yr-1 and 0.78 yr-1 respectively. The length-at-first capture (Lc) = 31.51 cm, was slightly lower than the length-at-first maturity (Lm) = 33.7 cm for females. The exploitation ratio (E = 0.71) of the stocks in Ghanaian waters was above the optimal exploitation levels. Peak spawning period was observed from July to September. Mean fecundity was estimated to be 77,833 ± 13,012 eggs (mean ± SE). There was no significant difference observed in the sex ratio between males and females. The findings suggest the stocks are under high fishing pressure and so it is recommended that to avoid exploiting the spawning biomass, closed season could be observed during the spawning periods

The Agendas 21 of the Cordoba province. The identification of sustainability indicators, their diffusion and their impact on decision making

En la provincia de Córdoba se está consolidando la implantación de Agendas 21 tanto en lo que respecta a las Agendas 21 Locales como a la Agenda 21 Provincial. Una vez superadas las etapas iniciales, en la cuales se sientan las bases del proceso y se desarrolla la planificación estrategia hacia la sostenibilidad, resulta necesario plantear la puesta en valor de los logros alcanzados, sobre todo considerando la explotación de los indicadores de sostenibilidad ya determinadosIn the Cordoba province is consolidating the implenentation of Agenda 21 as in regard to Local Agenda 21 as to the Provincial. Once you get past the initial stages, in which the foundations of the process and develop the planning strategy towards sustainability, it is necessary to consider the enhancement of the achievements, above all considering the use of sustainability indicators already certainPeer Reviewe

Education mismatch and qualification mismatch: monetary and non-monetary consequences for workers

Using Spanish data from European Union Household Panel Survey corresponding to 2001, we find that the incidence and the consequences, monetary and non-monetary, are different for the job-worker qualification and education mismatches. In fact, only 36% of workers have the same type of fit under both criterions of classification. Additionally, the qualification mismatches have worse consequences for workers than education mismatches. Specifically, the monetary consequences are neutrals for overqualified workers, but negatives for underqualified workers, while the wage of educational mismatched workers is not significantly different of those who have similar characteristics and are accurately match in terms of formal education. However, the overeducated workers earn higher wages than their well-matched co-workers and the wage penalization for one year of undereducation is lower than the reward for one year of required education. On the other hand, the analysis of the non-monetary consequences, by means of job satisfaction, shows that the qualification mismatched workers have lower probability of being completely satisfied than those who are accurately match in terms of qualification, while the effects of education mismatch situations on job satisfaction are no significant. However, among similar jobs, the years of educational mismatch can have an effect even positive on job satisfaction

Can job/worker mismatches help to explain wages and job satisfaction differences among comparable workers?

The relevance of skill job-worker mismatches is analized along with that of education mismatch on Spanish data from the European Community Household Panel (ECHP) survey for the year 2001. Statistical analysis for the prevalence of both types of mismatches, as well as econometric analysis of their wage and job satisfaction consequences has been carried out. Three main findings emerge. First, the degree of statistical association between education and skill mismatches is rather low in the Spanish labour market, suggesting that education mismatch is a rather poor proxy for skill mismatch. Second, both skill and education mismatches appear to have separate, negative effects on wages although skill mismatches show stronger influences. Third, skill mismatches severely reduce workers job satisfaction while the effects of education mismatch weakened when skill mismatches are accounted for. Consequently, skill mismatch is found to be a relevant determinant of wage, as well as a stronger predictor of workers’ utility, than education mismatch