A Multiple Method Approach to Evaluate Landward Migration of Seawater Intrusion in the Floridian Aquifer

The Floridan aquifer of the Southeastern United States is an important freshwater resource for private and commercial groundwater users. Within the past few decades, certain parts of the aquifer have experienced saltwater intrusion, which has affected the viability of this critical freshwater resource. Groundwater withdrawals, variability in recharge and discharge rates, and sea level rise has caused saltwater to advance into this and other freshwater coastal aquifers. While the South Carolina Department of Natural Resources (SC DNR) monitors conductivity in several coastal Floridan aquifer wells, a comprehensive hydrochemical saltwater intrusion study of the aquifer in the Berkeley-Charleston-Dorchester tri-county region of South Carolina has not been conducted since the publication of a SC DNR report in 1985. The goal of this current project, conducted in cooperation between SC DNR and the College of Charleston, is to inspect the water quality in Floridan aquifer wells in the tri-county region to determine the extent of saltwater intrusion within the aquifer. Objectives of this project include analyzing and mapping the location of the freshwater-saltwater interface, using hydrochemical analyses to identify signal elements of saltwater intrusion in the aquifer, and providing updated information regarding the groundwater resources of the Floridan aquifer in the study area. In-situ hydrochemical data from Floridan wells and associated geospatial analyses have indicated the areas of the study region likely impacted by saltwater intrusion, and current and future work will include analysis of well water for strontium, bromide and boron to serve as signal elements. Correlations between these elements and chloride concentrations will also be established to strengthen a model of saltwater intrusion. These results about the properties of the Floridan aquifer are in high demand for many stakeholders, including municipalities, agricultural operations, industrial activities, and natural resource managers who depend on a stable source of groundwater as public and private water supplies

The 3.4 micron emission in comets

Emission features near 3.4 microns were detected in comet Bradfield (1987s) on 17 Nov. 1987 UT, and, marginally, on two earlier dates, with the Cooled Grating Array Spectrometer at the NASA Infrared Radio Telescope Facility (IRTF) (Brooke et al., 1988b). The central wavelength (3.36 microns) and width (approx. 0.15 microns) of the strongest feature coincide with those observed in comet Halley. A weaker emission feature at 3.52 microns and a strong feature extending shortward of 2.9 microns were also detected. This brings the number of comets in which these three features have been seen to three, two new (Bradfield, Wilson) and one old (Halley). It seems almost certain that the 3.4 micron features are emissions by C-H groups in complex molecules. Based on the similarity of the 3.4 micron features in comets Halley and Wilson, the authors suggest that a particular set of organic compounds may be common to all comets (Brooke et al. 1988a). The absence of the feature in some comets could then be due to photodestruction or evaporation of the organics when the comet approaches the sun, in combination with a predominance of thermal emission from non C-H emitting grains. Detection of the 3.4 micron emission feature in comet Bradfield at 4 = 0.9 AU provides support for this argument. Complex organics in comets could have been formed by particle irradiation of parent ices in the nucleus or been incorporated as grains at the time the comets formed. Since the most heavily irradiated layers of Halley would have been lost in its hundreds of perihelion passages, the authors believe the more likely explanation is that the 3.4 micron emitting material was incorporated in comet nuclei at the time of formation. The 3.4 micron comet feature resembles, but is not identical to, the interstellar 3.29 micron (and longer wavelength) emission features and the broad 3.4 micron feature seen in absorption toward the Galactic center. Detailed comparisons of cometary and interstellar organics will require comet spectra with signal-to-noise and spectral resolution comparable to that available in spectra of the interstellar medium. Such observations are currently being planned

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Recreational Fishing Impacts in an Offshore and Deep-Water Marine Park: Examining Patterns in Fished Species Using Hybrid Frequentist Model Selection and Bayesian Inference

No-take marine reserves are often located in remote locations far away from human activity, limiting perceived impact on extractive users but also reducing their use for investigating impacts of fishing. This study aimed to establish a benchmark in the distribution of fished species across the Ningaloo Marine Park – Commonwealth (NMP-Commonwealth), and adjacent comparable habitats within the Ningaloo Marine Park - State (NMP-State), in Western Australia to test if there was evidence of an effect of recreational fishing, as no commercial fishing is allowed within either marine park. We also examined whether the remote location of the newly established (2018) No-take Zone (NTZ), in NMP-Commonwealth, limits its use for studying the effects of fishing. Throughout the NMP-Commonwealth and NMP-State, where recreational fishing is permitted, we expected the abundance of recreationally fished fish species to increase with increasing distance to the nearest boat ramp, as a proxy of recreational fishing effort. Conversely, we did not expect the abundance of non-fished species and overall species richness to vary in response to the proxy for human activity. Distance to the nearest boat ramp was found to be a strong predictor of fished species abundance, indicating that the effect of recreational fishing can be detected across the NMP-Commonwealth. The effect of the NTZ on fished species abundance was weakly positive, but this difference across the NTZ is expected to increase over time. Habitat composition predictors were only found to influence species richness and non-fished species abundance. This study suggests a clear footprint of recreational fishing across the NMP-Commonwealth and as a result the new NTZ, despite its remote location, can act as a control in future studies of recreational fishing effects.publishedVersio

The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. VIII. Serpens Observed with MIPS

We present maps of 1.5 deg^2 of the Serpens dark cloud at 24, 70, and 160 μm observed with the Spitzer Space Telescope MIPS camera. We describe the observations and briefly discuss the data processing carried out by the c2d team on these data. More than 2400 compact sources have been extracted at 24 μm, nearly 100 at 70 μm, and four at 160 μm. We estimate completeness limits for our 24 μm survey from Monte Carlo tests with artificial sources inserted into the Spitzer maps. We compare source counts, colors, and magnitudes in the Serpens cloud to two reference data sets: a 0.50 deg^2 set on a low-extinction region near the dark cloud, and a 5.3 deg^2 subset of the SWIRE ELAIS N1 data that was processed through our pipeline. These results show that there is an easily identifiable population of young stellar object candidates in the Serpens cloud that is not present in either of the reference data sets. We also show a comparison of visual extinction and cool dust emission illustrating a close correlation between the two and find that the most embedded YSO candidates are located in the areas of highest visual extinction

Life course associations of height, weight, fatness, grip strength, and all-cause mortality for high socioeconomic status Guatemalans

Objectives: The objective of this study was to investigate the association between physical growth in pre-adult life with five outcomes at age 64-76: weight, body mass index, estimated body fat percentage, hand grip strength and mortality. Methods: Super-Imposition by Translation and Rotation (SITAR) growth curves of 40,484 Guatemalan individuals aged 3-19 years were modelled for the parameters of size, timing and intensity (peak growth velocity, e.g. cm/year) of height, weight, body mass index, and grip strength. Associations between the SITAR parameters and old age outcomes were tested using linear and binary logistic regression for a follow-up sample of high socioeconomic status (SES) Guatemalans, of whom 50 were aged 64-76 years old at re-measurement and 45 died prior to the year 2017. Results: SITAR models explained 69-98% of the variance in each outcome, with height the most precise. Individuals in the follow-up sample who had a higher BMI before age 20 years had higher estimated body fat (B=1.4 CI -0.02-2.8) and BMI (B=1.2, CI 0.2-2.2) at the ages 64-76 years. Those who grew slower in height but faster in weight and BMI before age 20 years, had higher BMI and body fat later in life. Conclusions: These findings highlight the importance of a life course perspective on health and mortality risk. Childhood exposures leading to variation in pre-adult growth may be key to better understanding health and mortality risks in old age

Four decades of socioeconomic inequalities and secular changes in the physical growth of Guatemalans [abstract]

Four decades of socioeconomic inequalities and secular changes in the physical growth of Guatemalans [abstract

Four decades of socio-economic inequality and secular change in the physical growth of Guatemalans

OBJECTIVE: To investigate changes in socio-economic inequalities in growth in height, weight, BMI and grip strength in children born during 1955-1993 in Guatemala, a period of marked socio-economic-political change. DESIGN: We modelled longitudinal data on height, weight, BMI and hand grip strength using Super-Imposition by Translation and Rotation (SITAR). Internal Z-scores summarising growth size, timing and intensity (peak growth velocity, e.g. cm/year) were created to investigate inequalities by socio-economic position (SEP; measured by school attended). Interactions of SEP with date of birth were investigated to capture secular changes in inequalities. SETTING: Urban and peri-urban schools in the region of Guatemala City, Guatemala. PARTICIPANTS: Participants were 40 484 children and adolescents aged 3-19 years of Ladino and Maya ancestry (nobservations 157 067). RESULTS: The difference in height (SITAR size) between lowest and highest SEP decreased from -2·0 (95 % CI -2·2, -1·9) sd to -1·4 (95 % CI -1·5, -1·3) sd in males, and from -2·0 (95 % CI -2·1, -1·9) sd to -1·2 (95 % CI -1·3, -1·2) sd in females over the study period. Inequalities also reduced for weight, BMI and grip strength, due to greater secular increases in lowest-SEP groups. The puberty period was earlier and shorter in higher-SEP individuals (earlier SITAR timing and higher SITAR intensity). All SEP groups showed increases in BMI intensity over time. CONCLUSIONS: Inequality narrowed between the 1960s and 1990s. The lowest-SEP groups were still >1 sd shorter than the highest. Risks remain for reduced human capital and poorer population health for urban Guatemalans

Deeptime: a Python library for machine learning dynamical models from time series data

Generation and analysis of time-series data is relevant to many quantitative fields ranging from economics to fluid mechanics. In the physical sciences, structures such as metastable and coherent sets, slow relaxation processes, collective variables, dominant transition pathways or manifolds and channels of probability flow can be of great importance for understanding and characterizing the kinetic, thermodynamic and mechanistic properties of the system. Deeptime is a general purpose Python library offering various tools to estimate dynamical models based on time-series data including conventional linear learning methods, such as Markov state models (MSMs), Hidden Markov Models and Koopman models, as well as kernel and deep learning approaches such as VAMPnets and deep MSMs. The library is largely compatible with scikit-learn, having a range of Estimator classes for these different models, but in contrast to scikit-learn also provides deep Model classes, e.g. in the case of an MSM, which provide a multitude of analysis methods to compute interesting thermodynamic, kinetic and dynamical quantities, such as free energies, relaxation times and transition paths. The library is designed for ease of use but also easily maintainable and extensible code. In this paper we introduce the main features and structure of the deeptime software. Deeptime can be found under https://deeptime-ml.github.io/