Recruitment Sources of Channel and Blue Catfishes Inhabiting the Middle Mississippi River

Insight into environments that contribute recruits to adult fish stocks in riverine systems is vital for effective population management and conservation. Catfish are an important recreational species in the Mississippi River and are commercially harvested. However, contributions of main channel and tributary habitats to catfish recruitment in large rivers are unknown. Stable isotope and trace elemental signatures in otoliths are useful for determining environmental history of fishes in a variety of aquatic systems, including the Mississippi River. The objectives of this study were to identify the principal natal environments of channel catfish Ictalurus punctatus and blue catfish I. furcatus in the middle Mississippi River (MMR) using otolith stable oxygen isotopic composition (δ18O) and strontium:calcium ratios (Sr:Ca). Catfishes were sampled during July-October 2013-2014 and lapilli otoliths were analyzed for δ18O and Sr:Ca. Water samples from the MMR and tributaries were collected seasonally from 2006-2014 to characterize site-specific signatures. Persistent differences in water δ18O and Sr:Ca among the MMR and tributaries (including the upper Mississippi, Illinois, and Missouri rivers as well as smaller tributaries) were evident, enabling identification of natal environment for individual fish. Blue and channel catfish stocks in the MMR primarily recruited from the large rivers (Missouri and Mississippi) in our study area, with minimal contributions from smaller tributaries. Recruitment and year class strength investigations and efforts to enhance spawning and nursery habitats should be focused in the large rivers with less emphasis in smaller tributaries

Reimagining large river management using the Resist–Accept–Direct (RAD) framework in the Upper Mississippi River

Background: Large-river decision-makers are charged with maintaining diverse ecosystem services through unprecedented social-ecological transformations as climate change and other global stressors intensify. The interconnected, dendritic habitats of rivers, which often demarcate jurisdictional boundaries, generate complex management challenges. Here, we explore how the Resist–Accept–Direct (RAD) framework may enhance large-river management by promoting coordinated and deliberate responses to social-ecological trajectories of change. The RAD framework identifies the full decision space of potential management approaches, wherein managers may resist change to maintain historical conditions, accept change toward different conditions, or direct change to a specified future with novel conditions. In the Upper Mississippi River System, managers are facing social-ecological transformations from more frequent and extreme high-water events. We illustrate how RAD-informed basin-, reach-, and site-scale decisions could: (1) provide cross-spatial scale framing; (2) open the entire decision space of potential management approaches; and (3) enhance coordinated inter-jurisdictional management in response to the trajectory of the Upper Mississippi River hydrograph. Results: The RAD framework helps identify plausible long-term trajectories in different reaches (or subbasins) of the river and how the associated social-ecological transformations could be managed by altering site-scale conditions. Strategic reach-scale objectives may reprioritize how, where, and when site conditions could be altered to contribute to the basin goal, given the basin’s plausible trajectories of change (e.g., by coordinating action across sites to alter habitat connectivity, diversity, and redundancy in the river mosaic). Conclusions: When faced with long-term systemic transformations (e.g., \u3e 50 years), the RAD framework helps explicitly consider whether or when the basin vision or goals may no longer be achievable, and direct options may open yet unconsidered potential for the basin. Embedding the RAD framework in hierarchical decision-making clarifies that the selection of actions in space and time should be derived from basin-wide goals and reach-scale objectives to ensure that site-scale actions contribute effectively to the larger river habitat mosaic. Embedding the RAD framework in large-river decisions can provide the necessary conduit to link flexibility and innovation at the site scale with stability at larger scales for adaptive governance of changing social-ecological systems

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Quantitative 18F-AV1451 Brain Tau PET Imaging in Cognitively Normal Older Adults, Mild Cognitive Impairment, and Alzheimer's Disease Patients

Recent developments of tau Positron Emission Tomography (PET) allows assessment of regional neurofibrillary tangles (NFTs) deposition in human brain. Among the tau PET molecular probes, 18F-AV1451 is characterized by high selectivity for pathologic tau aggregates over amyloid plaques, limited non-specific binding in white and gray matter, and confined off-target binding. The objectives of the study are (1) to quantitatively characterize regional brain tau deposition measured by 18F-AV1451 PET in cognitively normal older adults (CN), mild cognitive impairment (MCI), and AD participants; (2) to evaluate the correlations between cerebrospinal fluid (CSF) biomarkers or Mini-Mental State Examination (MMSE) and 18F-AV1451 PET standardized uptake value ratio (SUVR); and (3) to evaluate the partial volume effects on 18F-AV1451 brain uptake.Methods: The study included total 115 participants (CN = 49, MCI = 58, and AD = 8) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Preprocessed 18F-AV1451 PET images, structural MRIs, and demographic and clinical assessments were downloaded from the ADNI database. A reblurred Van Cittertiteration method was used for voxelwise partial volume correction (PVC) on PET images. Structural MRIs were used for PET spatial normalization and region of interest (ROI) definition in standard space. The parametric images of 18F-AV1451 SUVR relative to cerebellum were calculated. The ROI SUVR measurements from PVC and non-PVC SUVR images were compared. The correlation between ROI 18F-AV1451 SUVR and the measurements of MMSE, CSF total tau (t-tau), and phosphorylated tau (p-tau) were also assessed.Results:18F-AV1451 prominently specific binding was found in the amygdala, entorhinal cortex, parahippocampus, fusiform, posterior cingulate, temporal, parietal, and frontal brain regions. Most regional SUVRs showed significantly higher uptake of 18F-AV1451 in AD than MCI and CN participants. SUVRs of small regions like amygdala, entorhinal cortex and parahippocampus were statistically improved by PVC in all groups (p < 0.01). Although there was an increasing tendency of 18F-AV-1451 SUVRs in MCI group compared with CN group, no significant difference of 18F-AV1451 deposition was found between CN and MCI brains with or without PVC (p > 0.05). Declined MMSE score was observed with increasing 18F-AV1451 binding in amygdala, entorhinal cortex, parahippocampus, and fusiform. CSF p-tau was positively correlated with 18F-AV1451 deposition. PVC improved the results of 18F-AV-1451 tau deposition and correlation studies in small brain regions.Conclusion: The typical deposition of 18F-AV1451 tau PET imaging in AD brain was found in amygdala, entorhinal cortex, fusiform and parahippocampus, and these regions were strongly associated with cognitive impairment and CSF biomarkers. Although more deposition was observed in MCI group, the 18F-AV-1451 PET imaging could not differentiate the MCI patients from CN population. More tau deposition related to decreased MMSE score and increased level of CSF p-tau, especially in ROIs of amygdala, entorhinal cortex and parahippocampus. PVC did improve the results of tau deposition and correlation studies in small brain regions and suggest to be routinely used in 18F-AV1451 tau PET quantification

Conversion Discriminative Analysis on Mild Cognitive Impairment Using Multiple Cortical Features from MR Images

Neuroimaging measurements derived from magnetic resonance imaging provide important information required for detecting changes related to the progression of mild cognitive impairment (MCI). Cortical features and changes play a crucial role in revealing unique anatomical patterns of brain regions, and further differentiate MCI patients from normal states. Four cortical features, namely, gray matter volume, cortical thickness, surface area, and mean curvature, were explored for discriminative analysis among three groups including the stable MCI (sMCI), the converted MCI (cMCI), and the normal control (NC) groups. In this study, 158 subjects (72 NC, 46 sMCI, and 40 cMCI) were selected from the Alzheimer's Disease Neuroimaging Initiative. A sparse-constrained regression model based on the l2-1-norm was introduced to reduce the feature dimensionality and retrieve essential features for the discrimination of the three groups by using a support vector machine (SVM). An optimized strategy of feature addition based on the weight of each feature was adopted for the SVM classifier in order to achieve the best classification performance. The baseline cortical features combined with the longitudinal measurements for 2 years of follow-up data yielded prominent classification results. In particular, the cortical thickness produced a classification with 98.84% accuracy, 97.5% sensitivity, and 100% specificity for the sMCI–cMCI comparison; 92.37% accuracy, 84.78% sensitivity, and 97.22% specificity for the cMCI–NC comparison; and 93.75% accuracy, 92.5% sensitivity, and 94.44% specificity for the sMCI–NC comparison. The best performances obtained by the SVM classifier using the essential features were 5–40% more than those using all of the retained features. The feasibility of the cortical features for the recognition of anatomical patterns was certified; thus, the proposed method has the potential to improve the clinical diagnosis of sub-types of MCI and predict the risk of its conversion to Alzheimer's disease

Early role of vascular dysregulation on late-onset Alzheimer's disease based on multifactorial data-driven analysis

Multifactorial mechanisms underlying late-onset Alzheimer's disease (LOAD) are poorly characterized from an integrative perspective. Here spatiotemporal alterations in brain amyloid-β deposition, metabolism, vascular, functional activity at rest, structural properties, cognitive integrity and peripheral proteins levels are characterized in relation to LOAD progression. We analyse over 7,700 brain images and tens of plasma and cerebrospinal fluid biomarkers from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Through a multifactorial data-driven analysis, we obtain dynamic LOAD–abnormality indices for all biomarkers, and a tentative temporal ordering of disease progression. Imaging results suggest that intra-brain vascular dysregulation is an early pathological event during disease development. Cognitive decline is noticeable from initial LOAD stages, suggesting early memory deficit associated with the primary disease factors. High abnormality levels are also observed for specific proteins associated with the vascular system's integrity. Although still subjected to the sensitivity of the algorithms and biomarkers employed, our results might contribute to the development of preventive therapeutic interventions

AN EVALUATION OF THE LOWER OHIO RIVER CHANNEL, BLUE, AND FLATHEAD CATFISH FISHERY

In 2015, Illinois changed size and harvest limits for catfishes (blue catfish Ictalurus furcatus, flathead catfish Pylodictis olivaris, and channel catfish Ictalurus punctatus) in the Ohio River to match those of neighboring states in order to provide continuity of the regulations and promote a trophy catfish fishery. Regulations imposed a daily limit of one blue catfish or flathead catfish ≥ 35 inches (88.9 cm) and one channel catfish ≥ 28 inches (71.1 cm) per fisher and a 13 inch (33.0 cm) minimum length limit for all species with no bag limit. Although management regulations were implemented, potential efficacy of the implemented regulations and appropriate (i.e. most precise or accurate with fewest samples) monitoring protocols were unknown. Furthermore, there was general lack of understanding of early life movements, natal dispersal timing and principal recruitment sources that aide in determining appropriate spatial scale for monitoring and managing lower Ohio River catfish stocks.To fill these knowledge gaps the following methods were employed: 1) simulation modeling was used to evaluate precision in estimating catch and size distribution metrics for monitoring population trends with increasing sample size (i.e., sampling events), 2) N-mixture modeling was used to estimate size selectivity of multiple gears using detection probability as a robust alternative to size-specific catchability coefficients, 3) otolith microchemistry (Sr:Ca and Ba:Ca) was employed to determine principal recruitment sources, early life movement patterns, and provide fisheries managers with a better understanding of the spatial extent to which management actions should be implemented, 4) Bayesian modeling was used to estimate growth and mortality, 5) Yield-per-recruit modeling was used to estimate and evaluate fishing mortality rates that would result in growth overfishing (FMAX) and yield at FMAX (YPRMAX) for three management scenarios (no regulation, minimum length limit [33.0 cm or greater] and a permissive slot limit [33.0 cm – 88.9 cm; blue catfish and flathead catfish]). The simulation models presented account for the uncertainty associated with heterogeneous selectivity of a gear, and minimize the impact of rare or extreme catch values. Trotlines and low pulse (15-pps) electrofishing generally required the fewer samples to achieve stable values of catch per unit of effort (CPUE), proportional size distribution (quality; PSDQ), and coefficient of variation (CV) than other gears based on simulation modeling. Abundance and detection probabilities were estimated separately for each species of catfish by length category within and across gears, producing a species-gear-size correction for catch bias used in estimating Proportional Size Distribution - Quality (PSDQ). Corrected (i.e., accounting for detection) PSDQ values were lower than uncorrected estimates suggesting a positive bias for larger fish across the entire sampling regime. Managers should use a combination of low pulse electrofishing, trotlines, and high pulse (60-pps) electrofishing in their monitoring efforts for all three species. Based on microchemistry, ictalurid catfishes in the lower Ohio River appear to recruit from multiple sources and make movements across a broad geographic scale. Additionally, some catfish may be originating from outside the portion of the Ohio River that is managed by Illinois (lower 214 km). Fisheries managers should take this into account when implementing management actions. However, most ictalurid catfishes originated from riverine (e.g., Ohio and Mississippi River) natal environments and not from smaller tributaries, and managers should not expect tributaries to compensate for weak year-classes within the river. Based on yield per recruit modeling, catfish stocks are unlikely to benefit from current regulations or a theoretical minimum size limit given the near complete overlap of YPRMAX confidence intervals for all estimable scenarios and the small statistical difference (1 – 3%) based on FMAX between the most permissive and most restrictive scenarios. While statistical differences in FMAX exist, they are likely biologically irrelevant, exceeding the precision of estimation methods for F. While there is some indication that alignment and continuity of management regulations is warranted based on microchemistry, the efficacy of the current permissive slot regulations is questionable based on the models presented and the life history of these fishes. There is no advantage to implementing any of the modeled regulations in terms of increasing FMAX or YPRMAX

An evaluation Zequanox® efficacy and application strategies for targeted control of zebra mussels in shallow-water habitats in lakes

An evaluation of Zequanox® (a naturally derived biopesticide that is non-toxic to humans and other aquatic life and selectively kills dreissenid mussels) for controlling zebra mussel infestations in shallow-water habitats in lakes was conducted at Deep Quarry Lake in DuPage County, Illinois during summer 2012 and 2013. During the 2012 trial, three sets of paired 24-m² treatment and control sites were established within the lake, while a single 324-m² treatment site was established for the 2013 trial. Zequanox was applied to treatment plots, contained using PVC barrier curtains, and barriers were removed during the morning following application. Zebra mussel mortality and size distributions on natural substrates were assessed one day and one week post-treatment for 2012 trials and one day and two weeks posttreatment for 2013 trials; percent mortality of zebra mussels in mesh containers in treatment and control sites was also monitored up to 14 days and 48 days post-treatment in 2012 and 2013, respectively. Several water quality parameters were measured in control and treatment plots before and during application and up to 14 d post-treatment. Mean percent mortality for adult zebra mussels on natural and artificial substrates in treatment locations 7–48 d following Zequanox application ranged from 92–98% during both years, while mortality was consistently ≤10% in control locations. Mean percent mortality ranged from 15–76% in locations \u3e 5 m from and in water shallower than Zequanox application points (\u3c0.6 m depth) during the 2013 trial likely due to limited product dispersal into these areas. There was no significant difference in the size distribution of live and dead zebra mussels in treatment plots. Mean veliger mortality was 94.4% 20-h after the start of the 6-h Zequanox treatment period in the treatment area compared to 15.1% in untreated locations during the 2013 trial. Temporary but substantial reductions in dissolved oxygen were observed in treatment locations during the morning following Zequanox treatment in both 2012 and 2013 trials, likely due to the presence of the barriers that prevented well-oxygenated water from circulating into treatment zones from adjacent areas in the lake. Dissolved oxygen concentrations quickly rebounded to levels consistent with control sites upon removal of barriers. No effects of Zequanox treatment on ammonia, total nitrogen, total phosphorus, biochemical oxygen demand, chlorophyll a, pH, or conductivity were observed. Results suggest that Zequanox has potential as a tool for controlling zebra mussels in shallow-water habitats in lakes without significant long-term effects on water quality