Effects of habitat complexity and hydrodynamics on the abundance and diversity of small invertebrates colonizing artificial substrates

Invertebrate colonization in a shallow estuarine embayment was studied with the use of artificial substrates (bottle brushes) to create and mimic complex habitats. Substrates were manipulated to obtain varying levels of habitat density and surface area by shortening and/or removing bristles from the brushes. Complexity was quantified as the total surface area of bristles and bristle surface area within the geometric volume of the substrate (i.e., bristle density). Short-bristled brushes provided greater habitat density while long-bristled brushes provided larger surface area within the same removal treatment. Abundance of invertebrates that recruited from the water column (mostly from the meiobenthos) averaged 2500–7000 individuals per collector after 10 days, and abundances significantly increased with increasing habitat density (i.e., decreasing bristle removal). The abundance of nematodes and copepod species richness were more closely related to bristle density than surface area. Copepod abundance was more closely related to surface area than bristle density. Flow visualizations in a paddlewheel flume revealed that water was diverted around brushes with high bristle density (0% and 20% bristle removal), regardless of bristle length, when incident flow was 6 cm s−1. Relatively more water passed through the brushes in low bristle density treatments (80% removal) and when freestream velocity was increased to 12 cm s−1. Measurements of flow speed on the upstream and downstream sides of brushes confirmed that fractional transmission of velocity (transmissivity) increased with freestream velocity, but showed inconsistent patterns among length and removal treatments. Flow was substantially decreased by interaction with the brushes, which probably enhanced the retention of invertebrates. The dissimilar responses of nematodes and copepods suggest that not all small taxa respond to the same components of architectural complexity and that there are both physical and biological components to recruitment of these artificial substrates

The Potential use of Seagrass Herbivory Patterns as an Indicator of Herbivore Community Change after Tropical Marine Protected Area Establishment

Throughout the Caribbean, fishing pressure has decreased the abundance of many species, including both large predators and larger-bodied herbivores. In an effort to reverse these trends and reduce harvest pressure on vulnerable fish populations, Marine Protected Areas (MPAs) have been established throughout the Caribbean. Yet, the effort to monitor fish communities, is variable, and there are MPAs where no monitoring program exists. It is possible that other metrics may be used to determine whether the impact of MPA establishment. By comparing two seagrass herbivory experiments, one pre- and one post-MPA establishment, we provide evidence that the MPA established in Discovery Bay, Jamaica in 2009, may have altered the herbivore community. Seagrass grazing has decreased while the size of bites almost doubled after the MPA was established. This dramatic shift in herbivory rates and bite size might be useful indicators that the MPA in Discovery Bay is working, despite limited monitoring of fish populations

Are Eastern Oysters Being Bored to Death? Influence of \u3cem\u3eCliona celata\u3c/em\u3e on \u3cem\u3eCrassostrea virginica\u3c/em\u3e Condition, Growth and Survival

The boring sponge Cliona celata is a nuisance species that can have deleterious effects on eastern oyster Crassostrea virginica growth, condition, and survival. Surprisingly, however, these effects have not been well documented and when examined, results have been equi-vocal. In this study, we provide a direct comparison of growth, condition, and survival of sponge-colonized and uncolonized oysters in southeast North Carolina in 2 separate experiments. In the first experiment, sponge-colonized oysters exhibited significantly slower growth rates, reduced condition, and lower survival relative to uncolonized oysters, although results may have been confounded by oyster source. In the second experiment, using smaller oysters from the same source population, growth rate was again significantly reduced in colonized oysters relative to uncolonized oysters, however neither condition nor survival differed. In field surveys of the same population, colonized individuals across a range of sizes demonstrated significantly reduced condition. Further, condition index was negatively correlated with sponge biomass, which was positively correlated with oyster size, suggesting that the impact of the sponge changes with ontogeny. By investigating clearance rates, tissue isotopic and nutrient content, as well as caloric value, this study provides further evidence that sponge presence causes the oysters to divert energy into costly shell maintenance and repair at the expense of shell and somatic growth. Thus, although variable, our results demonstrate negative impacts of sponge infestation on oyster demographics, particularly as oysters grow larger

Carbon flux for the Caribbean giant barrel sponge Xestospongia muta (Sponge-loop)

Dataset: Carbon fluxBenthic suspension feeders are an important component of aquatic ecosystems, as they mediate benthic-pelagic coupling and the flow of energy and nutrients. There is increasing evidence that sponges are particularly important benthic suspension feeders in aquatic systems and especially on Caribbean coral reefs, where their biomass surpasses that of any other benthic group. The present study investigated the flux of particulate and dissolved organic carbon mediated by the Caribbean giant barrel sponge, Xestospongia muta. A total of 1 L of both incurrent (ambient) and excurrent seawater was collected in situ on Conch Reef, Key Largo, Florida, from 32 individuals with paired 100 mL syringes. Following seawater sample collection, the dimensions of each sponge were measured to obtain sponge volume estimates. Pumping rates were calculated from sponge volume using the relationship of McMurray et al. (2014). For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/685783NSF Division of Ocean Sciences (NSF OCE) OCE-155858

Periwinkle climbing response to water- and airbone predator chemical cues may depend on home-marsh geography

The salt marsh periwinkle, Littorina irrorata, exhibits a spatial refuge from predation by climbing the stems of Spartina alterniflora in order to avoid benthic predators. Salt marsh periwinkles have a broad geographic distribution, and for many species, responses to predators also varies with biogeography. This study sought to determine if the geographical location of the home marsh influenced the response of periwinkles (climbing height) to blue crab predator cues both via air and water. Snails from Louisiana (LA) climbed higher in general than those from North Carolina (NC), regardless of chemical cue. However, LA snails climbed 11 cm higher in the presence of waterborne predators than control snails with no cue, while NC snails only climbed five cm higher in the same comparisons. Airborne chemical cue tended to have snails climbing at intermediate heights. These responses were significantly enhanced when both populations of snails were housed together. Periwinkle response to predator cues was stronger in LA than NC, and so it is possible that the behavioral response of these snails to predators varies with biogeography of the home marsh. Also interestingly, the results of this study also suggest that cue delivery is probably occurring via mechanisms other than water, and potentially via airborne cues. Therefore, salt marsh periwinkles likely respond to numerous cues that initiate behavioral responses, including airborne cues, and these responses may vary by home-marsh geography

Restoring the sting to metric preheating

The relative growth of field and metric perturbations during preheating is sensitive to initial conditions set in the preceding inflationary phase. Recent work suggests this may protect super-Hubble metric perturbations from resonant amplification during preheating. We show that this possibility is fragile and sensitive to the specific form of the interactions between the inflaton and other fields. The suppression is naturally absent in two classes of preheating in which either (1) the vacua of the non-inflaton fields during inflation are deformed away from the origin, or (2) the effective masses of non-inflaton fields during inflation are small but during preheating are large. Unlike the simple toy model of a $g^2 \phi^2 \chi^2$ coupling, most realistic particle physics models contain these other features. Moreover, they generically lead to both adiabatic and isocurvature modes and non-Gaussian scars on super-Hubble scales. Large-scale coherent magnetic fields may also appear naturally.Comment: 6 pages, 3 ps figures, RevTex, revised discussion of backreaction and new figure. To appear Phys. Rev. D (Rapid Communication

Results from the centers for disease control and prevention's predict the 2013-2014 Influenza Season Challenge

Background: Early insights into the timing of the start, peak, and intensity of the influenza season could be useful in planning influenza prevention and control activities. To encourage development and innovation in influenza forecasting, the Centers for Disease Control and Prevention (CDC) organized a challenge to predict the 2013-14 Unites States influenza season. Methods: Challenge contestants were asked to forecast the start, peak, and intensity of the 2013-2014 influenza season at the national level and at any or all Health and Human Services (HHS) region level(s). The challenge ran from December 1, 2013-March 27, 2014; contestants were required to submit 9 biweekly forecasts at the national level to be eligible. The selection of the winner was based on expert evaluation of the methodology used to make the prediction and the accuracy of the prediction as judged against the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). Results: Nine teams submitted 13 forecasts for all required milestones. The first forecast was due on December 2, 2013; 3/13 forecasts received correctly predicted the start of the influenza season within one week, 1/13 predicted the peak within 1 week, 3/13 predicted the peak ILINet percentage within 1 %, and 4/13 predicted the season duration within 1 week. For the prediction due on December 19, 2013, the number of forecasts that correctly forecasted the peak week increased to 2/13, the peak percentage to 6/13, and the duration of the season to 6/13. As the season progressed, the forecasts became more stable and were closer to the season milestones. Conclusion: Forecasting has become technically feasible, but further efforts are needed to improve forecast accuracy so that policy makers can reliably use these predictions. CDC and challenge contestants plan to build upon the methods developed during this contest to improve the accuracy of influenza forecasts. © 2016 The Author(s)

Systematic In Vivo Analysis of the Intrinsic Determinants of Amyloid β Pathogenicity

Protein aggregation into amyloid fibrils and protofibrillar aggregates is associated with a number of the most common neurodegenerative diseases. We have established, using a computational approach, that knowledge of the primary sequences of proteins is sufficient to predict their in vitro aggregation propensities. Here we demonstrate, using rational mutagenesis of the Aβ42 peptide based on such computational predictions of aggregation propensity, the existence of a strong correlation between the propensity of Aβ42 to form protofibrils and its effect on neuronal dysfunction and degeneration in a Drosophila model of Alzheimer disease. Our findings provide a quantitative description of the molecular basis for the pathogenicity of Aβ and link directly and systematically the intrinsic properties of biomolecules, predicted in silico and confirmed in vitro, to pathogenic events taking place in a living organism

Comparison of MRI- and TRUS-Informed Prostate Biopsy for Prostate Cancer Diagnosis in Biopsy-Naive Men: A Systematic Review and Meta-Analysis.

PURPOSE: Multiparametric magnetic resonance imaging (mpMRI) with informed targeted biopsies (TGBX) has changed the paradigm of prostate cancer (PCa) diagnosis. Randomized studies have demonstrated a diagnostic benefit of Clinically significant (CS) for TGBX compared to standard systematic biopsies (SBX). We aimed to evaluate whether mpMRI-informed TGBX has superior diagnosis rates of any-, CS-, high-grade (HG)-, and clinically insignificant (CI)-PCa compared to SBX in biopsy-naive men. METHODS: Data was searched in Medline, Embase, Web of Science, and Evidence-based medicine reviews-Cochrane Database of systematic reviews from database inception until 2019. Studies were selected by two authors independently, with disagreements resolved by consensus with a third author. Overall 1951 unique references were identified, and 100 manuscripts underwent full-text review. Data were pooled using random-effects models. The meta-analysis is reported according to the PRISMA statement. The study protocol is registered with PROSPERO (CRD42019128468). RESULTS: Overall 29 studies (13,845 patients) were analyzed. Compared to SBX, use of mpMRI-informed TGBX was associated with a 15% higher rate of any PCa diagnosis (95% CI 10-20%, p\u3c0.00001). This relationship was not affected by the study methodology (p=0.11). Diagnosis of CS and HG PCa were more common in the mpMRI-informed TGBX group (risk difference of 11%, 95% CI 0-20%, p=0.05, and 2%, 95% CI 1-4%; p=0.005, respectively) while there was no difference in diagnosis of CI PCa (risk difference of 0, 95% CI -3-3%, p=0.96). Notably, the exclusion of SBX in the mpMRI-informed TGBX arm significantly modified the association between a mpMRI strategy and lower rates of CI PCa diagnosis (p=0.01) without affecting the diagnosis rates of CS- or HG-PCa. CONCLUSIONS: In comparison to SBX, a mpMRI-informed TGBX strategy results in a significantly higher diagnosis rate of any-, CS-, and HG-PCa. Excluding SBX from mpMRI-informed TGBX was associated with decreased rates of CI-PCa diagnosis without affecting diagnosis of CS- or HG-PCa