Damage-induced reactive oxygen species enable zebrafish tail regeneration by repositioning of Hedgehog expressing cells.

Many aquatic vertebrates have a remarkable ability to regenerate limbs and tails after amputation. Previous studies indicate that reactive oxygen species (ROS) signalling initiates regeneration, but the mechanism by which this takes place is poorly understood. Developmental signalling pathways have been shown to have proregenerative roles in many systems. However, whether these are playing roles that are specific to regeneration, or are simply recapitulating their developmental functions is unclear. Here, we analyse zebrafish larval tail regeneration and find evidence that ROS released upon wounding cause repositioning of notochord cells to the damage site. These cells secrete Hedgehog ligands that are required for regeneration. Hedgehog signalling is not required for normal tail development suggesting that it has a regeneration-specific role. Our results provide a model for how ROS initiate tail regeneration, and indicate that developmental signalling pathways can play regenerative functions that are not directly related to their developmental roles

Correlations Between Victim-Offender Relationship & Level of Sexual Aggression in Fantasy and Experience

This study examines sexual aggression in 13 contexts, differentiated by victimoffender relationship, by assessing the level of sexual aggression in reported fantasy and experience within the college population. All items pertaining to this study have been compiled into a multiple-choice questionnaire that specifically questions participants about sexually aggressive fantasies and experiences with partners of certain relationship types. The study was administered online to students enrolled in an introductory psychology course at a southwest university, concluding with 500 subjects. The results supported the hypotheses that sexual aggression is indeed discreet to victim-offender relationship, showing that sexual aggression is more associated with a certain relationship than with certain aggressive actions. The implications of this study will generate important information that is pertinent to many diverse fields, such as psychology, sociology, law, and criminal justice

Nrg1 is an injury-induced cardiomyocyte mitogen for the endogenous heart regeneration program in zebrafish.

Heart regeneration is limited in adult mammals but occurs naturally in adult zebrafish through the activation of cardiomyocyte division. Several components of the cardiac injury microenvironment have been identified, yet no factor on its own is known to stimulate overt myocardial hyperplasia in a mature, uninjured animal. In this study, we find evidence that Neuregulin1 (Nrg1), previously shown to have mitogenic effects on mammalian cardiomyocytes, is sharply induced in perivascular cells after injury to the adult zebrafish heart. Inhibition of Erbb2, an Nrg1 co-receptor, disrupts cardiomyocyte proliferation in response to injury, whereas myocardial Nrg1 overexpression enhances this proliferation. In uninjured zebrafish, the reactivation of Nrg1 expression induces cardiomyocyte dedifferentiation, overt muscle hyperplasia, epicardial activation, increased vascularization, and causes cardiomegaly through persistent addition of wall myocardium. Our findings identify Nrg1 as a potent, induced mitogen for the endogenous adult heart regeneration program

Channel Sediment Changes during a Stream Restoration Project

Streams and rivers with compromised riparian zone, especially those along agricultural landscapes, are particularly susceptible to an increased buildup of stream bottom sediment. An abundance of fine sediment within a stream system can congest the water, potentially smothering fish species, aquatic insects and oxygen producing plants. The Chesapeake Conservancy developed a stream restoration prioritization tool to identify properties based on lack of riparian forests, neighboring land use, and hydrologic flow paths. This tool was used to select sites for stream restorations. We are monitoring these sites and others to build a reference profile of the grain size characteristics of streams that are pristine trout streams to agriculturally impaired stream bottoms. We will compare the grain size statistics from before restoration projects are implemented with samples collected after the restoration. We hope to also analyze the relationships between stream bottom sediment characteristics and biological monitoring to determine if there are relationships between good stream habitat and its sediment profiles

Landscape Characteristics that Contribute to Successful Stream Restoration Projects

Riparian zone management practices influence the ecological issues attributed to agricultural land use and environmental quality. Geographic Information Systems can be utilized to prioritize areas adjacent to waterways that are used for agricultural purposes and have high rates of runoff where no riparian zone is present. The Chesapeake Conservancy has developed a prioritization tool that identified sites on Elk Creek, Spring Creek, and Pine Creek in Central PA for restoration. Using this priority tool for selecting sites, we are monitoring sites as stream restoration projects are begun. We wish to compare site-specific measurements of fish populations, macro-invertebrate populations, and stream sediment characteristics with the prioritization weights to determine whether sites selected using GIS tools can be significantly improved after stream restoration projects

Do Stream Restoration Projects Change Carbon and Nitrogen Dynamics in These Streams?

Pennsylvania is known for its river life. Property owners in the upper Susquehanna River basin in particular, take pride in any flowing water on their land. When these streams are degraded, conservancies and government agencies can provide help to landowners to install plantings, materials, devices and earth-moving to restore the stream channel. These strategies attempt to anchor sediments, re-vegetate the stream bank, remove nutrients from runoff, provide shade to the channel, and add structures that improve the stream bottom for improved fish and insect habitat. A stream prioritization tool from the Chesapeake Conservancy identified properties on Elk Creek in Central PA as a priority for restoration based on new hi-resolution land cover, flowpath analysis, and stream forests. Carbon and nitrogen in both stream water and stream sediments are being monitored during the stream restoration to determine if these concentrations change during after the stream channel is improved. By examining a range of PA streams, the carbon:nitrogen ratio of stream waters are about 44 for mountain trout streams while severely impaired streams have a ratio of about 1. In sediments, these ratios are 17 for pristine streams and \u3c1 in severely impaired streams. We are monitoring these ratios at 4 sites along Elk Creek to determine if this ratio can be improved following a stream restoration

Resistance to desiccation in aquatic invasive snails and implications for their overland dispersal

At least 30 species of nonindigenous freshwater snails have invaded North America. The risk of these snails invading new lakes depends upon their ability to survive overland transport. We first reviewed published laboratory experiments using freshwater snails, which show numerous species are able to tolerate days of air exposure. We then tested tolerance to drying of three species of invasive aquatic snails that are widespread in Wisconsin: Bithynia tentaculata, Cipangopaludina chinensis, and Viviparus georgianus. In a series of seven experiments, we simulated boater transport by placing snails individually in mesh bags, hung outdoors, and confined in a screen tent. The screen roof allowed exposure to both sun and rain, and an on-site weather station recorded temperature, precipitation, and humidity. All three species exhibited high survivorship, with some individuals alive at the end of most experiments: 42 days for B. tentaculata and V. georgianus and 63 days for C. chinensis. Viable young were released by C. chinensis after 54 days of exposure. Overall, our results indicate that these invasive snails should readily survive long periods of transport overland, indicating a need for continued vigilance of recreational boaters entering lakes

Can Need For Affect And Sexuality Differentiate Suicide Risk In Three Community Samples?

Suicide is a pressing community mental health problem, yet remains under investigated in certain vulnerable populations such as the bondage and sadomasochism (BDSM) community. As reflected by the Need for Affect (NFA), the present paper aims to test a new approach to understanding suicide risk from a Preferences in Information Processing perspective. Adult participants (n = 2,097) drawn from community, college, and BDSM community samples completed a health survey via online administration. Bivariate tests were used to identify correlates of elevated suicide risk, and logistic regression was employed to test primary hypotheses. Results yielded the following indicators of elevated suicide risk category membership: (1) female gender, (2) BDSM community membership, (3) lesbian, gay, bisexual and other sexual orientation identity minority status, (4) elevated depressive symptoms, (5) elevated NFA approach, and (6) elevated NFA Avoidance. BDSM and NFA results are largely new, and speak to the need for further attention. Results are discussed with respect to information processing preferences, as well as the intersection of sexuality-based marginalized groups, stigma, and health disparities. Implications for community mental health and suicide prevention are discussed

Prevalence Rates, Reporting, And Psychosocial Correlates Of Stalking Victimization: Results From A Three-Sample Cross-Sectional Study

Purpose: Public health and criminal justice stalking victimization data collection efforts are plagued by subjective definitions and lack of known psychosocial correlates. The present study assesses the question of stalking victimization prevalence among three groups. Psychosocial risk and protective factors associated with stalking victimization experiences were assessed. Methods: Archival data (n = 2159) were drawn from a three-sample (i.e., U.S. nationwide sexual diversity special interest group, college student, and general population adult) cross-sectional survey of victimization, sexuality, and health. Results: The range of endorsement of stalking-related victimization experiences was 13.0–47.9%. Reported perpetrators were both commonly known and unknown persons to the victim. Participants disclosed the victimization primarily to nobody or a family member/friend. Bivariate correlates of stalking victimization were female gender, Associates/Bachelor-level education, bisexual or other sexual orientation minority status, hypertension, diabetes, older age, higher weekly drug use, elevated trait aggression, higher cognitive reappraisal skills, lower rape myth acceptance, and elevated psychiatric symptoms. Logistic regression results showed the strongest factors in identifying elevated stalking victimization risk were: older age, elevated aggression, higher cognitive reappraisal skills, lesser low self-control, increased symptoms of suicidality and PTSD re-experiencing, and female and other gender minority status. Conclusions: Behavioral approaches to epidemiological and criminal justice stalking victimization are recommended. Victimization under reporting to healthcare and legal professionals were observed. Further research and prevention programming is needed to capitalize on data concerning personality and coping skills, sexual diversity, and trauma-related psychiatric symptoms

Loss-of-function genetic tools for animal models: cross-species and cross-platform differences

Our understanding of the genetic mechanisms that underlie biological processes has relied extensively on loss-of-function (LOF) analyses. LOF methods target DNA, RNA or protein to reduce or to ablate gene function. By analysing the phenotypes that are caused by these perturbations the wild-type function of genes can be elucidated. Although all LOF methods reduce gene activity the choice of approach (for example, mutagenesis, CRISPR-based gene editing, RNA interference, morpholinos or pharmacological inhibition) can have a major effect on phenotypic outcomes. Interpretation of the LOF phenotype must take into account the biological process that is targeted by each method. The practicality and efficiency of LOF methods also vary considerably between model systems. We describe parameters for choosing the optimal combination of method and system, and for interpreting phenotypes within the constraints of each method