Hydrology and invasive macrophytes may mediate freshwater mussel density and population size structure in a hydropeaking reservoir.

Globally-threatened freshwater mussels belonging to the order Unionida (Bivalvia) may be adversely affected by dense beds of submerged macrophytes that modify habitat at the sediment-water interface. Such effects can be particularly pronounced in modified lentic ecosystems such as reservoirs which are subject to hydrological regimes (e.g., hydropeaking) that can exacerbate macrophyte-mediated impacts, including anoxic or hypoxic conditions, the related release of toxic ions (e.g., ammonia), and silt accumulation that inhibits filter-feeding. Accordingly, we compared how population size-structure and biomass of the New Zealand mussel Echyridella menziesii varied inside and outside of dense beds of invasive macrophytes known to have similar impacts on water chemistry (e.g., anoxia) in two northern New Zealand hydroreservoir locations with contrasting hydrology (lacustrine location dominated by Ceratophyllum demersum; and riverine location dominated by Egeria densa). We found adverse sediment-water interface conditions were not always associated with dense submerged macrophyte beds in littoral zones. Nonetheless, where they occurred, adverse sediment-water interface conditions were related to reduced mussel density and adult skewed size-structure, inferring reduced recruitment. Disentangling direct and indirect effects with structural equation modelling indicated that increased pore-water ammonia did not impact these primarily adult populations of freshwater mussels. Increased sediment organic matter, silt, and previously recorded hypoxia and anoxia were exacerbated in the lacustrine section where variable flows promoting water mixing were not present. High densities of mussels <40 mm in length were associated with favourable sediment-water interface conditions of low silt and sediment organic matter, suggesting that enhanced water exchange in and around macrophyte beds may increase juvenile mussel survival in littoral zones of the riverine lake section. Our findings highlight a potential role for hydropeaking management in mitigating the development of adverse physicochemical conditions, and underscore the context-specific effects that dense non-native macrophyte beds can have on mussel populations.

A meta-analysis of prosocial media on prosocial behavior, aggression, and empathic concern: A multidimensional approach.

Studies examining the effects of exposure to prosocial media on positive outcomes are increasing in number and strength. However, existing meta-analyses use a broad definition of prosocial media that does not recognize the multidimensionality of prosocial behavior. The aim of the current study is to conduct a meta-analysis on the effects of exposure to prosocial media on prosocial behavior, aggression, and empathic concern while examining multiple moderators that the prosocial behavior literature suggests are important to our understanding of why individuals voluntarily help others (e.g., target, type, cost). Results from 72 studies involving 243 effect sizes revealed that exposure to prosocial media was related to higher levels of prosocial behavior and empathic concern and lower levels of aggressive behavior. Moderation analyses suggest that several moderators accounted for heterogeneity in the model, including age of participant, region, media type (active vs. passive), and study design. In terms of multidimensional moderators, prosocial media had stronger effects on prosocial behavior toward strangers than did any other target and on helping and prosocial thinking but not donating or volunteering. Comparisons with other meta-analyses on media effects are made and implications for parents, media producers, and researchers are discussed. (PsycINFO Database Record

"It's Just Not Very Realistic": Perceptions of Media Among Pregnant and Postpartum Women.

Although research has documented a connection between media and body image for women, little research has explored this connection among pregnant or postpartum women. The purpose of this study was to explore women's perceptions of media and body image during the perinatal period. Fredrickson's objectification theory provided a theoretical framework for the study. Data collection involved semi-structured in-depth interviews with 50 pregnant or postpartum women in which they were asked to describe their perceptions of media depictions of pregnant or postpartum women and its impact on their body image. Interviews were audio-recorded, transcribed verbatim, and analyzed thematically. Four major themes emerged: (1) participants questioned the realism of media depictions of pregnant and postpartum women, (2) participants described complex reactions to media messages including negative impacts on body image and strategies for mitigating negative impacts, (3) participants desired changes in media messages to be more realistic and to depict a more complex portrayal of the life stage, and (4) participants discussed the unique and complex role of social media including both negative and positive impacts. Implications of the findings for pregnant and postpartum women, communication scholars, and healthcare professionals are discussed.

The Effect of Media on Body Image in Pregnant and Postpartum Women.

Much research has found that exposure to certain types of media portrayals of women can be related to body image concerns among women. The current paper focuses on the impact of certain messages on pregnant and postpartum women. These women are rarely examined in a media research context but are particularly vulnerable to body image concerns. This experimental study involved 192 pregnant or postpartum women who read a magazine containing glamorized media portrayals of pregnant/postpartum women or a control magazine. Pregnant women reported lower body image after only five minutes of exposure to the magazine with pregnant/postpartum women compared to the control group. There was no immediate effect on postpartum women. Implications for the media industry, health professionals, and women are discussed.

Parenting and Digital Media.

Understanding the family dynamic surrounding media use is crucial to our understanding of media effects, policy development, and the targeting of individuals and families for interventions to benefit child health and development. The Families, Parenting, and Media Workgroup reviewed the relevant research from the past few decades. We find that child characteristics, the parent-child relationship, parental mediation practices, and parents' own use of media all can influence children's media use, their attitudes regarding media, and the effects of media on children. However, gaps remain. First, more research is needed on best practices of parental mediation for both traditional and new media. Ideally, this research will involve large-scale, longitudinal studies that manage children from infancy to adulthood. Second, we need to better understand the relationship between parent media use and child media use and specifically how media may interfere with or strengthen parent-child relationships. Finally, longitudinal research on how developmental processes and individual child characteristics influence the intersection between media and family life is needed. The majority of children's media use takes place within a wider family dynamic. An understanding of this dynamic is crucial to understanding child media use as a whole.

Pow! Boom! Kablam! Effects of Viewing Superhero Programs on Aggressive, Prosocial, and Defending Behaviors in Preschool Children.

Many schools and parents try to motivate children to become defenders of victimized peers. Defending behavior is common in the media (particularly in superhero programs); however, no study has examined the effect of media on defending behavior. The aim of the study was to examine longitudinal associations between superhero engagement and a variety of aggressive, prosocial, and defending behaviors in preschool children. Participants consisted of 240 preschoolers (49% male) and their parents who reported on child media use and outcomes at 2 different time points. Preschooler's engagement with superheroes was related to increased physical and relational aggression 1 year later. Engagement with superheroes was not related to prosocial or defending behaviors. Implications of the results are discussed.

Does parental mediation of media influence child outcomes? A meta-analysis on media time, aggression, substance use, and sexual behavior.

The current study examined how parental mediation of media (restrictive mediation, active mediation, and coviewing) influenced child outcomes. Three meta-analyses, 1 for each type of mediation, were conducted on a total of 57 studies. Each analysis assessed the effectiveness of parental mediation on 4 pertinent child outcomes: media use, aggression, substance use, and sexual behavior. The overall results indicated small, but significant relationships between child outcomes and restrictive mediation (r+ = -.06), and coviewing (r+ = .09). Overall active mediation was nonsignificant, though active mediation was individually related to lower levels of aggression (r+ = -.08), sexual behavior (r+ = -.06), and substance use (r+ = -.11). This analysis revealed that parents may have the ability to mitigate some of the adverse effects of the media by using certain mediation strategies. Overall, a cooperative effort from the communication and parenting fields is necessary for a comprehensive analysis of parental mediation as well as a disentanglement of the various parental mediation measures. (PsycINFO Database Record

Longitudinal relations between parental media monitoring and adolescent aggression, prosocial behavior, and externalizing problems.

The current study examined longitudinal relations between parental media monitoring and adolescent behavior, and explored indirect effects via sympathy and self-regulation. A sample of adolescents and their mothers from Northwestern and Mountain West cities in the USA participated in a study at three time points, approximately one year apart (N = 681; M age of child at Time 3 = 13.33, SD = 1.06; 51% female; 73% European American, 9% African American, 17% Multi-ethnic). Though findings varied by reporter, results suggested that restrictive and active media monitoring were indirectly associated with adolescents' prosocial behavior, aggression, and externalizing behavior, with restrictive monitoring being somewhat maladaptive and active monitoring adaptive. The discussion focuses on the need to examine multiple aspects of media monitoring, and highlights implications of findings for parents.

Longitudinal relations between prosocial television content and adolescents' prosocial and aggressive behavior: The mediating role of empathic concern and self-regulation.

The current study examined longitudinal cross-lagged associations between prosocial TV (content and time) and prosocial and aggressive behavior during adolescence, and explored the mediating role of empathic concern and self-regulation. Participants were 441 adolescents who reported on their 3 favorite TV shows at 2 time points, approximately 2 years apart (M age of child at Time 3 = 13.31, SD = 1.06; 52% female; M age of child at Time 5 = 15.27, SD = 1.06). Results suggested that prosocial content at Time 3 was negatively associated with aggressive behavior 2 years later, and aggressive behavior at Time 3 was positively associated with aggressive content 2 years later. Results also suggested that prosocial behavior toward strangers at Time 3 was associated with both empathic concern and self-regulation at Time 4, which were in turn associated with prosocial and aggressive content at Time 5. Discussion focuses on the important role of behavior and prosocial personality on media selection during adolescence and the relevance of the target of prosocial behavior.

"Just how graphic are graphic novels?" An examination of aggression portrayals in manga and associations with aggressive behavior in adolescents.

Manga, a type of graphic novel, represent a widely popular literary genre worldwide and are one of the fastest growing areas of the publishing arena aimed at adolescents in the United States. However, to our knowledge, there has been almost no empirical research examining content or effects of reading manga. This article consists of 2 studies. Study 1 represents a content analysis of aggressive behavior in best-selling manga aimed at adolescents. Results revealed that aggression was common and was often portrayed in ways that may influence subsequent behavior. Study 2 examined the relationship between reading manga and aggressive behavior in 223 adolescents. Manga readers were more physically aggressive than non-manga readers and also reported more peer relationships with lonely individuals and smaller groups. In addition, reading manga with particularly high levels of aggression was associated with physical aggression even after controlling for media violence exposure in other media. Implications regarding these findings are discussed.

Primary biliary tract melanoma: Report of a case and review of the literature.

INTRODUCTION: Primary melanoma of the bile duct is extremely rare with only nine cases of primary melanoma of the bile duct reported in the literature. PRESENTATION OF CASE: A 55-year-old previously healthy gentleman developed increasing jaundice over several months and subsequently underwent an ERCP with stone extraction. Cytology brushings in an area of a distal stricture in the bile duct were concerning for cholangiocarcinoma. The patient was referred to our institution and underwent a pancreaticoduodenectomy. The surgical specimen showed a single 4.5cm polypoid lesion located in the bile duct. A diagnosis of melanoma was rendered after immunohistochemical studies on the tumor demonstrated positivity for melanoma markers. Follow-up of the patient with skin, ocular, and lymph node exams showed no evidence of melanoma. A PET scan 4 and 10 months post-surgery failed to reveal either a primary skin lesion or other sites of metastases. DISCUSSION: The vast majority of melanomas of the bile duct represent metastases from a cutaneous source and tend to present as multiple flat pigmented lesions. Conversely, cases of primary bile duct melanoma are characterized by a distinct gross morphology consisting of a solitary intraluminal polypoid lesion attached by a pedicle with no other identifiable primary lesion. Other supporting criteria include absence of other involved sites and presence of an in situ junctional component. CONCLUSION: Given the clinical history, gross findings, and lack of a primary cutaneous site or other demonstrable metastases, this patient likely represents the tenth reported case of primary biliary tract melanoma.

Identifying dissolved oxygen variability and stress in tidal freshwater streams of northern New Zealand.

Tidal streams are ecologically important components of lotic network, and we identify dissolved oxygen (DO) depletion as a potentially important stressor in freshwater tidal streams of northern New Zealand. Other studies have examined temporal DO variability within rivers and we build on this by examining variability between streams as a basis for regional-scale predictors of risk for DO stress. Diel DO variability in these streams was driven by: (1) photosynthesis by aquatic plants and community respiration which produced DO maxima in the afternoon and minima early morning (range, 0.6-4.7 g/m(3)) as a product of the solar cycle and (2) tidal variability as a product of the lunar cycle, including saline intrusions with variable DO concentrations plus a small residual effect on freshwater DO for low-velocity streams. The lowest DO concentrations were observed during March (early autumn) when water temperatures and macrophyte biomass were high. Spatial comparisons indicated that low-gradient tidal streams were at greater risk of DO depletions harmful to aquatic life. Tidal influence was stronger in low-gradient streams, which typically drain more developed catchments, have lower reaeration potential and offer conditions more suitable for aquatic plant proliferation. Combined, these characteristics supported a simple method based on the extent of low-gradient channel for identifying coastal streams at risk of DO depletion. High-risk streams can then be targeted for riparian planting, nutrient limits and water allocation controls to reduce potential ecological stress.

A rapid method to score stream reaches based on the overall performance of their main ecological functions.

A method was developed to score the ecological condition of first- to third-order stream reaches in the Auckland region of New Zealand based on the performance of their key ecological functions. Such a method is required by consultants and resource managers to quantify the reduction in ecological condition of a modified stream reach relative to its unmodified state. This is a fundamental precursor for the determination of fair environmental compensation for achieving no-net-loss in overall stream ecological value. Field testing and subsequent use of the method indicated that it provides a useful measure of ecological condition related to the performance of stream ecological functions. It is relatively simple to apply compared to a full ecological study, is quick to use, and allows identification of the degree of impairment of each of the key ecological functions. The scoring system was designed so that future improvements in the measurement of stream functions can be incorporated into it. Although the methodology was specifically designed for Auckland streams, the principles can be readily adapted to other regions and stream types.

Linking multimetric and multivariate approaches to assess the ecological condition of streams.

Few attempts have been made to combine multimetric and multivariate analyses for bioassessment despite recognition that an integrated method could yield powerful tools for bioassessment. An approach is described that integrates eight macroinvertebrate community metrics into a Principal Components Analysis to develop a Multivariate Condition Score (MCS) from a calibration dataset of 511 samples. The MCS is compared to an Index of Biotic Integrity (IBI) derived using the same metrics based on the ratio to the reference site mean. Both approaches were highly correlated although the MCS appeared to offer greater potential for discriminating a wider range of impaired conditions. Both the MCS and IBI displayed low temporal variability within reference sites, and were able to distinguish between reference conditions and low levels of catchment modification and local habitat degradation, although neither discriminated among three levels of low impact. Pseudosamples developed to test the response of the metric aggregation approaches to organic enrichment, urban, mining, pastoral and logging stressor scenarios ranked pressures in the same order, but the MCS provided a lower score for the urban scenario and a higher score for the pastoral scenario. The MCS was calculated for an independent test dataset of urban and reference sites, and yielded similar results to the IBI. Although both methods performed comparably, the MCS approach may have some advantages because it removes the subjectivity of assigning thresholds for scoring biological condition, and it appears to discriminate a wider range of degraded conditions.

Coupling GIS and multivariate approaches to reference site selection for wadeable stream monitoring.

Geographic Information System (GIS) was used to identify potential reference sites for wadeable stream monitoring, and multivariate analyses were applied to test whether invertebrate communities reflected a priori spatial and stream type classifications. We identified potential reference sites in segments with unmodified vegetation cover adjacent to the stream and in >85% of the upstream catchment. We then used various landcover, amenity and environmental impact databases to eliminate sites that had potential anthropogenic influences upstream and that fell into a range of access classes. Each site identified by this process was coded by four dominant stream classes and seven zones, and 119 candidate sites were randomly selected for follow-up assessment. This process yielded 16 sites conforming to reference site criteria using a conditional-probabilistic design, and these were augmented by an additional 14 existing or special interest reference sites. Non-metric multidimensional scaling (NMS) analysis of percent abundance invertebrate data indicated significant differences in community composition among some of the zones and stream classes identified a priori providing qualified support for this framework in reference site selection. NMS analysis of a range standardised condition and diversity metrics derived from the invertebrate data indicated a core set of 26 closely related sites, and four outliers that were considered atypical of reference site conditions and subsequently dropped from the network. Use of GIS linked to stream typology, available spatial databases and aerial photography greatly enhanced the objectivity and efficiency of reference site selection. The multi-metric ordination approach reduced variability among stream types and bias associated with non-random site selection, and provided an effective way to identify representative reference sites.

The frequency of peptic ulcer as a cause of upper-GI bleeding is exaggerated.

BACKGROUND: Peptic ulcer disease is considered the cause of upper-GI bleeding in 50% of cases. A recent decline in the proportion of cases of upper-GI bleeding because of a peptic ulcer was noted by us. The objectives of this study were to evaluate the frequency of peptic ulcer in patients with upper-GI bleeding and the proportion of bleeding peptic ulcers with a non-bleeding visible vessel. METHODS: Patients with upper-GI bleeding seen from December 1999 until April 2001 at a tertiary, university-affiliated medical center were studied prospectively. The Clinical Outcome Research Initiative (CORI) database was used to correlate the single institution data with nationwide data. Endoscopic data in the CORI database for patients who had endoscopy for upper-GI bleeding between December 1999 and July 2001 were retrieved and analyzed. RESULTS: A total of 126 patients were included in the prospective study. The endoscopic findings were: peptic ulcer in 31.8%: 95% confidence interval (CI) [23.7%, 40.6%] of patients; a non-bleeding visible vessel was present in 10%: 95% CI[2.8%, 23.7%] of these peptic ulcers. From the nationwide CORI database, data for 7822 patients with upper-GI bleeding were obtained. The endoscopic findings were: peptic ulcer in 20.6%:95% CI[19.7%, 21.5%] of patients with upper-GI bleeding; a non-bleeding visible vessel was present in 7.3%: 95% CI[6.1%, 8.6%] of the ulcers. CONCLUSIONS: The frequency of peptic ulcer in patients with upper-GI bleeding and the proportion of bleeding ulcers with a non-bleeding visible vessel are less than previously reported.