Prevalence and stability of blood-injection-injury phobia in childhood-A prospective community study in Norway.

AIM: An individual with a blood-injection-injury (BII) phobia often avoids exposure to triggers, such as blood tests and clinic appointments, leading to potentially serious health complications. This population-based study examined the prevalence, stability and course of BII phobia in children and adolescents. METHODS: The data came from the Trondheim Early Secure Study, conducted from 2007 to 2018. All children born in Trondheim, Norway, in 2003 and 2004 were invited to attend. Clinical interviews were conducted by trained personnel to assess BII phobia in 1042 children (51% female) every 2 years from 4 to 14 years of age. Latent growth curves and logistic regression analyses were used in the data analysis. RESULTS: Just under 20% of the cohort experienced a BII phobia at least once, with no significant sex differences. The prevalence of BII phobias increased from 3% at 4 years of age and peaked at about 8% at 10 years of age, before levelling off. The two-year stability increased as 12-14 years of age approached. CONCLUSION: The prevalence of BII was affected by age, but not sex. Early BII phobias often recede with time, but children may need treatment if they persist from 8 years of age.

Evolutionary predictions for a parasite metapopulation: Modelling salmon louse resistance to pest controls in aquaculture.

Pests often evolve resistance to pest controls used in agriculture and aquaculture. The rate of pest adaptation is influenced by the type of control, the selective pressure it imposes, and the gene flow between farms. By understanding how these factors influence evolution at the metapopulation level, pest management strategies that prevent resistance from evolving can be developed. We developed a model for the metapopulation and evolutionary dynamics of the salmon louse (Lepeophtheirus salmonis), which is a major parasite affecting salmon aquaculture. Different management scenarios were simulated across a network of salmon farms covering half of Norway, and their effects on louse epidemiology and evolution were investigated. We compared louse controls that differed in how they were deployed through time (discrete vs. continuous), how they impacted the louse life cycle, and in their overall efficacy. We adjusted the strength of selection imposed by treatments, the dominance effect of the resistant allele, and the geographic location at which resistance originated. Continuously acting strategies (e.g., louse-resistant salmon) were generally more effective than discrete strategies at controlling lice, especially when they increased louse mortality during early developmental stages. However, effective strategies also risked imposing frequent and/or strong selection on lice, thus driving rapid adaptation. Resistant alleles were more likely to be lost through genetic drift when they were recessive, had a low-fitness advantage, or originated in low-farm-density areas. The north-flowing current along the Norwegian coastline dispersed resistant genes from south to north, and limited gene flow in the opposite direction. We demonstrate how evolutionary models can produce quantitative predictions over large spatial and temporal scales and for a range of pest control scenarios. Quantitative outputs can be translated into practical management decisions applied at a regional level to minimise the risk of resistance developing.

Time series covering up to four decades reveals major changes and drivers of marine growth and proportion of repeat spawners in an Atlantic salmon population.

Wild Atlantic salmon populations have declined in many regions and are affected by diverse natural and anthropogenic factors. To facilitate management guidelines, precise knowledge of mechanisms driving population changes in demographics and life history traits is needed.Our analyses were conducted on (a) age and growth data from scales of salmon caught by angling in the river Etneelva, Norway, covering smolt year classes from 1980 to 2018, (b) extensive sampling of the whole spawning run in the fish trap from 2013 onwards, and (c) time series of sea surface temperature, zooplankton biomass, and salmon lice infestation intensity.Marine growth during the first year at sea displayed a distinct stepwise decline across the four decades. Simultaneously, the population shifted from predominantly 1SW to 2SW salmon, and the proportion of repeat spawners increased from 3 to 7%. The latter observation is most evident in females and likely due to decreased marine exploitation. Female repeat spawners tended to be less catchable than males by anglers.Depending on the time period analyzed, marine growth rate during the first year at sea was both positively and negatively associated with sea surface temperature. Zooplankton biomass was positively associated with growth, while salmon lice infestation intensity was negatively associated with growth.Collectively, these results are likely to be linked with both changes in oceanic conditions and harvest regimes. Our conflicting results regarding the influence of sea surface temperature on marine growth are likely to be caused by long-term increases in temperature, which may have triggered (or coincided with) ecosystem shifts creating generally poorer growth conditions over time, but within shorter datasets warmer years gave generally higher growth. We encourage management authorities to expand the use of permanently monitored reference rivers with complete trapping facilities, like the river Etneelva, generating valuable long-term data for future analyses.

Parasite management in aquaculture exerts selection on salmon louse behaviour.

The evolution of pest resistance to management strategies is a major challenge for farmed systems. Mitigating the effects of pest adaptation requires identifying the selective pressures imposed by these strategies. In Atlantic salmon (Salmo salar) aquaculture, barriers are used to prevent salmon louse (Lepeophtheirus salmonis) larvae (copepodids) from entering salmon cages. These barriers are effective against shallow-swimming copepodids, but those swimming deeper can pass underneath and infest salmon. Laboratory experiments suggest that depth regulation in copepodids is a variable behavioural trait with a genetic basis. We used biological-hydrodynamic dispersal models to assess how this trait variation alters the dispersion of lice through the ocean environment and into farms. The dispersal of copepodids with 3 behavioural phenotypes (deep, mean or shallow) was modelled over winter-spring and spring-summer periods in a Norwegian fjord system with intensive aquaculture. The infestation pressure of each phenotype on barrier cages was estimated from their modelled depth distributions: copepodids deeper than 10 m were predicted to successfully pass underneath barriers. The deep phenotype was the most abundant below 10 m and reached infestation pressures 3 times higher than that of the mean phenotype. In contrast, the shallow phenotype infestation pressure reached less than half that of the mean phenotype. These differences in relative fitness indicate that barriers can impose strong directional selection on the swimming behaviour of copepodids. The strength of this selection varied seasonally and geographically, with selection for the deep phenotype stronger in winter-spring and at coastal locations than in spring-summer and within fjords. These findings can be applied across farms to slow louse adaptation, by limiting barriers during situations of strong selection, although this must be balanced against trade-offs to short-term efficacy. More broadly, our study highlights new ways in which dispersal models can address evolutionary questions crucial for sustainable parasite management in aquaculture.

Spatial distribution of mercury in seawater, sediment, and seafood from the Hardangerfjord ecosystem, Norway.

Hardangerfjord is one of the longest fjords in the world and has historical mercury (Hg) contamination from a zinc plant in its inner sector. In order to investigate the extent of Hg transferred to abiotic and biotic ecosystem compartments, Hg and monomethylmercury (MeHg) concentrations were measured in seawater, sediment, and seafood commonly consumed by humans. Although total mercury in seawater has been described previously, this investigation reports novel MeHg data for seawater from Norwegian fjords. Total Hg and MeHg concentrations in seawater, sediment, and biota increased towards the point source of pollution (PSP) and multiple lines of evidence show a clear PSP effect in seawater and sediment concentrations. In fish, however, similar high concentrations were found in the inner part of another branch adjacent to the PSP. We postulate that, in addition to PSP, atmospheric Hg, terrestrial run-off and hydroelectric power stations are also important sources of Hg in this fjord ecosystem. Hg contamination gradually increased towards the inner part of the fjord for most fish species and crustaceans. Since the PSP and the atmospheric Hg pools were greater towards the inner part of the fjord, it is not entirely possible to discriminate the full extent of the PSP and the atmospheric Hg contribution to the fjord food web. The European Union (EU) Hg maximum level for consumption was exceeded in demersal fish species including tusk (Brosme brosme), blue ling (Molva dypterygia) and common ling (Molva molva) from the inner fjord (1.08 to 1.89 mg kg-1 ww) and from the outer fjord (0.49 to 1.07 mg kg-1 ww). Crustaceans were less contaminated and only European lobster (Homarus gammarus) from inner fjord exceeded the EU limit (0.62 mg kg-1 ww). Selenium (Se) concentrations were also measured in seafood species and Se-Hg co-exposure dynamics are also discussed.

Identifying 'firebreaks' to fragment dispersal networks of a marine parasite.

Marine ecosystems are beset by disease outbreaks, and efficient strategies to control dispersal of pathogens are scarce. We tested whether introducing no-farming areas or 'firebreaks' could disconnect dispersal networks of a parasitic disease affecting the world's largest marine fish farming industry (∼1000 farms). Larval salmon lice (Lepeophtheirus salmonis) are released from and transported among salmon farms by ocean currents, creating inter-farm networks of louse dispersal. We used a state-of-the-art biophysical model to predict louse movement along the Norwegian coastline and network analysis to identify firebreaks to dispersal. At least one firebreak that fragmented the network into two large unconnected groups of farms was identified for all seasons. During spring, when wild salmon migrate out into the ocean, and louse levels per fish at farms must be minimised, two effective firebreaks were created by removing 13 and 21 farms (1.3% and 2.2% of all farms in the system) at ∼61°N and 67°N, respectively. We have demonstrated that dispersal models coupled with network analysis can identify no-farming zones that fragment dispersal networks. Reduced dispersal pathways should lower infection pressure at farms, slow the evolution of resistance to parasite control measures, and alleviate infection pressure on wild salmon populations.

Correction: Evaluation of a national operational salmon lice monitoring system-From physics to fish.

[This corrects the article DOI: 10.1371/journal.pone.0201338.].

Evaluation of a national operational salmon lice monitoring system-From physics to fish.

The Norwegian government has decided that the aquaculture industry shall grow, provided that the growth is environmentally sustainable. Sustainability is scored based on the mortality of wild salmonids caused by the parasitic salmon lice. Salmon lice infestation pressure has traditionally been monitored through catching wild sea trout and Arctic char using nets or traps or by trawling after Atlantic salmon postsmolts. However, due to that the Norwegian mainland coastline is nearly 25 000 km, complementary methods that may be used in order to give complete results are needed. We have therefore developed an operational salmon lice model, which calculates the infestation pressure all along the coast in near real-time based on a hydrodynamical ocean model and a salmon lice particle tracking model. The hydrodynamic model generally shows a negative temperature bias and a positive salinity bias compared to observations. The modeled salmon lice dispersion correlates with measured lice on wild salmonids caught using traps or nets. This allows for using two complementary data sources in order to determine the infestation pressure of lice originating from fish farms on wild salmonids, and thereby provide an improved monitoring system for assessing risk and sustainability which forms the basis for knowledge-based advice to management authorities.

Predicting the effectiveness of depth-based technologies to prevent salmon lice infection using a dispersal model.

Salmon lice is one of the major parasitic problems affecting wild and farmed salmonid species. The planktonic larval stages of these marine parasites can survive for extended periods without a host and are transported long distances by water masses. Salmon lice larvae have limited swimming capacity, but can influence their horizontal transport by vertical positioning. Here, we adapted a coupled biological-physical model to calculate the distribution of farm-produced salmon lice (Lepeophtheirus salmonis) during winter in the southwest coast of Norway. We tested 4 model simulations to see which best represented empirical data from two sources: (1) observed lice infection levels reported by farms; and (2) experimental data from a vertical exposure experiment where fish were forced to swim at different depths with a lice-barrier technology. Model simulations tested were different development time to the infective stage (35 or 50°-days), with or without the presence of temperature-controlled vertical behaviour of lice early planktonic stages (naupliar stages). The best model fit occurred with a 35°-day development time to the infective stage, and temperature-controlled vertical behaviour. We applied this model to predict the effectiveness of depth-based preventive lice-barrier technologies. Both simulated and experimental data revealed that hindering fish from swimming close to the surface efficiently reduced lice infection. Moreover, while our model simulation predicted that this preventive technology is widely applicable, its effectiveness will depend on environmental conditions. Low salinity surface waters reduce the effectiveness of this technology because salmon lice avoid these conditions, and can encounter the fish as they sink deeper in the water column. Correctly parameterized and validated salmon lice dispersal models can predict the impact of preventive approaches to control this parasite and become an essential tool in lice management strategies.

Simple Trapeziectomy for Arthrosis of the Basal Joint of the Thumb: 49 Thumbs Reviewed After Two Years.

BACKGROUND: Many different surgical strategies for arthrosis of the carpometacarpal joint of the thumb are described in the literature. In 2010 we changed our routine procedure from an interposition arthroplasty using the abductor pollicis longus (APL) tendon to simple trapeziectomy without suspension or interposition. The purpose of this study was to review the clinical outcome after trapeziectomy and to compare it to those we had achieved with the APL procedure. METHODS: We examined 49 hands operated with simple trapeziectomy during 2011-2012. Time between operation and review was 26 (15-26) months. Subjective estimation of pain before and after surgery and satisfaction with the general results were evaluated with visual analogue scales. The ability to participate in various activities of daily living before and after the operation were noted and patients completed the Quick-DASH and the PRWHE questionnaires. The mobility of the thumb and wrist were recorded and grip and key pinch strength were measured. The distance between the base of the first metacarpal and the scaphoid was noted on radiographs. RESULTS: There were no significant differences between the present results and those we had achieved with the APL procedure regarding subjective estimation of pain and satisfaction, activities of daily living, mobility, strength and radiographic carpometacarpal distance. For many outcome parameters there was a non-significant trend for better results among the trapeziectomy patients, but increased clumsiness was reported by 20 of them. CONCLUSIONS: We conclude that our results with simple trapeziectomy are at least as good as with the APL procedure. However, the considerable number of patients complaining of clumsiness is worrying.

Orbitofrontal cortex provides cross-modal valuation of self-generated stimuli.

Prior research has shown that the orbitofrontal cortex (OFC) plays an important role in the representation of the evaluation of stimuli, regardless of stimulus modality. Based on these findings, researchers have proposed that the OFC serves a common currency function, allowing for the direct comparison of different types of perceptual stimuli (e.g. food, drink, money). The present study was designed to extend this research and investigate whether these same regions of OFC that have been identified in previous research are involved in evaluating imagined stimuli. Specifically, we asked participants to draw on prior attitudinal knowledge to generate internal representations of liked and disliked exemplars from different categories during functional magnetic resonance imaging. The results of this study support the idea that imagined stimuli (regardless of stimulus category) are evaluated in the OFC using a common system that has been identified in previous research for externally perceived stimuli.

Affective flexibility: evaluative processing goals shape amygdala activity.

Although early research implicated the amygdala in automatic processing of negative information, more recent research suggests that it plays a more general role in processing the motivational relevance of various stimuli, suggesting that the relation between valence and amygdala activation may depend on contextual goals. This study provides experimental evidence that the relation between valence and amygdala activity is dynamically modulated by evaluative goals. During functional magnetic resonance imaging, participants evaluated the positive, negative, or overall (positive plus negative) aspects of famous people. When participants were providing overall evaluations, both positive and negative names were associated with amygdala activation. When they were evaluating positivity, positive names were associated with amygdala activity, and when they were evaluating negativity, negative names were associated with amygdala activity. Evidence for a negativity bias was found; modulation was more pronounced for positive than for negative information. These data suggest that the amygdala flexibly processes motivationally relevant evaluative information in accordance with current processing goals, but processes negative information less flexibly than positive information.

PTSD symptom clusters associated with physical health and health care utilization in rural primary care patients exposed to natural disaster.

This study investigated the influence of exposure to a tornado disaster and disaster-related posttraumatic stress disorder (PTSD) symptomatology on physical health complaints and primary health care utilization among rural medical patients. One-hundred five patients completed self-report measures assessing disaster exposure, PTSD symptoms, and self-reported physical health complaints. Objective rates of health care utilization were gathered by a review of medical records. Tornado disaster exposure and generalized psychological distress were associated with physical health complaints one year following the disaster. After controlling for age, gender, and levels of predisaster health care utilization, PTSD Cluster C (avoidance) symptoms were associated with increased rates of postdisaster health care utilization. Implications of these findings for interventions within the medical system are discussed.