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Wetlands are prevalent in the Sudbury, Ontario region and often operate at the interface between terrestrial and aquatic ecosystems, modifying water chemistry and potentially affecting the recovery of impacted lakes. The deposition of metals and sulphur in Sudbury in 2010-2012 was far below that reported in the 1970's, but still higher than background values. Wetlands in the area have accumulated large quantities of metals, and high concentrations of these metals in streams occurred primarily in response to SO4-related acidification events or associated with high dissolved organic carbon production in early summer. Concentrations of most metals in streams exceeded provincial guidelines and fluxes of some metals from catchments exceeded deposition inputs to lakes by as much as 12 times. The release of metals long after emissions reductions have been achieved must be considered in ecosystem recovery studies, particularly as dry conditions may become more prevalent in boreal regions affected by mining. [ABSTRACT FROM AUTHOR]

Abstract: A method has recently been developed for producing fibre-reinforced composites (FRC) with porous surfaces, intended for use as load-bearing orthopaedic implants. This study focuses on evaluation of the bone-bonding behaviour of FRC implants. Three types of cylindrical implants, i.e. FRC implants with a porous surface, solid polymethyl methacrylate (PMMA) implants and titanium (Ti) implants, were inserted in a transverse direction into the intercondular trabeculous bone area of distal femurs and proximal tibias of New Zealand White rabbits. Animals were sacrificed at 3, 6 and 12 weeks post operation, and push-out tests (n =5–6 per implant type per time point) were then carried out. At 12 weeks the shear force at the porous FRC–bone interface was significantly higher (283.3±55.3N) than the shear force at interfaces of solid PMMA/bone (14.4±11.0N; p <0.001) and Ti/bone (130.6±22.2N; p =0.001). Histological observation revealed new bone growth into the porous surface structure of FRC implants. Solid PMMA and Ti implants were encapsulated mostly with fibrous connective tissue. Finite element analysis (FEA) revealed that porous FRC implants had mechanical properties which could be tailored to smooth the shear stress distribution at the bone–implant interface and reduce the stress-shielding effect. [Copyright &y& Elsevier]

Abstract: Wood is a natural porous fibre composite, which has some structural similarities to bone. Recently, it has been used as a modelling material in developing synthetic fibre-reinforced composite to be used as load-bearing non-metallic artificial bone material. In this study, the behaviour of wood implanted into bone was studied in vivo in the femur bone of the rabbit. Wood was pre-treated by heat, which altered its chemical composition and structure, as well as the biomechanical properties. In the heat treatment, wood’s dimensional stability is enhanced, equilibrium moisture content reduces and the biological durability increases. Cone-shaped implants were manufactured from heat-treated (at 200 and 140°C) birch wood (Betula pubescens) and from untreated birch. A total of 62 implants were placed in the distal femur of 50 white New Zealand rabbits. The behaviour of the implants was studied at 4, 8 and 20weeks with histological and histometrical analysis. Osteoconductive contact line and the presence of fibrous tissue and foreign body reaction were determined. The amount of fibrous tissue diminished with time, and the absence of foreign body reaction was found to be in correlation to the amount of heat treatment. Histologically found contact between the implant and the host bone at the interface was significantly more abundant in the 200°C group (avg. 12.8%) vs. the 140°C (avg. 2.7%) and the untreated groups (avg. 0.6%). It was observed that the heat treatment significantly modified the biological behaviour of the implanted wood. The changes of the wood by heat treatment showed a positive outcome concerning osteoconductivity of the material. [Copyright &y& Elsevier]

Summary: Background: St. John''s Wort (SJW), also known as Hypericum perforatum, is a herbal remedy available over-the-counter. There is evidence that it can treat mild to moderate depression but has potential side effects and important drug interactions. Objective: To determine general practitioners’ (GPs’) knowledge and recommendation of SJW for mild to moderate depression within a climate of widespread community use of complementary therapies and debate about regulation. Design and setting: Postal survey of a random sample of 350 Australian GPs. Results: Forty-eight percent responded. One-third (31%) reported recommending SJW to patients with mild to moderate depression. Of these, only one-third (32%) reported specific dosage instructions. Respondents’ knowledge of side effects and interactions was much less than for selective serotonin reuptake inhibitor antidepressants. Conclusions: Australian GPs know less about safety of SJW than antidepressants and do not widely recommend it to patients. Despite this, many patients use SJW, probably in combination with other pharmaceuticals. Effective dissemination of further research into effectiveness and risk profiles of complementary therapies is needed to inform health professionals, regulatory bodies and consumers. [Copyright &y& Elsevier]

PURPOSE: This small, prospective cohort study of 162 12- to 15-year-old girls examines timing of changes in sexual cognitions and behaviors (breast fondling, genital contact, and sexual intercourse) over a 1-year period. METHODS: Girls from community sites in New York City provided information about sexual experiences and related cognitions (arousability, sexual agency, abstinence attitudes, perceived parental and peer approval, and sexual self-esteem) in 2 interviews 1 year apart. RESULTS: Percentages who reported breast fondling, genital contact, and sexual intercourse (18%, 24%, and 6%) increased significantly over the year (42%, 44%, and 19%) and with age. For each behavior, analyses compared girls who did not report the behavior at either Time 1 or 2, those who reported by Time 2 but not 1, or those who reported at both time points. Girls with no breast fondling experience at either time point had stronger abstinence values, and lower arousability, agency, peer approval, and sexual self-esteem scores compared to girls who initiated breast fondling over the year (transitioners). Transitioners were markedly similar in sexual cognitions to girls with this experience before Time 1, suggesting that changes in sexual cognitions precede actual experience. A similar pattern was found between groups for genital contact. Few differences between groups by comparison were noted for sexual intercourse, which occurs later in the trajectory. CONCLUSIONS: Sexual experiences that occur before intercourse (e.g., breast fondling) are central to research on sexual development and related to greater changes in girls' sexual cognitions than is intercourse. Changes in cognitions precede, rather than follow, new sexual experiences. [ABSTRACT FROM AUTHOR]

PURPOSE: To examine whether generation of 'socially appropriate' responses or divergent responses to continued peer pressure is a more effective deterrent of actual delinquency. METHODS: The sample of 129 urban adolescents included both boys and girls (51.9% male) and was predominantly black (48.%) and Hispanic (28.7%). They were studied longitudinally from seventh to eighth grade in New York City from 2000-2001. Resistance strategies to offers to smoke and to shoplift were assessed in two separate videotaped role-plays. Socially appropriate responses were defined as assertive and nonaggressive, including the use of a simple no; direct, declarative statements; and offering prosocial alternatives. Divergent responses were defined as multiple unique response types within the same situation regardless of appropriateness. Data were analyzed using hierarchical logistic regressions. RESULTS: High use of divergent responses was consistently associated favorably with changes in delinquency from seventh to eighth grade. High use of divergent responses was associated with lowered likelihood to vandalize, steal or shoplift, and commit multiple acts of any type of delinquency, even after controlling for seventh grade delinquency. Socially appropriate responses showed little association to any delinquent behavior. CONCLUSIONS: Different social pressure situations and contexts may require different responses. As trying to teach effective responses for every single potential peer pressure situation would be impossible, promoting divergent thinking may be an attractive alternative. [ABSTRACT FROM AUTHOR]

PURPOSE: To evaluate underlying mechanisms of the association between early pubertal timing and both aggression and delinquency among a sample of minority males and females from an urban community. METHODS: The association between perceived early pubertal maturation and aggressive or delinquent behaviors for African American and Latino males and females (n = 1366) was examined, as well as pathways between early maturation and these negative outcomes longitudinally across 6th, 7th, and 8th grades. RESULTS: Early maturers reported higher mean levels of both aggression and delinquency at all time points regardless of gender or ethnicity. Associating with delinquent peers in 6th grade fully mediated the association between early maturation and both aggression and delinquency at all time points. Early maturers did not differentially associate with greater numbers of delinquent peers in either 7th or 8th grade. CONCLUSIONS: These results provide valuable information regarding at-risk groups and inform future intervention efforts. [ABSTRACT FROM AUTHOR]

We studied abundance and tree use (foraging and drumming) of the cavity-nesting woodpecker guild (7 species) in northern Maine to assess effects of uneven-aged forest management (an irregular shelterwood system) on woodpecker populations. Woodpecker abundance in managed and unmanaged hardwood stands showed no difference. Abundance in managed softwood stands was greater than in unmanaged softwood stands. Woodpeckers preferred (use greater than availability) to forage and drum onlarge-diameter (greater than 30cm) living trees (hardwood and softwood). Living trees used by woodpeckers, however, were commonly in a state of decline, with characteristics such as fungal conks, broken limbs, and broken tops. When dead trees were used, woodpeckers preferredlarge-diameter, recently-dead trees. Although we identified tree types preferred by woodpeckers, the abundance of preferred trees in a stand was a poor predictor of woodpecker abundance. The uneven-aged management we studied did not reduce the number of preferred trees or snags to a level that affected woodpecker abundance. [ABSTRACT FROM AUTHOR]