The effect of different nutrient concentrations on the growth rate and nitrogen storage of watercress (Nasturtium officinale R. Br.)

The mechanisms that allow broadly distributed aquatic plants to inhabit variable resource environments are unclear, yet understanding these mechanisms is important because broad environmental tolerance is often linked to invasiveness in terrestrial and aquatic plants. In an experimental stream, we examined the effects of different nutrient concentrations on the growth rate, biomass, and foliar nutrient concentrations of a cosmopolitan and potentially invasive aquatic plant, Nasturtium officinale (R. Br.). Nasturtium seedlings were grown under six nutrient treatment levels ranging from 0.64 μm N:0.09 μm P to 1531 μm N:204.13 μm P, for 8 weeks. Absolute and relative growth rates, and biomass of seedlings increased along a gradient of increasing nutrient concentrations but the effect of nutrient concentration was dependent on growing time. Seedling biomass varied among nutrient treatments in weeks 4 through 8 of the experiment, but did not differ in week 2. By week 8, the two highest nutrient treatments had greater biomass than the two lowest nutrient treatments. Foliar nitrogen concentration increased, whereas carbon concentration and C:N ratios decreased in response to increasing nutrients. Nasturtium grows slowly in nutrient-poor conditions but rapidly increases its growth, biomass accrual, and nitrogen storage as conditions become nutrient-rich. The response of Nasturtium to enhanced nutrient conditions may indicate how aquatic nuisance species successfully invade and dominate plant communities in streams, where resources often vary both temporally and spatially

Understanding the impact of children's and young people's self‐harm on parental well‐being: a systematic literature review of qualitative and quantitative findings

Background: Self‐harm in children and young people is increasing. Parents are vital in supporting young people; however, parents may experience distress linked to the self‐harm. Previous reviews have highlighted the emotional impact and need for information and support, however, have not elucidated the relationships between these themes, nor examined the quantitative data examining parents' well‐being. Methods: We conducted a mixed methods review, with qualitative meta‐synthesis focusing on links between themes and quantitative synthesis of parental well‐being findings, including pooled means. PsycInfo, Medline, EMBASE, AMED, CINHAL and Web of Science were searched to identify relevant records. References of included studies were also searched. Every abstract was screened by two authors. Data were extracted by one author and checked by another. Results: We identified 39 reports of 32 studies: 16 with qualitative data and 17 with quantitative data (one had both). Qualitative findings showed how parents' emotions were associated to their knowledge and beliefs about self‐harm. Parents' emotions often evidenced the need to self‐care, but emotions of guilt reduced engagement in self‐care. How parents supported their young person was linked to their knowledge, and the management of their own emotions, and influenced if they could engage in self‐care. Quantitative findings were mixed, however suggested poor general mental health amongst these parents. Conclusions: Further good quality quantitative studies are needed, with measurement of psychological mechanisms that may underpin parental distress. Current evidence supports peer‐support and interventions that go beyond information provision to address the connected factors of knowledge, emotion, self‐care, and parenting behaviours

Nondegenerate Four-Wave Mixing in a Dual-Mode Injection-Locked InAs/InP(100) Nanostructure Laser

International audienceThe nondegenerate four-wave mixing (NDFWM) characteristics in a quantum-dot Fabry-Perot laser are investigated, employing the dual-mode injection-locking technique. The solitary laser features two lasing peaks, which provides the possibility for efficient FWM generation. Under optical injection, the NDFWM is operated up to a detuning range of 1.7 THz with a low injection ratio of 0.42. The normalized conversion efficiency (NCE) and the side-mode suppression ratio (SMSR) with respect to the converted signal are analyzed. The highest NCE of 17 dB associated with a SMSR of 20.3 dB is achieved at detuning of 110 GHz

Understanding the impact of children's and young people's self-harm on parental well-being: a systematic literature review of qualitative and quantitative findings

Background Self-harm in children and young people is increasing. Parents are vital in supporting young people; however, parents may experience distress linked to the self-harm. Previous reviews have highlighted the emotional impact and need for information and support, however, have not elucidated the relationships between these themes, nor examined the quantitative data examining parents' well-being. Methods We conducted a mixed methods review, with qualitative meta-synthesis focusing on links between themes and quantitative synthesis of parental well-being findings, including pooled means. PsycInfo, Medline, EMBASE, AMED, CINHAL and Web of Science were searched to identify relevant records. References of included studies were also searched. Every abstract was screened by two authors. Data were extracted by one author and checked by another. Results We identified 39 reports of 32 studies: 16 with qualitative data and 17 with quantitative data (one had both). Qualitative findings showed how parents' emotions were associated to their knowledge and beliefs about self-harm. Parents' emotions often evidenced the need to self-care, but emotions of guilt reduced engagement in self-care. How parents supported their young person was linked to their knowledge, and the management of their own emotions, and influenced if they could engage in self-care. Quantitative findings were mixed, however suggested poor general mental health amongst these parents. Conclusions Further good quality quantitative studies are needed, with measurement of psychological mechanisms that may underpin parental distress. Current evidence supports peer-support and interventions that go beyond information provision to address the connected factors of knowledge, emotion, self-care, and parenting behaviours