Climatic displacement exacerbates the negative impact of drought on plant performance and associated arthropod abundance.

Climate change is acting on species and modifying communities and ecosystems through changes not only with respect to mean abiotic conditions, but also through increases in the frequency and severity of extreme events. Changes in mean aridity associated with climate change can generate ecotype by environment mismatch (i.e., climatic displacement). At the same time, variability around these shifting means is predicted to increase, resulting in more extreme droughts. We characterized the effects of two axes of climate change, climatic displacement and drought, on the shrub Artemisia californica and its arthropods. We established common gardens of plants sourced along an aridity gradient (3.5-fold variation in mean annual precipitation) in an arid region of the species distribution, thus generating a gradient of climatic displacement (sustained increase in aridity) as predicted with climate change. We surveyed plants and arthropods over eight years where precipitation varied sixfold, including both extreme drought and relatively mesic conditions. These two axes of climate change interacted to influence plant performance, such that climatically displaced populations grew slowly regardless of drought and suffered substantial mortality during drought years. Conversely, local populations grew quickly, increased growth during wet years, and had low mortality regardless of drought. Effects on plant annual arthropod yield were negative and additive, with drought effects exceeding that of climatic displacement by 24%. However, for plant lifetime arthropod yield, incorporating effects on both plant growth and survival, climatic displacement exacerbated the negative effects of drought. Collectively these results demonstrate how climatic displacement (through increasing aridity stress) strengthens the negative effects of drought on plants and, indirectly, on arthropods, suggesting the possibility of climate-mediated trophic collapse.

Gender differences in externalizing and internalizing problems in Singaporean children and adolescents with attention-deficit/hyperactivity disorder.

BACKGROUND: Studies on gender differences in attention-deficit/hyperactivity disorder (ADHD) comorbidities in the Asian populations have been limited and previous studies have shown inconclusive findings. Singapore is a city-state country in Southeast Asia with a population of 5.7 million. This study examined gender differences in internalizing and externalizing problems in Singaporean children and adolescents with ADHD. The plausible social factors underlying the gender differences were discussed. METHODS: A total of 773 participants (aged 6 to 18, 88% males) newly diagnosed with ADHD were recruited from the largest public child and adolescent psychiatric center in Singapore. Their internalizing and externalizing problems were assessed using the Child Behavioral Checklist and Teacher's Report Form by parents and teachers respectively. Demographics and relevant social factors were collected using parent questionnaires. RESULTS: Females with ADHD were reported to have less delinquent and aggressive behavior but more depressive symptoms than their male counterparts, similar to findings in the Western literature. Gender remained a significant predictor of externalizing problem after controlling for other factors. Lower socioeconomic status and parental use of physical punishment were significant predictors of both internalizing and externalizing problems. CONCLUSIONS: Gender differences in ADHD comorbidities do exist in the Asian clinical population. The lack of externalizing symptoms in females with ADHD has made timely referral and diagnosis challenging. More research is needed in understanding the gender differences in ADHD and the biopsychosocial mechanism underlying the differences in order to improve the detection of ADHD in females.

A randomized controlled trial of a brain-computer interface based attention training program for ADHD.

OBJECTIVE: The use of brain-computer interface in neurofeedback therapy for attention deficit hyperactivity disorder (ADHD) is a relatively new approach. We conducted a randomized controlled trial (RCT) to determine whether an 8-week brain computer interface (BCI)-based attention training program improved inattentive symptoms in children with ADHD compared to a waitlist-control group, and the effects of a subsequent 12-week lower-intensity training. STUDY DESIGN: We randomized 172 children aged 6-12 attending an outpatient child psychiatry clinic diagnosed with inattentive or combined subtypes of ADHD and not receiving concurrent pharmacotherapy or behavioral intervention to either the intervention or waitlist-control group. Intervention involved 3 sessions of BCI-based training for 8 weeks, followed by 3 training sessions per month over the subsequent 12 weeks. The waitlist-control group received similar 20-week intervention after a wait-time of 8 weeks. RESULTS: The participants' mean age was 8.6 years (SD = 1.51), with 147 males (85.5%) and 25 females (14.5%). Modified intention to treat analyzes conducted on 163 participants with at least one follow-up rating showed that at 8 weeks, clinician-rated inattentive symptoms on the ADHD-Rating Scale (ADHD-RS) was reduced by 3.5 (SD 3.97) in the intervention group compared to 1.9 (SD 4.42) in the waitlist-control group (between-group difference of 1.6; 95% CI 0.3 to 2.9 p = 0.0177). At the end of the full 20-week treatment, the mean reduction (pre-post BCI) of the pooled group was 3.2 (95% CI 2.4 to 4.1). CONCLUSION: The results suggest that the BCI-based attention training program can improve ADHD symptoms after a minimum of 24 sessions and maintenance training may sustain this improvement. This intervention may be an option for treating milder cases or as an adjunctive treatment.

Genetically based latitudinal clines in Artemisia californica drive parallel clines in arthropod communities.

Intraspecific variation in plant traits has been clearly shown to drive the structure of associated arthropod communities at the spatial scale of individual plant populations. Nevertheless, it is largely unknown whether plant trait variation among populations drives landscape-scale variation in arthropod communities, and how the strength of such plant genetic effects compares to, and interacts with, those of environmental variation. We documented the structure of arthropod communities on Artemisia californica for two consecutive years in a common garden of plants sourced from five populations along a 5° latitudinal gradient and grown under precipitation treatments approximating the four-fold difference between the north and south range margins for this species. Previous study of plant traits from this garden documented clinal genetic variation, suggesting local adaptation to this environmental gradient, as well as effects of precipitation manipulation that were consistent among populations (i.e., no genotype-by-environment interaction). Within the common garden, arthropod density, evenness, and diversity increased clinally with population source latitude, and arthropod community composition (i.e., species relative abundance) showed a north-south divide. The 2.6-fold cline of northward increase in arthropod density in the common garden was mirrored by a 6.4-fold increase in arthropod density on wild plants sampled along the species range. In contrast to the strong influence of plant genotype, the precipitation manipulation only influenced arthropod community composition, and plant genetic effects on arthropods operated independently of precipitation regime (no genotype-by-environment interaction). Accordingly, we conclude that the strongest driver of landscape-level variation in arthropod communities in this foundational plant species is not variation in the abiotic environment itself, but rather variation in plant traits underlain by the evolutionary process of plant local adaptation.

Prevalence of antibiotic resistance genes and their relationship with antibiotics in the Huangpu River and the drinking water sources, Shanghai, China.

The prevalence of antibiotic resistance genes (ARGs) and their relationship with antibiotics in the surface waters of the Huangpu River and the drinking water sources of Shanghai, China, were investigated. 39 ARGs, including four sulfonamide ARGs, 23 tetracycline ARGs, four chloramphenicol ARGs, five ß-lactam ARGs and three penicillin ARGs were targeted in this study. Two sulfonamide ARGs (sul I and sul II), eight tetracycline ARGs (tet(A), tet(B), tet(C), tet(G), tet(M), tet(O), tet(W) and tet(X)), and one ß-lactam ARG (TEM) were detected to be present in water samples by polymerase chain reaction (PCR), with the detection frequencies ranging from 42.86% to 100%. The average concentrations of the 11 ARGs ranged from 3.66×10(1) copy/mL (tet(B)) to 1.62×10(5) copy/mL (sul II), quantified by quantitative real-time PCR (QPCR). The number of detected ARGs and the ARG concentrations were generally higher in suburban sampling sites than in urban sites. Being in or near suburban rural areas, some raw drinking water sources were observed to have comparatively higher ARG contamination, drawing an urgent attention for the concern of public health. Generally consistent relations were observed between the concentrations of tet genes and the tetracycline levels and between the concentrations of sul genes and the sulfonamide levels.