Objectives: To investigate whether exercise, proposed to enhance neuroplasticity and potentially cognitive function (CF) and academic performance (AP), may be beneficial during adolescence when ...important developmental changes occur. Design: Systematic review evaluating the impact of acute or chronic exercise on CF and AP in adolescents (13-18 years). Methods: Nine databases (AMED, AusportMed, CINAHL, COCHRANE, Embase, Medline, Scopus, SPORTdiscus, Web of Science) were searched from earliest records to 31st October 2016, using keywords related to exercise, CF, AP and adolescents. Eligible studies included controlled trials examining the effect of any exercise intervention on CF, AP or both. Effect size (ES) (Hedges g) were calculated where possible. Results: Ten papers (11 studies) were reviewed. Cognitive domains included: executive function (n = 4), memory (n = 4), attention/concentration (n = 2), visuo-motor speed (n = 1), logical sequencing (n = 1) and psychometric aptitude (n = 1). All papers, nine of 10 being acute studies, reported at least one parameter showing a significant effect of exercise in improving CF and AP. However, the CF parameters displayed substantial heterogeneity, with only 37% favouring acute and chronic exercise. Where ES could be calculated, 52% of the acute CF parameters favoured rest. Memory was the domain most consistently improved by exercise. Academic performance demonstrated a significant improvement with exercise in one of two acute studies and the only chronic study (p (/= 0.001). Conclusions: The evidence for the effect of exercise on CF and AP in adolescents is equivocal and limited in quantity and quality. Well-designed research is therefore warranted to determine the benefits of exercise in enhancing CF and AP and reducing sedentary behaviour. (Autor).
This study examined heat flux from 15 Canadian northern rivers that drain to the Arctic Ocean and the Hudson/James Bay. Based on statistical analysis of available water temperature and discharge ...data, we determined patterns and characteristics of discharge, water temperature, and heat flux in relation to seasonal air temperature and precipitation. We found similar seasonal cycles of discharge and water temperature across the study region, i.e. most rivers experiencing maximum discharge in June/July and highest water temperatures in July/August. The mean flows during the open water season (May to Oct.) vary from west to east along the Arctic Coast (with higher yield from the Mackenzie and Peel rivers), while river flows are higher with warmer water temperatures in western and southern Hudson Bay. The summed heat flux for the studied rivers was about 10.0 × 1012 MJ along the Arctic Coast and 2.0x1012MJ around the Hudson Bay. Among the 9 rivers flowing directly into the Arctic Ocean, the Mackenzie River with the highest flow and warmest water temperature delivered the highest heat flux, i.e. average 9.5 × 1012 MJ over the open water season during 1960–2015. These observed patterns in discharge, water temperature and heat flux were generally consistent with CHANGE model simulations for most rivers in northern Canada. The outcomes of our study provide critical knowledge of river thermal condition and heat transport to the northern seas, which will be useful for large-scale climate and ocean model development and validation, and climate/hydrology change investigations in the broader northern regions.
•Determined patterns of discharge (Q), water temperature (WT), and heat flux (HF) for 15 northern rivers in Canada.•Similar seasonal cycles of Q, WT and HF for the rivers, most rivers with max Q in June/July and highest WT in July/August.•Total warm season HF of 10.0x1012 MJ from the 9 rivers along Arctic Coast and 2.0x1012MJ for the 6 rivers into Hudson Bay.•Mackenzie River with highest Q and warmest WT delivered highest HF, 9.5x1012 MJ in open water season during 1960-2015.•Observations and CHANGE model HF simulations were generally consistent for most rivers in northern Canada.
Deep brain stimulation (DBS) is an established surgical therapy for treatment of a number of neurological and neuropsychiatric disorders based on the modulation of neuronal firing deep in the brain. ...However, the delicate surgical operation and extremely expensive cost of the current DBS technology impede its wide applications. For non-invasive brain stimulation, transcranial magnetic stimulation and transcranial direct current stimulation have been tried in various therapeutic applications with little success due to two major imitations with their applied electromagnetic field: 1) the field does not focus on targeted brain functional sites, and 2) the field penetration depth is too shallow to be effective in stimulating targeted brain functional sites. In this paper, a novel magnetic field projector (MFP) capable of magnetically inducing deep brain modulation of neuronal firing is presented. The MFP projects a focused magnetic field to deep brain regions while suppressing the field on the scalp. The field penetration depth can be adjusted by configuring the structure parameters of the device as well as the excitation pulse current amplitude. An MFP prototype has been developed and tested on rats to modulate upward the neuronal firing frequency at the brain functional site ventrolateral preoptic nucleus for sleep induction, with the brain responses measured by EEG. The results showed that EEG sleep spindles were induced by a train of 9 Hz magnetic stimulation pulses for 10 s.
Inhibitory immune receptors are important for maintaining immune homeostasis. We identified epigenetic alterations in 2 members of this group, LAIR1 and LAIR2, in lymphoma patients with inflammatory ...tissue damage and susceptibility to infection. We predicted that the expression of LAIR genes is controlled by immune mediators acting on transcriptional regulatory elements. Using flow cytometry, quantitative reverse-transcription polymerase chain reaction, and RNA sequencing, we measured LAIR1 and LAIR2 in human and murine immune cell subsets at baseline and posttreatment with immune mediators, including type I and II interferons, tumor necrosis factor α, and lipopolysaccharide (LPS). We identified candidate regulatory elements using epigenome profiling and measured their regulatory activity using luciferase reporters. LAIR1 expression substantially increases during monocyte differentiation to macrophages in both species. In contrast, murine and human macrophages exhibited opposite changes in LAIR1 in response to immune stimuli: human LAIR1 increased with LPS while mouse LAIR1 increased with interferon γ. LAIR genes had distinct patterns of enhancer activity with variable responses to immune stimuli. To identify relevant transcription factors (TFs), we developed integrative bioinformatic techniques applied to TF chromatin immunoprecipitation sequencing, RNA sequencing, and luciferase activity, revealing distinct sets of TFs for each LAIR gene. Most strikingly, LAIR1 TFs include nuclear factor kappa B factors RELA and RELB, while Lair1 and LAIR2 instead include STAT3 and/or STAT5. Regulation by nuclear factor kappa B factors may therefore explain the LPS-induced increase in LAIR1 expression, in contrast to Lair1 decrease. Our findings reveal new insights into transcriptional mechanisms that control distinct expression patterns of LAIR genes in response to inflammatory stimuli in human and murine myeloid and lymphoid cells.
The chemical composition of river water can be used to diagnose change on land, while playing a determining role in the ecology and biogeochemistry of riverine‐influenced ocean waters. Despite this, ...little is known about the seasonal and geographic variability of riverine chemistry throughout much of the Canadian north. Here we assess the chemical composition of a broad suite of rivers draining to the Canadian Arctic Ocean and Hudson Bay using previously unpublished government data. We focus on inorganic and organic carbon (alkalinity and dissolved organic carbon), using paired chemistry and discharge measurements to assess constituent flux. Concentrations and area‐normalized yields vary substantially across the northern Canadian landscape, with dissolved organic carbon typically highest in rivers draining the Hudson Bay Lowland, alkalinity highest in rivers draining Cordillera and Plains terrains, and the ratio of organic to inorganic species highest in rivers draining the Canadian Shield. Yields of major weathering ions show that carbonate weathering—a notable proportion of which may be driven by sulfide oxidation—dominates inorganic carbon delivery from the rivers we assess. Despite the reasonably diverse coverage of the data set, we find that clear gaps exist, including a lack of data through to the present day for many rivers, and a dearth of measurements from the Arctic Archipelago and eastern shores of Hudson Bay. We therefore use a modeling approach to extrapolate fluxes to the full Canadian Arctic drainage basin. Region‐specific differences between our results and previous models reinforce the need for targeted river water chemistry measures throughout the Canadian Arctic domain.
Key Points
The concentration and flux of organic and inorganic carbon vary substantially across Canadian Arctic rivers but track latitude and physiographic region
Alkalinity in this region is largely derived from carbonate weathering, with sulfide oxidation potentially an important contributor to the weathering flux
Geographic and temporal data gaps hamper our ability to definitively quantify riverine chemistry through large swaths of northern Canada
Most people are much less generous toward strangers than close others, a bias termed social discounting. But people who engage in extraordinary real-world altruism, like altruistic kidney donors, ...show dramatically reduced social discounting. Why they do so is unclear. Some prior research suggests reduced social discounting requires effortfully overcoming selfishness via recruitment of the temporoparietal junction. Alternatively, reduced social discounting may reflect genuinely valuing strangers' welfare more due to how the subjective value of their outcomes is encoded in regions such as rostral anterior cingulate cortex (ACC) and amygdala. We tested both hypotheses in this pre-registered study. We also tested the hypothesis that a loving-kindness meditation (LKM) training intervention would cause typical adults' neural and behavioral patterns to resemble altruists. Altruists and matched controls (
= 77) completed a social discounting task during functional magnetic resonance imaging; 25 controls were randomized to complete LKM training. Neither behavioral nor imaging analyses supported the hypothesis that altruists' reduced social discounting reflects effortfully overcoming selfishness. Instead, group differences emerged in social value encoding regions, including rostral ACC and amygdala. Activation in these regions corresponded to the subjective valuation of others' welfare predicted by the social discounting model. LKM training did not result in more generous behavioral or neural patterns, but only greater perceived difficulty during social discounting. Our results indicate extraordinary altruists' generosity results from the way regions involved in social decision-making encode the subjective value of others' welfare. Interventions aimed at promoting generosity may thus succeed to the degree they can increase the subjective valuation of others' welfare.
Hippo signaling pathways are evolutionarily conserved signal transduction mechanisms mainly involved in organ size control, tissue regeneration, and tumor suppression. However, in mammals, the ...primary role of Hippo signaling seems to be regulation of immunity. As such, humans with null mutations in
STK4
(mammalian homologue of
Drosophila Hippo
; also known as
MST1
) suffer from recurrent infections and autoimmune symptoms. Although dysregulated T cell homeostasis and functions have been identified in MST1-deficient human patients and mouse models, detailed cellular and molecular bases of the immune dysfunction remain to be elucidated. Although the canonical Hippo signaling pathway involves transcriptional co-activator Yes-associated protein (YAP) or transcriptional coactivator with PDZ motif (TAZ), the major Hippo downstream signaling pathways in T cells are YAP/TAZ-independent and they widely differ between T cell subsets. Here we will review Hippo signaling mechanisms in T cell immunity and describe their implications for immune defects found in MST1-deficient patients and animals. Further, we propose that mutual inhibition of Mst and Akt kinases and their opposing roles on the stability and function of forkhead box O and β-catenin may explain various immune defects discovered in mutant mice lacking Hippo signaling components. Understanding these diverse Hippo signaling pathways and their interplay with other evolutionarily-conserved signaling components in T cells may uncover molecular targets relevant to vaccination, autoimmune diseases, and cancer immunotherapies.
Research Summary
This research develops a multilevel framework to study optimal distinctiveness (OD) at two levels. We distinguish between within‐organization distinctiveness and between‐organization ...distinctiveness of product design and examine how they independently and interactively influence performance. Analyzing a unique data set of 2,203 model‐year observations for automobiles sold in the U.S. market from 2001 to 2016, we found that while within‐organization distinctiveness of product design hurts market performance, between‐organization distinctiveness of product design increases market performance. Moreover, when between‐organization distinctiveness of product design is high, the negative impact of within‐organization distinctiveness of product design on performance is weakened. These findings contribute to OD research by improving the understanding of OD as a multilevel construct and elaborating on its contextual contingency.
Managerial Summary
How should multiproduct organizations design their products to achieve better performance? This article provides a multilevel perspective that encourages managers of multiproduct organizations to consider different frames of references when designing products. We suggest that a product's design should be consistent with the prototypical design of its organization, whereas the prototypical design of this organization should be different from the average design in the industry. We also found that an atypical design is more desirable if it is from an organization known for distinctive designs in its industry. Our findings help managers of multiproduct organizations achieve the optimal levels of design distinctiveness at both the product and organizational levels.
Purpose: Instagram has grown over the years to become one of the most popular social media platforms, and three quarters of teens who use social media use Instagram. In recent years, "Finstas", or ..."fake" Instagrams have grown in popularity among US teenagers. Finsta accounts are subsidiary Instagram accounts with highly selected audiences where owners can post material that is not associated with their main account. Public Twitter posts (tweets) can provide insight into communication about these clandestine accounts not available through Instagram due to the inherent private nature of these accounts. This exploratory study uses natural language processing (NLP) techniques on tweets about Finsta accounts to gain insight into this phenomenon. Methods: An R-script was developed to pull data from the Twitter API to capture tweets longitudinally that were in English, from North America, and specifically mention some form of the stem and lemmatized word "Finsta." As there are no current studies on Finsta accounts, a comprehensive thematic analysis was then performed on the corpus of tweets to develop qualitative insights on this phenomenon. A quantitative process involved further cleaning and removing of stop-words to develop a Ngram frequency chart of the lemmatized words in the corpus of tweets to better understand the ways in which people were communicating about Finsta accounts. Results: 10,000 tweets containing the word "Finsta" were pulled from the Twitter API. After a comprehensive cleaning process, 5,159 tweets were then analyzed qualitatively to identify themes as a preliminary inquiry into this relatively new phenomenon. Themes identified within the corpus were: a desire for privacy compared to their main account, a place to share information that may be politically incorrect or would get users in trouble if shared on accounts with wider viewership, and a place to showcase real life. Ngram frequency words highlight similar words common to social media, "follow," "like," and "post" being amongst the most popular; however, within this corpus there are high frequencies of the words, "private," "sad," "nudes," "spam," "rant," "exposed," "emotional," and "outlet," tied to contextual themes indicating that Finstas may be an outlet for emotional catharsis in a "safe space." A Finsta user may have twenty followers (as opposed to 1000 on their main account) that include their closest friends. They may post blurry pictures without filters, with long captions detailing their negative emotional state. This sensitive content is posted with the underlying assumption that their friends will keep this information private. Conclusions: Preliminary analyses indicate that Finstas are a new way for teens to connect with peers in a controlled space online, where they can truly express themselves. Additionally, there is also a great deal of gossip, exhibitionism, risk-taking, and other attention-seeking behaviors typical of adolescence that manifest in ways not seen on users' primary accounts. Finsta accounts fulfill a vital role in the lives of adolescents looking for ways to authentically connect, share, and create community that is not offered through traditional uses of social media.
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