521 research outputs found
Effects of oral, smoked, and vaporized cannabis on endocrine pathways related to appetite and metabolism: a randomized, double-blind, placebo-controlled, human laboratory study.
As perspectives on cannabis continue to shift, understanding the physiological and behavioral effects of cannabis use is of paramount importance. Previous data suggest that cannabis use influences food intake, appetite, and metabolism, yet human research in this regard remains scant. The present study investigated the effects of cannabis administration, via different routes, on peripheral concentrations of appetitive and metabolic hormones in a sample of cannabis users. This was a randomized, crossover, double-blind, placebo-controlled study. Twenty participants underwent four experimental sessions during which oral cannabis, smoked cannabis, vaporized cannabis, or placebo was administered. Active compounds contained 6.9 ± 0.95% (~50.6 mg) ∆9-tetrahydrocannabinol (THC). Repeated blood samples were obtained, and the following endocrine markers were measured: total ghrelin, acyl-ghrelin, leptin, glucagon-like peptide-1 (GLP-1), and insulin. Results showed a significant drug main effect (p = 0.001), as well as a significant drug × time-point interaction effect (p = 0.01) on insulin. The spike in blood insulin concentrations observed under the placebo condition (probably due to the intake of brownie) was blunted by cannabis administration. A significant drug main effect (p = 0.001), as well as a trend-level drug × time-point interaction effect (p = 0.08) was also detected for GLP-1, suggesting that GLP-1 concentrations were lower under cannabis, compared to the placebo condition. Finally, a significant drug main effect (p = 0.01) was found for total ghrelin, suggesting that total ghrelin concentrations during the oral cannabis session were higher than the smoked and vaporized cannabis sessions. In conclusion, cannabis administration in this study modulated blood concentrations of some appetitive and metabolic hormones, chiefly insulin, in cannabis users. Understanding the mechanisms underpinning these effects may provide additional information on the cross-talk between cannabinoids and physiological pathways related to appetite and metabolism
Roots, Rights and Risk: Canada, Childhood and the COVID-19 Global Pandemic
The COVID-19 global pandemic highlights pre-existing inequities as well as the challenge of ensuring the protection of children’s human rights in countries like Canada that have ratified the United Nations Convention on the Rights of the Child. SARS-CoV-2, referred to as the 2019 novel Coronavirus disease or COVID-19, presents a significant threat to public health. Although children are considered to be low risk of contracting, spreading, and serious complications of the disease, are considerably impacted by COVID-19 government-sanctioned distancing measures. COVID-19 is a persistent public health threat, thus, the long-term consequences are largely unknown. This qualitative research study, a content analysis of online Canadian media reports of COVID-19 and children, engaged transdisciplinary social justice methodology, social constructions of childhood at the intersection of race, socio-economic status, gender, and disability. The findings suggest COVID-19 reinforces the impact of social exclusion and economic disparity on equity-seeking young people and families in Canada
On the form-function dichotomy in linguistic theory
This paper focuses on an important divide in theoretical linguistics between two broad perspectives on the structural properties of human languages, generative and functionalist. In the former, linguistic structure is explained in terms of discrete categories and highly abstract principles, which may be language-independent or language-specific and purely formal or functional in nature. In the latter, explanation for why languages have the structure that they do is found ‘outside’ language, in the general principles of human cognition and the communicative functions of language. The aim of this paper is to highlight the need for abstractness, explicitness, simplicity and theoretical economy in linguistic description and explanation. The question is not whether principles of grammar are formal or functional. The question is whether the principles that are postulated to explain linguistic structure express true generalizations
Super-Spreaders or Victims of Circumstance? Childhood in Canadian Media Reporting of the COVID-19 Pandemic: A Critical Content Analysis
This qualitative research study, a critical content analysis, explores Canadian media reporting of childhood in Canada during the COVID-19 global pandemic. Popular media plays an important role in representing and perpetuating the dominant social discourse in highly literate societies. In Canadian media, the effects of the pandemic on children and adolescents' health and wellbeing are overshadowed by discussions of the potential risk they pose to adults. The results of this empirical research highlight how young people in Canada have been uniquely impacted by the COVID-19 global pandemic. Two dominant narratives emerged from the data: children were presented "as a risk" to vulnerable persons and older adults and "at risk" of adverse health outcomes from contracting COVID-19 and from pandemic lockdown restrictions. This reflects how childhood was constructed in Canadian society during the pandemic, particularly how children's experiences are described in relation to adults. Throughout the pandemic, media reports emphasized the role of young people's compliance with public health measures to prevent the spread of COVID-19 and save the lives of older persons
Comparing Behavioral Health Graduate Students in Spiritual and Religious Competence
When it comes to the integration of spirituality and religion within mental health training, standards remain ambiguous, particularly in non-religious affiliated institutions and individual practitioners. The aim of this study sought to examine the competence levels of mental health graduate students utilizing the Revised Spiritual Competence Scale II (SCS-R-II) and the Spiritual and Religious Competency Assessment (SARCA). Participants were recruited by contacting over 68 program directors of both Christian and secular accredited counseling, psychology, and social work schools in the United States and through the Counselor Education and Supervision Network Listserv and American Psychological Association of Graduate Students directory. 125 students with varying degrees of professed religious affiliation, completed the survey. Counselor trainees scored highest on both measures, yet without statistical significance. Students with very strong personal religious affiliation and attendees of Christian affiliated schools scored statistically higher on both measures. Findings indicated Christian institutions and trainees who professed very high Christian affiliation seemed to possess greater competence at integrating spiritual and religious constructs within mental health counseling. However, the results are limited due to sample size. Further, results pointed to convergent validity for the SCS-R-II and SARCA. Implications and future recommendations for behavior science educators and clinicians are discussed
Connectionist perspectives on language learning, representation and processing.
The field of formal linguistics was founded on the premise that language is mentally represented as a deterministic symbolic grammar. While this approach has captured many important characteristics of the world\u27s languages, it has also led to a tendency to focus theoretical questions on the correct formalization of grammatical rules while also de-emphasizing the role of learning and statistics in language development and processing. In this review we present a different approach to language research that has emerged from the parallel distributed processing or \u27connectionist\u27 enterprise. In the connectionist framework, mental operations are studied by simulating learning and processing within networks of artificial neurons. With that in mind, we discuss recent progress in connectionist models of auditory word recognition, reading, morphology, and syntactic processing. We argue that connectionist models can capture many important characteristics of how language is learned, represented, and processed, as well as providing new insights about the source of these behavioral patterns. Just as importantly, the networks naturally capture irregular (non-rule-like) patterns that are common within languages, something that has been difficult to reconcile with rule-based accounts of language without positing separate mechanisms for rules and exceptions
Exploring the measurement of markedness and its relationship with other linguistic variables
Antonym pair members can be differentiated by each word's markedness-that distinction attributable to the presence or absence of features at morphological or semantic levels. Morphologically marked words incorporate their unmarked counterpart with additional morphs (e.g., "unlucky" vs. "lucky"); properties used to determine semantically marked words (e.g., "short" vs. "long") are less clearly defined. Despite extensive theoretical scrutiny, the lexical properties of markedness have received scant empirical study. The current paper employs an antonym sequencing approach to measure markedness: establishing markedness probabilities for individual words and evaluating their relationship with other lexical properties (e.g., length, frequency, valence). Regression analyses reveal that markedness probability is, as predicted, related to affixation and also strongly related to valence. Our results support the suggestion that antonym sequence is reflected in discourse, and further analysis demonstrates that markedness probabilities, derived from the antonym sequencing task, reflect the ordering of antonyms within natural language. In line with the Pollyanna Hypothesis, we argue that markedness is closely related to valence; language users demonstrate a tendency to present words evaluated positively ahead of those evaluated negatively if given the choice. Future research should consider the relationship of markedness and valence, and the influence of contextual information in determining which member of an antonym pair is marked or unmarked within discourse
Mitochondrial dysfunction in an Opa1Q285STOP mouse model of dominant optic atrophy results from Opa1 haploinsufficiency
Mutations in the opa1 (optic atrophy 1) gene lead to autosomal dominant optic atrophy (ADOA), a hereditary eye disease. This gene encodes the Opa1 protein, a mitochondrial dynamin-related GTPase required for mitochondrial fusion and the maintenance of normal crista structure. The majority of opa1 mutations encode truncated forms of the protein, lacking a complete GTPase domain. It is unclear whether the phenotype results from haploinsufficiency or rather a deleterious effect of truncated Opa1 protein. We studied a heterozygous Opa1 mutant mouse carrying a defective allele with a stop codon in the beginning of the GTPase domain at residue 285, a mutation that mimics human pathological mutations. Using an antibody raised against an N-terminal portion of Opa1, we found that the level of wild-type protein was decreased in the mutant mice, as predicted. However, no truncated Opa1 protein was expressed. In embryonic fibroblasts isolated from the mutant mice, this partial loss of Opa1 caused mitochondrial respiratory deficiency and a selective loss of respiratory Complex IV subunits. Furthermore, partial Opa1 deficiency resulted in a substantial resistance to endoplasmic reticulum stress-induced death. On the other hand, the enforced expression of truncated Opa1 protein in cells containing normal levels of wild-type protein did not cause mitochondrial defects. Moreover, cells expressing the truncated Opa1 protein showed reduced Bax activation in response to apoptotic stimuli. Taken together, our results exclude deleterious dominant-negative or gain-of-function mechanisms for this type of Opa1 mutation and affirm haploinsufficiency as the mechanism underlying mitochondrial dysfunction in ADOA
BH3 domains of BH3-only proteins differentially regulate Bax-mediated mitochondrial membrane permeabilization both directly and indirectly
activate Bax directly and can only act indirectly to reliev
Nucleocytoplasmic transport: a thermodynamic mechanism
The nuclear pore supports molecular communication between cytoplasm and
nucleus in eukaryotic cells. Selective transport of proteins is mediated by
soluble receptors, whose regulation by the small GTPase Ran leads to cargo
accumulation in, or depletion from the nucleus, i.e., nuclear import or nuclear
export. We consider the operation of this transport system by a combined
analytical and experimental approach. Provocative predictions of a simple model
were tested using cell-free nuclei reconstituted in Xenopus egg extract, a
system well suited to quantitative studies. We found that accumulation capacity
is limited, so that introduction of one import cargo leads to egress of
another. Clearly, the pore per se does not determine transport directionality.
Moreover, different cargo reach a similar ratio of nuclear to cytoplasmic
concentration in steady-state. The model shows that this ratio should in fact
be independent of the receptor-cargo affinity, though kinetics may be strongly
influenced. Numerical conservation of the system components highlights a
conflict between the observations and the popular concept of transport cycles.
We suggest that chemical partitioning provides a framework to understand the
capacity to generate concentration gradients by equilibration of the
receptor-cargo intermediary.Comment: in press at HFSP Journal, vol 3 16 text pages, 1 table, 4 figures,
plus Supplementary Material include
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