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1.
Nat Plants ; 9(5): 720-732, 2023 05.
Article in English | MEDLINE | ID: mdl-37142751

ABSTRACT

Grass leaves develop from a ring of primordial initial cells within the periphery of the shoot apical meristem, a pool of organogenic stem cells that generates all of the organs of the plant shoot. At maturity, the grass leaf is a flattened, strap-like organ comprising a proximal supportive sheath surrounding the stem and a distal photosynthetic blade. The sheath and blade are partitioned by a hinge-like auricle and the ligule, a fringe of epidermally derived tissue that grows from the adaxial (top) leaf surface. Together, the ligule and auricle comprise morphological novelties that are specific to grass leaves. Understanding how the planar outgrowth of grass leaves and their adjoining ligules is genetically controlled can yield insight into their evolutionary origins. Here we use single-cell RNA-sequencing analyses to identify a 'rim' cell type present at the margins of maize leaf primordia. Cells in the leaf rim have a distinctive identity and share transcriptional signatures with proliferating ligule cells, suggesting that a shared developmental genetic programme patterns both leaves and ligules. Moreover, we show that rim function is regulated by genetically redundant Wuschel-like homeobox3 (WOX3) transcription factors. Higher-order mutations in maize Wox3 genes greatly reduce leaf width and disrupt ligule outgrowth and patterning. Together, these findings illustrate the generalizable use of a rim domain during planar growth of maize leaves and ligules, and suggest a parsimonious model for the homology of the grass ligule as a distal extension of the leaf sheath margin.


Subject(s)
Plant Leaves , Poaceae , Poaceae/genetics , Plant Leaves/metabolism , Zea mays , Mutation , Meristem , Gene Expression Regulation, Plant
2.
Psychol Women Q ; 47(1): 127-143, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36742155

ABSTRACT

Scholars have long explored the expectations of women to maintain intimate relationships and the gendered discourses governing those expectations. Despite the dating landscape changes, having intimate relationships remains important for young women. Amid these changes and the impacts of #MeToo/#TimesUp, investigating the discourses at play within women's talk about intimate relationships produces a current snapshot that contrasts with past literature. Young, heterosexual women of diverse racial, educational/work, and relationship backgrounds aged 18-24 years (N = 28) attended one of five online videoconferencing focus groups. Using an eclectic theoretical approach informed by feminist post-structuralism and discursive psychology, we analyzed women's talk about doing relationships. Mobilizing a discourse of intimate relationship necessity/importance, young women (a) were positioned as "the silenc(ed/ing) woman," demonstrating a shared understanding of the necessity of silence when doing intimate relationships; and/or (b) actively took up "the communicative woman," which they conceptualized as the hallmark of a healthy relationship. Tensions between these subject positions were evident (e.g., needing to be "cool"). Also, women described no-win situations in relationships despite attempts to contend with these contradictions and limitations. These findings may contribute to educational materials and youth programming delivered in high school or college.

3.
Br J Soc Psychol ; 57(3): 505-523, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29453778

ABSTRACT

The implicit association test (IAT) and concept of implicit bias have significantly influenced the scientific, institutional, and public discourse on racial prejudice. In spite of this, there has been little investigation of how ordinary people make sense of the IAT and the bias it claims to measure. This article examines the public understanding of this research through a discourse analysis of reactions to the IAT and implicit bias in the news media. It demonstrates the ways in which readers interpreted, related to, and negotiated the claims of IAT science in relation to socially shared and historically embedded concerns and identities. IAT science was discredited in accounts that evoked discourses about the marginality of academic preoccupations, and helped to position test-takers as targets of an oppressive political correctness and psychologists as liberally biased. Alternatively, the IAT was understood to have revealed widely and deeply held biases towards racialized others, eliciting accounts that took the form of psychomoral confessionals. Such admissions of bias helped to constitute moral identities for readers that were firmly positioned against racial bias. Our findings are discussed in terms of their implications for using the IAT in prejudice reduction interventions, and communicating to the public about implicit bias.


Subject(s)
Association , Mass Media , Prejudice , Psychological Tests , Adult , Humans
4.
J Health Psychol ; 23(3): 408-424, 2018 03.
Article in English | MEDLINE | ID: mdl-28810453

ABSTRACT

In contrast to the institutionalization of health psychology in North America and Europe, much psychological work on health issues in South Africa emerged as part of a critical revitalization of South African psychology as a whole, coinciding with the dismantling of Apartheid and global shifts in health discourse. The field's development reflects attempts to engage with urgent health problems in the context of rapid sociopolitical changes that followed democratic transition in the 1990s, and under new conditions of knowledge production. We provide an account of these issues, as well as reflections on the field's future, as inflected through the experiences of 12 South African psychologists whose careers span the emergence of health-related psychology to the present day.


Subject(s)
Behavioral Medicine/history , Behavioral Medicine/methods , History, 20th Century , Humans , Interviews as Topic , South Africa
5.
Inflamm Bowel Dis ; 23(10): 1730-1740, 2017 10.
Article in English | MEDLINE | ID: mdl-28906292

ABSTRACT

BACKGROUND: The integrity of the gut barrier in patients with inflammatory bowel disease is known to be impaired but the exact mechanisms remain mostly unknown. SHANK3 mutations are associated with autism, and patients with autism are known to have higher proportions of inflammatory bowel disease. Here, we explore the role of SHANK3 in inflammatory bowel disease, both in vivo and in vitro. METHODS: Dextran sulfate sodium colitis was induced in SHANK3 knockout mice. Transepithelial electrical resistance, paracellular permeability, and Salmonella invasion assays were used to evaluate epithelial barrier function, in vitro and in vivo. Expression of tight junction proteins, protein kinases, and MAP kinase phosphorylation changes were analyzed by immunoblotting after overexpression or knockdown of SHANK3 expression. SHANK3 expression in intestinal tissue from patients with Crohn's disease was analyzed by quantitative polymerase chain reaction and immunohistochemistry. RESULTS: SHANK3 knockout mice were more susceptible to dextran sulfate sodium. SHANK3 knockout resulted in a leaky epithelial barrier phenotype, as demonstrated by decreased transepithelial electrical resistance, increased paracellular permeability, and increased Salmonella invasion. Overexpression of SHANK3 enhanced ZO-1 expression, and knockdown of SHANK3 resulted in decreased expression of ZO-1. Regulation of ZO-1 expression by SHANK3 seems to be mediated through a PKCε-dependent pathway. SHANK3 expression correlated with ZO-1 and PKCε in colonic tissue of patients with Crohn's disease. CONCLUSIONS: The expression level of SHANK3 affects ZO-1 expression and the barrier function in intestinal epithelial cells. This may provide novel insights in Crohn's disease pathogenesis and treatment.


Subject(s)
Cell Membrane Permeability/genetics , Colitis/genetics , Crohn Disease/genetics , Nerve Tissue Proteins/genetics , Zonula Occludens-1 Protein/genetics , Animals , Caco-2 Cells , Colitis/chemically induced , Colon/pathology , Crohn Disease/pathology , Dextran Sulfate/administration & dosage , Disease Models, Animal , Epithelial Cells/metabolism , HCT116 Cells , Humans , MAP Kinase Signaling System , Male , Mice , Mice, Knockout , Microfilament Proteins , Phosphorylation , Protein Kinase C-epsilon/genetics , Salmonella
6.
BMC Med Ethics ; 17(1): 54, 2016 09 06.
Article in English | MEDLINE | ID: mdl-27600117

ABSTRACT

BACKGROUND: Health research increasingly relies on organized collections of health data and biological samples. There are many types of sample and data collections that are used for health research, though these are collected for many purposes, not all of which are health-related. These collections exist under different jurisdictional and regulatory arrangements and include: 1) Population biobanks, cohort studies, and genome databases 2) Clinical and public health data 3) Direct-to-consumer genetic testing 4) Social media 5) Fitness trackers, health apps, and biometric data sensors Ethical, legal, and social challenges of such collections are well recognized, but there has been limited attention to the broader societal implications of the existence of these collections. DISCUSSION: Although health research conducted using these collections is broadly recognized as beneficent, secondary uses of these data and samples may be controversial. We examine both documented and hypothetical scenarios of secondary uses of health data and samples. In particular, we focus on the use of health data for purposes of: Forensic investigations Civil lawsuits Identification of victims of mass casualty events Denial of entry for border security and immigration Making health resource rationing decisions Facilitating human rights abuses in autocratic regimes CONCLUSIONS: Current safeguards relating to the use of health data and samples include research ethics oversight and privacy laws. These safeguards have a strong focus on informed consent and anonymization, which are aimed at the protection of the individual research subject. They are not intended to address broader societal implications of health data and sample collections. As such, existing arrangements are insufficient to protect against subversion of health databases for non-sanctioned secondary uses, or to provide guidance for reasonable but controversial secondary uses. We are concerned that existing debate in the scholarly literature and beyond has not sufficiently recognized the secondary data uses we outline in this paper. Our main purpose, therefore, is to raise awareness of the potential for unforeseen and unintended consequences, in particular negative consequences, of the increased availability and development of health data collections for research, by providing a comprehensive review of documented and hypothetical non-health research uses of such data.


Subject(s)
Data Collection , Databases, Factual/ethics , Dual Use Research/ethics , Human Rights , Records , Humans , Informed Consent , Privacy
7.
Hist Psychol ; 19(2): 77-92, 2016 May.
Article in English | MEDLINE | ID: mdl-26881425

ABSTRACT

As part of a growing literature on the histories of psychology in the Global South, this article outlines some historical developments in South African psychologists' engagement with the problem of "health." Alongside movements to formalize and professionalize a U.S.-style "health psychology" in the 1990s, there arose a parallel, eclectic, and more or less critical psychology that contested the meaning and determinants of health, transgressed disciplinary boundaries, and opposed the responsibilization of illness implicit in much health psychological theorizing and neoliberal discourse. This disciplinary bifurcation characterized South African work well into the postapartheid era, but ideological distinctions have receded in recent years under a new regime of knowledge production in thrall to the demands of the global market. The article outlines some of the historical-political roots of key trends in psychologists' work on health in South Africa, examining the conditions that have impinged on its directions and priorities. It raises questions about the future trajectories of psychological research on health after 20 years of democracy, and argues that there currently is no "health psychology" in South Africa, and that the discipline is the better for it.


Subject(s)
Apartheid , Behavioral Medicine/history , Politics , Apartheid/history , Behavioral Medicine/methods , Behavioral Medicine/organization & administration , History, 20th Century , South Africa
8.
J Pediatr Psychol ; 40(2): 167-74, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25273000

ABSTRACT

The field of pediatric psychology arose in the 1960s in response to a variety of societal and professional needs. 2 seminal articles written during this time, by Jerome Kagan (1965) and Logan Wright (1967), played key roles in the field's development. However, their efficacy in galvanizing a response from medical professionals and psychologists had much to do with broad-ranging developments in pediatric public health, intraprofessional changes among medical specialties, and a growing preoccupation with "psychosocial" and parenting issues. The purpose of this paper is to situate Kagan's (1965) and Wright's (1967) contributions within their social and historical contexts, and thereby to elicit reflection on the field's subsequent and continued development.


Subject(s)
Psychology, Child/history , Publishing , Child , History, 20th Century , Humans
9.
Transcult Psychiatry ; 40(4): 542-61, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14979467

ABSTRACT

This discourse analytic study explores constructions of culture and illness in the talk of psychiatrists, psychologists and indigenous healers as they discuss possibilities for collaboration in South African mental health care. Versions of 'culture', and disputes over what constitutes 'disorder', are an important site for the negotiation of power relations between mental health practitioners and indigenous healers. The results of this study are presented in two parts. Part I explores discourses about western psychiatric/psychological professionalism, tensions in diagnosis between cultural relativism and psychiatric universalism, and how assertion of 'cultural differences' may be used to resist psychiatric power. Part II explores how discursive constructions of 'African culture' and 'African madness' work to marginalize indigenous healing in South African mental health care, despite repeated calls for collaboration.


Subject(s)
Attitude to Health , Cultural Characteristics , Medicine, African Traditional , Mental Disorders/ethnology , Power, Psychological , Adult , Humans , Interview, Psychological , Male , Mental Disorders/therapy , Mental Health Services , South Africa/ethnology
10.
Transcult Psychiatry ; 40(4): 562-84, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14979468

ABSTRACT

This discourse analytic study explores constructions of culture and illness in the talk of psychiatrists, psychologists and indigenous healers as they discuss possibilities for collaboration in South African mental health care. Disjunctive versions of what 'culture' is in relation to the illness of a person form an important site for the negotiation of power relations between mental health practitioners and indigenous healers. The results of this study are presented in two parts. Part I explores how a professionalist discourse structured western psychiatric and psychological practice as rational, pragmatic and effective. 'Cultural differences' were variously deployed to support and subvert western psychiatric power. Part II explores the various constructions of African culture'--as 'collectivist' and 'pathogenic'--and the 'African mind'--as 'primitive' and 'irrational'--and how these formulations work to disqualify egalitarian positioning for indigenous healers within formal mental health care settings in South Africa.


Subject(s)
Cultural Characteristics , Medicine, African Traditional , Mental Disorders/ethnology , Mental Health , Power, Psychological , Attitude to Health , Humans , Mental Disorders/therapy , Mental Healing , South Africa
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