127 research outputs found

    Transcriptional regulatory framework for vascular cambium development in Arabidopsis roots

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    Vascular cambium, a lateral plant meristem is a central producer of woody biomass. Although a few transcription factors (TFs) have been shown to regulate cambial activity1, the phenotypes of the corresponding loss-of-function mutants are relatively modest, highlighting our limited understanding of the underlying transcriptional regulation. Here, we utilize cambium cell-specific transcript profiling followed by a combination of TF network and genetic analyses to identify 62 novel TF genotypes displaying an array of cambial phenotypes. This approach culminated in virtual loss of cambial activity when both WUSCHEL-RELATED HOMEOBOX 4 (WOX4) and KNOTTED-like from Arabidopsis thaliana 1 (KNAT1; also known as BREVIPEDICELLUS (BP) were mutated, thereby unlocking the genetic redundancy in the regulation of cambium development. We also identified TFs with dual functions in cambial cell proliferation and xylem differentiation, including WOX4, SHORT VEGETATIVE PHASE (SVP) and PETAL LOSS (PTL). Using the TF network information, we combined overexpression of the cambial activator WOX4 and removal of the putative inhibitor PTL to engineer Arabidopsis for enhanced radial growth. This line also showed ectopic cambial activity, thus further highlighting the central roles of WOX4 and PTL in cambium development.This work was supported by Finnish Centre of Excellence in Molecular Biology of Primary Producers (Academy of Finland CoE program 2014-2019) decision #271832, the Gatsby Foundation (GAT3395/PR3)), the University of Helsinki (award 799992091) and the European Research Council Advanced Investigator Grant SYMDEV (No. 323052) to Y.H.; Academy of Finland (grants #132376, #266431, #271832), University of Helsinki HiLIFE fellowship to A.P.M.; National Research Foundation of Korea (2018R1A5A1023599 and 2016R1A2B2015258) to J-Y. L

    Diagnostically Challenging Epithelial Odontogenic Tumors: A Selective Review of 7 Jawbone Lesions

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    Considerable variation in the clinicopathologic presentation of epithelial odontogenic tumors can sometimes be confusing and increase the chance of misdiagnosis. Seven diagnostically challenging jawbone lesions are described. There were 2 cases of mistaken identity in our ameloblastoma file. One unicystic type, initially diagnosed and treated as a lateral periodontal cyst, showed destructive recurrence 6 years postoperatively. The other globulomaxillary lesion was managed under the erroneous diagnosis of adenomatoid odontogenic tumor and recurred 4 times over an 11-year period. This tumor was found in retrospect to be consistent with an adenoid ameloblastoma with dentinoid. The diagnosis of cystic squamous odontogenic tumor (SOT) occurring as a radicular lesion of an impacted lower third molar was one of exclusion. Of two unsuspected keratocystic odontogenic tumors, one depicted deceptive features of pericoronitis, while the other case has long been in our files with the diagnosis of globulomaxillary SOT. Two cases of primary intraosseous squamous cell carcinoma appeared benign clinically and exhibited unexpected findings; an impacted third molar began to erupt in association with the growth of carcinoma and another periradicular carcinoma showed dentinoid formation. Cases selectively reviewed in this article present challenging problems which require clinical and radiographic correlation to avoid potential diagnostic pitfalls

    Newborn care and knowledge translation - perceptions among primary healthcare staff in northern Vietnam

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    <p>Abstract</p> <p>Background</p> <p>Nearly four million neonatal deaths occur annually in the world despite existing evidence-based knowledge with the potential to prevent many of these deaths. Effective knowledge translation (KT) could help to bridge this know-do gap in global health. The aim of this study was to explore aspects of KT at the primary healthcare level in a northern province in Vietnam.</p> <p>Methods</p> <p>Six focus-group discussions were conducted with primary healthcare staff members who provided neonatal care in districts that represented three types of geographical areas existing in the province (urban, rural, and mountainous). Recordings were transcribed verbatim, translated into English, and analyzed using content analysis.</p> <p>Results</p> <p>We identified three main categories of importance for KT. Healthcare staff used several channels for acquisition and management of knowledge (1), but none appeared to work well. Participants preferred formal training to reading guideline documents, and they expressed interest in interacting with colleagues at higher levels, which rarely happened. In some geographical areas, traditional medicine (2) seemed to compete with evidence-based practices, whereas in other areas it was a complement. Lack of resources, low frequency of deliveries and, poorly paid staff were observed barriers to keeping skills at an adequate level in the healthcare context (3).</p> <p>Conclusions</p> <p>This study indicates that primary healthcare staff work in a context that to some extent enables them to translate knowledge into practice. However, the established and structured healthcare system in Vietnam does constitute a base where such processes could be expected to work more effectively. To accelerate the development, thorough considerations over the current situation and carefully targeted actions are required.</p

    Still too far to walk: Literature review of the determinants of delivery service use

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    BACKGROUND: Skilled attendance at childbirth is crucial for decreasing maternal and neonatal mortality, yet many women in low- and middle-income countries deliver outside of health facilities, without skilled help. The main conceptual framework in this field implicitly looks at home births with complications. We expand this to include "preventive" facility delivery for uncomplicated childbirth, and review the kinds of determinants studied in the literature, their hypothesized mechanisms of action and the typical findings, as well as methodological difficulties encountered. METHODS: We searched PubMed and Ovid databases for reviews and ascertained relevant articles from these and other sources. Twenty determinants identified were grouped under four themes: (1) sociocultural factors, (2) perceived benefit/need of skilled attendance, (3) economic accessibility and (4) physical accessibility. RESULTS: There is ample evidence that higher maternal age, education and household wealth and lower parity increase use, as does urban residence. Facility use in the previous delivery and antenatal care use are also highly predictive of health facility use for the index delivery, though this may be due to confounding by service availability and other factors. Obstetric complications also increase use but are rarely studied. Quality of care is judged to be essential in qualitative studies but is not easily measured in surveys, or without linking facility records with women. Distance to health facilities decreases use, but is also difficult to determine. Challenges in comparing results between studies include differences in methods, context-specificity and the substantial overlap between complex variables. CONCLUSION: Studies of the determinants of skilled attendance concentrate on sociocultural and economic accessibility variables and neglect variables of perceived benefit/need and physical accessibility. To draw valid conclusions, it is important to consider as many influential factors as possible in any analysis of delivery service use. The increasing availability of georeferenced data provides the opportunity to link health facility data with large-scale household data, enabling researchers to explore the influences of distance and service quality

    From little things, big things grow: trends and fads in 110 years of Australian ornithology

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    Publishing histories can reveal changes in ornithological effort, focus or direction through time. This study presents a bibliometric content analysis of Emu (1901&ndash;2011) which revealed 115 trends (long-term changes in publication over time) and 18 fads (temporary increases in publication activity) from the classification of 9,039 articles using 128 codes organised into eight categories (author gender, author affiliation, article type, subject, main focus, main method, geographical scale and geographical location). Across 110 years, private authorship declined, while publications involving universities and multiple institutions increased; from 1960, female authorship increased. Over time, question-driven studies and incidental observations increased and decreased in frequency, respectively. Single species and &lsquo;taxonomic group&rsquo; subjects increased while studies of birds at specific places decreased. The focus of articles shifted from species distribution and activities of the host organisation to breeding, foraging and other biological/ecological topics. Site- and Australian-continental-scales slightly decreased over time; non-Australian studies increased from the 1970s. A wide variety of fads occurred (e.g. articles on bird distribution, 1942&ndash;1951, and using museum specimens, 1906&ndash;1913) though the occurrence of fads decreased over time. Changes over time are correlated with technological, theoretical, social and institutional changes, and suggest ornithological priorities, like those of other scientific disciplines, are temporally labil

    The embedding of transnational entrepreneurs in diaspora networks:Leveraging the assets of foreignness

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    In this paper we examine how foreign actors capitalize on their ethnic identity to gain skills and capabilities that enable them to operate in a new and strange environment. We explore the mechanisms by which Bulgarian entrepreneurs in London use their ethnic identity to develop competitive advantage and business contacts. We find that the entrepreneurs studied gain access to a diaspora network, which enables them to develop essential business capabilities and integrate knowledge from both home and host country environments. The diaspora community possesses a collective asset (transactive memory) that allows its members to remove competition from the interfirm level to the network level (i.e., diaspora networks vs. networks of native businesspeople). Additionally, the cultural identity and networks to which community members have access provide bridging capabilities that allow diaspora businesspeople to make links to host country business partners and thus embed themselves in the host country environment. Thus, this paper adds to the growing body of work showing how foreignness can serve as an asset in addition to its better-known role as a liability
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