538 research outputs found

    The Māuipreneur

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    The concept of the Māuipreneur is a metaphor that brings together two apparently unrelated domains interacting to create new meaning or insight that did not exist before the metaphor was encountered. In this case the two unrelated domains are the Māui stories of Aotearoa New Zealand and that of the entrepreneur thus creating the Māuipreneur. The Māuipreneur is the entrepreneur who seizes the opportunity created in the space left void in the movement from tapu (restricted space) to noa (unrestricted space) and through research, development and planning fills it with product. The paper presents a discussion about the Māuipreneur and explains how the theory and associated model relating to the Māuipreneur is found in the stories of the ancestor hero, Māui-Tikitiki-A-Tāranga. This paper was first presented at the Tauira-a-Māui Symposium, Te Whare Wānanga o Raukawa, Otaki, New Zealand, 11-13 November 2009

    Development of a Model for Functional Studies of ABCG2 (Breast Cancer Resistance Protein) Efflux Employing a Standard BeWo Clone (B24)

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    Human choriocarcinoma-derived BeWo cells express high levels of breast cancer resistance protein (BCRP/ABCG2) with no functional P-glycoprotein (P-gp) (ABCB1) activity, making them a potential model to study bidirectional ABCG2-mediated drug transport. However, the original BeWo clone (B24) available to researchers does not form confluent monolayers with tight junctions required by the model. Our aim was to adapt culture conditions to attempt to generate confluent BeWo monolayers for drug transport studies using the standard B24 clone. BeWo cells (B24; American Type Culture collection [ATCC]) were cultured in six-well plates or polycarbonate millicell inserts in a number of media formulations, growth supplements, and basement membrane substitutes. Cells were examined for confluence by microscopy, and transepithelial electrical resistance (TEER) was measured daily; monolayer permeability was assessed when TEER had stabilized. Optimal growth rates were achieved in culture conditions consisting of Medium 199 (M199) supplemented with epidermal growth factor (EGF; 20 ng/mL), vitamin supplements, and 10% fetal calf serum (FCS) with collagen coating. A TEER of 170 Ω in 0.6 cm2 inserts was achieved 2 weeks after seeding under optimal conditions. The cell-impermeable diffusion marker 5(6) carboxy-2,7dichlorodihydrofluorescein (C-DCDHF) had a permeability coefficient of 3.5 x 10-6 cm/s, indicative of minimal paracellular permeability. ABCG2 expression, as determined by immunoblotting, remained unaffected by confluency. In conclusion, we describe culture conditions for the B24 BeWo clone that facilitate the formation of monolayers with tighter junctions and reduced paracellular transport compared to previously published models. These growth conditions provide a good model of ABCG2-mediated drug transport in a human placental cell line

    An Eleméntàry Linguistic Definition of Upstate New York

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    This paper examines a hitherto undiscussed dialectological feature of Upstate New York: the pronunciation of words like elementary (documentary, complimentary, etc.) as eleméntàry, with secondary stress on the penultimate syllable. We report the results of three studies examining the geographic distribution of this feature. In the first study, data from 119 sociolinguistic interviews in communities in eastern New York establish the widespread usage of the feature in this region. In the second study, data from 59 sociolinguistic interviews in far western New York and northwestern Pennsylvania show that the geographic extent of the feature hews very close to the New York–Pennsylvania state line in that region. The third study is a rapid and anonymous telephone survey of the lexical item elementary including 188 towns across the entire state of New York and nearby parts of adjacent states. This study finds that the stressed-penultimate pattern is nearly confined to Upstate New York, bleeding only into the Northern Tier of counties in Pennsylvania and a few towns in southwestern Vermont. In addition to providing empirical evidence for the geographic extent of this dialectolgical feature, this study analyzes the relationship between the distribution of the -méntàry pronunciation and other isoglosses that serve as boundaries between major dialect regions in the area. The analysis shows that the geographic extent of the -méntàry pronunciation does not always pattern closely with dialect regions defined by phonological criteria; rather, it coincides more closely with the cultural boundary delimiting the region of Upstate New York. We argue that this type of linguistic boundary is caused primarily by communication patterns (as opposed to constraints internal to the linguistic system), and that it is more likely to be observed in variants involving analogical change, such as the -méntàry pronunciation

    Pseudoreplication Revisited

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    Umbilical cord blood testosterone and childhood internalizing and externalizing behavior: a prospective study

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    Extent: 8 p.Antenatal testosterone exposure influences fetal neurodevelopment and gender-role behavior in postnatal life and may contribute to differences in developmental psychopathology during childhood. We prospectively measured the associations between umbilical cord blood testosterone levels at birth and childhood behavioral development in both males and females from a large population based sample. The study comprised 430 females and 429 males from the Western Australian Pregnancy Cohort (Raine) Study where umbilical cord blood had been collected. Total testosterone concentrations were determined by mass spectrometry and bioavailable testosterone (BioT) levels were calculated. At two, five, eight and ten years of age, the participants completed the Child Behavior Checklist (CBCL). Linear regression models were used to analyse the relationship between BioT concentrations (in quartiles) and CBCL scores (total, internalizing, externalizing and selected syndrome). Boys had higher mean CBCL T-scores than girls across all ages of follow-up. There was no significant relationship between cord blood BioT quartiles and CBCL total, internalizing and externalizing T-scores at age two or five to ten combined. In the syndrome score analyses, higher BioT quartiles were associated with significantly lower scores for attention problems for boys at age five, eight and ten, and greater withdrawal symptoms in pre-school girls (age five). We did not identify a consistent relationship between antenatal testosterone exposure and total, internalizing or externalizing behavioral difficulties in childhood. Higher umbilical cord BioT levels were associated with lower scores for attention problems in boys up to 10 years and more withdrawn behavior in 5-year-old girls; however, these findings were not consistent across ages and require further investigation in a larger sample.Monique Robinson, Andrew J.O. Whitehouse, Peter Jacoby, Eugen Mattes, Michael G. Sawyer, Jeffrey A. Keelan and Martha Hicke

    Reversible Dissociation of a Dialumene

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    Dialumenes are neutral Al(I) compounds with Al=Al multiple bonds. We report the isolation of an amidophosphine‐supported dialumene. Our X‐ray crystallographic, spectroscopic, and computational DFT analyses reveal a long and extreme trans‐bent Al=Al bond with a low dissociation energy and bond order. In solution, the dialumene can dissociate into monomeric Al(I) species. Reactivity studies reveal two modes of reaction: as dialumene or as aluminyl monomers

    Detection of Osmotic Shock-Induced Extracellular Nucleotide Release with a Genetically Encoded Fluorescent Sensor of ADP and ATP

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    Purinergic signals, such as extracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP), mediate intercellular communication and stress responses throughout mammalian tissues, but the dynamics of their release and clearance are still not well understood. Although physiochemical methods provide important insight into physiology, genetically encoded optical sensors have proven particularly powerful in the quantification of signaling in live specimens. Indeed, genetically encoded luminescent and fluorescent sensors provide new insights into ATP-mediated purinergic signaling. However, new tools to detect extracellular ADP are still required. To this end, in this study, we use protein engineering to generate a new genetically encoded sensor that employs a high-affinity bacterial ADP-binding protein and reports a change in occupancy with a change in the Förster-type resonance energy transfer (FRET) between cyan and yellow fluorescent proteins. We characterize the sensor in both protein solution studies, as well as live-cell microscopy. This new sensor responds to nanomolar and micromolar concentrations of ADP and ATP in solution, respectively, and in principle it is the first fully-genetically encoded sensor with sufficiently high affinity for ADP to detect low levels of extracellular ADP. Furthermore, we demonstrate that tethering the sensor to the cell surface enables the detection of physiologically relevant nucleotide release induced by hypoosmotic shock as a model of tissue edema. Thus, we provide a new tool to study purinergic signaling that can be used across genetically tractable model systems

    Structural mechanisms of DREAM complex assembly and regulation

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    The DREAM complex represses cell cycle genes during quiescence through scaffolding MuvB proteins with E2F4/5 and the Rb tumor suppressor paralog p107 or p130. Upon cell cycle entry, MuvB dissociates from p107/p130 and recruits B-Myb and FoxM1 for up-regulating mitotic gene expression. To understand the biochemical mechanisms underpinning DREAM function and regulation, we investigated the structural basis for DREAM assembly. We identified a sequence in the MuvB component LIN52 that binds directly to the pocket domains of p107 and p130 when phosphorylated on the DYRK1A kinase site S28. A crystal structure of the LIN52–p107 complex reveals that LIN52 uses a suboptimal LxSxExL sequence together with the phosphate at nearby S28 to bind the LxCxE cleft of the pocket domain with high affinity. The structure explains the specificity for p107/p130 over Rb in the DREAM complex and how the complex is disrupted by viral oncoproteins. Based on insights from the structure, we addressed how DREAM is disassembled upon cell cycle entry. We found that p130 and B-Myb can both bind the core MuvB complex simultaneously but that cyclin-dependent kinase phosphorylation of p130 weakens its association. Together, our data inform a novel target interface for studying MuvB and p130 function and the design of inhibitors that prevent tumor escape in quiescence

    Offspring conceived through ART have normal thyroid function in adolescence and as young adults

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    STUDY QUESTION: Are there differences in thyroid function between adolescents and young adults conceived with and without ART? SUMMARY ANSWER: This study demonstrated no evidence of clinically relevant differences in thyroid function between adolescents and young adults conceived with and without ART. WHAT IS KNOWN ALREADY: Studies to date have reported an increase in subclinical hypothyroidism in offspring conceived after ART. It has been suggested that the increase in maternal estrogen (E2) after fresh embryo transfers could affect thyroid function of the offspring. Suboptimal thyroid function at a young age can cause irreversible damage to the central nervous system, which makes early detection and correct treatment essential. STUDY DESIGN, SIZE, DURATION: The Growing Up Healthy Study (GUHS) is a prospective cohort study, which aimed to recruit all adolescents born after conception with ART between 1991 and 2001 in the study area. The included participants (n = 303, aged 13-20 years) completed various health assessments. Depending on the age at enrolment, participants completed thyroid assessments at the 14-or 20-year follow-up. The outcomes of these replicated thyroid assessments were compared to those of participants conceived without ART from the Raine Study Generation 2 (Gen2). The Gen2 participants (n = 2868) were born between 1989 and 1992 and have been recognized to be representative of the local population. PARTICIPANTS/MATERIALS, SETTING, METHODS: Thyroid function assessments were compared between n = 134 GUHS and n = 1359 Gen2 adolescents at age 14 years and between n = 47 GUHS and n = 914 Gen2 young adults at age 20 years. The following mean thyroid hormone concentrations were compared between the cohorts: Thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) and thyroid peroxidase antibodies (TPOAb). The prevalence of the following thyroid hormone profiles, based on individual thyroid hormone concentrations, was compared: euthyroidism, subclinical and overt hypo-and hyperthyroidism and thyroid autoimmunity. Outcomes were compared between the cohorts, and univariately between fresh embryo transfers (ET) and frozen ET (FET) within the GUHS. The correlation between maternal peak E2 concentrations (pE2) and fT4 was assessed within the GUHS. MAIN RESULTS AND THE ROLE OF CHANCE: All mean thyroid function outcomes fell within the normal range. At both ages, we report no differences in TSH concentrations. At age 14 years, lower fT3 concentrations (4.80 versus 5.35 pmol/L, P \u3c 0.001) and higher fT4 concentrations (12.76 versus 12.19 pmol/L, P \u3c 0.001) were detected in the GUHS adolescents compared to Gen2 adolescents. At age 20 years, higher fT3 and fT4 concentrations were reported in GUHS adolescents (4.91 versus 4.63 pmol/L, P = 0.012; 13.43 versus 12.45 pmol/L, P \u3c 0.001, respectively) compared to Gen2 participants. No differences in the prevalence of subclinical and overt hypo-and hyperthyroidism or thyroid autoimmunity were demonstrated between the cohorts at age 14 and 20 years. Thyroid function did not differ between ET and FET, and no correlation between pE2 and fT4 was reported. LIMITATIONS, REASONS FOR CAUTION: The observational nature of the study limits the ability to prove causation. Furthermore, the comparison of ET and FET offspring at age 20 years may be lacking power. We were unable to differentiate between different types of ART (e.g. IVF versus ICSI) owing to the low number of ICSI cycles at the time of study. As ART laboratory and clinic data were collected contemporaneously with the time of treatment, no other data pertaining to the ART cycles were sought retrospectively; hence, some factors could not be accounted for. WIDER IMPLICATIONS OF THE FINDINGS: This study does not support previous findings of clinically relevant differences in thyroid function when comparing a cohort of adolescents conceived after ART to counterparts conceived without ART. The minor differences detected in fT3 and fT4 were considered not biologically relevant. Although these findings appear reassuring, they warrant reinvestigation in adulthood. STUDY FUNDING/COMPETING INTERESTS: This project was funded by an NHMRC Grant (Hart et al., ID 1042269). R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director and a shareholder of PIVET Medical Centre, Perth, Western Australia. TRIAL REGISTRATION NUMBER: N/A
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