66 research outputs found
Lkb1 Deficiency Alters Goblet and Paneth Cell Differentiation in the Small Intestine
The Lkb1 tumour suppressor is a multitasking kinase participating in a range of physiological processes. We have determined the impact of Lkb1 deficiency on intestinal homeostasis, particularly focussing on secretory cell differentiation and development since we observe strong expression of Lkb1 in normal small intestine Paneth and goblet cells. We crossed mice bearing an Lkb1 allele flanked with LoxP sites with those carrying a Cyp1a1-specific inducible Cre recombinase. Lkb1 was efficiently deleted from the epithelial cells of the mouse intestine after intraperitoneal injection of the inducing agent β-naphthoflavone. Bi-allelic loss of Lkb1 led to the perturbed development of Paneth and goblet cell lineages. These changes were characterised by the lack of Delta ligand expression in Lkb1-deficient secretory cells and a significant increase in the levels of the downstream Notch signalling effector Hes5 but not Hes1. Our data show that Lkb1 is required for the normal differentiation of secretory cell lineages within the intestine, and that Lkb1 deficiency modulates Notch signalling modulation in post-mitotic cells
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Collectively Improving Our Teaching: Attempting Biology Department–wide Professional Development in Scientific Teaching
Many efforts to improve science teaching in higher education focus on a few faculty members at an institution at a time, with limited published evidence on attempts to engage faculty across entire departments. We created a long-term, department-wide collaborative professional development program, Biology Faculty Explorations in Scientific Teaching (Biology FEST). Across 3 years of Biology FEST, 89% of the department's faculty completed a weeklong scientific teaching institute, and 83% of eligible instructors participated in additional semester-long follow-up programs. A semester after institute completion, the majority of Biology FEST alumni reported adding active learning to their courses. These instructor self-reports were corroborated by audio analysis of classroom noise and surveys of students in biology courses on the frequency of active-learning techniques used in classes taught by Biology FEST alumni and nonalumni. Three years after Biology FEST launched, faculty participants overwhelmingly reported that their teaching was positively affected. Unexpectedly, most respondents also believed that they had improved relationships with departmental colleagues and felt a greater sense of belonging to the department. Overall, our results indicate that biology department-wide collaborative efforts to develop scientific teaching skills can indeed attract large numbers of faculty, spark widespread change in teaching practices, and improve departmental relations
The genetic architecture of the human cerebral cortex
The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder
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The impact of PICALM genetic variations on reserve capacity of posterior cingulate in AD continuum
Phosphatidylinositolbinding clathrin assembly protein (PICALM) gene is one novel genetic player associated with late-onset Alzheimer’s disease (LOAD), based on recent genome wide association studies (GWAS). However, how it affects AD occurrence is still unknown. Brain reserve hypothesis highlights the tolerant capacities of brain as a passive means to fight against neurodegenerations. Here, we took the baseline volume and/or thickness of LOAD-associated brain regions as proxies of brain reserve capacities and investigated whether PICALM genetic variations can influence the baseline reserve capacities and the longitudinal atrophy rate of these specific regions using data from Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset. In mixed population, we found that brain region significantly affected by PICALM genetic variations was majorly restricted to posterior cingulate. In sub-population analysis, we found that one PICALM variation (C allele of rs642949) was associated with larger baseline thickness of posterior cingulate in health. We found seven variations in health and two variations (rs543293 and rs592297) in individuals with mild cognitive impairment were associated with slower atrophy rate of posterior cingulate. Our study provided preliminary evidences supporting that PICALM variations render protections by facilitating reserve capacities of posterior cingulate in non-demented elderly
Conversion Discriminative Analysis on Mild Cognitive Impairment Using Multiple Cortical Features from MR Images
Neuroimaging measurements derived from magnetic resonance imaging provide important information required for detecting changes related to the progression of mild cognitive impairment (MCI). Cortical features and changes play a crucial role in revealing unique anatomical patterns of brain regions, and further differentiate MCI patients from normal states. Four cortical features, namely, gray matter volume, cortical thickness, surface area, and mean curvature, were explored for discriminative analysis among three groups including the stable MCI (sMCI), the converted MCI (cMCI), and the normal control (NC) groups. In this study, 158 subjects (72 NC, 46 sMCI, and 40 cMCI) were selected from the Alzheimer's Disease Neuroimaging Initiative. A sparse-constrained regression model based on the l2-1-norm was introduced to reduce the feature dimensionality and retrieve essential features for the discrimination of the three groups by using a support vector machine (SVM). An optimized strategy of feature addition based on the weight of each feature was adopted for the SVM classifier in order to achieve the best classification performance. The baseline cortical features combined with the longitudinal measurements for 2 years of follow-up data yielded prominent classification results. In particular, the cortical thickness produced a classification with 98.84% accuracy, 97.5% sensitivity, and 100% specificity for the sMCI–cMCI comparison; 92.37% accuracy, 84.78% sensitivity, and 97.22% specificity for the cMCI–NC comparison; and 93.75% accuracy, 92.5% sensitivity, and 94.44% specificity for the sMCI–NC comparison. The best performances obtained by the SVM classifier using the essential features were 5–40% more than those using all of the retained features. The feasibility of the cortical features for the recognition of anatomical patterns was certified; thus, the proposed method has the potential to improve the clinical diagnosis of sub-types of MCI and predict the risk of its conversion to Alzheimer's disease
Quantitative 18F-AV1451 Brain Tau PET Imaging in Cognitively Normal Older Adults, Mild Cognitive Impairment, and Alzheimer's Disease Patients
Recent developments of tau Positron Emission Tomography (PET) allows assessment of regional neurofibrillary tangles (NFTs) deposition in human brain. Among the tau PET molecular probes, 18F-AV1451 is characterized by high selectivity for pathologic tau aggregates over amyloid plaques, limited non-specific binding in white and gray matter, and confined off-target binding. The objectives of the study are (1) to quantitatively characterize regional brain tau deposition measured by 18F-AV1451 PET in cognitively normal older adults (CN), mild cognitive impairment (MCI), and AD participants; (2) to evaluate the correlations between cerebrospinal fluid (CSF) biomarkers or Mini-Mental State Examination (MMSE) and 18F-AV1451 PET standardized uptake value ratio (SUVR); and (3) to evaluate the partial volume effects on 18F-AV1451 brain uptake.Methods: The study included total 115 participants (CN = 49, MCI = 58, and AD = 8) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Preprocessed 18F-AV1451 PET images, structural MRIs, and demographic and clinical assessments were downloaded from the ADNI database. A reblurred Van Cittertiteration method was used for voxelwise partial volume correction (PVC) on PET images. Structural MRIs were used for PET spatial normalization and region of interest (ROI) definition in standard space. The parametric images of 18F-AV1451 SUVR relative to cerebellum were calculated. The ROI SUVR measurements from PVC and non-PVC SUVR images were compared. The correlation between ROI 18F-AV1451 SUVR and the measurements of MMSE, CSF total tau (t-tau), and phosphorylated tau (p-tau) were also assessed.Results:18F-AV1451 prominently specific binding was found in the amygdala, entorhinal cortex, parahippocampus, fusiform, posterior cingulate, temporal, parietal, and frontal brain regions. Most regional SUVRs showed significantly higher uptake of 18F-AV1451 in AD than MCI and CN participants. SUVRs of small regions like amygdala, entorhinal cortex and parahippocampus were statistically improved by PVC in all groups (p < 0.01). Although there was an increasing tendency of 18F-AV-1451 SUVRs in MCI group compared with CN group, no significant difference of 18F-AV1451 deposition was found between CN and MCI brains with or without PVC (p > 0.05). Declined MMSE score was observed with increasing 18F-AV1451 binding in amygdala, entorhinal cortex, parahippocampus, and fusiform. CSF p-tau was positively correlated with 18F-AV1451 deposition. PVC improved the results of 18F-AV-1451 tau deposition and correlation studies in small brain regions.Conclusion: The typical deposition of 18F-AV1451 tau PET imaging in AD brain was found in amygdala, entorhinal cortex, fusiform and parahippocampus, and these regions were strongly associated with cognitive impairment and CSF biomarkers. Although more deposition was observed in MCI group, the 18F-AV-1451 PET imaging could not differentiate the MCI patients from CN population. More tau deposition related to decreased MMSE score and increased level of CSF p-tau, especially in ROIs of amygdala, entorhinal cortex and parahippocampus. PVC did improve the results of tau deposition and correlation studies in small brain regions and suggest to be routinely used in 18F-AV1451 tau PET quantification
Cycles of Conquest
After more than fifty years, Cycles of Conquest is still one of the best syntheses of more than four centuries of conquest, colonization, and resistance ever published. It explores how ten major Native groups in northern Mexico and what is now the United States responded to political incorporation, linguistic hegemony, community reorganization, religious conversion, and economic integration. Thomas E. Sheridan writes in the new foreword commissioned for this special edition that the book is “monumental in scope and magisterial in presentation.” Cycles of Conquest remains a seminal work, deeply influencing how we have come to view the greater Southwest and its peoples
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Pascua: A Yaqui Village in Arizona
The Yaqui of Mexico were early converts to Christianity in New Spain. Yet they came to be regarded with hostility by the newly emerging Mexican government. Many Yaquis fled Mexico in the early twentieth century and established a settlement in Arizona where they resumed a peaceful existence centered around their ceremonial calendar. Edward Spicer devoted most of his professional career to the study of the Yaquis and came to be regarded as a leading authority on that tribe. At the inception of his forty years of research stands Pascua, a firsthand description of daily village life.Andrew W. Mellon Foundation, as part of the Humanities Open Book Program funded jointly by the National Endowment for the Humanities and the Andrew W. Mellon Foundation.LIST OF ILLUSTRATIONS -- LIST OF TABLES -- I. PASCUA VILLAGE -- The Setting of the Village -- Yaqui Villages in Arizona -- The Population of Pascua -- Material Culture -- History -- Summary -- II. ECONOMICS -- The Means of Subsistence -- The Level of Subsistence -- The Use of Money -- Property -- Economic Aspects of the Fiesta -- Economic Attitudes -- Summary -- III. KINSHIP -- Kinship Terms -- Kinship Behavior -- Marriage -- The Kinship Groups -- Recent Changes in Kinship Behavior -- Summary -- IV. CEREMONIAL SPONSORSHIP -- Terminology -- The Nature of Ceremonial Sponsorship -- The Nature of the Obligations -- The Padrino Group -- The Ideas Underlying Ceremonial Sponsorship -- How the System Works -- Summary -- V. THE CEREMONIAL SOCIETIES -- The Men's Societies -- The Women's Societies Membership in a Ceremonial Society -- The Obligations of Members -- The Obligations of Societies to Members -- The Composition of the Ceremonial Societies -- Summary -- VI. THE CHURCH AND THE PUEBLO -- The Pueblo -- The Church -- Social Control -- Summary -- VII. THE Pascola DANCERS -- Organization of the Activities of the Pasco/as -- Ceremonies in Which Pasco/as Appear -- The Dancers and Their Dance -- Ritual Functions of the Pasco/as -- The Deer-Dancer -- Native Interpretations -- Attitudes toward the Pasco/as. -- Summary -- VIII. THE CEREMONIAL SYSTEM: EVENTS AND PATTERNS -- The Ceremonial Calendar -- Noncalendrical Ceremonies -- The Elements of the Ritual -- Summary -- IX. THE CEREMONIAL SYSTEM: ANCESTORS AND DEITIES -- The Channels of Tradition -- Death and the Ancestors -- The Virgin Mary -- Jesus: El Senor -- The Animals -- The Element of Burlesque -- Individual Attitudes -- Summary -- X. ORGANIZATION AND CONFLICT -- The Nature of the Social Organization -- The Nature of the Conflict -- XI. CONCLUSION: THE HYPOTHESIS OF FUNCTIONAL INCONSISTENCY -- BIBLIOGRAPHY -- INDEX.This title from the Open Arizona collection is made available by the University of Arizona Press and University of Arizona Libraries. If you have questions about this title, please contact the UA Press at https://uapress.arizona.edu/contact
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Cycles of Conquest: The Impact of Spain, Mexico, and the United States on Indians of the Southwest, 1533-1960
After more than fifty years, Cycles of Conquest is still one of the best syntheses of more than four centuries of conquest, colonization, and resistance ever published. It explores how ten major Native groups in northern Mexico and what is now the United States responded to political incorporation, linguistic hegemony, community reorganization, religious conversion, and economic integration. Thomas E. Sheridan writes in the new foreword commissioned for this special edition that the book is “monumental in scope and magisterial in presentation.”
Cycles of Conquest remains a seminal work, deeply influencing how we have come to view the greater Southwest and its peoples.Andrew W. Mellon Foundation, as part of the Humanities Open Book Program funded jointly by the National Endowment for the Humanities and the Andrew W. Mellon Foundation.This title from the Open Arizona collection is made available by the University of Arizona Press and University of Arizona Libraries. If you have questions about this title, please contact the UA Press at https://uapress.arizona.edu/contact
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