291 research outputs found
Corrigendum to “Dissemination in time and space in presymptomatic granulin mutation carriers: A spatial chronnectome study” [Neurobiology of Aging Volume 108, December 2021, Pages 155–167]
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Enrico Premi, Marcello Giunta, Armin Iraji, Srinivas Rachakonda, Vince D. Calhoun, Stefano Gazzina, Alberto Benussi, Roberto Gasparotti, Silvana Archetti, Martina Bocchetta, Dave Cash, Emily Todd, Georgia Peakman, Rhian Convery, John C. van Swieten, Lize Jiskoot, Raquel Sanchez-Valle, Fermin Moreno, Robert Laforce, Caroline Graff, Matthis Synofzik, Daniela Galimberti, James B. Rowe, Mario Masellis, Carmela Tartaglia, Elizabeth Finger, Rik Vandenberghe, Alexandre de Mendonça, Fabrizio Tagliavini, Chris R. Butler, Isabel Santana, Alexander Gerhard, Isabelle Le Ber, Florence Pasquier, Simon Ducharme, Johannes Levin, Adrian Danek, Sandro Sorbi, Markus Otto, Jonathan D. Rohrer, Barbara Borroni
Dissemination in time and space in presymptomatic granulin mutation carriers: a GENFI spatial chronnectome study. Neurobiology of Aging, Volume 108, December 2021, Pages 155-167 DOI of original article: 10.1016/j.neurobiolaging.2021.09.001.© 2022 Elsevier Inc. The authors regret that the GENFI authors were listed at the end of the article in the Appendix. The GENFI authors are also part of co-authors. The updated author list is below. The authors would like to apologise for any inconvenience caused
White Matter Tracts of Speech and Language
No full textDiffusion tensor imaging (DTI) has been used to investigate the white matter (WM) tracts underlying the perisylvian cortical regions known to be associated with language function. The arcuate fasciculus is composed of 3 segments (1 long and 2 short) whose separate functions correlate with traditional models of conductive and transcortical motor or sensory aphasia, respectively. DTI mapping of language fibers is useful in presurgical planning for patients with dominant hemisphere tumors, particularly when combined with functional magnetic resonance imaging. DTI has found damage to language networks in stroke patients and has the potential to influence poststroke rehabilitation and treatment. Assessment of the WM tracts involved in the default mode network has been found to correlate with mild cognitive impairment, potentially explaining language deficits in patients with apparently mild small vessel ischemic disease. Different patterns of involvement of language-related WM structures appear to correlate with different clinical subtypes of primary progressive aphasias. (C) 2014 Elsevier Inc. All rights reserved
Optimization process of the forensic investigation regarding home invasion robberies
No full textThe forensic investigation is one of the first steps in the criminal investigation process concerning home invasion robberies. The forensic investigation consists of objectively capturing the crime scene as it is when starting the investigation. Regarding home invasion robberies, the most important traces are fingerprints and DNA which are used for identification of individual suspects. Currently, there is little knowledge about the process of a secured trace to a result used in court. Crime scene investigators are confronted with multiple decisions during the investigation and it is important to know with what goal in mind an investigator acts on the crime scene, as this influences the decision-making. The forensic data obtained from the forensic investigation is shared within a forensic data infrastructure. This infrastructure consists of the following criminal justice system partners involved in the process from crime scene investigation to conviction: crime scene investigators, detectives, experts at forensic laboratories, prosecutors, defense attorneys and judges. These partners are all contributing in different ways and at different times. The forensic data infrastructure comes with sensibilities and tensions, such as tunnel vision, incomplete crime scene investigation reports, misunderstandings and one-way communication. Solving these sensibilities and tensions is crucial to the functioning of the infrastructure. By use of a questionnaire, insights are provided into the goals and aspects of the forensic investigation that are important to the involved partners. The goals important to crime scene investigators differ little from the goals of other involved partners. The questionnaire results are reflected on in an expert reflection session. This session is part of the participatory design, which contributes in creating a mutual understanding of needs between partners. A second expert session is developed to fulfill these needs and implement solutions to solve sensibilities and tensions in an optimized forensic investigation. The optimization process includes the optimization of the forensic investigation itself and the optimization of the forensic data infrastructure by proposing a structured forensic investigation scheme. A new experiment is presented to analyze the optimized forensic investigation.Biomedical Engineerin
Two novel variants in <i>GRN</i>:the relevance of CNV analysis and genetic screening in FTLD patients with a negative family history
Get PDFBackground: Frontotemporal lobar degeneration (FTLD) is one of the leading causes of early onset dementia. Pathogenic variants in GRN have been reported to cause 5–25% of familial and 5% of sporadic FTLD. Here, we present two novel, likely pathogenic variants in GRN. Methods: Four patients from four different families underwent whole exome sequencing (WES) with additional copy-number variance (CNV) analysis in a clinical setting. TMEM106B rs1990622 and rs3173615 SNPs and 3’UTR insertion were tested in one presymptomatic carrier. In three probands and one presymptomatic carrier, plasma progranulin (PGRN) levels were measured using a specific ELISA kit. In two probands, neuropathological diagnosis was established using current neuropathological criteria. Results: Through CNV analysis on WES data, we identified a partial deletion, NM_002087.2 (GRN):c.1179 + 104_1536delinsCTGA, p.(?), in three patients with primary progressive aphasia and/or corticobasal syndrome. Haplotype analysis revealed a shared haplotype block, suggesting that the deletion represents a founder mutation. Additionally, we found a novel, missense variant, NM_002087.2 (GRN):c.23 T > A, p.(Val8Glu), in one proband with a negative family history. The proband’s unaffected parent—in their 80 s—carried the same variant, yet was homozygous for the TMEM106B risk haplotype. The pathogenicity of both GRN variants was supported by typical neuropathological features and reduced PGRN levels. Conclusion: We recommend a thorough genetic screening, including CNV analysis, for both familial and apparent sporadic FTLD patients. Furthermore, the presymptomatic carrier homozygous for the TMEM106B risk haplotype exemplifies the presence of other protective factors that modify disease onset and urges caution in genetic counselling based on the TMEM106B haplotype.</p
C Louis Leipoldt’s The Valley : constructing an alternative past?
Get PDFThesis (DPhil)--University of Pretoria, 2012.The South African author C Louis Leipoldt is known as an Afrikaans poet and as one of the ‘Driemanskap’ with Celliers and Totius. Together with Eugene Marais, they wrote the first serious Afrikaans literary poetry in the early decades of the Twentieth Century. The ‘Driemanskap’, grouped together for its clear national(ist) thrust, is well-known as part of the Tweede Afrikaanse Taalbeweging not only for celebrating the universal effects of nature but also for extolling the virtues of forgiveness after the South African War. Apart from his extensive canon of Afrikaans literature and a sizable discourse in the culinary field, not much is known about The Valley, Leipoldt’s so-called ‘English’ novels written in the late 1920s and early 1930s in English, a language he was equally at home in. The titles of these novels making up The Valley trilogy are Gallows Gecko, Stormwrack and The Mask. Despite several efforts to have the novels published with leading publishing houses in both Britain and the United States of America, both during and after his lifetime, the three ‘English’ novels of C Louis Leipoldt remained unpublished for 69 years. It was in 2001 that for the first time they appeared unedited in a compendium volume. Prior to 2001, two of the novels were published −in 1980, the year of the centenary of Leipoldt’s birth, an abridged edition of Stormwrack appeared, edited by Stephen Gray and published by David Philip, Cape Town. It was re-published by Human&Rousseau in 2000. An abridged edition of Gallows Gecko appeared in 2001, under the title Chameleon on the Gallows which the editor Stephen Gray explains he changed for stylistic reasons. Leipoldt uses the form of historical fiction in his trilogy as a way of conveying historical meaning by relating the chronicle (1820 – 1930) of the place he calls the Valley, recognizable as Clanwilliam. Initially, the Valley is at peace and is sketched in its idyllic state. After the Jameson Raid of 1895, the prospects of the South African War become a reality for the inhabitants of the Cederberg as they are torn apart by their emotions, feelings and loyalties. The course of events drastically changes when war finally comes to the District. Discontinuity and change is a strong theme in the novels. Eventually the inhabitants ofthe Valley find that the former, respectful relations, based on tradition and tolerance, have given way to sectarian interests. This changes the social fibre of the once idyllic environment. The Valley is a lamentation of lost opportunities for a culturally unified South Africa. Its voice is one of moderateness and is inclusive for all South Africans, addressing race relations as a theme as well as decrying sectionalism. In the light of this, it is argued that Leipoldt is revealed as a political liberal and cultural pluralist. This can be heard through the voices of the characters in The Valley and seen by the way Leipoldt meant the events in his fiction to serve as an allegory for the way he saw South Africa emerging at the time. He was writing against the Nationalists, particularly against the narrative of Gustav S Preller, who spent his working life constructing a volksgeskiedenis that resulted in a significant public history that dominated Afrikaner historical thinking from circa 1905 to 1938. In this sense, it is argued, The Valley is an alternative history to the dominating Preller historiography, and because it is in the form of narrative/historical fiction, it can also be seen as an alternative form of history, to be read against certain theoretical texts, without in any way detracting from the voices of criticism against deconstructivist history.Historical and Heritage Studiesunrestricte
The Impact of Advanced Glycation End-Products (AGEs) on Proliferation and Apoptosis of Primary Stem Cells: A Systematic Review
No full textStem cell-based regenerative therapies hold great promises to treat a wide spectrum of diseases. However, stem cell engraftment and survival are still challenging due to an unfavorable transplantation environment. Advanced glycation end-products (AGEs) can contribute to the generation of these harmful conditions. AGEs are a heterogeneous group of glycated products, nonenzymatically formed when proteins and/or lipids become glycated and oxidized. Our typical Western diet as well as cigarettes contain high AGEs content. AGEs are also endogenously formed in our body and accumulate with senescence and in pathological situations. Whether AGEs have an impact on stem cell viability in regenerative medicine remains unclear, and research on the effect of AGEs on stem cell proliferation and apoptosis is still ongoing. Therefore, this systematic review provides a clear overview of the effects of glycated proteins on cell viability in various types of primary isolated stem cells used in regenerative medicine.Figures were created using images from Servier Medical Art Commons Attribution 3.0 Unported License (http://smart.servier.com). Servier Medical Art by Servier is licensed under a Creative Commons Attribution 3.0 Unported License. This work was supported by a Bijzonder onderzoeksfonds (BOF) grant from Hasselt University (grant number: 16NI05BOF). HB benefits from an aspirant PhD mandate (grant number: 1154120N) of the `Research Foundation-Flanders' (fonds voor wetenschappelijk onderzoek (FWO)). PG is also supported by the FWO (grant numbers: 12U7718N and 1502120N).Bito, V (corresponding author), Hasselt Univ, Biomed BIOMED Res Inst, Agoralaan Bldg C, B-3590 Diepenbeek, Belgium.
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Caregiver Burden in a Culturally Diverse Memory Clinic Population: The Caregiver Strain Index-Expanded
Get PDFIntroduction: Although qualitative studies have highlighted substantial barriers to dementia diagnosis and care in culturally diverse populations in Europe, quantitative studies examining the level of caregiver burden in these populations have been lacking thus far and are urgently needed. Methods: We compared the caregiver burden levels on the Caregiver Strain Index (CSI)-Expanded of 63 culturally diverse patient-caregiver dyads from a multicultural memory clinic with 30 native Dutch patient-caregiver dyads and examined the association between caregiver burden and determinants of burden. Results: Informal caregivers in the multicultural memory clinic cohort experienced a high level of caregiver burden (mean CSI-score multicultural cohort: 6.1 [SD: 3.3]; mean CSI-score native Dutch cohort: 4.8 [SD: 3.2]). Burden was significantly associated with impairment on proxy-rated and objective measures of cognitive functioning, such as the Informant Questionnaire on Cognitive Decline and the Rowland Universal Dementia Assessment Scale, and with instrumental activities of daily living. Burden was the highest in spousal caregivers. The positive subscale of the CSI-Expanded provided limited additional information. Conclusion: Caregivers of culturally diverse patients experience a high level of caregiver burden, in particular at more advanced disease stages. This study highlights the need to screen culturally diverse caregivers in European memory clinics on caregiver burden to identify those in need of caregiver support
Cross-cohort generalizability of deep and conventional machine learning for MRI-based diagnosis and prediction of Alzheimer's disease
No full textThis work validates the generalizability of MRI-based classification of Alzheimer's disease (AD) patients and controls (CN) to an external data set and to the task of prediction of conversion to AD in individuals with mild cognitive impairment (MCI). We used a conventional support vector machine (SVM) and a deep convolutional neural network (CNN) approach based on structural MRI scans that underwent either minimal pre-processing or more extensive pre-processing into modulated gray matter (GM) maps. Classifiers were optimized and evaluated using cross-validation in the Alzheimer's Disease Neuroimaging Initiative (ADNI; 334 AD, 520 CN). Trained classifiers were subsequently applied to predict conversion to AD in ADNI MCI patients (231 converters, 628 non-converters) and in the independent Health-RI Parelsnoer Neurodegenerative Diseases Biobank data set. From this multi-center study representing a tertiary memory clinic population, we included 199 AD patients, 139 participants with subjective cognitive decline, 48 MCI patients converting to dementia, and 91 MCI patients who did not convert to dementia. AD-CN classification based on modulated GM maps resulted in a similar area-under-the-curve (AUC) for SVM (0.940; 95%CI: 0.924–0.955) and CNN (0.933; 95%CI: 0.918–0.948). Application to conversion prediction in MCI yielded significantly higher performance for SVM (AUC = 0.756; 95%CI: 0.720-0.788) than for CNN (AUC = 0.742; 95%CI: 0.709-0.776) (p<0.01 for McNemar's test). In external validation, performance was slightly decreased. For AD-CN, it again gave similar AUCs for SVM (0.896; 95%CI: 0.855–0.932) and CNN (0.876; 95%CI: 0.836–0.913). For prediction in MCI, performances decreased for both SVM (AUC = 0.665; 95%CI: 0.576-0.760) and CNN (AUC = 0.702; 95%CI: 0.624-0.786). Both with SVM and CNN, classification based on modulated GM maps significantly outperformed classification based on minimally processed images (p=0.01). Deep and conventional classifiers performed equally well for AD classification and their performance decreased only slightly when applied to the external cohort. We expect that this work on external validation contributes towards translation of machine learning to clinical practice.</p
A system dynamics approach to understanding the ostrich industry of South Africa
Get PDFThesis (MEng)--Stellenbosch University, 2016.ENGLISH ABSTRACT: Although the livestock production sector is recognised as an essential contributor to the green economy in South Africa, there is a lack of simulation tool development for the green economy transition of livestock production. The ostrich production industry, mainly exporting leather and meat, is a significant part of livestock production of South Africa. In terms of the global ostrich product market, the ostrich industry of South Africa accounts for approximately
70% of the total supply. Ostrich leather is positioned as an exclusive luxury item, while meat is positioned as an every-day alternative to red meat
in their respective markets. A strong relationship exists between previous market supply of ostrich leather and current income from leather, while the
ostrich meat income is considered to be largely unaffected by market supply of ostrich meat. The meat market has the potential to absorb more than tenfold the current market supply of meat. This study contributed the only systems thinking analysis of the ostrich production industry in South Africa, known to the author. The analysis in the form of a system dynamics model, proposed a causal loop diagram, as well as a stock and flow diagram that represented the structure of the ostrich production industry of South Africa. The livestock model proposed was set within a different socio-economic environment, as well as a different type of commodity market, to that of the well-known hog cycle proposed by Meadows (1970).
The model, known as the Ostrich Industry Model of South Africa (OIMSA), assumed that ostrich producers base their decision in terms of future production amounts on the gross pro t margin per ostrich, mainly influenced by income from leather, income from meat, as well as the production cost. The model forecasted future production size and income received from each commodity, in addition to replicating historical behaviour. Results from an extensive scenario and policy analysis indicated that the only influence that can cause a sustainable increase in the ostrich industry size is the market size of ostrich leather. Scenarios including disturbances is exchange rates, changes in
market demands, changes in product values, food safety concerns, fluctuations in production cost as well as changes in economic climate are also investigated.
Recommendations regarding the green economy transition of the South African ostrich industry include fixing the long term industry focus on ostrich
leather, as well as the development of additional ostrich leather demand. Additionally, new entrant black farmers should be included into the industry at a rate corresponding to the growth in leather demand. The highly contentious subject of a mandatory transition to a small camp breeding system is shown to be sustainable, yet highly unpopular. The two potential policies, carbon
tax per ostrich produced, and water tax on irrigated crops used for ostrich feed, will have the exact same effect of ostrich production, and is therefore not
recommended to implement the two types of taxes simultaneously.AFRIKAANSE OPSOMMING: Hoewel die vee produksie sektor erken word as 'n noodsaaklike bydrae tot die groen ekonomie in Suid-Afrika, is daar 'n gebrek aan simulasie hulpmiddel ontwikkeling om die groen ekonomie oorgang, in terme van vee produksie, te bestudeer. Die volstruis bedryf, hoofsaaklik uitgemaak deur die uitvoer van leer en vleis, is 'n belangrike deel van vee produksie in Suid-Afrika. Die volstruis bedryf van Suid-Afrika is verantwoordelik vir ongeveer 70% van die wêreldwye volstruis produk aanbod. Volstruis leer is geposisioneer as 'n eksklusiewe en luukse item, terwyl volstruis vleis geposisioneer is as 'n daaglikse verbruiker alternatief tot rooivleis in hul onderskeie internasionale markte. 'n Sterk verhouding bestaan tussen vorige mark aanbod van leer en die huidige inkomste uit leer, terwyl vleis inkomste grootliks onaangeraak is deur mark aanbod van vleis. Die vleis mark het die potensiaal om meer as tien keer
die huidige aanbod te absorbeer. Hierdie studie stel die enigste stelsels dink ontleding van die volstruis bedryf, wat bekend is aan die skrywer, voor. Die
ontleding, in die vorm van 'n stelsel dinamiese model, stel 'n oorsaaklike lus diagram, sowel as 'n voorraad en vloei diagram voor om die struktuur van die volstruis bedryf in Suid-Afrika te verteenwoordig. Die vee model wat voorgestel word, word bevind in 'n ander sosio-ekonomiese omgewing, sowel as 'n ander tipe kommoditeit mark, as die wat deur Meadows (1970) se bekende vark siklus voorgestel word.
Die model, genoem die Ostrich Industry Model of South Africa (OIMSA), veronderstel dat volstruis produsente hulle besluit oor toekomstige produksie baseer op die bruto winsmarge per volstruis. Die bruto winsmarge word hoofsaaklik beïnvloed deur inkomste uit leer, inkomste uit vleis, asook die produksiekoste.
Die model herhaal historiese gedrag in van die volstruis bedryf en voorspel toekomstige produksie grootte en inkomste ontvang uit elke kommoditeit.
Die model, in 'n toestand van ewewig, ondergaan ook uitgebreide scenario en beleid analise. Resultate van 'n uitgebreide scenario en beleid analise dui aan dat die enigste invloed wat 'n volhoubare toename in die volstruis bedryf grootte kan veroorsaak word, is die mark aanvraag grootte van volstruis leer. Scenario's insluitend versteurings in wisselkoerse, veranderinge in die mark aanvraag, veranderinge in die produk waardes, voedselveiligheid kommer, veranderinge in produksiekoste sowel as 'n verandering in ekonomiese klimaat was ook ondersoek.
Aanbevelings ten opsigte van die groen ekonomie oorgang van die Suid-Afrikaanse volstruis bedryf sluit die vasstelling van die langtermyn industrie
fokus op volstruis leer, sowel as die ontwikkeling van bykomende volstruis leer aanvraag in. Daarbenewens moet nuwe toetreder swart boere by die bedryf ingesluit word teen 'n koers wat ooreenstem met die groei in leer aanvraag.
Die hoogs omstrede onderwerp van 'n verpligte oorgang na 'n klein kamp stelsel is bewys as volhoubaar, tog baie ongewild. Dit word nie aanbeveel om die twee potensiële beleide, koolstof belasting per volstruis geproduseer, en water belasting op besproeide gewasse gebruik word vir volstruis voer, gelyktydig te implementeer nie, aangesien die twee tipes belastings presies dieselfde uitwerking op die volstruis bedryf sal hê
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