Um die anderen Arten von Veröffentlichungen zu diesem Thema anzuzeigen, folgen Sie diesem Link: Desikanty.
Zeitschriftenartikel zum Thema „Desikanty“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit Top-28 Zeitschriftenartikel für die Forschung zum Thema "Desikanty" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Sehen Sie die Zeitschriftenartikel für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.
1
Hasibuan, Rosdanelli, und Muhammad Alfikri Ridhatullah. „Pengaruh Ketebalan Bahan Dan Jumlah Desikan Terhadap Laju Pengeringan Jahe (Zingiber Officinale Roscoe) Pada Pengering Kombinasi Surya dan Desikan“. Jurnal Teknik Kimia USU 8, Nr. 2 (29.09.2019): 61–66. http://dx.doi.org/10.32734/jtk.v8i2.1882.
Der volle Inhalt der QuelleAnnotation:
Ginger is a spice plant that is usually used as a seasoning in cooking or raw material for medicine, traditional or industrial medicine. Ginger has a high-water content so its easily contaminated with microbes and has active ingredients (gingerol) which are easily damaged by high temperatures. Ginger drying is intended for maintaining the quality of dry ginger and keep ginger from microbes. The drying process has done in continuously with solar dryer using flat plate type collector during the day and at night using the Molecular Sieve 13x desiccant. Drying varies the thickness of ginger 2 mm, 4 mm, and 6 mm, and the amount ratio of desiccant: 1:1; 1:2; and 1:3. To get drying characteristics, every 1-hour mass calculated using an electric scale, and data logger every 5 minutes calculates the temperature and humidity rate (RH) in the drying chamber. The result from ginger drying is the thickness of 6 mm needed more than 20 hours of drying process so that it needed the combination of dryer compared to other thickness, and from quality analysis results of dry ginger, ash content parameters already accordance with SNI standards, and 1:1 material and desiccant ratio is the variation that most closely matches the SNI standard.
2
Rosdanelli Hasibuan und Ivo Dian Sari Marbun. „EFEKTIFITAS JENIS DESIKAN DAN KECEPATAN UDARA TERHADAP PENYERAPAN UAP AIR DI UDARA“. Jurnal Teknik Kimia USU 7, Nr. 1 (04.04.2018): 41–47. http://dx.doi.org/10.32734/jtk.v7i1.1635.
Der volle Inhalt der QuelleAnnotation:
Dry air is widely used in many fields, but the excessive water vapor in the air will make some problem and should be minimized to get the required dry air. The purpose of this research to observe the effect of air velocity and various of desiccants on the absorption of water vapor in the air on the tray dryer. The process of absorption of water vapor in the air performed with variations of the normal air velocity, 1.2 m/s, 2.3 m/s, and 3.6 m/s or volumetric rate of 0.059 m3/s; 0.113 m3/s; 0.178 m3/s and the type of desiccant of silica gel, alumina, and zeolite. Adsorption of water vapor in the air by desiccant was done by weighing the mass of desiccant before and after being crossed by air every interval of 60 minutes for 3 hours. Humidity measurement are performed on the upstream and downstream of the tray dryer to obtain a decrease in air humidity. The highest moisture adsorption using silica gel was obtained at velocities of 2.3 m/s and 3.6 m/s with adsorption of 0.266 grams water vapor / grams adsorbent and 0.264 grams water vapor / grams adsorbent as well as humidity of final air of 0.0194 kg water vapor/ kg dry air and 0.0198 kg water vapor/ kg dry air . The highest adsorption of water vapor using alumina was obtained at velocities of 2.3 m/s and 3.6 m/s with adsorption of 0.147 grams water vapor / gram adsorbent and 0.140 grams water vapor / gram adsorbent and the final humidity of 0.0207 kg water vapor / kg dry air and 0.0194 kg water vapor / kg dry air and the highest water vapor adsorption using zeolite was obtained at 3.6 m/s with the adsorption capacity of 0.130 grams water vapor / grams adsorbent and the final humidity of 0.0193 kg water vapor / kg dry air. Silica gel was the best desiccant in the process of moisture adsorption in air compared to alumina and zeolite.
3
Potvin, Olivier, Louis Dieumegarde und Simon Duchesne. „Freesurfer cortical normative data for adults using Desikan-Killiany-Tourville and ex vivo protocols“. NeuroImage 156 (August 2017): 43–64. http://dx.doi.org/10.1016/j.neuroimage.2017.04.035.
Der volle Inhalt der Quelle
4
Vögele, Martin, Ramachandra M. Bhaskara, Estefania Mulvihill, Katharina van Pee, Özkan Yildiz, Werner Kühlbrandt, Daniel J. Müller und Gerhard Hummer. „Reply to Desikan et al.: Micelle formation among various mechanisms of toxin pore formation“. Proceedings of the National Academy of Sciences 117, Nr. 10 (25.02.2020): 5109–10. http://dx.doi.org/10.1073/pnas.1922488117.
Der volle Inhalt der Quelle
5
Zdanovskis, Nauris, Ardis Platkājis, Andrejs Kostiks, Guntis Karelis und Oļesja Grigorjeva. „Brain Structural Connectivity Differences in Patients with Normal Cognition and Cognitive Impairment“. Brain Sciences 11, Nr. 7 (18.07.2021): 943. http://dx.doi.org/10.3390/brainsci11070943.
Der volle Inhalt der QuelleAnnotation:
Advances in magnetic resonance imaging, particularly diffusion imaging, have allowed researchers to analyze brain connectivity. Identification of structural connectivity differences between patients with normal cognition, cognitive impairment, and dementia could lead to new biomarker discoveries that could improve dementia diagnostics. In our study, we analyzed 22 patients (11 control group patients, 11 dementia group patients) that underwent 3T MRI diffusion tensor imaging (DTI) scans and the Montreal Cognitive Assessment (MoCA) test. We reconstructed DTI images and used the Desikan–Killiany–Tourville cortical parcellation atlas. The connectivity matrix was calculated, and graph theoretical analysis was conducted using DSI Studio. We found statistically significant differences between groups in the graph density, network characteristic path length, small-worldness, global efficiency, and rich club organization. We did not find statistically significant differences between groups in the average clustering coefficient and the assortativity coefficient. These statistically significant graph theory measures could potentially be used as quantitative biomarkers in cognitive impairment and dementia diagnostics.
6
Fathur Rahmi, Atika, Agus Purwito, Ali Husni und Diny Dinarti. „Embriogenesis dan Desikasi Embrio Somatik Jeruk Keprok Batu 55 (Citrus reticulata Blanco.) untuk Meningkatkan Frekuensi Perkecambahan“. Jurnal Hortikultura Indonesia 8, Nr. 2 (08.02.2018): 79. http://dx.doi.org/10.29244/jhi.8.2.79-87.
Der volle Inhalt der QuelleAnnotation:
<p align="center"><strong><em>ABSTRACT</em></strong></p><p><em>In vitro breeding technique of citrus is effective when optimum explant regeneration method is obtained. Low germination frequency and high abnormality were barrier in citrus somatic embryogenesis. This research aimed at optimizing somatic embryogenesis in Tangerine var. Batu 55. This research consisted of 3 experiments. First experiment was maturation of embryogenesis, using Completely Randomized Design (CRD) method. Modified MS+MW was used as basic media added with 500 mg L<sup>-1 </sup>malt extract (control) and addition of 3 mg L<sup>-1</sup> BAP, and 2.5 mg L<sup>-1</sup> ABA as treatments. Second experiment was SE (cotyledonary phage) desiccation. Factorial CRD used in two factors. First factor was poly-ethylene-glicol/PEG 8000 (0, 2.5, 5, 7.5 and 10%), while second factor was immersed periods (control, 3, 6, and 9 hours), in desiccant solution (base medium + PEG). Third experiment was studied of plantlet growth and development planlets. Based on CRD 2 factor method, the first factor was PEG concentrations from the second experiment. Second factor were active charcoal treatments (with or without), in basic media. The result showed that 2.5 mg L<sup>-1</sup> ABA produced has highest mature somatic embryo (SE). Desiccation for 9 hours, induced the highestt germination frequencies (90.29%). The best growth of plantlets shown in previous experiments immersed desiccant PEG 2.5% for 9 hours, and cultured in basic media with 2 g L<sup>-1</sup> of activated charcoal.</em></p><p><em>Keywords: desiccant, embryogenic callus, maturation, PEG 8000, somatic embryo</em></p><p align="center"><strong> </strong></p><p align="center"><strong>ABSTRAK</strong><strong> </strong></p><p>Pemuliaan tanaman melalui teknik <em>in vitro</em> efektif bila metode regenerasi eksplan optimum telah diperoleh. Rendahnya frekuensi perkecambahan dan tingginya abnormalitas, menjadi kendala pada embriogenesis somatik jeruk. Penelitian terdiri atas 3 percobaan paralel, bertujuan mengoptimalkan metode embriogenesis somatik jeruk, khususnya Keprok Batu 55. Percobaan pertama pematangan kalus embriogenik menggunakan Rancangan Acak Lengkap (RAL) satu faktor, dengan perlakuan penambahan ZPT (kontrol, 3 mg L<sup>-1</sup> BAP, dan 2.5 mg L<sup>-1</sup> ABA) pada media dasar (MS modifikasi vitamin MW) diperkaya 500 mg L<sup>-1</sup> ekstrak malt. Percobaan kedua desikasi embrio somatik (fase kotiledon) menggunakan RAL dua faktor. Faktor pertama konsentrasi <em>poly-ethylene-glicol/</em>PEG 8000 (0, 2.5, 5, 7.5 dan 10%), dan faktor kedua waktu perendaman (kontrol, 3, 6, dan 9 jam) pada larutan desikan (media dasar + PEG). Percobaan ketiga mempelajari pertumbuhan dan perkembangan planlet, menggunakan RAL dua faktor. Faktor pertama konsentrasi PEG planlet pada percobaan kedua, dan faktor kedua perbedaan media dasar (tanpa dan dengan arang aktif). Hasil percobaan menunjukkan penambahan 2.5 mg L<sup>-1</sup> ABA menghasilkan maturasi embrio somatik terbaik. Desikasi 9 jam menghasilkan frekuensi perkecambahan 90.29%. Pertumbuhan terbaik ditunjukkan planlet yang pada percobaan sebelumnya direndam 9 jam desikan PEG 2.5%, dan dibesarkan pada media dasar dengan 2 g L<sup>-1 </sup>arang aktif.</p><p>Kata kunci : desikan, embrio somatik, kalus embriogenik, PEG 8000, pematangan</p>
7
Guedj, Benjamin, und Bhargav Srinivasa Desikan. „Kernel-Based Ensemble Learning in Python“. Information 11, Nr. 2 (25.01.2020): 63. http://dx.doi.org/10.3390/info11020063.
Der volle Inhalt der QuelleAnnotation:
We propose a new supervised learning algorithm for classification and regression problems where two or more preliminary predictors are available. We introduce KernelCobra, a non-linear learning strategy for combining an arbitrary number of initial predictors. KernelCobra builds on the COBRA algorithm introduced by Biau et al. (2016), which combined estimators based on a notion of proximity of predictions on the training data. While the COBRA algorithm used a binary threshold to declare which training data were close and to be used, we generalise this idea by using a kernel to better encapsulate the proximity information. Such a smoothing kernel provides more representative weights to each of the training points which are used to build the aggregate and final predictor, and KernelCobra systematically outperforms the COBRA algorithm. While COBRA is intended for regression, KernelCobra deals with classification and regression. KernelCobra is included as part of the open source Python package Pycobra (0.2.4 and onward), introduced by Srinivasa Desikan (2018). Numerical experiments were undertaken to assess the performance (in terms of pure prediction and computational complexity) of KernelCobra on real-life and synthetic datasets.
8
Wei, Yongbin, Lianne H. Scholtens, Elise Turk und Martijn P. van den Heuvel. „Multiscale examination of cytoarchitectonic similarity and human brain connectivity“. Network Neuroscience 3, Nr. 1 (Januar 2019): 124–37. http://dx.doi.org/10.1162/netn_a_00057.
Der volle Inhalt der QuelleAnnotation:
The human brain comprises an efficient communication network, with its macroscale connectome organization argued to be directly associated with the underlying microscale organization of the cortex. Here, we further examine this link in the human brain cortex by using the ultrahigh-resolution BigBrain dataset; 11,660 BigBrain profiles of laminar cell structure were extracted from the BigBrain data and mapped to the MRI based Desikan–Killiany atlas used for macroscale connectome reconstruction. Macroscale brain connectivity was reconstructed based on the diffusion-weighted imaging dataset from the Human Connectome Project and cross-correlated to the similarity of laminar profiles. We showed that the BigBrain profile similarity between interconnected cortical regions was significantly higher than those between nonconnected regions. The pattern of BigBrain profile similarity across the entire cortex was also found to be strongly correlated with the pattern of cortico-cortical connectivity at the macroscale. Our findings suggest that cortical regions with higher similarity in the laminar cytoarchitectonic patterns have a higher chance of being connected, extending the evidence for the linkage between macroscale connectome organization and microscale cytoarchitecture.
9
Jao, Chi-Wen, Chi Ieong Lau, Li-Ming Lien, Yuh-Feng Tsai, Kuang-En Chu, Chen-Yu Hsiao, Jiann-Horng Yeh und Yu-Te Wu. „Using Fractal Dimension Analysis with the Desikan–Killiany Atlas to Assess the Effects of Normal Aging on Subregional Cortex Alterations in Adulthood“. Brain Sciences 11, Nr. 1 (14.01.2021): 107. http://dx.doi.org/10.3390/brainsci11010107.
Der volle Inhalt der QuelleAnnotation:
Normal aging is associated with functional and structural alterations in the human brain. The effects of normal aging and gender on morphological changes in specific regions of the brain are unknown. The fractal dimension (FD) can be a quantitative measure of cerebral folding. In this study, we used 3D-FD analysis with the Desikan–Killiany (DK) atlas to assess subregional morphological changes in adulthood. A total of 258 participants (112 women and 146 men) aged 30–85 years participated in this study. Participants in the middle-age group exhibited a decreased FD in the lateral frontal lobes, which then spread to the temporal and parietal lobes. Men exhibited an earlier and more significant decrease in FD values, mainly in the right frontal and left parietal lobes. Men exhibited more of a decrease in FD values in the subregions on the left than those in the right, whereas women exhibited more of a decrease in the lateral subregions. Older men were at a higher risk of developing mild cognitive impairment (MCI) and exhibited age-related memory decline earlier than women. Our FD analysis using the DK atlas-based prediagnosis may provide a suitable tool for assessing normal aging and neurodegeneration between groups or in individual patients.
10
Batubara, Siti Suleho, John Nefri und Nofrianil. „Analisis Pengaruh Pelapisan Benih dengan Bahan Desikan dan Lama Penyimpanan Terhadap Kualitas Benih Kakao (Theobroma Cacao L.) di Pusat Penelitian Kopi dan Kakao Indonesia, Jember“. Agroteknika 1, Nr. 2 (31.12.2018): 99–110. http://dx.doi.org/10.32530/agtk.v1i2.27.
Der volle Inhalt der QuelleAnnotation:
Peran benih dari perbanyakan generatif sangat besar. Benih berkualitas biasanya disediakan oleh perkebunan besar yang jauh dari perkebunan petani kecil sehingga pengiriman benih membutuhkan waktu lama. Hal ini dapat menyebabkan penurunan kualitas biji kakao. upaya untuk menjaga kualitas benih dengan perlakuan pektin desiccant dan Polyethylene glycol 6000. Penelitian ini bertujuan untuk menganalisis pengaruh pemberian bahan pengering, lama penyimpanan, dan interaksi keduanya dalam menjaga kualitas biji kakao. Penelitian ini dilakukan di Pusat Penelitian Kopi dan Kakao Indonesia, Jember. Penelitian yang digunakan adalah Rancangan Acak Lengkap (RAL) Faktorial yang diulang dua kali. Faktor pertama adalah desikan dan faktor kedua adalah lama penyimpanan. Hasil penelitian menunjukkan bahwa bahan pengeringan memiliki pengaruh yang signifikan pada galat 1% terhadap kadar air, tingkat perkecambahan, dan indeks vigor biji kakao, dan pada tingkat 5% terhadap benih berjamur selama penyimpanan, tidak signifikan dalam Berat biji setelah disimpan. Lama penyimpanan secara signifikan pada galat 1% mempengaruhi kadar air, tingkat perkecambahan biji, dan terbukti dalam perdagangan 5% dari indeks vigor benih kakao, tidak signifikan dalam berat benih setelah simpan, dan benih berkecambah selama penyimpanan. Pengaruh kedua faktor memiliki pengaruh yang signifikan pada galat 1% terhadap kadar air, benih berjamur selama penyimpanan, perkecambahan, dan indeks vigor benih, dan tidak ada pengaruh yang signifikan terhadap berat benih setelah penyimpanan dan benih berkecambah dalam penyimpanan.
11
Guragain, Hari, Jan Cimbalnik, Matt Stead, David M. Groppe, Brent M. Berry, Vaclav Kremen, Daniel Kenney-Jung, Jeffrey Britton, Gregory A. Worrell und Benjamin H. Brinkmann. „Spatial variation in high-frequency oscillation rates and amplitudes in intracranial EEG“. Neurology 90, Nr. 8 (24.01.2018): e639-e646. http://dx.doi.org/10.1212/wnl.0000000000004998.
Der volle Inhalt der QuelleAnnotation:
ObjectiveTo assess the variation in baseline and seizure onset zone interictal high-frequency oscillation (HFO) rates and amplitudes across different anatomic brain regions in a large cohort of patients.MethodsSeventy patients who had wide-bandwidth (5 kHz) intracranial EEG (iEEG) recordings during surgical evaluation for drug-resistant epilepsy between 2005 and 2014 who had high-resolution MRI and CT imaging were identified. Discrete HFOs were identified in 2-hour segments of high-quality interictal iEEG data with an automated detector. Electrode locations were determined by coregistering the patient's preoperative MRI with an X-ray CT scan acquired immediately after electrode implantation and correcting electrode locations for postimplant brain shift. The anatomic locations of electrodes were determined using the Desikan-Killiany brain atlas via FreeSurfer. HFO rates and mean amplitudes were measured in seizure onset zone (SOZ) and non-SOZ electrodes, as determined by the clinical iEEG seizure recordings. To promote reproducible research, imaging and iEEG data are made freely available (msel.mayo.edu).ResultsBaseline (non-SOZ) HFO rates and amplitudes vary significantly in different brain structures, and between homologous structures in left and right hemispheres. While HFO rates and amplitudes were significantly higher in SOZ than non-SOZ electrodes when analyzed regardless of contact location, SOZ and non-SOZ HFO rates and amplitudes were not separable in some lobes and structures (e.g., frontal and temporal neocortex).ConclusionsThe anatomic variation in SOZ and non-SOZ HFO rates and amplitudes suggests the need to assess interictal HFO activity relative to anatomically accurate normative standards when using HFOs for presurgical planning.
12
Moon, Hyeong Cheol, Byeong Ho Oh, Chaejoon Cheong, Won Seop Kim, Kyung Soo Min, Young Gyu Kim und Young Seok Park. „Precentral and cerebellar atrophic changes in moyamoya disease using 7-T magnetic resonance imaging“. Acta Radiologica 61, Nr. 4 (03.08.2019): 487–95. http://dx.doi.org/10.1177/0284185119866808.
Der volle Inhalt der QuelleAnnotation:
Background Chronic repeated transient ischemic changes are one of the common symptoms of moyamoya disease that could affect cortical and subcortical atrophy. Purpose We aimed to assess the cortical gray matter volume and thickness, white matter subcortical volume, and clinical characteristics using 7-T magnetic resonance imaging (MRI) and MR angiography (MRA). Material and Methods In this case-control study, whole-brain parcellation of gray matter and subcortical volumes were manually assessed in nine patients with moyamoya disease (18 hemispheres; median age = 34 years; age range = 10–60 years) and nine healthy controls (18 hemispheres; median age = 29 years; age range = 20–62 years) matched for age and sex, who underwent both 7-T MRI and MRA. The volumes were measured using high-resolution image (<1 mm) processing based on the Desikan-Killiany-Tourville (DKT) atlas, via an automated segmentation method (FreeSurfer version 6.0). Results The gray matter volume of the left precentral cortex and the white matter volume of the subcortical cerebellum were lower in both hemispheres in the patients with moyamoya disease compared to the healthy controls. Conclusion Gray matter atrophy in the precentral cortex and cerebellar white matter were detected in this 7-T MRI volumetric analysis study of patients with moyamoya disease who experienced repeated transient ischemic changes. Cortical atrophy in precentral cortex and cerebellum could explain the transient motor weakness in patients with moyamoya disease, as one of the early findings was that patients with moyamoya disease do not have detectable infarction changes on conventional MRI images.
13
Huang, Chuan, Minos Kritikos, Sean A. P. Clouston, Yael Deri, Mario Serrano-Sosa, Lev Bangiyev, Stephanie Santiago-Michels et al. „White Matter Connectivity in Incident Mild Cognitive Impairment: A Diffusion Spectrum Imaging Study of World Trade Center Responders at Midlife“. Journal of Alzheimer's Disease 80, Nr. 3 (06.04.2021): 1209–19. http://dx.doi.org/10.3233/jad-201237.
Der volle Inhalt der QuelleAnnotation:
Background: Individuals who participated in response efforts at the World Trade Center (WTC) following 9/11/2001 are experiencing elevated incidence of mild cognitive impairment (MCI) at midlife. Objective: We hypothesized that white matter connectivity measured using diffusion spectrum imaging (DSI) would be restructured in WTC responders with MCI versus cognitively unimpaired responders. Methods: Twenty responders (mean age 56; 10 MCI/10 unimpaired) recruited from an epidemiological study were characterized using NIA-AA criteria alongside controls matched on demographics (age/sex/occupation/race/education). Axial DSI was acquired on a 3T Siemen’s Biograph mMR scanner (12-channel head coil) using a multi-band diffusion sequence. Connectometry examined whole-brain tract-level differences in white matter integrity. Fractional anisotropy (FA), mean diffusivity (MD), and quantified anisotropy were extracted for region of interest (ROI) analyses using the Desikan-Killiany atlas. Results: Connectometry identified both increased and decreased connectivity within regions of the brains of responders with MCI identified in the corticothalamic pathway and cortico-striatal pathway that survived adjustment for multiple comparisons. MCI was also associated with higher FA values in five ROIs including in the rostral anterior cingulate; lower MD values in four ROIs including the left rostral anterior cingulate; and higher MD values in the right inferior circular insula. Analyses by cognitive domain revealed nominal associations in domains of response speed, verbal learning, verbal retention, and visuospatial learning. Conclusions: WTC responders with MCI at midlife showed early signs of neurodegeneration characterized by both increased and decreased white matter diffusivity in regions commonly affected by early-onset Alzheimer’s disease.
14
Di Biase, Maria Angelique, Fan Zhang, Amanda Lyall, Marek Kubicki, René C. W. Mandl, Iris E. Sommer und Ofer Pasternak. „Neuroimaging auditory verbal hallucinations in schizophrenia patient and healthy populations“. Psychological Medicine 50, Nr. 3 (14.02.2019): 403–12. http://dx.doi.org/10.1017/s0033291719000205.
Der volle Inhalt der QuelleAnnotation:
AbstractBackgroundAuditory verbal hallucinations (AVH) are a cardinal feature of schizophrenia, but they can also appear in otherwise healthy individuals. Imaging studies implicate language networks in the generation of AVH; however, it remains unclear if alterations reflect biologic substrates of AVH, irrespective of diagnostic status, age, or illness-related factors. We applied multimodal imaging to identify AVH-specific pathology, evidenced by overlapping gray or white matter deficits between schizophrenia patients and healthy voice-hearers.MethodsDiffusion-weighted and T1-weighted magnetic resonance images were acquired in 35 schizophrenia patients with AVH (SCZ-AVH), 32 healthy voice-hearers (H-AVH), and 40 age- and sex-matched controls without AVH. White matter fractional anisotropy (FA) and gray matter thickness (GMT) were computed for each region comprising ICBM-DTI and Desikan–Killiany atlases, respectively. Regions were tested for significant alterations affecting both SCZ-AVH and H-AVH groups, relative to controls.ResultsCompared with controls, the SCZ-AVH showed widespread FA and GMT reductions; but no significant differences emerged between H-AVH and control groups. While no overlapping pathology appeared in the overall study groups, younger (<40 years) H-AVH and SCZ-AVH subjects displayed overlapping FA deficits across four regions (p < 0.05): the genu and splenium of the corpus callosum, as well as the anterior limbs of the internal capsule. Analyzing these regions with free-water imaging ascribed overlapping FA abnormalities to tissue-specific anisotropy changes.ConclusionsWe identified white matter pathology associated with the presence of AVH, independent of diagnostic status. However, commonalities were constrained to younger and more homogenous groups, after reducing pathologic variance associated with advancing age and chronicity effects.
15
Oh, Byeong H., Hyeong C. Moon, Aryun Kim, Hyeon J. Kim, Chae J. Cheong und Young Seok Park. „Prefrontal and hippocampal atrophy using 7-tesla magnetic resonance imaging in patients with Parkinson’s disease“. Acta Radiologica Open 10, Nr. 2 (Februar 2021): 205846012098809. http://dx.doi.org/10.1177/2058460120988097.
Der volle Inhalt der QuelleAnnotation:
Background The pathology of Parkinson’s disease leads to morphological changes in brain structure. Currently, the progressive changes in gray matter volume that occur with time and are specific to patients with Parkinson’s disease, compared to healthy controls, remain unclear. High-tesla magnetic resonance imaging might be useful in differentiating neurological disorders by brain cortical changes. Purpose We aimed to investigate patterns in gray matter changes in patients with Parkinson’s disease by using an automated segmentation method with 7-tesla magnetic resonance imaging. Material and Methods High-resolution T1-weighted 7 tesla magnetic resonance imaging volumes of 24 hemispheres were acquired from 12 Parkinson’s disease patients and 12 age- and sex-matched healthy controls with median ages of 64.5 (range, 41–82) years and 60.5 (range, 25–74) years, respectively. Subgroup analysis was performed according to whether axial motor symptoms were present in the Parkinson’s disease patients. Cortical volume, cortical thickness, and subcortical volume were measured using a high-resolution image processing technique based on the Desikan-Killiany-Tourville atlas and an automated segmentation method (FreeSurfer version 6.0). Results After cortical reconstruction, in 7 tesla magnetic resonance imaging volume segmental analysis, compared with the healthy controls, the Parkinson’s disease patients showed global cortical atrophy, mostly in the prefrontal area (rostral middle frontal, superior frontal, inferior parietal lobule, medial orbitofrontal, rostral anterior cingulate area), and subcortical volume atrophy in limbic/paralimbic areas (fusiform, hippocampus, amygdala). Conclusion We first demonstrated that 7 tesla magnetic resonance imaging detects structural abnormalities in Parkinson’s disease patients compared to healthy controls using an automated segmentation method. Compared with the healthy controls, the Parkinson’s disease patients showed global prefrontal cortical atrophy and hippocampal area atrophy.
16
Dina, Sari Farah, und Harry P. Limbong. „Performa Pengeringan Kontinyu dan Terputus Pada Biji Kakao Fermentasi dengan Metode Pengeringan Lapis Tipis“. Jurnal Riset Teknologi Industri 10, Nr. 1 (31.08.2016): 46–55. http://dx.doi.org/10.26578/jrti.v10i1.1752.
Der volle Inhalt der QuelleAnnotation:
This study aims to determine the performance of a continuous and intermittent sun drying of fermented-cocoa bean by using thin-layer drying method. Continuous drying using a solar dryer finned-flat plate collector type which is operated in two modes drying time, daytime and night time. During the day, the cocoa beans are dried in the drying chamber using hot air generated by the solar collectors. In the nighttime, desiccant (CaCl2) was added to the drying chamber that had been isolated. Open sun drying as intermittent drying of cocoa beans is done only on daytime. The drying process is terminated when equilibrium moisture content has been achieved. The results showed that the continuous drying rate higher than the intermittent drying. Dried-cocoa beans produced from continuous drying showed a lower moisture content (7.34% vs 7.50%), a better physical appearance, but the higher the degree of acidity (pH = 5.93 vs. 6.13). Total fat content and free fatty acids slightly lower than the intermittent sun-drying.ABSTRAKPenelitian ini bertujuan untuk mengetahui performa pengeringan kontinyu dan terputus pada biji kakao fermentasi menggunakan metode pengeringan lapis tipis. Pengeringan kontinyu menggunakan alat pengering surya tipe kolektor pelat datar bersirip yang dioperasikan dalam dua mode pengeringan, waktu siang dan waktu malam. Pada siang hari, biji kakao dikeringkan didalam ruang pengering menggunakan udara panas yang dihasilkan oleh kolektor surya. Pada malam hari desikan (CaCl2) dimasukkan kedalam ruang pengering yang telah diisolasi. Penjemuran langsung biji kakao di matahari sebagai pengeringan terputus dilakukan hanya pada sinag hari. Proses pengeringan dihentikan ketika kondisi keseimbangan kadar air dicapai. Hasil penelitian menunjukkan bahwa pengeringan kontinyu menghasilkan laju pengeringan yang lebih tinggi dibandingkan dengan pengeringan terputus. Biji kakao yang dihasilkan dari pengeringan kontinyu juga menunjukkan kadar air yang lebih rendah (7.34% vs 7.50%), penampilan fisik yang lebih baik, tetapi derajat keasaman lebih tinggi (pH=5,93 vs 6,13). Kadar lemak total dan asam lemak bebas sedikit lebih rendah dibanding penjemuran langsung. Kata kunci : biji kakao fermentasi, pengeringan kontinyu, pengeringan terputus, performa.
17
Ong, Ju Lynn, Azrin Jamaluddin, Ruth Leong, June Lo und Michael Chee. „154 Cortical thickness and sleep slow wave activity mediates age-related improvements in cognition during late adolescence“. Sleep 44, Supplement_2 (01.05.2021): A63. http://dx.doi.org/10.1093/sleep/zsab072.153.
Der volle Inhalt der QuelleAnnotation:
Abstract Introduction Adolescence is a period of rapid brain maturation, and studies have independently documented reductions in cortical thickness, reduced sleep slow wave activity (0.5-4Hz), and improved cognition as a child transitions into adulthood. In the present work, we investigate whether these factors interact in late adolescence. Methods 114 adolescents aged 15-19y (52 males) underwent a structural MRI scan, polysomnography (PSG) and a series of cognitive tests assessing fluid intelligence, sustained attention, speed of processing and working memory. As sleep history has been known to affect EEG measures of slow wave activity, actigraphic recordings ensured that participants received 9h of night the week prior to the PSG session. Cognitive scores were combined to obtain a single measure of global cognition. For assessment of cortical thickness, the Freesurfer (v5.3) pipeline was used to obtain measures for all regions of interest from the Desikan-Killiany cortical atlas. Pearson correlations were conducted to independently confirm associations between aging and reductions in cortical thickness, slow wave activity and improved global cognition, controlling for sex. Finally, a serial mediation model (SPSS PROCESS Model 6) was performed to test the mediating role of cortical thickness and slow wave activity between aging and global cognition. Results Reductions in EEG sleep slow wave activity, cortical thickness and improved global cognition was observed with increasing age, likely representing synaptic pruning and a decrease in waking metabolic activity that contributes to increased overall neural efficiency. Regions in the temporal and parietal areas showed the steepest age-related reductions. In addition, the age-related improvement in cognition was found to be mediated by both cortical thinning as well as reduced SWA activity, particularly in the middle temporal cortex. Conclusion The adolescent brain undergoes rapid growth in preparation for adulthood. Cortical restructuring through pruning of neural circuits during this period is associated with reduced slow wave activity, mediating the age-related improvement in cognition. Future work should investigate whether insults to the brain during this critical period alters this trajectory. Support (if any) This work was supported by grants awarded to Michael Chee (NMRC/STaR/015/2013, NRF2016-SOL002-001 and the Far East Organization).
18
Rahardjo, Pudji. „Pengaruh pemberian abu sekam padi sebagai bahan desikan pada penyimpanan benih terhadap daya tumbuh dan pertumbuhan bibit kakao (The effects of rice husk ash as desiccation material of seed storage on viability and cocoa seedling growth).“ Pelita Perkebunan (a Coffee and Cocoa Research Journal) 28, Nr. 2 (31.08.2012): 90–99. http://dx.doi.org/10.22302/iccri.jur.pelitaperkebunan.v28i2.202.
Der volle Inhalt der QuelleAnnotation:
Rice husk ash as desiccation material can be used to maintain seed viability in storage through its ability to absorb humidity during its storage. High relative humidity caused seed moisture content to increase so the respiration rate of seed increases and uses faster food stock. Finally the viability of seed is lost. A research on use of rice husk ash as desiccation material of cocoa seed storage was conducted in Agronomy Laboratory and Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute. Completely Randomized Design was used in this research with treatment of rice husk ash application on cocoa seed as follows: 0 g/100 seeds (A), 5 g/100 seeds (B), 10 g/100 seeds (C), 15 g/100 seeds (D), and 20 g/100 seeds (E). This experiment used four replications. Cocoa seeds were stored in plastic bag within carton box in ambient temperature. The storage periods were 1, 2, and 3 weeks, and parameters of observation consisted of electrical conductivity of dipped water of cocoa seeds, percentage of seed germination, percentage of seed emergence, early growth parameters at one month old including seedlings height of seedling, diameter, leaf number, root length, and dry weight. The result of the experiment showed that the use of rice husk ash at 5-10 g/100 seeds could maintain electrical conductivity of dipped water at low level, percentage of seed germination at 99-100 % and percentage of seed emergence at 79-91% after two weeks storage. The use of rice husk ash at 5-10 g/100 seeds after two weeks storage affected height of cacao seedling, but did not affected stem diameters, leaf numbers, root lengths, and dry weights
19
Antoniades, Mathilde, Igor Nenadic, Tilo Kircher, Alex Krug, Tina Meller, Dominik Grotegerd, Alex Fornito et al. „M156. CORTICAL NEUROANATOMICAL SIGNATURE OF SCHIZOTYPY IN 2,695 INDIVIDUALS ASSESSED IN A WORLDWIDE ENIGMA STUDY“. Schizophrenia Bulletin 46, Supplement_1 (April 2020): S195. http://dx.doi.org/10.1093/schbul/sbaa030.468.
Der volle Inhalt der QuelleAnnotation:
Abstract Background Cortical neuroanatomical abnormalities have been reported along a continuum between individuals with chronic schizophrenia, first-episode psychosis, clinical high risk for psychosis, and healthy individuals self-reporting subclinical psychotic-like experiences (or schizotypy). Recently, the Schizophrenia Working Group within the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) consortium provided meta-analytic evidence for robust cortical thickness abnormalities in schizophrenia, while also indicating that these abnormalities are influenced by illness severity and treatment with antipsychotic medications. In this context, schizotypy research allows the investigation of cortical neuroanatomy associated with the expression of subclinical psychotic-like symptoms without the potential influence of a psychotic illness, its severity, or the use of antipsychotics. This study presents the first large-scale imaging meta-analysis of cortical thickness in schizotypy using standardized methods from 23 datasets worldwide. Methods Cortical thickness and surface area were assessed in MRI scans of 2,695 healthy individuals (mean [range] age of 29.1 [17–55.8], 46.3% male) who had also completed validated self-report schizotypy questionnaires. Each site processed their local T1-weighted MRI scans using FreeSurfer and, following the protocol outlined in the ENIGMA Schizophrenia Working Group study, extracted cortical thickness for 70 Desikan-Killiany (DK) atlas regions (34 regions per hemisphere + left and right hemisphere mean thickness). At each site, partial correlation analyses were performed between regional cortical thickness by ROI and total schizotypy scores in R, predicting the left, right and mean cortical thickness, adjusting for sex, age and site. Random-effects meta-analyses of partial correlation effect sizes for each of the DK atlas regions were performed using R’s metafor package. False discovery rate (pFDR < .05) was used to control for multiple comparisons. Results We found significant positive associations between subclinical psychotic-like experiences and mean cortical thickness of the medial orbitofrontal cortex (r = .077; pFDR = .006) and the frontal pole (r = .073; pFDR = .006). When assessed separately by hemisphere, meta-analysis revealed a significant positive association between subclinical psychotic-like experiences and cortical thickness of the left medial orbitofrontal cortex (r = .066; pFDR = .044), and at trend-level with the right medial orbitofrontal cortex (r = .062; pFDR = .053) and the left frontal pole (r = .062; pFDR = .053). No significant associations were observed for surface area. Discussion Worldwide cooperative analyses of large-scale brain imaging data support a profile of cortical thickness abnormalities involving prefrontal cortical regions positively related to schizotypy in healthy individuals. These findings are not secondary to potential influences of disease chronicity or antipsychotic medication on the neuroanatomical correlates of psychotic-like experiences. The directionality of the observed meta-analytical effects in schizotypy is opposite to those previously reported in patients with schizophrenia (i.e., thinner cortex). The present findings of increased thickness may indicate early microstructural deficits (e.g. in myelination) that contribute to vulnerability for psychosis. Alternatively, these may reflect mechanisms of resilience associated with the expression of subclinical manifestations of psychotic symptoms in otherwise healthy individuals.
20
Lemvigh, Cecilie, Rachel Brouwer, Louise Baruel Johansen, Rikke Hilker, Christos Pantelis, Birte Glenthoj und Birgitte Fagerlund. „T60. GENETIC INFLUENCES ON MEMORY FUNCTIONS AND RELATED BRAIN STRUCTURES AND ASSOCIATIONS WITH SCHIZOPHRENIA SPECTRUM DISORDERS: A NATION-WIDE TWIN STUDY“. Schizophrenia Bulletin 46, Supplement_1 (April 2020): S254. http://dx.doi.org/10.1093/schbul/sbaa029.620.
Der volle Inhalt der QuelleAnnotation:
Abstract Background Impaired memory is among the most profound cognitive deficits observed in patients with schizophrenia. Evidence from twin studies suggests that memory is mainly influenced by genetics. Moreover, a few twin studies have demonstrated genetic overlap between specific memory functions and schizophrenia. Memory deficits in schizophrenia seem to involve abnormalities in frontal cortical areas and the middle temporal lobe, particularly the hippocampus. In the general population, twin studies have consistently demonstrated genetic influences on brain volumes, however, evidence from twin pairs discordant for schizophrenia suggests that hippocampus volumes may be more susceptible to environmental effects in patients. Methods Twin pairs concordant or discordant for a diagnosis in the schizophrenia spectrum were recruited nation-wide by linking The Danish Twin Register and The Danish Psychiatric Central Research Register. Both monozygotic (MZ) and dizygotic (DZ) proband pairs as well as healthy control (HC) pairs were identified. A total of 216 twins participated in this study consisting of 32 complete MZ and 24 complete DZ proband pairs, 29 complete MZ and 20 complete DZ HC pairs, and six twins from proband pairs were included without their sibling. Verbal memory was assessed using the list learning task from the Brief Assessment of Cognition in Schizophrenia (BACS), visual memory using the Rey Complex Figure Test (RCFT) and associative memory using 15 word pairs. Structural brain scans were acquired with T1-weighted sequence on a Philips 3.0 T Achieva MRI scanner with a 32-channel SENSE head coil. Images were processed using FreeSurfer (version 5.3) and the Desikan-Killiany atlas was used to extract the volumes of bilateral hippocampi, superior frontal, rostral and caudal middle frontal cortices as well as the whole brain volume. Structural equation modelling was applied to examine the genetic and environmental contributions to the variability in memory and brain measures and to quantify associations with schizophrenia spectrum liability. Results Significant heritability estimates were observed for verbal memory (h2=0.53), visual memory (h2=0.58) and associative memory (immediate h2=0.33, delayed h2=0.54), whereas the copy and recognition task from RCFT were only explained by unique environmental factors. Except for verbal memory, all memory measures were significantly associated with schizophrenia spectrum liability, and these were mainly due to overlapping genetic factors. Genetic factors also significantly contributed to whole brain (h2=0.36), right superior frontal (h2=0.48), left rostral middle frontal (h2=0.40) and hippocampus volumes (right h2=0.29, left h2=0.50). Common environmental factors significantly influenced whole brain (c2=0.51), right hippocampus (c2=0.51) and right rostral middle frontal (c2=0.47) volumes. Hippocampus volumes were significantly associated with schizophrenia spectrum liability, and for the left hippocampus this association was due to overlapping genetic factors. Discussion Specific memory measures and related brain areas were heritable, providing further evidence of the importance of genetics in memory functioning. Furthermore, the majority of the applied memory measures and left hippocampal volume were (genetically) associated with schizophrenia spectrum liability, suggesting a partially shared etiology. The heritable memory measures and related brain areas showing associations with disease may represent endophenotypes for schizophrenia spectrum disorders. In future analyses, we plan to examine the covariance between memory, brain volumes and schizophrenia.
21
Henri-Bellemare, Charlie, Raihaan Patel, Katie Lavigne, M. Mallar Chakravarty und Martin Lepage. „M160. INVESTIGATING STRUCTURAL CONNECTIVITY CORRELATES OF VERBAL MEMORY DEFICITS AMONG FIRST-EPISODE PSYCHOSIS PATIENTS“. Schizophrenia Bulletin 46, Supplement_1 (April 2020): S196—S197. http://dx.doi.org/10.1093/schbul/sbaa030.472.
Der volle Inhalt der QuelleAnnotation:
Abstract Background Verbal memory is one of the most affected cognitive domains in patients with schizophrenia and related psychoses. Several studies have found associations between cognitive abilities and white matter fractional anisotropy (FA) in schizophrenia; however, only a few tractography studies have investigated FA relative to verbal memory in patients with a first episode of psychosis (FEP) compared with healthy controls (HC). Although white matter tractography differences have been well established between chronic patients and HC, the direction of findings from FEP studies has been inconsistent. Thus, the present study aims to examine whole-brain white matter differences and its association with verbal memory in individuals with a FEP relative to HC using tractography. Methods Diffusion-weighted images were acquired on a 1.5T scanner for patients (n=65) and controls (n=54) at baseline. The Wechsler Memory Scale was used as a measure of verbal memory. Pre-processing was performed on a subject-by-subject basis using MRtrix. Diffusion tractography was generated using a probabilistic anatomically-constrained tractography algorithm, which constrains the reconstruction to specific biological priors. Furthermore, the spherical-deconvolution informed filtering of tractograms (SIFT) tool will be used to ensure the tractogram is biologically meaningful. This results in subject-specific connectomes defining the mean FA between two regions of interest that were defined using the Desikan- Killiany atlas. A linear model was used to test for main effect of group and main effect of verbal memory on white matter tract FA, covarying for age and sex. For both sets of analyses, results were corrected for multiple comparisons using false discovery rate (FDR). Results A significant main effect of group on whole-brain average FA was observed, with patients displaying lower average FA compared to healthy controls (Patients=0.291, controls=0.300, p<0.05). Whole-brain white matter tract FA analysis revealed that there are widespread differences between controls and individuals with a FEP. Group most strongly predicted white matter tract FA differences between left caudal anterior cingulate and left lateral orbitofrontal (patients mean FA=0.302, controls mean FA=0.342), left hippocampus and right isthmus cingulate (patient mean FA= 0.217 controls mean FA= 0.318), and finally left lingual and left rostral anterior cingulate (patients mean FA=0.162, controls mean FA= 0.249. However, none survived correction for multiple comparisons. Further, there was no significant association between verbal memory and white matter tract FA in FEP or HC. Discussion Findings from this study suggest there are some significant differences in whole-brain average FA between individuals experiencing a FEP and healthy controls. However, when analyzing whole-brain tract FA, none of the connections survived corrections for multiple comparisons. These findings might be limited by the scanner resolution included in this study, which may not capture more subtle differences. Nonetheless, these results are consistent with a cross-sectional study comparing healthy individuals to chronic and first-episode patients suggesting that modest differences are present early in the disease and increase as the disease progresses. We suggest that future studies analyze white matter tract using a longitudinal design to identify disease progression.
22
„Rahul S Desikan“. Lancet Neurology 17, Nr. 9 (September 2018): 745. http://dx.doi.org/10.1016/s1474-4422(18)30291-6.
Der volle Inhalt der Quelle
23
Cihan, Ertuğrul, Barış Kavasoğulları und Hasan Demir. „SIVI DESİKANT NEM ALMA SİSTEMİNİN TASARIMI VE PERFORMANSININ GELİŞTİRİLMESİ“. Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi 32, Nr. 3 (07.09.2017). http://dx.doi.org/10.17341/gazimmfd.337617.
Der volle Inhalt der Quelle
24
Lesilolo, M. K., Jacob Patty und N. Tetty. „Penggunaan Desikan Abu Dan Lama Simpan Terhadap Kualitas Benih Jagung (Zea mays L.) Pada Penyimpanan Ruang Terbuka“. Agrologia 1, Nr. 1 (28.02.2018). http://dx.doi.org/10.30598/a.v1i1.298.
Der volle Inhalt der QuelleAnnotation:
This study was aimed to determine the proper dose of ash desiccant on maize seed stored for 30, 60 and 90 days. The design used was a Completely Randomized Factorial Design, with two factors and three replications. The first factor was desiccant dose (D) : Do = 0 % (control), D1 = 5 % (12.5 g of seed weight), D2 = 10% (25 g of seed weight), D3 = 15 % (37 g of seed weight), D4 = 20 % (50 %g of seed weight), D5 = 25 % (62.5 g of seed weight). The second factor was length of storage (S) : S1 = 30 day storage, S2 = 60 day storage and S3 = 90 day storage. The result show that use of desiccant only gave effect on the water content of seeds (12.31 %) and speed of seed growth vigor parameters (24.84 %). Use of desiccant in 90 day storage were able to maintain water content of seeds (12.43 %), seed germination viability parameter (100 %), and vigor of seeds, which consisted of seed growth simultaneity (66.77 %) and seed growth speed (28.71 %). The interaction between the use off ash desiccant and the length of storage had no effect on viability and vigor of maize (Zea mays L) seeds but had an effect on their water content after storage (12.73%).
25
Alexander, Bonnie, Wai Yen Loh, Lillian G. Matthews, Andrea L. Murray, Chris Adamson, Richard Beare, Jian Chen et al. „Desikan-Killiany-Tourville Atlas Compatible Version of M-CRIB Neonatal Parcellated Whole Brain Atlas: The M-CRIB 2.0“. Frontiers in Neuroscience 13 (05.02.2019). http://dx.doi.org/10.3389/fnins.2019.00034.
Der volle Inhalt der Quelle
26
Bhagwat, Nikhil, Amadou Barry, Erin W. Dickie, Shawn T. Brown, Gabriel A. Devenyi, Koji Hatano, Elizabeth DuPre et al. „Understanding the impact of preprocessing pipelines on neuroimaging cortical surface analyses“. GigaScience 10, Nr. 1 (Januar 2021). http://dx.doi.org/10.1093/gigascience/giaa155.
Der volle Inhalt der QuelleAnnotation:
Abstract Background The choice of preprocessing pipeline introduces variability in neuroimaging analyses that affects the reproducibility of scientific findings. Features derived from structural and functional MRI data are sensitive to the algorithmic or parametric differences of preprocessing tasks, such as image normalization, registration, and segmentation to name a few. Therefore it is critical to understand and potentially mitigate the cumulative biases of pipelines in order to distinguish biological effects from methodological variance. Methods Here we use an open structural MRI dataset (ABIDE), supplemented with the Human Connectome Project, to highlight the impact of pipeline selection on cortical thickness measures. Specifically, we investigate the effect of (i) software tool (e.g., ANTS, CIVET, FreeSurfer), (ii) cortical parcellation (Desikan-Killiany-Tourville, Destrieux, Glasser), and (iii) quality control procedure (manual, automatic). We divide our statistical analyses by (i) method type, i.e., task-free (unsupervised) versus task-driven (supervised); and (ii) inference objective, i.e., neurobiological group differences versus individual prediction. Results Results show that software, parcellation, and quality control significantly affect task-driven neurobiological inference. Additionally, software selection strongly affects neurobiological (i.e. group) and individual task-free analyses, and quality control alters the performance for the individual-centric prediction tasks. Conclusions This comparative performance evaluation partially explains the source of inconsistencies in neuroimaging findings. Furthermore, it underscores the need for more rigorous scientific workflows and accessible informatics resources to replicate and compare preprocessing pipelines to address the compounding problem of reproducibility in the age of large-scale, data-driven computational neuroscience.
27
Boutzoukas, Emanuel M., Andrew O'Shea, Alejandro Albizu, Nicole D. Evangelista, Hanna K. Hausman, Jessica N. Kraft, Emily J. Van Etten et al. „Frontal White Matter Hyperintensities and Executive Functioning Performance in Older Adults“. Frontiers in Aging Neuroscience 13 (28.06.2021). http://dx.doi.org/10.3389/fnagi.2021.672535.
Der volle Inhalt der QuelleAnnotation:
Frontal lobe structures decline faster than most other brain regions in older adults. Age-related change in the frontal lobe is associated with poorer executive function (e.g., working memory, switching/set-shifting, and inhibitory control). The effects and presence of frontal lobe white matter hyperintensities (WMH) on executive function in normal aging is relatively unknown. The current study assessed relationships between region-specific frontal WMH load and cognitive performance in healthy older adults using three executive function tasks from the NIH Toolbox (NIHTB) Cognition Battery. A cohort of 279 healthy older adults ages 65–88 completed NIHTB and 3T T1-weighted and FLAIR MRI. Lesion Segmentation Toolbox quantified WMH volume and generated lesion probability maps. Individual lesion maps were registered to the Desikan-Killiany atlas in FreeSurfer 6.0 to define regions of interest (ROI). Independent linear regressions assessed relationships between executive function performance and region-specific WMH in frontal lobe ROIs. All models included age, sex, education, estimated total intracranial volume, multi-site scanner differences, and cardiovascular disease risk using Framingham criteria as covariates. Poorer set-shifting performance was associated with greater WMH load in three frontal ROIs including bilateral superior frontal (left β = −0.18, FDR-p = 0.02; right β = −0.20, FDR-p = 0.01) and right medial orbitofrontal (β = −0.17, FDR-p = 0.02). Poorer inhibitory performance associated with higher WMH load in one frontal ROI, the right superior frontal (right β = −0.21, FDR-p = 0.01). There were no significant associations between working memory and WMH in frontal ROIs. Our study demonstrates that location and pattern of frontal WMH may be important to assess when examining age-related differences in cognitive functions involving switching/set-shifting and inhibition. On the other hand, working memory performance was not related to presence of frontal WMH in this sample. These data suggest that WMH may contribute selectively to age-related declines in executive function. Findings emerged beyond predictors known to be associated with WMH presence, including age and cardiovascular disease risk. The spread of WMH within the frontal lobes may play a key role in the neuropsychological profile of cognitive aging. Further research should explore whether early intervention on modifiable vascular factors or cognitive interventions targeted for executive abilities may help mitigate the effect of frontal WMH on executive function.
28
Hirosawa, Tetsu, Kyung-min An, Daiki Soma, Yuka Shiota, Masuhiko Sano, Masafumi Kameya, Shoryoku Hino et al. „Epileptiform discharges relate to altered functional brain networks in autism spectrum disorders“. Brain Communications 3, Nr. 3 (2021). http://dx.doi.org/10.1093/braincomms/fcab184.
Der volle Inhalt der QuelleAnnotation:
Abstract Many individuals with autism spectrum disorders have comorbid epilepsy. Even in the absence of observable seizures, interictal epileptiform discharges are common in individuals with autism spectrum disorders. However, how these interictal epileptiform discharges are related to autistic symptomatology remains unclear. This study used magnetoencephalography to investigate the relation between interictal epileptiform discharges and altered functional brain networks in children with autism spectrum disorders. Instead of particularly addressing individual brain regions, we specifically examine network properties. For this case-control study, we analysed 70 children with autism spectrum disorders (52 boys, 18 girls, 38–92 months old) and 19 typically developing children (16 boys, 3 girls, 48–88 months old). After assessing the participants’ social reciprocity using the Social Responsiveness Scale, we constructed graphs of functional brain networks from frequency band separated task-free magnetoencephalography recordings. Nodes corresponded to Desikan–Killiany atlas-based 68 brain regions. Edges corresponded to phase lag index values between pairs of brain regions. To elucidate the effects of the existence of interictal epileptiform discharges on graph metrics, we matched each of three pairs from three groups (typically developing children, children with autism spectrum disorders who had interictal epileptiform discharges and those who did not) in terms of age and sex. We used a coarsened exact matching algorithm and applied adjusted regression analysis. We also investigated the relation between social reciprocity and the graph metric. Results show that, in children with autism spectrum disorders, the average clustering coefficient in the theta band was significantly higher in children who had interictal epileptiform discharges. Moreover, children with autism spectrum disorders who had no interictal epileptiform discharges had a significantly lower average clustering coefficient in the theta band than typically developing children had. However, the difference between typically developing children and children with autism spectrum disorder who had interictal epileptiform discharges was not significant. Furthermore, the higher average clustering coefficient in the theta band corresponded to severe autistic symptoms in children with autism spectrum disorder who had interictal epileptiform discharges. However, the association was not significant in children with autism spectrum disorders who had no interictal epileptiform discharge. In conclusion, results demonstrate that alteration of functional brain networks in children with autism spectrum disorders depends on the existence of interictal epileptiform discharges. Interictal epileptiform discharges might ‘normalize’ the deviation of altered brain networks in autism spectrum disorders, increasing the clustering coefficient. However, when the effect exceeds tolerance, it actually exacerbates autistic symptoms.