Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
Add more filters










Database
Language
Publication year range
1.
J Med Imaging (Bellingham) ; 11(4): 044001, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38988990

ABSTRACT

Purpose: Our study investigates the potential benefits of incorporating prior anatomical knowledge into a deep learning (DL) method designed for the automated segmentation of lung lobes in chest CT scans. Approach: We introduce an automated DL-based approach that leverages anatomical information from the lung's vascular system to guide and enhance the segmentation process. This involves utilizing a lung vessel connectivity (LVC) map, which encodes relevant lung vessel anatomical data. Our study explores the performance of three different neural network architectures within the nnU-Net framework: a standalone U-Net, a multitasking U-Net, and a cascade U-Net. Results: Experimental findings suggest that the inclusion of LVC information in the DL model can lead to improved segmentation accuracy, particularly, in the challenging boundary regions of expiration chest CT volumes. Furthermore, our study demonstrates the potential for LVC to enhance the model's generalization capabilities. Finally, the method's robustness is evaluated through the segmentation of lung lobes in 10 cases of COVID-19, demonstrating its applicability in the presence of pulmonary diseases. Conclusions: Incorporating prior anatomical information, such as LVC, into the DL model shows promise for enhancing segmentation performance, particularly in the boundary regions. However, the extent of this improvement has limitations, prompting further exploration of its practical applicability.

2.
Ann Clin Transl Neurol ; 11(5): 1280-1289, 2024 May.
Article in English | MEDLINE | ID: mdl-38647181

ABSTRACT

OBJECTIVE: Magnetic resonance imaging can detect neurodegenerative iron accumulation in the motor cortex, called the motor band sign. This study aims to evaluate its sensitivity/specificity and correlations to symptomatology, biomarkers, and clinical outcome in amyotrophic lateral sclerosis. METHODS: This prospective study consecutively enrolled 114 persons with amyotrophic lateral sclerosis and 79 mimics referred to Karolinska University Hospital, and also 31 healthy controls. All underwent 3-Tesla brain susceptibility-weighted imaging. Three raters independently assessed motor cortex susceptibility with total and regional motor band scores. Survival was evaluated at a median of 34.2 months after the imaging. RESULTS: The motor band sign identified amyotrophic lateral sclerosis with a sensitivity of 59.6% and a specificity of 91.1% versus mimics and 96.8% versus controls. Higher motor band scores were more common with genetic risk factors (p = 0.032), especially with C9orf72 mutation, and were associated with higher neurofilament light levels (std. ß 0.22, p = 0.019). Regional scores correlated strongly with focal symptoms (medial region vs. gross motor dysfunction, std. ß -0.64, p = 0.001; intermediate region vs. fine motor dysfunction, std. ß -0.51, p = 0.031; lateral region vs. bulbar symptoms std. ß -0.71, p < 0.001). There were no associations with cognition, progression rate, or survival. INTERPRETATION: In a real-life clinical setting, the motor band sign has high specificity but relatively low sensitivity for identifying amyotrophic lateral sclerosis. Associations with genetic risk factors, neurofilament levels and somatotopic correspondence to focal motor weakness suggest that the motor band sign could be a suitable biomarker for diagnostics and clinical trials in amyotrophic lateral sclerosis.


Subject(s)
Amyotrophic Lateral Sclerosis , Magnetic Resonance Imaging , Motor Cortex , Humans , Amyotrophic Lateral Sclerosis/physiopathology , Amyotrophic Lateral Sclerosis/diagnosis , Amyotrophic Lateral Sclerosis/genetics , Male , Female , Middle Aged , Aged , Motor Cortex/diagnostic imaging , Motor Cortex/physiopathology , Prospective Studies , Adult , Sensitivity and Specificity , C9orf72 Protein/genetics
3.
J Exp Bot ; 69(10): 2483-2493, 2018 04 27.
Article in English | MEDLINE | ID: mdl-29529250

ABSTRACT

Stem rust, caused by Puccinia graminis (Pg), remains a devastating disease of wheat, and the emergence of new Pg races virulent on deployed resistance genes fuels the ongoing search for sources of durable resistance. Despite its intrinsic durability, non-host resistance (NHR) is largely unexplored as a protection strategy against Pg, partly due to the inherent challenge of developing a genetically tractable system within which NHR segregates. Here, we demonstrate that Pg's far less studied ancestral host, barberry (Berberis spp.), provides such a unique pathosystem. Characterization of a natural population of B. ×ottawensis, an interspecific hybrid of Pg-susceptible B. vulgaris and Pg-resistant B. thunbergii (Bt), reveals that this uncommon nothospecies can be used to dissect the genetic mechanism(s) of Pg-NHR exhibited by Bt. Artificial inoculation of a natural population of B. ×ottawensis accessions, verified via genotyping by sequencing to be first-generation hybrids, revealed 51% susceptible, 33% resistant, and 16% intermediate phenotypes. Characterization of a B. ×ottawensis full sib family excluded the possibility of maternal inheritance of the resistance. By demonstrating segregation of Pg-NHR in a hybrid population, this study challenges the assumed irrelevance of Bt to Pg epidemiology and lays a novel foundation for the genetic dissection of NHR to one of agriculture's most studied pathogens.


Subject(s)
Basidiomycota/physiology , Berberis/genetics , Disease Resistance , Hybridization, Genetic , Plant Diseases/microbiology , Berberis/microbiology
4.
Am J Bot ; 102(10): 1599-609, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26451038

ABSTRACT

PREMISE OF THE STUDY: Climate change has resulted in major changes in the phenology of some species but not others. Long-term field observational records provide the best assessment of these changes, but geographic and taxonomic biases limit their utility. Plant specimens in herbaria have been hypothesized to provide a wealth of additional data for studying phenological responses to climatic change. However, no study to our knowledge has comprehensively addressed whether herbarium data are accurate measures of phenological response and thus applicable to addressing such questions. METHODS: We compared flowering phenology determined from field observations (years 1852-1858, 1875, 1878-1908, 2003-2006, 2011-2013) and herbarium records (1852-2013) of 20 species from New England, United States. KEY RESULTS: Earliest flowering date estimated from herbarium records faithfully reflected field observations of first flowering date and substantially increased the sampling range across climatic conditions. Additionally, although most species demonstrated a response to interannual temperature variation, long-term temporal changes in phenological response were not detectable. CONCLUSIONS: Our findings support the use of herbarium records for understanding plant phenological responses to changes in temperature, and also importantly establish a new use of herbarium collections: inferring primary phenological cueing mechanisms of individual species (e.g., temperature, winter chilling, photoperiod). These latter data are lacking from most investigations of phenological change, but are vital for understanding differential responses of individual species to ongoing climate change.


Subject(s)
Climate Change , Flowers/growth & development , Plant Development , Massachusetts , Seasons , Species Specificity , Temperature , Time Factors
5.
Appl Plant Sci ; 3(2)2015 Feb.
Article in English | MEDLINE | ID: mdl-25699222

ABSTRACT

UNLABELLED: • PREMISE OF THE STUDY: Microsatellite primers were developed in the beach plum, Prunus maritima, to investigate the genetic composition of remaining populations in need of conservation and, in future studies, to determine its relation to P. maritima var. gravesii. • METHODS AND RESULTS: Fourteen primer pairs were identified and tested in four populations throughout the species' geographic range. Of these 14 loci, 12 were shown to be polymorphic among a total of 60 P. maritima individuals sampled (15 individuals sampled from four populations). Among the polymorphic loci, the number of alleles ranged from two to 10 and observed heterozygosity of loci ranged from 0.07 to 0.93 among specimens tested. • CONCLUSIONS: These microsatellites will be useful in evaluating the population genetic composition of P. maritima and in developing approaches for further conservation and management of this species within the endangered coastal dune ecosystem of the northeastern United States.

6.
J Agric Food Chem ; 61(36): 8581-8, 2013 Sep 11.
Article in English | MEDLINE | ID: mdl-23941506

ABSTRACT

Polyphenols from underutilized black, purple, and red aronia (Aronia melanocarpa, Aronia prunifolia, and Aronia arbutifolia) and 'Viking' (Aronia mitschurinii) berries were characterized. Anthocyanin and nonanthocyanin flavonoids were quantitated by UHPLC-DAD-MS and proanthocyanidins by normal-phase HPLC. On a dry weight basis, anthocyanins were mainly cyanidin-3-galactoside, highest in black aronia (3.4-14.8 mg/g) and lowest in red aronia (0.5-0.8 mg/g) as cyandin-3-galactoside equivalents. Berries from 'Viking' and the red accession UC021 had substantially more proanthocyanidins than the other accessions, with 3.3 and 3.8 mg catechin equiv/g, respectively. Chlorogenic acids and quercetin glycosides were most abundant in purple UC047 berries, at 17.3 and 1.3 mg/g, respectively. In contrast to anthocyanin content, total phenol values were highest in berries from red and purple accessions and attributed to phenolic acid and proanthocyanin content. Thus, red, purple, and black aronia berries are rich sources of polyphenols with various levels of polyphenol classes.


Subject(s)
Anthocyanins/analysis , Coumaric Acids/analysis , Flavonoids/analysis , Fruit/chemistry , Photinia/chemistry , Proanthocyanidins/analysis , Chromatography, High Pressure Liquid/methods , Mass Spectrometry/methods
SELECTION OF CITATIONS
SEARCH DETAIL
...