2,392 research outputs found
Drought-related root morphological traits and non-structural carbohydrates in the seedlings of the alien Quercus rubra and the native Quercus robur: possible implication for invasiveness
Quercus rubra L. is a moderately shade-tolerant tree species native to eastern North America, readily regenerating since its introduction in the Central and Southern European forests to displace the native pedunculate oak (Quercus
robur). Under a scenario of increasing drought, understanding the seedling responses of these two species to water limitation is critical for forest conservation and management. To this aim, morphological, physiological and non-structural carbohydrates analyzes were performed on very-fine and fine roots of Q. robur and Q. rubra seedlings grown under controlled conditions and exposed to two levels of drought before allowing them to recover. Results show significant differences between species for all the investigated traits. The alien Q. rubra showed lower shoot and root biomasses than the native Q. robur, particularly for the thicker fine root 1–2 mm diameter class. However, both species equally invested more biomass in the shoot than the root system (R:S ratio <1). A significant response to drought was observed for the 0.5–1 mm fine root class, with moderate and severe droughted seedlings showing slightly higher biomass than control, particularly in Q. rubra. The overall growth reduction of Q. rubra suggests that the costs associated with the construction and maintenance outweigh the inputs from aboveground, as supported by the lower values of photochemical efficiency (Fv/Fm), quantum yield (ΦPSII) of PSII and stomatal conductance. In particular, the reduced stomatal conductance assured high midday leaf water potential (i.e., tissue hydration levels) at the expense of growth. The low starch concentration in Q. rubra’s very-fine roots correlated positively with the low photochemical efficiency under drought conditions, probably due to the reduction of photosynthate inputs from aboveground. In contrast to the anisohydric behavior reported, these outcomes highlight a rather isohydric behavior for Q. rubra, at least at the seedling stage and in the adopted experimental conditions, making this species highly competitive under the drier condition in the canopy openings during the summer period
C/EBPδ regulates cell cycle and self-renewal of human limbal stem cells
Human limbal stem cells produce transit amplifying progenitors that migrate centripetally to regenerate the corneal epithelium. Coexpression of CCAAT enhancer binding protein δ (C/EBPδ), Bmi1, and ΔNp63α identifies mitotically quiescent limbal stem cells, which generate holoclones in culture. Upon corneal injury, a fraction of these cells switches off C/EBPδ and Bmi1, proliferates, and differentiates into mature corneal cells. Forced expression of C/EBPδ inhibits the growth of limbal colonies and increases the cell cycle length of primary limbal cells through the activity of p27Kip1 and p57Kip2. These effects are reversible; do not alter the limbal cell proliferative capacity; and are not due to apoptosis, senescence, or differentiation. C/EBPδ, but not ΔNp63α, indefinitely promotes holoclone self-renewal and prevents clonal evolution, suggesting that self-renewal and proliferation are distinct, albeit related, processes in limbal stem cells. C/EBPδ is recruited to the chromatin of positively (p27Kip1 and p57Kip2) and negatively (p16INK4A and involucrin) regulated gene loci, suggesting a direct role of this transcription factor in determining limbal stem cell identity
Foix-Chavany-Marie syndrome in a 17-year-old female with congenital cytomegalovirus infection.
Foix-Chavany-Marie syndrome is characterized by bilateral facio-glosso-pharyngo-masticatory paralysis of voluntary movement due to bilateral anterior opercular lesions. We describe the case of a 17-year-old female affected by Foix-Chavany-Marie syndrome and congenital cytomegalovirus infection, evaluating the possible etiopathogenetic correlation between cerebral cortical dysplasia and intrauterine infections
Design, implementation and evaluation of a spiral module combining data science, digital health and evidence-based medicine in the undergraduate medical curriculum: A mixed methods study
Background:
Digital health, data science and health informatics are increasingly important in health and healthcare, but largely ignored in undergraduate medical training.//
Methods:
In a large UK medical school, with staff and students, we co-designed a new, ‘spiral’ module (with iterative revisiting of content), covering data science, digital health and evidence-based medicine, implementing in September 2019 in all year groups with continuous evaluation and improvement until 2022.//
Results:
In 2018/19, a new module, ‘Doctor as Data Scientist’, was co-designed by academic staff (n = 14), students (n = 23), and doctors (n = 7). The module involves 22 staff, 120 h (43 sessions: 22 lectures, 15 group and six other) over a 5-year curriculum. Since September 2019, 5,200 students have been taught with good attendance. Module student satisfaction ratings were 92%, 84%, 84% and 81% in 2019, 2020, 2021 and 2022 respectively, compared to the overall course (81%).//
Conclusions:
We designed, implemented and evaluated a new undergraduate medical curriculum that combined data science and digital health with high student satisfaction ratings
Aiding the conservation of two wooden Buddhist sculptures with 3D imaging and spectroscopic techniques
The conservation of Buddhist sculptures that were transferred to Europe at some point during their lifetime raises numerous questions: while these objects historically served a religious, devotional purpose, many of them currently belong to museums or private collections, where they are detached from their original context and often adapted to western taste.
A scientific study was carried out to address questions from Museo d'Arte Orientale of Turin curators in terms of whether these artifacts might be forgeries or replicas, and how they may have transformed over time. Several analytical techniques were used for materials identification and to study the production technique, ultimately aiming to discriminate the original materials from those added within later interventions
Pengaruh Kuat Arus Dan Waktu Pengelasan Pada Proses Las Titik (Spot Welding) Terhadap Kekuatan Tarik Dan Mikrostuktur Hasil Las Dari Baja Fasa Ganda (Feritte-Martensite)
This research was conducted to investigate the appropiate spot welding variable to get the maximum tensile strength. The highest of tensile strength referred as good quality of weldment.The plate was made from low carbon steel with phase ferrite and martensite. The current of welding used 0.9 kA, 1.6 kA, dan 1.85 kA with welding time were 0.25, 0.5 , 0.75 and 1 second. Mechanical properties testing done involved tensile strength to know shear strength of weld joint. Microstructure test used optical microscope.The results show that spot welding with thecurrent of 1.85kA and welding time of 1 second has the highest tensile strength (about 237.04N/mm2). On the other hand, the lowest tensile strength (150 N/mm2) was produced by combination of 0.9 kA and 0.25 second welding time. It was caused by recrystallization phasedeformation on steel
Clinical care pathway program versus open-access system: a study on appropriateness, quality, and efficiency in the delivery of colonoscopy in the colorectal cancer
Open-access colonoscopy (OAC), whereby the colonoscopy is performed without a prior office visit with a gastroenterologist, is affected by inappropriateness which leads to overprescription and reduced availability of the procedure in case of alarming symptoms. The clinical care pathway (CCP) is a healthcare management tool promoted by national health systems to organize work-up of various morbidities. Recently, we started a CCP dedicated to colorectal cancer (CRC), including a colonoscopy session for CRC diagnosis and prevention. We aimed to evaluate the appropriateness, the quality, and the efficiency in the delivery of colonoscopy with the open-access system and a CCP program in the CRC. Quality indicators for colonoscopy in subjects in the CCP were compared to referrals by general practitioners (OAC) or by non-gastroenterologist physicians (non-gastroenterologist physician colonoscopy, NGPC). Attendance rate to colonoscopy was greater in the CCP group and NGPC group than in the OAC group (99%, 99%, and 86%, respectively). Waiting time in the CCP group was shorter than in the OAC group (3.88 ± 2.27 vs. 32 ± 22.31 weeks, respectively). Appropriateness of colonoscopy prescription was better in the CCP group than in the OAC group (92 vs. 50%, respectively). OAC is affected by the lack of timeliness and low appropriateness of prescription. A CCP reduces the number of inappropriate colonoscopies, especially for post-polypectomy surveillance, and improves the delivery of colonoscopy in patients requiring a fast-track examination. The high rate of inappropriate OAC suggests that this modality of healthcare should be widely reviewed
Corticomotor Plasticity Predicts Clinical Efficacy of Combined Neuromodulation and Cognitive Training in Alzheimer’s Disease
Objective: To investigate the efficacy of repetitive transcranial magnetic stimulation (rTMS) combined with cognitive training for treatment of cognitive symptoms in patients with Alzheimer’s disease (AD). A secondary objective was to analyze associations between brain plasticity and cognitive effects of treatment. Methods: In this randomized, sham-controlled, multicenter clinical trial, 34 patients with AD were assigned to three experimental groups receiving 30 daily sessions of combinatory intervention. Participants in the real/real group (n = 16) received 10 Hz repetitive transcranial magnetic stimulation (rTMS) delivered separately to each of six cortical regions, interleaved with computerized cognitive training. Participants in the sham rTMS group (n = 18) received sham rTMS combined with either real (sham/real group, n = 10) or sham (sham/sham group, n = 8) cognitive training. Effects of treatment on neuropsychological (primary outcome) and neurophysiological function were compared between the 3 treatment groups. These, as well as imaging measures of brain atrophy, were compared at baseline to 14 healthy controls (HC). Results: At baseline, patients with AD had worse cognition, cerebral atrophy, and TMS measures of cortico-motor reactivity, excitability, and plasticity than HC. The real/real group showed significant cognitive improvement compared to the sham/sham, but not the real/sham group. TMS-induced plasticity at baseline was predictive of post-intervention changes in cognition, and was modified across treatment, in association with changes of cognition. Interpretation: Combined rTMS and cognitive training may improve the cognitive status of AD patients, with TMS-induced cortical plasticity at baseline serving as predictor of therapeutic outcome for this intervention, and potential mechanism of action. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01504958.publishersversionpublishe
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Reply to: New Meta- and Mega-analyses of Magnetic Resonance Imaging Findings in Schizophrenia: Do They Really Increase Our Knowledge About the Nature of the Disease Process?
This work was supported by National Institute of Biomedical Imaging and Bioengineering Grant No. U54EB020403 (to the ENIGMA consortium)
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