Ninety hectares in a treed fen in north central Alberta were drained to improve growth of stagnant black spruce (Picea mariana (Mill.) B.S.P.) and tamarack (Larix laricina (Du Roi) K. Koch) stands. ...Installation of 30-, 40-, 50-, and 60-m ditch spacings resulted in a lowering of the average water table by 79, 66, 56, and 73 cm, respectively. The results and the groundwater level criteria used (drainage norm, 40 cm; flood duration limit, 14 days) indicated that the 50-m ditch spacing was hydrologically the most appropriate one for this area. Given the relatively high hydraulic conductivity of the area, it is believed the 30-m spacing was too narrow and resulted in an excessively low average water table. The 60-m spacing was also overeffective, but in this case, overeffectiveness was attributed more to "edge effects" i.e., to site factors such as the proximity to uplands and the small size of upstream source areas, than to the distance between ditches. The results illustrate the importance, for ditch network design purposes, of taking into account hydrologic conditions both within and well beyond the boundaries of an area proposed to be drained. Peat subsidence after drainage appeared to be related to the average drop in water table level and amounted to about 5 cm.a-1.
The adult brain exhibits a local increase in cortical blood flow in response to external stimulus. However, broadly varying hemodynamic responses in the brains of newborn and young infants have been ...reported. Particular controversy exists over whether the "true" neonatal response to stimulation consists of a decrease or an increase in local deoxyhemoglobin, corresponding to a positive (adult-like) or negative blood oxygen level-dependent (BOLD) signal in functional magnetic resonance imaging (fMRI), respectively. A major difficulty with previous studies has been the variability in human subjects and measurement paradigms. Here, we present a systematic study in neonatal rats that charts the evolution of the cortical blood flow response during postnatal development using exposed-cortex multispectral optical imaging. We demonstrate that postnatal-day-12-13 rats (equivalent to human newborns) exhibit an "inverted" hemodynamic response (increasing deoxyhemoglobin, negative BOLD) with early signs of oxygen consumption followed by delayed, active constriction of pial arteries. We observed that the hemodynamic response then matures via development of an initial hyperemic (positive BOLD) phase that eventually masks oxygen consumption and balances vasoconstriction toward adulthood. We also observed that neonatal responses are particularly susceptible to stimulus-evoked systemic blood pressure increases, leading to cortical hyperemia that resembles adult positive BOLD responses. We propose that this confound may account for much of the variability in prior studies of neonatal cortical hemodynamics. Our results suggest that functional magnetic resonance imaging studies of infant and child development may be profoundly influenced by the maturing neurovascular and autoregulatory systems of the neonatal brain.
We purified, cloned, and expressed aggrecanase, a protease that is thought to be responsible for the degradation of cartilage aggrecan in arthritic diseases. Aggrecanase-1 a disintegrin and ...metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) is a member of the ADAMTS protein family that cleaves aggrecan at the glutamic acid-373-alanine-374 bond. The identification of this protease provides a specific target for the development of therapeutics to prevent cartilage degradation in arthritis.
Background
The functional modulation of blood flow in the brain is critical for brain health and is the basis of contrast in functional magnetic resonance imaging. There is evident coupling between ...increases in neuronal activity and increases in local blood flow; however, many aspects of this neurovascular coupling remain unexplained by current models. Based on the rapid dilation of distant pial arteries during cortical functional hyperemia, we hypothesized that endothelial signaling may play a key role in the long‐range propagation of vasodilation during functional hyperemia in the brain. Although well characterized in the peripheral vasculature, endothelial involvement in functional neurovascular coupling has not been demonstrated.
Methods and Results
We combined in vivo exposed‐cortex multispectral optical intrinsic signal imaging (MS‐OISI) with a novel in vivo implementation of the light‐dye technique to record the cortical hemodynamic response to somatosensory stimulus in rats before and after spatially selective endothelial disruption. We demonstrate that discrete interruption of endothelial signaling halts propagation of stimulus‐evoked vasodilation in pial arteries, and that wide‐field endothelial disruption in pial arteries significantly attenuates the hemodynamic response to stimulus, particularly the early, rapid increase and peak in hyperemia.
Conclusions
Involvement of endothelial pathways in functional neurovascular coupling provides new explanations for the spatial and temporal features of the hemodynamic response to stimulus and could explain previous results that were interpreted as evidence for astrocyte‐mediated control of functional hyperemia. Our results unify many aspects of blood flow regulation in the brain and body and prompt new investigation of direct links between systemic cardiovascular disease and neural deficits.
Rationale To elucidate role of fungal pathogens in the etiology of nasal polyposis, we have examined the relationship between the presence and level of Alternaria-specific IgE antibodies, ...eosinophilic inflammation and the development of nasal polyps (NP).
The aim of this study was to recommend protocols for instrumental assessment of voice production in the areas of laryngeal endoscopic imaging, acoustic analyses, and aerodynamic procedures, which ...will (a) improve the evidence for voice assessment measures, (b) enable valid comparisons of assessment results within and across clients and facilities, and (c) facilitate the evaluation of treatment efficacy.
Existing evidence was combined with expert consensus in areas with a lack of evidence. In addition, a survey of clinicians and a peer review of an initial version of the protocol via VoiceServe and the American Speech-Language-Hearing Association's Special Interest Group 3 (Voice and Voice Disorders) Community were used to create the recommendations for the final protocols.
The protocols include recommendations regarding technical specifications for data acquisition, voice and speech tasks, analysis methods, and reporting of results for instrumental evaluation of voice production in the areas of laryngeal endoscopic imaging, acoustics, and aerodynamics.
The recommended protocols for instrumental assessment of voice using laryngeal endoscopic imaging, acoustic, and aerodynamic methods will enable clinicians and researchers to collect a uniform set of valid and reliable measures that can be compared across assessments, clients, and facilities.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
We explored whether breast cancer outcomes are associated with endoxifen and other metabolites of tamoxifen and examined potential correlates of endoxifen concentration levels in serum including ...cytochrome P450 2D6 (CYP2D6) metabolizer phenotype and body mass index (BMI). Concentration levels of tamoxifen, endoxifen, 4‐hydroxytamoxifen (4OH‐tamoxifen), and N‐desmethyltamoxifen (ND‐tamoxifen) were measured from samples taken from 1,370 patients with estrogen receptor (ER)‐positive breast cancer who were participating in the Women's Healthy Eating and Living (WHEL) Study. We tested these concentration levels for possible associations with breast cancer outcomes and found that breast cancer outcomes were not associated with the concentration levels of tamoxifen, 4‐hydroxytamoxifen, and ND‐tamoxifen. For endoxifen, a threshold was identified, with women in the upper four quintiles of endoxifen concentration appearing to have a 26% lower recurrence rate than women in the bottom quintile (hazard ratio (HR) = 0.74; 95% confidence interval (CI), (0.55–1.00)). The predictors of this higher‐risk bottom quintile were poor/intermediate metabolizer genotype, higher BMI, and lower tamoxifen concentrations as compared with the mean for the cohort as a whole. This study suggests that there is a minimal concentration threshold above which endoxifen is effective against the recurrence of breast cancer and that ~80% of tamoxifen takers attain this threshold.
Clinical Pharmacology & Therapeutics (2011) 89 5, 718–725. doi:10.1038/clpt.2011.32
Initial Results From the Super‐Parameterized E3SM Hannah, W. M.; Jones, C. R.; Hillman, B. R. ...
Journal of advances in modeling earth systems,
January 2020, Letnik:
12, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Results from the new Department of Energy super‐parameterized (SP) Energy Exascale Earth System Model (SP‐E3SM) are analyzed and compared to the traditionally parameterized E3SMv1 and previous ...studies using SP models. SP‐E3SM is unique in that it utilizes Graphics Processing Unit hardware acceleration, cloud resolving model mean‐state acceleration, and reduced radiation to dramatically increase the model throughput and allow decadal experiments at 100‐km external resolution. It also differs from other SP models by using a spectral element dynamical core on a cubed‐sphere grid and a finer vertical grid with a higher model top. Despite these differences, SP‐E3SM generally reproduces the behavior of other SP models. Tropical wave variability is improved relative to E3SM, including the emergence of a Madden‐Julian Oscillation and a realistic slowdown of Moist Kelvin Waves. However, the distribution of precipitation exhibits indicates an overly frequent occurrence of rain rates less than 1 mm day
−1, and while the timing of diurnal rainfall shows modest improvements the signal is not as coherent as observations. A notable grid imprinting bias is identified in the precipitation field and attributed to a unique feedback associated with the interactions between the explicit cloud resolving model convection and the spectral element grid structure. Spurious zonal mean column water tendencies due to grid imprinting are quantified—while negligible for the conventionally parameterized E3SM, they become large with super‐parameterization, approaching 10% of the physical tendencies. The implication is that finding a remedy to grid imprinting will become especially important as spectral element dynamical cores begin to be combined with explicitly resolved convection.
Key Points
SP‐E3SM improves tropical variability like previous super‐parameterized models but shows modest improvements in the diurnal precipitation
The spectral element grid leads to an imprinting bias when used with super‐parameterization and has nonnegligible effects on the climate
The throughput of SP‐E3SM was increased to roughly 1.2–1.4 simulated years per day through hardware (GPU) and algorithmic acceleration
Hypoglossal nerve stimulation (HNS) decreases obstructive sleep apnoea (OSA) severity
genioglossus muscle activation and decreased upper airway collapsibility. This study assessed the safety and ...effectiveness at 6 months post-implantation of a novel device delivering bilateral HNS
a small implanted electrode activated by a unit worn externally, to treat OSA: the Genio™ system.
This prospective, open-label, non-randomised, single-arm treatment study was conducted at eight centres in three countries (Australia, France and the UK). Primary outcomes were incidence of device-related serious adverse events and change in the apnoea-hypopnoea index (AHI). The secondary outcome was the change in the 4% oxygen desaturation index (ODI). Additional outcomes included measures of sleepiness, quality of life, snoring and device use. This trial was registered with ClinicalTrials.gov, number NCT03048604.
22 out of 27 implanted participants (63% male, aged 55.9±12.0 years, body mass index (BMI) 27.4±3.0 kg·m
) completed the protocol. At 6 months BMI was unchanged (p=0.85); AHI decreased from 23.7±12.2 to 12.9±10.1 events·h
, a mean change of 10.8 events·h
(p<0.001); and ODI decreased from 19.1±11.2 to 9.8±6.9 events·h
, a mean change of 9.3 events·h
(p<0.001). Daytime sleepiness (Epworth Sleepiness Scale; p=0.01) and sleep-related quality of life (Functional Outcomes of Sleep Questionnaire-10; p=0.02) both improved significantly. The number of bed partners reporting loud, very intense snoring, or leaving the bedroom due to participant snoring decreased from 96% to 35%. 91% of participants reported device use >5 days per week, and 77% reported use for >5 h per night. No device-related serious adverse events occurred during the 6-month post-implantation period.
Bilateral HNS using the Genio™ system reduces OSA severity and improves quality of life without device-related complications. The results are comparable with previously published HNS systems despite minimal implanted components and a simple stimulation algorithm.
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