A one-dimensional quasi-Eulerian model, describing the biological and chemical interactions of autotrophic and heterotrophic plankton populations within the upper 100
m of the water column, was used ...to explain the relative impact of iron fertilization from Saharan dust on phosphorus cycling by the cyanobacterium,
Trichodesmium spp. We examined the Caribbean surface waters off the west coast of Barbados using seasonal cases of dust delivery (summer peak) in relation to periods of elevated phosphorus stocks found in episodic pulses of Amazon River water advected past Barbados by the Guiana Current. The additional iron and phosphorus supplied by fluvial sources, available after biological depletion of nitrogen, could alleviate the growth limitation of
Trichodesmium far downstream of the river plumes. The model results were compared with measurements made of
Trichodesmium stocks 8
km off the west coast of Barbados. Modeled concentrations within the low-salinity Amazon plumes reached ∼7.4
mg
chl
m
−2, as seen at Barbados. In the absence of the low-salinity signal, the
Trichodesmium biomass shifted to phosphorus limitation with little response to iron fertilization. This indicates that
Trichodesmium stocks may indeed be mainly a function of phosphorus availability within the upper water column. Therefore, the supply of phosphorus from subtropical/tropical rivers, such as the Amazon and Orinoco, limits the potential cyanophyte response, despite adequate atmospheric iron delivery. This alters our view not only of the western North Atlantic nitrogen budget, but potentially several regions downstream of low N:P river systems.
Daily administration of vitamin D is important for maintaining bone homeostasis. The orthopedic community has shown increased interest in vitamin D supplementation and patient outcomes after ...fracture. The current study used data from a large hip fracture trial to determine the proportion of patients who consistently used vitamin D after hip fracture surgery and to determine whether supplementation was associated with improved health-related quality of life and reduced reoperation rates. The FAITH study is a multicenter trial of elderly patients with femoral neck fracture treated with internal fixation. The current study asked a subset of patients included in the FAITH study about vitamin D supplementation and categorized them as consistent users, inconsistent users, or nonusers. This study also evaluated whether supplementation was associated with improved quality of life and reduced reoperation rates. The final analysis included 573 patients (mean age, 74.1 years; female, 66.3%; nondis-placed fractures, 72.4%). A total of 18.7% of participants reported no use of vitamin D, 35.6% reported inconsistent use, and 45.7% reported consistent use. Adjusted analysis found that consistent supplementation was associated with a 2.42 increase of the Short Form-12 physical component score 12 months postoperatively (P=.033). However, supplementation was not associated with reduced reoperation rates (P=.386). Despite guidelines recommending vitamin D supplementation, a low proportion of elderly patients with hip fracture use vitamin D consistently, suggesting a need for additional strategies to promote compliance. This study found that the use of vitamin D was associated with a statistically significant but not clinically significant improvement in health-related quality of life after hip fracture. Further research is needed to confirm these findings. Orthopedics. 2017; 40(5):e868-e875..
Environmental DNA (eDNA) analysis allows the simultaneous examination of organisms across multiple trophic levels and domains of life, providing critical information about the complex biotic ...interactions related to ecosystem change. Here we used multilocus amplicon sequencing of eDNA to survey biodiversity from an eighteen-month (2015-2016) time-series of seawater samples from Monterey Bay, California. The resulting dataset encompasses 663 taxonomic groups (at Family or higher taxonomic rank) ranging from microorganisms to mammals. We inferred changes in the composition of communities, revealing putative interactions among taxa and identifying correlations between these communities and environmental properties over time. Community network analysis provided evidence of expected predator-prey relationships, trophic linkages, and seasonal shifts across all domains of life. We conclude that eDNA-based analyses can provide detailed information about marine ecosystem dynamics and identify sensitive biological indicators that can suggest ecosystem changes and inform conservation strategies.
Biosensors present exciting opportunities in novel medical and scientific applications. However, sensor tags presented to date cannot interface with practical sensors, lack addressability, and/or ...require a custom (high-cost) interrogator. Our tag provides these features via ultra-low-power circuitry including a low-noise biosignal amplifier, unique tag ID generator, calibration-free 3 MHz oscillator, and EPC C1 Gen2 protocol compatibility. In addition to design details and measurement data from the fabricated IC, we present in vivo muscle temperature measurement from an untethered in-flight hawkmoth.
Light-activated ion channels provide a precise and noninvasive optical means for controlling action potential firing, but the genes encoding these channels must first be delivered and expressed in ...target cells. Here we describe a method for bestowing light sensitivity onto endogenous ion channels that does not rely on exogenous gene expression. The method uses a synthetic photoisomerizable small molecule, or photoswitchable affinity label (PAL), that specifically targets K+ channels. PALs contain a reactive electrophile, enabling covalent attachment of the photoswitch to naturally occurring nucleophiles in K+ channels. Ion flow through PAL-modified channels is turned on or off by photoisomerizing PAL with different wavelengths of light. We showed that PAL treatment confers light sensitivity onto endogenous K+ channels in isolated rat neurons and in intact neural structures from rat and leech, allowing rapid optical regulation of excitability without genetic modification.
Determining the genetic basis of cancer requires comprehensive analyses of large collections of histopathologically well-classified primary tumours. Here we report the results of a collaborative ...study to discover somatic mutations in 188 human lung adenocarcinomas. DNA sequencing of 623 genes with known or potential relationships to cancer revealed more than 1,000 somatic mutations across the samples. Our analysis identified 26 genes that are mutated at significantly high frequencies and thus are probably involved in carcinogenesis. The frequently mutated genes include tyrosine kinases, among them the EGFR homologue ERBB4; multiple ephrin receptor genes, notably EPHA3; vascular endothelial growth factor receptor KDR; and NTRK genes. These data provide evidence of somatic mutations in primary lung adenocarcinoma for several tumour suppressor genes involved in other cancers--including NF1, APC, RB1 and ATM--and for sequence changes in PTPRD as well as the frequently deleted gene LRP1B. The observed mutational profiles correlate with clinical features, smoking status and DNA repair defects. These results are reinforced by data integration including single nucleotide polymorphism array and gene expression array. Our findings shed further light on several important signalling pathways involved in lung adenocarcinoma, and suggest new molecular targets for treatment.
Surgical treatment comparisons in rare diseases are difficult secondary to the geographic distribution of patients. Fortunately, emerging technologies offer promise to reduce these barriers for ...research.
To prospectively compare the outcomes of the 3 most common surgical approaches for idiopathic subglottic stenosis (iSGS), a rare airway disease.
In this international, prospective, 3-year multicenter cohort study, 810 patients with untreated, newly diagnosed, or previously treated iSGS were enrolled after undergoing a surgical procedure (endoscopic dilation ED, endoscopic resection with adjuvant medical therapy ERMT, or cricotracheal resection CTR). Patients were recruited from clinician practices in the North American Airway Collaborative and an online iSGS community on Facebook.
The primary end point was days from initial surgical procedure to recurrent surgical procedure. Secondary end points included quality of life using the Clinical COPD (chronic obstructive pulmonary disease) Questionnaire (CCQ), Voice Handicap Index-10 (VHI-10), Eating Assessment Test-10 (EAT-10), the 12-Item Short-Form Version 2 (SF-12v2), and postoperative complications.
Of 810 patients in this cohort, 798 (98.5%) were female and 787 (97.2%) were white, with a median age of 50 years (interquartile range, 43-58 years). Index surgical procedures were ED (n = 603; 74.4%), ERMT (n = 121; 14.9%), and CTR (n = 86; 10.6%). Overall, 185 patients (22.8%) had a recurrent surgical procedure during the 3-year study, but recurrence differed by modality (CTR, 1 patient 1.2%; ERMT, 15 12.4%; and ED, 169 28.0%). Weighted, propensity score-matched, Cox proportional hazards regression models showed ED was inferior to ERMT (hazard ratio HR, 3.16; 95% CI, 1.8-5.5). Among successfully treated patients without recurrence, those treated with CTR had the best CCQ (0.75 points) and SF-12v2 (54 points) scores and worst VHI-10 score (13 points) 360 days after enrollment as well as the greatest perioperative risk.
In this cohort study of 810 patients with iSGS, endoscopic dilation, the most popular surgical approach for iSGS, was associated with a higher recurrence rate compared with other procedures. Cricotracheal resection offered the most durable results but showed the greatest perioperative risk and the worst long-term voice outcomes. Endoscopic resection with medical therapy was associated with better disease control compared with ED and had minimal association with vocal function. These results may be used to inform individual patient treatment decision-making.
We present the NeuralWISP, a wireless neural interface operating from far-field radio-frequency RF energy. The NeuralWISP is compatible with commercial RF identification readers and operates at a ...range up to 1 m. It includes a custom low-noise, low-power amplifier integrated circuit for processing the neural signal and an analog spike detection circuit for reducing digital computational requirements and communications bandwidth. Our system monitors the neural signal and periodically transmits the spike density in a user-programmable time window. The entire system draws an average 20 muA from the harvested 1.8-V supply.
Objectives
Serial intralesional steroid injection (SILSI) has been increasingly used to treat idiopathic subglottic stenosis (iSGS). Prior studies have shown effectiveness, but not in all patients. ...This multi‐institutional study evaluates the effect of SILSI on time to recurrent operation, peak expiratory flow (PEF), and dyspnea.
Methods
Post‐hoc secondary analysis of the North American Airway Collaborative data were performed to evaluate the outcomes of iSGS patients undergoing and not undergoing SILSI. The primary outcome was time to recurrent operation, evaluated using Kaplan–Meier curves and Cox regression analysis. Secondary outcomes were change in PEF and clinical chronic obstructive pulmonary disease questionnaire (CCQ) score. Within patients undergoing SILSI, demographics, time from last procedure, and PEF at initiation of SILSI were evaluated to determine the effect on recurrence.
Results
Two hundred and ninety patients were included, 238 undergoing endoscopic dilation alone and 52 undergoing dilation and SILSI. No differences in baseline characteristics were observed. There was no difference in time to recurrence (hazard ratio: 0.64; p = 0.183). There were no differences in PEF or CCQ across the 2.5‐year study period. Among 52 patients undergoing SILSI, PEF at the time of starting SILSI did not affect recurrence (χ2 = 0.09, p = 0.77).
Conclusion
Patients undergoing and not undergoing SILSI had similar times to recurrence, PEF, and CCQ. Factors predicting recurrence among patients undergoing SILSI were not identified. These results support a randomized controlled trial with a uniform SILSI protocol to quantify the effects of SILSI on objective and subjective outcomes and help determine which iSGS patients benefit most.
Level of Evidence
3 Laryngoscope, 133:2255–2263, 2023
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