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101.
William D. Bowman Diana R. Nemergut Diane M. McKnight Matthew P. Miller Mark W. Williams 《Plant Ecology & Diversity》2015,8(5-6):727-738
Background: Nitrogen (N) deposition in the Front Range of the southern Rocky Mountains has been increasing for several decades, and has exceeded the critical load for several ecological metrics.Aims: Our objective was to predict potential future ecological changes in alpine zones in response to anthropogenic N deposition based on a review of research from Niwot Ridge, Colorado.Results: Empirical observations and experimental studies indicate that plant, algal and soil microbe species compositions are changing in response to N deposition, with nitrophilic species increasing in abundance. Biotic sequestration of N deposition is insufficient to compensate for greater nitrate production, leading to the potential for acidification and base cation loss.Conclusions: Changes in biotic composition in both terrestrial and aquatic ecosystems have important impacts on ecosystem functioning, including a lower capacity to take up and neutralise the acidifying effect of anthropogenic N, increasing phosphorus limitation of production in terrestrial and aquatic systems, and shifts in rates of N and carbon cycling. Continued elevated N deposition rates coupled with ongoing climate change, including warmer summer temperatures and lower snow cover of shorter duration, will influence the ecological thresholds for biotic and functional changes. We suggest that these thresholds will occur at lower inputs of N deposition under future climate change, meriting reconsideration of current N critical loads to protect sensitive alpine ecosystems. 相似文献
102.
Özgür Keleṣ Nicholas P. Barcenas Daniel H. Sprys Keith J. Bowman 《AAPS PharmSciTech》2015,16(6):1455-1464
Fracture strength of pharmaceutical compacts varies even for nominally identical samples, which directly affects compaction, comminution, and tablet dosage forms. However, the relationships between porosity and mechanical behavior of compacts are not clear. Here, the effects of porosity on fracture strength and fracture statistics of microcrystalline cellulose compacts were investigated through diametral compression tests. Weibull modulus, a key parameter in Weibull statistics, was observed to decrease with increasing porosity from 17 to 56 vol.%, based on eight sets of compacts at different porosity levels, each set containing ∼50 samples, a total of 407 tests. Normal distribution fits better to fracture data for porosity less than 20 vol.%, whereas Weibull distribution is a better fit in the limit of highest porosity. Weibull moduli from 840 unique finite element simulations of isotropic porous materials were compared to experimental Weibull moduli from this research and results on various pharmaceutical materials. Deviations from Weibull statistics are observed. The effect of porosity on fracture strength can be described by a recently proposed micromechanics-based formula.Key words: diametral compression test, finite element simulations, normal distribution, reliability, Weibull modulus 相似文献
103.
104.
Hoang H. Nguyen George F. Van Hare Michael Rudokas Tammy Bowman Jennifer N. A. Silva 《PloS one》2015,10(8)
Objectives
Smartphone-enabled ECG devices have the potential to improve patient care by enabling remote ECG assessment of patients with potential and diagnosed arrhythmias. This prospective study aimed to assess the usefulness of pediatric ECG tracings generated by the AliveCor device (Oklahoma City, OK) and to assess user satisfaction.Study Design
Enrolled pediatric patients with documented paroxysmal arrhythmia used the AliveCor device over a yearlong study period. Pediatric electrophysiologists reviewed all transmitted ECG tracings. Patient completed surveys were analyzed to assess user satisfaction.Results
35 patients were enrolled with the following diagnoses: supraventricular tachycardia (SVT, 57%), atrial fibrillation (AF, 11%), ectopic atrial tachycardia (EAT, 6%), atrial tachycardia (AT, 3%), and ventricular tachycardia (VT, 23%). A total of 238 tracings were received from 20 patients, 96% of which were of diagnostic quality for sinus rhythm, sinus tachycardia, SVT, and AF. 126 patient satisfaction surveys (64% from parents) were completed. 98% of the survey responses indicated that it was easy to obtain tracings, 93% found it easy to transmit the tracings, 98% showed added comfort in managing arrhythmia by having the device, and 93% showed interest in continued use of the device after the study period ended.Conclusions
Smartphone-enabled ECG devices can generate tracings of diagnostic quality in children. User satisfaction was extremely positive. Use of the device to manage certain patients with AF and SVT showcases the future role of remote ECGs in the successful outpatient management of arrhythmias in children by potentially reducing Emergency Department visits and healthcare costs. 相似文献105.
Noninvasive genetic sampling enables biomonitoring without the need to directly observe or disturb target organisms. This paper describes a novel and promising source of noninvasive spider and insect DNA from spider webs. Using black widow spiders (Latrodectus spp.) fed with house crickets (Acheta domesticus), we successfully extracted, amplified, and sequenced mitochondrial DNA from spider web samples that identified both spider and prey to species. Detectability of spider DNA did not differ between assays with amplicon sizes from 135 to 497 base pairs. Spider and prey DNA remained detectable at least 88 days after living organisms were no longer present on the web. Spider web DNA as a proof-of-concept may open doors to other practical applications in conservation research, pest management, biogeography studies, and biodiversity assessments. 相似文献
106.
107.
Rajani Sarojam Pia G. Sappl Alexander Goldshmidt Idan Efroni Sandra K. Floyd Yuval Eshed John L. Bowman 《The Plant cell》2010,22(7):2113-2130
In seed plants, leaves are born on radial shoots, but unlike shoots, they are determinate dorsiventral organs made of flat lamina. YABBY genes are found only in seed plants and in all cases studied are expressed primarily in lateral organs and in a polar manner. Despite their simple expression, Arabidopsis thaliana plants lacking all YABBY gene activities have a wide range of morphological defects in all lateral organs as well as the shoot apical meristem (SAM). Here, we show that leaves lacking all YABBY activities are initiated as dorsiventral appendages but fail to properly activate lamina programs. In particular, the activation of most CINCINNATA-class TCP genes does not commence, SAM-specific programs are reactivated, and a marginal leaf domain is not established. Altered distribution of auxin signaling and the auxin efflux carrier PIN1, highly reduced venation, initiation of multiple cotyledons, and gradual loss of the SAM accompany these defects. We suggest that YABBY functions were recruited to mold modified shoot systems into flat plant appendages by translating organ polarity into lamina-specific programs that include marginal auxin flow and activation of a maturation schedule directing determinate growth. 相似文献
108.
Xiang-Yang Ye Stephanie Chen Hao Zhang Kenneth T. Locke Kevin O’Malley Litao Zhang Raijit Srivastava Bowman Miao Daniel Meyers Hossain Monshizadegan Debra Search Denise Grimm Rongan Zhang Jonathan Lippy Celeste Twamley Jodi K. Muckelbauer Chiehying Chang Yongmi An Vinayak Hosagrahara Lisa Zhang Joseph A. Tino 《Bioorganic & medicinal chemistry letters》2010,20(9):2933-2937
The synthesis and follow-up SAR studies of our development candidate 1 by incorporating 2-aryl-4-oxazolylmethoxy and 2-aryl-4-thiazolylmethoxy moieties into the oxybenzylglycine framework of the PPARα/γ dual agonist muraglitazar is described. SAR studies indicate that different substituents on the aryloxazole/thiazole moieties as well as the choice of carbamate substituent on the glycine moiety can significantly modulate the selectivity of PPARα versus PPARγ. Potent, highly selective PPARα activators 2a and 2l, as well as PPARα activators with significant PPARγ activity, such as 2s, were identified. The in vivo pharmacology of these compounds in preclinical animal models as well as their ADME profiles are discussed. 相似文献
109.
110.
Prediction of genetic merit using dense SNP genotypes can be used for estimation of breeding values for selection of livestock, crops, and forage species; for prediction of disease risk; and for forensics. The accuracy of these genomic predictions depends in part on the genetic architecture of the trait, in particular number of loci affecting the trait and distribution of their effects. Here we investigate the difference among three traits in distribution of effects and the consequences for the accuracy of genomic predictions. Proportion of black coat colour in Holstein cattle was used as one model complex trait. Three loci, KIT, MITF, and a locus on chromosome 8, together explain 24% of the variation of proportion of black. However, a surprisingly large number of loci of small effect are necessary to capture the remaining variation. A second trait, fat concentration in milk, had one locus of large effect and a host of loci with very small effects. Both these distributions of effects were in contrast to that for a third trait, an index of scores for a number of aspects of cow confirmation ("overall type"), which had only loci of small effect. The differences in distribution of effects among the three traits were quantified by estimating the distribution of variance explained by chromosome segments containing 50 SNPs. This approach was taken to account for the imperfect linkage disequilibrium between the SNPs and the QTL affecting the traits. We also show that the accuracy of predicting genetic values is higher for traits with a proportion of large effects (proportion black and fat percentage) than for a trait with no loci of large effect (overall type), provided the method of analysis takes advantage of the distribution of loci effects. 相似文献