50 research outputs found
Evaluation of azlocillin in-vitro and in discriminative animal models of infection
Azlocillin was more active in vitro than ticarcillin or carbenicillin against 561 aminoglycoside-resistant strains of Pseudomonas aeruginosa collected from 74 hospitals distributed over a wide geographic area in the eastern United States. Azlocillin was compared with various other antimicrobial agents in discriminative animal models of Ps. aeruginosa pyelonephritis, osteomyelitis, endocarditis, and meningitis in a variety of mammalian species. Cefsulodin was more effective than azlocillin in reducing Ps. aeruginosa kidney concentrations in rat pyelonephritis induced by intrarenal inoculation. The mean±s.d. logl0 cfu/g kidney after three days of therapy were as follows: controls = 5.4±1.5, azlocillin = 4.4±1.8, cefsulodin = 2.6±0.9 (P < 0.01) but the MBC for the test strain was eight-fold higher for azlocillin (8 vs. 1 mg/l) and effective concentrations were maintained longer in rat serum for cefsulodin as against azlocillin. In addition, ticarcillin reduced kidney bacterial concentrations faster than azlocillin in a mouse pyelonephritis model induced by intravenous Ps. aeruginosa inoculation with subsequent iron loading. Azlocillin was less effective than tobramycin in experimental chronic Ps. aeruginosa osteomyelitis induced in rabbits by direct injection into the tibia. An azlocillin-tobramycin regimen was not more effective than tobramycin alone. After 28 days of therapy, the percentages of positive bone cultures after death were as follows: no antibiotic (controls) = 92%, azlocillin = 95%, tobramycin = 76%, azlocillin plus tobramycin = 60%. Both ticarcillin and azlocillin were less active than tobramycin in experimental Ps. aeruginosa endocarditis induced in rabbits by intravenous inoculation of 108 cfu following 1 h of catheter induced aortic valve trauma. The best results were noted with an azlocillin-tobramycin regimen. The mean±s.d. log10 cfu Ps. aeruginosa/g vegetation after five days of therapy were as follows: no antibiotic controls = 8.1 ± 1.1, tobramycin = 4.5 ±0.8, ticarcillin = 6.9 ± 0.8, azlocillin = 5.7 ± 1.5, ticarcillin phis tobramycin = 4.9 ± 1.0, azlocillin plus tobramycin = 3.3 ± 1.6. Sterile vegetations were rarely attained with any regimen. The mean percentage penetration into purulent cerebrospinal fluid (CSF) in experimental Ps. aeruginosa meningitis for azlocillin was 13.3%, comparable to many other β-lactam antibiotics. Azlocillin was the single most active (P < 0.01) agent evaluated after 8 h intravenous infusions in this model. An azlocillin-amikacin regimen was more rapidly bactericidal (P < 0.01) than either agent alone in vivo. None of the agents evaluated alone or in combination, however, produced a sterile CSF after 8 h of therapy in any anima
US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in
Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference
The Bank of Standardized Stimuli (BOSS), a New Set of 480 Normative Photos of Objects to Be Used as Visual Stimuli in Cognitive Research
There are currently stimuli with published norms available to study several psychological aspects of language and visual cognitions. Norms represent valuable information that can be used as experimental variables or systematically controlled to limit their potential influence on another experimental manipulation. The present work proposes 480 photo stimuli that have been normalized for name, category, familiarity, visual complexity, object agreement, viewpoint agreement, and manipulability. Stimuli are also available in grayscale, blurred, scrambled, and line-drawn version. This set of objects, the Bank Of Standardized Stimuli (BOSS), was created specifically to meet the needs of scientists in cognition, vision and psycholinguistics who work with photo stimuli
Neurophysiologic effects of spinal manipulation in patients with chronic low back pain
<p>Abstract</p> <p>Background</p> <p>While there is growing evidence for the efficacy of SM to treat LBP, little is known on the mechanisms and physiologic effects of these treatments. Accordingly, the purpose of this study was to determine whether SM alters the amplitude of the motor evoked potential (MEP) or the short-latency stretch reflex of the erector spinae muscles, and whether these physiologic responses depend on whether SM causes an audible joint sound.</p> <p>Methods</p> <p>We used transcranial magnetic stimulation to elicit MEPs and electromechanical tapping to elicit short-latency stretch reflexes in 10 patients with chronic LBP and 10 asymptomatic controls. Neurophysiologic outcomes were measured before and after SM. Changes in MEP and stretch reflex amplitude were examined based on patient grouping (LBP vs. controls), and whether SM caused an audible joint sound.</p> <p>Results</p> <p>SM did not alter the erector spinae MEP amplitude in patients with LBP (0.80 ± 0.33 vs. 0.80 ± 0.30 μV) or in asymptomatic controls (0.56 ± 0.09 vs. 0.57 ± 0.06 μV). Similarly, SM did not alter the erector spinae stretch reflex amplitude in patients with LBP (0.66 ± 0.12 vs. 0.66 ± 0.15 μV) or in asymptomatic controls (0.60 ± 0.09 vs. 0.55 ± 0.08 μV). Interestingly, study participants exhibiting an audible response exhibited a 20% decrease in the stretch reflex (p < 0.05).</p> <p>Conclusions</p> <p>These findings suggest that a single SM treatment does not systematically alter corticospinal or stretch reflex excitability of the erector spinae muscles (when assessed ~ 10-minutes following SM); however, they do indicate that the stretch reflex is attenuated when SM causes an audible response. This finding provides insight into the mechanisms of SM, and suggests that SM that produces an audible response may mechanistically act to decrease the sensitivity of the muscle spindles and/or the various segmental sites of the Ia reflex pathway.</p
Nature's Swiss Army Knives: Ovipositor Structure Mirrors Ecology in a Multitrophic Fig Wasp Community
Resource partitioning is facilitated by adaptations along niche dimensions that range from morphology to behaviour. The exploitation of hidden resources may require specially adapted morphological or sensory tools for resource location and utilisation. Differences in tool diversity and complexity can determine not only how many species can utilize these hidden resources but also how they do so.The sclerotisation, gross morphology and ultrastructure of the ovipositors of a seven-member community of parasitic wasps comprising of gallers and parasitoids developing within the globular syconia (closed inflorescences) of Ficus racemosa (Moraceae) was investigated. These wasps also differ in their parasitism mode (external versus internal oviposition) and their timing of oviposition into the expanding syconium during its development. The number and diversity of sensilla, as well as ovipositor teeth, increased from internally ovipositing to externally ovipositing species and from gallers to parasitoids. The extent of sclerotisation of the ovipositor tip matched the force required to penetrate the syconium at the time of oviposition of each species. The internally ovipositing pollinator had only one type of sensillum and a single notch on the ovipositor tip. Externally ovipositing species had multiple sensilla types and teeth on their ovipositors. Chemosensilla were most concentrated at ovipositor tips while mechanoreceptors were more widely distributed, facilitating the precise location of hidden hosts in these wasps which lack larval host-seeking behaviour. Ovipositor traits of one parasitoid differed from those of its syntopic galler congeners and clustered with those of parasitoids within a different wasp subfamily. Thus ovipositor tools can show lability based on adaptive necessity, and are not constrained by phylogeny.Ovipositor structure mirrored the increasingly complex trophic ecology and requirements for host accessibility in this parasite community. Ovipositor structure could be a useful surrogate for predicting the biology of parasites in other communities
Scientists' warning on climate change and insects
Climate warming is considered to be among the most serious of anthropogenic stresses to the environment, because it not only has direct effects on biodiversity, but it also exacerbates the harmful effects of other human-mediated threats. The associated consequences are potentially severe, particularly in terms of threats to species preservation, as well as in the preservation of an array of ecosystem services provided by biodiversity. Among the most affected groups of animals are insects—central components of many ecosystems—for which climate change has pervasive effects from individuals to communities. In this contribution to the scientists' warning series, we summarize the effect of the gradual global surface temperature increase on insects, in terms of physiology, behavior, phenology, distribution, and species interactions, as well as the effect of increased frequency and duration of extreme events such as hot and cold spells, fires, droughts, and floods on these parameters. We warn that, if no action is taken to better understand and reduce the action of climate change on insects, we will drastically reduce our ability to build a sustainable future based on healthy, functional ecosystems. We discuss perspectives on relevant ways to conserve insects in the face of climate change, and we offer several key recommendations on management approaches that can be adopted, on policies that should be pursued, and on the involvement of the general public in the protection effort
Global transpiration data from sap flow measurements : the SAPFLUXNET database
Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land-atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized and quality-controlled individual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80 % of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50 % of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56 % of the datasets. Many datasets contain data for species that make up 90 % or more of the total stand basal area, allowing the estimation of stand transpiration in diverse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository (https://doi.org/10.5281/zenodo.3971689; Poyatos et al., 2020a). The "sapfluxnetr" R package - designed to access, visualize, and process SAPFLUXNET data - is available from CRAN.Peer reviewe
Author Correction: The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data
The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data
The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.Peer reviewe