Acute hematogenous osteomyelitis (AHO) is a relatively common condition in children, and identifying the offending pathogen with blood or tissue cultures aids in diagnosis and medical management ...while reducing treatment failure. Recent 2021 AHO clinical practice guidelines from the Pediatric Infectious Disease Society recommend obtaining routine tissue cultures, particularly in cases with negative blood cultures. The purpose of this study was to identify variables associated with positive tissue cultures when blood cultures are negative.
Children with AHO from 18 pediatric medical centers throughout the United States through the Children's ORthopaedic Trauma and Infection Consortium for Evidence-based Study were evaluated for predictors of positive tissue cultures when blood cultures were negative. Cutoffs of predictors were determined with associated sensitivity and specificity.
One thousand three children with AHO were included, and in 688/1003 (68.6%) patients, both blood cultures and tissue cultures were obtained. In patients with negative blood cultures (n=385), tissue was positive in 267/385 (69.4%). In multivariate analysis, age ( P <0.001) and C-reactive protein (CRP) ( P =0.004) were independent predictors. With age >3.1 years and CRP >4.1 mg/dL as factors, the sensitivity of obtaining a positive tissue culture when blood cultures were negative was 87.3% (80.9-92.2%) compared with 7.1% (4.4-10.9%) if neither of these factors was present. There was a lower ratio of methicillin-resistant Staphylococcus aureus in blood culture-negative patients who had a positive tissue culture 48/188 (25.5%), compared with patients who had both positive blood and tissue cultures 108/220 (49.1%).
AHO patients with CRP ≤ 4.1 mg/dL and age under 3.1 years are unlikely to have clinical value from tissue biopsy that exceeds the morbidity associated with this intervention. In patients with CRP > 4.1 mg/dL and age over 3.1 years, obtaining a tissue specimen may add value; however, it is important to note that effective empiric antibiotic coverage may limit the utility of positive tissue cultures in AHO.
Level III-Retrospective comparative study.
Environmental temperature has strong and systematic effects on biological processes at all levels of organization, ranging from cells to ecosystems. The large temporal and spatial variation in ...Earth's temperature creates a complex thermal landscape within which life evolves and operates. Here, we present a data set on how diverse biological rates and times respond to temperature, which we hope will aid in the search for general mechanisms of thermal dependence. For nearly a century, intraspecific studies (within single species' populations) of thermal responses have been conducted on a wide range of organismal traits. Comparative studies of these data are essential for elucidating mechanisms underlying thermal response curves. However, such comparative intraspecific studies have been limited because of a lack of a comprehensive database that organizes these data with consistent units and trait definitions. Here, we present a database of 2352 thermal responses for 220 traits for microbes, plants, and animals compiled from 270 published sources. This represents the most diverse and comprehensive thermal response data set ever compiled. The traits in this database span levels of biological organization from internal physiology to species interactions and were measured in marine, freshwater, and terrestrial habitats for 411 species. Although we include some physiological rates, most data are for ecological traits, which we define here to mean any organismal trait that directly determines interactions between individuals within or across species. We hope that publication of our data set will encourage others to compile complementary data sets, especially on individual physiology and life history traits. Intraspecific and interspecific (across species' populations) analyses of our data set should provide new insights into generalities and deviations in the thermal dependence of biological traits, and thus how biological systems, from cells to ecosystems, respond to temperature change. Such insights are essential for understanding how natural biological systems function, and how life is responding to Earth's complex and rapidly changing thermal landscape.
Trophic interactions govern biomass fluxes in ecosystems, and stability in food webs. Knowledge of how trophic interaction strengths are affected by differences among habitats is crucial for ...understanding variation in ecological systems. Here we show how substantial variation in consumption-rate data, and hence trophic interaction strengths, arises because consumers tend to encounter resources more frequently in three dimensions (3D) (for example, arboreal and pelagic zones) than two dimensions (2D) (for example, terrestrial and benthic zones). By combining new theory with extensive data (376 species, with body masses ranging from 5.24 x 10.sup.-14 kg to 800 kg), we find that consumption rates scale sublinearly with consumer body mass (exponent of approximately 0.85) for 2D interactions, but superlinearly (exponent of approximately 1.06) for 3D interactions. These results contradict the currently widespread assumption of a single exponent (of approximately 0.75) in consumer-resource and food-web research. Further analysis of 2,929 consumer-resource interactions shows that dimensionality of consumer search space is probably a major driver of species coexistence, and the stability and abundance of populations.
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DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ecologists are increasing the use of remote technologies in their research, as these methods are less labor intensive than traditional methods and oftentimes minimize the number of human errors. ...Camera traps can be used to remotely measure abundance and community composition and offer the potential to measure some phenotypic traits, such as body size. We designed a camera-trap setup that enabled us to capture images of both large and small animals and used our camera-trap design to investigate the community composition of mammals and birds and to estimate the biomass of mammals along two transects in a conservation reserve in Missouri. One transect ran from the edge of an agricultural field to an upland forest, and the other transect ran from the edge of a wetland to an upland forest. Over the 4.5-wk study, our cameras recorded 2,245 images that comprised 483 individuals of 16 species of mammals and birds. Coyotes Canis latrans and nine-banded armadillos Dasypus novemcinctus were unique to the riparian transect, as were several bird species. Fewer species used the forest immediately adjacent to the agricultural field, but more species used the forest immediately adjacent to the wetland. Biomass estimates from our camera-trap images were similar to those of published accounts. This is the first study to use camera traps to successfully estimate biomass. We showed that the value and utility of camera traps in wildlife studies and monitoring can be expanded by 1) using multiple cameras at different heights from the ground so as to capture different-sized animals and 2) obtaining phenotypic information of the captured animals.
...the consumption-rate data consist mainly of laboratory experiments, which can overestimate field consumption rates through container effects (in the 3D data, foraging arenas are proportionally ...smaller for larger consumers; that is, container size scales sublinearly with consumer size, see Methods) that allow large consumers to feed unhindered by fear of predation13 while reducing the efficacy of predator evasion by prey12. ...the authors implicitly emphasize interspecific patterns, but their model is based on principles equally applicable to intra- and interspecific size variation, and both were included in their empirical data. ...shifts are common10 and should be considered before combining life-history theory with the superlinear scaling of consumption rate. ...as we emphasized1, and as Giacomini et al. acknowledge2, our theory is for consumption rate per trophic link, whereas consumers rarely feed exclusively on a single resource.
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DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Recognition that intermittent pools are a single habitat phase of an intermittent pool bed that cycles between aquatic and terrestrial habitat greatly enhances their usefulness for addressing general ...questions in ecology. The aquatic phase has served as a model system in many ecological studies, because it has distinct habitat boundaries in space and time and is an excellent experimental system, but the aquatic to terrestrial transition and terrestrial phase remain largely unstudied. We conducted a field experiment within six replicate natural intermittent pool beds to explore macroinvertebrate community dynamics during the transition from aquatic to terrestrial habitat and during the terrestrial phase. We monitored and compared macroinvertebrate communities within leaf packs that i) remained wet, ii) underwent drying (i.e., started wet and then dried), and iii) remained dry. Our results show that i) a diverse macroinvertebrate community inhabits all phases of intermittent pool beds, ii) pool drying involves colonization by an assemblage of macroinvertebrates not recorded in permanently terrestrial leaf packs, iii) the community within dried leaf packs remains distinct from that of permanently terrestrial leaf packs for an extended period following drying (possibly until subsequent refilling), and iv) there are likely to be strong spatial and temporal resource linkages between the aquatic and terrestrial communities. The unique environmental characteristics of intermittent pool beds, which repeatedly cycle from aquatic to terrestrial habitat, should continue to make them valuable study systems.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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