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BackgroundIt is now apparent that the complex microbial communities found on and in the human body vary across individuals. What has largely been missing from previous studies is an understanding of how these communities vary over time within individuals. To the extent to which it has been considered, it is often assumed that temporal variability is negligible for healthy adults. Here we address this gap in understanding by profiling the forehead, gut (fecal), palm, and tongue microbial communities in 85 adults, weekly over 3 months.ResultsWe found that skin (forehead and palm) varied most in the number of taxa present, whereas gut and tongue communities varied more in the relative abundances of taxa. Within each body habitat, there was a wide range of temporal variability across the study population, with some individuals harboring more variable communities than others. The best predictor of these differences in variability across individuals was microbial diversity; individuals with more diverse gut or tongue communities were more stable in composition than individuals with less diverse communities.ConclusionsLongitudinal sampling of a relatively large number of individuals allowed us to observe high levels of temporal variability in both diversity and community structure in all body habitats studied. These findings suggest that temporal dynamics may need to be considered when attempting to link changes in microbiome structure to changes in health status. Furthermore, our findings show that, not only is the composition of an individual's microbiome highly personalized, but their degree of temporal variability is also a personalized feature.

External forces play complex roles in cell organization, fate, and homeostasis. Changes in these forces, or how cells respond to them, can result in abnormal embryonic development and diseases in adults. How cells sense and respond to these mechanical stimuli requires an understanding of the biophysical principles that underlie changes in protein conformation and result in alterations in the organization and function of cells and tissues. Here, we discuss mechano-transduction as it applies to protein conformation, cellular organization, and multi-cell (tissue) function.

Climate warming is predicted to cause many changes in ectotherm communities, one of which is phenological mismatch, wherein one species' development advances relative to an associated species or community. Phenological mismatches already lead to loss of pollination services, and we predict that they also cause loss of biological control. Here, we provide evidence that a pest develops earlier due to urban warming but that phenology of its parasitoid community does not similarly advance. This mismatch is associated with greater egg production that likely leads to more pests on trees.

BackgroundOsteoarthritis of the knee is commonly diagnosed and monitored with radiography. However, the reliability of radiographic classification systems for osteoarthritis and the correlation of these classifications with the actual degree of confirmed degeneration of the articular cartilage of the tibiofemoral joint have not been adequately studied.MethodsAs the Multicenter ACL (anterior cruciate ligament) Revision Study (MARS) Group, we conducted a multicenter, prospective longitudinal cohort study of patients undergoing revision surgery after anterior cruciate ligament reconstruction. We followed 632 patients who underwent radiographic evaluation of the knee (an anteroposterior weight-bearing radiograph, a posteroanterior weight-bearing radiograph made with the knee in 45° of flexion [Rosenberg radiograph], or both) and arthroscopic evaluation of the articular surfaces. Three blinded examiners independently graded radiographic findings according to six commonly used systems-the Kellgren-Lawrence, International Knee Documentation Committee, Fairbank, Brandt et al., Ahlbäck, and Jäger-Wirth classifications. Interobserver reliability was assessed with use of the intraclass correlation coefficient. The association between radiographic classification and arthroscopic findings of tibiofemoral chondral disease was assessed with use of the Spearman correlation coefficient.ResultsOverall, 45° posteroanterior flexion weight-bearing radiographs had higher interobserver reliability (intraclass correlation coefficient = 0.63; 95% confidence interval, 0.61 to 0.65) compared with anteroposterior radiographs (intraclass correlation coefficient = 0.55; 95% confidence interval, 0.53 to 0.56). Similarly, the 45° posteroanterior flexion weight-bearing radiographs had higher correlation with arthroscopic findings of chondral disease (Spearman rho = 0.36; 95% confidence interval, 0.32 to 0.39) compared with anteroposterior radiographs (Spearman rho = 0.29; 95% confidence interval, 0.26 to 0.32). With respect to standards for the magnitude of the reliability coefficient and correlation coefficient (Spearman rho), the International Knee Documentation Committee classification demonstrated the best combination of good interobserver reliability and medium correlation with arthroscopic findings.ConclusionsThe overall estimates with the six radiographic classification systems demonstrated moderate (anteroposterior radiographs) to good (45° posteroanterior flexion weight-bearing radiographs) interobserver reliability and medium correlation with arthroscopic findings. The International Knee Documentation Committee classification assessed with use of 45° posteroanterior flexion weight-bearing radiographs had the most favorable combination of reliability and correlation.Level of evidenceDiagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

HypothesisThe purpose of this cross-sectional study is to determine whether the duration of symptoms influences the features seen in patients with atraumatic, full-thickness rotator cuff tears. Our hypothesis is that an increasing duration of symptoms will correlate with more advanced findings of rotator cuff tear severity on magnetic resonance imaging, worse shoulder outcome scores, more pain, decreased range of motion, and less strength.MethodsWe enrolled 450 patients with full-thickness rotator cuff tears in a prospective cohort study to assess the effectiveness of nonoperative treatment and factors predictive of success. The duration of patient symptoms was divided into 4 groups: 3 months or less, 4 to 6 months, 7 to 12 months, and greater than 12 months. Data collected at patient entry into the study included (1) demographic data, (2) history and physical examination data, (3) radiographic imaging data, and (4) validated patient-reported measures of shoulder status. Statistical analysis included a univariate analysis with the Kruskal-Wallis test and Pearson test to identify statistically significant differences in these features for different durations of symptoms.ResultsA longer duration of symptoms does not correlate with more severe rotator cuff disease. The duration of symptoms was not related to weakness, limited range of motion, tear size, fatty atrophy, or validated patient-reported outcome measures.ConclusionsThere is only a weak relationship between the duration of symptoms and features associated with rotator cuff disease.

BackgroundFor many orthopaedic disorders, symptoms correlate with disease severity. The objective of this study was to determine if pain level is related to the severity of rotator cuff disorders.MethodsA cohort of 393 subjects with an atraumatic symptomatic full-thickness rotator-cuff tear treated with physical therapy was studied. Baseline pretreatment data were used to examine the relationship between the severity of rotator cuff disease and pain. Disease severity was determined by evaluating tear size, retraction, superior humeral head migration, and rotator cuff muscle atrophy. Pain was measured on the 10-point visual analog scale (VAS) in the patient-reported American Shoulder and Elbow Surgeons (ASES) score. A linear multiple regression model was constructed with use of the continuous VAS score as the dependent variable and measures of rotator cuff tear severity and other nonanatomic patient factors as the independent variables. Forty-eight percent of the patients were female, and the median age was sixty-one years. The dominant shoulder was involved in 69% of the patients. The duration of symptoms was less than one month for 8% of the patients, one to three months for 22%, four to six months for 20%, seven to twelve months for 15%, and more than a year for 36%. The tear involved only the supraspinatus in 72% of the patients; the supraspinatus and infraspinatus, with or without the teres minor, in 21%; and only the subscapularis in 7%. Humeral head migration was noted in 16%. Tendon retraction was minimal in 48%, midhumeral in 34%, glenohumeral in 13%, and to the glenoid in 5%. The median baseline VAS pain score was 4.4.ResultsMultivariable modeling, controlling for other baseline factors, identified increased comorbidities (p = 0.002), lower education level (p = 0.004), and race (p = 0.041) as the only significant factors associated with pain on presentation. No measure of rotator cuff tear severity correlated with pain (p > 0.25).ConclusionsAnatomic features defining the severity of atraumatic rotator cuff tears are not associated with the pain level. Factors associated with pain are comorbidities, lower education level, and race.Level of evidencePrognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Extended-spectrum beta-lactamase (ESBL) Escherichia coli (E. coli) is an emerging pathogen of high concern given its resistance to extended-spectrum cephalosporins. Broiler chicken, which is the number one consumed meat in the United States and worldwide, can be a reservoir of ESBL E. coli. Backyard poultry ownership is on the rise in the United States, yet there is little research investigating prevalence of ESBL E. coli in this setting. This study aims to identify the prevalence and antimicrobial resistance profiles (phenotypically and genotypically) of ESBL E. coli in some backyard and commercial broiler farms in the U.S. For this study ten backyard and ten commercial farms were visited at three time-points across flock production. Fecal (n = 10), litter/compost (n = 5), soil (n = 5), and swabs of feeders and waterers (n = 6) were collected at each visit and processed for E. coli. Assessment of ESBL phenotype was determined through using disk diffusion with 3rd generation cephalosporins, cefotaxime and ceftazidime, and that with clavulanic acid. Broth microdilution and whole genome sequencing were used to investigate both phenotypic and genotypic resistance profiles, respectively. ESBL E. coli was more prevalent in backyard farms with 12.95% of samples testing positive whereas 0.77% of commercial farm samples were positive. All isolates contained a blaCTX-M gene, the dominant variant being blaCTX-M-1, and its presence was entirely due to plasmids. Our study confirms concerns of growing resistance to fourth generation cephalosporin, cefepime, as roughly half (51.4%) of all isolates were found to be susceptible dose-dependent and few were resistant. Resistance to non-beta lactams, gentamicin and ciprofloxacin, was also detected in our samples. Our study identifies prevalence of blaCTX-M type ESBL E. coli in U.S. backyard broiler farms, emphasizing the need for interventions for food and production safety. [ABSTRACT FROM AUTHOR]

Length-mass relationships, while often overlooked, form the basis of many fisheries science applications. Fisheriesindependent research surveys compile large databases of biological data that could hold a wealth of information regarding species' life history, which, for many, are data deficient and infrequently sampled. A flexible model using permutations of a broken stick and variance shift was applied to length-mass relationships to evaluate changes in the mean or variability of mass-at-length using data from deep-sea fishes and focusing on particularly poorly known deep-sea chondrichthyans. Changes in body shape and (or) in the scale of variability around mean mass-at-length were estimated for most species (94% of data sets examined). Such changes seemed likely to be correlated with biological factors, such as the onset of reproduction; 70% of length estimates for a variance shift correlated with the expected length-at-maturity. The model presented here could be applied to any fish where length and mass data are available, providing a way to estimate, validate, and investigate biological factors in species where macroscopic evaluations are unavailable or difficult to estimate. Les relations longueur-poids, bien que souvent negligees, forment la base de nombreuses applications en sciences halieutiques. Les releves de recherche independants des peches compilent d'imposantes bases de donnees biologiques qui pourraient contenir un tresor d'information concernant les cycles biologiques d'especes dont, pour bon nombre, les donnees sont insuffisantes et l'echantillonnage n'est pas frequent. Un modele souple reposant sur des permutations d'un baton rompu et d'un changement de variance a ete applique a des relations longueur-poids pour evaluer les variations de la moyenne ou de la variabilite du poids en fonction de la longueur en utilisant des donnees sur des poissons de grands fonds et en mettant l'accent sur des chondrichthyens de grands fonds particulierement meconnus. Les variations de la forme du corps ou de l'ampleur de la variabilite autour de la moyenne du poids en fonction de la longueur ont ete estimees pour la plupart des especes (94% des ensembles de donnees examines). Il semble probable que de telles variations soient correlees a des facteurs biologiques, comme le debut de la reproduction; 70% des estimations de la longueur pour un changement de variance etaient correlees a la longueur a la maturite attendue. Le modele presente pourrait etre applique a n'importe quel poisson pour lequel des donnees de longueur et de poids sont disponibles, offrant ainsi un moyen d'estimer, de valider et d'etudier des facteurs biologiques chez des especes pour lesquelles des evaluations macroscopiques sont indisponibles ou difficiles a estimer. [Traduit par la Redaction], Introduction The relationship between length and mass, while often overlooked, is an important component of fisheries population models (Froese 2006). The relationship between length (L) and mass (W) is conventionally [...]

PurposeTo assess the effectiveness of a specific nonoperative physical therapy program in treating atraumatic full-thickness rotator cuff tears using a multicenter prospective cohort study design.Materials and methodsPatients with atraumatic full-thickness rotator cuff tears who consented to enroll provided data via questionnaire on demographics, symptom characteristics, comorbidities, willingness to undergo surgery, and patient-related outcome assessments (Short Form 12 score, American Shoulder and Elbow Surgeons score, Western Ontario Rotator Cuff score, Single Assessment Numeric Evaluation score, and Shoulder Activity Scale). Physicians recorded physical examination and imaging data. Patients began a physical therapy program developed from a systematic review of the literature and returned for evaluation at 6 and 12 weeks. At those visits, patients could choose 1 of 3 courses: (1) cured (no formal follow-up scheduled), (2) improved (continue therapy with scheduled reassessment in 6 weeks), or (3) no better (surgery offered). Patients were contacted by telephone at 1 and 2 years to determine whether they had undergone surgery since their last visit. A Wilcoxon signed rank test with continuity correction was used to compare initial, 6-week, and 12-week outcome scores.ResultsThe cohort consists of 452 patients. Patient-reported outcomes improved significantly at 6 and 12 weeks. Patients elected to undergo surgery less than 25% of the time. Patients who decided to have surgery generally did so between 6 and 12 weeks, and few had surgery between 3 and 24 months.ConclusionNonoperative treatment using this physical therapy protocol is effective for treating atraumatic full-thickness rotator cuff tears in approximately 75% of patients followed up for 2 years.

BackgroundThe factors that lead to patients failing multiple anterior cruciate ligament (ACL) reconstructions are not well understood.HypothesisMultiple-revision ACL reconstruction will have different characteristics than first-time revision in terms of previous and current graft selection, mode of failure, chondral/meniscal injuries, and surgical charactieristics.Study designCase-control study; Level of evidence, 3.MethodsA prospective multicenter ACL revision database was utilized for the time period from March 2006 to June 2011. Patients were divided into those who underwent a single-revision ACL reconstruction and those who underwent multiple-revision ACL reconstructions. The primary outcome variable was Marx activity level. Primary data analyses between the groups included a comparison of graft type, perceived mechanism of failure, associated injury (meniscus, ligament, and cartilage), reconstruction type, and tunnel position. Data were compared by analysis of variance with a post hoc Tukey test.ResultsA total of 1200 patients (58% men; median age, 26 years) were enrolled, with 1049 (87%) patients having a primary revision and 151 (13%) patients having a second or subsequent revision. Marx activity levels were significantly higher (9.77) in the primary-revision group than in those patients with multiple revisions (6.74). The most common cause of reruptures was a traumatic, noncontact ACL graft injury in 55% of primary-revision patients; 25% of patients had a nontraumatic, gradual-onset recurrent injury, and 11% had a traumatic, contact injury. In the multiple-revision group, a nontraumatic, gradual-onset injury was the most common cause of recurrence (47%), followed by traumatic noncontact (35%) and nontraumatic sudden onset (11%) (P < .01 between groups). Chondral injuries in the medial compartment were significantly more common in the multiple-revision group than in the single-revision group, as were chondral injuries in the patellofemoral compartment.ConclusionPatients with multiple-revision ACL reconstructions had lower activity levels, were more likely to have chondral injuries in the medial and patellofemoral compartments, and had a high rate of a nontraumatic, recurrent injury of their graft.