Decreased temperature variance associated with biotic composition enhances coastal shrub encroachment.

Regime shift from grasslands to shrub-dominated landscapes occur worldwide driven by altered land-use and climate change, affecting landscape function, biodiversity, and productivity. Warming winter temperatures are a main driver of expansion of the native, evergreen shrub, Morella cerifera, in coastal landscapes. Shrub establishment in these habitats alters microclimate, but little is known about seasonal differences and microclimate variance. We assessed influence of shrubs on microclimate variance, community composition, and community physiological functioning across three vegetation zones: grass, transitional, and shrub in a coastal grassland. Using a novel application of a time-series analysis, we interpret microclimatic variance modification and elucidate mechanisms of shrub encroachment at the Virginia Coast Reserve, Long-Term Ecological Research site. As shrub thickets form, diversity is reduced with little grass/forb cover, while transpiration and annual productivity increase. Shrub thickets significantly reduced temperature variance with a positive influence of one day on the next in maximum air, minimum air, and maximum ground temperature. We also show that microclimatic temperature moderation reduces summer extreme temperatures in transition areas, even before coalescence into full thickets. Encroachment of Morella cerifera on the Virginia barrier islands is driven by reduced local exposure to cold temperatures and enhanced by abiotic microclimatic modification and biotic physiological functioning. This shift in plant community composition from grassland to shrub thicket alters the role of barrier islands in productivity and can have impacts on the natural resilience of the islands.

Pediatric Ventilator-Associated Events: Analysis of the Pediatric Ventilator-Associated Infection Data.

OBJECTIVES: To compare the prevalence of infection applying the proposed pediatric ventilator-associated events criteria versus clinician-diagnosed ventilator-associated infection to subjects in the pediatric ventilator-associated infection study. DESIGN: Analysis of prospectively collected data from the pediatric ventilator-associated infection study. SETTING: PICUs of 47 hospitals in the United States, Canada, and Australia. PATIENTS: Two-hundred twenty-nine children ventilated for greater than 48 hours who had respiratory secretion cultures performed to evaluate for suspected ventilator-associated infection. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Applying the proposed pediatric ventilator-associated event criteria, 15 of 229 subjects in the ventilator-associated infection study qualified as "ventilator-associated condition" and five of 229 (2%) met criteria for "infection-related ventilator-associated complication." This was compared with 89 of 229 (39%) diagnosed as clinical ventilator-associated infection (Kappa = 0.068). Ten of 15 subjects identified as ventilator-associated condition did not meet criteria for infection-related ventilator-associated complication primarily because they did not receive 4 days of antibiotics. Ventilator-associated condition subjects were similar demographically to nonventilator-associated condition subjects and had similar mortality (13% vs 10%), PICU-free days (6.9 ± 7.7; interquartile range, 0-14 vs 9.8 ± 9.6; interquartile range, 0-19; p = 0.25), but fewer ventilator-free days (6.6 ± 9.3; interquartile range, 1-15 vs 12.4 ± 10.7; interquartile range, 0-22; p = 0.04). The clinical ventilator-associated infection diagnosis in the ventilator-associated infection study was associated with fewer PICU-free days but no difference in mortality or ventilator-free days. CONCLUSIONS: The ventilator-associated event criteria appear to be insensitive to the clinical diagnosis of ventilator-associated infection. Differentiation between ventilator-associated condition and infection-related ventilator-associated complication was primarily determined by the clinician decision to treat with antibiotics rather than clinical signs and symptoms. The utility of the proposed pediatric ventilator-associated event criteria as a surrogate for ventilator-associated infection criteria is unclear.

Pediatric Ventilator-Associated Infections: The Ventilator-Associated INfection Study.

OBJECTIVE: Suspected ventilator-associated infection is the most common reason for antibiotics in the PICU. We sought to characterize the clinical variables associated with continuing antibiotics after initial evaluation for suspected ventilator-associated infection and to determine whether clinical variables or antibiotic treatment influenced outcomes. DESIGN: Prospective, observational cohort study conducted in 47 PICUs in the United States, Canada, and Australia. Two hundred twenty-nine pediatric patients ventilated more than 48 hours undergoing respiratory secretion cultures were enrolled as "suspected ventilator-associated infection" in a prospective cohort study, those receiving antibiotics of less than or equal to 3 days were categorized as "evaluation only," and greater than 3 days as "treated." Demographics, diagnoses, comorbidities, culture results, and clinical data were compared between evaluation only and treated subjects and between subjects with positive versus negative cultures. SETTING: PICUs in 47 hospitals in the United States, Canada, and Australia. SUBJECTS: All patients undergoing respiratory secretion cultures during the 6 study periods. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Treated subjects differed from evaluation-only subjects only in frequency of positive cultures (79% vs 36%; p < 0.0001). Subjects with positive cultures were more likely to have chronic lung disease, tracheostomy, and shorter PICU stay, but there were no differences in ventilator days or mortality. Outcomes were similar in subjects with positive or negative cultures irrespective of antibiotic treatment. Immunocompromise and higher Pediatric Logistic Organ Dysfunction scores were the only variables associated with mortality in the overall population, but treated subjects with endotracheal tubes had significantly lower mortality. CONCLUSIONS: Positive respiratory cultures were the primary determinant of continued antibiotic treatment in children with suspected ventilator-associated infection. Positive cultures were not associated with worse outcomes irrespective of antibiotic treatment although the lower mortality in treated subjects with endotracheal tubes is notable. The necessity of continuing antibiotics for a positive respiratory culture in suspected ventilator-associated infection requires further study.

Identification of Differential Gene Expression Patterns after Acute Exposure to High and Low Doses of Low-LET Ionizing Radiation in a Reconstituted Human Skin Tissue.

In this study we utilized a systems biology approach to identify dose- (0.1, 2.0 and 10 Gy) and time- (3 and 8 h) dependent responses to acute ionizing radiation exposure in a complex tissue, reconstituted human skin. The low dose used here (0.1 Gy) falls within the range of certain medical diagnostic procedures. Of the two higher doses used, 2.0 Gy is typically administered for radiotherapy, while 10 Gy is lethal. Because exposure to any of these doses is possible after an intentional or accidental radiation events, biomarkers are needed to rapidly and accurately triage potentially exposed individuals. Here, tissue samples were acutely exposed to X-ray-generated low-linear-energy transfer (LET) ionizing radiation, and direct RNA sequencing (RNA-seq) was used to quantify altered transcripts. The time points used for this study aid in assessing early responses to exposure, when key signaling pathways and biomarkers can be identified, which precede and regulate later phenotypic alterations that occur at high doses, including cell death. We determined that a total of 1,701 genes expressed were significantly affected by high-dose radiation, with the majority of genes affected at 10 Gy. Expression levels of a group of 29 genes, including GDF15, BBC3, PPM1D, FDXR, GADD45A, MDM2, CDKN1A, TP53INP1, CYCSP27, SESN1, SESN2, PCNA and AEN, were similarly altered at both 2 and 10 Gy, but not 0.1 Gy, at both time points. A much larger group of upregulated genes, including those involved in inflammatory responses, was significantly altered only after 10 Gy irradiation. At high doses, downregulated genes were associated with cell cycle regulation and exhibited an apparent linear response between 2 and 10 Gy. While only a few genes were significantly affected by 0.1 Gy irradiation, using stringent statistical filters, groups of related genes regulating cell cycle progression and inflammatory responses consistently exhibited opposite trends in their regulation compared to high-dose irradiated groups. Differential regulation of PLK1 signaling at low- and high-dose irradiation was confirmed using qRT-PCR. These results indicate that some alterations in gene expression are qualitatively different at low and high doses of ionizing radiation in this model system. They also highlight potential biomarkers for radiation exposure that may precede the development of overt physiological symptoms in exposed individuals.

Factorial Validity of the Decisional Involvement Scale as a Measure of Content and Context of Nursing Practice.

Decisional involvement is widely recognized as an essential component of a professional nursing practice environment. In recent years, researchers have added to the conceptualization of nurses' role in decision-making to differentiate between the content and context of nursing practice. Yet, instruments that clearly distinguish between these two dimensions of practice are lacking. The purpose of this study was to examine the factorial validity of the Decisional Involvement Scale (DIS) as a measure of both the content and context of nursing practice. This secondary analysis was conducted using data from a longitudinal action research project to improve the quality of nursing practice and patient care in six hospitals (N = 1,034) in medically underserved counties of Pennsylvania. A cross-sectional analysis of baseline data from the parent study was used to compare the factor structure of two models (one nested within the other) using confirmatory factor analysis. Although a comparison of the two models indicated that the addition of second-order factors for the content and context of nursing practice improved model fit, neither model provided optimal fit to the data. Additional model-generating research is needed to develop the DIS as a valid measure of decisional involvement for both the content and context of nursing practice.

Longitudinal consent-related abilities among research participants with schizophrenia: results from the CATIE study.

OBJECTIVE: Research participants must have adequate consent-related abilities to provide informed consent at the time of study enrollment. We sought to determine if research participants with schizophrenia maintain adequate consent-related abilities during a longitudinal study. If participants lose abilities during a trial they may not be able to judge and protect their interests. If reduced abilities are common or can be predicted, special protections can be targeted appropriately. METHOD: We examined longitudinal consent-related abilities of participants in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) schizophrenia study using the MacArthur Competence Assessment Tool-Clinical Research (MacCAT-CR) at protocol-specified times over 18 months. RESULTS: Of 1158 research participants in this analysis, most (n=650, 56%) had a stable pattern of MacCAT-CR Understanding scores, 235 (20%) improved substantially with no evidence of decline, 273 (24%) had at least one assessment with substantial worsening. During the course of the trial, 43 (4%) fell below the initial threshold for adequate capacity, which was predicted by lower Understanding scores, more severe positive symptoms, and poorer neurocognitive functioning at baseline, and by increases in negative symptoms and deteriorating global status. CONCLUSIONS: Most participants in this long-term study had stable or improved consent-related abilities, but almost one-fourth experienced substantial worsening and 4% of participants fell below the study's capacity threshold for enrollment. Clinical investigators should monitor with special care individuals with marginal capacity or higher levels of psychotic symptoms at study entry and those who exhibit clinical worsening during a study.

The role of the family and improvement in treatment maintenance, adherence, and outcome for schizophrenia.

INTRODUCTION: In the context of a large, random assignment, controlled study evaluating the relative effectiveness and safety of antipsychotic medication (CATIE), we examined the relationship between treatment outcome and 2 family variables: their presence and their ability to support treatment adherence. METHODS: Post hoc, we assessed the 50 study patients (40 of whom had families) and their families by dividing them into 2 groups. The first had a family/significant other, available and mostly supportive, to work collaboratively on adherence with the treatment team (n = 27). The second group either did not have the family/significant other or, if they did, lacked support for long-term maintenance (n = 23). Next, we examined outcome on 2 measures: study completion (vs discontinuation) and global outcome. RESULTS: Of 27 patients with available/supportive families, 23 remained in treatment for the full study course. In contrast, 13 of 23 patients, who were discontinued or dropped out, either did not have families or, if they had them, were unable to support adherence (P < 0.01). As to global outcome, 24 of the 27 patients who had supportive families improved, compared with only 9 of the 23 of the other group (P < 0.001). DISCUSSION: In summary, in the context of a large medication efficacy-effectiveness trial, we present data suggesting that having a "family" available and supportive (regardless of the interpersonal issues between patient and family) improves outcome mediated by improving long-term adherence.