Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

The biology and thermal requirements of the fennel aphid Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae)

The relationship between the insect development rate and temperature was established very early and represents an important ecological variable for modeling the population dynamics of insects. The accurate determination of thermal constant values and the lower and upper developmental thresholds of Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) on fennel (Foeniculum vulgare Miller (Apiales: Apiaceae)) crops would obviously benefit the effective application of control measures. This paper is a study of the biology and thermal requirements of H. foeniculi. Winged insects were collected from fennel crops at the Embrapa Algodao in Campina Grande, Paraiba. Nymphs (age <= 24 h) produced by winged insects were subjected to constant temperatures of 15, 20, 25, 28, 30 or 33 degrees C, a photophase of 12 h and a relative humidity of 70 +/- 10%. The results of the study showed that at temperatures between 15 and 30 degrees C, H. foeniculi nymphs were able to develop normally. The four instars were found at all temperatures tested. However, temperatures of 3 and 33 degrees C were lethal to the nymphs. The nymph stage development time varied from 5 (30 degrees C) to 19 (15 degrees C) days. The influence of temperature on the development time is dependent on the instar. The base temperature (Tb) and the thermal constant (K) for the nymph stage were estimated at 11.2 degrees C and 107.5 degree-days, respectively. The shortest nymph development stage was observed at 30 degrees C, and the highest nymph viability (85.0%) was observed at 28 degrees C. This information can be used for developing phenological models based on the temperature and development rate relationships so that outbreaks of H. foeniculi in the fennel crop can be predicted, therefore improving the application of control programs targeting this fennel pest.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Estimating the development of the fennel aphid, Hyadaphis foeniculi (Passerini) (Hemiptera: Aphiididae), using non-linear models

BACKGROUNDNon-linear models making it possible to predict agricultural pest outbreaks and optimise control tactics are of primary importance for integrated pest management. The development period for immature stages of the fennel aphid Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) at constant temperatures was modelled in order to determine mathematical functions for simulating the aphid&apos;s development. Non-linear models were used to describe the relationship between temperature and development rates of H. foeniculi subjected to constant temperatures.RESULTSThe models used were found to be good fits for estimating H. foeniculi development rates as a function of temperature, with the exception of the Davidson model. The development time of H. foeniculi nymphs ranged from 2.73days (first instar) to 6.18days (fourth instar) at 15 degrees C, from 2.57days (first instar) to 4.52days (fourth instar) at 20 degrees C and from 1.53days (first instar) to 2.05days (fourth instar) at 28 degrees C.CONCLUSIONThese models provide important tools for better elucidation of the relationship between temperature and development rates in H. foeniculi. The results could be used for predicting the occurrence of the various immature stages of H. foeniculi in the fennel crop in Brazil, making it possible to predict more accurately the best periods for implementing pest control. (c) 2014 Society of Chemical IndustryConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Feeding and Dispersal Behavior of the Cotton Leafworm, <i>Alabama argillacea</i> (Hübner) (Lepidoptera: Noctuidae), on Bt and Non-Bt Cotton: Implications for Evolution and Resistance Management

<div><p>The host acceptance of neonate <i>Alabama argillacea</i> (Hübner) (Lepidoptera: Noctuidae) larvae to Bt cotton plants exerts a strong influence on the potential risk that this pest will develop resistance to Bt cotton. This will also determine the efficiency of management strategies to prevent its resistance such as the “refuge-in-the-bag” strategy. In this study, we assessed the acceptance of neonate <i>A. argillacea</i> larvae to Bt and non-Bt cotton plants at different temperatures during the first 24 h after hatching. Two cotton cultivars were used in the study, one a Bt DP 404 BG (Bollgard) cultivar, and the other, an untransformed isoline, DP 4049 cultivar. There was a greater acceptance by live neonate <i>A. argillacea</i> larvae for the non-Bt cotton plants compared with the Bt cotton plants, especially in the time interval between 18 and 24 h. The percentages of neonate <i>A. argillacea</i> larvae found on Bt or non-Bt plants were lower when exposed to temperatures of 31 and 34°C. The low acceptance of <i>A. argillacea</i> larvae for Bt cotton plants at high temperatures stimulated the dispersion of <i>A. argillacea</i> larvae. Our results support the hypothesis that the dispersion and/or feeding behavior of neonate <i>A. argillacea</i> larvae is different between Bt and non-Bt cotton. The presence of the Cry1Ac toxin in Bt cotton plants, and its probable detection by the <i>A. argillacea</i> larvae tasting or eating it, increases the probability of dispersion from the plant where the larvae began. These findings may help to understand how the <i>A. argillacea</i> larvae detect the Cry1Ac toxin in Bt cotton and how the toxin affects the dispersion behavior of the larvae over time. Therefore, our results are extremely important for the management of resistance in populations of <i>A. argillacea</i> on Bt cotton.</p></div

Physiological selectivity of pesticides used in citrus culture on parasitoid Tamarixia radiata (Waterson, 1922) (Hymenoptera: Eulophidae)

The Brazilian citrus culture is the second largest pesticides consumer, demanding roughly 17.5 kg of active ingredient per hectare annually. This research evaluated the physiological selectivity of 50 pesticides (22 insecticides, 16 acaricides, 10 fungicides, 1 mineral oil and 1 vegetable oil) used in citrus on parasitoid Tamarixia radiata. For that purpose, discs of the Valencia sweet orange variety, 3.5 cm diameter were sprayed using a Burkhard-Pottertower adjusted to a pressure of 15 lb.pol-2, enabling the application of 1.8 ± 0.1 mg of chemical solution.cm-2, according to the methodology proposed by IOBC/WPRS. After application, the discs were kept at room temperature for three hours to dry the residues. Next, the discs were placed in Petri dishes containing 2 mL of a not gelled agar-water solution at 2.5%. Then, adult parasitoids with no more than 48 hours after emergence were exposed to residues. The experimental design was completely randomized with 51 treatments and five replicates, and each replication comprised 10 adults of the parasitoid. The parasitoids survival was recorded 24 hours after exposure of adults to the toxic residues. Insecticides azadirachtin, etofenproxi, gamma-cyhalothrin, pyriproxyfen, tebufenozide, and diflubenzuron; the acaricides pyridaben, etoxazole, diflubenzuron, and fenpyroximate hexitiazoxi, and fungicides azoxystrobin, folpet, copper hydroxide, copper oxychloride, mancozeb + copper oxychloride, pyraclostrobin, thiophanate-methyl, and trifloxystrobin were innocuous to parasitoid T. radiata. The other pesticides should be evaluated under semi-field and field conditions to verify the impact on the parasitoid T. radiata in citrus

Physiological selectivity of pesticides used in citrus culture on parasitoid Tamarixia radiata (Waterson, 1922) (Hymenoptera: Eulophidae)

The Brazilian citrus culture is the second largest pesticides consumer, demanding roughly 17.5 kg of active ingredient per hectare annually. This research evaluated the physiological selectivity of 50 pesticides (22 insecticides, 16 acaricides, 10 fungicides, 1 mineral oil and 1 vegetable oil) used in citrus on parasitoid Tamarixia radiata. For that purpose, discs of the Valencia sweet orange variety, 3.5 cm diameter were sprayed using a Burkhard-Pottertower adjusted to a pressure of 15 lb.pol-2, enabling the application of 1.8 ± 0.1 mg of chemical solution.cm-2, according to the methodology proposed by IOBC/WPRS. After application, the discs were kept at room temperature for three hours to dry the residues. Next, the discs were placed in Petri dishes containing 2 mL of a not gelled agar-water solution at 2.5%. Then, adult parasitoids with no more than 48 hours after emergence were exposed to residues. The experimental design was completely randomized with 51 treatments and five replicates, and each replication comprised 10 adults of the parasitoid. The parasitoids survival was recorded 24 hours after exposure of adults to the toxic residues. Insecticides azadirachtin, etofenproxi, gamma-cyhalothrin, pyriproxyfen, tebufenozide, and diflubenzuron; the acaricides pyridaben, etoxazole, diflubenzuron, and fenpyroximate hexitiazoxi, and fungicides azoxystrobin, folpet, copper hydroxide, copper oxychloride, mancozeb + copper oxychloride, pyraclostrobin, thiophanate-methyl, and trifloxystrobin were innocuous to parasitoid T. radiata. The other pesticides should be evaluated under semi-field and field conditions to verify the impact on the parasitoid T. radiata in citrus

Summarized model of the three-way analysis of variance (ANOVA) for the effects of cultivar¹, exposure time interval of neonate larvae to Bt cotton or non-Bt cotton², and temperature³ on the percentage of neonate larvae of <i>A. argillacea</i> recovered from Bt cotton and non-Bt near isoline cotton plants.

1<p>Cultivars: Bt cotton and non-Bt near isoline cotton.</p>2<p>Time intervals: 0–6 h, 6–12 h, 12–18 h, and 18–24 h.</p>3<p>Temperatures (°C): 22, 25, 28, 31, and 34. Analysis was performed with the data transformed with arcsine square root percentage.</p><p>Summarized model of the three-way analysis of variance (ANOVA) for the effects of cultivar^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111588#nt101" target="_blank">1</a>}, exposure time interval of neonate larvae to Bt cotton or non-Bt cotton^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111588#nt102" target="_blank">2</a>}, and temperature^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111588#nt103" target="_blank">3</a>} on the percentage of neonate larvae of <i>A. argillacea</i> recovered from Bt cotton and non-Bt near isoline cotton plants.</p