Changes in atmospheric circulation and evapotranspiration are reducing rainfall in the Brazilian Cerrado.

Here we analyze the trends of rainfall and the frequency of rainy days over the Brazilian Cerrado between 1960 and 2021 in four distinct periods according to the seasonal patterns over the region. We also evaluated trends in evapotranspiration, atmospheric pressure, winds, and atmospheric humidity over the Cerrado to elucidate the possible reasons for the detected trends. We recorded a significant reduction in rainfall and frequency of rainy days in the northern and central Cerrado regions for all periods except at the beginning of the dry season. The most pronounced negative trends were recorded during the dry season and the beginning of the wet season, where we recorded reductions of up to 50% in total rainfall and the number of rainy days. These findings are associated with the intensification of the South Atlantic Subtropical Anticyclone, which has been shifting atmospheric circulation and raising regional subsidence. Moreover, during the dry season and the beginning of the wet season, there was a reduction in regional evapotranspiration, which also potentially contributed to the rainfall reduction. Our results suggest an expansion and intensification of the dry season in the region, potentially bringing broad environmental and social impacts that transcend the Cerrado boundaries.

A multiple linear regression approach to the estimation of carboxylic acid ester and lactone alkaline hydrolysis rate constants.

Pesticides, pharmaceuticals, and other organic contaminants often undergo hydrolysis when released into the environment; therefore, measured or estimated hydrolysis rates are needed to assess their environmental persistence. An intuitive multiple linear regression (MLR) approach was used to develop robust QSARs for predicting base-catalyzed rate constants of carboxylic acid esters (CAEs) and lactones. We explored various combinations of independent descriptors, resulting in four primary models (two for lactones and two for CAEs), with a total of 15 and 11 parameters included in the CAE and lactone QSAR models, respectively. The most significant descriptors include pKa, electronegativity, charge density, and steric parameters. Model performance is assessed using Drug Theoretics and Cheminformatics Laboratory's DTC-QSAR tool, demonstrating high accuracy for both internal validation (r2 = 0.93 and RMSE = 0.41-0.43 for CAEs; r2 = 0.90-0.93 and RMSE = 0.38-0.46 for lactones) and external validation (r2 = 0.93 and RMSE = 0.43-0.45 for CAEs; r2 = 0.94-0.98 and RMSE = 0.33-0.41 for lactones). The developed models require only low-cost computational resources and have substantially improved performance compared to existing hydrolysis rate prediction models (HYDROWIN and SPARC).

Factors associated with outcome and gradual improvement in survival over time in 1065 equine neonates admitted to an intensive care unit.

REASONS FOR PERFORMING STUDY: There is a paucity of information regarding the association between common disorders and outcome over time in a large population of ill equine neonates. OBJECTIVES: To describe the relative frequency of neonatal disorders in a large population of foals admitted to a neonatal intensive care unit, to determine the disorders and factors associated with nonsurvival and determine if the outcome of ill neonatal foals has improved over time. STUDY DESIGN: Retrospective study. METHODS: Cases were selected from equine neonatal (≤14 days of age) admissions between 1982 and 2008. Multivariable logistic regression was used to identify the disorders, clinical parameters and laboratory variables associated with nonsurvival or natural death and assess survival over time after accounting for potential confounding variables. RESULTS: A total of 1065 foals were included in the study. Overall, 775 of 1065 (72.8%) foals survived to be discharged from the hospital and 290 (27.2%) foals were nonsurvivors. Age at admission, sepsis score, proportion of foals with positive blood cultures and proportion of survivors were significantly different (P<0.001) between primary disease categories. Variables retained in the multivariable model for nonsurvival included positive blood culture, neutrophils <2.28 × 109 /l, temperature ≤37.6°C, bicarbonate, PCO2 , presence of infectious orthopaedic disorders and sepsis score. The adjusted odds of survival for foals admitted in the 2000s were approximately 3.4 (95% CI = 1.9-6.0, P<0.001) times higher than that of foals admitted in the 1980s. CONCLUSIONS: Primary disorders, sepsis, temperature, acid base status and neutropenia are the main factors that affect outcome in this population of equine neonates. The survival of foals admitted to a neonatal intensive care unit has increased dramatically over a 26 year period.

Liver and Kidney on Chips: Microphysiological Models to Understand Transporter Function.

Because of complex cellular microenvironments of both the liver and kidneys, accurate modeling of transport function has remained a challenge, leaving a dire need for models that can faithfully recapitulate both the architecture and cell-cell interactions observed in vivo. The study of hepatic and renal transport function is a fundamental component of understanding the metabolic fate of drugs and xenobiotics; however, there are few in vitro systems conducive for these types of studies. For both the hepatic and renal systems, we provide an overview of the location and function of the most significant phase I/II/III (transporter) of enzymes, and then review current in vitro systems for the suitability of a transporter function study and provide details on microphysiological systems that lead the field in these investigations. Microphysiological modeling of the liver and kidneys using "organ-on-a-chip" technologies is rapidly advancing in transport function assessment and has emerged as a promising method to evaluate drug and xenobiotic metabolism. Future directions for the field are also discussed along with technical challenges encountered in complex multiple-organs-on-chips development.

Re-evaluation of the sepsis score in equine neonates.

REASONS FOR PERFORMING STUDY: The modified sepsis scoring system provides a method to identify sepsis in foals early in the disease process, but inconsistent results have been obtained from its clinical application in previous studies. OBJECTIVES: To evaluate the sensitivity and specificity of the modified sepsis score in a larger population of foals. A secondary objective was to identify factors associated with sepsis. STUDY DESIGN: Retrospective cohort study. METHODS: Records were retrospectively analysed for neonatal admissions to the University of Florida Large Animal Hospital from 1982 to 2008. Backwards stepwise multivariable logistic regression was used to evaluate objective clinical factors associated with sepsis. Receiver operating chararacteristic ROC curve analysis was performed on the modified sepsis score and used to determine an optimal cut point. RESULTS: A total of 1065 foals were included in the study. The modified sepsis score had a sensitivity of 56.4% and specificity of 73.4% for the originally suggested cut point (>11). Receiver operating chararacteristic analysis revealed an optimal cut point of >7 (sensitivity 84.4%, specificity 41.8%). The modified sepsis score performed better than the generated regression model which included age, creatinine, lymphocytes, potassium and IgG>8 g/l (P = 0.026). Diagnostic performance of the modified sepsis score did not change significantly over time. CONCLUSIONS: Sensitivity and specificity of the modified sepsis score were not as high as previously documented, but the score still outperformed a regression model derived from objective clinical data. The Summary is available in Chinese - see Supporting information.

Sediment-associated reactions of aromatic amines. 1. Elucidation of sorption mechanisms.

Sorption of aromatic amines to sediments and soils can occur by both reversible physical processes and irreversible chemical processes. To elucidate the significance of these sorption pathways, the sorption kinetics of aniline and pyridine were studied in resaturated pond sediment. Aniline and pyridine behaved quite differently in the sediment-water systems. The sorption kinetics of pyridine were quite fast, reaching equilibrium within 1-2 h. In contrast, the sorption kinetics of aniline were characterized by a rapid initial loss of aniline from the aqueous phase followed by a much slower rate of disappearance. The rapid initial sorption of aniline upon respiking after an equilibration period of 200 h, and results of sorption kinetic studies as a function of substrate concentration, demonstrated that sorptive sites were not being saturated at the nominal concentration of aniline. Sequential extraction of a sediment treated with 14C-labeled pyridine and aniline suggested that pyridine was bound primarily through a reversible cation-exchange process, whereas aniline sorbed through both cation-exchange and covalent binding processes. At longer reaction periods sorption became increasingly dominated by covalent binding. The reaction kinetics for the slow, irreversible sorption of aniline appeared to be limited by the reactivity and/or availability of covalent binding sites. The initial rate and extent of aniline sorption was pH dependent (sorption increased with decreasing pH). At pH values above the pKa of aniline, sorption kinetics for the slower, irreversible loss of aniline were independent of pH.

Effect of continuously nebulized ipratropium bromide plus albuterol on emergency department length of stay and hospital admission rates in patients with acute bronchospasm. A randomized, controlled trial.

OBJECTIVE: To compare the outcome of patients with acute bronchospasm treated with continuously nebulized albuterol plus ipratropium bromide vs albuterol alone. SETTING: The Emergency Department (ED) at the University of California San Francisco Medical Center. PARTICIPANTS: Patients > or = 18 years old presenting to the ED with acute bronchospasm and a peak expiratory flow rate (PEFR) of < 70% predicted. INTERVENTIONS: This was a prospective, randomized, double-blind, placebo-controlled trial. Subjects were treated with either a combination of albuterol (10 mg/h) plus ipratropium bromide (1.0 mg/h) or albuterol alone via continuous nebulization for a maximum of 3 h. Vital signs, Borg dyspnea score, and PEFR were recorded hourly. Primary outcome measures were improvement in PEFR, hospital admission rates, and length of stay in the ED. MEASUREMENTS AND RESULTS: Data was analyzed for 67 subjects. The mean age (-/+ SD) was 47.5+/-18.8, and mean initial PEFR was 44.8+/-12.5% of predicted. The median length of stay for all subjects was 225 min, and 31% of all subjects were admitted. Patients given combination therapy averaged 6.3% greater improvement in PEFR compared with control subjects (95% confidence interval [CI], -15% to 27%. The odds ratio for admission with combination therapy was 0.88 (95% CI, 0.28 to 2.8). The median length of stay in the ED was 35 min shorter for those receiving combination treatment (210 vs 245 min; p = 0.03). However, when adjusted for initial PEFR, there was no statistically significant difference (p = 0.26). CONCLUSION: Although the direction of all three outcome measures favored combination therapy, there was no statistically significant difference between ED patients with acute bronchospasm receiving continuous albuterol plus ipratropium bromide and those receiving albuterol alone.

Positive-outcome bias and other limitations in the outcome of research abstracts submitted to a scientific meeting.

CONTEXT: Studies with positive results are more likely to be published in biomedical journals than are studies with negative results. However, many studies submitted for consideration at scientific meetings are never published in full; bias in this setting is poorly studied. OBJECTIVE: To identify features associated with the fate of research abstracts submitted to a scientific meeting. DESIGN AND SETTING: Prospective observational cohort, with 5-year follow-up of all research submitted for consideration to the major annual 1991 US research meeting in the specialty of emergency medicine. PARTICIPANTS: All research abstracts submitted for consideration at the meeting for possible presentation. MAIN OUTCOME MEASURES: Characteristics associated with acceptance for presentation at the meeting and subsequent publication as a full manuscript. RESULTS: A total of 492 research abstracts were submitted from programs in emergency medicine and other specialties affiliated with 103 US medical schools. A total of 179 (36%) were accepted for presentation and 214 (43%) were published in 44 journals. Of the 179 abstracts accepted for presentation, 111 studies were published. Scientific quality of abstracts or prestige of the journal in which the study was eventually published did not predict either of these outcomes. The best predictors (by logistic regression) of meeting acceptance were a subjective "originality" factor (odds ratio [OR], 2.07; 95% confidence interval [CI], 1.13-3.89) and positive results (OR, 1.99; 95% CI, 1.07-3.84), and, for publication, meeting acceptance (OR, 2.49; 95% CI, 1.49-4.35) and large sample size (OR, 2.26; 95% CI, 1.23-4.31). Forty-nine percent (241) of abstracts did not report on blinding, and 24% (118) did not report on randomization. Acceptance and publication were both more likely for positive outcomes (P=.03). Funnel plots showed the classic distribution of positive-outcome ("publication") bias at each of the submission, acceptance, and publication phases. Meeting acceptance predicted publication with a sensitivity of only 51%, specificity of 71%, positive predictive value of 57%, and negative predictive value of 66%. CONCLUSIONS: Positive-outcome bias was evident when studies were submitted for consideration and was amplified in the selection of abstracts for both presentation and publication, neither of which was strongly related to study design or quality.

Unpublished research from a medical specialty meeting: why investigators fail to publish.

CONTEXT: It is not known whether peer review of research abstracts submitted to scientific meetings influences subsequent attempts at publication. OBJECTIVE: To determine why research submitted to a scientific meeting is not subsequently published. We hypothesized that authors of abstracts rejected by a meeting are less likely to pursue publication than those whose abstracts are accepted, regardless of research quality. DESIGN AND PARTICIPANTS: Blinded review of abstracts submitted to a medical specialty meeting in 1991 and not published as full manuscripts within 5 years. In 1996, authors of 266 unpublished studies were asked to complete questionnaires. MAIN OUTCOME MEASURES: Submission of a full manuscript to a journal between 1991 and 1996; failure to submit a manuscript to a journal because the investigator believed it would not be accepted for publication. RESULTS: A total of 223 (84%) of the unpublished investigators returned the questionnaire. Only 44 (20%) had submitted manuscripts to a journal. Manuscript submission was not associated with abstract quality (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.80-1.64), positive results (OR, 0.75; 95% CI, 0.31-1.57), or other study characteristics. Having an abstract accepted for presentation at the meeting weakly predicted submission of a manuscript to a journal (OR, 1.88; 95% CI, 0.84-4.10). Authors of accepted abstracts were significantly less likely to believe a journal would not publish their manuscript than were authors of rejected abstracts (OR, 0.23; 95% CI, 0.0001-0.61). CONCLUSIONS: Study characteristics do not predict attempts to publish research submitted to a scientific meeting. Investigators whose research is rejected by a meeting are pessimistic about chances for publication and may make less effort to publish.

Plantar puncture wounds: a survey to determine the incidence of infection.

OBJECTIVE: To determine the incidence of plantar puncture wound infections. METHODS: Ambulatory emergency patients were surveyed with regard to a previous history of plantar puncture wounds and any subsequent infections. RESULTS: 200 questionnaires were analysed. Forty four percent of respondents had previously sustained at least one plantar puncture wound. Of 156 wounds, 79 (50%) came to the attention of a physician. There were 10 infections, nine of which were seen by a physician. Counting only those wounds seen by a physician, the apparent infection rate in the study population is 11.4%. When all wounds are included, the infection rate is 6.4%. CONCLUSIONS: The infection rate of plantar puncture wounds is lower than most studies report because many wounds with a benign outcome never come to medical attention. Recommendations for treatment of fresh puncture wounds in the emergency department should be evaluated in light of this infection rate.

Heart rate and sustained attention during childhood: age changes in anticipatory heart rate, primary bradycardia, and respiratory sinus arrhythmia.

This study examined age changes in three aspects of heart rate responsivity elicited in an auditory oddball task; anticipatory heart rate change, primary bradycardia, and respiratory sinus arrhythmia. Three age groups (5-, 7-, and 9-year-old boys) were presented with series of target (15%) and standard (85%) tones. The results were consistent with the findings reported previously in the adult literature. Heart rate decreased in anticipation of the target tone. The morphology of anticipatory deceleration was somewhat different for the 5-year-olds compared to the older children. Stimuli presented during the early part of the cardiac cycle induced added deceleration, but this primary bradycardia did not differ between age groups. Respiratory sinus arrhythmia did not discriminate between age groups but was suppressed during the performance of the oddball task relative to base level. It was concluded that these three aspects of heart rate responsivity show developmental constancy rather than change.

A nonstationarity test for the spectral analysis of physiological time series with an application to respiratory sinus arrhythmia.

The spectral analysis of time series requires the signal to be at least weakly stationary; i.e., the mean, (co-) variance, and spectrum of the time series should not vary from segment to segment. It is commonly assumed that psychophysiological time series are not stationary. This study introduces a nonstationarity test to the psychophysiological literature, which is derived from evolutionary spectral analysis. Basically, the test consists of a double window technique in both the time and frequency domains, leading to a two-way analysis of variance for times and frequencies. In the current study, the nonstationarity test is applied to heart rate data obtained in a typical psychophysiological setting. Heart rate and respiration were measured in four age groups under four conditions--rest, paced breathing, vigilance, and reaction time. The results indicate that only few physiological time series were completely stationary. However, for every subject, and in every condition stationary stretches could be found that were long enough to apply spectral analysis. Spectral measures (power, coherence, and phase spectra) were then compared for stationary parts of the data and the total data. This comparison indicated that nonstationarity affects all spectral measures. Most importantly, Stationarity x Task Condition x Frequency Band interactions were observed for coherence and phase spectra, and there were significant interactions with age for each of the spectral indices. These findings suggest that nonstationarity may result in biased outcomes of significance tests of the effects of task manipulations on the spectral indices of cardiac time series. Thus, it was concluded that the stationarity test should be routinely applied in the spectral analysis of physiological time series. In addition, it was suggested that the nonstationarity test has an even wider range of application that might be of interest to the psychophysiologist.

Thermal discrimination thresholds in normal subjects and in patients with diabetic neuropathy.

Using two identical thermostimulators which operated on the Peltier principle, thermal cutaneous sensation of the hand and the foot was investigated in 36 normal subjects and in 20 patients with diabetic neuropathy. Using a two-alternative forced-choice testing procedure, thermal discrimination thresholds were determined twice. The values found in normal subjects are comparable with data from the literature. It was confirmed that thermal discrimination of the foot decreased with increasing age. In patients with diabetic neuropathy the increased thresholds for the foot could be correlated with length-dependent degeneration of small nerve fibres.

Variation in corn (Zea mays L.) for fatty acid compositions of triglycerides and phospholipids.

The percentage of linoleic acid in corn germ oil of three crosses, C103D x B73, C103D x B84, and T220 x H51, and their reciprocals was investigated. Corn germ oil from F2, F3, and backcrossed generations was also examined. More than one gene locus appeared to be involved in conditioning the linoleic acid content in these crosses. Strong maternal effects were exhibited in the F1's. Genotype also superimposed variations in fatty acid compositions within the characteristic lipid class patterns of the phospholipids, phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. Fatty acid placements in triglycerides, digalactosyldiglycerides, and phospholipids of one inbred, H51, were determined by lipase and phospholipase hydrolysis. The overall pattern of placement showed that the fatty acids at the 1 position were predominantly saturated saturated and those at the 2 position were predominantly unsaturated, but the fatty acid distribution was different for each individual lipid class. The molecular species of the phosphatidylcholines and phosphatidylethanolamines were separated by silver nitrate thin-layer chromatography. The major differences in the molecular species were a higher level of the dienoic-dienoic species and a lower level of the monoenoic-monoenoic species in the phosphatidylethanolamines than in the phosphatidylcholines.

Influence of trichloroacetic acid-phosphotungstic acid on the thin layer chromatographic mobility of gangliosides.

Trichloroacetic acid (TCA)-phosphotungstic acid (PTA) precipitation has been used as a faster procedure than dialysis for the isolation of gangliosides, but the TCA-PTA treatment causes striking abnormalities in the thin layer chromatographic mobilities of the gangliosides. However, a normal chromatographic pattern can be restored by treating the precipitated gangliosides with the tetrasodium salt of ethylenediamine tetraacetic acid followed by dialysis. Hence, TCA-PTA treatment does not appear to cause artifacts or hydrolysis of the gangliosides.

Differential cold tolerance, starch, sugar, protein, and lipid of yellow and purple nutsedge tubers.

From measurements of viability after exposure of tubers to natural overwintering in the soil and 6 weeks exposure at 2 C, species cold tolerance of the tubers was ranked in decreasing order: yellow nutsedge ;I' (Cyperus esculentus L.), an ecotype originating in Illinois; yellow nutsedge ;G', an ecotype originating in Georgia; and purple nutsedge (Cyperus rotundus L.). The ratios of unsaturated-saturated fatty acids in tuber triglycerides, tuber polar lipids, and leaf polar lipids followed the same order as the cold tolerance rankings, with the most cold-hardy species having the highest ratios. Lipid content was less than 1% of dry weight in purple nutsedge tubers, but was from 5 to 7% in both yellow nutsedge tubers. Starch, sugar, and lipid contents increased significantly in the hardy yellow nutsedge ;I' tubers during a 6-week exposure to 2 C, but did not change in the susceptible purple nutsedge tubers; only sugar increased in yellow nutsedge ;G' tubers after this treatment. Protein content was not altered by the 2 C treatment in any of the tubers. Apparently, several factors involving starch, sugar, lipids, and fatty acids are related to the differences in tolerance to cold in these species.

Changes in structure of triglycerides from maturing kernels of corn.

Kernels of corn inbred H51 were collected at five intervals after hand pollination. The triglyceride content of the total lipids increased from 8.6% at 10 days after pollination to 78.3% at 60 days. The most active period of triglyceride synthesis occurred from 20 to 45 days after pollination, when the weight of triglycerides per kernel increased from 1.1 to 7.5 mg. Over all the collection periods the percentages of palmitic, linoleic and linolenic acids decreased while oleic acid increased, but from 30 to 60 days after pollination the fatty acid composition of the triglycerides was nearly constant. Stereospecific analysis revealed a general fatty acid pattern for the triglycerides, in which the concentration of the saturated acids was highest in position 1, linoleic acid in 2 and oleic acid in 3. From 20 to 60 days after pollination there was little change in the fatty acid composition at the 1 position, but the largest changes occurred at the 3 position where palmitic and oleic acids decreased 5.1% and 7.3%, respectively, and linoleic acid increased 13.4%. The variations in the molecular species of the triglycerides were determined by silver nitrate thin layer chromatography and were found to be small from 20 to 60 days after pollination, except for an increase in trilinolein from 5.2 to 11.9%. Stereospecific analyses of four major triglycerides species, SMD, M2D, SD2, and MD2, revealed larger changes in fatty acid distribution at individual positions during maturation than were apparent from analyses of the total triglycerides.