Physiology Variables Research Articles

Efficacy of 1-methylcyclopropene in promoting shoot growth of tomato transplants

The ethylene inhibitor 1-methylcyclopropene (1-MCP) is commonly used to increase the shelf life of fruits. However, the application of 1-MCP to modulate the shoot growth of vegetable transplants is unknown. The objective of this study was to assess the influence of 1-MCP on improving the growth and quality of tomato transplants. Eight tomato cultivars ('Florida 47', 'Shanty', 'Volante', 'Tycoon', 'TAMU-Hot', 'Felicity', 'Charger', and 'BHN685') were grown in greenhouse conditions for seven weeks and then 1-MCP (50 mg L-1) was applied to transplants using a boom fertigation system. After treatments, both the 1-MCP and untreated plants were transferred to 0.5-L pots and placed in three growth chamber environments differing in day/night temperature regimes, 30/20°C (optimum), 34/24°C constant (stress) and 34/24°C ramping (stress). The plant morphology and physiology variables were collected during the study period. 1-MCP application significantly increased the leaf area, stem diameter and plant height of 'Florida 47' across all temperature regimes. 'TAMU-Hot', which was grown only in the 34/24 environment (ramping) also positively responded to 1-MCP. However, the leaf gas exchange (photosynthetic rate and stomatal conductance) and SPAD measurements were inconsistent across cultivars. 1-MCP had no negative effect on the transplant growth across all cultivars in the 30/20 environment but reduced growth components in Felicity and Tycoon in the 34/24 environment. Our results showed that the application of 1-MCP to improve the transplant quality is promising. Since genetics and environment may influence the sensitivity of tomato plants to 1-MCP, future studies should aim to identify the optimal microclimate growth conditions for specific cultivars.

Carbon isotope composition of birch syrup

Birch syrup is a forest product produced from tree sap using methods similar to those used in maple syrup production. This study presents the first measurements of the carbon isotope ratio of birch syrup, which is ultimately a function of tree physiology and environmental variables. Birch syrup has an average δ13C value = −25.31 ± 0.62‰ VPDB (1σ, n = 28), which is comparable to maple syrup. A few other tree syrups were analyzed for comparison: black walnut syrup has an average δ13C value = −25.52 ± 0.33‰ (n = 4) and one butternut syrup has a δ13C value = −23.88‰. All of these syrups are within the range of carbon isotope ratios typical of C3 plants, and are distinct from the carbon ratios of common C4 sugars derived from corn and sugarcane (δ13C value≈ −11 to −12‰). Detection of exogenous C4 sugars using carbon isotope ratio can be applied to birch syrup in the same way as it is used for other C3 foods such as maple syrup, honey, and fruit products.

Hemodynamic, Biochemical, and Ventilatory Parameters are Independently Associated with Outcome after Cardiac Arrest.

Hypotension, hyperglycemia, dysoxia, and dyscarbia may contribute to reperfusion injury, and each is independently associated with poor outcome (PO) after cardiac arrest. We investigated whether the combined effects of these physiological derangements are associated with cardiac arrest outcomes. This institutional review board-approved retrospective cohort study included consecutive resuscitated cardiac arrest patients that received targeted temperature management at Maine Medical Center from 2013 to 2015. We abstracted demographics, intra-arrest factors, and physiological parameters. The primary outcome was dichotomized cerebral performance category (CPC 1-2 vs 3-5) at hospital discharge. After comparing demographics, clinical factors, and persistent post-arrest physiological derangements in patients with good and PO, we constructed a logistic regression model comprised of clinical and demographic factors separately associated with severity, and physiology variables, attempting to evaluate the independent effects of persistent physiological derangements on outcome. Sixty-eight of 222 (31%) patients had CPC 1-2 (good outcome [GO]) at discharge. In bivariate analysis, factors associated with PO included increased time from collapse to resuscitation, non-shockable rhythm, and age-combined Charlson comorbidity index. In multivariate analysis, each persistent physiological derangement incrementally decreased the likelihood of GO [OR GO per derangement 0.71 (interquartile range [IQR] 0.51-0.99), p=0.042, area under the curve (AUC) for final model 0.769]. Uncorrected physiological derangements in the first 24h after cardiac arrest are independently associated with PO. Although causality cannot be established, these findings support preclinical models suggesting that aggressive normalization of physiology after resuscitation may be a reasonable strategy to decrease reperfusion injury.

Physiological Aspects of Cauliflower Plants Affected by Fertigation Intervals and Doses of Various Inter - Season Soil Ameliorants in Coastal Sandy Land

Cauliflower is one of vegetable commodities mostly consumed. The study aimed to determine fertigation interval and application of soil ameliorants including the types, doses, and frequency that are appropriate for the growth and productivity of cauliflower plants in coastal sandy land. The research was carried out in the sandy beach area of Jetis, Banjarsari Village, Nusawungu District, Cilacap Regency from April 2017 to September 2017. The study was arranged in Randomized Complete Block Design (RCBD) factorial split plot. Data were analyzed by ANOVA followed by DMRT at 5 %. The results showed that (1) the fertigation interval did not significantly affect the growth, yield and physiology variables of cauliflower plants; (2) the frequency of soil ameliorants application had significant effect on the variable growth and yield of cauliflower plants. The application of soil ameliorants every season gave the best results compared to application every two seasons; (3) the application of soil ameliorants of Vertisol soil and manure could increase growth and yield variables compared but did not affect the physiology of cauliflower plants.

The quick and the dead: microbial demography at the yeast thermal limit.

The niche of microorganisms is determined by where their populations can expand. Populations can fail to grow because of high death or low birth rates, but these are challenging to measure in microorganisms. We developed a novel technique that enables single-cell measurement of age-structured birth and death rates in the budding yeast, Saccharomyces cerevisiae, and used this method to study responses to heat stress in a genetically diverse panel of strains. We find that individual cells show significant heterogeneity in their rates of birth and death during heat stress. Genotype-by-environment effects on processes that regulate asymmetric cell division contribute to this heterogeneity. These lead to either premature senescence or early life mortality during heat stress, and we find that a mitochondrial inheritance defect explains the early life mortality phenotype of one of the strains we studied. This study demonstrates how the interplay of physiology, genetic variation and environmental variables influence where microbial populations survive and flourish.

The promise of wearable sensors and ecological momentary assessment measures for dynamical systems modeling in adolescents: a feasibility and acceptability study

Intervention development can be accelerated by using wearable sensors and ecological momentary assessment (EMA) to study how behaviors change within a person. The purpose of this study was to determine the feasibility and acceptability of a novel, intensive EMA method for assessing physiology, behavior, and psychosocial variables utilizing two objective sensors and a mobile application (app). Adolescents (n=20) enrolled in a 20-day EMA protocol. Participants wore a physiological monitor and an accelerometer that measured sleep and physical activity and completed four surveys per day on an app. Participants provided approximately 81% of the expected survey data. Participants were compliant to the wrist-worn accelerometer (75.3%), which is a feasible measurement of physical activity/sleep (74.1% complete data). The data capture (47.8%) and compliance (70.28%) with the physiological monitor were lower than other study variables. The findings support the use of an intensive assessment protocol to study real-time relationships between biopsychosocial variables and health behaviors.

Mango resistance against Ceratocystis fimbriata is impaired by local starch mobilization

Mango wilt, caused by Ceratocystis fimbriata, is one of the most serious diseases affecting mango production worldwide. Considering the great variation in the basal level of wilt resistance among mango cultivars, this study aimed to assess changes in photosynthesis and the role played by the carbon metabolism on two mango cultivars with contrasting responses to C. fimbriata infection. Assessment of disease and plant physiology variables was performed over 21 days. The response of the mango cultivars against fungal infection was associated with an increase on the mobilization of starch from the leaf tissue around the infection sites on stems. Plants of cv. Uba were less susceptible to mango wilt and, presumably, better capable of mobilizing reserves for the production of defense compounds, which prevented colonization of the stem inner tissues and the consequent disruption of xylem hydraulic conductivity and leaf photosynthesis. On the other hand, the inability in mobilizing and targeting carbon for the production of defense-related compounds should have accounted for the higher susceptibility of cv. Palmer to C. fimbriata infection.

Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.

BackgroundAlthough several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.ObjectiveThe purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.MethodsA total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from −950 HU to −701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated.ResultsCT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P <0.0001). NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).ConclusionThe measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

Commentary on "Near-Death Experiences with Hallucinatory Features"

Abstract: In this response to Keith Augustine's paper, I discuss the question of the nature and causation of near-death experiences (NDEs) with hallucinatory features. The attribution of hallucinations to either a brain mechanism or a peek into the afterworld raises fundamental questions about both the epistemology and ontology of our neuroscience, and of our scientific models of an afterlife. It also raises questions about the physiological state of the brain giving rise to NDEs that arise in very different situations and are clearly unlikely to have a unitary cause. These fundamental questions can be answered only in proper prospective trials when both the brain physiology and psychological variables of the experiencer are known.

Staging of idiopathic pulmonary fibrosis: past, present and future.

Idiopathic pulmonary fibrosis (IPF) is traditionally staged with terms such as "mild", "severe", "early" and "advanced" based on pulmonary function tests. This approach allows physicians to monitor disease progression and advise patients and their families. However, it is not known if the stages of this model reflect distinct biological or clinical phenotypes and the therapeutic and prognostic value of this system is limited. Novel methods of IPF staging have recently been developed. The GAP model includes four baseline variables that were found to be predictive of outcome, as identified by logistic regression. These factors are: gender (G), age (A) and two lung physiology variables (P) (forced vital capacity and diffusing capacity of the lung for carbon monoxide). The clinical utility and accuracy of staging models may be further improved in the future by the integration of dynamic parameters that can be measured over time, as well as biological data from biomarkers which may be able to directly measure disease activity. The development of an evidence-based, multidimensional IPF staging model that builds on the current staging approaches to IPF is an important objective for improving the management of IPF.

Disease-specific Severity Measures and Health-related Quality of Life in Idiopathic Pulmonary Fibrosis

Objective: To elucidate the correlation between two disease-specific severity measures (CPI, composite physiologic index; GAP, gender, age, lung physiology variables) and health-related quality of life in patients with idiopathic pulmonary fibrosis (IPF). Methods: We used data from a previously reported observational cohort study using the Medical Outcome Study Short Form 36 (SF-36) for measuring health-related quality of life. Of the 44 patients with IPF who participated in the initial cross-sectional study, 32 patients participated in the follow-up study. The CPI and the GAP index were calculated at baseline and follow-up. Results: In the cross-sectional study, the CPI only correlated with one SF-36 domain and the GAP index did not correlate with any of the SF-36 domains. In the current longitudinal study (the median follow-up; 14 months), there was a significant increase in both indices: ΔCPI = 11.5 (95% confidence interval; 6.8, 16.1) and ΔGAP index = 0.59 (95% confidence interval; 0.25, 0.93). Within-subject changes in the CPI and the GAP index were significantly correlated with those of 5 and 3 subscales of the SF-36, respectively. Declines in 4 subscales of the SF-36 were significantly more severe in subjects whose CPI increased by ≥ 5 than in subjects whose CPI did not. Similarly, declines in 3 subscales were significantly more severe in subjects whose GAP stage increased than in subjects whose GAP stage did not. Conclusion: Serial changes in the CPI and the GAP index may be useful to predict changes in the healthrelated quality of life of IPF patients.

The Clinical Performance of Lenses Disposed of Daily Can Vary Considerably

To evaluate clinical performance of three lens types disposed of on a daily disposable (DD) basis. A total of 120 participants were randomized into one of three lens types (etafilcon A, narafilcon A, and senofilcon A), all worn bilaterally on a DD regime. Participants were observed at baseline, 2-week, and 1- and 3-month visits where ocular physiology and lens performance variables were collected on a 0 to 4 grading scale in 0.1 increments. Subjective comfort and vision ratings were collected on a 1 to 100 rating scale and in the form of symptom severity. Forty participants wore each lens type with no differences in age or gender between groups (P>0.05). Etafilcon A exhibited more limbal redness compared with either of the other lens types (P<0.01). More superior corneal staining was noted with narafilcon A lenses compared with senofilcon A (P<0.01), and more superior conjunctival indentation was noted for narafilcon A compared with etafilcon A (P=0.001). No differences were found between lenses in the 1 to 100 rating scale (P>0.05). Narafilcon A showed more moderate to severe dryness symptoms and symptoms of blurred vision at lens wearing visits (P<0.05). One bilateral contact lens papillary conjunctivitis, one unilateral superior epithelial arcuate lesion, and one infiltrative keratitis were associated with narafilcon A only. Of the seven discontinuations, six were from the narafilcon A group. Different contact lens materials and designs, worn on the same DD modality, elicit different ocular and patient responses. Narafilcon A did not perform clinically as well as etafilcon A and senofilcon A worn on a DD modality.

A Multidimensional Index and Staging System for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with an overall poor prognosis. A simple-to-use staging system for IPF may improve prognostication, help guide management, and facilitate research. To develop a multidimensional prognostic staging system for IPF by using commonly measured clinical and physiologic variables. A clinical prediction model was developed and validated by using retrospective data from 3 large, geographically distinct cohorts. Interstitial lung disease referral centers in California, Minnesota, and Italy. 228 patients with IPF at the University of California, San Francisco (derivation cohort), and 330 patients at the Mayo Clinic and Morgagni-Pierantoni Hospital (validation cohort). The primary outcome was mortality, treating transplantation as a competing risk. Model discrimination was assessed by the c-index, and calibration was assessed by comparing predicted and observed cumulative mortality at 1, 2, and 3 years. Four variables were included in the final model: gender (G), age (A), and 2 lung physiology variables (P) (FVC and Dlco). A model using continuous predictors (GAP calculator) and a simple point-scoring system (GAP index) performed similarly in derivation (c-index of 70.8 and 69.3, respectively) and validation (c-index of 69.1 and 68.7, respectively). Three stages (stages I, II, and III) were identified based on the GAP index with 1-year mortality of 6%, 16%, and 39%, respectively. The GAP models performed similarly in pooled follow-up visits (c-index ≥71.9). Patients were drawn from academic centers and analyzed retrospectively. The GAP models use commonly measured clinical and physiologic variables to predict mortality in patients with IPF.

Derivation and validation of a risk adjustment model for predicting seven day mortality in emergency medical admissions: mixed prospective and retrospective cohort study

Objectives To derive and validate a risk adjustment model for predicting seven day mortality in emergency medical admissions, to test the value of including physiology and blood parameters, and to...

Testing the Validity of the ATLS Classification of Hypovolaemic Shock

The Advanced Trauma Life Supports (ATLS) classification of hypovolemic shock is often used resuscitating patients with major trauma. Although cited by numerous articles and guidelines, its sensitivity and specificity for shock are unclear. This retrospective study sought to assess the validity of the ATLS classification of shock by comparing it with physiological data recorded in the emergency department (ED) from patients in the Trauma Audit and Research Network (TARN) database. Admission physiology, injury, and outcome variables from 107,649 injured adult patients presenting to hospitals in England and Wales between 1989 and 2007 were included. Eligible patients were those sustaining traumatic injury necessitating admission to the hospital for≥3 days, transfer for more advanced care, or death within 93 days. Eligible patients were divided into groups representing the four ATLS shock subgroups, based on their presenting heart rate (HR), systolic blood pressure (SBP), respiratory rate (RR), and Glasgow Coma Scale score (GCS). Although ATLS class IV shock is characterized by HR>140 beats/min, RR>35 breaths/min, and a reduced SBP, the physiologic data from the TARN database reveals that in patients with HR>140 beats/min, the median RR was only 24 breaths/min and the upper quartile was only 30 breaths/min. In addition, few patients would have met the standard definition of hypotension and thus qualified as class IV shock, as the median SBP for injured patients with a median age of 35 years was 130 mm Hg and the lower quartile was 103 mm Hg. Although these results indicate there likely is an association between elevated HRs, lowered SBPs, and raised RRs, these changes do not always occur simultaneously and to the degree indicated by the ATLS classification of shock. Based on this, the authors concluded that for both blunt and penetrating trauma patients, ATLS seems to overestimate the degree of hypotension and tachypnea associated with tachycardia.

Vital signs and estimated blood loss in patients with major trauma: Testing the validity of the ATLS classification of hypovolaemic shock

Aim The Advanced Trauma Life Support (ATLS) system classifies the severity of shock. The aim of this study is to test the validity of this classification. Methods Admission physiology, injury and outcome variables from adult injured patients presenting to hospitals in England and Wales between 1989 and 2007 and stored on the Trauma Audit and Research Network (TARN) database, were studied. For each patient, the blood loss was estimated and patients were divided into four groups based on the estimated blood loss corresponding to the ATLS classes of shock. The median and interquartile ranges (IQR) of the heart rate (HR) systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Score (GCS) were calculated for each group. Results The median HR rose from 82 beats per minute (BPM) in estimated class 1 shock to 95 BPM in estimated class 4 shock. The median SBP fell from 135 mm Hg to 120 mm Hg. There was no significant change in RR or GCS. Conclusion With increasing estimated blood loss there is a trend to increasing heart rate and a reduction in SBP but not to the degree suggested by the ATLS classification of shock.

Evidence-Based Systematic Review: Effects of Oral Motor Interventions on Feeding and Swallowing in Preterm Infants

To conduct an evidence-based systematic review and provide an estimate of the effects of oral motor interventions (OMIs) on feeding/swallowing outcomes (both physiological and functional) and pulmonary health in preterm infants. A systematic search of the literature published from 1960 to 2007 was conducted. Articles meeting the selection criteria were appraised by 2 reviewers and vetted by a 3rd for methodological quality. Twelve studies were included and focused on 3 OMIs-nonnutritive sucking (NNS), oral/perioral stimulation, and NNS plus oral/perioral stimulation. Six studies addressed the effects of OMI on the feeding/swallowing physiology outcomes of feeding efficiency or sucking pressures. Ten studies addressed the functional feeding/swallowing outcomes of oral feeding or weight gain/growth. No studies reported data on pulmonary health. Methodological quality varied greatly. NNS alone and with oral/perioral stimulation showed strong positive findings for improvement in some feeding/swallowing physiology variables and for reducing transition time to oral feeding. Prefeeding stimulation showed equivocal results across the targeted outcomes. None of the OMIs provided consistent positive results on weight gain/growth. Although some OMIs show promise for enhancing feeding/swallowing in preterm infants, methodological limitations and variations in results across studies warrant careful consideration of their clinical use.

Testing the validity of the ATLS classification of hypovolaemic shock

Aim The Advanced Trauma Life Support system classifies the severity of shock. The aim of this study is to test the validity of this classification. Methods Admission physiology, injury and outcome variables from adult injured patients presenting to hospitals in England and Wales between 1989 and 2007 and stored on the Trauma Audit and Research Network (TARN) database, were studied. Patients were divided into groups representing the four ATLS classes of shock, based on heart rate (HR) systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Score (GCS). The relationships between variables were examined by classifying the cohort by each recorded variable in turn and deriving the median and interquartile range (IQR) of the remaining three variables. Patients with penetrating trauma and major injuries were examined in sub-group analyses. Results In blunt trauma patients grouped by HR, the median SBP decreased from 128 mm Hg in patients with HR < 100 BPM to 114 mm Hg in those with HR > 140 BPM. The median RR increased from 18 to 22 bpm and the GCS reduced from 15 to 14. The median HR in hypotensive patients was 88 BPM compared to 83 BPM in normotensive patients and the RR was the same. When grouped by RR, the HR increased with increasing RR but there were no changes in SBP. Conclusion In trauma patients there is an inter-relationship between derangements of HR, SBP, RR and GCS but not to the same degree as that suggested by the ATLS classification of shock.

M1243 Successful Biofeedback in Patients with Multiple Sclerosis Is Related to Disability and Mood Factors More Than Anorectal Physiology Variables

M1243 Successful Biofeedback in Patients with Multiple Sclerosis Is Related to Disability and Mood Factors More Than Anorectal Physiology Variables

Anterior Anal Sphincter Repair for Fecal Incontinence: Good Longterm Results Are Possible

Anterior anal sphincter repair (ASR) is standard treatment for fecal incontinence resulting from an obstetrically damaged anal sphincter. Longterm results of repair have generally been shown to be poor. This review of single-unit series aimed to determine longterm outcomes of primary ASR for patients with fecal incontinence from obstetrically damaged anal sphincter. This study included patients undergoing ASR from 1995 to 1999. We perform standard overlapping ASR, but external and internal sphincters are repaired separately. The internal sphincter is sutured by direct method and only if damaged. Telephone interview was conducted with all patients, after which questionnaires, including SF-36 survey, Fecal Incontinence Quality of Life Scale questions, and Wexner score-type questions, were sent at median followup of 7 years. Demographic data, anorectal physiology, and data on short-term followup (median 12 months) were prospectively collected. Sixty-four of 72 patients returned questionnaires and the operation was considered a success in 80% of patients at median followup of 84 months. Six patients underwent additional procedures for incontinence and 58 patients were analyzed. Fourteen patients reported complete continence to stool and flatus (20%). Continence had improved from median Wexner score of 14 to 7 (p < 0.001). Ninety-five percent of patients were satisfied with their operation. There was substantial improvement in all aspects of Fecal Incontinence Quality of Life Scale questionnaire and SF-36. None of the anorectal physiology variables were of value in predicting outcomes. We have shown that good longterm results can be achieved with anterior anal sphincter repair. The independent muscle repair technique could explain the improved outcomes.