scholarly journals Ultradian regulation of rest and activity bouts in mice

2019 ◽  
Author(s):  
Bharath Ananthasubramaniam ◽  
Johanna H. Meijer
Keyword(s):  
Average Length ◽  
Behavioral Activity ◽  
Time Interval ◽  
Behavioral State ◽  
Infrared Sensors ◽  
Continuous Darkness ◽  
Subjective Night ◽  
Activity Bout ◽  
Central Pacemaker ◽  
Light Input

AbstractThe suprachiasmatic nucleus (SCN), which serves as the central pacemaker in mammals, regulates the 24-hour rhythm in behavioral activity. However, it is currently unclear whether and how bouts of activity and rest are regulated within the 24-hour cycle (i.e., over ultradian time scales). Therefore, we used passive infrared sensors to measure behavior in mice housed under either a light-dark (LD) cycle or continuous darkness (DD). We found that a probabilistic Markov model captures the ultradian changes in the behavioral state over a 24-hour cycle. In this model, the animal’s behavioral state in the next time interval is determined solely by the animal’s current behavioral state and by the “toss” of a proverbial “biased coin”. We found that the bias of this “coin” is regulated by light input and by the phase of the clock. Moreover, the bias of this “coin” for an animal is related to the average length of rest and activity bouts in that animal. In LD conditions, the average length of rest bouts was greater during the day compared to during the night, whereas the average length of activity bouts was greater during the night compared to during the day. Importantly, we also found that day-night changes in the rest bout lengths were significantly greater than day-night changes in the activity bout lengths. Finally, in DD conditions, the activity and rest bouts also differed between subjective night and subjective day, albeit to a lesser extent compared to LD conditions. The persistent differences in bout length over the circadian cycle following loss of the external LD cycle indicate that the central pacemaker plays a role in regulating rest and activity bouts on an ultradian time scale.

Assessing early unplanned reoperations in neurosurgery: opportunities for quality improvement

2015 ◽  
Vol 123 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Nancy McLaughlin ◽  
Peng Jin ◽  
Neil A. Martin
Keyword(s):  
Quality Improvement ◽  
Quality Indicator ◽  
Outpatient Surgery ◽  
Care Delivery ◽  
Average Length ◽  
Medical Center ◽  
Postoperative Bleeding ◽  
Time Interval ◽  
Neurosurgical Procedures ◽  
Neurosurgical Department

OBJECT Review of morbidities and mortality has been the primary method used to assess surgical quality by physicians, hospitals, and oversight agencies. The incidence of reoperation has been proposed as a candidate quality indicator for surgical care. The authors report a comprehensive assessment of reoperations within a neurosurgical department and discuss how such data can be integrated into quality improvement initiatives to optimize value of care delivery. METHODS All neurosurgical procedures performed in the main operating room or the outpatient surgery center at the Ronald Reagan UCLA Medical Center and UCLA Santa Monica Medical Center from July 2008 to December 2012 were considered for this study. Interventional radiology and stereotactic radiosurgery procedures were excluded. Early reoperations within 7 days of the index surgery were reviewed and their preventability status was evaluated. RESULTS The incidence of early unplanned reoperation was 2.6% (occurring after 183 of 6912 procedures). More than half of the patients who underwent early unplanned reoperation initially had surgery for shunt-related conditions (34.4%) or intracranial tumor (23.5%). Shunt failure was the most common indication for early unplanned reoperation (34.4%), followed by postoperative bleeding (20.8%) and postoperative elevated intracranial pressure (9.8%). The average time interval (± SD) between the index surgery and reoperation was 3.0 ± 1.9 days. The average length of stay following reoperation was 12.1 ± 14.4 days. CONCLUSIONS This study enabled an in-depth assessment of reoperations within an academic neurosurgical practice and identification of strategic opportunities for department-wide quality improvement initiatives. The authors provide a nuanced discussion regarding the use of absolute reoperations as a quality indicator for neurosurgical patient populations.

scholarly journals 781. Nurse-Driven Time-of-Triage Sepsis Screening Tool Improves Timely Intervention in Ambulatory Emergency Department (ED) Patients with Suspected Sepsis

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S346-S347
Author(s):  
Catalina Howland ◽  
Arthur Chang ◽  
Stephen Selvanayagam ◽  
Stacy Kim ◽  
Mark Bounthavong ◽  
...  
Keyword(s):  
Primary Outcome ◽  
Screening Tool ◽  
Early Recognition ◽  
Average Length ◽  
Primary Outcome Measure ◽  
Medical Attention ◽  
Time Interval ◽  
Antibiotic Administration ◽  
Suspected Sepsis ◽  
Sepsis Screening

Abstract Background Sepsis is a potentially life-threatening, systemic complication of infection. Rapid intervention is critical to reduce morbidity and mortality; however, early recognition of sepsis is challenging due to a highly variable and nonspecific presentation. Recognition is particularly problematic in ambulatory (walk-in) patients who receive minimal to no medical attention prior to ED presentation. There is limited literature addressing sepsis intervention among the ambulatory population in the ED. Our organization has employed an electronic, nurse-driven sepsis screening tool into the triage process for all ambulatory patients who present to the ED. Methods This was a retrospective, quasi-experimental study conducted from November 2015 to May 2018 in three consecutive timeframes: pre-implementation (12 months), implementation (7 months), and post-implementation (12 months). Adult ambulatory ED patients were included if they had a coded diagnosis of sepsis, septic shock, or an infectious syndrome, had fever or hypothermia and systemic inflammatory response syndrome signs on presentation. The primary outcome measure was hourly time interval to antibiotic administration from time of ED registration. Results A total of 902 patients were included with 286, 208, and 408 patients in the pre-implementation, implementation and post-implementation cohorts, respectively. Baseline characteristics including comorbid conditions and infection source were similar between cohorts. The primary outcome of hourly time interval to antibiotic administration was significantly different (P = 0.044) between the three cohorts with the most substantial increase in administration specifically in the less than 1-hour interval. Between the pre-implementation, implementation, and post-implementation cohorts, significant decreases were observed in mean time to fluids (3.6, 3.0, and 2.5 hours, respectively, P = 0.003) and average length of stay (5.5, 5.8, and 4.2 days, respectively, P < 0.001) and a significant increase was observed in ED sepsis alert activations (26%, 48%, 51%, respectively, P < 0.001). Conclusion A nurse-driven electronic time-of-triage sepsis screening tool improved timely recognition and intervention in ambulatory ED patients with suspected sepsis. Disclosures All authors: No reported disclosures.

scholarly journals Reproductive Biology of Oci Fish Selaroides leptolepis in Tomini Bay

2020 ◽  
Vol 9 (4) ◽  
pp. 407-415
Author(s):  
Nuralim Pasisingi ◽  
Putri Sapira Ibrahim ◽  
Zulkifli Arsalam Moo ◽  
Munirah Tuli
Keyword(s):  
Reproductive Biology ◽  
Sampling Method ◽  
Average Length ◽  
Time Interval ◽  
Gonad Maturity ◽  
Length Range ◽  
Management Policies ◽  
Interval Sampling ◽  
First Maturity ◽  
Fisheries Biology

Local people name Selaroides leptolepis distributed in Tomini Bay as Oci Fish. A study of the fish reproductive biology, which is one aspect of fisheries biology, is crucial to support the implementation of sustainable Oci Fish resource management policies. This study aims to determine the average length at first maturity, gonad maturity stages, and fecundity of the fish in Tomini Bay. Sampling was carried out using a stratified random sampling method from the catches of the fishermen landed in Fish Landing Base Kampung Tenda, Gorontalo City. The time interval sampling was conducted per month during April, May, and June 2020. Fish and egg samples preserved using ice cubes and a 10% formaldehyde solution correspondingly. The results of the study showed that the Oci Fish in Tomini Bay had a length range of the first maturity between 166 and 174 mm with a gonad maturity index ranging from 1.773 to 2.760%. The average fish fecundity was 16623 ± 4850 eggs.

The Effect of a Biological Clock on the Developmental Rate of Drosophila Pupae

1965 ◽  
Vol 42 (2) ◽  
pp. 323-337
Author(s):  
JANET E. HARKER
Keyword(s):  
Biological Clock ◽  
Bright Light ◽  
Developmental Rate ◽  
Time Of Day ◽  
Time Interval ◽  
Light Cycle ◽  
Continuous Darkness ◽  
Pupal Development ◽  
Wide Range ◽  
Three Stages

1. A study of the course of pupal development in two strains of Drosophila melanogaster has been made in an attempt to establish the factors affecting the time of adult eclosion. 2. The time taken to complete three stages of pupal development has been measured for pupae entering each stage at each particular hour of the day when insects were kept in 12 hr. light:12 hr. darkness, 12 hr. bright light: 12 hr. dim light, or in continuous darkness. 3. The duration of each stage, in both strains, is affected by the time of day, relative to the light cycle, at which the stage is entered. The duration of each stage for pupae kept in continuous darkness is affected by the time of day at which the stage is entered, relative to the light cycle to which they had been exposed as larvae. 4. The time-interval curves for all three stages of any one strain take the same form. 5. Because of the very wide range of developmental rates, dependent upon the time within the light cycle at which each stage begins, a population in which the larvae all pupate within a 24 hr. period will continue to produce adult flies over several days. 6. The eclosion rhythm is a population effect and does not reflect the phasing of individuals to a dawn eclosion; the majority of adults emerge at dawn because of the summation effect of circadian rhythms of development at earlier stages.

scholarly journals Regulation of light's action in the mammalian circadian clock: role of the extrasynaptic GABAA receptor

2009 ◽  
Vol 296 (5) ◽  
pp. R1606-R1612 ◽  
Author(s):  
J. Christopher Ehlen ◽  
Ketema N. Paul
Keyword(s):  
Wheel Running ◽  
Phase Shifts ◽  
Constant Darkness ◽  
Receptor Subtypes ◽  
Mrna Levels ◽  
Subjective Night ◽  
Behavioral Phase ◽  
Free Running ◽  
Light Input

GABAA receptor agonists act in the suprachiasmatic nucleus (SCN) to reset circadian rhythms during the day but inhibit the ability of light to reset rhythms during the night. In the present study, we examined whether these paradoxical differences in the effect of GABAA receptor stimulation on the circadian system are mediated by separate GABAA receptor subtypes. 4,5,6,7-Tetrahydroisoxazolo[5,4- c]pyridin-3-ol (THIP), a GABAA receptor agonist, preferentially activates GABAA receptors in extrasynaptic locations. THIP, muscimol (a GABAA agonist), or vehicle were microinjected into the SCN region of Syrian hamsters free-running in constant darkness during the mid-subjective day, early subjective night, or late subjective night. The subjective night injections were followed by a light pulse or sham control. Behavioral phase shifts of wheel running rhythms and both Period1 ( Per1) and Per2 mRNA levels in the SCN were assessed. Animals that received THIP during the subjective day did not exhibit significant phase alterations. During the early and late subjective night, however, THIP abolished the phase-shifting effects of light and the ability of light to increase Per1 and Per2 mRNA levels. The ability of N-methyl-d-aspartic acid to phase-shift wheel running rhythms was also attenuated by THIP. Together these data demonstrate that THIP does not produce phase shifts during the subjective day, but does inhibit the ability of light to produce phase shifts. Thus, extrasynaptic GABAA receptors appear to play a role in regulating light input to the SCN, while a different population of GABAA receptors appears to be responsible for daytime effects of GABA.

scholarly journals Impact of COVID-19 Outbreak on the Emergency Presentation of Acute Appendicitis

2020 ◽  
Vol 86 (11) ◽  
pp. 1508-1512
Author(s):  
Mariana Kumaira Fonseca ◽  
Eduardo N. Trindade ◽  
Omero P. Costa Filho ◽  
Miguel P. Nácul ◽  
Artur P. Seabra
Keyword(s):  
Postoperative Complications ◽  
Length Of Stay ◽  
Acute Appendicitis ◽  
Symptom Onset ◽  
Hospital Admissions ◽  
Average Length ◽  
Hospital Length ◽  
Hospital Length Of Stay ◽  
Time Interval ◽  
Emergency Presentation

Background The global crisis resulting from the coronavirus pandemic has imposed a large burden on health systems worldwide. Nonetheless, acute abdominal surgical emergencies are major causes for nontrauma-related hospital admissions and their incidences were expected to remain unchanged. Surprisingly, a significant decrease in volume and a higher proportion of complicated cases are being observed worldwide. Methods The present study assesses the local impact of the coronavirus pandemic on the emergency presentation of acute appendicitis in a Brazilian hospital. A retrospective analysis was conducted on patients undergoing emergency surgery for the clinically suspected diagnosis of acute appendicitis during the 2-month period of March and April 2020 and the same time interval in the previous year. Data on demographics, timing of symptom onset and hospital presentation, intraoperative details, postoperative complications, hospital length of stay, and histological examination of the specimen were retrieved from individual registries. Results The number of appendectomies during the pandemic was 36, which represents a 56% reduction compared to the 82 patients operated during the same period in 2019. The average time of symptom onset to hospital arrival was significantly higher in 2020 (40.6 vs. 28.2 hours, P = .02). The classification of appendicitis revealed a significant higher proportion of complicated cases than the previous year (33.3% vs. 15.2%, P = .04). The rate of postoperative complications and the average length of stay were not statistically different between the groups. Conclusion Further assessment of patients’ concerns and systematic monitoring of emergency presentations are expected to help us understand and adequately address this issue.

Cerebral oxidative metabolism in lambs during perinatal period: relationship to electrocortical state

1989 ◽  
Vol 257 (5) ◽  
pp. R1251-R1257 ◽  
Author(s):  
B. S. Richardson ◽  
L. Carmichael ◽  
J. Homan ◽  
R. Gagnon
Keyword(s):  
Blood Flow ◽  
High Voltage ◽  
Oxidative Metabolism ◽  
Low Voltage ◽  
Perinatal Period ◽  
Behavioral Activity ◽  
Behavioral State ◽  
Fetal Sheep ◽  
Awake State ◽  
Cerebral Oxidative Metabolism

Cerebral oxidative metabolism and regional blood flow were studied, with changes in behavioral state over the immediate perinatal period, to determine the change in cerebral metabolism at birth and the relationship to behavioral activity. Nine unanesthetized fetal sheep (139-142 days gestation) were each studied during a period of high-voltage and low-voltage electrocorticogram (ECOG) activity and then again after cesarean delivery at 2 h of age while awake and at 24 h of age while awake and during a period of high-voltage ECOG sleep. Preductal arterial and sagittal vein blood samples were analyzed for O2 content, blood gases, and pH. Blood flow was measured with a radioactive microsphere technique. Cerebral oxidative metabolism showed no significant perinatal change, although a coupling to behavioral state was evident with significant increases during both the perinatal low-voltage ECOG state and the awake state at 24 h. Blood flow to the brain showed a significant perinatal decrease after birth and state-related increases during both the prenatal low-voltage ECOG state and the awake state at 24 h consistent with the tight coupling of flow and/or O2 delivery to metabolic needs reported for normal brain tissue. The cerebral metabolic rate of the prenatal low-voltage ECOG state suggested a level of functional excitation comparable with that of the awake state after birth, supporting the importance of the rapid-eye-movement (REM) state mechanism as a source of endogenous stimulation during the perinatal period of brain growth and development.

scholarly journals Evaluation of the Manchester Triage System quality indicator: service time

2021 ◽  
Vol 42 ◽  
Author(s):  
Ana Paula Santos de Jesus ◽  
Ruth Ester Assayag Batista ◽  
Cassia Regina Vancini Campanharo ◽  
Maria Carolina Barbosa Teixeira Lopes ◽  
Meiry Fernanda Pinto Okuno
Keyword(s):  
Medical Care ◽  
Average Length ◽  
Waiting Times ◽  
Time Interval ◽  
System Quality ◽  
Cross Sectional ◽  
Manchester Triage System ◽  
Average Length Of Stay ◽  
The Times

ABSTRACT Objective: to verify the conformity of the time interval between the end of the risk classification and the beginning of medical care with that recommended by the Manchester protocol and to relate the times of care and the risk categories with the outcome. Method: Cross-sectional, retrospective, and analytical study. The t test, the analysis of variance and the generalized linear model were used. Results: The average time for medical care in the red and orange categories was 3 and 39.5 minutes, respectively. Death outcome was associated with the red category, with an average time to start the classification of 5.5 minutes and an average length of stay of 2.3 hours. Conclusion: The waiting time for medical care in the high priority categories was longer than recommended, which suggests the need to continuously monitor the system. Shorter waiting times for classification and permanence were related to the red category and the outcome of death.

scholarly journals Molecular Genetic Analysis of Flowering in Arabidopsis and Tomato

2002 ◽  
Author(s):  
D. Ry Wagner ◽  
Eliezer Lifschitz ◽  
Steve A. Kay
Keyword(s):  
Molecular Mechanisms ◽  
Crop Yields ◽  
Phase Response Curve ◽  
Continuous Light ◽  
Phase Response ◽  
Period Length ◽  
Response Curves ◽  
Subjective Night ◽  
Light Input

The primary objectives for the US lab included: the characterization of ELF3 transcription and translation; the creation and characterization of various transgenic lines that misexpress ELF3; defining genetic pathways related to ELF3 function regulating floral initiation in Arabidopsis; and the identification of genes that either interact with or are regulated by ELF3. Light quality, photoperiod, and temperature often act as important and, for some species, essential environmental cues for the initiation of flowering. However, there is relatively little information on the molecular mechanisms that directly regulate the developmental pathway from the reception of the inductive light signals to the onset of flowering and the initiation of floral meristems. The ELF3 gene was identified as possibly having a role in light-mediated floral regulation since elj3 mutants not only flower early, but exhibit light-dependent circadian defects. We began investigating ELF3's role in light signalling and flowering by cloning the ELF3 gene. ELF3 is a novel gene only present in plant species; however, there is an ELF3 homolog within Arabidopsis. The Arabidopsis elj3 mutation causes arrhythmic circadian output in continuous light; however, we show conclusively normal circadian function with no alteration of period length in elj3 mutants in dark conditions and that the light-dependent arrhythmia observed in elj3 mutants is pleiotropic on multiple outputs regardless of phase. Plants overexpressing ELF3 have an increased period length in constant light and flower late in long-days; furthermore, etiolated ELF3-overexpressing seedlings exhibit a decreased acute CAB2 response after a red light pulse, whereas the null mutant is hypersensitive to acute induction. This finding suggests that ELF3 negatively regulates light input to both the clock and its outputs. To determine whether ELF3's action is phase dependent, we examined clock resetting by light pulses and constructed phase response curves. Absence of ELF3 activity causes a significant alteration of the phase response curve during the subjective night, and overexpression of ELF3 results in decreased sensitivity to the resetting stimulus, suggesting that ELF3 antagonizes light input to the clock during the night. Indeed, the ELF3 protein interacts with the photoreceptor PHYB in the yeast two-hybrid assay and in vitro. The phase ofELF3 function correlates with its peak expression levels of transcript and protein in the subjective night. ELF3 action, therefore, represents a mechanism by which the oscillator modulates light resetting. Furthermore, flowering time is dependent upon proper expression ofELF3. Scientifically, we've made a big leap in the understanding of the circadian system and how it is coupled so tightly with light reception in terms of period length and clock resetting. Agriculturally, understanding more about the way in which the clock perceives and relays temporal information to pathways such as those involved in the floral transition can lead to increased crop yields by enabling plants to be grown in suboptimal conditions.

scholarly journals Treatment of Chylothorax complicating pulmonary resection with hypertonic glucose Pleurodesis

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Kejian Zhang ◽  
Changyuan Li ◽  
Mingrui Zhang ◽  
Yang Li
Keyword(s):  
Conservative Treatment ◽  
Pulmonary Resection ◽  
Average Length ◽  
Lung Resection ◽  
Time Interval ◽  
Ductus Thoracicus ◽  
Hypertonic Glucose ◽  
Average Length Of Stay ◽  
Closed Drainage ◽  
Chest Drainage Tube

Abstract Background To retrospectively assess the efficacy of hypertonic glucose pleurodesis for treatment of chylothorax after pulmonary resection. Methods Out of a total of 8252 patients who underwent pulmonary resection (at least lobectomy) at department of thoracic surgery, between June 2008 and December 2015, 58 patients (0.7%) developed postoperative chylothorax. All patients received conservative treatment, including thoracic closed drainage, oral fasting, and total parenteral nutrition. Results Conservative treatment was successful in 50 (86.2%) patients, while eight patients [mean age: 58.0 years (range, 45–75)] were treated with hypertonic glucose pleurodesis. All eight patients had undergone operation for lung cancer (four squamous cell carcinomas and four adenocarcinomas). The bronchial stump was covered by pleural flap in three patients. After pleurodesis, three patients developed fever but without empyema; thoracentesis was performed in two patients. The mean time interval between pleurodesis and operation was 4.3 days (range,3–5) days. The average length of stay was 23.1 days (range, 18–31). No recurrent pleural effusion was observed over a mean follow-up duration of 28 months. Conclusion Hypertonic glucose pleurodesis performed via the chest drainage tube is a viable treatment option for chylothorax after lung resection, prior to resorting to a thoracoscopic or thoracotomic ductus thoracicus ligation of the thoracic duct leak. It is a simple, safe and efficient modality associated with rapid recovery and less pain.

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