An aggregative response of the tropical Australian magpie goose (Anseranas semipalmata) to seasonal floodplains

Abstract:We describe the spatial aggregation of the magpie goose (Anseranas semipalmata) in relation to the dynamics of the ephemeral floodplains of northern Australia. Past broad-scale studies have linked geese to floodplains dominated by the sedge, Eleocharis dulcis, but the type of response has not been determined, nor the impact of predation on food plants. Moreover, departure thresholds are not known. We develop hypotheses on aggregation and departure and confront these with field data. Thus, from 2005–2007 we established two sites on the floodplains of Kakadu National Park (three 1-ha plots per site, six plots in total) and used for monthly, dry season bird counts. An airboat was used to collect data from each of the six plots, including sedge tubers and measures of water level and soil viscosity. Further, we built exclosures (three per site, six in total) to test the impact of herbivory on E. dulcis. Generalized linear models and information theory were used to test the strength of supporting evidence for alternate hypotheses. Geese showed a clear aggregative response to E. dulcis tubers, were forced to depart following floodplain drying and had a marked impact on E. dulcis tuber density. Despite this, there was no evidence of a negative-feedback mechanism between plant–herbivore populations, suggesting that the system is driven by extrinsic parameters (here rainfall).

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Kinetic Model of Translational Autoregulation

10.1101/432658 ◽

2018 ◽

Author(s):

Vivian Tyng ◽

Michael E. Kellman

Keyword(s):

Steady State ◽

Phase Space ◽

Kinetic Model ◽

Molecular Biology ◽

Messenger Rna ◽

Linear Models ◽

Feedback Mechanism ◽

Negative Feedback Mechanism ◽

Feedback Set ◽

System Phase

AbstractWe investigate dynamics of a kinetic model of inhibitory autoregulation as exemplified when a protein inhibits its own production by interfering with its messenger RNA, known in molecular biology as translational autoregulation. We first show how linear models without feedback set the stage with a nonequilibrium steady state that constitutes the target of the regulation. However, regulation in the simple linear model is far from optimal. The negative feedback mechanism whereby the protein “jams” the mRNA greatly enhances the effectiveness of the control, with response to perturbation that is targeted, rapid, and metabolically efficient. Understanding the full dynamics of the system phase space is essential to understanding the autoregulation process.

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Ultrastructural morphology of nontumorous lactotrophs in human pituitaries exposed to high prolactin levels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128766 ◽

1987 ◽

Vol 45 ◽

pp. 896-897

Author(s):

S. Jalalah ◽

K. Kovacs ◽

E. Horvath

Keyword(s):

Anterior Pituitary ◽

Secretory Activity ◽

Pituitary Hormones ◽

Feedback Mechanism ◽

Endocrine Activity ◽

Hormone Synthesis ◽

Anterior Pituitary Hormones ◽

Negative Feedback Mechanism ◽

Ultrastructural Morphology ◽

Transmission Electron

Lactotrophs, as many other endocrine cells, change their morphology in response to factors influencing their secretory activity. Secretion of prolactin (PRL) from lactotrophs, like that of other anterior pituitary hormones, is under the control of the hypothalamus. Unlike most anterior pituitary hormones, PRL has no apparent target gland which could modulate the endocrine activity of lactotrophs. It is generally agreed that PRL regulates its own release from lactotrophs via the short loop negative feedback mechanism exerted at the level of the hypothalamus or the pituitary. Accordingly, ultrastructural morphology of lactotrophs is not constant; it is changing in response to high PRL levels showing signs of suppressed hormone synthesis and secretion.By transmission electron microscopy and morphometry, we have studied the morphology of lactotrophs in nontumorous (NT) portions of 7 human pituitaries containing PRL-secreting adenoma; these lactotrophs were exposed to abnormally high PRL levels.

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Faculty Opinions recommendation of A deadenylation negative feedback mechanism governs meiotic metaphase arrest.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1108758.564878 ◽

2008 ◽

Author(s):

Angel Nebreda

Keyword(s):

Negative Feedback ◽

Feedback Mechanism ◽

Meiotic Metaphase ◽

Metaphase Arrest ◽

Negative Feedback Mechanism

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Socio-economic consequences of mental distress: quantifying the impact of self-reported mental distress on the days of incapacity to work and medical costs in a two-year period: a longitudinal study in Germany

BMC Public Health ◽

10.1186/s12889-021-10637-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Gerhard Müller ◽

Manuela Bombana ◽

Monika Heinzel-Gutenbrenner ◽

Nikolaus Kleindienst ◽

Martin Bohus ◽

...

Keyword(s):

Mental Disorders ◽

Mental Distress ◽

Linear Models ◽

Longitudinal Research ◽

Depression Scale ◽

Routine Data ◽

Medical Costs ◽

First Year ◽

Second Year ◽

The Impact

Abstract Background Mental disorders are related to high individual suffering and significant socio-economic burdens. However, it remains unclear to what extent self-reported mental distress is related to individuals’ days of incapacity to work and their medical costs. This study aims to investigate the impact of self-reported mental distress for specific and non-specific days of incapacity to work and specific and non-specific medical costs over a two-year span. Method Within a longitudinal research design, 2287 study participants’ mental distress was assessed using the Hospital Anxiety and Depression Scale (HADS). HADS scores were included as predictors in generalized linear models with a Tweedie distribution with log link function to predict participants’ days of incapacity to work and medical costs retrieved from their health insurance routine data during the following two-year period. Results Current mental distress was found to be significantly related to the number of specific days absent from work and medical costs. Compared to participants classified as no cases by the HADS (2.6 days), severe case participants showed 27.3-times as many specific days of incapacity to work in the first year (72 days) and 10.3-times as many days in the second year (44 days), and resulted in 11.4-times more medical costs in the first year (2272 EUR) and 6.2-times more in the second year (1319 EUR). The relationship of mental distress to non-specific days of incapacity to work and non-specific medical costs was also significant, but mainly driven from specific absent days and specific medical costs. Our results also indicate that the prevalence of presenteeism is considerably high: 42% of individuals continued to go to work despite severe mental distress. Conclusions Our results show that self-reported mental distress, assessed by the HADS, is highly related to the days of incapacity to work and medical costs in the two-year period. Reducing mental distress by improving preventive structures for at-risk populations and increasing access to evidence-based treatments for individuals with mental disorders might, therefore, pay for itself and could help to reduce public costs.

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152. Applying A Difference-in-Difference Analysis to Assess Effect of Antimicrobial Stewardship Strategies on Changes in Antimicrobial Use

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.197 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S86-S86

Author(s):

Ann F Chou ◽

Yue Zhang ◽

Makoto M Jones ◽

Christopher J Graber ◽

Matthew B Goetz ◽

...

Keyword(s):

Antimicrobial Stewardship ◽

Clinical Pharmacist ◽

Antibiotic Use ◽

Feedback Mechanism ◽

Health Care Facilities ◽

Antimicrobial Use ◽

Time Points ◽

The Difference ◽

The Impact ◽

Over Time

Abstract Background About 30–50% of inpatient antimicrobial therapy is sub-optimal. Health care facilities have utilized various antimicrobial stewardship (AS) strategies to optimize appropriate antimicrobial use, improve health outcomes, and promote patient safety. However, little evidence exists to assess relationships between AS strategies and antimicrobial use. This study examined the impact of changes in AS strategies on antimicrobial use over time. Methods This study used data from the Veterans Affairs (VA) Healthcare Analysis & Informatics Group (HAIG) AS survey, administered at 130 VA facilities in 2012 and 2015, and antimicrobial utilization from VA Corporate Data Warehouse. Four AS strategies were examined: having an AS team, feedback mechanism on antimicrobial use, infectious diseases (ID) attending physicians, and clinical pharmacist on wards. Change in AS strategies were computed by taking the difference in the presence of a given strategy in a facility between 2012–2015. The outcome was the difference between antimicrobial use per 1000 patient days in 2012–2013 and 2015–2016. Employing multiple regression analysis, changes in antimicrobial use was estimated as a function of changes in AS strategies, controlling for ID human resources in and organizational complexity. Results Of the 4 strategies, only change in availability of AS teams had an impact on antimicrobial use. Compared to facilities with no AS teams at both time points, antibiotic use decreased by 63.9 uses per 1000 patient days in facilities that did not have a AS team in 2012 but implemented one in 2015 (p=0.0183). Facilities that had an AS team at both time points decreased use by 62.2 per 1000 patient days (p=0.0324). Conclusion The findings showed that AS teams reduced inpatient antibiotic use over time. While changes in having feedback on antimicrobial use and clinical pharmacist on wards showed reduced antimicrobial use between 2012–2015, the differences were not statistically significant. These strategies may already be a part of a comprehensive AS program and employed by AS teams. In further development of stewardship programs within healthcare organizations, the association between AS teams and antibiotic use should inform program design and implementation. Disclosures All Authors: No reported disclosures

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Influenza With an Infiltrate: Investigating the New Community-Acquired Pneumonia Guidelines

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.884 ◽

2020 ◽

Vol 41 (S1) ◽

pp. s302-s302

Author(s):

Amanda Barner ◽

Lou Ann Bruno-Murtha

Keyword(s):

Demographic Data ◽

Retrospective Chart Review ◽

Vaccination Rate ◽

Community Acquired Pneumonia ◽

Teaching Hospitals ◽

Antibiotic Prescribing ◽

Supporting Evidence ◽

Radiographic Findings ◽

Significant Difference ◽

The Impact

Background: The Infectious Diseases Society of America released updated community-acquired pneumonia (CAP) guidelines in October 2019. One of the recommendations, with a low quality of supporting evidence, is the standard administration of antibiotics in adult patients with influenza and radiographic evidence of pneumonia. Procalcitonin (PCT) is not endorsed as a strategy to withhold antibiotic therapy, but it could be used to de-escalate appropriate patients after 48–72 hours. Radiographic findings are not indicative of the etiology of pneumonia. Prescribing antibiotics for all influenza-positive patients with an infiltrate has significant implications for stewardship. Therefore, we reviewed hospitalized, influenza-positive patients at our institution during the 2018–2019 season, and we sought to assess the impact of an abnormal chest x-ray (CXR) and PCT on antibiotic prescribing and outcomes. Methods: We conducted a retrospective chart review of all influenza-positive admissions at 2 urban, community-based, teaching hospitals. Demographic data, vaccination status, PCT levels, CXR findings, and treatment regimens were reviewed. The primary outcome was the difference in receipt of antibiotics between patients with a negative (<0.25 ng/mL) and positive PCT. Secondary outcomes included the impact of CXR result on antibiotic prescribing, duration, 30-day readmission, and 90-day mortality. Results: We reviewed the medical records of 117 patients; 43 (36.7%) received antibiotics. The vaccination rate was 36.7%. Also, 11% of patients required intensive care unit (ICU) admission and 84% received antibiotics. Moreover, 109 patients had a CXR: 61 (55.9%) were negative, 29 (26.6%) indeterminate, and 19 (17.4%) positive per radiologist interpretation. Patients with a positive PCT (OR, 12.7; 95% CI, 3.43–60.98; P < .0007) and an abnormal CXR (OR, 7.4; 95% CI, 2.9–20.1; P = .000003) were more likely to receive antibiotics. There was no significant difference in 30-day readmission (11.6% vs 13.5%; OR, 0.89; 95% CI, 0.21–3.08; P = 1) and 90-day mortality (11.6% vs 5.4%; OR, 2.37; 95% CI, 0.48–12.75; P = .28) between those that received antibiotics and those that did not, respectively. Furthermore, 30 patients (62.5%) with an abnormal CXR received antibiotics and 21 (43.7%) had negative PCT. There was no difference in 30-day readmission or 90-day mortality between those that did and did not receive antibiotics. Conclusions: Utilization of PCT allowed selective prescribing of antibiotics without impacting readmission or mortality. Antibiotics should be initiated for critically ill patients and based on clinical judgement, rather than for all influenza-positive patients with CXR abnormalities.Funding: NoneDisclosures: None

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Regulation of Store-Operated Ca2+ Entry by SARAF

Cells ◽

10.3390/cells10081887 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1887

Author(s):

Inbal Dagan ◽

Raz Palty

Keyword(s):

Molecular Mechanisms ◽

Feedback Mechanism ◽

Cellular Biology ◽

Excitable Cells ◽

Major Pathway ◽

Negative Feedback Mechanism ◽

Crac Channels ◽

Dependent Inactivation ◽

Crac Channel ◽

The One

Calcium (Ca2+) signaling plays a dichotomous role in cellular biology, controlling cell survival and proliferation on the one hand and cellular toxicity and cell death on the other. Store-operated Ca2+ entry (SOCE) by CRAC channels represents a major pathway for Ca2+ entry in non-excitable cells. The CRAC channel has two key components, the endoplasmic reticulum Ca2+ sensor stromal interaction molecule (STIM) and the plasma-membrane Ca2+ channel Orai. Physical coupling between STIM and Orai opens the CRAC channel and the resulting Ca2+ flux is regulated by a negative feedback mechanism of slow Ca2+ dependent inactivation (SCDI). The identification of the SOCE-associated regulatory factor (SARAF) and investigations of its role in SCDI have led to new functional and molecular insights into how SOCE is controlled. In this review, we provide an overview of the functional and molecular mechanisms underlying SCDI and discuss how the interaction between SARAF, STIM1, and Orai1 shapes Ca2+ signaling in cells.

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Direct observation of a coil-to-helix contraction triggered by vinculin binding to talin

Science Advances ◽

10.1126/sciadv.aaz4707 ◽

2020 ◽

Vol 6 (21) ◽

pp. eaaz4707 ◽

Cited By ~ 7

Author(s):

Rafael Tapia-Rojo ◽

Alvaro Alonso-Caballero ◽

Julio M. Fernandez

Keyword(s):

Focal Adhesions ◽

Interaction Force ◽

Magnetic Tweezers ◽

Feedback Mechanism ◽

Force Transmission ◽

Mechanical Coupling ◽

Negative Feedback Mechanism ◽

The Reformation ◽

Energy Penalty ◽

First Time

Vinculin binds unfolded talin domains in focal adhesions, which recruits actin filaments to reinforce the mechanical coupling of this organelle. However, it remains unknown how this interaction is regulated and its impact on the force transmission properties of this mechanotransduction pathway. Here, we use magnetic tweezers to measure the interaction between vinculin head and the talin R3 domain under physiological forces. For the first time, we resolve individual binding events as a short contraction of the unfolded talin polypeptide caused by the reformation of the vinculin-binding site helices, which dictates a biphasic mechanism that regulates this interaction. Force favors vinculin binding by unfolding talin and exposing the vinculin-binding sites; however, the coil-to-helix contraction introduces an energy penalty that increases with force, defining an optimal binding regime. This mechanism implies that the talin-vinculin-actin association could operate as a negative feedback mechanism to stabilize force on focal adhesions.

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HOPF BIFURCATION FROM NEW-KEYNESIAN TAYLOR RULE TO RAMSEY OPTIMAL POLICY

Macroeconomic Dynamics ◽

10.1017/s1365100519001032 ◽

2020 ◽

pp. 1-33

Author(s):

Jean-Bernard Chatelain ◽

Kirsten Ralf

Keyword(s):

Hopf Bifurcation ◽

Optimal Policy ◽

Ad Hoc ◽

Taylor Rule ◽

Dynamic Properties ◽

Feedback Mechanism ◽

New Keynesian ◽

Negative Feedback Mechanism ◽

Positive Feedback Mechanism ◽

Forward Looking

This paper compares different implementations of monetary policy in a new-Keynesian setting. We can show that a shift from Ramsey optimal policy under short-term commitment (based on a negative feedback mechanism) to a Taylor rule (based on a positive feedback mechanism) corresponds to a Hopf bifurcation with opposite policy advice and a change of the dynamic properties. This bifurcation occurs because of the ad hoc assumption that interest rate is a forward-looking variable when policy targets (inflation and output gap) are forward-looking variables in the new-Keynesian theory.

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