23,265 results match your criteria negative feedback


The temporal development of plant-soil feedback is contingent on competition and nutrient availability contexts.

Authors:
Petr Dostál

Oecologia 2021 Apr 13. Epub 2021 Apr 13.

Institute of Botany, The Czech Academy of Sciences, 252 43, Průhonice, Czech Republic.

Strength and direction of plant-soil feedback (PSF), the reciprocal interactions between plants and soil, can change over time and have distinct effects on different life stages. PSF and its temporal development can also be modified by external biotic and abiotic factors such as competition and resource availability, yet most PSF research is conducted in simple experimental settings without considering temporal changes. Here I have studied the effect of different competitive settings (intraspecific, interspecific, and no competition) and nutrient addition on the magnitude and direction of biomass-based PSF (performance in conspecific relative to heterospecific inoculum) across 46 grassland species, estimated at the 4th, 10th, and 13th month of the response phase. Read More

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Energetic constraints imposed on trophic interaction strengths enhance resilience in empirical and model food webs.

J Anim Ecol 2021 Apr 12. Epub 2021 Apr 12.

Institute of Biochemistry and Biology, University of Potsdam, 14469, Potsdam, Germany.

Food web stability and resilience are at the heart of understanding the structure and functioning of ecosystems. Previous studies show that models of empirical food webs are substantially more stable than random ones, due to a few strong interactions embedded in a majority of weak interactions. Analyses of trophic interaction loops show that in empirical food webs the patterns in the interaction strengths prevent the occurrence of destabilizing heavy loops and thereby enhances resilience. Read More

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Networks of friends and foes and the fate of tree seedlings.

Authors:
Thomas W Kuyper

New Phytol 2021 Apr 12. Epub 2021 Apr 12.

Soil Biology Group, Wageningen University & Research, PO Box 47, Wageningen, 6700 AA, the Netherlands.

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Inhibitory Smads suppress pancreatic stellate cell activation through negative feedback in chronic pancreatitis.

Ann Transl Med 2021 Mar;9(5):384

Institute of Pancreas, Southeast University, Nanjing, China.

Background: Activation of pancreatic stellate cells (PSCs) is a key cause of chronic pancreatitis (CP), while inhibition of transforming growth factor-β (TGF-β) signaling renders PSCs inactive. Inhibitory Smads (I-Smads) impede TGF-β intracellular signaling and may provide a way to alleviate CP. Thus, we aimed to investigate the molecular mechanism of I-Smads in CP animals and freshly-isolated PSCs. Read More

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Expression of Rasd1 in mouse endocrine pituitary cells and its response to dexamethasone.

Stress 2021 Apr 10:1-8. Epub 2021 Apr 10.

Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.

Dexamethasone-induced Ras-related protein 1 (Rasd1) is a member of the Ras superfamily of monomeric G proteins that have a regulatory function in signal transduction. Rasd1, also known as Dexras1 or AGS1, is rapidly induced by dexamethasone (Dex). While prior data indicates that Rasd1 is highly expressed in the pituitary and that the gene may function in regulation of corticotroph activity, its exact cellular localization in this tissue has not been delineated. Read More

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Stellar feedback and triggered star formation in the prototypical bubble RCW 120.

Sci Adv 2021 Apr 9;7(15). Epub 2021 Apr 9.

Department of Astronomy, University of Maryland, College Park, MD 20742, USA.

Radiative and mechanical feedback of massive stars regulates star formation and galaxy evolution. Positive feedback triggers the creation of new stars by collecting dense shells of gas, while negative feedback disrupts star formation by shredding molecular clouds. Although key to understanding star formation, their relative importance is unknown. Read More

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"I didn't want to say something and them to go outside and tell everyone": The acceptability of a dissonance-based body image intervention among adolescent girls in the UK.

Body Image 2021 Apr 6;38:80-84. Epub 2021 Apr 6.

Centre for Appearance Research, University of the West of England, Bristol, BS16 1QY, United Kingdom.

Cognitive dissonance-based interventions (CDIs) have been well established as effective programs for the prevention of eating disorders. However, limited research has qualitatively explored adolescent girls experience of such interventions. The present study examined the acceptability of a cognitive dissonance-based body image intervention among adolescent girls in UK secondary schools. Read More

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Effector-mediated ERM activation locally inhibits RhoA activity to shape the apical cell domain.

J Cell Biol 2021 Jun;220(6)

Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY.

Activated ezrin-radixin-moesin (ERM) proteins link the plasma membrane to the actin cytoskeleton to generate apical structures, including microvilli. Among many kinases implicated in ERM activation are the homologues LOK and SLK. CRISPR/Cas9 was used to knock out all ERM proteins or LOK/SLK in human cells. Read More

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Gut Immunity and Microbiota Dysbiosis Are Associated with Altered Bile Acid Metabolism in LPS-Challenged Piglets.

Oxid Med Cell Longev 2021 25;2021:6634821. Epub 2021 Mar 25.

National Engineering Laboratory of Biological Feed Safety and Pollution Prevention and Control, Zhejiang University, Hangzhou 310058, China.

Bacterial infections are among the major factors that cause stress and intestinal diseases in piglets. Lipopolysaccharide (LPS), a major component of the Gram-negative bacteria outer membrane, is commonly employed for inducing an immune response in normal organisms for convenience. The association between LPS stimulation and gut immunity has been reported. Read More

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Dynamical Mechanisms for Gene Regulation Mediated by Two Noncoding RNAs in Long-Term Memory Formation.

Neural Plast 2021 25;2021:6668389. Epub 2021 Mar 25.

School of Mathematics and Systems Science and LMIB, Beihang University, Beijing 100191, China.

Noncoding RNAs such as miRNAs and piRNAs have long-lasting effects on the regulation of gene expression involved in long-term synaptic changes. To characterize gene regulation mediated by small noncoding RNAs associated with long-term memory in , we consider two noncoding RNAs stimulated by 5-HT into a gene regulatory network motif model, including miR-124 that binds to and inhibits the mRNA of CREB1 and piR-F that facilitates serotonin-dependent DNA methylation to lead to repression of CREB2. Codimension-1 and -2 bifurcation analyses of 5-HT regulating both miR-124 and piR-F and a negative feedback strength for oscillation reveal rich dynamical properties of bistability and oscillations robust to variations in all other parameters. Read More

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CCL8 mediates crosstalk between endothelial colony forming cells and triple-negative breast cancer cells through IL-8, aggravating invasion and tumorigenicity.

Oncogene 2021 Apr 8. Epub 2021 Apr 8.

Duksung Innovative Drug Center, College of Pharmacy, Duksung Women's University, Seoul, Korea.

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer with a poor prognosis for which no effective therapeutic measures are currently available. The present study aimed to investigate whether interactions with endothelial colony-forming cells (ECFCs) promote aggressive progression of TNBC cells. Herein, using an indirect co-culture system, we showed that co-culture increased the invasive and migratory phenotypes of both MDA-MB-231 TNBC cells and ECFCs. Read More

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Lowered progesterone metabolite excretion and a variable LH excretion pattern are associated with vasomotor symptoms but not negative mood in the early perimenopausal transition: Study of Women's Health Across the Nation.

Maturitas 2021 May 5;147:26-33. Epub 2021 Mar 5.

Center for Health and the Environment, University of California Davis, Davis, CA, United States.

Objective: The menopausal transition is characterized by progressive changes in ovarian function and increasing circulating levels of gonadotropins, with some women having irregular menstrual cycles well before their final menstrual period. These observations indicate a progressive breakdown of the hypothalamic-pituitary-ovarian axis often associated with an increase in menopausal symptoms. Relationships between vasomotor symptoms (VMS) and depressed mood and sleep as well as a bidirectional association between VMS and depressed mood in mid-life women have been reported, but the endocrine foundations and hormone profiles associated with these symptoms have not been well described. Read More

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Potentiation of the Anticancer Effects by Combining Docetaxel with Ku-0063794 Against Triple-Negative Breast Cancer Cells.

Cancer Res Treat 2021 Apr 5. Epub 2021 Apr 5.

Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.

Purpose: mTORC1 and mTORC2 inhibition by Ku-0063794 could confer profound anticancer effects against cancer cells because it eliminates feedback activation of Akt. Herein, we aimed to determine anticancer effects of docetaxel and Ku-0063794, individually or in combination, against breast cancer cells, especially triple negative breast cancer (TNBC) cells.

Material And Methods: MCF-7 breast cancer and MDA-MB-231 TNBC cell lines for in vitro studies and mouse xenograft model for in vivo studies were used to investigate the effect of docetaxel, Ku-0063794, or their combination. Read More

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Speech Intensity Response to Altered Intensity Feedback in Individuals With Parkinson's Disease.

J Speech Lang Hear Res 2021 Apr 8:1-15. Epub 2021 Apr 8.

Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.

Purpose Hypophonia (low speech intensity) is the most common speech symptom experienced by individuals with Parkinson's disease (IWPD). Previous research suggests that, in IWPD, there may be abnormal integration of sensory information for motor production of speech intensity. In the current study, intensity of auditory feedback was systematically manipulated (altered in both positive and negative directions) during sensorimotor conditions that are known to modulate speech intensity in everyday contexts in order to better understand the role of auditory feedback for speech intensity regulation. Read More

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Pain or gain? Understanding how trait empathy impacts leader effectiveness following the provision of negative feedback.

J Appl Psychol 2021 Apr 8. Epub 2021 Apr 8.

Although providing negative performance feedback can enhance employee performance, leaders are sometimes reluctant to engage in this activity. Reflecting this, prior research has identified negative feedback provision as an aversive, yet potentially rewarding, managerial activity. However, little is known about how providing negative feedback impacts the effectiveness of leaders who do so. Read More

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Perception of solar UV radiation by plants: photoreceptors and mechanisms.

Plant Physiol 2021 Apr 7. Epub 2021 Apr 7.

Organismal and Evolutionary Biology, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland.

About 95% of the ultraviolet (UV) photons reaching the Earth's surface are UV-A (315-400 nm) photons. Plant responses to UV-A radiation have been less frequently studied than those to UV-B (280-315 nm) radiation. Most previous studies on UV-A radiation have used an unrealistic balance between UV-A, UV-B, and photosynthetically active radiation (PAR). Read More

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Genes and hormones of the hypothalamic-pituitary-adrenal axis in post-traumatic stress disorder. What is their role in symptom expression and treatment response?

J Neural Transm (Vienna) 2021 Apr 7. Epub 2021 Apr 7.

Department of Education and Psychology, Division of Clinical Psychological Intervention, Freie Universität Berlin, Berlin, Germany.

Background: Less than half of all individuals with post-traumatic stress disorder (PTSD) remit spontaneously and a large proportion of those seeking treatment do not respond sufficiently. This suggests that there may be subgroups of individuals who are in need of augmentative or alternative treatments. One of the most frequent pathophysiological findings in PTSD is alterations in the hypothalamic-pituitary-adrenal (HPA) axis, including enhanced negative feedback sensitivity and attenuated peripheral cortisol. Read More

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Shared Components of the FRQ-Less Oscillator and TOR Pathway Maintain Rhythmicity in .

J Biol Rhythms 2021 Apr 7:748730421999948. Epub 2021 Apr 7.

Department of Biology, York University, Toronto, ON, Canada.

Molecular models for the endogenous oscillators that drive circadian rhythms in eukaryotes center on rhythmic transcription/translation of a small number of "clock genes." Although substantial evidence supports the concept that negative and positive transcription/translation feedback loops (TTFLs) are responsible for regulating the expression of these clock genes, certain rhythms in the filamentous fungus continue even when clock genes (, , and ) are not rhythmically expressed. Identification of the rhythmic processes operating outside of the TTFL has been a major unresolved area in circadian biology. Read More

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Atypical Reinforcement Learning in Developmental Dyslexia.

J Int Neuropsychol Soc 2021 Apr 7:1-11. Epub 2021 Apr 7.

Department of Special Education, Edmond J. Safra Brain Research Center for the Study of Learning Disabilities, University of Haifa, Haifa, Israel.

Objectives: According to the Procedural Deficit Hypothesis, abnormalities in corticostriatal pathways could account for the language-related deficits observed in developmental dyslexia. The same neural network has also been implicated in the ability to learn contingencies based on trial and error (i.e. Read More

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Conserved and Differentiated Functions of CIK Receptor Kinases in Modulating Stem Cell Signaling in Arabidopsis.

Mol Plant 2021 Apr 3. Epub 2021 Apr 3.

Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China. Electronic address:

Shoot apical meristem (SAM) and root apical meristem (RAM) act as pools of stem cells to give rise to aboveground and underground tissues and organs in higher plants. Despite the structure differences between these two meristems, they evolve similar signaling pathways to maintain stem cell homeostasis. The CLAVATA3 (CLV3)-WUSCHEL (WUS) negative feedback loop acts as a core pathway in controlling SAM homeostasis, while CLV3/EMBRYO SURROUNDING REGION (ESR) 40 (CLE40) and WUSCHEL-RELATED HOMEOBOX5 (WOX5), homologues of CLV3 and WUS, direct columella stem cell fate. Read More

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