scholarly journals Breakdown of modularity in complex networks

2017 ◽  
Author(s):  
Sergi Valverde
Keyword(s):  
Simple Model ◽  
General Theory ◽  
Complex Networks ◽  
Stress Responses ◽  
Common Property ◽  
Cost Constraints ◽  
Modular Networks ◽  
Wide Range ◽  
Modular Organisation ◽  
Different Parts

The presence of modular organisation is a common property of a wide range of complex systems, from cellular or brain networks to technological graphs. Modularity allows some degree of segregation between different parts of the network and has been suggested to be a prerequisite for the evolvability of biological systems. In technology, modularity defines a clear division of tasks and it is an explicit design target. However, many natural and artificial systems experience a breakdown in their modular pattern of connections, which has been associated to failures in hub nodes or the activation of global stress responses. In spite of its importance, no general theory of the breakdown of modularity and its implications has been advanced yet. Here we propose a new, simple model of network landscape where it is possible to exhaustively characterise the breakdown of modularity in a well-defined way. We found that evolution cannot reach maximally modular networks under the presence of functional and cost constraints, implying the breakdown of modularity is an adaptive feature.

scholarly journals Assessing evidence for adaptive evolution in two hearing-related genes important for high-frequency hearing in echolocating mammals

2021 ◽  
Author(s):  
Hui Wang ◽  
Hanbo Zhao ◽  
Yujia Chu ◽  
Jiang Feng ◽  
Keping Sun
Keyword(s):  
Adaptive Evolution ◽  
Hair Cells ◽  
High Frequency ◽  
Phylogenetic Trees ◽  
Outer Hair Cells ◽  
Functional Domain ◽  
Coding Region ◽  
Selective Pressures ◽  
Wide Range ◽  
Different Parts

Abstract High-frequency hearing is particularly important for echolocating bats and toothed whales. Previously, studies of the hearing-related genes Prestin, KCNQ4, and TMC1 documented that adaptive evolution of high-frequency hearing has taken place in echolocating bats and toothed whales. In this study, we present two additional candidate hearing-related genes, Shh and SK2, that may also have contributed to the evolution of echolocation in mammals. Shh is a member of the vertebrate Hedgehog gene family and is required in the specification of the mammalian cochlea. SK2 is expressed in both inner and outer hair cells, and it plays an important role in the auditory system. The coding region sequences of Shh and SK2 were obtained from a wide range of mammals with and without echolocating ability. The topologies of phylogenetic trees constructed using Shh and SK2 were different; however, multiple molecular evolutionary analyses showed that those two genes experienced different selective pressures in echolocating bats and toothed whales compared to non-echolocating mammals. In addition, several nominally significant positively selected sites were detected in the non-functional domain of the SK2 gene, indicating that different selective pressures were acting on different parts of the SK2 gene. This study has expanded our knowledge of the adaptive evolution of high-frequency hearing in echolocating mammals.

scholarly journals Antimicrobial Nodule-Specific Cysteine-Rich Peptides Induce Membrane Depolarization-Associated Changes in the Transcriptome of Sinorhizobium meliloti

2013 ◽  
Vol 79 (21) ◽  
pp. 6737-6746 ◽  
Author(s):  
Hilda Tiricz ◽  
Attila Szűcs ◽  
Attila Farkas ◽  
Bernadett Pap ◽  
Rui M. Lima ◽  
...  
Keyword(s):  
Stress Responses ◽  
Sinorhizobium Meliloti ◽  
Antimicrobial Agents ◽  
Cellular Functions ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Peptide Family ◽  
Wide Range ◽  
Natural Target

ABSTRACTLeguminous plants establish symbiosis with nitrogen-fixing alpha- and betaproteobacteria, collectively called rhizobia, which provide combined nitrogen to support plant growth. Members of the inverted repeat-lacking clade of legumes impose terminal differentiation on their endosymbiotic bacterium partners with the help of the nodule-specific cysteine-rich (NCR) peptide family composed of close to 600 members. Among the few tested NCR peptides, cationic ones had antirhizobial activity measured by reduction or elimination of the CFU and uptake of the membrane-impermeable dye propidium iodide. Here, the antimicrobial spectrum of two of these peptides, NCR247 and NCR335, was investigated, and their effect on the transcriptome of the natural targetSinorhizobium melilotiwas characterized. Both peptides were able to kill quickly a wide range of Gram-negative and Gram-positive bacteria; however, their spectra were only partially overlapping, and differences were found also in their efficacy on given strains, indicating that the actions of NCR247 and NCR335 might be similar though not identical. Treatment ofS. meliloticultures with either peptide resulted in a quick downregulation of genes involved in basic cellular functions, such as transcription-translation and energy production, as well as upregulation of genes involved in stress and oxidative stress responses and membrane transport. Similar changes provoked mainly in Gram-positive bacteria by antimicrobial agents were coupled with the destruction of membrane potential, indicating that it might also be a common step in the bactericidal actions of NCR247 and NCR335.

Review on pharmacological and phytochemical prospects of traditional medicinal plant: Persicaria hydropiper (Smartweed)

2021 ◽  
Vol 21 ◽  
Author(s):  
Abdul Nasir ◽  
Atif Ali Khan Khalil ◽  
Muhammad Zeeshan Bhatti ◽  
Ashfaq Ur Rehman ◽  
Jiayi Li ◽  
...  
Keyword(s):  
Medicinal Plant ◽  
Traditional Medicine ◽  
Northern Hemisphere ◽  
Biological Activities ◽  
Folk Medicine ◽  
Present Review ◽  
Polygonum Hydropiper ◽  
Wide Range ◽  
Pharmacological Data ◽  
Different Parts

: Persicaria hydropiper (L.) Delarbre (family Polygonacea), commonly known as Polygonum hydropiper, is a popular medicinal plant used in traditional medicine. The plant is indigenous to the tropical northern hemisphere and temperate zone including China, Bangladesh, India, and Japan. The plant is used in folk medicine for numerous ailments such as hemorrhoids, antifertility, diarrhea, and dyspepsia. Its medicinal usage in Unani, Ayurveda, Siddha, and other traditional medicine is well-recognized. So far, a wide range of active phytochemicals of this plant has been identified, such as flavonoids, sulphated flavonoids, terpenoids, anthraquinones, steroids, coumarin, simple phenolics, and others. Pharmacological data reported in the literature suggest that various parts of P. hydropiper exhibit antimicrobial, antioxidant, hypoglycemic, antidepressant, cardioprotective, hepatoprotective, anticancer, and antifertility effects. The present review aim is to compile the coherently document research on the phytochemical, pharmacological, and biological activities of P. hydropiper from different parts of the globe.

scholarly journals Impact of clock-associated Arabidopsis pseudo-response regulators in metabolic coordination

2009 ◽  
Vol 106 (17) ◽  
pp. 7251-7256 ◽  
Author(s):  
Atsushi Fukushima ◽  
Miyako Kusano ◽  
Norihito Nakamichi ◽  
Makoto Kobayashi ◽  
Naomi Hayashi ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Stress Responses ◽  
Clock Genes ◽  
Higher Plants ◽  
Tricarboxylic Acid Cycle ◽  
Integrated Analysis ◽  
Response Regulators ◽  
Triple Mutant ◽  
Mitochondrial Functions ◽  
Wide Range

In higher plants, the circadian clock controls a wide range of cellular processes such as photosynthesis and stress responses. Understanding metabolic changes in arrhythmic plants and determining output-related function of clock genes would help in elucidating circadian-clock mechanisms underlying plant growth and development. In this work, we investigated physiological relevance of PSEUDO-RESPONSE REGULATORS (PRR 9, 7, and 5) in Arabidopsis thaliana by transcriptomic and metabolomic analyses. Metabolite profiling using gas chromatography–time-of-flight mass spectrometry demonstrated well-differentiated metabolite phenotypes of seven mutants, including two arrhythmic plants with similar morphology, a PRR 9, 7, and 5 triple mutant and a CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1)-overexpressor line. Despite different light and time conditions, the triple mutant exhibited a dramatic increase in intermediates in the tricarboxylic acid cycle. This suggests that proteins PRR 9, 7, and 5 are involved in maintaining mitochondrial homeostasis. Integrated analysis of transcriptomics and metabolomics revealed that PRR 9, 7, and 5 negatively regulate the biosynthetic pathways of chlorophyll, carotenoid and abscisic acid, and α-tocopherol, highlighting them as additional outputs of pseudo-response regulators. These findings indicated that mitochondrial functions are coupled with the circadian system in plants.

scholarly journals Hexokinase and glucokinases are essential for fitness and virulence in the pathogenic yeastCandida albicans

2018 ◽  
Author(s):  
Romain Laurian ◽  
Karine Dementhon ◽  
Bastien Doumèche ◽  
Alexandre Soulard ◽  
Thierry Noel ◽  
...  
Keyword(s):  
Stress Responses ◽  
Galleria Mellonella ◽  
Glucose Repression ◽  
Metabolic Adaptation ◽  
Metabolic Flexibility ◽  
Pathogenic Yeast ◽  
Regulatory Pathways ◽  
Metabolic Role ◽  
Wide Range ◽  
Hexose Phosphorylation

AbstractMetabolic flexibility promotes infection and commensal colonization by the opportunistic pathogenCandida albicans.Yeast cell survival depends upon assimilation of fermentable and non-fermentable locally available carbon sources. Physiologically relevant sugars like glucose and fructose are present at low level in host niches. However, because glucose is the preferred substrate for energy and biosynthesis of structural components, its efficient metabolization is fundamental for the metabolic adaptation of the pathogen. We explored and characterized theC. albicanshexose kinase system composed of one hexokinase (CaHxk2) and two glucokinases (CaGlk1 and CaGlk4). Using a set of mutant strains, we found that hexose phosphorylation is mostly assured by CaHxk2, which sustains growth on hexoses. Our data on hexokinase and glucokinase expression point out an absence of cross regulation mechanisms at the transcription level and different regulatory pathways. In the presence of glucose, CaHxk2 migrates in the nucleus and contributes to the glucose repression signaling pathway. In addition, CaHxk2 participates to oxidative, osmotic and cell wall stress responses, while glucokinases are overexpressed under hypoxia. Hexose phosphorylation is a key step necessary for filamentation, that is affected in the hexokinase mutant. Virulence of this mutant is clearly impacted in theGalleria mellonellaand macrophage models. Filamentation, glucose phosphorylation and stress response defects of the hexokinase mutant prevent host killing byC. albicans.By contributing to metabolic flexibility, stress answer response and morphogenesis, hexose kinase enzymes play an essential role in the virulence ofC. albicans.Author summaryThe pathogenic yeastC. albicansis both a powerful commensal and pathogen of humans that can infect wide range of organs and body sites. To grow in its host and establish an infection, the pathogen must assimilate carbon from these heterogenous environments.C. albicansregulates central carbon metabolism in a niche-specific manner, activating alternatively gluconeogenesis, glyoxylate cycle and the glycolytic metabolism. For yeast and other microorganisms, glucose is the preferred carbon and energy source and its accurate detection and metabolism is essential. However, the glycolytic hexose kinase system has not been investigated yet inC. albicans.In this report, we showed that hexokinase and glucokinases contribute to the fitness and virulence ofC. albicans.We revealed the main metabolic role of the hexokinase CaHxk2 which impacts on growth, glucose signalling, morphological transition and virulence. However, glucokinases contribute to the anoxic response and their implication in regulation processes is suggested.

scholarly journals Prevalence of Musculoskeletal Disorders among Dentists in Al-Madinah, Kingdom of Saudi Arabia

2017 ◽  
Vol 03 (01) ◽  
pp. 015-019
Author(s):  
Talat Al-Gunaid ◽  
Rayan Abdulhai ◽  
Baha Flemban
Keyword(s):  
Saudi Arabia ◽  
Musculoskeletal Disorders ◽  
Dental Students ◽  
The Body ◽  
Musculoskeletal Symptoms ◽  
Kingdom Of Saudi Arabia ◽  
Increased Risk ◽  
Dental Practitioners ◽  
Wide Range ◽  
Different Parts

Abstract Introduction: Musculoskeletal disorders (MSDs) are one of the most common occupational hazards associated with a wide range of occupations. Dental professionals have an increased risk of developing such disorders caused by repetitive, hard, or stressful gestures. Taking this issue into consideration, we felt the necessity to investigate the prevalence and distribution of musculoskeletal symptoms among dentists in Al-Madinah. Materials and methods: A self-reported questionnaire was distributed to a random sample of 180 dentists from different parts of Al-Madinah, Kingdom of Saudi Arabia. The questionnaire was about musculoskeletal symptoms in different parts of the body. Results: A total of 70 questionnaires were completed and returned. Of the respondents, 47 (67.1%) were males and 23 (32.9%) were females. The mean age of respondents was 36.1 ± 8.7. Majority were general dental practitioners [45 (64.2%)], with the remainder being specialists [25 (35.8%)]. Prevalence of MSD during the past 12 months was reported to be lower back pain (65.7%), neck pain (48.6%), and shoulder pain (45.7%), with the lowest prevalence pain being found in the hips and thighs (17.1%). Conclusion: The results suggested that the prevalence of musculoskeletal symptoms among dentists in Al-Madinah, Kingdom of Saudi Arabia, is high. Continuing education for dentists and dental students about the proper and correct dental positions as well as practicing ergonomic skills and incorporating them into the curriculum would be beneficial.

scholarly journals Early life adversity and the epigenetic programming of hypothalamic-pituitary-adrenal function

2014 ◽  
Vol 16 (3) ◽  
pp. 321-333 ◽  
Keyword(s):  
Stress Responses ◽  
Childhood Adversity ◽  
Adrenal Function ◽  
Early Life Adversity ◽  
Hypothalamic Pituitary Adrenal ◽  
Expression Of Genes ◽  
Epigenetic Programming ◽  
Social Adversity ◽  
Wide Range ◽  
Nonhuman Species

We review studies with human and nonhuman species that examine the hypothesis that epigenetic mechanisms, particularly those affecting the expression of genes implicated in stress responses, mediate the association between early childhood adversity and later risk of depression. The resulting studies provide evidence consistent with the idea that social adversity, particularly that involving parent-offspring interactions, alters the epigenetic state and expression of a wide range of genes, the products of which regulate hypothalamic-pituitary-adrenal function. We also address the challenges for future studies, including that of the translation of epigenetic studies towards improvements in treatments.

Occurrence and Significance of Toxic Cyanobacteria in Southern Africa

1991 ◽  
Vol 23 (1-3) ◽  
pp. 175-180 ◽  
Author(s):  
W. E. Scott
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Single Species ◽  
Practical Significance ◽  
Toxic Species ◽  
Toxic Cyanobacteria ◽  
Cyanobacterial Species ◽  
Wide Range ◽  
Toxic Blooms ◽  
Different Parts

A comprehensive list is provided of more than forty cyanobacterial species and genera reported to have toxic properties. In South Africa the majority of animal poisonings since 1927 have been caused by a single species Microcystis aeruginosa. Although other toxic species also occur in southern Africa, to date they have been of little practical significance. The widespread distribution of M. aeruginosa throughout southern Africa indicates a tremendous potential for toxic blooms to develop with increasing eutrophication. Using HPLC techniques up to six different toxin variants have been quantified in natural blooms of M. aeruginosa collected in different parts of South Africa. The amounts and proportions of the different toxins in the different samples varied over a wide range. Several additional unidentified toxins were detected.

The EMDR Integrative Group Treatment Protocol for Patients With Cancer

2016 ◽  
Vol 10 (3) ◽  
pp. 199-207 ◽  
Author(s):  
Ignacio Jarero ◽  
Lucina Artigas ◽  
Susana Uribe ◽  
Laura Evelyn García
Keyword(s):  
Stress Responses ◽  
Traumatic Stress ◽  
Group Treatment ◽  
Terminal Illness ◽  
Treatment Protocol ◽  
Individual Treatment ◽  
Adult Women ◽  
Patients With Cancer ◽  
Wide Range ◽  
Adolescents And Adults

Experiencing cancer is a peculiar stressor within the infrastructure of posttraumatic stress disorder (PTSD) because this debilitating disease involves ongoing stressors and is both acute and potentially chronic. The experience can include a wide range of associated adverse events, such as tumor detection, diagnosis, severity of disease, and prognosis; aggressive treatment; disfigurement and bodily dysfunction; side effects of treatment; impaired physical, social, and occupational functioning; and sometimes, recurrence and diagnosis of terminal illness. This article provides a detailed description of the clinical application of the Eye Movement Desensitization and Reprocessing (EMDR) Integrative Group Treatment Protocol (EMDR-IGTP) Adapted for Adolescents and Adults Living with Ongoing Traumatic Stress for the patients with cancer. This protocol administers the eight phases of EMDR individual treatment to a group of patients using an art therapy format (i.e., drawings) and the butterfly hug (a self-administered bilateral stimulation method to process traumatic material). A previous study (Jarero et al., 2015) showed that after 6 sessions of EMDR-IGTP, there was a significant decrease in PTSD symptoms related to the diagnosis and treatment of different types of cancer in adult women. Effects were maintained at 90-day follow-up. In this article, we discuss how this protocol can be used to effectively provide intensive EMDR treatment to large groups of patients, and we provide detailed instructions for its provision to address one of the major psychological dimensions of cancer: the ongoing traumatic stress responses experienced by patients with cancer. A clinical example illustrates the treatment process.

RECOGNITION OF PERSIAN ONLINE HANDWRITING USING ELASTIC FUZZY PATTERN RECOGNITION

2007 ◽  
Vol 21 (03) ◽  
pp. 491-513 ◽  
Author(s):  
RAMIN HALAVATI ◽  
SAEED BAGHERI SHOURAKI
Keyword(s):  
Linguistic Terms ◽  
Input Stream ◽  
Cursive Handwriting ◽  
Novel Approach ◽  
Wide Range ◽  
Fuzzy Pattern ◽  
School Books ◽  
Fuzzy Linguistic ◽  
Online Handwriting ◽  
Different Parts

Persian is a fully cursive handwriting in which each character may take different forms in different parts of the word, characters overlap and there is a wide range of possible styles. These complexities make automatic recognition of Persian a very hard task. This paper presents a novel approach on recognition of such writings systems which is based on the description of input stream by a sequence of fuzzy linguistic terms; representation of character patterns with the same descriptive language; and comparison of inputs with character patterns using a novel elastic pattern matching approach. As there is no general benchmark for recognition of Persian handwriting, the approach has been tested on the set of words in first primary Iranian school books including 1250 words resulting in 78% correct recognition without dictionary and 96% with dictionary.

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