Static features of the executive control network (ECN), dorsal attention network (DAN), default mode network (DMN), and salience network (SN) have displayed dysfunction in people with autism spectrum disorder (ASD). However, research on the dynamic brain function of these networks in ASD is rare. In this study, co-activation pattern (CAP) analysis was performed on the whole cortex to study dynamic dysfunction in ASD using a large multisite resting-state fMRI dataset (295 ASDs, 446 healthy controls). Eight transient network states (TNSs) were defined, the dwell time, persistence, and transitions of each TNS were calculated to evaluate dynamic brain function. Using hierarchical clustering, the eight TNSs were divided into three clusters: ‘DMN activating’, ‘SN activating’, and ‘ECN and DAN activating’. We found ‘ASD-biased’ DMN and SN TNSs, which showed larger dwell time and longer persistence in ASD group than healthy control (CON) group. More transition within ‘ASD-biased’ TNSs were found in ASD group. Dwell time of the ‘ASD-biased’ ‘SN activating’ TNS was significantly correlated with social deficits only in the ASD group. Our results imply the dynamic dysfunction of ASD does not come from the occurrence of DMN, ECN, or SN, but comes from the atypical co-activation patterns within them. Our results also indicate people with ASD have stronger negative connectivity between DMN and ECN in childhood. This connection dosen’t change significantly with age in ASD group, but is supposed to increase with age until adulthood as the growth trajectory in healthy inviduals, which implies the early overgrowth of ASD children.
This study is focused on the anisotropic fatigue crack growth (FCG) behaviour of an aluminium AA7050-T7451 plate. L-T and S-T orientations were studied in M(T) samples with W=50 mm, in mode I loading, with R-ratio of +0.05. A numerical approach was used, assuming that crack tip plastic strain is the crack driving force. A purely kinematic elastic-plastic model was calibrated using experimental data from low cycle fatigue tests of smooth specimens in L and S orientations. The predicted FCG rates agree well with experimental trends in the Paris’ regime, suggesting that cyclic plastic deformation is the main damage mechanism. The numerical model was used to estimate the stress ratio effect for both orientations, which was found to be linked with crack closure variations. However, the closure free predicted trends for both microstructural orientations at R=0.05 are not overlapped, suggesting an effect of microstructure not linked to crack closure.
Owing to the emergence of energy storage and electric vehicles, the desire for safe high-energy-density energy storage devices has increased research interest in anode-free lithium metal batteries (AFLMBs). Unlike general LMBs, in which excess Li exists to compensate for the irreversible loss of Li, only the current collector is employed as an anode and paired with a lithiated cathode in the fabrication of AFLMBs. Owing to their unique cell configuration, AFLMBs have attractive characteristics, including the highest energy density, safety, and cost-effectiveness. However, developing AFLMBs with extended cyclability remains an issue for practical applications because the high reactivity of Li with limited inventory causes severely low Coulombic efficiency, poor cyclability, and dendrite growth. To address these issues, tremendous effort has been devoted to stabilize Li-metal anodes for AFLMBs. In this review, we highlight the importance and challenges of AFLMBs. Then, we thoroughly review diverse strategies, such as modifying current collectors, the formation of robust interfaces by engineering advanced electrolytes, and operation protocols. Finally, a future perspective on the strategy is provided to insight into the basis of future research. We hope that this review provides a comprehensive understanding by reviewing previous research and arousing more interest in this field.
Undesired oscillation components appear in active and reactive powers, electromagnetic torque and DC-link voltage of doubly fed induction generators (DFIGs) connected to unbalanced grid voltage. These components oscillate at double source frequency as a result of negative sequence components in voltage and current. Different direct power control (DPC) techniques were studied in literatures to damp these oscillations. However, these techniques require sequence decomposition process, axes transformation of stator voltage/current and estimation of different power components which complicate the overall control system. This paper presents a simplified DPC of DFIGs in stationary reference frame under normal and unbalanced grid voltage. Decomposition process, axes transformation and compensation power terms are totally eliminated. Vector proportional- integral (VPI) controllers are designed to regulate stator active and reactive powers. The performance of the proposed DPC scheme using VPI and proportional-integral-resonant (PIR) controllers is analyzed and compared under different operating conditions. Bode diagram of open loop and closed loop control using VPI and PIR are studied to illustrate stability, steady state and transient response of the two controllers. Also, the performance of proposed technique and previous DPCs designed in synchronous reference frame is compared to prove the validity of proposed one. The results show that proposed DPC using VPI has superior performance in steady state and transient conditions with simple implementation.
Introduction:Malaria infects humans through the bite of the Anopheles mosquito that transmits the Plasmodium parasite. There are five species of plasmodium: falciparum, vivax, ovale , Malariae and Knowlesi. Some Authors have suggested that Malarial splenic complications are associated with plasmodium vivax infection Malaria infection alone has the greatest impact on global health, affecting more than 500 million individuals with more than 2.5 million deaths every year. It can manifest as an acute febrile illness, but it can lead to severe complications such as shock, respiratory distress, severe anemia, convulsions, intra-abdominal organ inflammation, and bleeding caused by spontaneous splenic rupture  According to the WHO, malaria is endemic in Sudan, and over 1.8 million cases have been reported in 2019, representing 12.4% of all diseases surveyed by the health sector with a mortality rate of 13 per 10,000. . Malarial infection incidence in Sudan was estimated to be 9 million cases per year in 2007 with 44,000 deaths related to malaria complications. The spleen plays an important role in immunity against malaria by producing antibodies against malaria parasites, this can lead to splenic enlargement making it more susceptible to complications such as hematoma formation and rupture .
Reproductive isolation plays an important role in maintaining the species integrity of sympatric close relatives. For sympatric Arisaema species, interspecific gene flow is expected to be effectively prevented by pre-pollination barriers, particularly strong pollinator isolation mediated by fungus gnats. However, due to the lack of quantitative studies combining multiple pre- and post-pollination barriers, it is not known whether pre-pollination isolation is complete, and whether post-pollination barriers also contribute to reproductive isolation among some Arisaema species. We studied five pre- and post-pollination barriers (geographic isolation, phenological isolation, pollinator isolation, hybrid fruit production, and hybrid seed formation) among three sympatric Arisaema species (A. bockii, A. lobatum, and A. erubescens). The strength of individual barriers and their contribution to total isolation were quantified.The habitat elevations of the three Arisaema species mostly overlapped. Although phenological isolation and pollinator isolation reduced the frequencies of interspecific pollen transfer among these species, the partial overlap of flowering times and pollinator assemblages resulted in pre-pollination isolation that does not adequately prevent interspecific hybridization. Post-pollination barriers also contributed to reproductive isolation at the hybrid fruit and seed formation stages.We propose that, although pre-pollination barriers are expected to contribute more to total isolation than post-pollination barriers in Arisaema, pre-pollination barriers may not completely prevent interspecific pollen transfer among some Arisaema species. Post-pollination barriers, which are generally ignored, may also have contributed significantly to reproductive isolation in Arisaema.
The Mississippi River channel from New Orleans to the Gulf of Mexico (GOM) is a key deep draft navigation channel and an active deltaic lobe. Natural and engineered lateral exits from this reach into adjacent receiving basins historically has provided mineral sediment for wetland accretion in the face of rising relative sea level and supported estuarine-coastal food webs. However, our analysis indicates water losses from the channel have increased by 25% since 2004 due to (1) bank failures during large floods since 2012 that have created several large exit channels downriver of the flood protection levee, and (2) the opening of an engineered diversion at West Bay in 2004. This has resulted in a 60-80% loss in stream power in the lowermost navigation channel that is accompanied by net shoaling between 2012 and 2022 and an increased dredging need. Our 2022 survey in the GOM exit passes indicates that only 20% of the freshwater, 5% of the total suspended sediment (2% of the sand) at New Orleans now reaches the GOM: this supports previous research indicating the delta front is retreating after centuries of progradation. Together these results indicate that (1) river containment and the sustainability of the navigation channel is threatened, (2) sediment load reaching the seaward end of the delta may be insufficient to avoid major degradation, and (3) the increased freshwater flux into adjacent shallow coastal water bodies has unknown implications for coastal hypoxia and food webs, including commercial species (e.g., oysters) and marine mammals. Future acceleration in sea level rise rates and tropical storm frequency/intensity likely will worsen these trends.
Background: Students’ academic achievement is regarded as the scholastic standing of students at the end of a given study period that is expressed in terms of grades. The key to bridging the attainment gap at the end of their study period is through their cumulative grade points over the duration of the study. Predictive validity study on students first-year GPA as a predictor of their final-year CGPA was carried out to predict the students’ academic performance in Chemical, Civil, Electrical, and Mechanical Engineering. Purpose/Hypothesis: This study examined the relationship between first-year GPA and final-year CGPA, as well as the relationship between Age, Gender and Geopolitical zones on first-year GPA and CGPA of Engineering students in the Faculty of Engineering students University of Abuja, Nigeria. The data obtained from the four Departments; Chemical, Civil, Electrical and Mechanical were analyzed. Two hypotheses were formulated to guide the study. Design/Method: An ex-post factor research approach was adopted, and Pearson’s correlation and Regression Analysis were fitted with the data using Minitab software. Results: The results of the study highlighted that first-year GPA had a strong positive relationship with final-year CGPA. Age, Gender and Geopolitical zones have no correlation with students’ final-year CGPA. The regression equations can be used to predict students’ CGPA to bridge the attainment gap at the end of their studies. Conclusions: Finally, the study emphasized the need to admit more female students in Engineering studies as they constitute 12.9% of the population.
In contrast to the Western world, China is a less religious country. whether in a country without real religions believing in religion would contribute to the variation in value strain is a worth noting issue. Based on previous studies, this study further examined the relationship between religion and suicidality with value strain as a mediating factor among Chinese college students. Employing cluster sampling, there were 13,250 college students recruited across seven provinces in China. Three psychometric scales were used to examine religiousness (Religious Orientation-Revised Scale), value strain levels (Psychological Strain Scale), and suicidal behaviors (Suicidal Behaviors Questionnaire-Revised). Both univariate and multivariate analyses were used to identify the influencing power of religion on value strain and suicidality. In addition, a series of linear regression analyses were conducted to examine the mediating effect of value strain on the association between religion and suicidality. the findings showed that first, positive relationships between religion and value strain, and suicidality were both detected; second, adherents to religion were marginalized which may have caused more value conflict further leading to a higher suicidal risk among believers.
Working memory (WM) is one of the fundamental cognitive functions associated with the dorsolateral prefrontal cortex (DLPFC). However, we still know little about the neurochemical mechanisms of WM in the DLPFC. Here, we investigated WM-related dynamic neurometabolite and hemodynamic responses in the DLPFC. We measured Glx (glutamate+glutamine) and GABA alterations as well as blood-oxygen-level-dependent (BOLD) signal changes during a WM task combining functional magnetic resonance spectroscopy and functional magnetic resonance imaging (fMRI). In the DLPFC, we found that a 2-back task increased Glx concentrations and larger BOLD signal changes, and that these task-modulated Glx increases were positively correlated with task-induced regional activity. Importantly, task induced Glx changes in the DLPFC were associated with individual WM performance. Higher Glx increases were associated with increased DLPFC activation and lower WM task performance in the individuals. There were no changes in DLPFC GABA levels during WM processing. Our findings suggest that glutamatergic modulation in the DLPFC may play a critical role in WM processing and its performance.
Leucine and Isoleucine are two amino acids that differ only by the positioning of one methyl group. This small difference has however important consequences in α-helices, as the β-branching of Ile results in helix destabilization. We set out to investigate whether there are general trends for the occurrences of Leu and Ile residues in structures and sequences of class A GPCRs (G protein-coupled receptors). GPCRs are integral membrane proteins in which α-helices span the plasma membrane seven times and which play a crucial role in signal transmission into the cell. We found that Leu side chains are generally present in less densely packed regions and are more protein-surface exposed than Ile side chains. We explored whether this difference might be attributed to different functions of the two amino acids and tested if Leu adjusts the hydrophobicity of the transmembrane domain based on the Wimley-White whole-residue hydrophobicity scales. In class A GPCRs, Leu decreases the variation in hydropathy between receptors and Leu content correlates positively with hydropathy calculated without Leu. Both measures indicate that hydropathy is tuned by Leu. To test this idea further, we generated protein sequences with random amino acid compositions using a simple numerical model, in which hydropathy was tuned by adjusting the number of Leu residues. The model was able to replicate the observations made with class A GPCR sequences. We speculate that Leu tunes the hydropathy of the transmembrane domain of class A GPCRs to facilitate correct insertion into membranes and/or for stability within them.
Ecosystems function in a series of feedback loops that can change or maintain vegetation structure. Vegetation structure influences the ecological niche space available for animals to partition, shaping many aspects of behavior and reproduction. In turn, animals perform ecological functions that shape vegetation structure. However, most studies concerning 3D vegetation structure consider only one of these relationships. Here, we review these separate lines of research and integrate them into a single concept that describes a feedback mechanism. We also show how remote sensing and animal tracking technologies are now available at the global scale to describe feedback loops and their consequences for ecosystem functioning. An improved understanding of how animals interact with vegetation structure in feedback loops is needed to conserve ecosystems that face major disruptions in response to climate and land use change.
Development of disposable, rapid and convenient biosensor with high sensitivity and reliability is the most desired method of viral disease prevention. To achieve this goal, in this work, a practical impedimetric biosensor has been implemented into a disposable electrode on a screen-printed carbon electrode (SPCE) for the detection of two mosquito-borne viruses. The biosensor fabrication has step-wisely carried out on the disposable electrode surface at room temperature: starting from conductive film formation, physical binding of the gold nanoparticles (AuNPs)-polyaniline (PAni) into the conductive film, and biofunctionalization. To get the maximum efficiency of the antibody, biotinylated antibody has been conjugated on the surface of AuNP-PAni /PAni-SPCE via the streptavidin-biotin conjugation method which is a critical factor for the high sensitivity. Using the antibody-antigen interaction, this disposable electrode has designed to detect mosquito-borne infectious viruses, Chikungunya virus (CHIKV) and Zika Virus (ZIKV) separately in a wide linear range of 100 fg/mL to 1 ng/mL with a low detection limit of 1.33 fg/mL and 12.31 fg/mL, respectively.
Background: Serotonin syndrome is a potentially life-threatening syndrome with manifestations spanning from mild adverse effects to life-threatening toxicity. The syndrome is caused by overstimulation of serotonin receptors by serotonergic drugs. Since the use of serotonergic drugs is increasing, primarily due to the widespread use of selective serotonin reuptake inhibitors, cases of serotonin syndrome have likely seen a parallel increase. The true incidence of serotonin syndrome remains unknown due to its diffuse clinical presentation. Objectives: This review aims to provide a clinically focused overview of serotonin syndrome, covering its pathophysiology, epidemiology, clinical manifestations, diagnostic criteria, differential diagnosis, and treatment as well as classifying serotonergic drugs and their mechanism of action. The pharmacological context is emphasized, as it is crucial for detection and management of serotonin syndrome. Methods: Focused review based on a literature search using the PubMed database. Findings and conclusion: Serotonin syndrome can occur through therapeutic use or overdose of a single serotonergic drug, or as a drug interaction between two or more serotonergic drugs. Central clinical features consist of neuromuscular excitation, autonomic dysfunction and altered mental status, occurring in a patient undergoing new or altered serotonergic therapy. Early clinically recognition and treatment are crucial to prevent significant morbidity.
Soil salinization is a serious problem leading to ecological degradation. Melia azedarach is highly salt-tolerant, and its application to saline-alkali land is a promising strategy for restoring degraded lands. In this study, we analyzed the soil properties and metabolome of M. azedarach roots grown in low- (< 3 g/kg; L), medium- (5~8 g/kg; M), and high- (> 10 g/kg; H) salinity soils to explore the amelioration effect and adaptation mechanism of M. azedarach to soils with differential salinity. Cultivation of M. azedarach was associated with a decrease in the concentration of Na + and increases in organic matter content and alkaline phosphatase and urease activities in the rhizosphere soil. The metabolome analysis revealed that a total of 382 (ESI+) and 277 (ESI-) differential metabolites (DEMs) were detected. The number of DEMs in roots rose with increased soil salinity, such as sugars and flavonoids in H vs. L, and amino acids in M vs. L. The most up-regulated DEMs were 13-S-hydroxyoctadecadienoic acid, 2’-Deoxyuridine and 20-hydroxyleukotriene B4. Combined analysis of soil properties and M. azedarach DEMs indicated that alkaline phosphatase activity was positively correlated with traumatic acid concentration. Taken together, these results indicate that M. azedarach has the potential to reduce soil salinity and enhance soil enzyme activity, and it can adapt to salt stress by regulating metabolites like sugars, amino acids, and flavonoids . This study provided a basis for understanding the mechanism underlying the adaptation of M. azedarach to saline-alkali soil and its amelioration.