Mechanism in Biology

The severe damage of precast concrete wall structures that have been recorded in the past earthquake has led to the innovation of the rocking wall concept which can demonstrate free or minimum damage aftershock of an earthquake. Furthermore, extensive research works have been well conducted in the past three decades on the establishment of precast rocking wall systems, designs, details, and techniques. Despite this extensive development, little attention has been devoted to investigate the interaction between the rocking wall systems and the flooring diaphragm. The historical perspective on the development of rocking wall systems over the past few decades in the precast concrete structures is presented. Subsequently, the limited research works on the interaction of precast rocking wall to the floor diaphragm are described. Apart from that, this paper attempts to highlight the application of rocking wall systems in the context of precast connection for the precast load-bearing structures. In this contribution, the precast rocking wall-floor connection for precast load-bearing structures is proposed and presented in this paper.

While epidemiological studies provide statistical evidence on associations of exposures such as stressful work with elevated risks of stress-related disorders (e.g., coronary heart disease or depression), additional information on biological pathways and biomarkers underlying these associations is required. In this contribution, we summarize the current state of the art on research findings linking stressful work, in terms of an established theoretical model-effort-reward imbalance-with a broad range of biomarkers. Based on structured electronic literature search and recent available systematic reviews, our synthesis of findings indicates that associations of work stress with heart rate variability, altered blood lipids, and risk of metabolic syndrome are rather consistent and robust. Significant relationships with blood pressure, heart rate, altered immune function and inflammation, cortisol release, and haemostatic biomarkers were also observed, but due to conflicting findings add...

Lysenin is a pore-forming toxin, which self-inserts open channels into sphingomyelin containing membranes and is known to be voltage regulated. The mechanistic details of its voltage gating mechanism, however, remains elusive despite much recent efforts. Here, we have employed a novel combination of experimental and computational techniques to examine a model for voltage gating, that is based on the existence of an “effective electric dipole” inspired by recent reported structures of lysenin. We support this mechanism by the observations that (i) the charge-reversal and neutralization substitutions in lysenin result in changing its electrical gating properties by modifying the strength of the dipole, and (ii) an increase in the viscosity of the solvent increases the drag force and slows down the gating. In addition, our molecular dynamics (MD) simulations of membrane-embedded lysenin provide a mechanistic picture for lysenin conformational changes, which reveals, for the first time,...

β-Secretase1 (BACE1) protein concentrations and rates of enzyme activity, analyzed in human bodily fluids, are promising candidate biological markers for guidance in clinical trials investigating BACE1 inhibitors to halt or delay the dysregulation of the amyloid-β pathway in Alzheimer’s disease (AD). A robust body of evidence demonstrates an association between cerebrospinal fluid/blood BACE1 biomarkers and core pathophysiological mechanisms of AD, such as brain protein misfolding and aggregration, neurodegeneration, and synaptic dysfunction.In pharmacological trials, BACE1 candidate biomarkers may be applied to a wide set of contexts of use (CoU), including proof of mechanism, dose-finding, response and toxicity dose estimation. For clinical CoU, BACE1 biomarkers show good performance for prognosis and disease prediction.The roadmap toward validation and qualification of BACE1 biomarkers requires standardized pre-analytical and analytical protocols to reduce inter-site variance tha...

Hedonic overconsumption is often considered to be caused by impulsive factors. The current paper investigates whether self-licensing, relying on reasons to justify subsequent gratification, can also be included as a significant contributor to hedonic consumption. Two studies were conducted to investigate whether self-licensing can account for an increase in hedonic consumption while ruling out impulsive factors such as resource depletion, negative affect, and visceral state as alternative explanations. A pilot study indicated that perceiving oneself as having invested greater effort and thus having a self-licensing cue did not lead to a decline in self-control capacity compared with not having a self-licensing cue. The main study employed the same procedure and established that having a licensing cue did lead to increased snack intake while controlling for impulsive factors. Together, these studies support the notion that self-licensing is a separate mechanism leading to hedonic gratification independent of impulsive factors.

Hedonic overconsumption is often considered to be caused by impulsive factors. The current paper investigates whether self-licensing, relying on reasons to justify subsequent gratification, can also be included as a significant contributor to hedonic consumption. Two studies were conducted to investigate whether self-licensing can account for an increase in hedonic consumption while ruling out impulsive factors such as resource depletion, negative affect, and visceral state as alternative explanations. A pilot study indicated that perceiving oneself as having invested greater effort and thus having a self-licensing cue did not lead to a decline in self-control capacity compared with not having a self-licensing cue. The main study employed the same procedure and established that having a licensing cue did lead to increased snack intake while controlling for impulsive factors. Together, these studies support the notion that self-licensing is a separate mechanism leading to hedonic gratification independent of impulsive factors.

Knowledge transfer within organizations has important implications for organizational performance and competitive advantage. In this virtual special issue, we review articles on this topic published in Organization Science between 2014 and 2020 and identify 53 articles for their theoretical and empirical contributions. These articles examine knowledge transfer through five transfer mechanisms: social networks, routines, personnel mobility, organizational design, and search. We consider the intersection of each transfer mechanism with important components of knowledge transfer (characteristics of sources/recipients, characteristics of knowledge, and characteristics of contexts). We present 15 exemplar articles, each of which reflects the intersection of a mechanism and a component of knowledge transfer. We also present an overview of the methodological approaches and empirical contexts that are utilized. We conclude our article with a discussion of future research opportunities. The ...

In this paper we propose a framework in order to analyze the dynamical process of decision and opinion formation of two economic homogeneous and boundedly rational agents that interact and learn from each other over time. The decisional process described in our model is an adaptive adjustment mechanism in which two agents take into account the difference between their own opinion and the opinion of the other agent. The smaller that difference, the larger the weight given to the comparison of the opinions. We also assume that if the distance between the two opinions is larger than a given threshold, then there is no interaction and the agents do not change their opinion anymore. Introducing an auxiliary variable describing the distance between the opinions, we obtain a one-dimensional map for which we investigate, mainly via analytical tools, the stability of the steady states, their bifurcations, as well as the existence of chaotic dynamics and multistability phenomena, i.e., the presence of coexisting attractors.

Ischemic heart disease (IHD) is one of the primary causes of death around the world. Therapeutic angiogenesis is a promising innovative approach for treating IHD, improving cardiac function by promoting blood perfusion to the ischemic myocardium. This treatment is especially important for targeting patients that are unable to undergo angioplasty or bypass surgery. Chinese herbal medicines have been used for more than 2,500 years and they play an important role alongside contemporary medicines in China. Growing evidence in animal models show Chinese herbal medicines can provide therapeutic effect on IHD by targeting angiogenesis. Identifying the mechanism in which Chinese herbal medicines can promote angiogenesis in IHD is a major topic in the field of traditional Chinese medicine, and has the potential for advancing therapeutic treatment. This review summarizes the progression of research and highlights potential pro-angiogenic mechanisms of Chinese herbal medicines in IHD. In addition, an outline of the limitations of Chinese herbal medicines and challenges they face will be presented.

Ischemic heart disease (IHD) is one of the primary causes of death around the world. Therapeutic angiogenesis is a promising innovative approach for treating IHD, improving cardiac function by promoting blood perfusion to the ischemic myocardium. This treatment is especially important for targeting patients that are unable to undergo angioplasty or bypass surgery. Chinese herbal medicines have been used for more than 2,500 years and they play an important role alongside contemporary medicines in China. Growing evidence in animal models show Chinese herbal medicines can provide therapeutic effect on IHD by targeting angiogenesis. Identifying the mechanism in which Chinese herbal medicines can promote angiogenesis in IHD is a major topic in the field of traditional Chinese medicine, and has the potential for advancing therapeutic treatment. This review summarizes the progression of research and highlights potential pro-angiogenic mechanisms of Chinese herbal medicines in IHD. In addit...

EL INSTITUTO DE BIOMECÁNICA DE VALENCIA (IBV) HA DESARROLLADO UN NUEVO CONCEPTO DE articulación ortésica de rodilla, basada en un mecanismo de cuatro barras cruzado, diseñada especialmente para mejorar la comodidad y la protección de los ligamentos de la rodilla. La nueva articulación se ha diseñado para reproducir la trayectoria del eje instantáneo de rotación (EIR) de la rodilla humana, en el lugar donde ésta irá situada. La metodología de algoritmos genéticos se ha aplicado como herramienta matemática para solucionar este complejo problema de optimización. Esta metodología permite determinar el mecanismo de cuatro barras óptimo para cumplir con los requisitos particulares del diseño de forma personalizada. Esta investigación se ha desarrollado en el marco del proyecto europeo GAIT, oferta Nº: IST-2001-37751, cuyo objetivo es desarrollar un nuevo sistema de ortesis activa para la evaluación biomecánica y la compensación de problemas musculares del cuadriceps.

This article examines the role of technology in modern education. It discusses how technology has facilitated the learning process, expanded access to knowledge, and transformed the roles of teachers and students. The article highlights online education, digital classrooms, e-learning platforms, and both the advantages and challenges of technology in education. Furthermore, it explores the global impact of technology on educational quality and the potential for enhancing learning outcomes. This study is useful for educators, researchers, and students seeking to understand the integration of technology into contemporary educational systems.

The article focuses on investments as a tool for solving economic development problems of the national economy. Based on the analysis of macroeconomic systems' development factors, it is concluded that it is necessary to accelerate economic development to ensure national competitiveness within the current global economy. The necessity of forming the organizational mechanism for the country's economic growth at a transitional stage of development is substantiated. The analysis of foreign investments in Ukraine is carried out. The paper defines the key points, tools, and measures for forming the corresponding mechanism on the example of Ukraine as an economic system in the transitional stage of development. The organizational scheme for economic growth by executive authorities is proposed. One of the critical roles in this mechanism is assigned to the Investment Department and Independent National Science Council; tasks and functions of these units in the structure of the agen...

The database computer (DBC) is a specialized back-end computer which is capable of managing data 10 10 bytes in size and supporting known data models such as relational, network, hierarchical and attribute-based models. It is also perhaps the first database machine to have a built-in security mechanism for access control. At the outset, the security mechanism was made an integral part of the DBC design. This design philosophy not only allowed us to construct a system that has no “backdoors”, but also ensured that all access requests are, in fact, controlled by DBC's security mechanism. The DBC security mechanism is based on the concept of security atoms, aggregates of data units being definable by the user in terms of conjunctions of query predicates. The fundamental gain in utilizing query conjunctions for the purpose of access control is that any data that is accessible or updateable is also protectable. It is believed that the DBC security mechanism is less cumbersome than th...

Usually in the presence of a background noise an increased effort put in controlling a system stabilizes its behavior. Rarely it is thought that an increased control of the system can lead to a looser response and, therefore, to a poorer performance. Strikingly there are many systems that show this weird behavior; examples can be drawn form physical, biological, and social systems. Until now no simple and general mechanism underlying such behaviors has been identified. Here we show that such a mechanism, named stochastic resonant damping, can be provided by the interplay between the background noise and the control exerted on the system. We experimentally verify our prediction on a physical model system based on a colloidal particle held in an oscillating optical potential. Our result adds a tool for the study of intrinsically noisy phenomena, joining the many constructive facets of noise identified in the past decades-for example, stochastic resonance, noise-induced activation, and Brownian ratchets.

The goal of this paper is to provide a characterisation of the monetary policy transmission mechanism in Romania over the period 2000 -2011. The main contribution of this paper is the layering of empirical evidence regarding the transmission mechanism split such as to compare the results before and after the implementation of the inflation targeting regime by National Bank of Romania. The methodology used in the article is that of vector autoregressions, a widely used empirical methodology in order to analyse the monetary policy. The results of the analysis show that the National Bank of Romania was more successful in controlling the transmission mechanism after implementing the direct inflation targeting and this monetary regime was properly chosen so as to allow the central bank to deal with the complexity and uncertainty issues raised by the current structural problems of the Romanian economy. Moreover, this strategy provides the National Bank of Romania a similar policy framework to that of the European Central Bank, this fact being an advantage given the desired adoption of the euro.

Solid dispersions (SDs) of atorvastatin (ATS) using PEO-PPO block copolymer resulted in the formation of an amorphous product with enhanced dissolution and bioavailability. Solubility enhancement was observed in the presence of selected carriers and it increased with the increase in concentration of carriers. The carrier and the active ingredient are dissolved in a suitable organic solvent is evaporated to an elevated temperature or under vaccum. As the solvent is being removed, super saturation occurs followed by simultaneous precipitation of the constituents resulting in a solid residue. The solvent-based process uses organic solvent to dissolve and intimately disperse the drug and carrier molecule The accumulative solubility of atorvastatin (ATS) from PEO-PPO block copolymer (Poloxamer 188) was found to be superior from glyceryl monostearate and PEG 4000 carriers due to increased content which played major role in solubility enhancement thus improving dissolution rate of SD2 batch with maximum drug release (98.08 %) in 120 minutes. The optimized SDs were characterized by saturation solubility study, drug content, in vitro dissolution, fourier transform infra-red spectroscopy, scanning electron microscopy, and x-ray diffraction. Capsules containing optimized SDs were prepared and compared with marketed brand (LIPITOR®). Finally it can be concluded that optimized SDs of ATS ameliorate the solubility and dissolution of drug. Since the batch SD2 elicited superior results, it can be proposed as good candidate for systemic product development.

Urdu novels have long served as a powerful mirror reflecting the plight of society's lower strata. The flexibility and scope of the novel form have always captivated writers, allowing them to explore the intricate connections between literature and social realities. This rich tradition features Urdu novelists from various eras who employed satire to expose social ills like the caste system and the stark divide between the wealthy and the underprivileged. Their narratives often depict the powerful as cruel and oppressive, controlling the lives of the poor in every aspect. The wealthy are portrayed as exploiting the impoverished, draining their resources and leaving them in a state of perpetual despair. By highlighting these injustices, Urdu novelists throughout history have shed light on the systemic oppression faced by the lower classes for centuries.

In this report, we describe cyclization of o-alkynylbenzaldehyde thioacetals catalyzed by PdI 2 . Recently, however, we have found a few publications closely related to this reaction. Rearrangement of ortho-palladated arylthioacetals was reported (

Military drill injury is a significant part of military medical research. The increase of training intensity and changes in training methods lead to differences in injury types. The ideal therapeutic modality should allow rapid healing at a reasonable cost and minimize impact on patients’ life. Platelet -rich plasma (PRP), a platelet concentrate, is rich in a variety of growth factors and widely used clinically as a minimally invasive treatment. It plays an important role in injury repair and rehabilitation. In this article, we review the therapeutic role of PRP in military drill injury and its possible underlying mechanisms, with a focus on plantar fasciitis, stress fractures and other common injuries, in order to provide basic support for military reserve.

Military drill injury is a significant part of military medical research. The increase of training intensity and changes in training methods lead to differences in injury types. The ideal therapeutic modality should allow rapid healing at a reasonable cost and minimize impact on patients' life. Platelet -rich plasma (PRP), a platelet concentrate, is rich in a variety of growth factors and widely used clinically as a minimally invasive treatment. It plays an important role in injury repair and rehabilitation. In this article, we review the therapeutic role of PRP in military drill injury and its possible underlying mechanisms, with a focus on plantar fasciitis, stress fractures and other common injuries, in order to provide basic support for military reserve.

Background Epstein-Barr virus (EBV) presumably plays an important role in the pathogenesis of nasopharyngeal carcinoma (NPC), but the molecular mechanism of EBV-dependent neoplastic transformation is not well understood. The combination of bioinformatics with evidences from biological experiments paved a new way to gain more insights into the molecular mechanism of cancer. Results We profiled gene expression using a meta-analysis approach. Two sets of meta-genes were obtained. Meta-A genes were identified by finding those commonly activated/deactivated upon EBV infection/reactivation. These genes could be key players for pathways de-regulated by EBV during latent infection and lytic proliferation. Meta-B genes were obtained from differential genes commonly expressed in NPC and PEL (primary effusion lymphoma). We then integrated meta-A, meta-B and associated factors into an interaction network using acquired information. Our analysis suggests that NPC transformation depends on timely...

post-HCT (10-pre-HCT and 5-post-HCT) comprising the Imatinib group and the remaining 17-patients, who either never received Imatinib (n 5 13) or received it at time of relapse (n 5 4), were the non-Imatinib group. Overall survival and relapse-free survival at 2 years was 73% and 65% for the Imatinib group compared to 34% and 35% for the non-Imatinib group (p 5 0.14 and 0.1, respectively). However, the incidence of relapse for these two groups was 8% (95% CI: 0.00, 0.24) and 41% (95% CI: 0.17, 0.66), respectively (p 5 0.02). Transplant related mortality at 2-years was similar between groups (27% and 24%; p 5 0.81). Of note, cardiac toxicity [defined as a reduction in left ventricular ejection fraction of .20% below baseline, cardiac hypertrophy or EKG abnormalities (ST changes, T-wave abnormalities, ischemia and/or infarction)] was less in the Imatinib group, 23% (95% CI: 0.00, 0.49) versus 47% (95% CI: 0.22, 0.72) (p 5 0.09). In conclusion, the use of Imatinib therapy in patients with Ph1 ALL in either the pre-or-post-HCT setting decreases the rate of relapse with a trend toward improved RFS and OS. Furthermore, Imatinib treated patients have no obvious increased risk of cardiac toxicity.

Duplex and super duplex materials possess the properties of both Austenite and Martensitic steels. Properties like hardness and toughness are very high for duplex grades and are difficult to machine. In this study, machining performance of duplex stainless steel (DSS 2205) and super duplex stainless steel (SDSS 2507) were estimated during CNC dry milling operation. Cutting parameters, namely feed rate, spindle speed, and depth of cut, were considered for this investigation and were optimized by considering surface roughness, cutting force, and cutting temperature during CNC milling using Taguchi technique. Results revealed that depth of cut has more effect on cutting force than spindle speed and feed rate. Surface roughness was more influenced by feed rate than spindle speed and least influenced by depth of cut for both the materials. Results also showed that cutting temperature is mainly influenced by spindle speed. Optimum value for all the responses was obtained at spindle speed of 4200 rpm, feed rate of 50 mm/min, and depth of cut of 0.35 mm for both DSS 2205 and SDSS 2507.

Background: HIV stigma contributes to the ongoing HIV epidemic especially in sub-Sahara Africa, where new infection rate is highest and the number of HIV-inf ected persons who commenced treatment is low. HIV s tigma exists in community and social institutions includi ng health institution. Most student nurses who ente r i to healthtraining institutions are members of the society an d might exhibit stigma towards HIV-infected persons which could be due to poor knowledge about HIV. This study inve stigated the HIV stigma mechanism of student nurses a well as their knowledge about HIV across a state in Sout hwestern Nigeria. Methods: A cross-sectional survey was conducted on 395 nurs ing students in their second and third year of stud y across four schools of nursing in a southwestern Ni gerian state from December, 2016 to January, 2017. Data were analysed using frequency, percentage, and mean scor es t explore demographic variables, knowledge abou t HIV, HIV stigma mechanism of prejud...

Technological strategic alliance (TSA) formation represents an important competitive mechanism for firms, and it can be considered as a real option on future technological opportunities. Our objective is to analyse, under a real options reasoning, how firms decide between forming TSAs or adopting alternatives one-step technology strategies. Using a panel of 29376 observations from 4050 manufacturing firms operating in Spain -covering the 1998-2005 period -, we find that the greater the firm's absorptive capacity and the greater the degree of technological risk, the more likely is the firm to form a TSA rather than adopting other technology strategies. Our results also show that the greater the risk of pre-emption by rivals and the greater the opportunity costs associated with TSA formation, the less likely is the firm to form a TSA.

Exoskeletons are a promising tool to support individuals with a decreased level of motor performance. Lower limb exoskeleton robotics has emerged as a transformative solution in assistive &rehabilitative mobility technologies, particularly benefiting individuals with gait impairments, spinal cord injuries, or age-related motor decline. This review presents a comprehensive analysis of mechatronics-based systems designed for lower limb exoskeletons, emphasizing the integration of mechanical structures, sensor networks, actuators, and control algorithms.materials and method synthesizes existing scholarly works, prototype evaluations, and case studies published between 2005 and 2024. Key components such as joint torque actuators, real-time feedback systems, and bio-signal interfaces (e.g., EMG, EEG) are examined to evaluate system responsiveness, stability, and adaptability. Advances in control strategies, including impedance control, model predictive control, and machine learning-enhanced gait prediction, are discussed. The paper also identifies persistent challenges, including power management, system weight, and human-machine coordination. Finally, future directions are outlined, with a focus on intelligent autonomy, lightweight material development, and clinical validation. This review aims to support the design and implementation of next-generation lower limb exoskeletons in both medical and industrial contexts.

It is generally recognized that ovarian cancer tends to remain intra-abdominal even in advanced stages. This case report describes a patient with ovarian carcinoma who had an ulcerated fungating growth in her left groin area. Case history: A 35yrs para2 women presented with a fungating left inguinal node of 5 x 4 cm for last 3 months. Biopsy revealed metastatic papillary adenocarcinoma. Clinical examination showed left sided pedal oedema. Laboratory investigation revealed increased CA125 (412IU/ml).Radiological studies were normal. In view of the raised Ca 125 she was treated in the lines of FIGO stage III cancer ovary with Paclitaxel 260mg and Carboplatin 450mg for three cycles. She responded dramatically with completely healedinguinal nodes. Then laparotomy with total hysterectomy, bilateral salpingo-oophorectomy partial omentectomy and inguinal lymph node dissection were performed. Histology confirmed right ovarian adenocarcinoma consistentwith the earlier histology of the left inguinal lymph node. There were noother sites of involvement. Postoperatively, the patient received three more cycle of chemotherapy. Ovarian cancer with inguinal lymph node metastasis is uncommon and only around 1% of ovarian carcinoma have a normal sized ovary. This case report demonstrates that early distal metastasis, although rare, can occur in patients with ovarian cancer and may be a compelling symptom of ovarian cancer.

Liver's contribution to innate immunity is eminent. However, uncontrolled inflammatory conditions predispose the liver to immune-mediated injury. Nigella sativa L. is traditionally implicated in infectious, inflammatory, metabolic and hepatorenal complications. This study aimed to evaluate the protective role of N. sativa seed extract (NSE) against concanavalin A (ConA)-induced acute immunological liver injury in mice. In vitro, NSE was subjected to quantitative phytochemical characterization and 1,1-diphenyl-2-picryhydrazyl (DPPH) analysis. In vivo, male Balb/c mice were pretreated with NSE (100, 200 and 400 mg/kg/day, p.o.) and pioglitazone (5 mg/kg/day, p.o.) for seven consecutive days. A single dose of ConA (12 mg/kg, i.v.) was injected and samples were collected for biochemical, histopathological and qRT-PCR analyses after 8 h of ConA injection. In vitro analysis showed considerable quantities of polyphenols and significant DPPH scavenging ability of NSE. In mice, ConA resulted in a significant (p<0.05) increase in liver injury markers (ALT, AST, ALP and TBil) and hepatic oxidative stress (SOD, CAT and MDA). Also, a substantial elevation of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) in liver tissues was noticed. Furthermore, ConA HIGHLIGHTS • Nigella sativa seed extract (NSE) possess significant polyphenol contents and antioxidant potential. • NSE attenuated concanavalin A-induced liver injury and oxidative stress. • NSE suppressed liver inflammation through modulating PPARγ/JAK2/STAT3 pathway. • NSE inhibited hepatocyte apoptosis via downregulating Bcl-2/Bax/Caspase-9 pathway.

Obesity and iron deficiency (ID) are two of the most common nutritional disorders in the world. In children both conditions deserve particular attention. Several studies revealed an association between obesity and iron deficiency in children and, in some cases, a reduced response to oral supplementation. The connecting mechanism, however, is not completely known. This review is focused on: (1) iron deficiency in obese children and the role of hepcidin in the connection between body fat and poor iron status; (2) iron status and consequences on health, in particular on cognitive function; (3) cognitive function and obesity; (4) suggestion of a possible link between cognitive dysfunction and ID in pediatric obesity; and implications for therapy and future research.

Nervous system is characterized by its uniqueness in cells origin, their variability, electrical properties of the nervous cell membrane, response to external signals, neuronal network and changes in synapses activity that are the basis of higher brain functions, such as learning and memory. Brain is a superior organ of human body with an extremely efficient regulation system. Apart from protein and small-molecule regulators, ribonucleic acids (RNAs), especially noncoding proteins (ncRNAs), play a crucial controlling role in the brain. They are present in every cell, from bacteria to primates and have regulatory, catalytic as well as structural function. Many specific ncRNAs have been identified in human brain, responsible for development and functioning. Disturbances in ncRNA synthesis and mechanism of action are connected to diseases such as autism, schizophrenia, Alzheimer disease, Prader-Willi syndrome and others.

Complex mechanisms regulate the cellular distribution of cholesterol (CHL), a critical component of eukaryote membranes involved in regulation of membrane protein functions directly and through the physiochemical properties of membranes. StarD4, a member of the steroidogenic acute regulator-related lipid-transfer (StART) domain (StARD)-containing protein family, is a highly-efficient sterol-specific transfer protein involved in cholesterol homeostasis. Experimental data show that sterol transfer by StarD4 is modulated by the organelle-dependent composition of phosphatidylinositol phosphate (PIP) subtypes present in the sterol donating or accepting membrane. The kinetics of StarD4-mediated sterol transport between vesicles containing PIP2 are higher compared to vesicles containing Phosphatidylserine (PS), and PI(4,5)P2 cause a stronger acceleration effect than PI(3,5)P2. To understand the molecular mechanisms underlying the modulation of StarD4 efficiency through PIP-subtype recognition, we study the effect of membrane composition on the StarD4 cholesterol trafficking process using molecular dynamics (MD) simulations. We find that StarD4 embeds differently into membranes containing PI(4,5)P2, PI(3,5)P2 or PS, and have identified different modes of lipid binding to StarD4 in each system. The interaction modes of StarD4 with the different membrane lipid compositions depend on the specific anionic lipid molecules, suggesting a potential mechanism of PIP2-subtype recognition of StarD4. Membrane embedded StarD4 exhibits significant differences in the preference of allosteric gate opening conformations and lipid interaction, resulting in different kinetics of sterol transport as evaluated by the free energy barrier along the CHL release pathways. These findings suggest a detailed model of the molecular mechanism of regulation of sterol transport and organelle preference by StarD4 recognition of different PIP-subtypes in the target membranes.

Nuclear pore complexes (NPCs) mediate the exchange of materials between the nucleoplasm and cytoplasm, playing a key role in the separation of nucleic acids and proteins into their required compartments. The static structure of the NPC is relatively well defined by recent cryo-EM and other studies. The functional roles of dynamic components in the pore of the NPC, phenylalanyl-glycyl (FG) repeat rich nucleoporins, is less clear because of our limited understanding of highly dynamic protein systems. These proteins form a ‘restrained concentrate’ which interacts with and concentrates nuclear transport factors (NTRs) to provide facilitated nucleocytoplasmic transport of cargoes. Very rapid on- and off-rates among FG repeats and NTRs supports extremely fast facilitated transport, close to the rate of macromolecular diffusion in cytoplasm, while complexes without specific interactions are entropically excluded, though details on several aspects of the transport mechanism and FG repeat be...

The increasing relevance of complex systems in dynamic environments has received special attention from researchers during the last decade. Due to the need of a flexible and quick response to the clients' requirements, such systems become an important challenge. In this paper, self-organizing mechanisms capable to compose services in an automatic, flexible and decentralized manner are presented, mostly in which their adaptive behavior is concerned. Due to the distributed approach, we also investigate the adaptation regarding the structure of each entity. We thus propose an innovative self-learning mechanism that allows the distributed entities to learn structural relations allowing the system's evolution. This hypothesis were explored and validated by implementing a multi-agent system, in accordance with trust mechanisms to improve the interaction of agents. The achieved results show the correct agent's states in which the agents must evolve and self-organize, improving the system benefits band increasing the organization performance.

environmental contaminants. Here we present the crystal structure of the terminal oxygenase component of the biphenyl dioxygenase (BphA1A2) derived from Rhodococcus strain sp. RHA1. This is the first crystal structure of the biphenyl dioxygenase. We also determined the crystal structure of the BphA1A2-biphenyl complex. Structural comparison between the substrate free and complex forms revealed that the substrate-binding pocket makes significant conformational changes upon substrate binding to accommodate the substrate into the pocket. The analysis with the two crystal structures suggested that the residues in the substrate-binding pocket can be classified into three groups, which respectively seem to be responsible for the catalytic reaction, the orientation/conformation of the substrate, and the conformational changes of the substrate-binding pocket.

In this paper, a reaction-force compensation system for an XY linear motion stage, without an additional external isolation structure or extra motors, is developed. This system consists of a movable magnet track, a spring, a dummy weight, and a dedicated sensor module that measures the relative positions of the movable magnet track with respect to the motor coil. The reaction force compensation system is modeled, and simulations are carried out to optimize design parameters such as the moving distance of the magnet track, the transmission force, the dummy weight, and the allowed size of the mechanism. An XY linear motion stage is built, incorporating the reaction force compensation system, and the performance of the system is verified experimentally. For acceleration and deceleration values of 10 m/s 2 , 85% of the reaction force is absorbed by the reaction force compensation system.

Reaction force compensation (RFC) mechanism can relieve the vibration of base system caused by acceleration and deceleration of mover. In this paper, we propose a new passive RFC mechanism with a movable additional mass to reduce vibration of the system base as well as displacement of the magnet track. First, equation of motion for the new passive RFC mechanism is derived and simulated to tune design parameters such as masses and spring coefficients. Simulation results show that the vibration of the system base of the stage with the new RFC mechanism.

Predicting for best network connection with highest accuracy of prediction deems to be a desire for anticipating most reliable network communication. Besides the ordinary function of any predictive mechanism to understand certain behaviour and trends, we have adopted such mechanism to mitigate network evaluation delays that occur every time switching to other network. In this paper, we propose a predictive analytics mechanism based on existing network selection models. The mechanism uses connection speed as main parameter to determine the network behaviour before a selection being made. We conducted a few predictive models that are able to predict the network speed based on the input data that we have recorded daily at an interval of 15 minutes. The root mean squared error (RMSE) and squared error (SE) values were calculated for each predictive model used. It was found that, the W-M5Rules and W-M5P have the lowest error difference amongst other tested predictive models. For our sample size dataset, it is appropriate to say that the W-M5Rules and W-M5P show the best accuracy that resembles the actual collected data.