Extension Mechanism Research Articles

Pancreatic acinar cell carcinoma with extension into the main pancreatic duct: a case report

BackgroundPancreatic acinar cell carcinoma (PACC) is a rare exocrine malignant tumor. Its widespread intraductal extension into the main pancreatic duct (MPD) is also rare.Case presentationWe report the case of a 71-year-old man with PACC with MPD extension. The patient was assessed with laboratory and radiographic investigations that facilitated a preoperative diagnosis. Endoscopic ultrasonography (EUS) and dynamic thin-slice multi-detector row computed tomography (MDCT) were useful for determining the resection line of the pancreas. EUS-guided fine needle aspiration (EUS-FNA) was also helpful in determining the tumor biology and treatment strategy. Distal pancreatectomy was performed. The MPD was occupied by the tumor 35 mm downstream and 5 mm upstream. Histopathologically, the pancreatic tail tumor extended continuously into the MPD. The tumor was solid with cells showing eosinophilic and granular cytoplasm, indicating the diagnosis of PACC. This is an interesting case of PACC with intraductal extension into the MPD. We discuss the possible mechanisms of tumor extension in this rare case together with a review of the literature.ConclusionsWe describe a rare pancreatic acinar cell carcinoma that could be adequately treated using preoperative precise imaging and histopathological evaluations. When an intraductal tumor extension in the MPD is encountered, the diagnosis of a rare pancreatic tumor should be considered, as in our case.

Mechanism of the lifespan extension induced by submaximal SERCA inhibition in C. elegans

We have reported recently that submaximal inhibition of the Sarco Endoplasmic Reticulum Ca2+ ATPase (SERCA) produces an increase in the lifespan of C. elegans worms. We have explored here the mechanism of this increased survival by studying the effect of SERCA inhibition in several mutants of signaling pathways related to longevity. Our data show that the mechanism of the effect is unrelated with the insulin signaling pathway or the sirtuin activity, because SERCA inhibitors increased lifespan similarly in mutants of these pathways. However, the effect required functional mitochondria and both the AMP kinase and TOR pathways, as the SERCA inhibitors were ineffective in the corresponding mutants. The same effects were obtained after reducing SERCA expression with submaximal RNAi treatment. The SERCA inhibitors did not induce ER-stress at the concentrations used, and their effect was not modified by inactivation of the OP50 bacterial food. Altogether, our data suggest that the effect may be due to a reduced ER-mitochondria Ca2+ transfer acting via AMPK activation and mTOR inhibition to promote survival.

Cap-independent translation: A shared mechanism for lifespan extension by rapamycin, acarbose, and 17α-estradiol.

We hypothesized that rapamycin (Rapa), acarbose (ACA), which both increase mouse lifespan, and 17α‐estradiol, which increases lifespan in males (17aE2) all share common intracellular signaling pathways with long‐lived Snell dwarf, PAPPA‐KO, and Ghr−/− mice. The long‐lived mutant mice exhibit reduction in mTORC1 activity, declines in cap‐dependent mRNA translation, and increases in cap‐independent translation (CIT). Here, we report that Rapa and ACA prevent age‐related declines in CIT target proteins in both sexes, while 17aE2 has the same effect only in males, suggesting increases in CIT. mTORC1 activity showed the reciprocal pattern, with age‐related increases blocked by Rapa, ACA, and 17aE2 (in males only). METTL3, required for addition of 6‐methyl‐adenosine to mRNA and thus a trigger for CIT, also showed an age‐dependent increase blunted by Rapa, ACA, and 17aE2 (in males). Diminution of mTORC1 activity and increases in CIT‐dependent proteins may represent a shared pathway for both long‐lived‐mutant mice and drug‐induced lifespan extension in mice.

Hydrogen sulfide treatment at the late growth stage of Saccharomyces cerevisiae extends chronological lifespan.

Previous studies demonstrated that lifelong treatment with a slow H2S releasing donor extends yeast chronological lifespan (CLS), but it is not clear when the action of H2S benefits to CLS during yeast growth. Here, we show that short H2S treatments by using NaHS as a fast H2S releasing donor at 96 hours after inoculation extended yeast CLS while NaHS treatments earlier than 72 hours after inoculation failed to do so. To reveal the mechanism, we analyzed the transcriptome of yeast cells with or without the early and late NaHS treatments. We found that both treatments had similar effects on pathways related to CLS regulation. Follow-up qPCR and ROS analyses suggest that altered expression of some antioxidant genes by the early NaHS treatments were not stable enough to benefit CLS. Moreover, transcriptome data also indicated that some genes were regulated differently by the early and late H2S treatment. Specifically, we found that the expression of YPK2, a human SGK2 homolog and also a key regulator of the yeast cell wall synthesis, was significantly altered by the late NaHS treatment but not altered by the early NaHS treatment. Finally, the key role of YPK2 in CLS regulation by H2S is revealed by CLS data showing that the late NaHS treatment did not enhance the CLS of a ypk2 knockout mutant. This study sheds light on the molecular mechanism of CLS extension induced by H2S, and for the first time addresses the importance of H2S treatment timing for lifespan extension.

Characterization, Design, and Experimentation of a Fabric-Based Wearable Joint Sensing Device on Human Elbow

Abstract The use of conductive fabrics (CFs) in the design of wearables for joint sensing has recently received much interest in a wide range of applications such as robotics, rehabilitation, personal wellness, and sports. However, one key limitation in the existing measurement approach is that the user’s anthropometric information is required to relate the joint parameters to the CF sensor strain reading. This paper seeks to address this limitation by evaluating a new wearable device concept that comprises a CF strain–voltage sensor embedded as part of an inverted slider-crank (ISC) mechanism for joint extension sensing. This benefits from not requiring anthropometric information from the user to relate the joint parameters to the fabric strain readings, as opposed to an existing design. We first characterize the electromechanical property of a commercially available CF. Second, we formulate the joint sensing device’s geometric synthesis procedure as a constrained revolute joint system, where the CF is designed and introduced as an RPR chain to obtain an ISC linkage. Lastly, we designed our wearable sensing device and validated against an ISC linkage fixture representing an elbow joint and an actual healthy human subject’s left elbow. The ISC linkage fixture experimental setup shows that our designed joint sensing device can track the elbow extension motion of 140 deg with a maximum error of 7.66%. The results from our human subject’s left elbow show that it can track the elbow flexion–extension at various angular motion, with error ranges between 8.24 deg and 12.86 deg, and have provided us with an acceptable average Spearman’s coefficient values rs at 0.95.

A glucose-supplemented diet enhances gut barrier integrity in Drosophila.

ABSTRACTDietary intervention has received considerable attention as an approach to extend lifespan and improve aging. However, questions remain regarding optimal dietary regimes and underlying mechanisms of lifespan extension. Here, we asked how an increase of glucose in a chemically defined diet extends the lifespan of adult Drosophila melanogaster. We showed that glucose-dependent lifespan extension is not a result of diminished caloric intake, or changes to systemic insulin activity, two commonly studied mechanisms of lifespan extension. Instead, we found that flies raised on glucose-supplemented food increased the expression of cell-adhesion genes, delaying age-dependent loss of intestinal barrier integrity. Furthermore, we showed that chemical disruption of the gut barrier negated the lifespan extension associated with glucose treatment, suggesting that glucose-supplemented food prolongs adult viability by enhancing the intestinal barrier. We believe our data contribute to understanding intestinal homeostasis, and may assist efforts to develop preventative measures that limit effects of aging on health.

The antioxidant MnTBAP does not effectively downregulate CD4 expression in T cells in vivo

The antioxidant MnTBAP was previously shown to down-regulate the surface expression of CD4 molecule in T cells. This observation obviously holds great potential impact in a number of pathological human conditions, including autoimmunity. Three different single doses of MnTBAP reduced the frequency of CD4high cells. However, the median florescent intensity (MFI) was not different. Initiation of in vivo pharmacotherapy or vehicle control was performed inC57BL/6 mice that were actively immunized for experimental autoimmune encephalomyelitis (EAE). In contrast to published reports, the mean frequency of CD4high cells, and the median fluorescent intensity (MFI) of CD4 was similar in both treatment groups. 25-day survival following active immunization among the MnTBAP treated animals compared to vehicle controls was16.6 ± 6.9 days vs 23.6 ± 2.7 days; (P value <0.05). We conclude that MnTBAP (Sack and Herzog, 2009 (Sack and Herzog, 2009)) does not effectively downregulate CD4 expression in T cells in vivo, probably due to extensive mechanism that distinguishes it from an in vitro model (Harding, 1993 (Harding, 1993)) possesses toxic properties that may limit its clinic use in possible doses that could deliver the immunomodulation through down regulation of CD4 expression, and (Saizawa et al., 1987 (Saizawa et al., 1987)) has limited availability in specific tissues, including the CNS.

Extension of Drosophila Lifespan by Astragalus polysaccharide through a Mechanism Dependent on Antioxidant and Insulin/IGF-1 Signaling.

Historical literature and pharmacological studies demonstrate that Astragalus polysaccharide (APS) has anti-inflammatory and antioxidative effects. Studies into the longevity effects of APS are limited, and the molecular mechanism of lifespan extension by APS is not elucidated yet. Here, the longevity effect of APS was investigated in Drosophila melanogaster by feeding dose-dependent APS. APS significantly extended the lifespan and improved the reproduction. Meanwhile, APS increased locomotion, TAG level, and starvation resistance and reduced the mortality rate induced by hydrogen peroxide. The activities of superoxide dismutase (SOD) and catalase (CAT) were increased in flies treated with APS diet. Moreover, APS significantly enhanced expressions of antioxidant genes (Sod1, Sod2, and Cat), dFoxO, and 4E − BP, decreased the expressions of insulin-like peptides (dilp2, dilp3, and dilp5), and longevity gene MTH. Together, these results indicate that APS can prolong the lifespan by regulating antioxidant ability and insulin/IGF-1 signaling and also enhance the reproduction ability in Drosophila. APS may be explored as a novel agent for slowing the aging process and improving reproduction.

A Runtime-Enabled P4 Extension to the Open vSwitch Packet Processing Pipeline

A hypervisor switch, such as Open vSwitch (OVS), plays a key role in the virtualized data centers implementing overlay networking to provide network isolation. The hypervisor switch is running on each compute node as a software application and switches packets between virtual machines. Software switches frequently require upgrading and customization of network protocol's stack to introduce novel or domain-specific networking techniques. However, it is still difficult to extend OVS to support new network features as it requires mastery of network protocol design, programming expertise, and familiarity with the complex codebase of OVS. Moreover, there is currently no solution that enables the deployment of network features recompilation of OVS. In this article, we present P4rt-OVS, an original extension of OVS that enables runtime programming of protocol-independent and stateful packet processing pipelines. It extends the forwarding model of OVS with the userspace Berkeley Packet Filter (uBPF), bringing a new extensibility mechanism. Moreover, P4rt-OVS comes with a P4-to-uBPF compiler, which allows developers to write data plane programs in the high-level P4 language, compile them to the BPF bytecode and inject them to the OVS packet processing pipeline at runtime. Our design results in a hybrid approach that provides P4 programmability without sacrificing the well-known features of OVS. We provide thorough performance results, including end-to-end performance tests, microbenchmarks and a performance test of an exemplary network application (Broadband Network Gateway). The performance evaluation shows that P4rt-OVS does not introduce significant processing overhead, yet enables runtime protocol extensions and stateful packet processing. Moreover, we discuss features of P4rt-OVS and provide programming guidelines to help developers achieve the best performance of P4 programs for P4rt-OVS.

A dietary sterol trade-off determines lifespan responses to dietary restriction in Drosophila melanogaster females.

Diet plays a significant role in maintaining lifelong health. In particular, lowering the dietary protein: carbohydrate ratio can improve lifespan. This has been interpreted as a direct effect of these macronutrients on physiology. Using Drosophila melanogaster, we show that the role of protein and carbohydrate on lifespan is indirect, acting by altering the partitioning of limiting amounts of dietary sterols between reproduction and lifespan. Shorter lifespans in flies fed on high protein: carbohydrate diets can be rescued by supplementing their food with cholesterol. Not only does this fundamentally alter the way we interpret the mechanisms of lifespan extension by dietary restriction, these data highlight the important principle that life histories can be affected by nutrient-dependent trade-offs that are indirect and independent of the nutrients (often macronutrients) that are the focus of study. This brings us closer to understanding the mechanistic basis of dietary restriction.

Modeling the resistance mechanism of passive knee joint flexion and extension for use in rehabilitation equipment.

The purpose of this study was to model the resistance mechanism of Passive Knee Joint Flexion and Extension to create a similar torque mechanism in rehabilitation equipment. In order to better model the behavior of passive knee tissues, it is necessary to exactly calculate the two coefficients of elasticity of time-independent and time-dependent parts. Ten healthy male volunteers (mean height 176.4+/-4.59 cm) participated in this study. Passive knee joint flexion and extension occurred at velocities of 15, 45, and 120 (degree/s), and in five consecutive cycles and within the range of 0 to 100° of knee movement on the sagittal plane on Cybex isokinetic dynamometer. To ensure that the muscles were relaxed, the electrical activity of knee muscles was recorded. The elastic coefficient, (KS) increased with elevating the passive velocity in flexion and extension. The elastic coefficient, (KP) was observed to grow with the passive velocity increase. While, the viscous coefficient (C) diminished with passive velocity rise in extension and flexion. The heightened passive velocity of the motion resulted in increased hysteresis (at a rate of 42%). The desired of passive velocity is lower so that there is less energy lost and the viscoelastic resistance of the tissue in the movement decreases. The Coefficient of Determination, R2 between the model-responses and experimental curves in the extension was 0.96 < R2 < 0.99 and in flexion was 0.95 < R2 < 0.99. This modeling is capable of predicting the true performance of the components of passive knee movement and we can create a resistance mechanism in the rehabilitation equipment to perform knee joint movement. Quantitative measurements of two elastic coefficients of Time-independent and Time-dependent parts passive knee joint coefficients should be used for better accurate simulation the behavior of passive tissues in the knee which is not seen in other studies.

Chronic Sphenoiditis With Deep Neck Space Extension: Case Report With Review of the Literature and Postulated Mechanisms for Extracranial Extension.

Isolated primary sphenoid sinusitis is a rare occurrence, estimated to make up less than 3% of sinus infections. The posterior anatomic location of the sphenoid makes treatment challenging when it becomes infected. Complications involving intracranial extension to surrounding structures often result in cranial nerve deficits due to their proximity. A single case of chronic sphenoiditis with direct extracranial extension into the prevertebral space is reported with a discussion on clinical presentation, diagnosis, and management. A 46-year-old female patient with diffuse headaches radiating into the neck and throat was evaluated in the office. Computed tomography demonstrated sphenoiditis with direct extension into the prevertebral space. Imaging revealed a purported route of direct extension through the clinoid and directly into the clivus to form an abscess in the longus colli muscle. The patient underwent endoscopic surgical management including drainage of the prevertebral abscess and has since made a full recovery. This is the first reported case of direct extension of sphenoiditis into the prevertebral space. The findings highlight the importance of aggressive treatment of chronic sphenoid infections to prevent detrimental complications. Computed tomography imaging proved an advantageous imaging modality to demonstrate bony erosion and sinus tracts from the skull base to the deep neck space.

The active DNA-PK holoenzyme occupies a tensed state in a staggered synaptic complex

In the non-homologous end-joining (NHEJ) of a DNA double-strand break, DNA ends are bound and protected by DNA-PK, which synapses across the break to tether the broken ends and initiate repair. There is little clarity surrounding the nature of the synaptic complex and the mechanism governing the transition to repair. We report an integrative structure of the synaptic complex at a precision of 13.5Å, revealing a symmetric head-to-head arrangement with a large offset in the DNA ends and an extensive end-protection mechanism involving a previously uncharacterized plug domain. Hydrogen/deuterium exchange mass spectrometry identifies an allosteric pathway connecting DNA end-binding with the kinase domain that places DNA-PK under tension in the kinase-active state. We present a model for the transition from end-protection to repair, where the synaptic complex supports hierarchical processing of the ends and scaffold assembly, requiring displacement of the catalytic subunit and tension release through kinase activity.

Neural Network Instruction Set Extension and Code Mapping Mechanism

PDF HTML XML Export Cite reminder Neural Network Instruction Set Extension and Code Mapping Mechanism DOI: 10.21655/ijsi.1673-7288.00251 Author: Affiliation: Clc Number: Fund Project: Article | Figures | Metrics | Reference | Related | Cited by | Materials | Comments Abstract:In recent years, Convolutional Neural Network (CNN) has received widespread attention in the field of machine learning due to its high-accuracy performance in character recognition and image classification. Nevertheless, the compute-intensive and memory-intensive characteristics of CNN have posed huge challenges to the general-purpose processor, which needs to support various workloads. Therefore, a large number of CNN-specific hardware accelerators have emerged to improve efficiency. Though significantly efficient, previous accelerators are not flexible enough. In this study, classical CNN models are analyzed and a domain-specific instruction set of 10 matrix instructions, called RV-CNN, is design based on the promising RISC-V architecture. By abstracting CNN computation into instructions, the proposed design can provide sufficient flexibility for CNN and possesses a higher code density than the general ISA. On this basis, a code-to-instruction mapping mechanism is proposed. By using the RV-CNN to build different CNN models on the Xilinx ZC702, this paper found that compared to x86 processors, RV-CNN has an average of 141 times energy efficiency and 8.91 times the code density; compared to GPU, it has an average of 1.25 times energy efficiency and 1.95 times the code density. In addition, compared to previous CNN accelerators, the design supports typical CNN models while at high energy efficiency. Reference Related Cited by

Design, Modeling, and Demonstration of a New Dual-Mode Back-Assist Exosuit with Extension Mechanism.

Occupational exoskeletons and exosuits have been shown to reduce muscle demands and fatigue for physical tasks relevant to a variety of industries (e.g. logistics, construction, manufacturing, military, healthcare). However, adoption of these devices into the workforce has been slowed by practical factors related to comfort, form-factor, weight, and not interfering with movement or posture. We previously introduced an un-motorized, low-profile, dual-mode exosuit comprised of textile and elastic materials to address these adoption barriers. Here we build upon this prior work by introducing an extension mechanism that increases the moment arm of the exosuit while in engaged mode, then collapses in disengaged mode to retain key benefits related to being lightweight, low-profile, and unobstructive. Here we demonstrate both analytically and empirically how this extensible exosuit concept can (i) reduce device-to-body forces (which can improve comfort for some users and situations), or (ii) increase the magnitude of torque assistance about the low back (which may be valuable for heavy-lifting jobs) without increasing shoulder or leg forces relative to the prior form-fitting exosuit. We also introduce a novel mode-switching mechanism, as well as a human-exosuit biomechanical model to elucidate how individual design parameters affect exosuit assistance torque and device-to-body forces. The proof-of-concept prototype, case study, and modeling work provide a foundation for understanding and implementing extensible exosuits for a broad range of applications. We envision promising opportunities to apply this new dual-mode extensible exosuit concept to assist heavy-lifting, to further enhance user comfort, and to address the unique needs of last-mile delivery workers.

An Extended Text Combination Classification Model for Short Video Based on Albert

With the rise and rapid development of short video sharing websites, the number of short videos on the Internet has been growing explosively. The organization and classification of short videos have become the basis for the effective use of short videos, which is also a problem faced by major short video platforms. Aiming at the characteristics of complex short video content categories and rich extended text information, this paper uses methods in the text classification field to solve the short video classification problem. Compared with the traditional way of classifying and understanding short video key frames, this method has the characteristics of lower computational cost, more accurate classification results, and easier application. This paper proposes a text classification model based on the attention mechanism of multitext embedding short video extension. The experiment first uses the training language model Albert to extract sentence‐level vectors and then uses the attention mechanism to study the text information in various short video extensions in a short video classification weight factor. And this research applied Google’s unsupervised data augmentation (UDA) method based on unsupervised data, creatively combining it with the Chinese knowledge graph, and realized TF‐IDF word replacement. During the training process, we introduced a large amount of unlabeled data, which significantly improved the accuracy of model classification. The final series of related experiments is aimed at comparing with the existing short video title classification methods, classification methods based on video key frames, and hybrid methods, and proving that the method proposed in this article is more accurate and robust on the test set.

Legal bases of activity of law enforcement bodies in the field of security in border areas of Ukraine

This article is intended for the theoretical foundations of the strategy of security in the border areas of Ukraine by law enforcement agencies. Law enforcement agencies are existing in society and the state institutions and organizations that perform law enforcement and law enforcement functions whose main task is to ensure security in the border areas of Ukraine. At the current stage of development of Ukraine as a democratic social and legal state, taking into account the recent global changes in the world, the development of law enforcement agencies to ensure national and internal security from internal and external threats is one of the priorities of European policy. The choice of the population of Ukraine highlighted the problem of implementation of ratified agreements with the European Union, including the provisions of the European Charter in the field of security in the border areas of the state, as important components of the political and legal system of Ukraine. Ensuring state security, protection of the state border and protection in the border area of Ukraine in accordance with the Constitution of Ukraine is entrusted to military formations and law enforcement agencies of the state. The state pays special attention to improving the legislation in the field of administrative and legal regulation in the field of national and internal security of the state from internal and external threats. The formation of the scientific doctrine of the scientific order in Ukraine has its own difficult history. Maintaining and strengthening the rule of law in society in modern conditions, as a necessary prerequisite for the effective functioning of an extensive human rights mechanism with the participation of state institutions, law enforcement agencies, civil society require thorough doctrinal support.

In vivo stiffness assessment of patellar and quadriceps tendons by strain ultrasound elastography

BACKGROUND:The patellar and quadriceps tendons are responsible for the extension mechanism of the knee joint and frequently become inflamed during sports. Diagnosis and determination of when an athlete can return to sports following these injuries are usually performed by assessing morphological features and functional outcomes. Nevertheless, mechanical properties are not being assessed.OBJECTIVE:To describe the stiffness characteristics of these two tendons over the range of knee flexion and to test the feasibility of using strain ultrasound elastography (SE).METHODS:SE with an acoustic coupler as the reference was performed for nine healthy males. Relative stiffness measurements were obtained using the strain ratio (SR = target tissue strain/reference strain) by placing the knee in five different flexion angles. Lower SR indicates higher relative stiffness.RESULTS:This study showed reliable measurement with good intra- and inter-rater agreement for SR at 30°. SR of the quadriceps tendon decreases as knee flexion increases, indicating increased relative stiffness. In the patellar tendon, no significant difference was observed between 30° and 60°. Beyond 60°, relative stiffness increased constantly.CONCLUSIONS:SE is a reproducible and feasible tool to monitor relative stiffness of the patellar and quadriceps tendons in routine clinical settings.

RiskaBPMN - a BPMN extension for risk assessment

Abstract The growth in use of business processes (BP) in critical systems, vital to create or maintain business value in organizations, has driven the need and interest in assessing their risk. For assessing risk in BPs, one needs to characterize risk and its representation in BPs. To support risk characterization, we can find in the literature some proposals that enrich the BPMN language with risk information, such as risk events, likelihood, impact, and mitigation actions. However, none of them comprises risk assessment with a standard BPMN extension. In this work we define a BPMN extension, using its native extension mechanism, for quantitative risk assessment. It enriches BPMN with information about likelihood and consequences of failures, in terms of business value, in different granularities of processes fragments. In addition, we also consider a quantitative risk acceptance criterion, which will be used for risk evaluation.

Zeus: Improving Resource Efficiency via Workload Colocation for Massive Kubernetes Clusters

With the popularity of container-based microservices and cloud-native architectures, Kubernetes has established itself as the de facto standard for container orchestration. Kubernetes is known for its advantage in easy deployment and operations for applications; however, it suffers from low resource utilization, incurring high server provisioning and operational costs, due to following reasons. First, it is common practice for latency-sensitive services to be over-provisioned for the peak load: Kubernetes might consider such peak-load provisioning as constant, even though the actual resource utilization is low. Second, the isolation between different containers is poor and cannot prevent performance degradation when best-effort jobs and latency-sensitive services run together. Users may have to run these two classes of workloads on separate machines to avoid interference, resulting in higher provisioning costs. This paper presents a highly scalable cluster scheduling system named Zeus, which is designed based on Kubernetes extension mechanisms. Zeus achieves safe colocation of best-effort jobs and latency-sensitive services. Furthermore, Zeus schedules best-effort jobs based on the real server utilization and can adaptively allocate resources between the two classes of workloads. In addition, Zeus enhances container isolation by coordinating software and hardware isolation features. As a result, Zeus can effectively improve the resource utilization of Kubernetes clusters. We discuss the design and implementation of Zeus and evaluate its effectiveness using latency-sensitive services and best-effort jobs in a massive production environment. The results show that by colocating latency-sensitive services with best-effort jobs, Zeus can increase the average CPU utilization from 15% to 60% without SLO violations.