A Study of Linux Perf and Slab Allocation Sub-Systems

Today, modern processors are equipped with a special unit named PMU that enables software developers to gain access to micro-architectural level information such as CPU cycles count and executed instructions count. The PMU provides a set of programmable registers called hardware performance counters that can be programmed to count the specific hardware events. In the Linux operating system, many low-level interfaces are designed to provide access to the hardware counters facilities. One of these interfaces is perf_event, which was merged as a sub-system to the kernel mainline in 2009, and became a widely used interface for hardware counters. Firstly, we investigate the perf_event Linux sub-system in the kernel-level by exploring the kernel source code to identify the potential sources of overhead and counting error. We also study the Perf tool as one of the end-user interfaces that was built on top of the perf_event sub-system to provide an easy-to-use measurement and profiling tool in the Linux operating system. Moreover, we conduct some experiments on a variety of processors to analyze the overhead, determinism, and accuracy of the Perf tool and the underlying perf_event sub-system in counting hardware events. Although our results show 47% error in counting the number of taken branches as well as 5.92% relative overhead on the Intel Pentium 4 processors, we do not observe a significant overhead or defect on the modern x86 and ARM processors. Secondly, we explore a memory management sub-system of Linux kernel called slab allocator, that plays a crucial role in the overall performance of the system. We study three different implementations of the slab allocator that are currently available in the Linux kernel mainline and enumerate the advantages and disadvantages of each implementation. We also investigate the binning effect of the slab allocator on the Linux system calls execution time variation. Moreover, we introduce a new metric called Slab Metric that is assigned to each system call to represent the interaction level with the slab allocator. The results show a correlation coefficient of 0.78 between the dynamic slab metric and the execution time variation of the Linux system calls

New Constraints for the On‐Shore Makran Subduction Zone Crustal Structure

Funder: Institute for Advanced Studies in Basic Sciences; Id: http://dx.doi.org/10.13039/501100007513Abstract: The Makran Subduction Zone is the primary seismic/tsunami hazard of the northwestern Indian Ocean, but little is known of its on‐shore seismic structure. We derived a shear wave velocity model extending to > $>$ 100 km depth beneath a ∼400 km‐long seismic profile oriented parallel to the convergence vector of the Arabian Sea Plate. Receiver function/surface wave analysis shows that the average structure in the coastal region comprises a ∼22–28 km‐thick low wavespeed sedimentary cover and a 6–8 km‐thick gradient zone overlying > $>$ 100 km‐thick high wavespeed upper mantle. The ocean‐basement interface dips gently northward, remaining a positive impedance contrast to ∼50 km depth at ∼250 km north of the coast where it disappears as the basaltic/gabbroic oceanic crust has probably transformed to eclogite. Further north, a weak arrival at ∼5 s in the receiver functions appears, grading northward into the Moho arrival of the continental Iranian Plateau. This disruption in the seismic signature of the Moho occurs in the forearc region where the dip of the subducting oceanic plate steepens. The southern Iranian Plateau's continental crust has an average V s of 3.55 ± 0.05 km s−1, an almost flat Moho 40–45 km deep, and a sub‐Moho mantle V s of 3.75 ± 0.05 km s−1 in the 50–80 km depth range. Weak Moho conversions probably result from ∼20% serpentinization of peridotite in the mantle wedge. Receiver functions indicate a flat continental Moho – no crustal root beneath the high topography region of the volcanic belt, which therefore must be compensated by low upper mantle densities. The high V p /V s ratio observed for the mantle wedge suggests ∼1%–2% partial melt

Conjugation of R-Phycoerythrin to a Polyclonal Antibody and F (ab')2 Fragment of a Polyclonal Antibody by Two Different Methods

Abstract R-Phycoerythrin (R-PE), a fluorescent protein from phycobiliprotein family, is isolated from red algae. Conjugation of antibodies to R-PE facilitates multiple fluorescent staining methods. In the present study polyclonal antibodies and polyclonal F(ab')2 fragment antibodies were conjugated to R-PE by two different methods. The efficiency of the methods was evaluated using Immunocytochemistry (ICC) and Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE). In the first conjugation method, PE was attached to SMCC linker followed by conjugation of antibody to PE-SMCC. In the second method, SH groups were added onto R-PE molecule, while the antibody was attached to SPDP linker. Then, the antibody-SPDP molecule was conjugated to R-PE. Our results showed that the two conjugation methods did not have any abrogative effects on the antibody binding activity

The Post-Eocene Evolution of the Doruneh Fault Region (Central Iran): The Intraplate Response to the Reorganization of the Arabia-Eurasia Collision Zone

The Cenozoic deformation history of Central Iran has been dominantly accommodated by the activation of major intracontinental strike-slip fault zones, developed in the hinterland domain of the Arabia-Eurasia convergent margin. Few quantitative temporal and kinematic constraints are available from these strike-slip deformation zones, hampering a full assessment of the style and timing of intraplate deformation in Iran and the understanding of the possible linkage to the tectonic reorganization of the Zagros collisional zone. This study focuses on the region to the north of the active trace of the sinistral Doruneh Fault. By combing structural and low-temperature apatite fission track (AFT) and (U-Th)/He (AHe) thermochronology investigations, we provide new kinematic and temporal constraints to the deformation history of Central Iran. Our results document a post-Eocene polyphase tectonic evolution dominated by dextral strike-slip tectonics, whose activity is constrained since the early Miocene in response to an early, NW-SE oriented paleo-σ1 direction. A major phase of enhanced cooling/exhumation is constrained at the Miocene/Pliocene boundary, caused by a switch of the maximum paleo-σ1 direction to N-S. When integrated into the regional scenario, these data are framed into a new tectonic reconstruction for the Miocene-Quaternary time lapse, where strike-slip deformation in the intracontinental domain of Central Iran is interpreted as guided by the reorganization of the Zagros collisional zone in the transition from an immature to a mature stage of continental collision

Pain control with lavender essential oil

Pain is an unpleasant experience that results from physical and psychological responses to injury. Since, the main goal of treatment is to control pain, finding safe, easy, and inexpensive methods for pain control is still a necessity. Aromatherapy has long been used to relieve pain and treatment of various diseases. Lavender is one of the most famous plants in aromatherapy that has importance and particular value in relieving pain and treatment of different diseases and has many applications in clinical practice. The use of Lavender as an alternative method of treatment decreases the need to chemical drugs in some of the physical and psychological problems. A review of literature on the analgesic effects of Lavender showed different effects and results. So, the need to further studies is tangible. Due to the necessity, this review study was done with aim to evaluate pain control with essential oil of Lavender. We reviewed articles indexed in the Medline, Pubmed, Scopus, Google scholar databases, between 2004 and 2015. The search was conducted by using key words: pain, pain control, aromatherapy and Lavender and relevant articles were extracted.  Finally, 36 articles were studied. The results showed that the effects of Lavender in the management of acute and chronic pain, cancer pain and etc. mainly depend on the nature of pain and the method of administration. But in the most cases, Lavender has analgesic effects. Based on these findings, it is recommended further studies to prove it in various clinical situations and to determine the amount of required lavende

Design of a non‐ferromagnetic spoke array Vernier permanent magnet generator with iron‐bar based on enhanced equivalent magnetic network model

Abstract The spoke‐type arrangement of permanent magnets (PMs) in rotor of Vernier PM (VPM) machines was first introduced in a dual‐stator topology to overcome low‐power drawback of VPM machines. However, this structure is mostly applicable for high‐power motor drives. A non‐ferromagnetic spoke array VPM generator with a special rotor structure for small‐scale wind turbine generator is presented. The leakage flux lines tend to be aligned with the main flux routes due to a special design of flux barriers in end portion of PM housings. High torque‐density, low weight, torque‐speed curve with a wide constant torque region, promising efficiency, and power factor are the advantages of the proposed machine. An Equivalent‐Magnetic‐Network (EMN) model is established for predicting the complex behaviour of flux lines and operating quantities of the proposed structure with reasonable accuracy. The contribution of the modelling method includes a special mesh cell for the air‐gap permeance network to more accurately capture the flux routes, continuous positioning method for omitting spikes on post‐processing waveforms due to numerical errors, and a stable solving flowchart with a high convergence rate. The validity of the EMN model is validated by comparing the operating waveforms of the machine with the corresponding waveforms obtained by the finite element and experiments. The cover image is based on the Research Article Design of a non‐ferromagnetic spoke array Vernier permanent magnet generator with iron‐bar based on enhanced equivalent magnetic network model by Mehrage Ghods et al., https://doi.org/10.1049/elp2.12272

Potential biomarkers for testicular germ cell tumour: Risk assessment, diagnostic, prognostic and monitoring of recurrence

Testicular germ cell tumour (TGCT) is considered a relatively rare malignancy usually occurring in young men between 15 and 35 years of age, and both genetic and environmental factors contribute to its development. The majority of patients are diagnosed in an early-stage of TGCTs with an elevated 5-year survival rate after therapy. However, approximately 25 of patients show an incomplete response to chemotherapy or tumours relapse. The current therapies are accompanied by several adverse effects, including infertility. Aside from classical serum biomarker, many studies reported novel biomarkers for TGCTs, but without proper validation. Cancer cells share many similarities with embryonic stem cells (ESCs), and since ESC genes are not transcribed in most adult tissues, they could be considered ideal candidate targets for cancer-specific diagnosis and treatment. Added to this, several microRNAs (miRNA) including miRNA-371-3p can be further investigated as a molecular biomarker for diagnosis and monitoring of TGCTs. In this review, we will illustrate the findings of recent investigations in novel TGCTs biomarkers applicable for risk assessment, screening, diagnosis, prognosis, prediction and monitoring of the relapse. © 2021 Wiley-VCH Gmb

Comparison of the Photobleaching and Photostability Traits of Alexa Fluor 568- and Fluorescein Isothiocyanate- conjugated Antibody

Objective: Synthetic fluorescent dyes that are conjugated to antibodies are useful tools toprobe molecules. Based on dye chemical structures, their photobleaching and photostabilityindices are quite diverse. It is generally believed that among different fluorescent dyes,Alexa Fluor family has greater photostability than traditional dyes like fluorescein isothiocyanate(FITC) and Cy5. Alexa Fluor 568 is a member of Alexa Fluor family presumed tohave superior photostability and photobleahing profiles than FITC.Materials and Methods: In this experimental study, we conjugated Alexa Fluor 568 andFITC dyes to a mouse anti-human nestin monoclonal antibody (ANM) to acquire their photobleachingprofiles and photostability indices. Then, the fluorophore/antibody ratios werecalculated using a spectrophotometer. The photobleaching profiles and photostability indicesof conjugated antibodies were subsequently studied by immunocytochemistry (ICC).Samples were continuously illuminated and digital images acquired under a fluorescentmicroscope. Data were processed by ImageJ software.Results: Alexa Fluor 568 has a brighter fluorescence and higher photostability thanFITC.Conclusion: Alexa Fluor 568 is a capable dye to use in photostaining techniques and ithas a longer photostability when compared to FITC