bluuebunny/crossref_metadata_2025 huggingface dataset:
A Test System for Plastic Metal Materials Subjected to Multi-particle Erosion via Air Ejector
Authors: Fang Zi Qiang , Peng Song Lin , Zhang Liang
Published: October 2022

Erosive wear of working part is an usual damage mode of mechanized equipment in engineering, which is caused by multiple particle impacts with different impact angles and velocities. A test system for plastic metal materials subjected to multi-particle erosion is designed and manufactured. Based on the test system, trial samples of plastic metal materials suffered to multiple particle impacts can be produced via an air ejector, while images of corresponding damage surface can be observed with electron microscope. Erosion experiments of the twice particle erosions in succession were carried out through the experimental system with two different impact angles, i.e. 90° and 30°, and at a fixed impact velocity of 120 m/s. From the experiment results, it can be expected that the experimental system is suitable to laboratory tests of multi-particle erosion for plastic metal materials with reference to practical conditions in engineering.
Effective Thermal Conductivity of Structured Porous Medium: Numerical Study
Authors: Popov A.I. , Bragin D.M. , Eremin Anton V.
Published: October 2022

The paper presents a numerical study of thermal conductivity of porous structures using the Ansys software package. Unlike the well-known porous materials used in construction and engineering, it is proposed to use porous materials with an ordered law of cavity placement. The porous material proposed is formed by dividing the volume into cubes of equal size with a spherical cavity placed in the center of each cube. The numerical calculation of an effective thermal conductivity coefficient of a porous medium is performed using the Ansys Mechanical computer modeling tool. The values obtained are compared with solutions based on classical methods for determining the effective thermal conductivity of porous materials. A dependency graph of effective thermal conductivity in a porous material based on pores geometric parameters (distance between cavities, diameter of cavities), as well as an analytical dependence to obtain the effective thermal conductivity value is presented. Additive technologies available today provide producing the proposed porous material with an ordered law of cavity placement with any accuracy and any pore geometric parameters. Such materials open up wide opportunities for engineers, especially in the field of thermal power engineering, because it has predictable thermophysical and mechanical properties.
Price Formation, Seller Satisfaction and Degree of Competition in the Colombo Tea Auction
Authors: Sankalpana H. S. A. , Gajanayake B. , Kumara Kithsiri K. H. S.
Published: October 2022

Colombo Tea Auction is the main marketing channel to dispose bulk tea in Sri Lanka. This study was carried out to assess the price formation, market concentration, degree of competition among buyers and to examine the sellers’ satisfaction at the Colombo Tea Auction. Primary data were collected from tea producers (sellers), brokers and officers of Sri Lanka Tea Board (SLTB). Secondary data were collected from Colombo Brokers Association, SLTB and selected brokering companies. Tea price formation factors, market share and competitiveness of buyers at the auction were analysed using Multiple Linear Regression, four firm Concentration Ratio (CR4) and Herfindahal-Hirshman Index (HHI) respectively. The results revealed that, tea grade, elevation, previous auction price, valuation price and net quantity of the tea lot affected 93.9% for the price formation. Results further revealed that CR4 and HHI were 28% and 370.9 respectively indicating that the public auction is operating on a relatively more competitive scale and also showing a favourable market among stakeholders due to the relatively quick return on investment, transparency and lowering of the risks than the other marketing channels. A few buyers dominate in the auction influencing negatively to the degree of competition. The study suggests that the price given to producers should mainly depend on quality rather than on other contributory factors and for competitive trading. This should be developed as a policy revision by the SLTB and Colombo Tea Trader Association.
T Cell Transcriptome in Chromosome 22q11.2 Deletion Syndrome
Authors: Raje Nikita R , Noel-MacDonnell Janelle R , Shortt Katherine A , Gigliotti Nicole M , Chan Marcia A , Heruth Daniel P
Published: October 2022

Phenotypic variations of chromosome 22q11.2 deletion syndrome (22qDS) have unclear explanations. T cell lymphopenia in 22qDS related to varying degrees of thymic hypoplasia contributes to the phenotypic heterogeneity. No phenotype correlation with genotype or deletion size is known for lymphopenia. We investigated gene expression in human T cells of participants with and without 22qDS and T cells of participants with 22qDS with low or normal T cells. Peripheral blood was collected from participants aged 5–8 y. Immune function was checked. RNA sequencing was completed on isolated T cells, and differential gene expression profiles of T cells between 22qDS and healthy control subjects were established. A total of 360 genes were differentially expressed (q < 0.05) between T cells of patients with 22qDS (n = 13) and healthy control subjects (n = 6) (log2 fold change range, −2.0747, 15.6724). We compared gene expression between participants with 22qDS with low (n = 7) and normal T cell counts (n = 6), finding 94 genes that were differentially expressed (q < 0.05) (log2 fold change range, −4.5445, 5.1297). Twenty-nine genes correlated with T cell counts and markers CD3, CD4, CD8, and CD45RA+CD4 (R ≥ 0.8). We found significantly differentially expressed genes in participants with 22qDS compared with healthy control subjects and in participants with 22qDS with low T cell counts compared with those with normal T cell counts. Several enriched pathways suggest a role of T cells in defective communication between T cells and the innate immune system in 22qDS. Among these, the liver X receptor/retinoid X receptor pathway was noted to show several differentially expressed genes affecting participants with 22qDS compared with healthy control subjects and more so those with low T cell counts than in those with normal T cell counts.
Protein Kinase CK2 Controls CD8+ T Cell Effector and Memory Function during Infection
Authors: Yang Wei , Wei Hairong , Benavides Gloria A , Turbitt William J , Buckley Jessica A , Ouyang Xiaosen , Zhou Lianna , Zhang Jianhua , Harrington Laurie E , Darley-Usmar Victor M , Qin Hongwei , Benveniste Etty N
Published: October 2022

Protein kinase CK2 is a serine/threonine kinase composed of two catalytic subunits (CK2α and/or CK2α′) and two regulatory subunits (CK2β). CK2 promotes cancer progression by activating the NF-κB, PI3K/AKT/mTOR, and JAK/STAT pathways, and also is critical for immune cell development and function. The potential involvement of CK2 in CD8+ T cell function has not been explored. We demonstrate that CK2 protein levels and kinase activity are enhanced upon mouse CD8+ T cell activation. CK2α deficiency results in impaired CD8+ T cell activation and proliferation upon TCR stimulation. Furthermore, CK2α is involved in CD8+ T cell metabolic reprogramming through regulating the AKT/mTOR pathway. Lastly, using a mouse Listeria monocytogenes infection model, we demonstrate that CK2α is required for CD8+ T cell expansion, maintenance, and effector function in both primary and memory immune responses. Collectively, our study implicates CK2α as an important regulator of mouse CD8+ T cell activation, metabolic reprogramming, and differentiation both in vitro and in vivo.
The Transcription Factor Zfp335 Promotes Differentiation and Persistence of Memory CD8+ T Cells by Regulating TCF-1
Authors: Liu Haiyan , Wang Xin , Ding Renyi , Jiao Anjun , Zheng Huiqiang , Zhang Cangang , Feng Zhao , Su Yanhong , Yang Xiaofeng , Lei Lei , Sun Lina , Zhang Lianjun , Sun Chenming , Zhang Baojun
Published: October 2022

Memory CD8+ T cells play an essential role in providing effective and lifelong protection against pathogens. Comprehensive transcriptional and epigenetic networks are involved in modulating memory T cell development, but the molecular regulations of CD8+ memory T cell formation and long-term persistence remain largely unknown. In this study, we show that zinc finger protein 335 (Zfp335) is indispensable for CD8+ T cell memory establishment and maintenance during acute infections. Mice with Zfp335 deletion in CD8+ T cells exhibit a significant reduction of memory T cells and memory precursor cells in the contraction phase. Zfp335 deficiency in CD8+ T cells resulted in decreased expression of memory featured genes Eomes and IL-2Rβ, leading to a loss of memory identity and an increase of apoptosis in response to IL-7 and IL-15. Mechanistically, Zfp335 directly binds to and regulates TCF-1, known to be critical for memory T cell development. Importantly, overexpression TCF-1 could rescue the defects in the survival of both CD8+ memory precursors and memory T cells caused by Zfp335 deficiency. Collectively, our findings reveal that Zfp335 serves as a novel transcriptional factor upstream of TCF-1 in regulating CD8+ T cell memory.
Med1 Controls Effector CD8+ T Cell Differentiation and Survival through C/EBPβ-Mediated Transcriptional Control of T-bet
Authors: Jiao Anjun , Liu Haiyan , Ding Renyi , Zheng Huiqiang , Zhang Cangang , Feng Zhao , Lei Lei , Wang Xin , Su Yanhong , Yang Xiaofeng , Sun Chenming , Zhang Lianjun , Bai Liang , Sun Lina , Zhang Baojun
Published: October 2022

Effector CD8+ T cells are crucial players in adaptive immunity for effective protection against invading pathogens. The regulatory mechanisms underlying CD8+ T cell effector differentiation are incompletely understood. In this study, we defined a critical role of mediator complex subunit 1 (Med1) in controlling effector CD8+ T cell differentiation and survival during acute bacterial infection. Mice with Med1-deficient CD8+ T cells exhibited significantly impaired expansion with evidently reduced killer cell lectin-like receptor G1+ terminally differentiated and Ly6c+ effector cell populations. Moreover, Med1 deficiency led to enhanced cell apoptosis and expression of multiple inhibitory receptors (programmed cell death 1, T cell Ig and mucin domain–containing-3, and T cell immunoreceptor with Ig and ITIM domains). RNA-sequencing analysis revealed that T-bet– and Zeb2-mediated transcriptional programs were impaired in Med1-deficient CD8+ T cells. Overexpression of T-bet could rescue the differentiation and survival of Med1-deficient CD8+ effector T cells. Mechanistically, the transcription factor C/EBPβ promoted T-bet expression through interacting with Med1 in effector T cells. Collectively, our findings revealed a novel role of Med1 in regulating effector CD8+ T cell differentiation and survival in response to bacterial infection.
Contribution of Lipid Mediators in Divergent Outcomes following Acute Bacterial and Viral Lung Infections in the Obese Host
Authors: Schwarz Benjamin , Roberts Lydia M , Bohrnsen Eric , Jessop Forrest , Wehrly Tara D , Shaia Carl , Bosio Catharine M
Published: October 2022

Obesity is considered an important comorbidity for a range of noninfectious and infectious disease states including those that originate in the lung, yet the mechanisms that contribute to this susceptibility are not well defined. In this study, we used the diet-induced obesity (DIO) mouse model and two models of acute pulmonary infection, Francisella tularensis subspecies tularensis strain SchuS4 and SARS-CoV-2, to uncover the contribution of obesity in bacterial and viral disease. Whereas DIO mice were more resistant to infection with SchuS4, DIO animals were more susceptible to SARS-CoV-2 infection compared with regular weight mice. In both models, neither survival nor morbidity correlated with differences in pathogen load, overall cellularity, or influx of inflammatory cells in target organs of DIO and regular weight animals. Increased susceptibility was also not associated with exacerbated production of cytokines and chemokines in either model. Rather, we observed pathogen-specific dysregulation of the host lipidome that was associated with vulnerability to infection. Inhibition of specific pathways required for generation of lipid mediators reversed resistance to both bacterial and viral infection. Taken together, our data demonstrate disparity among obese individuals for control of lethal bacterial and viral infection and suggest that dysregulation of the host lipidome contributes to increased susceptibility to viral infection in the obese host.
Epitope Mapping of Therapeutic Antibodies Targeting Human LAG3
Authors: Agnihotri Pragati , Mishra Arjun K , Agarwal Priyanka , Vignali Kate M , Workman Creg J , Vignali Dario A A , Mariuzza Roy A
Published: October 2022

Lymphocyte activation gene 3 protein (LAG3; CD223) is an inhibitory receptor that is highly upregulated on exhausted T cells in tumors and chronic viral infection. Consequently, LAG3 is now a major immunotherapeutic target for the treatment of cancer, and many mAbs against human (h) LAG3 (hLAG3) have been generated to block its inhibitory activity. However, little or no information is available on the epitopes they recognize. We selected a panel of seven therapeutic mAbs from the patent literature for detailed characterization. These mAbs were expressed as Fab or single-chain variable fragments and shown to bind hLAG3 with nanomolar affinities, as measured by biolayer interferometry. Using competitive binding assays, we found that the seven mAbs recognize four distinct epitopes on hLAG3. To localize the epitopes, we carried out epitope mapping using chimeras between hLAG3 and mouse LAG3. All seven mAbs are directed against the first Ig-like domain (D1) of hLAG3, despite their different origins. Three mAbs almost exclusively target a unique 30-residue loop of D1 that forms at least part of the putative binding site for MHC class II, whereas four mainly recognize D1 determinants outside this loop. However, because all the mAbs block binding of hLAG3 to MHC class II, each of the epitopes they recognize must at least partially overlap the MHC class II binding site.
Impact of Estrogen and Progesterone on Immune Cells and Host–Pathogen Interactions in the Lower Female Reproductive Tract
Authors: Collins Morgan K , McCutcheon Cole R , Petroff Margaret G
Published: October 2022

Microbial infections are a threat to women’s reproductive health. Although reproductive cycles and pregnancy are controlled by sex hormones, the impact of hormones on host–pathogen interactions and immune function in the female reproductive tract are understudied. Furthermore, the changing endocrine environment throughout pregnancy may influence how and when women are susceptible to ascending infection. Because most intrauterine microbial infections originate in the lower reproductive tract, it is vital that future studies determine how different hormonal conditions influence the lower reproductive tract’s susceptibility to infection to understand temporal components of infection susceptibilities across pregnancy. These studies should also extend to nonpregnant women, as it is critical to establish how hormonal fluctuations across the menstrual cycle and hormonal contraceptives may influence disease susceptibility. This review summarizes current knowledge of how estrogen and progesterone impact vaginal and cervical mucosal immunity, barrier function, and interactions with microbial communities.
Pre–Germinal Center Interactions with T Cells Are Natural Checkpoints to Limit Autoimmune B Cell Responses
Authors: Parham Kate A , Tan Xiu Xia Sherry , Morelli Daniel M , Chowdhury Lika , Craig Heather C , Kerfoot Steven M
Published: October 2022

Interactions with Ag-specific T cells drive B cell activation and fate choices that ultimately determine the quality of high-affinity Ab responses. As such, these interactions, and especially the long-lived interactions that occur before germinal center formation, may be important checkpoints to regulate undesirable responses. Using mouse model Ag systems, we directly observed interactions between T and B cells responding to the self-antigen myelin oligodendrocyte glycoprotein (MOG) and found that they are of lower quality compared with interactions between cells responding to the model foreign Ag nitrophenyl-haptenated OVA. This was associated with reduced expression of molecules that facilitate these interactions on the B cells, but not on T cells. B cell expression of these molecules was not dictated by the T cell partner, nor could the relative lack of expression on MOG-specific (MOG-sp.) B cells be reversed by a multivalent Ag. Instead, MOG-sp. B cells were inherently less responsive to BCR stimulation than MOG-non-sp. cells. However, the phenotype of MOG-sp. B cells was not consistent with previous descriptions of autoimmune B cells that had been tolerized via regular exposure to systemically expressed self-antigen. This suggests that alternate anergy pathways may exist to limit B cell responses to tissue-restricted self-antigens.
Electromechanical Modeling and Testing of a Novel Electrically Driven Stacked Rotor System
Authors:   University of Texas Austin, Asper Matthew ,   LaunchPoint EPS, Ricci Michael , Sirohi Jayant , A. George
Published: October 2022

A novel thrust control method for an electrically-driven stacked rotor system is described. The stacked rotor comprises of two two-bladed rotors spinning in the same direction at the same speed, with a fixed axial spacing and variable azimuthal spacing. Changing the azimuthal spacing by around 22° results in a 17% change in the total rotor system thrust. An electromechanical model of the rotor and drive system is developed incorporating a blade element aerodynamic model and field oriented control of two phase-synchronized electric motors, each driving one rotor of the stacked system. The model is validated with measurements on a single, 2m diameter rotor in hover driven by a single electric motor at constant speed as well as during transient rotor speed changes. The validated model is used to explore the behavior of the system in response to a commanded change in rotor azimuthal spacing. At a blade loading of 0.08, and a rotor speed of 1200 RPM, computations indicated that a 5° change in azimuthal spacing could be achieved in less than 0.2s, or less than five rotor revolutions, requiring a transient power increase of 12% the mean power. These results indicate the feasibility of achieving small changes in thrust at a high bandwidth with a small increase in motor power output.
Multi-rotor eVTOL Flight Simulation and Assessment under Atmospheric Turbulence
Authors:   Rensselaer Polytechnic Institute, Bahr Matthew , Ferede Etana , Gandhi Farhan , Hebbar Ullhas
Published: October 2022

Atmospheric turbulence is applied to a 1200 lb quadcopter to evaluate the aircraft’s rigid body response together with the rotor speed and motor current responses. Turbulence is generated using TurbSim to produce a full-field flow which is convected downstream over the aircraft. Three levels of turbulence intensity (mild, moderate, and severe) are applied to the aircraft, with the increasing levels of turbulence corresponding to higher velocity fluctuation in the f low-field. An outer loop flight controller, tuned to meet Level 1 handling qualities, is used to reject the disturbances to the aircraft airspeed. Various levels of turbulence produce larger aircraft response, with the severe case producing the largest peak-to-peak values for rigid body, rotor speed, and motor current response (4.74◦, 114 RPM, and 160A, respectively). While the severe turbulence case is the most demanding on the motors, it is less than what has been previously seen for typical maneuvers. Therefore, motor size is limited by aircraft maneuver constraint, given the turbulence cases considered.
Design and Simulation of a Novel E-VTOL Aircraft AM20 to Understand Challenges in Certification and Flight Testing
Authors:   AeroMech Inc., Umapathy Nirmal , Gopalakrishnan Nandini , Wiederkehr Tony
Published: October 2022

Scale model and sub-scale model flights are used across the globe to demonstrate the feasibility of new and novel eVTOL concepts. Surrogate models are widely used by the industry to analyze and optimize these designs. An approach of using high fidelity simulation models is currently being investigated as a part of continued research and development to aid the industry, certifying agencies and flight test engineers to understand the challenges in testing and certifying eVTOL vehicles. This methodology will serve as a means of understanding the full-scale flight characteristics. This paper describes the initial efforts in developing an eVTOL vehicle for this purpose. Emphasis is placed on the design process, optimization tools, aerodynamic analysis using low fidelity tools, and CFD (Computational Fluid Dynamics). A brief discussion on the progress of the X-Plane simulation model along with the various possibilities of the proposed approach in improving flight test and handling qualities have been presented.
Effects of Disk Loading on Handling Qualities of Large-Scale, Variable-RPM Quadcopters
Authors:   Rensselaer Polytechnic Institute, Walter Ariel , Gandhi Farhan , Niemiec Robert
Published: October 2022

The performance of Urban Air Mobility (UAM) scale quadcopters with fixed-pitch, variable-speed rotors is examined at different values of disk loading. Three 544kg (1200lb) aircraft are considered in hover with disk loadings of 287N/m2, 574N/m2, and 861N/m2 (6psf, 12psf, and 18psf), corresponding to rotor radii of 1.2m, 0.86m, and 0.70m (4.0ft, 2.8ft, and 2.3ft). Optimized explicit-model-following controllers are designed to meet standard handling qualities criteria using CONDUIT. In trim, it is seen that increased disk loading results in increased power, but with reduced motor torque due to higher rotor speeds. Time domain simulations are considered in order to examine the peak torque required by the aircraft, which is used to estimate required motor weight. Based on a step command in heave rate, a 54% reduction (total reduction of 40.6kg) in motor weight is seen for the 18psf quadcopter. Assuming a step change in rotor speed, the peak torque required for the heave maneuver is also predicted in closed form using an analytical model based on momentum and blade element theory. The analytical model captures the trend in peak torque during the heave rate step response, with predicted values within 12% of the values from the time domain simulation.
Development of UH-72A Simulator Model in Support of ADS-33 Training
Authors:   US Naval Test Pilot School, Geyer William , Gordon Barbara , Mattei Christopher , Robinson Dwight
Published: October 2022

The U.S. Naval Test Pilot School (USNTPS) qualifies engineering test pilots and flight test engineers for the Department of Defense (DoD) and foreign militaries. The school operates UH-72A and UH-60L aircraft as core rotary wing platforms used for airborne instruction in performance, flying qualities (FQ) and advanced flight control systems flight testing. The stability and control portion of the syllabus teaches both time and frequency domain flight test techniques in the evaluation of aircraft handling qualities (HQ); however, only classic time domain techniques have been instructed in the aircraft to support the curriculum. As frequency domain testing has become common practice across the DoD and within industry, the importance of providing entry level instruction in those flight test techniques cannot be overstated. Having students conduct many of the frequency domain test techniques in the aircraft is not practical. Providing adequate control measures such as real-time data monitoring and instructor pilot involvement on each flight to ensure safe execution would place an unrealistic burden on the USNTPS staff and adversely impact the airworthiness of the school’s aircraft. The USNTPS simulation laboratory recently received a high fidelity UH-60 flight dynamics simulation model enabling the instruction of frequency domain flight test techniques and the collection of predictive HQ data as defined within the ADS-33E-PRF, Handling Qualities Requirements for Military Rotorcraft. These data are used to support assigned HQ flights flown on Naval Test Wing Atlantic’s ADS-33 Mission Task Element course. Conducting systems identification testing and the subsequent development of a high fidelity UH-72A flight dynamics simulation model allows the execution of the entire Low Airspeed FQ exercise across both core platforms. Simulator-based predictive HQ data are now utilized in support of assigned HQ flights in the respective aircraft. This paper covers the development of the UH-72A simulation model, flight test efforts supporting that development and the successful integration of the model as a means to collect predictive HQ data in support of the Low Airspeed FQ exercise at the USNTPS.
A Theoretical Framework Unifying Handling Qualities, Workload, Stability and Control
Authors:   San Jose State University, Bachelder Edward ,   NASA Ames Research Center, Aponso Bimal
Published: October 2022

The concepts and principle developed in this work offer a novel and integrative approach for exploring fundamental issues surrounding pilot performance, handling qualities (HQs), and workload. Fundamental laws of sensory perception are extended to multi-input sensing, showing that multiple sensory inputs add logarithmically. It is proposed rather than being just a sensational response, a pilot’s perception of workload is a skill that is acquired and used for the purpose of modulating system stability (i.e., phase margin) during a tracking task. Evidence is presented indicating than an operator perceives workload and behaves such that workload is linearly related to phase margin (PM). It is also shown that this behavior associated with PM linearization serves to reduce workload. PM-workload linearization would enable a straightforward transformation of workload to PM, allowing PM to be set by the pilot to facilitate loop control. A perceptual transformation of the variables available to the pilot (control activity, error) couples with the behavioral conditioning to complete the linearization between PM and sensed workload. Two contrasting sets of experimental data were used to examine pilot response, indicating that pilot compensation is conducted via both frequency modulation (lead-lag) and temporal modulation (pure time delay). HQ sensing is treated as multi-input perception, where time delay and the lead-lag ratio are the stimuli for compensation sensing, and tracking error is the stimulus for performance sensing. A HQ metric arising from the logarithmic addition of these two sensations is shown to yield promising results. A cost function representing pilot behavioral objectives is developed that serves to modulate the following four items: 1) Tracking error; 2) Workload; 3) Linearity between workload and PM; and 4) Setting a reference PM. The pilot cost function was implemented in an optimal pilot which produced pilot time delay and pilot compensation estimates that closely matched the actual pilot data.
A Model for Inferred Gross Weight using HUMS Data
Authors:   GPMS Inc., Bechhoefer Eric ,   Purdue University, Wells Thomas
Published: October 2022

Weight and balance are part of every pilot's preflight. Gross weight (GW) and center-of-balance impacts the static and dynamics of flight. However, from a condition monitoring perspective, understanding the GW could be used to determine the accumulated damage to structural component. This, in turn, allows for the calculation of components remaining useful life and improved retirement time of structural components. As life limits for a critical component are based on the worst-case assumption of usage, an actual estimate of GW allows for a more accurate assessment of loads, thus providing a more precise usage spectrum. This then provides a path toward extending the time between overhaul or extending the maintenance interval. This paper solves for GW using HUMS parameter data to solve an inverse performance problem.
A Brief History of VTOL In-Flight Aircrew Rescue Systems
Authors:   Kaman Corporation, Virasak Jacques ,   Bell Textron Inc., Jr. Erasmo
Published: October 2022

This paper will provide a limited historical survey of what has been investigated, designed, and tested in the area of Vertical Take-Off and Landing (VTOL) aircraft (including rotorcraft) aircrew rescue systems. Not only the paper will cover legacy aircrew survivability systems, but in some specific cases, current applications will be presented for completeness. This paper is an attempt to summarize the challenges and reasons why the deployment of special escape systems has not been universally implemented and in significant numbers. While 200 to 280 knots capable rotorcrafts are being developed or in service, the availability of reliable escape and/or aircrew extraction from a stricken rotorcraft comparable to fixed-wing high performance aircraft have not reached the same level of communality expected on such high-performance rotorcraft. The authors desire to provide the background from which new and effective crew survival systems can be derived.
Assessment of tuberculosis case notification rate: spatial mapping of hotspot, coverage and diagnostics in Katsina State, north-western Nigeria
Authors: Milaham Makplang , Van Gurp Margo , Adewusi Oluwafemi J. , Okonuga Oluwaseun Chidera , Ormel Hermen , Bayly Tristan , Adeojo Solomon , Yusuf Abdulrasheed , Gidado Mustapha
Published: October 2022

Tuberculosis (TB) is prevalent in Nigeria, and Katsina, along with other 12 states in the country, accounts for a high proportion of unnotified TB cases: constituting the high priority-intervention States in the country. Interventions focused on TB detection and coverage in the state could benefit from a better understanding of hotspot Local Government Areas (LGAs) that trigger and sustain the disease. Therefore, this study investigated the spatial distribution of TB Case Notification Rates (CNRs), diagnostics and coverage across the LGAs. Using 2017 to 2019 TB case finding data, the geocoordinates of diagnostic facilities and shapefiles, a retrospective ecological study was conducted. The data were analysed with QGIS and GeoDa. Moran’s I and LISA were used to locate and quantify hotspots. The coverage of microscopy and GeneXpert facilities was assessed on QGIS using a 5 km and 20 km radius, respectively. The CNR in the state, and 29 of the 34 LGAs, increased steadily from 2017 to 2019. Hotspots of high CNRs were also identified in 2017 (Moran’s I=0.106, p-value=0.090) and 2018 (Moran’s I=-0.020, p-value=0.370). While CNRs increased along with presumptive TB rates across most LGAs over the years, the positivity yield and bacteriological and Xpert diagnostic rates decreased. Bacteriological and GeneXpert coverage were 78% and 49% respectively. Additionally, only 51% of the state’s population lived within 20km of a GeneXpert facility. These results suggest that TB program interventions had some positive impact on the CNR, however, diagnostic facilities need to be equitably distributed and more innovative approaches need to be explored to find the missing cases.
Anti-arthritic effect of Distemonanthus benthamianus extracts against rheumatoid arthritis in rats
Authors: William Yousseu Nana , Hoki Kwenteh Ernest Allah , Gilbert Ateufack , Gonzal Tsafack Eric , Flore Djuichou Nguemnang Stephanie , Linda Fagni Njoya Zenab , Donatien Atsamo Albert , Mba Matah Marthe Vanessa , Flore Adjouzem Carine , Karelle Madjo Kouam Yacine , Elvira Ngoufack Azanze , Marius Mbiantcha
Published: October 2022

Objective:

To evaluate the anti-arthritic effect of aqueous and methanolic extracts of Distemonanthus benthamianus.

Methods:

Monoarthritis was induced by an injection of 0.3 mL zymosan A (0.9% NaCl, v/v) in the right posterior knee joints of rats. Then, joint diameter and pain threshold were determined. Polyarthritis was induced by an intracaudal injection of complete Freund’s adjuvant and rats were treated from day 14 post 1st complete Freund’s adjuvant injection until 28 day. The clinical, hematological, biochemical and oxidative stress parameters were evaluated. In addition, histological analysis of the knee joint was perfomed in both tests.

Results:

The aqueous and methanolic extracts of Distemonanthus benthamianus at a dose of 500 mg/kg ameliorated zymosan A-induced monoarthritis, as evidenced by reduced joint diameter, increased pain threshold, as well as improved joint architecture. In addition, both extracts of Distemonanthus benthamianus markedly increased body weight and pain threshold, while reducing paw edema in polyarthritic rats. They also led to a marked decrease in platelets and white blood cells (P<0.05), as well as a significant increase in red blood cells, hemoglobin and hematocrit (P<0.05). The aqueous and methanolic extracts of Distemonanthus benthamianus significantly reduced alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities, while increasing serum protein levels (P<0.05) with no significant variation in creatinine level. Moreover, both extracts increased catalase and glutathione activities (P<0.05), and inhibited malondialdehyde and nitric oxide production (P<0.01 and P<0.001) in the liver and kidneys. Histological analysis of the joints showed that both extracts triggered tissue reparation.

Conclusions:

Distemonanthus benthamianus could be used as a potential candidate in the treatment of rheumatoid arthritis.
Rhamnus crenata leaf extracts exhibit anti-inflammatory activity via modulating the Nrf2/HO-1 and NF-κB/MAPK signaling pathways
Authors: Eo Hyun Ji , Kim Da Som , Park Gwang Hun
Published: October 2022

Objective:

To elucidate the potential anti-inflammatory mechanisms of Rhamnus crenata leaf extracts using RAW264.7 cells.

Methods:

We used 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay to measure cell viability. Nitric oxide (NO) production was measured using Griess reagent. Western blotting and RT-PCR assays were carried out for analyzing the protein and gene expressions of pro-inflammatory mediators, respectively. Moreover, PD98059 (ERK1/2 inhibitor), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor), and BAY11-7082 (NF-κB inhibitor) were used to evaluate the anti-inflammatory mechanism of Rhamnus crenata leaf extract.

Results:

Rhamnus crenata leaf extracts significantly inhibited the production of the pro-inflammatory mediators such as NO, iNOS, COX-2, IL-1β, and TNF-α in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Rhamnus crenata leaf extracts also suppressed LPS-induced degradation of IκB-α and nuclear accumulation of p65, which resulted in the inhibition of NF-κB activation in RAW264.7 cells. Additionally, the extracts attenuated the phosphorylation of p38, ERK1/2, and JNK in LPS-stimulated RAW264.7 cells. Moreover, HO-1 expression induced by Rhamnus crenata leaf extracts was significantly downregulated by SB230580, PD98059, SP600125 and BAY11-7082.

Conclusions:

Rhamnus crenata leaf extract may upregulate HO-1 expression through inhibition of p38, ERK1/2, and NF-κB activation, which may contribute to the anti-inflammatory activity of the extracts. Rhamnus crenata leaf extracts may have great potential for the development of anti-inflammatory drugs to treat acute and chronic inflammatory diseases.
Erianin inhibits oral cancer cell growth, migration, and invasion via the Nrf2/HO-1/ GPX4 pathway
Authors: Tian Xiu-Yun , Han Rui , Huang Qing-Yang , Zhou Mei-Yun , Luo Bin , Chen Xin-Ru , Xu Jin-Cheng
Published: October 2022

Objective:

To evaluate the effect of erianin on the viability, migration, and invasion of KB cells and elucidate its underlying mechanisms.

Methods:

Cell Counting Kit-8, colony formation, wound healing, and Transwell assays were used to determine the proliferation, migration, and invasion of oral cancer KB cells. Furthermore, malondialdehyde (MDA) and glutathione (GSH) levels were determined. Fluorescent probes were used to detect changes in intracellular reactive oxygen species and iron ions. Additionally, the expressions of ferroptosis-related proteins, NF-E2-related factor 2 (Nrf2), ferritin heavy chain 1 (FTH1), heme oxygenase 1 (HO-1), and glutathione peroxidase 4 (GPX4) were analyzed by Western blotting assays.

Results:

Erianin induced ferroptosis and inhibited the proliferation, migration, and invasion of KB cells. Moreover, erianin decreased GSH level, increased MDA level, elevated intracellular ROS and Fe2+ contents, and downregulated the expression of the ferroptosis-related proteins Nrf2, HO-1, GPX4, and FTH1 in KB cells. These effects of erianin were effectively reversed by a ferroptosis inhibitor, ferrostatin-1.

Conclusions:

Erianin inhibits the proliferation, migration, and invasion of oral cancer cells and induces ferroptosis via the Nrf2/HO-1/GPX4 signaling pathway. Therefore, erianin may be a potential candidate for the treatment of oral cancer.
Association of methylenetetrahydrofolate reductase polymorphism and male infertility in type 2 diabetes mellitus patients
Authors: Babu K. Ranjith , Vijayaraman Manibalan , Shastri Deepti , Manivannan E.
Published: October 2022

INTRODUCTION:

As per World Health Organization, Infertility is a condition which is characterized by not getting conceived with more than 1-year of unprotected sexual intercourse without usage of any contraceptive aids. Folate has a significant role in the metabolism of the cells, like nucleic acids synthesis, gene expression by means of remethylation of the homocysteine into methionine. In the males, deficiency of folate leads to reduced proliferation of the sperm cells. Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase genes result in alterations of the methylations resulting pathological conditions being a potential risk factor for male infertility.

MATERIALS AND METHODS:

A total of 100 diabetic infertile males were selected as the study group and 100 nondiabetic fertile males were included as the control group. Blood samples were analyzed for the MTHFR polymorphisms. DNA extraction was done and the extract is subjected to polymerase chain reaction amplification. The resultant is subjected to electrophoresis for MTHFR gene allele confirmation. Statistical analysis was done using IBM SPSS Statistics 20 package. Chi-square test, odds ratio has been done and P < 0.05 is considered statistically significant.

RESULTS:

Genotype frequencies of MTHFR C677T, A1298C in all the subjects were analyzed for the Hardy–Weinberg law of genetic equilibrium. Mutant polymorphisms of MTHFR C677T, i.e., thymine-thymine and cytosine-thymine were increased significantly. Similarly, MTHFR A1298C mutant polymorphisms, i.e. adenine-cytosine, cytosine-cytosine were increased significantly in the infertile group than in the fertile group.

DISCUSSION:

Mutations of both MTHFR C677T, A1298C are found to be linked with lowered enzyme activity. We found that the occurrence of mutant homozygous and mutant heterozygous genotypes was increased in a diabetic male infertile group when compared to nondiabetic fertile group. Hence, it can be concluded that presence of single-nucleotide polymorphisms of MTHFR will increase the risk of infertility in diabetic male population.
Theophylline and meloxicam-induced Stevens-Johnson syndrome (SJS)
Authors: Varghese Anjaly M. , Kandra Naga V. , Vangoori Yakaiah , Uppala Praveen K. , Uttaravelli Upendrarao , Saibaba Somarouthu V. , Lavanya Butti , Balijepalli Murali K.
Published: October 2022

Stevens-Johnson syndrome (SJS) is an infrequent, multisystemic, fatal, immune-mediated hypersensitivity reaction. SJS may be due to adverse effects of drug intake often characterized by mucocutaneous rash, bullae, and blisters spread over the skin and mucous membranes, hyperpigmentation, puffiness, erosive lesions on lips and face. The most common cause of drug-induced SJS is antimicrobials, followed by NSAIDs, allopurinol, antipsychotics, and antiepileptic drugs. Two cases of atypical SJS presentation associated with the use of theophylline and meloxicam are reported here. Early identification and appropriate corticosteroid therapy might improve the condition. The reason for publishing these case reports is to raise an alarm among our health care fraternity and common man regarding medication-induced SJS, which may be dreadful especially due to theophylline used in bronchial asthma and meloxicam used for osteoarthritis and thereby preventing the expected serious sequelae in SJS.
Causa contractus
Authors: Duret Caroline
Published: October 2022

La causa contractus (i.e. cause du contrat) a été récemment l’objet de controverses, d’aucuns arguant son inutilité pour la validité du contrat. Une réévaluation fonctionnelle de la notion romaine de causa, dont la conceptualisation est une nouveauté, est l’occasion de comprendre ses contours au plus proche des sources et de la casuistique de droit classique. Les juristes et législateurs modernes trouveront peut-être de quoi s’inspirer pour appréhender la pratique moderne du droit. Cet ouvrage apporte la nouveauté de définir fonctionnellement la causa et d’analyser en profondeur ses dérivés et résurgences dans le contexte de l’action en répétition d’une attribution patrimoniale exécutée mais orpheline de la contrepartie attendue. - Une approche audacieuse d’un sujet classique et des conclusions novatrices, possible source d’inspiration pour les juristes de droit moderne - Un texte de lecture facile malgré la complexité du sujet
Tiempo y gubernamentalidad: Aproximaciones al gobierno del tiempo en el neoliberalismo
Authors: Hernández Zapata Edwin , Bedoya Hernández Mauricio
Published: October 2022

En este trabajo problematizamos los diagnósticos sobre gubernamentalidad neoliberal, analizando las formas en que hoy son dirigidas las conductas de los sujetos con base en ritmos caracterizados por la velocidad, el presentismo y la competencia. Estudiar estas formas marcan un precedente para el abordaje de los procesos de subjetivación contemporánea a partir de la analítica de la temporalidad. Así, la pregunta de investigación que guía este trabajo es la siguiente: ¿Cómo los diagnósticos sobre la racionalidad neoliberal describen la experiencia del tiempo que tienen los sujetos contemporáneos? Utilizamos el método histórico crítico, específicamente lo que Foucault denominó ontología del presente, que constituye el corazón de todo ejercicio genealógico. Los resultados señalan que, en el neoliberalismo los sujetos bajo el imperativo de la auto-gestión, sincronizan constantemente sus ritmos con los movimientos acelerados del mercado. Esto conduce a formular dos planteamientos que han de seguir siendo discutidos teóricamente y examinados a partir de diseños metodológicos específicos: (1) el neoliberalismo produce un aplanamiento del tiempo y (2) mediante tal aplanamiento, esta racionalidad contemporánea nos gobierna. Siendo contrastadas estas hipótesis a nivel teórico-metodológico, sería propicio describir con detalle, los sistemas de veridicción, así como las técnicas y procedimientos utilizados por el neoliberalismo para ejercer un gobierno del tiempo humano. Frente a las discusiones, encontramos que los estudios sobre gubernamentalidad revisados, no sitúan la experiencia temporal como eje central para el análisis de los procesos de subjetivación. Sin embargo, en estos, pueden identificarse elementos relacionados con la temporalidad que han de ser problematizados y nutridos por otros enfoques de las ciencias sociales y humanas que, de antemano han ubicado el tiempo como concepto central de reflexión.
A Qualitative Inquiry into the Socio-Economic Implications of Land Grabs Among the Nuer People in the Gambella Region of Ethiopia
Authors: Fisseha Mehari
Published: October 2022

The paper analyses the socio-economic implications of land grabbing among the Nuer people in the Gambella region of Ethiopia. To achieve its goals, the study is underpinned by two interrelated questions. The first question is: what are the socio-economic implications of land grabs in the Gambella Region of Ethiopia? The second question reads: what are the contestations and perceptions of the Nuer peoples in terms of gains and losses from the land grabs? The study was carried out among a Nilo-Saharan group known as the Nuer which traces its roots from Sudan within the qualitative research methodology. Findings from the study shows that land grabbing, which comes through large scale land takeovers in the Gambella region of Ethiopia, contradicts a state-remaking project under a dispossessive political economy. It was noted that the land grabs destruct the Nuer people’s identity, strip them of their dignity, disturb their ancestral philosophies, and negatively affect their livelihoods.
An Analysis of Total Factor Productivity of Rice in Assam
Authors: Deka Nivedita
Published: October 2022

The present study was conducted of estimating the total factor productivity (TFP) growth of rice and its contribution to rice production in Assam and examining the determinants of TFP. The study was carried out for two decades, from 1991-92 to 2010-11, using secondary data, estimated us the Tornqvist Theil index. The input, output, and TFP indices were calculated at a constant price (for 1991-92) of the inputs and outputs to nullify the nominal price effect. Again, the indices were computed for per hectare area and total area under rice in the state to know how efficiently inputs were utilized in both situations. To evaluate the determinants of TFP in Assam, regression was carried out by using Cobb Douglas production function. The study revealed that TFP growth for rice at a constant price was found to be positive in both per hectare area and total area for the study period. Determinants like investment in agriculture and allied activities, expenditure in agricultural research and education, HYV area, rural literacy, irrigation, and cropping intensity were found to have a positive impact on TFP.
Tools and Development Drivers for the Gastronomic Tourism
Authors: Nesterchuk Inna
Published: October 2022

The article examines the concept and features of gastronomic tourism, its history and its importance in the modern world. It is noted that gastronomic tourism meets all the requirements in transitioning from a service economy to an experience economy. The basis of gastronomic tourism is an authentic product identified by territorial characteristics and can attract tourists to the region. Gastronomic tourism is based on the concept of knowing and exploring, eating, tasting and enjoying the gastronomic culture of a region or country. The uniqueness of gastro tourism is highlighted as it links such policy development and integrated planning, product development and packaging, promotion and marketing, distribution and sales, and operations and services in tourism destinations, which are vital core activities in the tourism value chain. Ancillary activities related to the gastronomic product include transport and infrastructure, human resource development, technology and systems of other ancillary goods and services, which may not be associated with the leading tourism business but have a significant impact on the value of tourism. Also, the article discusses in detail the strategic plan for developing gastro-tourism, which includes the following phases: analysis and diagnosis of the situation; general strategic planning; operational planning; informing and disseminating the plan. The participants in the gastronomic process are listed, such as gastronomic heritage; gastronomic products, manufacturers and food industry; hospitality sector; specialized trade; campaigns for organizing gastronomic events and for the dissemination of gastronomic culture; areas for gastronomic education; centres for gastronomic research and training.