bluuebunny/crossref_metadata_2025 huggingface dataset:
Soft Frequency Reuse Based Spectrum Sharing Scheme in the Integrated Satellite and Terrestrial Network
Authors: Yang Mingchuan , Xue Guanchang , Xie Bingyu , Dou Yingzhe
Published: March 2022

The integrated satellite and terrestrial network has become one of the frontier technologies of the next generation mobile communication system. The satellite network is used as an extension and supplement of the ground network to achieve seamless coverage of wireless mobile communications. The spectrum sharing of the integrated satellite and terrestrial network is realized from the perspective of spectrum planning, considering the number of co-frequency terminals and the distance between the terminal and the center of the satellite beam. The existing spectrum sharing schemes use the concept of geographic isolation, which will limit the available bandwidth of the terrestrial network. Therefore, the concept of time domain isolation is proposed, and a soft frequency reuse based spectrum sharing scheme in the integrated satellite and terrestrial network is designed. The allocation of time slots increases the degree of spectrum isolation and improves the signal to interference ratio of the network. In addition, due to the increase in the utilization rate of the satellite spectrum, the capacity of the satellite system is improved.
QM/MM Study of the H2 Formation on the Surface of a Water Ice Grain Doped With Formaldehyde: Molecular Dynamics and Reaction Kinetics
Authors: Kerkeni Boutheïna , Boukallaba Malek , Hechmi Mariem , Duflot Denis , Toubin Céline
Published: March 2022

Formaldehyde has been widely observed in the icy mantle of interstellar grains. H2CO may be formed from successive hydrogenations of CO and may further contribute to the chemical complexity of the Interstellar medium (ISM) participating to heterogeneous reactions with colliding gas phase atoms. Within this context, Eley-Rideal and Langmuir-Hinshelwood rate constants of H2 formation on a formaldehyde doped amorphous water ice grain model of the ISM, were computed over a wide temperature range [15–2000 K]. We used classical molecular dynamics (MD) simulations to build the model of the H2CO doped ice surface. Then we studied theoretically by means of hybrid QM/MM ab initio and molecular mechanics methodology (ONIOM) H atoms abstraction from formaldehyde molecules and the H2 formation. Specifically, we investigate the reactivity of the gas phase H atom toward one formaldehyde molecule lying at one of the slab surfaces. The reaction path and the energetics are predicted, the mechanism is found to be exothermic by 14.89 kcal/mol and the barrier is 6.75 kcal/mol at the QM level CBS/DLPNO-CCSD(T)//ONIOM/aug-cc-pVTZ. We employ two approaches that take into account tunnelling and non-classical reflection effects by means of the Zero Curvature Tunnelling (ZCT), and the Small Curvature Tunnelling (SCT) which all provided comparable results to predict the kinetics of the reaction path. The rate constants show important quantum tunnelling effects at low temperatures when compared to rates obtained from the purely classical transition-state theory (TST) and from the canonical variational transition state theory (CVT). Corner cutting effects are highlighted in the SCT calculations by 4 to 5 orders of magnitude with respect to ZCT rate constants at low temperatures.
Case Report and Review of Literature: Familial Malignant Pleural Mesothelioma in a 39 Years Old Patient With an Inconclusive 18F-FDG PET/CT Result
Authors: Idkedek Mayar , Tahayneh Kareem S. , Abu-Akar Firas , Bakri Izzeddin A.
Published: March 2022

Malignant pleural mesothelioma (MPM) is a rare yet aggressive neoplasm that was linked only to asbestos exposure for decades, although familial clusters were diagnosed with MPM without a known history of asbestos exposure most likely due to genetic susceptibility. Here, we describe a case of familial malignant mesothelioma in a 39 years old patient with a confirmed BAP1 mutation in addition to a known family history with the same mutation. The patient presented with progressive shortness of breath and recurrent pleural effusions and diagnosis was made through biopsies taken during uniportal Video-Assisted Thoracoscopic Surgery. After the inconclusive result of 18F-FDG PET/CT scan, subxiphoid uniportal Video-Assisted Thoracoscopic Surgery left pleural and laparoscopic peritoneal biopsies were obtained for staging and evaluating contralateral lung and peritoneal cavity. Finally, two important educational values should be acquired from this case: genetic predisposition and BAP1 tumor suppressor gene mutation might affect the age of presentation and overall prognosis of the disease. Also, 18F-FDG PET/CT scan may not be the best modality for staging and confirming the diagnosis of malignant pleural mesothelioma.
Clinical Features of Craniopharyngioma With Tumoral Hemorrhage: A Retrospective Case-Controlled Study
Authors: Chen Yusi , Hu Feng , Wang Junwen , Huang Kuan , Liu Weihua , Tan Yutang , Zhao Kai , Xiao Qungen , Lei Ting , Shu Kai
Published: March 2022

Background

Craniopharyngioma (CP) with tumoral hemorrhage is a very rare syndrome presenting with various manifestation and unfavorable outcomes. The current retrospective study was performed to summarize the clinical features of CP with tumoral hemorrhage.

Methods

In this study, 185 patients with pathological diagnosis of CP (18 patients with hemorrhage) were enrolled. Clinical characteristics, radiological and surgical treatments, and post-operative complications were analyzed. In addition, the correlations between sexual hormones and tumor volume were explored.

Results

Drowsiness, acute syndrome, and pituitary deficiency were more frequent in patients with hemorrhage patients. Prothrombin time (PT) were higher in patients with hemorrhage. Luteinizing hormone (LH) and testosterone (T) were lower in male patients with hemorrhage. Post-operative electrolyte disturbances, hypothalamic syndrome, and death appeared more frequently in the hemorrhage group. Moreover, prolactin (PRL) and cortisol 8AM were found to be correlated with the volume of the tumor and the hematoma, respectively.

Conclusion

The current study presented the clinical features of CP apoplexy from the aspects of clinical characteristics, radiography, surgical treatment, and post-operative complications. Patients with CP apoplexy could benefit from the proper processing of peritumoral hemorrhage and post-operative monitoring of the electrolyte.
The Global Status of Research in Ankle Fracture: A Bibliometric and Visualized Study
Authors: Zeng Jianshuang , Xu Cheng , Xu Gaoxiang , Wang Daofeng , Zhang Wupeng , Li Hua , Gan Xuewen , Xiong Ying , Li Jiantao , Zhang Licheng , Tang Peifu
Published: March 2022

Background

Ankle fractures are common lower extremity fractures that pose a significant economic and social burden. This study analyzed the ankle fracture research literature between 2000 and 2021 to clarify the current status of ankle fracture research and predict future research trends.

Methods

Publications related to ankle fractures published between 2000 and 2021 were retrieved from the Web of Science Core Collection. Then Bibliometric analysis and Visualized Study were performed by VOSviewer software.

Results

A total of 2656 publications were retrieved. The number of publications related to ankle fractures is increasing every year. The top countries and journals in terms of the total number of publications, number of citations, and H-index ranking were USA and foot and ankle int. Lorich DG had the most publications in this field. University of Amsterdam's research group had the biggest number of publications in this field. Co-occurrence analysis clustered the keywords into seven clusters: survival analysis and prognosis study, internal fixation treatment study, treatment study of combined deltoid ligament rupture, treatment study of combined inferior tibiofibular ligament injury, treatment study of posterior ankle fracture, treatment study of postoperative traumatic arthritis of ankle fracture, and treatment study of ankle injury in children.

Conclusions

The importance of ankle fractures is increasing year by year with the aging process, and the number of publications related to ankle fractures will not continue to increase in the future. Survival and prognosis studies, internal fixation studies, combined deltoid ligament rupture studies, and combined inferior tibiofibular ligament injury studies may become the future research hotspots in the field of ankle fractures.
Clinical Classification, Pregnancy Outcomes and Risk Factors Analysis of Severe Preeclampsia Complicated With HELLP Syndrome
Authors: Huang Hui , Liu Bo , Gao Xia , Wang Yunju
Published: March 2022

Purpose

To investigate the clinical classification, pregnancy outcomes and risk factors of pregnant women with severe preeclampsia (SPE) complicated with HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome.

Methods

The clinical data of 50 pregnant women diagnosed with SPE complicated with HELLP syndrome in our hospital from January 2014 to January 2021 were retrospectively analyzed, and they were selected as the observation group. An additional 50 maternities diagnosed with preeclampsia (PE) during the same period were selected as the control group. The clinical classification and pregnancy outcomes of pregnant women in the observation group were recorded. The age and gestational age of onset of pregnancy were recorded and compared between the two groups. Univariate analysis and multivariate logistic regression model were used to analyze the risk factors for its occurrence.

Results

Among the 50 maternities in the observation group, there were 10 cases of type I, accounting for 20.00%; 35 cases of type II, accounting for 70.00%; 5 cases of type III, accounting for 10.00%. Partial 33 cases, the composition ratio of 66.00%; complete 17 cases, the composition ratio of 34.00%. Among the fetuses of 50 maternities in the observation group, 35 were premature, accounting for 70.00%; 13 had fetal growth restriction, accounting for 26.00%; and 2 died during perinatal period, accounting for 4.00%. Among the 50 maternities in the observation group, 48 cases were cesarean section, the composition ratio was 96.00%; 2 cases were induced labor, the composition ratio was 4.00%; there was no natural birth, the composition ratio was 0.00%. Univariate analysis showed that age, gestational age at onset, gestational age at termination of pregnancy, HGB, LDH, ALT, AST, TBIL, PLT, PT, and FIB were all associated with the occurrence of SPE complicated with HELLP syndrome (P < 0.05). Multivariate logistic analysis showed that gestational age at onset, gestational age at termination of pregnancy, HGB, LDH, ALT, AST, TBIL, PLT, and FIB were independent risk factors for SPE complicated with HELLP syndrome (P < 0.05).

Conclusion

SPE complicated with HELLP syndrome has significantly increased adverse pregnancy outcomes. Understanding its clinical classification is of great significance for the preventive application of platelet transfusion therapy and the selection of transfusion timing. Gestational age at onset and gestational age at termination of pregnancy are independent risk factors for its occurrence. Fully understanding the high-risk factors of HELLP syndrome, taking preventive measures in time, and carrying out targeted nursing can effectively improve the prognosis of pregnant women and reduce the risk of HELLP syndrome.
Distribution and Magnitude of Regional Volumetric Lung Strain and Its Modification by PEEP in Healthy Anesthetized and Mechanically Ventilated Dogs
Authors: Araos Joaquin , Cruces Pablo , Martin-Flores Manuel , Donati Pablo , Gleed Robin D. , Boullhesen-Williams Tomas , Perez Agustin , Staffieri Francesco , Retamal Jaime , Vidal Melo Marcos F. , Hurtado Daniel E.
Published: March 2022

The present study describes the magnitude and spatial distribution of lung strain in healthy anesthetized, mechanically ventilated dogs with and without positive end-expiratory pressure (PEEP). Total lung strain (LSTOTAL) has a dynamic (LSDYNAMIC) and a static (LSSTATIC) component. Due to lung heterogeneity, global lung strain may not accurately represent regional total tissue lung strain (TSTOTAL), which may also be described by a regional dynamic (TSDYNAMIC) and static (TSSTATIC) component. Six healthy anesthetized beagles (12.4 ± 1.4 kg body weight) were placed in dorsal recumbency and ventilated with a tidal volume of 15 ml/kg, respiratory rate of 15 bpm, and zero end-expiratory pressure (ZEEP). Respiratory system mechanics and full thoracic end-expiratory and end-inspiratory CT scan images were obtained at ZEEP. Thereafter, a PEEP of 5 cmH2O was set and respiratory system mechanics measurements and end-expiratory and end-inspiratory images were repeated. Computed lung volumes from CT scans were used to evaluate the global LSTOTAL, LSDYNAMIC, and LSSTATIC during PEEP. During ZEEP, LSSTATIC was assumed zero; therefore, LSTOTAL was the same as LSDYNAMIC. Image segmentation was applied to CT images to obtain maps of regional TSTOTAL, TSDYNAMIC, and TSSTATIC during PEEP, and TSDYNAMIC during ZEEP. Compliance increased (p = 0.013) and driving pressure decreased (p = 0.043) during PEEP. PEEP increased the end-expiratory lung volume (p < 0.001) and significantly reduced global LSDYNAMIC (33.4 ± 6.4% during ZEEP, 24.0 ± 4.6% during PEEP, p = 0.032). LSSTATIC by PEEP was larger than the reduction in LSDYNAMIC; therefore, LSTOTAL at PEEP was larger than LSDYNAMIC at ZEEP (p = 0.005). There was marked topographic heterogeneity of regional strains. PEEP induced a significant reduction in TSDYNAMIC in all lung regions (p < 0.05). Similar to global findings, PEEP-induced TSSTATIC was larger than the reduction in TSDYNAMIC; therefore, PEEP-induced TSTOTAL was larger than TSDYNAMIC at ZEEP. In conclusion, PEEP reduced both global and regional estimates of dynamic strain, but induced a large static strain. Given that lung injury has been mostly associated with tidal deformation, limiting dynamic strain may be an important clinical target in healthy and diseased lungs, but this requires further study.
Prognostic Value of Comorbidity for Patients with Upper Tract Urothelial Carcinoma after Radical Nephroureterectomy
Authors: Ke Hung-Lung , Li Ching-Chia , Lee Hsiang-Ying , Tu Hung-Pin , Wei Yu-Ching , Yeh Hsin-Chih , Wu Wen-Jeng , Li Wei-Ming
Published: March 2022

Patients with upper tract urothelial carcinoma (UTUC) have a high prevalence of comorbidities. However, the prognostic impact of comorbidities in these patients is not well studied. We aimed to outline the comorbidity burden in UTUC patients and investigate its relationship with overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS). We retrospectively reviewed the clinicopathological data of 409 non-metastatic UTUC patients who received radical nephroureterectomy between 2000 and 2015. The comorbidity burden was evaluated using the Adult Comorbidity Evaluation-27 (ACE-27). Kaplan-Meier survival analysis showed that high ACE-27 grade was significantly associated with worse PFS, CSS, and OS. In multivariate Cox regression and competing risk analyses, we found that ACE-27 grade, tumor stage, and tumor grade were independent prognosticators of OS, CSS, and PFS. We combined these three significant factors to construct a prognostic model for predicting clinical outcomes. A receiver operating characteristic curve revealed that our prognostic model had high predictive performance. The Harrel’s concordance indices of this model for predicting OS, CSS, and PFS were 0.81, 0.85, and 0.85, respectively. The results suggest that the UTUC patient comorbidity burden (ACE-27) provides information on the risk for meaningful clinical outcomes of OS, CSS, and PFS.
A Bout of High-Intensity Interval Training (HIIT) in Children and Adolescents during Acute Cancer Treatment—A Pilot Feasibility Study
Authors: Kesting Sabine , Weeber Peter , Schönfelder Martin , Pfluger Anja , Wackerhage Henning , von Luettichau Irene
Published: March 2022

Low- and moderate-intensity exercise is safe and feasible during childhood cancer treatment. The feasibility of a bout of high-intensity interval training (HIIT) in this population has not been analyzed to date. Pediatric cancer patients aged between 6 and 18 years were selected based on clinical conditions to perform ten sets of 15 s HIIT (>90% of estimated maximal heart rate (HRmax)) and 1 min active recovery on a bicycle ergometer within the first three chemotherapy courses. We assessed safety and feasibility criteria and the following parameters: perceived exertion rate, heart rate, and lactate and adrenaline concentrations. Out of 212 eligible patients, 11 patients aged 13.9 ± 3.6 years (n = 7 ♂) with lymphoma, leukemia, rhabdomyosarcoma, nephroblastoma, and synovial sarcoma completed the bout of HIIT without serious adverse events. During exercise, patients reached a BORG value maxima of 16 ± 1.2, and their heart rates rose from 78 ± 17 beats per minute (bpm) at rest to 178 ± 12 bpm after exercise (90 ± 6% estimated HRmax). The power-to-weight ratio was 2 ± 0.5 W/kg (watt per kilogram). Blood lactate concentrations increased from 1.09 ± 0.50 mmol/L (millimole per liter) at rest to 5.05 ± 1.88 mmol/L post-exercise. Our preliminary data suggest that HIIT is applicable only in a small number of childhood cancer patients. Individually adapted exercise protocols for patients with multiple impairments are needed.
Is Maintaining Thyroid-Stimulating Hormone Effective in Patients Undergoing Thyroid Lobectomy for Low-Risk Differentiated Thyroid Cancer? A Systematic Review and Meta-Analysis
Authors: Won Ho-Ryun , Jeon Eonju , Chang Jae Won , Kang Yea Eun , Song Kunho , Kim Sun Wook , Lim Dong Mee , Ha Tae Kwun , Chung Ki-Wook , Kim Hyo-Jeong , Park Young Joo , Koo Bon Seok
Published: March 2022

There is no clear evidence that post-operative maintenance of thyroid-stimulating hormone (TSH) in the mid to lower reference range (0.5–2 mU/L) improves prognosis in patients undergoing thyroid lobectomy for low-risk differentiated thyroid cancer (DTC). The purpose of this systematic review and meta-analysis was to compare and analyze the recurrence rate according to whether the serum TSH level was maintained below 2 mU/L in patients who underwent thyroid lobectomy for low-risk DTC. Clinical data and outcomes were collected from MEDLINE, Embase, and the Cochrane Database of Systematic Reviews. The inclusion criteria were related studies on TSH maintenance or serum TSH concentration after surgery for DTC. Seven observational studies with a total of 3974 patients were included in this study. In the patients who received TSH maintenance less than 2 mU/L, the recurrence rate during the follow-up period was 2.3%. A subgroup analysis of five studies showed that the odds ratio for recurrence in patients who received TSH maintenance was 1.45 (p-value = 0.45) compared to patients who did not receive TSH maintenance. In conclusion, the evidence for the effectiveness of post-operative TSH maintenance less than 2 mU/L in patients undergoing thyroid lobectomy for low-risk DTC is insufficient.
The Structure and Location of 18-Crown-6 Ether in Zeolites RHO and ZK-5
Authors: Nearchou Antony , Dejoie Catherine , Raithby Paul R. , Sartbaeva Asel
Published: March 2022

The use of organic additives presents the greatest versatility and control of zeolite synthesis in order to prepare novel architectures for desired applications. Despite this prospect, there is little clarity of how organic additives are involved in framework assembly and the range of behaviours that are available. To address this issue, we have considered zeolites RHO and ZK-5 which can both be prepared using 18-crown-6 ether as an additive. Previously, this additive has shown to employ different structure directing behaviours to assemble a variety of zeolites. We have used high resolution powder X-ray diffraction and Rietveld refinement to determine structural models for zeolites RHO and ZK-5 with 18-crown-6 ether occluded in the framework. In doing so, we can observe the identity, location and orientation of the occluded additive and reason the structure directing behaviour in synthesis. We report that the isolated 18-crown-6 ether molecule is involved in the assembly of zeolite RHO, and for zeolite ZK-5 it is the K+ coordinated macrocation. In both cases the relevant additive is disordered in the framework, suggesting that they behave as space-filling species that stabilise the formation of the α-cage.
Applicability of Common Algorithms in Species–Area Relationship Model Fitting
Authors: Liu Zhidong , Liu Xiaoke , Shen Tsung-Jen
Published: March 2022

The species–area relationship (SAR) describes a law of species richness changes as the sampling area varies. SAR has been studied for more than 100 years and is of great significance in the fields of biogeography, population ecology, and conservation biology. Accordingly, there are many algorithms available for fitting the SARs, but their applicability is not numerically evaluated yet. Here, we have selected three widely used algorithms, and discuss three aspects of their applicability: the number of iterations, the time consumption, and the sensitivity to the initial parameter setting. Our results showed that, the Gauss–Newton method and the Levenberg–Marquardt method require relatively few iterative steps and take less time. In contrast, the Nelder–Mead method requires relatively more iteration steps and consumes the most time. Regarding the sensitivity of the algorithm to the initial parameters, the Gauss–Newton and the Nelder–Mead methods are more sensitive to the choice of initial parameters, while the Levenberg–Marquardt method is relatively insensitive to the choice of initial parameters. Considering that the Gauss–Newton method and the Levenberg–Marquardt method can only be used to fit smooth SAR models, we concluded that the Levenberg–Marquardt model is the best choice to fit the smooth SARs, while the Nelder–Mead method is the best choice to fit the non-smooth SARs.
Information–Theoretic Aspects of Location Parameter Estimation under Skew–Normal Settings
Authors: Contreras-Reyes Javier E.
Published: March 2022

In several applications, the assumption of normality is often violated in data with some level of skewness, so skewness affects the mean’s estimation. The class of skew–normal distributions is considered, given their flexibility for modeling data with asymmetry parameter. In this paper, we considered two location parameter (μ) estimation methods in the skew–normal setting, where the coefficient of variation and the skewness parameter are known. Specifically, the least square estimator (LSE) and the best unbiased estimator (BUE) for μ are considered. The properties for BUE (which dominates LSE) using classic theorems of information theory are explored, which provides a way to measure the uncertainty of location parameter estimations. Specifically, inequalities based on convexity property enable obtaining lower and upper bounds for differential entropy and Fisher information. Some simulations illustrate the behavior of differential entropy and Fisher information bounds.
Voltage Control in MV Network with Distributed Generation—Possibilities of Real Quality Enhancement
Authors: Pijarski Paweł , Kacejko Piotr , Wancerz Marek
Published: March 2022

Connecting an increasing number of distributed sources in MV (medium voltage) and LV (low voltage) distribution networks causes voltage problems resulting mainly from periodic power flows towards the HV/MV (HV—high voltage) transformer station. This temporarily changes the nature of distribution networks from receiving to supply networks and causes an increase in the voltage values deep within the network, often above the permissible level. Therefore, it is necessary to search for new voltage control methods that take into account the active participation of distributed sources. The article proposes a concept of such a system in which the control signals are transformer taps in the HV/LV station and the values of reactive powers generated or consumed by RES (renewable energy sources). These values can be determined either by solving the optimisation problem (according to a given quality indicator criterion) or on the basis of appropriately selected settings of the Q(U) characteristics of the inverters and the HV/LV transformer ratio. The article describes both approaches, pointing to the advantages and disadvantages of each of them.
Numerical Investigation on the Mechanism of Transpiration Cooling for Porous Struts Based on Local Thermal Non-Equilibrium Model
Authors: Yang Haiwei , Liu Xue , Bian Yuyang , Wang Ge
Published: March 2022

Struts as an important structure in the combustion chamber of hypersonic flight vehicles to inject fuel into main flow face a severe thermal environment. Transpiration cooling is considered as a potential method to provide a thermal protection for struts. This paper presents a numerical investigation on transpiration cooling for a strut based on Darcy–Forchheimer model and the local thermal non-equilibrium model and analyzes the mechanism of transpiration cooling. A coolant film and a velocity boundary layer are formed on the strut surface and the shock wave is pushed away from the strut, which can effectively reduce the heat load exerted on the strut. The temperature difference between coolant and solid matrix inside the porous strut is analyzed, a phenomenon is found that the fluid temperature is higher than solid temperature at the leading edge inside the porous strut. As flowing in the porous medium, the coolant absorbs heat from solid matrix, and the fluid temperature is higher than solid temperature at the stagnation point of the strut. The influence of coolant mass flow rate and various coolants on transpiration cooling is studied. As mass flow rate increases, the cooling efficiency becomes higher and the temperature difference between fluid and solid in the porous medium is smaller. The coolant with a lower density and a higher specific heat will form a thicker film on the strut surface and absorbs more heat from solid matrix, which brings a better cooling effect for strut.
Numerical Study on Flow and Heat Transfer Characteristics of Supercritical CO2 in Zigzag Microchannels
Authors: Tu Yi , Zeng Yu
Published: March 2022

The zigzag channel is the uppermost channel type of an industrial printed circuit heat exchanger (PCHE). The effect of geometric properties on the flow and heat transfer performance of the channel is significant to the PCHE design and optimization. Numerical investigations were conducted on the flow and heat transfer characteristics of supercritical CO2 (sCO2) in semicircular zigzag channels by computational fluid dynamics method. The shear stress transfer (SST) k–ω model was used as turbulence model and the National Institute of Standards and Technology (NIST) real gas model with REFPROP database was used to evaluate the thermophysical parameters of sCO2 in this numerical method. The effectiveness of the simulation method is verified by experimental data. Thermal hydraulic performance for zigzag channels with different pitch lengths, bending angles, and hydraulic diameters are studied comparatively based on this numerical method, with the boundary conditions which cover the pseudocritical point. The comparison results show that reducing the bending angle and pitch length will strengthen the effect of boundary layer separation on the leeward side of the wall and enhance the heat transfer performance, but the pressure drop of the channel will also increase, and the decrease of channel hydraulic diameter is beneficial to the heat transfer enhancement, but it is not as significant as that of the straight channel.
Prediction of Pressure Increase during Waste Water Injection to Prevent Seismic Events
Authors: Jin Lu , Wojtanowicz Andrew K. , Ge Jun
Published: March 2022

A considerable increase of seismicity has occurred in the USA in the last decade (2009–2020) with an annual average of 345 M3+ earthquakes. Numerous field cases have shown that excessive well pressure due to a high injection rate may have triggered seismic events. This study defines conditions for inducing a seismic event by excessive injection in the well’s pressure that may cause geomechanical damage to the rock. Introduced here is an analytical model and method for predicting pressure increase during injection of produced water contaminated with oil. The model calculates time-dependent advancement of the captured oil saturation causing the well’s injectivity damage and pressure increase. Critical conditions for a seismic event are set by defining rock failure when well pressure exceeds the fracturing pressure of the wellbore or when the increased pore pressure reduces the effective normal stress at the “weak” interface inside the rock, computed with a geomechanical model. This concept is demonstrated in three field case studies using data from geological formations in areas of petroleum operations. The results confirm field observations of the initial rapid increase of oil invasion and injection pressure that could only be controlled by reducing the rate of injection to assure continuing long-time operation.
Performance Optimization of a Ten Check MPPT Algorithm for an Off-Grid Solar Photovoltaic System
Authors: Awan Muhammad Mateen Afzal , Javed Muhammad Yaqoob , Asghar Aamer Bilal , Ejsmont Krzysztof
Published: March 2022

In order to operate a solar photovoltaic (PV) system at its maximum power point (MPP) under numerous weather conditions, it is necessary to achieve uninterrupted optimal power production and to minimize energy losses, energy generation cost, and payback time. Under partial shading conditions (PSC), the formation of multiple peaks in the power voltage characteristic curve of a PV cell puzzles conventional MPP tracking (MPPT) algorithms trying to identify the global MPP (GMPP). Meanwhile, soft-computing MPPT algorithms can identify the GMPP even under PSC. Drawbacks such as structural complexity, computational complexity, huge memory requirements, and difficult implementation all affect the viability of soft-computing algorithms. However, those drawbacks have been successfully overcome with a novel ten check algorithm (TCA). To improve the performance of the TCA in terms of MPPT speed and efficiency, a novel concept of data arrangement is introduced in this paper. The proposed structure is referred to as Optimized TCA (OTCA). A comparison of the proposed OTCA and classic TCA algorithms was conducted for standard benchmarks. The results proved the superiority of the OTCA algorithm compared to both TCA and flower pollination (FPA) algorithms. The major advantage of OTCA in MPPT stems from its speed as compared to TCA and FPA, with almost 86% and 90% improvement, respectively.
Long-Term Carbon Sequestration in Pine Forests under Different Silvicultural and Climatic Regimes in Spain
Authors: Navarro-Cerrillo Rafael M. , Ruiz-Gómez Francisco J. , Camarero Jesús J. , Castillo Víctor , Barberá Gonzalo G. , Palacios-Rodríguez Guillermo , Navarro Francisco B. , Blanco Juan A. , Imbert Juan B. , Cachinero-Vivar Antonio M. , Molina Antonio J. , del Campo Antonio D.
Published: March 2022

Proactive silviculture treatments (e.g., thinning) may increase C sequestration contributing to climate change mitigation, although, there are still questions about this effect in Mediterranean pine forests. The aim of this research was to quantify the storage of biomass and soil organic carbon in Pinus forests along a climatic gradient from North to South of the Iberian Peninsula. Nine experimental Pinus spp trials were selected along a latitudinal gradient from the pre-Pyrenees to southern Spain. At each location, a homogeneous area was used as the operational scale, and three thinning intensity treatments: unthinned or control (C), intermediate thinning (LT, removal of 30–40% of the initial basal area) and heavy thinning (HT, removal of 50–60%) were conducted. Growth per unit area (e.g., expressed as basal area increment-BAI), biomass, and Soil Organic Carbon (SOC) were measured as well as three sets of environmental variables (climate, soil water availability and soil chemical and physical characteristics). One-way ANOVA and Structural Equation Modelling (SEM) were used to study the effect of thinning and environmental variables on C sequestration. Biomass and growth per unit area were higher in the control than in the thinning treatments, although differences were only significant for P. halepensis. Radial growth recovered after thinning in all species, but it was faster in the HT treatments. Soil organic carbon (SOC10, 0–10 cm depth) was higher in the HT treatments for P. halepensis and P. sylvestris, but not for P. nigra. SEM showed that Pinus stands of the studied species were beneficed by HT thinning, recovering their growth quickly. The resulting model explained 72% of the variation in SOC10 content, and 89% of the variation in silvicultural condition (basal area and density) after thinning. SOC10 was better related to climate than to silvicultural treatments. On the other hand, soil chemical and physical characteristics did not show significant influence over SOC10- Soil water availability was the latent variable with the highest influence over SOC10. This work is a new contribution that shows the need for forest managers to integrate silviculture and C sequestration in Mediterranean pine plantations.
A Survey on Intrusion Detection Systems for Fog and Cloud Computing
Authors: Chang Victor , Golightly Lewis , Modesti Paolo , Xu Qianwen Ariel , Doan Le Minh Thao , Hall Karl , Boddu Sreeja , Kobusińska Anna
Published: March 2022

The rapid advancement of internet technologies has dramatically increased the number of connected devices. This has created a huge attack surface that requires the deployment of effective and practical countermeasures to protect network infrastructures from the harm that cyber-attacks can cause. Hence, there is an absolute need to differentiate boundaries in personal information and cloud and fog computing globally and the adoption of specific information security policies and regulations. The goal of the security policy and framework for cloud and fog computing is to protect the end-users and their information, reduce task-based operations, aid in compliance, and create standards for expected user actions, all of which are based on the use of established rules for cloud computing. Moreover, intrusion detection systems are widely adopted solutions to monitor and analyze network traffic and detect anomalies that can help identify ongoing adversarial activities, trigger alerts, and automatically block traffic from hostile sources. This survey paper analyzes factors, including the application of technologies and techniques, which can enable the deployment of security policy on fog and cloud computing successfully. The paper focuses on a Software-as-a-Service (SaaS) and intrusion detection, which provides an effective and resilient system structure for users and organizations. Our survey aims to provide a framework for a cloud and fog computing security policy, while addressing the required security tools, policies, and services, particularly for cloud and fog environments for organizational adoption. While developing the essential linkage between requirements, legal aspects, analyzing techniques and systems to reduce intrusion detection, we recommend the strategies for cloud and fog computing security policies. The paper develops structured guidelines for ways in which organizations can adopt and audit the security of their systems as security is an essential component of their systems and presents an agile current state-of-the-art review of intrusion detection systems and their principles. Functionalities and techniques for developing these defense mechanisms are considered, along with concrete products utilized in operational systems. Finally, we discuss evaluation criteria and open-ended challenges in this area.
A Voting-Based Ensemble Deep Learning Method Focused on Multi-Step Prediction of Food Safety Risk Levels: Applications in Hazard Analysis of Heavy Metals in Grain Processing Products
Authors: Wang Zuzheng , Wu Zhixiang , Zou Minke , Wen Xin , Wang Zheng , Li Yuanzhang , Zhang Qingchuan
Published: March 2022

Grain processing products constitute an essential component of the human diet and are among the main sources of heavy metal intake. Therefore, a systematic assessment of risk factors and early-warning systems are vital to control heavy metal hazards in grain processing products. In this study, we established a risk assessment model to systematically analyze heavy metal hazards and combined the model with the K-means++ algorithm to perform risk level classification. We then employed deep learning models to conduct a multi-step prediction of risk levels, providing an early warning of food safety risks. By introducing a voting-ensemble technique, the accuracy of the prediction model was improved. The results indicated that the proposed model was superior to other models, exhibiting the overall accuracy of 90.47% in the 7-day prediction and thus satisfying the basic requirement of the food supervision department. This study provides a novel early-warning model for the systematic assessment of the risk level and further allows the development of targeted regulatory strategies to improve supervision efficiency.
The Power of Single-Cell RNA Sequencing in eQTL Discovery
Authors: Maria Maleeha , Pouyanfar Negar , Örd Tiit , Kaikkonen Minna U.
Published: March 2022

Genome-wide association studies have successfully mapped thousands of loci associated with complex traits. During the last decade, functional genomics approaches combining genotype information with bulk RNA-sequencing data have identified genes regulated by GWAS loci through expression quantitative trait locus (eQTL) analysis. Single-cell RNA-Sequencing (scRNA-Seq) technologies have created new exciting opportunities for spatiotemporal assessment of changes in gene expression at the single-cell level in complex and inherited conditions. A growing number of studies have demonstrated the power of scRNA-Seq in eQTL mapping across different cell types, developmental stages and stimuli that could be obscured when using bulk RNA-Seq methods. In this review, we outline the methodological principles, advantages, limitations and the future experimental and analytical considerations of single-cell eQTL studies. We look forward to the explosion of single-cell eQTL studies applied to large-scale population genetics to take us one step closer to understanding the molecular mechanisms of disease.
Glutamate Uptake Is Not Impaired by Hypoxia in a Culture Model of Human Fetal Neural Stem Cell-Derived Astrocytes
Authors: Shrivastava Vadanya , Dey Devanjan , Singal Chitra Mohinder Singh , Jaiswal Paritosh , Singh Ankit , Sharma Jai Bhagwan , Chattopadhyay Parthaprasad , Nayak Nihar Ranjan , Palanichamy Jayanth Kumar , Sinha Subrata , Seth Pankaj , Sen Sudip
Published: March 2022

Hypoxic ischemic injury to the fetal and neonatal brain is a leading cause of death and disability worldwide. Although animal and culture studies suggest that glutamate excitotoxicity is a primary contributor to neuronal death following hypoxia, the molecular mechanisms, and roles of various neural cells in the development of glutamate excitotoxicity in humans, is not fully understood. In this study, we developed a culture model of human fetal neural stem cell (FNSC)-derived astrocytes and examined their glutamate uptake in response to hypoxia. We isolated, established, and characterized cultures of FNSCs from aborted fetal brains and differentiated them into astrocytes, characterized by increased expression of the astrocyte markers glial fibrillary acidic protein (GFAP), excitatory amino acid transporter 1 (EAAT1) and EAAT2, and decreased expression of neural stem cell marker Nestin. Differentiated astrocytes were exposed to various oxygen concentrations mimicking normoxia (20% and 6%), moderate and severe hypoxia (2% and 0.2%, respectively). Interestingly, no change was observed in the expression of the glutamate transporter EAAT2 or glutamate uptake by astrocytes, even after exposure to severe hypoxia for 48 h. These results together suggest that human FNSC-derived astrocytes can maintain glutamate uptake after hypoxic injury and thus provide evidence for the possible neuroprotective role of astrocytes in hypoxic conditions.
The Impact of COVID-19 Pandemic on Female Sexual Function
Authors: Fuchs Anna , Szul Mateusz , Dulska Agnieszka , Bodziony Jakub , Matonóg Aleksandra , Pilarska Joanna , Sieradzka Paulina , Stojko Rafał , Drosdzol-Cop Agnieszka
Published: March 2022

Introduction: The outbreak of the COVID-19 pandemic affected many aspects of life involving sexual functioning. Methods: This prospective, noninterventional, observational research was performed from July 2020 to August 2020, involving a total of 644 patients. Female sexual function index (FSFI) scores of those women were compared in relation to results of our research from April 2020. Questionnaires were collected concerning socio-demographic characteristics of patients as well as the impact of the COVID-19 pandemic on their lives. Results: Every domain significantly decreased in the first month of the lockdown. Before the pandemic, the total FSFI was reported at 30.1 ± 4.4, while in the first month of the pandemic it was at 25.8 ± 9.7 (p < 0.001). The lowest FSFI score was reported by women who lived in average conditions. There was a statistically significant increase in the overall FSFI score in the fifth month of the pandemic (27.5 ± 6.8) when compared to the FSFI score in the first month of the pandemic (25.8 ± 9.7). The scores in arousal, lubrication, orgasm and pain were reported as higher (respectively p < 0.001, p < 0.001, p < 0.001, p < 0.05), while desire was reported lower (p < 0.001). The satisfaction score remained almost the same (p < 0.05). Conclusions: Our study indicates a significant decrease in FSFI scores across all domains. There are still many questions whether the statue from the vaccinated person or convalescents affects the sense of security and, thus, increases sexual satisfaction.
A Systematic Review of Factors Associated with Sport Participation among Adolescent Females
Authors: Hopkins Casey S. , Hopkins Chris , Kanny Samantha , Watson Amanda
Published: March 2022

Sport participation provides a direct means to attain health-enhancing physical activity; however, sport participation declines during adolescence, and over 85% of adolescent females fail to meet the recommended 60 min of moderate-vigorous physical activity daily. Given the importance of overcoming barriers to sport and increasing equity in women’s sports, the purpose of this systematic review was to identify factors associated with sport participation among adolescent girls and operationalize those factors into theoretical constructs to guide future research. Six databases were systematically searched, and 36 records were included for review. Factors impacting girls’ sport participation were categorized as personal, peer, family, socioeconomic, environmental, or other factors. Of these categories, personal factors, including self perceptions and desirable personal outcomes related to sport, were most frequently associated with sport participation. Most research on girls’ sport participation lacks theoretical framework, so to aid future studies, this review categorized important participatory factors into the constructs of the theory of planned behavior. Future research would benefit from theory-driven prospective approaches to make clear and consistent predictions about factors impacting sport participation, as well as mixed-method approaches aimed to provide more robust understanding of girls’ experiences with and perceptions of factors impacting their participation in sports.
Noise Parameters of Headsets Designed for Communication Platforms
Authors: Kozlowski Emil
Published: March 2022

Headsets are increasingly used in the working environment. In addition to being frequently used by call-centre staff, they are also becoming more popular with remote workers and teleconference participants. The aim of this work was to describe and evaluate the acoustic signal parameters reproduced by headsets and examine the factors affecting the values of these parameters. The tests were carried out in laboratory conditions using a manikin (head and torso simulator) designed for acoustic research. A total of 12 headset models were tested during the research. The results show that the A-weighted sound pressure level of the test signal reproduced by four (100% gain) and two (75% gain) headsets exceeded 85 dB. The highest equivalent A-weighted sound pressure level was 92.5 dB, which means that the headset should not be used for more than approx. 1 h and 25 min; otherwise, the criterion value will be exceeded. The analysis of the acoustic signal reproduced by the headsets confirmed that the A-weighted sound pressure level affected the gain level in the test signal reproduction path. This value also depended on the type of connector used, the computer from which the test signal was reproduced and the type of sound card used.
Risk Factors for Brain Health in Agricultural Work: A Systematic Review
Authors: Sturm Emily Terese , Castro Colton , Mendez-Colmenares Andrea , Duffy John , Burzynska Agnieszka (Aga) Z. , Stallones Lorann , Thomas Michael L.
Published: March 2022

Certain exposures related to agricultural work have been associated with neurological disorders. To date, few studies have included brain health measurements to link specific risk factors with possible neural mechanisms. Moreover, a synthesis of agricultural risk factors associated with poorer brain health outcomes is missing. In this systematic review, we identified 106 articles using keywords related to agriculture, occupational exposure, and the brain. We identified seven major risk factors: non-specific factors that are associated with agricultural work itself, toluene, pesticides, heavy metal or dust exposure, work with farm animals, and nicotine exposure from plants. Of these, pesticides are the most highly studied. The majority of qualifying studies were epidemiological studies. Nigral striatal regions were the most well studied brain area impacted. Of the three human neuroimaging studies we found, two focused on functional networks and the third focused on gray matter. We identified two major directions for future studies that will help inform preventative strategies for brain health in vulnerable agricultural workers: (1) the effects of moderators such as type of work, sex, migrant status, race, and age; and (2) more comprehensive brain imaging studies, both observational and experimental, involving several imaging techniques.