bluuebunny/crossref_metadata_2025 huggingface dataset:
Physiology of Cultured Human Microglia Maintained in a Defined Culture Medium
Authors: Tewari Manju , Khan Maheen , Verma Megha , Coppens Jeroen , Kemp Joanna M , Bucholz Richard , Mercier Philippe , Egan Terrance M
Published: April 2021

Microglia are the primary immune cell of the CNS, comprising 5–20% of the ∼60 billion neuroglia in the human brain. In the developing and adult CNS, they preferentially target active neurons to guide synapse maturation and remodeling. At the same time, they are the first line of defense against bacterial, fungal, and viral CNS infections. Although an extensive literature details their roles in rodents, less is known about how they function in humans because of the difficulty in obtaining tissue samples and the understandable inability to extensively study human microglia in situ. In this study, we use recent advances in the study of brain microenvironments to establish cultures of primary human microglia in a serum-free medium. Postsurgical samples of human brain were enzymatically and mechanically dissociated into single cells, and microglia were isolated at high purity by positive selection using CD11b Ab–coated microbeads. The CD11b+ cells were plated on poly-l-lysine–coated surfaces and bathed in serum-free DMEM/F12 supplemented with three essential components (TGF-β, IL-34, and cholesterol). Under these conditions, microglia assumed a ramified morphology, showed limited proliferation, actively surveyed their surroundings, and phagocytosed bacterial microparticles. In the presence of LPS, they assumed a more compact shape and began production of proinflammatory cytokines and reactive oxygen species. LPS on its own triggered release of TNF-α, whereas release of IL-1β required costimulation by ATP. Thus, human microglia maintained in a defined medium replicate many of the characteristics expected of native cells in the brain and provide an accessible preparation for investigations of human microglial physiology, pharmacology, and pathophysiology.
Impact of HIV-1 Infection and Antigen Class on T Follicular Helper Cell Responses to Pneumococcal Polysaccharide–Protein Conjugate Vaccine-13
Authors: Jha Vibha , Nicholson Lindsay K. , Gardner Edward M. , Rahkola Jeremy T. , Pratap Harsh , Scott James , Borgeson Mandy , Jacobelli Jordan , Janoff Edward N.
Published: April 2021

Pneumococcal infections are common and serious complications of HIV-1 disease. Prevention has been compromised by the limited magnitude and quality of Ab responses to T cell–independent type 2 pneumococcal capsular polysaccharides (PPS). The pneumococcal polysaccharide–protein conjugate vaccine-13 (PCV-13) contains PPS conjugated to the T cell–dependent protein (diphtheria toxoid [DT] [CRM197]). We investigated the differential response to PPS and DT by human Ab-secreting B cells (ASC) after immunization with PCV-13 in newly diagnosed healthy HIV+ and control adults. The numbers of PPS-specific IgG ASC increased significantly and similarly in HIV+ and controls. However, DT-specific IgG ASC increased in controls but not HIV+ subjects. To determine the cellular basis of these disparate responses to DT and PPS, we characterized the frequency and activation of T follicular helper (Tfh) cells, the predominant T cell subset providing B cell help. Expression of inducible T cell costimulator (ICOS), which sustains Tfh function and phenotype, increased significantly among controls, when compared with the HIV+ group. Increases in ICOS+ Tfh correlated with changes in T-dependent, DT-specific IgG ASC in controls but not in HIV+. In contrast, ICOS expression did not correlate with T cell–independent type 2 PPS-specific ASC in either group. Of note, upon optimized ex vivo stimulation, CD4 T cells from HIV+ subjects differentiated into Tfh cells and formed synapses with Raji B cells at frequencies similar to that of controls. In summary, PCV-13–induced increase in ICOS expression on Tfh was associated with responses to DT, which was compromised in recently diagnosed healthy HIV+ adults and can be restored ex vivo by providing effective Tfh-differentiating signals.
Vertebrates in the “Palude di Torre Flavia” Special Protection Area (Lazio, central Italy): an updated checklist
Authors: Battisti Corrado , Cento Michele , Fraticelli Fulvio , Hueting Steven , Muratore Sergio
Published: April 2021

Here we present the checklist of the vertebrates of the “Palude di Torre Flavia”, a protected area in Tyrrhenian central Italy (Special Protection Area according to the Directive 2009/147/EC). To draw up the checklist, we collated all the records found in the literature, in private collections, and in the Ornitho.it website database, as well as sporadic historical observations. We obtained evidence documented between 1981 and 2020 for 291 taxa of which 259 native, 26 allochthonous and 6 domesticated species in 5 classes: 5 actinopterygians (4 native species and 1 allochtonous), 2 amphibians, 20 reptiles (11 native species and 9 allochthonous; the last being all freshwater terrapins), 244 birds (including 14 non-native taxa and 6 domestic forms) and 20 mammals (including 2 allochthonous). Forty-three species are listed as of conservation concern on a national scale. The area has shown to be an important biodiversity hotspot, and a major stopover site for migrating birds. Further research should be focused on some still poorly investigated taxonomic groups, in particular: Actinopterygii, Amphibia Salamandridae, Carnivora Mustelidae, and Chiroptera.
A Suturing Method without Exposure of Barbs on the Wound Surface Using a Unidirectional Barbed Monofilament Absorbable Suture (STRATAFIX™) in Laparoscopic Myomectomy
Authors: Ota Yoshiaki , Ota Kuniaki , Takahashi Toshifumi , Suzuki Soichiro , Sano Rikiya , Shiota Mitsuru
Published: April 2021

Objectives:

We examined whether a new suturing method that used a single-thread unidirectional barbed suture without exposing the barbs on the wound surface was acceptable compared with the conventional suture method during laparoscopic myomectomy (LM).

Materials and Methods:

This was a retrospective study. The subjects were 26 women who underwent LM for symptomatic uterine fibroids. The operative time, amount of blood loss, and number of threads used were compared between a group in which suturing was performed with a conventional synthetic absorbable suture (conventional suture group, n = 13) and a group in which suturing was performed using a barbed suture (barbed suture group, n = 13).

Results:

Operative time in the barbed suture group was significantly shorter than that in the conventional suture group, while blood loss during LM in the barbed suture group was significantly lower than that in the conventional suture group. The number of threads used in the conventional suture group was significantly larger than that in the barbed suture group. No complications were observed in both the groups during LM.

Conclusion:

This new technique using a barbed suture is safe and feasible for LM.
Value of Crossover Sign in Anticipating Under-8-week Cesarean Scar Pregnancy Treatment by Foley Insertion Combined with Suction Curettage in Vietnam
Authors: Vo Tuan Minh , Dinh Hoang T. , Van Thong P. , Nguyen Christopher Son
Published: April 2021

Objectives:

An earlier study completed at TuDu Hospital presented the efficacy of Foley insertion combined with fetal suction curettage at a high rate of success in treatment of cesarean scar pregnancy (CSP) of < 8 weeks, but the efficacy of prognosticating factors for this approach has not been specifically addressed yet, especially crossover sign (COS) on ultrasound. We aimed to investigate the correlation between COS on ultrasound and the treatment results of CSP using Foley insertion combined with fetal suction.

Materials and Methods:

A case–control study of CSPs ≤ 8 weeks treated at TuDu Hospital during September 2017–April 2019 included 63 failures in the case group and 98 successes in the control group.

Results:

COS-2 + increased the likelihood of treatment success by 4.9 times (95% confidence interval: 1.8–13.5) compared with COS-1 cases. In addition, other factors favoring treatment success with statistical significance included no vascularization at cesarean scar on ultrasound (odds ratio [OR] = 7.1), gestational mass volume ≤4 cm3 (OR = 3.7), and β-human chorionic gonadotropin at hospital admission ≤ 10,000 mIU/mL (OR = 6.1).

Conclusion:

COS imaging played an important role in the prediction of treatment outcomes for CSP ≤ 8 weeks by the combined approach of Foley insertion and fetal suction curettage.
Dowling–Degos Disease
Authors: Al Hawsawi Khalid , Aser Rehab , Khoj Zaker , Barnawi Ghassan , Alhawsawi Waseem
Published: April 2021

Dowling–Degos disease (DDD) is an uncommon autosomal dominant genodermatosis characterized by reticular hyperpigmentation in the intertriginous areas. Herein, we report a case of follicular DDD which is a very rare variant of DDD. A 45-year-old healthy male presented with 1-year-history of asymptomatic slowly progressive skin lesions in the axillae. Skin examination revealed multiple nonscaly pigmented follicular papules and macules in both axillae but more severe in the right side. No other skin lesions elsewhere in the body. Hair, nails, and mucus membrane were all normal. Skin biopsy showed follicular plugging with the presence of pigmented filiform rete ridges originating from the follicular epithelium. The patient was diagnosed as follicular DDD. The patient was reassured. Electrocautery treatment was used, which leads to a remarkable improvement of the lesions.
Acral Subcorneal Hematoma
Authors: Nassar Ahmed H. , Abu-Aliat Abdullah S. , Hawwam Soha A.
Published: April 2021

Background:

Acral subcorneal hematoma (ASH) is a dark-colored skin lesion of the palms and/or soles due to bleeding. ASH may be difficult to be clinically differentiated from acral melanocytic lesions, resulting in unnecessary biopsies. Few researches reported the importance of dermoscopy in differentiating ASH from acral melanocytic lesions.

Purpose:

This study aims at reporting the dermoscopic features in a series of ASH to facilitate precise diagnosis and to avoid performing unnecessary surgical techniques.

Methods:

Eighteen patients with ASH were studied. Dermoscopic images were obtained using a handheld dermoscope and a dermoscope-adopted phone camera. Paring test was performed on all lesions.

Results:

The preliminary diagnoses of the lesions were ASH in 55.6%, acral melanocytic nevi in 33.3%, and acral lentiginous melanoma in the remaining 11.1%. Dermoscopically, the lesion colors were red-black in 44.4%, black in 27.8%, and brown in the remaining 27.8%. The pigmentation patterns were homogeneous (structureless) in 55.6%, parallel ridge in 27.8%, and negative pseudonetwork in the remaining 16.6%. Over 44% of the lesions had red and/or brown globular satellites. Peripheral red lines with/without radial extensions were noticed around ASH in 55.6%. Paring led to complete removal of pigmentation in all ASH (100%), with the appearance of post-paring blood-tinged serum in 55.6%. No skin biopsies were performed.

Conclusion:

Although there is clinical similarity between ASH and acral melanocytic lesions, dermoscopy and paring test can facilitate a precise diagnosis and markedly decrease the need for unnecessary invasive procedures.
Clinico-Epidemiological Factors Related to Lichen Planus and Its Clinical Variants at a Tertiary Care Hospital
Authors: Gupta Ankit , Nayak Chitra S.
Published: April 2021

Background:

Lichen planus (LP) is an immune_mediated, chronic inflammatory disease involving skin, oral and genital mucosa, nails, and hair with several morphologic variants. The exact etiology remains unclear, but several factors have been implicated.

Purpose:

To study the clinico-epidemiological profile of patients of LP and its clinical variants and to find out whether LP is relatively uncommon in children.

Methods:

This prospective, cross-sectional, descriptive, time-bound, clinico-epidemiological study was conducted in the outpatient department of dermatology at a tertiary care hospital during the period of June 2017 to October 2018. A total of 170 patients were included in the study. Microsoft Excel and SPSS 23 software packages were used for data entry and statistical analysis. The results were averaged for each parameter for continuous data and numbers and percentage for categorical data. Statistical tests were applied wherever necessary.

Results:

The overall prevalence of LP was 0.4% (n = 170) out of 42,127 patients who attended the OPD during the study period. The gender-wise prevalence of LP was 41% among females and 59% among males, and the difference was not statistically significant (P = 0.3). The male-to-female ratio was 1.5:1. The highest prevalence among the variants of LP was of classical form (29%) and lowest was of inverse LP (0.6%). Overall, the mean age of the patients was 36 years, with a standard deviation of 17. There was one instance of LP occurring in both father and son.

Conclusion:

The most common age group of LP was 18 -40 years. Most patients came to seek health care within 1 year of beginning of disease. More than one variant of LP can coexist in the same individual. Childhood LP is not uncommon in the Indian subcontinent.
An elderly male with nonresolving consolidation
Authors: Iyer Hariharan , Vinod Kutty Sharada , Mohan Anant , Mallick Saumyaranjan
Published: April 2021

An 81-year-old male presented with a background history of progressive shortness of breath for 3 years with recent worsening in the past 6 months. Clinicoradiological investigations were consistent with a nonresolving consolidation involving predominantly right lung. This clinicopathologic conference discusses the differential diagnoses of pneumonia of long-standing duration and their management options.
Surgical Management of Hemorrhagic Retinal Detachment Secondary to Peripheral Exudative Hemorrhagic Chorioretinopathy
Authors: Semidey Valmore A. , Al Taisan Abdulaziz A. , Schatz Patrik , Taskintuna Ibrahim , Mura Marco
Published: April 2021

The purpose of the study is to report a case of peripheral exudative hemorrhagic chorioretinopathy (PEHCR), managed surgically with favorable visual outcome. A 66-year-old female presented with painless visual loss due to dense vitreous and subretinal hemorrhage extending from the far periphery to the macula. Pars plana vitrectomy (PPV) with subretinal tissue plasminogen activator (TPA) injection was performed resulting in good anatomical and visual outcome. PEHCR can present with severe visual loss. Surgical management with PPV and subretinal TPA injection might result in favorable anatomical and visual outcome.
Effect of Oral Propranolol on Periocular Infantile Capillary Hemangioma
Authors: Bejjanki Kavya M. , Akhtar Kahkashan , Gupta Arushi P. , Kaliki Swathi
Published: April 2021

PURPOSE:

To evaluate the efficacy of oral propranolol in the treatment of periocular infantile capillary hemangioma (CHI) based on the involvement of embryological facial placodes and their extent of anatomical involvement.

METHODS:

Retrospective study of 27 patients.

RESULTS:

The mean age at the presentation of periocular CHI was 4 months (median, 3 months; range, <1–14 months). There were 11 (41%) males and 16 (59%) females. Based on embryological facial placodes, the involvement was focal in 16 (59%) cases and segmental in 11 (41%) cases. Based on the anatomical distribution, the lesions were preseptal in 4 (15%), postseptal in 13 (48%), and combined in 10 (37%) cases. The duration of use of oral propranolol was 10 months (median, 10 months; range, 4–16 months). Overall, the mean % resolution of periocular CHI was 78% (median, 90%; range, 20%–100%). The mean percentage resolution of focal lesions was 69% (median, 83%; range, 20%–100%), and segmental lesions were 92% (median, 95%; range, 70%–100%). The mean percentage resolution of preseptal component of lesions was 94% (median, 95%; range, 80%–100%) and postseptal component was 74% (median, 85%; range, 20%–100%) over a mean follow-up period of 16 months (median, 15 months; range, 4–37 months). Four (15%) patients exhibited flare-up of lesion after tapering oral propranolol.

CONCLUSION:

Oral propranolol is effective in the treatment of periocular CHI. Segmental and preseptal lesions respond better to the treatment compared to focal and postseptal lesions.
Fourier multipliers and transfer operators
Authors: Pollicott Mark
Published: April 2021

A recent paper of Chen and Volkmer estimated a quantity related to the spectral radius of a transfer operator and with significance in the study of Fourier multipliers. We provide a rigorous proof of their conjectured numerical value.
Асимптотика собственных значений взвешенного полигармонического оператора с сингулярной мерой
Authors: Rozenblum Grigorii Vladimirovich , Shargorodskii Evgenii Mikhailovich
Published: April 2021

Установлено, что в критическом случае $2l={\mathbf N}$ собственные значения задачи $\lambda(-\Delta)^{l}u=Pu$ с сингулярной мерой $P$ с носителем на липшицевой поверхности произвольной размерности в $\mathbb{R}^{\mathbf N}$ удовлетворяют асимптотической формуле того же порядка, что и в для абсолютно непрерывной меры.
Формула Вейля-Титчмарша для спектральной плотности класса матриц Якоби в критическом случае
Authors: Naboko Sergei Nikolaevich , Simonov Sergey Aleksandrovich
Published: April 2021

В работе рассматривается класс матриц Якоби с неограниченными матричными элементами в так называемом критическом случае (случае двойного корня, или случае жордановой клетки). Доказана формула, связывающая спектральную плотность матрицы с асимптотикой ассоциированных с ней ортогональных многочленов.
Универсальные соотношения в асимптотических формулах для ортогональных полиномов
Authors: Yafaev Dmitrii Rauel'evich
Published: April 2021

Ортогональные полиномы $P_{n}(\lambda)$ являются осциллирующими функциями от $n$ при $n\to\infty$ для $\lambda$ из абсолютно непрерывного спектра соответствующего оператора Якоби $J$. Мы показываем, что, независимо от конкретных предположений о коэффициентах оператора $J$, амплитуда и фаза в асимптотических формулах для $P_{n}(\lambda)$ связаны найденными в работе универсальными соотношениями. Доказательства этих соотношений основаны на изучении зависящей от времени эволюции, порождаемой подходящими функциями оператора $J$.
Два следствия неравенства Харди в версии Дэвиса
Authors: Frank R L , Larson S
Published: April 2021

Неравенство Харди в версии Дэвиса дает оценку снизу интеграла Дирихле функции, равной нулю на границе области, через интеграл от квадрата функции с весом, включающим усредненную функцию расстояния до границы. В работе показано применение этого неравенства для простого вывода двух классических результатов спектральной теории: неравенства Э. Либа для первого собственного значения лапласиана Дирихле и оценки Г. Розенблюма для функции распределения собственных значений лапласиана в неограниченной области через количество дизъюнктных шаров заданного размера, имеющих достаточно большое пересечение с областью.
Pheromone deposition/updating strategy in a network: using ant colony optimization (ACO) approach
Authors: Ogban Felix U. , Nentui Roy
Published: April 2021

The study and understanding of the social behavior of insects has contributed to the definition of some algorithms that are capable of solving several types of optimization problems. The most important and challenging problems that the ants encounters when routing through a network arc, is their ability to searching for the path with a shorter length as well as to minimize the total cost incurred in the process of routing  through the network. In this paper, we introduced some features to the existing Ant Colony Optimization (ACO) algorithm to help tackle this problem. First, we defined two kinds of pheromone and then we also defined three kinds of heuristic information to guide the searching direction of ants for this bi-criteria problem. Each of the ants uses the heuristic types and the pheromone types in each iteration based on the probability, controlled by two parameters. These two parameters are adaptively adjusted in the process of the algorithm. Second, we used the information of the partial solutions to modify the bias of ants so that inferior choices will be ignored. Finally, we tested the performance of the experimental results of the algorithm in an application under different Deadline constraints and the performance of the algorithm prove to be more promising, for it outperformed the performance of most of the algorithm we downloaded on line.Keywords: Ant Colony Optimization algorithm, Pheromone Deposition, Pheromone Updating strategy, Cost Minimization, Network Routing, Optimization problem.
Accessing good quality water in hazardous mining environments: coping mechanisms for young women in selected districts of Mashonaland central, Zimbabwe.
Authors: Makwerere David , Chinzete Gillian Tafadzwa , Massimo Charles
Published: April 2021

The study focused on how environmental degradation due to unregulated illegal mining activities is affecting the welfare of communities in general and women in particular with regards to access good quality water. The methodological design was a qualitative approach and focused on the two districts of Shamva and Bindura in Mashonaland Central Province, Zimbabwe. The study noted that the area of environmental policing has remained weak and compromised owing to a combination of factors, key among them being the difficult socio-economic environment which has often seen a lot of communities destroying the environment around them, political populism leading to the destruction of local ecologies and general disregard of responsibilities by companies operating mining, construction, and other enterprises.This has seen the gradual destruction and pollution of fresh water bodies across the communities.The study revealed that there is a considerable level of pollution on some water bodies in the two districts. The pollution is largely caused by the use of mercury and cyanide by the illegal gold panners and artisanal miners in the area. This has restricted opportunities for women’s access to safe domestic water. Women are using strategies such as outsourcing from neighboring communities with relatively safe water for domestic use, differentiating water for cooking and drinking and for other activities like bathing and laundry, water harvesting during rain seasons and buying from shops in extreme circumstances. In conclusion, the coping mechanisms only offer temporary relief and are not be sustainable in the long run.Keywords: Hazards, Coping Mechanisms, Mining, Environment, Legislation, Kyoto Protocol, Human Right
Carbothermal Upgrading of the Awaso Bauxite Ore using Sawdust and Coconut Shells as Reductant
Authors: Fosu A. Y. , Fosu N. , Owusu K. B. , Dankwah J. R.
Published: April 2021

Ghana’s bauxite is exported in the raw state with no value addition. One way to achieve value addition is to carbothermally upgrade the ore into magnetic and nonmagnetic fractions, followed by separation using a magnet. This work investigates the carbothermal upgrading of the Awaso bauxite ore using reductant generated from locally available saw dust (SD) and coconut shells (CNS). Composite pellets of bauxite-reductant were prepared, air-dried and cured for 72 hours. The cured pellets were placed in a fire-clay crucible and heated in a custom-made gas-fired furnace for 30 minutes. The fired composite pellets were separated into magnetic and non-magnetic portions using a low intensity hand-held magnet. The various portions were then characterised using XRD, XRF and SEM analyses. XRD results showed magnetite as the predominant species present in the magnetic fraction whilst the non-magnetic fraction showed alumina as the predominant peaks along with some traces of unreduced hematite, silica, carbon and titania but no hercynite.  Keywords: Bauxite, Palm Nut Shells, Gas-Fired Furnace, Hercynite, Char
Improving Land Tenure Security through Customary Boundary Demarcation- A Case Study
Authors: Asenso-Gyambibi D. , Affam M. , Amoafo E. Y. , Acquah S. B.
Published: April 2021

In sub-Saharan Africa, one of the barriers to development and wealth creation in the peri urban and rural areas is land tenure insecurity. This is mainly due to a number of factors including the absence of clear unambiguous boundaries between allodial owners and the absence of credible documentation of land rights. This research sought to establish and document over 190 km of the boundary of Juaben paramouncy in a manner that ensured peace, harmony and tenure security. Disputes were resolved through less costly Alternative Dispute Resolution (ADR) mechanisms and Customary Land Secretariat (CLS) that catalogued and maintained up to date register on the land. This resulted in conflicts that have raged on for decades, sometimes leading to injury, property destruction and loss of lives come to an end. The benefits of this improved land tenure security are enhanced agricultural productivity, wealth creation for rural dwellers, peace and stability. Boundary demarcations and documentations established were important steps in the process of reformation and improving land tenure security in the rural communities. Information retrieval was simplified and transaction cost made cheaper. Keywords: Land Tenure Security, Customary Boundary Demarcation (CBD), Alternative Dispute Resolution (ADR)
Understanding the Mechanism of Arsenic Mobilisation and Behaviour in Tailings Dams
Authors: Koomson B. , Asiam E. K. , Skinner W. , Addai-Mensah J.
Published: April 2021

This study was carried out on leaching of tailings at 30 ᵒC and 40 ᵒC. The mineralogical and chemical composition of the tailings material were determined by Quantitative X-Ray Diffractometry (QXRD) and Scanning Electron Microscopy combined with Energy Dispersive Spectroscopy (SEM-EDAX). The study revealed that the tailings contain sulphides (arsenopyrite and pyrite) which can leach to produce arsenic (As) and other ions in solution. The acid released during leaching depends on the temperature of leaching. More acid was produced at higher temperature (40 ᵒC) than lower temperature (30 ᵒC). It was established that arsenic precipitation from solution was higher at higher temperature (40 ᵒC) than lower temperature (30 ᵒC). Mimicking the study in a typical tailings environment, it could be proposed that As mobilisation will be enhanced at lower temperature (30 ᵒC) than at higher temperature (40 ᵒC). Keywords: Tailings, Leaching, Arsenopyrite, Heavy metals and Temperature
Groundwater Vulnerability Assessment of the Tarkwa Mining Area Using SINTACS Approach and GIS
Authors: Ewusi A. , Ahenkorah I. , Kuma J. S. Y.
Published: April 2021

Groundwater vulnerability assessment to delineate areas that are susceptible to contamination from mining and anthropogenic activities has become an important element for resource management and landuse planning. In view of the extensive mining in the Tarkwa area, quality of groundwater has become an important issue. This study estimates aquifer vulnerability by applying the SINTACS model which uses seven environmental parameters to evaluate aquifer vulnerability and geographical information system (GIS) in the Tarkwa mining area. Sensitivity analysis has also been carried out to evaluate the relative importance of the model parameters for aquifer vulnerability. The SINTACS model results show that the intrusive rocks within the Tarkwaian and the Birimian rocks are dominated by very high vulnerability classes while the Banket Series is characterised by high vulnerability class. The Huni Sandstones have moderately high vulnerability. In addition, the Kawere Group and the Tarkwa Phyllites displayed medium vulnerability. Analysis from the variogram model shows that all parameters used in the SINTACS model have a strong spatial structure. From statistical analysis, depth to water parameter inflicted the highest impact on the vulnerability of the aquifer followed by effective infiltration, vadose zone media, soil media, aquifer media, topography and hydraulic conductivity in the order of decreasing impact. Sensitivity analysis indicated that the aquifer media, hydraulic characteristics and topography cause large variation in vulnerability index. Depth to water and effective infiltration were found to be more effective in assessing aquifer vulnerability. Keywords: Groundwater, Vulnerability, Tarkwa, SINTACS, GIS
Recycling Waste Polyurethane as a Carbon Resource in Ironmaking
Authors: Dankwah J. R. , Buah W. K.
Published: April 2021

Globally, major avenues available for dealing with waste Poly-Urethane (PU) are disposal at landfill sites and incineration. However, PU contains high levels of carbon and hydrogen that can be recovered for use as reductant in metal extraction processes. In this work the use of post-consumer PU as reductant for the production of metallic iron from iron oxide was investigated in a horizontal tube furnace through the composite pellet approach. Composite pellets were formed from mixtures of iron oxide and post-consumer PU. The iron oxide-PU composites were heated from room temperature to 1200 °C and then between 1200-1600 °C in a continuous stream of pure argon and the off gas was analysed continuously using an infrared (IR) gas analyser. Elemental analyses of samples of the reduced metal were performed chemically for its oxygen content using a LECO oxygen/nitrogen analyser. The extent of reduction was then determined at two temperatures 1200 °C and 1550 °C. Gas emission studies revealed the emission of large volumes of the reductant gas CO along with CO2. It is further demonstrated that post-consumer PU is effective at reducing iron oxide to produce metallic iron with complete reduction achieved in less than 4 min at 1550 °C. Keywords: Polyurethane, Composite Pellets, Infrared gas Analyser, LECO Carbon/Sulphur Analyser
Appraisal of ANN and ANFIS for Predicting Vertical Total Electron Content (VTEC) in the Ionosphere for GPS Observations
Authors: Yakubu I. , Ziggah Y. Y. , Asafo-Agyei D.
Published: April 2021

Positional accuracy in the usage of GPS receiver is one of the major challenges in GPS observations. The propagation of the GPS signals are interfered by free electrons which are the massive particles in the ionosphere region and results in delays in the transmission of signals to the Earth. Therefore, the total electron content is a key parameter in mitigating ionospheric effects on GPS receivers. Many researchers have therefore proposed various models and methods for predicting the total electron content along the signal path. This paper focuses on the use of two different models for predicting the Vertical Total Electron Content (VTEC). Artificial Neural Network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) algorithms have been developed for the prediction of VTEC in the ionosphere.  The developed ANN and ANFIS model gave Root Mean Square Error (RMSE) of 1.953 and 1.190 respectively.  From the results it can be stated that the ANFIS is more suitable tool for the prediction of VTEC. Keywords: Artificial Neural Network, Adaptive Neuro Fuzzy Inference System, Vertical Total Electron
Mining and Metal Pollution: Assessment of Water Quality in the Tarkwa Mining Area
Authors: Ewusi A. , Apeani B. Y. , Ahenkorah I. , Nartey R. S.
Published: April 2021

The quality of water in mining communities is uncertain since metals associated with acid mine drainage are known to saturate these waters. Previous studies in Tarkwa, an area noted for gold and manganese extraction, have reported large concentrations of aluminium, arsenic, cadmium, copper, lead, manganese and mercury in water samples. This research aimed at investigating the chemistry of groundwater with special focus on the contamination status of trace elements. It also compared levels of metal concentration with those that were determined in previous research works, to identify changes that might have occurred. Thirty-eight water samples from boreholes, hand-dug wells and streams, within the Tarkwa area were obtained and analysed. Results show that 90 % of water in the area is acidic and Eh was determined to be positive, depicting oxidizing conditions. Mean groundwater temperature was 28.9 ºC. Thirty-two samples had either temperature or pH values falling outside the range recommended by the World Health Organisation (WHO). Thirty samples had at least one metal concentration exceeding the WHO guideline values. Among the list of elements that exceeded the guideline, arsenic, manganese, nitrate, nitrite and iron were the most predominant. The dominant ions in the samples were sodium and bicarbonate. High concentrations of Fe and SO42- in some parts of the study area point to the influence of acid mine drainage (AMD). Comparisons of results of metal concentrations with findings from previous research in the area showed a reduction in concentration. Hydrochemical modelling with PhreeqC attributed this reduction to sorption processes. Comparison of levels of metal concentration in the different water supply facilities (borehole, hand-dug well and stream) showed no significant variations. Keywords: Water Quality, Drinking Water, Hydrochemical Modelling, Heavy Metals
Waste Dump Closure and Cost Estimates at AngloGold Ashanti Iduapriem
Authors: Arhinful K. O. A. , Agyei G.
Published: April 2021

AngloGold Ashanti Iduapriem Mine is a surface gold mine which produces waste rock in its operations. The waste rock forms waste dumps which grow over the years, and will ultimately need to be closed down when they are filled to the maximum capacity. The mine has closure plans for the waste dumps and the closure activity will incur cost. This research was carried out to study the waste dump reclamation and closure plan for the Ajopa waste dump, and estimate the associated cost. The aim of the closure is to establish a permanent stable landscape that is environmentally compatible with surrounding undisturbed land. The waste dump will be closed with a progressive rehabilitation technique. The key activities involved in the reclamation plan, which are earthworks, capping and revegetation were identified and studied into detail. The reclamation plan and cost estimates were prepared on the basis that AngloGold Ashanti Iduapriem Mine would contract with a third-party contractor to fully execute the required closure and reclamation activities. The cost was then estimated using price quotes from vendors or contractors located around the mining area. Results showed that waste dump closure and reclamation programme for Iduapriem Mine are consistent with Ghana Mining and Environmental guidelines. The total closure and reclamation cost was estimated to be US$ 581 488.18. Since any delay in the closure and reclamation could incur additional cost, it was advised that the mine should execute the closure and reclamation plan without delay. Keywords: Waste Dump, Reclamation, Revegetation, Estimates
Evaluation of Groundwater Suitability for Irrigation in the Lambussie-Karni District of Ghana
Authors: Asante-Annor Asare , Bewil P. N. , Boateng D.
Published: April 2021

The populace of the Lambussie-Karni District are mainly farmers who have resorted to the use of groundwater for irrigation during the dry season because of long drought and inadequate surface water bodies. The temporal variation of the groundwater quality for irrigation in the District was assessed using sixteen boreholes. Richard Plot indicates that groundwater in the study area is within the low salinity to low sodium hazard and medium salinity to low sodium hazard class. Wilcox Plot shows groundwater to be within excellent to good class in the catchment. Irrigation water quality index (IWQI) map was also developed to determine precisely the degree and areal extent of groundwater suitability for irrigation. ArcGIS 10.1 was used to generate thematic maps for sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), sodium percentage (Na %), HCO3-, pH and electrical conductivity. The results were compared to Food and Agricultural Organisations (FAO) standard guidelines. An IQWI map for the Lambussie- Karni District shows that groundwater is generally suitable for irrigation, about 24.57 % of the district will require crops which can tolerate high amount of salts. A percentage (39.82 %) of the catchment has groundwater, which is highly suitable for crops which are least resistant to salt. Keywords: Groundwater Suitability; Irrigation Water Quality; SAR; IWQI Map; Lambussie-Karni District
The Effect of Clay Pozzolana-Cement-Composite on the Strength Development of a Hydraulic Backfill
Authors: Eshun S. N. , Gidigasu Solomon Senyo Robert , Gawu S. K. Y.
Published: April 2021

The study sought to investigate the potential application of clay pozzolana as a supplement for cement in hydraulic backfill, using classified tailings from AngloGold Ashanti, Obuasi Mine. The percentage of the Portland cement that could be substituted with the clay pozzolana to produce backfill with best strength was determined. 10%, 25%, 30%, 35% and 40% of the ordinary Portland cement were replaced with clay pozzolana and then mixed with tailings and water. The slurry produced was cast into cylindrical specimen of 50mm diameter by 120mm high and tested for compressive strength after curing for 7, 14, 21, 28 and 56 days. The results indicate that, clay pozzolana-cement composite has potential for application in hydraulic back fill production without increased risk to safety and dilution. It was noted that hydraulic backfill with 10%, 25%, 30% and 35% of the ordinary portland cement replaced with clay pozzolana had strengths greater than those obtained for ordinary portland cement alone. Ten percent (10%) pozzolana content gave the maximum strength followed by 25% pozzolana. It is recommended that for safety and economic considerations, the cement content should be replaced by 25% pozzolana in the production of backfills. Keywords: Hydraulic Backfill, Portland Cement, Clay Pozzolana, Unconfined Compressive Strength
Assessment of Rescue Facilities and Personnel in the Ghanaian Underground Mines
Authors: Yenzanya Sylvester , Amegbey Newton
Published: April 2021

Stochastic simulation was conducted to analyse the fuel consumption of a shovel-truck system. An example shovel-truck system, comprising a single shovel and four trucks was considered. At 95% confidence interval, the monthly simulated fuel consumption by the shovel-truck system was found to be about 198 127 litres against the actual fuel consumption of 203 772 litres, registering a variance of -2.70%. About 22 000 litres of fuel was consumed per month due to truck waiting. Optimising the fuel consumption and truck waiting time can result in significant fuel savings. The paper demonstrates that stochastic simulation is an effective tool for optimising the utilisation of fossil-based fuels in mining and related industries.  Keywords: Stochastic, Simulation Modelling, Mining, Optimisation, Shovel-Truck Material Handling
GLOBAL FINANCIAL CRISIS: AN ISLAMIC MANAGEMENT APPROACH
Authors: Santoso Ivan Rahmat , Olilingo Fahruddin Zain
Published: April 2021

The purpose of this study is to determine the solutions to financial crises based on the perspective of Islamic management. It also discusses the roles of faith and Islamic monotheism in managing the global financial crisis. The qualitative method was used to obtain data from books and articles related to Islamic management based on Qur’an and Hadith. These data were further analyzed and used as a solution to problems related to the global financial crisis by Islamic values. The result showed that the values of faith and monotheism following organizational policy and management tend to minimize financial speculative actions and greed. In addition, these values assist managers in planning, organizing, directing, and supervising their subordinates under Islamic rules and regulations. The application of this value is mainly reflected in the aspects of behavior, organizational aspects, and system aspects through the mechanism of placing the sharia supervisory board and profit-sharing in Islamic financial institutions, simplicity, and avoiding is in organizational management as well as the principle of prudence and avoiding speculative action. This research supports the role of the Islamic management system in winning finances and implementing organizational policies to overcome global financial problems.

JELClassification Codes: G01, H12, D46.
Menanamkan Nilai Kesabaran di dalam Keluarga pada Masa Pandemi Covid-19
Authors: Marbun Ernida
Published: April 2021

This article describes strategies to instill the value of patience in families during the Covid-19 Pandemic. This is very necessary because during the Covid-19 pandemic there was a problem of impatience between family members. The strategy of cultivating the value of patience is of course carried out with a Christian religious education approach in the family, meaning that the values of patience are taught by parents to their children. This article describes a problem-solving strategy based on John 15: 1-10, imitating Jesus' teaching to the disciples to be patient with the problems they will face in the future. The goal is that family members during the Covid-19 pandemic will continue to live patiently in Christ. The method used in this research is a qualitative method with a descriptive approach.
"Robustifying passive closed-loop Port-Hamiltonian systems using Observer Based Control"
Authors: Nacusse Matías , Donaire Alejandro , Junco Sergio
Published: April 2021

"This paper contributes a passivity-based approach to obtain a control law that robustifies Port-Hamiltonian (pH) control systems under external and state-dependent disturbances using disturbance observers (DO). A twostage design procedure is used to define the Disturbance Observed Based Control (DOBC) scheme. In the first stage a passivity based control law, called Interconnection and Damping assignment (IDA-PBC) is designed in the Bond Graph (BG) domain via BG prototyping, using an undisturbed model of the physical system. This stage is not the main issue of this paper and therefore the IDA-PBC law will be assumed to be known. The second stage, the main result of this paper, consists in the design of the DO and its integration with the IDA-PBC control law. The DO is derived in the BG domain via the integration of the residual signal computed from a Diagnostic Bond Graph (DBG). The methodology is developed through examples in the BG domain and formalized and extended in the pH framework."
"Study of supply chain vulnerabilities based on cognitive engineering and ARIMA formal models"
Authors: Sakli Leila , Mercantini Jean Marc , Hennet Jean Claude
Published: April 2021

"This research concerns the formulation of models and methods for supply chains risk analysis. An ontological approach using the KOD method (Knowledge Oriented Design) has been implemented to clearly identify relationships between the concepts of supply chain, risk, vulnerability and disturbances (critical scenarios). As a result, conceptual models of supply chains facing risk situations and critical scenarios are proposed. From the resulting conceptual models and mathematical models proposed in the literature, a multi-stage supply chain model using ARIMA models incorporating the randomness of the demand has been elaborated. In order to adapt this model to scenario criticality, constraints on orders and inventories have been taken into account. Under critical disturbances on information flows (demand) and physical flows (quality of the product supplied), constraints can be reached and supply chain behaviours can evolve toward critical dynamics or even become unstable. Supply chain vulnerabilities has been assessed and discussed."
Trends and Situation of Forest Fire in Indonesia 2015-2018, Based on Three Factors: Peatland,Timber Concession, and Forest Area
Authors: Soraya Mila
Published: April 2021

This research addresses the reoccurrence of forest fires and their size with regional-spatial information. This study is attained to the Sustainable Development Goal in the year 2030 (climate action and life on land) and is consistent with the mission of JISDeP. Probit and tobit regression analyses were applied to the regional-spatial panel data from 2015 to 2018 in Indonesia with the observations of forest-fire events, peatland, forest area, and timber concession on an annual basis. Such analyses would characterize the possible determinants for the forest fire reoccurrence together with their sizes. Comparatively, this study tries to fill the gap by examining the reoccurrence of forest fires. This research tries to fill in the gap on studies about land and forest fires by combining quantitative analysis using probit and tobit regression and using spatial approach of peatland, forest and timber concession area. The regression results reveal the following outcomes. The first outcome is whether forest fire reoccurrence positively (negatively) associated with peatland and forest areas (timber concession). Second, forest fires tend to decrease with the repetition of past forest fires but increase with timber concession, peatland, and forest areas. Overall, these results imply that the reoccurrence of forest fires and their sizes is highly concerned with timber concession and types of areas, suggesting that Indonesia should organize the policies regarding forest timber concession and areas to reduce forest fires and the associated damage.
Dos amores constituyeron dos grandes pastores
Authors: Morillo Rey Pablo Antonio
Published: April 2021

En el presente artículo, analizamos la influencia que el “gran Doctor del Occidente” ha ejercido sobre el pensamiento doctrinal de Juan Pablo II, un Pontífice que, a través de su magisterio, lleno de santidad y de sabiduría de Dios, ha demostrado al mundo entero cómo las palabras sabias y elocuentes de este “gran hombre y santo” resuenan aún con fuerza dentro del seno de la Iglesia. Es por ello que, basándonos en algunas Encíclicas o Cartas Apostólicas, corroboramos el “buen olor agustiniano” tanto en la vida como en la obra de este papa santo cuyo único propósito, al igual que san Agustín, fue el de servir a Dios y a la Iglesia, defendiendo en todo momento la fe católica. Así, como reza el título de este artículo, “dos amores constituyeron dos grandes pastores”: el amor a Dios y el amor al prójimo, las dos “alas de la caridad” (en Ps. 149,5), pues “Ama y haz lo que quieras” (ep. Jo. 7,8).
Apuntes de ética de la liberación desde Ignacio Ellacuría
Authors: Castellón Martín José Joaquín
Published: April 2021

Este artículo busca poner en diálogo la reflexión ética de Ignacio Ellacuría con la reflexión de filosofía ética y política actual, así como poner de manifiesto las virtualidades que su pensamiento crítico-realista posee. Comienza por un análisis personal del autor sobre el concepto de libertad que servirá de horizonte para situar las diversas reflexiones éticas y políticas, también la ética de la liberación ellacuriana.
Proceso de purificación al Vicario de Estepa por su actitud durante la ocupación napoleónica de la villa
Authors: Jordán Fernández José Alberto
Published: April 2021

Con el presente trabajo nos acercamos a la figura de don Pedro José Baena y Núñez, quien fuera vicario general de Estepa, esto es, titular de una prelacía menor que gobernaba eclesiásticamente una jurisdicción exenta o nullius dioecesis que comprendía el territorio de lo que fue el marquesado de Estepa; especialmente se analiza su comportamiento durante la ocupación francesa de este territorio entre los años 1810 y 1812, del cual hemos tenido conocimiento a través de un proceso judicial que se le incoó, llamado de purificación, al poco tiempo de la marcha de los franceses y que se conserva en el archivo de la vicaría de Estepa, custodiado hoy en el del arzobispado hispalense.
THE ROLE OF "KINDNESS" CATEGORY IN THE DEVELOPMENT OF THE CULTURE OF WRITTEN SPEECH
Authors: Yakubov Jamoliddin
Published: April 2021

Мазкур мақоланинг мақсади франция ишбилармон вакилларининг ўзаро миллий-маданий расмий ёзма мулоқатларидаги бизнес ҳамкорлигидаги муносабатлари намоён этиш. Ушбу  мулоқотлардаги хушмуомалалик категорияси француз тилда грамматик ва лексик воситалар билан келиши чуқур таҳлил қилинган.