Regenerative Post COVID-19 Recovery Measures: The Case of Rwanda

Governments worldwide are scrambling to combat both the biological and economic effects of the global COVID-19 pandemic. By using Rwanda as a case study, this paper analyzes two of the existent home-grown poverty alleviation initiatives for food security: Girinka (Have a cow) and Akarima k’igikoni (Kitchen Gardens). Using descriptive statistical data gathered during the pandemic in Rwanda’s capital, Kigali, we found rainwater collection practices already well established. We find that many households already separate waste, but that only some households in the peri-urban areas we investigated practice composting and home-gardening. We conclude with several recommendations on how the Rwandan government’s commitment to sustainable development and urban agglomeration in the Vision 2050 strategy can be achieved. Using already well-established policy mechanisms like the “Umudugudu” (=Village) network and the Akarima k’igikoni initiative, Rwanda can better weather the economic effects of the global pandemic. These mechanisms present a valuable opportunity for Rwandan businesses to invest in composting activities and regenerative practices in their buildings and waste management systems. Other developing countries can also learn valuable lessons from an environmentally sustainable and home-grown poverty alleviation policy

PHOTOLUMINESCENCE SPECTROSCOPIC STUDIES OF MN2O3/CO3O4-GLUCOSE/LACTOSE COMPLEXES

As nanoparticles serve as mediators in the electron transfer between biomolecules and a biosensor’s electrode surface, this study is dedicated to investigating Mn2O3 and Co3O4 nanoparticles and their photoluminescence effect that play a critical role in sensing glucose and lactose. The chemical coprecipitation method was adopted for preparing the nanoparticles that were characterized by X-Ray Diffraction, Transmission Electron Microscope, Fourier Transform Infrared spectroscopy, Energy Dispersive X-ray, UV-vis spectroscopy, and Vibrating Sample Magnetometry. It was found that the obtained Mn2O3 and Co3O4 nanoparticles were successfully prepared, with a crystallite size of 65.91 and 58.00 nm, respectively. The high specific surface area of 1.2808´104 and 0.5711´104 m2/kg was noticed for the Mn2O3 and Co3O4 nanoparticles that exhibited highly agglomerated cubic and spherical nanoparticles, respectively. The energy gap, Urbach energy, and steepness parameter were obtained (1.72 eV, 1.049 eV and 24.644´10-3 for Mn2O3 and 1.285/2.165 eV, 2.893 eV and 8.936´10-3 for Co3O4) and discussed. Antiferromagnetism and weak ferromagnetism were detected for Mn2O3 and Co3O4 nanoparticles, respectively, with higher saturation magnetization for Mn2O3 (2.435 emu/g). Moreover, the non-enzymatic glucose and lactose biosensor’s compatibility was evaluated utilizing photoluminescence changes. The glucose/lactose interactions with Mn2O3 /Co3O4 nanoparticles were measured by photoluminescence spectroscopy, at room temperature, in a phosphate buffer medium. The addition of Mn2O3 nanoparticles to glucose and lactose demonstrated higher shifts in the photoluminescence intensities with larger binding constants (1625 and 1840 M-1) and more negative Gibbs energy (-17.608 and -18.753 kJ.mol-1). These characteristics promote the investigation of Mn2O3 nanoparticles in glucose and lactose biosensors

Position-based routing algorithms for three-dimensional ad hoc networks

In position-based routing algorithms, the nodes use the geographical information to make routing decisions. Recent research in this field addresses such routing algorithms in two-dimensional (2 D ) space. However, in real applications, the nodes may be distributed in three-dimensional (3 D ) space. Transition from 2 D to 3 D is not always easy, since many problems in 3 D are significantly harder than their 2 D counterparts. This dissertation focuses on providing a reliable and efficient position-based routing algorithms with the associated pre-processing algorithms for various 3 D ad hoc networks. In the first part of this thesis, we propose a generalization of the Yao graph where the cones used are adaptively centered on the nearest set of neighbors for each node, thus creating a directed or undirected spanning subgraph of a given unit disk graph (UDG). We show that these locally constructed spanning subgraphs are strongly connected, have bounded out-degree, are t -spanners with bounded stretch factor, contain the Euclidean minimum spanning tree as a subgraph, and are orientation-invariant. Then we propose the first local, constant time algorithm that constructs an independent dominating set and connected dominating set of a Unit Disk Graph in a 3 D environment. We present a truncated octahedral tiling system of the space to assign to each node a class number depending on the position of the node within the tiling system. Then, based on the tiling system, we present our local algorithms for constructing the dominating sets. The new algorithms have a constant time complexity and have approximation bounds that are completely independent of the size of the network. In the second part of this thesis, we implement 3 D versions of many current 2 D position-based routing algorithms in addition to creating many new algorithms that are specially designed for a 3 D environment. We show experimentally that these new routing algorithms can achieve nearly guaranteed delivery while discovering routes significantly closer in length to a shortest path. Because many existing position-based routing algorithms for ad hoc and sensor networks use the maximum transmission power of the nodes to discover neighbors, which is a very power-consuming process. We propose several localized power-aware 3 D position-based routing algorithms that increase the lifetime of a network by maximizing the average lifetime of its nodes. These new algorithms use the idea of replacing the constant transmission power of a node with an adjusted transmission power during two stages. The simulation results show a significant improvement in the overall network lifetime over the current power-aware routing algorithm

Fabrication of Antimicrobial Hydrogel Using Biodegradable Blended Materials for Skin Applications

Biodegradable polymers are very useful polymers in biomedical applications. In this research, several hydrogels were fabricated by using two polymers, Polyvinyl alcohol (PVA) and Chitosan (Chs) by the solvent casting method in order to use them for skin applications. Several tests were carried out on these membranes such as Agar diffusion method to examine their antimicrobial activities, Fourier transform infrared microscopy (FTIR) test to study the differences in their chemical structures. Uniaxial tensile test was performed to examine the mechanical characteristics of these membranes. In addition, the wettability test was used to investigate the hydrophobicity or hydrophilicity of the surfaces. The results showed that all membranes are hydrophilic, of which the contact angles are less than 90°. The membrane manufactured from 75:25 Chs-PVA is more hydrophobic (contact angle is 74°) than other membranes made of 50:50 Chs-PVA and 25:75 Chs-PVA as the contact angles were 59° and 61°, respectively. The tensile test results indicate that the membrane fabricated of the PVA and the membrane that was fabricated by 75% Chs and 25% PVA has the highest tensile strength of 17.9 MPa, 16.2 MPa and Young^’ s Modulus of 181.2 MPa and 7.18 MPa, respectively. The highest strain at break was observed by the membrane of 25:75 Chs-PVA which equals to 24.67%. Chitosan membranes showed inhibition zones of about 2.99 cm and 2.75 cm in length, and 75:25 Chs-PVA membranes showed 5.1 and 5.91 cm in length for E.coli. To sum up, this copolymer is considered as promising hydrogel for skin applications such as wound dressing

Arthroscopic Onlay Suprapectoral Bicipital Tenodesis Using Suture Anchor; A Prospective Cohort Study

Background: The long head of the biceps (LHB) tendon was assumed to be a common source of anterior shoulder pain. The inflammatory pathogenesis was considered to be the commonest. Different modalities of treatment were assigned, including conservative, physical therapy, and surgical. Biceps tenotomy and tenodesis were considered the commonest surgical techniques. Methods: We performed a prospective cohort study on 23 patients who presented with anterior shoulder pain due to pathology in the LHB from June 2019 to December 2021. participants were recruited for arthroscopic suprapectoral tenodesis and followed up at two endpoints; six and 12 months. To detect the clinical and functional outcomes, we used the Constant-Murley score, which included four domains pain, strength, range of motion, and Activities of daily living. Also, we calculated the incidence of the Popeye sign, which represented the rupture of LHB. Results: Patients could have a significant improvement in the Constant-Murley score postoperatively at both six and 12 months compared with the preoperative values, with a postoperative mean of 82.3 (78 - 88) at six months and 85.13 (80 - 91) at 12 months. Also, they achieved significant improvement in each of its components; pain, ADL, stability, and motility at six months compared with the baseline values. Additionally, only three patients developed the Popeye sign. Conclusion: The suprapectoral tenodesis was an effective procedure in the treatment of the pain of the LHB tendon with few side effects. It could significantly improve the Constant-Murley score at both six months and one year

Unusual manifestation of cystic mycetoma lesions:: A case report

Mycetoma is a chronic and debilitating infectious disease characterized by localized swellings and granulomatous lesions. It primarily affects individuals in tropical and subtropical regions and is caused by certain fungi or bacteria. While mycetoma typically presents with sinuses and discharge, this case report presents a unique cystic presentation without these features. The patient, a 12-year-old female from Sudan, presented with a painless swelling on the dorsum of her right foot. Physical examination revealed a round, non-tender, and fluctuant mass. Histopathological examination confirmed actinomycetoma caused by Streptomyces somaliensis. The patient was successfully treated with a combination of antibiotherapy. This atypical presentation underscores the need for healthcare professionals to consider uncommon variations of mycetoma for accurate diagnosis and management

Reproductive biology of greasy grouper, Epinephelus tauvina and coral hind grouper Cephalopholis miniata (Family: Serranidae) in the southern Red Sea, Shalatien, Egypt

Groupers are the main component of commercial fisheries in the Red Sea. The reproductive biology of Epinephelus tauvina and Cephalopholis miniata collected at the Shalatien landing site in the southern Egyptian Red Sea were investigated from January to December 2017. A total of 212 specimens of E. tauvina with a total length range of 23.6 to 70.3 cm and 243 specimens of C. miniata with a total length range of 17.4 to 42.1 cm were examined. Females of E. tauvina and C. miniata accounted for 61.7 and 61.9% of the total fish sampled, showing a 1:1.61 and 1:1.63 male-to-female sex ratio, respectively. The monthly distribution of maturity stages and gonadosomatic index values showed that the spawning season for both sexes was extended from April to October for E. tauvina and from April to September for C. miniata. The lengths at first sexual maturity of the males and females of E. tauvina were estimated at 49 and 48.1 cm, respectively, while those for C. miniata were estimated at 23.2 and 22.7 cm, respectively. All our results can help in the proper management of these valuable resources

A new RSA public key encryption scheme with chaotic maps

Public key cryptography has received great attention in the field of information exchange through insecure channels. In this paper, we combine the Dependent-RSA (DRSA) and chaotic maps (CM) to get a new secure cryptosystem, which depends on both integer factorization and chaotic maps discrete logarithm (CMDL). Using this new system, the scammer has to go through two levels of reverse engineering, concurrently, so as to perform the recovery of original text from the cipher-text has been received. Thus, this new system is supposed to be more sophisticated and more secure than other systems. We prove that our new cryptosystem does not increase the overhead in performing the encryption process or the decryption process considering that it requires minimum operations in both. We show that this new cryptosystem is more efficient in terms of performance compared with other encryption systems, which makes it more suitable for nodes with limited computational ability

Concurrent Use of Oral Anticoagulants and Sulfonylureas in Individuals With Type 2 Diabetes and Risk of Hypoglycemia: A UK Population-Based Cohort Study

OBJECTIVE: To investigate the association of concurrent use of oral anticoagulants (OACs) and sulfonylureas and the risk of hypoglycemia in individuals with type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS: A retrospective cohort study was conducted between 2001 and 2017 using electronic primary healthcare data from the IQVIA Medical Research Data (IMRD) that incorporates data supplied by The Health Improvement Network (THIN), a propriety database of Cegedim SA. Individuals with T2DM who received OAC prescription and sulfonylureas were included. We compared the risk of hypoglycemia with sulfonylureas and OACs using propensity score matching and Cox regression. RESULTS: 109,040 individuals using warfarin and sulfonylureas and 77,296 using direct oral anticoagulants (DOACs) and sulfonylureas were identified and included. There were 285 hypoglycemia events in the warfarin with sulfonylureas group (incidence rate = 17.8 per 1,000 person-years), while in the sulfonylureas only, 304 hypoglycemia events were observed (incidence rate = 14.4 per 1,000 person-years). There were 14 hypoglycemic events in the DOACs with sulfonylureas group (incidence rates = 14.8 per 1,000 person-years), while in the sulfonylureas alone group, 60 hypoglycemia events were observed (incidence rate =23.7 per 1,000 person-years). Concurrent use of warfarin and sulfonylureas was associated with increased risk of hypoglycemia compared with sulfonylureas alone (HR 1.38; 95% CI 1.10–1.75). However, we found no evidence of an association between concurrent use of DOACs and sulfonylureas and risk of hypoglycemia (HR 0.54; 95% CI, 0.27–1.10) when compared with sulfonylureas only. CONCLUSIONS: We provide real-world evidence of possible drug-drug interactions between warfarin and sulfonylureas. The decision to prescribe warfarin with coexistent sulfonylureas to individuals with T2DM should be carefully evaluated in the context of other risk factors of hypoglycemia, and availability of alternative medications

In Vitro Anticancer Properties of Novel Bis-Triazoles

Here, we describe the anticancer activity of our novel bis-triazoles MS47 and MS49, developed previously as G-quadruplex stabilizers, focusing specifically upon the human melanoma MDA-MB-435 cell line. At the National Cancer Institute (NCI), USA, bis-triazole MS47 (NCS 778438) was evaluated against a panel of sixty human cancer cell lines, and showed selective, distinct multi-log differential patterns of activity, with GI50 and LC50 values in the sub-micromolar range against human cancer cells. MS47 showed highly selective cytotoxicity towards human melanoma, ovarian, CNS and colon cancer cell lines; in contrast, the leukemia cell lines interestingly showed resistance to MS47 cytotoxic activity. Further studies revealed the potent cell growth inhibiting properties of MS47 and MS49 against the human melanoma MDA-MB-435 cell line, as verified by MTT assays; both ligands were more potent against cancer cells than MRC-5 fetal lung fibroblasts (SI > 9). Melanoma colony formation was significantly suppressed by MS47 and MS49, and time- and dose-dependent apoptosis induction was also observed. Furthermore, MS47 significantly arrested melanoma cells at the G0/G1 cell cycle phase. While the expression levels of Hsp90 protein in melanoma cells were significantly decreased by MS49, corroborating its binding to the G4-DNA promoter of the Hsp90 gene. Both ligands failed to induce senescence in the human melanoma cells after 72 h of treatment, corroborating their weak stabilization of the telomeric G4-DNA