218 research outputs found
A Simulation Based Performance Evaluation of Optical Ethernet Switch
With the advent of several new Cloud Radio Access Network (C-RAN)
technologies, todays networking environment is dramatically altered and is
experiencing a rapid transformation. One of the most important is Ethernet
based C-RAN, in support of which many products such as optical Ethernet
switches have recently appeared on the market. This paper presents the
performance analysis of such switches with respect to Packet Loss Ratio (PLR),
Latency and Packet Delay Variation (PDV). We employed the Simula based on
Discrete Event Modelling on Simula (DEMOS), a context class for discrete event
simulation to simulate a cut-through optical Ethernet switch under two types of
traffics: High priority (HP) traffic and Low priority (LP) traffic. In this
way, the paper evaluates the optical Ethernet switch performance
quantitatively. The results obtained from the simulator showed that the high
quality of service was reflected on HP traffic and the low quality of service
in LP traffic. Hence, HP traffic can be used for transporting Radio over
Ethernet (RoE) traffic while LP traffic can used for transporting time
insensitive application. It is also found that HP traffic experiences a PDV
equals to the duration of maximum sized LP traffic in Optical Ethernet switch.Comment: arXiv admin note: text overlap with arXiv:1911.0761
Management of Root-knot Nematode (Meloidogyne incognita) onPittosporum tobira Under Greenhouse, Field, and On-farm Conditions in Florida
Root-knot nematodes are important pests of cut foliage crops in Florida. Currently, effective nematicides for control of these nematodes on cut foliage crops are lacking. Hence, research was conducted at the University of Florida to identify pesticides or biopesticides that could be used to manage these nematodes. The research comprised on-farm, field, and greenhouse trials. Nematicide treatments evaluated include commercial formulations of spirotetramat, furfural, and Purpureocillium lilacinum (=Paecilomyces lilacinus) strain 251. Treatment applications were made during the spring and fall seasons according to manufacturer's specifications. Efficacy was evaluated based on J2/100 cm3 of soil, J2/g of root, and crop yield (kg/plot). Unlike spirotetramat, which did not demonstrate any measurable effects on Meloidogyne incognita J2 in the soil, furfural and P. lilacinum were marginally effective in reducing the population density of M. incognita on Pittosporum tobira. However, nematode reduction did not affect yield significantly. Although furfural and P. lilacinum have some potential for management of M. incognita on cut foliage crops, their use as a lone management option would likely not provide the needed level of control. Early treatment application following infestation provided greater J2 suppression compared to late application,suggesting the need for growers to avoid infested fields
Vertical Distribution of Pasteuria penetrans Parasitizing Meloidogyne incognita on Pittosporum tobira in Florida
Pasteuria penetrans is considered as the primary agent responsible for soil suppressiveness to root-knot nematodes widely distributed in many agricultural fields. A preliminary survey on a Pittosporum tobira field where the grower had experienced a continuous decline in productivity caused by Meloidogyne incognita showed that the nematode was infected with Pasteuria penetrans. For effective control of the nematode, the bacterium and the host must coexist in the same root zone. The vertical distribution of Pasteuria penetrans and its relationship with the nematode host in the soil was investigated to identify (i) the vertical distribution of P. penetrans endospores in an irrigated P. tobira field and (ii) the relationship among P. penetrans endospore density, M. incognita J2 population density, and host plant root distribution over time. Soil bioassays revealed that endospore density was greater in the upper 18 cm of the top soil compared with the underlying depths. A correlation analysis showed that the endospore density was positively related to the J2 population density and host plant root distribution. Thus, the vertical distribution of P. penetrans was largely dependent on its nematode host which in turn was determined by the distribution of the host plant roots. The Pasteuria was predominant mostly in the upper layers of the soil where their nematode host and the plant host roots are abundant, a factor which may be a critical consideration when using P. penetrans as a nematode biological control agent
Potentially Inappropriate Use of Medication and Its Determinants Among Ambulatory Older Adults in Six Community Chain Pharmacies in Asmara, Eritrea: A Cross-Sectional Study Using the 2023 American Geriatric Society Beers Criteria®
Saleh Idrisnur,1 Nuru Abdu,2 Filipos Yohannes,3 Tomas Tewelde,4 Natnael Russom,5 Eyasu H Tesfamariam6 1Product Evaluation and Registration Unit, National Medicine and Food Administration, Ministry of Health, Asmara, Eritrea; 2Department of Pharmacy, Adi-Tekelezan Community Hospital, Ministry of Health, Adi-Tekelezan, Eritrea; 3Department of Pharmacy, Ghindae Zonal Referral Hospital, Ministry of Health, Ghindae, Eritrea; 4Gash-Barka Zonal Pharmaceutical Services, Ministry of Health, Barentu, Eritrea; 5Eritrean Pharmacovigilance Center, National Medicine and Food Administration, Ministry of Health, Asmara, Eritrea; 6Biostatistics and Epidemiology, Department of Statistics, College of Sciences, Mai-Nefhi, EritreaCorrespondence: Saleh Idrisnur, Product Evaluation and Regulation Unit, National Medicine and Food Administration, Ministry of Health, Asmara, Eritrea, Tel +291-7455570, Email [email protected]: Potentially inappropriate medication (PIM) use is one of the main drug-related problems encountered in older adults. It is associated with adverse drug events, morbidity, mortality, increased economic costs, and negative effects on the quality of life that requires strict monitoring of prescriptions in older adults. Thus, the study aimed to assess potentially inappropriate medication use and its determinants among older adults.Methods: A cross-sectional study was conducted among all outpatient prescriptions dispensed to older adults (aged 65 years and above) in six community chain pharmacies in Asmara, Eritrea. Data were collected retrospectively, between June 16 and July 16, 2023. PIMs were detected using the 2023 American Geriatric Society (AGS) Beers Criteria®. Descriptive statistics and logistic regression analysis were performed using IBM SPSS® (Version-26.0).Results: A total of 2680 outpatient prescriptions dispensed to older adults were included in this study. The prevalence of PIM among prescriptions was 18.1% (95% CI: 16.7, 19.6). Moreover, a total of 470 medications were found to be avoided in older adults. The most commonly prescribed PIMs were sulfonylureas (27.2%) and substituted alkylamines (16.2%). The prevalence of prescriptions containing medications to be used with caution in older adults was 13.2% (95% CI: 12.0, 14.5). Age (Adjusted Odds Ratio (AOR))=0.98, 95% CI: 0.97, 0.99), polypharmacy (AOR=2.77, 95% CI: 1.49, 5.15), and general practitioner prescriber (AOR=1.38, 95% CI: 1.11, 1.70) were significantly associated with PIMs.Conclusion: A considerable number of ambulatory older adults were exposed to PIMs which require a close attention by policymakers, program managers, and healthcare professionals.Keywords: potentially inappropriate medications, determinants, older adults, AGS Beers Criteria®, community chain pharmacy, Eritre
Nitrogen Management in Grasslands and Forage-Based Production Systems–Role of Biological Nitrification Inhibition (BNI)
Nitrogen (N), being the most critical and essential nutrient for plant growth, largely determines the productivity in both extensive- and intensive- grassland systems. Nitrification and denitrification processes in the soil are the primary drivers generating reactive-N: NO3-, N2O, and NO, and is largely responsible for N-loss and degradation of grasslands. Suppressing nitrification can thus facilitate the retention of soil-N to sustain long-term productivity of grasslands and forage-based production systems. Certain plants can suppress soil nitrification by releasing inhibitors from roots, a phenomenon termed ‘biological nitrification inhibition’ (BNI). Recent methodological developments (e.g. bioluminescence assay to detect BNIs from plant-root systems) led to significant advances in our ability to quantify and characterize BNI function in pasture grasses. Among grass-pastures, BNI-capacity is strongest in low-N adapted grasses such as Brachiaria humidicola and weakest in high-N environment grasses such as Italian ryegrass (Lolium perenne) and B. brizantha. The chemical identity of some of the BNIs produced in plant tissues and released from roots has now been established and their mode of inhibitory action determined on nitrifying bacteria Nitrosomonas. Synthesis and release of BNIs is a highly regulated and localized process, triggered by the presence of NH4+ in the rhizosphere, which facilitates the release of BNIs close to soil-nitrifier sites. Substantial genotypic variation is found for BNI-capacity in B. humidicola, which opens the way for its geneticmanipulation. Field studies suggest that Brachiaria grasses suppress nitrification and N2O emissions from soil. The potential for exploiting BNI function (from a genetic improvement and a system perspective) to develop production systems that are low-nitrifying, low N2O-emitting, economically efficient and ecologically sustainable, will be the subject of discussion
Biological nitrification inhibition in sorghum: the role of sorgoleone production
Nitrification and denitrification are the two most important processes that contribute to greenhouse gas emission and inefficient use of nitrogen. Suppressing soil nitrification through the release of nitrification inhibitors from roots is a plant function, and termed “Biological Nitrification Inhibition (BNI)”. We report here the role and contribution of sorgoleone release to sorghum-BNI function
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