The Internet shutdown muzzle(s) freedom of expression in Ethiopia: competing narratives

Freedom of expression is a foundational stone for democracy and embraces a number of other rights, including – freedom to seek, receive, and impart information using any medium. Around 16 million Ethiopians, comprising 15.4% of the total population, use the Internet. The Ethiopian Internet shutdown saga has been marked by competing narratives. On one hand, the government has been using two governing narratives, i.e. national security narrative and ‘economic growth’ narrative to justify shutdowns of the Internet. But, the individuals’ self-expressions on social media find itself as competing narrative. Since 2016, the Internet has been closed more than six times under the cloak of national security, quelling rising protests, controlling strikes, and exam cheating. As such, freedom of expression of millions has been muzzled. The article argues blanket Internet shutdowns do not meet the caveats of human rights law.     

Alcohol Determination in Distilled Alcoholic Beverages by Liquid Phase Fourier Transform Mid-Infrared and Near-Infrared Spectrophotometries

Fourier transform mid-infrared spectrophotometry (FT-MIR), 1180–950 cm^?1, and near-infrared spectrophotometry (NIR), 1720–1660 nm, have been used complementarily for the direct determination of ethanol and methanol in distilled alcoholic beverages. In mid-infrared ethanol and methanol identified separately, hence, it has been used to confirm the absence or presence of methanol. In the absence of methanol, both were used to determine the alcoholic strength independently; however, near-infrared was used without diluting the samples. Ethanol and methanol contents were evaluated using the calibration curves established by a plot of peak height or peak area versus concentration % (w/w). The linearity range for ethanol was up to 15 and 50 % (w/w) for mid- and near-infrared, respectively. The developed methods are simple, fast, precise, and accurate. Moreover, the results obtained were in excellent agreement with the results obtained from gas chromatographic measurements. No sample preparation was required at all, and in all samples, methanol was not detected.     

The effect of increased interrogation zone,reader antenna polarization and application factors in the performance of UHF RFID tag detection on modified atmosphere packaged meat

The effect of conveyor speed, test sample size, antenna to sample distance, antenna polarization and ideal tag location in relation to the coupling capabilities of ultra‐high frequency radio frequency identification on optimal reader antenna placement were studied. The influence of each individual factor and its interaction was determined using the general linear model analysis of variance. In decreasing order of significance of the variables tested were sample type (F = 4174.40, p < 0.0005), smaller samples preferred for coupling; distance (F = 863.83, p < 0.0005), where distance between sample and antenna should be kept to a minimum; inlay design (F = 167.82, p < 0.0005), where AD‐612 preformed best due to its large antenna area; and reader antenna polarization (F = 149.64, p < 0.0005), where circular polarization preformed better yet comparative advantage decreased with distance. A reader antenna offset of 95 mm, while not significant, (F = 1.73, p = 0.188) tended to decrease coupling capabilities of the system despite increasing the zone of influence. Ideal tag location on sample was found to be on the right, back and front face with y‐orientation proving superior than either x or z. A 190‐mm centre–to‐centre reader antenna offset resulted in a decrease in the average tag detection rate from 62 to 49% highlighting the importance of optimal reader antenna placement which needs to be confirmed if a similar result is to be obtained when a large number of tags are interrogated simultaneously. Copyright © 2010 John Wiley & Sons, Ltd.     

The effects of item composition,tag inlay design,reader antenna polarization,power and transponder orientation on the dynamic coupling efficiency of backscatter ultra‐high frequency radio frequency identification

The effects of packaged content, packaging material, transponder inlay design, reader antenna polarization, interrogation power and transponder orientation on the detection rate of ultra‐high frequency radio frequency identification (UHF RFID) passive transponders were studied. The influence of individual factors and their interactions were determined using general linear model analysis of variance. Influences originated in order of importance, from sample type, antenna polarization, power and inlay design. Important interactions in decreasing order of significance exist between: power and antenna polarization; sample type and antenna polarization; sample type and inlay design; inlay design and antenna polarization; sample type, power and antenna polarization; sample type and power; inlay design and power; sample type, inlay design and power. It was also observed that random orientation of tags did not cause a statistically significant variation in tag detection rate. It can be concluded that the use of UHF RFID for item level of food requires multi‐parameter assessment before hand. Copyright © 2009 John Wiley & Sons, Ltd.     

Detection and classification of large bowel obstruction from X-ray images using machine learning algorithms

Large bowel obstruction (LBO) occurs when there is a blockage or twisting in the large bowel that prevents wastes and gas from passing through. If left untreated, the blockage cuts off blood supply to the colon, causing sections of it to die which results in high rates of morbidity and fatality. The examination of clinical symptoms of LBO involves careful inspection of the cecum and colon. Radiologists use X-rays to inspect the clinical signs. Some research has been done to automate the detection of related abdominal and intestinal diseases. However, all these studies concentrate only on detecting Crohn's, ulcerative colitis, Acute Appendicitis, colorectal cancer, celiac diseases, liver diseases, and chronic kidney diseases. Automatic detection and classification of LBO has not been given due attention so far to the best of the authors knowledge. To address this challenge, we have designed a model for the detection and classification of LBO. The models development comprises of stages such as preprocessing, detection, segmentation, feature extraction, and classification. We used YOLOv3 for detection and used a gray scale level co-occurrence matrix (GLCM), and a convolutional neural network for feature extraction, while support vector machine (SVM) and softmax were used for classification. The proposed model achieved a diagnostic accuracy of 89% when feature extraction methods such as CNN and median filter with softmax classifier were used. CNN and Gaussian filter with soft max classifier achieved 91%, while CNN and anisotropic filter with soft max classifier achieved 92%. GLCM with threshold segmentation and Gaussian filter with SVM classifier achieved 87%, while CNN with watershed segmentation and Gaussian filter with SVM classifier achieved 97% and CNN-GLCM with watershed segmentation and anisotropic diffusion filter with SVM classifier achieved 98% for detection and classification of LBO. Finally, this paper presented a performance analysis of various machine learning approaches for detection and classification of LBO. Hence, our model is designed to assist human experts (Radiologists) in diagnosing LBO.     

Population dynamics and exploitation patterns of Oreochromis niloticus in Lake Tana,northwest Ethiopia

Oreochromis niloticus is the dominant commercial fish in the Lake Tana region. However, its fishery is progressively declining over time. Little or no updated information exists on the population dynamics and exploitation patterns of the species, which is crucial to guide its sustainable management. Accordingly, the purpose of the present study was to generate essential biological parameters on the growth, mortality and stock status of O. niloticus, using length‐frequency data collected monthly from the commercial fish catches of 1 year (2014–2015). The total mortality coefficient (Z) was derived from the length‐converted catch curve. Biological reference points were predicted from relative yield‐ and biomass‐per‐recruit analyses. The estimated values of the von Bertalanffy growth parameters were L_∞ = 44.1 cm, K = 0.44/year, and t₀ = ?0.34/year, and the growth performance index (Φ′) was 2.93. The total mortality (Z), natural (M) and fishing mortality (F) rates were 2.37, 0.98 and 1.39 per year, respectively. The current fishery exploitation rate of 0.59 exceeds the estimated biological reference points of E_max (0.52), confirming the stock of O. niloticus in the lake is being overexploited above optimum levels. Size indicators of the catches further illustrate 31% of the landed fish are harvested before reaching sexual maturity, with mega‐spawners comprising only 15%. This indicates the stock is suffering from both growth and recruitment overfishing. The logistic selection model indicated 50% of the fish vulnerable to capture was at 18.14 cm TL. The fish exhibited a year‐round recruitment pattern, with a major peak during May and June. Sustainably managing the fishery, therefore, requires increasing the fish size at first capture (L_c) towards L_opt.     

Estimation and coordinated control for distributed parameter processes with a moving radiant actuator

This paper presents an estimation and control scheme for a class of industrial processes described by distributed parameter models with a moving radiant actuator. To overcome the lack of direct sensing alternatives for process state, a dual extended Kalman filter is established for estimating process status online based on a reduced process model and available output measurements. A distinct challenge that is addressed is the selection and construction of a suitable feedback signal from the distributed state estimate following the moving radiant actuator. The estimated status is then integrated into a rule-based feedback controller, which coordinates two manipulated variables of the moving radiant actuator to achieve the control objective. The two manipulated variables are the velocity and the radiant flux or power of the moving actuator. Both the estimation and feedback control strategies are demonstrated using computer simulations of one-dimensional distributed parameter models for an ultraviolet (UV) coating curing process involving a moving UV source. The results show that the proposed estimation and control schemes can significantly improve process quality and compensate for unknown disturbances on the target.     

Combining Tithonia diversifolia and minjingu phosphate rock for improvement of P availability and maize grain yields on a chromic acrisol in Morogoro,Tanzania

A 2-year field experiment was conducted to evaluate the effects of Tithonia diversifolia green manure combined with either Minjingu phosphate rock (MPR) or triple super phosphate (TSP) on soil chemical properties that influence P availability, P pools and maize grain yields, on a Chromic Acrisol in Morogoro, Tanzania. Leafy biomass of tithonia was applied before maize planting for two consecutive growing seasons. Treatments compared were the control, MPR and TSP each at 80 kg P ha⁻¹; tithonia alone at 2.5, 5.0, and 7.5 Mg ha⁻¹ dry matter and tithonia combined with MPR or TSP at 40 kg P ha⁻¹. Tithonia led to significant increases in soil pH, exchangeable Ca, labile (resin and NaHCO₃-Pi), and moderately labile inorganic P (NaOH-Pi). It reduced exchangeable Al and P sorption. Application of MPR alone had liming effects and resulted in increase in labile P. Combining tithonia with MPR had similar but more intense effects. Triple superphosphate alone led to acidification and this was reversed when TSP was co-applied with tithonia. Increasing the application rates of tithonia either alone or in combination with TSP or MPR led to more pronounced liming effects but the differences between 2.5 and 5.0 Mg tithonia ha⁻¹ were not significant due to moisture stress that was experienced during the season. The P and Ca concentrations of the maize plants at tasselling increased with the application of tithonia alone or combined with MPR or TSP, and were significantly correlated with maize grain yields (r = 0.75 and 0.64 for MPR and TSP, respectively). Tithonia added consecutively for 2 years increased total maize grain yields by 70% compared to that in the control. The relative agronomic effectiveness (RAE) of MPR increased from 46% in the first year of application to > 142% in the second year, indicating that the initially slow dissolution of MPR improved by combined application of tithonia and MPR, attributed to reduction of P sorption. It is concluded that tithonia can enhance P availability from the Chromic Acrisol through modification of soil properties associated with P transformation and availability. In cases where tithonia is found within the farmers’ fields its combined application with MPR can increase maize yields at a much-reduced cost associated with tithonia procurement.     

Accumulation of heavy metals in soils and plants after long-term use of fertilizers and fungicides in Tanzania

A study was undertaken to assess the accumulation of some heavy metals in soils and tobacco leaves from farms which received phosphate fertilizers or copper fungicides for many years. Surface soil samples were collected from various locations in the Iringa district of Tanzania, representing virgin soils, soils receiving low fertilizer inputs, those with high fertilizer inputs, and those receiving Cu fungicides. Locally occurring rock phosphate samples were also included in the study. Heavy metals in the samples were extracted using aqua regia, DTPA, or NH₄NO₃. Tobacco leaves were sampled to assess their heavy metal concentration. Cadmium, Zn, Mn, Cu, Ni, and Pb were determined using atomic absorption or flame emission spectrophotometry. There was a significant heavy metal enrichment of soils receiving the high fertilizer and Cu fungicide inputs relative to virgin or low input soils. This resulted in higher concentrations of the metals in the leaves of tobacco grown in these soils. Although the magnitudes were not big, therefore probably posing no immediate danger, greater risks may arise in the future due to the observed increasing trend. The phosphate rock samples contained very low concentrations of Cd but some had very high levels of Mn.