scholarly journals Nursery substrates and provenances influence rooting performance of juvenile, single-node vine cuttings of Gnetum africanum Welw. (Gnetaceae)

Afrika Focus ◽  
2017 ◽  
Vol 27 (3) ◽  
Author(s):  
Roseline Gusua Caspa ◽  
Apollinaire Biloso ◽  
Claude Akalakou ◽  
Joseph Mafolo ◽  
Alain Tsobeng ◽  
...  

Gnetum africanum Welw. (Gnetaceae) is a forest vine that is highly valued for its leaves which are a source of food and income. Because wild populations are threatened by over-harvesting, there is an increasing need to cultivate the plant, which in turn entails a need for developing good quality planting material. This study investigates the effects of four provenances, four substrates and their interactions on rooting and shoot development of vine cuttings of G. africanum using the non-mist propagation system developed by ICRAF. Single-node, half-leafed vine cuttings were used and data on rooting and leaf production were collected monthly from the second to the fifth months. Rooting percentages were subjected to analysis of variance using logistic regression procedures in Genstat version 12. Provenance (P<0.001), substrate (P<0.001) and interaction between provenance and substrate (P<0.001) showed highly significant effects on rooting. Excel was used to determine rooting percentages, with the highest observed in fine sand on cuttings from Lekie- Assi (81%) and Boumnyebel (79%) which are high G. africanum exploitation areas in the Centre Region of Cameroon. Boumnyebel showed a signficantly higher shoot development than the other provenances. Fine sand and sharp sand can be recommended for rapid, low-cost production of G. africanum planting material. Key words: domestication, rooting substrate, non-mist propagator, vine cuttings 

Alloy Digest ◽  
1977 ◽  
Vol 26 (2) ◽  

Abstract SAF 1039 steel can be used in the hot-rolled, normalized, oil-quenched-and-tempered or water-quenched-and-tempered condition for general-purpose construction and engineering. Its manganese content is a little higher than some of the other standard carbon steels with comparable carbon levels; this gives it slightly higher hardenability and hardness. It provides medium strength and toughness at low cost. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CS-66. Producer or source: Carbon steel mills.


2019 ◽  
Vol 9 (2) ◽  
pp. 157-160
Author(s):  
Ali Hasani

Background: Laser ablation method has high-yield and pure SWCNHs. On the other hand, arc discharge methods have low-cost production of SWCNHs. However, these techniques have more desirable features, they need special expertness to use high power laser or high current discharge that either of them produces very high temperature. As for the researches, the temperatures of these techniques are higher than 4727°C to vaporize the graphite. So, to become aware of the advantages of SWCNHs, it is necessary to find a new way to synthesize SWCNHs at a lower temperature. In other words, reaction field can be expandable at a moderate temperature. This paper reports a new way to synthesize SWCNHs at an extremely reduced temperature. Methods: According to this study, the role of N2 is the protection of the copper holder supporting the graphite rod by increasing heat transfer from the holder. After the current of 70 A was supplied to the system, the temperature of graphite rod was raised to 1600°C. It is obvious that this temperature is somehow higher than the melting point of palladium, 1555°C, and much lower than graphite melting point, 3497°C. Results: Based on the results, there are transitional precursors simultaneous with the SWCNHs. This composition can be created by distortion of the primary SWCNTs at the higher temperature. Subsequently, each SWCNTs have a tendency to be broken into individual horns. With increasing the concentration of the free horns, bud-like SWCNHs can be produced. Moreover, there are individual horns almost separated from the mass of single wall carbon nanohorns. This structure is not common in SWCNHs synthesized by the usual method such as arc discharge or laser ablation. Through these regular techniques, SWCNHs are synthesized as cumulative particles with diameters about 30-150 nm. Conclusion: A simple heating is needed for SWCNTs transformation to SWCNHs with the presence of palladium as catalyst. The well-thought-out mechanism for this transformation is that SWCNTs were initially changed to highly curled shape, and after that were formed into small independent horns. The other rout to synthesize SWCNHs is the pyrolysis of palm olein at 950°C with the assistance of zinc nitrate and ferrocene. Palm olein was used as a promising, bio-renewable and inexpensive carbon source for the production of carbon nanohorns.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 780
Author(s):  
Kazunori Takahashi ◽  
Takashi Miwa

The paper discusses a way to configure a stepped-frequency continuous wave (SFCW) radar using a low-cost software-defined radio (SDR). The most of high-end SDRs offer multiple transmitter (TX) and receiver (RX) channels, one of which can be used as the reference channel for compensating the initial phases of TX and RX local oscillator (LO) signals. It is same as how commercial vector network analyzers (VNAs) compensate for the LO initial phase. These SDRs can thus acquire phase-coherent in-phase and quadrature (I/Q) data without additional components and an SFCW radar can be easily configured. On the other hand, low-cost SDRs typically have only one transmitter and receiver. Therefore, the LO initial phase has to be compensated and the phases of the received I/Q signals have to be retrieved, preferably without employing an additional receiver and components to retain the system low-cost and simple. The present paper illustrates that the difference between the phases of TX and RX LO signals varies when the LO frequency is changed because of the timing of the commencement of the mixing. The paper then proposes a technique to compensate for the LO initial phases using the internal RF loopback of the transceiver chip and to reconstruct a pulse, which requires two streaming: one for the device under test (DUT) channel and the other for the internal RF loopback channel. The effect of the LO initial phase and the proposed method for the compensation are demonstrated by experiments at a single frequency and sweeping frequency, respectively. The results show that the proposed method can compensate for the LO initial phases and ultra-wideband (UWB) pulses can be reconstructed correctly from the data sampled by a low-cost SDR.


2021 ◽  
pp. 107755952199417
Author(s):  
Katherine R. Brendli ◽  
Michael D. Broda ◽  
Ruth Brown

It is a common assumption that children with disabilities are more likely to experience victimization than their peers without disabilities. However, there is a paucity of robust research supporting this assumption in the current literature. In response to this need, we conducted a logistic regression analysis using a national dataset of responses from 26,572 parents/caregivers to children with and without disabilities across all 50 states, plus the District of Columbia. The purpose of our study was to acquire a greater understanding of the odds of victimization among children with and without intellectual disability (ID), while controlling for several child and parent/adult demographic correlates. Most notably, our study revealed that children with ID have 2.84 times greater odds of experiencing victimization than children without disabilities, after adjusting for the other predictors in the model. Implications for future research and practice are discussed.


2011 ◽  
Vol 4 (4) ◽  
pp. 385-394 ◽  
Author(s):  
J. Meneely ◽  
F. Ricci ◽  
S. Vesco ◽  
M. Abouzied ◽  
M. Sulyok ◽  
...  

Many different immunochemical platforms exist for the screening of naturally occurring contaminants in food from the low cost enzyme linked immunosorbent assays (ELISA) to the expensive instruments such as optical biosensors based on the phenomenon of surface plasmon resonance (SPR). The primary aim of this study was to evaluate and compare a number of these platforms to assess their accuracy and precision when applied to naturally contaminated samples containing HT-2/T-2 mycotoxins. Other important factors considered were the speed of analysis, ease of use (sample preparation techniques and use of the equipment) and ultimately the cost implications. The three screening procedures compared included an SPR biosensor assay, a commercially available ELISA and an enzymelinked immunomagnetic electrochemical array (ELIME array). The qualitative data for all methods demonstrated very good overall agreements with each other, however on comparison with mass spectrometry confirmatory results, the ELISA and SPR assay performed slightly better than the ELIME array, exhibiting an overall agreement of 95.8% compared to 91.7%. Currently, SPR is more costly than the other two platforms and can only be used in the laboratory whereas in theory both the ELISA and ELIME array are portable and can be used in the field, but ultimately this is dependent on the sample preparation techniques employed. Sample preparative techniques varied for all methods evaluated, the ELISA was the most simple to perform followed by that of the SPR method. The ELIME array involved an additional clean-up step thereby increasing both the time and cost of analysis. Therefore in the current format, field use would not be an option for the ELIME array. In relation to speed of analysis, the ELISA outperformed the other methods.


2021 ◽  
Author(s):  
Fermanto Lianto ◽  
Lilianny Sigit Arifin ◽  
Y. Basuki Dwisusanto ◽  
Rudy Trisno

Abstract Sharing a corridor space in a rusunawa could form patterns of adaptation and exemplify the phenomenon of territorial mastery. This research aims to understand the form of this mastery as perceived by the occupants using the Grounded Theory method. The results show a theory of territorial mastery that can be developed from the findings in the field is a new theory of territorial characteristics, based on hard and soft territory. The hard territory is territorial control that is tangible or intangible, fixed or unchanged, and firm, whose existence is clear in a space that can be seen, occupied or controlled and maintained, and recognized by other residents. On the other hand, the soft territory is territorial control that is tangible and intangible, and which allows for flexible and soft shifts because it is an expression of the family and cultural emotions of guyub, so that mastery of the soft territory occurs not only because of tolerance, but also because of the prioritization of the feeling of kinship in living under one roof, and the harmonization of guyub relationships amongst people in a community


Author(s):  
Mitrotasios M

The aim of the present study was to describe how corner kicks were taken and to identify key variables associated with final attempts during Greek Super League season 2018-19. There was a total of 424 final attempts after corner kick, of which, 16.3% were attempts off target, 6.8% attempts on target and 2.8% resulting in a goal. Bivariate analysis presented that attempts on target were increased when the ball was delivered outswing, no players positioned at the goal posts, >1 intervening attackers, attacking player the 1st contact and ball delivered into the central zones of the 18-yard box. Binary logistic regression (Final attempt/ No Final attempt) revealed that the model was statistically significant for the final attempt (p < 0.001) and showed that the intervening attackers (p < 0.001) and the player of the 1st contact (p < 0.001) contributed significantly to the model. These results can aid coaches to enhance on one hand the attacking effectiveness; on the other hand the defensive efficacy of corner kicks within Greek football.


1979 ◽  
Vol 51 (1) ◽  
pp. 158-162 ◽  
Author(s):  
Antti Jaakkola ◽  
Johan Korkman ◽  
Tuomo Juvankoski

The aim of the study was to find out to what extent the cadmium contained in fertilizer influences the cadmium content of vegetables. For this purpose, highly cadmium-bearing batches of fertilizer were prepared from selected quantities of raw material with an exceptionally high cadmium content. To one such batch of fertilizer, an extra amount of cadmium was added at the mixing stage. In a two-year field experiment carried out in soil consisting of clayey fine sand and begun in 1977, 1000 kg/ha of NPK fertilizer with a cadmium content of either 57 or 81 mg/kg brought about a clear increase in the cadmium content of radish tops. The cadmium content of radish roots, spinach and lettuce appeared likewise to rise, but the differences registered were not, owing to the unevenness of the field, significant. The cadmium content of the dry matter of rye grass was lower than that of the other experimental plants, and it appeared to rise less with an increase in the cadmium content of the fertilizer. Owing to the wide range of variation, the cadmium uptake of the experimental plants could not be determined reliably, The spinach, however, appeared to have taken up the largest amount of cadmium, and the rye grass the least amount. The increase in the cadmium content of the spinach harvested in 1978 corresponded to 1.5‰ of the cadmium introduced into the ground during the two-year period through application of the fertilizer with the highest content of the metallic element.


2020 ◽  
Author(s):  
Hong Xu ◽  
Yong Gan ◽  
Daikun Zheng ◽  
Bo Wu ◽  
Xian Zhu ◽  
...  

BACKGROUND So far, there have been no published population studies on the relationship between a COVID-19 infection and public risk perception, information source, knowledge, attitude, and behaviors during the COVID-19 outbreak in China. OBJECTIVE This study aims to understand the relationships between COVID-19 infection; four personal nonpharmaceutical interventions (NPIs; handwashing, proper coughing habits, social distancing, and mask wearing); and public risk perception, knowledge, attitude, and other social demographic variables. METHODS An online survey of 8158 Chinese adults between February 22 and March 5, 2020, was conducted. Bivariate associations between categorical variables were examined using Fisher exact test. We also explored the determinants of four NPIs as well as their association with COVID-19 infection using logistic regression. RESULTS Of 8158 adults included, 57 (0.73%) were infected with COVID-19. The overwhelming majority of respondents showed a positive attitude (n=8094, 99.2%), positive risk perception (n=8146, 99.9%), and high knowledge levels that were among the strongest predictors of the four adopted NPIs (handwashing: n=7895, 96.8%; proper coughing: 5997/6444, 93.1%; social distancing: n=7104/8158, 87.1%; and mask wearing: 5011/5120, 97.9%). There was an increased risk of COVID-19 infection for those who did not wash their hands (2.28% vs 0.65%; risk ratio [RR] 3.53, 95% CI 1.53-8.15; <i>P</i>=.009), did not practice proper coughing (1.79% vs 0.73%; RR 2.44, 95% CI 1.15-5.15; <i>P</i>=.03), did not practice social distancing (1.52% vs 0.58%; RR 2.63, 95% CI 1.48-4.67; <i>P</i>=.002), and did not wear a mask (7.41% vs 0.6%; RR 12.38, 95% CI 5.81-26.36; <i>P</i>&lt;.001). For those who did practice all other three NPIs, wearing a mask was associated with a significantly reduced risk of infection compared to those who did not wear a mask (0.6% vs 16.7%; <i>P</i>=.04). Similarly, for those who did not practice all or part of the other three NPIs, wearing a mask was also associated with a significantly reduced risk of infection. In a penalized logistic regression model including all four NPIs, wearing a mask was the only significant predictor of COVID-19 infection among the four NPIs (odds ratio 7.20, 95% CI 2.24-23.11; <i>P</i>&lt;.001). CONCLUSIONS We found high levels of risk perception, positive attitude, desirable knowledge, as well as a high level of adopting the four NPIs. The relevant knowledge, risk perception, and attitude were strong predictors of adapting the four NPIs. Mask wearing, among the four personal NPIs, was the most effective protective measure against COVID-19 infection, with added preventive effect among those who practiced all or part of the other three NPIs.


2016 ◽  
Vol 31 (3) ◽  
pp. 402-415 ◽  
Author(s):  
Rémi Boivin ◽  
Chloé Leclerc

This article analyzes reported incidents of domestic violence according to the source of the complaint and whether the victim initially supported judicial action against the offender. Almost three quarters of incidents studied were reported by the victim (72%), and a little more than half of victims initially wanted to press charges (55%). Using multinomial logistic regression models, situational and individual factors are used to distinguish 4 incident profiles. Incidents in which the victim made the initial report to the police and wished to press charges are the most distinct and involve partners who were already separated at the time of the incident or had a history of domestic violence. The other profiles also show important differences.


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