Standard Hybrid Research Articles

Estimation of General and Specific Combining Ability Effects for Quality Protein Maize Inbred Lines

Background: Maize (Zea mays L.) plays a critical role in meeting high food demand. It is globally one of the most widely adapted and cultivated crops. Hybrid development from fixed inbred lines is one of the strategies for the improvement of maize production. The national average maize yield in Ethiopia is low and thus, selection of promising germplasm and knowledge of combining ability are prerequisites to developing high yielding maize varieties. Forty-two Quality Protein Maize (QPM) crosses (21 inbred lines each crossed with two testers) along with three popular standard hybrids were evaluated in two replications using alpha lattice during the 2017 cropping season at Ambo, Arsi-Negele, and Kulumsa. The objectives of this study were to identify lines with high GCA and estimate the SCA of crosses for grain yield, and other agronomic and morphological characters.
 Results: Significant difference among crosses was observed for 19 traits at Ambo, 14 traits at Arsi-Negele, and 19 traits at Kulumsa in the hybrid trial. Regarding the GCA effect, L8 had a significant difference to the positive side with the highest magnitude of GCA effect at three locations (3.40, 2.03, and 1.88 GCA effect values at Arsi-Negele, Ambo, and Kulumsa, respectively) which is followed by L7 for GY. All crosses did not show a significant SCA effect for GY in both directions at Ambo and Arsi-Negele but at Kulumsa, five crosses: L2xT1(1.89), L13xT2(1.88), L7xT1(1.86), L4xT2(1.49) and L19xT1(1.41) showed significant difference. In the combined analysis for six traits, Additive gene action was more important which was manifested by a higher sum square contribution of DS (79.6) EPP (79.3%), EL (80.0%), KPR (80.1%), ED (78.5%) and TSW (79.1%).
 Conclusion: Based on mean grain yield, and combining ability, L8xT2, L7xT1, L8xT1, L19xT1, L6xT2, and L18xT1 are promising crosses that could be forwarded for further use in maize breeding programs for further works.

Design optimization and control of dividing wall column for purification of trichlorosilane

• TA C appr . is proposed as a novel objective function for DWC parameter optimization. • Optimal energy control structure can be achieved by manipulating liquid split ratio. • MPC-PI hybrid structure balances both control performance and safety performance. • Simulated annealing algorithm is employed to optimize the weights of MPC controller. Polysilicon quality and energy consumption are directly affected by the purification process of trichlorosilane. In this work, the dividing wall column (DWC) as a promising energy-saving technology is utilized for trichlorosilane purification, with the design optimization carried out using steady-state simulation. Compared with conventional distillation process, DWC can reduce total annual cost (TAC), CO 2 emissions and exergy loss ( El ) by 35.81%, 53.56% and 54.10% on average, respectively. Established on the characteristics of superfractionator, four control structures are proposed in this work, two of which are multi-loop proportional-integral (PI) control schemes including condenser duty ( C ), distillate flow rate ( D ), bottom flow rate ( B )/reflux flow rate ( R ), side flow rate ( S ), reboiler duty ( V ) control structure and optimal energy control structure. The other two are model predictive control (MPC) schemes including standard MPC structure and MPC-PI hybrid structure. The weights of MPC controller are optimized using the simulated annealing (SA) algorithm. Dynamic simulation results demonstrate that MPC schemes achieve improved closed-loop performance in terms of minor overshoot, shorter transition time and reduced oscillation than PI control schemes. The integral absolute error (IAE) is introduced to further quantitatively evaluate MPC schemes. The simulation results demonstrate that the standard MPC structure achieves the best control performance and the MPC-PI hybrid structure enhances process safety while maintaining the desired control performance.

Performance Evaluation and Identification of Highland Quality Protein Maize Hybrids in Ethiopia

Background: Maize plays an indispensable role in meeting high food demand. It is globally one of the most widely adopted and cultivated crops. Hybrid development from fixed inbred lines is one of the strategies for the improvement of maize production. The national average maize yield is low in East Africa; thus, the selection of promising germplasm has a great role to meet the high food demand of growing the population. Forty-two Quality Protein Maize (QPM) crosses (21 inbred lines each crossed with two testers) along with three popular standard hybrids checks were evaluated in two replications using alpha lattice during the 2017 cropping season at Ambo, Arsi-Negele, and Kulumsa. The objective of this study was to evaluate and select the best new QPM hybrids for grain yield, and other agronomic and morphological characteristics.
 Results: Significant difference among crosses was observed for 19 traits at Ambo, 14 traits at Arsi-Negele, and 19 traits at Kulumsa. Out of 28 traits studied, six of them did not show genotype by location interaction but they showed a significant genotypic effect. These traits were: Days to Silking (DS), Number of Ears per plant (EPP), Ear Length (EL), Kernels Per Row (KPR), Ear Diameter (ED), and Thousand Seed Weight (TSW). Based on the mean performance in the combined analysis, from 42 new QPM crosse, six of them (L8xT2, L7xT1, L8xT1, L19xT1, L6xT2, and L18xT1) were scored higher grain yield compared with the mean of the three standard checks and best conventional maize (CM) check (AMH853). L8xT2, L7xT1, L8xT1 crosses showed a higher grain yield advantage over the best check (AMH853) by 20.87, 14.13, and 13.63%, respectively.
 Conclusion: The study implicated the existence of a difference between the newly developed hybrids and the standard check varieties. In general, the study enabled us to identify promising crosses that could be forwarded for further use in maize breeding programs in future work.

Mid-parent and Better Parent Heterosis Study on Highland Quality Protein Maize Hybrids in Ethiopia

Determination of heterosis in maize hybrids is necessary for the identification of superior F1 hybrids for breeding programs. Therefore, this study was conducted to estimate the amount of mid parent (MPH) and better parent heterosis (BPH) for grain yield, yield-related, agronomic, and morphological traits. Hybrid development from fixed inbred lines is one of the strategies for the improvement of maize production. The national average maize yield in Ethiopia is low and thus, selection of promising germplasm, knowledge of combining ability, and heterotic grouping are prerequisites to developing high-yielding maize varieties. Forty-two Quality Protein Maize (QPM) crosses (21 inbred lines each crossed with two testers) along with three popular standard hybrids were evaluated in two replications using alpha lattice during the 2017 cropping season at Ambo and, Arsi-Negele. Parental line trials consisting of 21 lines, two testers, and one conventional maize (CM) parent check (FS67) were established in two replications laid out using RCBD side by side with the hybrid trials at Ambo and Arsi-Negele. At Ambo, almost all crosses showed positive and significant BPH except three crosses (L1xT1, L4xT1, and L13xT1). The maximum BPH (276.2%) was obtained from L17xT2. Similarly, at Arsi-Negele, most of the crosses had positive and significant BPH except for five crosses for BPH which are showing negative heterosis. The highest BPH was obtained from L10xT2 at Arsi-Negele. Generally, the high yielding crosses had reasonable BPH. Based on the result promising crosses and lines were identified. Some of the crosses showed good performance in terms of heterosis against the mid parent and better parent: L17xT2 (329.88% MPH, 276.18% BPH), L3xT2(320.05% MPH, 273.91%BPH), and L19xT2(2802.57% MPH, 247.31% BPH) at Ambo, whereas at Arsi-Negele L10xT2 (128.38% MPH, 111.27%BPH) and L11xT2(115.33% MPH, 98.00% BPH) showed the higher heterosis compared with the mid parent and better parent. Crosses that showed best yield performance were: L8xT2, L7xT1, L8xT1, L19xT1, L6xT2, and L18xT1. These crosses should be reconsidered for further evaluation and possible release.

Design and analysis of the Extended Hybrid High-Order method for the Poisson problem

We propose an Extended Hybrid High-Order scheme for the Poisson problem with solution possessing weak singularities. Some general assumptions are stated on the nature of this singularity and the remaining part of the solution. The method is formulated by enriching the local polynomial spaces with appropriate singular functions. Via a detailed error analysis, the method is shown to converge optimally in both discrete and continuous energy norms. Some tests are conducted in two dimensions for singularities arising from irregular geometries in the domain. The numerical simulations illustrate the established error estimates, and show the method to be a significant improvement over a standard Hybrid High-Order method.

Oil-con hybrids as a potential tool to prevent eared dove damage to sunflower crops

Abstract Eared doves (Zenaida auriculata) cause significant economic damage to mature sunflower in Argentina. Empirical evidences indicate that some sunflower hybrids (e.g. confectionary and stripped oilseed) might be less susceptible to bird damage than others (e.g. black oilseed). However, these less susceptible hybrids could imply a trade-off between damage reduction and oil content on the seeds. In this work, we investigated the potential of a new oil-con hybrid types (OC: oilseed × confectionary cross) as a tool to prevent eared dove damage to sunflower crops. We compared the performance (damage values), morphological characteristics and nutritive quality of this hybrid compared to other three standard sunflower hybrids (BO: black oilseed, SO: striped oilseed, and CON: confectionary), both in the field and in cages. In both tests, doves significantly selected BO and SO hybrids over CON and OC hybrids. The OC hybrid was not selected, despite its high nutritional value. Results suggest that achene size could be an important morphological trait influenced eared dove selection of hybrids, independently of other seed characteristics. Based on these results, the OC hybrid tested in this study seems to be a promising tool for preventing eared dove damage to sunflower in Argentina.

Heterosis for grain yield contributing traits in pearl millet (Pennisetum glaucum)

The general expectation of the pearl millet farmers is mainly focused on level of superiority of newly released hybrids than the local standard hybrids, which is grown widely. Hence, the standard check RHB-173, RHB-177 and MPMH-17 were used as standard hybrid. The hybrid namely RMS-7 × RIB-3135-18 expressed highest significant standard heterotic value for grain yield per plant and fourassociated traits out of nine studied traits including dry fodder yield per plot also showed positive significant standard heterosis. Similarly, another hybrid namely RMS-7 × RIB-16296 showed highest significant standard heterosis for dry fodder yield per plot. The showed cross combination, viz. ICMA-00444 × RIB-16S/110, ICMA-00111 × RIB-494, ICMA-00444 × RIB-16296 and ICMA-00444 × RIB-16328 were good for other studied traits. At the end, among 100 hybrids studied, one hybrid, viz. RMS-7 × RIB-3135-18 was selected as best cross since, it expressed high significant standard heterosis over best check for many of the traits including grain yield and dryfodder yield and may have potential to replace old cultivar in the future.

Оценка фертильности пыльцы гибридов подсолнечника методом сплит-опыления

The main objective of the study was to study the effect of pollen from sunflower hybrids on the real seed productivity and setting of achenes in CMS-tester plants as the final indicators of pollen fertility. The studies were carried out in 2019 and 2021 at V.S. Pusotvoit All-Russian Research Institute of Oil Crops, Krasnodar. The object of the study was cultivated sunflower plants of Helianthus annuus L.: Oksi and NK Brio hybrids as paternal forms, as well as the sterile hybrid Kubansky 93 and the line VK1-klp A as CMS testers. On one vertical part of a separate head, the pollen of the Oksi hybrid was applied, and on the other, the pollen of the NK Brio hybrid was used, i.e. we applied the split-pollination method. The number of fiiled seeds on the head of the CMS tester when pollinated with the pollen of the hybrid Oksi was significantly less than that of the standard hybrid NK Brio. On average, over two years, a decrease in real seed productivity was observed in the hybrid Oksi by 1.97 times in relation to the hybrid NK Brio. The development of a larger number of achenes to technical maturity led to the progressive growth of a part of the head pollinated by the pollen of the NK Brio hybrid. A similar pattern was also noted for the seed set. On the heads of the CMS-tester, on average for two years, the pollen of the hybrid Oksi showed a significant decrease in the setting of achenes in relation to the standard – by 2.24 times. Our earlier data on the presence of morphological anomalies in the pollen of the Oksi sunflower hybrid are consistent with the facts of reduced seed productivity and seed set when evaluating the pollen quality of this hybrid crossed with the CMS-tester, established in this work. The question remains open at what stages the negative impact of the genetic factors of the reproductive function of the pollen of the Oksi hybrid occurs: pre- or post-zygotic.

Clinical Validation of the Fully Automated NeuMoDx HPV Assay for Cervical Cancer Screening.

The NeuMoDx HPV assay is a novel fully automated, real-time PCR-based assay for the qualitative detection of high-risk human papillomavirus (HPV) DNA in cervical specimens. The assay specifically identifies HPV16 and HPV18 and concurrently detects 13 other high-risk HPV types at clinically relevant infection levels. Following the international guidelines, the clinical performance of the NeuMoDx HPV assay for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) against the reference standard Hybrid Capture 2, as well as intra- and inter-laboratory reproducibility were assessed on PreservCyt samples. The clinical accuracy of the assay was additionally evaluated against the clinically validated Alinity m HR HPV and COBAS 4800 HPV Test on PreservCyt samples, and against the clinically validated HPV-Risk assay on SurePath samples. The NeuMoDx HPV assay performance for CIN2+ was non-inferior to the reference methods on both sample types (all p < 0.05), and showed excellent intra- and inter-laboratory reproducibility (95.7%; 95% CI: 93.9–97.3; kappa value 0.90 (95% CI: 0.86–0.94); and 94.5%; 95% CI: 92.6–96.2; kappa value 0.87 (95% CI: 0.82–0.92), respectively). In conclusion, the NeuMoDx HPV assay meets international guideline criteria for cross-sectional accuracy and reproducibility, and performs equally well on cervical screening specimens collected in two widely used collection media. The NeuMoDx HPV assay fulfils the requirements to be used for primary cervical screening.

Transfer Characteristics Analysis of Single Electron Transistor

Single Electron Transistor is often referred to as a nanometer scale because it can be made very small and can detect the movement of individual electrons. However, the SET has a high input impedance, low voltage gain, and is sensitive to random background charges. The Transfer characteristics features of a SET are calculated by analyzing the different resistance of the tunnels and the tunneling capacitance. Tunneling method is considering a stochastic process, and the state master equation is solving to calculate the free energy change. There are some unusual variations that set the limit for parallel circuit parameters for proper operation. The SET can maintain its scalability and control the movement of individual electrons. In this paper, we have provided a comparative and simulated study of standard CMOS device, SET and hybrid circuits such as a switched capacitor filter.

Competitive ability of sunflower (Helianthus annuus L.) breeding material under Cyperus rotundus infestation

Abstract Weed infestation induces intense competition with the sunflower crop for soil nutrients, space and light causing significant yield losses of the sunflower. Therefore, study was undertaken during the year 2013–15 at College of Agriculture, University of Sargodha, Pakistan to determine the effect of Cyperus rotundus infestation on various morphological and biochemical traits. Initially a screening experiment was carried out to screen against C. rotundus infestation. Later on, cross combinations of selected cytoplasmic male sterile and restorer lines were attempted to develop F1 progenies which were compared with commercial hybrids along with parents. There were 6 parental lines (3 A and 3 R lines) along with 9 single cross combinations obtained from these parents. Experiment was carried out in complete randomized design having factorial arrangement with three replications. Weed in one of regime latter called as control were completely absent, while in weed infestation regimes 5 and 10 plants of C. rotundus were maintained. Results showed that C. rotundus infestation causes significant damage to the sunflower plants. Generally cross combination showed a decrease of leaf area by 440% and 264%, 61% and 49% for chlorophyll contents, 133% and 191% for head weight under low and high weed infestation regime respectively. However, antioxidant activity increased by 44% and 49% under low and high infestation regime induced by C. rotundus. Sunflower genotypes also showed variability in competitive ability against C. rotundus weed. Cross combinations coded as (A10, A7 and A2) showed lower comparative decrease for seed yield and oil contents when compared with standard hybrids under the presence of C. rotundus. Development of sunflower hybrids with better competitive ability under the presence of weeds such as C. rotundus may able to enhance plant development and lower yield losses in sunflower field with minimum the use of herbicide.

Standard slot waveguide and double hybrid plasmonic waveguide configurations for enhanced evanescent field absorption methane gas sensing

Herein, a numerical study on standard slot waveguide and double hybrid plasmonic waveguide based on a silicon-on-insulator platform is presented. The geometric parameters of both the waveguides are optimized for the operational wavelength of 3.39 μm (absorption line of methane gas) to obtain the maximum evanescent field ratio (EFR). By utilizing Lambert-Beer’s law, the gas sensing capability of both the waveguides is determined. It is found out that both the waveguides of length 100 μm offer high EFR resulting in the 3dB decay of the propagating mode power for the methane gas concentration of 20-22 % in the chamber. The study provides the foundation for the practical realization of compact and highly sensitive gas sensors. Full Text: PDF ReferencesJ.Y. Yo, Y.S. Kwon, J.W. Lee, J.S. Park, B.H. Rho, W. II. Choi. "Acute Respiratory Distress Due to Methane Inhalation", Tuberculosis and Respiratory Diseases 74, 120-123 (2013). CrossRef M. A. Butt, S. A. Degtyarev, S. N. Khonina and N. L. Kazanskiy. "An evanescent field absorption gas sensor at mid-IR 3.39 μm wavelength", Journal of Modern Optics 64, 1892-1897 (2017). CrossRef M. A. Butt, S. N. Khonina and N. L. Kazanskiy. "Modelling of Rib channel waveguides based on silicon-on-sapphire at 4.67 μm wavelength for evanescent field gas absorption sensor", Optik 168, 692-697, (2018). CrossRef M. A. Butt, S. N. Khonina and S. N. Kazanskiy. "Silicon on silicon dioxide slot waveguide evanescent field gas absorption sensor", Journal of Modern Optics 65, 174-178, (2017). CrossRef S. N. Khonina, N. L. Kazanskiy and M. A. Butt. "Evanescent Field Ratio Enhancement of a Modified Ridge Waveguide Structure for Methane Gas Sensing Application", IEEE Sensors Journal 20, 8469-8476 (2020). CrossRef M.Vlk, A. Datta, S. Alberti, H.D. Yallew, V. Mittal, G. S. Murugan, J. Jagerska. "Extraordinary evanescent field confinement waveguide sensor for mid-infrared trace gas spectroscopy", Light: Science &amp; Applications 10, 26 (2021). CrossRef M.A. Butt, S.N. Khonina, N.L. Kazankiy. "Enhancement of evanescent field ratio in a silicon strip waveguide by incorporating a thin metal film", Laser Physics 29, 076202 (2019). CrossRef M. A. Butt, N. L. Kazanskiy and S. N. Khonina, "Highly integrated plasmonic sensor design for the simultaneous detection of multiple analytes", Current Applied Physics 20, 1274-1280 (2020). CrossRef T. Milde, M. Hoppe, H. Tatenguem, C. Assmann, W. Schade, J. Sacher. "Comparison of the spectral excitation behavior of methane according to InP, GaSb, IC, and QC lasers as excitation source by sensor applications", Applied Optics 58, C84 (2019). CrossRef N. L. Kazanskiy, S.N. Khonina, M.A. Butt. "Polarization-Insensitive Hybrid Plasmonic Waveguide Design for Evanescent Field Absorption Gas Sensor", Photonic Sensors 11, 279-290 (2021). CrossRef D. Popa, F. Udrea. "Towards Integrated Mid-Infrared Gas Sensors", Sensors 19, 2076 (2019). CrossRef S-W. Kang, K. Sasaki, H. Minamitani. "Sensitivity analysis of a thin-film optical waveguide biochemical sensor using evanescent field absorption", Applied Optics 32, 3544-3549 (1993). CrossRef

Structural effect of Low-dimensional carbon nanostructures on Long-term stability of dye sensitized solar cells

A major challenge in upscaling and commercializing dye-sensitized solar cells (DSSC) is to simultaneously rely on a robust photoconversion efficiency (PCE) along with long-term device stability. Two-dimensional (2D) nanocarbon materials are known to improve the PCE and stability of devices made of hybrid nanocomposite photoanodes. However, there is inadequate knowledge on how the morphology of 2D nanocarbon materials plays an important role in improving photovoltaic (PV) performance and stability. Here we report the comparative effect on the PV performance and the long-term stability of DSSCs made of optimal loadings of few-layer graphene (FLG) flakes and graphene nanoribbons (GNR) into the mesoporous TiO2 active layer. DSSCs were fabricated by using standard nanocrystalline TiO2, GNR-TiO2 and FLG-TiO2 hybrid mesoporous films as anodes and subjected to continuous visible light irradiation to monitor their long-term stability. Results show that the optimized incorporation of GNR (0.005 wt%) and FLG (0.010 wt%) in the mesoporous TiO2 active layer enhances the PCE by 34% and 21% compared to pristine TiO2, respectively. Moreover, the operational stability of hybrid devices shows a 51.6% (for GNR-TiO2) and a 10% (for FLG-TiO2) sustained higher PCE than the device based on bare TiO2, after 273 h of continuous one sunlight soaking. The electrochemical impedance spectroscopy (EIS) and transient photovoltage decay were studied to investigate how GNR strikingly reduces degradation of device performance as compared to its counterpart FLG-TiO2 and TiO2 based cells. This significant enhancement can be attributed to the structural modifications induced by GNR within the TiO2 photoanode, which improves the electron lifetime and reduces non-radiative carrier recombination.

Reciprocity and Antireciprocity Criteria by Elementary Matrix Techniques

Reciprocity and antireciprocity criteria for controlled affine resistive components are derived by elementary matrix techniques that make calculations compact and straightforward. First, formulae for the standard (homogeneous, hybrid, and transmission) representations, then, formulae for the general representation are provided. Finally, by resorting to some kind of canonic form, three general results of the literature on the subject are proven through basic arguments of linear algebra.

Improved impedance/admittance switching controller for the interaction with a variable stiffness environment

Hybrid impedance/admittance control aims to provide an adaptive behavior to the manipulator in order to interact with the surrounding environment. In fact, impedance control is suitable for stiff environments, while admittance control is suitable for soft environments/free motion. Hybrid impedance/admittance control, indeed, allows modulating the control actions to exploit the combination of such behaviors. While some work has addressed the proposed topic, there are still some open issues to be solved. In particular, the proposed contribution aims: (i) to satisfy the continuity of the interaction force in the switching from impedance to admittance control when a feedforward velocity term is present; and (ii) to adapt the switching parameters to improve the performance of the hybrid control framework to better exploit the properties of both impedance and admittance controllers. The proposed approach was compared in simulation with the standard hybrid impedance/admittance control in order to show the improved performance. A Franka EMIKA panda robot was used as a reference robotic platform to provide a realistic simulation.

Heterosis studies on yield components in hybrid rice (Oryza sativa. L)

Thirty-two hybrids developed from crossing four CMS lines and eight testers were evaluated for relative heterosis, heterobeltiosis and standard checks for yield traits in rice (Oryza sativa L.) during kharif 2019. The results indicated that heterobeltiosis for grain yield was significantly positive and superior over eleven hybrids ranging from -52.94 (CMS 64A X JGL 34985) to 149.24% (JMS 19A X JGL 34985) and ten hybrids over check (PA 6444) ranging from -47.76 (CMS 64A X JGL 34985) to 67.35% (JMS 19A X JGL 34985). Most of the crosses exhibiting superiority over better parent or standard check for grain yield showed significant heterosis for spikelet fertility and 1000 grain weight. The top hybrids JMS 19A X JGL 34985, CMS 14A X NSR 61 and CMS 64A X JGL 34984 exhibiting significant positive heterosis for yield over standard hybrid (PA 6444) were can be further exploited commercially.

Force-Activated DNA Substrates for In Situ Generation of ssDNA and Designed ssDNA/dsDNA Structures in an Optical-Trapping Assay.

Single-molecule force spectroscopy can precisely probe the biomechanical interactions of proteins that unwind duplex DNA and bind to and wrap around single-stranded (ss)DNA. Yet assembly of the required substrates, which often contain a ssDNA segment embedded within a larger double-stranded (ds)DNA construct, can be time-consuming and inefficient, particularly when using a standard three-way hybridization protocol. In this chapter, we detail how to construct a variety of force-activated DNA substrates more efficiently. To do so, we engineered a dsDNA molecule with a designed sequence of specified GC content positioned between two enzymatically induced, site-specific nicks. Partially pulling this substrate into the overstretching transition of DNA (~65pN) using an optical trap led to controlled dissociation of the ssDNA segment delineated by the two nicks. Here, we describe protocols for generating ssDNA of up to 1000 nucleotides as well as more complex structures, such as a 120-base-pair DNA hairpin positioned next to a 33-nucleotide ssDNA segment. The utility of the hairpin substrate was demonstrated by measuring the motion of E. coli. RecQ, a 3'-to-5' DNA helicase.

Online versus face-to-face learning in introductory university physics following COVID-19

The use of technology in higher education science classrooms rose significantly in the advent of the COVID-19 pandemic. In many universities, academic programs including introductory physics classes were taken online. Some institutions adopted online learning but also maintained face-to-face (F2F) laboratories when COVID-19 restrictions began to ease. Here, the effectiveness of the online learning approach in comparison with F2F learning is explored. The percentage difference in performance for students who took the online introductory physics course, Physics for Scientists and Engineers, versus that of students simultaneously taking the same course F2F is reported. This is done both across different sections taught by different instructors, and for the same course taught online versus F2F by the same professor. Furthermore, a short survey was conducted to assess the student learning experience and opinion about online and F2F learning. The results show equal or better overall performance for online learning with 4.2% higher performance when comparing results across different sections taught by different instructors. A similar 6.1% performance improvement was seen when comparing results across different sections taught by the same instructor. In contrast with the performance outcomes, the survey results indicate that about 72% of students prefer F2F compared to online learning. The findings provide a useful reference as many institutions and programs transition back to more standard F2F or hybrid learning modes. The benefits and drawbacks of each mode are discussed in the specific context of student preferences and challenges faced in online learning during COVID-19.

Simulated Annealing Applied to HIO Method for Phase Retrieval

Phase retrieval utilizing Fourier amplitudes plays a significant role in image recovery. Iterative phase retrieval algorithms have been developed to retrieve phase information that cannot be recorded by detectors directly. However, iterative algorithms face the problem of being trapped in local minima due to the nonconvexity of phase retrieval, and most existing works addressed this by optimizing in multiple runs parallelly to improve the possibility that one of these could reach the global minimum. Alternatively, we propose in this work to increase the probability of reaching the global minimum with one arbitrary initial distribution by adapting simulated annealing in the standard hybrid input-output (HIO) algorithm. Numerical and experimental results demonstrate that the proposed method reconstructs images with mean square errors 50.12% smaller than those reconstructed by HIO. More importantly, the proposed method can be applied to any HIO-based algorithm with multiple runs to further improve the performance.

Safety and efficacy of intermittent presumptive treatment with sulfadoxine-pyrimethamine using rapid diagnostic test screening and treatment with dihydroartemisinin-piperaquine at the first antenatal care visit (IPTp-SP+): study protocol for a randomized controlled trial

BackgroundIntermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended by the World Health Organization for the prevention of malaria in pregnancy (MIP)-associated adverse outcomes in high burden areas. However, the efficacy of IPTp-SP has decreased in step with increasing parasite drug resistance. Suitable alternative strategies are needed.MethodsThis is a protocol for a phase IIIb open-label, two-armed randomized controlled superiority trial to assess the safety and efficacy of a hybrid approach to IPTp combining screening and treatment with dihydroartemisinin-piperaquine (DP) to the current IPTp-SP regimen at the first antenatal care clinic visit. Pregnant women without HIV infection and without signs or symptoms of malaria will be randomized to either standard IPTp-SP or hybrid IPTp-SP plus screening and treatment (IPTp-SP+). In the IPTp-SP+ arm, participants who screen positive by rapid diagnostic test for P. falciparum will be treated with DP at the first antenatal visit while those who screen negative will receive SP per current guidelines. All participants will be administered SP on days 35 and 63 and will be actively followed biweekly up to day 63 and then monthly until delivery. Infants will be followed until 1 year after delivery. The primary endpoint is incident PCR-confirmed MIP at day 42. Secondary endpoints include incident MIP at other time points, placental malaria, congenital malaria, hemoglobin trends, birth outcomes, and incidence of adverse events in infants up to the first birthday.DiscussionA hybrid approach to IPTp that combines screening and treatment with an artemisinin-based combination therapy at the first visit with standard IPTp-SP is hypothesized to confer added benefit over IPTp-SP alone in a high malaria transmission area with prevalent SP resistant parasites.Trial registrationPan African Clinical Trials Registry 201905721140808. Registered retrospectively on 11 May 2019