Use of the FAO AquaCrop model in developing sowing guidelines for rainfed maize in Zimbabwe

This paper presents a procedure in which the water-driven water productivity model AquaCrop was fine-tuned and validated for maize for the local conditions in Zimbabwe and then applied to develop sowing management options for decision support. Data from experiments of 2 seasons in Harare and from 5 other sites around Zimbabwe were used for the local calibration and validation of AquaCrop. Model parameters such as the reference harvest index (HIo); the canopy growth coefficient (CGC); early canopy decline and normalised biomass water productivity (WPb*) were adjusted during model calibration. Model performance was satisfactory after calibration with a Nash-Sutcliffe model efficiency parameter (EF = 0.81), RMSE = 15% and R2 = 0.86 upon validation. To develop sowing guidelines, historical climate series from 13 meteorological stations around Zimbabwe were used to simulate maize yield for 6 consecutive sowing dates determined according to criteria applicable in Zimbabwe. Three varieties and typical shallow and deep soil types were considered in the simulation scenarios. The simulated yield was analysed by an optimisation procedure to select the optimum sowing time that maximised long-term mean yield. Results showed that highest yields depended on the climate of the site (rainfall availability), variety (length of growing cycle) and soil depth (soil water storage capacity). The late variety gave higher mean yields for all sowing dates in the maize belt. Staggered sowing is recommended as a way of combating the effects of rainfall variability and as an answer to labour constraints.Keywords: biomass water productivity, AquaCrop, maize sowing dates, crop modellin

Enantioseparation of flurbiprofen enantiomers using chiral ionic liquids by liquid‐liquid extraction

Flurbiprofen is a kind of nonsteroidal anti‐inflammatory drug, which has been widely used in clinic for treatment of rheumatoid arthritis and osteoarthritis. It has been reported that S‐flurbiprofen shows good performance on clinic anti‐inflammatory treatment, while R‐enantiomer almost has no pharmacological activities. It has important practical values to obtain optically pure S‐flurbiprofen. In this work, chiral ionic liquids, which have good structural designability and chiral recognize ability, were selected as the extraction selector by the assistance of quantum chemistry calculations. The distribution behaviors of flurbiprofen enantiomers were investigated in the extraction system, which was composed of organic solvent and aqueous phase containing chiral ionic liquid. The results show that maximum enantioselectivity up to 1.20 was attained at pH 2.0, 25°C using 1,2‐dichloroethane as organic solvent, 1‐butyl‐3‐methylimidazole L‐tryptophan ([Bmim][L‐trp]) as chiral selector. The racemic flurbiprofen initial concentration was 0.2 mmol L−1, and [Bmim][L‐trp] concentration was 0.02 mol L−1. Furthermore, the recycle of chiral ionic liquids has been achieved by reverse extraction process of the aqueous phase with chiral selector, which is significant for industrial application of chiral ionic liquids and scale‐up of the extraction process

High-resolution measurements of the exited states (n,pn), (n,dn) C-12 cross sections

Measurements of C12 cross sections for the excited states (n,p 0 ) up to (n,p 4 ) and (n,d 0 ), (n,d 1 ) have been carried out. The Van de Graaff neutron generator of the EC-JRC-IRMM laboratory has been used for these measurements. A very thin tritiated target (263 μg/cm 2 ) was employed with deuteron beams energies impinging on the target in the range 2.5–4.0 MeV. Neutrons in the range 18.9–20.7 MeV were produced with an intrinsic energy spread of 0.2–0.25% FWHM. With such narrow neutron energy spread, using a high energy resolution device such as a single crystal diamond detector, several peaks from the outgoing charged particles produced by the (n,p n ), (n,d n ) and also (n,α 0 ) reactions appear in the pulse height spectrum. The peaks can be identified using the reaction Q-values. The diamond detector used for these measurements has shown an intrinsic energy resolution lower than 0.9% FWHM. The analysis of the peaks has permitted to derive the partial carbon reaction cross sections for several excited states. The results are presented in this paper with the associated uncertainties and they are compared with different versions of TENDL compilation when these data are available (e.g. versions 2009, 2010, 2011 and 2015) and also with experimental results available in the EXFOR database

High-precision prompt-γ-ray spectral data from the reaction Pu 241 (nth, f)

In this paper we present results from the first high-precision prompt-γ-ray spectral measurements from the reaction Pu241(nth, f). Apart from one recent experiment, no data are reported in the literature for this fissioning system, which motivated a new dedicated experiment. We have measured prompt-fission γ rays with three cerium-doped LaBr3 (two 5.08cm×5.08 cm and one 7.62cm×7.62 cm) and one CeBr3 (5.08cm×5.08 cm) scintillation detectors, which all exhibit excellent timing and good energy resolution. The average γ-ray multiplicity was determined to be ν̄γ=(8.21±0.09) per fission, the average energy to be εγ=(0.78±0.01) MeV, and the total energy to be Eγ,tot=(6.41±0.06) MeV as the weighted average from all detectors. Since the results from all detectors are in excellent agreement, and the total released γ energy is modestly higher than the one in the present evaluated nuclear data files, we suspect that the underestimation of the prompt-γ heating in nuclear reactors is due to fast-neutron-induced fission on U238 or rather from fission induced by γ rays from neutron capture in the construction material.European Commision NeutAndalus FP7-PEOPLE-2012-CIGPrograma ERINDA 26949

Perceptions of academic staff about mentoring in a Faculty of Dentistry in a public university in South Africa

noneINTRODUCTION: Mentoring programs contribute to the development and retention of academics in dental education. OBJECTIVES: To describe the perceptions of academic staff of the Faculty of Dentistry, University of the Western Cape, South Africa, about a funded pilot mentoring process. DESIGN: Cross-sectional, purposive sampling qualitative design. METHODS: Twenty mentees who had engaged in the funded mentoring process were targeted for semi-structured interviews, to describe their perceptions about the ongoing mentorship process, experiences in other mentoring processes, and expectations about future formal mentoring in the faculty. Quantitative data was analysed descriptively, while content analysis of the qualitative data was performed to identify themes FINDINGS AND CONCLUSIONS: Perceptions of eight mentees, aged 37 to 59 years and spent between 3 and over 20 years in the faculty, were categorized into two themes - 'A welcome initiative' and 'Mentorship seen as a holistic experience'. The program provided the much-needed space where mentees felt they could seek guidance for their development. Expectations from a future formal program included assistance in meeting institutional and personal demands. Participants' expectations were broader than what the pilot program offered, though the benefits reported were similar to earlier studies.non

Kemungkinan Kehadiran Sistiserkus/cacing taenia saginata taiwanensis di Bali

Telah dilakukan suatu penelitian pendahuluan untuk mengetahui kemungkinan adanya sistiserkus atau cacing Taenia saginata taiwanensis di Bali. Pengamatan dilakukanterhadap adanya infeksi sistiserkus secara alami pada hati 638 ekor babi yang dipotong di RPH Denpasar , dari bulan Juni sampai Juli 1993.Bintik-bintik kecil kekuningan atau putih susu, yang diduga merupakan kista T.s. taiwanensis, ditemukan pada 146 hati babi (22,88%). Setiap hati yang terinfeksi mengandung 1 - 6 kista, yang menyebar secara acak di masing-masing lobus. Kebanyakan kista yang ditemukan telah mengalami degenerasi (66.43%) atau kalsifikasi (32.8%). Satu kista mature yang ditemukan (0.7%) dari hati yang positif, ternyata mengandung skoleks taenia yang diperlengkapi dengan kait-kait. Temuan ini menunjukkan kemungkinan adanya sisteserkus cacing Ts. taiwanensis di Bali sebab hati babi bukanlah tempat predileksi utama sistiserkus cacing Taenia solium