Warm nights drive Coffea arabica ripening in Tanzania.

Studies have demonstrated that plant phenophases (e.g. budburst, flowering, ripening) are occurring increasingly earlier in the season across diverse ecologies globally. Despite much interest that climate change impacts have on coffee (Coffea arabica), relatively little is known about the driving factors determining its phenophases. Using high-resolution microclimatic data, this study provides initial insights on how climate change is impacting C. arabica phenophases in Tanzania. In particular, we use generalized additive models to show how warming nocturnal temperatures (Tnight), as opposed to day-time or maximum temperatures, have a superseding effect on the ripening of coffee and subsequent timing of harvest. A warm night index (WNI), generated from mean nocturnal temperature, permits accurate prediction of the start of the harvest season, which is superior to existing methods using growing degree days (GDD). The non-linear function indicates that a WNI of 15 °C is associated with the latest ripening coffee cherries (adjusted R2 = 0.95). As the WNI increases past the inflection point of ~ 16 °C, ripening occurs earlier and progresses more or less linearly at a rate of ~ 17 ± 1.95 days for every 1 °C increase in WNI. Using the WNI will thus not only allow farmers to more accurately predict their harvest start date, but also assist with identifying the most suitable adaptation strategies which may reduce harvest-related costs and buffer potential losses in quality and production.

Application of thermography for monitoring stomatal conductance of Coffea arabica under different shading systems.

Stomatal regulation is a key process in the physiology of Coffea arabica (C. arabica). Intrinsically linked to photosynthesis and water relations, it provides insights into the plant's adaptive capacity, survival and growth. The ability to rapidly quantify this parameter for C. arabica under different agroecological systems would be an indispensable tool. Using a Flir E6 MIR Camera, an index that is equivalent to stomatal conductance (Ig) was compared with stomatal conductance measurements (gs) in a mature coffee plantation. In order to account for varying meteorological conditions between days, the methods were also compared under stable meteorological conditions in a laboratory and Ig was also converted to absolute stomatal conductance values (g1). In contrast to typical plant-thermography methods which measure indices once per day over an extended time period, we used high resolution hourly measurements over daily time series with 9 sun and 9 shade replicates. Eight daily time series showed a strong correlation between methods, while the remaining 10 were not significant. Including several other meteorological parameters in the calculation of g1 did not contribute to any stronger correlation between methods. Total pooled data (combined daily series) resulted in a correlation of ρ=0.66 (P≤2.2e-16), indicating that our approach is particularly useful for situations where absolute values of stomatal conductance are not required, such as for comparative purposes, screening or trend analysis. We use the findings to advance the protocol for a more accurate methodology which may assist in quantifying advantageous microenvironment designs for coffee, considering the current and future climates of coffee growing regions.

Looking back and moving forward: 50 years of soil and soil fertility management research in sub-Saharan Africa.

Low and declining soil fertility has been recognized for a long time as a major impediment to intensifying agriculture in sub-Saharan Africa (SSA). Consequently, from the inception of international agricultural research, centres operating in SSA have had a research programme focusing on soil and soil fertility management, including the International Institute of Tropical Agriculture (IITA). The scope, content, and approaches of soil and soil fertility management research have changed over the past decades in response to lessons learnt and internal and external drivers and this paper uses IITA as a case study to document and analyse the consequences of strategic decisions taken on technology development, validation, and ultimately uptake by smallholder farmers in SSA. After an initial section describing the external environment within which soil and soil fertility management research is operating, various dimensions of this research area are covered: (i) 'strategic research', 'Research for Development', partnerships, and balancing acts, (ii) changing role of characterization due to the expansion in geographical scope and shift from soils to farms and livelihoods, (iii) technology development: changes in vision, content, and scale of intervention, (iv) technology validation and delivery to farming communities, and (v) impact and feedback to the technology development and validation process. Each of the above sections follows a chronological approach, covering the last five decades (from the late 1960s till today). The paper ends with a number of lessons learnt which could be considered for future initiatives aiming at developing and delivering improved soil and soil fertility management practices to smallholder farming communities in SSA.

Population pharmacokinetics of gentamicin in preterm neonates: evaluation of a once-daily dosage regimen.

Population pharmacokinetic parameters of gentamicin in preterm neonates on a once-daily dosage regimen of 3.0 mg/kg given intravenously every 24 hours were established prospectively. In 34 preterm neonates with a mean gestational age of 32 +/- 4 (SD), 182 serum gentamicin levels (91 peak/trough pairs) were determined. Individual adjustments of dose or dosage interval were calculated by computer-aided Bayesian forecasting. The parameters Vd, ke, and CL for each patient were obtained by the nonparametric estimation of maximization method. The predictive power of the model was calculated and the pharmacokinetic estimates were statistically analyzed with SPSS/PC. Cluster analysis showed a division into 2 subpopulations (designated 1 and 2) on the basis of postnatal age. The mean +/- SD postnatal age of subpopulation 1 (n = 29) was 6 +/- 2 days (range 1-7) and of subpopulation 2 (n = 5) 15 +/- 4 days (range 12-24). The mean +/- SD gentamicin relative clearances of subpopulation 1 and subpopulation 2 were 0.0515 +/- 0.0128 and 0.1026 +/- 0.0102 L kg(-1) hr(-1), respectively (p < 0.05). The mean +/- SD values for Vd (Lkg(-1)) in both populations 1 and 2 were 0.6916 +/- 0.1670 and 0.7509 +/- 0.1961, respectively (not significantly different). For ke these data were 0.0744 +/- 0.0200 and 0.1366 +/- 0.0522 (p < 0.05). Statistics showed that the data for Vd and ke of subpopulation 1 were normally distributed (Vd and ke skewness 1.61 and 1.46; kurtosis 3.09 and 3.10 respectively). The model yielded a bias of -0.11 mg/L and a precision of 0.36 mg/L. It is recommended that gentamicin be started in a dosage of 3.5 mg/kg intravenously once-daily under close monitoring.

Cytogenetic effects on lymphocytes in osteoporotic patients on long-term fluoride therapy.

The genotoxicity of fluoride in vivo in seven patients with osteoporosis was cytogenetically investigated. The patients were treated with fluoride-containing formulations (disodium monofluorophosphate and sodium fluoride) for a period of 15 months up to 49 months. Fluoride intake ranged from 22.6-33.9 mg F/day and serum fluoride concentrations were between 0.1 mg F/l and 0.2 mg F/l. Peripheral blood lymphocytes of these patients were cultured in vitro and examined for chromosomal aberrations, micronuclei in cytokinesis-blocked binucleated lymphocytes as well as cell cycle progression. When a comparison was made between patients' group and a matched control group, it was found that fluoride at the tested concentrations had no detectable genotoxic potential in human.

Absolute bioavailability of fluoride from disodium monofluorophosphate and enteric-coated sodium fluoride tablets.

OBJECTIVES: The absolute bioavailability and other pharmacokinetic parameters of two fluoride formulations were investigated in 13 healthy volunteers, aged 61-70 years. METHODS: The following formulations were administered, under fasting conditions, in a single-dose three-way cross-over design: tablets of 76 mg disodium monofluoro phosphate (MFP, equivalent to 10.0 mg F- ion), enteric-coated (e.c.) tablets of 25 mg sodium fluoride (NaFor, equivalent of 11.3 mg F- ion), and an isoosmotic aqueous injection solution (4 ml) of 22.1 mg sodium fluoride (NaFiv, equivalent of 10.0 mg F- ion). There was a wash-out period of at least one week between each administration. Blood was sampled before and during a 24-hour period after administration. For F- excretion urine was sampled 48 hours before (baseline) and over the 48 hours after the administration. RESULTS: The mean t1/2 values of the three formulations were 8.3, 8.7 and 8.3 h for MFP, NaFor and NaFiv respectively, and were not significant different. Mean Cmax after MFP was significantly higher than after NaFor [344 vs 142 micrograms.l-1]. Mean tmax for MFP was shorter than for NaFor [1.1 vs 4.6 h]. MFP had significantly higher bioavailability [102.8%] than NaFor [64.2%]. CONCLUSION: The MFP formulation showed higher bioavailability with smaller variation than the NaFor formulation. MFP is preferable, therefore, for fluoride therapy in clinical practice, and changing from NaFor to MFP will require adjustment of the dose.

Compatibility of bupivacaine and iohexol in two mixtures for paediatric regional anaesthesia.

The compatibility of bupivacaine (0.25% and 0.125% wt/vol) with iohexol 300 mg I/ml was investigated. At room temperature bupivacaine does not decompose in these mixtures over a period of 24 h. pH Values (7.10 and 7.33), clarity, osmolality (370 and 379 mOsm/kg) and buffer capacity (0.035 ml and 0.010 ml 0.1000 mol/l NaOH per 10 ml) meet requirements for epidural injection. Both mixtures are suitable for epidurography.

Stability of solutions of doxorubicin and epirubicin in plastic minibags for intravesical use after storage at -20 degrees C and thawing by microwave radiation.

Doxorubicin and epirubicin solutions in plastic minibags for intravesical use were stored at -20 degrees C and thawed at room temperature or by microwave radiation. Concentrations were measured with HPLC and TLC. Doxorubicin and epirubicin solutions could be frozen and stored at -20 degrees C during at least two and four weeks, respectively, and subsequently thawed without loss of content. When the thawed doxorubicin solutions were refrozen and thawed again five weeks later, only a slight decrease of content was measured.

The effect of activated prothrombin-complex concentrate (FEIBA) on joint and muscle bleeding in patients with hemophilia A and antibodies to factor VIII. A double-blind clinical trial.

We designed a double-blind trial to study the effect of an "activated" prothrombin-complex concentrate (FEIBA) on joint and muscle bleeding in hemophiliacs with antibodies to factor VIII. Fifteen patients received either FEIBA or the control preparation (a nonactivated prothrombin-complex concentrate) for a total of 150 bleeding episodes (four mucocutaneous bleeding, 117 joint bleeding, and 29 muscle bleeding). In 64 per cent of the episodes, FEIBA was judged by the physician to be effective; the control preparation was perceived as effective in 52 per cent of the episodes in which it was used. Pairwise comparison of FEIBA and the control preparation for bleeding in the same joint or muscle showed a significantly better result with FEIBA (P = 0.0085). Joint mobility after the use of FEIBA was significantly improved (P = 0.006). There was a high incidence of hepatitis (three of the 15 patients) and of transient disturbances of liver function (nine of 15) during the 15-month observation period.

One and three doses of propranolol a day in hypertension.

In 26 patients with essential hypertension who were on continuous chlorthalidone therapy, 1 and 3 daily doses of propranolol were compared in a crossover study. Plasma propranolol levels and heart rates had larger daily fluctuations on single-dose therapy than on 3 times daily; plasma renin activity was more constant. There was no significant difference in blood pressures. Once-daily propranolol dosage was well tolerated and possibly gave less rise to the troublesome side effect of vivid dreaming.

Gene frequencies of blood groups in Dutch swine breeds.

Gene frequencies of blood groups at 6 loci were estimated within two Dutch breeds of swine, Dutch Landrace and Dutch Large White. At all loci there were significant differences between breeds. The relationship of the two breeds with, respectively, the Germany Landrace breed and the German Large White breed could be confirmed by the gene frequencies.