Regulation of Nitrogen Metabolism,Photosynthetic Activity,and Yield Attributes of Spring Wheat by Nitrogen Fertilizer in the Semi-arid Loess Plateau Region

It is critical for spring wheat (Triticum aestivum L.) production in the semi-arid Loess Plateau to understand the impact of nitrogen (N) fertilizer on changes in N metabolism, photosynthetic parameters, and their relationship with grain yield and quality. The photosynthetic capacity of flag leaves, dry matter accumulation, and N metabolite enzyme activities from anthesis to maturity were studied on a long-term fertilization trial under different N rates [0 kg ha^?1(N1), 52.5 kg ha^?1 (N2), 105 kg ha^?1 (N3), 157.5 kg ha^?1 (N4), and 210 kg ha^?1 (N5)]. It was observed that N3 produced optimum total dry matter (5407 kg ha^?1), 1000 grain weight (39.7 g), grain yield (2.64 t ha^?1), and protein content (13.97%). Our results showed that N fertilization significantly increased photosynthetic parameters and N metabolite enzymes at all growth stages. Nitrogen harvest index, partial productivity factor, agronomic recovery efficiency, and nitrogen agronomic efficiency were decreased with increased N. Higher N rates (N3–N5) maintained higher photosynthetic capacity and dry matter accumulation and lower intercellular CO₂ content. The N supply influenced NUE by improving photosynthetic properties. The N3 produced highest chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate, grain yield, grain protein, dry matter, grains weight, and N metabolite enzyme activities compared to the other rates (N1, N2, N4, and N5). Therefore, increasing N rates beyond the optimum quantity only promotes vegetative development and results in lower yields.

     

Impacts of cage culture on physico-chemical and bacteriological water quality in Lake Volta,Ghana

The effects of cage fish farming on physico-chemical and bacteriological water quality in Lake Volta, Ghana, were investigated in 2013–2014. Farmed and unfarmed (control) areas of the lake were selected for monitoring. Nutrients, temperature, dissolved oxygen, conductivity, turbidity, pH, total coliforms, Pseudomonas and Vibrio spp. in the water were monitored monthly. Analyses of the water samples were carried out according to standard procedures. Physico-chemical quality of the water in both farm and control sites were within ranges typical of minimally impacted water and did not vary significantly between the two contrasting sites. The bacteriological analysis, however, revealed contamination of the lake water by fish farming. The bacterial counts at the farmed sites were significantly higher (p < 0.05) than those of the control sites, with figures at the farmed sites ranging from 132 to 1 708 cfu 100 ml?1 for total coliforms, 514 to 5 170 cfu 100 ml?1 Pseudomonas spp. and 14 to 516 cfu 100 ml?1 for Vibrio spp. The results suggested that cage fish farming has increased bacterial loads in the lake water, but has had minimal impact on its physico-chemical quality.     

Influence of peripheral hydrogen bonding on the mechanical properties of photo-cross-linked star-shaped poly(D,L-lactide) networks

Four-arm, star-shaped poly(D,L-lactide) (PDLLA) oligomers of controlled molar mass and narrow molar mass distribution were successfully synthesized by use of an ethoxylated pentaerythritol initiator. Derivatization of the terminal hydroxyl groups with either methacrylic anhydride (MAAH) or 2-isocyanatoethyl methacrylate (IEM) to yield PDLLA-M (M = methacrylate end group) and PDLLA-UM (UM = urethane methacrylate end group), respectively, was monitored by in situ Fourier transform infrared (FTIR) spectroscopy. Photo-cross-linking of the functional oligomers yielded networks with high gel contents (>95%). The glass transition temperature (T(g)) of these networks was strongly dependent on prepolymer molar mass, and networks based on low molar mass precursors were more rigid than the networks obtained from higher molar mass oligomers. The tensile strength (TS) and Young's modulus of the PDLLA-M samples, approximately 7 and 17 MPa, respectively, were significantly lower than the values of 19 MPa (TS) and 113-354 MPa (Young's modulus) for the PDLLA-UM samples. The introduction of terminal hydrogen-bonding sites that were adjacent to the photo-cross-linking site resulted in higher performance poly(lactide)-based bioadhesives.     

Whole-body vibration therapy does not improve the peripheral nerve regeneration in experimental model

Objectives:Whole-body vibration (WBV) is commonly used to improve motor function, balance and functional performance, but its effects on the body are not fully understood. The main objective was to evaluate the morphometric and functional effects of WBV in an experimental nerve regeneration model.Methods:Wistar rats were submitted to unilateral sciatic nerve crush and treated with WBV (4-5 weeks), started at 3 or 10 days after injury. Functional performances were weekly assessed by sciatic functional index, horizontal ladder rung walking and narrow beam tests. Nerve histomorphometry analysis was assessed at the end of the protocol.Results:Injured groups, sedentary and WBV started at 3 days, had similar functional deficits. WBV, regardless of the start time, did not alter the histomorphometry parameters in the regeneration process.Conclusions:The earlier therapy did not change the expected and natural recovery after the nerve lesion, but when the WBV starts later it seems to impair function parameter of recovery.     

Rapid determination of isoamyl nitrite in pharmaceutical preparations by flow injection analysis with on‐line UV irradiation and luminol chemiluminescence detection

Isoamyl nitrite is used as a therapeutic reagent for cardiac angina and as an antidote for cyanide poisoning, but it is abused because of its euphoric properties. Therefore, a method to determine isoamyl nitrite is required in many fields, including pharmaceutical and forensic studies. In this study, a simple, rapid and sensitive method for the determination of isoamyl nitrite was developed using a flow injection analysis system equipped with a chemiluminescence detector and on‐line photoreactor. This method is based on on‐line ultraviolet irradiation of isoamyl nitrite and subsequent luminol chemiluminescence detection without the addition of an oxidant. A linear standard curve was obtained up to 1.0 μM of isoamyl nitrite with a detection limit (blank + 3SD) of 0.03 μM. The method was successfully applied to determine isoamyl nitrite content in pharmaceutical preparations. Copyright © 2013 John Wiley & Sons, Ltd.     

Accuracy of rapid tests for malaria and treatment outcomes for malaria and non-malaria cases among under-five children in rural Ghana

Background

WHO now recommends test-based management of malaria across all transmission settings. The accuracy of rapid diagnostic test (RDT) and the outcome of treatment based on the result of tests will influence acceptability of and adherence to the new guidelines.

Method

We conducted a study at the Kintampo hospital in rural Ghana to evaluate the performance of CareStart, a HRP-2 based RDT, using microscopy as reference. We applied IMCI treatment guidelines, restricted ACT to RDT-positive children and followed-up both RDT-positive (malaria) and RDT-negative (non-malaria) cases over 28 days.

Results

436 children were enrolled in the RDT evaluation and 391 (children with haemoglobin >8.0 gm/dl) were followed-up to assess treatment outcomes. Mean age was 25.4 months (s.d. 14.6). Sensitivity and specificity of the RDT were 100.0% and 73.0% respectively. Over the follow-up period, 32 (18.5%) RDT-negative children converted to positive, with 7 (4.0%) of them presenting with fever. More children in the non-malaria group made unscheduled visits than children in the malaria group (13.3% versus 7.7%) On all scheduled follow-up visits, proportion of children having a temperature higher than that recorded on day 0 was higher in the non-malaria group compared to the malaria group. Reports of unfavourable treatment outcomes by caregivers were higher among the non-malaria group than the malaria group.

Conclusions

The RDT had good sensitivity and specificity. However a minority of children who will not receive ACT based on RDT results may develop clinical malaria within a short period in high transmission settings. This could undermine caregivers'' and health workers'' confidence in the new guidelines. Improving the quality of management of non-malarial febrile illnesses should be a priority in the era of test-based management of malaria.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00832754","term_id":"NCT00832754"}}NCT00832754