Optimal Nutrient Levels Research Articles

Impact of enhanced recovery after surgery on postoperative blood management following primary total knee arthroplasty: a propensity score-matched analysis.

To evaluate the efficacy of blood management in patients underwent unilateral Total Knee Arthroplasty (TKA)under an enhanced recovery after surgery (ERAS) program. Patients underwent unilateral TKA from January 2019 to October 2023 in a university hospital were retrospectively studied. A total of 200 cases were selected in the analysis. After matching with propensity scoring, 51 patients in each group were included. The postoperative Haemoglobin (Hb), albumin (Alb), C-reactive protein (CRP), total length of stay (LOS), and estimated blood loss after operation were compared between the two groups. Clinical outcomes including Western Ontario and McMaster Universities Arthritis Index (WOMAC), SF-12, and Oxford Knee Score (OKS) were also compared atsixweek and threemonth follow-up. The results showed that the Hb of the ERAS group was significantly higher than those of the non-ERAS group (P < 0.05) on the third postoperative. The mean CRP level was lower, LOS was shorter, and Alb level was higher in the ERAS group compared to that in the non-ERAS group (P < 0.05). The clinical outcomes such as WOMAC and OKS, SF-12 scores were higher in the ERAS group at both follow-up. ERAS protocol effectively minimizes perioperative blood loss and supports optimal nutrient levels in patients. ERAS management significantly contributes to the postoperative recovery of knee function in patients undergoing primary total knee arthroplasty.

Modeling uncertainty: the impact of noise in T cell differentiation

BackgroundThe regulatory mechanisms guiding CD4 T cell differentiation are complex and are further influenced by intrinsic cell variability along with that of microenvironmental cues, such as cytokine and nutrient availability.ObjectiveThis study aims to expand our understanding of CD4 T cell differentiation by examining the influence of intrinsic noise on cell fate.MethodologyA model based on a complex regulatory network of early signaling events involved in CD4 T cell activation and differentiation was described in terms of a set of stochastic differential equation to assess the effect of noise intensity on differentiation efficiency to the Th1, Th2, Th17, Treg, and TFH effector phenotypes under defined cytokine and nutrient conditions.ResultsThe increase of noise intensity decreases differentiation efficiencies. In a microenvironment of Th1-inducing cytokines and optimal nutrient conditions, noise levels of 3%, 5% and 10% render Th1 differentiation efficiencies of 0.87, 0.76 and 0.62, respectively, underscoring the sensitivity of the network to random variations. Further increments of noise reveal that the network is relatively stable until noise levels of 20%, where the resulting cell phenotypes becomes heterogeneous. Notably, Treg differentiation showed the highest robustness to noise perturbations. A combined Th1-Th2 cytokine environment with optimal nutrient levels induces a dominant Th1 phenotype; however, removal of glutamine shifts the balance towards the Th2 phenotype at all noise levels, with an efficiency similar to that obtained under Th2-only cytokine conditions. Similarly, combinations of Th1/Treg and Treg/Th17-inducing cytokines along with the removal of either tryptophan or oxygen shift the dominant Th1 and Treg phenotypes towards Treg and Th17 respectively. Model results are consistent with differentiation efficiency patterns obtained under well-controlled experimental settings reported in the literature.ConclusionThe stochastic CD4 T cell mathematical model presented here demonstrates a noise-dependent modulation of T cell differentiation induced by cytokines and nutrient availability. Modeling results can be explained by the network topology, which assures that the system will arrive at stable states of cell functionality despite variable levels of biological intrinsic noise. Moreover, the model provides insights into the robustness of the T cell differentiation process.

In vitro exploration of Acinetobacter strain (SG-5) for antioxidative potential and phytohormone biosynthesis in maize (Zea mays L.) cultivars differing in cadmium tolerance.

Cadmium (Cd) poses serious threats to plant growth and development, whereas the use of plant growth-promoting rhizobacteria (PGPR) has emerged a promising approach to diminish Cd retention in crops. A pot experiment was conducted to evaluate the effect of Cd tolerant strain Acinetobacter sp. SG-5 on growth, phytohormonal response, and Cd uptake of two maize cultivars (3062 and 31P41) under various Cd stress levels (0, 5, 12, 18, 26, and 30μM CdCl2). The results revealed that CdCl2 treatment significantly suppressed the seed germination and growth together with higher Cd retention in maize cultivars in a dose-dependent and cultivar-specific manner with pronounced negative effect in 31P41. However, SG-5 strain exerted positive impact by up-regulating seed germination traits, plant biomass, photosynthetic pigments, enzymatic and non-enzymatic antioxidants, endogenous hormone level indole-3-acetic acid (IAA), abscisic acid (ABA), and sustained optimal nutrient's levels in both cultivars but predominantly in Cd-sensitive one (31P41). Further, Cd-resistant PGPR decreased the formation of reactive oxygen species in terms of malondialdehyde (MDA) and hydrogen peroxide (H2O2) verified through 3, 3'-diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) analysis in conjunction with reduced Cd uptake and translocation in maize root and shoots in comparison to controls, advocating its sufficiency for bacterial-assisted Cd bioremediation. In conclusion, both SG-5 inoculated cultivars exhibited maximum Cd tolerance but substantial Cd tolerance was acquired by Cd susceptible cultivar-31P41 than Cd-tolerant one (3062). Current work recommended SG-5 strain as a promising candidate for plant growth promotion and bacterial-assisted phytomanagement of metal-polluted agricultural soils.

Characterization of Physiology, Photosynthesis, and Nutrition Based on Induced Deficiencies of Macro- and Micronutrients in Basil (Ocimum basilicum L.)

Basil (Ocimum basilicum L.) contains abundant nutrients and is considered an economically important edible vegetable. The optimal nutrient levels will increase the productivity and basil quality. However, prominent research on basil regarding the diagnostic nutrient deficiency standard and the corresponding nutrient uptake is still scarce. To this end, the basil plants were hydroponically cultured and subjected to one of 14 nutrient solution treatments, corresponding to the omission of a single nutrient element (designated as -N, -P, -K, -Ca, -Mg, -NH4+, -NO3−, -S, -Fe, -Mn, -B, -Zn, -Mo, and -Cu) and a complete nutrient solution (CS) as the control. The most common nutrient deficiency symptoms were chlorosis, stunted roots and growth, and even leaf necrosis and abscission, in particular of -N, -P, -NO3−, and -Fe. We also found that basil is a NH4+-sensitive species. The photosynthetic capacity (photosynthesis pigments, Fv/Fm ratio, and greenness index) was disturbed to varying degrees when a single nutrient was omitted from the nutrient solution. Additionally, the omission of a specific single nutrient confers significant differences in the tissue nutrients, regardless of the macronutrients and micronutrients considered. Concomitantly, multivariate analysis suggested the correlations among certain important nutrients were distinctly different under different treatments (correlation analysis); the influences of different nutrient deficiencies on the tissue nutrient concentrations showed similarity (principal component analysis). Collectively, the growth, physiological, and biochemical changes studied in this trial not only improved our knowledge for diagnosing nutrient deficiency symptoms for practical cultivation but also provided a comprehensive understanding of the internal nutrient associations in basil.

Comparative Analysis of Spray-Dried Porcine Plasma and Hydrolyzed Porcine Protein as Animal-Blood-Derived Protein Ingredients for Pet Nutrition

Spray-dried porcine plasma (SDPP) and hydrolyzed porcine protein (HPP) are promising animal protein ingredients sourced from healthy animal blood that are rich in biomolecules, including immunoglobulins, and can be an appropriate and valuable animal protein ingredient to supply the growing need for ingredients that meet the natural needs of carnivorous pets. The aim of this preliminary study was to analyze the chemical composition and mineral profile of a novel HPP compared with results for SDPP. The basic composition analysis followed AOAC guidelines, and the elemental analysis utilized atomic absorption spectrometry. Statistical comparisons employed an independent Student’s t-test (p &lt; 0.05). Both SDPP and HPP are low in moisture (&lt;4.3%) and rich in protein, with SDPP significantly exceeding HPP (75.4% vs. 71.4%). They boast mineral richness indicated by crude ash content (12.7% and 12.5%), featuring Na, K, P, and the trace elements Mo, Fe, and Zn. Notably, SDPP contains elevated molybdenum levels (51.39 mg/100 g vs. 10.93 mg/100 g in HPP), an essential element for diverse animal functions. Quantifying these elements in raw materials aids in achieving optimal nutrient levels in the final product. The study underscores SDPP as an excellent protein source, confirming that its nutritional value is similar to or better than other protein components in pet food.

Improvement and validation of a decision support system to maintain optimal nutrient levels in crops grown in closed-loop soilless systems

To support growers in their transition towards recycling of water and fertilisers in soilless crops, an algorithm consisting of mass balance models was developed and applied via the decision support system NUTRISENSE. This algorithm is commissioned to readjust the composition of the nutrient solution (NS) supplied to plants after a chemical analysis of the drainage solution (DS), aiming to match nutrient input with crop nutrient uptake, thus maintaining the nutrient concentrations within target ranges in the root zone. The algorithm was tested in a pilot study conducted in a commercial greenhouse with tomato grown in a closed-loop soilless system and the data were further used for scenario analyses to assess its sensitivity to inaccuracies in the parameters fed to the models. The nutrient concentrations in the root solution were closer to the target levels after supplying NS readjusted using the current algorithm, thus confirming its efficiency to maintain optimal nutrient levels in the root zone of soilless crops when the DS is recycled. The scenario analysis showed that the algorithm is not sensitive to inaccuracies in input parameters related to the daily volume of NS supplied to the crop, or to the volume of available NS per plant in the soilless system. However, it was moderately sensitive to inaccurate determinations of the nutrient concentrations in the DS. Furthermore, a case study with a closed-loop soilless crop of cucumber managed with NUTRISENSE was conducted, aimed to confirm the efficiency of the algorithm to maintain optimal nutrient levels in the root environment. The case study showed that the readjustment of the nutrient supply using NUTRISENSE could successfully maintain the EC, pH and macronutrient levels within a range of ± 10% variation from the target level. Only SO42- showed a larger discrepancy than ± 10% from the target value, because the supply level of this macronutrient was not estimated directly through the current algorithm but indirectly, through the anion to cation balance. However, this problem can be easily tackled by setting a minimum level of SO42- supply as a present value in NUTRISENSE.

Adipose-derived stem cells (ASCs) culture in spinner flask: improving the parameters of culture in a microcarrier-based system.

Prior to clinical use, extensive in vitro proliferation of human adipose-derived stem cells (ASCs) is required. Among the current options, spinner-type stirred flasks, which use microcarriers to increase the yield of adherent cells, are recommended. Here, we propose a methodology for ASCs proliferation through cell suspension culture using Cultispher-S® microcarriers (MC) under agitation in a spinner flask, with the aim of establishing a system that reconciles the efficiency of cell yield with high viability of the culture during two distinct phases: seeding and proliferation. The results showed that cell adhesion was potentiated under intermittent stirring at 70rpm in the presence of 10% FBS for an initial cell concentration of 2.4 × 104 cells/mL in the initial 24h of cultivation. In the proliferation phase, kinetic analysis showed that cell growth was higher under continuous agitation at 50rpm with a culture medium renewal regime of 50% every 72h, which was sufficient to maintain the culture at optimal levels of nutrients and metabolites for up to nine days of cultivation, representing an 11.1-fold increase and a maximum cell productivity of 422 cells/mL/h (1.0 × 105 viable cells/mL). ASCs maintained the immunophenotypic characteristics and mesodermal differentiation potential of both cell lines from different donors. The established protocol represents a more efficient and cost-effective method to obtain a high proliferation rate of ASCs in a microcarrier-based system, which is necessary for large-scale use in cell therapy, highlighting that the manipulation of critical parameters optimizes the ASCs production process.

Crop yield response functions in nutrient application: A review

AbstractThe question of the optimal nutrient application in agricultural production continues to gather attention because of its relevance in increasing the profitability of crop production and protecting the environment. Economically optimal nutrient application decision rules are commonly derived by fitting crop yield functions to nutrients. The choice of the appropriate yield functional form thus is critical for estimating unbiased and more precise nutrient recommendations. This review explores recent developments in yield response functions to the nutrient application. We first introduce the concept of the economic theory of production and yield response functions. We then explain, with mathematical equations, some commonly used functional forms: quadratic response, Mitscherlich–Baule, deterministic, and stochastic plateau functions. We also summarize the strengths and weaknesses of each functional form and its implications for nutrient management strategies from an economic perspective. In recent studies, researchers have suggested that stochastic plateau functional forms, both linear and quadratic, could explain yield response to the nutrient application in a better way. Finally, we recommend fitting stochastic plateau functions in conjunction with carryover information in a dynamic optimization setting may yield more accurate optimal nutrient levels. Future research should continue to investigate whether these functional forms perform better in different crop and soil environments.

Soybean Seed Analysis as a Nutritional Diagnostic Tool

ABSTRACT Our study examined whether the nutrient content analysis of soybean seed could be used to assess the plant nutritional status, generating results as or more accurate than those obtained by leaf analysis. We hypothesized that soybean nutritional assessment could be carried out using seeds as a reference. Nutritional diagnosis in soybean leaves and seeds was assessed using the Mathematical Chance (MCh), Diagnosis and Recommendation Integrated System (DRIS), and Compositional Nutrient Diagnosis (CND) methods. Results showed that optimal nutrient levels in soybean leaves and seeds estimated by DRIS and CND were equal or close to the average content in the reference population, while slightly different values were obtained by MCh method. Nutrient average contents were larger for soybean seeds than for leaves for nitrogen, phosphorus, sulfur, and zinc; and lower for potassium, calcium, magnesium, boron, copper, iron, and manganese. The ranges of optimum levels obtained for seed nutrient content showed normality in results for the three studied methods (MCh, DRIS, and CND). This indicates that using seeds as a diagnostic tissue for assessing soybean nutritional status is promising. Optimal nutrients levels in soybean seeds estimated mainly by the CND and DRIS methods could help to monitor soybean nutritional status.

Optimisation of xanthan production on glycerol-based medium using response surface methodology

Xanthan is one of the most important biopolymers characterised by a high commercial value. Since the availability of essential nutrients influences its biosynthesis, the aim of this study was the optimisation of carbon, organic and inorganic nitrogen content in glycerol-based medium employing response surface methodology. The cultivation of strain Xanthomonas campestris ATCC 13951 was carried out under appropriate conditions on media with glycerol, peptone and ammonium-nitrate formulated according to Box-Behnken design (33), while the desirability function approach was used for determination of optimal nutrient levels. The final model predicts that the maximal amount of xanthan (12.95 g/L) is produced when the initial contents of glycerol, peptone and ammonium-nitrate in the medium are 32.96 g/L, 0.55 g/L and 0.73 g/L, respectively. To minimize the residual nutrient content and therefore the costs of effluent processing, additional optimisation was performed. In order to validate the optimisation model developed and examine the bioprocess success with crude glycerol as the sole carbon source, additional experiments were performed. The results represent reliable information for further investigations.

Comparative Metabolomics Unravel the Effect of Magnesium Oversupply on Tomato Fruit Quality and Associated Plant Metabolism.

In general, greenhouse cultivation involves the rampant application of chemical fertilizers, with the aim of achieving high yields. Oversaturation with mineral nutrients that aid plant growth, development, and yield may lead to abiotic stress conditions. We explore the effects of excess magnesium on tomato plant metabolism, as well as tomato fruit quality using non-targeted mass spectrometry (MS)-based metabolomic approaches. Tomato plants were subjected to three different experiments, including high magnesium stress (MgH), extremely high magnesium stress (MgEH), and a control with optimal nutrient levels. Leaves, roots, and fruits were harvested at 16 weeks following the treatment. A metabolic pathway analysis showed that the metabolism induced by Mg oversupply was remarkably different between the leaf and root. Tomato plants allocated more resources to roots by upregulating carbohydrate and polyamine metabolism, while these pathways were downregulated in leaves. Mg oversupply affects the fruit metabolome in plants. In particular, the relative abundance of threonic acid, xylose, fucose, glucose, fumaric acid, malic acid, citric acid, oxoglutaric acid, threonine, glutamic acid, phenylalanine, and asparagine responsible for the flavor of tomato fruits was significantly decreased in the presence of Mg oversupply. Altogether, we concluded that Mg oversupply leads to drastically higher metabolite transport from sources (fully expanded leaves) to sinks (young leaves and roots), and thus, produces unfavorable outcomes in fruit quality and development.

Mitigation of effect of salt stress on the nodulation, nitrogen fixation and growth of chickpea (Cicer arietinum L.) by triple microbial inoculation

Plant-associated microorganisms play a critical role in agricultural productivity. Symbiotic microorganisms interact with each other and allow their host leguminous plants to maintain optimal nutrient levels and enhance their growth. Therefore, the goal of the current study was to investigate the synergistic interaction of different symbiotic microbes and its beneficial effect on the nodulation, nodule efficiency, and growth of salt-affected chickpea plants (Cicer arietinum L.). Rhizobium sp. (MK358859) was isolated from the root nodules of chickpea plants. In vitro, magnetite nanoparticles (Fe3O4-NPs) at a concentration of 150 μg/ml significantly enhanced the growth ofRhizobium compared with bulk FeCl3. The impact of seven soil salinity levels (0, 25, 50, 75, 100, 150, and 200 mM NaCl) on germination and subsequent growth was measured. The salinity levels ranging from 25 to 150 mM significantly inhibited the growth of chickpea plants, while the 200 mM level hindered their germination. The influence of triple microbial inoculation of chickpea plants grown in soil with 0, 75 and 150 mM NaCl was studied. Inoculation with mycorrhizal fungi, Fe3O4 NP-inducedRhizobium, and endophytic Stenotrophomonas maltophilia significantly improved the nodulation, leghaemoglobin content, nitrogenase activity, and growth of chickpea grown at salinity level of 75 and 150 mM compared with the controls. The mitigation of the destructive effect of salinity stress was due to improvement in the nutritional status of plants as determined by their K, P, carbohydrate and protein contents. Such triple microbial inoculation could be a successful bio-fertilizer that can contribute to protecting chickpea plants from salinity by attenuating salt-induced oxidative damage.

A practical solution to improve the nutritional balance of Korean dine-out menus using linear programming.

We analysed optimal nutrient levels using linear programming (LP) to reveal nutritional shortcomings of Korean dine-out meals and to stress the importance of fruits and dairy products for maintaining a healthy diet. LP models that minimize deviation from recommended nutrient values were formulated to analyse deficiency or excess of nutrients under the best situation. Korean dine-out menus and nutritional information were taken from the nutrient composition tables for dine-out menus developed by the Ministry of Food and Drug Safety and the nutrient database from Computerized Analysis Program. Acceptable macronutrient distribution ranges of macronutrients such as carbohydrate, protein and fat, and recommended intake levels for energy, vitamins, minerals and cholesterol, by sex, were based on the Dietary Reference Intake for Koreans aged 30-49 years.ParticipantsOptimization was performed on selecting the optimal Korean meal combination. LP optimization models showed that it is unlikely to satisfy all nutrient recommendations with any combination of dine-out menus. Specifically, meal combinations of Korean dine-out menus had high levels of Na and cholesterol and low levels of vitamins and minerals. Four formulations were considered to compare the effects of controlling Na and including fruit and dairy products. The unbalanced diet was resolved with extra consumption of fruits and dairy products. The best meal combination in dine-out menus, even though the proportion and pairing of menus may be unrealistic, is not healthy, and thus one should consume fruits and dairy products to maintain a balanced diet.

Feeding growth restricted premature neonates: a challenging perspective.

Nutrition in the postnatal period is essential to achieve optimal growth and maintain biochemical normality. Feeding growth-restricted premature neonates remains a big challenge for pediatricians and neonatologists. The choice of milk is one of the biggest challenges. Breast milk is recommended, although feeding with preterm formulas can ensure a more consistent delivery of optimal levels of nutrients. The timing of introduction of feeds and the rate of advancement of those feeds in preterm infants are both topics of significant controversy. Early feeding is advantageous because it improves the functional adaptation of the gastrointestinal tract and reduces the duration of total parenteral nutrition. A faster rate of advancement will also reduce the duration of need for parenteral nutrition. Despite this, enteral feeding is often delayed and is often slowly increased in high-risk infants because of a possible increased risk of necrotizing enterocolitis (NEC). Growth-restricted neonates are at increased risk of developing NEC due to a combination of antenatal and postnatal disturbances in gut perfusion. If enteral feeding is introduced earlier and advanced more quickly, this may lead to increased risk of NEC, but slower feeds extend the duration of parenteral nutrition and its risks and may have adverse consequences for survival, growth, and development. Premature infants pose a significant nutritional challenge. Overall, we would suggest the preferential use of human breast milk, early minimal enteral feeds, and standardized feeding protocols with cautious advancements of feeds to facilitate gastrointestinal adaptation and reduce the risk of NEC, however further research is needed.

Effects of nutrient enrichment, irradiance control, and boiling on the color of the brown alga Undaria pinnatifida

The color of Undaria pinnatifida after boiling is an important factor determining its marketable value. Our previous study showed that decreased nutrients and elevated irradiance resulted in increases of lightness and yellowness (i.e., discoloration) of this alga. However, little is known about the optimal levels of nutrients and irradiance required to decrease these color values and the combined effects of these factors and boiling. We conducted two culture experiments to test the effects of nutrients (non-enriched and 1.25, 5, and 25% PESI enriched treatments), irradiance (0, 10, 30, and 180 µmol m−2 s−1), and boiling on lightness L*, redness a*, and yellowness b* of this alga. L* and b* did not differ between non-enriched and 1.25–5% PESI treatments, but were lower in the 25% PESI treatment. L* and b* were lowest at 0–10 µmol m−2 s−1, although negative growth occurred at 0 µmol m−2 s−1. Decreased irradiance had a positive or little effect on a* before boiling, but had a negative effect after boiling. These results suggest that around 25% PESI and 10 µmol m−2 s−1 were the optimal levels to decrease the three color values of this species after boiling.

Formula versus donor breast milk for feeding preterm or low birth weight infants.

When sufficient maternal breast milk is not available, alternative sources of enteral nutrition for preterm or low birth weight infants are donor breast milk or artificial formula. Donor breast milk may retain some of the non-nutritive benefits of maternal breast milk for preterm or low birth weight infants. However, feeding with artificial formula may ensure more consistent delivery of optimal levels of nutrients. Uncertainty exists about the balance of risks and benefits of feeding formula versus donor breast milk for preterm or low birth weight infants. To determine the effect of feeding with formula compared with donor breast milk on growth and development in preterm or low birth weight infants. We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 3), MEDLINE (1966 to March 2014), EMBASE (1980 to March 2014), CINAHL (1982 to March 2014), conference proceedings and previous reviews. Randomised or quasi-randomised controlled trials comparing feeding with formula versus donor breast milk in preterm or low birth weight infants. We extracted data using the standard methods of the Cochrane Neonatal Group, with separate evaluation of trial quality and data extraction by two review authors. Nine trials, in which 1070 infants participated, fulfilled the inclusion criteria. Four trials compared standard term formula versus donor breast milk and five compared nutrient-enriched preterm formula versus donor breast milk. Only the two most recent trials used nutrient-fortified donor breast milk. The trials contain various methodological quality weaknesses, specifically uncertainty about adequate allocation concealment methods in three trials and lack of blinding in most of the trials.Formula-fed infants had higher in hospital rates of increase in weight [mean difference (MD): 2.58 (95% confidence interval (CI) 1.98 to 3.71) g/kg/day], length [MD 1.93 (95% CI 1.23 to 2.62) mm/week] and head circumference [MD 1.59 (95% CI 0.95 to 2.24) mm/week]. We did not find evidence of an effect on post-discharge growth rates or neurodevelopmental outcomes. Formula feeding increased the risk of necrotising enterocolitis: typical risk ratio 2.77 (95% CI 1.40 to 5.46); risk difference 0.04 (95% CI 0.02 to 0.07). In preterm and low birth weight infants, feeding with formula compared with donor breast milk results in a higher rate of short-term growth but also a higher risk of developing necrotising enterocolitis. Limited data on the comparison of feeding with formula versus nutrient-fortified donor breast milk are available. This limits the applicability of the findings of this review as nutrient fortification of breast milk is now a common practice in neonatal care. Future trials may compare growth, development and adverse outcomes in infants who receive formula milk versus nutrient-fortified donor breast milk given as a supplement to maternal expressed breast milk or as a sole diet.

Effect of a commercial seaweed extract (Kelpak®) and polyamines on nutrient-deprived (N, P and K) okra seedlings

In agriculture, nutrient depleted soil is a common problem, hence large amounts of applied fertilizer are required to maintain optimal nutrient levels. Nutrient-deficient plants are often vulnerable to pathogens and show a reduction in yield. In this study, the nutrient-stress-relieving effects of the seaweed concentrate, Kelpak® and a polyamine (PA) solution were investigated. Kelpak® is prepared from Ecklonia maxima (Osbeck) Papenfuss and recently shown to contain endogenous PAs. Okra seedlings [Abelmoschus esculentus (L.) Moench] deprived of nitrogen (N), phosphorous (P) and potassium (K) were treated with either a 0.4% Kelpak® solution or a 10−4M PA solution (a combination of putrescine, spermidine and spermine) three times a week under greenhouse conditions. Both Kelpak® and PA treatments significantly enhanced seedling vigor under nitrogen-deprived conditions. Kelpak® treatment was effective in significantly improving most of the seedling growth parameters under P and K deficiency compared to the respective controls. Although, the PA treatment resulted in some improvement in the growth of the seedlings in P and K deficient plants, these results were not significantly different from the control. The beneficial effect of Kelpak® in relieving nutrient deficiency, especially N deficiency, may in part be due to the PAs present in Kelpak® acting in synergy with other plant growth regulators such as auxin. The application of seaweed concentrate as part of a fertilizing regime could potentially help mitigate the detrimental effects of major nutrient deficiencies, minimizing the use of expensive chemical fertilizers.

Fertilizer response for hybrid and open-pollinated canola and economic optimal nutrient levels

Hybrid (HY) canola (Brassica napus L.) produces a higher seed yield than open-pollinated (OP) canola. While it is expected higher-yielding HY canola may require higher total available nutrients, especially nitrogen (N), the evidence is not conclusive. This study used canola yield data from several site-years and fertility experiments to determine whether HY and OP canola types require different rates of total available N (TAN) and total available phosphorus (TAP). The yield response of the two canola genotypes to TAP was the same, but for TAN the yield response was greater for HY canola. The quadratic yield response results were confirmed using three plateau equations. Optimal TAN for HY canola was higher than for OP canola. Soil test laboratories and producers growing HY canola need to modify N fertility for HY canola, compared with OP canola for which most of the current N fertilizer recommendations were developed. Key words: Economics, fertilizer, yield response, canola, hybrid, open-pollinated

Relationship Between Nutrient Intake and Bone Mineral Density in 20∼30 Year-old Korean Women

The achievement of maximal peak bone mineral density (BMD) in early life is one of the most important strategies for the prevention of osteoporosis, which is affected by nutritional status. However, it has been reported that young Korean women do not consume the optimal levels of nutrients because of the frequent practice of body weight reduction. Therefore, this study was conducted to investigate the relationship between nutrient intakes and BMD in young Korean women. Bone mineral density was measured at the lumbar spine by dual-energy X-ray absorptiometry. Information on health status, lifestyle and physical activity was obtained by questionnaire. Dietary intake was ascertained from a 3-day dietary record. The study sample included 112 Korean women aged 20～39 yr. In accordance with the energy intake of subjects, individuals who had an energy intake that was greater than 80% of the Korean Dietary Reference Intake (KDRI) were assigned to the control group (Control), while those who had an energy intake lower than 80% of the KDRI were assigned to the low intake group (LI). The intake of all nutrients in the LI group was significantly lower than that of the Control. Control subjects also showed nutrient intakes higher than the KDRI, except for Ca and folate. However, LI subjects showed intakes of energy, fiber, Ca, Fe, K, Zn, vitamin A, vitamin B1, vitamin B2 and folate that were lower than the KDRI. The BMD of the lumbar spine in LI subjects was significantly lower than that of the Control subjects. These results suggested that lower nutrient intake has a negative impact on BMD in young women.

Revenue Capacity Efficiency of Pear Trees and Its Decomposition

In this paper we analyze the sources of variation in revenue per unit of trunk cross-sectional area (TCA) across a 0.87-ha block of 272 pear (Pyrus communis L.) trees in 2003. Revenue capacity efficiency associated with TCA provides an overall measure of nutrient deficiency and revenue inefficiency caused by environmental constraints in the fruit production process. Data envelopment analysis (DEA) is adopted to estimate revenue capacity efficiency and its components. The deficiencies of macro- and micronutrients are measured and optimal nutrient levels computed for each individual tree. These measures are aggregated for comparing between grids and between rootstocks.