Enhancing soil health and productivity of Lycopersicon esculentum Mill. using Sargassum johnstonii Setchell & Gardner as a soil conditioner and fertilizer

This study was aimed at developing a protocol for improving soil health using Sargassum johnstonii as a conditioner and fertilizer. Tomato (Lycopersicon esculentum) plants were raised on seaweed-amended soil in experimental fields of Department of Botany, University of Delhi, India. Soil was amended with granular (G) and powder (P) seaweed forms in the proportion of 12.5 % (G₁ and P₁), 25 % (G₂ and P₂), and 37.5 % (G₃ and P₃) (w/w). To compare the efficacy of seaweed fertilizer with a conventional organic fertilizer, a parallel series (positive control) was run with vermicompost (V) in the above-mentioned proportions. Unamended soil served as control (C). The nutrient status of S. johnstonii and vermicompost was analyzed prior to giving treatments. Physicochemical properties of the amended soils as well as growth, productivity, and biochemical constituents of tomato grown in soil with each treatment were analyzed. Higher concentration of granular form of seaweed (G₃) in the soil resulted in 144, 268, 122, 138, and 188 % increase in Na, K, Mg, Ca, and Zn, respectively. Seaweed-amended soil had higher porosity and water-holding capacity as compared to C. Tomato plants raised on seaweed (G₃ and P₃)-amended soil showed an increased overall growth, with earlier flowering and fruiting as compared to control plants. Plants raised on G₃-amended soil showed significantly higher levels of proteins (95 mg?g^?1 FW) in leaves, and vitamin C (99.2 mg 100 g^?1) and lycopene (5.78 mg 100 g^?1) in fruits. The present study showed that S. johnstonii biomass has a high potential to condition and fertilize the soil for improved crop productivity.     

Timing of eating during transition impacts feedlot cattle diet and liveweight gain

The timing of eating, relative to when feed is offered, is affected by the social rank of feedlot cattle due to limited feed bunk space. As cattle can select feed based on dietary preference, the timing of eating for cattle in feedlot may be associated with the ingested diet composition. Our objectives were to determine the nutritive value and timing of feed ingested by 100 feedlot cattle during transition and the association of timing of eating with feeding behaviours and average daily gain (ADG). Cattle behaviour and timing of eating were determined on 100 feedlot cattle using accelerometer-based ear tag sensors from days 3 to 6 post feedlot induction (observation period), and the ongoing impact of this period on ADG was determined for the full feed period (75 days). To determine eating patterns at the time of feed offer, cattle were grouped according to the number of days they were recorded as eating within 1 h of feed being offered across 4 observation days, G⁰: not present across 4 days, G¹: present for 1 day, G²: 2 days, G³: 3 days and G⁴: present for each of the 4 days. Total mixed ration (TMR) samples were collected for nutritive value analysis from four locations along the feed bunk from the time feed was offered and at hourly intervals thereafter for 7 h each day during the observation period. The composition of feed in the bunk changed across the 7 h of measurement (P < 0.05). The DM and CP of feed increased from 65 to 70% and 15 to 16%, respectively, and the NDF decreased from 36 to 32%. Thus, the preferred TMR feed component was the fibrous dietary fraction. However, the overall composition of the ingested diet for 7 h post feeding was similar between groups. Cattle in G⁰ had reduced eating time (0.7 vs 4.8%; P < 0.001), rumination time (4.5 vs 19.5%; P < 0.001) and ADG (1.0 vs 1.3 kg/d; P < 0.05) across the study, as compared with cattle in G⁴. Offering a more fibrous ration during feedlot transition, and customised cattle segregation and/or customised feeding regimes based on sensor derived feeding behaviour profiles during acclimation to feedlot can optimise ADG, animal welfare and feedlot profit.     

The effects of corticosteroids on immunoregulation in sarcoidosis.

The effects of in vivo hydrocortisone administration on the kinetics and functional capabilities of cells involved in the immune response in sarcoidosis were examined. Untreated sarcoidosis patients have a decrease in the absolute numbers of circulating T lymphocytes (P < 0.05). However, with regard to the proportions of T lymphocyte subpopulations, there is an increase in the relative proportions of IgG Fc receptor positive T cells (T_G) (P < 0.01), which have suppressor capabilities in certain in vitro systems of mitogen-induced antibody production, and a relative decrease in IgM Fc receptor positive T lymphocytes (T^M) which have helper effects in this system (P < 0.05). Additionally, sarcoidosis patients have circulating “suppressor” monocytes capable of suppressing anti-sheep red blood cell (SRBC) plaque-forming cell (PFC) responses by pokeweed mitogen (PWM)-stimulated lymphocytes. The in vitro removal of this cell abrogated this depressed response (P < 0.01). Intravenous administration of hydrocortisone produced a transient absolute T lymphocytopenia (P < 0.01) accompanied by a relative increase in T^G cells (P < 0.01) and a relative decrease in T_M cells (P < 0.02). Four hours after hydrocortisone therapy, at the point of maximal hydrocortisone-induced monocytopenia (P < 0.01), the suppressed ability of sarcoidosis lymphocytes to synthesize and secrete in vitro anti-SRBC antibody after polyclonal activation was corrected (P < 0.01), and PFC responses comparable to those seen in untreated normal subjects were obtained. These studies demonstrate that corticosteroid administration has profound effects on certain in vitro demonstrable immunoregulatory abnormalities in sarcoidosis.     

Modelling photosynthesis in shallow algal production ponds

Shallow ponds with rapidly photosynthesising cyanobacteria or eukaryotic algae are used for growing biotechnology feedstock and have been proposed for biofuel production but a credible model to predict the productivity of a column of phytoplankton in such ponds is lacking. Oxygen electrodes and Pulse Amplitude Modulation (PAM) fluorometer technology were used to measure gross photosynthesis (P _G) vs. irradiance (E) curves (P _G vs. E curves) in Chlorella (chlorophyta), Dunaliella salina (chlorophyta) and Phaeodactylum (bacillariophyta). P _G vs. E curves were fitted to the waiting-in-line function [P _G = (P _Gmax × E/E_opt) × exp(1 — E/E_opt)]. Attenuation of incident light with depth could then be used to model P _G vs. E curves to describe P _G vs. depth in pond cultures of uniformly distributed planktonic algae. Respiratory data (by O2-electrode) allowed net photosynthesis (P _N) of algal ponds to be modelled with depth. Photoinhibition of photosynthesis at the pond surface reduced P _N of the water column. Calculated optimum depths for the algal ponds were: Phaeodactylum, 63 mm; Dunaliella, 71 mm and Chlorella, 87 mm. Irradiance at this depth is ≈ 5 to 10 μmol m^?2 s^?1 photosynthetic photon flux density (PPFD). This knowledge can then be used to optimise the pond depth. The total net P _N [μmol(O2) m^?2 s^?1] were: Chlorella, ≈ 12.6 ± 0.76; Dunaliella, ≈ 6.5 ± 0.41; Phaeodactylum ≈ 6.1 ± 0.35. Snell’s and Fresnel’s laws were used to correct irradiance for reflection and refraction and thus estimate the time course of P _N over the course of a day taking into account respiration during the day and at night. The optimum P _N of a pond adjusted to be of optimal depth (0.1–0.5 m) should be approximately constant because increasing the cell density will proportionally reduce the optimum depth of the pond and vice versa. Net photosynthesis for an optimised pond located at the tropic of Cancer would be [in t(C) ha^?1 y^?1]: Chlorella, ≈ 14.1 ± 0.66; Dunaliella, ≈ 5.48 ± 0.39; Phaeodactylum, ≈ 6.58 ± 0.42 but such calculations do not take weather, such as cloud cover, and temperature, into account.     

Using combined measurements of gas exchange and chlorophyll fluorescence to investigate the photosynthetic light responses of plant species adapted to different light regimes

One broad-leaved pioneer tree, Alnus formosana, two broad-leaved understory shrubs, Ardisia crenata and Ardisia cornudentata, and four ferns with different light adaptation capabilities (ranked from high to low, Pyrrosia lingus, Asplenium antiquum, Diplazium donianum, Archangiopteris somai) were used to elucidate the light responses of photosynthetic rate and electron transport rate (ETR). Pot-grown materials received up to 3 levels of light intensity, i.e., 100%, 50% and 10% sunlight. Both gas exchange and chlorophyll (Chl) fluorescence were measured simultaneously by an equipment under constant temperature and 7 levels (0?C2,000 ??mol m^?2 s^?1) of photosynthetic photon flux density (PPFD). Plants adapted to-or acclimated to high light always had higher light-saturation point and maximal photosynthetic rate. Even materials had a broad range of photosynthetic capacity [maximal photosynthetic rate ranging from 2 to 23 ??mol(CO₂) m^?2 s^?1], the ratio of ETR to gross photosynthetic rate (P _G) was close for A. formosana and the 4 fern species when measured under constant temperature, but the PPFD varied. In addition, P. lingus and A. formosana grown under 100% sunlight and measured at different seasonal temperatures (15, 20, 25, and 30°C) showed increased ETR/P _G ratio with increasing temperature and could be fitted by first- and second-order equations, respectively. With this equation, estimated and measured P _G were closely correlated (r ² = 0.916 and r ² = 0.964 for P. lingus and A. formosana, respectively, p<0.001). These equations contain only the 2 easily obtained dynamic indicators, ETR and leaf temperature. Therefore, for some species with near ETR/P _G ratio in differential levels of PPFD, these equations could be used to simulate dynamic variation of leaf scale photosynthetic rate under different temperature and PPFD conditions.     

Light induction of nonphotochemical quenching,CO2 fixation,and photoinhibition in woody and fern species adapted to different light regimes

We aimed to find out relations among nonphotochemical quenching (NPQ), gross photosynthetic rate (P _G), and photoinhibition during photosynthetic light induction in three woody species (one pioneer tree and two understory shrubs) and four ferns adapted to different light regimes. Pot-grown plants received 100% and/or 10% sunlight according to their light-adaptation capabilities. After at least four months of light acclimation, CO₂ exchange and chlorophyll fluorescence were measured simultaneously in the laboratory. We found that during light induction the formation and relaxation of the transient NPQ was closely related to light intensity, light-adaption capability of species, and P _G. NPQ with all treatments increased rapidly within the first 1–2 min of the light induction. Thereafter, only species with high P _G and electron transport rate (ETR), i.e., one pioneer tree and one mild shade-adapted fern, showed NPQ relaxing rapidly to a low steady-state level within 6–8 min under PPFD of 100 μmol(photon) m^?2 s^?1 and ambient CO₂ concentration. Leaves with low P _Gand ETR, regardless of species characteristics or inhibition by low CO₂ concentration, showed slow or none NPQ relaxation up to 20 min after the start of low light induction. In contrast, NPQ increased slowly to a steady state (one pioneer tree) or it did not reach the steady state (the others) from 2 to 30 min under PPFD of 2,000 μmol m^?2 s^?1. Under high excess of light energy, species adapted to or plants acclimated to high light exhibited high NPQ at the initial 1 or 2 min, and showed low photoinhibition after 30 min of light induction. The value of fastest-developing NPQ can be quickly and easily obtained and might be useful for physiological studies.     

The reversal of the myosin and actomyosin ATPase reactions and the free energy of ATP binding to myosin

Evidence is presented that both myosin and actomyosin in presence of Mg²⁺ and KCl catalyze an incorporation of ³²P_i into ATP. The rate with actomyosin is about $\text{1}\text{500}$ the rate of ATP hydrolysis; the rate with myosin is less than $\text{1}\text{100}$ of that with actomyosin. With myosin, but not with actomyosin, an apparent initial “burst” of ³²P_i incorporation into ATP is observed. Actin binding thus promotes ATP dissociation. The data with myosin allow estimation of both the amount of enzyme-bound [³²P]-ATP present and the rate constant, k_?1, for dissociation of the myosin· ATP. From these results and other data a ?ΔG^o for ATP binding to myosin of 12–13 kcal/mole may be estimated, with a much lower ?ΔG^o for hydrolysis of enzyme-bound ATP. Protein conformational change accompanying ATP binding appears to be the principal means of capture of energy from the overall reaction of ATP cleavage.     

Effects of irradiance and salinity on the growth of carpospore-derived tetrasporophytes of Gracilaria edulis and Gracilaria tenuistipitata var liui (Rhodophyta)

Gracilaria edulis and Gracilaria tenuistipitata var liui are agarophytes with high commercial value which are currently cultivated in countries like India and Thailand. They have great potential for mariculture in Malaysia. Experiments were carried out to study carpospore germination and determine the effects of irradiance and salinity on the growth of these two species. Both species showed the Dumontia type of carpospore development. Both species showed increased daily growth rate (% day^?1) with increasing irradiance and tolerance for a wide range of salinity with a preference for low salinity. G. edulis grew best at 100 μmol photons m^?2 s^?1 and 15 psu while G. tenuistipitata var liui grew best at 60–130 μmol photons m^?2 s^?1 and 15 psu. The highest growth rate obtained for G. edulis and G. tenuistipitata var liui was 13.57 and 19.7 % day^?1 respectively. tenuistipitata var liui. ANOVA showed that both irradiance and salinity have significant effect on the growth of both species (P?<?0.05). The results showed that G. tenuistipitata var liui is a good candidate for mass cultivation in Malaysian brackish waters. Besides, this study also showed the feasibility of using spore culture to provide stocks for sustainable farming of Gracilaria.     

IGERS: Inferring Gibbs Energy Changes of Biochemical Reactions from Reaction Similarities

Mathematical analysis and modeling of biochemical reaction networks requires knowledge of the permitted directionality of reactions and membrane transport processes. This information can be gathered from the standard Gibbs energy changes (ΔG⁰) of reactions and the concentration ranges of their reactants. Currently, experimental ΔG⁰ values are not available for the vast majority of cellular biochemical processes. We propose what we believe to be a novel computational method to infer the unknown ΔG⁰ value of a reaction from the known ΔG⁰ value of the chemically most similar reaction. The chemical similarity of two arbitrary reactions is measured by the relative number (T) of co-occurring changes in the chemical attributes of their reactants. Testing our method across a validated reference set of 173 biochemical reactions with experimentally determined ΔG⁰ values, we found that a minimum reaction similarity of T = 0.6 is required to infer ΔG⁰ values with an error of <10 kJ/mol. Applying this criterion, our method allows us to assign ΔG⁰ values to 458 additional reactions of the BioPath database. We believe our approach permits us to minimize the number of ΔG⁰ measurements required for a full coverage of a given reaction network with reliable ΔG⁰ values.     

The phosphorylation potentials generated by respiring Ehrlich ascites tumor mitochondria

The extra- and intramitochondrial phosphorylation potentials (ΔG_p(out) and ΔG_p(in), respectively) generated by respiring Ehrlich ascites tumor mitochondria were determined, using succinate, pyruvate + malate, ascorbate + N,N,N′,N′-tetramethyl-p-phenylenediamine, and ascorbate + ferrocyanide as substrate systems. Values of ΔG_p(out) exceeding 15 kcal mol^?1 (62.8 kJ mol^?1) in post-ADP state 4 respiration were found with succinate as substrate, in agreement with data on normal rat liver mitochondria. ΔG_p(out) values exceeding 15 kcal mol^?1 (62.8 kJ mol^?1) were also observed with ascorbate + TMPD or ascorbate + ferrocyanide as substrates. Slightly lower values of ΔG_p(out) were found with the NAD-linked substrates pyruvate + malate. The intramitochondrial ΔG_p(in) developed by respiring Ehrlich ascites tumor mitochondria respiring on succinate approached 12 kcal mol^?1 (50.2 kJ mol^?1), in agreement with reported values on rat liver mitochondria. The prior accumulation of Ca²⁺ and phosphate by the Ehrlich cell mitochondria did not lower the extramitochondrial ΔG_p(out) developed after a subsequent addition of ADP. Although the rate of oxidative phosphorylation of Ehrlich ascites tumor cells is reduced by intramitochondrial Ca²⁺ and phosphate (Villalobo and Lehninger (1980) J. Biol. Chem., 255, 2457–2464) they are still capable of generating ATP in the suspending medium against a high thermodynamic gradient, as expressed by the [ATP]/[ADP][P_i]mass action ratio.     

The Influence of H+ on the Membrane Potential and Ion Fluxes of Nitella

The resting membrane potential of the Nitella cell is relatively insensitive to [K]_o, but behaves like a hydrogen electrode. K⁺ and Cl^- effluxes from the cell were measured continuously, while the membrane potential was changed either by means of a negative feedback circuit or by external pH changes. The experiments indicate that P_K and P_Cl are independent of pH but are a function of membrane potential. Slope ion conductances, G_K, G_Cl, and G_Na were calculated from efflux measurements, and their sum was found to be negligible compared to membrane conductance. The possibility that a boundary potential change might be responsible for the membrane potential change was considered but was ruled out by the fact that the peak of the action potential remained at a constant level regardless of pH changes in the external solution. The conductance for H⁺ was estimated by measuring the membrane current change during an external pH change while the membrane potential was clamped at K⁺ equilibrium potential. In the range of external pH 5 to 6, H⁺ chord conductance was substantially equal to the membrane conductance. However, the [H]_i measured by various methods was not such as would be predicted from the [H]_o and the membrane potential using the Nernst equation. In artificial pond water containing DNP, the resting membrane potential decreased; this suggested that some energy-consuming mechanism maintains the membrane potential at the resting level. It is probable that there is a H⁺ extrusion mechanism in the Nitella cell, because the potential difference between the resting potential and the H⁺ equilibrium potential is always maintained notwithstanding a continuous H⁺ inward current which should result from the potential difference.     

Disruption of the allosteric phosphorylase a regulation of the hepatic glycogen-targeted protein phosphatase 1 improves glucose tolerance in vivo

Type 2 diabetes is characterised by elevated blood glucose concentrations, which potentially could be normalised by stimulation of hepatic glycogen synthesis. Under glycogenolytic conditions, the interaction of hepatic glycogen-associated protein phosphatase-1 (PP1–G_L) with glycogen phosphorylase a is believed to inhibit the dephosphorylation and activation of glycogen synthase (GS) by the PP1–G_L complex, suppressing glycogen synthesis. Consequently, the interaction of G_L with phosphorylase a has emerged as an attractive anti-diabetic target, pharmacological disruption of which could provide a novel mechanism to lower blood glucose levels by increasing hepatic glycogen synthesis. Here we report for the first time the in vivo consequences of disrupting the G_L–phosphorylase a interaction, using a mouse model containing a Tyr284Phe substitution in the phosphorylase a-binding region of the G_L protein. The resulting G_L^Y284F/Y284F mice display hepatic PP1–G_L activity that is no longer sensitive to allosteric inhibition by phosphorylase a, resulting in increased GS activity under glycogenolytic conditions, demonstrating that regulation of G_L by phosphorylase a operates in vivo. G_L^Y284F/Y284F and G_L^Y284F/+ mice display improved glucose tolerance compared with G_L^+/+ littermates, without significant accumulation of hepatic glycogen. The data provide the first in vivo evidence in support of targeting the G_L–phosphorylase a interaction for treatment of hyperglycaemia. During prolonged fasting the G_L^Y284F/Y284F mice lose more body weight and display decreased blood glucose levels in comparison with their G_L^+/+ littermates. These results suggest that, during periods of food deprivation, the phosphorylase a regulation of G_L may prevent futile glucose–glycogen cycling, preserving energy and thus providing a selective biological advantage that may explain the observed conservation of the allosteric regulation of PP1–G_L by phosphorylase a in mammals.     

The influence of dietary calcium and phosphorus on intestinal calcium transport in rats given vitamin D metabolites.

A new method for the simple analysis of methylated amino acids based on autoradiography is introduced. With this technique a survey of protein methylation in a prokaryote, Escherichia coli, and a eukaryote, fibroblasts in culture, was carried out in an attempt to identify, quantitate, and determine the subcellular localization of all the methylated amino acids found in the proteins of these organisms.In mammalian cells using an established mouse fibroblast line (3T3), we have found that nuclei-free and mitochondria-free cytoplasm contain readily detectable amounts of four identifiable methylated amino acids: N^?,N^?-dimethyllysine, N^?,N^?,N^?-trimethyllysine, N^G,N^G-dimethylarginine (or N^G-methylarginine), and N^G,N′^G-dimethylarginine. The crude nuclear pellet also contains these methylated amino acids, but in addition contains N^?-methyllysine and a new as yet unidentified methylated compound. Histones purified from these nuclei contain essentially the same array of methylated compounds.The ribosomal subunits of the mammalian cells contained only small amounts of the methylated amino acids; the 40S subunit contained a substantial amount of just one, N^G,N^G-dimethylarginine (or N^G-methylarginine), and smaller amounts of N^G,N′^G-dimethylarginine, and an as yet unidentified methylated compound. The 60S subunit contained even smaller amounts of methylated amino acids, 50% of which was N^?,N^?,N^?-trimethyllysine and smaller amounts of N^?-methyllysine, N^?,N^?-dimethyllysine, and N^G,N^G-dimethylarginine. These subunits also contained an as yet unidentified methylated compoundThese results were in marked contrast to those that we obtained with the prokaryote, Escherichia coli. Only the proteins of the 50S ribosomal subunit of the bacteria contained methylated amino acids. Of those present 50% was N^?,N^?,N^?-trimethyllysine, with the remainder distributed about equally between N^?-methyllysine and three unknowns, one of which is apparently the same as that found in the 60S subunit of the mouse fibroblasts. All of the N^?-methyllysine was apparently in the small acidic proteins, L7 and L12.     

Genetic parameters for carcass weight,conformation and fat in five beef cattle breeds

Profitability of beef production can be increased by genetically improving carcass traits. To construct breeding value evaluations for carcass traits, breed-specific genetic parameters were estimated for carcass weight, carcass conformation and carcass fat in five beef cattle breeds in Finland (Hereford, Aberdeen Angus, Simmental, Charolais and Limousin). Conformation and fat were visually scored using the EUROP carcass classification. Each breed was separately analyzed using a multitrait animal model. A total of 6879–19 539 animals per breed had phenotypes. For the five breeds, heritabilities were moderate for carcass weight (h²=0.39 to 0.48, s.e.=0.02 to 0.04) and slightly lower for conformation (h²=0.30 to 0.44, s.e.=0.02 to 0.04) and carcass fat (h²=0.29 to 0.44, s.e.=0.02 to 0.04). The genetic correlation between carcass weight and conformation was favorable in all breeds (r_G=0.37 to 0.53, s.e.=0.04 to 0.05), heavy carcasses being genetically more conformed. The phenotypic correlation between carcass weight and carcass fat was moderately positive in all breeds (r_P=0.21 to 0.32), implying that increasing carcass weight was related to increasing fat levels. The respective genetic correlation was the strongest in Hereford (r_G=0.28, s.e.=0.05) and Angus (r_G=0.15, s.e.=0.05), the two small body-sized British breeds with the lowest conformation and the highest fat level. The correlation was weaker in the other breeds (r_G=0.08 to 0.14). For Hereford, Angus and Simmental, more conformed carcasses were phenotypically fatter (r_P=0.11 to 0.15), but the respective genetic correlations were close to zero (r_G=−0.05 to 0.04). In contrast, in the two large body-sized and muscular French breeds, the genetic correlation between conformation and fat was negative and the phenotypic correlation was close to zero or negative (Charolais: r_G=−0.18, s.e.=0.06, r_P=0.02; Limousin: r_G=−0.56, s.e.=0.04, r_P=−0.13). The results indicate genetic variation for the genetic improvement of the carcass traits, favorable correlations for the simultaneous improvement of carcass weight and conformation in all breeds, and breed differences in the correlations of carcass fat.     

Plant mitochondria use two pathways for the biogenesis of tRNAHis

All tRNA^His possess an essential extra G_–1 guanosine residue at their 5′ end. In eukaryotes after standard processing by RNase P, G_–1 is added by a tRNA^His guanylyl transferase. In prokaryotes, G_–1 is genome-encoded and retained during maturation. In plant mitochondria, although trnH genes possess a G_–1 we find here that both maturation pathways can be used. Indeed, tRNA^His with or without a G_–1 are found in a plant mitochondrial tRNA fraction. Furthermore, a recombinant Arabidopsis mitochondrial RNase P can cleave tRNA^His precursors at both positions G₊₁ and G_–1. The G_–1 is essential for recognition by plant mitochondrial histidyl-tRNA synthetase. Whether, as shown in prokaryotes and eukaryotes, the presence of uncharged tRNA^His without G_–1 has a function or not in plant mitochondrial gene regulation is an open question. We find that when a mutated version of a plant mitochondrial trnH gene containing no encoded extra G is introduced and expressed into isolated potato mitochondria, mature tRNA^His with a G_–1 are recovered. This shows that a previously unreported tRNA^His guanylyltransferase activity is present in plant mitochondria.