Application of Overall Dynamic Body Acceleration as a Proxy for Estimating the Energy Expenditure of Grazing Farm Animals: Relationship with Heart Rate

Estimating the energy expenditure of farm animals at pasture is important for efficient animal management. In recent years, an alternative technique for estimating energy expenditure by measuring body acceleration has been widely performed in wildlife and human studies, but the availability of the technique in farm animals has not yet been examined. In the present study, we tested the potential use of an acceleration index, overall dynamic body acceleration (ODBA), as a new proxy for estimating the energy expenditure of grazing farm animals (cattle, goats and sheep) at pasture with the simultaneous evaluation of a conventional proxy, heart rate. Body accelerations in three axes and heart rate for cows (n = 8, two breeds), goats (n = 6) and sheep (n = 5) were recorded, and the effect of ODBA calculated from the body accelerations on heart rate was analyzed. In addition, the effects of the two other activity indices, the number of steps and vectorial dynamic body acceleration (VeDBA), on heart rate were also investigated. The results of the comparison among three activity indices indicated that ODBA was the best predictor for heart rate. Although the relationship between ODBA and heart rate was different between the groups of species and breeds and between individuals (P<0.01), the difference could be explained by different body weights; a common equation could be established by correcting the body weights (M: kg): heart rate (beats/min) = 147.263∙M ^-0.141 + 889.640∙M ^-0.179∙ODBA (g). Combining this equation with the previously reported energy expenditure per heartbeat, we estimated the energy expenditure of the tested animals, and the results indicated that ODBA is a good proxy for estimating the energy expenditure of grazing farm animals across species and breeds. The utility and simplicity of the procedure with acceleration loggers could make the accelerometry technique a worthwhile option in field research and commercial farm use.     

Isolation,Structures and Biological Activities of Colletotrichins,Phytotoxic Substances from Colletotrichum nicotianae

From the phytopathogenic fungus, Colletotrichum nicotianae, three phytotoxic substances have been isolated and named colletotrichin, colletotrichins B and C (1, 2 and 3). The structures of these compounds have been elucidated from the physical and chemical evidence. When applied on the tobacco leaves, colletotrichins induced the symptom similar to that of the tobacco anthracnose caused by C. nicotianae. The compounds were also toxic to the lettuce and rice seedlings.     

Induction of the H+ Release from Thylakoid Membranes by Illumination in the Presence of Protonophores at High Concentrations

The generally observed light-induced uptake of protons intothe thylakoid lumen is diminished by adding protonophores. Insteadof the H⁺ uptake, the release of protons was observed duringillumination in the presence of various protonophores at highconcentrations, namely, 1 µM nigericin, 10 µM carbonylcyanidem-chlorophenylhydrazone or 30 µM gramicidin. An uncoupler,NH₄C1 (4 mM), and a detergent, Triton X-100 (0.02%), also inducedthe H⁺ release but a K⁺ ionophore, valinomycin, did not. Theamount of H⁺ released reached about 100 nmol H⁺ (mg Chl)^–1at pH 7.5 under continuous illumination. The rate of the H⁺release was similar to that of the conventional H⁺ uptake butits dark relaxation was much slower than that of the H⁺ uptake.We compared the H⁺ release in protonophore-added thylakoidswith the previously reported H⁺ release in coupling factor 1(CF₁-depleted thylakoids. The H⁺ release in thylakoids withnigericin showed similar characteristics to that in CF₁-depletedthylakoids in terms of their responses to pH, phenazine methosulfateand light intensity. Both types of H⁺ release were relativelyinsensitive to DCMU and were stimulated somewhat by DCMU atlow concentrations (around 200 nM). Nigericin did not inhibitthe superoxide dismutase activity of the membranes. These resultsindicate that the H⁺ release in protonophore-added thylakoidsand that in CF₁ depleted thylakoids involve the same mechanismand that water-derived protons from PS II that result from animpairment of the activity of superoxide dismutase, as previouslyproposed, are not involved. Judging from the rate of electronflow and the lumenal acidification under the illumination, weconclude that the H⁺ release is a light-dependent scalar processwhich can be observed in thylakoid membranes with high H⁺ permeability.The H⁺ release of this type was not observed in mitochondriafrom rat liver or in chromatophores from Rhodobacter sphaeroides. (Received November 29, 1990; Accepted June 27, 1991)     

Cyanide Insensitive Respiration of Sporobolomyces Red Yeast

The respiration of a Sporobolomyces red yeast is investigated with intact cells. The results show that the respiration is not inhibited at all, but moderately accelerated by cyanide and CO. Although the chemical nature of this fact is not yet clarified, the existence of a heat-labile and cyanide-insensitive oxidative enzyme system in this yeast is presumable.     

Computational analysis and functional expression of ancestral copepod luciferase

We recently reported the cDNA sequences of 11 copepod luciferases from the superfamily Augaptiloidea in the order Calanoida. They were classified into two groups, Metridinidae and Heterorhabdidae/Lucicutiidae families, by phylogenetic analyses. To elucidate the evolutionary processes, we have now further isolated 12 copepod luciferases from Augaptiloidea species (Metridia asymmetrica, Metridia curticauda, Pleuromamma scutullata, Pleuromamma xiphias, Lucicutia ovaliformis and Heterorhabdus tanneri). Codon-based synonymous/nonsynonymous tests of positive selection for 25 identified copepod luciferases suggested that positive Darwinian selection operated in the evolution of Heterorhabdidae luciferases, whereas two types of Metridinidae luciferases had diversified via neutral mechanism. By in silico analysis of the decoded amino acid sequences of 25 copepod luciferases, we inferred two protein sequences as ancestral copepod luciferases. They were expressed in HEK293 cells where they exhibited notable luciferase activity both in intracellular lysates and cultured media, indicating that the luciferase activity was established before evolutionary diversification of these copepod species.     

Histone distribution in chromosomes revealed by antihistone sera

Each of the five histone fractions is located along the entire length of each chromosome present in a tissue. The use of antisera, specific to each histone type, in conjunction with differential extraction of histones may serve as a tool for chromosome identification by the histone pattern.     

Physiological characterization of the cold-shock-induced humoral factor for wing color-pattern changes in butterflies

Butterfly wing color patterns can be modified by the application of temperature shock to pupae immediately after pupation, which has been attributed to a cold-shock-induced humoral factor called cold-shock hormone (CSH). Here, we physiologically characterized CSH and pharmacological action of tungstate, using a nymphalid butterfly Junonia orithya. We first showed that the precise patterns of modification were dependent on the time-point of the cold-shock treatment after pupation, and confirmed that the modification properties induced in a cold-shocked pupa were able to be transferred to another pupa in a parabiosis experiment. Cold-shock application after removal of the head and prothorax together still produced modified wings, excluding major involvement of the brain-retrocerebral neuroendocrine complex. Furthermore, tungstate injection induced modifications even in individuals whose head and prothorax were removed. Importantly, transplantation of tracheae isolated from cold-shocked pupae induced modifications in the recipient wings. We identified a chemical peak in hemolymph of the cold-shocked individuals using HPLC, which corresponded to dopamine, and demonstrated that dopamine and its related biogenic amines have ability to induce small color-pattern changes. Taken together, the present study suggests that CSH is likely to be secreted from trachea-associated endocrine cells upon cold-shock treatment and that tungstate may change color patterns via its direct action on wings.     

Evaluation of extensional and torsional stiffness of single actin filaments by molecular dynamics analysis

It is essential to investigate the mechanical behaviour of cytoskeletal actin filaments in order to understand their critical role as mechanical components in various cellular functional activities. These actin filaments consisting of monomeric molecules function in the thermal fluctuations. Hence, it is important to understand their mechanical behaviour on the microscopic scale by comparing the stiffness based on thermal fluctuations with the one experimentally measured on the macroscopic scale. In this study, we perform a large-scale molecular dynamics (MD) simulation for a half-turn structure of an actin filament. We analyse its longitudinal and twisting Brownian motions in equilibrium and evaluated its apparent extensional and torsional stiffness on the nanosecond scale. Upon increasing the sampling-window durations for analysis, the apparent stiffness gradually decreases and exhibits a trend to converge to a value that is close to the experimental value. This suggests that by extrapolating the data obtained in the MD analysis, we can estimate the experimentally determined stiffness on the microsecond to millisecond scales. For shorter temporal scales, the apparent stiffness is larger than experimental values, indicating that fast, local motions of the molecular structure are dominant. To quantify the local structural changes within the filament on the nanosecond scale and investigate the molecular mechanisms, such as the binding of the actin-regulatory proteins to the filaments, it is preferable to analyse the mechanical behaviour on the nanometre and nanosecond scales using MD simulation.     

Histamine stimulates human lung fibroblast migration

Histamine is a potent mediator in allergic inflammatory processes and is released by basophils and mast cells. The aim of this study was to investigate the effect of histamine on in vitro migration of human fetal lung fibroblasts (HFL-1) to human plasma fibronectin (HFn), a chemoattractant. Using the blindwell chamber technique, histamine alone had no chemotactic activity. However, histamine augmented HFn-induced HFL-1 migration at concentrations ranging between 0 and 10^?7 M (290.6 ± 20.8%) (P < 0.05). The concentration-response was bell-shaped. The effect of histamine increased with time. The stimulatory effect of histamine on HFL-1 migration was inhibited by an H4 receptor antagonist, JNJ7777120 (10^?5 M). Histamine’s effect was also inhibited by pertussis toxin (50 ng/ml), showing that the effect was mediated by the H4 receptor. This study demonstrated that histamine has the potential to stimulate human lung fibroblast migration, and thus may contribute to regulation of wound healing and the development of fibrotic disorders of the lung.