Consensus on the terminologies and methodologies for masticatory assessment

A large number of methodological procedures and experimental conditions are reported to describe the masticatory process. However, similar terms are sometimes employed to describe different methodologies. Standardisation of terms is essential to allow comparisons among different studies. This article was aimed to provide a consensus concerning the terms, definitions and technical methods generally reported when evaluating masticatory function objectively and subjectively. The consensus is based on the results from discussions and consultations among world-leading researchers in the related research areas. Advantages, limitations and relevance of each method are also discussed. The present consensus provides a revised framework of standardised terms to improve the consistent use of masticatory terminology and facilitate further investigations on masticatory function analysis. In addition, this article also outlines various methods used to evaluate the masticatory process and their advantages and disadvantages in order to help researchers to design their experiments

Characteristic Metabolism of Free Amino Acids in Cetacean Plasma: Cluster Analysis and Comparison with Mice

From an evolutionary perspective, the ancestors of cetaceans first lived in terrestrial environments prior to adapting to aquatic environments. Whereas anatomical and morphological adaptations to aquatic environments have been well studied, few studies have focused on physiological changes. We focused on plasma amino acid concentrations (aminograms) since they show distinct patterns under various physiological conditions. Plasma and urine aminograms were obtained from bottlenose dolphins, pacific white-sided dolphins, Risso's dolphins, false-killer whales and C57BL/6J and ICR mice. Hierarchical cluster analyses were employed to uncover a multitude of amino acid relationships among different species, which can help us understand the complex interrelations comprising metabolic adaptations. The cetacean aminograms formed a cluster that was markedly distinguishable from the mouse cluster, indicating that cetaceans and terrestrial mammals have quite different metabolic machinery for amino acids. Levels of carnosine and 3-methylhistidine, both of which are antioxidants, were substantially higher in cetaceans. Urea was markedly elevated in cetaceans, whereas the level of urea cycle-related amino acids was lower. Because diving mammals must cope with high rates of reactive oxygen species generation due to alterations in apnea/reoxygenation and ischemia-reperfusion processes, high concentrations of antioxidative amino acids are advantageous. Moreover, shifting the set point of urea cycle may be an adaption used for body water conservation in the hyperosmotic sea water environment, because urea functions as a major blood osmolyte. Furthermore, since dolphins are kept in many aquariums for observation, the evaluation of these aminograms may provide useful diagnostic indices for the assessment of cetacean health in artificial environments in the future

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Compression Test of Soft Food Gels Using a Soft Machine with an Artificial Tongue

Care food is increasingly required in the advanced-aged society. Mechanical properties of such foods must be modified such that the foods are easily broken by the tongue without chewing. When foods are compressed between the tongue and the hard palate, the tongue deforms considerably, and only soft foods are broken. To simulate tongue compression of soft foods, artificial tongues with stiffness similar to that of the human tongue were created using clear soft materials. Model soft gels were prepared using gellan gums. A piece of gel on an artificial tongue was compressed using a texture analyzer. The deformation profile during the compression test was obtained using a video capture system. The soft machine equipped a soft artificial tongue sometimes fractured food gels unlike hard machine, which always fracture gels. The fracture properties measured using the soft machine were better than those obtained from a conventional test between hard plates to mimic natural oral processing in humans. The fracture force on foods measured using this soft machine may prove useful for the evaluation of food texture that can be mashed using the tongue

食品ハイドロコロイドのゾル-ゲル転移に関する物理化学的研究

本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものである京都大学0048新制・論文博士博士(農学)乙第8457号論農博第1892号新制||農||671(附属図書館)学位論文||H6||N2668(農学部図書室)UT51-94-C93(主査)教授 土井 悦四郎, 教授 安本 教傳, 教授 森 友彦学位規則第4条第2項該当Doctor of Agricultural ScienceKyoto UniversityDFA

Medullary reticulospinal tract mediating a generalized motor inhibition in cats: III. Functional organization of spinal interneurons in the lower lumbar segments

http://dx.doi.org/10.1016/S0306-4522(03)00542-6The previous report of intracellular recording of hindlimb motoneurons in decerebrate cats [[Delwaide, 2001] 511] has suggested that the following mechanisms are involved in a generalized motor inhibition induced by stimulating the medullary reticular formation. First, the motor inhibition, which was prominent in the late latency (30–80 ms), can be ascribed to the inhibitory effects in parallel to motoneurons and to interneuronal transmission in reflex pathways. Second, both a group of interneurons receiving inhibition from flexor reflex afferents and a group of Ib interneurons mediate the late inhibitory effects upon the motoneurons. To substantiate the above mechanisms of motor inhibition we examined the medullary stimulus effects upon intracellular (n=55) and extracellular (n=136) activity of spinal interneurons recorded from the lower lumbar segments (L6–L7). Single pulses or stimulus trains (1–3) pulses, with a duration of 0.2 ms and intensity of 20–50 μA) applied to the medullary nucleus reticularis gigantocellularis evoked a mixture of excitatory and inhibitory effects with early (30 ms) latencies. The medullary stimulation excited 55 interneurons (28.8%) with a late latency. Thirty-nine of the cells, which included 10 Ib interneurons, were inhibited by volleys in flexor reflex afferents (FRAs). These cells were mainly located in lamina VII of Rexed. On the other hand, the late inhibitory effects were observed in 67 interneurons (35.1%), which included cells mediating reciprocal Ia inhibition, non-reciprocal group I (Ib) inhibition, recurrent inhibition and flexion reflexes. Intracellular recording revealed that the late inhibitory effects were due to inhibitory postsynaptic potentials with a peak latency of about 50 ms and a duration of 50–60 ms. The inhibitory effects were attenuated by volleys in FRAs. Neither excitatory nor inhibitory effects with a late latency were observed in 69 (36.1%) cells which were located in the intermediate region and dorsal horn. These results suggest the presence of a functional organization of the spinal cord with respect to the production of the generalized motor inhibition. Lamina VII interneurons that receive inhibition from volleys in FRAs possibly mediate the postsynaptic inhibition from the medullary reticular formation in parallel to motoneurons and to interneurons in reflex pathways

Compression Test of Soft Food Gels Using a Soft Machine with an Artificial Tongue

Care food is increasingly required in the advanced-aged society. Mechanical properties of such foods must be modified such that the foods are easily broken by the tongue without chewing. When foods are compressed between the tongue and the hard palate, the tongue deforms considerably, and only soft foods are broken. To simulate tongue compression of soft foods, artificial tongues with stiffness similar to that of the human tongue were created using clear soft materials. Model soft gels were prepared using gellan gums. A piece of gel on an artificial tongue was compressed using a texture analyzer. The deformation profile during the compression test was obtained using a video capture system. The soft machine equipped a soft artificial tongue sometimes fractured food gels unlike hard machine, which always fracture gels. The fracture properties measured using the soft machine were better than those obtained from a conventional test between hard plates to mimic natural oral processing in humans. The fracture force on foods measured using this soft machine may prove useful for the evaluation of food texture that can be mashed using the tongue

Changes in the excitability of hindlimb motoneurons during muscular atonia induced by stimulating the pedunculopontine tegmental nucleus in cats

http://dx.doi.org/10.1016/j.neuroscience.2003.12.016We have previously reported that electrical stimulation delivered to the ventral part of the pedunculopontine tegmental nucleus (PPN) produced postural atonia in acutely decerebrated cats [Neuroscience 119 (2003) 293]. The present study was designed to elucidate synaptic mechanisms acting on motoneurons during postural atonia induced by PPN stimulation. Intracellular recording was performed from 72 hindlimb motoneurons innervating extensor and flexor muscles, and the changes in excitability of the motoneurons following the PPN stimulation were examined. Repetitive electrical stimulation (20–50 μA, 50 Hz, 5–10 s) of the PPN hyperpolarized the membrane potentials of both the extensor and flexor motoneurons by 2.0–12 mV (6.0±2.3 mV, n=72). The membrane hyperpolarization persisted for 10–20 s even after termination of the stimulation. During the PPN stimulation, the membrane hyperpolarization was associated with decreases in the firing capability (n=28) and input resistance (28.5±6.7%, n=14) of the motoneurons. Moreover the amplitude of Ia excitatory postsynaptic potentials was also reduced (44.1±13.4%, n=14). After the PPN stimulation, these parameters immediately returned despite that the membrane hyperpolarization persisted. Iontophoretic injections of chloride ions into the motoneurons reversed the polarity of the membrane hyperpolarization during the PPN stimulation. The polarity of the outlasting hyperpolarization however was not reversed. These findings suggest that a postsynaptic inhibitory mechanism, which was mediated by chloride ions, was acting on hindlimb motoneurons during PPN-induced postural atonia. However the outlasting motoneuron hyperpolarization was not due to the postsynaptic inhibition but it could be due to a decrease in the activity of descending excitatory systems. The functional role of the PPN in the regulation of postural muscle tone is discussed with respect to the control of behavioral states of animals