Ultrasound and actinidin enzyme treatments : effects on tenderness and in vitro protein digestibility of New Zealand abalone (Haliotis iris) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology at Massey University, Manawatu, New Zealand

Canned pāua, Haliotis iris, is a premium New Zealand product that is exported to Asia. However, meat toughness is a common problem of thermally processed abalone, worldwide. The objective of this research was to investigate the effects of different technologies such as ultrasound and actinidin enzyme treatments on pāua texture, microstructure and in vitro protein digestibility. Ultrasound treatment was chosen as it has been reported to cause tenderisation by physical disruption of muscle cells or release of endogenous enzymes and/or calcium that hastens proteolysis in meat. Actinidin enzyme from kiwifruit has been reported to tenderise tough beef cuts by hydrolysing the myofibrillar proteins and connective tissues. Whole pāua meat was pre-treated in ultrasound (20 kHz, 464 ± 9 W) for 5 min in water (with or without subsequent soaking in water at 4 °C for 24 h), or in 1% actinidin solution. Post-treatment cooking of canned pāua was done in a water retort at 116 °C for 30 min. All ultrasound pre-treated cooked pāua yielded lower slice shear force values (SSFV) than untreated canned and cooked samples; the lowest SSFV was attained when ultrasound pre-treatment in water was followed by soaking at 4 °C for 24 h. The increased tenderness in ultrasound pre-treated cooked pāua could be linked to the observed changes in the microstructure. Histological analysis of raw samples revealed disintegration of myofibers and formation of gaps between myofibers. Transmission electron micrographs (TEM) of raw pāua showed collagenous fragmentations in ultrasound pre-treated samples, and this was more pronounced in pāua ultrasonicated in enzyme solution, which also exhibited myofibril fragmentations. Cooked control pāua muscle fibres appeared very compact while ultrasound pretreated samples had wider spaces between myofibers. In vitro protein digestibility was determined for raw and cooked control; and cooked ultrasound pre-treated pāua. Raw pāua exhibited significantly higher (p < 0.05) free amino N values during in vitro digestion and also protein breakdown as observed through SDS-PAGE than cooked control and ultrasound pre-treated samples However, cooked ultrasound pre-treated pāua was more digestible than control cooked sample. In conclusion, ultrasound treatment in water for 5 min, followed by soaking in water for 24 h caused changes in the microstructure of pāua muscle tissues, which led to increased tenderness of cooked pāua. The SSFV for this sample was 31% lower than the control cooked and a commercial canned sample

The interpretation of the field angle dependence of the critical current in defect-engineered superconductors

We apply the vortex path model of critical currents to a comprehensive analysis of contemporary data on defect-engineered superconductors, showing that it provides a consistent and detailed interpretation of the experimental data for a diverse range of materials. We address the question of whether electron mass anisotropy plays a role of any consequence in determining the form of this data and conclude that it does not. By abandoning this false interpretation of the data, we are able to make significant progress in understanding the real origin of the observed behavior. In particular, we are able to explain a number of common features in the data including shoulders at intermediate angles, a uniform response over a wide angular range and the greater discrimination between individual defect populations at higher fields. We also correct several misconceptions including the idea that a peak in the angular dependence of the critical current is a necessary signature of strong correlated pinning, and conversely that the existence of such a peak implies the existence of correlated pinning aligned to the particular direction. The consistency of the vortex path model with the principle of maximum entropy is introduced.Comment: 14 pages, 7 figure

Yolk utilization and growth during the early larval life of the Silver Perch, Bidyanus bidyanus (Mitchell, 1838)

The aim of this research was to investigate the yolk sac and oil globule utilization by silver perch (Bidyanus bidyanus) larvae produced from domesticated broodfish. The larvae were kept unfed in the holding tank, sampled, and investigated by image analysis software to determine various characteristics, such as the diameters of ova, water-hardened eggs, yolk-sac, oil globules, and the total length of larvae. The research illustrated that, with the exception of oil globule diameter, all other morphometric parameters were significantly lower (P &lt; 0.05) when compared to the larvae from the wild broodfish. The yolk sac was completely absorbed at 96 h post-hatching (hph) and the oil globule was visible until 240 hph. The larvae exhibited predatory movements and tried to catch rotifer at 4 days post hatching (dph). However, the onset of feeding took place at 5 dph, while 100% of feeding occurred at 6 dph. During the first 96 h (h), larvae grew significantly faster than the next 144 h. Larvae encountered low mortalities (&lt;10%) during the first 96 hph, before increasing significantly in the next 24 h and no unfed larvae survived post 240 h. The results also suggested that the exogenous feed should be available at 96 hph, which is well after the yolk sac is completely depleted. In addition, although most of eggs and larval performance from domesticated broodfish were inferior compared to the wild one, it has larger oil globule that could make longer of its mixed feeding period and therefore could have better in viability

Neurofeedback Using Real-Time Near-Infrared Spectroscopy Enhances Motor Imagery Related Cortical Activation

Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practices in the form of motor imagery have been implemented in rehabilitation regimes of stroke patients with favorable results. Because direct monitoring of motor imagery is difficult, feedback of cortical activities related to motor imagery (neurofeedback) could help to enhance efficacy of mental practice with motor imagery. To determine the feasibility and efficacy of a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS), two separate experiments were performed. Experiment 1 was used in five subjects to evaluate whether real-time cortical oxygenated hemoglobin signal feedback during a motor execution task correlated with reference hemoglobin signals computed off-line. Results demonstrated that the NIRS-mediated neurofeedback system reliably detected oxygenated hemoglobin signal changes in real-time. In Experiment 2, 21 subjects performed motor imagery of finger movements with feedback from relevant cortical signals and irrelevant sham signals. Real neurofeedback induced significantly greater activation of the contralateral premotor cortex and greater self-assessment scores for kinesthetic motor imagery compared with sham feedback. These findings suggested the feasibility and potential effectiveness of a NIRS-mediated real-time neurofeedback system on performance of kinesthetic motor imagery. However, these results warrant further clinical trials to determine whether this system could enhance the effects of mental practice in stroke patients

Altered Connectivity Pattern of Hubs in Default-Mode Network with Alzheimer's Disease: An Granger Causality Modeling Approach

Background: Evidences from normal subjects suggest that the default-mode network (DMN) has posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC) and inferior parietal cortex (IPC) as its hubs; meanwhile, these DMN nodes are often found to be abnormally recruited in Alzheimer’s disease (AD) patients. The issues on how these hubs interact to each other, with the rest nodes of the DMN and the altered pattern of hubs with respect to AD, are still on going discussion for eventual final clarification. Principal Findings: To address these issues, we investigated the causal influences between any pair of nodes within the DMN using Granger causality analysis and graph-theoretic methods on resting-state fMRI data of 12 young subjects, 16 old normal controls and 15 AD patients respectively. We found that: (1) PCC/MPFC/IPC, especially the PCC, showed the widest and distinctive causal effects on the DMN dynamics in young group; (2) the pattern of DMN hubs was abnormal in AD patients compared to old control: MPFC and IPC had obvious causal interaction disruption with other nodes; the PCC showed outstanding performance for it was the only region having causal relation with all other nodes significantly; (3) the altered relation between hubs and other DMN nodes held potential as a noninvasive biomarker of AD. Conclusions: Our study, to the best of our knowledge, is the first to support the hub configuration of the DMN from the perspective of causal relationship, and reveal abnormal pattern of the DMN hubs in AD. Findings from young subject

Comparative Composition, Diversity and Trophic Ecology of Sediment Macrofauna at Vents, Seeps and Organic Falls

Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but there has yet to be a systematic comparison of the community-level attributes of sediment macrobenthos in various reducing ecosystems. Here we review key similarities and differences in the sediment-dwelling assemblages of each system with the goals of (1) generating a predictive framework for the exploration and study of newly identified reducing habitats, and (2) identifying taxa and communities that overlap across ecosystems. We show that deep-sea seep, vent and organic-fall sediments are highly heterogeneous. They sustain different geochemical and microbial processes that are reflected in a complex mosaic of habitats inhabited by a mixture of specialist (heterotrophic and symbiont-associated) and background fauna. Community-level comparisons reveal that vent, seep and organic-fall macrofauna are very distinct in terms of composition at the family level, although they share many dominant taxa among these highly sulphidic habitats. Stress gradients are good predictors of macrofaunal diversity at some sites, but habitat heterogeneity and facilitation often modify community structure. The biogeochemical differences across ecosystems and within habitats result in wide differences in organic utilization (i.e., food sources) and in the prevalence of chemosynthesis-derived nutrition. In the Pacific, vents, seeps and organic-falls exhibit distinct macrofaunal assemblages at broad-scales contributing to ß diversity. This has important implications for the conservation of reducing ecosystems, which face growing threats from human activities

The pawikan album: The sea turtles captured around Panay and Guimaras Islands, Philippines

SEAFDEC FishWorld worked with fishers and government officers to document 93 sea turtles captured by fishing gears along the coasts of Panay and Guimaras Islands, Philippines in 2000-2009: three leatherbacks Dermochelys coriacea (128-150 cm curved carapace length), two loggerheads Caretta caretta (77 cm), 18 olive ridleys Lepidochelys olivacea (47-69 cm), 18 hawksbills Eretmochelys imbricata (20-89 cm), and 52 green turtles Chelonia mydas (30-108 cm). Most green turtles were caught in near shore fish corrals, and most olive ridleys by gill nets and long lines. Of the 18 hawksbills, 2 adults were caught in fish corrals, 3 juveniles were entangled in nets in Iloilo Strait, 6 were pets off our people,and 7 were captives at a turtle feeding station near a known hawksbill nesting site in Lawi, Guimaras. Sixty documented turtles were released, 47 of them with monel or inconel tags of the Pawikan Conservation Project, Department of Environment and Natural Resources. The others died from entanglement, serious injuries, slaughter for market, and diseases. Six female green turtles had multiple fibropapillomas; two died, three were released, and the latest one healed well after the surgical removal of several large tumors and was released. One green turtle brought to FishWorld has advanced shell rot, is unable to submerge, but is doing well on a diet of red seaweed Gracilaria. Three pet hawksbills were retrained for life at sea; one was released after 17 months, another after 57 months, but one is still at FishWorld as Conservation Ambassador. The most important result of FishWorld's work in the past 10 years is that many captured sea turtles were checked for health condition, treated where necessary or possible, tagged, and released back to sea. In addition, data on 93 sea turtles were gathered that can be used in the continuing effort to monitor the locations, risks and threats, health and diseases, and movements of these endangered species

Neural processing of threat-related stimuli in patients with chronic low back pain

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Neural substrates of phonological selection for Japanese character Kanji based on fMRI investigations

Japanese and Chinese both share the same ideographic/logographic character system. How these characters are processed, however, is inherently different for each language. We harnessed the unique property of homophone judgment in Japanese kanji to provide an analogous Chinese condition using event-related functional magnetic resonance imaging (fMRI) in 33 native Japanese speakers. We compared two types of kanji: (1) kanji that usually evokes only one pronunciation to Japanese speakers, which is representative of most Chinese characters (monophonic character); (2) kanji that evoked multiple pronunciation candidates, which is typical in Japanese kanji (heterophonic character). Results showed that character pairs with multiple sound possibilities increased activation in posterior regions of the left, middle and inferior frontal gyri (MFG and IFG), the bilateral anterior insulae, and the left anterior cingulate cortex as compared with those of kanji with only one sound. The activity seen in the MFG, dorsal IFG, and ventral IFG in the left posterior lateral prefrontal cortex, which was thought to correspond with language components of orthography, phonology, and semantics, respectively, was discussed in regards to their potentially important roles in information selection among competing sources of the components. A comparison with previous studies suggested that detailed analyses of activation in these language areas could explain differences between Japanese and Chinese, such as a greater involvement of the prefrontal language production regions for Japanese, whereas, for Chinese there is more phonological processing of inputs in the superior temporal gyrus