Net depth response of a depth-controllable (towed) gillnet for fish sampling

SUMMARY: Flume-tank experiments were performed to examine the depth response of a new type of depth-controlled gillnet. Variations of net depth were investigated as the warp was paid out and wound up for different changes of warp length, main sinker weights, and winch speeds. In most experiments, when the warp finished paying out, the net continued to descend and then ascended slightly to an equilibrium depth (overshoot phenomenon). The overshoot distance was nearly constant when the warp was wound up and increased linearly with increasing winch speed when the warp was paid out. An increase in winch speed reduced net settling time, which converged on a constant value for both paying out and winding up.     

Catalog of Micro-Tom tomato responses to common fungal, bacterial, and viral pathogens

Lycopersicon esculentum cultivar Micro-Tom is a miniature tomato with many advantages for studies of the molecular biology and physiology of plants. To evaluate the suitability of Micro-Tom as a host plant for the study of pathogenesis, Micro-Tom plants were inoculated with 16 well-known fungal, bacterial, and viral pathogens of tomato. Athelia rolfsii, Botryotinia fuckeliana, Oidium sp., Phytophthora infestans, and Sclerotinia sclerotiorum caused typical symptoms and sporulated abundantly on Micro-Tom. Micro-Tom was resistant to Alternaria alternata, Corynespora cassiicola, and Fusarium oxysporum. When Micro-Tom was inoculated with 17 isolates of Ralstonia solanacearum, many isolates induced wilt symptoms. Agrobacterium tumefaciens also was pathogenic, causing crown galls on stem tissue after needle prick inoculation. In Micro-Tom sprayed with Pseudomonas syringae pv. tomato, P. s. pv. tabaci, or P. s. pv. glycinea, bacterial populations did not increase, and yellow lesions appeared only on leaves sprayed with P. s. pv. tomato. Tomato mosaic virus, Tomato aspermy virus, and Cucumber mosaic virus systemically infected Micro-Tom, which developed symptoms characteristic of other cultivars of tomato after infection with the respective virus. These results indicated that Micro-Tom was generally susceptible to most of the important tomato pathogens and developed typical symptoms, whereas certain pathogens were restricted by either hypersensitive resistance or nonhost resistance on Micro-Tom. Therefore, an assortment of Micro-Tom–pathogen systems should provide excellent models for studying the mechanism of susceptible and resistant interactions between plants and pathogens.     

Growth hormone suppresses the expression of IGFBP-5, and promotes the IGF-I-induced phosphorylation of Akt in bovine mammary epithelial cells

Growth hormone (GH) plays a specific role to inhibit apoptosis in the bovine mammary gland through the insulin-like growth factor (IGF)-I system, however, the mechanism of GH action is poorly understood. In this study, we show that GH dramatically inhibits the expression of IGFBP-5, and GH along with IGF-I enhanced the phosphorylation of Akt through the reduction of IGF binding protein (IGFBP)-5. To determine how GH affects Akt through IGF-I in bovine mammary epithelial cells (BMECs), we examined the phosphorylation of Akt in GH treated BMECs and found that IGF-I induced phosphorylation of Akt was significantly enhanced by the treatment with GH. We demonstrated that GH reduces mRNA and protein expression of IGFBP-5 in BMECs, but it does not affect the expression of IGFBP-3. To determine that the enhanced effect of the Akt phosphorylation by the treatment of GH is due to the inhibition of the expression of IGFBP-5, we examined the effect of IGFBP-3 and -5 on the phosphorylation of Akt through IGF-I in the GH-treated BMECs. The phosphorylation of Akt was inhibited in a dose-dependent manner when IGFBP-5 was added at varying concentrations and was also inhibited in the presence of IGFBP-3. The results of this study suggest that GH plays an important role on mammary gland involution in bovine mammary epithelial cells.     

Effects of leptin and tumor necrosis factor-alpha on degranulation and superoxide production of polymorphonuclear neutrophils from Holstein cows

Leptin, a pleiotropic hormone regulating food intake and energy expenditure, has been shown to directly modulate human polymorphonuclear neutrophil (PMN) functions or indirectly through the action of tumor necrosis factor-alpha (TNF-alpha). Bovine PMN have considerable different characteristics from human PMN. For example, it does not respond to N-formyl-Methionyl-Leucyl-phenylalanine, a well known human PMN activator. In the present study, we tested the effects of leptin and TNF-alpha on superoxide production and degranulation of bovine peripheral PMN, in which both long isoform of leptin receptor (Ob-Rb) and TNF receptor 1 were expressed. Human leptin, human TNF-alpha, phorbol myristate acetate (PMA) and opsonized zymosan particles (OZP) did not stimulate degranulation responses, while zymosan-activated serum (ZAS) did. Neither leptin nor TNF-alpha enhanced the ZAS-induced degranulation responses. TNF-alpha, PMA, OZP and ZAS increased superoxide production in different magnitudes, whereas leptin did not. TNF-alpha, but not leptin, enhanced OZP- and ZAS-induced superoxide production, possibly, in part due to facilitating translocation of p47(phox), a component of NADPH oxidase. These results indicate that, unlike in human PMN, leptin does not have any direct effect on degranulation and superoxide production in bovine PMN, although TNF-alpha influences superoxide production.     

Development and evaluation of pyramiding lines carrying early or late heading QTLs in the indica rice cultivar ‘IR64’

The heading date is an important trait for determining regional and climatic adaptability in rice. To expand the adaptability of the indica rice cultivar ‘IR64’, we pyramided multiple early or late heading quantitative trait locus (QTLs) in the ‘IR64’ genetic background by crossing previously developed near-isogenic lines (NILs) with a single QTL for early or late heading. The effects of pyramiding QTLs were observed in three different climatic zones of the Philippines, Madagascar, and Japan. The early heading pyramiding lines (PYLs) headed 6.2 to 12.8 days earlier than ‘IR64’ while the late heading PYLs headed 18.8 to 27.1 days later than ‘IR64’. The PYLs tended to produce low grain yield compared to ‘IR64’. The low yield was not improved by combining SPIKE, which is a QTL that increases the number of spikelets per panicle. Conversely, ‘IR64-PYL(7+10)’ carrying Hd5 and Hd1 headed earlier, produced more tillers, and more panicles per m² than ‘IR64’, and mitigated the yield decrease in early heading. These results suggest that the effects of pyramided QTLs on heading date were consistent across various environments and PYLs could be used to enhance the adaptation of ‘IR64’ in other rice growing environments.     

Suppurative meningoencephalitis and perineuritis caused by Streptococcus gallolyticus in a Japanese Black calf

A 179-day-old calf, which was weak and stunted, showed neurological signs and was euthanized. Postmortem examination revealed extensive and severe cloudy area in the meninges, and pleural pneumonia. Gram-positive cocci were isolated from systemic organs. Biochemical and 16S rRNA gene sequence analyses identified the isolate as Streptococcus gallolyticus, and its subspecies was suggested to be gallolyticus (SGG). The isolate was classified as a novel sequence type (ST115) by the multilocus sequence typing scheme for SGG and showed susceptibility to penicillin, ampicillin, amoxicillin, florfenicol, sulfamethoxazole-trimethoprim, and chloramphenicol. Histopathologically, suppurative meningoencephalitis and perineuritis were detected. As SGG has been isolated solely from a cow with mastitis in Japan, this is the first SGG infection in a calf with suppurative meningoencephalitis and perineuritis in this country.     

Development of a plant conveyance system using an AGV and a self-designed plant-handling device: A case study of DIY plant phenotyping

Plant phenotyping technology has been actively developed in recent years, but the introduction of these technologies into the field of agronomic research has not progressed as expected, in part due to the need for flexibility and low cost. “DIY” (Do It Yourself) methodologies are an efficient way to overcome such obstacles. Devices with modular functionality are critical to DIY experimentation, allowing researchers flexibility of design. In this study, we developed a plant conveyance system using a commercial AGV (Automated Guided Vehicle) as a case study of DIY plant phenotyping. The convey module consists of two devices, a running device and a plant-handling device. The running device was developed based on a commercial AGV Kit. The plant-handling device, plant stands, and pot attachments were originally designed and fabricated by us and our associates. Software was also developed for connecting the devices and operating the system. The run route was set with magnetic tape, which can be easily changed or rerouted. Our plant delivery system was developed with low cost and having high flexibility, as a unit that can contribute to others’ DIY’ plant research efforts as well as our own. It is expected that the developed devices will contribute to diverse phenotype observations of plants in the greenhouse as well as to other important functions in plant breeding and agricultural production.     

Low water exchange Gracilariopsis bailiniae Zhang & B.M. Xia culture in intensive milkfish culture effluents: effects of seaweed density on seaweed production and effluent treatment

This study tested the feasibility of a low-cost seaweed biofiltration system for pond-based aquaculture through an indoor-integrated fish-seaweed culture experiment using weekly nutrient supply regime and different seaweed stocking densities. The culture experiment was conducted in glass aquaria that were stocked with Gracilariopsis bailiniae at 3 densities (low = 0.5 kg m^?2, middle = 2 kg m^?2 and high = 3.5 kg m^?2) and provided either with effluents from intensive milkfish (Chanos chanos) culture or with effluent-free seawater (control) as nutrient source. Stocking density was used as a factor in optimizing nutrient availability for growth and nutrient removal under such low water exchange conditions. Our results showed that G. bailiniae cultivated in milkfish effluents had higher growth, biomass and nitrogen yields than those cultivated in effluent-free seawater. Among the different stocking densities tested, highest growth rate (1.03 % day^?1) was obtained in the middle density. Increasing biomass and nitrogen yields were also obtained at this density until the end of the culture period. Poorer growth rates at low and high stocking densities were attributed to light limitation from phytoplankton and self-shading, respectively. Due to seaweed treatment, average outflow concentration of NH₄ ⁺ was reduced from half of its pretreated level. This study showed that a weekly effluent supply at 2 kg m^?2 seaweed stocking density can sustainably support the growth of G. bailiniae as long as the dissolved nutrients are present at high levels.     

Sodium alginate supplementation modulates gut microbiota,health parameters,growth performance and growth‐related gene expression in Malaysian Mahseer Tor tambroides

This study investigated the effects of sodium alginate supplementation on gut microbiota composition, health parameters, growth performances and growth‐related gene expression of Malaysian mahseer. Five test diets were formulated by supplementing 0%, 0.1%, 0.2%, 0.4% and 0.8% sodium alginate. Triplicate groups of juvenile Tor tambroides (2.19 ± 0.05 g) were stocked in 15 aquaria (20 individuals per aquarium) and fed at 3.0% body weight per day for 60 days. PCoA and UPGMA analysis showed that gut bacterial community were more convergence in higher sodium alginate‐supplemented diets. The percentage of Porphyromonadaceae, Bacteroides, Plesiomonas and Shewanella were substantially higher and Aeromonas, Entomoplasmatales and Prevotellaceae were drastically lower in higher sodium alginate (0.2%–0.8%) diets. Sodium alginate supplementation (≥0.2%) significantly improved the haematocrit value and respiratory burst activity of T. tambroides. Growth performances and feed utilization were significantly higher in 0.2%–0.4% sodium alginate‐supplemented diets. The increased growth rate of T. tambroides was governed by both hyperplastic and hypertrophic muscle growth. Real‐time PCR data demonstrated that most of the growth‐related genes were significantly upregulated in 0.2%–0.4% sodium alginate‐supplemented diet. Finally, it can be concluded that sodium alginate should be supplemented at 2 g/kg in practical fish feed formulation.     

Post-molt processes of cuticle formation and calcification in the Japanese mitten crab <Emphasis Type="Italic">Eriocheir japonicus</Emphasis>

This study examines the following in the Japanese mitten crab: (1) the structure of the exoskeleton with special reference to its calcification; (2) the progression of post-molt cuticle formation and calcification. In the crab, the structure and calcification state of the exoskeleton at the molt and during the inter-molt stage were similar to those of other crustaceans. During the inter-molt, the exoskeleton consisted of four cuticle layers; the outermost epicuticle, the exocuticle, the endocuticle and the innermost membrane layer. Intense calcification was observed in the exo- and endocuticle. At the molt, the synthesis of the epi- and exocuticle was already complete, and the addition of the endocuticle began after the molt. Calcification of the exocuticle initiated soon after the molt, but there was a delay between endocuticle matrix synthesis and calcification. Histology showed that the process of calcification was similar to that in other crustaceans. However, calcium concentrations within the exoskeleton continued to increase and never reached the levels of the inter-molt stage at the end of the experiment. This suggests that the Japanese mitten crab is relatively slow to calcify compared to other crustaceans.