Tissue Dry Weight Research Articles

Accumulation of phlorotannins in the abalone Haliotis discus hannai after feeding the brown seaweed Ecklonia cava

Value-added abalone Haliotis discus hannai containing bioactive phlorotannins is produced by simply changing the feed to phlorotannin-rich brown seaweed Ecklonia cava 2 weeks prior to harvesting. We assessed the accumulation of phlorotannins by feeding with the seaweed after 4 days of starvation. Reverse-phase high-performance liquid chromatography afforded isolation of the major phlorotannins, which were identified by mass spectrometry and 1H-nuclear magnetic resonance to be 7-phloroeckol and eckol. Throughout the E. cava feeding period of 20 days, 7-phloroeckolol accumulated in the flesh (foot muscle tissue), up to 0.85 ± 0.21 mg g−1 dry weight of tissue after 12 days. Eckol reached 0.31 ± 0.08 mg g−1 dry tissue after 14 days. Feeding Laminaria japonica as a control, we detected no phlorotannins in the abalone muscle tissue. Abalone seaweed consumption and growth rate were similar when fed with E. cava or L. japonica for 20 days. Reduction in phlorotannins to half-maximal accumulation took 1.0 and 2.7 days for 7-phloroeckol and eckol, respectively, after replacement of the feed with L. japonica.

Effects of ploidy and gear on the performance of cultured oysters, Crassostrea virginica: Survival, growth, shape, condition index and Vibrio abundances

In 2011 at a commercial oyster farm in Grand Bay, Alabama, we conducted an experimental field test of ploidy (triploids and half-sibling diploids) and gear type: 1) LowPro bottom cages (Chesapeake Bay Oyster Company — CBOC), 2) adjustable long-line baskets (BST, Ltd.), 3) OysterGro floating cages (Ketcham Supply) and 4) floating bags (CBOC). Eastern oysters, Crassostrea virginica, were deployed in the four gear types from May 5 to October 11 (166days), with replicate bags of each ploidy assigned to each gear type (n≥3). Survival, growth (both shell dimensions and weight measurements, adjusted to account for differences between the ploidies at the onset of the experiment), and oyster shape (‘fan’ & ‘cup’ ratios) were quantified at the conclusion of the experiment. Condition indices were determined in both August and October, while abundances of the bacteria, Vibrio vulnificus and V. parahaemolyticus, were quantified in August and September. Survival was equivalent between ploidies, but differed significantly among gear types with poor survival in the bottom cages (affected by the oyster drill, Stramonita haemastoma). In terms of growth, triploids grew better than diploids for almost all metrics. Among gear types, growth was poorest in the bottom cages. For dry tissue weight, there was a significant ploidy by gear interaction; within floating bags, there was no difference between triploids and diploids, but triploids had higher dry tissue weight than the diploids in any other gear type. No differences were observed in fan ratios among treatments, but triploids had significantly higher cup ratios than diploids. For condition index, unexpectedly there was no clear pattern explained by ploidy in the August sample. In October, however, triploid condition index exceeded the diploid condition index. Finally, there was no significant effect of gear or ploidy on the abundances of the two Vibrio spp. assessed, but there was a tendency for these abundances to be lower in triploids than diploids. This study adds to the growing body of published evidence of the benefits of genetic triploidy to the Eastern oyster aquaculture industry. We conclude that oyster farmers could expect to benefit from raising triploid oysters, but that the magnitude of these benefits will depend on the type of gear selected.

First Report of Fusarium sambucinum Associated on Pinus elliottii Seeds in Brazil.

An elevated incidence of the fungal genus Fusarium was ascertained during a health quality analysis of a batch of Pinus elliottii Englm. seeds obtained from the Florestas Institute for Agricultural and Forest Research (Fundação Estadual de Pesquisa Agropecuária [FEPAGRO] Florestas) in Santa Maria (29° 39' 55″ S and 53° 54' 45″ W), state of Rio Grande do Sul, Brazil. This genus comprised about 75% of all fungal genera observed in a blotter test. The fungus was then isolated and purified to perform pathogenicity tests. Healthy seeds of P. elliottii were inoculated by contact with fungal mycelium for 48 h (3). Forty-two days after inoculation, a reduction was observed in the germination potential of the seeds; however, those seeds that germinated developed normally until, as seedlings, they suffered damping-off. Fusarium was isolated from the affected vegetal material by transferring mycelium tips to potato dextrose agar (PDA) medium in petri dishes in order to morphologically identify the species. After 72 h, a tan mycelial pad 5.5 cm in diameter had formed. After transfer to carnation leaf agar (CLA), pale orange sporodochia that formed macroconidia could be observed. The macronidia were relatively short and narrow (40.2 × 4.7 μm), each containing a mean of 5 septa; the apical cell was pointed, while the basal one was foot-shaped (2,4). The chlamydospores formed in clusters, while the conidiogenous cells could be seen on top of monophialides. Primer pairs ITS1 and ITS4, EF1-T and EF1-567R, and βtub-F and βtub were employed to amplify the three regions ITS1.8S ITS2, elongation factor - 1α (TEF 1-α), and β-tubulin, respectively. The sequences of these three regions showed 97, 95, and 99% of similarity with Fusarium sambucinum Fückel, respectively. The pathogen was reinoculated on P. elliottii seeds in order to complete Koch's postulates. The pathogenicity test was repeated with the same conditions described before and the results were confirmed. No occurrence of damping-off was observed in the control seedlings. The inoculated seedlings showed, besides damping-off, a visible reduction in root system expansion as well as reductions in fresh and dry tissue weight. F. sambucinum has already been reported on P. radiata D. Don in New Zealand, causing root rot and dieback (1); however, in Brazil, the present study is, to the best of our knowledge, the first to report the association of this pathogen with P. elliottii.

Risk of Aluminum Exposure from Noni (Morinda citrifolia L.) Leaf Products1

Accumulation of soil aluminum in plant tissues can increase aluminum exposure during use of botanical products for food or medicines. We determined the potential for excessive exposure to aluminum in leaves of Morinda citrifolia (Rubiaceae) trees growing in eight contrasting soils in four Western Pacific islands. Mean aluminum content of green leaves ranged from 47–536 μg⋅g-1 tissue dry weight among the eight sites. Mean aluminum content of yellow, senescing noni leaves ranged from 96–988 μg⋅g-1 tissue dry weight. The trees growing in acid soils exhibited greatly elevated aluminum concentration when compared with trees growing in alkaline soils, and leaves from one replication in acid soils exhibited 1659 μg·g-1 aluminum. Results indicate avoidance of old leaves and trees growing in acid soils would greatly reduce aluminum exposure during ingestion of M. citrifolia leaf products.

Suspended versus bottom oyster culture in eastern Canada: Comparing stocking densities and clearance rates

The objectives of this study were to compare the stocking density of suspended versus bottom oyster (Crassostrea virginica) culture in Atlantic Canada and to estimate the capacity of these oysters to clear particles from the water column. Surveys of multiple leases indicated that stocking densities for floating bag and floating cage culture techniques were on average 0.3±0.1 and 0.5±0.1kg oystersm−2, respectively. Bottom culture density was estimated at 1.0±0.1kg oystersm−2, whereas natural reef density was assessed at 2.2±1.1kg oystersm−2. In terms of grazing potential, suspended oysters had significantly lower gill areas per unit dry tissue weight than bottom oysters. This result was consistent with power functions relating clearance rate (CR, l h−1) to dry tissue weight (DTW, g). CR increases relative to DTW were significantly lower in the suspended oyster category than in the bottom oyster category, as indicated by the exponent in the relationships CR=6.35±0.59×DTW0.78±0.08 (bottom) and CR=4.34±0.32×DTW0.41±0.08 (suspended). Based on this information it was calculated that CR per unit area (CRArea) in the most heavily exploited leases was 66.5±8.5 (floating bags), 86.5±8.6 (floating cages), and 197.3±144.4 (bottom culture) lh−1m−2. The CRArea for suspended techniques was on average 10 to 14 times lower than the CRArea for healthy oyster reefs. A bay-scale assessment of an intensive culture site led to the conclusion that cultivated oysters do not exert a dominant top-down control on phytoplankton abundance.

A dynamic distention protocol for whole-organ bladder decellularization: histological and biomechanical characterization of the acellular matrix

A combined physical-chemical protocol for whole full-thickness bladder decellularization is proposed, based on organ cyclic distention through repeated infusion/withdrawal of the decellularization agents through the urethra. The dynamic decellularization was intended to enhance cell removal efficiency, facilitating the delivery of detergents within the inner layers of the tissue and the removal of cell debris. The use of mild chemical detergents (hypotonic solution and non-ionic detergent) was employed to limit adverse effects upon matrix 3D ultrastructure. Inspection of the presence of residual DNA and RNA was carried out on decellularized matrices to verify effective cell removal. Histological investigation was focused on assessing the retention of adequate structural and functional components that regulate the biomechanical behaviour of the acellular tissue. Biomechanical properties were evaluated through uniaxial tensile loading tests of tissue strips and through ex vivo filling cystometry to evaluate the whole-organ mechanical response to a physiological-like loading state. According to our results, a dynamic decellularization protocol of 17 h duration with a 5 ml/min detergent infusion flow rate revealed higher DNA removal efficiency than standard static decellularization, resulting in residual DNA content < 50 ng/mg dry tissue weight. Furthermore, the collagen network and elastic fibres distribution were preserved in the acellular ECM, which exhibited suitable biomechanical properties in the perspective of its future use as an implant for bladder augmentation.

Wound-Healing Potential of the Root Extract of Albizzia lebbeck

The present investigation is an attempt to scientifically validate the traditional use of the roots of the plant Albizzia lebbeck in Ayurvedic system of medicine for curing wounds. The study included phytochemical standardization of the ethanol root extract of A.lebbeck, which was further subjected to oral acute toxicity study. Wound-healing activity of the ethanol root extract was evaluated using incision and excision wound models. Biochemical parameters such as hydroxyproline, hexuronic acid, hexosamine, and antioxidant enzymes like superoxide dismutase, reduced glutathione and free radical parameters including lipid peroxidation and nitric oxide were evaluated on the 10th post-wounding day following dead space method. For confirmation of activity, histopathology of the wounds and granulation tissues from excision and dead space wound model were performed. The study also included assessment of antibacterial activity of ethanol root extract against strains implicated in wound infection. The ethanol root extract was found to be highly rich in flavonoids, saponins, phenols, and tannins, while the amount of rutin was found to be 4.66 % w/w. It significantly increased the wound breaking strength showing a ceiling effect at 500 mg/kg p. o. The ethanol root extract at 500 mg/kg p. o. depicted an optimum wound contraction on the 18th day, while complete wound contraction was observed at the 22nd post wound day. It also demonstrated a significant increase in dry tissue weight, total protein, hydroxyproline, hexosamine, hexuronic acid, superoxide dismutase, and reduced glutathione levels, whereas a decrease in the levels of lipid peroxidation and nitric oxide was also observed with a potential antibacterial activity. Histopathological studies revealed a normal epithelization and fibrosis which was evidenced through an increase in collagen density. Thus, the study scientifically validated the wound-healing activity of the ethanol root extract along with a potential antibacterial property which may be attributed to the enhanced collagen synthesis and a potential antioxidant activity.

Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu

Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope (65Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65–91%) to Cu bioaccumulation is always higher than that from sediments (9–35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors.

Dysfunctions of the translational machinery in digestive glands of mussels exposed to mercury ions

Mercury is an element naturally occurring in the biosphere, but is also released into the environment by human activities, such as mining, smelting, and industrial discharge. Mercury is a biologically harmful element and any exposure of living organisms mainly due to contamination, can cause severe or even lethal side effects. In every form detected, elemental, inorganic, or organic, mercury exhibits toxicity associated with induced oxidative stress. Although the genotoxicity of mercury has been well demonstrated in mussels, little is known about its toxic effects on the translational machinery at the molecular level. To investigate possible effects, we exposed the common mussel Mytilus galloprovincialis in seawater supplemented by 30μg/L Hg2+ for 15 days. We observed that Hg2+ was significantly accumulated in the digestive glands of mussels, reaching a level around 80μg/g tissue (dry weight) at the 15th day of exposure. Exposure of mussels to Hg2+ resulted in failure of redox homeostasis, as reflected on lipid peroxidation levels and superoxide dismutase activity in glands, and micronucleus frequency in gills. Extracts from digestive glands after 15-day exposure to Hg2+ exhibited decreased tRNA aminoacylation ability and, moreover, a 70% reduction in the ability of 40S ribosomal subunits to form the 48S initiation ribosomal complex. A similar reduction was detected in the ability of ribosomes to translocate peptidyl-tRNA from the A-site to the P-site, an observation coinciding with the notion that regulation of protein synthesis by Hg2+ mainly occurs at the initiation and elongation stages of translation. A-site binding, peptidyl transferase activity, and termination of peptide chain synthesis underwent less pronounced but measurable reductions, a finding which explains why poly(Phe)-synthesis in ribosomes isolated from exposed mussels is reduced by 70%. In conclusion, Hg2+ apart from being a genotoxic ion acts as a modulator of protein synthesis in mussels, an observation probably related with its ability to induce oxidative stress.

Quantifying the historic contribution of Olympia oysters to filtration in Pacific Coast (USA) estuaries and the implications for restoration objectives

The Olympia oyster, Ostrea lurida Carpenter, was formerly widespread in many US Pacific coast estuaries. Following dramatic declines in the late 1800s and early 1900s, this species is now the focus of renewed restoration efforts. Restoration is undertaken for brood stock rehabilitation as well as a range of ecosystem services such as filtration; however, these ecosystem services are as yet poorly quantified. We present the first laboratory measurements of filtration rates (FR) for O. lurida, to which we fit a model of FR as a function of dry tissue weight and water temperature. We find that O. lurida has a FR at optimum temperature similar to previously established means across oyster species at 1 g dry tissue weight (DTW), but lower than many Crassostrea species. We also find that the allometric exponent relating FR to DTW in O. lurida is lower than the previously published mean across oyster species. Based on our derived filtration rates and historical data, we estimate the historic impact of filtration by O. lurida in five Pacific coast estuaries. We find that historic O. lurida populations did not have the capacity to filter the full volume of the estuary within the estuary residence time in any of the estuaries examined. This result is primarily driven by the low water temperatures and the short estuary residence times that typify the Pacific coast. We conclude that, unlike Crassostrea virginica Gmelin on the Atlantic and Gulf coasts, the Olympia oyster was not historically a dominant force in regulating seston concentrations at large scales in Pacific coast estuaries. Given the differences in the ecological role and habitat structure of these two oyster species, we recommend that analogies between them be drawn with caution. We discuss the implications of our results for developing restoration objectives.

两种海星对三种双壳贝类的捕食选择性和摄食率

Sea stars are one of the primary predators of shellfish and often cause mass mortality among cultured shellfish.To develop effective control strategies,it is critical to understand the feeding ecophysiology(e.g.,feeding rate and prey selection) of sea stars. Asterias amurensis and Asterina pectinifera are the dominant sea star species in the coastal waters of China.We evaluated prey selection and the feeding rate of these two sea stars on three species of bivalves: scallops Chlamys farreri,clams Ruditapes philippinarum,and blue mussels Mytilus galloprovincialis.The experimental sea stars and bivalves were collected from Sanggou Bay,Northern China and transported to our seaside laboratory.The animals were acclimated to laboratory conditions for 7 d prior to the initiation of the experiment.The experiment was conducted between March 19 and April 5,2008,at different seawater temperatures.Following acclimation,the sea stars were placed in cement tanks(L×W×H=6×1×0.5 m) at a density of 5 individuals per tank(single species per tank).The sea water was pumped from Sanggou Bay and sand filtered.Daily water exchange was ca 100%.We placed the bivalves(N=30 per species) evenly in each tank to ensure the sea stars had an equal probability of encountering the three species of bivalves.Each treatment was conducted in triplicate(N= 3 tanks).The number of bivalves of each species preyed upon by the sea stars was recorded twice daily at 7:00 and 17:00.In addition,we measured the Q10 coefficient at water temperatures ranging from 4.3—7.8℃ and from 7.8—13.3℃. Both species of sea star preyed on all three bivalve species.Similarly,both species exhibited preference in the order clammusselscallop.During the first part of the experiment(March 19—24),A.amurensis preyed on 64.28,28.57,and 7.14% of the scallops,clams,and blue mussels,respectively.A.pectinifera preyed upon 50,44.44,and 5.56% of the bivalve species,respectively.The mean feeding rates of A.amurensis and A.pectinifera on the clam(0.50 and 0.37 ind/d,respectively) and blue mussel(0.26 and 0.27 ind/d,respectively) were significantly higher than those on the scallop(0.05 and 0.07 ind/d,respectively).The feeding rate was significantly influenced by water temperature and generally increased with increasing water temperature.The total mean feeding rates of the two sea stars were 0.69 and 0.79 g · d-1,respectively(based on dry tissue weight of bivalves).As water temperature increased from 4.3 to 7.8℃,the Q10coefficients for A.amurensis and A.pectinifera were 6.38 and 2.33,respectively.However,when the water temperature was increased from 7.8 to 13.3℃,there was no increase in the feeding rate(Q10=1.13 and 1.22,respectively).Our results have implications for the provision of protective refuges for the species of interest(i.e.,scallops) during culture in suspended lantern nets.Protective strategies are most likely to be needed when the water temperature increases above 4.3℃,as the feeding rate and activity of sea stars increased significantly above this point.Based on prey selectivity,bivalves that have a lower commercial value(e.g.,blue mussels) may be co-cultured in the scallop lantern nets to serve as a buffer against predators.Furthermore,any sea stars present in the cultivation nets should be removed during the buffering period.

Leaf removal before flooding influences recovery of avocado (Persea americana Mill.) trees from flooding stress

Three experiments (Expts. 1, 2 and 3) were conducted to test the effects of removing a portion of the leaf canopy of avocado trees (Persea americana Mill.) prior to flooding on plant stress, survival and recovery from short-term flooding. Trees in each experiment were divided into two flooding treatments: (1) flooded, or (2) non-flooded. Trees in each flooding treatment were divided into two pruning treatments in Expt. 1: (1) approximately two-thirds of the canopy removed by pruning, or (2) non-pruned (control). In Expt. 2, trees in each flooding treatment were divided into three “canopy” treatments: (1) removal of two-thirds of the total number of leaves from the bottom of the canopy upward (2/3 LR), (2) foliar application of a chemical photosynthetic inhibitor and no leaf removal (CP), or (3) no leaf removal or photosynthetic inhibitor applied (control). Trees in each flooding treatment in Expt. 3 were divided into two treatments: (1) two-thirds of the total number of leaves removed from the bottom of the canopy upward, or (2) no leaves removed (control). In each experiment, net CO2 assimilation (A) and stomatal conductance of water vapor (gs) were determined daily during the flooding period and periodically after the flooding period until trees were harvested. Plant survival and tissue dry weights were determined several weeks after plants were removed from flooding (unflooded) in Expts. 1 and 2. Root carbohydrate concentrations were determined immediately after the flooding period in Expt. 3. Pruning, leaf removal or foliar application of a chemical photosynthetic inhibitor immediately prior to flooding resulted in significantly lower A of flooded compared to non-flooded trees. Concentration of the C7 sugar, d-mannoheptulose, was higher in non-flooded than in flooded plants. In flooded plants, concentration of the C7 sugar alcohol, perseitol, was higher in plants with no leaves removed than those in the 2/3 LR treatment. Reducing photosynthesis of avocado trees prior to flooding, either by pruning, leaf removal, or the application of a chemical photosynthetic inhibitor, makes trees more susceptible to flooding stress. Reducing A prior to flooding limits carbohydrate transport to the roots, thereby limiting the amount of substrate for respiration of flooded roots, making the plants more susceptible to flooding stress.

Multiple Categories of Resistance to Wheat Curl Mite (Acari: Eriophyidae) Expressed in Accessions of &lt;I&gt;Aegilops tauschii&lt;/I&gt;

The wheat curl mite, Aceria tosichella Keifer, is an important pest in the western plains of the United States as well as in most major wheat-growing regions of the world. This mite is a vector of the economically important diseases wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and High Plains virus (HPV). This study looked at seven accessions of Aegilops tauschii (Coss) Schmal to determine if they exhibit antibiosis, tolerance, and/or antixenosis to the wheat curl mite using 'Jagger', a known wheat curl mite-susceptible variety, and OK05312, a known wheat curl mite-resistant variety, as controls. Four of the seven tested accessions showed antibiotic effects on the population growth of wheat curl mite, as demonstrated by low number of wheat curl mite adults and nymphs at the end of the experiment. Three accessions and the commercial wheat variety Jagger showed some level of tolerance to wheat curl mite infestations, as demonstrated by a significantly reduced percentage proportional tissue dry weight and by tolerance index values. Four accessions demonstrated a strong antixenotic effect on the wheat curl mite, as demonstrated by significantly reduced numbers of mite adults at the end of the experiment. This study also established an effective method for determining antixenosis to the wheat curl mite in wheat that can be used for future experiments. All accessions demonstrated at least one type of plant resistance that could provide a genetic source for control of the wheat curl mite that may have the potential to be transferred into commercial wheat varieties.

Biomassa Kerang Anadara granosa pada Perairan Pantai Kabupaten Indragiri Hilir

The present study was carried out to investigate the biomass of cockle (Anadara granosa) from coastal waters ofSouth Indragiri District, Riau Province. The biomass was investigated by quadrad sampling method in the intertidalarea along the Concong beach, where fishing of cockles mainly occured. The first station was near by the Concongestuary, while the second station was about 3 miles away from the fisrt one. Samples were collected from threedifferent portions of the intertidal zone that of High Intertidal Mid-Intertidal, and Low Intertidal. The result showedthat the highest biomass was found at the lower partion of the intertidal zone. Soft tissue of A. granosa was about24.8% of total wet-weight and 7.2 % of dry-weight. While material organic was about 85 % of soft tissue dry-weight.Water qualities of the sampling station showed that the overall water qualities were still in normal condition.

국내육성 주요 딸기 품종에서 발생하는 구리(Cu) 과잉 증상 및 영양진단을 위한 식물체 내 한계농도

미량원소인 Cu 시비농도를 인위적으로 조절하여 '금향', '매향' 및 '설향' 딸기를 재배하면서 시비수준이 생장에 미치는 영향을 구명하였다. 또한 생육을 우수하게 유지할 수 있는 식물체의 Cu 한계농도를 밝혀 딸기 재배 시 영양장해를 진단할 수 있는 기초 자료로 활용될 수 있도록 하기 위하여 본 연구를 수행하였다. Cu 시비농도에 영향을 받은 세 종류 딸기 품종의 건물중에서 '금향'과 '매향'은 0.25mM-1.0mM 시비구 간, '설향' 딸기의 경우 0.25mM-3.0mM 시비구 간통계적인 유의차가 없었고, '설향'이 '금향'이나 '매향'보다 Cu 과다시비에 대한 내성이 강함을 알 수 있었다. Cu가 과다하게 시비되어 식물체의 흡수량이 증가하면 신엽에서 엽맥 간 황화현상이나 엽맥 사이에 직선형태의 황화현상이 그리고 하위엽에서는 잎 가장자리가 주황색으로 변하는 증상이 나타났다. 관비용액의 Cu 시비농도를 증가시켜도 세 종류 딸기의 식물체 내 P, K, Ca 및 Mg 함량은 뚜렷한 경향을 발견할 수 없었다. 미량원소 중 Cu 함량은 시비농도가 높아짐에 따라 식물체 내 함량이 직선적으로 증가하였으며, Fe 및 Mo 함량은 관비용액의 Cu 농도에 대한 반응이 뚜렷하지 않았고, 경향도 발견할 수 없었다. '금향', '매향' 및 '설향' 딸기의 최대생장량보다 10% 적은 생장량과 이 때의 식물체내 Cu 함량을 정상 생장을 위한 최대한계점으로 간주하면 '금향' <TEX>$71.4mg{\cdot}kg^{-1}$</TEX>, '매향' <TEX>$57.9mg{\cdot}kg^{-1}$</TEX>, 그리고 '설향' <TEX>$74.81mg{\cdot}kg^{-1}$</TEX> 이하를 유지하도록 Cu 시비농도를 조절해야 한다고 판단하였다. This study was carried out to investigate the influence of copper concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. The characterization of toxicity symptoms as well as tissue analyses based on dry weight of above ground tissue were also conducted to determine the threshold levels in plants when toxicity developed in copper. The dry weights of the above ground tissue were not significantly different among the treatments of 0.25 mM to 1.0 mM in 'Keumhyang' and 'Maehyang' strawberries and that of 0.25 mM to 3.0 mM in 'Seolhyang' strawberry. This indicates that the 'Seolhyang' strawberry is more tolerant to copper toxicity than 'Keumhyang' or 'Maehyang' strawberries. Application of copper at high concentrations resulted in severe toxicity such as death of extensive areas of leaves. The lower leaves became yellow and die rapidly as the symptoms spread up the plants. The leaf blades and petioles died back to the crown and hang on by mechanical attachment. Symptoms of copper toxicity in lower leaves developed as browning on leaf margins and in patches between leaf veins that became necrotic. The elevation of copper concentrations in fertilizer solution did not influence the tissue phosphorus, potassium, calcium, and magnesium contents based on the dry weight of the above ground tissue. The tissue copper contents increased lineally as the copper concentrations in fertilizer solution were elevated. But the tissue iron, manganese and boron contents were not influenced by the concentrations. When the concentration of copper at which growth of a plant is retarded by 10% is regarded as threshold level, the copper contents based on dry weight of above ground plant tissue should be lower than 71.4, 57.9 and 74.8 <TEX>$mg{\cdot}kg^{-1}$</TEX> in 'Keumhyang', 'Maehyang' and 'Seolhyang' strawberries, respectively. The symptom characterization and established threshold level in copper toxicity would help growers to prevent the reduction of crop growth and yield in 'Seolhyang' strawberry cultivation.

Results from a 1-year, open-label, single arm, multi-center trial evaluating the efficacy and safety of oral Deferasirox in patients diagnosed with low and int-1 risk myelodysplastic syndrome (MDS) and transfusion-dependent iron overload

The majority of patients with myelodysplastic syndrome (MDS) present with anemia and will become dependent on regular transfusions of packed red blood cells (PRBC) with the risk of iron overload (IOL). Liver iron content best reflects the total body iron content, and measurement of liver iron concentration (LIC) by MRI is a validated tool for detection, but data in MDS is rather limited. Here we present the results of a multi-center trial evaluating the efficacy and safety of deferasirox (DFX) in low and intermediate-1 risk MDS patients with transfusion-dependent IOL. Three patients with transfusion frequency of > 4 units PRBC per month were initially treated with 30mg/kg/day while in 46 patients with a lower transfusion burden deferasirox was initiated at 20mg/kg/day, due to patient related reasons one patient received DFX in a dose of 6mg/kg/day only. LIC was measured by MRI at baseline and end of study using the method by St. Pierre et al. The intention to treat population consisted of 50 MDS patients (28 male; 22 female) with a median age of 69years who were treated with DFX for a median duration of 354days. Mean daily dose of DFX was 19mg/kg/day. Median serum ferritin level (SF) at baseline was 2,447ng/mL and decreased to 1,685ng/mL (reduction by 31%) at end of study (p = 0.01). In 7 (13%) patients the initially chosen dose had to be increased due to unsatisfactory efficacy of chelation therapy. For 21 patients, LIC measurement by liver MRI was performed at baseline and for 19 of these patients at the end of study: mean LIC decreased significantly from 16,8mg/g dry tissue weight (± 8.3mg/g dry tissue weight) at study entry to 10,8mg/g dry tissue weight (± 10.4mg/g dry tissue weight) at end of study (p = 0.01). Of all patients exposed to the study drug (n = 54), 28 (52%) did not complete the 12month study period most commonly due to AEs in 28% (n = 15) and abnormal laboratory values in 7% (n = 4), respectively. The most common adverse events (≥ 10% of all patients) with suspected drug relationship were diarrhea (n = 25, 46%), nausea (n = 13, 24%), upper abdominal pain (n = 8, 15%), serum creatinine increase (n = 16, 30%) and rash (n = 5, 9%). Adverse events making dose adjustments or interruption of study drug necessary occurred in 33 patients (61%). Hematologic improvement according to IWG criteria (2006) was observed in 6 patients (11%). Initiation of treatment of IOL with DFX depending on the transfusion burden yields sufficient reduction of excess iron indicated by serum ferritin levels and most importantly by liver MRI. The safety profile of DFX was comparable to previous observations.

Incorporation of salmon fish feed and feces components in mussels (Mytilus edulis): Implications for integrated multi-trophic aquaculture in cool-temperate North Atlantic waters

The incorporation of salmon fish feed and feces components in the digestive gland, mantle, and gill tissue of blue mussels (Mytilus edulis), and associated growth in shell length and soft tissue dry weight, were studied in a 28day laboratory experiment. Mussels were fed mixed rations of either salmon fish feed and Rhodomonas baltica, salmon feces and R. baltica or mono rations of either a full or half ration of R. baltica. Feed rations were designed to supply a particulate organic carbon ration equal to ~5% of soft tissue carbon content ind−1day−1.Significant changes in the fatty acid composition, which appointed that of the food profiles, were evident in the digestive gland and gill tissue (p<0.05), whereas no changes were found in mantle tissue. For digestive gland data, a principal component analysis particularly identified the contribution of 18:1 (n−9), 18:3 (n−3), 18:2 (n−6) and 20:1 (n−9) and as being the single fatty acids most responsible for the difference between the various diets.A significant growth in length was found for mussels fed fish feed and R. baltica (p<0.05), but not for mussels fed feces and R. baltica. The dry weight was significantly higher for mussels fed the full diet with R. baltica compared to the other diets, and significantly lower for mussels fed feces and R. baltica than fish feed and R. baltica at the end of the experiment (p<0.05).A more pronounced incorporation of salmon feed compared to salmon feces components in mussel tissues suggested that mussels will utilize fish feed more efficiently than feces particles in an integrated aquaculture with salmon.

Posidonia-based Compost as a Peat Substitute for Lettuce Transplant Production

Posidonia [Posidonia oceanica (L.) Delile] is a marine phanerogam endemic of the Mediterranean Sea that grows all along the coast forming extensive underwater meadows. Senescent posidonia leaves, together with fibers (residues of rhizomes and decomposed leaves), periodically accumulate along Mediterranean beaches, covering vast areas of coast. Removal and disposal of these large volumes of plant biomasses represent a high cost for local administrations. Therefore, in this experiment, beached residues of posidonia were composted with olive pruning and green wastes with the objective to assess the efficacy of posidonia-based compost (63% on a volume basis) as a peat replacement. The compost was then mixed with a peat-based commercial substrate at rates of 0% (C0, pure peat-based commercial substrate tested as control), 25% (C25), 50% (C50), 75% (C75), and 100% (C100, pure posidonia-based compost) v/v. Mixtures were used as growing media to produce lettuce seedlings for transplant. Two lettuce cultivars (8511RZ and Satine) were tested. Main physical and chemical properties of the five growing media, shoot and root fresh and dry weight, leaf area, root morphology, and elemental leaf tissue composition were studied. Growing media containing posidonia-based compost, C25 and C50 in particular, showed good physical properties. Increasing compost proportions in the mixtures resulted in enhanced: 1) availability of macro- and micronutrients in the growing media; and 2) overall growth parameters of lettuce seedlings, in particular for the cultivar Satine. In conclusion, posidonia-based compost shows a considerable potential as a peat substitute in horticultural substrates; posidonia residues are a low-cost renewable material. In growing media for lettuce seedlings production, posidonia-based compost could be used as a complement to peat at a rate of 25% or 50% to obtain optimal physical properties and to limit the negative effects of high B content, which are typical of posidonia residues.

Increased nitric oxide activity compensates for increased oxidative stress to maintain endothelial function in rat aorta in early type 1 diabetes

Hyperglycaemia and oxidative stress are known to acutely cause endothelial dysfunction in vitro, but in the initial stages of diabetes, endothelium-dependent relaxation is preserved. The aim of this study was to investigate how endothelium-dependent relaxation is maintained in the early stages of type 1 diabetes. Diabetes was induced in Sprague-Dawley rats with a single injection of streptozotocin (48mg/kg, i.v.), and after 6weeks, endothelium-dependent and endothelium-independent relaxations were examined in the thoracic aorta in vitro. Lucigenin-enhanced chemiluminescence was used to measure superoxide generation from the aorta. Diabetes increased superoxide generation by the aorta (2,180 ± 363 vs 986 ± 163AU/mg dry tissue weight). Acetylcholine (ACh)-induced relaxation was similar in aortae from control (pEC(50) 7.36 ± 0.09, R (max) 95 ± 3%) and diabetic rats (pEC(50) 7.33 ± 0.10, R (max) 88 ± 5%). The ACh-induced relaxation was abolished by the combined presence of the nitric oxide synthase inhibitor N-nitro-L-arginine (L-NNA, 100μM) and an inhibitor of soluble guanylate cyclase, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10μM) in control rats, but under the same conditions, the diabetic aortic rings showed significant relaxation to ACh (pEC(50) 6.75 ± 0.15, R (max) 25 ± 4%, p < 0.05). In diabetic aortae, the addition of haemoglobin, which inactivates nitric oxide, to L-NNA + ODQ abolished the response to ACh. The addition of the potassium channel blockers, apamin and TRAM-34, to L-NNA + ODQ also abolished the relaxation response to ACh. Diabetes significantly elevated plasma total nitrite/nitrate and increased expression of endothelial nitric oxide synthase (eNOS) and calmodulin in aortae. These data indicate that after 6weeks of diabetes, despite increased oxidant stress, endothelium-dependent relaxation is maintained due to the increased eNOS expression resulting in increased NO synthesis. In diabetic arteries, NO acts both through and independently of cGMP pathways to cause relaxation.

국내육성 주요 딸기 품종에서 발생하는 Mo 과잉 증상 및 영양진단을 위한 식물체 내 한계농도

미량원소인 Mo의 시비농도를 인위적으로 조절하여 '금향', '매향' 및 '설향' 딸기를 재배하면서 생장에 미치는 시비수준의 영향, 생육을 우수하게 유지할 수 있는 식물체의 한계농도, 그리고 과잉에 의해 발현되는 생리장해의 특징을 구명하기 위하여 본 연구를 수행하였다. 관비용액의 Mo 농도를 높일 경우 엽록소 함량이 뚜렷하게 직선적으로 감소하여 세 종류 딸기에서 Mo 시비농도의 처리간 차이가 인정되었다. '금향'과 '매향'은 3.0mM 이상, 그리고 '설향' 딸기는 1.0mM 이상의 고농도 Mo 시비구에서 이보다 낮은 Mo 시비구보다 유의하게 생체중 및 건물중이 감소하였다. Mo이 과다하게 시비될 경우 최초의 Mo 과잉증상이 하위엽에서 발현되었으며, 하위엽 가장자리가 황화된 후 괴사하면서 그 부위가 점차 확대되는 양상으로 변화되었다. 또한 하위엽 가장자리가 점차 구리색으로 변하면서 그 부위가 상위엽으로 확대되었으며, 신생엽에서는 엽맥 간 황화현상이 나타났다. Mo 시비농도를 증가시켜도 세 종류 딸기의 식물체 내 P, K 및 Mg 함량은 처리간 통계적인 차이와 경향을 발견할 수 없었다. '금향'과 '설향' 딸기에서 Mo 시비농도에 따른 처리간 Ca 함량의 차이가 인정되었는데 1.0mM Mo 시비구에서 가장 높고, 이보다 높거나 낮은 Mo 시비농도에서 Ca함량이 감소하였다. 관비용액의 Mo 농도를 0.25mM로 조절한 처리의 식물체 내 Mo 함량이 '금향', '매향' 및 '설향'이 각각 76.5, 104.0, <TEX>$187.3mg{\cdot}kg^{-1}$</TEX>였지만, 시비농도가 높아질수록 식물체내 Mo 함량이 직선적으로 증가하여 4.0mM 시비구에서 각각 4,155, 5,367 및 <TEX>$2,190mg{\cdot}kg^{-1}$</TEX>으로 분석되었다. 최대생장량의 90% 생장량과 이때의 식물체 내 Mo 함량을 정상적인 작물재배를 위한 최대한계점으로 간주하면 '금향', '매향' 및 '설향' 딸기의 건물중에 기초한 Mo 함량이 각각 653.4, 686.2, 그리고 <TEX>$589.73mg{\cdot}kg^{-1}$</TEX> 이하를 유지하도록 Mo 시비농도를 조절해야 한다고 판단하였다. This study was carried out to investigate the influence of molybden (Mo) concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. Tissue analysis based on the dry weight was also conducted to determine the threshold levels in plants when Mo toxicity developed in strawberries. The leaf chlorophyll contents decreased lineally as Mo concentrations in the fertilizer solution were elevated. The differences among treatments in chlorophyll contents were statistically significant. The fresh and dry weights decreased significantly when the Mo concentrations in fertilizer solution were higher than 3.0 mM in 'Keumhyang' and 'Maehyang' strawberries and 1.0 mM in 'Seolhyang' strawberry. The elevation of Mo concentrations in fertilizer solution resulted in severe toxicity and crops developed the unique symptoms. The margin of older leaves became yellow and desiccated. Then, the margin of leaf blade rapidly became bronze colored and died as the symptoms spread up the plants. The interveinal area of the young leaves became yellowing. The elevation of Mo concentrations in fertilizer solution did not influence the tissue P, K, and Mg contents based on the dry weight. The tissue Ca contents were higher in 1.0 mM treatment than other treatments of 'Keumhyang' and 'Seolhyang' strawberries. The tissue Mo contents based on the dry weight of 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries were 76.5, 104.0, and 187.3 <TEX>$mg{\cdot}kg^{-1}$</TEX>, respectively, in the 0.25 mM treatments and 4,155, 5,367, and 2,190 <TEX>$mg{\cdot}kg^{-1}$</TEX>, respectively, in the 4.0 mM treatments. The contents increased lineally as Mo concentrations in fertilizer solution were elevated. When the concentration of Mo at which growth of crops were retarded by 10% is regarded as threshold level, the Mo contents based on dry weight of above ground plant tissue should be lower than 653.4, 686.2, and 589.7 <TEX>$mg{\cdot}kg^{-1}$</TEX>, in 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries, respectively.