A preliminary study on the protein requirements of Chanos chanos (Forskal) fry in a controlled environment

Milkfish (Chanos chanos) fry with an average weight of 40 mg per fish were stocked in 60-l wooden-glass aquaria filled with 30 l of filtered sea water with a salinity of 32–34 p.p.t. and a temperature of 25–28°C. They were fed diets containing 20, 30, 40, 50 and 60% protein and 2740 kcal of digestible energy per kg at a daily rate of 10% of the biomass for a period of 30 days. Fish which were fed the diet containing 40% protein had the highest weight gain which was significantly higher (P < 0.05) than those of fish receiving the lower dietary levels of protein. Slightly lower weight gains were obtained when fish were fed diets containing 50 and 60% protein. Although feed conversion values were not statistically different (P < 0.05) among all treatments, the value for the 40% protein diet (1.96) was the best. The mean survival rates were low for all treatments but was highest for the 40% protein diet. No significant difference (P < 0.05) was found in the survival rates of fish receiving different treatments. Results show that a dietary level of 40% protein was required by milkfish fry for maximum growth, efficient feed conversion and high survival rate.     

Tapered conduits can buffer hydraulic conductance from path-length effects

The model of West, Brown and Enquist showed that total hydraulic resistance in trees can be independent of path length, provided that vascular conduits taper sufficiently. This model assumes that the tree branch network is volume-filling, so that segment lengths increase exponentially from tree top to base. We show that partial buffering of hydraulic resistance from path-length effects can occur even for moderate tapering, and that this effect is stronger when segment lengths are fixed. Still needed are measurements of tracheary size and hydraulic resistance designed to test this model, which shows how hydraulic limitation of tree height growth may be mitigated.     

Long- and short-term flooding effects on survival and sink-source relationships of swamp-adapted tree species

About 95% of swamp tupelo (Nyssa sylvatica var. biflora (Walt.) Sarg.) and sweetgum (Liquidambar styraciflua L.) seedlings survived continuous root flooding for more than two years, whereas none of the swamp chestnut oak (Quercus michauxii Nutt.) and cherrybark oak (Q. falcata var. pagodifolia Ell.) seedlings survived one year of flooding. Death of oak seedlings occurred in phases associated with periods of major vegetative growth, e.g., after bud burst in spring, after summer stem elongation, and during the winter deciduous stage, suggesting that stored reserves and sources were inadequate to maintain the seedlings when vegetative sinks were forming. Additional evidence that flooding induced a source deficiency in oak was that leaves of flooded oak were 65 to 75% smaller than leaves of nonflooded oak. Flooded swamp tupelo seedlings had a normal leaf size and patchy stomatal opening compared with nonflooded seedlings. Flooding caused increases in alcohol dehydrogenase (ADH) specific activity in taproot cambial tissues and increases in starch concentrations of swamp tupelo seedlings that were reversed when seedlings were removed from flooding. Flooding had little effect on soluble sugar concentrations in swamp tupelo or sweetgum. In the long-term flood-dry-flood treatment, in which all species had survivors, upper canopy leaf photosynthetic rates were higher in all species during the dry period than in nonflooded controls, whereas their starch and soluble sugars concentrations were similar to those of nonflooded controls. Based on seedling survival and the sink-source relationships, the order of flood tolerance was: swamp tupelo > sweetgum > swamp chestnut oak > cherrybark oak.     

Characterization of proanthocyanidin in hot water extract isolated from <Emphasis Type="Italic">Pinus radiata</Emphasis> bark

Proanthocyanidins (PAs) in the hot water extract prepared from Pinus radiata bark were isolated by a Sephadex LH-20 chromatography. The PAs were characterized using UV/Visible, FT-IR and ¹³C nuclear magnetic resonance (NMR) spectroscopic techniques, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS), and gel permeation chromatography (GPC) analysis. Bate-Smith acidic alcoholysis and FT-IR spectrum of the PAs indicated the predominant presence of the procyanidin (PC) structure. The ¹³C NMR spectrum revealed that the PAs comprise PC (94%) together with a small amount of prodelphinidin (PD, 6%), and also that they contain the higher trans configuration rather than the cis configuration of C2–C3. The MALDI-TOF MS results obviously proved the presence of PD units, but the maximum degree of polymerization (DP) was limited to octamer. The average molar mass (Mw, Mn), polydispersity (Mw/Mn), and DP of the pine bark PAs were 3,800 (Mw), 1,200 (Mn), 3.2, and 13, respectively.     

Vitamin D Status in Different Stages of Disease Severity in Dogs with Chronic Valvular Heart Disease

Background

In humans with heart disease, vitamin D deficiency is associated with disease progression and a poor prognosis. A recent study showed that serum 25‐hydroxyvitamin D [25(OH)D] concentration, the hallmark of vitamin D status, was lower in dogs with heart failure than in normal dogs, and a low concentration was associated with poor outcome in dogs with heart failure.

Objectives

To elucidate the vitamin D status of dogs with chronic valvular heart disease (CVHD) at different stages of disease severity.

Animals

Forty‐three client‐owned dogs with CVHD.

Methods

In this cross‐sectional study, dogs were divided into 3 groups (14 dogs in Stage B1, 17 dogs in Stage B2, and 12 dogs in Stage C/D) according to ACVIM guidelines. Dogs underwent clinical examination including echocardiography. Serum 25(OH)D concentrations were measured in each dog.

Results

Serum 25(OH)D concentration was significantly lower in Stage B2 (median, 33.2 nmol/L; range, 4.9–171.7 nmol/L) and C/D (13.1 nmol/L; 4.9–58.1 nmol/L) than in Stage B1 (52.5 nmol/L; 33.5–178.0 nmol/L) and was not significantly different between Stage B2 and Stage C/D. Among clinical variables, there were significant negative correlations between 25(OH)D concentration and both left atrial‐to‐aortic root ratio and left ventricular end‐diastolic diameter normalized for body weight.

Conclusions and Clinical Importance

These results indicate that vitamin D status is associated with the degree of cardiac remodeling, and the serum 25(OH)D concentration begins to decrease before the onset of heart failure in dogs with CVHD.     

Determination of reference intervals for metabolic profile of Hanwoo cows at early,middle and late gestation periods

Background

Metabolic profile was initially designed as a presymptomatic diagnostic aid based on statistical analyses of blood metabolites to provide an early warning of certain types of metabolic disorder. However, there is little metabolic profile data available about Korean Hanwoo cows. Therefore, this study aimed to determine the reference intervals of metabolic profile for Korean Hanwoo cows.

Methods

Healthy animals (2,205) were selected and divided into early (day 1 to 95), middle (day 96 to 190) and late (day 191 to 285) period according to their gestating period. Metabolic profile including total protein (TP), albumin (Alb), urea (UREA), glucose (Glu), total cholesterol (T-Cho), long-chain fatty acid (LCFA), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), creatinine (Crea), calcium (Ca), inorganic phosphorous (iP) and magnesium (Mg) were analyzed using a TBA-40FR automatic biochemical analyzer. The data of Korean Hanwoo cows were then compared to those of the Japanese Wagyu cows.

Results

Most of the data of the Korean Hanwoo cows were relatively higher than those of Japanese Wagyu cows, with the exception of Glu and GGT. This may indicate that the nutritional level of feed for the Korean Hanwoo cows was higher than that of the Japanese Wagyu cows because of the different feeding system. In particular, relatively higher levels of UREA and LCFA were observed in the Korean Hanwoo cows, and this may also contribute to the low reproduction efficiency.

Conclusions

These findings may provide some theoretical basis for understanding the reproductive and feeding situation of Korean Hanwoo cows.     

Antioxidant and antimelanogenic activities of polyamine conjugates from corn bran and related hydroxycinnamic acids

The antioxidant activity of three major polyamine conjugates, N,N'-dicoumaroyl-putrescine (DCP), N-p-coumaroyl-N'-feruloylputrescine (CFP), and N,N'-diferuloyl-putrescine (DFP) isolated from corn bran, and their related hydroxycinnamic acids, p-coumaric acid and ferulic acid, were evaluated by three antioxidant in vitro assay systems, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide and hydroxyl radicals generated by enzymatic and nonenzymatic reactions. Additionally, five phenolic compounds were evaluated for melanogenesis inhibitory activity using mushroom tyrosinase and B16 melanoma cells. Most of the phenolic compounds significantly scavenged DPPH, superoxide, and hydroxyl radicals in a dose-dependent manner. Particularly, DFP showed potent DPPH (IC50 = 38.46 microM) and superoxide (IC50 = 291.62 microM) radical scavenging activities, while DCP exhibited the strongest hydroxyl radical scavenging activity (IC50 = 120.55 microM). CFP also exerted moderate DPPH, superoxide, and hydroxyl radical scavenging activities. Meanwhile, DCP (IC50 = 181.73 microM) showed potent tyrosinase inhibitory activity toward l-tyrosine as the substrate, whereas DFP (IC50 = 733.64 microM) significantly inhibited melanin synthesis in B16 melanoma cells. These current results indicate that these three polyamine conjugates from corn bran may be useful potential sources of natural antioxidants and skin-whitening agents.     

Protective effect of heat-processed American ginseng against diabetic renal damage in rats

We investigated the effects of American ginseng (AG) and heat-processed American ginseng (H-AG) on diabetic renal damage using streptozotocin (STZ)-induced diabetic rats in this study. The diabetic rats showed a loss of body weight gain, and increases in kidney weight, food intake, water intake, and urine volume, whereas the oral administration of H-AG at a dose of 100 mg/kg of body weight per day for 20 days attenuated these diabetes-induced physiological abnormalities. Among the renal function parameters, the elevated urinary protein levels in diabetic control rats were significantly decreased by the AG or H-AG administrations, and the decreased creatinine clearance level was significantly increased in H-AG-administered rats. In addition, the markedly high serum levels of glucose and glycosylated protein in diabetic control rats were significantly decreased by the administration of H-AG, implying that H-AG might prevent the pathogenesis of diabetic complications caused by impaired glucose metabolism and glycosylation of serum proteins. Although no significant ameliorations were shown in overexpressed protein expressions related to diabetic oxidative stress by the AG or H-AG administrations, the accumulation of N (epsilon)-(carboxymethyl)lysine and receptors for advanced glycation endproduct (AGE) expressions were significantly reduced by the administration of H-AG. On the basis of these results, we found that AG and H-AG inhibit AGE accumulation in diabetic rat kidney by their hypoglycemic and renal function ameliorating effects, and this effect was stronger in the H-AG-administered group than in the AG-administered group. These findings indicate that H-AG may have beneficial effect on pathological conditions associated with diabetic nephropathy.     

Characterization of aerosols containing microcystin

Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackish water sources throughout the world. One class of cyanobacterial toxins, called microcystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likely route of human exposure. A significant increase in reporting of minor symptoms, particularly respiratory symptoms was associated with exposure to higher levels of cyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxins can be aerosolized by a bubble-bursting process with a wind-driven white-capped wave mechanism. The purposes of this study were to: evaluate sampling and analysis techniques for microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory, and deploy the sampling instruments in field studies. A high-volume impactor and an IOM filter sampler were tried first in the laboratory to collect droplets containing microcystins. Samples were extracted and analyzed for microcystin using an ELISA method. The laboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distribution with the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 mum. The sampling and analysis methods were successfully used in a pilot field study to measure microcystin aerosol in situ.