Abundance of biting midge species (Diptera: Ceratopogonidae,Culicoides spp.) on cattle farms in Korea

Culicoides biting midges were collected on three cattle farms weekly using light traps overnight from May to October between 2010 and 2011 in the southern part of Korea. The seasonal and geographical abundance of Culicodes spp. were measured. A total of 16,538 biting midges were collected from 2010 to 2011, including seven species of Culicoides, four of which represented 98.42% of the collected specimens. These four species were Culicodes (C.) punctatus (n = 14,413), C. arakawae (n = 1,120), C. oxystoma (n = 427), and C. maculatus (n = 318). C. punctatus was the predominant species (87.15%).     

Evidence for functional G-coupled protein receptors 43 and 120 in subcutaneous and intramuscular adipose tissue of Angus crossbred steers

We conducted 3 independent experiments to demonstrate functional G-coupled protein receptor 43 (GPR43) and GPR120 in bovine intramuscular (i.m.) and subcutaneous (s.c.) adipose tissues. We hypothesized that media volatile fatty acids and long-chain fatty acids would affect cAMP-activated protein kinase-alpha (AMPKα) protein expression and cAMP concentrations differently in i.m. and s.c. adipose tissue. Experiment 1: oleic acid (18:1n-9) decreased phosphorylated AMPKα protein (p-AMPKα) and the p-AMPKα/AMPKα protein ratio in i.m. preadipocytes, increased the p-AMPKα/AMPKα protein ratio in bovine satellite cells, and had no effect in s.c. preadipocytes. Experment 2: ex vivo explants from the 5th to 8th longissimus thoracic rib muscle section of Angus crossbred steers were cultured 48 hr in media containing 0.25 µM ciglitizone, 5 mM glucose, and 5 mM acetate, in the absence or the presence of 100 µM oleic acid. Oleic acid increased acetate incorporation into fatty acids and GPR43 gene expression in i.m. adipose tissue (P < 0.05), but oleic acid had no effect on fatty acid synthesis or GPR43 expression in s.c. adipose tissue. Experiment 3: fresh s.c. and i.m. adipose tissue from the 5th to 8th longissimus thoracic rib muscle section of Angus crossbred steers was transferred immediately to 6-well culture plates containing 3 mL of KHB/Hepes/5 mM glucose. Samples were preincubated with 0.5 mM theophylline plus 10 μM forskolin for 30 min, after which increasing concentrations of acetate or propionate (0, 10⁻³, 10^−2.3, and 10⁻³ M) in the absence or the presence of 100 μM oleic acid or 100 µM palmitic acid (16:0) were added to the incubation media. Acetate had no effect on forskolin-stimulated cAMP production in s.c. adipose tissue but decreased cAMP in i.m. adipose tissue (P < 0.05); this indicates a functional GPR43 receptor in i.m. adipose tissue. The combination of 10⁻² M acetate and oleic acid decrease cAMP production in s.c. adipose tissue, consistent with GPR120 receptor activity, but oleic acid and palmitic acid attenuated the depression of cAMP production caused by acetate in i.m. adipose tissue. Palmitic acid depressed cAMP production in s.c. adipose tissue, and increased cAMP production in i.m. adipose tissue (P < 0.05). Propionate had no effect on cAMP production in s.c. or i.m. adipose tissue. These results provide evidence for functional GPR43 receptors in i.m. adipose tissue and GPR120 receptors in s.c. adipose tissue, both of which would suppress lipolysis.     

Ochratoxin A in Korean food commodities: occurrence and safety evaluation

To evaluate the exposure of Koreans to ochratoxin A, we conducted a survey in 2003 for ochratoxin A in various domestic food commodities: 60 polished rices, 22 barleys, 35 wheat flours, 46 beers, and 14 unstrained rice wine (makkolli) samples. They were analyzed for ochratoxin A using immunoaffinity column and high-performance liquid chromatography (HPLC)-fluorescence detection, and the positive samples were confirmed using HPLC-tandem mass spectrometry. By combining results from different surveys on the levels of ochratoxin A in selected foods and the consumption patterns, we obtained the Korean probable daily intakes (PDI) of ochratoxin A. The polished rice commodity had the highest mean levels of ochratoxin A, which ranged from 0.2 (not detected, i.e., ND = 0) to 1.0 ng/g (ND = limit of detection, i.e., LOD). The estimated PDI for all Koreans fell into the range of 0.8-4.1 ng/kg bw/day, while for heavy consumers the estimates ranged from 1.7 to 9.1 ng/kg bw/day, which did not exceed the PTDI value (14 ng/kg bw/day). Staple rice is the major contributor (>90%) to the Korean dietary intake of ochratoxin A. On the basis of these estimates, it may be concluded that there is at present no considerable risk of ochratoxin A exposure for the average Korean consumer.     

Lipid distribution in potato tubers

Summary To elaborate on off-flavour development in dehydrated potato granules, lipids in subcellular particles and membrane systems of the tuber were investigated. Lipid acyl-hydrolase and lipoxygenase activities were suppressed in tuber homogenates by a buffer isolation medium of pH 7.8 containing nupercaine which minimized the breakdown of phospho- and galactolipids. Phospholipid, glycolipid and neutral lipid constitutents, their fatty acid composition, and unsaturation ratios were reported for amyloplasts, cell wall, microsomes, mitochondria, peroxisomes, and plasmalemma.

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Zusammenfassung Analysen von Kartoffelknollen wurden durch lipidabbauende Enzyme, Lipidacylhydrolase (LAH) und Lipoxygenase (LOX) behindert. Die LOX-Aktivit?t in handelsüblicherzugten Kartoffeln war hoch (Tabelle 1) und konnte durch gew?hnliche Inhibitoren nicht beeinflusst werden (Tabelle 2). Die LAH-Aktivit?t, die mit Phospholipiden (PL) und Galactolipiden als Substrate hoch war, wurde durch Nupercaine in verschiedenem Ausmass unterdrückt (Tabelle 3), dessen Weglassung w?hrend der Lipidanalyse von Kartoffelmembranen und subzellularen Partikeln hohe Lipidverluste verursachen k?nnte (Tabelle 4). Lipidergebnisse für mikrosomale Pr?parate, Mitochondrien, Peroxisomen, Plasmalemmen und St?rkek?rner (Tabellen 5–9) wurden wiedergegeben: nach Isolation bei pH 7,2, wenn die LOX-Aktivit?t nicht gehemmt war (Verfahren A); in einer Puffersubstanz von pH 7,8 ohne Nupercaine, wenn wohl die Aktivit?t von LOX unterdrückt war, nicht aber jene von LAH (Verfahren B); und bei pH 7,8 mit Nupercaine, wenn die Aktivit?t beider Enzyme unterdrückt war (Verfahren C). In den meisten Analysen zeigte die Lipidzusammensetzung, wenn die Aktivit?t beider Enzyme nicht unterdrückt wurde, eine entsprechende Anreicherung von PL, Sterollipiden und freien Fetts?uren (FFA) und ihrer Abbauprodukte sowie eine Abnahme im Gehalt an Galactolipiden. Kleine Mengen von Lipiden wurden in Form von Lipidpartikeln und verbunden mit Knollenzellw?nden gefunden (Tabelle 10). Die Fetts?urezusammensetzung des Gesamtlipids und einige besondere Lipidbestandteile und ihr Nichts?ttigungsverh?ltnis (UR) wurden nur für Verfahren C berechnet. Wenn dieses Verfahren weggelassen wurde, wie dargestellt mit Hilfe der St?rkelipid-Zusammensetzung, ergab sich nicht nur ein Verlust von Membran-PL und Galactolipiden. Fast die H?lfte der zurückgebliebenen neutralen Lipidfraktion war in Form von FFA in verschiedenen Graden oxydiert (Tabelle 9). Das UR der Gesamtlipide (TL) schwankte zwischen 0,4 und 2,9. Es war niedrig in der Zellwand, h?her im Plasmalemma und am h?chsten innerhalb der Zytoplasmamembranen. Das UR nahm dann bei den Vacuolen mit St?rkek?rnern ab. Die Bedeutung der Ergebnisse für die Bestimmung der Funktion von Lipiden in einem handelsüblichen Verfahren zur Herstellung von Püreepulver wirdt diskutiert.

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Résumé La dégradation enzymatique des lipides par la lipide acyl hydrolase (LAH) et par la lipoxygénase (LOX) génait l’analyse biochimique des tubercules de pomme de terre. L’activité de la LOX était importante dans les pommes de terre cultivées pour la commercialisation (tableau 1) et n’était pas affectée par les inhibiteurs courants (tableau 2). L’activité de la LAH, qui était forte avec les phospholipides (PL) et les galactolipides, était inhibée sur différents substrats par la nuperca?ne (tableau 3); l’absence de cette dernière durant l’analyse de la membrane et des organites intracellulaires du tubercule causait de fortes pertes en lipides (tableau 4). Les résultats obtenus avec les lipides des préparations de microsomes, mitochondries, peroxysomes, plasmalemme et de grains d’ amidon (tableaux 5 à 9) sont exposés; après isolement à pH 7,2 sans inhibition de l’activité de la LOX (procédé A); dans une solution tampon à pH 7,8 sans nuperca?ne alors que l’activité de la LOX est inhibée mais non celle de la LAH (procédé B); et à pH 7,8 avec nuperca?ne et inhibition de l’activité des deux enzymes (procédé C). Dans le cas où l’activité des deux enzymes n’était pas inhibée, la composition en lipides montrait un enrichissement relatif en PL, stérols, acides gras libres (FFA) et en leurs produits de dégradation ainsi qu’une diminution de la teneur en galactolipides. Une petite quantité de lipides était retrouvée sous la forme de particules lipidiques associées aux membranes cellulaires (tableau 10). L’étude de la composition en acides gras des lipides totaux et de quelques constituants lipidiques ainsi que la mesure de leur taux d’insaturation (U.R.) ont été effectuées seulement pour le procédé C. Quand ce procédé n’était pas employé, comme l’illustre la composition en lipides de l’amidon, il y avait non seulement une perte de PL et galactolipides membranaires mais la moitié de la fraction lipidique neutre retenue se trouvait sous la forme de FFA oxydés à différents degrés (tableau 9). L’U.R. des lipides totaux (TL) variait de 0,4 à 2,9; il était bas dans les membranes cellulaires, plus élevé dans le plasmalemme et le plus haut dans les membranes cytoplasmiques. L’U.R. diminuait dans les vacuoles contenant des grains d’amidon. L’intérêt de cette découverte pour la détermination des lipides au cours de la fabrication industrielle de granules de pomme de terre est discuté.

     

麦园蜘蛛(Penthaleus sp.)及麦长腿蜘蛛(Petrobia latens(Müller))的生物学研究

1953—1955年在晋南、北京等地对麦园蜘蛛及麦长腿蜘蛛的发生规律及生活习性进行了研究。结果明确两种麦蜘蛛一年中:秋季密度最大时期为11月上、中旬。春季密度最大的时期,麦园蜘蛛在3月下旬至4月上旬;麦长腿蜘蛛在5月上旬前后。两种麦蜘蛛均以滞育卵越夏。直至10月中旬,越夏卵始孵化,孵化最盛在11月上旬,此时幼、若虫出现最多,若进行防治可基本上防止以后的猖獗。根据结果分析,估计麦园蜘蛛每年发生2—3代,麦长腿蜘蛛发生3—4代。室内饲育初步观察麦园蜘蛛一世代(从卵到产卵)历时平均约57.8天;麦长腿蜘蛛为32.1天。两种麦蜘蛛都是单性生殖。麦长腿蜘蛛的滞育卵,具多年滞育习性,初步观察有些卵能在土中生活两年。两种麦蜘蛛的分布和猖獗都受湿度的影响,主要猖獗为害地区麦长腿蜘蛛在黄河以北的旱地;麦园蜘蛛在黄淮地区的水浇地或低洼地。耕作栽培对麦蜘蛛的发生有重要影响;连作对两种麦蜘蛛发生有利;深耕能将卵翻至深土之下,可以减少发生;晚播影响麦蜘蛛孵化后的食料。因此,合理轮作、深耕和适当晚播是综合防治中的重要措施。     

Lipid Extraction from Wheat Flour Using Supercritical Fluid Extraction

Environmental concerns, the disposal cost of hazardous waste, and the time required for extraction in current methods encouraged us to develop an alternate method for analysis of wheat flour lipids. Supercritical fluid extraction (SFE) with carbon dioxide has provided that medium and the method is fully automatic. Crude fats or nonstarch free lipids (FL) were extracted from 4–5 g of wheat flour by an SFE system. To develop optimum conditions for SFE, various extraction pressures, temperatures, and modifier volumes were tried to provide a method that would produce an amount of lipids comparable to those extracted by the AACC Approved Soxhlet Method and the AOCS Official Butt Method using petroleum ether as solvent. Using several wheat flour samples, the best conditions were 12.0 vol% ethanol (10.8 mol%) at 7,500 psi and 80°C to extract the amount of FL similar to those by the AACC and AOCS methods. Using solid‐phase extraction, lipids were separated into nonpolar lipid (NL), glycolipid (GL), and phospholipid (PL) fractions. The mean value of five flours was 1.15% (flour weight, db) by the SFE method, 1.07% by the Butt method, and 1.01% by the Soxhlet methhod. The SFE‐extracted lipids contained less NL and more GL than either the Butt or Soxhlet methods. All three methods extracted lipids with qualitatively similar components. The overall benefit for SFE over the Soxhlet or Butt methods was to increase the number of samples analyzed in a given time, reduce the cost of analysis, and reduce exposure to toxic chemicals.     

Flood damage assessment on rice crop in the Stung Sen River Basin of Cambodia

Paddy and Water Environment - In Cambodia, rice production is important for the majority of rural populations as the main source of income. However, historical extreme flood events, especially the...     

Evaluation of high nutrient diets and additional dextrose on reproductive performance and litter performance of heat‐stressed lactating sows

This study investigated the litter performance of lactating sows fed nutrient‐dense diets with or without dextrose at farrowing to weaning, during the summer with an average room temperature of 28.4°C. A total of 60 (13 first parity, 13 second parity, 19 third parity, and 15 forth parity) cross‐bred sows were assigned to three treatments. The three treatments were: standard diet (ST), high nutrient diet (HN; ST + 3% higher energy and 18.0% protein), and high nutrient diet plus dextrose (HND; 3% higher energy, 18.0% protein, and 5% dextrose). BW loss was reduced in the HND sows compared with the ST sows during lactation. The HN and HND sows had a higher piglet and litter weight at weaning. Also, the HND sows had the highest post‐prandial insulin levels at weaning and the shortest weaning‐to‐service interval (WSI). Serum LH was higher in the HND sows than the ST sows. The milk fat level was higher in the HND sows compared with the ST sows, but similar to the HN sows. In conclusion, these results suggest that it is possible to increase the blood insulin response by supplementing dextrose to a high nutrient diet, thus, improving WSI interval and litter growth during heat stress.