Attraction of the parasitic mite varroa to the drone larvae of honey bees by simple aliphatic esters

An important parasitic threat to honey bees, the mite Varroa jacobsoni, is attracted to its major prey, drone larvae, by methyl and ethyl esters of straight-chain fatty acids, in particular methyl palmitate. These esters were extracted from drone larvae with n-hexane and were identified by gas chromatography-mass spectrometry. Their behavioral effect was evaluated with the use of a four-arm airflow olfactometer.     

不同成熟度对烤烟叶片膜脂过氧化特性的影响

研究了不同成熟度对河南南阳烤烟叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)和多酚氧化酶(PPO)及丙二醛(MDA)含量的影响。结果表明:(1)随着烤烟烟叶成熟度的加深,SOD、POD、PPO活性总体呈现先上升后下降,MDA含量总体上则呈现持续增加的趋势,且在不同的成熟期,各种酶活性出现的峰值不同,中上部叶PPO活性的峰值出现在成熟档次,下部叶PPO活性的峰值出现在尚熟档次;而POD活性和SOD活性的峰值在中上部叶中分别出现在欠熟档次和尚熟档次。(2)PPO、SOD、POD活性从未熟至成熟均表现出中上部叶活性大于下部叶,在尚熟-成熟阶段下部叶SOD、POD和PPO活性急剧下降。综合评价认为,下部叶应在尚熟-成熟阶段采收,中上部叶应在成熟-过熟阶段采收。     

新疆阿勒泰地区阿勒泰羊毛绒品质分析

 对新疆阿勒泰地区富蕴县、福海县阿勒泰羊毛绒品质进行了分析,结果表明阿勒泰羊毛绒含绒率高,并且在细度、长度、色度等方面均比较优良,应加以合理的开发利用,并对今后阿勒泰羊育种提出了建议。     

A decision support approach for cane supply management within a sugar mill area

Increased competition between agri-food supply chains has strained relationships between farmers and processing factories while reducing individual profit margins. Decisions at different levels of the supply chain can no longer be considered independently, since they may influence profitability throughout the supply chain. This paper presents a decision support approach based on the MAGI^® simulation tool, which aims to facilitate discussion and negotiation between stakeholders while collectively exploring satisfactory solutions.The simulation tool helps sugarcane growers and millers in designing and assessing new ways of organizing cane supply management within a mill area. It addresses key issues such as restructuring mill areas or changing cane delivery allocation rules in order to increase total sugar production and total net revenue at the mill area level. This approach has been implemented for two mills in Réunion and one mill in South Africa. Simulations showed that sugar gains may be obtained by rearranging supply scheduling according to quality-based zoning within a mill area. Discussions led to further studies regarding the practicality of the best scenarios. MAGI^® is now available as freeware for testing in different settings.     

Color and albedo heterogeneity of Vesta from Dawn

Multispectral images (0.44 to 0.98 μm) of asteroid (4) Vesta obtained by the Dawn Framing Cameras reveal global color variations that uncover and help understand the north-south hemispherical dichotomy. The signature of deep lithologies excavated during the formation of the Rheasilvia basin on the south pole has been preserved on the surface. Color variations (band depth, spectral slope, and eucrite-diogenite abundance) clearly correlate with distinct compositional units. Vesta displays the greatest variation of geometric albedo (0.10 to 0.67) of any asteroid yet observed. Four distinct color units are recognized that chronicle processes--including impact excavation, mass wasting, and space weathering--that shaped the asteroid's surface. Vesta's color and photometric diversity are indicative of its status as a preserved, differentiated protoplanet.     

留苗密度与施氮量对不同株型谷子生长发育及产量的影响

为研究不同株型优质高产谷子品种保213和济谷14的适宜留苗密度和施氮量,2010～2011年在保定市农业科学研究所试验基地进行了留苗密度(52.5、60.0、67.5和75株/m2)和氮肥施用量(0.0、4.5、9.0、13.5和18 g/m2)的裂区试验,系统比较了不同处理对保213和济谷14产量和生理性状的影响。结果表明:不同处理保213的产量和各生理指标显著优于济谷14。在试验条件范围内,不同施氮量处理对保213和济谷14产量影响不显著,施氮量为9.0～13.5 g/m2时可以满足高产需求;而不同密度处理对保213和济谷14产量有显著影响,其中济谷14在留苗密度为67.5株/m2时产量最高,而保213在留苗密度为52.5株/m2时产量最高。与松散型品种济谷14相比,紧凑型品种保213具有较强的抗倒伏性能,更适合在高肥、高密下获得高产。本研究对指导谷子优质高产栽培具有重要的理论和实践意义。     

食品流通中绿色物流的运用现状与对策

随着经济的发展,物流业的兴起,食品流通的安全问题日益严重,绿色物流是目前解决这些问题的重要选择。阐述了在食品流通行业中运用绿色物流的重要性和必要性,分析了中国食品行业绿色物流发展现状和瓶颈,并借鉴发达国家的经验,从绿色物流的效率、规范化、基建及专业人才培养等方面提出了相关的措施和建议,以此来解决所面对的食品安全问题。     

Weaned piglets display low gastrointestinal digestion of pea (Pisum sativum L.) lectin and pea albumin 2

A study was conducted to investigate the biochemistry of digestion of field pea (Pisum sativum L.) albumins and globulins in the stomach and along the small intestine of weaned piglets with a particular emphasis on the respective roles of these compartments in pea protein digestion. Twenty-four piglets were weaned at 28 d of age. They were allocated to 2 diets (control and pea) and 3 slaughter times (3, 6, or 9 h after the last meal) in a 2 x3 factorial arrangement of treatments in a randomized complete block design. Pea flour provided 30% of total dietary protein in the pea diet. The diets were fed for 2 wk after weaning. After slaughter, gastrointestinal tract (GIT) compartments were weighed, digesta were collected, and pH was measured. Digesta from the stomach and cranial, middle, and caudal small intestine (SI) were extracted for soluble proteins and analyzed for specific pea proteins using SDS-PAGE, immunoblotting, and mass spectrometry. Tissue weight of the whole GIT (P = 0.015), cecum (P <0.001), and colon (P <0.001) was greater in the pea diet. Digesta pH in the stomach and caudal SI was lower (P = 0.02) in the pea diet than the control diet. In the stomach, vicilin, lectin, and pea albumin 2 were not digested, whereas legumin was only partly digested. Legumin and vicilin were totally digested in the SI in less than 3 h. A resistant peptide of 15 kDa located at the N-terminus of pea albumin 2 was transiently detected at 3 h. A protein band at 20 kDa was consistently identified as lectin. It was present in high intensity in intestinal digesta of pea-fed piglets at all times after the meal compared with those fed the control diet (P <0.001). Various proteins of, presumably, endogenous origin displayed differential digestion patterns between the control and the pea-fed piglets (P<0.05). In conclusion, differences in digestion between specific pea proteins were observed along the GIT of piglets. They could be partly explained by differences in protein digestion in the stomach.     

城市污泥与园林绿化废弃物共堆肥效果研究

为促进城市有机废弃物的减量化与资源化利用,以城市污泥和园林绿化废弃物为堆肥原料,研究城市污泥与园林绿化废弃物不同配比对共堆肥效果的影响。结果表明：不同配比对共堆肥效果具有显著影响。与质量比2∶3和3∶3的处理相比,城市污泥与园林绿化废弃物采用45∶3的比例可显著加快堆体升温进程,提高堆体温度并延长高温持续时间;各处理水溶性有机碳与有机质含量均随堆肥进行而下降,其中4.5∶3与6∶3处理的降解量显著高于2∶3与3∶3;堆肥后相对全氮含量较堆肥前均有所增加,且4.5∶3与6∶3处理要显著高于2∶3与3∶3,但前两者绝对氮损失率要高于后者。考虑到为将两种废弃物同时最大化处理并取得较好的堆肥效果,建议城市污泥与园林绿化废弃物采用质量比4.5∶3的比例混合共堆肥。     

博落回生物碱提取工艺初步研究

分别以氯仿、甲醇和工业乙醇为溶剂，对博落回全草中的生物碱进行超声萃取，然后采用3种不同的萃取工艺对各粗提取物中的生物碱进行初步分离。通过对各粗提物和萃取物的提取率与生物碱的比较分析，确定出博落回总碱的最佳提取和分离工艺。其最佳工艺为：工业乙醇超声提取，浸膏溶于正丁醇／水(V／V1：1)的混合溶液，并用正丁醇萃取。然后将正丁醇浸膏溶于氯仿／水(V／V1：1)混合溶液，调pH至10～11，再用氯仿萃取脂溶性总碱。此后，将水相调pH至中性再用正丁醇萃取水溶性总碱，总生物碱提取率可达3．1％。