海南岛沿岸牡蛎体内DDTs的时空分布特征及评价

于2006年~2012年在海南岛东寨港、马袅港、八所港和榆林港4个典型港湾采集近江牡蛎（Crassostrea rivularis ）样品,用气相色谱法测定其滴滴涕（DDTs）的质量分数。结果显示,DDTs残留范围为未检出-4.51 ng·g-1（湿质量）,平均为1.45 ng·g-1,4个采样点w（DDTs）的区域差异不显著（P〉0.05）。与国内外其他海域相比,海南岛沿岸贝类体内DDTs残留水平较低。在2006年~2012年间,DDTs于2007年出现了一个相对高值,之后5年呈先下降后趋于平稳的趋势。此研究结果与1985年海南岛近海贝类体内的DDTs残留量均处于100 ng·g-1水平级范围。通过对牡蛎样品DDTs的组分特征分析,认为目前检测到的DDTs主要来源于历史使用残留,但推断2006年~2007年可能有三氯杀螨醇来源的DDTs输入。结果表明,海南岛沿岸牡蛎体内DDTs符合中国《海洋生物质量》一类质量标准,也未超出中国相关残留限量标准,其食品安全风险在可接受范围内。     

苹果×梨属间杂交新品种‘甘金’的选育

甘金系元帅苹果(Malus pumila cv.Delicious)为母本,苹果梨(pyrus prifoliacv. Pingguoli)作父本杂交选育而成。通过花器官和果实心室变异性状、过氧化物酶同工酶和花药孢粉扫描电镜观察检查,证明系元帅苹果与苹果梨的属间杂种。甘金树势强健、腋花芽结果、丰产优质,花芽越冬性强,抗寒,适应性强。果实平均重200g,果肉绿黄色,果心小,肉质脆嫩味香甜,品质极上,可溶性固形物15%。在窑洞通风窖中可贮藏到次年3月,不绵、不沙、不皱皮。以垂丝海棠(Malus halliana)作砧木,耐旱性强,是河西走廊广大地区适宜栽培的苹果品种。     

植原体及马铃薯相关病害研究进展

植原体能引起多种植物的丛枝、缩叶、紫顶及果实和花畸形。近年来植原体引起的马铃薯病害已严重影响了马铃薯的质量和产量。对植原体病害的传播特点和植原体的分类学研究进行了概述,总结了植原体基因组和质粒研究现状,分泌蛋白、寄主抗病基因克隆和致病机理相关的研究进展;对几种马铃薯植原体病害进行阐述;讨论了植原体病害研究所存在的问题及发展趋势。以期为植原体病害研究、田间快速检测及病害流行预测、植原体重要功能基因挖掘和马铃薯抗病育种提供参考。     

Administration of carbetocin—a long-acting oxytocin analogue—before sperm collection by transrectal ultrasound-guided massage of the accessory sex glands in bucks (Capra hircus) and ibexes (Capra pyrenaica)

Transrectal ultrasonic-guided massage of the accessory sex glands (TUMASG) is a technique that allows collecting semen requiring few electrical stimuli or even no pulse. A long-acting analogue of oxytocin (carbetocin, 0.1 mg) was i.v. administered before TUMASG in 10 conscious bucks (Experiment 1) and 10 anaesthetized Iberian ibexes (Experiment 2) to shorten the time of semen collection, decrease the number of electrical stimuli and/or improve the semen quality. The ejaculated volume, concentration, quality parameters and kinetics variables of the sperm were determined in fresh semen. The time length of the procedures and the number of electric pulses applied were recorded. Furthermore, stress response indicators (number of vocalizations in Experiment 1; heart and respiratory rates, rectal temperature, cortisol levels, totals proteins and neutrophil-to-lymphocyte ratio in Experiment 2) were documented. In bucks, the administration of carbetocin tended to shorten the time needed for semen collection but no-showed differences in the fresh seminal quality. In the Iberian ibexes, there were no significant differences between groups in the time length of procedures or in the number of animals that ejaculated. Carbetocin administration only reduced the respiratory rate, did it modify fresh semen characteristics in ibexes. In conclusion, the administration of carbetocin did not appear as a useful tool to improve welfare during semen collection with TUMASG or semen quality in conscious bucks and anaesthetized ibexes, having only slight advantages related to the procedure.     

Naturally monozygotic quadruplets in a Braford cow confirmed by DNA analysis: A case report

Cattle are a monotocous species, despite naturally conceived multiple births are sometimes observed. Although the number of twins has consistently increased, triplet and quadruplet pregnancies represent 0.015% and 0.004% of the total births, respectively. Multiple births are the result of multiple ovulation and/or the spontaneous cleavage of one fertilized oocyte, which is known as monozygotic (MZ) twinning. In cattle, approximately 5% to 14% of all twin births are MZ, and births with more than two MZ calves are extremely rare. Monozygotic animals are genetically identical, and those derived from two or more zygotes are genetically different. Furthermore, the presence of placental vascular anastomosis can result in foetal chimerism. Notwithstanding, animals born as single calves can be chimeras when one of the foetal twins dies undetected in utero. Here, we used DNA testing to study the zygotic condition of an unusual female quadruplet born from a Braford cow bred in a multi-sire natural mating system without hormone stimulation. Two tissues with different embryological origin were sampled to test zygosity and possible chimerism. The results showed an identical genotype, confirming they all originated in an MZ pregnancy and suggesting the lack of chimerism in all animals. The use of MZ twins in breeding and selection systems provides an alternative to the conventional progeny testing. Some works have suggested a genetic background of MZ twins in humans. This female and her daughters could be the founders of a lineage to study the possible inheritance of MZ multiple births in cattle.     

Integration of socio-economic and environmental variables for modelling long-term fire danger in Southern Europe

In Mediterranean forests fire danger assessment is of crucial importance for any fire prevention policy, both at the local and global scale. The objective of this study is to model large scale structural forest fire danger in Southern Europe. This was done through the identification of those physiographic, socioeconomic and environmental factors that best explain fire occurrence in this region. The modeling process consisted of a multi-step analysis based on multiple regression techniques. In this work, a balance is reached between the objectivity of mechanical methods, and the thoroughness entailed by an exhaustive selection of the variables. Due to the different availability of input data, two different fire danger models were built. One model was derived for Portugal, Spain, France, Italy and Greece, using an initial set of 32 independent variables. A second model was derived for a reduced area (Spain, France and Italy) using these 32 plus another 5 variables. Both models were built using the same methodology, which was based on the search for best intermediate models. The dependent variable used to represent forest fire danger was computed through the annual average of fire occurrence. Statistically, both models performed satisfactorily. The final fits for the first and second model yielded R ² values of 0.60 and 0.71, respectively. Given the structural condition of the variables considered, the resulting models can be used to support the design of fire prevention policies on the long-term basis.

Changes in forest structure modify understory and livestock occurrence along the natural cycle and different management strategies in Nothofagus antarctica forests

Agroforestry Systems - Sustainable forest management is proposed as a solution for many ecological and socio-economic trade-offs associated with different forest uses. In Patagonia, silvopastoral...     

Can spleen aspirations be safely used for the parasitological diagnosis of canine visceral leishmaniosis? A study on assymptomatic and polysymptomatic animals

The purpose of this study was to evaluate the safety of spleen aspiration as a sampling technique for the parasitological detection by culture and microscopy of Leishmania (chagasi) infantum. Two hundred and nine domiciled dogs from an endemic area for visceral leishmaniasis in Bahia State, Brazil, were studied. Most dogs (87%) were seropositive for anti-L. chagasi antibodies by ELISA. Clinical signs of disease were recorded and the animals monitored during and after spleen puncture in order to detect possible complications associated with the procedure. From a total of 257 splenic punctures in the 209 animals, only three minor events occurred, with no significant consequence for the animals and no association with risk factors. Leishmania was isolated from 149/180 (83%) seropositive dogs, and from 6/26 (23%) seronegative animals. The procedure did not cause adverse side effects or unnecessary suffering and confirmed the diagnosis in a large percentage of dogs. We conclude that spleen aspiration can be considered an effective and safe procedure for the definitive diagnosis of canine visceral leishmaniosis.     

Survey of persistent organochlorine contaminants (PCBs, PCDD/Fs, and PAHs), heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic in food samples from Huelva (Spain): levels and health implications

Concentrations of PCBs, PCDDs, and PCDFs, heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic have been determined in a great variety of food samples purchased in different markets across the city of Huelva, located in southwestern Spain and under strong industrial activity. All samples analyzed presented concentrations below the maximum allowed by the European Community regarding PCDD/Fs, with the exception of samples within the meat group. An estimation of the daily intake resulted in 1.15 pg of WHO(PCDD/Fs)-TEQ/kg of body weight/day for a 70 kg person and 2.63 pg of WHO-TEQ/kg of body weight/day when PCBs were included, therefore accounting for a similar or even higher percentage than PCDD/Fs and showing the importance of their inclusion in monitoring studies. Meat and meat products, together with vegetable oils and dairy products, were the major food groups contributing to the estimated daily intake. For heavy metals and arsenic, the concentrations found were under the value proposed by European regulations, and estimated daily intakes were well below those proposed by the WHO for all metals investigated. PAHs have been analyzed in food samples from marine origin, values ranging from 8.22 to 71.4 ng/g of fresh weight. Pyrene was the most abundant compound, accounting for >80% in the samples investigated. The most carcinogenic PAHs, such as benzo[a]pyrene and dibenz[a,h]anthracene, were in all cases below the limits of detection. Therefore, the samples analyzed in this survey can be considered as safe with regard to the levels obtained and the in-force legislation.     

Significant suppression of invasive emerald ash borer by introduced parasitoids: potential for North American ash recovery

Journal of Pest Science - Successful management of invasive forest pests with sustainable approaches, such as biological control, is critical to the restoration of the affected or damaged forest...