Earthworm casts form stable aggregates in physically degraded soils

Topsoils affected by surface mining suffer severe physical degradation and lose most of their earthworm populations. After mining, replaced soils are planted to grassland and managed to improve soil structure. Earthworm inoculation into selected restored areas produced populations similar to those of undisturbed soils within 3 years. Soil properties in inoculated areas were compared with those of controls to evaluate the contribution of casts to bulk soil aggregation, and soil organic matter and root content responses to earthworm activity. Crumb porosity and coarse particle content were measured in water-stable macro-aggregates and earthworm casts to establish whether aggregates were formed by earthworms. Over a 5- to 6-year period, inoculation increased stable aggregation (>2 μm, >60 μm and >3 mm), even at 0- to 5-cm depth where it reduced soil organic matter content. Productivity and root content were also increased by inoculation; roots and organic matter were re-distributed to greater depth. Crumb porosity decreased with casts > aggregates (inoculated plots) > aggregates (control plots). Coarse particle content increased with casts < aggregates (inoculated plots) < aggregates (control plots). Coarse particle and porosity data were consistent with much of the newly aggregated soil being processed and formed by earthworms as casts. Whilst levels of soil organic matter were often closely associated with percentage stable aggregation, root content showed weaker associations. Aggregation percentage was most closely associated with abundance of Aporrectodea longa, although at particular depths significant correlations were also obtained for Aporrectodea caliginosa and Lumbricus terrestris. Results suggest that earthworms, rather than plant roots, initiate aggregation in severely degraded grassland soils.     

Toxicity and electrophysiological effects of Spilanthes amella Murr. extracts on Periplaneta americana L.

The potential insecticidal activity of Spilanthes acmella Murr. (Compositae) extracts was assessed in this study. The extracts were shown to be toxic against adults of American cockroach, Periplaneta americana L. The active component in S. acmella extract was isolated and identified as N-isobutyl-2,6,8-decatrienamide (spilanthol). The results from topical application of spilanthol show that it has a high acute toxicity and spilanthol was the most potent compound when compared to three conventional insecticides. The potency was found to be 1.3, 2.6 and 3.8 times more toxic than carbaryl, bioresmethrin and lindane, respectively. Electrophysiological studies indicated immediate hyperexcitation followed by complete inhibition of the cockroach cercal nerve activity.     

Effect of replacing fishmeal with canola meal on growth and nutrient utilization in kuruma shrimp Marsupenaeus japonicus (Bate)

A feeding trial was conducted to assess the nutritional values of canola meal as a substitute for fishmeal in diets for kuruma shrimp using five isocaloric diets (190 kJ kg^?1) prepared by replacing 0%, 10%, 20%, 30% and 40% of fishmeal protein with canola meal protein in CM0, CM10, CM20, CM30 and CM40 diets respectively. Triplicate groups of juveniles (0.19 g) were fed the respective diets for 60 days in tanks. At the end of trial, weight gain (%) and specific growth rate (% day^?1) were not significantly (P > 0.05) different among shrimp fed CM0, CM10 and CM20 diets. However, growth was significantly (P < 0.05) decreased in shrimp fed CM30 and CM40 diets. As with growth performance, feed intake, feed conversion ratio and protein efficiency ratio were also decreased (P < 0.05) in CM30 and CM40 groups. Whole body dry matter, methionine and proline were significantly decreased with canola meal substitution levels. In general, retention efficiency of protein and indispensible amino acids were decreased as canola meal increased in diets. It may be concluded that 20% fishmeal protein can be successfully replaced with canola meal, while supplementation of amino acids or blending with complementary proteins could facilitate higher fishmeal replacements in kuruma shrimp diets.     

Shrimp lectin–conjugated copper sulfide nanoparticles enhance immune response and gene expression in Etroplus suratensis infected with Aeromonas hydrophila

Aquaculture International - Lectins are hemagglutinating glycoproteins which act as pathogen recognition receptors that can bind to the pathogen-associated molecular patterns. Shrimp lectin...     

A greenhouse method for screening lettuce for resistance to Sclerotinia sclerotiorum

Agar blocks colonized by Sclerotinia sclerotiorum, causal agent of lettuce drop, were used as inoculum in screening for resistance to this pathogen in the greenhouse.Since the degree of resistance to the pathogen among cultivars varied with the time observed after inoculation, resistance was assessed by the number of days for 50% of the plants of each cultivar to die, as well as the number of plants that died. The cultivars ‘PI (Plant Introduction) 250427’, ‘Taiwan’, ‘PI 251790’, ‘PI 255568’, ‘MSU 73-44’ and ‘Bibb’ were found to have a higher level of resistance to S. sclerotiorum than the cultivar ‘Grand Rapids’ at 12 or 15 days following inoculation.     

Production and characterization of monoclonal antibodies against formalin-inactivated Nipah virus isolated from the lungs of a pig

Eight clones of monoclonal antibodies (Mabs) to Nipah virus (NV) were produced against formalin-inactivated NV antigens. They reacted positive by indirect immunofluorescent antibody test, and one of them also demonstrated virus neutralizing activity. They were classified into six different types based on their biological properties. These Mabs will be useful for immunodiagnosis of NV infections in animals and further research studies involving the genomes and proteins of NV.     

Novel and simple approach using synthesized nickel nanoparticles to control blood-sucking parasites

The present study was on assessment of the anti-parasitic activities of nickel nanoparticles (Ni NPs) against the larvae of cattle ticks Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum (a.) anatolicum (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, Culex quinquefasciatus and Culex gelidus (Diptera: Culicidae). The metallic Ni NPs were synthesized by polyol process from Ni-hydrazine as precursor and Tween 80 as both the medium and the stabilizing reagent. The synthesized Ni NPs were characterized by Fourier transform infrared (FTIR) spectroscopy analysis which indicated the presence of Ni NPs. Synthesized Ni NPs showed the X-ray diffraction (XRD) peaks at 42.76°, 53.40°, and 76.44°, identified as 1 1 1, 2 2 0, and 2 0 0 reflections, respectively. Scanning electron microscopy (SEM) analysis of the synthesized Ni NPs clearly showed that the Ni NPs were spherical in shape with an average size of 150 nm. The Ni NPs showed maximum activity against the larvae of R. (B.) microplus, H. a. anatolicum, A. subpictus, C. quinquefasciatus and C. gelidus with LC₅₀ values of 10.17, 10.81, 4.93, 5.56 and 4.94 mg/L; r² values of 0.990, 0.993, 0.992, 0.950 and 0.988 and the efficacy of Ni-hydrazine complexes showed the LC₅₀ values of 20.35, 22.72, 8.29, 9.69 and 7.83 mg/L; r² values of 0.988, 0.986, 0.989, 0.944 and 0.978, respectively. The findings revealed that synthesized Ni NPs possess excellent larvicidal parasitic activity. To the best of our knowledge, this is the first report on larvicidal activity of blood feeding parasites using synthesized Ni NPs.     

小麦茎生长点转化研究初报

为了躲避转基因技术对组织培养的过分依赖,本研究以小麦为材料尝试了一种对生长点直接进行转化的方法,并初步证明了这一方法的可行性。具体做法是：将种子萌芽,然后剥去胚芽鞘暴露出生长点,再用玻璃纤维制作的小刷子将生长点刺伤,最后用带有外源基因的农杆菌进行侵染处理。用携带hph-GUS基因的LBA4404农杆菌,侵染处理1～11日龄幼苗(生长点),共培养7d后检测新生芽中GUS的瞬时表达情况;侵染1～2日龄幼苗(生长点),取长成植株的2～3朵小花进行GUS稳定表达检测。又用携带BADH和npt Ⅱ基因的AGL1农杆菌菌株侵染1日龄的幼苗(生长点),在含：100mg／L卡那霉素的蛭石中进行选择。结果表明,GUS的瞬时表达率随被处理幼苗的日龄增加而降低,以2日龄幼苗为最高(10．7％)。用花序检测GUS的稳定表达,被侵染受体为1日龄幼苗时的表达率高于2日龄的幼苗。蔗糖的存在并不提高GUS基因在花序中表达的频率。不过花序表现为GUS阳性的植株后代,经PCR检测后并没有证实GUS基因存在。用AGL1菌株进行转化,获得了13．6％的抗卡那霉素的绿色植株,但只有3株呈现PCR阳性,且只有1株结了实。     

Physicochemical Characteristics of Biochars Derived From Corn,Hardwood, Miscanthus,and Horse Manure Biomasses

Biochar, a carbon-rich by-product of biomass pyrolysis, is widely recognized as a potential ingredient for soil amendment, fertility, and carbon sequestration owing to its favorable physicochemical properties. The objective of this study was to investigate the chemical and physical properties of biochars produced through pyrolysis at 450°C from agricultural residues available in Northwest Missouri, namely hardwood (HW), corn stover (CR), miscanthus (MS), and horse manure (HM). These properties were assessed through the analysis of pyrolysis yield, pH, volatile matter, fixed carbon, ash and carbon (C), hydrogen (H), sulfur (S), nitrogen (N) contents, trace metal concentrations, surface morphology, surface functional groups, bulk density, and water holding capacity. The biochars derived from HW, MS and CR materials showed high volatile-matter (33–42%), high fixed carbon contents (42–47%), very low ash contents (6–15%), and low bulk density (0.14–0.28 g cm^?3) as compared to that of HM. A wide range of trace elements was observed in biochar samples with significant differences in concentrations. In addition, CR, HW and MS biochars displayed a disordered graphitic-like structure with well-developed pores and surface areas of 23, 70 and 90 m²/g respectively, and high water-holding capacity up to 750%, indicating their potential application as a soil amendment.