Content of Nutrient and Antinutrient in Edible Flowers of Wild Plants in Mexico

Nutrient and antinutritional/toxic factors present in some edible flowers consumed in Mexico were determined. The edible flowers were: Agave salmiana, Aloe vera, Arbutus xalapensis, Cucurbita pepo (cultivated), Erythrina americana, Erythrina caribaea, Euphorbia radians benth and Yucca filifera. The nutrient content in the flowers studied is similar to that of the edible leaves and flowers studied mainly in Africa. The moisture content of the flowers varied from 860 to 932 g kg⁻¹. Crude protein (CP) was between 113 to 275 g kg⁻¹ DM, crude fiber, 104 to 177 g kg⁻¹ DM and the nitrogen free extract, between 425 to 667 g kg⁻¹ DM. The highest chemical score (CS) was found in E. americana and A. salmiana; in five samples the limiting amino acid was lysine, and in three of them it was tryptophan. Trypsin inhibitors and hemaglutinnins had a very low concentration. Alkaloids were present in both the Erythrina species and the saponins in A. salmiana and Y. filifera. Cyanogenic glucosides were not found in the studied flowers. The traditional process of preparing these specific flowers before consumption is by cooking them and discarding the broth; in this way the toxic substances are diminished or eliminated. These edible flowers from wild plants consumed in local areas of the country play an important role in the diet of the people at least during the short time of the season where they are blooming.     

Effect of tool angles on the chips generated during milling of wood by straight router-bits

 The effect of tool angles on the shapes of chips generated by parallel-to-grain and end-grain milling was explored for China fir and maple under fixed spindle and feed speeds and cutting depth. The milling path was up-milling by straight router-bits with a diameter of 12 mm. The chip shapes could be distinguished as five types: spiral, splinter, flow, thin, and granules or powder. The flow and thin chips were generated most often (on a weight percentage basis) for all tool angles investigated for parallel-to-grain and end-grain milling of China fir and maple. More granule chips were produced with parallel-to-grain milling than with end-grain milling for both woods. The measured chip thickness (t′) was thicker than the calculated thickness (t _max). Thicker and longer maple chips were produced by end-grain milling than by parallel-to-grain milling. The tool geometries of 40°/15° (sharpness of the angle–rake angle), 50°/15°, and 60°/15° for China fir and 40°/25°, 50°/5°, and 60°/5° for maple produced relatively more flow chips with parallel-to-grain milling. Furthermore, the tool geometries of 40°/5°, 50°/15° and 60°/25° produced more flow chips (weight percentage) by end-grain milling of China fir and maple. Received: May 23, 2001 / Accepted: June 28, 2002 Acknowledgment This study was supported by a grant from the National Council of Science, Taiwan (NSC89-2313-B-415-011).     

磷肥诱导下层植被伴生的辐射松苗生长、磷素营养和土壤有效磷变化

通过在温室条件下施加不同剂量的重过磷酸钙(0,50和100mg·kg-1P),对典型水铝英石土壤(Orthic Allophanic Soil)的土壤植物有效磷、磷素营养和伴生有金雀花(Cytisus scoparius)或黑麦草(Lolium multiflorum)的辐射松苗木生长变化情况进行了研究。结果表明,施加磷肥增强了辐射松根际和磷素匮乏土体的有效磷。与辐射松苗伴生的金雀花、黑麦草根际土壤有效磷也增加。辐射松新枝和老枝松针、茎和根系中磷含量随施加重过磷酸钙剂量的增加而增加;但是金雀花、黑麦草对辐射松苗磷素营养的影响依赖于土壤磷状态。未施肥处理下,与金雀花伴生的辐射松新枝和老村松针、茎和根系中磷含量要高于与黑麦草伴生的辐射松苗,而施肥处理下,结果相反。这可能与金雀花生长大量消耗土壤中有效磷有关。因为,在两个施肥剂量(50mg·kg-1P和100mg·kg-1P)上,与金雀花伴生的辐射松根际土壤中Bray-2磷含量始终低于与黑麦草伴生的辐射松根际土壤。此外,在施肥浓度100mg·kg-1下,与金雀花伴生的辐射松苗干特质量低于黑麦草伴生的辐射松。说明在中、高施肥水平,辐射松苗与黑麦草伴生生长好于与金雀花伴...     

Use of serology and real time PCR to control an outbreak of bovine brucellosis at a dairy cattle farm in the Nile Delta region,Egypt

Background

Bovine brucellosis remains one of the most prevalent zoonotic infections affecting dairy cattle in developing countries where the applied control programs often fail. We analyzed the epidemiologic pattern of bovine brucellosis in a dairy cattle herd that showed several cases of abortions after regular vaccination with RB51 (B. abortus vaccine). In 2013 thirty dairy cows, from a Holstein-Friesian dairy herd with a population of 600 cattle, aborted five months post vaccination by a regular RB51 vaccine. Blood samples were drawn from milking cows and growing heifers, as well as heifers and cows pregnant up to 6 months. These samples were collected in June 2013 (n?=?257) and May 2014 (n?=?263) and were tested by real time (rt)-PCR as well as serological tests, in particular Rose Bengal Test (RBT), Enzyme-Linked Immunosorbent Assays (ELISA) and Fluorescence Polarization Assay. Tissue specimens were also collected from an aborted fetus and cultured. Isolates were subjected to bacteriological typing tests at the genus and species levels.

Results

Five months post vaccination with RB51 vaccine, Brucella (B.) DNA was detected in blood samples of cows by rt-PCR. The serological tests also revealed the spread of Brucella field strains within the herd in 2013. Four Brucella isolates were recovered from specimens collected from the aborted fetus. These isolates were typed as follows: one B. abortus RB51 vaccine strain and three isolates of B. abortus field strain. The seropositive cows with positive rt-PCR might indicate an infection by the Brucella field strain; while the positive rt-PCR results from seronegative animals may either be due to circulating RB51 vaccine DNA in vaccinated animals or to circulating field strain in infected animals before seroconversion.

Conclusion

The results herein suggest that PCR can be a good supplementary tool in an outbreak situation, if an assay is available that can differentiate vaccine and field strains with a high analytical sensitivity. We recommend using RBT and ELISA in parallel in outbreak situations, to identify as many infected animals as possible during the initial screenings. This test procedure should be repeated for at least three successive negative tests, with one month interval.

     

Comparative effectiveness of two alkylammonium compounds as wood preservatives

This study describes a laboratory evaluation of the efficacy of two alkylammonium compounds [didecyldimethylammonium tetrafluoroborate (DBF) and didecyldimethylammonium chloride (DDAC)] when applied via vacuum impregnation or superficial treatment. Treated wood specimens were tested for their termite and microbial resistance under controlled laboratory conditions. The higher chemical retentions were needed to suppress the feeding by Coptotermes formosanus ≦3% mass loss in the multichoice test than in the no-choice test. The DBF and DDAC retention levels necessary to meet the performance requirement ≦3% mass loss after 12-week fungal exposure varied with wood species. The retention level of 3 kg/m³ for DBF and DDAC was generally high to keep the nondurable wood species free of decay. Although there was no difference between DBF and DDAC in the efficacy against decay and termite attack, the former slightly outperformed the latter as an antimold and antisapstain agent.     

Impact of epistasis and QTL × environmental interaction on the oil filling rate of soybean seed at different developmental stages

The oil accumulation in the developing soybean seed has been shown to be a dynamic process with different rates and activities at different phases affected by both genotype and environment. The objective of the present study was to investigate additive, epistatic and quantitative trait loci (QTL) × environment interaction (QE) effects of the QTL controlling oil filling rate in soybean seed. A total of 143 recombinant inbred lines (RILs) derived from the cross of Charleston and Dongnong 594 were used in this study to obtain 2 years of field data (2004 and 2005). A total of 26 QTL with significantly unconditional and conditional additive (a) effect and/or additive × environment interaction (ae) effect at different filling stages were identified on 14 linkage groups. Among the QTL with significant a effects, 18 QTL showed positive effects and 6 QTL had negative effects on seed filling rate of oil content during seed development. A total of 29 epistatic pairwise QTL underlying seed filling rate were identified at different filling stages. About 28 pairs of the QTL showed additive × additive epistatic (aa) effects and 14 pairs of the QTL showed aa × environment interaction (aae) effects at different filling stages. QTL with aa and aae (additive × additive × environment) effects appeared to vary at different filling stages. Our results demonstrated that oil filling rate in soybean seed were under genetic, developmental and environmental control.     

Mechanical behavior of nylon 66 tyre cord under monotonic and cyclic extension: Experiments and constitutive modeling

Many industrial products are made of cord-rubber composite materials. Their mechanical behavior not only depends on rubber but also depends on cord. Nylon 66 cord is one of the most important reinforcement in these products. This paper research the mechanical behavior of nylon 66 cord under various load cases. A series of experiments were carried out to obtaining stress-strain curves under different load cases. Complex changes of the modulus and Mullins effect can be found in monotonic and cyclic tension, respectively. Mechanism of these behaviors has been analyzed considering both the twisted structure and material. A phenomenological constitutive model, accounting for different loading conditions, has been firstly proposed base on strain energy density function and damage mechanics method. The proposed model has been verified by comparing the predicted results with experimental data. It has been found that the proposed model predicted the stress-strain curves that were consistent with the experimental data. The proposed model can be implemented in finite element software for engineering design and application.     

Chloropicrin Soil Fumigation Reduces <Emphasis Type="Italic">Spongospora subterranea</Emphasis> Soil Inoculum Levels but Does Not Control Powdery Scab Disease on Roots and Tubers of Potato

The effect of chloropicrin fumigation on the soil populations of Spongospora subterranea and the development of powdery scab, formation of root galls and tuber yield was investigated in seven field trials conducted in Minnesota and North Dakota. Sixteen potato cultivars, with different levels of susceptibility to disease on roots and tubers, were planted in plots treated with chloropicrin at rates ranging from zero to 201.8 kg a.i. ha^?1. The amount of S. subterranea DNA in soil was determined using qPCR. Bioassays were conducted to further assess the effect of chloropicrin fumigation on root colonization by S. subterranea in two potato cultivars with contrasting disease susceptibility. In the field, chloropicrin applied at rates between 70.1 to 201.8 kg a.i. ha^?1 significantly decreased S. subterranea initial inoculum in soil but increased the amount of disease observed on roots and tubers of susceptible cultivars. The effect of increasing disease was confirmed in controlled conditions experiments. Although the amount of S. subterranea DNA in roots of bioassay plants increased with increasing chloropicrin rates, it remained similar among potato cultivars. Chloropicrin fumigation significantly increased tuber yield which in cultivars such as Shepody and Umatilla Russet were associated with the amount root galls (r = 0.30; P < 0.03). Results of these studies contradict earlier reports on the use of chloropicrin fumigation for the control of powdery scab. Factors other than inoculum level, such as environmental conditions that affect inoculum efficiency and host susceptibility, may be significant contributors to the development of powdery scab and root gall formation.     

Preference and performance of <Emphasis Type="Italic">Plutella xylostella</Emphasis> (L.) (Lepidoptera: Plutellidae) on canola cultivars

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important insect pest of canola, Brassica napus L., in Ardabil, Iran. Host plant resistance is an essential component of integrated management of P. xylostella. We investigated the preferences and performance of P. xylostella on nine commercial cultivars of canola, namely Zarfam, RGS003, Adder, Okapi, Opera, Hyola401, Ebonite Option500 and Elite under greenhouse conditions at 23 ± 1°C, 50 ± 5% RH and 14L:10D. In free-choice situation, oviposition was lowest on Opera (23.5) and highest on Zarfam (44.7). In the life table study, fecundity of new generation female moths was lowest on Opera (95.4) and highest on Adder (145.7). Survival from egg to adult was significantly lower on Opera, Option500 and Hyola401 than on other tested cultivars. The intrinsic rate of natural increase (r _m) and population growth rate (λ) were lowest on Opera and highest on Zarfam. The generation time (T) was shortest on Zarfam (17.2 days) and longest on Hyola401 (19.9 days) whereas doubling time (DT) was longest on Opera (3.9 days) and shortest on Zarfam (3.0 days). Our results clearly suggest that Opera was the most resistant host among the tested cultivars and has the potential to be used in the integrated management of P. xylostella.     

Estimation of rubberwood production in Cambodia

We estimated the production of rubberwood from 1996 to 2011 in Cambodia. We employed data from interview surveys with three rubberwood processing companies and statistics from estate rubber plantations and wood retailing companies. The result was that the end use of rubberwood in Cambodia was the sawntimber products, being exported to Vietnam and China. The yield rate from rubberwood stumpage into sawn timber was between 11.6 and 14.9%, closely matching the rates of Malaysia and Thailand. The average production of rubberwood roundwood from 1996 to 2011 was 254,697 m³/year, of which sawn timber as well as residuals in secondary processing was 84,559 and 170,138 m³/year, respectively. Although the timber production of Cambodia has declined sharply due to the strict restriction of natural forest logging, rubberwood could explain more than 60% of the domestic industrial roundwood production from 2000. We suggest the necessity of monitoring the expansion of rubber plantations in new rubber producing countries and linking the rubberwood production with the regional wood resource management.