“How to” and “why”: assessing the enviro–social impacts of pesticides

A typology is proposed to distinguish among three quite different types and applications for pesticide impact assessment tools (which are also known as “pesticide risk indicators”): (1) decision support systems for farmers and other property managers; (2) “ecolabeling” or “green labeling” systems designed to influence consumer opinion and market behavior; and (3) indicators of impact and risk used by governments, industry and academia to assess policies and programs. These types are differentiated by their objectives, decision makers, factors or variables considered, arena of activity, scale and unit of analysis, handling of an economic dimension, format of results, and method or approach.     

A critique of “Preventive control and desert locust plagues”

Magor, J.I., Lecoq, M., Hunter, D.M. [2008. Preventive control and desert locust plagues. Crop Protection 27, 1527–1533, doi:10.1016/j.cropro.2008.08.006], claim that their version of a desert locust preventive control programme has caused plagues to be rarer, shorter and geographically more limited, but without producing any evidence of control campaign success. There are many reasons why success is unlikely, some of which they admit. Their “model” does not support the case; it has sundry flaws and is not consistent with actual events.     

Resistance risk evaluation, “a European regulatory perspective”

The European Union directive 91/414 on the inclusion of new and existing active substances requires an assessment of the potential risk of resistance being developed by target organisms and for management strategies to be introduced to address such risks. The European and Mediterranean Plant Protection Organisation (EPPO) worked with regulatory authorities and industry's Global Crop Protection Federation's (GCPF) Resistance Action Committees to develop a guideline that would satisfy these requirements. The new resistance risk analysis guideline was published in April 2000. Implementation of this guideline will force significant changes in the way crop protection products are developed. Applicants for registration of crop protection products will need to evaluate resistance risk and develop acceptable use patterns early in the development process. Registration applications for uses that are associated with an unacceptable resistance risk may be refused. In such cases, restriction or modification of supported use patterns to achieve acceptable levels of resistance risk, could result in use patterns which are no longer consistent with other elements of the registration dossier. It is therefore essential that resistance risk is evaluated early in development so that registration dossiers may be developed with this criteria in mind.     

Optimization of non-fermented gluten-free dough composition based on rheological behavior for industrial production of “empanadas” and pie-crusts

Celiac disease is an autoimmune disorder caused by intolerance to gluten, which is found in wheat and similar proteins in barley, rye and oats. The present study was designed to examine the effects of the addition of gums, whey protein concentrate, dry egg, and water to corn and cassava starches on the rheological properties of a non-fermented dough used for the production of “empanadas” (a traditional meal in Latin América) and pie-crusts suitable for people with celiac disease. A 2⁴ full factorial design was chosen. Viscoelastic measurements and texture analysis (puncture and elongation tests) were performed. The increase in gums content and the decrease in water level produced an increase in both moduli (G′ and G″) and a more elastic dough was obtained. Higher protein contents interfered with the formation of the three-dimensional gum network making the dough less ductile. Texture analysis led to similar conclusions to those obtained by dynamic rheological analysis. Formulations containing higher percentages of gums and lower water content led to an appropriate behavior for industrial production of these doughs.     

大气CO2浓度对茶叶品质的影响

通过开顶式气室控制CO₂浓度,对盆栽茶树进行试验测定,研究了大气CO₂浓度升高对茶叶品质成分氨基酸、茶多酚、咖啡碱、可溶性糖和主要营养元素含量的影响。结果表明,在大气CO₂浓度为550和750βμmol/mol时,与正常大气CO₂水平相比,春茶氨基酸含量下降4.5%和12.2%,夏茶氨基酸含量降低1.7%和6.7%,秋茶降幅为2.9%和10.8%;茶叶咖啡碱含量降低3.1%~4.6%和5.1%~10.7%;但茶叶茶多酚和可溶性糖含量降CO₂浓度升高而提高,茶多酚含量提高3.8%~6.0%和6.9%~11.3%,可溶性糖含量增加8.4%~14.4%和18.1%~28.2%。同时,大气CO₂浓度的升高使茶叶营养元素氮、钾、钙、磷、钠含量有不同程度降低,而锌、镁、铁含量有所增加,其中,茶叶氮、钾元素含量降低6.1%~16.3%和12.9%~22.9%,锌、镁含量分别提高5.8%~17.8%和11.3%~16.0%。     

A Novel α4/7-Conotoxin QuIA Selectively Inhibits α3β2 and α6/α3β4 Nicotinic Acetylcholine Receptor Subtypes with High Efficacy

α6β4 nAChR is expressed in the peripheral and central nervous systems and is associated with pain, addiction, and movement disorders. Natural α-conotoxins (α-CTxs) can effectively block different nAChR subtypes with higher efficacy and selectivity. However, the research on α6β4 nAChR is relatively poor, partly because of the lack of available target-specific α-CTxs. In this study, we synthesized a novel α-4/7 conotoxin QuIA that was found from Conus quercinus. We investigated the efficacy of this peptide to different nAChR subtypes using a two-electrode voltage-clamp technique. Remarkably, we found α-QuIA inhibited the neuronal α3β2 and α6/α3β4 nAChR subtypes with significantly high affinity (IC₅₀ was 55.7 nM and 90.68 nM, respectively), and did not block other nAChR subtypes even at a high concentration of 10 μM. In contrast, most α-CTxs have been determined so far to effectively block the α6/α3β4 nAChR subtype while also maintaining a similar higher efficacy against the closely related α6β2β3 and/or α3β4 subtypes, which are different from QuIA. In conclusion, α-QuIA is a novel α4/7-CTx, which has the potential to develop as an effective neuropharmacology tool to detect the function of α6β4 nAChR.     

“Summer sowing”: A successful innovation to increase the adoption of key species of annual forage legumes for agriculture in Mediterranean and temperate environments

This paper reports on the evaluation of “summer sowing,” an innovative approach to increase the adoption of recently domesticated species of hard seeded annual legumes in Mediterranean and temperate Agriculture. The research revealed that several species of annual legumes whose seed can be readily harvested on‐farm and which possess natural hard seed dormancy, may be sown into dry soil in late summer without additional processing. These studies proved that the hard seed dormancy was broken down sufficiently in the soil over 4–6 weeks to produce robust legume pastures with more than 150 seedlings per m² following the first winter rains, in replicated field sites established across wide agro‐ecological zones in Western Australia (WA) and New South Wales (NSW). Ornithopus sativus Brot., O. compressus L. and Trifolium spumosum L. were suitable for summer sowing based on both hard seed breakdown patterns and subsequent seedling survival in WA. While in NSW, in addition to these legumes, Biserrula pelecinus L., T. vesiculosum Savi. and T. glanduliferum Boiss. were also suitable for summer sowing. A 1.5‐ to 10‐fold increase in herbage production was achieved relative to conventionally sown T. subterraneum L. This development represents a step change in forage legume development for renovated pastures in these environments. Importantly, the experiments revealed differences in G x E effects on seedling establishment, total herbage production and seed yield in different climatic zones. The summer sowing approach is presented as a revolutionary method for pasture renovation that overcomes significant barriers to adoption.     

Interactions of Globular and Ribbon [γ4E]GID with α4β2 Neuronal Nicotinic Acetylcholine Receptor

The α4β2 nAChR is implicated in a range of diseases and disorders including nicotine addiction, epilepsy and Parkinson’s and Alzheimer’s diseases. Designing α4β2 nAChR selective inhibitors could help define the role of the α4β2 nAChR in such disease states. In this study, we aimed to modify globular and ribbon α-conotoxin GID to selectively target the α4β2 nAChR through competitive inhibition of the α4(+)β2(−) or α4(+)α4(−) interfaces. The binding modes of the globular α-conotoxin [γ4E]GID with rat α3β2, α4β2 and α7 nAChRs were deduced using computational methods and were validated using published experimental data. The binding mode of globular [γ4E]GID at α4β2 nAChR can explain the experimental mutagenesis data, suggesting that it could be used to design GID variants. The predicted mutational energy results showed that globular [γ4E]GID is optimal for binding to α4β2 nAChR and its activity could not likely be further improved through amino-acid substitutions. The binding mode of ribbon GID with the (α4)₃(β2)₂ nAChR was deduced using the information from the cryo-electron structure of (α4)₃(β2)₂ nAChR and the binding mode of ribbon AuIB. The program FoldX predicted the mutational energies of ribbon [γ4E]GID at the α4(+)α4(−) interface, and several ribbon[γ4E]GID mutants were suggested to have desirable properties to inhibit (α4)₃(β2)₂ nAChR.     

Cultivar and Environmental Effects on (1→3,1→4)-β-D-Glucan and Protein Content in Malting Barley

A low β-glucan and protein content is desirable for malting barley. In China high β-glucan content has been considered a major factor contributing to the inferior malting quality of local barleys. In this study 10 barley cultivars were planted in multi-location trials in the southern winter-barley zone to determine genotypic and environmental effects on β-glucan and protein content. There were highly significant differences in both β-glucan and protein content between the 10 barleys, the eight locations and the 2 planting years. The average β-glucan content over the 2 years for the 10 cultivars in the eight locations ranged from 3·91% for Gangpi 1 to 4·95% for Xiumei 3, and from 3·76% for Hangzhou to 4·75% for Taian in eight locations. Correspondingly, the protein contents of the 10 cultivars ranged from 11·37% for Yanyin 1 to 12·52% for ZAU, and of the eight locations from 9·5% for Hangzhou to 14·69% for Taian. Environmental factors contributed the largest component of the variation in both β-glucan and protein content. Five climatic factors, namely the total accumulated temperature, accumulated temperature to 25 °C and to 30 °C, precipitation and days with rain during seed development were included in a regression equation relating climatic factors and β-glucan content. In the regression equation relating climatic factors and protein content, two other factors, days from heading to maturity and accumulated temperature to 20 °C were included, in addition to the five climatic factors that significantly affected β-glucan content.     

旱季灌水对金菠萝产量、品质及糖酸积累的影响

水分是影响果实生长发育的重要因素,水分通过影响植株生长直接或间接来调控果实品质的形成。季节性干旱严重制约菠萝植株生长发育,但旱季灌水对菠萝产量和品质的影响尚不明确。为了探明季节性干旱期菠萝产量和品质对水分输入的响应特征,以金菠萝‘MD-2’为研究对象,在监测旱季实际降雨量的基础上,设计4个增加灌水量梯度水平（W₁ 20 mm、W₂ 50 mm、W₃ 100 mm、W₄ 150 mm）的试验,并以不灌水为对照（CK 0 mm）,分析测定菠萝产量、品质指标以及糖酸组分含量。结果表明,旱季增加灌水可显著增加金菠萝果实产量、平均单果重及商品果率,其中产量最高和最低的梯度水平分别是W₄和CK（W₄比CK增加了45.56%）;随旱季灌水量的增加,金菠萝果实的维生素C、可溶性固形物和可滴定酸度均逐渐减小,可溶性总糖和糖酸比呈现先增大后减少的趋势,其整体表现为W₂>W₁>CK> W₃>W₄,其中W₂的可溶性总糖和糖酸比最高为12.94%和26.95,显著大于CK,其增幅分别为87.26%、64.6%;金菠萝果实的蔗糖含量随旱季灌水量的增加呈现一元二次曲线函数增加（P<0.05）,其比例由CK的38.8%提高到W₄的65.1%,整体表现为W₄>W₃>W₁>W₂>CK;而果糖和葡萄糖含量均随旱季灌水量的增加呈线性函数降低（P<0.01）,二者比例的整体表现均为：CK>W₂>W₁>W₃>W₄。可见,旱季灌水促进金菠萝果实果糖和葡萄糖转化为蔗糖,且改变了其糖种类比例,进而改变了菠萝果实风味品质。随着旱季灌水量的增加,柠檬酸和奎宁酸含量均呈先增大后减小的一元二次函数关系（P<0.05）,苹果酸含量呈极显著的线性函数增加（P<0.001）,且旱季不同灌水量处理间,柠檬酸比例相对稳定均达到50%,而苹果酸比例仅在W₄处理时显著增大,奎宁酸比例在W₄处理时显著减小。综合考虑产量及果实风味品质,旱季进行灌水是非常必要的,且根据实际自然降雨量的多少,适当调整灌溉,使其总供水量保持在300 mm左右可实现雷州半岛地区菠萝果实优质高产。     

CO_2浓度倍增对大豆生长及光合作用的影响

以‘齐黄27’大豆为材料,研究人工气候室模拟大气CO2浓度倍增(700μmol.mol-1)的环境条件下大豆植株在生长、色素含量及光合作用相关指标的变化。结果表明:CO2倍增显著增加株高、干鲜重和根瘤数,显著降低根冠比;CO2浓度倍增处理增加了叶绿素、花青素和类胡萝卜素含量,使光合速率、Rubsico的活性、气孔导度和PSⅡ的功能都有所增加。CO2浓度倍增处理对大豆植株的生长具有促进作用,主要是由于高浓度CO2增加了根瘤的数量,增加了叶片叶绿素和类胡萝卜素含量,提高了Rubsico活性,增强了PSⅡ功能并且提高了气孔导度,最终使光合速率增加所致。     

Characterization of an α 4/7-Conotoxin LvIF from Conus lividus That Selectively Blocks α3β2 Nicotinic Acetylcholine Receptor

Nicotinic acetylcholine receptor (nAChR), a member of pentameric ligand-gated ion channel transmembrane protein composed of five subunits, is widely distributed in the central and peripheral nervous system. The nAChRs are associated with various neurological diseases, including schizophrenia, Alzheimer’s disease, Parkinson’s disease, epilepsy and neuralgia. Receptors containing the α3 subunit are associated with analgesia, generating our interest in their role in pharmacological studies. In this study, α-conotoxin (α-CTx) LvIF was identified as a 16 amino acid peptide using a genomic DNA clone of Conus lividus (C. lividus). The mature LvIF with natural structure was synthesized by a two-step oxidation method. The blocking potency of α-CTx lvIF on nAChR was detected by a two-electrode voltage clamp. Our results showed that α-CTx LvIF was highly potent against rα3β2 and rα6/α3β2β3 nAChR subtypes, The half-maximal inhibitory concentration (IC₅₀) values of α-CTx LvIF against rα3β2 and rα6/α3β2β3 nAChRs expressed in Xenopus oocytes were 8.9 nM and 14.4 nM, respectively. Furthermore, α-CTx LvIF exhibited no obvious inhibition on other nAChR subtypes. Meanwhile, we also conducted a competitive binding experiment between α-CTxs MII and LvIF, which showed that α-CTxs LvIF and MII bind with rα3β2 nAChR at the partial overlapping domain. These results indicate that the α-CTx LvIF has high potential as a new candidate tool for the studying of rα3β2 nAChR related neurophysiology and pharmacology.     

Alpha‐tocopherol and β‐carotene in legume–grass mixtures as influenced by wilting,ensiling and type of silage additive

Effects of wilting, ensiling and type of additive on α‐tocopherol and β‐carotene contents in legume–grass mixtures were examined. Swards of birdsfoot trefoil + timothy (Bft + Ti), red clover + timothy (Rc + Ti) and red clover + meadow fescue (Rc + Mf) were harvested as a first regrowth in August 2005. Forage was wilted to a dry‐matter (DM) content of 273 g kg^?1 and ensiled without additive or with an inoculant or acid. Wilting decreased α‐tocopherol concentration by 30% in the Bft + Ti mixture (P = 0·015). Untreated Bft + Ti silage had higher α‐tocopherol content than red clover silages (56·9 vs. 34·2 mg kg^?1 DM; P = 0·015). The α‐tocopherol concentration of Bft + Ti forages increased during ensiling from 41·1 mg kg^?1 DM in wilted herbage to 56·9, 65·2 and 56·8 mg kg^?1 DM in untreated, inoculated and acid‐treated silage respectively (P = 0·015). The inoculant increased α‐tocopherol content in the red clover silages (50·1 vs. 34·2 mg kg^?1 DM; P = 0·015) compared with untreated red clover silages. Red clover mixtures had lower β‐carotene content than Bft + Ti (32·3 vs. 46·2 mg kg^?1 DM; P = 0·016), averaged over treatments. In conclusion, wilting had small effects but the use of bacterial inoculant as an additive and a Bft + Ti mixture increased α‐tocopherol concentration in the silage.     

低温胁迫下2种木薯幼苗形态及抗渗透差异

为探究木薯的耐寒性及其在低温胁迫下抗渗透响应,对耐寒‘F200’木薯和低温敏感品种‘华南8号’（‘SC8’）木薯幼苗在人工低温条件下进行4 ℃低温处理,分别观测处理前和处理3、6、12、24 h下不同木薯品种生长表型情况以及渗透性物质含量变化情况。结果表明：随着胁迫时间的增加,‘F200’木薯幼苗上部和下部叶片出现轻度萎焉,而‘SC8’所有叶片均严重萎焉,顶部叶片甚至出现脱水现象;‘F200’木薯叶片受H₂O₂的损害轻于‘SC8’,相对于‘SC8’的损伤持续增加,‘F200’呈现先加重后减轻的趋势;随着低温胁迫时间的延长,木薯叶片的相对叶绿素含量呈现先急剧下降、再上升、后下降的过程;相对电导率（REC）和丙二醛（MDA）、可溶性糖（SS）、可溶性蛋白（SP）、脯氨酸（Pro）的含量均逐渐升高;低温胁迫下,‘F200’木薯的总叶绿素减少64.23%,且小于‘SC8’的78.15%,二者差异不显著;REC增加11.48%,且显著小于‘SC8’的188%;MDA增加14.74%,且显著小于‘SC8’的20.98%;Pro增加90.53%,显著大于‘SC8’的27.95%;SP增加12.96%,且大于‘SC8’的17.82%,二者无显著差异;SP增加45.18%,且显著大于‘SC8’的2.16%。可见,低温胁迫下,‘F200’木薯通过增强H₂O₂的清除能力、增强光合作用、增加渗透调节物质含量等途径,缓解了低温对木薯幼苗造成的伤害。低温耐受型木薯‘F200’和低温敏感型木薯‘SC8’的形态结构和生理指标在低温胁迫下存在明显差异,可作为木薯种质资源耐低温性评价的参考指标。     

茶叶纤维对Cu2+的吸附性能研究

对茶叶纤维吸附Cu²⁺的性能进行了研究。结果表明,茶叶纤维对Cu²⁺有明显的吸附作用。pH值为4.55左右,温度在30℃左右时,对Cu²⁺的吸附较为有利;当Cu²⁺的质量浓度为200 mg/L时,随着茶叶纤维添加量增加,吸附量先升后降,茶叶纤维添加量为90 mg左右时吸附量最大。茶叶纤维对Cu²⁺的吸附过程符合拟二级动力学方程。Langmuir等温吸附方程比Freundlich方程能更好地描述茶叶纤维对Cu²⁺的平衡吸附行为,最大吸附量达到16.78 mg/g。     

Effect of Altitude on the Response of Net Photosynthetic Rate to Carbon Dioxide Increase by Spring Wheat

Abstract: The partial pressure of CO₂ in air decreases with the increase in altitude. Therefore, increase in molar concentration of CO₂ is smaller at higher altitudes than at lower altitudes for increases in molar fraction of CO₂. This study aimed to predict the effect of global CO₂ increase on net photosynthetic rateof spring wheat (Triticum aestivum L.) at high altitudes. The net photosynthetic rate of spring wheat grown in Lhasa (3688 m above sea level), China, was compared with that of the same cultivar grown in Sapporo (15 m above sea level), Japan. At the current level of CO₂, it was significantly lower in Lhasa than in Sapporo, and stomatal conductance, chlorophyll content (SPAD value) and apparent quantum yield were similar in both locations. The interaction ofCO₂ level and altitude was suggested; the amount of increase in net photosynthetic rate caused by increase in CO₂ was smaller at high altitudes than at low altitudes. Lower CO₂ partial pressure at higher altitude could explain the difference in net photosynthetic rate between altitudes, and the interaction of CO₂ level and altitude.     

A System for the Measurement of Vertical Gradients of CO2, H2O and Air Temperature within and above the Canopy of Plant

Absract

This technical report describes a gradient system for characterizing the vertical gradients of CO₂, H₂O, and air temperature within and above the canopy of plants. The system is low in cost and easy to use. The instruments were fitted and placed in one box with a total weight of about 10 kg. The box can be carried and moved from one site to another. The features of this apparatus are high frequency sampling cycle as short as 1 min per cycle for all six measurement levels and fast response gas analyzer for measurement as short as 10s per level. Two exhaust pumps, one sampling pump, six 3-way solenoid valves, and flow meter were used to insure simultaneous flow rate of air in all tubes from all measurement levels. This system transfers data from the data-logger directly to the add-in Spreadsheet of Microsoft Excel by using an Ethernet cable to automatically convert digital data to scientific units in less time. This system also allows the use of multiple micro-environmental sensors that can be sampled at the same time. It is useful not only for agricultural ecosystems but is also adequately sensitive and rapidly responds to the gas analyzer with a modifiable flow rate meter for use in forest ecosystems. This system also has potential for use in the measurement of CO₂, H₂O, associated environmental elements, and CO₂ storage flux within the canopy of plant, and other processes including a CO₂ sink and source.