农产品远程价格信息采集和发布系统的研究

利用TC35与低功耗单片机结合设计便携式手持数据采集终端,采用手持信息采集终端收集信息,通过GSM方式传送到数据中心,数据中心负责处理和发布信息,实现了农产品远程价格信息的采集和发布,用户可通过上网或手机短信进行价格查询。系统实时性好,可靠性高,克服了以往信息采集发布的缺点,能够有效的进行农产品价格信息方面的信息传递工作及数据统计。详细阐述了手机模块TC35中SMS功能的工作原理、便携式手持终端的硬件设计与软件实现。经示范应用,系统达到了设计目标。     

利用AMMI模型分析稻米镉含量的基因型与环境互作效应

以湖南推广种植的10个早稻和8个晚稻品种为基因型材料,在安全区、轻微度和轻度污染区选择4个试验点进行试验,通过AMMI模型研究基因型与环境互作效应对稻米Cd积累量及其稳定性的影响。结果表明:土壤Cd污染程度和生长季节对稻米的Cd积累量均有显著影响,污染区晚稻品种的稻米Cd超标率明显高于早稻;基因型对早稻稻米的Cd含量具有极显著影响,因而可通过选择种植稻米含量低且遗传稳定性好的低积累品种来降低稻米的Cd积累量;环境对晚稻稻米Cd积累量的影响占主导效应,可通过分析品种地点的互作效应来确定低积累品种的适宜推广区域。稳定性参数Di值的计算明晰了稻米Cd积累量的稳定性,对于正确指导低积累品种的推广应用具有重要意义。     

褪黑素对大鼠胰岛瘤细胞INS-1胰岛素和Gαi/o蛋白基因表达的影响

【目的】研究褪黑素对大鼠胰岛瘤细胞INS-1中胰岛素和Gαi/o蛋白基因表达的影响,探究褪黑素在m RNA水平对Gαi/o和Insulin1调节作用中可能存在的分子机制。褪黑素(melatonin,MT)是松果腺分泌的一种吲哚类神经内分泌激素,在机体内可调节胰岛素的分泌而使其呈现昼夜节律性分泌,影响葡萄糖昼夜代谢水平的变化进而维持机体血糖的相对恒定,故对于褪黑素影响胰岛素表达的研究可能会对褪黑素在胰岛素昼夜节律性分泌中的调控作用提供依据。【方法】将冻存的INS-1细胞复苏培养至第三代,INS-1细胞传代后,用RPMI1640培养基培养INS-1细胞约24—48 h,当细胞密度达60%—70%时,使用无血清无葡萄糖的RPMI1640洗2次,然后在INS-1细胞培养外液中分别加入不同浓度(0、10、20、30、50 mmol·L-1)的葡萄糖及100 nmol·L-1褪黑素和不同浓度葡萄糖孵育INS-1细胞12 h,观察和统计INS-1细胞的形态学变化。利用Easy Pure?RNA Kit提取INS-1细胞的总RNA,核酸蛋白测定仪测定细胞总RNA的浓度和纯度,其次利用甲醛变性琼脂糖凝胶电泳检测细胞的总RNA质量,Trans Script One-Step g DNA Removal and c DNA Synthesis Super Mix反转录合成c DNA。利用Primer Premier5.0引物设计软件,参考Gen Bank上已登录的基因序列进行Insulin1、Gαi1、Gαi2、Gαo、PKA和PKCα引物的设计。应用q RT-PCR法进行检测处理后的INS-1细胞Insulin1、Gαi1、Gαi2、Gαo、PKA和PKCαm RNA水平的变化。【结果】用含不同浓度葡萄糖培养液孵育INS-1细胞后,观察发现随着培养基中葡萄糖浓度含量的增加INS-1细胞突触的增长呈现先增加后减少的趋势,其中20 mmol·L-1葡萄糖处理组INS-1细胞突触的增长明显,而20 mmol·L-1葡萄糖和100 nmol·L-1褪黑素处理组INS-1细胞表面积增大,但突触增长却不明显;培养基中含不同浓度葡萄糖的处理组中,Insulin1 m RNA水平呈现先升后降的趋势,Gαi1 m RNA水平则呈现先降后升的趋势,其中20 mmol·L-1葡萄糖处理组,Insulin1 m RNA水平显著增加(P0.05),Gαi1 m RNA水平显著减少(P0.05),而Gαi2和Gαo则无显著变化(P0.05),因而Gαi1表现出与Insulin1 m RNA水平呈现负相关性而非Gαi2、Gαo与Insulin1 m RNA水平呈现负相关性;20 mmol·L-1葡萄糖和褪黑素处理组和20 mmol·L-1葡萄糖处理组相比,20 mmol·L-1葡萄糖和褪黑素处理组的Gαi1 m RNA水平显著增高(P0.05),且Insulin1和PKCαm RNA水平显著减少(P0.05),PKA m RNA水平则减少不显著(P0.05)。【结论】褪黑素能够抑制INS-1细胞Insulin1的表达,减少胰岛素的分泌导致INS-1细胞适应性增生。褪黑素与其受体结合后可促进Gαi1 m RNA水平增高而抑制PKCα的表达,使得Insulin1的表达受到抑制,胰岛素分泌减少,使血糖在夜间得以维持相对恒定。     

opaque2对糯玉米子粒食味和营养品质的影响分析

玉米opaque2(o2)是胚乳发育的核心调控基因，对子粒发育至关重要。基于9组糯玉米o2近等基因系(o2-NILs)及对应轮回亲本，对鲜食期和成熟期子粒的种皮厚度、总淀粉含量、可溶性糖含量等性状进行分析。结果表明，黄糯2/o2o2和中63-2/o2o2鲜食期子粒的食味品质性状均有提高，其他o2-NILs子粒品质变化不一。鲜食期o2突变对种皮厚度影响较大，但与成熟期无直接相关性。o2突变使玉米子粒赖氨酸含量增加，营养价值提高，但多数近等基因系成熟期淀粉含量和百粒重降低，仅糯2/o2o2、淀粉含量和百粒重均不受影响。糯2/o2o2、SY1-2/o2o2、赵OP-6/o2o2中27 KD γ-zein表达量显著增加、子粒饱满度与轮回亲本相近，但均表现为粉质胚乳，因此认为，优质蛋白糯玉米硬质胚乳的恢复需多个o2胚乳修饰基因协同作用。     

Hydrophysical degradation associated with hiking‐trail use: a case study of Hawai'iloa Ridge Trail,O'ahu,Hawai'i

Recreational activities can have significant impacts on geomorphic and hydrologic processes in drainage basins, often out of proportion to their areal extent. With increased stress on hiking trails nationwide, there is a need to characterize the impacts of human trampling on soil properties. We examine an 810 m segment of Hawai'iloa Ridge Trail (O'ahu, Hawai'i, USA). Soil compaction and surface erosion on moderate to steeply sloping sites have degraded the trail environment. Bulk density, penetration resistance, and vane shear strength were significantly higher on the trail than in adjacent undisturbed areas, with median differences ranging from 29 to 120 per cent. With compaction and exposure of subsoil on the trail, void ratio, air‐filled porosity, saturated hydraulic conductivity, effective and preferential porosity were significantly lower, with relative change values ranging from 23–93 per cent. No significant changes were noted in meso‐ or micro‐porosity, but macropores with a radius of >110 μm decreased significantly by 58 per cent for on‐trail locations. This comprehensive dataset indicates that hiking stress is deleterious to the soil–hydrologic system. Data point to a trail system that would be dominated by Hortonian overland flow and this was supported by field evidence during a storm event. Increased runoff has incised rills on some trail segments and there is evidence that run‐on to adjacent side slopes has lead to accelerated erosion. Management on most trails in Hawai'i, including the one studied, is limited, but from our data it is apparent that on‐trail sites directly influenced by an overhanging canopy of rapidly growing (aggressive) exotics were least impacted due to increased organic contributions to the surface and root network development. These data will allow land managers to more effectively address the potential geomorphic and hydrologic impacts of recreational land use. Copyright © 2001 John Wiley & Sons, Ltd.