The potential for grass-fed livestock: resource constraints

Using pasture and grazed forest-range for a system of producing live-stock by feeding grass alone reduces the inputs of energy about 60 percent and land resources about 8 percent, but also reduces by about half the production of animal protein in the United States. Under a system in which only grass was fed, livestock would be restricted to beef, milk, and lamb production. The amount of grain fed to U.S. livestock is about 135 million tons (metric) or about ten times the amount consumed by the U.S. population.     

S5-95U可编程控制器在热媒炉控制系统中的应用

介绍了东黄输油管道热煤加热炉中应用西门子Ｓ５－９５Ｕ自动控制系统情况。利用Ｓ５－９５Ｕ可编顺控制器开发的９５Ｕ炉控系统及炉控人机操作界面，优化了控制结构，使加热系统安全运行，收到了良好效果。     

磷脂酶C参与ParA1诱导的烟草悬浮细胞死亡和防卫反应

【目的】研究寄生疫霉Phytophthora parasitica分泌的蛋白激发子ParA1诱导烟草悬浮细胞后,磷脂酶C(phospholipase C,PLC)参与ParA1诱导烟草过敏细胞死亡(hypersensitive cell death,HCD)和防卫反应。【方法】采用药理学方法,在烟草悬浮细胞中添加PLC抑制剂,比较烟草悬浮细胞受ParA1诱导后细胞死亡和多种防卫反应的差别。【结果】PLC特异性抑制剂U73122能完全抑制ParA1引起的烟草悬浮细胞死亡,氧迸发、胞外基质碱化和植保素scopoletin(7-羟基-6-甲氧基香豆素)积累都能显著地被抑制,5种防卫基因hin1、hsr203J、PR(pathogenesis-related)-1a、PR-1b和PAL等的转录表达也都受到U73122不同程度的抑制。【结论】ParA1处理烟草悬浮细胞后,PLC参与了ParA1诱导细胞死亡和防卫反应的信号传导过程。     

PLC在沥青拌和站控制系统中的应用

本文介绍了可编程控制器(PLC)在沥青拌和站控制系统中的应用，它采用了可编程控制器怍为下层数据采集和处理的核心设备，实现了系统控制的自动化，先进的硬件技术和优化的软件设计使整个系统的可靠性得到了较大的提高。该系统已在实践中得到了广泛的应用，取得了较好的效果。     

Small nuclear ribonucleoprotein remodeling during catalytic activation of the spliceosome

Major structural changes occur in the spliceosome during its activation just before catalyzing the splicing of pre-messenger RNAs (pre-mRNAs). Whereas changes in small nuclear RNA (snRNA) conformation are well documented, little is known about remodeling of small nuclear ribonucleoprotein (snRNP) structures during spliceosome activation. Here, human 45S activated spliceosomes and a previously unknown 35S U5 snRNP were isolated by immunoaffinity selection and were characterized by mass spectrometry. Comparison of their protein components with those of other snRNP and spliceosomal complexes revealed a major change in protein composition during spliceosome activation. Our data also suggest that the U5 snRNP is dramatically remodeled at this stage, with the Prp19 complex and other factors tightly associating, possibly in exchange for other U5 proteins, and suggest that after catalysis the remodeled U5 is eventually released from the postsplicing complex as a 35S snRNP particle.     

PROFIBUS-DP现场总线在热连轧控制系统中的应用

简述了德龙850mm热连轧生产线自动化控制系统的配置。重点介绍了PROFIBUS-DP现场总线的应用,PROFIBUS-DP网中PLC主站与直流调速装置、变频器、S7-200、编码器等数据交换,各种厂家的产品在PROFIBUS-DP网做主站或从站的详细配置,PLC控制器对数据的读写。     

磷脂酶C对血小板粘附性及表面膜GpIb的影响

采用旋转玻球法测定了磷脂酶C(PLC)经十二指肠给药后对家兔血小板粘附性的影响,同时利用竞争性酶联免疫法测定了PLC对人血小板表面膜糖蛋白Ib(GpIb)分子数的影响。结果表明,PLC冻干辅料及100和200U/kg的PLC对家兔血小板粘附率无明显影响,而400～1000U/kgPLC对血小板粘附率具有明显的影响。PLC冻干辅料对人血小板表面膜GpIb分子数没有明显影响,而每mL血浆(PRP)中加入0.5,1.0和2.0U的PLC对人血小板表面GpIb分子数可产生明显影响。     

5S RNA synthesized by Escherichia coli in presence of chloramphenicol: different 5'-terminal sequences

Escherichia coli cells, grown in the presence of chloramphenicol, synthesize a low molecular weight RNA (CM-5S RNA) not bound to ribosomes which is similar to ribosomal 5S RNA. Oligonucleotide patterns derived from ribonuclease digests of 5S RNA and of CM-5S RNA are indistinguishable except that the 5'-terminal oligonucleotides differ. Whereas the nucleotide sequence of the 5'-terminus of normal 5S RNA is (p)U(p)G-, there are three alternate sequences of the 5'-terminus of CM-5S RNA: (p)U(p)U(p)G-, (p)U(p)U(p)U(p)G-, and (p)A(p)U(p)U(p)U(p)G-.     

秸秆和DCD对冬小麦不同生育期施入尿素的土壤行为的影响Ⅱ：硝态氮的动态变化

[目的]通过田间试验研究秸秆和DCD对冬小麦不同生育期施入尿素土壤行为的影响。[方法]试验设5个处理：对照（不施秸秆、DCD和尿素,CK）;单施尿素（U）;尿素＋秸秆（U＋S）;尿素＋DCD（U＋DCD）;尿素＋秸秆＋DCD（U＋S＋DCD）。[结果]在田间条件下,在尿素配施DCD的处理中,在一定时间内土壤NO3-N数量明显低于未加DCD处理;在配施秸秆处理中,秸秆加入后,延缓了硝化作用的发生以及土壤NO3-N的积累速率。[结论]该研究为揭示尿素在土壤中的行为特征及合理施用尿素提供理论依据。     

PLC在暗调控气孔运动中的作用

[目的]探究PLC在暗调控的气孔运动中的作用。[方法]采用药理学试验和气孔分析,研究PLC参与暗诱导的气孔关闭的作用。[结果]U73122阻止暗诱导的气孔关闭;L-NAME和c-PTIO能够逆转暗诱导的气孔关闭。[结论]暗中PLC活性较高。PLC与NO可能存在某种联系。     

Cohen-Boyer patent to be issued soon

The U.S. Patent Office is expected to approve shortly a genetic engineering claim filed in 1978 by Stanley Cohen of Stanford University and Herbert Boyer of the University of California at San Francisco. The application, regarded as a test case by the biotechnology community, was preliminarily rejected in 1982 when the Patent Office raised questions about the inventorship status of a third researcher, and about the completeness of the information disclosed in the claim. Just how these questions were resolved will be made public when the patent is formally issued and the universities open their correspondence files.     

PLC在节能型日光温室温度监控系统中的应用

利用收集验证完善得到的PPI协议实现了上位机对PLC的监控,将西门子S7-200 PLC与各个控制节点相连,上位机通过控制PLC来实现自动和手动控制各个节点,以实现节能型日光温室温度监控系统的自动化.     

蜂王浆中超氧化物歧化酶活力测定

本文以邻苯三酚自氧化法测得蜂王浆中具有较高的SOD活性,酶活力约为135U/g.其随贮藏期延长.酶活力逐渐下降,至第六天完全消失.但通过对同批冷冻保存一个月未融化过的蜂王浆中SOD活力测定,发现酶活力变化不大,保持原鲜王浆酶活力,其结果表明:引起蜂王浆中SOD活力下降的主要原因是由于反复冻融所致,由此可见SOD活力对温度较为敏感.本文以邻苯三酚自氧化法测得蜂王浆中具有较高的SOD活性,酶活力约为135U/g.其随贮藏期延长.酶活力逐渐下降,至第六天完全消失.但通过对同批冷冻保存一个月未融化过的蜂王浆中SOD活力测定,发现酶活力变化不大,保持原鲜王浆酶活力,其结果表明:引起蜂王浆中SOD活力下降的主要原因是由于反复冻融所致,由此可见SOD活力对温度较为敏感.     

秸秆和DCD对不同施用期尿素土壤行为的影响Ⅲ：硝态氮的淋失特征

[目的]研究秸秆和DCD对冬小麦不同生育期施入尿素土壤行为的影响—硝态氮的淋失特征。[方法]通过田间试验,在不同时期取土样,采用连续流运分析仪法测定NO3-N。试验设5个处理：对照（不施秸秆、DCD和尿素,CK）;单施尿素（U）;尿素＋秸秆（U＋S）;尿素＋DCD（U＋DCD）;尿素＋秸秆＋DCD（U＋S＋DCD）。[结果]在田间试验条件下,总的趋势是加DCD的2个处理能有效减少NO3-N的淋失;加入秸秆后虽能减少部分NO3-N向下淋洗,但作用不明显。[结论]DOD和秸秆对不同时期施入尿素的土壤行为和硝态氮的淋失特征均产生一定影响。     

可编程控制器在南通狼山空中缆车中的应用

介绍了可编程控制器（ＰＬＣ）在南通狼山空中缆车中的应用及该系统的软、硬件结构。系统采用日本ＯＭＲＯＮ公司生产的Ｃ６０Ｐ－ＣＤＲ－Ａ主机、Ｃ６０Ｐ－ＥＤＲ－Ａ扩展机和少量的中间继电器来代替传统的继电－接触器控制系统,各接触器都有辅助触点反馈回ＰＬＣ,采用行程显示技术以实时显示吊厢的实际位置,出进站时的加减速均采用软硬件双重控制,用梯形图编制开／停车逻辑控制、速度给定处理、行程显示、各种紧停及报警处理程序。实践证明,该系统具有有效的故障自诊断能力,灵活的控制方式,检修、维护更简便,可靠性大大提高。     

可编程控制器在南通狼山空中缆车中的应用

介绍了可编程控制器（ＰＬＣ）在南通狼山空中缆车中的应用及该系统的软、硬件结构。系统采用日本ＯＭＲＯＮ公司生产的Ｃ６０Ｐ－ＣＤＲ－Ａ主机、Ｃ６０Ｐ－ＥＤＲ－Ａ扩展机和少量的中间继电器来代替传统的继电－接触器控制系统,各接触器都有辅助触点反馈回ＰＬＣ,采用行程显示技术以实时显示吊厢的实际位置,出进站时的加减速均采用软硬件双重控制,用梯形图编制开／停车逻辑控制、速度给定处理、行程显示、各种紧停及报警处理程序。实践证明,该系统具有有效的故障自诊断能力,灵活的控制方式,检修、维护更简便,可靠性大大提高。     

早熟 优质 抗病 耐运番茄新品种冀P135和冀$136的选育

冀P135和冀S136均为无限生长类型粉红番茄杂交种,分别由自交系JBF2—2．3-M与HZF2—3．1-M、FGF2-1-3-M与HZF2-3—3-M配制而成。其中,冀P135早熟,果实正圆形,果实较硬,果皮较厚,单果重230g左右,一般产量9．00万～9．75万kg／hm^2;冀S136中早熟,果实圆形,无绿肩,外形美观,商品性好,坐果率高,单果重250g左右,一般产量9．75万～10．50万kg／hm^2。2个番茄品种均生长势中等,叶片稀疏,通风透光好,省工省时,容易管理。     

不同施肥水平对马铃薯农艺性状及产量的影响

[目的]为冬作马铃薯高效合理施肥提供理论依据。[方法]试验采用N∶P2O5∶K2O为1∶0.5∶2的肥料配比,氮素基准设4个水平:90、1351、80和225 kg/hm2,不施N肥为CK,研究不同施肥水平下马铃薯主茎数、株高、块茎数量与产量的差异。[结果]不同施肥水平下马铃薯主茎数、株高、块茎数量与产量差异显著。主茎数与施肥量在一定范围内呈负相关;随着施肥量增加,株高表现出"U"形变化趋势,N肥水平为180 kg/hm2时植株最矮;N肥水平为135 kg/hm2时增产效果最好,比对照增产64.9%。其次是90 kg/hm2,增产8.0%。[结论]该配方肥中N肥水平为90~135 kg/hm2时,对马铃薯有较好的增产作用。     

Impacts of bovine spongiform encephalopathy and avian influenza on U.S. meat demand

This paper examines the U.S. meat demand impacts of the announced outbreaks of bovine spongiform encephalopathy(BSE) and avian influenza(AI). Findings indicate that beef and chicken demand was negatively affected by BSE and AI disease outbreaks. Specifically, in the short run, U.S. consumers shift demand due to both outbreaks but more so due to domestic disease outbreaks than for outbreaks occurring overseas-the impact of U.S. AI outbreaks is about 0.5% for beef and the impact of U.S. BSE cases is around –0.42% for beef and 0.4% for pork, respectively. Regarding the BSE shock on meat demand, there is a high rate of beef demand adjusted from disturbance to the long-run equilibrium and a lower adjustment rate for chicken demand because of the repeated outbreaks of AI worldwide. In the long run, information related to severe, persistently recurring overseas animal disease outbreaks changes U.S. consumers' meat consumption patterns. Although effects of animal diseases on U.S. meat demand were statistically significant, the magnitudes were small-the impact of WHO reported human death numbers for AI is 0.005% for beef, –0.002% for pork, and –0.006% for chicken and the impact of U.S. BSE cases is 1.1% for pork and –0.7% for chicken.     

U.s. Competitiveness: beyond the trade deficit

Large trade deficits and the corresponding increase in U.S. international indebtedness have raised concerns about the long-run competitiveness of the United States. But being competitive requires more than balance in our foreign trade; it requires an improving standard of living. The long-term U.S. competitive problem is largely caused by low saving rates, high costs of capital, and the resulting inadequate level of both visible and invisible investment. As long as the U.S. national saving rate remains far below that of all our major competitor nations, there is little chance for restoring America's international economic position.