Mirror-image confusion in single neurons of the macaque inferotemporal cortex

Humans and animals confuse lateral mirror images, such as the letters "b" and "d," more often than vertical mirror images, such as the letters "b" and "p." Experiments were performed to find a neural correlate of this phenomenon. Visually responsive pattern-selective neurons in the inferotemporal cortex of macaque monkeys responded more similarly to members of a lateral mirror-image pair than to members of a vertical mirror-image pair. The phenomenon developed within 20 milliseconds of the onset of the visual response and persisted to its end. It occurred during presentation of stimuli both at the fovea and in the periphery.     

Corrections and clarifications

In table 1 (p. 1124) of the article "Prehistoric extinction of Pacific island birds: Biodiversity meets zooarchaeology," by David W. Steadman (24 Feb., p. 1123), the column headings for modern and fossil record were reversed; under each island name, the letters "F M" should have appeared.     

马铃薯不同品种叶片再生体系的建立

以马铃薯6个品种为材料,建立叶片再生体系。结果表明,6-BA和GA3对马铃薯叶片愈伤组织生长量和不定芽分化率均有显著影响。不同马铃薯愈伤组织生长最高的6-BA质量浓度分别是"大西洋"、"底西瑞"和"虎头"1mg/L,"费乌瑞它"和"夏坡蒂"2mg/L,"紫花白"3mg/L;愈伤组织生长最高的GA3质量浓度分别是"大西洋","费乌瑞它","夏坡蒂"和"紫花白"5mg/L,"底西瑞"0.02和0.15mg/L,"虎头"0.02,0.05和0.1mg/L。在不同培养基中获得的最大愈伤组织生长量分别为"大西洋"0.039 5g,"费乌瑞它"0.037 5g,"夏坡蒂"0.041g,"紫花白"0.0396g,"底西瑞"0.042 5g和"虎头"0.039 5g。不同马铃薯不定芽分化最高的6-BA质量浓度分别是"大西洋","费乌瑞它"和"夏坡蒂"2mg/L,"紫花白"和"底西瑞"1mg/L,"虎头"0.1mg/L;不定芽分化最高的GA3质量浓度分别"大西洋"0mg/L,"费乌瑞它"2mg/L,"夏坡蒂"1mg/L,"紫花白"5mg/L,"底西瑞"和"虎头"0.1mg/L。在不同培养基中获得的最高不定芽分化率分别是"大西洋"18.18%,"费乌瑞它"13.04%,"夏坡蒂"17.86%,"紫花白"15.00%,"底西瑞"44.44%和"虎头"47.83%。诱导6个马铃薯品种生根的最佳培养基为1/2MS+0.1mg/LNAA,生根率分别为"大西洋"95.2%,"费乌瑞它"83.3%,"夏坡蒂"92.4%,"紫花白"94.8%,"底西瑞"96.7%和"虎头"95.6%。6个马铃薯品种的移栽成活率均为90%以上。     

Metrology and the state: science, revenue, and commerce

"Natural measures of quantity, such as fathoms, cubits, inches, taken from the proportion of the human body, were once in use with every nation," taught Adam Smith in his lecture "Money as the measure of value and medium of exchange," delivered in 1763. "But by a little observation," he continued, "they found that one man's arm was longer or shorter than another's, and that one was not to be compared with the other; and therefore wise men who attended to these things would endeavour to fix upon some more accurate measure, that equal quantities might be of equal values. Their method became absolutely necessary when people came to deal in many commodities, and in great quantities of them." Smith's comments and the rationale underpinning them became increasingly urgent toward the end of the eighteenth century.     

Biotech policy draws flood of comments

The federal government's draft plan to regulate the biotechnology industry has elicited dozens of letters from researchers, industry, environmental groups, and others in response to the Environmental Protection Agency's (EPA) proposed role. Many commentators took issue with the EPA's intention to subject the products of genetic engineering to more rigorous scrutiny than conventionally manufactured products, a policy that the agency defends on the premise that genetically manipulated substances may pose more risks. Several respondents also claimed that products produced by genetic techniques not involving recombinant DNA are not "new," and therefore not subject to EPA's authority. Questions were asked as well about the need for the Biotechnology Science Board that the government plans to establish to oversee review committees in federal agencies involved with biotechnology research.     

农地整理前后生态系统服务价值变化测算

农地整理工程改变了整理区的土地利用类型,使其原生态系统的能量流、物质流和信息流发生改变,进而导致生态系统服务价值发生变化。依据不同的地貌类型,在湖北省境内选取3个典型项目作为研究对象,测算了农地整理前后项目区的生态系统服务价值。研究结果表明:新增耕地数量最多的是"竹山项目"、净增348.84 hm2,居中的是"当阳项目"、净增62.32 hm2,最少的是"钟祥项目"、净增44.27 hm2。3个农地整理项目区的生态系统服务价值都发生损失,"竹山项目"净减271.0×104元/年,"当阳项目"净减51.0×104元/年,"钟祥项目"净减8.0×104元/年。不同地貌类型项目区的单项生态系统服务价值损失存在较大差异,"竹山项目"的气体调节价值损失最大,"当阳项目"的气体调节价值损失最小;"竹山项目"的食物生产价值增加11.0×104元/年,"钟祥项目"增加1.0×104元/年。研究得到的政策启示:农地整理目标必须从新增耕地数量向更加注重耕地质量和生态环境转变,紧紧围绕和考虑生产、生活和生态,实施数量、质量、生态三位一体的整理模式。     

Superiority, competition, and opportunism in the evolutionary radiation of dinosaurs

The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates and morphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows that dinosaurs exhibited lower disparity and an indistinguishable rate of character evolution. The radiation of Triassic archosaurs as a whole is characterized by declining evolutionary rates and increasing disparity, suggesting a decoupling of character evolution from body plan variety. The results strongly suggest that historical contingency, rather than prolonged competition or general "superiority," was the primary factor in the rise of dinosaurs.     

Obestatin, a peptide encoded by the ghrelin gene, opposes ghrelin's effects on food intake

Ghrelin, a circulating appetite-inducing hormone, is derived from a prohormone by posttranslational processing. On the basis of the bioinformatic prediction that another peptide also derived from proghrelin exists, we isolated a hormone from rat stomach and named it obestatin-a contraction of obese, from the Latin "obedere," meaning to devour, and "statin," denoting suppression. Contrary to the appetite-stimulating effects of ghrelin, treatment of rats with obestatin suppressed food intake, inhibited jejunal contraction, and decreased body-weight gain. Obestatin bound to the orphan G protein-coupled receptor GPR39. Thus, two peptide hormones with opposing action in weight regulation are derived from the same ghrelin gene. After differential modification, these hormones activate distinct receptors.     

论“五行”范式的演化、扩展和价值取向

"五行"原初是中国古人对自然界万物构成的基本元素的概括,并从它们之间的关系中演绎出万物化生的序列性法则。后来"五行"在思孟学派那里演变为概括社会领域内道德伦理秩序的"五德"。接着邹衍将它变为中国古代历史发展和政治治理法则。最后,董仲舒使它成为宇宙秩序与政治秩序、道德秩序的统一体。促使这种演变不断发生的是中国古人的人则天地、必须以自然为师的价值信仰和终极关怀落脚于人间秩序的价值取向。     

Thyroxine: effects of neonatal administration on maturation, development, and behavior

In the report, "Thyroxine: effects of neonatal administration on maturation, development, and behavior," by S. Schapiro and R. J. Norman (10 Mar., p. 1279), the first line of Fig. 2 should read: "Fig. 2. Electroencephalograms from the cortex of thyroxine-treated and control infant...."     

我国农业推广体系现状·存在问题及改革

通过分析我国农业推广体系的现状,指出当前我国农业推广体系存在管理体系混乱、推广人员素质偏差且经费不足等问题。另外,介绍了美国"三位一体"农业推广体系、日本"区域分担方式"农业推广体系、荷兰"非政府性质"农业推广体系、以色列"一主多元"节约型农业推广体系。借鉴国外经验,探讨了其对我国农业推广体系发展的启示,主张政府应加强对农业推广体系的领导和支持,加强农业推广主题和内容多样化建设,加大对农业推广的财政投入,加强农业科研、教育、推广部门之间的协调互作。     

西藏园林植物资源数据库检索系统的构建

为合理有序地保护、开发利用和管理西藏野生园林植物资源,采用Visual Basic、MS Access、MS Excel等软件进行了数据库检索系统的开发,并由Setup Factory制作安装程序,构建了能够在Windows 98以上操作系统中通过可视化界面进行独立安装、运行的西藏园林植物资源数据库检索系统。该系统采用...     

修身之道与治国之道的统一——古代行政管理经验的总结之作:《大学衍义》与《大学衍义补》

儒家学说以为,如何造就完美人格,对于社会的领袖人物与精英人物至关重要。《大学》一书提出了"明明德"、"亲民"、"止于至善"的"三纲领"和"格物"、"致知"、"诚意"、"正心"、"修身"、"齐家"、"治国"、"平天下"的"八条目"。但这至多只是提供了一种道德原则和实用知识的理论"间架"(朱熹语),如何"填补"和充实这一理论"间架",则是留给后世儒者的任务。南宋真德秀的《大学衍义》和明代邱浚的《大学衍义补》完成了这个任务。这两部书集古代政府行政管理经验之大成,被当时及后世称为"帝王之学",是帝王以及各级官员的     

西藏农村城镇居民收入与消费关系研究

运用因子分析和二次多项式回归分析方法,借助DPS和SPSS统计软件进行统计分析,以西藏自治区2007年农村城镇居民可支配收入与消费支出为研究对象,客观、合理地分析可支配收入和消费支出的内在关系。结果可知,第1个因子主要解释“衣着”、“家庭设备用品及服务”、“医疗保健”、“交通通讯”、“教育文化娱乐”,第2个因子主要反映“食品”和“居住”,第3个因子主要解释“其他商品和服务”,分析结果与实际情况吻合。根据因子得分可知,“拉萨”的消费综合水平最好,“阿里”、“昌都”良好,“日喀则”、“山南”和“那曲”较好,“林芝”一般。     

马铃薯耐盐突变体的离体筛选

以4个马铃薯栽培品种的叶片为外植体进行耐盐突变体筛选,结果表明:不同品种愈伤组织的耐盐性存在差异,东农303、鄂1号两品种在细胞水平对NaCl的最大耐受质量浓度为8g/L,费乌瑞它为6g/L,夏波帝为4g/L。当继代次数低于10次,叶片耐盐愈伤组织在无盐胁迫诱导分化培养基上才有进一步诱导再生植株发生的能力;而在盐胁迫诱导分化培养基中,愈伤组织继代次数超过8次即很难继续分化再生。     

Lunar rock compositions and some interpretations

Samples of igneous "gabbro," "basalt," and lunar regolith have compositions fundamentally different from all meteorites and terrestrial basalts. The lunar rocks are anhydrous and without ferric iron. Amounts of titanium as high as 7 weight percent suggest either extreme fractionation of lunar rocks or an unexpected solar abundance of titanium. The differences in compositions of the known, more "primitive" rocks in the planetary system indicate the complexities inherent in defining the solar abundances of elemizents and the initial compositions of the earth and moon.     

浙江水生蔬菜栽培技术和模式的创新

通过水生蔬菜栽培技术和模式创新研究,先后总结出单季茭"一茬双收"栽培技术、双季茭"三改两优化"栽培技术、莲藕"五改"早熟栽培技术、子莲"早鲜多"栽培技术和菱角"带果移栽"长季栽培技术等,并在产区得到大面积推广,取得明显成效。     

Errata for Volume 123

In the article "Pronuclear fusion as affected by x-rays and by postirradiation anaerobiosis," by C. S. Bachofer, in the issue of 27 Jan., page 139, the last sentence in column 1 should begin "The term (1/4)-fused is used to designate ...," not "The sum (1/4)-fused . . ." as printed. In the article "Magnetic techniques for in vitro isolation of leucocytes," by Sumner Levine, in the issue of 3 Feb., page 186, the equation should read micro radicaln(n+2)=4.90 Bohr magnetons, instead of as printed with the square root sign covering the last part of the equation.     

Corrections and clarifications

In the article "Molecular basis of mammalian sexual determination: Activation of Müllerian inhibiting substance gene expression by SRY" by C. M. Haqq et al. (2 Dec., p. 1494), parts B and C of figure 1 were inadvertently interchanged. In figure 3A, the third, fourth, and fifth lanes should have been labeled "A(7) --> T," "A(7) -->C," and "A(7) --> G," respectively. In figure 5, the factor labeled "SRIF's" should have been labeled "SRYIF's."     

Erratum

Due to a printer's error, the word "nitrite" was altered to "nitrate" in two instances in the article, "Ever so cautiously, the FDA moves to-ward a ban on nitrites," (8 September, p. 887). The lead sentence should read," The hazard to animals and man of eating excessive amounts of nitrates and nitrites...." The first sentence in the fourth paragraph should read," These circumstances ... the existent but unquantified hazard of adding nitrites to food." Nitrites-not nitrates-are deliberately added to foods.