Ramon and maya ruins: an ecological, not an economic, relation

Economically important trees such as ramón have been shown to have a high density in the civic-ceremonial core zone of ancient Maya ruins. The distribution of such trees is probably the result of their requirements for growth and reproduction, which are optimal on the ruins, and not because they are the descendants of trees planted by the Maya aristocracy.     

Analysis of obsidian from moho cay, belize: new evidence on classic maya trade routes

Trace element analysis of obsidian artifacts from Moho Cay, Belize, reveals that the obsidian derives primarily from the El Chayal outcrop in highland Guatemala and not from the Ixtepeque source. This is contrary to the widely accepted obsidian trade route model for Classic Maya civilization and suggests that Classic Maya obsidian trade was a more complex economic phenomenon than has been recognized.     

都市农业流通组织及其物流配送的发展趋势

温州都市农业流通组织在改革开放以来发生了巨变,其物流配送也发生了相应的转变。参考先进地区的发展经验、结合温州市的特点,总结该行业在流通组织和物流配送方面的发展趋势,并向农民、合作社、企业和政府等相关方面提出具体的操作建议。     

从社会组织试验看我国农村土地流转:新兴古典框架

农村土地流转实质上是一种分工演进的过程,它不仅受到交易效率的制约,而且受到社会组织试验效率的制约,而自由价格和自由企业制度的市场机制是保证社会组织试验效率的基本制度.社会组织试验对我国农地流转的启示是:农地流转制度和政策本质上是在一定的条件下,通过农户职能分工与农业经济组织演进,实现交易效率的提升和农民收益的增加.而在新的历史背景下,农地流转制度要着眼于流转主体划分及其效率激励,长期来说,促成一个自由的市场体制才是农村土地流转的根本保证.     

不同坐果灵处理对小型无籽西瓜坐果能力及产量品质的影响

研究了3种坐果灵处理对小型无籽西瓜坐果能力及产量、品质的影响。结果表明:3种坐果灵均可降低坐果节位,增加果实的畸形和裂果风险,降低果实的中心糖含量。     

桃果实果胶、可溶性糖、可滴定酸含量和果实大小与果实硬度关系的研究

以普通桃、油桃和蟠桃为试材,研究了桃果实果胶、可溶性糖、可滴定酸含量、果实大小与果实硬度之间的关系。结果表明,果实原果胶和可溶性果胶含量分别与果实带皮硬度呈显著正相关和极显著负相关,总果胶含量、可溶性糖、可滴定酸含量及果实大小与果实硬度之间均没有显著的相关性。     

果蔗新品种黔糖5号的选育及应用

以崖城红皮为父本、CO419为母本,通过杂交选育获得果蔗新品种黔糖5号,2009年通过贵州省农作物品种审定委员会审定。该品种植株性状好,适应性广,抗逆性强,宿根性好,单产7~8 t/667m2,糖分含量较高,商品性好,适宜在贵州低热河谷蔗区种植。     

TDZ对苹果叶片光合功能、开花座果及果实发育的影响

在苹果开花期,对富士和元帅品种的树上喷施不同浓度ＴＤＺ．结果表明处理比对照的叶片Ｐｎ、Ｇｓ、叶绿素相对含量等光合功能显著增强．并还能延长开花时间,提高座果率,促进果实发育,从而显著提高果实品质．     

板栗新品种云丰结果枝粗度、结苞量及坚果重量的研究

本文在调查板栗新品种云丰结果枝生长状态和结苞量、坚果重量的基础上,进行统计分析。认为（1）云丰板栗不同粗度结果枝出现频率呈正态分布,97％以上的结果枝基部粗度在0.40.9 cm之间。（2）云丰板栗结苞量与结果枝基部粗度相关性最为密切,结果枝粗度对结苞量呈正相关。（3）结果枝粗度、结苞数和单果重呈线性关系,在结果枝粗度相同的情况下,结苞数与单果重呈负相关。为云丰板栗定株定产、定枝定果、疏花疏果、限产保质、合理修剪、确定量化指标提供依据。     

新兴特色水果甜杨桃的引种栽培试验

对引进的香蜜和水晶2个甜杨桃品种进行了2年的试种观测.结果表明:嫁接苗春季定植,当年即初花试果,第2年正式投产,单株产量8.3～15.5 kg,平均产量687.5～863.5 kg/667m2,产值达到2 750～3 454元/667m2.在贵州低海拔河谷区表现出适应性强、生长快、结果早、产量高、品质优、病虫害轻、耐旱耐寒、经济生态效果好、投资回报快等特点.适宜在贵州红水河及南、北盘江流域海拔600 m以下、年均温19.5℃以上、年积温6 500℃以上、土层深厚、水肥条件较好的低热河谷区推广种植.     

Human T-cell gamma chain genes: organization, diversity, and rearrangement

The human T-cell gamma chain genes have been characterized in an attempt to better understand their role in immune response. These immunoglobulin-like genes are encoded in the genome in variable, joining, and constant segments. The human gamma genes include at least six variable region genes, two joining segments, and two constant-region genes in germline DNA. Variable and joining segments recombine during the development of T cells to form rearranged genes. The diversity of human gamma genes produced by this recombinational mechanism is greater than that produced by the murine genome but is more limited than that of other immunoglobulin-like genes.     

How social organization shapes crop diversity: an ecological anthropology approach among Tharaka farmers of Mount Kenya

The conservation of in situ crop diversity is a key issue to ensure food security. Understanding the processes that shape it is crucial for efficiently managing such diversity. In most rural societies, crop diversity patterns are affected by farmers’ practices of seed exchange, transmission, and selection, but the role of social organization in shaping those practices has been overlooked. This study proposes an ecological anthropology approach to investigate the relation between crop diversity patterns and the social organization of Tharaka farmers in Kenya. The Tharaka are organized in neighborhood-groups, clans, and age-sets. We quantified the influence of these three major social institutions on crop diversity patterns, for both crop species and sorghum landraces. General linear models were used to test the relations between crop species richness and each social factor, while the crop species and sorghum landraces compositions of cropping systems were compared separately through a between-class correspondence analysis. Crop species and sorghum landraces are not randomly distributed among farms, and neighborhood-groups constitute a significant factor organizing crop diversity at both specific and infraspecific levels. Adjacent neighborhood-groups present significantly different crop richness and composition. The results for species were consistent with those obtained for sorghum landraces, confirming that crop diversity was socially structured. The influence of social organization on seed networks and selection processes is discussed.     

葡萄浆果发育期果皮、果肉和叶中內源激素含量的变化

为探讨葡萄浆果发育期间叶、果肉和果皮中内源激素的变化规律,以"巨峰"、"98-2"、"京亚"和"洛浦早生"为试材,采用酶联免疫吸附分析法(ELISA)测定了葡萄叶、果肉和果皮中IAA、GA3、ZR、ABA含量的变化。结果表明:4个葡萄品种在果实发育期叶中IAA、GA3、ZR、ABA的含量的变化差异较大;果肉IAA、GA3、ZR、ABA的含量变化趋势相似,都是一个单峰曲线,在花后30 d或40 d即果实缓慢生长期开始前后达到高峰,峰值的出现时期与成熟期的早晚无关;果皮中IAA、GA3、ZR的含量变化趋势相似,都有一明显的峰值,峰值的出现时期与果实发育期长短有关;果皮中ABA在果实发育的后期含量很高,但果实发育期长短不同高含量ABA所持续的时间不同。果皮中激素的变化与果实发育期长短比果肉中激素的变化与果实发育期长短的关系更密切。