Age and growth of the estuarine dolphin (Sotalia guianensis) (Cetacea, Delphinidae) on the Paraná Coast, southern Brazil

Teeth of 71 estuarine dolphins (Sotalia guianensis) incidentally caught on the coast of Paraná State, southern Brazil, were used to estimate age. The oldest male and female dolphins were 29 and 30 years, respectively. The mean distance from the neonatal line to the end of the first growth layer group (GLG) was 622.4 ±19.1 μm (n=48). One or two accessory layers were observed between the neonatal line and the end of the first GLG. One of the accessory layers, which was not always present, was located at a mean of 248.9 ±32.6 μm (n=25) from the neonatal line, and its interpretation remains uncertain.The other layer, located at a mean of 419.6 ±44.6 μm (n=54) from the neonatal line, was always present and was first observed between 6.7 and 10.3 months of age. This accessory layer could be a record of weaning in this dolphin. Although no differences in age estimates were observed between teeth sectioned in the anterior-posterior and buccal-lingual planes, we recommend sectioning the teeth in the buccal-lingual plane in order to obtain on-center sections more easily. We also recommend not using teeth from the most anterior part of the mandibles for age estimation. The number of GLGs counted in those teeth was 50% less than the number of GLGs counted in the teeth from the median part of the mandible of the same animal. Although no significant difference (P>0.05) was found between the total lengths of adult male and female estuarine dolphins, we observed that males exhibited a second growth spurt around five years of age. This growth spurt would require that separate growth curves be calculated for the sexes. The asymptotic length (TL∞), k, and t0 obtained by the von Bertalanffy growth model were 177.3 cm, 0.66, and –1.23, respectively, for females and 159.6 cm, 2.02, and –0.38, respectively, for males up to five years, and 186.4 cm, 0.53 and –1.40, respectively, for males older than five years. The total weight (TW)/total length (TL) equations obtained for male and female estuarine dolphins were TW = 3.156 × 10−6 × TL 3.2836 (r=0.96), and TW = 8.974 × 10−5 × TL 2.6182 (r=0.95), respectively.

牡丹花芽分化类型与促成连续二次开花

牡丹（Paeonia suffruticosa Andr.），芍药科芍药属植物，是我国的传统名花，因花朵硕大、花色丰富、花型齐全而显雍容华贵、富丽端庄，“惟有牡丹真国色，花开时节动京城”，深受人民的喜爱。人们在欣赏牡丹的过程中，一方面为其艳丽多姿而赞叹，同时又为其自然花期较短且集中而遗憾，“弄花一年，看花十日”，因此，如何通过栽培等技术措施使牡丹连续开花，一直是牡丹研究者探索的重要课题。近年，在对牡丹栽培的系统研究中，发现不同牡丹品种的花芽分化类型（数量、梯度）直接影响其开花数量和开花次数。为了有效地利用不同类型的牡丹，选育出更多的丰花、同株可连续开花的品种，服务于牡丹的产业化生产，本试验对4个牡丹品种群的135个品种进行了同枝条芽数的统计分析及花芽分化梯度的划分，阐明了花芽分化类型与促成连续二次开花的关系。初步测定了具有促成连续二次开花习性的牡丹品种‘High Noon’不同芽位腋芽内源激素的含量，揭示了牡丹同株连续二次开花过程中不同芽位腋芽内源激素的生理变化规律，为解决牡丹同株花期短、不能同株连续开花的难题奠定了理论基础。本研究主要结果如下： 1、牡丹花芽分化类型与自然开花的关系 通过对135个牡丹品种花芽分化数量和梯度类型的调查，将同枝条的芽数聚类为少（3-4）、中等（5-7）、多（8-10）三类;将花芽分化梯度划分为小、中、大三种类型。芽数类型和花芽分化梯度类型均与品种群有一定的关系。中原品种群中90%的品种属于芽数少的类型，47%的品种属于分化梯度大的类型;日本品种群中73%的品种属于芽数中等的类型，52%的品种属于分化梯度中的类型;法国品种群和美国品种群品种调查数量较少，但大多数品种属于芽数中等的类型，分别占80%和44%，分化梯度小的品种分别占调查总数的40%和67%。绝大部分品种的腋花芽因在枝条上着生的位置不同而有明显的异质性，上部芽顶端优势强，萌动率和开花率均高，芽数多的品种中、下部芽在春天自然开花季节常处于休眠状态。 2、牡丹花芽分化类型与促成连续二次开花的关系 花芽分化数量的多少与梯度的大小直接影响着开花次数。花芽分化数量少、梯度大的品种不建议直接用于同株促成连续二次开花栽培;花芽分化数量中等或多、梯度小的品种可以实现同株促成连续二次开花，10个试验牡丹品种中的中原牡丹品种‘如花似玉（Ru Hua Si Yu）’和美国牡丹品种‘High Noon’具有同株连续二次开花能力，且二次开花率达75%以上，两次开花品质均优良。 3、‘High Noon’不同芽位腋芽内源激素与促成连续开花的关系 通过测定美国牡丹品种‘High Noon’同枝条不同芽位腋芽萌动前期、后期内源激素含量，结果表明：萌动后期不同芽位腋芽的GA3、IAA、ZRs含量增加，尤其1位芽、2位芽含量增加显著;萌动后期ABA含量则随着芽位自上而下增加显著，可能是导致下部芽继续保持休眠状态的主要原因;萌动后期下部芽的ABA/ZRs配比增幅较高，说明ABA/ZRs配比与芽的生长与休眠关系密切。

中国古牡丹资源调查及衰老相关研究

牡丹（Paeonia suffruticosa Andr.）是芍药科芍药属牡丹组植物，花大、色艳、型美、香郁、药用范围广、文化内涵丰富，被尊为“国色天香”、“花中之王”。我国植牡丹、赏牡丹有1600多年的历史，培育了许多价值高的品种，遗憾的是个别黄色、鲜红色、绿色等珍贵品种不断消失，而且现有的一些文化价值与观赏价值极高的古牡丹、著名的牡丹园的老牡丹均出现了衰弱现象，有的已奄奄一息。为了探索传统牡丹品种消失及牡丹衰老的原因，本研究在充分调查、整理国内品种资源的基础上，总结了牡丹品种的传承和消失情况，掌握了古牡丹的资源状况。通过连作土壤栽培试验证明了牡丹连作障碍的存在，并选定了生长在同一区域的5、10、15、20、25、30年生6个株龄的‘洛阳红（Luo Yang Hong）’为研究对象，从形态指标的调查、生理指标的测定、根际土壤及根系浸提液的化感成分分析三个方面着手，确定了牡丹开始衰老的时期;揭示了牡丹衰老机理;总结了古牡丹保留、复壮、养护办法;为牡丹专类园的管理及可持续性发展提供了理论和技术指导。本研究主要结果如下： 1、牡丹品种和古牡丹资源 通过对中国牡丹品种资源的文献查阅和实地考察，系统整理了我国不同时代的品种状况，调查结果表明：宋、元、明、清共有品种1109种，目前仅存143种，品种资源消失十分严重。收集整理了49处古牡丹资料，并据此绘制了我国目前古牡丹分布图;实地调查了17处24株古牡丹，详细介绍了部分品种的来历传说、生长状况和衰亡原因。5个优良传统品种在中国科学院植物研究所牡丹种质资源圃内得以保存，其中潞城古牡丹，植株最大（高2.3 m，冠径5.6 m），且生长旺盛;西溪牡丹属丰花品种，40年植株可开花811朵。 2、牡丹连作障碍 利用牡丹连作根际土壤及其浸出液栽培牡丹，结果表明，播种苗及分株苗的生长均受到了抑制;连作年限越久的处理抑制作用越强;根际土壤浸出液对牡丹生长的影响较大，对前期地下部和后期地上部都有很强的抑制作用，而且还抑制了上胚轴休眠的解除;根际土壤对后期株高和展叶幅的影响较大，对播种苗前期生根影响不大。牡丹存在连作障碍现象，连作障碍是牡丹衰弱的重要原因。 3、牡丹衰老时间及机理 通过对6 个株龄‘洛阳红’的形态、生理指标及根际土壤化感成分的比较得出，牡丹在同一地方大约栽植15 年后开始衰弱，20 年以内应该采取复壮措施。利用气相色谱—质谱联用技术（Gas Chromatograph-Mass Spectrometer, GC-MS）检测到根际土壤及根系浸提液中主要存在：烷烃、烯烃、芳香烃、醇、醚、酚醌、有机酸、醛、酮、酯、苯、胺等12 类有机物。对比分析得出有12 种物质可能是根系分泌物，根际土壤中可能具毒害作用的物质有40 种，栽植牡丹使土壤中增加的物质有24 种。 4、古牡丹复壮技术及应用 栽培基质中添加活性炭、沙子、麦饭石等均能有效的促进牡丹的生长，以活性炭的效果最好。对“汉牡丹”实施了综合复壮措施，效果明显。

Carbon nanotube based cathodes for microwave amplifiers

We have studied two different kinds of electron tubes using a cold field emission cathode as the electron source. This cathode is an array of vertically aligned multiwall carbon nanotubes. The first device is a triode. With this device, we demonstrated the modulation at 32 GHZ of a 1.4 A/cm2 peak current density with a 82% modulation ratio. The second device is a traveling wave tube. For this device, the objective is to test a cathode delivering a 2 A/cm 2 electron beam. ©2009 IEEE.

Natural 13C abundance as a tracer for studies of soil organic matter dynamics

A method for measuring the long- and medium-term turnover of soil organic matter is described. Its principle is based on the variations of 13C natural isotope abundance induced by the repeated cultivations of a plant with a high 13C/12C ratio (C4 photosynthetic pathway) on a soil which has never carried any such plant. The 13C/12C ratio in soil organic matter being about equal to the 13C/12C ratio of plant materials from which it is derived, changing the 13C content of the organic inputs to the soil (by altering vegetation from C3 type into C4 type) is equivalent to a true labelling in situ of the organic matter. Two cases of continuous corn cultivation (Zea mays: δ13C = −12%.) on soils whose initial organic matter average δ13C is −26%. were studied. The quantity of organic carbon originating from corn (that is the quantity which had turned-over since the beginning of continuous cultivation) was estimated using the 13C natural abundance data. After 13 yr, 22% of total organic carbon had turned-over, in the system studied. Particle size fractions coarser than 50μm on the one hand, and finer than 2μm on the other. contained the youngest organic matters. The turnover rate of silt-sized fractions was slower

Structural stability and electronic properties of Ba2MIrO6 (M = La, Y) by first principles

We investigate the structural stability and electronic properties of ordered perovskite-type compounds Ba2MIrO6 (M = La, Y) by use of density functional theory. Cubic (Fm-3m), rhombohedral (R-3) and monoclinic (P2(1)/n) phases are considered for each compound. It was found that the most energetically stable phase for Ba2YIrO6 and Ba2LaIrO6 is P2(1)/n andR-3, respectively. It is also interesting to find that Ba2YIrO6 in R-3 phase, which was not reported in experiment, has a slightly lower energy than experimentally observed cubic Fm-3m phase.

Demonstração de diferentes protocolos para implantação de parcelas permanentes em Floresta Ombrófila Mista.

2008

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: araçá.

2009

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: canela-branca.

2009

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: canela-guaicá.

2009

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: canela-imbuia.

2009

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: canjarana.

2009

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: caporoquinha.

2009

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: caroba.

2009

Monitoramento da fenologia de espécies arbóreas das florestas brasileiras: carvalho-brasileiro.

2009