桥弯藻科和异极藻科（硅藻门）植物中国7种新记录

对采自黑龙江省东南部兴凯湖湿地的100余号硅藻标本进行分类研究,共发现桥弯藻科、异极藻科（硅藻门）中国新记录植物5种2变种,分别为亚粗糙桥弯藻（Cymbella peraspera Krammer）、尖头弯肋藻［Cymbopleura cuspidata (Kützing) Krammer］、不显内丝藻高山变种（Encyonema obscurum var.alpina Krammer）、西里西亚内丝藻翼形变种（Encyonema silesiacum var.lata Krammer）、耳状异极藻（Gomphonema auritum Braun & Kützing）、棍棒异极藻（Gomphonema clava Reichardt）、极细异极藻［Gomphonema exilissimum (Grunow) Lange-Bertalot & Reichardt］。对其分类学特征进行了详细的描述,与同属中相似的种类进行了比较与讨论,为今后该区域的藻类研究提供了基础的资料。     

Three-Dimensional Trabecular Alignment Model

The Shear-slip Mesh Update Method (SSMUM) is being used in flow simulations involving large but regular displacements of one or more boundaries of the computational domain. We follow up the earlier discussion of the method with notes on practical implementation aspects. In order to establish a benchmark problem for this class of flow problems, we define and report results from a two-dimensional viscous flow around a rotating stirrer in a square chamber. The application potential of the method is demonstrated in the context of biomedical design problem, as we perform an analysis of blood flow in a centrifugal left ventricular assist device, or blood pump, which involves a rotating impeller in a non-axisymmetric housing.     

Mitochondrial and nuclear markers support the monophyly of Dolichopodidae and suggest a rapid origin of the subfamilies (Diptera: Empidoidea)

Abstract. The Dolichopodidae is a species‐rich dipteran group with almost 7000 described species. The monophyly of the subfamilies and their relationships remain largely unknown because the polarities of key morphological characters are unclear and molecular data are available only for 9 of the 19 proposed subfamilies. Here we test whether molecular data from two nuclear (18S, 28S) and four mitochondrial (12S, 16S, Cytb, COI) genes can resolve the higher‐level relationships within the family. Our study is based on 76 Oriental species from 12 dolichopodid subfamilies and uses eight species of Empididae and Hybotidae as outgroups. Parsimony and likelihood analyses confirm the monophyly of the Dolichopodidae, as well as the monophyly of five of the ten subfamilies represented by more than two species [Sympycninae, Sciapodinae, Dolichopodinae, Hydrophorinae (excluding tribe Aphrosylini), Neurigoninae]. There is strong support for restoring the tribe Aphrosylini as a separate subfamily Aphrosylinae. The monophyly of Medeterinae, Peloropeodinae and Diaphorinae is dependent on which tree reconstruction technique is used, how indels are coded, and whether the fast‐evolving sites are excluded. Overall, we find that our sample of Oriental species is largely compatible with the subfamily concepts that were developed for the northern temperate fauna. However, our data provide little support for relationships between the subfamilies. Branch lengths, saturation, and distance plots suggest that this is probably the result of the rapid origin of dolichopodid subfamilies over a relatively short time. We find that genera that are difficult to place into subfamilies based on morphological characters are generally also difficult to place using molecular data. We predict that a dense, balanced taxon sample and protein‐encoding nuclear genes will be needed to resolve the higher‐level relationships in the Dolichopodidae.     

Detarieae sensu lato (Fabaceae) from the Late Oligocene (27.23 Ma) Guang River flora of north‐western Ethiopia

New species of caesalpinioid legumes, Cynometra sensu lato and Afzelia, are described from the Late Oligocene (27.23 Ma) Guang River flora in north‐western Ethiopia. Both taxa show leaf characteristics that are shared with extant species in the Guineo‐Congolian, Sudanian and/or Zambezian regions of Africa today. The presence of these two species in Ethiopia during the Palaeogene provides further evidence of the importance of the legume tribe Detarieae in northern and north‐eastern Africa throughout much of the Cenozoic, even although the clade is poorly represented in these regions today. The fossil record documents a significant palaeogeographical and evolutionary history of Detarieae in Africa, especially compared with that of Europe and Anatolia. Based on this evidence, it is unlikely that significant diversification of extant African Detarieae took place on the Eurasian landmass. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 44–54.     

FOOD-INDUCED BODY PIGMENTATION QUESTIONS THE TAXONOMIC VALUE OF COLOUR IN THE SELF-FERTILIZING SLUG CARINARION SPP

Body pigmentation is a popular taxonomic marker in slugs to discriminateclosely related species. However, the genetic background ofbody pigmentation is known only for a few species, while inmany others body pigmentation is influenced by age, food and/orclimate. In this study, we investigated the effects of differentfood items on body pigmentation expression in two selfing pulmonategastropods, Arion (Carinarion) silvaticus and Arion (Carinarion) fasciatus.Both species mainly differ in the distribution of yellow-orangegranules on the body, which in A. fasciatus are concentratedin lateral bands, and in A. silvaticus are evenly scattered.Animals were raised individually under the same conditions, whilethey laid eggs as a consequence of selfing. This F₁ generation wasafterwards divided into two groups, which were fed with different fooditems. A diet of carrot, lettuce or paper had no effect on the distributionof the yellow-orange granules in A. silvaticus, but provokeda loss of the yellow-orange lateral bands in A. fasciatusso that externally these F₁ specimens became similar to A. silvaticus.In both species, a diet of nettle resulted in a strong yellow-orangepigmentation, which often formed yellow-orange lateral bands.These results indicate that food can probably influence the'species-specific' body pigmentation in Carinarion, and thusquestion the reliability of colour traits to distinguish A.silvaticus and A. fasciatus. (Received 5 May 2000; accepted 29 September 2000)     

A Three-Dimensional Finite Element Analysis of Heat Transfer in the Forearm

The finite element method was used to analyze heat transfer within a section of the forearm while exposed to different ambient conditions and with different metabolic states. The three-dimensional model accounts for the different material properties of bone, muscle and blood and incorporates a single artery-vein pair for counter-current heat exchange. The geometry of the model was developed from anatomical cross-sectional images of the forearm. The model was used to determine the effects or rest vs. exercise, free vs. forced surface convection and 0 degrees C vs. -20 degrees C external temperatures. The results of the model were compared to experimental data and the model exhibits qualitatively correct behaviour. This model can be used to study hyperthermia, burns and cryogenic freezing of tissue.     

The relationship between sea surface temperature and population change of Great Cormorants Phalacrocorax carbo breeding near Disko Bay,Greenland

Arctic seas have warmed and sea ice has retreated. This has resulted in range contraction and population declines in some species, but it could potentially be a boon for others. Great Cormorants Phalacrocorax carbo have a partially wettable plumage and seem poorly suited to foraging in Arctic waters. We show that rates of population change of Cormorant colonies around Disko Bay, Greenland, are positively correlated with sea surface temperature, suggesting that they may benefit from a warming Arctic. However, although Cormorant populations may increase in response to Arctic warming, the extent of expansion of their winter range may ultimately be limited by other factors, such as sensory constraints on foraging behaviour during long Arctic nights.     

Fine-structural Alterations in Leishmania tropica within Human Macrophages Exposed to Antileishmanial Drugs in Vitro1

The mechanism of action of antileishmanial compounds is poorly understood. Ultrastructural changes in Leishmania tropica within human macrophages exposed in vitro to Pentostam, pentamidine, amphotericin B, WR 6026, ketoconazole, and Formycin B were examined in these experiments. In Pentostam-treated cultures, some organisms exhibited diminished definition of mitochondrial and other membranes, while other organisms had completely disintegrated. Pentostam-exposed macrophages demonstrated loss of membrane definition in the absence of further alterations; it is therefore hypothesized that impaired macrophage membrane function may contribute towards the effect of this drug against macrophage-contained organisms. Leishmania parasites in pentamidine-treated cultures initially demonstrated swollen kinetoplasts and fragmentation of the kinetoplast DNA core. The initial observed effect of the other four drugs on the parasites was cytoplasmic condensation. These ultrastructural studies suggest that all five non-antimonial drugs may have different mechanisms of action than antimony (Pentostam) against Leishmania.     

Individual‐level differences in generalist caterpillar responses to a plant–plant cue

1. Plant–plant communication has been found to affect interactions between herbivores and plants in several model systems. In these systems, herbivore‐induced volatile chemical cues are emitted and perceived by other plants (receivers), which subsequently change their defensive phenotypes. Most studies have focused on how the effects of volatile cues affect plant damage, whereas herbivore performance has rarely been examined. 2. In this study, it is shown that plant–plant communication between willows reduced the growth rate, feeding rate, and conversion efficiency of some individuals but not others of a generalist caterpillar, Orgyia vetusta. 3. Using a paired, no‐choice trial design, there was substantial variation between caterpillar individuals in their response to willows that had been induced with a volatile plant–plant cue. This variation was explained by feeding parameters of the individual herbivores. Individuals behaved similarly when fed induced and non‐induced willow leaves. Specifically, growth rates of caterpillars that grew rapidly on non‐induced willow leaves were negatively affected by plant–plant cues, but growth rates of caterpillars that grew slowly on non‐induced willow leaves were not affected by the responses to volatiles from neighbouring willows. 4. Induction by volatile plant–plant cues reduced the growth rates of those individual herbivores that caused the greatest damage to willow, but had little effect on weak growers.