Survey of Helminth Parasites in Populations of <Emphasis Type="Italic">Alouatta palliata mexicana</Emphasis> and <Emphasis Type="Italic">A. pigra</Emphasis> in Continuous and in Fragmented Habitat in Southern Mexico

The 2 howler species that occur in southern Mexico, Alouatta palliata mexicana and Alouatta pigra are endangered, mainly as a result of habitat loss and fragmentation from human activity. Little is known about the gastrointestinal parasite communities affecting their populations, and lack of baseline information for populations of howler species in continuous forest habitats, makes evaluations of gastrointestinal parasite prevalence in populations in fragmented landscapes difficult. We report the results of a one-time broad survey of gastrointestinal parasites in fecal samples of individuals from several demographically stable populations of Alouatta palliata mexicana and A. pigra existing in continuous and/or protected forests. We further report similar data for populations of both species in human-fragmented landscapes. We detected 6 parasites for each howler monkey species, but only 3 of them (Trematode I, Controrchis biliophilus, Trypanoxyuris sp.) were common to both species. While parasitic prevalence in populations of both howler species was, in general, higher in the fragmented habitat than in continuous and/or protected forests. The difference is only marginally significant in Alouatta pigra. Some parasites (Coccidia and Strongylid) only appeared in populations in fragmented landscapes. Preliminary data suggest that adult males tended to have higher parasite prevalence values than those of adult females in both howler species. Parasite prevalence is associated to average group size, but not to population density in Alouatta pigra.     

Manufacture of IRDye800CW-coupled Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles and their applications in cell labeling and <Emphasis Type="Italic">in vivo</Emphasis> imaging

Background  

In recent years, near-infrared fluorescence (NIRF)-labeled iron nanoparticles have been synthesized and applied in a number of applications, including the labeling of human cells for monitoring the engraftment process, imaging tumors, sensoring the in vivo molecular environment surrounding nanoparticles and tracing their in vivo biodistribution. These studies demonstrate that NIRF-labeled iron nanoparticles provide an efficient probe for cell labeling. Furthermore, the in vivo imaging studies show excellent performance of the NIR fluorophores. However, there is a limited selection of NIRF-labeled iron nanoparticles with an optimal wavelength for imaging around 800 nm, where tissue autofluorescence is minimal. Therefore, it is necessary to develop additional alternative NIRF-labeled iron nanoparticles for application in this area.     

Dissociation and Reassociation of RTF and r-Determinants of the R-factor <Emphasis Type="Italic">NR1</Emphasis> in <Emphasis Type="Italic">Proteus mirabilis</Emphasis>

A model is proposed for the regulation of the number of copies of drug resistance genes per host cell by their dissociation and reassociation with transfer factors.     

Vocal Diversity and Taxonomy of <Emphasis Type="Italic">Nomascus</Emphasis> in Central Vietnam and Southern Laos

Previous researchers suggested that gibbon song repertoire is genetically determined and song characteristics are useful for assessing systematic relationships. The southern white-cheeked crested gibbon is regarded as either a subspecies of Nomascus leucogenys or its own species (Nomascus siki). I studied vocal diversity among different wild populations of Nomascus in central Vietnam and southern Laos to assess their taxonomic relationships and to examine whether their vocal patterns correspond to forms previously described for Nomascus siki. I examined the songs of 7 Nomascus populations in Vietnam and Laos. I analyzed 192 song bouts from different gibbon groups including 173 phrases of 42 females and 192 phrases of 42 males. Linear discriminant analysis, classification trees, and multidimensional scaling revealed marked separation of groups in the northern and southern populations. Within the 2 geographic populations, there is little variability and the vocal characteristics exhibited no apparent cline. I conclude that the northern and southern geographic populations may represent 2 distinct taxa. I postulate that a taxonal boundary such as large rivers existing between southern Quang Binh province and northern Thua-Thien Hue province in Vietnam and northern Phou Xang He NBCA and southern Dong Phou Vieng NBCA in Laos has limited gene flow between the populations. Differing topographic features could also serve as a selective force for improved sound transmission in a highly territorial species, driving the divergence between the 2 populations.     

MitoK<Subscript>ATP</Subscript> activity in healthy and ischemic hearts

In addition to their role in energy transduction, mitochondria play important non-canonical roles in cell pathophysiology, several of which utilize the mitochondrial ATP-sensitive K⁺ channel (mitoK_ATP). In the normal heart, mitoK_ATP regulates energy transfer through its regulation of intermembrane space volume and is accordingly essential for the inotropic response during periods of high workload. In the ischemic heart, mitoK_ATP is the point of convergence of protective signaling pathways and mediates inhibition of the mitochondrial permeability transition, and thus necrosis. In this review, we outline the experimental evidence that support these roles for mitoK_ATP in health and disease, as well as our hypothesis for the mechanism by which complex cardioprotective signals that originate at plasma membrane receptors traverse the cytosol to reach mitochondria and activate mitoK_ATP.     

杨品种‘普瑞’和‘107’对模拟酸雨胁迫的生理响应

通过测定杨(Populus×euramericana)抗硫新品种‘普瑞’和‘107’在3种梯度酸雨胁迫下的各项生理指标,研究酸雨胁迫对2个杨品种影响的差异。结果显示,在酸雨胁迫下,‘普瑞’叶片受伤害程度明显轻于‘107’,可以维持较稳定的光合作用,显示出较强的抗酸雨胁迫能力。酸雨胁迫下,‘107’光合作用强度显著下降,非气孔因素是其下降的主要原因。酸雨在一定程度上破坏了2个杨品种的水分平衡,尤其对‘107’的影响程度更为明显,但气孔关闭不是引起其光合作用强度下降的主要原因。研究结果表明杨品种‘普瑞’在酸雨环境下具有更强耐受性。     

Biomass accumulations and the distribution of nitrogen and phosphorus within three<Emphasis Type="Italic">Quercus acutissima</Emphasis> stands in central Korea

Above- and belowground biomass and nitrogen (N) and phosphorus (P) distribution within threeQuercus acutissima stands were investigated in central Korea. The average age (year) and diameter at breast height (DBH, cm) were 10.8 and 7.9 for Stand 1, 38.2 and 17.1 for Stand 2, and 44.0 and 20.7 for Stand 3, respectively. Fifteen trees were destructively harvested for dimension analysis of component biomass (stem wood, stem bark, foliage, branches, and roots) plus N and P concentrations. Total biomass (t ha^-1) was 88.7 for Stand 1, 154.9 for Stand 2, and 278.1 for Stand 3 while N and P contents in all tree components (kg ha^-1) were 483.3 and 52.2, 697.1 and 55.0, and 1113.9 and 83.7. Nitrogen concentrations were highest in the foliage, followed by the stem bark, branches or roots, and stem wood. In contrast, P concentrations were greatest in the roots, then foliage, branches, stem bark, and stem wood. In general, N and P concentrations in these components significantly decreased with tree age and DBH, while N and P contents significantly increased with age and size. These relationships were stronger for size than for age. Our current data could be utilized to estimate N and P budgets for silvicultural practices, including fertilization, thinning, and harvesting.     

Effect of environment and shoot architecture on floral transition and gene expression in <Emphasis Type="Italic">Eucalyptus occidentalis</Emphasis> and <Emphasis Type="Italic">Metrosideros excelsa</Emphasis>

Metrosideros excelsa and Eucalyptus occidentalis exhibit different strategies prior to flowering—the former passes through a long juvenile phase and must acquire a degree of architectural complexity to flower, whereas the latter flowers precociously even on stems still exhibiting juvenile foliage. As expediting flowering is of interest to breeders and horticulturalists alike we compared these species by growing plants with two branch architecture treatments in factorial combination with two growth environments. Plants were either allowed to branch freely or constrained to a single stem before subsequently being allowed to branch; one environment was inductive for flowering and the other not. Three meristem identity genes (the equivalents of LEAFY, APETALA1 and TERMINAL FLOWER1) were used as indicators of flowering. Constraining E. occidentalis plants to a single stem delayed the onset of the main flush of flowering in contrast to M. excelsa, although in both species a complex interaction between branching and environment occurred. We show that the complexity of the architecture can impact on production of flowers and can be used to expedite or enhance flowering for breeding purposes, but this is dependent on the species. AP1 appears to be a useful marker not just for floral organ differentiation but also as an indicator of floral induction having occurred.     

Distribution of <Emphasis Type="Italic">Doronicum clusii</Emphasis> and <Emphasis Type="Italic">D. stiriacum</Emphasis> (Asteraceae) in the Alps and Carpathians

In the course of a taxonomic revision of the Doronicum clusii agg. (Asteraceae), we present an updated and commented distribution map of D. clusii (All.) Tausch and D. stiriacum (Vill.) Dalla Torre from the Alps and Carpathians, completed with information on biogeography and taxonomy. We show that D. stiriacum was erroneously indicated for the Carpathians south and southeast of the Rodna Mountains in Romania and for the Western Alps. In the Western Carpathians, it has only been rarely mentioned for the Nízke Tatry (Lower Tatras) and the Belianske Tatry (Belá Tatras) in Slovakia.     

Comparison of in vivo and in vitro inactivation of endospores of <Emphasis Type="Italic">Rhinosporidium seeberi</Emphasis> following dapsone treatment

Rhinosporidiosis in humans and animals, caused by Rhinosporidium seeberi, can now be termed an emerging infective disease worldwide. The pharmacokinetics of dapsone when used as an antimicrobial agent in patients with rhinosporidiosis was compared with its pharmacodynamics in the inactivation of purified rhinosporidial endospores in vitro. A marked discrepancy was noted between the in vitro inactivation, which commenced on day 1 and was a maximum at day 4, whereas earlier reports on the response of endospores in patients under dapsone therapy indicated that the degeneration and disappearance of the endospores was not observed for 18–36 weeks after therapy began. Reasons for this discrepancy that operate in vivo are postulated: (a) impermeability of the barriers of down-growths of squamous epithelium in which the endospore-containing rhinosporidial sporangia are embedded; (b) presence of a mucoid matrix in which the endospores exist within the sporangia. These explanations contribute to resolving the controversial problem of general correlations between in vitro and in vivo results from studies on the action of antimicrobial drugs.     

Regulation of Extracellular Chitinases and Proteases in the Entomopathogen and Acaricide <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis>

Metarhizium anisopliae infects insects and ticks via a combination of specialized structures and cuticle degradation. Hydrolytic enzymes are accepted as key factors for the penetration step. The search for pathogenicity determinants has demonstrated that the process is multifactorial. Host specificity is an important factor to be addressed. The study of the enzymes produced during infection is important to discover those with a role in the process. To address some of the enzymes that take part during the infection of the tick, Boophilus microplus, we have analyzed the secretion of proteases and chitinases in single and combined carbon/nitrogen sources as compared with such complex substrates as chitin and B. microplus cuticles. Two chitinases, endo- and N-acetylglucosaminidases, and two proteases, subtilisin and trypsin-like proteases, were analyzed. Enzyme activities were detected in all carbon sources tested, but higher levels were found when combinations of carbon sources were used. A major 30-kDa protein apparently secreted during M. anisopliae growth on all carbon/nitrogen sources tested was demonstrated by SDS–PAGE. Received: 8 May 2002 / Accepted: 8 June 2002     

Zein accumulation in forage species (<Emphasis Type="Italic">Lotus corniculatus</Emphasis> and <Emphasis Type="Italic">Medicago sativa</Emphasis>) and co-expression of the γ-zein:KDEL and β-zein:KDEL polypeptides in tobacco leaf

Plants of birdsfoot trefoil (Lotus corniculatus), alfalfa (Medicago sativa) and tobacco (Nicotiana tabacum) were transformed by Agrobacterium with binary vectors harbouring genes that code either for wild-type and %-zein:KDEL, or for #-zein:KDEL. The maize seed storage proteins %-zein and #-zein are rich in sulphur amino acids, and our long-term goal is to improve alfalfa and birdsfoot trefoil forage quality. Significant levels of zeins were detected in leaves of birdsfoot trefoil transformants, ranging up to 0.055% and 0.30% of total extractable protein for %-zein and #-zein:KDEL, respectively. In leaves of alfalfa, the %-zein:KDEL expression level was up to 0.026% of the total extractable protein. From a F₁ population of transgenic tobacco, a plant was selected in which the amount of zeins (%-zein:KDEL plus #-zein:KDEL) accounted for 1.1% of the total extractable protein.     

Coordination complexes of 4-methylimidazole with Zn<Superscript>II</Superscript> and Cu<Superscript>II</Superscript> in gas phase and in water: a DFT study

A quantum chemistry study of mononuclear metal coordination with four 4-methylimidazole ligands (4-MeIm) was investigated. The four complexes [Cu(4-MeIm)₄]²⁺, [Cu(4-MeIm)₄, H₂O]²⁺, [Zn(4-MeIm)₄]²⁺ and [Zn(4-MeIm)₄, H₂O]²⁺ were studied with particular attention to the Nπ or Nτ possible coordinations of the 4-MeIm ring with the metals, using different DFT methods. The results suggest that the Nτ coordination of 4-MeIm ring to Zn^II or Cu^II is more favorable whatever the level of calculation. In contrast, the addition of one water molecule in the first coordination sphere of the metal ions provides five-coordinated complexes showing no Nπ or Nτ preferences. There is good agreement between the DFT-calculated structure and those available experimentally. When metal ions are four-fold coordinated, they adopt a tetrahedral geometry. When Cu^II and Zn^II are five-fold coordinated, highly symmetric structures or intermediate structures are calculated. Similar energies are calculated for different structures, suggesting flat potential energy surfaces. The addition of implicit solvent modifies the calculated first coordination sphere, especially for [Cu(4-MeIm)₄, H₂O]²⁺ structures. The QTAIM and ELF topological analyses of the interaction between Cu^II and the neutral ligands, clearly indicate a dative bonding with a strong ionic character.     

Morphological and Phylogenetic Resolution of <i>Diplodia neojuniperi</i> Emerging <i>Diplodia</i> Top Dieback of <i>Pinus thunbergii</i> Parl. in China

In Bazhong City, Sichuan Province, China, top dieback symptoms were found on many pine trees (Pinus thunbergii Parl). The tips of old needles first turned grayish-green and then developed into brown bands in the field. Phylogenetic analysis of concatenated ITS and EF1-α indicated the pathogen of this dieback disease as Diplodia neojuniperi. Additionally, effects of temperature, pH and medium on the mycelial growth were also characterized. The most favorable temperature and pH level for mycelial growth are 25°C and 8, respectively. The optimal medium for mycelial growth is PDA medium. To our knowledge, this is the first report of D. neojuniperi causes Diplodia top dieback on Pinus thunbergii. Our results provide fundamental information for monitoring and preventing such disease in the future.     

Relationship between Growth and Ageing in <Emphasis Type="Italic">Drosophila</Emphasis>

THERE are two principal groups of theories of ageing—those which hold that random cell damage is chiefly responsible for the events characteristic of ageing, which culminate in death and those which hold that ageing and death are genetically controlled. It is too soon to decide between these points of view and in any case Bullough¹ has shown that they are not mutually exclusive. So far experiments to test the random error theories of ageing, involving exposure of organisms to unnaturally large or even small amounts of agents such as X-rays and mutagenic agents (for reviews, see refs. 2 and 3), have been controversial and inconclusive.     

Variation in embolism occurrence and repair along the stem in drought‐stressed and re‐watered seedlings of a poplar clone

Root pressure and plasma membrane intrinsic protein (PIP) availability in the xylem have been recognized to participate in the refilling of embolized conduits, yet integration of the two mechanisms has not been reported in the same plant. In this study, 4‐month‐old seedlings of a hybrid poplar (Populus alba × Populus glandulosa) clone 84K were subjected to two contrasting soil‐water treatments, with the drought treatment involving withholding of water for 17 days to reduce the soil‐water content to 10% of the saturated field capacity, followed by a re‐watering cycle. The percentage loss of stem hydraulic conductance (PLC) sharply increased, and stomatal conductance and photosynthesis declined in response to drought stress; these processes were gradually restored following the subsequent re‐watering. Embolism was most severe in the middle portions of the stem, followed by the basal and top portions of the stems of seedlings subjected to drought stress and subsequent re‐watering. Although drought stress eliminated root pressure, re‐watering partially restored it in a short period of time. The expression of PIP genes in the xylem was activated by drought stress, and some PIP genes were further stimulated in the top portion after re‐watering. The dynamics of root pressure and differential expression of PIP genes along the stem coincided with changes in PLC, suggesting that root pressure and PIPs work together to refill the embolized vessels. On the basis of the recovery dynamics in PLC and g_smax (maximum stomatal conductance) after re‐watering, the stomatal closure and xylem cavitation exhibited fatigue due to drought stress.     

Conservation and divergence of ADAM family proteins in the <Emphasis Type="Italic">Xenopus</Emphasis> genome

Background  

Members of the disintegrin metalloproteinase (ADAM) family play important roles in cellular and developmental processes through their functions as proteases and/or binding partners for other proteins. The amphibian Xenopus has long been used as a model for early vertebrate development, but genome-wide analyses for large gene families were not possible until the recent completion of the X. tropicalis genome sequence and the availability of large scale expression sequence tag (EST) databases. In this study we carried out a systematic analysis of the X. tropicalis genome and uncovered several interesting features of ADAM genes in this species.