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1.
Japanese knotweed s.l. comprises Fallopia japonica, F. sachalinensis, F. × bohemica and any F2s or backcrosses. The parental taxa were introduced from the East to the West as garden ornamentals in the nineteenth century, and soon spread beyond the confines of the garden to become widespread and persistent weeds. Since only female F. japonica var. japonica was introduced, its impressive spread has occurred solely by vegetative means. However, the initial lack of genetic variability has been complemented by an extensive series of hybridisations in the adventive range. We examine the history, spread, reproductive biology and ecological impact of these species in the West. The role and importance of polyploidy and hybridisation in their invasion of the West is discussed, as are the implications of these factors for the potential further evolution of the group.  相似文献   
2.
Antibiotic resistance genes can act as either cell autonomous or non-cell autonomous genetic markers with which to monitor the excision of plant transposons. To convert spectinomycin resistance from a noncell autonomous resistance to cell autonomous resistance, a transit peptide for chloroplast localization from a petunia ribulose bisphosphate carboxylase (rbcS) gene was fused in-frame to the aadA gene, which confers spectinomycin and streptomycin resistance. Constructs were generated in which the expression of this chimeric gene was prevented by the presence, in the 5 untranslated leader, of the maize transposons Activator (Ac) or Dissociation (Ds). When progeny of tobacco or tomato plants transformed with these constructs were germinated on spectinomycin-containing medium, germinally revertant and somatically variegated individuals could be distinguished.  相似文献   
3.

Background

Persons with unsuppressed HIV viral load (VL) who disengage from care may experience poor clinical outcomes and potentially transmit HIV. We assessed the feasibility and yield of using the San Francisco Department of Public Health (SFDPH) enhanced HIV surveillance system (eHARS) to identify and re-engage such persons in care.

Methods

Using SFDPH eHARS data as of 4/20/2012 (index date), we selected HIV-infected adults who were alive, had no reported VL or CD4 cell count results in the past nine months (proxy for “out-of-care”) and a VL >200 copies/mL drawn nine to 15 months earlier. We prioritized cases residing locally for investigation, and used information from eHARS and medical and public health databases to contact them for interview and referral to the SFDPH linkage services (LINCS). Twelve months later, we matched-back to eHARS data to assess how HIV laboratory reporting delays affected original eligibility, and if persons had any HIV laboratory results performed and reported within 12 months after index date (‘new labs’).

Results

Among 434 eligible persons, 282 were prioritized for investigation, of whom 75 (27%) were interviewed, 79 (28%) could not be located, and 48 (17%) were located out of the area. Among the interviewed, 54 (72%) persons accepted referral to LINCS. Upon match-back to eHARS data, 324 (75%) in total were confirmed as eligible, including 221 (78%) of the investigated; most had new labs.

Conclusions

Among the investigated persons presumed out-of-care, we interviewed and offered LINCS referral to about one-quarter, demonstrating the feasibility but limited yield of our project. Matching to updated surveillance data revealed that a substantial minority did not disengage from care and that most re-engaged in HIV care. Verifying persons’ HIV care status with medical providers and improving timeliness of transfer and cross-jurisdictional sharing of HIV laboratory data may aid future efforts.  相似文献   
4.
Lock JE 《Biology letters》2012,8(3):408-411
Parental effects on offspring life-history traits are common and increasingly well-studied. However, the extent to which these effects persist into offspring in subsequent generations has received less attention. In this experiment, maternal and paternal effects on offspring and grand-offspring were investigated in the biparental burying beetle Nicrophorus vespilloides, using a split-family design. This allowed the separation of prenatal and postnatal transgenerational effects. Grandparent and parent gender were found to have a cumulative effect on offspring development and may provide a selection pressure on the division of parental investment in biparental species.  相似文献   
5.
Developmental processes are closely connected to certain states of epigenetic information which, among others, rely on methylation of chromatin. S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are key cofactors of enzymes catalyzing DNA and histone methylation. To study the consequences of altered SAH/SAM levels on plant development we applied 9-(S)-(2,3-dihydroxypropyl)-adenine (DHPA), an inhibitor of SAH-hydrolase, on tobacco seeds during a short phase of germination period (6 days). The transient drug treatment induced: (1) dosage-dependent global DNA hypomethylation mitotically transmitted to adult plants; (2) pleiotropic developmental defects including decreased apical dominance, altered leaf and flower symmetry, flower whorl malformations and reduced fertility; (3) dramatic upregulation of floral organ identity genes NTDEF, NTGLO and NAG1 in leaves. We conclude that temporal SAH-hydrolase inhibition deregulated floral genes expression probably via chromatin methylation changes. The data further show that plants might be particularly sensitive to accurate setting of SAH/SAM levels during critical developmental periods.  相似文献   
6.
We compared the family distances of patients with autosomal recessive disorders with those of a random control group and a matched control group. Only in the great-grandparental generation were weak-significant differences found. We also found that the family distances of persons with an urban origin were significantly larger than those of persons with a rural origin. In our study, family distance seems to be a more powerful measure of hidden consanguinity than the parental distance.  相似文献   
7.
Literary scholars are generally suspicious of the concept of universals: there are presently no candidates for literary universals that a high proportion of literary scholars would accept as valid. This paper reports results from a content analysis of patterns of characterization in folktales from 48 culture areas, aimed at identifying patterns of characterization that apply across regions of the world and levels of cultural complexity. The search for these patterns was guided by evolutionary theory and the findings are consistent with previous research on patterns of altruism, sex differences in mate preferences, sex differences in reproductive strategy, and differing emphases on male and female physical attractiveness. World literature, especially originally oral literature, represents a vast and neglected repository of information that researchers can use to more precisely map the contours of human nature. Jonathan Gottschall received his Ph.D. in English from Binghamton University and now teaches at St. Lawrence University in Canton, New York. His research focuses on integrating Darwinian approaches to human behavior and psychology with literary studies. The other authors are undergraduate students at St. Lawrence University.  相似文献   
8.
    
Recent morphology-based investigations of freshwater Arctic diatoms suggest that many species remain to be discovered, reflecting a unique polar flora. During a survey of the freshwater diatom flora of northern Billefjorden, including the Petuniabukta fjord region (Spitsbergen), several morphodemes belonging to the Achnanthidium minutissimum species complex were recorded. Molecular phylogenies based on rbcL, 28S and 18S sequences, including single cells from Canada and strains from Marion Island (sub-Antarctica) and GenBank revealed the presence of 12 distinct A. minutissimum complex lineages, of which three contained strains from Spitsbergen. One Arctic lineage is described as a new species. Achnanthidium digitatum sp. nov. is morphologically characterized by narrow, linear to only slightly lanceolate valves and usually two areolae per stria. The two remaining Arctic lineages are in need of a more complete morphological and molecular comparison with other representatives of the A. minutissimum complex to clarify their taxonomic identity. It is argued that implementation of molecular data in the taxonomy of Achnanthidium will be essential to solve the taxonomic problems associated with this group, eventually resulting in a better understanding of the biogeography and niche differentiation of different species belonging to the A. minutissimum complex. Ideally, this should be based on more variable genes than the currently widely used 18S, which does not have a species level resolution in the A. minutissimum complex.  相似文献   
9.
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10.
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