On the Equivalence of Geometric and Analytic K-Homology

We give a proof that the geometric K-homology theory for finite CW-complexes defined by Baum and Douglas is isomorphic to Kasparov's K-homology. The proof is a simplification of more elaborate arguments which deal with the geometric formulation of equivariant K-homology theory.Comment: 29 pages, v4: corrected definition of E in proof of Prop 3.

Dynamic Time-Dependent Route Planning in Road Networks with User Preferences

There has been tremendous progress in algorithmic methods for computing driving directions on road networks. Most of that work focuses on time-independent route planning, where it is assumed that the cost on each arc is constant per query. In practice, the current traffic situation significantly influences the travel time on large parts of the road network, and it changes over the day. One can distinguish between traffic congestion that can be predicted using historical traffic data, and congestion due to unpredictable events, e.g., accidents. In this work, we study the \emph{dynamic and time-dependent} route planning problem, which takes both prediction (based on historical data) and live traffic into account. To this end, we propose a practical algorithm that, while robust to user preferences, is able to integrate global changes of the time-dependent metric~(e.g., due to traffic updates or user restrictions) faster than previous approaches, while allowing subsequent queries that enable interactive applications

International Perspectives on Women and Work in Hotels, Catering and Tourism

[Excerpt] Hotels, catering and tourism (HCT) is a large and fast-growing service sector, with an average female participation of 55.5 per cent at global level and up to 70 per cent at regional level. They are employed in a wide variety of roles, including as cleaners and kitchen staff, front-line customer service workers and senior management. The recruitment, retention and promotion of talented women for technical and managerial leadership positions will be necessary to meet the future skills and productivity requirements of the sector. Moreover, women will comprise an even larger proportion of the sector‟s client base as more will travel for business and leisure. This too will have an impact on gender equality in the recruitment of employees. This working paper highlights the structural and cultural issues which determine the roles that women play within the HCT workforce and the strategies which can make a difference to their status and opportunities within the industry. Some of these issues relate to occupational sex segregation, wage parity, career opportunities, the role of women within micro-enterprises and the informal hotel/catering/tourism economy. The links between equality of opportunity and treatment for women and men in quality jobs, workforce development, training opportunities and employment in the sector have been explored to a certain degree at national or local levels. However, there is less information regarding gender equality provisions and major international companies in global and regional contexts. The findings of this study point to issues of importance for employment of women as a basis for future dialogue. They also highlight important innovations, good practices and interesting case studies in support of future human resources planning for governments, employers‟ and workers‟ organizations

Upper bounds for the first eigenvalue of the Dirac operator on surfaces

In this paper we will prove new extrinsic upper bounds for the eigenvalues of the Dirac operator on an isometrically immersed surface $M^2 \hookrightarrow {\Bbb R}^3$ as well as intrinsic bounds for 2-dimensional compact manifolds of genus zero and genus one. Moreover, we compare the different estimates of the eigenvalue of the Dirac operator for special families of metrics.Comment: Latex2.09, 23 page

The plant‐parasitic cyst nematode effector GLAND4 is a DNA‐binding protein

Cyst nematodes are plant pathogens that infect a wide range of economically important crops. One parasitic mechanism employed by cyst nematodes is the production and in planta delivery of effector proteins to modify plant cells and suppress defenses to favor parasitism. This study focused on GLAND4, an effector of Heterodera glycines and H. schachtii, the soybean and sugar beet cyst nematodes, respectively. We showed that GLAND4 is recognized by the plant cellular machinery and is transported to the plant nucleus, an organelle where little is known about plant nematode effector functions. We showed that GLAND4 has DNA-binding ability and repressed reporter gene expression in a plant transcriptional assay. One DNA-fragment that bound to GLAND4 was localized in an Arabidopsis chromosomal region associated with the promoters of two lipid transfer protein (LTP) genes. These LTPs have known defense functions and are downregulated in the nematode feeding site. When expressed in Arabidopsis, the presence of GLAND4 caused downregulation of the two LTP genes in question, which was associated also with increased susceptibility to the plant-pathogenic bacterium Pseudomonas syringae. Furthermore, overexpression of one of the LTP genes reduced plant susceptibility to H. schachtii and P. syringae, confirming that LTP repression likely suppresses plant defenses. This study made GLAND4 one of a small subset of characterized plant nematode nuclear effectors and identified GLAND4 as the first DNA-binding plantparasitic nematode effector

Susceptibility to the Sugar Beet Cyst Nematode Is Modulated by Ethylene Signal Transduction in Arabidopsis thaliana

Previously, we identified Arabidopsis thaliana mutant rhd1-4 as hypersusceptible to the sugar beet cyst nematode Heterodera schachtii. We assessed rhd1-4 as well as two other rhd1 alleles and found that each exhibited, in addition to H. schachtii hypersusceptibility, decreased root length, increased root hair length and density, and deformation of the root epidermal cells compared with wild-type A. thaliana ecotype Columbia (Col-0). Treatment of rhd1-4 and Col-0 with the ethylene inhibitors 2-aminoeth-oxyvinylglycine and silver nitrate and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid suggests that the rhd1-4 hypersusceptibility and root morphology phenotypes are the result of an increased ethylene response. Assessment of known ethylene mutants further support the finding that ethylene plays a role in mediating A. thaliana susceptibility to H. schachtiibecause mutants that overproduce ethylene (eto1-1, eto2, and eto3) are hypersusceptible to H. schachtii and mutants that are ethylene-insensitive (etr1-1, ein2-1, ein3-1, eir1-1, and axr2) are less susceptible to H. schachtii. Because the ethylene mutants tested show altered susceptibility and altered root hair density and length, a discrimination between the effects of altered ethylene signal transduction and root hair density on susceptibility was accomplished by analyzing the ttg and gl2 mutants, which produce ectopic root hairs that result in greatly increased root hair densities while maintaining normal ethylene signal transduction. The observed normal susceptibilities to H. schachtii of ttg and gl2 indicate that increased root hair density, per se, does not cause hypersusceptibility. Furthermore, the results of nematode attraction assays suggest that the hypersusceptibility of rhd1-4and the ethylene-overproducing mutant eto3 may be the result of increased attraction of H. schachtii-infective juveniles to root exudates of these plants. Our findings indicate that rhd1 is altered in its ethylene response and that ethylene signal transduction positively influences plant susceptibility to cyst nematodes

Sequence and Spatiotemporal Expression Analysis of CLE-Motif Containing Genes from the Reniform Nematode (Rotylenchulus reniformis Linford & Oliveira)

The reniform nematode, Rotylenchulus reniformis, is a sedentary semi-endoparasitic species with a host range that encompasses more than 77 plant families. Nematode effector proteins containing plant-ligand motifs similar to CLAVATA3/ESR (CLE) peptides have been identified in the Heterodera, Globodera, and Meloidogyne genera of sedentary endoparasites. Here, we describe the isolation, sequence analysis, and spatiotemporal expression of three R. reniformis genes encoding putative CLE motifs named Rr-cle-1, Rr-cle-2, and Rr-cle-3. The Rr-cle cDNAs showed .98% identity with each other and the predicted peptides were identical with the exception of a short stretch of residues at the carboxy(C)-terminus of the variable domain (VD). Each RrCLE peptide possessed an amino-terminal signal peptide for secretion and a single C-terminal CLE motif that was most similar to Heterodera CLE motifs. Aligning the Rr-cle cDNAs with their corresponding genomic sequences showed three exons with an intron separating the signal peptide from the VD and a second intron separating the VD from the CLE motif. An alignment of the RrCLE1 peptide with Heterodera glycines and Heterodera schachtii CLE proteins revealed a high level of homology within the VD region associated with regulating in planta trafficking of the processed CLE peptide. Quantitative RT-PCR (qRT-PCR) showed similar expression profiles for each Rr-cle transcript across the R. reniformis life-cycle with the greatest transcript abundance being in sedentary parasitic female nematodes. In situ hybridization showed specific Rr-cle expression within the dorsal esophageal gland cell of sedentary parasitic females

Finite group extensions and the Baum-Connes conjecture

In this note, we exhibit a method to prove the Baum-Connes conjecture (with coefficients) for extensions with finite quotients of certain groups which already satisfy the Baum-Connes conjecture. Interesting examples to which this method applies are torsion-free finite extensions of the pure braid groups, e.g. the full braid groups, or certain fundamental groups of complements of links in S^3.Comment: AMS-Latex, logical structure clarified, final version, to appear in Geometry and Topolog