PRESIDENTIAL ADDRESS: NOTHING SUCCEEDS LIKE EXCESS

To the members of the American Society of Parasitologists, I offer my appreciation for the opportunity to serve as your president. When I was notified of my successful election as an officer, it brought to mind that famous remark by Adlai Stevenson who said, ‘‘In America, anybody can be president. That’s one of the risks you take.’’ So, what I initially perceived as somewhat of a risky venture, proved to be a more valuable and interesting experience than I anticipated. Let’s hope that my presidential address has a similar outcome

Revised List of Type Specimens on Deposit in the University of California Davis Nematode Collection

The list of deposited type specimens is updated for the University of California Davis Nematode Collection, as recommended by the International Code of Zoological Nomenclature. The type collection includes 1,001 species and more than 11,000 individual specimens mounted on microscope slides. This list can be used as a reference to locate specimens but is not meant to clarify ambiguities that may exist concerning the type status of particular specimens

PHYLOGENETIC RELATIONSHIPS OF PALAEACANTHOCEPHALA (ACANTHOCEPHALA) INFERRED FROM SSU AND LSU rDNA GENE SEQUENCES

The Palaeacanthocephala is traditionally represented by 2 orders, Echinorhynchida and Polymorphida, with 10 and 3 families, respectively. To test the monophyly of the class, these 2 orders, and certain families, phylogenies were inferred using nuclear small-subunit (SSU) and large-subunit (LSU) ribosomal DNA sequences obtained for 29 species representing 10 families, 2 other classes of acanthocephalans, and 3 rotifer outgroups. Phylogenetic relationships were inferred by analyzing combined SSU and LSU sequences using maximum parsimony (MP) and maximum likelihood (ML) methods. Parsimony and ML trees inferred from combined analysis of these rDNA data strongly supported monophyly of Palaeacanthocephala and provided good resolution among species. Neither Polymorphida nor Echinorhynchida was monophyletic. Gorgorhynchoides bullocki (Echinorhynchida) was nested within the 6 species representing Polymorphida, and this clade was nested within species representing Echinorhynchida. Three of 4 palaeacanthocephalan families that could be evaluated were not monophyletic, and this finding was strongly supported. These results indicate that the family level classification of palaeacanthocephalans, which is mainly based on combinations of shared characters (not shared derived characters), needs to be reevaluated with respect to comprehensively sampled phylogenetic hypotheses

Spinoza on the Wise and the Free

This paper is a response to Sanem Soyarslan’s objections to my reading of Spinoza’s free person (homo liber). She argues that on my interpretation the free person, unlike the wise person (vir sapiens), while subject to passive affects, does not experience bondage to the passions; and so only the latter, but not the former, can serve as a viable “model of human nature.” I argue that, in fact, the free person and the wise person are, for Spinoza, one and the same indiviual, and thus constitute a single ideal model that we can more or less closely approximate

Acte et motivation dans la philosophie morale de Spinoza

Dans son œuvre maîtresse, l’Éthique, Spinoza a beaucoup à dire sur la vertu, la raison et le bonheur – en un mot, sur tous les grands thèmes de la philosophie morale. Il soutient également la thèse du caractère résolument égoïste de la motivation. Toute l’activité humaine dérive de l’effort de chacun pour persévérer dans son être et maximiser sa puissance. Cependant, même si Spinoza rejette l’évaluation morale de l’action en termes de « bien » ou de « mal », il croit en l’existence de critères normatifs permettant de juger les actions, selon qu’elles contribuent de fait à l’effort égoïste de l’agent. Toutefois, il ne s’ensuit pas que les motivations de l’agent jouent un quelconque rôle dans l’évaluation de l’action ou même dans celle de l’agent lui-même, principalement parce que tous les agents semblent avoir la même motivation fondamentale : leur propre intérêt. Dès lors, y a-t-il la moindre place, dans la philosophie de Spinoza, pour une discrimination entre des motivations plus ou moins « bonnes », ou pour leur prise en compte dans l’évaluation morale des actions ?In his philosophical masterpiece, the Ethics, Spinoza has much to say about virtue, reason, and happiness, all standard topics in moral philosophy. He is also committed to a thoroughgoing egoism when it comes to motivation. All human action derives from a striving to preserve one’s being and maximize one’s power. While Spinoza eschews moral evaluations of actions in terms of ‘right’ and ‘wrong’, he nonetheless believes that there are certain normative ways of assessing actions, according to the degree to which they do in fact contribute to the agent’s egoistic striving. However, it does not follow that an agent’s motives play any role in the assessment of the action, nor even in the assessment of the agent him/herself ‒ primarily because all agents would seem to have one and the same basic motive: self-interest. Still, is there any room in Spinoza’s thought for discriminating “better” or “worse” motives, and for taking these into account when assessing actions from a moral perspective

Description of \u3ci\u3eScottnema lindsayae\u3c/i\u3e Timm, 1971 (Rhabditida: Cephalobidae) from Taylor Valley, Antarctica and Its Phylogenetic Relationship

The endemic Antarctic nematode Scottnema lindsayae is described from specimens collected in Taylor Valley, McMurdo Dry Valleys, Victoria Land. The recently collected material is compared with the original description and other subsequent descriptions of the species. A more complete scanning electron microscopy (SEM) study of the species is presented. The phylogenetic position of S. lindsayae is inferred using a secondary structure-based alignment of a partial sequence of nuclear Large Subunit (LSU) ribosomal DNA. Phylogenetic trees were inferred using base-paired substitution models implemented in PHASE 2 software and Bayesian inference, and show S. lindsayae as the sister group to Stegelletina taxa

Description of \u3ci\u3eScottnema lindsayae\u3c/i\u3e Timm, 1971 (Rhabditida: Cephalobidae) from Taylor Valley, Antarctica and Its Phylogenetic Relationship

The endemic Antarctic nematode Scottnema lindsayae is described from specimens collected in Taylor Valley, McMurdo Dry Valleys, Victoria Land. The recently collected material is compared with the original description and other subsequent descriptions of the species. A more complete scanning electron microscopy (SEM) study of the species is presented. The phylogenetic position of S. lindsayae is inferred using a secondary structure-based alignment of a partial sequence of nuclear Large Subunit (LSU) ribosomal DNA. Phylogenetic trees were inferred using base-paired substitution models implemented in PHASE 2 software and Bayesian inference, and show S. lindsayae as the sister group to Stegelletina taxa

Protein kinase C-dependent signaling controls the midgut epithelial barrier to malaria parasite infection in anopheline mosquitoes.

Anopheline mosquitoes are the primary vectors of parasites in the genus Plasmodium, the causative agents of malaria. Malaria parasites undergo a series of complex transformations upon ingestion by the mosquito host. During this process, the physical barrier of the midgut epithelium, along with innate immune defenses, functionally restrict parasite development. Although these defenses have been studied for some time, the regulatory factors that control them are poorly understood. The protein kinase C (PKC) gene family consists of serine/threonine kinases that serve as central signaling molecules and regulators of a broad spectrum of cellular processes including epithelial barrier function and immunity. Indeed, PKCs are highly conserved, ranging from 7 isoforms in Drosophila to 16 isoforms in mammals, yet none have been identified in mosquitoes. Despite conservation of the PKC gene family and their potential as targets for transmission-blocking strategies for malaria, no direct connections between PKCs, the mosquito immune response or epithelial barrier integrity are known. Here, we identify and characterize six PKC gene family members--PKCδ, PKCε, PKCζ, PKD, PKN, and an indeterminate conventional PKC--in Anopheles gambiae and Anopheles stephensi. Sequence and phylogenetic analyses of the anopheline PKCs support most subfamily assignments. All six PKCs are expressed in the midgut epithelia of A. gambiae and A. stephensi post-blood feeding, indicating availability for signaling in a tissue that is critical for malaria parasite development. Although inhibition of PKC enzymatic activity decreased NF-κB-regulated anti-microbial peptide expression in mosquito cells in vitro, PKC inhibition had no effect on expression of a panel of immune genes in the midgut epithelium in vivo. PKC inhibition did, however, significantly increase midgut barrier integrity and decrease development of P. falciparum oocysts in A. stephensi, suggesting that PKC-dependent signaling is a negative regulator of epithelial barrier function and a potential new target for transmission-blocking strategies

Genetic Structure of Midwestern \u3ci\u3eAscaris suum\u3c/i\u3e Populations: A Comparison of Isoenzyme and RAPD Markers

Isoenzyme and random amplified polymorphic DNA (RAPD) markers were used to characterize the genetics of geographic variation among population samples of Ascaris suum from midwestern localities. Independent estimates of fixation indices (FST) based on isoenzyme and RAPD markers showed the same general patterns of differentiation and substantial statistical correlation (r=0.70). Of the total estimated gene diversity, 9.4% (isoenzyme) and 9.2% (RAPD) was distributed among infrapopulations. Geographic localities accounted for 7.8% (isoenzyme) and 6.2% (RAPD) of the total gene diversity. Only infrapopulations and localities, which indicates significant population subdivision among A. suum from farms within geographic regions. Departures from random mating were revealed by deficiencies of heterozygotes within infrapopulations and by high positive values of FIS among and between infrapopulations. The average inbreeding (FIS) coefficient among all infrapopulations was 0.22. Thus, the genetic composition of these A. suum infrapopulations, whether from a general geographic region or a single farm, was not consistent with a model of random recruitment from a larger panmictic pool of parasite life cycle stages