Essence and Cause: Making Something Be What It Is

Aristotle frequently describes essence as a “cause” or “explanation”, thus ascribing to essence some sort of causal or explanatory role. This explanatory role is often explicated by scholars in terms of essence “making the thing be what it is” or “making it the very thing that it is”. I argue that this is problematic, at least on the assumption that “making” expresses an explanatory relation, since it violates certain formal features of explanation. I then consider whether Aristotle is vulnerable to this problem by examining the explanatory role of essence in Posterior Analytics and Metaphysics Z 17

Revision of the species of Melipona of the fuliginosa group (Hymenoptera, Apoidea, Apidae, Meliponini)

Três espécies são reconhecidas: Melipona (Michmelia) fuliginosa Lepeletier, 1836, de larga distribuição, do Suriname e Guiana Francesa até o sudeste do Brasil e noroeste da Argentina, M. (Michmelia) titania Gribodo, 1893 (revalidado), endêmica do oeste da Amazônia, e M. (Michmelia) fallax sp. nov., do noroeste do Equador até a América Central. Melipona fuliginosa distingue-se pela pilosidade dos tergos metassomáticos II-V, tanto do macho como da operária, densa e plumosa, e pelo primeiro tarsômero da perna III do macho mais largo que longo. Em M. titania e M. fallax sp. nov., a pilosidade dos tergos II-V é escassa e simples, não-plumosa, e o primeiro tarsômero tão longo quanto largo ou mais longo que largo. Operárias de Melipona titania e M. fallax sp. nov. separam-se pela forma do penicilo, que é fortemente sinuoso em M. titania, e nos machos de M. fallax sp. nov. as órbitas internas dos olhos são paralelas, enquanto em M. titania as órbitas são convergentes embaixo. Novos registros geográficos, dados bionômicos e uma chave para identificação das espécies são apresentados. Adicionalmente, são feitos comentários sobre o padrão biogeográfico e sobre as glândulas tergais das rainhas.Three species are recognized: Melipona (Michmelia) fuliginosa Lepeletier, 1836, widely distributed, from Suriname and French Guiana to southeastern Brazil and northwestern Argentina, M. (Michmelia) titania Gribodo, 1893 (revalidated), endemic to western Amazon and M. (Michmelia) fallax sp. nov., from northwestern Ecuador to Central America. Melipona fuliginosa differs from the other species by the pilosity of metasomal terga II-V, dense and plumose, in both male and workers, and the first tarsomere of leg III of the male wider than long. In M. titania and M. fallax sp. nov., the pilosity of terga II-V is scarce and simple, non-plumose, and the first tarsomere of leg III of the male is as long as wide or longer. Workers of Melipona titania and M. fallax sp. nov. differ by the shape of the penicillum, which is strongly sinuous in M. titania, and in the males of M. fallax sp. nov. the internal orbits of the eyes are parallel, while in M. titania the orbits are convergent below. New geographic records, bionomic data and an identification key for the species are presented. In addition, comments are given on geographic patterns and tergal glands of the queens

Serologically defined variations in malaria endemicity in Pará state, Brazil

BACKGROUND: Measurement of malaria endemicity is typically based on vector or parasite measures. A complementary approach is the detection of parasite specific IgG antibodies. We determined the antibody levels and seroconversion rates to both P. vivax and P. falciparum merozoite antigens in individuals living in areas of varying P. vivax endemicity in Pará state, Brazilian Amazon region. METHODOLOGY/PRINCIPAL FINDINGS: The prevalence of antibodies to recombinant antigens from P. vivax and P. falciparum was determined in 1,330 individuals. Cross sectional surveys were conducted in the north of Brazil in Anajás, Belém, Goianésia do Pará, Jacareacanga, Itaituba, Trairão, all in the Pará state, and Sucuriju, a free-malaria site in the neighboring state Amapá. Seroprevalence to any P. vivax antigens (MSP1 or AMA-1) was 52.5%, whereas 24.7% of the individuals were seropositive to any P. falciparum antigens (MSP1 or AMA-1). For P. vivax antigens, the seroconversion rates (SCR) ranged from 0.005 (Sucuriju) to 0.201 (Goianésia do Pará), and are strongly correlated to the corresponding Annual Parasite Index (API). We detected two sites with distinct characteristics: Goianésia do Pará where seroprevalence curve does not change with age, and Sucuriju where seroprevalence curve is better described by a model with two SCRs compatible with a decrease in force of infection occurred 14 years ago (from 0.069 to 0.005). For P. falciparum antigens, current SCR estimates varied from 0.002 (Belém) to 0.018 (Goianésia do Pará). We also detected a putative decrease in disease transmission occurred ∼29 years ago in Anajás, Goianésia do Pará, Itaituba, Jacareacanga, and Trairão. CONCLUSIONS: We observed heterogeneity of serological indices across study sites with different endemicity levels and temporal changes in the force of infection in some of the sites. Our study provides further evidence that serology can be used to measure and monitor transmission of both major species of malaria parasite

Near-infrared spectroscopy of blood plasma with chemometrics towards HIV discrimination during pregnancy

Abstract: Prevention of mother-to-child transmission programs have been one of the hallmarks of success in the fight against HIV/AIDS. In Brazil, access to antiretroviral therapy (ART) during pregnancy has increased, leading to a reduction in new infections among children. Currently, lifelong ART is available to all pregnant, however yet challenges remain in eliminating mother-to-child transmission. In this paper, we focus on the role of near-infrared (NIR) spectroscopy to analyse blood plasma samples of pregnant women with HIV infection to differentiate pregnant women without HIV infection. Seventy-seven samples (39 HIV-infected patient and 38 healthy control samples) were analysed. Multivariate classification of resultant NIR spectra facilitated diagnostic segregation of both sample categories in a fast and non-destructive fashion, generating good accuracy, sensitivity and specificity. This method is simple and low-cost, and can be easily adapted to point-of-care screening, which can be essential to monitor pregnancy risks in remote locations or in the developing world. Therefore, it opens a new perspective to investigate vertical transmission (VT). The approach described here, can be useful for the identification and exploration of VT under various pathophysiological conditions of maternal HIV. These findings demonstrate, for the first time, the potential of NIR spectroscopy combined with multivariate analysis as a screening tool for fast and low-cost HIV detection