Functional approach to the electromagnetic response function: the Longitudinal Channel

In this paper we address the (charge) longitudinal electromagnetic response for a homogeneous system of nucleons interacting via meson exchanges in the functional framework. This approach warrants consistency if the calculation is carried on order-by-order in the mesonic loop expansion with RPA-dressed mesonic propagators. At the 1-loop order and considering pion, rho and omega exchanges we obtain a quenching of the response, in line with the experimental results.Comment: RevTeX, 18 figures available upon request - to be published in Physical Review

Latitude, digit ratios, and Allen's and Bergmann's rules: a comment on Loehlin, McFadden, Medland, and Martin (2006)

Comments on an article by J. C. Loehlin, D. McFadden, S. E. Medland and N. G. Martin (see record 2007-07455-014). The authors investigated the relationship between latitude and digit ratio (2D:4D). Like digit ratio, height has been suggested to reflect physical masculinization. Height is also positively correlated with perceptual-verbal ability (in women) and mental rotation ability. Latitude effect may not be completely independent of the hypothesized organizational effects of testosterone. Sex ratios appear to be influenced by circulating hormone levels in the parents around the time of conception and sex ratios at birth appear to be male-biased towards the equator and relatively male-biased at high latitudes. Regardless, any link between organizational testosterone and stature on the one hand and digit ratio on the other, and inter-ethnic variation in all three physical traits, requires further investigation. We suggest that much of the variance in digit ratio attributable to latitude is actually due to an allometric relationship between body size and digit ratio across populations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83881/1/latitude_digit_ratios_a_comment_on_loehlin.pd

The Perceived Benefits of Height: Strength, Dominance, Social Concern, and Knowledge among Bolivian Native Amazonians

Research in industrial countries suggests that, with no other knowledge about a person, positive traits are attributed to taller people and correspondingly, that taller people have slightly better socioeconomic status (SES). However, research in some non-industrialized contexts has shown no correlation or even negative correlations between height and socioeconomic outcomes. It remains unclear whether positive traits remain attributed to taller people in such contexts. To address this question, here we report the results of a study in a foraging-farming society of native Amazonians in Bolivia (Tsimane’)–a group in which we have previously shown little association between height and socioeconomic outcomes. We showed 24 photographs of pairs of Tsimane’ women, men, boys, and girls to 40 women and 40 men >16 years of age. We presented four behavioral scenarios to each participant and asked them to point to the person in the photograph with greater strength, dominance, social concern, or knowledge. The pairs in the photographs were of the same sex and age, but one person was shorter. Tsimane’ women and men attributed greater strength, dominance, and knowledge to taller girls and boys, but they did not attribute most positive traits to taller adults, except for strength, and more social concern only when women assessed other women in the photographs. These results raise a puzzle: why would Tsimane’ attribute positive traits to tall children, but not tall adults? We propose three potential explanations: adults’ expectations about the more market integrated society in which their children will grow up, height as a signal of good child health, and children’s greater variation in the traits assessed corresponding to maturational stages

Studies relating to heterocyclic ring formation

1,3-Diphenoxypropane has been prepared and its decomposition under various acid conditions has been studied. By refluxing with aluminium chloride in benzene, a good yield of chroman has been obtained. These optimum conditions have been applied to the decomposition of other 1,3-diphenoxypropanes and it has been found that good yields of substituted chromans are obtained from diethers containing electron donating or weakly electron withdrawing substituents which do not react with the catalyst. From the decomposition of related compounds under the same conditions, it has been shown that such a cyclisation reaction is limited to a propyl alkyl chain. 3-Anilinopropyl phenyl ether has been prepared and decomposed to give some N-phenylazetidine, rather than the expected 1,2,3,4-tetrahysroquinoline, under the standard decomposition conditions. The possible reaction paths for the chroman forming reaction are discussed and an investigation of the relative rates of decomposition of some 1,3-diphenoxypropanes has led to confirmation of a predicted synchronous mechanism

The preparation and cyclisation of some N-(3-bromopropyl) arylamine hydrohalides

A number of N-(3-bromopropyl) arylamine hydrohalides have been prepared. Their behaviour with various bases has been investigated and it has been shown that, under certain conditions, these starting materials may be cyclised to N-arylazetidines, A brief study has also been made of the possibility of forming 1,4-dihydro-4-oxocyclohexa-2,5-dienespiro-2'-pyrrolidine from N-(3-bromopropyl)-p-hydroxyaniline hydrobromide

Primaquine synergises the activity of chloroquine against chloroquine-resistant P. falciparum

In recent years, resistance to the antimalarial drug, chloroquine, has become widespread. It is, therefore, imperative to find compounds that could replace chloroquine or work synergistically with this drug to overcome chloroquine resistance. We have examined the interaction between chloroquine, a 4-aminoquinoline, and a number of 8-aminoquinolines, including primaquine, a drug that is widely used to treat Plasmodium vivax infections. We find that primaquine is a potent synergiser of the activity of chloroquine against chloroquine-resistant Plastnodium falciparum. Analysis of matched transfectants expressing mutant and wild-type alleles of the P.falciparum chloroquine resistance transporter (PfCRT) indicate that primaquine exerts its activity by blocking PfCRT, and thus enhancing chloroquine accumulation. Our data suggest that a novel formulation of two antimalarial drugs already licensed for use in humans could be used to treat chloroquine-resistant parasites. (c) 2005 Elsevier Inc. All rights reserved