1,212 research outputs found
Female Fertility Affects Men's Linguistic Choices
We examined the influence of female fertility on the likelihood of male participants aligning their choice of syntactic construction with those of female confederates. Men interacted with women throughout their menstrual cycle. On critical trials during the interaction, the confederate described a picture to the participant using particular syntactic constructions. Immediately thereafter, the participant described to the confederate a picture that could be described using either the same construction that was used by the confederate or an alternative form of the construction. Our data show that the likelihood of men choosing the same syntactic structure as the women was inversely related to the women's level of fertility: higher levels of fertility were associated with lower levels of linguistic matching. A follow-up study revealed that female participants do not show this same change in linguistic behavior as a function of changes in their conversation partner's fertility. We interpret these findings in the context of recent data suggesting that non-conforming behavior may be a means of men displaying their fitness as a mate to women
Fine Tuning of Ca(V)1.3 Ca2+ Channel Properties in Adult Inner Hair Cells Positioned in the Most Sensitive Region of the Gerbil Cochlea
Hearing relies on faithful signal transmission by cochlear inner hair cells (IHCs) onto auditory fibres over a wide frequency
and intensity range. Exocytosis at IHC ribbon synapses is triggered by Ca2+
inflow through CaV1.3 (L-type) Ca2+
channels. We
investigated the macroscopic (whole-cell) and elementary (cell-attached) properties of Ca2+
currents in IHCs positioned at
the middle turn (frequency ,2 kHz) of the adult gerbil cochlea, which is their most sensitive hearing region. Using near
physiological recordings conditions (body temperature and a Na+
based extracellular solution), we found that the
macroscopic Ca2+
current activates and deactivates very rapidly (time constant below 1 ms) and inactivates slowly and only
partially. Single-channel recordings showed an elementary conductance of 15 pS, a sub-ms latency to first opening, and a
very low steady-state open probability (Po: 0.024 in response to 500-ms depolarizing steps at ,218 mV). The value of Po
was significantly larger (0.06) in the first 40 ms of membrane depolarization, which corresponds to the time when most Ca2+
channel openings occurred clustered in bursts (mean burst duration: 19 ms). Both the Po and the mean burst duration were
smaller than those previously reported in high-frequency basal IHCs. Finally, we found that middle turn IHCs are likely to
express about 4 times more Ca2+
channels per ribbon than basal cells. We propose that middle-turn IHCs finely-tune CaV1.3
Ca2+
channel gating in order to provide reliable information upon timing and intensity of lower-frequency sounds
An ENU-induced mutation of miR-96 associated with progressive hearing loss in mice.
Progressive hearing loss is common in the human population, but little is known about the molecular basis. We report a new N-ethyl-N-nitrosurea (ENU)-induced mouse mutant, diminuendo, with a single base change in the seed region of Mirn96. Heterozygotes show progressive loss of hearing and hair cell anomalies, whereas homozygotes have no cochlear responses. Most microRNAs are believed to downregulate target genes by binding to specific sites on their mRNAs, so mutation of the seed should lead to target gene upregulation. Microarray analysis revealed 96 transcripts with significantly altered expression in homozygotes; notably, Slc26a5, Ocm, Gfi1, Ptprq and Pitpnm1 were downregulated. Hypergeometric P-value analysis showed that hundreds of genes were upregulated in mutants. Different genes, with target sites complementary to the mutant seed, were downregulated. This is the first microRNA found associated with deafness, and diminuendo represents a model for understanding and potentially moderating progressive hair cell degeneration in hearing loss more generally
Evidence for Restriction of Ancient Primate Gammaretroviruses by APOBEC3 but Not TRIM5α Proteins
Because of evolutionary pressures imposed through episodic colonization by retroviruses, many mammals express factors, such as TRIM5α and APOBEC3 proteins, that directly restrict retroviral replication. TRIM5 and APOBEC restriction factors are most often studied in the context of modern primate lentiviruses, but it is likely that ancient retroviruses imposed the selective pressure that is evident in primate TRIM5 and APOBEC3 genes. Moreover, these antiretroviral factors have been shown to act against a variety of retroviruses, including gammaretroviruses. Endogenous retroviruses can provide a ‘fossil record’ of extinct retroviruses and perhaps evidence of ancient TRIM5 and APOBEC3 antiviral activity. Here, we investigate whether TRIM5 and APOBEC3 proteins restricted the replication of two groups of gammaretroviruses that were endogenized in the past few million years. These endogenous retroviruses appear quite widespread in the genomes of old world primates but failed to colonize the human germline. Our analyses suggest that TRIM5α proteins did not pose a major barrier to the cross-species transmission of these two families of gammaretroviruses, and did not contribute to their extinction. However, we uncovered extensive evidence for inactivation of ancient gammaretroviruses through the action of APOBEC3 cytidine deaminases. Interestingly, the identities of the cytidine deaminases responsible for inactivation appear to have varied in both a virus and host species–dependent manner. Overall, sequence analyses and reconstitution of ancient retroviruses from remnants that have been preserved in the genomes of modern organisms offer the opportunity to probe and potentially explain the evolutionary history of host defenses against retroviruses
Food allergy knowledge, attitudes and beliefs: Focus groups of parents, physicians and the general public
<p>Abstract</p> <p>Background</p> <p>Food allergy prevalence is increasing in US children. Presently, the primary means of preventing potentially fatal reactions are avoidance of allergens, prompt recognition of food allergy reactions, and knowledge about food allergy reaction treatments. Focus groups were held as a preliminary step in the development of validated survey instruments to assess food allergy knowledge, attitudes, and beliefs of parents, physicians, and the general public.</p> <p>Methods</p> <p>Eight focus groups were conducted between January and July of 2006 in the Chicago area with parents of children with food allergy (3 groups), physicians (3 groups), and the general public (2 groups). A constant comparative method was used to identify the emerging themes which were then grouped into key domains of food allergy knowledge, attitudes, and beliefs.</p> <p>Results</p> <p>Parents of children with food allergy had solid fundamental knowledge but had concerns about primary care physicians' knowledge of food allergy, diagnostic approaches, and treatment practices. The considerable impact of children's food allergies on familial quality of life was articulated. Physicians had good basic knowledge of food allergy but differed in their approach to diagnosis and advice about starting solids and breastfeeding. The general public had wide variation in knowledge about food allergy with many misconceptions of key concepts related to prevalence, definition, and triggers of food allergy.</p> <p>Conclusion</p> <p>Appreciable food allergy knowledge gaps exist, especially among physicians and the general public. The quality of life for children with food allergy and their families is significantly affected.</p
Optimized two-dimensional thin layer chromatography to monitor the intracellular concentration of acetyl phosphate and other small phosphorylated molecules
Acetyl phosphate (acetyl-P) serves critical roles in coenzyme A recycling and ATP synthesis. It is the intermediate of the Pta-AckA pathway that inter-converts acetyl-coenzyme A and acetate. Acetyl-P also can act as a global signal by donating its phosphoryl group to specific two-component response regulators. This ability derives from its capacity to store energy in the form of a high-energy phosphate bond. This bond, while critical to its function, also destabilizes acetyl-P in cell extracts. This lability has greatly complicated biochemical analysis, leading in part to widely varying acetyl-P measurements. We therefore developed an optimized protocol based on two-dimensional thin layer chromatography that includes metabolic labeling under aerated conditions and careful examination of the integrity of acetyl-P within extracts. This protocol results in greatly improved reproducibility, and thus permits precise measurements of the intracellular concentration of acetyl-P, as well as that of other small phosphorylated molecules
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