Stress “Deafness” Reveals Absence of Lexical Marking of Stress or Tone in the Adult Grammar

A Sequence Recall Task with disyllabic stimuli contrasting either for the location of prosodic prominence or for the medial consonant was administered to 150 subjects equally divided over five language groups. Scores showed a significant interaction between type of contrast and language group, such that groups did not differ on their performance on the consonant contrast, while two language groups, Dutch and Japanese, significantly outperformed the three other language groups (French, Indonesian and Persian) on the prosodic contrast. Since only Dutch and Japanese words have unpredictable stress or accent locations, the results are interpreted to mean that stress “deafness” is a property of speakers of languages without lexical stress or tone markings, as opposed to the presence of stress or accent contrasts in phrasal (post-lexical) constructions. Moreover, the degree of transparency between the locations of stress/tone and word boundaries did not appear to affect our results, despite earlier claims that this should have an effect. This finding is of significance for speech processing, language acquisition and phonological theory.     

International External Quality Assessment Study for Molecular Detection of Lassa Virus

Lassa virus (LASV) is a causative agent of hemorrhagic fever in West Africa. In recent years, it has been imported several times to Europe and North America. The method of choice for early detection of LASV in blood is RT-PCR. Therefore, the European Network for Diagnostics of ‘Imported’ Viral Diseases (ENIVD) performed an external quality assessment (EQA) study for molecular detection of LASV. A proficiency panel of 13 samples containing various concentrations of inactivated LASV strains Josiah, Lib-1580/121, CSF, or AV was prepared. Samples containing the LASV-related lymphocytic choriomeningitis virus (LCMV) and negative sera were included as specificity controls. Twenty-four laboratories from 17 countries (13 European, one African, one Asian, two American countries) participated in the study. Thirteen laboratories (54%) reported correct results, 4 (17%) laboratories reported 1 to 2 false-negative results, and 7 (29%) laboratories reported 3 to 5 false-negative results. This EQA study indicates that most participating laboratories have a good or acceptable performance in molecular detection of LASV. However, several laboratories need to review and improve their diagnostic procedures.     

Is Meat Flavor a Factor in Hunters’ Prey Choice Decisions?

By focusing on the caloric composition of hunted prey species, optimal foraging research has shown that hunters usually make economically rational prey choice decisions. However, research by meat scientists suggests that the gustatory appeal of wildlife meats may vary dramatically. In this study, behavioral research indicates that Mayangna and Miskito hunters in Nicaragua inconsistently pursue multiple prey types in the optimal diet set. We use cognitive methods, including unconstrained pile sorts and cultural consensus analysis, to investigate the hypothesis that these partial preferences are influenced by considerations of meat flavor. Native informants exhibit high agreement on the relative appeal of different meats. Given the absence of other noteworthy differences between spider monkeys (Ateles geoffroyi) and howler monkeys (Alouatta palliata), the unappealing flavor of howler monkeys seems to be a factor in the partial preference for this species.     

Absence of male reproductive skew,along with high frequency of polyandry and conspecific brood parasitism in the lekking Houbara bustard Chlamydotis undulata undulata

Behavioural studies have led to the perception that lekking species experience a high male reproductive skew as a consequence of females’ selective mate choice. In addition, observations suggest that females copulate only once and therefore polyandry seems unlikely as females are supposed to choose the best male available. In order to analyse the mating strategy of the Houbara bustard, an endangered lekking species under reinforcement in eastern Morocco, we used microsatellite data to perform paternity analyses. None of our observations followed common expectations under a lek mating system: we found no male reproductive skew suggesting no apparent selective female mate choice and no apparent male benefit from lekking. In contrast, a high level of polyandry (60 % of the nests) was recorded suggesting that sperm competition may operate. In addition, we present another case of conspecific brood parasitism in a lekking species and this was an unexpected alternative strategy for a species presenting high parental cost and low fecundity. The increasing number of studies contradicting common assumptions on lekking species suggests that alternative breeding strategies such as males pursuing an off‐lek mating strategy, female polyandry and even conspecific brood parasitism might be more widespread in lekking species than previously thought.     

Comparative analysis of virulence genes, genetic diversity, and phylogeny of commensal and enterotoxigenic Escherichia coli isolates from weaned pigs

If the acquisition of virulence genes (VGs) for pathogenicity were not solely acquired through horizontal gene transfers of pathogenicity islands, transposons, and phages, then clonal clusters of enterotoxigenic Escherichia coli (ETEC) would contain few or even none of the VGs found in strains responsible for extraintestinal infections. To evaluate this possibility, 47 postweaning diarrhea (PWD) ETEC strains from different geographical origins and 158 commensal E. coli isolates from the gastrointestinal tracts of eight group-housed healthy pigs were screened for 36 extraintestinal and 18 enteric VGs using multiplex PCR assays. Of 36 extraintestinal VGs, only 8 were detected (fimH, traT, fyuA, hlyA, kpsMtII, k5, iha, and ompT) in the ETEC collection. Among these, hlyA (alpha-hemolysin) and iha (nonhemagglutinating adhesin) occurred significantly more frequently among the ETEC isolates than in the commensal isolates. Clustering analysis based on the VG profiles separated commensal and ETEC isolates and even differentiated serogroup O141 from O149. On the other hand, pulsed-field gel electrophoresis (PFGE) successfully clustered ETEC isolates according to both serotype and geographical origin. In contrast, the commensal isolates were heterogeneous with respect to both serotype and DNA fingerprint. This study has validated the use of VG profiling to examine pathogenic relationships between porcine ETEC isolates. The clonal relationships of these isolates can be further clarified by PFGE fingerprinting. The presence of extraintestinal VGs in porcine ETEC confirmed the hypothesis that individual virulence gene acquisitions can occur concurrently against a background of horizontal gene transfers of pathogenicity islands. Over time, this could enable specific clonotypes to respond to host selection pressure and to evolve into new strains with increased virulence.     

Effect of the purinergic receptor P2X7 on Chlamydia infection in cervical epithelial cells and vaginally infected mice

Ligation of the purinergic receptor, P2X7R, with its agonist ATP has been previously shown to inhibit intracellular infection by chlamydiae and mycobacteria in macrophages. The effect of P2X7R on chlamydial infection had never been investigated in the preferred target cells of chlamydiae, cervical epithelial cells, nor in vaginally infected mice. In this study, we show that treatment of epithelial cells with P2X7R agonists inhibits partially Chlamydia infection in epithelial cells. Chelation of ATP with magnesium or pretreatment with a P2X7R antagonist blocks the inhibitory effects of ATP. Similarly to previous results obtained with macrophages, ATP-mediated inhibition of infection in epithelial cells requires activation of host-cell phospholipase D. Vaginal infection was also more efficient in P2X7R-deficient mice, which also displayed a higher level of acute inflammation in the endocervix, oviduct, and mesosalpingeal tissues than in infected wild-type mice. However, secretion of IL-1beta, which requires P2X7R ligation during infection by other pathogens, was decreased mildly and only at short times of infection. Taken together, these results suggest that P2X7R affects Chlamydia infection by directly inhibiting infection in epithelial cells, rather than through the ability of P2X7R to modulate IL-1beta secretion.     

Association of TLR4 polymorphisms with symptomatic respiratory syncytial virus infection in high-risk infants and young children

Respiratory syncytial virus (RSV) is a leading cause of infant mortality worldwide. Although anti-RSV Ab prophylaxis has greatly reduced infant mortality in the United States, there is currently no vaccine or effective antiviral therapy. RSV fusion (F) protein activates cells through TLR4. Two single nucleotide polymorphisms (SNPs) encoding Asp299Gly and Thr399Ile substitutions in the TLR4 ectodomain were previously associated with TLR4 hyporesponsiveness and increased susceptibility to bacterial infection. Prevalence of these SNPs was analyzed in a case series of 105 DNA samples extracted from archived nasal lavage samples from high-risk infants/young children with confirmed RSV disease who participated in two seminal clinical trials for anti-RSV prophylaxis. Frequencies of TLR4 SNPs in the case series were compared with those of literature controls, healthy adults, infants, and young children who presented with symptoms of respiratory infections (but not preselected for high risk for RSV). Both SNPs were highly associated with symptomatic RSV disease in this largely premature population (p < 0.0001), with 89.5% and 87.6% of cases being heterozygous for Asp299Gly and Thr399Ile polymorphisms versus published control frequencies of 10.5% and 6.5%, respectively. The other two control groups had similarly low frequencies. Our data suggest that heterozygosity of these two extracellular TLR4 polymorphisms is highly associated with symptomatic RSV disease in high-risk infants and support a dual role for TLR4 SNPs in prematurity and increased susceptibility to RSV not revealed by analysis of either alone.     

Non-invasive measurement of small peptides in the common marmoset (Callithrix jacchus): a radiolabeled clearance study and endogenous excretion under varying social conditions

A non-invasive assay for measurement of oxytocin (OT) and vasopressin (AVP) in primates would enable researchers to study the relationship between the endocrine system and behavior without disturbing potentially endangered animals in their natural habitats. In order to test whether or not OT specifically would be measurable in the urine of a primate, 10 microCi of tritium-labeled OT were injected into the peripheral blood supply of four adult male common marmosets (Callithrix jacchus), with continuous urinary collection over 48 h. When urine was processed by HPLC separation and beta counting for radioactive clearance, the label was present in all samples in the fraction where OT elutes. Large amounts of OT were also seen in a fraction other than that containing the OT standard, indicating that OT is measurable but that it also undergoes substantial metabolic breakdown. In a second experiment, we isolated six common marmosets for 48 h and then exposed them to social contact to evaluate the effect of changing social stimuli on endogenous urinary measurement of both OT and AVP. Both were measured after HPLC separation to isolate the intact molecule and also to control for cross-reactivity with metabolites in subsequent RIA. Cortisol was also measured to objectively evaluate the stress response. A priori assumptions were that urinary OT and AVP would be lower during a period of isolation and higher during periods of social contact. These assumptions were met, leading us to conclude that peripheral OT and AVP are measurable via urinary assay and that such an assay is a valid means of evaluating social condition in this species.     

Synthesis and biophysical evaluation of minor-groove binding C-terminus modified pyrrole and imidazole triamide analogs of distamycin

Five polyamide derivatives with rationally modified C-terminus moieties were synthesized and their DNA binding specificity and affinity determined. A convergent approach was employed to synthesize polyamides containing an alkylaminopiperazine (4 and 5), a truncated piperazine (6), or an alkyldiamino-C-terminus moiety (7 and 8) with two specific objectives: to investigate the effects of number of potential cationic centers and steric bulk at the C-terminus. CD studies confirmed that compounds 4, 5, 7, and 8 bind in the minor groove of DNA. The alkylpiperazine containing compounds (4 and 5) showed only moderate binding to DNA with DeltaT(m) values of 2.8 and 8.3 degrees C with their cognate sequence, respectively. The alkyldiamino compounds (7 and 8) were more impressive producing a DeltaT(m) of >17 and >22 degrees C, respectively. Compound 6 (truncated piperazine) did not stabilize its cognate DNA sequence. Footprints were observed for all compounds (except compound 6) with their cognate DNA sequence using DNase I footprinting, with compound 7 producing a footprint of 0.1 microM at the expected 5'-ACGCGT-3' site. SPR analysis of compound 7 binding to 5'-ACGCGT-3', 5'-ACCGGT-3', and 5'-AAATTT-3' produced binding affinities of 2.2x10(6), 3.3x10(5), and 1x10(5)M(-1), respectively, indicating a preference for its cognate sequence of 5'-ACGCGT-3'. These results are in good agreement with the footprinting data. The results indicate that steric crowding at the C-terminus is important with respect to binding. However, the number of cationic centers within the molecule may also play a role. The alkyldiamino-containing compounds (7 and 8) warrant further investigation in the field of polyamide research.