Influence de l'âge des grand-parents sur l'apparition des mâles chez le Rotifère Notommata copeus Ehr.

When parental females (♀♀P = mothers) of the rotifer Notommata copeus are placed in light conditions inducing the appearance of mictic females in their offspring (F₁), the age of the parents of these parental females significantly affects the ratio of mictic females in the F₁ generation.

The preparental females (♀♀PP = grandmothers), the parental females and the F₁ females are isolated in a medium changed at each generation and, in the second experimental series, changed daily: the preparental age effect implicates the transmission of substances on two generations.

This influence of the preparental age is rhythmic: the ratio of mictic females in F₁ related to this age varies in a sinusoidal manner. This influence is endogenous: it persists, always in a sinusoidal form, when the medium in which each grandmother is placed is changed daily.

Furthermore, the net reproduction ratio, Ro, does not vary significantly with the preparental age during these experiments.     

Physical violence against intimate partners and related exposures to violence among South African men

Background

Despite high rates of intimate partner violence in South Africa, there have been no national studies of men''s perpetration of violence against female partners.

Methods

We analyzed data from the South Africa Stress and Health Study, a cross-sectional, nationally representative study, specifically examining data for men who had ever been married or had ever cohabited with a female partner. We calculated the prevalence of physical violence against intimate female partners and used logistic regression to examine associations with physical abuse during childhood and exposure to parental and community violence.

Results

A total of 834 male participants in the South Africa Stress and Health Study met the study criteria. Of these, 27.5% reported using physical violence against their current or most recent female partner during their current or most recent marriage or cohabiting relationship. Crude odds ratios (ORs) and 95% confidence intervals (CIs) indicated significant associations between perpetration of violence against an intimate partner and witnessing parental violence (OR 3.91, 95% CI 2.66–5.73) or experiencing physical abuse during childhood (OR 3.24, 95% CI 2.27–4.63), but not exposure to community violence (OR 1.29, 95% CI 0.88–1.88). The 2 significant associations persisted in adjusted analyses: OR 3.22 (95% CI 1.94–5.33) for witnessing parental violence and OR 1.73 (95% CI 1.07–2.79) for experiencing physical abuse during childhood.

Interpretation

We found a high prevalence of physical violence perpetrated by men against their intimate partners. Men who experienced physical abuse during childhood or were exposed to parental violence were at the greatest risk.Most research about men''s perpetration of violence against female intimate partners has concentrated on elucidating the factors that put women at risk for experiencing such violence and identifying the related service needs. Less work has been done to investigate the factors affecting men''s risk of perpetrating violence against women. Such work is needed to inform development of empirically based public health programs to reduce men''s use of such violence. Intimate partner violence is of pandemic proportions, with global estimates indicating that 15% to 75% of women have experienced such abuse.^1,2 Such violence may confer grave health consequences, including transmission of HIV/AIDS.³The overwhelming majority of research on violence against intimate partners perpetrated by men has been conducted in Western countries, with the focus on men at high risk for such activity (e.g., prisoners, people enrolled in intervention programs for batterers).^4,5 This work has highlighted the importance of exposure to violence early in life (e.g., witnessing parental violence, experiencing child abuse) in predicting perpetration of violence against a partner during adulthood.⁶ Recently, the potential relations between community violence and men''s perpetration of violence against intimate partners have also been examined.⁷Fewer studies have been done in developing nations, but several notable investigations have recently assessed men''s perpetration of violence against intimate partners in South Africa, specifically in Eastern Cape and Cape Town. Two of these studies have indicated high rates of violence against intimate partners: 31.8% in Eastern Cape⁸ and 42.3% in Cape Town.⁹ The extent to which these findings reflect national rates is unknown. Furthermore, work with both men and women in South Africa has demonstrated strong relations between violence (men''s perpetration and women''s victimization) and higher rates of sexually risky behaviours.^3,8 Associations between women''s experience as victims of intimate partner violence and HIV infection have also been documented.³ These data strongly suggest that men''s perpetration of violence against intimate partners is common in South Africa and that it may play an important role in this nation''s HIV epidemic,^3,8 which currently ranks highest in the world with respect to the number of people living with HIV.¹⁰In the study reported here, we sought to build upon prior work by using a national sample of South African men to examine the prevalence of physical violence perpetrated by men against their female intimate partners and potential violence-related risk factors (i.e., exposure to parental violence, experience of abuse in childhood and exposure to community violence).     

Identification of an S-locus glycoprotein allele introgressed from B. napus ssp. rapifera to B. napus ssp. oleifera.

We have previously described a developmentally regulated mRNA in maize that accumulates in mature embryos and is involved in a variety of stress responses in the plant. The sequence of the encoded 16 kDa protein (MA16) predicts that it is an RNA-binding protein, since it possesses a ribonucleoprotein consensus sequence-type RNA-binding domain (CS-RBD). To assess the predicted RNA binding property of the protein and as a starting point to characterize its function we have used ribohomopolymer-binding assays. Here we show that the MA16-encoded protein binds preferentially to uridine- and guanosine-rich RNAs. In light of these results a likely role for this protein in RNA metabolism during late embryogenesis and in the stress response is discussed.     

Cleavage efficient 2A peptides for high level monoclonal antibody expression in CHO cells

Linking the heavy chain (HC) and light chain (LC) genes required for monoclonal antibodies (mAb) production on a single cassette using 2A peptides allows control of LC and HC ratio and reduces non-expressing cells. Four 2A peptides derived from the foot-and-mouth disease virus (F2A), equine rhinitis A virus (E2A), porcine teschovirus-1 (P2A) and Thosea asigna virus (T2A), respectively, were compared for expression of 3 biosimilar IgG1 mAbs in Chinese hamster ovary (CHO) cell lines. HC and LC were linked by different 2A peptides both in the absence and presence of GSG linkers. Insertion of a furin recognition site upstream of 2A allowed removal of 2A residues that would otherwise be attached to the HC. Different 2A peptides exhibited different cleavage efficiencies that correlated to the mAb expression level. The relative cleavage efficiency of each 2A peptide remains similar for expression of different IgG1 mAbs in different CHO cells. While complete cleavage was not observed for any of the 2A peptides, GSG linkers did enhance the cleavage efficiency and thus the mAb expression level. T2A with the GSG linker (GT2A) exhibited the highest cleavage efficiency and mAb expression level. Stably amplified CHO DG44 pools generated using GT2A had titers 357, 416 and 600 mg/L for the 3 mAbs in shake flask batch cultures. Incomplete cleavage likely resulted in incorrectly processed mAb species and aggregates, which were removed with a chromatin-directed clarification method and protein A purification. The vector and methods presented provide an easy process beneficial for both mAb development and manufacturing.     

Landscape genetics of an endangered lemur (Propithecus tattersalli) within its entire fragmented range

Habitat fragmentation may strongly reduce individuals’ dispersal among resource patches and hence influence population distribution and persistence. We studied the impact of landscape heterogeneity on the dispersal of the golden‐crowned sifaka (Propithecus tattersalli), an endangered social lemur species living in a restricted and highly fragmented landscape. We combined spatial analysis and population genetics methods to describe population units and identify the environmental factors which best predict the rates and patterns of genetic differentiation within and between populations. We used non‐invasive methods to genotype 230 individuals at 13 microsatellites in all the main forest fragments of its entire distribution area. Our analyses suggest that the Manankolana River and geographical distance are the primary structuring factors, while a national road crossing the region does not seem to impede gene flow. Altogether, our results are in agreement with a limited influence of forest habitat connectivity on gene flow patterns (except for North of the species’ range), suggesting that dispersal is still possible today among most forest patches for this species. Within forest patches, we find that dispersal is mainly among neighbouring social groups, hence confirming previous behavioural observations.     

The histological structure of the calcified lung of the fossil coelacanth Axelrodichthys araripensis (Actinistia: Mawsoniidae)

Abstract: The palaeohistological study of the calcified internal organ of Axelrodichthys araripensis Maisey, 1986, a coelacanthiform from the Lower Cretaceous of Brazil (Crato (Aptian) and Santana (Albian) formations of the Araripe Basin), shows that the walls of this organ consist of osseous blades of variable thickness separated from each other by the matrix. This indicates that, in the living individuals, the walls were reinforced by ossified plates, probably separated by conjunctive tissue. This calcified sheath present in Axelrodichthys, as well as in other fossil coelacanths, lies in ventral position relative to the gut and its single anterior opening is located under the opercle, suggesting a direct connection with the pharynx or the oesophagus. The calcified organ of Axelrodichthys, like that of other fossil coelacanths, is here regarded as an ‘ossified lung’ and compared with the ‘fatty lung’ of the extant coelacanth Latimeria. The reinforcement of the pulmonary walls by the overlying osseous blades could be interpreted as a means of adapting volumetric changes in the manner of bellows, a necessary function for ventilation in pulmonary respiration. Other functional hypotheses such as hydrostatic and/or acoustic functions are also discussed.     

Nitrogen dioxide promotes allergic sensitization to inhaled antigen

Allergen sensitization and allergic airway disease are likely to come about through the inhalation of Ag with immunostimulatory molecules. However, environmental pollutants, including nitrogen dioxide (NO2), may promote adaptive immune responses to innocuous Ags that are not by themselves immunostimulatory. We tested in C57BL/6 mice whether exposure to NO2, followed by inhalation of the innocuous protein Ag, OVA, would result in allergen sensitization and the subsequent development of allergic airway disease. Following challenge with aerosolized OVA alone, mice previously exposed via inhalation to NO2 and OVA developed eosinophilic inflammation and mucus cell metaplasia in the lungs, as well as OVA-specific IgE and IgG1, and Th2-type cytokine responses. One hour of exposure to 10 parts per million NO2 increased bronchoalveolar lavage fluid levels of total protein, lactate dehydrogenase activity, and heat shock protein 70; promoted the activation of NF-kappaB by airway epithelial cells; and stimulated the subsequent allergic response to Ag challenge. Furthermore, features of allergic airway disease were not induced in allergen-challenged TLR2-/- and MyD88-/- mice exposed to NO2 and aerosolized OVA during sensitization. These findings offer a mechanism whereby allergen sensitization and asthma may result under conditions of high ambient or endogenous NO2 levels.