Novel information on the endocranial morphology of the abelisaurid theropod Carnotaurus sastrei

The endocranial morphology of the abelisaurid Carnotaurus sastrei, from the Upper Cretaceous of Patagonia, is studied using X-ray Computed Tomography (CT). The CT scans provided information that allowed the first reconstruction of the brain, inner ear and braincase pneumaticity for this South American taxon. The endocranial morphology confirms that abelisaurids share an overall conformation of the brain and inner ear. However, some traits, such as the height of the dorsal sinuses and the length of the flocculus in the cranial endocast, and a large subsellar recess in the basicranium, appear to characterize the South-American abelisaurids only. Moreover, the olfactory acuity of Carnotaurus resembles that reported for other abelisaurids (e.g., Majungasaurus, Viavenator), suggesting that the sense of smell had an important role. However, some attributes of the endocranial features of Carnotaurus (i.e. development and orientation of the olfactory bulbs and tracts) may imply particular olfactory capacities when compared with other abelisaurids.     

Microtubule poleward flux in human cells is driven by the coordinated action of four kinesins

Mitotic spindle microtubules (MTs) undergo continuous poleward flux, whose driving force and function in humans remain unclear. Here, we combined loss‐of‐function screenings with analysis of MT‐dynamics in human cells to investigate the molecular mechanisms underlying MT‐flux. We report that kinesin‐7/CENP‐E at kinetochores (KTs) is the predominant driver of MT‐flux in early prometaphase, while kinesin‐4/KIF4A on chromosome arms facilitates MT‐flux during late prometaphase and metaphase. Both these activities work in coordination with kinesin‐5/EG5 and kinesin‐12/KIF15, and our data suggest that the MT‐flux driving force is transmitted from non‐KT‐MTs to KT‐MTs by the MT couplers HSET and NuMA. Additionally, we found that the MT‐flux rate correlates with spindle length, and this correlation depends on the establishment of stable end‐on KT‐MT attachments. Strikingly, we find that MT‐flux is required to regulate spindle length by counteracting kinesin 13/MCAK‐dependent MT‐depolymerization. Thus, our study unveils the long‐sought mechanism of MT‐flux in human cells as relying on the coordinated action of four kinesins to compensate for MT‐depolymerization and regulate spindle length.     

Identification and origin of host-associated volatiles attractive to Prorops nasuta, a parasitoid of the coffee berry borer

Previous studies have shown that prepupae/pupae and dust/frass from Hypothenemus hampei (Ferrari) reared on coffee berries were attractive to its parasitoid Prorops nasuta Waterston, while the same biological materials obtained from an artificial diet were not. In this study, we identified the volatiles from prepupae/pupae and dust/frass from H. hampei reared on Coffea canephora Pierre ex Froehner berries and artificial diet by gas chromatography coupled with mass spectrometry (GC?CMS), evaluated their behavioural activity, and investigated the possible origin of the kairomones in the H. hampei dust/frass attractive to P. nasuta. The GC?CMS analysis indicated that 24 peaks were consistently present in the headspace volatiles of dust/frass from H. hampei reared on coffee berries, 18 of these peaks were identified. Nineteen compounds were found in the dust/frass from H. hampei reared on an artificial diet. The compounds 1-octen-3-ol, limonene, n-tridecane, n-tetradecane, longifolene, n-pentadecane and n-heptadecane were common in dust/frass from H. hampei reared on coffee berries and artificial diet. Parasitoids were more attracted to 3-octanone, limonene, longifolene and n-dodecane compared to clean air. In contrast, P. nasuta preferred clean air to n-tetradecane. The rest of the compounds did not influence the behaviour of parasitoids. Two compounds were released by prepupae/pupae from H. hampei obtained from coffee berries, whereas six compounds were emitted by prepupae/pupae from the artificial diet. The compounds n-hexadecane and n-heptadecane were found in both types of prepupae/pupae. Parasitoids were more attracted to n-hexadecane than to clean air. In contrast, females did not show any preference for n-heptadecane or clean air. Among the compounds identified from dust/frass from H. hampei attractive to P. nasuta, only longifolene was found in the healthy C. canephora berry volatiles. Four species of fungi were isolated from the dust/frass of H. hampei, including Fusarium solani (Mart.) Sacc., Penicillium crustosum Thom, Aspergillus aculeatus lizuka and Mucor sp. Among the compounds identified in the dust/frass from H. hampei attractive to P. nasuta females, only 3-octanone was detected in the volatiles from F. solani and P. crustosum.     

Control of osteogenesis by the canonical Wnt and BMP pathways in vivo

Although many regulators of skeletogenesis have been functionally characterized, one current challenge is to integrate this information into regulatory networks. Here, we discuss how the canonical Wnt and Smad‐dependent BMP pathways interact together and play antagonistic or cooperative roles at different steps of osteogenesis, in the context of the developing vertebrate embryo. Early on, BMP signaling specifies multipotent mesenchymal cells into osteochondroprogenitors. In turn, the function of Wnt signaling is to drive these osteochondroprogenitors towards an osteoblastic fate. Subsequently, both pathways promote osteoblast differentiation, albeit with notable mechanistic differences. In osteocytes, the ultimate stage of osteogenic differentiation, the Wnt and BMP pathways exert opposite effects on the control of bone resorption by osteoclasts. We describe how the dynamic molecular wiring of the canonical Wnt and Smad‐dependent BMP signaling into the skeletal cell genetic programme is critical for the generation of bone‐specific cell types during development.     

Oxidative stress induces alkaloid production in Uncaria tomentosa root and cell cultures in bioreactors

The effect of oxidative stress on indole alkaloids accumulation by cell suspensions and root cultures of Uncaria tomentosa in bioreactors was investigated. Hydrogen peroxide (H₂O₂, 200 μM) added to U. tomentosa cell suspension cultures in shaken flasks induced the production of monoterpenoid oxindole alkaloids (MOA) up to 40.0 μg/L. In a stirred tank bioreactor, MOA were enhanced by exogenous H₂O₂ (200 μM) from no detection up to 59.3 μg/L. Root cultures grew linearly in shaken flasks with a μ=0.045 days^?1 and maximum biomass of 12.08±1.24 g DW/L (at day 30). Roots accumulated 3α‐dihydrocadambine (DHC) 2354.3±244.8 μg/g DW (at day 40) and MOA 348.2±32.1 μg/g DW (at day 18). Exogenous addition of H₂O₂ had a differential effect on DHC and MOA production in shaken flasks. At 200 μM H₂O₂, MOA were enhanced by 56% and DHC by 30%; while addition of 800 and 1000 μM H₂O₂, reduced by 30–40% DHC accumulation without change in MOA. Root cultures in the airlift reactor produced extracellular H₂O₂ with a characteristic biphasic profile after changing aeration. Maximum MOA was 9.06 mg/L at day 60 while at this time roots reached ca. 1 mg/L of DHC. Intracellular H₂O₂ in root cultures growing in the bioreactor was 0.87 μmol/g DW compared to 0.26 μmol/g DW of shaken flasks cultures. These results were in agreement with a higher activity of the antioxidant enzymes superoxide dismutase and peroxidase by 6‐ and 2‐times, respectively. U. tomentosa roots growing in the airlift bioreactor were exposed to an oxidative stress and their antioxidant system was active allowing them to produce oxindole alkaloids.     

School-Based Internet Obesity Prevention Programs for Adolescents: A Systematic Literature Review

In response to the childhood obesity epidemic, numerous studies on school-based Internet obesity prevention interventions have been conducted. The purpose of this systematic review is to describe, synthesize, and evaluate the research on school-based Internet obesity prevention programs for adolescents. Medline, CINAHL, and PsycInfo were searched from January 1995 to August 2012 to locate relevant studies. Ninety-one reports were initially identified, with 12 meeting the inclusion criteria. Studies had variable control groups, program content, and sample characteristics. Though few authors reported on implementation processes or body mass index (BMI) outcomes, the majority of studies were effective in improving health behaviors in the short term. Most studies were judged to have a high or unclear risk of bias in at least two domains, thus the quality of evidence for this body of literature is moderate. Further research is needed to examine programs of longer duration, optimal dose and timing of programs, cost-effectiveness, and mediators and moderators of intervention outcomes.