Nitrogen forms affect root structure and water uptake in the hybrid poplar

The study analyses the effects of two different forms of nitrogen fertilisation (nitrate and ammonium) on root structure and water uptake of two hybrid poplar (Populus maximowiczii x P. balsamifera) clones in a field experiment. Water uptake was studied using sap flow gauges on individual proximal roots and coarse root structure was examined by excavating 18 whole-root systems. Finer roots were scanned and analyzed for architecture. Nitrogen forms did not affect coarse-root system development, but had a significant effect on fine-root development. Nitrate-treated trees presented higher fine:coarse root ratios and higher specific root lengths than control or ammonium treated trees. These allocation differences affected the water uptake capacity of the plants as reflected by the higher sapflow rate in the nitrate treatment. The diameter of proximal roots at the tree base predicted well the total root biomass and length. The diameter of smaller lateral roots also predicted the lateral root mass, length, surface area and the number of tips. The effect of nitrogen fertilisation on the fine root structure translated into an effect on the functioning of the fine roots forming a link between form (architecture) and function (water uptake)

Bioreactor technologies to support liver function in vitro

Liver is a central nexus integrating metabolic and immunologic homeostasis in the human body, and the direct or indirect target of most molecular therapeutics. A wide spectrum of therapeutic and technological needs drives efforts to capture liver physiology and pathophysiology in vitro, ranging from prediction of metabolism and toxicity of small molecule drugs, to understanding off-target effects of proteins, nucleic acid therapies, and targeted therapeutics, to serving as disease models for drug development. Here we provide perspective on the evolving landscape of bioreactor-based models to meet old and new challenges in drug discovery and development, emphasizing design challenges in maintaining long-term liver-specific function and how emerging technologies in biomaterials and microdevices are providing new experimental models.National Institutes of Health (U.S.) (R01 EB010246)National Institutes of Health (U.S.) (P50-GM068762-08)National Institutes of Health (U.S.) (R01-ES015241)National Institutes of Health (U.S.) (P30-ES002109)5UH2TR000496-02National Science Foundation (U.S.). Emergent Behaviors of Integrated Cellular Systems (CBET-0939511)United States. Defense Advanced Research Projects Agency. Microphysiological Systems Program (W911NF-12-2-0039

Isolation in Globalizing Academic Fields: A Collaborative Autoethnography of Early Career Researchers

This study examines academic isolation – an involuntary perceived separation from the academic field to which one aspires to belong, associated with a perceived lack of agency in terms of one’s engagement with the field – as a key challenge for researchers in increasingly globalized academic careers. While prior research describes early career researchers’ isolation in their institutions, we theorize early career researchers’ isolation in their academic fields and reveal how they attempt to mitigate isolation to improve their career prospects. Using a collaborative autoethnographic approach, we generate and analyze a dataset focused on the experiences of ten early career researchers in a globalizing business academic field known as Consumer Culture Theory. We identify bricolage practices, polycentric governance practices, and integration mechanisms that work to enhance early career researchers’ perceptions of agency and consequently mitigate their academic isolation. Our findings extend discussions on isolation and its role in new academic careers. Early career researchers, in particular, can benefit from a deeper understanding of practices that can enable them to mitigate isolation and reclaim agency as they engage with global academic fields

The role of vision on postural strategy evaluated in patients affected by congenital nystagmus as an experimental model

he role of vision in postural control is crucial and is strictly related to the characteristics of the visual stimulus and to the performance of the visual system. The purpose of this investigation was to evaluate the effects of chronically reduced visual cues upon postural control in patients affected by Congenital Nystagmus (CN). These patients have developed since birth a postural strategy mainly based on vestibular and somatosensorial cues. Fifteen patients affected by CN and 15 normal controls (NC) were enrolled in the study and evaluated by means of dynamic posturography. The overall postural control in CN patients was impaired as demonstrated by the equilibrium score and by the changes of the postural strategy. This impairment was even more enhanced in CN than in NC group when somatosensorial cues were experimentally reduced. An aspecific pattern of visual impairment and a pathological composite score were also present. Our data outline that in patients affected by CN an impairment of the postural balance is present especially when the postural control relies mainly on visual cues. Moreover, a decrease in accuracy of the somatosensory cues has a proportionally greater effect on balance than it has on normal subjects