Towards a methodical framework for comprehensively assessing forest multifunctionality

Funded by Deutsche Forschungsgemeinschaft. Grant Number: DFG FOR 891/1-3 National Natural Science Foundation of China. Grant Numbers: 30710103907, 30930005, 31170457, 31210103910 Swiss National Science Foundation (SNSF) Sino-German Centre for Research Promotion in Beijing. Grant Number: GZ 986Peer reviewedPublisher PD

How much time do health services spend on antenatal care? Implications for the introduction of the focused antenatal care model in Tanzania

BACKGROUND: Antenatal care (ANC) is a widely used strategy to improve the health of pregnant women and to encourage skilled care during childbirth. In 2002, the Ministry of Health of the United Republic of Tanzania developed a national adaptation plan based on the new model of the World Health Organisation (WHO). In this study we assess the time health workers currently spent on providing ANC services and compare it to the requirements anticipated for the new ANC model in order to identify the implications of Focused ANC on health care providers' workload. METHODS: Health workers in four dispensaries in Mtwara Urban District, Southern Tanzania, were observed while providing routine ANC. The time used for the overall activity as well as for the different, specific components of 71 ANC service provisions was measured in detail; 28 of these were first visits and 43 revisits. Standard time requirements for the provision of focused ANC were assessed through simulated consultations based on the new guidelines. RESULTS: The average time health workers currently spend for providing ANC service to a first visit client was found to be 15 minutes; the provision of ANC according to the focused ANC model was assessed to be 46 minutes. For a revisiting client the difference between current practise and the anticipated standard of the new model was 27 minutes (9 vs. 36 min.). The major discrepancy between the two procedures was related to counselling. On average a first visit client was counselled for 1:30 minutes, while counselling in revisiting clients did hardly take place at all. The simulation of focused ANC revealed that proper counselling would take about 15 minutes per visit. CONCLUSION: While the introduction of focused ANC has the potential to improve the health of pregnant women and to raise the number of births attended by skilled staff in Tanzania, it may need additional investment in human resources. The generally anticipated saving effect of the new model through the reduction of routine consultations may not materialise because the number of consultations is already low in Tanzania with a median of only 4 visits per pregnancy. Special attention needs to be given to counselling attitudes and skills during the training for Focused ANC as this component is identified as the major difference between old practise and the new model. Our estimated requirement of 46 minutes per first visit consultation matches well with the WHO estimate of 40 minutes

Early lineage restriction in temporally distinct populations of Mesp1 progenitors during mammalian heart development.

Cardiac development arises from two sources of mesoderm progenitors, the first heart field (FHF) and the second (SHF). Mesp1 has been proposed to mark the most primitive multipotent cardiac progenitors common for both heart fields. Here, using clonal analysis of the earliest prospective cardiovascular progenitors in a temporally controlled manner during early gastrulation, we found that Mesp1 progenitors consist of two temporally distinct pools of progenitors restricted to either the FHF or the SHF. FHF progenitors were unipotent, whereas SHF progenitors were either unipotent or bipotent. Microarray and single-cell PCR with reverse transcription analysis of Mesp1 progenitors revealed the existence of molecularly distinct populations of Mesp1 progenitors, consistent with their lineage and regional contribution. Together, these results provide evidence that heart development arises from distinct populations of unipotent and bipotent cardiac progenitors that independently express Mesp1 at different time points during their specification, revealing that the regional segregation and lineage restriction of cardiac progenitors occur very early during gastrulation.This is the author's accepted manuscript and will be under embargo until the 24th of February 2015. The final version is published by NPG in Nature Cell Biology here: http://www.nature.com/ncb/journal/v16/n9/full/ncb3024.html

Toward a methodical framework for comprehensively assessing forest multifunctionality

Biodiversity-ecosystem functioning (BEF) research has extended its scope from communities that are short-lived or reshape their structure annually to structurally complex forest ecosystems. The establishment of tree diversity experiments poses specific methodological challenges for assessing the multiple functions provided by forest ecosystems. In particular, methodological inconsistencies and nonstandardized protocols impede the analysis of multifunctionality within, and comparability across the increasing number of tree diversity experiments. By providing an overview on key methods currently applied in one of the largest forest biodiversity experiments, we show how methods differing in scale and simplicity can be combined to retrieve consistent data allowing novel insights into forest ecosystem functioning. Furthermore, we discuss and develop recommendations for the integration and transferability of diverse methodical approaches to present and future forest biodiversity experiments. We identified four principles that should guide basic decisions concerning method selection for tree diversity experiments and forest BEF research: (1) method selection should be directed toward maximizing data density to increase the number of measured variables in each plot. (2) Methods should cover all relevant scales of the experiment to consider scale dependencies of biodiversity effects. (3) The same variable should be evaluated with the same method across space and time for adequate larger-scale and longer-time data analysis and to reduce errors due to changing measurement protocols. (4) Standardized, practical and rapid methods for assessing biodiversity and ecosystem functions should be promoted to increase comparability among forest BEF experiments. We demonstrate that currently available methods provide us with a sophisticated toolbox to improve a synergistic understanding of forest multifunctionality. However, these methods require further adjustment to the specific requirements of structurally complex and long-lived forest ecosystems. By applying methods connecting relevant scales, trophic levels, and above? and belowground ecosystem compartments, knowledge gain from large tree diversity experiments can be optimized

Nanophotonic chiral sensing: how does it actually work?

Nanophotonic chiral sensing has recently attracted a lot of attention. The idea is to exploit the strong light–matter interaction in nanophotonic resonators to determine the concentration of chiral molecules at ultralow thresholds, which is highly attractive for numerous applications in life science and chemistry. However, a thorough understanding of the underlying interactions is still missing. The theoretical description relies on either simple approximations or on purely numerical approaches. We close this gap and present a general theory of chiral light–matter interactions in arbitrary resonators. Our theory describes the chiral interaction as a perturbation of the resonator modes, also known as resonant states or quasi-normal modes. We observe two dominant contributions: A chirality-induced resonance shift and changes in the modes’ excitation and emission efficiencies. Our theory brings deep insights for tailoring and enhancing chiral light–matter interactions. Furthermore, it allows us to predict spectra much more efficiently in comparison to conventional approaches. This is particularly true, as chiral interactions are inherently weak and therefore perturbation theory fits extremely well for this problem

Gold nanocrystal-mediated sliding of doublet DNA origami filaments

Sliding is one of the fundamental mechanical movements in machinery. In macroscopic systems, double-rack pinion machines employ gears to slide two linear tracks along opposite directions. In microscopic systems, kinesin-5 proteins crosslink and slide apart antiparallel microtubules, promoting spindle bipolarity and elongation during mitosis. Here we demonstrate an artificial nanoscopic analog, in which gold nanocrystals can mediate coordinated sliding of two antiparallel DNA origami filaments powered by DNA fuels. Stepwise and reversible sliding along opposite directions is in situ monitored and confirmed using fluorescence spectroscopy. A theoretical model including different energy transfer mechanisms is developed to understand the observed fluorescence dynamics. We further show that such sliding can also take place in the presence of multiple DNA sidelocks that are introduced to inhibit the relative movements. Our work enriches the toolbox of DNA-based nanomachinery, taking one step further toward the vision of molecular nanofactories.Peer reviewe

DNA-assembled nanoarchitectures with multiple components in regulated and coordinated motion

Coordinating functional parts to operate in concert is essential for machinery. In gear trains, meshed gears are compactly interlocked, working together to impose rotation or translation. In photosynthetic systems, a variety of biological entities in the thylakoid membrane interact with each other, converting light energy into chemical energy. However, coordinating individual parts to carry out regulated and coordinated motion within an artificial nanoarchitecture poses challenges, owing to the requisite control on the nanoscale. Here, we demonstrate DNA-directed nanosystems, which comprise hierarchically-assembled DNA origami filaments, fluorophores, and gold nanocrystals. These individual building blocks can execute independent, synchronous, or joint motion upon external inputs. These are optically monitored in situ using fluorescence spectroscopy, taking advantage of the sensitive distance-dependent interactions between the gold nanocrystals and fluorophores positioned on the DNA origami. Our work leverages the complexity of DNA-based artificial nanosystems with tailored dynamic functionality, representing a viable route towards technomimetic nanomachinery.Peer reviewe