Low-frequency cortical activity is a neuromodulatory target that tracks recovery after stroke.

Recent work has highlighted the importance of transient low-frequency oscillatory (LFO; <4 Hz) activity in the healthy primary motor cortex during skilled upper-limb tasks. These brief bouts of oscillatory activity may establish the timing or sequencing of motor actions. Here, we show that LFOs track motor recovery post-stroke and can be a physiological target for neuromodulation. In rodents, we found that reach-related LFOs, as measured in both the local field potential and the related spiking activity, were diminished after stroke and that spontaneous recovery was closely correlated with their restoration in the perilesional cortex. Sensorimotor LFOs were also diminished in a human subject with chronic disability after stroke in contrast to two non-stroke subjects who demonstrated robust LFOs. Therapeutic delivery of electrical stimulation time-locked to the expected onset of LFOs was found to significantly improve skilled reaching in stroke animals. Together, our results suggest that restoration or modulation of cortical oscillatory dynamics is important for the recovery of upper-limb function and that they may serve as a novel target for clinical neuromodulation

Sources and distribution of organic matter in northern Patagonia fjords, Chile (~44–47° S) : a multi–tracer approach for carbon cycling assessment

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Continental Shelf Research 31 (2011): 315-329, doi:10.1016/j.csr.2010.05.013.We investigated the provenance of organic matter in the inner fjord area of northern Patagonia, Chile (~44–47° S), by studying the elemental (organic carbon, total nitrogen), isotopic (δ13C, δ15N), and biomarker (n–alkanoic acids from vascular plant waxes) composition of surface sediments as well as local marine and terrestrial organic matter. Average end–member values of N/C, δ13C, and δ15N from organic matter were 0.127 ± 0.010, –19.8 ± 0.3‰, and 9.9 ± 0.5‰ for autochthonous (marine) sources and 0.040 ± 0.018, –29.3 ± 2.1‰, 0.2 ± 3.0‰ for allochthonous (terrestrial) sources. Using a mixing equation based on these two end–members, we calculated the relative contribution of marine and terrestrial organic carbon from the open ocean to the heads of fjords close to river outlets. The input of marine–derived organic carbon varied widely and accounted for 13 to 96% (average 61%) of the organic carbon pool of surface sediments. Integrated regional calculations for the inner fjord system of northern Patagonia, which encompasses an area of ~ 4,280 km2, suggest that carbon accumulation may account for between 2.3 and 7.8 x 104 ton C yr–1. This represents a storage capacity of marine–derived carbon between 1.8 and 6.2 x 104 tons yr–1, which corresponds to an assimilation rate of CO2 by marine photosynthesis between 0.06 and 0.23 x 106 tons yr–1. This rate suggests that the entire fjord system of Patagonia, which covers an area of ~ 240,000 km2, may represent a potentially important region for the global burial of marine organic matter and the sequestration of atmospheric CO2.J. Sepúlveda was funded by a M.S. scholarship from the Graduate School at UDEC and by Fundación Andes through the Woods Hole Oceanographic Institution (WHOI)/UDEC agreement during a research visit at WHOI. This research was funded by the Ministerio de Hacienda de Chile and the Comité Oceanográfico Nacional (CONA) through the CIMAR–7 FIORDO Program (Grant C7F 01–10 to SP), CONICYT/NSF Grant 2001–120, Fundación Andes–Chile, and the Center for Oceanographic Research in the eastern South Pacific (COPAS) and COPAS Sur– Austral (PFB–31/2007)

Marine reserves can mitigate and promote adaptation to climate change

Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future

Modulation of Sn concentration in ZnO nanorod array: intensification on the conductivity and humidity sensing properties

Tin (Sn)-doped zinc oxide (ZnO) nanorod arrays (TZO) were synthesized onto aluminum-doped ZnO-coated glass substrate via a facile sonicated sol–gel immersion method for humidity sensor applications. These nanorod arrays were grown at different Sn concentrations ranging from 0.6 to 3 at.%. X-ray diffraction patterns showed that the deposited TZO arrays exhibited a wurtzite structure. The stress/strain condition of the ZnO film metamorphosed from tensile strain/compressive stress to compressive strain/tensile stress when the Sn concentrations increased. Results indicated that 1 at.% Sn doping of TZO, which has the lowest tensile stress of 0.14 GPa, generated the highest conductivity of 1.31 S cm− 1. In addition, 1 at.% Sn doping of TZO possessed superior sensitivity to a humidity of 3.36. These results revealed that the optimum performance of a humidity-sensing device can be obtained mainly by controlling the amount of extrinsic element in a ZnO film

Probing Nucleation Mechanism of Self-Catalyzed InN Nanostructures

The nucleation and evolution of InN nanowires in a self-catalyzed growth process have been investigated to probe the microscopic growth mechanism of the self-catalysis and a model is proposed for high pressure growth window at ~760 Torr. In the initial stage of the growth, amorphous InNx microparticles of cone shape in liquid phase form with assistance of an InNx wetting layer on the substrate. InN crystallites form inside the cone and serve as the seeds for one-dimensional growth along the favorable [0001] orientation, resulting in single-crystalline InN nanowire bundles protruding out from the cones. An amorphous InNx sheath around the faucet tip serves as the interface between growing InN nanowires and the incoming vapors of indium and nitrogen and supports continuous growth of InN nanowires in a similar way to the oxide sheath in the oxide-assisted growth of other semiconductor nanowires. Other InN 1D nanostructures, such as belts and tubes, can be obtained by varying the InN crystallites nucleation and initiation process

Firsthand Experience and The Subsequent Role of Reflected Knowledge in Cultivating Trust in Global Collaboration

While scholars contend that firsthand experience - time spent onsite observing the people, places, and norms of a distant locale - is crucial in globally distributed collaboration, how such experience actually affects interpersonal dynamics is poorly understood. Based on 47 semistructured interviews and 140 survey responses in a global chemical company, this paper explores the effects of firsthand experience on intersite trust. We find firsthand experience leads not just to direct knowledge of the other, but also knowledge of the self as seen through the eyes of the other - what we call “reflected knowledge”. Reflected and direct knowledge, in turn, affect trust through identification, adaptation, and reduced misunderstandings

The Formation of the First Massive Black Holes

Supermassive black holes (SMBHs) are common in local galactic nuclei, and SMBHs as massive as several billion solar masses already exist at redshift z=6. These earliest SMBHs may grow by the combination of radiation-pressure-limited accretion and mergers of stellar-mass seed BHs, left behind by the first generation of metal-free stars, or may be formed by more rapid direct collapse of gas in rare special environments where dense gas can accumulate without first fragmenting into stars. This chapter offers a review of these two competing scenarios, as well as some more exotic alternative ideas. It also briefly discusses how the different models may be distinguished in the future by observations with JWST, (e)LISA and other instruments.Comment: 47 pages with 306 references; this review is a chapter in "The First Galaxies - Theoretical Predictions and Observational Clues", Springer Astrophysics and Space Science Library, Eds. T. Wiklind, V. Bromm & B. Mobasher, in pres

The Relative Role of Perceived Partner Risks in Promoting Condom Use in a Three-City Sample of High-Risk, Low-Income Women

We examined the effect of women’s perceptions of sexual partner risks on condom use. Women from three US cities (n = 1,967) were recruited to provide data on HIV risks. In univariate models, increased odds of condom use were associated with perceiving that partners had concurrent partners and being unaware of partners': (a) HIV status, (b) bisexuality, (c) concurrency; and/or (d) injection drug use. In multivariate models, neither being unaware of the four partner risk factors nor perceiving a partner as being high risk was associated with condom use. Contextual factors associated with decreased odds of condom use were having sex with a main partner, homelessness in the past year, alcohol use during sex, and crack use in the past 30 days. Awareness of a partner’s risks may not be sufficient for increasing condom use. Contextual factors, sex with a main partner in particular, decrease condom use despite awareness of partner risk factors