bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct detection OFDMA‐PON based on optical single sideband modulation and polarisation multiplexing
Authors: Yu Song , Yang Zhanyu , Lan Mingying , Lu Jianhao , Li Jian , Wu Guohua , Gu Wanyi
Published: August 2013

A low complexity scheme is proposed for direct detection orthogonal frequency division multiple access passive optical network, based on optical single sideband modulation and polarisation multiplexing. By utilising Hermitian symmetry mapping and Hilbert transformation, the hardware requirement is reduced. Theoretical expressions are presented to explain the cross‐polarisation interference, and a channel estimation algorithm is proposed for polarisation crosstalk. In addition, system parameters are discussed to optimise the performance of the proposed scheme. Copyright © 2013 John Wiley & Sons, Ltd.
Performance evaluation of cooperative strategies for Vehicular Delay‐Tolerant Networks
Authors: Dias João A.F.F. , Rodrigues Joel J.P C. , Zhou Liang
Published: August 2013

Vehicular Delay‐Tolerant Networks emerge as a vehicular networks technology that can be deployed on a wide range of scenarios. For example, it can be applied in sparse and remote regions characterised by sparse connectivity to allow data communications, as well as in urban scenarios. Frequent network partitioning, intermittent connectivity, long propagation delays, high error rates and short contact durations characterise these environments. To overcome some of these issues, cooperation approaches should be considered to force nodes to share their own resources. It is important to perform this task because nodes may be unwilling to cooperate due to a selfish behaviour. Selfish nodes affect considerably the functionality and the performance of the overall network. This paper overviews the most relevant contributions on cooperation for vehicular networks. It also proposes four different cooperation strategies for Vehicular Delay‐Tolerant Networks and studies their impact on the performance of the network. These strategies are enforced on two delay‐tolerant networks routing protocols (Epidemic and Spray‐and‐Wait). Across all the experiments, it was shown that all the strategies contribute to the improvement of the overall network performance by increasing the bundle delivery probability and consequently decrease the bundle average delivery delay. Copyright © 2013 John Wiley & Sons, Ltd.
The proportion of remineralized nitrate on the ice‐covered eastern Bering Sea shelf evidenced from the oxygen isotope ratio of nitrate
Authors: Granger Julie , Prokopenko Maria G. , Mordy Calvin W. , Sigman Daniel M.
Published: August 2013

We present measurements of nitrate and its natural abundance oxygen isotope composition (18O/16O) in the water column of the broad and shallow eastern Bering Sea shelf in the late winter and early spring of 2007 and 2008. In both years, nitrate concentrations showed a characteristic decrease, from 25 µM at the slope to ≤5 µM inshore. The 18O/16O ratio of nitrate (δ18ONO3 versus SMOW) also decreased from 3.2‰ at the slope to 1.5‰ inshore in 2007 and to as low as −1‰ inshore in 2008, indicating that nitrate inshore was nitrified at least once since having been entrained as nitrate from the slope. The shoreward decrease was less pronounced in 2007 due to 18O enrichment of nitrate from incident phytoplankton assimilation in the ice‐covered water column, whereas little to no algal growth in the water column was evident in 2008. By comparing the δ18O of nitrate to that of ambient water in spring 2008, we estimate the fraction of nitrate that was remineralized in situ rather than recently advected from the slope. These estimates indicate that 20%–100% of the nitrate in winter water of the middle and inner shelves derives from regeneration directly on the shelf rather than from the seasonal entrainment of slope waters, with recycling being the dominant mode of seasonal nitrate recharge from the 70 m isobath shoreward. These observations indicate substantial nutrient recycling on the shallow shelf, which has direct implications for the extent of fixed N loss to benthic denitrification and the fertility of the eastern shelf.
Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX
Authors: Martin Patrick , van der Loeff Michiel Rutgers , Cassar Nicolas , Vandromme Pieter , d'Ovidio Francesco , Stemmann Lars , Rengarajan R. , Soares Melena , González Humberto E. , Ebersbach Friederike , Lampitt Richard S. , Sanders Richard , Barnett Bruce A. , Smetacek Victor , Naqvi S. Wajih A.
Published: August 2013

A closed eddy core in the Subantarctic Atlantic Ocean was fertilized twice with two tons of iron (as FeSO4), and the 300 km2 fertilized patch was studied for 39 days to test whether fertilization enhances downward particle flux into the deep ocean. Chlorophyll a and primary productivity doubled after fertilization, and photosynthetic quantum yield (FV/FM) increased from 0.33 to ≥0.40. Silicic acid (<2 µmol L−1) limited diatoms, which contributed <10% of phytoplankton biomass. Copepods exerted high grazing pressure. This is the first study of particle flux out of an artificially fertilized bloom with very low diatom biomass. Net community production (NCP) inside the patch, estimated from O2:Ar ratios, averaged 21 mmol POC m−2 d−1, probably ±20%. 234Th profiles implied constant export of ~6.3 mmol POC m−2 d−1 in the patch, similar to unfertilized waters. The difference between NCP and 234Th‐derived export partly accumulated in the mixed layer and was partly remineralized between the mixed layer and 100 m. Neutrally buoyant sediment traps at 200 and 450 m inside and outside the patch caught mostly <1.1 mmol POC m−2 d−1, predominantly of fecal origin; flux did not increase upon fertilization. Our data thus indicate intense flux attenuation between 100 and 200 m, and probably between the mixed layer and 100 m. We attribute the lack of fertilization‐induced export to silicon limitation of diatoms and reprocessing of sinking particles by detritus feeders. Our data are consistent with the view that nitrate‐rich but silicate‐deficient waters are not poised for enhanced particle export upon iron addition.
Space‐based lidar measurements of global ocean carbon stocks
Authors: Behrenfeld Michael J. , Hu Yongxiang , Hostetler Chris A. , Dall'Olmo Giorgio , Rodier Sharon D. , Hair John W. , Trepte Charles R.
Published: August 2013

Global ocean phytoplankton biomass (Cphyto) and total particulate organic carbon (POC) stocks have largely been characterized from space using passive ocean color measurements. A space‐based light detection and ranging (lidar) system can provide valuable complementary observations for Cphyto and POC assessments, with benefits including day‐night sampling, observations through absorbing aerosols and thin cloud layers, and capabilities for vertical profiling through the water column. Here we use measurements from the Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) to quantify global Cphyto and POC from retrievals of subsurface particulate backscatter coefficients (bbp). CALIOP bbp data compare favorably with airborne, ship‐based, and passive ocean data and yield global average mixed‐layer standing stocks of 0.44 Pg C for Cphyto and 1.9 Pg for POC. CALIOP‐based Cphyto and POC data exhibit global distributions and seasonal variations consistent with ocean plankton ecology. Our findings support the use of spaceborne lidar measurements for advancing understanding of global plankton systems.
Smart, texture‐sensitive instrument classification for in situ rock and layer analysis
Authors: Wagstaff K. L. , Thompson D. R. , Abbey W. , Allwood A. , Bekker D. L. , Cabrol N. A. , Fuchs T. , Ortega K.
Published: August 2013

Science missions have limited lifetimes, necessitating an efficient investigation of the field site. The efficiency of onboard cameras, critical for planning, is limited by the need to downlink images to Earth for every decision. Recent advances have enabled rovers to take follow‐up actions without waiting hours or days for new instructions. We propose using built‐in processing by the instrument itself for adaptive data collection, faster reconnaissance, and increased mission science yield. We have developed a machine learning pixel classifier that is sensitive to texture differences in surface materials, enabling more sophisticated onboard classification than was previously possible. This classifier can be implemented in a Field Programmable Gate Array (FPGA) for maximal efficiency and minimal impact on the rest of the system's functions. In this paper, we report on initial results from applying the texture‐sensitive classifier to three example analysis tasks using data from the Mars Exploration Rovers.
Stable, rapid rate of slip since inception of the San Jacinto fault, California
Authors: Blisniuk Kimberly , Oskin Michael , Mériaux Anne‐Sophie , Rockwell Thomas , Finkel Robert C. , Ryerson Frederick J.
Published: August 2013

In California, where the San Jacinto fault (SJF) and San Andreas fault (SAF) accommodate the majority of the dextral shear deformation between the Pacific and North American plates, initiation of the SJF led to an apparent decline in the slip rate of the SAF. Previous studies suggest that since then, slip rate has covaried between these faults (possibly due to changes in fault strength, variation in topographic loading along a fault, or the development of new faults) and that presently the SJF is the dominant plate boundary structure. However, we dated displaced sedimentary deposits and landforms over three distinct time intervals since ~700 ka, and our results imply a constant slip rate of 12.1+3.4/−2.6 mm/yr. This rate is similar to the fault's lifetime rate and from rates derived from geodesy, suggesting that since the SJF initiated, its slip rate has remained relatively stable and does not exceed that of the SAF.
Long‐periodic strong radar echoes in the summer polar D region correlated with oscillations of high‐speed solar wind streams
Authors: Lee Young‐Sook , Kirkwood Sheila , Shepherd Gordon G. , Kwak Young‐Sil , Kim Kyung‐Chan
Published: August 2013

We report long‐periodic oscillations of polar mesospheric summer echoes (PMSEs) correlated with high‐speed solar wind streams (HSSs) as observed between 1 June and 8 August in the solar minimum years 2006 and 2008. PMSEs (80–90 km altitudes) were observed by 52 MHz VHF radar measurements at Esrange, Sweden (67.8°N, 20.4°E). Correlations between PMSE volume reflectivity/counts, HSSs, and AE index are primarily found at 7‐day, 9‐day, and 13‐day periodicities as well as 9‐day and 13.5‐day periodicities in 2006 and 2008, respectively. The observations show that the effects of HSSs appear in PMSEs. During corotating interaction region (CIR)‐induced HSSs, the long‐lasting enhancement of PMSEs, geomagnetic disturbances, and D‐region ionization suggests that a favorable condition in generating PMSEs can be provided by the precipitating energetic electrons (>30 keV), which are frequently multiplied in the magnetosphere during HSSs.
Why marine ice sheet model predictions may diverge in estimating future sea level rise
Authors: Pattyn Frank , Durand Gaël
Published: August 2013

Despite major recent efforts, marine ice sheet models aiming at predicting future mass loss from ice sheets still suffer from uncertainties with respect to grounding line migration. A recent model intercomparison provided tools to test how models treat grounding line dynamics in a three‐dimensional setting. Here we use these tools to address to what extent differences in mass loss occur according to the approximation to the Stokes equations, describing marine ice sheet flow, used. We find that models that neglect components of vertical shearing in the force budget wrongly estimate ice sheet mass loss by ±50% over century time scales when compared to models that solve the full Stokes system of equations. Models that only include horizontal stresses also misrepresent velocities and ice shelf geometry, suggesting that interactions between the grounded ice sheet and the ocean will also be modeled incorrectly. Based on these findings, we strongly advise the use of high‐order models to compute reliable projections of ice sheet contribution to sea level rise.
Scattered waves from low‐frequency earthquakes and plate boundary structure in northern Cascadia
Authors: Nowack Robert L. , Bostock Michael G.
Published: August 2013

We use 3‐D waveform modeling of LFEs (low‐frequency earthquakes) to investigate their relation to plate boundary structure along a linear transect in northern Cascadia. To account for crustal velocity heterogeneity, a smoothed 3‐D model of subduction zone structure is assembled that incorporates constraints from regional tomographic and plate boundary models. Scattered phases within LFE waveforms are identified based on synthetic predictions that incorporate thrust mechanisms aligned parallel to a dipping plate boundary atop a high‐Vp/Vs low‐velocity zone (LVZ). Scattering for near‐vertical paths is dominated by S‐to‐P/S‐to‐S reflections/conversions from the LVZ. The modeling suggests that LFEs lie at or very close to the plate boundary and that the LVZ structure is laterally heterogeneous but broadly consistent with results from teleseismic analysis.
Infrasonic crackle and supersonic jet noise from the eruption of Nabro Volcano, Eritrea
Authors: Fee David , Matoza Robin S. , Gee Kent L. , Neilsen Tracianne B. , Ogden Darcy E.
Published: August 2013

The lowermost portion of an explosive volcanic eruption column is considered a momentum‐driven jet. Understanding volcanic jets is critical for determining eruption column dynamics and mitigating volcanic hazards; however, volcanic jets are inherently difficult to observe due to their violence and opacity. Infrasound from the 2011 eruption of Nabro Volcano, Eritrea has waveform features highly similar to the “crackle” phenomenon uniquely produced by man‐made supersonic jet engines and rockets and is characterized by repeated asymmetric compressions followed by weaker, gradual rarefactions. This infrasonic crackle indicates that infrasound source mechanisms in sustained volcanic eruptions are strikingly similar to jet noise sources from heated, supersonic jet engines and rockets, suggesting that volcanologists can utilize the modeling and physical understandings of man‐made jets to understand volcanic jets. The unique, distinctive infrasonic crackle from Nabro highlights the use of infrasound to remotely detect and characterize hazardous eruptions and its potential to determine volcanic jet parameters.
Novel RNA oligonucleotide improves liver function and inhibits liver carcinogenesis in vivo
Authors: Reebye Vikash , Sætrom Pål , Mintz Paul J. , Huang Kai-Wen , Swiderski Piotr , Peng Ling , Liu Cheng , Liu Xiaoxuan , Lindkær-Jensen Steen , Zacharoulis Dimitris , Kostomitsopoulos Nikolaos , Kasahara Noriyuki , Nicholls Joanna P. , Jiao Long R. , Pai Madhava , Spalding Duncan R. , Mizandari Malkhaz , Chikovani Tinatin , Emara Mohamed M. , Haoudi Abdelali , Tomalia Donald A. , Rossi John J. , Habib Nagy A.
Published: August 2013

Hepatocellular carcinoma (HCC) occurs predominantly in patients with liver cirrhosis. Here we show an innovative RNA-based targeted approach to enhance endogenous albumin production while reducing liver tumor burden. We designed short-activating RNAs (saRNA) to enhance expression of C/EBPα (CCAAT/enhancer-binding protein-α), a transcriptional regulator and activator of albumin gene expression. Increased levels of both C/EBPα and albumin mRNA in addition to a 3-fold increase in albumin secretion and 50% decrease in cell proliferation was observed in C/EBPα-saRNA transfected HepG2 cells. Intravenous injection of C/EBPα-saRNA in a cirrhotic rat model with multifocal liver tumors increased circulating serum albumin by over 30%, showing evidence of improved liver function. Tumor burden decreased by 80% (

P

= 0.003) with a 40% reduction in a marker of preneoplastic transformation. Since C/EBPα has known antiproliferative activities by way of retinoblastoma, p21, and cyclins, we used messenger RNA (mRNA) expression liver cancer-specific microarray in C/EBPα-saRNA-transfected HepG2 cells to confirm down-regulation of genes strongly enriched for negative regulation of apoptosis, angiogenesis, and metastasis. Up-regulated genes were enriched for tumor suppressors and positive regulators of cell differentiation. A quantitative polymerase chain reaction (PCR) and western blot analysis of C/EBPα-saRNA-transfected cells suggested that in addition to the known antiproliferative targets of C/EBPα, we also observed suppression of interleukin (IL)6R, c-Myc, and reduced STAT3 phosphorylation.

Conclusion :

A novel injectable saRNA-oligonucleotide that enhances C/EBPα expression successfully reduces tumor burden and simultaneously improves liver function in a clinically relevant liver cirrhosis/HCC model.
Stress and the engagement of multiple memory systems: Integration of animal and human studies
Authors: Schwabe Lars
Published: August 2013

Learning and memory can be controlled by distinct memory systems. How these systems are coordinated to optimize learning and behavior has long been unclear. Accumulating evidence indicates that stress may modulate the engagement of multiple memory systems. In particular, rodent and human studies demonstrate that stress facilitates dorsal striatum‐dependent “habit” memory, at the expense of hippocampus‐dependent “cognitive” memory. Based on these data, a model is proposed which states that the impact of stress on the relative use of multiple memory systems is due to (i) differential effects of hormones and neurotransmitters that are released during stressful events on hippocampal and dorsal striatal memory systems, thus changing the relative strength of and the interactions between these systems, and (ii) a modulatory influence of the amygdala which biases learning toward dorsal striatum‐based memory after stress. This shift to habit memory after stress can be adaptive with respect to current performance but might contribute to psychopathology in vulnerable individuals. © 2013 Wiley Periodicals, Inc.
Homeostatic regulation of memory systems and adaptive decisions
Authors: Mizumori Sheri J.Y. , Jo Yong Sang
Published: August 2013

While it is clear that many brain areas process mnemonic information, understanding how their interactions result in continuously adaptive behaviors has been a challenge. A homeostatic‐regulated prediction model of memory is presented that considers the existence of a single memory system that is based on a multilevel coordinated and integrated network (from cells to neural systems) that determines the extent to which events and outcomes occur as predicted. The “multiple memory systems of the brain” have in common output that signals errors in the prediction of events and/or their outcomes, although these signals differ in terms of what the error signal represents (e.g., hippocampus: context prediction errors vs. midbrain/striatum: reward prediction errors). The prefrontal cortex likely plays a pivotal role in the coordination of prediction analysis within and across prediction brain areas. By virtue of its widespread control and influence, and intrinsic working memory mechanisms. Thus, the prefrontal cortex supports the flexible processing needed to generate adaptive behaviors and predict future outcomes. It is proposed that prefrontal cortex continually and automatically produces adaptive responses according to homeostatic regulatory principles: prefrontal cortex may serve as a controller that is intrinsically driven to maintain in prediction areas an experience‐dependent firing rate set point that ensures adaptive temporally and spatially resolved neural responses to future prediction errors. This same drive by prefrontal cortex may also restore set point firing rates after deviations (i.e. prediction errors) are detected. In this way, prefrontal cortex contributes to reducing uncertainty in prediction systems. An emergent outcome of this homeostatic view may be the flexible and adaptive control that prefrontal cortex is known to implement (i.e. working memory) in the most challenging of situations. Compromise to any of the prediction circuits should result in rigid and suboptimal decision making and memory as seen in addiction and neurological disease. © 2013 The Authors. Hippocampus Published by Wiley Periodicals, Inc.
Factors that influence the relative use of multiple memory systems
Authors: Packard Mark G. , Goodman Jarid
Published: August 2013

Neurobehavioral evidence supports the existence of at least two anatomically distinct “memory systems” in the mammalian brain that mediate dissociable types of learning and memory; a “cognitive” memory system dependent upon the hippocampus and a “stimulus‐response/habit” memory system dependent upon the dorsolateral striatum. Several findings indicate that despite their anatomical and functional distinctiveness, hippocampal‐ and dorsolateral striatal‐dependent memory systems may potentially interact and that, depending on the learning situation, this interaction may be cooperative or competitive. One approach to examining the neural mechanisms underlying these interactions is to consider how various factors influence the relative use of multiple memory systems. The present review examines several such factors, including information compatibility, temporal sequence of training, the visual sensory environment, reinforcement parameters, emotional arousal, and memory modulatory systems. Altering these parameters can lead to selective enhancements of either hippocampal‐dependent or dorsolateral striatal‐dependent memory, and bias animals toward the use of either cognitive or habit memory in dual‐solution tasks that may be solved adequately with either memory system. In many learning situations, the influence of such experimental factors on the relative use of memory systems likely reflects a competitive interaction between the systems. Research examining how various factors influence the relative use of multiple memory systems may be a useful method for investigating how these systems interact with one another. © 2013 Wiley Periodicals, Inc.
Decreased functional magnetic resonance imaging activity in the hippocampus in favor of the caudate nucleus in older adults tested in a virtual navigation task
Authors: Konishi Kyoko , Etchamendy Nicole , Roy Shumita , Marighetto Aline , Rajah Natasha , Bohbot Véronique D.
Published: August 2013

The neuroimaging literature has shown consistent decreases in functional magnetic resonance imaging (fMRI) activity in the hippocampus of healthy older adults engaged in a navigation task. However, navigation in a virtual maze relies on spatial or response strategies known to depend on the hippocampus and caudate nucleus, respectively. Therefore, since the proportion of people using spatial strategies decreases with normal aging, we hypothesized that it was responsible for the observed decreases in fMRI activity in the hippocampus reported in the literature. The aim of this study was to examine the effects of aging on the hippocampus and caudate nucleus during navigation while taking into account individual navigational strategies. Young (N = 23) and older adults (N = 29) were tested using fMRI on the Concurrent Spatial Discrimination Learning Task, a radial task that dissociates between spatial and response strategies (in Stage 2) after participants reached criteria (in Stage 1). Success on Stage 2 requires that participants have encoded the spatial relationship between the target object and environmental landmarks, that is, the spatial strategy. While older adults required more trials, all participants reached criterion. fMRI results showed that, as a group, young adults had significant activity in the hippocampus as opposed to older adults who instead had significant activity in the caudate nucleus. Importantly, individual differences showed that the older participants who used a spatial strategy to solve the task had significant activity in the hippocampus. These findings suggest that the aging process involves a shift from using the hippocampus toward the caudate nucleus during navigation but that activity in the hippocampus is sustained in a subset of healthy older adults engaged in spatial strategies. © 2013 Wiley Periodicals, Inc.
Shear‐Responsive Platelet Mimetics for Targeted Drug Delivery
Authors: Korin Netanel , Kanapathipillai Mathumai , Ingber Donald E.
Published: August 2013

Most targeted drug delivery approaches utilize molecular targets or regional variations in chemical or structural properties of the tissue microenvironment to localize drug at disease sites. Here we briefly describe a novel nanotherapeutic drug delivery platform that relies upon local mechanical activation by high fluid shear stresses to selectively target drugs to sites of vascular obstruction. This strategy is based on the use of microscale aggregates of nanoparticles that are shear sensitive and break up into individual nanoscale components that adhere to the surface of stenotic vessels in regions of abnormally high fluid shear stress, much as natural platelets do. This biomimetic approach to targeted drug delivery offers a potential new therapeutic approach for treatment of pulmonary embolism, stroke, atherosclerosis, and other hemodynamic‐related disorders that are caused by vascular clots, stenosis or obstruction.
Minding the Baby: Enhancing Reflectiveness to Improve Early Health and Relationship Outcomes in an Interdisciplinary Home‐Visiting Program
Authors: Sadler Lois S. , Slade Arietta , Close Nancy , Webb Denise L. , Simpson Tanika , Fennie Kristopher , Mayes Linda C.
Published: August 2013

In this article, we focus on the first wave of outcomes in a pilot‐phase randomized control trial of a home‐based intervention for infants and their families: Minding the Baby, an interdisciplinary, mentalization‐based intervention in which home‐visiting services are provided by a team which includes a nurse practitioner and a clinical social worker. Families are recruited during mother's pregnancy and continue through the child's second birthday. Analyses revealed that intervention families were more likely to be on track with immunization schedules at 12 months, had lower rates of rapid subsequent childbearing, and were less likely to be referred to child protective services. In addition, mother–infant interactions were less lilkely to be disrupted at 4 months when mothers were teenagers, and all intervention infants were more likely to be securely attached and less likely to be disorganized in relation to attachment at 1 year of age. Finally, mothers’ capacity to to reflect on their own and their child's experience improved over the course of the intervention in the most high‐risk mothers.
Changes of MicroRNA Profile and MicroRNA-mRNA Regulatory Network in Bones of Ovariectomized Mice
Authors: An Jee Hyun , Ohn Jung Hun , Song Jung Ah , Yang Jae-Yeon , Park Hyojung , Choi Hyung Jin , Kim Sang Wan , Kim Seong Yeon , Park Woog-Yang , Shin Chan Soo
Published: August 2013

Growing evidence shows the possibility of a role of microRNAs (miRNA) in regulating bone mass. We investigated the change of miRNAs and mRNA expression profiles in bone tissue in an ovariectomized mice model and evaluated the regulatory mechanism of bone mass mediated by miRNAs in an estrogen-deficiency state. Eight-week-old female C3H/HeJ mice underwent ovariectomy (OVX) or sham operation (Sham-op), and their femur and tibia were harvested to extract total bone RNAs after 4 weeks for microarray analysis. Eight miRNAs (miR-127, -133a, -133a*, -133b, -136, -206, -378, -378*) were identified to be upregulated after OVX, whereas one miRNA (miR-204) was downregulated. Concomitant analysis of mRNA microarray revealed that 658 genes were differentially expressed between OVX and Sham-op mice. Target prediction of differentially expressed miRNAs identified potential targets, and integrative analysis using the mRNA microarray results showed that PPARγ and CREB pathways are activated in skeletal tissues after ovariectomy. Among the potential candidates of miRNA, we further studied the role of miR-127 in vitro, which exhibited the greatest changes after OVX. We also studied the effects of miR-136, which has not been studied in the context of bone mass regulation. Transfection of miR-127 inhibitor has enhanced osteoblastic differentiation in UAMS-32 cells as measured by alkaline phosphatase activities and mRNA expression of osteoblast-specific genes, whereas miR-136 precursor has inhibited osteoblastic differentiation. Furthermore, transfection of both miR-127 and miR-136 inhibitors enhanced the osteocyte-like morphological changes and survival in MLO-Y4 cells, whereas precursors of miR-127 and -136 have aggravated dexamethasone-induced cell death. Both of the precursors enhanced osteoclastic differentiation in bone marrow macrophages, indicating that both miR-127 and -136 are negatively regulating bone mass. Taken together, these results suggest a novel insight into the association between distinct miRNAs expression and their possible role through regulatory network with mRNAs in the pathogenesis of estrogen deficiency–induced osteoporosis. © 2014 American Society for Bone and Mineral Research.
The Impact of Acute Kidney Injury With Temporary Dialysis on the Risk of Fracture
Authors: Wang Wei-Jie , Chao Chia-Ter , Huang Yu-Chin , Wang Cheng-Yi , Chang Chia-Hsui , Huang Tao-Min , Lai Chun-Fu , Huang Hui-Yu , Shiao Chih-Chung , Chu Tzong-Shinn , Chen Yung-Ming , Wu Vin-Cent , Ko Wen-Je , Wu Kwan-Dun ,   the National Taiwan University Study Group on Acute Renal Failure
Published: August 2013

Acute kidney injury (AKI) has a negative impact on long-term renal function and prognosis. However, the association between acute renal dysfunction and long-term effects on bone disorders has not yet been characterized. Using a population-based cohort study, we aimed to evaluate associations between AKI and long-term effects on bone fractures. We identified relevant data of all hospitalized patients aged >18 years with histories of dialysis-requiring AKI, with subsequent recovery and discharge, from the claim records of the Taiwan National Health Insurance database between 2000 and 2008. We determined long-term de novo bone fracture and all-cause mortality after patients' index-hospitalization discharge using propensity score–adjusted Cox proportional hazard model. Varying-time models were used to adjust for long-term effects of end-stage renal disease (ESRD) on main outcomes. Among 448 AKI patients who had dialysis and survived 90 days after index-hospitalization discharge without reentering dialysis, 273 were male (60.9%) with a mean age of 61.4 ± 16.6 years. Controls included 1792 hospitalized patients without AKI, dialysis, or bone fracture history. In the AKI recovery group, bone fracture incidence was 320 per 10,000 person-years and hazard ratio (HR) of long-term bone fracture was 1.25 (p = 0.049) compared with the control group, independent of subsequent ESRD status (HR = 1.55; p = 0.01). Both AKI recovery status (HR = 2.31; p < 0.001) and time varying factor of bone fracture (HR = 1.43; p < 0.001) were independent predictors of mortality compared with controls. In conclusion, AKI requiring temporary dialysis independently increases long-term risk of bone fracture, regardless of subsequent progression to ESRD. Long-term bone fractures may negatively impact patient mortality. © 2014 American Society for Bone and Mineral Research.
Targeted Disruption of Shp2 in Chondrocytes Leads to Metachondromatosis With Multiple Cartilaginous Protrusions
Authors: Kim Harry KW , Feng Gen-Sheng , Chen Di , King Philip D , Kamiya Nobuhiro
Published: August 2013

Metachondromatosis is a benign bone disease predominantly observed in the hands and feet of children or young adults demonstrating two different manifestations: a cartilage-capped bony outgrowth on the surface of the bone called exostosis and ectopic cartilaginous nodules inside the bone called enchondroma. Recently, it has been reported that loss-of-function mutations of the SHP2 gene, which encodes the SHP2 protein tyrosine phosphatase, are associated with metachondromatosis. The purpose of this study was to investigate the role of SHP2 in postnatal cartilage development, which is largely unknown. We disrupted Shp2 during the postnatal stage of mouse development in a chondrocyte-specific manner using a tamoxifen-inducible system. We found tumor-like nodules on the hands and feet within a month after the initial induction. The SHP2-deficient mice demonstrated an exostosis-like and enchondroma-like phenotype in multiple bones of the hands, feet, and ribs as assessed by X-ray and micro-computed tomography (CT). Histological assessment revealed the disorganization of the growth plate cartilage, a cartilaginous protrusion from the epiphyseal bone, and ectopic cartilage nodules within the bones, which is consistent with the pathological features of metachondromatosis in humans (ie, both exostosis and enchondroma). At molecular levels, we observed an abundant expression of Indian hedgehog protein (IHH) and fibroblast growth factor 2 (FGF2) and impaired expression of mitogen-activated protein kinases (MAPK) in the affected cartilage nodules in the SHP2-deficient mice. In summary, we have generated a mouse model of metachondromatosis that includes manifestations of exostosis and enchondroma. This study provides a novel model for the investigation of the pathophysiology of the disease and advances the understanding of metachondromatosis. This model will be useful to identify molecular mechanisms for the disease cause and progression as well as to develop new therapeutic strategies in the future. © 2014 American Society for Bone and Mineral Research.
Extreme Thermal Noxious Stimuli Induce Pain Responses in Zebrafish Larvae
Authors: Malafoglia Valentina , Colasanti Marco , Raffaeli William , Balciunas Darius , Giordano Antonio , Bellipanni Gianfranco
Published: August 2013

Exposing tissues to extreme high or low temperature leads to burns. Burned animals sustain several types of damage, from the disruption of the tissue to degeneration of axons projecting through muscle and skin. Such damage causes pain due to both inflammation and axonal degeneration (neuropathic‐like pain). Thus, the approach to cure and alleviate the symptoms of burns must be twofold: rebuilding the tissue that has been destroyed and alleviating the pain derived from the burns. While tissue regeneration techniques have been developed, less is known on the treatment of the induced pain. Thus, appropriate animal models are necessary for the development of the best treatment for pain induced in burned tissues. We have developed a methodology in the zebrafish aimed to produce a new animal model for the study of pain induced by burns. Here, we show that two events linked to the onset of burn‐induced inflammation and neuropathic‐like pain in mammals, degeneration of axons innervating the affected tissues and over‐expression of specific genes in sensory tissues, are conserved from zebrafish to mammals. J. Cell. Physiol. 229: 300–308, 2014. © 2013 Wiley Periodicals, Inc.
Biodegradability and kinetics of the removal of new peralkylated imidazolium ionic liquids
Authors: Liwarska‐Bizukojc Ewa , Maton Cedric , Stevens Christian V. , Gendaszewska Dorota
Published: August 2013

BACKGROUND

Ionic liquids are regarded as potential substitutes for volatile organic solvents. Thus, gaining knowledge about their biological properties is an important task. The main aim of this work was to estimate the biodegradability of newly synthesized tetra‐ and completely substituted imidazolium ionic liquids. Additionally, the kinetic parameters for the biological treatment of wastewater containing one of these ionic liquids were determined.

RESULTS

The results of OECD tests showed that none of the ionic liquids studied can be classified as readily or inherently biodegradable. The tetra‐substituted ionic liquid with the longest alkyl side chain consisting of six carbon atoms was more susceptible to biodegradation than the other ionic liquids tested. The values of Monod kinetic parameters estimated for the biological treatment of wastewater containing one of these ionic liquids were usually in the range of the values determined for municipal wastewater.

CONCLUSION

Newly synthesized tetra‐ and completely substituted imidazolium ionic liquids are not susceptible to microbial decomposition. At the same time their presence in wastewater neither reduces the growth rate of activated sludge biomass nor decreases the affinity of substrate to biomass. © 2013 Society of Chemical Industry
The influence of atmospheric tide and planetary wave variability during sudden stratosphere warmings on the low latitude ionosphere
Authors: Pedatella N. M. , Liu H.‒L.
Published: August 2013

Numerical simulations are performed for a sudden stratosphere warming (SSW) under different atmospheric tide and planetary wave forcing conditions to investigate the tidal variability in the mesosphere and lower thermosphere (MLT). The influence of variability of different tides in the MLT on generating perturbations to the low latitude ionosphere is also investigated. Significant changes are found to occur in the migrating semidiurnal solar (SW2) and lunar (M2) tides as well as in the westward propagating nonmigrating semidiurnal tide with zonal wave number 1 (SW1). The changes in the zonal mean atmosphere that occur during SSWs lead to an enhancement in the SW2 and M2 tides. The vertical wavelength of the SW2 is also changed, resulting in phase variability in the SW2 at a constant altitude. Significant enhancements in the SW1 are found to occur only in the presence of additional planetary wave forcing, and this demonstrates that nonlinear planetary wave‒tide interactions lead to the enhanced SW1 during SSWs. The amplitude and phase variability of the SW2 is found to be capable of producing temporal variability in the vertical plasma drift velocity that is similar to the observed variability. Changes in the M2 during SSWs can contribute up to an additional ∼30% of the total ionosphere variability; however, the overall influence of the lunar tide is found to be dependent upon the phase of the moon relative to the timing of the SSW. Although the influence is relatively minor, the SW1 also contributes to the low latitude ionosphere variability during SSWs. The simulation results for the vertical plasma drift velocity and total electron content (TEC) further illustrate that significant longitude variability occurs in the ionosphere response to SSWs.
Statistical properties of planetary heavy‐ion precipitations toward the Martian ionosphere obtained from Mars Express
Authors: Hara Takuya , Seki Kanako , Futaana Yoshifumi , Yamauchi Masatoshi , Barabash Stas , Fedorov Andrei O. , Yagi Manabu , Delcourt Dominique C.
Published: August 2013

The interplanetary magnetic field (IMF) embedded in the solar wind interacts with the Martian crustal magnetic field and atmosphere. The IMF orientation is one of the important parameters to control the acceleration and precipitation of planetary heavy ions (PHIs). We statistically investigate the effects of the IMF orientation on PHI precipitations toward the ionosphere based on observations by Mars Express (MEX). We identified 59 PHI precipitation events between July 2007 and September 2009. To estimate the IMF orientation without magnetometer that MEX does not carry, we used the velocity distribution of exospheric‐origin pickup protons. We estimated the IMF orientation without its polarity for 10 events. The results show that the precipitations of PHIs tend to be observed around pole regions in the MSE (Mars‐centered, solar electrical) coordinates determined from the solar wind electric field (Esw), in which the pole axis directs to the parallel or antiparallel to Esw due to the ambiguity in the IMF polarity determination. The observed precipitating PHIs are accelerated only up to a few keV. This feature may reflect the short distance from the picked‐up region. For one of these 10 events, we estimated the IMF polarity by comparing the velocity distribution of exospheric‐origin pickup protons observed by MEX with those obtained from statistical trajectory tracing simulations under two cases of possible IMF polarity conditions. The estimated polarity indicates that the PHI precipitation in this event is observed in the downward electric field hemisphere in MSE, where Esw points to Mars in the pole region.
A hydrologic model for the uppermost oceanic crust constrained by temperature estimates from carbonate minerals
Authors: Anderson B. W. , Gillis K. M. , Coogan L. A.
Published: August 2013

Hydrologic models of the oceanic crust commonly assume that the uppermost igneous extrusive layer of the aquifer is thermally well mixed, although this assumption has not been rigorously tested. Here, the assumption of a thermally well‐mixed aquifer is tested against the geological record using O isotope‐derived crystallization temperatures of carbonates in the lavas as a record of the temperatures experienced by the aquifer. It is found that carbonate formation temperatures are higher than can be explained by a model of outcrop‐to‐outcrop flow in a well‐mixed aquifer at four of the seven drilling locations analyzed. A poorly mixed aquifer is developed to further explore the crustal hydrology at these locations. Relative to a well‐mixed aquifer, a poorly mixed aquifer can achieve higher average temperatures, develops larger lateral pressure gradients driving flow, and requires a lower permeability to achieve a given lateral fluid flux. O isotope data from most of the carbonate samples analyzed are consistent with temperatures achievable in a poorly mixed aquifer; those samples which are not consistent can be explained by plausible special circumstances (such as formation at a discharge zone, where ascending fluid may warm the uppermost aquifer).
The nocturnal water cycle in an open‐canopy forest
Authors: Berkelhammer M. , Hu J. , Bailey A. , Noone D. C. , Still C. J. , Barnard H. , Gochis D. , Hsiao G. S. , Rahn T. , Turnipseed A.
Published: August 2013

The movement of moisture into, out‐of, and within forest ecosystems is modulated by feedbacks that stem from processes which couple plants, soil, and the atmosphere. While an understanding of these processes has been gleaned from Eddy Covariance techniques, the reliability of the method suffers at night because of weak turbulence. During the summer of 2011, continuous profiles of the isotopic composition (i.e., δ18O and δD) of water vapor and periodic measurements of soil, leaf, and precipitation pools were measured in an open‐canopy ponderosa pine forest in central Colorado to study within‐canopy nocturnal water cycling. The isotopic composition of the nocturnal water vapor varies significantly based on the relative contributions of the three major hydrological processes acting on the forest: dewfall, exchange of moisture between leaf waters and canopy vapor, and periodic mixing between the canopy and background air. Dewfall proved to be surprisingly common (∼30% of the nights) and detectable on both the surface and within the canopy through the isotopic measurements. While surface dew could be observed using leaf wetness and soil moisture sensors, dew in the foliage was only measurable through isotopic analysis of the vapor and often occurred even when no dew accumulated on the surface. Nocturnal moisture cycling plays a critical role in water availability in forest ecosystems through foliar absorption and transpiration, and assessing these dynamics, as done here, is necessary for fully characterizing the hydrological controls on terrestrial productivity.
A global atmospheric model of meteoric iron
Authors: Feng Wuhu , Marsh Daniel R. , Chipperfield Martyn P. , Janches Diego , Höffner Josef , Yi Fan , Plane John M. C.
Published: August 2013

The first global model of meteoric iron in the atmosphere (WACCM‐Fe) has been developed by combining three components: the Whole Atmosphere Community Climate Model (WACCM), a description of the neutral and ion‐molecule chemistry of iron in the mesosphere and lower thermosphere (MLT), and a treatment of the injection of meteoric constituents into the atmosphere. The iron chemistry treats seven neutral and four ionized iron containing species with 30 neutral and ion‐molecule reactions. The meteoric input function (MIF), which describes the injection of Fe as a function of height, latitude, and day, is precalculated from an astronomical model coupled to a chemical meteoric ablation model (CABMOD). This newly developed WACCM‐Fe model has been evaluated against a number of available ground‐based lidar observations and performs well in simulating the mesospheric atomic Fe layer. The model reproduces the strong positive correlation of temperature and Fe density around the Fe layer peak and the large anticorrelation around 100 km. The diurnal tide has a significant effect in the middle of the layer, and the model also captures well the observed seasonal variations. However, the model overestimates the peak Fe+concentration compared with the limited rocket‐borne mass spectrometer data available, although good agreement on the ion layer underside can be obtained by adjusting the rate coefficients for dissociative recombination of Fe‐molecular ions with electrons. Sensitivity experiments with the same chemistry in a 1‐D model are used to highlight significant remaining uncertainties in reaction rate coefficients, and to explore the dependence of the total Fe abundance on the MIF and rate of vertical transport.
Simvastatin treatment showed no prophylactic effect in influenza virus‐infected mice
Authors: Glück Brigitte , Schmidtke Michaela , Walther Mario , Meerbach Astrid , Wutzler Peter
Published: August 2013

Simvastatin, a cholesterol‐lowering drug, is reported to have immunomodulatory properties that attenuated acute lung injury independent of their major lipid lowering effects. Based on these reports, simvastatin is expected to be used for influenza prophylaxis and treatment. The present study evaluated the efficacy of simvastatin against influenza A/PR/8/34 virus infection in a murine model. In a first study, simvastatin was administered orally. To achieve high plasma levels, intraperitoneal application was used in a second study. Survival, body weight loss, viral titers in lung and trachea, and histologic lung injury were measured. Surprisingly, treatment with simvastatin resulted in lower survival rates and in more distinct body mass loss in comparison to virus‐infected control mice. Furthermore, the viral load in lungs and tracheas as well as histopathological lesions were not reduced by simvastatin. Overall, these results showed that simvastatin failed to protect mice against influenza virus infection. J Med. Virol. 85:1978–1982, 2013. © 2013 Wiley Periodicals, Inc.