bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractWe 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

AbstractA 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.
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

AbstractIn 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.
Scattered waves from low‐frequency earthquakes and plate boundary structure in northern Cascadia
Authors: Nowack Robert L. , Bostock Michael G. 
Published: August 2013

AbstractWe 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.
Stress and the engagement of multiple memory systems: Integration of animal and human studies
Authors: Schwabe Lars 
Published: August 2013

ABSTRACTLearning 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

ABSTRACTWhile 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

ABSTRACTNeurobehavioral 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

ABSTRACTThe 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

AbstractMost 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

ABSTRACTIn 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

ABSTRACT

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

ABSTRACT

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 &gt;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 &lt; 0.001) and time varying factor of bone fracture (HR = 1.43; p &lt; 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

ABSTRACT

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.