bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forkhead Transcription Factor Foxq1 Promotes Epithelial–Mesenchymal Transition and Breast Cancer Metastasis
Authors: Zhang Haijun , Meng Fanyan , Liu Gang , Zhang Bin , Zhu Jun , Wu Feng , Ethier Stephen P. , Miller Fred , Wu Guojun 
Published: February 2011

Abstract
Epithelial–mesenchymal transition (EMT) promotes cancer invasion and metastasis, but the integrative mechanisms that coordinate these processes are incompletely understood. In this study, we used a cross-species expression profiling strategy in metastatic cell lines of human and mouse origin to identify 22 up-regulated and 12 down-regulated genes that are part of an essential genetic program in metastasis. In particular, we identified a novel function in metastasis that was not previously known for the transcription factor Forkhead Box Q1 (Foxq1). Ectopic expression of Foxq1 increased cell migration and invasion in vitro, enhanced the lung metastatic capabilities of mammary epithelial cells in vivo, and triggered a marked EMT. In contrast, Foxq1 knockdown elicited converse effects on these phenotypes in vitro and in vivo. Neither ectopic expression nor knockdown of Foxq1 significantly affected cell proliferation or colony formation in vitro. Notably, Foxq1 repressed expression of the core EMT regulator E-cadherin by binding to the E-box in its promoter region. Further mechanistic investigation revealed that Foxq1 expression is regulated by TGF-β1, and that Foxq1 knockdown blocked TGF-β1-induced EMT at both morphological and molecular levels. Our findings highlight the feasibility of cross-species expression profiling as a strategy to identify metastasis-related genes, and they reveal that EMT induction is a likely mechanism underlying a novel metastasis-promoting function of Foxq1 defined here in breast cancer. Cancer Res; 71(4); 1292–301. ©2011 AACR.
Annual Cycle of Surface Longwave Radiation
Authors: Mlynczak Pamela E. , Smith G. Louis , Wilber Anne C. , Stackhouse Paul W. 
Published: February 2011

AbstractThe annual cycles of upward and downward longwave fluxes at the earth’s surface are investigated by use of the NASA Global Energy and Water Cycle Experiment (GEWEX) Surface Radiation Budget Dataset. Principal component analysis is used to quantify the annual cycles. Because of the immense difference between the heat capacity of land and ocean, the surface of the earth is partitioned into these two categories. Over land, the first principal component describes over 95% of the variance of the annual cycle of the upward and downward longwave fluxes. Over ocean the first term describes more than 87% of these annual cycles. Empirical orthogonal functions show the corresponding geographical distributions of these cycles. Phase-plane diagrams of the annual cycles of upward longwave fluxes as a function of net shortwave flux show the thermal inertia of land and ocean.
Dynamical Evolution of North Atlantic Ridges and Poleward Jet Stream Displacements
Authors: Woollings Tim , Pinto Joaquim G. , Santos João A. 
Published: February 2011

Abstract
The development of a particular wintertime atmospheric circulation regime over the North Atlantic, comprising a northward shift of the North Atlantic eddy-driven jet stream and an associated strong and persistent ridge in the subtropics, is investigated. Several different methods of analysis are combined to describe the temporal evolution of the events and relate it to shifts in the phase of the North Atlantic Oscillation and East Atlantic pattern. First, the authors identify a close relationship between northward shifts of the eddy-driven jet, the establishment and maintenance of strong and persistent ridges in the subtropics, and the occurrence of upper-tropospheric anticyclonic Rossby wave breaking over Iberia. Clear tropospheric precursors are evident prior to the development of the regime, suggesting a preconditioning of the Atlantic jet stream and an upstream influence via a large-scale Rossby wave train from the North Pacific. Transient (2–6 days) eddy forcing plays a dual role, contributing to both the initiation and then the maintenance of the circulation anomalies. During the regime there is enhanced occurrence of anticyclonic Rossby wave breaking, which may be described as low-latitude blocking-like events over the southeastern North Atlantic. A strong ridge is already established at the time of wave-breaking onset, suggesting that the role of wave-breaking events is to amplify the circulation anomalies rather than to initiate them. Wave breaking also seems to enhance the persistence, since it is unlikely that a persistent ridge event occurs without being also accompanied by wave breaking.
Do Planetary Wave Dynamics Contribute to Equable Climates?
Authors: Lee Sukyoung , Feldstein Steven , Pollard David , White Tim 
Published: February 2011

Abstract
Viable explanations for equable climates of the Cretaceous and early Cenozoic (from about 145 to 50 million years ago), especially for the above-freezing temperatures detected for high-latitude continental winters, have been a long-standing challenge. In this study, the authors suggest that enhanced and localized tropical convection, associated with a strengthened paleo–warm pool, may contribute toward high-latitude warming through the excitation of poleward-propagating Rossby waves. This warming takes place through the poleward heat flux and an overturning circulation that accompany the Rossby waves. This mechanism is tested with an atmosphere–mixed layer ocean general circulation model (GCM) by imposing idealized localized heating and compensating cooling, a heating structure that mimics the effect of warm-pool convective heating.
The localized tropical heating is indeed found to contribute to a warming of the Arctic during the winter. Within the range of 0–150 W m−2 for the heating intensity, the average rate for the zonal mean Arctic surface warming is 0.8°C per (10 W m−2) increase in the heating for the runs with an atmospheric CO2 level of 4 × PAL (Preindustrial Atmospheric Level, 1 PAL = 280 ppmv), the Cretaceous and early Cenozoic values considered for this study. This rate of warming for the Arctic is lower in model runs with 1 × PAL CO2, which show an increase of 0.3°C per (10 W m−2). Further increase of the heating intensity beyond 150 W m−2 produces little change in the Arctic surface air temperature. This saturation behavior is interpreted as being a result of nonlinear wave–wave interaction, which leads to equatorward wave refraction.
Under the 4 × PAL CO2 level, raising the heating from 120 W m−2 (estimated warm-pool convective heating value for the present-day climate) to 150 and 180 W m −2 (estimated values for the Cretaceous and early Cenozoic) produces a warming of 4°–8°C over northern Siberia and the adjacent Arctic Ocean. Relative to the warming caused by a quadrupling of CO2 alone, this temperature increase accounts for about 30% of the warming over this region. The possible influence of warm-pool convective heating on the present-day Arctic is also discussed.
Scales, Growth Rates, and Spectral Fluxes of Baroclinic Instability in the Ocean
Authors: Tulloch Ross , Marshall John , Hill Chris , Smith K. Shafer 
Published: February 2011

Abstract
An observational, modeling, and theoretical study of the scales, growth rates, and spectral fluxes of baroclinic instability in the ocean is presented, permitting a discussion of the relation between the local instability scale; the first baroclinic deformation scale Rdef; and the equilibrated, observed eddy scale. The geography of the large-scale, meridional quasigeostrophic potential vorticity (QGPV) gradient is mapped out using a climatological atlas, and attention is drawn to asymmetries between midlatitude eastward currents and subtropical return flows, the latter of which has westward and eastward zonal velocity shears. A linear stability analysis of the climatology, under the “local approximation,” yields the growth rates and scales of the fastest-growing modes. Fastest-growing modes on eastward-flowing currents, such as the Kuroshio and the Antarctic Circumpolar Current, have a scale somewhat larger (by a factor of about 2) than Rdef. They are rapidly growing (e folding in 1–3 weeks) and deep reaching, and they can be characterized by an interaction between interior QGPV gradients, with a zero crossing in the QGPV gradient at depth. In contrast, fastest-growing modes in the subtropical return flows (as well as much of the gyre interiors) have a scale smaller than Rdef (by a factor of between 0.5 and 1), grow more slowly (e-folding scale of several weeks), and owe their existence to the interaction of a positive surface QGPV gradient and a negative gradient beneath.
These predictions of linear theory under the local approximation are then compared to observed eddy length scales and spectral fluxes using altimetric data. It is found that the scale of observed eddies is some 2–3 times larger than the instability scale, indicative of a modest growth in horizontal scale. No evidence of an inverse cascade over decades in scale is found. Outside of a tropical band, the eddy scale varies with latitude along with but somewhat less strongly than Rdef.
Finally, exactly the same series of calculations is carried out on fields from an idealized global eddying model, enabling study in a more controlled setting. Broadly similar conclusions are reached, thus reinforcing inferences made from the data.
Significance of the Coupled Term in the Doppler Weather Radar Spectrum Width Equation
Authors: Fang Ming , Doviak Richard J. , Albrecht Bruce A. 
Published: February 2011

AbstractThere is an additional zero mean random variable term that couples mean wind shear and turbulence in the Doppler radar spectrum width equation. This random variable, labeled the “coupled term,” has been neglected heretofore in the literature. Herein, the variance of the squared spectrum width ascribed to this coupled term is determined from data collected with a Weather Surveillance Radar-1988 Doppler (WSR-88D) in two snowstorms; it can exceed 1 m4 s−4. Thus, this coupled term can be a significant contributor to the variance of the spectrum width and must be considered when using spectrum width to deduce turbulence.
Effects of an Age-Specific Anterior Cruciate Ligament Injury Prevention Program on Lower Extremity Biomechanics in Children
Authors: DiStefano Lindsay J. , Blackburn J. Troy , Marshall Stephen W. , Guskiewicz Kevin M. , Garrett William E. , Padua Darin A. 
Published: February 2011

Background: Implementing an anterior cruciate ligament injury prevention program to athletes before the age at which the greatest injury risk occurs (15-17 years) is important from a prevention standpoint. However, it is unknown whether standard programs can modify lower extremity biomechanics in pediatric populations or if specialized training is required. Hypothesis/Purpose: To compare the effects of traditional and age-specific pediatric anterior cruciate ligament injury prevention programs on lower extremity biomechanics during a cutting task in youth athletes. The authors hypothesized that the age-specific pediatric program would result in greater sagittal plane motion (ie, hip and knee flexion) and less motion in the transverse and frontal plane (ie, knee valgus, knee and hip rotation) as compared with the traditional program. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Sixty-five youth soccer athletes (38 boys, 27 girls) volunteered to participate. The mean age of participants was 10 ± 1 years. Teams (n, 7) were cluster randomized to a pediatric injury prevention program, a traditional injury prevention program, or a control group. The pediatric program was modified from the traditional program to include more feedback, progressions, and variety. Teams performed their programs as part of their normal warm-up routine. Three-dimensional lower extremity biomechanics were assessed during a sidestep cutting task before and after completion of the 9-week intervention period. Results: The pediatric program reduced the amount of knee external rotation at initial ground contact during the cutting task, F(2,62) = 3.79, P = .03 (change: pediatric, 7.73° ± 10.71°; control, –0.35° ± 7.76°), as compared with the control group after the intervention period. No other changes were observed. Conclusion: The injury prevention program designed for a pediatric population modified only knee rotation during the cutting task, whereas the traditional program did not result in any changes in cutting biomechanics. These findings suggest limited effectiveness of both programs for athletes younger than 12 years of age in terms of biomechanics during a cutting task.
Articular Cartilage Changes in Patients With Osteoarthritis After Osteotomy
Authors: Parker David A. , Beatty Karen T. , Giuffre Bruno , Scholes Corey J. , Coolican Myles R. J. 
Published: February 2011

Background: High tibial osteotomy (HTO) is a method used to treat medial compartmental osteoarthritis in the knee. The realignment of the knee changes the loading patterns within the joint and may allow for regeneration of articular cartilage. Magnetic resonance imaging methods can be used to assess the quality of the regenerated cartilage. Hypothesis: Altering mechanical alignment through HTO will have predictable effects on articular cartilage, allowing cartilage preservation and possible regeneration. Quality of regenerated cartilage will be inferior to normal articular cartilage. Study Design: Case series; Level of evidence, 4. Methods: Ten patients undergoing medial opening wedge HTO were evaluated using dGEMRIC methods (ie, delayed gadolinium-enhanced magnetic resonance imaging of cartilage) preoperatively and at 6 months, 1 year, and 2 years after HTO. Magnetic resonance images were evaluated by hand segmentation, and T1Gd relaxation times reflective of glycosaminoglycan content were determined for these regions of interest using magnetic resonance imaging analysis software. Results: The lateral compartment displayed higher T1Gd values than the medial compartment at baseline. Initially, a decrease in T1Gd values on the medial side were observed for all patients at 6 months and remained reduced for all but 2 participants at 1 year and 2 years after HTO. However, on the medial side after 6 months, the rate of change for T1Gd values shifted from being negative (−9.6 milliseconds per month) to being positive (1.7 milliseconds per month). A positive change in the T1Gd of the medial tibial plateau was responsible for the positive overall change in the medial compartment. There was no significant difference in the rate of change on the lateral side ( P = .141), with the average over the 2-year period being a decrease of 2.28 milliseconds per month. Conclusion: Medial opening wedge HTO provides subjective improvements in pain and quality of life, but the potential benefit of allowing articular cartilage preservation and possible regeneration is not well established. Results showed that after a nonweightbearing period, the rate of change in the medial compartment changes from negative to positive, indicating the potential for articular cartilage recovery secondary to an improved mechanical environment.
Sagittal Alignment of the Knee and Its Relationship to Noncontact Anterior Cruciate Ligament Injuries
Authors: Terauchi Masanori , Hatayama Kazuhisa , Yanagisawa Sinya , Saito Kenichi , Takagishi Kenji 
Published: February 2011

Background: Knee hyperextension and tibial posterior slope are related to sagittal alignment of the knee. The relationship of sagittal alignment to noncontact anterior cruciate ligament (ACL) injuries has been reported with conflicting results. Purpose: To determine whether there is a difference in sagittal alignment of the knee between an ACL-deficient group and a negative control group and to find risk factors contributing to noncontact ACL injuries. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Magnetic resonance images of the knee in full extension were acquired in the patient group, which consisted of 33 male and 40 female patients with noncontact ACL injuries, and in the negative control group, which consisted of 28 male and 30 female participants. Three angles were measured: the angle between the femoral axis and the tibial axis, designated as the extension angle; the femoral plateau angle, between the femoral axis and a line tangent to the concave profile of the medial tibial plateau (P line); and the tibial posterior slope angle, 90° minus the angle made by the intersection of the tibial axis and the P line. Results: In the female group, the femoral plateau angle and the tibial posterior slope angle were significantly larger in the ACL-deficient patients than in the negative control group, although these differences were not seen in the male group. In the female subjects, a negative correlation between the extension angle and the tibial posterior slope angle was seen in the ACL-deficient group, suggesting that knees with hyperextension had a small tibial posterior slope, whereas knees without hyperextension had a large tibial posterior slope. Conclusion: There were 2 types of large femoral plateau angles: one had its origin in an increasing tibial posterior slope; the other resulted from hyperextension of the knee. Large posterior tibial slope and hyperextension are both correlated with noncontact ACL injury in women.
Activation of the unfolded protein response is associated with impaired granulopoiesis in transgenic mice expressing mutant Elane
Authors: Nanua Suparna , Murakami Mark , Xia Jun , Grenda David S. , Woloszynek Jill , Strand Marie , Link Daniel C. 
Published: February 2011

AbstractSevere congenital neutropenia (SCN) is an inborn disorder of granulopoiesis that in many cases is caused by mutations of the ELANE gene, which encodes neutrophil elastase (NE). Recent data suggest a model in which ELANE mutations result in NE protein misfolding, induction of endoplasmic reticulum (ER) stress, activation of the unfolded protein response (UPR), and ultimately a block in granulocytic differentiation. To test this model, we generated transgenic mice carrying a targeted mutation of Elane (G193X) reproducing a mutation found in SCN. The G193X Elane allele produces a truncated NE protein that is rapidly degraded. Granulocytic precursors from G193X Elane mice, though without significant basal UPR activation, are sensitive to chemical induction of ER stress. Basal and stress granulopoiesis after myeloablative therapy are normal in these mice. Moreover, inaction of protein kinase RNA-like ER kinase (Perk), one of the major sensors of ER stress, either alone or in combination with G193X Elane, had no effect on basal granulopoiesis. However, inhibition of the ER-associated degradation (ERAD) pathway using a proteosome inhibitor resulted in marked neutropenia in G193X Elane. The selective sensitivity of G913X Elane granulocytic cells to ER stress provides new and strong support for the UPR model of disease patho-genesis in SCN.
Regulation of Insulin-Stimulated Glucose Uptake in Rat White Adipose Tissue upon Chronic Central Leptin Infusion: Effects on Adiposity
Authors: Bonzón-Kulichenko Elena , Fernández-Agulló Teresa , Moltó Eduardo , Serrano Rosario , Fernández Alejandro , Ros Manuel , Carrascosa José M. , Arribas Carmen , Martínez Carmen , Andrés Antonio , Gallardo Nilda 
Published: February 2011

Abstract
Leptin enhances the glucose utilization in most insulin target tissues and paradoxically decreases it in white adipose tissue (WAT), but knowledge of the mechanisms underlying the inhibitory effect of central leptin on the insulin-dependent glucose uptake in WAT is limited. After 7 d intracerebroventricular leptin treatment (0.2 μg/d) of rats, the overall insulin sensitivity and the responsiveness of WAT after acute in vivo insulin administration were analyzed. We also performed unilateral WAT denervation to clarify the role of the autonomic nervous system in leptin effects on the insulin-stimulated [3H]-2-deoxyglucose transport in WAT. Central leptin improved the overall insulin sensitivity but decreased the in vivo insulin action in WAT, including insulin receptor autophosphorylation, insulin receptor substrate-1 tyrosine-phosphorylation, and Akt activation. In this tissue, insulin receptor substrate-1 and glucose transporter 4 mRNA and protein levels were down-regulated after central leptin treatment. Additionally, a remarkable up-regulation of resistin, together with an augmented expression of suppressor of cytokine signaling 3 in WAT, was also observed in leptin-treated rats. As a result, the insulin-stimulated glucose transporter 4 insertion at the plasma membrane and the glucose uptake in WAT were impaired in leptin-treated rats. Finally, denervation of WAT abolished the inhibitory effect of central leptin on glucose transport and decreased suppressor of cytokine signaling 3 and resistin levels in this tissue, suggesting that resistin, in an autocrine/paracrine manner, might be a mediator of central leptin antagonism of insulin action in WAT. We conclude that central leptin, inhibiting the insulin-stimulated glucose uptake in WAT, may regulate glucose availability for triacylglyceride formation and accumulation in this tissue, thereby contributing to the control of adiposity.
Impairment of Peripheral Circadian Clocks Precedes Metabolic Abnormalities in ob/ob Mice
Authors: Ando Hitoshi , Kumazaki Masafumi , Motosugi Yuya , Ushijima Kentarou , Maekawa Tomohiro , Ishikawa Eiko , Fujimura Akio 
Published: February 2011

Abstract
Recent studies have demonstrated relationships between the dysfunction of circadian clocks and the development of metabolic abnormalities, but the chicken-and-egg question remains unresolved. To address this issue, we investigated the cause-effect relationship in obese, diabetic ob/ob mice. Compared with control C57BL/6J mice, the daily mRNA expression profiles of the clock and clock-controlled genes Clock, Bmal1, Cry1, Per1, Per2, and Dbp were substantially dampened in the liver and adipose tissue, but not the hypothalamic suprachiasmatic nucleus, of 10-wk-old ob/ob mice. Four-week feeding of a low-calorie diet and administration of leptin over a 7-d period attenuated, to a significant and comparable extent, the observed metabolic abnormalities (obesity, hyperglycemia, hyperinsulinemia, and hypercholesterolemia) in the ob/ob mice. However, only leptin treatment improved the impaired peripheral clocks. In addition, clock function, assessed by measuring levels of Per1, Per2, and Dbp mRNA at around peak times, was also reduced in the peripheral tissues of 3-wk-old ob/ob mice without any overt metabolic abnormalities. Collectively these results indicate that the impairment of peripheral clocks in ob/ob mice does not result from metabolic abnormalities but may instead be at least partially caused by leptin deficiency itself. Further studies are needed to clarify how leptin deficiency affects peripheral clocks.