bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasound in Labor and Delivery
Authors: Molina Francisca S. , Nicolaides Kypros H.
Published: March 2010

Ultrasound may play an important role in the management of labor and delivery. Induction of labor is a common obstetric intervention, performed in about 20% of pregnancies. Pre-induction cervical length, measured by transvaginal sonography, has been shown to have a significant association with the induction-to-delivery interval and the risk for cesarean section. In the management of labor there is extensive evidence that digital pelvic examination does not provide accurate assessment of the position and descend of the fetal head both during the first but also in the second stage of labor. Several recent studies using both two- and three-dimensional ultrasound have now described objective measures of progression of the fetal head during labor. In instrumental deliveries an important determinant of a successful and safe use of vacuum and forceps is the correct determination of the fetal head position and appropriate application of the instrument. However, ultrasound studies have shown that digital examination before instrumental delivery fails to identify the correct fetal position in a high proportion of cases. The use of ultrasound is of crucial importance in performing a safe operative delivery and can help in the prediction of whether a vaginal delivery would be successful.
Impact of Quality of Nuchal Translucency Measurements on Detection Rates of Trisomies 13 and 18
Authors: Evans Mark I. , Pergament Eugene
Published: March 2010

Objective: To determine the relative contribution of nuchal translucency (NT) to the biochemical detection rates of combined screening for trisomies 13 and 18 in two healthcare systems practicing different quality-control systems of nuchal measurement. Methods: De-identified data collected from the Fetal Medicine Foundation in the United Kingdom and laboratory data from NTD laboratories in the United States were compared for detection rate and false-positive rate (FPR) for combined trisomies 13 and 18 screening and were subcategorized by biochemical only and biochemistry combined with NT measurement. Results: US and UK biochemical detection rates were virtually identical: 83% for a FPR of 1.8%. When NT measurement was added, the US rate increased to 88% for a 0.7 FPR, but in the UK the rate increased to 94% for a FPR of 0.3%. The mean NT was 1.69 mm in the US and 2.82 mm in the UK. Conclusions: NT measurement as practiced in the UK system with tight quality control significantly increased the detection rate and significantly reduced the FPR of combined screening for trisomies 13 and 18, when compared to the US with apparently less rigid quality control.
Maternal Serum Placental Protein 13 at Eleven to Thirteen Weeks in Chromosomally Abnormal Pregnancies
Authors: Akolekar Ranjit , Pérez Penco José María , Skyfta Evdoxia , Rodríguez Calvo Jesús , Nicolaides Kypros H.
Published: March 2010

Objective: To investigate whether the maternal serum concentration of placental protein 13 (PP13) is altered in chromosomally abnormal pregnancies and to examine the potential value of this placental protein in screening for aneuploidies at 11–13 weeks. Methods: The maternal serum concentration of PP13 at 11–13 weeks was compared in 536 euploid and 134 aneuploid pregnancies (trisomy 21: n = 49; trisomy 18: n = 28; trisomy 13: n = 19; Turner syndrome: n = 28; triploidy: n = 10). Results: Serum PP13, expressed as multiples of the median (MoM) of the euploid group, was not significantly different in trisomy 21 (1.12 MoM) pregnancies, but the levels were decreased in trisomy 18 (0.75 MoM), trisomy 13 (0.65 MoM), Turner syndrome (0.61 MoM) and triploidy (0.19 MoM). In both euploid and aneuploid pregnancies there was a significant association of serum PP13 with both serum pregnancy-associated plasma protein A (PAPP-A) and free β-human chorionic gonadotropin (β-hCG; p < 0.0001 for both). Logistic regression analysis demonstrated that the addition of serum PP13 did not improve the prediction of trisomy 13 and 18 provided by a combination of maternal age, nuchal translucency, and serum free β-hCG and PAPP-A. Conclusion: The measurement of maternal serum PP13 at 11–13 weeks does not improve the performance of screening for aneuploidies achieved by current algorithms.
Leucine at Position 383 of Fusion Protein Is Responsible for Fusogenicity of Wild-Type Mumps Virus in B95a Cells
Authors: Yoshida Naoko , Nakayama Tetsuo
Published: March 2010

Objective: Mumps virus is isolated in Vero cells and, recently, B95a cells have been reported to be susceptible to it. Currently circulating wild-type mumps virus strains (genotypes B, G, J and L) induced cytopathic effects in both Vero and B95a cells. On the other hand, the Hoshino vaccine strain (KO3) did not induce cytopathic effects in B95a cells. In this study, differences in fusion inducibility were investigated. Methods: Nucleotide sequences of the fusion (F) and hemagglutinin-neuraminidase (HN) protein regions were compared. The F and HN expression plasmids were constructed and fusion analysis was conducted, using recombinant F expression plasmids under the control of T7 RNA polymerase. Results: Extensive cell fusion was observed when B95a cells were transfected with the wild-type F expression plasmid as the F expression partner; 13–16 amino acid differences were observed in the F protein region between the KO3 and the wild types. F expression plasmids with leucine at position 383 of the F protein induced large cell fusion in B95a cells. Conclusion: Leucine at position 383 of the F protein of the wild types was the critical amino acid for fusion inducibility in B95a cells.
Response to Adefovir Depends on Mutation Patterns in Precore Region, Basal Core Promoter and Reverse Transcriptase, and On-Treatment Responses in Lamivudine-Resistant Chronic Hepatitis B Patients
Authors: Song Byung-Cheol , Cui Xiu Ji , Shin Jung Woo , Park Neung Hwa , Cho Yoo-Kyung , Song Hyun Joo , Hyun Soyoung , Jeong Seung Uk , Choi Eun Kwang , Kim Heung Up
Published: March 2010

Objective: In vitro studies showed that mutations in the basal core promoter (BCP) or precore (PC) region restore the replication inefficiency of the lamivudine-resistant mutant. The aim of this study was to clarify the effect of molecular characteristics on the antiviral response to adefovir in patients with lamivudine-resistant chronic hepatitis B (CHB). Methods: Sixty-six lamivudine-resistant patients who were treated with adefovir monotherapy were studied. Sequences of BCP, PC region and reverse transcriptase were determined before adefovir therapy. In patients with virologic breakthrough, reverse transcriptase sequencing was performed. Results: The cumulative probabilities of virologic response were 23.3, 46, 52.7 and 59.5% at years 1, 2, 3 and 4, respectively. PC mutation, the absence of compensatory mutations (rtL80I/V or rtV173L), and a decrease in serum hepatitis B virus (HBV) DNA by 3 log or greater at 6 months were independent predictors of virologic response. The cumulative probabilities of virologic breakthrough were 0, 12.9, 30.7 and 44.5% at years 1, 2, 3 and 4, respectively. BCP mutation and a less than 3 log decrease in serum HBV DNA at 6 months were 2 independent risk factors for virologic breakthrough. Conclusion: Response to adefovir depends on mutation patterns in the BCP, PC region and reverse transcriptase, and on-treatment decreases in serum HBV DNA in lamivudine-resistant CHB patients.
Oxidative Stress Regulates Left Ventricular PDE5 Expression in the Failing Heart
Authors: Lu Zhongbing , Xu Xin , Hu Xinli , Lee Sangjin , Traverse Jay H. , Zhu Guangshuo , Fassett John , Tao Yi , Zhang Ping , Remedios Cris dos , Pritzker Marc , Hall Jennifer L. , Garry Daniel J. , Chen Yingjie
Published: March 2010

Background—

Phosphodiesterase type 5 (PDE5) inhibition has been shown to exert profound beneficial effects in the failing heart, suggesting a significant role for PDE5 in the development of congestive heart failure (CHF). The purpose of this study is to test the hypothesis that oxidative stress causes increased PDE5 expression in cardiac myocytes and that increased PDE5 contributes to the development of CHF.

Methods and Results—

Myocardial PDE5 expression and cellular distribution were determined in left ventricular samples from patients with end-stage CHF and normal donors and from mice after transverse aortic constriction (TAC)-induced CHF. Compared with donor human hearts, myocardial PDE5 protein was increased ≈4.5-fold in CHF samples, and the increase of myocardial PDE5 expression was significantly correlated with myocardial oxidative stress markers 3′-nitrotyrosine or 4-hydroxynonenal expression (
P
<0.05). Histological examination demonstrated that PDE5 was mainly expressed in vascular smooth muscle in normal donor hearts, but its expression was increased in both cardiac myocytes and vascular smooth muscle of CHF hearts. Myocardial PDE5 protein content and activity also increased in mice after TAC-induced CHF (
P
<0.05). When the superoxide dismutase (SOD) mimetic M40401 was administered to attenuate oxidative stress, the increased PDE5 protein and activity caused by TAC was blunted, and the hearts were protected against left ventricular hypertrophy and CHF. Conversely, increased myocardial oxidative stress in superoxide dismutase 3 knockout mice caused a greater increase of PDE5 expression and CHF after TAC. In addition, administration of sildenafil to inhibit PDE5 attenuated TAC-induced myocardial oxidative stress, PDE5 expression, and CHF.

Conclusions—

Myocardial oxidative stress increases PDE5 expression in the failing heart. Reducing oxidative stress by treatment with M40401 attenuated cardiomyocyte PDE5 expression. This and selective inhibition of PDE5 protected the heart against pressure overload-induced left ventricular hypertrophy and CHF.
Early Surgery Versus Conventional Treatment in Asymptomatic Very Severe Aortic Stenosis
Authors: Kang Duk-Hyun , Park Sung-Ji , Rim Ji Hye , Yun Sung-Cheol , Kim Dae-Hee , Song Jong-Min , Choo Suk Jung , Park Seung Woo , Song Jae-Kwan , Lee Jae-Won , Park Pyo-Won
Published: March 2010

Background—

The optimal timing of surgical intervention remains controversial in asymptomatic patients with very severe aortic stenosis. We therefore compared the long-term results of early surgery and a conventional treatment strategy.

Methods and Results—

From 1996 to 2006, we prospectively included a total of 197 consecutive asymptomatic patients (99 men; age, 63±12 years) with very severe aortic stenosis. Patients were excluded if they had angina, syncope, exertional dyspnea, ejection fraction <0.50, significant mitral valve disease, or age >85 years. Very severe aortic stenosis was defined as a critical stenosis in the aortic valve area ≤0.75 cm
2
accompanied by a peak aortic jet velocity ≥4.5 m/s or a mean transaortic pressure gradient ≥50 mm Hg on Doppler echocardiography. The primary end point was defined as the composite of operative mortality and cardiac death during follow-up. Early surgery was performed on 102 patients, and a conventional treatment strategy was used for 95 patients. There were no significant differences between the 2 groups in terms of age, gender, European System for Cardiac Operative Risk Evaluation score, or ejection fraction. During a median follow-up of 1501 days, the operated group had no operative mortalities, no cardiac deaths, and 3 noncardiac deaths; the conventional treatment group had 18 cardiac and 10 noncardiac deaths. The estimated actuarial 6-year cardiac and all-cause mortality rates were 0% and 2±1% in the operated group and 24±5% and 32±6% in the conventional treatment group, respectively (
P
<0.001), and for 57 propensity score-matched pairs, the risk of all-cause mortality was significantly lower in the operated group than in the conventional treatment group (hazard ratio, 0.135; 95% confidence interval, 0.030 to 0.597;
P
=0.008).

Conclusions—

Compared with the conventional treatment strategy, early surgery in patients with very severe aortic stenosis is associated with an improved long-term survival by decreasing cardiac mortality. Early surgery is therefore a therapeutic option to further improve clinical outcomes in asymptomatic patients with very severe aortic stenosis and low operative risk.
Factor XIIa Inhibitor Recombinant Human Albumin Infestin-4 Abolishes Occlusive Arterial Thrombus Formation Without Affecting Bleeding
Authors: Hagedorn Ina , Schmidbauer Stefan , Pleines Irina , Kleinschnitz Christoph , Kronthaler Ulrich , Stoll Guido , Dickneite Gerhard , Nieswandt Bernhard
Published: March 2010

Background—

Blood coagulation is a tightly regulated process of sequentially activated serine proteases culminating in fibrin formation, which is critical for limiting posttraumatic blood loss but also may contribute to acute thrombotic diseases, most notably myocardial infarction and stroke. Recent studies with factor XII–deficient mice revealed that the factor XII–induced intrinsic coagulation pathway is essential for pathological thrombus formation but dispensable for hemostasis. Consequently, these findings led to the hypothesis that factor XII could be a promising pharmacological target for safe antithrombotic therapy.

Methods and Results—

The complementary DNA of the previously described factor XIIa inhibitor Infestin-4, cloned from the midgut of
Triatoma infestans
, was fused to recombinant human albumin (rHA) and analyzed in vitro. The resulting protein rHA-Infestin-4 specifically inhibits factor XIIa and causes prolonged activated partial thromboplastin time in human, mouse, and rat plasma. To assess its inhibitory potency in vivo, mice and rats were injected with rHA-Infestin-4 and challenged in pathological thrombus formation models. In addition, bleeding assays were performed. rHA-Infestin-4 completely abolished occlusive arterial thrombus formation in mice and rats while leaving hemostasis fully intact. Furthermore, rHA-Infestin-4 was highly protective in a murine model of ischemic stroke.

Conclusion—

These results identify rHA-Infestin-4 as a promising agent to achieve powerful protection from ischemic cardiovascular and cerebrovascular events without affecting hemostasis.
Increased Sensitivity to Angiotensin II Is Present Postpartum in Women With a History of Hypertensive Pregnancy
Authors: Saxena Aditi R. , Karumanchi S. Ananth , Brown Nancy J. , Royle Caroline M. , McElrath Thomas F. , Seely Ellen W.
Published: March 2010

Pregnancies complicated by new-onset hypertension are associated with increased sensitivity to angiotensin II, but it is unclear whether this sensitivity persists postpartum. We studied pressor response to infused angiotensin II in 25 normotensive postpartum women in both high- and low-sodium balance. Ten women had a history of hypertensive pregnancy (5 with preeclampsia; 5 with transient hypertension of pregnancy), and 15 women had a history of uncomplicated, normotensive pregnancy. Systolic and diastolic blood pressures, aldosterone, and soluble fms-like tyrosine kinase 1 levels were measured before and after angiotensin II infusion in both dietary phases. In high sodium balance, women with a history of hypertensive pregnancy were normotensive but had significantly higher systolic and diastolic blood pressures than controls (115 versus 104 mm Hg and 73 versus 65 mm Hg, respectively;
P
<0.05). Women with a history of hypertensive pregnancy had a pressor response to salt loading, demonstrated by an increase in systolic blood pressure on a high-salt diet. They also had greater systolic pressor response (10 versus 2 mm Hg;
P
=0.03), greater increase in aldosterone (56.8 versus 30.8 ng/dL;
P
=0.03), and increase in soluble fms-like tyrosine kinase 1 levels (11.0 versus −18.9 pg/mL;
P
=0.02) after infusion of angiotensin II in low-sodium balance compared with controls. Thus, women with a history of hypertensive pregnancy demonstrated salt sensitivity of blood pressure and had increased pressor, adrenal, and soluble fms-like tyrosine kinase 1 responses to infused angiotensin II in low-sodium balance. Increased sensitivity to angiotensin II observed during pregnancy in women with hypertensive pregnancy is present postpartum; this feature may contribute to future cardiovascular risk in these women.
Effect of Sodium Loading/Depletion on Renal Oxygenation in Young Normotensive and Hypertensive Men
Authors: Pruijm Menno , Hofmann Lucie , Maillard Marc , Tremblay Sylvie , Glatz Nicolas , Wuerzner Gregoire , Burnier Michel , Vogt Bruno
Published: March 2010

The goal of this study was to investigate the effect of sodium intake on renal tissue oxygenation in humans. To this purpose, we measured renal hemodynamics, renal sodium handling, and renal oxygenation in normotensive (NT) and hypertensive (HT) subjects after 1 week of a high-sodium and 1 week of a low-sodium diet. Renal oxygenation was measured using blood oxygen level–dependent magnetic resonance. Tissue oxygenation was determined by the measurement of R2* maps on 4 coronal slices covering both kidneys. The mean R2* values in the medulla and cortex were calculated, with a low R2* indicating a high tissue oxygenation. Ten male NT (mean age: 26.5±7.4 years) and 8 matched HT subjects (mean age: 28.8±5.7 years) were studied. Cortical R2* was not different under the 2 conditions of salt intake. Medullary R2* was significantly lower under low sodium than high sodium in both NT and HT subjects (28.1±0.8 versus 31.3±0.6 s
−1
;
P
<0.05 in NT; and 27.9±1.5 versus 30.3±0.8 s
−1
;
P
<0.05, in HT), indicating higher medullary oxygenation under low-sodium conditions. In NT subjects, medullary oxygenation was positively correlated with proximal reabsorption of sodium and negatively with absolute distal sodium reabsorption, but not with renal plasma flow. In HT subjects, medullary oxygenation correlated with the 24-hour sodium excretion but not with proximal or with the distal handling of sodium. These data demonstrate that dietary sodium intake influences renal tissue oxygenation, low sodium intake leading to an increased renal medullary oxygenation both in normotensive and young hypertensive subjects.
Prevalence of Chronic Kidney Disease in Persons With Undiagnosed or Prehypertension in the United States
Authors: Crews Deidra C. , Plantinga Laura C. , Miller Edgar R. , Saran Rajiv , Hedgeman Elizabeth , Saydah Sharon H. , Williams Desmond E. , Powe Neil R.
Published: March 2010

Hypertension is both a cause and a consequence of chronic kidney disease, but the prevalence of chronic kidney disease throughout the diagnostic spectrum of blood pressure has not been established. We determined the prevalence of chronic kidney disease within blood pressure categories in 17 794 adults surveyed by the National Health and Nutrition Examination Survey during 1999–2006. Diagnosed hypertension was defined as self-reported provider diagnosis (n=5832); undiagnosed hypertension was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg, without report of provider diagnosis (n=3046); prehypertension was defined as systolic blood pressure ≥120 and <140 mm Hg or diastolic blood pressure ≥80 and <90 mm Hg (n=3719); and normal was defined as systolic blood pressure <120 mm Hg and diastolic blood pressure <80 mm Hg (n=5197). Chronic kidney disease was defined as estimated glomerular filtration rate <60 mL/min per 1.73 m
2
or urinary albumin:creatinine ratio >30 mg/g. Prevalences of chronic kidney disease among those with prehypertension and undiagnosed hypertension were 17.3% and 22.0%, respectively, compared with 27.5% with diagnosed hypertension and 13.4% with normal blood pressure, after adjustment for age, sex, and race in multivariable logistic regression. This pattern persisted with varying definitions of kidney disease; macroalbuminuria (urinary albumin:creatinine ratio >300 mg/g) had the strongest association with increasing blood pressure category (odds ratio: 2.37 [95% CI: 2.00 to 2.81]). Chronic kidney disease is prevalent in undiagnosed and prehypertension. Earlier identification and treatment of both these conditions may prevent or delay morbidity and mortality from chronic kidney disease.
A Climatology of Inland Winds from Tropical Cyclones for the Eastern United States
Authors: Kruk Michael C. , Gibney Ethan J. , Levinson David H. , Squires Michael
Published: March 2010

Tropical cyclones pose a significant threat to life and property along coastal regions of the United States. As these systems move inland and dissipate, they can also pose a threat to life and property, through heavy rains, high winds, and other severe weather such as tornadoes. While many studies have focused on the impacts from tropical cyclones on coastal counties of the United States, this study goes beyond the coast and examines the impacts caused by tropical cyclones on inland locations. Using geographical information system software, historical track data are used in conjunction with the radial maximum extent of the maximum sustained winds at 34-, 50-, and 64-kt (1 kt ≈ 0.5 m s−1) thresholds for all intensities of tropical cyclones and overlaid on a 30-km equal-area grid that covers the eastern half of the United States. The result is a series of maps with frequency distributions and an estimation of return intervals for inland tropical storm– and hurricane-force winds. Knowing where the climatologically favored areas are for tropical cyclones, combined with a climatological expectation of the inland penetration frequency of these storms, can be of tremendous value to forecasters, emergency managers, and the public.
The Midsummer Dry Spell’s Impact on Vegetation in Jamaica
Authors: Allen Theodore L. , Curtis Scott , Gamble Douglas W.
Published: March 2010

The annual rainfall pattern of the intra-Americas sea reveals a bimodal feature with a minimum during the midsummer known as the midsummer dry spell (MSD). A first attempt is made to examine the impact of the MSD on vegetation through a normalized difference vegetation index (NDVI) analysis in Jamaica. Tropical Rainfall Measuring Mission rainfall estimates and NDVI derived from the Terra Moderate Resolution Imaging Spectroradiometer highlight a consistent MSD feature in both rainfall and vegetative vigor. Spatial variation of this MSD NDVI response is evident throughout Jamaica, with the strongest relationship between the rainfall reduction and NDVI decline throughout the southern portions of Jamaica including the area of major domestic food production. In all years except 2005 there is a notable reduction from early-summer NDVI to midsummer NDVI in this agricultural region. However, the lagged vegetative response undergoes clear interannual variation and is affected by other forcings besides rainfall, such as brush fires and extreme wind.
Dissipative Energization of Baroclinic Waves by Surface Ekman Pumping
Authors: Lee Sukyoung
Published: March 2010

A two-layer quasigeostrophic model is used to study the effect of lower boundary Ekman pumping on the energetics of baroclinic waves. Although the direct impact of the Ekman pumping is to damp the total eddy energy, either the eddy available potential energy (EAPE) or the eddy kinetic energy (EKE), individually, can grow because of the Ekman pumping. Growth of EAPE is favored if the phase difference between the upper and lower wave fields is less than a quarter wavelength, and EKE is favored if the phase difference is greater than a quarter wavelength. A numerical model calculation shows that the EAPE growth occurs directly through the Ekman pumping and that the increased EAPE can in turn lead to further growth by strengthening the baroclinic energy conversion from zonal available potential energy to the EAPE. Through this indirect effect, the Ekman pumping can increase the net production of total eddy energy.
The Impact of ENSO on Wave Breaking and Southern Annular Mode Events
Authors: Gong Tingting , Feldstein Steven B. , Luo Dehai
Published: March 2010

This study examines the relationship between intraseasonal southern annular mode (SAM) events and the El Niño–Southern Oscillation (ENSO) using daily 40-yr ECMWF Re-Analysis (ERA-40) data. The data coverage spans the years 1979–2002, for the austral spring and summer seasons. The focus of this study is on the question of why positive SAM events dominate during La Niña and negative SAM events during El Niño. A composite analysis is performed on the zonal-mean zonal wind, Eliassen–Palm fluxes, and two diagnostic variables: the meridional potential vorticity gradient, a zonal-mean quantity that is used to estimate the likelihood of wave breaking, and the wave breaking index (WBI), which is used to evaluate the strength of the wave breaking. The results of this investigation suggest that the background zonal-mean flow associated with La Niña (El Niño) is preconditioned for strong (weak) anticyclonic wave breaking on the equatorward side of the eddy-driven jet, the type of wave breaking that is found to drive positive (negative) SAM events. A probability density function analysis of the WBI, for both La Niña and El Niño, indicates that strong anticyclonic wave breaking takes place much more frequently during La Niña and weak anticyclonic wave breaking during El Niño. It is suggested that these wave breaking characteristics, and their dependency on the background flow, can explain the strong preference for SAM events of one phase during ENSO. The analysis also shows that austral spring SAM events that coincide with ENSO are preceded by strong stratospheric SAM anomalies and then are followed by a prolonged period of wave breaking that lasts for approximately 30 days. These findings suggest that the ENSO background flow also plays a role in the excitation of stratospheric SAM anomalies and that the presence of these stratospheric SAM anomalies in turn excites and then maintains the tropospheric SAM anomalies via a positive eddy feedback.
On the Phase Relations between the Western North Pacific, Indian, and Australian Monsoons*
Authors: Gu Dejun , Li Tim , Ji Zhongping , Zheng Bin
Published: March 2010

The phase relationships of the western North Pacific (WNP) summer monsoon (WNPM) with the Australian monsoon (AM) and Indian monsoon (IM) are investigated using observational rainfall, SST, and NCEP reanalysis data for the period of 1979–2005. It is found that a strong WNPM often follows a strong AM but leads a weak AM, and a significant simultaneous negative correlation appears between WNPM and IM. The in-phase relationship from AM to the succeeding WNPM occurs often during the El Niño decaying phase when the warm eastern Pacific SST anomaly (SSTA) weakens AM through anomalous Walker circulation and the persistence of an anomalous WNP anticyclone from the boreal winter to summer leads to a weak WNPM. The out-of-phase relation from WNPM to the succeeding AM occurs either during the El Niño early onset year when the warm SSTA in June–August (JJA) is strong enough to force a low-level cyclonic flow anomaly in WNP and in December–February (DJF) the same warm SSTA forces a weak AM, or during the El Niño decaying phase when the persistence of the WNP anomalous anticyclone causes a weak WNPM and the transition of a warm to a cold episode causes a strong AM in DJF. The simultaneous negative correlation between WNPM and IM often appears either during the El Niño early onset years when the warm eastern Pacific SSTA induces the cyclonic wind shear that strengthens WNPM but suppresses convection over India, or during the El Niño decaying summer when a weak WNPM results from the persistence of the local anomalous anticyclone and a strong IM results from the El Niño-to-La Niña transition or a basin-wide Indian Ocean warming.
The Role of Mesoscale Eddies in the Rectification of the Southern Ocean Response to Climate Change
Authors: Farneti Riccardo , Delworth Thomas L. , Rosati Anthony J. , Griffies Stephen M. , Zeng Fanrong
Published: March 2010

Simulations from a fine-resolution global coupled model, the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.4 (CM2.4), are presented, and the results are compared with a coarse version of the same coupled model, CM2.1, under idealized climate change scenarios. A particular focus is given to the dynamical response of the Southern Ocean and the role played by the eddies—parameterized or permitted—in setting the residual circulation and meridional density structure. Compared to the case in which eddies are parameterized and consistent with recent observational and idealized modeling studies, the eddy-permitting integrations of CM2.4 show that eddy activity is greatly energized with increasing mechanical and buoyancy forcings, buffering the ocean to atmospheric changes, and the magnitude of the residual oceanic circulation response is thus greatly reduced. Although compensation is far from being perfect, changes in poleward eddy fluxes partially compensate for the enhanced equatorward Ekman transport, leading to weak modifications in local isopycnal slopes, transport by the Antarctic Circumpolar Current, and overturning circulation. Since the presence of active ocean eddy dynamics buffers the oceanic response to atmospheric changes, the associated atmospheric response to those reduced ocean changes is also weakened. Further, it is hypothesized that present numerical approaches for the parameterization of eddy-induced transports could be too restrictive and prevent coarse-resolution models from faithfully representing the eddy response to variability and change in the forcing fields.
What Sets the Strength of the Middepth Stratification and Overturning Circulation in Eddying Ocean Models?
Authors: Wolfe Christopher L. , Cessi Paola
Published: March 2010

The processes maintaining stratification in the oceanic middepth (between approximately 1000 and 3000 m) are explored using an eddy-resolving general circulation model composed of a two-hemisphere, semienclosed basin with a zonal reentrant channel in the southernmost eighth of the domain. The middepth region lies below the wind-driven main thermocline but above the diffusively driven abyssal ocean. Here, it is argued that middepth stratification is determined primarily in the model’s Antarctic Circumpolar Current. Competition between mean and eddy overturning in the channel leads to steeper isotherms and thus deeper stratification throughout the basin than would exist without the channel. Isotherms that outcrop only in the channel are nearly horizontal in the semienclosed portion of the domain, whereas isotherms that also outcrop in the Northern Hemisphere deviate from horizontal and are accompanied by geostrophically balanced meridional transport. A northern source of deep water (water with temperatures in the range of those in the channel) leads to the formation of a thick middepth thermostad. Changes in wind forcing over the channel influence the stratification throughout the domain. Since the middepth stratification is controlled by adiabatic dynamics in the channel, it becomes independent of the interior diffusivity κ as κ → 0. The meridional overturning circulation (MOC), as diagnosed by the mean meridional volume transport, also shows a tendency to become independent of κ as κ → 0, whereas the MOC diagnosed by water mass transport shows a continuing dependence on κ as κ → 0. A nonlocal scaling for MOC is developed that relates the strength of the northern MOC to the depth of isotherms in the southern channel. The results of this paper compare favorably to observations of large-scale neutral density in the World Ocean.
A Study of the NOAA Near-Nadir AMSU-A Brightness Temperatures over Antarctica
Authors: Mo Tsan
Published: March 2010

Daily mean brightness temperatures over Antarctica derived from measurements by three Advanced Microwave Sounding Unit-A (AMSU-A) radiometers on board NOAA-18, NOAA-19, and MetOp-A satellites are studied. To demonstrate the characteristics of the data over this test site, time series of daily averages of the brightness temperatures are constructed. These time series provide a useful pattern of annual variation of the AMSU-A measurements for intercalibration of microwave radiometers on board multiple satellites. To investigate the diurnal effect on the measurements, the time series of daily averaged brightness temperatures are constructed separately for the ascending and descending passes. Results show that there are little diurnal differences in measurements during the Antarctic winter months from each satellite. Therefore these measurements provide a practical approach to obtain relative channel biases of intersatellite data. The monthly averages of the measurements over July 2009 are employed to obtain the relative channel biases because it is the coldest month in Antarctica. The resultant channel biases for the three satellites are within the range of ±0.1 K for channels 1–5 and ±0.3 K for channels 6–15. This is strong evidence that Antarctica is a potentially good test site for intercalibration of microwave radiometers on board multiple satellites. The small relative biases at channels 1–5 indicate that Antarctica is a very stable test site that is particularly useful for intercalibration of measurements from the window channels. The establishment of a natural test site for calibration references is important for calibration and validation of spaceborne microwave instruments.
Some Characteristics of Time Interpolation Errors for Fluid Flows
Authors: Hoffman Ross N. , Leidner S. Mark
Published: March 2010

The size of errors due to linear time interpolation varies parabolically with a maximum at the center of the interpolation interval in most of the cases examined here. These cases include simple situations that are analyzed analytically and mesoscale model simulations of the ocean surface wind that are analyzed empirically.
The Role of Trade Wind Surges in Tropical Cyclone Formations in the Western North Pacific
Authors: Chang Lung-Yao , Cheung Kevin K. W. , Lee Cheng-Shang
Published: March 2010

A total of 40 out of 531 tropical cyclones that formed in the western North Pacific during 1986–2005 have accompanied trade wind surges located 5°–15° latitude to the north of the pretropical cyclone disturbance centers. Composite and empirical orthogonal function analyses indicate that the trade wind surges are related to a midlatitude eastward-moving high pressure system often found during the East Asian winter monsoon. Therefore, these trade wind surge tropical cyclones tend to occur in late season (with one-third of them in December), and at lower latitudes (7° latitude lower than the climatological average formation position).

The evolution of mesoscale features during formation of trade wind surge tropical cyclones is examined. Various satellite datasets show similar mesoscale patterns during their formations. A few convective lines form by convergence between the trade wind surges and the strengthening cyclonic circulation associated with incipient vortex within the 24 h before formation. Some mesoscale convective systems are embedded in the convective line with lifetimes of about 5 h, and these are illustrated through case studies. Formations usually occur when the trade winds start to decrease in magnitude and a short period after the major episodes of convection in the convective lines and mesoscale convective systems. The relationships between the temporal variability of synoptic-scale trade wind surges, the mesoscale features, and associated tropical cyclone formations are discussed.
Numerical Simulations of Radiative Cooling beneath the Anvils of Supercell Thunderstorms
Authors: Frame Jeffrey , Markowski Paul
Published: March 2010

Numerical simulations of supercell thunderstorms that include parameterized radiative transfer and surface fluxes are performed using the Advanced Regional Prediction System (ARPS) to investigate the effects of anvil shadows on the near-storm environment. If the simulated storm is nearly stationary, the maximum low-level air temperature deficits within the shadows are about 2 K, which is roughly half the cooling found in some previous observations. It is shown that the extinction of downwelling shortwave radiation by the anvil cloud creates a differential in the flux of downwelling shortwave radiation between the sun and the shade that is at least an order of magnitude greater than the differential of any other term in either the surface radiation or the surface energy budgets. The loss of strong solar heating of the model surface within the shaded regions leads to a reduction of surface temperatures and stabilization of the model surface layer beneath the anvil. The reduction in vertical mixing results in a shallow, strongly vertically sheared layer near the surface and calmer near-surface winds, which are limited to regions in the anvil shadow. This difference in radiative heating is shown not to affect the vertical thermodynamic or wind profiles above the near-surface layer (approximately the lowest 500 m). It is also found that these results are highly sensitive to the magnitude of the near-surface winds. If the initial hodograph is shifted such that the simulated storm acquires a substantial eastward propagation speed, the temperature deficit within the shadow is greatly diminished. This is due to both a weaker surface sensible heat flux and less time during which surface cooling and boundary layer stabilization can occur beneath the anvil.
Predecessor Rain Events ahead of Tropical Cyclones
Authors: Galarneau Thomas J. , Bosart Lance F. , Schumacher Russ S.
Published: March 2010

Twenty-eight predecessor rain events (PREs) that occurred over the United States east of the Rockies during 1995–2008 are examined from a synoptic climatology and case study perspective. PREs are coherent mesoscale regions of heavy rainfall, with rainfall rates ≥100 mm (24 h)−1, that can occur approximately 1000 km poleward of recurving tropical cyclones (TCs). PREs occur most commonly in August and September, and approximately 36 h prior to the arrival of the main rain shield associated with the TC. A distinguishing feature of PREs is that they are sustained by deep tropical moisture that is transported poleward directly from the TC. PREs are high-impact weather events that can often result in significant inland flooding, either from the PRE itself or from the subsequent arrival of the main rain shield associated with the TC that falls onto soils already saturated by the PRE.

The composite analysis shows that on the synoptic-scale, PREs form in the equatorward jet-entrance region of a 200-hPa jet on the western flank of a 925-hPa equivalent potential temperature ridge located east of a 700-hPa trough. On the mesoscale, PREs occur in conjunction with low-level frontogenetical forcing along a baroclinic zone where heavy rainfall is focused. A case study analysis was conducted of a PRE ahead of TC Erin (2007) that produced record-breaking rainfall (>250 mm) from southern Minnesota to Lake Michigan. This analysis highlighted the importance of frontogenetical forcing along a low-level baroclinic zone in the presence of deep tropical moisture from TC Erin in producing a long-lived, quasi-stationary mesoscale convective system.
Healthy for Now? A Cross-Sectional Study of the Comorbidities in Obese Preschool Children in the United States
Authors: Cockrell Skinner Asheley , Perrin Eliana M. , Steiner Michael J.
Published: March 2010

Objective. Examine health of preschoolers by BMI status. Methods. A cross-sectional analysis of children 3 to 5 years old in the 1999-2008 National Health and Nutrition Examination Survey was carried out. The measured age- and sex-specific BMI percentiles were used to categorize children as very obese, obese, overweight, or healthy weight. The authors used logistic regression to examine the effect of weight status on 17 available measures of current child health potentially related to obesity. Results. Except for very obese children, weight status had minimal effect on most measures of health for preschool-aged children (n = 2792). Parents of very obese children reported poorer general health and more activity limitations for their children. Additionally, very obese girls had more frequent/severe headaches, and overweight/obese boys had more asthma diagnoses. Conclusions. Only severe obesity appears consistently related to immediate health problems in preschool-aged children. Parental perception that very obese children have worse health and more activity limitations may lead to decreases in physical activity, which would perpetuate obesity.
University Students’ Perceptions of Childless Couples and Parents in Ankara, Turkey
Authors: Çopur Zeynep , Koropeckyj-Cox Tanya
Published: March 2010

Changing perceptions of childlessness have been documented in the United States, but little is known about perceptions in developing countries undergoing rapid social changes and globalization, including Turkey. This project uses a survey and hypothetical vignettes about childless couples and parents to assess university students’ perceptions of childlessness ( N = 850). The authors find that parents are rated higher on interpersonal warmth and marital relationship quality, but mothers are seen as more stressed. Childless men and women are perceived as more driven but also as more emotionally troubled. The results indicate the continued importance of parenthood among Turkish students but also an understanding of women’s stresses in combining work and motherhood. The authors find relatively few rural and urban differences, whereas gender and income differences may reflect greater awareness of work—family concerns and acceptance of childlessness among women and higher income students.
Consequences of Filial Support for Two Generations: A Narrative and Quantitative Review
Authors: Merz Eva-Maria , Schulze Hans-Joachim , Schuengel Carlo
Published: March 2010

This narrative and quantitative review synthesizes findings from 55 ( N = 54,550) studies on the association between providing support to elderly parents and well-being of adult children as well as well-being of parents, in an endeavor to determine the prevailing direction of effects, magnitude of effects, and possible factors that may moderate these effects. The relation between caring for an elderly parent and well-being and/or caregiver burden in adult children was found to be insubstantial. Likewise, being cared for by adult children was found to be weakly related to well-being in elderly parents. More complex models including psychological aspects of caring; aspects of the intergenerational relationship, such as quality; and the inclusion of both the adult child’s and the parent’s perspectives on providing and receiving support appear more promising for understanding caregiving and well-being in intergenerational relationships beyond childhood.
Parents and Adolescents Making Time Choices: “Choosing a Relationship”
Authors: Ashbourne Lynda M. , Daly Kerry J.
Published: March 2010

Drawing on 20 qualitative family interviews with mothers, fathers, and adolescents (aged 16 to 19 years), this study explores the time choices of parents and adolescents. Adolescents and their parents talk about having varying degrees of control over their time in response to external demands. They identify that they initiate time together and apart from each other to meet specific individual and relational needs. Time choices are made within the context of a future-orientation and shifting hierarchy in the relationship. Exercising personal agency with respect to time appears to serve as a means of enhancing individual development for both parents and adolescents, as well as influencing relationship change. A model of dialogic interaction, emergent meaning making, and a context of dialectical tensions and contradictions is demonstrated in this exploration of time choices and intention.
Sustainable Market Orientation: A New Approach to Managing Marketing Strategy
Authors: Mitchell Robert W. , Wooliscroft Ben , Higham James
Published: March 2010

Market orientation has been a foundation of corporate marketing strategy since the middle of the last century. There is a need for a broader conceptualization of market orientation and a new corporate marketing model is proposed: sustainable market orientation (SMO). Taking a macromarketing perspective, the new conceptualization proposes the use of three key sustainable development objectives in corporate marketing strategy; economic, social, and ecological sustainability. Corporate benefits from a SMO are discussed, a model for empirical testing is presented, and a range of research opportunities are discussed.
Biomechanical Evaluation of Shear Force Vectors Leading to Injury of the Biceps Reflection Pulley
Authors: Braun Sepp , Millett Peter J. , Yongpravat Charlie , Pault Joseph D. , Anstett Tyler , Torry Michael R. , Giphart J. Erik
Published: March 2010

Background

The clinical importance of the biceps reflection pulley (BRP), which stabilizes the long head of the biceps tendon (LHB) as it exits the joint, has been shown. However, there is controversy on the pathomechanism of injury to the BRP. The angular orientation of the LHB relative to its origin and distal course changes with joint positions and may place the BRP at risk for injury.

Purpose

To measure the course of the LHB in common arm positions and to determine the shear and normal (stabilizing) force vectors as well as the excursion of the LHB.

Study Design

Descriptive laboratory study.

Methods

The LHBs of 8 fresh-frozen cadaveric shoulders were marked with arthroscopically injected microbeads and mounted in a custom-built shoulder rig. Data for neutral arm position, forward flexion, and abduction were collected in internal, neutral, and external rotation using biplane fluoroscopy. Bone and LHB position were reconstructed in 3 dimensions.

Results

The shear component of the resulting vector was significantly higher during internal (28.4% ± 18.1%) compared with external rotation (18.9% ± 9.7%; P = .0157) and was highest in neutral arm position with internal rotation (39.2% ± 12.7%) and forward flexion with neutral rotation (36.2% ± 10.7%). The normal force vector, stabilizing the LHB, was significantly higher in abduction (55.2% ± 9.6%) compared with forward flexion (39.1% ± 12.4%; P < .0001) and neutral positions (39.1% ± 11.4%; P < .0001). The LHB excursion was significantly lower for neutral arm positions (0.7 ± 6.0 mm) compared with forward flexion (12.6 ± 8.3 mm; P < .0001) and abduction (12.0 ± 6.5 mm; P < .0001).

Conclusion

Increased shear load at forward flexion with internal or neutral arm rotation and internal rotation at neutral arm position may cause injury to the BRP. Additionally, a sawing mechanism caused by the 12-mm linear excursion combined with a load of the LHB through the BRP during elevation may also lead to lesions.

Clinical Relevance

Knowledge of the pathomechanisms of BRP injury may help in developing specific treatment and rehabilitation strategies as well as tests for physical examination.