bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Al/ZrO2/GaAs metal-oxide-semiconductor capacitors and determination of its electrical parameters in the frequency range of 10 kHz–1 MHz
Authors: Kundu Souvik , Roy Sandipta , Banerji P. , Chakraborty Supratic , Shripathi T.
Published: April 2011

Aluminum (Al)/zirconium oxide (ZrO2)/GaAs metal-oxide-semiconductor (MOS) capacitors were fabricated on p-GaAs. The carrier concentration of n-GaAs was varied by metal organic chemical vapor deposition. The ZrO2 gate dielectrics were prepared by the sol-gel process and then spin-coated onto GaAs substrates. Three different thicknesses of the ZrO2 layer, viz., 25, 40 and 50 nm, were used to study the effect of oxide thickness on different MOS parameters. Sulfur (S) passivation of the GaAs surface was done to control the interface state densities before ZrO2 deposition. It was found that S passivation resulted in both low hysteresis and high accumulation capacitance of the device. Frequency dependent studies on the dielectric characterizations were made in the frequency range of 10 kHz–1 MHz. It was found that within this frequency range dispersion of the oxide capacitance was 2%/decade. It was observed that interface trap densities (Dit) increased with an increase in the carrier concentration of n-GaAs from a value of 1.5×1012 cm−2 eV−1 at 1×1014 cm−3 to a value of 3.8×1012 cm−2 eV−1 at 3×1016 cm−3 doping concentration of the semiconductor. It was also found that Dit increased with an increase in the oxide thickness from a value of 0.75×1012 cm−2 eV−1 at 25 nm to a value of 2.4×1012 cm−2 eV−1 at 50 nm thickness of the oxide layer. Studies on temperature dependent current densities indicated that the leakage current decreased by three orders of magnitude with the change in temperature from 290 to 80 K. Leakage current was also found to decrease with an increase in the thickness of the dielectric layer due to a decrease in the transmission probability. Loss tangent was found to decrease with frequency, whereas the ac conductivity showed an opposite trend. Considering different MOS parameters investigated in the present study, it was observed that ZrO2 could be a potential candidate for GaAs based MOS devices.
Early Warnings of Regime Shifts: A Whole-Ecosystem Experiment
Authors: Carpenter S. R. , Cole J. J. , Pace M. L. , Batt R. , Brock W. A. , Cline T. , Coloso J. , Hodgson J. R. , Kitchell J. F. , Seekell D. A. , Smith L. , Weidel B.
Published: April 2011

High-frequency monitoring of manipulated and reference lakes enabled early detection of subsequent catastrophic regime shift.
Structural Basis for Methyl Transfer by a Radical SAM Enzyme
Authors: Boal Amie K. , Grove Tyler L. , McLaughlin Monica I. , Yennawar Neela H. , Booker Squire J. , Rosenzweig Amy C.
Published: April 2011

An enzyme harnesses methyl donation and reductive cleavage of its cofactor within a single active site to methylate RNA.
Monocyte chemoattractant protein-1 derived from biliary innate immunity contributes to hepatic fibrogenesis
Authors: Harada Kenichi , Chiba Mayumi , Okamura Atsushi , Hsu Maylee , Sato Yasunori , Igarashi Saya , Ren Xiang Shan , Ikeda Hiroko , Ohta Hajime , Kasashima Satomi , Kawashima Atsuhiro , Nakanuma Yasuni
Published: April 2011

Aims

Monocyte chemoattractant protein-1 (MCP-1) is a major chemotactic factor for hepatic stellate cells (HSCs) associated with hepatic fibrosis. In this study, among several fibrogenetic factors derived from biliary epithelial cells (BECs), MCP-1 produced by the biliary innate immune system was found to be most critical in the histogenesis of hepatic fibrogenesis.

Methods

Using cultured human BECs, the expression of five fibrogenetic factors including MCP-1 on stimulation with Toll-like receptor ligands, inflammatory cytokines or bile acids was examined. Moreover, in situ detection of MCP-1 and α-smooth muscle actin proteins was performed using sections from normal and diseased livers by immunohistochemistry.

Results

All fibrogenetic factors were detected in BECs, but only MCP-1 expression was upregulated, by all the Toll-like receptor ligands, IL-1β, and tumour necrosis factor-alpha. Proliferating bile ductules in interface areas expressed MCP-1 in diseased livers accompanying α-smooth muscle actin-positive activated HSCs.

Conclusions

Bile ductules proliferate in various hepatobiliary diseases, and its significance is still unknown. This study demonstrated that BECs in bile ductules could produce MCP-1, particularly, via biliary innate immunity, suggesting that MCP-1 derived from BECs plays an important role in the recruitment of HSCs to interface areas and the activation of HSCs resulting in the progression of periportal fibrosis.
Impact of smoke-free legislation on children's exposure to secondhand smoke: cotinine data from the Health Survey for England
Authors: Jarvis Martin J , Sims Michelle , Gilmore Anna , Mindell Jenny
Published: April 2011

Objective

To examine the impact of the ban on smoking in enclosed public places implemented in England in July 2007 on children's exposure to secondhand tobacco smoke.

Design

Repeated cross-sectional surveys of the general population in England.

Setting

The Health Survey for England.

Participants

Confirmed non-smoking children aged 4–15 with measured saliva cotinine participating in surveys from 1998 to 2008, a total of 10 825 children across years.

Main outcome measures

The proportion of children living in homes reported to be smoke-free; the proportion of children with undetectable concentrations of cotinine; geometric mean cotinine as an objective indicator of overall exposure.

Results

Significantly more children with smoking parents lived in smoke-free homes in 2008 (48.1%, 95% CI 43.0% to 53.1%) than in either 2006 (35.5%, 95% CI 29.7% to 41.7%) or the first 6 months of 2007, immediately before the ban came into effect (30.5%, 95% CI 19.7% to 43.9%). A total of 41.1% (95% CI 38.9% to 43.4%) of children had undetectable cotinine in 2008, up from 34.0% (95% CI 30.8% to 37.3%) in 2006. Geometric mean cotinine in all children combined was 0.21 ng/ml (95% CI 0.20 to 0.23) in 2008, slightly lower than in 2006, 0.24 ng/ml (95% CI 0.21 to 0.26).

Conclusions

Predictions that the 2007 legislative ban on smoking in enclosed public places would adversely affect children's exposure to tobacco smoke were not confirmed. While overall exposure in children has not been greatly affected by the ban, the trend towards the adoption of smoke-free homes by parents who themselves smoke has received fresh impetus.
Vanadium pentoxide (V2O5) induced mucin production by airway epithelium
Authors: Yu Dongfang , Walters Dianne M. , Zhu Lingxiang , Lee Pak-Kei , Chen Yin
Published: April 2011

Exposure to environmental pollutants has been linked to various airway diseases and disease exacerbations. Almost all chronic airway diseases such as chronic obstructive pulmonary disease and asthma are caused by complicated interactions between gene and environment. One of the major hallmarks of those diseases is airway mucus overproduction (MO). Excessive mucus causes airway obstruction and significantly increases morbidity and mortality. Metals are major components of environmental particulate matters (PM). Among them, vanadium has been suggested to play an important role in PM-induced mucin production. Vanadium pentoxide (V2O5) is the most common commercial source of vanadium, and it has been associated with occupational chronic bronchitis and asthma, both of which are MO diseases. However, the underlying mechanism is not entirely clear. In this study, we used both in vitro and in vivo models to demonstrate the robust inductions of mucin production by V2O5. Furthermore, the follow-up mechanistic study revealed a novel v-raf-1 murine leukemia viral oncogene homolog 1-IKK-NF-κB pathway that mediated V2O5-induced mucin production. Most interestingly, the reactive oxygen species and the classical mucin-inducing epidermal growth factor receptor (EGFR)-MAPK pathway appeared not to be involved in this process. Thus the V2O5-induced mucin production may represent a novel EGFR-MAPK-independent and environmental toxicant-associated MO model. Complete elucidation of the signaling pathway in this model will not only facilitate the development of the treatment for V2O5-associated occupational diseases but also advance our understanding on the EGFR-independent mucin production in other chronic airway diseases.
Lactate threshold predicting time-trial performance: impact of heat and acclimation
Authors: Lorenzo Santiago , Minson Christopher T. , Babb Tony G. , Halliwill John R.
Published: April 2011

The relationship between exercise performance and lactate and ventilatory thresholds under two distinct environmental conditions is unknown. We examined the relationships between six lactate threshold methods (blood- and ventilation-based) and exercise performance in cyclists in hot and cool environments. Twelve cyclists performed a lactate threshold test, a maximal O2 uptake (V̇o2max) test, and a 1-h time trial in hot (38°C) and cool (13°C) conditions, before and after heat acclimation. Eight control subjects completed the same tests before and after 10 days of identical exercise in a cool environment. The highest correlations were observed with the blood-based lactate indexes; however, even the indirect ventilation-based indexes were well correlated with mean power during the time trial. Averaged bias was 15.4 ± 3.6 W higher for the ventilation- than the blood-based measures ( P < 0.05). The bias of blood-based measures in the hot condition was increased: the time trial was overestimated by 37.7 ± 3.6 W compared with only 24.1 ± 3.2 W in the cool condition ( P < 0.05). Acclimation had no effect on the bias of the blood-based indexes ( P = 0.51) but exacerbated the overestimation by some ventilation-based indexes by an additional 34.5 ± 14.1 W ( P < 0.05). Blood-based methods to determine lactate threshold show less bias and smaller variance than ventilation-based methods when predicting time-trial performance in cool environments. Of the blood-based methods, the inflection point between steady-state lactate and rising lactate (INFL) was the best method to predict time-trial performance. Lastly, in the hot condition, ventilation-based predictions are less accurate after heat acclimation, while blood-based predictions remain valid in both environments after heat acclimation.
An amino acid mixture enhances insulin-stimulated glucose uptake in isolated rat epitrochlearis muscle
Authors: Kleinert Maximilian , Liao Yi-Hung , Nelson Jeffrey L. , Bernard Jeffrey R. , Wang Wanyi , Ivy John L.
Published: April 2011

Protein and certain amino acids (AA) have been found to lower blood glucose. Although these glucose-lowering AA are important modulators of skeletal muscle metabolism, their impact on muscle glucose uptake remains unclear. We therefore examined how an AA mixture consisting of 2 mM isoleucine, 0.012 mM cysteine, 0.006 mM methionine, 0.0016 mM valine, and 0.014 mM leucine impacts skeletal muscle glucose uptake in the absence or presence of a submaximal (sINS) or maximal insulin (mINS) concentration. The AA mixture, sINS, and mINS significantly increased 2-[3H]deoxyglucose (2-DG) uptake by 63, 79, and 298% above basal, respectively. When the AA mixture was combined with sINS and mINS, 2-DG uptake was further increased significantly by 26% ( P = 0.028) and 14% ( P = 0.032), respectively. Western blotting analysis revealed that the AA mixture increased basal and sINS Akt substrate of 160 kDa (AS160) phosphorylation, while AA mixture did not change phosphorylation of Akt or mammalian target of rapamycin (mTOR) under these conditions. Interestingly, addition of the AA mixture to mINS increased phosphorylation of mTOR, Akt as well as AS160, compared with mINS alone. These data suggest that certain AA increase glucose uptake in the absence of insulin and augment insulin-stimulated glucose uptake in an additive manner. Furthermore, these effects appear to be mediated via a pathway that is independent from the canonical insulin cascade and therefore may prove effective as an alternative therapeutic treatment for insulin resistance.
ID4 Imparts Chemoresistance and Cancer Stemness to Glioma Cells by Derepressing miR-9*–Mediated Suppression of SOX2
Authors: Jeon Hye-Min , Sohn Young-Woo , Oh Se-Young , Kim Sung-Hak , Beck Samuel , Kim Soonhag , Kim Hyunggee
Published: April 2011

Glioma stem cells (GSC) possess tumor-initiating potential and are relatively resistant to conventional chemotherapy and irradiation. Thus, they are considered to be major drivers for glioma initiation, progression, and recurrence. However, the precise mechanism governing acquisition of their drug resistance remains to be elucidated. Our previous study has shown that inhibitor of differentiation 4 (ID4) dedifferentiates Ink4a/Arf−/− mouse astrocytes and human glioma cells to glioma stem-like cells (induced GSCs or iGSCs). In this article, we report that ID4-driven iGSCs exhibit chemoresistant behavior to anticancer drugs through activation of ATP-binding cassette (ABC) transporters. We found that ID4 enhanced SOX2 protein expression by suppressing microRNA-9* (miR-9*), which can repress SOX2 by targeting its 3′-untranslated region. Consequently, ID4-mediated SOX2 induction enhanced ABCC3 and ABCC6 expression through direct transcriptional regulation, indicating that ID4 regulates the chemoresistance of iGSCs by promoting SOX2-mediated induction of ABC transporters. Furthermore, we found that short hairpin RNA-mediated knockdown of SOX2 in ID4-driven iGSCs resulted in loss of cancer stemness. Moreover, ectopic expression of SOX2 could dedifferentiate Ink4a/Arf−/− astrocytes and glioma cells to iGSCs, indicating a crucial role of SOX2 in genesis and maintenance of GSCs. Finally, we found that the significance of the ID4-miR-9*-SOX2-ABCC3/ABCC6 regulatory pathway is recapitulated in GSCs derived from patients with glioma. Together, our results reveal a novel regulatory mechanism by which ID4-driven suppression of miR-9* induces SOX2, which imparts stemness potential and chemoresistance to glioma cells and GSCs. Cancer Res; 71(9); 3410–21. ©2011 AACR.
MMSET Is Highly Expressed and Associated with Aggressiveness in Neuroblastoma
Authors: Hudlebusch Heidi Rye , Skotte Julie , Santoni-Rugiu Eric , Zimling Zarah Glad , Lees Michael James , Simon Ronald , Sauter Guido , Rota Rossella , De Ioris Maria Antonietta , Quarto Micaela , Johansen Jens Vilstrup , Jørgensen Mette , Rechnitzer Catherine , Maroun Lisa Leth , Schrøder Henrik , Petersen Bodil Laub , Helin Kristian
Published: April 2011

MMSET (WHSC1/NSD2) is a SET domain–containing histone lysine methyltransferase the expression of which is deregulated in a subgroup of multiple myelomas with the t(4;14)(p16;q32) translocation associated with poor prognosis. Recent studies have shown that MMSET mRNA levels are increased in other tumor types as well. We have carried out immunohistochemical staining of tissue microarrays and found that MMSET protein is frequently and highly expressed in neuroblastoma (MMSET positive in 75% of neuroblastomas, n = 164). The expression level of MMSET in neuroblastomas was significantly associated with poor survival, negative prognostic factors, and metastatic disease. Moreover, a subset of neuroblastomas for which pre- and postchemotherapy biopsies were available displayed a strong decrease in MMSET protein levels after chemotherapy. In agreement with neuroblastomas becoming more differentiated after treatment, we show that retinoic acid–induced differentiation of human neuroblastoma cells in vitro also leads to a strong decrease in MMSET levels. Furthermore, we show that the high levels of MMSET in normal neural progenitor cells are strongly downregulated during differentiation. Importantly, we show that MMSET is required for proliferation of neuroblastoma cells and brain-derived neural stem cells. Taken together, our results suggest that MMSET is implicated in neuroblastomagenesis possibly by supporting proliferation of progenitor cells and negatively regulating their differentiation. In this respect, MMSET might be a strong candidate therapeutic target in a subset of neuroblastomas with unfavorable prognosis. Cancer Res; 71(12); 4226–35. ©2011 AACR.
Complete Radiological Response of Colorectal Liver Metastases after Chemotherapy: What Can We Expect?
Authors: Gaujoux Sébastien , Goéré Diane , Dumont Frédéric , Souadka Amine , Dromain Clarisse , Ducreux Michel , Elias Dominique
Published: April 2011

Missing metastases, also called vanishing or disappearing liver metastases, concern about 5% of patients with colorectal liver metastasis undergoing chemotherapy, and this phenomenon is likely to become more frequent in the near future, with the widespread use of highly efficient chemotherapy. As their definition is highly dependent on the quality of initial imaging, a DLM on preoperative computed tomography scan should be systematically confirmed by a second imaging modality, ideally magnetic resonance imaging. It is important to note that a complete clinical response does not mean a complete pathologic response. Currently, there are no absolute criteria of a complete pathologic response. However, treatment with neoadjuvant and adjuvant hepatic arterial infusion in patients <60 years old with an initially low carcinoembryonic antigen level that normalizes under chemotherapy and who have no detectable lesion on both computed tomography and magnetic resonance imaging is probably more likely to yield a complete pathologic response. Whatever their treatment, patients with DLM run a high risk of recurrence that could be decreased with the use of HAI. Despite a high recurrence rate, the overall 5-year survival rate of patients with DLM ranges from 40 to 80%. Having a DLM should no longer be a contraindication to hepatic surgery since long-term survival is expected in these highly chemosensitive patients. The use of adjuvant HAI in addition to efficient systemic chemotherapy could reduce the risk of hepatic relapse.
Factors Influencing Dialysis Modality for End-Stage Renal Disease in Developing Countries: A Survey of Filipino Nephrologists
Authors: Cruz Dinna N. , Troidle Laura , Danguilan Romina , Padilla Benita , Frando Leilani , Sebastian Elizabeth , Sy-Lim Annabel , Luz Vimar , Finkelstein Fredric
Published: April 2011

Background: In the Philippines, 86% of incident dialysis patients are started on hemodialysis (HD) and 14% are treated with peritoneal dialysis (PD), representing a decline over a 2-year period. One important factor which affects patients’ choice of dialysis modality is the input of their physicians. Our objective was to identify the factors affecting attitudes and recommendations of Filipino nephrologists regarding HD and PD. Methods: Attendees of the annual national nephrology meeting completed an anonymous self-administered questionnaire. Results: Respondents were heavily involved in clinical dialysis work, and 86.7% had most/all of their patients on HD. Recommendations about dialysis modality were based most strongly on overall cost to patient (4.4 on a scale of 1 [not important] to 5 [most important], residual renal function (RRF) preservation (4.4), patient preference (4.3) availability of dialysis support staff (4.3), and comparative quality of life data (4.3). Least important was physician reimbursement (2.8). Patient-related factors favoring HD were: poor personal hygiene, impaired vision and manual dexterity; while favoring PD were: age <10 years, living far from HD unit, and the availability of trainable family members. When asked which modality they would recommend to an equally eligible patient, 49.2% responded they would not recommend either modality and would allow the patient to choose, while 40.7% would recommend HD and 10.2% would recommend PD. Conclusion: Respondents consider overall cost and RRF preservation as the most important factors in dialysis modality selection, yet only 10.2% would recommend PD as first choice. It is likely that factors other than those addressed in the survey are stronger determinants of the patient’s final choice of modality.
A New Device to Quantify Ocular Counterroll Using Retinal Afterimages
Authors: Arshad Q. , Kaski D. , Buckwell D. , Faldon M.E. , Gresty M.A. , Seemungal B.M. , Bronstein A.M.
Published: April 2011

Background: The integrity of vertical semicircular canal and otolith function remains difficult to assess in the clinical setting, partly due to difficulties in recording ocular counterroll. Here, we quantify static ocular counterroll from head tilt using a new head-mounted device. Methods: The device consists of an LED positioned 42 cm in front of one eye and a striated lens which produces a streak of light on the retina. The LED is illuminated at full intensity (80 cd) to generate a retinal afterimage. Subsequently, in darkness, the subject’s head is tilted in the roll plane. Finally, the LED is illuminated dimly (0.2 cd) and the subject rotates the striated lens to superimpose the dim light streak onto the afterimage. An angular scale indicates the angle through which the lens is rotated, giving a measure of the ocular counterroll. To validate the device, we recorded binocular counterroll simultaneously with 3D computerised video-oculography of the other eye in 16 normal subjects; 2 patients with acquired bilateral loss of vestibular function were also tested. Results: In the normal subjects, there was no significant difference between the two techniques (p = 0.24) when recording ocular counterroll and the correlation between the two techniques was R2 = 0.78. The 2 avestibular patients essentially showed no ocular counterroll with both techniques. Conclusions: We have devised a non-invasive, quick and reliable test of ocular counterroll. The lack of response in the 2 avestibular patients indicates that this device is clinically applicable to assess otolith function.
The Trends of Metabolic Syndrome in Normal-Weight Tehranian Adults
Authors: Hosseinpanah Farhad , Barzin Maryam , Amiri Parisa , Azizi Fereidoun
Published: April 2011

Background: In recent decades, more attention has been directed to the clustering of cardiometabolic risk factors in normal-weight adults. This study investigates trends of the prevalence of metabolic syndrome (MetS) in a normal-weight Tehranian adult population during 6.6 years of follow-up. Methods: In this population-based cohort study of 5,269 participants aged ≧20 years during the 3 phases (1999–2001, 2002–2005 and 2005–2008) of the Tehran Lipid and Glucose Study, we selected 390 males and 358 females with a normal body mass index (18.5–24.9) during all 3 periods of follow-up. MetS was defined according to the International Diabetes Federation criteria, and waist circumference (WC) cut points were ≧89 cm for males and ≧91 cm for females. Results: The overall prevalence of MetS increased from 2.3 and 4.0% in phases I and II to 9.6% in phase III. This trend was significant in males (p < 0.001) but not in females (p = 0.6). No significant changes in components of MetS were seen, except in WC among males. In the 3 study phases, prevalence of abdominal obesity was 3.1, 18.5 and 36.2% in males, respectively. Conclusions: There was a dramatic 4-fold increase in the prevalence of MetS in the Tehranian normal-weight adult population, highlighting the importance of MetS components, especially of WC, in normal-weight adult males.
Canine Scabies in Humans: A Case Report and Review of the Literature
Authors: Aydıngöz İkbal Esen , Mansur Ayşe Tülin
Published: April 2011

Background:Sarcoptes scabiei causes mange in many domestic and wild mammals, and it has been reported to be transmitted from animals to humans. Canine scabies is known to infest humans, as well. Case Report: We report a 27-year-old woman who presented with severe pruritic papules on the trunk and arms. The patient reported that she had just bought a puppy which was also itchy. Direct microscopy from the dog showed scabies mites. The patient was treated by 5% permethrin which accomplished full recovery. Discussion: Canine scabies in humans is a challenging disease to diagnose since mites are hard to find on skin scrapings of dogs and the burrows that are the hallmark of scabies are absent. Dermatological examination of the lesions in our patient did not show any burrows or a specific dermoscopic image of scabies. Instead, we observed curvilinear crusts on most of the papules. Conclusion: To our knowledge, dermoscopic appearance of canine scabies in humans has not been described before. We think this special pattern of excoriations is the result of superficially dug tunnels that had been torn leaving vacant curved linear remnants behind, and this may provide a good support for the diagnosis of canine scabies contributing to the spectrum of entodermoscopy.
SUMO1 Negatively Regulates Reactive Oxygen Species Production From NADPH Oxidases
Authors: Pandey Deepesh , Chen Feng , Patel Anand , Wang Cong-Yi , Dimitropoulou Christiana , Patel Vijay S. , Rudic R. Daniel , Stepp David W. , Fulton David J.
Published: April 2011

Objective—

Increased protein SUMOylation (small ubiquitin-related modifier [SUMO]) provides protection from cellular stress, including oxidative stress, but the mechanisms involved are incompletely understood. The NADPH oxidases (Nox) are a primary source of reactive oxygen species (ROS) and oxidative stress, and thus our goal was to determine whether SUMO regulates NADPH oxidase activity.

Methods and Results—

Increased expression of SUMO1 potently inhibited the activity of Nox1 to Nox5. In contrast, inhibition of endogenous SUMOylation with small interfering RNA to SUMO1 or ubiquitin conjugating enzyme 9 or with the inhibitor anacardic acid increased ROS production from human embryonic kidney-Nox5 cells, human vascular smooth muscle cells, and neutrophils. The suppression of ROS production was unique to SUMO1, and it required a C-terminal diglycine and the SUMO-specific conjugating enzyme ubiquitin conjugating enzyme 9. SUMO1 did not modify intracellular calcium or Nox5 phosphorylation but reduced ROS output in an isolated enzyme assay, suggesting direct effects of SUMOylation on enzyme activity. However, we could not detect the presence of SUMO1 conjugation on Nox5 using a variety of approaches. Moreover, the mutation of more than 17 predicted and conserved lysine residues on Nox5 did not alter the inhibitory actions of SUMO1.

Conclusion—

Together, these results suggest that SUMO is an important regulatory mechanism that indirectly represses the production of ROS to ameliorate cellular stress.
Endothelial Fate and Angiogenic Properties of Human CD34
+
Progenitor Cells in Zebrafish
Authors: Pozzoli Ombretta , Vella Pietro , Iaffaldano Grazia , Parente Valeria , Devanna Paolo , Lacovich Marta , Lamia Carla Lora , Fascio Umberto , Longoni Daniela , Cotelli Franco , Capogrossi Maurizio C. , Pesce Maurizio
Published: April 2011

Objective—

The vascular competence of human-derived hematopoietic progenitors for postnatal vascularization is still poorly characterized. It is unclear whether, in the absence of ischemia, hematopoietic progenitors participate in neovascularization and whether they play a role in new blood vessel formation by incorporating into developing vessels or by a paracrine action.

Methods and Results—

In the present study, human cord blood–derived CD34
+
(hCD34
+
) cells were transplanted into pre- and postgastrulation zebrafish embryos and in an adult vascular regeneration model induced by caudal fin amputation. When injected before gastrulation, hCD34
+
cells cosegregated with the presumptive zebrafish hemangioblasts, characterized by
Scl
and
Gata2
expression, in the anterior and posterior lateral mesoderm and were involved in early development of the embryonic vasculature. These morphogenetic events occurred without apparent lineage reprogramming, as shown by CD45 expression. When transplanted postgastrulation, hCD34
+
cells were recruited into developing vessels, where they exhibited a potent paracrine proangiogenic action. Finally, hCD34
+
cells rescued vascular defects induced by
Vegf-c
in vivo targeting and enhanced vascular repair in the zebrafish fin amputation model.

Conclusion—

These results indicate an unexpected developmental ability of human-derived hematopoietic progenitors and support the hypothesis of an evolutionary conservation of molecular pathways involved in endothelial progenitor differentiation in vivo.
Atheroprotective Reverse Cholesterol Transport Pathway Is Defective in Familial Hypercholesterolemia
Authors: Bellanger Natacha , Orsoni Alexina , Julia Zélie , Fournier Natalie , Frisdal Eric , Duchene Emilie , Bruckert Eric , Carrie Alain , Bonnefont-Rousselot Dominique , Pirault John , Saint-Charles Flora , Chapman M. John , Lesnik Philippe , Le Goff Wilfried , Guerin Maryse
Published: April 2011

Objective—

Low high-density lipoprotein (HDL) cholesterol levels are frequently observed in familial hypercholesterolemia (FH) and might be associated with functional alterations of HDL particles that may influence their efficaciousness in the reverse cholesterol transport pathway.

Methods and Results—

We evaluated key steps of the reverse cholesterol transport, ie, cellular free cholesterol efflux, cholesteryl ester transfer protein-mediated cholesteryl ester (CE) transfer from HDL to apolipoprotein B–containing lipoproteins, and hepatic HDL-CE uptake, in patients displaying FH (n=12) and in healthy normolipidemic control subjects (n=12). Large HDL2 particles isolated from FH patients displayed a reduced capacity to mediate free cholesterol efflux via both scavenger receptor-BI– and ABCG1–dependent pathways. A significant inverse relationship between scavenger receptor-BI–dependent HDL2 efflux capacity and carotid intima-media thickness (
r
=−0.473;
P
=0.0186), as well as between ABCG1-dependent HDL2 efflux capacity and carotid intima-media thickness (
r
=−0.485;
P
=0.0212), was detected. We also observed an elevated cholesteryl ester transfer protein-mediated CE transfer from HDL2 and HDL3 particles to low-density lipoprotein and a reduced capacity of HDL particles to deliver CEs to the liver.

Conclusion—

We demonstrated that the centripetal movement of cholesterol from peripheral tissues, including the vessel wall, to feces is defective in FH, thereby emphasizing its atherogenicity.
Validity and Reliability of the Barthel Index Administered by Telephone
Authors: Della Pietra Gian Luca , Savio Katia , Oddone Elodie , Reggiani Monica , Monaco Francesco , Leone Maurizio A.
Published: April 2011

Background and Purpose—

We aimed to evaluate validity and reliability of the Barthel Index administered telephonically compared with face-to-face assessment in clinically stable patients with stroke.

Methods—

One hundred thirty-one patients were interviewed twice by 2 registered nurses with identical training. Half of the patients were randomized to receive the telephone interview followed by the face-to-face interview and half the contrary. The sequence of interviewers was randomized.

Results—

The median value of the Barthel Index score was 30 (first to third interquartile range, 15 to 80) by telephone and 35 (15 to 75) by face-to-face (
P
=0.29). The weighted κ was 0.90 (95% CI, 0.85 to 0.94); κ values ranged from 0.70 (0.58 to 0.82) for bowel control to 0.91 (0.83 to 0.99) for bathing.

Conclusions—

Telephone assessment of stroke disability with the Barthel Index is reliable in comparison to direct face-to-face assessment.
The Central European and Russian Heat Event of July–August 2010
Authors: Grumm Richard H.
Published: April 2011

No abstract available.
Wind Speed Changes of North Atlantic Tropical Cyclones Preceding Landfall
Authors: Yaukey Peter
Published: April 2011

Landfalling tropical cyclones have been extensively researched, especially their degradation upon coming ashore and the hazardous weather they create along coastlines and farther inland. Many of the factors that weaken storms over land could begin to act when they are still at sea, yet prelandfall intensity change remains poorly documented. This study examined the consistency of prelandfall changes in tropical cyclone intensity throughout the North Atlantic Ocean from 1950 to present. On average, cyclones intensified by 3 m s−1 less in their final 12 h before landfall than in the 12 h preceding those, on both mainland shores and in the Greater Antilles, while smaller islands showed no such change. Contributions of increasing storm age and poleward movement to this reduction were negligible. Two possible contributing factors to declining intensification before landfall were examined. The presence of a spring–neap tidal pattern of ~2 m s−1 in the prelandfall decline is consistent with tidal mixing influencing ocean temperature on the continental shelf. The tendency for the decline to be greater at night suggested the possible influence of solar heating on tropical cyclones near shore.
On the Arctic Wintertime Climate in Global Climate Models
Authors: Svensson Gunilla , Karlsson Johannes
Published: April 2011

Energy fluxes important for determining the Arctic surface temperatures during winter in present-day simulations from the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset are investigated. The model results are evaluated over different surfaces using satellite retrievals and ECMWF interim reanalysis (ERA-Interim). The wintertime turbulent heat fluxes vary substantially between models and different surfaces. The monthly median net turbulent heat flux (upward) is in the range 100–200 W m−2 and −15 to 15 W m−2 over open ocean and sea ice, respectively. The simulated net longwave radiative flux at the surface is biased high over both surfaces compared to observations but for different reasons. Over open ocean, most models overestimate the outgoing longwave flux while over sea ice it is rather the downwelling flux that is underestimated. Based on the downwelling longwave flux over sea ice, two categories of models are found. One group of models that shows reasonable downwelling longwave fluxes, compared with observations and ERA-Interim, is also associated with relatively high amounts of precipitable water as well as surface skin temperatures. This group also shows more uniform airmass properties over the Arctic region possibly as a result of more frequent events of warm-air intrusion from lower latitudes. The second group of models underestimates the downwelling longwave radiation and is associated with relatively low surface skin temperatures as well as low amounts of precipitable water. These models also exhibit a larger decrease in the moisture and temperature profiles northward in the Arctic region, which might be indicative of too stagnant conditions in these models.
On the Role of Eddies and Surface Forcing in the Heat Transport and Overturning Circulation in Marginal Seas
Authors: Spall Michael A.
Published: April 2011

The factors that determine the heat transport and overturning circulation in marginal seas subject to wind forcing and heat loss to the atmosphere are explored using a combination of a high-resolution ocean circulation model and a simple conceptual model. The study is motivated by the exchange between the subpolar North Atlantic Ocean and the Nordic Seas, a region that is of central importance to the oceanic thermohaline circulation. It is shown that mesoscale eddies formed in the marginal sea play a major role in determining the mean meridional heat transport and meridional overturning circulation across the sill. The balance between the oceanic eddy heat flux and atmospheric cooling, as characterized by a nondimensional number, is shown to be the primary factor in determining the properties of the exchange. Results from a series of eddy-resolving primitive equation model calculations for the meridional heat transport, overturning circulation, density of convective waters, and density of exported waters compare well with predictions from the conceptual model over a wide range of parameter space. Scaling and model results indicate that wind effects are small and the mean exchange is primarily buoyancy forced. These results imply that one must accurately resolve or parameterize eddy fluxes in order to properly represent the mean exchange between the North Atlantic and the Nordic Seas, and thus between the Nordic Seas and the atmosphere, in climate models.
Understanding the Sensitivity of Different Drought Metrics to the Drivers of Drought under Increased Atmospheric CO2
Authors: Burke Eleanor J.
Published: April 2011

A perturbed physics Hadley Centre climate model ensemble was used to study changes in drought on doubling atmospheric CO2. The drought metrics analyzed were based on 1) precipitation anomalies, 2) soil moisture anomalies, and 3) the Palmer drought severity index (PDSI). Drought was assumed to occur 17% of the time under single CO2. On doubling CO2, in general, PDSI drought occurs more often than soil moisture drought, which occurs more often than precipitation drought. This paper explores the relative sensitivity of each drought metric to changes in the main drivers of drought, namely precipitation and available energy. Drought tends to increase when the mean precipitation decreases, the mean available energy increases, the standard deviation of precipitation increases, and the standard deviation of available energy decreases. Simple linear approximations show that the sensitivity of drought to changes in mean precipitation is similar for the three different metrics. However, the sensitivity of drought to changes in the mean available energy (which is projected to increase under increased atmospheric CO2) is highly dependent on metric: with PDSI drought the most sensitive, soil moisture less sensitive, and precipitation independent of available energy. Drought metrics are only slightly sensitive to changes in the variability of the drivers. An additional driver of drought is the response of plants to increased CO2. This process reduces evapotranspiration and increases soil moisture, and generally causes less soil moisture drought. In contrast, the associated increase in available energy generally causes an increase in PDSI drought. These differing sensitivities need to be taken into consideration when developing adaptation strategies.
Sensitivities of Simulated Convective Storms to Environmental CAPE
Authors: Kirkpatrick Cody , McCaul Eugene W. , Cohen Charles
Published: April 2011

A set of 225 idealized three-dimensional cloud-resolving simulations is used to explore convective storm behavior in environments with various values of CAPE (450, 800, 2000, and 3200 J kg−1). The simulations show that when CAPE = 2000 J kg−1 or greater, numerous combinations of other environmental parameters can support updrafts of at least 10 m s−1 throughout an entire 2-h simulation. At CAPE = 450 J kg−1, it is very difficult to obtain strong storms, although one case featuring a supercell is found. For CAPE = 800 J kg−1, mature storm updraft speeds correlate positively with strong low-level lapse rates and reduced precipitable water. In some cases, updrafts at this CAPE value can reach speeds that rival predictions of parcel theory, but such efficient conversion of CAPE to kinetic energy does not extend to all storms at CAPE = 800 J kg−1, nor to any storms in simulations at lower or higher CAPE. In simulations with CAPE = 2000 or 3200 J kg−1, the strongest time-averaged mature updrafts, while supercellular in character, feature generally less than 60% of the speeds expected from parcel theory, and even the strongest updraft found at CAPE = 450 J kg−1 fails to reach that relative strength. When CAPE = 2000 J kg−1 or more, updrafts benefit from enhanced shear, higher levels of free convection, and reduced precipitable water.

Strong low-level shear and a reduced height of the level of free convection correlate closely with low-level storm vertical vorticity when CAPE is at least 2000 J kg−1, consistent with previous findings. However, at CAPE = 800 J kg−1, low-level vorticity shares the same correlations with the environment as updraft strength. With respect to storm precipitation, in simulations initiated with only 30 mm of precipitable water (PW), all of the storms that last for an entire 2-h simulation tend to produce liquid precipitation at roughly similar rates, regardless of their CAPE. In environments where PW is increased to 60 mm, storms tend to produce the most rainfall at CAPE = 2000 J kg−1, with somewhat lesser rainfall rates at lower and higher CAPE. Nevertheless, over the simulation domain, the ground area that receives at least 10 mm of rainfall tends to increase as CAPE increases, owing to a greater number and size of precipitating updrafts in the domain.
Perceived Parental and Peer Support in Relation to Canadian, Cuban, and Spanish Adolescents’ Valuing of Academics and Intrinsic Academic Motivation
Authors: Vitoroulis Irene , Schneider Barry H. , Vasquez Consuelo Cerviño , de Toro Maria del Pilar Soteras , Gonzáles Yorkys Santana
Published: April 2011

The aim of this study was to explore possible parent and peer influences on adolescents’ valuing of academics and intrinsic academic motivation in cultures varying in traditional emphasis on the family unit (Cuba, Canada, and Spain). Perceived parent and peer support, parents’ expectations, and valuing of academics significantly predicted adolescents’ valuing of education and motivation. Spanish adolescents were less motivated than members of the other ethnic groups. The Spanish participants also reported lower perceived parental expectations than Chinese Canadians and less perceived peer support than did Cubans and Chinese Canadians. Perceived social support from same- and opposite-sex friends predicted adolescents’ valuing of academics and intrinsic motivation most strongly in the Canadian sample. Cuban parents’ perceived valuing of academics predicted adolescents’ intrinsic academic motivation more strongly than in the other cultures sampled.
Assessing Jail Inmates’ Proneness To Shame and Guilt
Authors: Tangney June P. , Stuewig Jeffrey , Mashek Debra , Hastings Mark
Published: April 2011

This study of 550 jail inmates (379 male and 171 female) held on felony charges examines the reliability and validity of the Test of Self Conscious Affect—Socially Deviant Version as a measure of offenders’ proneness to shame and proneness to guilt. Discriminant validity (e.g., vis-à-vis self-esteem, negative affect, social desirability/impression management) and convergent validity (e.g., vis-à-vis correlations with empathy; externalization of blame, anger, psychological symptoms; and substance use problems) were supported, paralleling results from community samples. Furthermore, proneness to shame and guilt were differentially related to widely used risk measures from the field of criminal justice (e.g., criminal history, psychopathy, violence risk, antisocial personality). Guilt-proneness appears to be a protective factor, whereas there was no evidence that shame-proneness serves an inhibitory function. Subsequent analyses indicate these findings generalize quite well across gender and race. Implications for intervention and sentencing practices are discussed.
Intellectual and Behavioral Functioning in a South African Cohort of Boys With Duchenne Muscular Dystrophy
Authors: Donald Kirsten A. M. , Mathema Hlengani , Thomas Kevin G. F. , Wilmshurst Jo M.
Published: April 2011

The authors describe the neurocognitive and behavioral phenotype of 16 South African children (ages 4-16 years) with Duchenne muscular dystrophy, compared with 13 controls. The preschool group performed significantly worse than the controls in measures of general developmental performance. The school-age group showed no significant differences in general intellectual abilities. However, our data identified that boys with Duchenne muscular dystrophy experience mild cognitive dysfunction across multiple domains, including visual memory, and verbal and nonverbal executive functioning. Parental reports of 11 boys with the disorder revealed high rates of general behavioral problems (54.5%). The cognitive profile of boys with Duchenne muscular dystrophy in South Africa is similar to that described elsewhere in the world. Behavioral problems in our cohort were higher than previously reported. This may be partially explained by the poor socioeconomic background of the majority of the cohort.
Complications of the Cut‐and‐Push Technique for Percutaneous Endoscopic Gastrostomy Tube Removal
Authors: Harrison Elizabeth , Dillon Jayne , Leslie Fiona C.
Published: April 2011

The use of the “cut‐and‐push” technique for percutaneous endoscopic gastrostomy (PEG) removal has been recognized since 1991. This technique is used in patients who are thought to have no risk of distal adhesions or strictures. Its use in selected patients is supported by current British Society of Gastorenterology guidelines. However, the risk of complications has long been debated. This report describes a patient who developed complications as a result of PEG removal using the cut‐and‐push technique. The patient had undergone previous abdominal surgery, and removal of the PEG endoscopically was not possible. A barium follow‐through was performed in light of the history, and it excluded any mechanical blockage. Follow‐up x‐ray showed passage of the remnant beyond the pylorus. Despite this, the remnant became lodged in the small bowel, eventually resulting in perforation and death. This case highlights the fact that impaction of the remnant can occur in patients without evidence of mechanical obstruction on investigation. This raises a question about the need for serial x‐rays to ensure passage of the remnant if the patient cannot confirm this visually.
Transnational Student Voices
Authors: Hoare Lynnel
Published: April 2011

The intensity of provision of transnational education (TNE) in the Asian region by Australian universities has been increasing over the past three decades. Although much is claimed, little is actually known about the outcomes and opinions of students enrolled in TNE programs. This article investigates student experiences through the longitudinal extension of an ethnographic study of one TNE program in Singapore. Student motivations, career paths, and adaptations are considered in the context of “second chance” and lifelong learning in Singapore. Analysis reveals something of a good news story in the face of much negativity about transnational education at the current time. The study reveals that TNE students are achieving high-level positional outcomes and developing transformative learning habits. Recommendations are made for the use of global comparative studies in TNE programs to facilitate mutual learning through respect for local knowledge.
Implicit Personality Conceptions of the Nguni Cultural-Linguistic Groups of South Africa
Authors: Valchev Velichko H. , van de Vijver Fons J. R. , Alewyn Nel Jan , Rothmann Sebastiaan , Meiring Deon , de Bruin Gideon P.
Published: April 2011

The present study explored the personality conceptions of the three main Nguni cultural-linguistic groups of South Africa: Swati, Xhosa, and Zulu. Semistructured interviews were conducted with 116 native speakers of Swati, 118 of Xhosa, and 141 of Zulu in their own language. Participants provided free descriptions of 10 target persons each; responses were translated into English. Twenty-six clusters of personality-descriptive terms were constructed based on shared semantic content and connotations of the original responses. These clusters accounted for largely identical content in all three groups. The clusters represented an elaborate conception of social-relational aspects of personality revolving around the themes of altruism, empathy, guidance, and harmony. The patterning of responses suggests that the individual is viewed as inextricably bound to his or her context of social relationships and situations. The findings are discussed with reference to the Big Five model of personality and the culture and personality framework.