bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Oxidative Stress and Indoxyl Sulfate in Progression of Cardiovascular Disease in Chronic Kidney Disease
Authors: Fujii Hideki , Nakai Kentaro , Fukagawa Masafumi
Published: January 2011

Several abnormalities of the cardiovascular system are observed in most cases of chronic kidney disease (CKD). Mechanisms underlying these abnormalities are complicated, and several factors contribute to their pathogenesis. Of these factors, oxidative stress and uremic toxins are considered to play key roles in the progression of cardiovascular disease (CVD) in CKD. Oxidative stress increases significantly in CKD and accelerates proteinuria and renal dysfunction. In addition, oxidative stress has been reported to induce cardiac hypertrophy and fibrosis. Indoxyl sulfate, a uremic toxin, has recently been suggested to play a crucial role in the development of CVD. Recent in vitro data suggest that indoxyl sulfate increases oxidative stress. Some reports have shown that AST‐120, which is an oral charcoal adsorbent, can reduce oxidative stress by lowering serum indoxyl sulfate levels. Recently, we have also demonstrated that indoxyl sulfate is associated with the production of oxidative stress, and that increased oxidative stress is significantly correlated with cardiac hypertrophy and fibrosis. Furthermore, results of our basic and clinical studies suggested that AST‐120 can prevent progression of cardiac hypertrophy by reducing oxidative stress in CKD. Thus, one of the main targets of the management of CKD and CVD is the control of oxidative stress and uremic toxins, such as indoxyl sulfate.
Tumor Necrosis Factor‐Related Apoptosis‐Inducing Ligand and Vascular Calcification
Authors: Chasseraud Maud , Liabeuf Sophie , Mozar Anaïs , Mentaveri Romuald , Brazier Michel , Massy Ziad A , Kamel Saïd
Published: January 2011

Vascular calcification is frequent in patients with chronic kidney disease. Osteoprotegerin (OPG, a soluble factor which blocks osteoclast differentiation) has recently been implicated in the genesis of vascular calcification. Given that OPG can bind the pro‐apoptotic tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL), we hypothesized that the TRAIL protein is involved in the formation of vascular calcification both in vitro and in vivo. Using an immunohistochemical approach, we evaluated TRAIL and OPG expression on aortic valves slides from non‐uremic and uremic wild type and apolipoprotein knockout (Apo E−/−) mice. We also tested the in vitro effects of TRAIL on cultured primary human vascular smooth muscle cells (hVSMC). We further assayed serum soluble TRAIL (sTRAIL) levels in hemodialysis patients and correlated them with vascular calcification scores. Our results demonstrated that: (i) TRAIL and OPG were expressed inside the atheroma plaque in non‐uremic ApoE−/− mice, but not in wild type mice; and (ii) uremia enhanced the expression levels. TRAIL enhanced the phosphate‐induced mineralization of hVSMCs in a dose‐dependent manner. In clinical terms, we demonstrated that sTRAIL is depressed in the sera of hemodialysis patients, but was not correlated with vascular calcification. Our results suggest that TRAIL may be involved in the formation of vascular calcification in certain experimental settings; however, its role in chronic kidney disease patients requires further evaluation.
Therapeutic Apheresis in the Treatment of Hemolytic Uremic Syndrome in View of Pathophysiological Aspects
Authors: Bambauer Rolf , Latza Reinhard , Schiel Ralf
Published: January 2011

Hemolytic‐uremic syndrome (HUS) is a disease that can lead to acute kidney injury and often to other serious sequelae, including death. The disease is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. In view of the different courses of HUS, a minimum of three different pathogenetic types leading to HUS can be subdivided as follows: HUS caused by infection, idiopathic HUS (non‐Shiga toxin HUS), and HUS in systemic diseases and after toxin exposure. The etiology and pathogenesis of HUS are not completely understood and its therapy is complicated. After the introduction of therapeutic apheresis as a supportive therapy in HUS, several authors reported successful treatment in more than 87% of treated patients. The supportive therapy is indicated basically in severe courses of HUS and is superior to available therapy interventions.
Role of TLR2‐dependent inflammation in metastatic progression
Authors: Kim Sunhwa , Karin Michael
Published: January 2011

Inflammation is a part of the host defense system, which provides protection against invading pathogens. However, it has become increasingly clear that inflammation can be evoked by endogenous mediators through Toll‐like receptors (TLRs) to enhance tumor progression and metastasis. Here, we discuss the roles of TLR‐mediated inflammation in tumor progression and the mechanisms through which it accomplishes this pathogenic function.
Comparison of Aliskiren/Hydrochlorothiazide Combination Therapy With Hydrochlorothiazide Monotherapy in Older Patients With Stage 2 Systolic Hypertension: Results of the ACTION Study
Authors: Basile Jan , Babazadeh Simon , Lillestol Michael , Botha Jaco , Yurkovic Carol , Weitzman Richard
Published: January 2011

Patients with stage 2 systolic hypertension require sizable blood pressure (BP) reductions to achieve recommended targets. This randomized double‐blind study compared a single‐pill combination of the direct renin inhibitor aliskiren and hydrochlorothiazide (aliskiren/HCTZ) with HCTZ monotherapy in older patients (older than 55 years) with systolic BP ≥160 mm Hg and <200 mm Hg. After a 1‐ to 4‐week washout, 451 patients were randomized to once‐daily aliskiren/HCTZ 150/12.5 mg or HCTZ 12.5 mg for 1 week, and then double the doses for 7 weeks. Overall baseline BP was 168.8/91.4 mm Hg. At week 4 (primary) end point, aliskiren/HCTZ provided significantly greater BP reductions from baseline than HCTZ monotherapy (29.6/9.3 mm Hg vs 22.3/6.8 mm Hg) and resulted in a greater proportion of patients achieving BP goal of <140/90 mm Hg (51.1% vs 33.3%). Aliskiren/HCTZ therapy provides substantial BP reductions and may thus be a useful treatment option for older patients with stage 2 hypertension. J Clin Hypertens (Greenwich). 2011;13:162–169. © 2011 Wiley Periodicals, Inc.
Safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000‐Hz scanning spot excimer laser
Authors: Khoramnia Ramin , Salgado Josefina P. , Wuellner Christian , Donitzky Christof , Lohmann Chris P. , Winkler von Mohrenfels Christoph
Published: January 2011

Purpose:  To evaluate the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000‐Hz scanning spot excimer laser (Concept System 1000; WaveLight GmbH, Erlangen, Germany).

Methods:  LASIK was performed on twenty eyes with myopia or myopic astigmatism (mean spherical equivalent refraction: −3.97 ± 1.72 dioptres (D); mean cylinder: −0.84 ± 0.77 D) using a microkeratome for flap creation and the Concept System 1000 for photoablation. Patients were examined preoperatively as well as 1, 3 and 6 months after the treatment. Manifest sphere and cylinder, uncorrected (UCDVA) and best corrected (BCDVA) distance visual acuity, corneal topography and pachymetry were analysed.

Results:  We observed no adverse events that might have been associated with the use of a repetition rate of 1000 Hz. All eyes maintained or had improved BCDVA at 6 months after treatment when compared to preoperative values. Six months after LASIK, UCDVA was 20/20 or better in 85% and 20/25 or better in 100% of the eyes. The spherical equivalent refraction was within ±0.50 D in 95% of the eyes at 6 months after surgery. The refraction stayed stable over time; 95% of the eyes changed <0.5 D postoperatively.

Conclusion:  LASIK with the prototype 1000‐Hz excimer laser was safe, efficient and predictable. The postoperative refraction was stable over time. There were no specific clinical side‐effects that might be associated with the use of such a high repetition rate.
The dynamics of pollen removal and deposition, and its effects on sexual phases in a protandrous plant: Glechoma longituba (Lamiaceae)
Authors: Zhang Yan‐Wen , Zhao Ji‐Min , Wang Yong
Published: January 2011

The duration of sexual phases in dichogamous plants are affected by many factors. Using both experimental and observational studies, we investigated natural patterns of pollen removal and deposition, visiting frequency of pollinators, patterns of nectar secretion, and effects of pollen removal and stigmatic pollen deposition on the duration of sexual phases in a protandrous plant, Glechoma longituba. We found that visiting frequency of pollinators correlated with the nectar secretion pattern. The nectar volume during the male phase was higher than during the female phase. In the morning, the main pollinator, the bee Anthophora plumipes, mainly foraged for nectar and showed no preference for flowers in male or female phase, despite male phase flowers producing higher amounts of nectar. However, in the afternoon, they changed their behavior and foraged mainly for pollen, and then showed a preference for flowers in male phase. Furthermore, the rates of pollen removal and stigmatic pollen deposition can affect the starting time and the duration of the female phase. When pollen removal and pollination rates are low due to scarcity of pollinator services, the sexual phase can be prolonged, leading to an overlap, and thereby enhance the chance for sexual reproduction through pollinator‐facilitated self‐pollination. We consider the variation of sexual phases in Glechoma longituba an adaptive mechanism prepared for both cross‐pollination enhancement and reproductive assurance depending on the available pollination services.
Geranium kikianum sp. nov. (Geraniaceae) from the southern Peloponnese, Greece
Authors: Tan Kit , Siljak‐Yakovlev Sonja , Vold Gert
Published: January 2011

Geranium kikianum Kit Tan & G. Vold sp. nov. (Geraniaceae) is illustrated and described as a new species endemic to Greece. It occurs beside streams and other wet places in open Pinus nigra forest at the foothills of Mt Taigetos in the southern Peloponnese. It is closely related to G. macrorrhizum, a species more widely distributed in southern and central Europe, ranging from the southern Alps to the Balkan Peninsula. It differs from the latter by its smaller and narrower deflexed petal limb, slender claw and occurrence in wet habitats. The genome sizes of G. kikianum and of Greek populations of G. macrorrhizum are presented here for the first time. The nuclear DNA content (2C values) of 2.84 pg for G. kikianum and 2.83 and 2.87 pg for two G. macrorrhizum populations from Greece probably corresponds to a 2n=92 cytotype while the smaller genome size of 1.45 pg in a population of G. macrorrhizum from Mt Smolikas, Greece may correspond to a 2n=46 cytotype.
Clinical and psychosocial factors associated with depression and anxiety in Singaporean patients with rheumatoid arthritis
Authors: HO Roger C. M. , FU Erin H. Y. , CHUA Anna N. C. , CHEAK Alicia A. C. , MAK Anselm
Published: January 2011

Aim:  To assess the frequency of, and factors associated with, depression and anxiety in Singaporean patients with rheumatoid arthritis (RA).

Method:  One hundred RA patients were recruited in a cross‐sectional study. Socio‐demographics, severity of anxiety and depression, disease activity, levels of serological markers and health‐related quality of life were analyzed.

Results:  Twenty‐six percent presented with anxiety, 15% with depression and 11% with both. Univariate regression showed that age (P = 0.039), Disease Activity Scale (DAS‐28) (P < 0.001), number of medications (P < 0.001) and rheumatoid factor (RF) (P < 0.001) were positively associated with severity of depression, while income (P = 0.001), education (P = 0.029), self‐perceived social support (P = 0.007), Short form 12 (SF‐12) physical health (P < 0.001) and SF‐12 mental health (P < 0.001) were negatively associated with severity of depression. After adjustment for confounding factors in multivariate regression, income (β = −0.347, P = 0.018), RF (β = 0.304, P = 0.043) and SF‐12 mental health (β = −0.501 P = 0.001) remained significantly associated with depression. Univariate regression showed that DAS‐28 (P = 0.009), number of medications (P = 0.004) and RF (P = 0.043) were positively associated with anxiety, while income (P = 0.022), self‐perceived social support (P = 0.04), SF‐12 physical health (P < 0.001) and SF‐12 mental health (P < 0.001) were negatively associated with anxiety. After adjustment for confounding factors, no factors remained significantly associated with anxiety.

Conclusion:  Low income, high levels of RF and poor mental health were associated with depression in RA. Our findings may help to formulate depression screening strategies. Further research is required to identify the role of RF in depression.
A cross‐sectional study of diastolic dysfunction in rheumatoid arthritis and its association with disease activity
Authors: ABDUL MUIZZ Abo Malek , MOHD SHAHRIR Mohamed Said , SAZLIYANA Shaharir , OTEH Masakun , SHAMSUL Azhar Shah , HUSSEIN Heselynn
Published: January 2011

Aims:  The aim of this study was to evaluate the left ventricular (LV) diastolic dysfunction in rheumatoid arthritis (RA) patients without clinically evident cardiovascular manifestations and to estimate whether there is any correlation between RA disease severity and disability and LV diastolic dysfunction.

Methods:  The study was a cross‐sectional study involving 53 patients (47 female and 6 male) with RA without clinically evident heart disease and 53 healthy subjects (47 female and 6 male) who served as a control group. Both groups were matched for age and sex. Echocardiographic and Doppler studies were conducted in all patients with RA and control subjects.

Results:  Of 17 cardiac parameters assessed, only two were abnormal. None of the specific cardiac diastolic dysfunction parameters were significantly different in RA patients compared to the control group. There was no significant correlation between diastolic function values in RA patients and value of Disease Activity Score 28 (DAS‐28) and value of Health Assessment Questionnaires Disability Index (HAQDI). Atrial (A) wave velocity was greater in RA patients compared to the control group (0.71 [0.58–0.83] vs. 0.61 [0.51–0.71]; P < 0.04). However, interventricular relaxation time (IVRT) ([73.08 ± 9.92 vs. 70.74 ± 9.02], P = 0.207), lower E/A ratio (1.27 [1.02–1.56] vs. 1.42 [1.20–1.68], P = 0.102), diastolic dysfunction parameters according to Redfield Classification (25 [47.2%] vs. 27 [50.9%] P = 0.56), diastolic dysfunction using E/A (P = 0.321) and tissue doppler imaging (E/E′) (P = 0.148) were not different.

Conclusion:  Prevalence of diastolic dysfunction in the rheumatoid arthritis group (47.2%) was not different from controls (50.9%). LV diastolic function had no significant correlation with RA disease severity and duration of disease.
Clinicopathological significance of nuclear factor‐κB activation in hepatocellular carcinoma
Authors: Yokoo Hideki , Yasuda Jun , Nakanishi Kazuaki , Chuma Makoto , Kamiyama Toshiya , Todo Satoru , Hirohashi Setsuo , Sakamoto Michiie
Published: January 2011

Aim:  Nuclear factor‐κB (NF‐κB) is a critical signaling mediator in inflammation, apoptosis resistance and oncogenesis. It has been reported that NF‐κB is activated in several cancers, including hepatocellular carcinoma (HCC). Studies of genetic disruptions in mice also suggest that NF‐κB plays critical roles in hepatocarcinogenesis. The aim of the present study is to characterize NF‐κB activation and correlate it with the degree of malignancy in HCC.

Methods:  To examine the correlation between the positivity of the nuclear p50 subunit and HCC recurrence, we analyzed immunostaining of the NF‐κB p50 subunit in two groups of HCC samples with known prognosis and Akt phosphorylation status: 49 patients showing early recurrence within 6 months (group A) and 50 patients who were recurrence‐free for at least for 3 years (group B).

Results:  In group A, positive nuclear staining of p50 was shown in 18 cases (36.7%), whereas only one case (2.0%) in group B had positive nuclear staining of p50 (P = 2.48839 × 10–5). This suggests a positive relationship between nuclear p50 and early recurrence and advanced HCC in humans. The presence of phosphorylated Akt correlated with nuclear staining of p50 in HCCs in group A (R2 = 0.213, P < 0.001).

Conclusion:  Our results indicate that nuclear staining of p50 was clearly associated with early recurrent HCC, and the Akt pathway might play a role in NF‐κB activation in a subset of early recurrent HCC.
Assessment of malignant potential of small hypervascular hepatocellular carcinoma using B‐mode ultrasonography
Authors: Moribata Kosaku , Tamai Hideyuki , Shingaki Naoki , Mori Yoshiyuki , Enomoto Shotaro , Shiraki Tatsuya , Deguchi Hisanobu , Ueda Kazuki , Inoue Izumi , Maekita Takao , Iguchi Mikitaka , Yanaoka Kimihiko , Oka Masashi , Ichinose Masao
Published: January 2011

Aim:  Evaluation of malignant potential is important to determine the treatment strategy for small hepatocellular carcinoma (HCC). The aim of the present study was to establish a method of assessing the malignant potential of small hypervascular HCC using B‐mode ultrasonography.

Methods:  One hundred and thirteen arterial hypervascular HCC nodules under 3 cm diagnosed by biopsy or surgical resection (20.5 ± 6.3 mm) were classified into two groups ultrasonographically: type 1 with (n = 27) and type 2 without (n = 86) a halo. Type 2 was categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with a smooth margin (n = 35); and type 2c, hypoechoic with an irregular or unclear margin (n = 42).

Results:  The mean diameter of type 2a nodules was significantly smaller than that of other HCC types (P < 0.05). Overall, moderately differentiated HCC was the predominant histological type, except for type 2a, all of which were well‐differentiated HCC. The percentage of poorly differentiated HCC was significantly higher in type 2c nodules (19%) than in other HCC types (P < 0.01). The percentage of Lens culinaris agglutinin‐reactive α‐fetoprotein (AFP‐L3) positivity was significantly higher in type 2c nodules (55%) than in other HCC types (P < 0.01). Classification on B‐mode ultrasonography was correlated with the histological differentiation and serum level, an indicator of a poor prognosis.

Conclusion:  The malignant potential of type 2a is the lowest and that of type 2c is the highest, both histologically and serologically. Assessment of the malignant potential of small, hypervascular HCC is possible by B‐mode ultrasonography.
New insights into the mineralogy and weathering of the Meridiani Planum meteorite, Mars
Authors: FLEISCHER Iris , SCHRÖDER Christian , KLINGELHÖFER Göstar , ZIPFEL Jutta , MORRIS Richard V. , ASHLEY James W. , GELLERT Ralf , WEHRHEIM Simon , EBERT Sandro
Published: January 2011

Abstract–

Meridiani Planum is the first officially recognized meteorite find on the surface of Mars. It was discovered at and named after the landing site of the Mars Exploration Rover Opportunity. Based on its composition, it was classified as a IAB complex iron meteorite. Mössbauer spectra obtained by Opportunity are dominated by kamacite (α‐Fe‐Ni) and exhibit a small contribution of ferric oxide. Several small features in the spectra have been neglected to date. To shed more light on these features, five iron meteorite specimens were investigated as analogs to Meridiani Planum with a laboratory Mössbauer setup. Measurements were performed on (1) their metallic bulk, (2) troilite (FeS) inclusions, (3) cohenite ((Fe,Ni,Co)3C) and schreibersite ((Fe,Ni)3P), and (4) corroded rims. In addition to these room‐temperature measurements, a specimen from the Mundrabilla IAB‐ungrouped meteorite was measured at Mars‐equivalent temperatures. Based on these measurements, the features in Meridiani Planum spectra can be explained with the presence of small amounts of schreibersite and/or cohenite and iron oxides. The iron oxides can be attributed to a previously reported coating on Meridiani Planum. Their presence indicates weathering through the interaction of the meteorite with small amounts of water.
Recent advances in the management of diabetic distal symmetrical polyneuropathy
Authors: Tesfaye Solomon
Published: January 2011

There is now little doubt that poor blood glucose control is an important risk factor for the development of diabetic peripheral neuropathy (DPN). Furthermore, traditional cardiovascular risk factors for macrovascular disease appear to be associated with an increased risk of DPN. The recently established International Expert Group on Diabetic Neuropathy has recommended new criteria for the diagnosis of DPN in the context of clinical and research settings. Studies in experimental diabetes examining the pathogenesis of DPN have identified a number of metabolic abnormalities including polyol pathway hyperactivity, increased advanced glycation end‐point formation, alterations in the protein kinase C beta pathway through diacylglycerol and oxidative stress. There is now strong evidence implicating nerve ischemia as the cause of DPN. Studies in human and animal models have shown reduced nerve perfusion and endoneurial hypoxia. These endoneurial microvascular changes strongly correlate with clinical severity and the degree of nerve‐fiber pathology. Unfortunately, many compounds that have been effective in animal models of neuropathy have not been successful in human diabetic neuropathy. The only compounds found to be efficacious in human diabetic neuropathy, and are in clinical use, are the anti‐oxidant, α‐lipoic acid and the aldose reductase inhibitor, epalrestat. Overall, the evidence emphasizes the importance of vascular dysfunction, driven by metabolic change, in the etiology of DPN, and highlights potential therapeutic approaches. Epidemiological data on diabetic painful neuropathic pain (DPNP) are limited. In one population‐based study, the prevalence of DPNP, as assessed by a structured questionnaire and examination, was estimated at 16%. It was notable that, of these patients, 12.5% had never reported symptoms to their doctor and 39% had never received treatment for their pain. Thus, despite being common, DPNP continues to be underdiagnosed and undertreated. Pharmacological treatment of DPNP include tricyclic compounds, serotonin noradrenalin reuptake inhibitors, the anti‐oxidant α‐lipoic acid, anticonvulsants, opiates, membrane stabilizers, topical capsaicin and so on. Management of the patient with DPNP must be tailored to individual requirements and will depend on the presence of other comorbidities. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00083.x)
Fine‐scale environmental variation in species distribution modelling: regression dilution, latent variables and neighbourly advice
Authors: McInerny Greg J. , Purves Drew W.
Published: January 2011

1. Developing the next‐generation of species distribution modelling (SDM) requires solutions to a number of widely recognised problems. Here, we address the problem of uncertainty in predictor variables arising from fine‐scale environmental variation.

2. We explain how this uncertainty may cause scale‐dependent ‘regression dilution’, elsewhere a well‐understood statistical issue, and explain its consequences for SDM. We then demonstrate a simple, general correction for regression dilution based on Bayesian methods using latent variables. With this correction in place, unbiased estimates of species occupancy vs. the true environment can be retrieved from data on occupancy vs. measured environment, where measured environment is correlated with the true environment, but subject to substantial measurement error.

3. We then show how applying our correction to multiple co‐occurring species simultaneously increases the accuracy of parameter estimates for each species, as well as estimates for the true environment at each survey plot – a phenomenon we call ‘neighbourly advice’. With a sufficient number of species, the estimates of the true environment at each plot can become extremely accurate.

4. Our correction for regression dilution could be integrated with models addressing other issues in SDM, e.g. biotic interactions and/or spatial dynamics. We suggest that Bayesian analysis, as employed here to address uncertainty in predictor variables, might offer a flexible toolbox for developing such next‐generation species distribution models.
Watch your time step: trapping and tracking dispersal in autocorrelated environments
Authors: Skarpaas Olav , Shea Katriona , Jongejans Eelke
Published: January 2011

1. Reliable estimates of dispersal kernels are needed for many applications in ecology. For both plants and animals, and for passive and active dispersal, the two most common methods for obtaining dispersal kernel estimates from direct measurements are following individual propagules (tracking) and counting propagules at fixed locations (trapping).

2. We consider the effect of the chosen sampling method on the estimation of dispersal kernels and highlight reasons why we should not necessarily expect estimates from the two methods to be the same. We illustrate this point using data from field experiments for three wind‐dispersed plant species (Carduus nutans, Carduus acanthoides and Crepis praemorsa) and a mechanistic dispersal model (WALD).

3. The field experiments demonstrate that the two sampling methods lead to different dispersal kernel estimates. Although estimated mean dispersal distances may be similar, short‐term tracking studies with random seed release generally lead to more peaked distributions with greater modal dispersal distances than long‐term trapping of naturally dispersing seeds.

4. Wind speed data and dispersal distributions estimated using the mechanistic dispersal model suggest that differences between the sampling methods arise from temporally autocorrelated environmental conditions interacting with study time frame and dispersal initiation processes. Single tracking events tend to provide biased estimates of wind statistics because of short‐term autocorrelation in wind speeds. Depending on the long‐term autocorrelation structure of wind speeds, and the sampling of wind speeds compared to natural seed release, single short‐term tracking studies may result in distributions that differ strongly from the ‘true’ distribution sampled by trapping over the dispersal season. Distributions from several tracking studies, weighted according to natural dispersal initiation, may therefore be needed to recapture the true dispersal distribution.

5. This study demonstrates that commonly used sampling methods for dispersal can result in dramatically different distributions under temporally autocorrelated environmental conditions. As autocorrelated environments are ubiquitous, this could lead to marked biases in predictions of movement and spread. These results are relevant for a wide range of ecological systems and to theoretical and applied problems relying on measurements and models of dispersal, for instance, conservation in fragmented landscapes, biological invasions and species re‐introductions. The measurement process should be taken into account in such applications.
Maternal obesity eliminates the neonatal lamb plasma leptin peak
Authors: Long Nathan M. , Ford Stephen P. , Nathanielsz Peter W.
Published: January 2011

Non technical summary  Leptin, an adipose tissue hormone, inhibits the brain's central drive to eat, enabling maintenance of normal body weight and composition. The leptin peak present in newborn rodents controls development of brain appetite regulatory areas, and alteration in its timing and amplitude predisposes to obesity in later life. However, unlike humans, rodents are born at an immature stage of development so to determine potential relevance to human development, we examined the leptin peak in newborn lambs, born at a more advanced level of maturity equivalent to humans. The normal peak was absent in lambs born to obese mothers who showed higher newborn levels of plasma cortisol. We conclude that similarities and differences exist in neonatal leptin in species born immature or mature. This information aids understanding of effects of the obesity epidemic in women on their offspring and will help promote diagnosis, prevention and therapy.
Functional expression of transgenic α1sDHPR channels in adult mammalian skeletal muscle fibres
Authors: DiFranco Marino , Tran Philip , Quiñonez Marbella , Vergara Julio L.
Published: January 2011

Non‐technical summary  In mammalian skeletal muscle, the coupling between action potential activation and contraction is supposed to be ultimately mediated by the interaction of two ion channels, the L‐type calcium channel (so‐called dihydropyridine receptor channel) at the transverse tubular system, and the sarcoplasmic reticulum (SR) calcium release channel (so‐called ryanodine receptor channel). This paper demonstrates that adult skeletal muscle fibres transfected in vivo with DNA plasmids are able to express functional transgenic dihydropyridine receptor channels. More importantly, the data suggest that transgenic dihydropyridine receptor channels replace native channels in their interaction with SR calcium release channels. Our findings open new avenues for structural and functional studies of the molecular interactions underlying excitation–contraction coupling within the physiologically relevant cellular context of adult mammalian skeletal muscle fibres.
Coherent Structures in Shallow Water Jets
Authors: Shinneeb A.-M. , Bugg J. D. , Balachandar R.
Published: January 2011

This paper reports an experimental investigation of a round jet discharging horizontally from a vertical wall into an isothermal body of water confined in the vertical direction by a flat wall on the bottom and a free surface on top. Specifically, this paper focuses on the effects of vertical confinement on the characteristics of large vortical structures. The jet exit velocity was 2.5 m/s, and the exit Reynolds number was 22,500. Experiments were performed at water layer depths corresponding to 15, 10, and 5 times the jet exit diameter (9 mm). The large-scale structures were exposed by performing a proper orthogonal decomposition (POD) analysis of the velocity field obtained using a particle image velocimetry system. Measurements were made on vertical and horizontal planes—both containing the axis of the jet. All fields-of-view were positioned at an axial location in the range 10<x/D<80. The number of modes used for the POD reconstruction of the velocity fields was selected to recover ∼40% of the turbulent kinetic energy. A vortex identification algorithm was then employed to quantify the size, circulation, and direction of rotation of the exposed vortices. A statistical analysis of the distribution of number, size, and strength of the identified vortices was carried out to explore the characteristics of the coherent structures. The results clearly reveal the existence of numerous vortical structures of both rotational senses in the jet flow, and their number generally decreases in the axial direction while their size increases. The size of vortices identified in the vertical plane is restricted by the water depth, while they are allowed to increase in size in the horizontal plane. Moreover, the results show a significant decrease in the number of small vortices for the shallowest case in the horizontal plane, with a corresponding increase in the number of large vortices and a significant increase in their size. This behavior was accompanied with an increase in the vortex circulation in the horizontal plane and a reduction in the circulation in the vertical plane. This is indicative of the dominance of the pairing process due to shallowness. Moreover, the balance between the positive and negative vortices in the vertical plane changed because of the formation of negative (clockwise) vortices near the solid wall at downstream locations.
Analysis of the effect of germanium preamorphization on interface defects and leakage current for high-k metal-oxide-semiconductor field-effect transistor
Authors: Roll G. , Jakschik S. , Goldbach M. , Wachowiak A. , Mikolajick T. , Frey L.
Published: January 2011

In this article, the authors analyze the impact of germanium amorphization on the interface defect concentration of state of the art high-k metal gate metal-oxide-semiconductor field-effect transistors. The gate etch is a crucial process step for the high-k gate first integration approach. Germanium implantation is used to amorphize the annealed and, therefore, nanocrystalline hafnium silicon oxide. This ensures a well controlled wet etch removal. The quality of the gate oxide to the channel interface of the transistor samples is monitored by charge pumping. The influence of the damage caused by the germanium implant at the unprotected gate edge is analyzed for different gate stacks by measuring the gate induced drain leakage. The defect concentration at the gate edge can be reduced by adjusting the germanium amorphization energy.
Spectroscopic detection of hopping induced mixed valence for Ti and Sc in GdSc1−xTixO3 for x greater than the percolation threshold of ∼0.16
Authors: Lucovsky Gerry , Miotti Leonardo , Bastos Karen Paz , Adamo Carolina , Schlom Darrell G.
Published: January 2011

Only two of the first row transition metals have elemental oxides that are either ferromagnetic or ferrimagnetic; these are CrO2 and Fe3O4. The electron spin alignment enabling ferromagnetism and/or ferrimagnetism in these oxides is associated with a double exchange mechanism that requires mixed valence and metallic conductivity. This article describes a novel way to realize these two necessary, but insufficient conditions for double exchange magnetism. These are mixed valence and a hopping conductivity that can force intraplane electron spin alignment in a complex oxide host perovskite, A(B,C)O3, where A is an ordinary metal or d0 lanthanide, B is a d0 transition metal, and C is a dn transition metal with n≥1 as, for example, in GdS1−xTixO3. This article combines x-ray absorption spectroscopy, multiplet theory, charge transfer multiplet theory, and degeneracy removal by Jahn–Teller effect mechanisms to demonstrate mixed valence for both Sc and Ti above a percolation limit, x>0.16, in which hopping transport gives rise to a metal to insulator transition. In this alloy, ferromagnetism/ferrimagnetism is not observed due to alternating spin alignment in sequenced (Sc,Ti)O2 planes.
Fabrication of trench nanostructures for extreme ultraviolet lithography masks by atomic force microscope lithography
Authors: Kwon Gwangmin , Ko Kyeongkeun , Lee Haiwon , Lim Woongsun , Yeom Geun Young , Lee Sunwoo , Ahn Jinho
Published: January 2011

We describe methods to fabricate extreme ultraviolet lithography (EUVL) absorber mask patterns by atomic force microscope (AFM) lithography and inductively coupled plasma (ICP) etching. AFM lithography, based on anodization and cross-linking polymer resist, was applied to fabricate trench structures using only Ta and Cr/Ta bilayers. In particular, the top Cr layer was used not only as a hard mask to etch the underlying Ta in dry-etching, but also as an absorber material together with Ta. The Cr oxide or Ta with respect to Cr was eliminated due to the clear etch-selectivity of ICP dry-etching using C4F8 gas. This is a simple fabrication technique using AFM lithography fabricated metal trenches for the production of isolated metal structures as well as for producing EUVL absorber patterns.
Molecular beam epitaxy approach to the graphitization of GaAs(100) surfaces
Authors: Simmonds Paul J. , Simon John , Woodall Jerry M. , Lee Minjoo Larry
Published: January 2011

The authors present a method for obtaining graphitized carbon on GaAs(100) surfaces. Carbon-doped GaAs is grown by molecular beam epitaxy before controlled thermal etching within the growth chamber. An AlAs layer beneath the carbon-doped GaAs acts as a thermal etch stop. As the GaAs is etched away, the carbon dopant atoms remain on the surface due to their low vapor pressure. The total number of carbon atoms available is precisely controllable by the doping density and thickness of the carbon-doped GaAs layer. Characteristic phonon modes in Raman spectra from the thermally etched surfaces show that the residual surface carbon atoms form sp2-bonded graphitic crystallites.
The effective spin concept to analyze coherent charge transport in mesoscopic systems
Authors: Wan J. , Liu W. , Cahay M. , Gasparian V. , Bandyopadhyay S.
Published: January 2011

The concept of effective spin is introduced to underpin the fundamental isomorphism between two apparently disparate fields of physics—phase coherent charge transport in mesoscopic systems and qubit operations in a spin-based quantum logic gate. Together with the Bloch sphere concept, this isomorphism allows transport problems to be formulated in a language more familiar to workers in spintronics and quantum computing. We exemplify the application of the effective spin concept by formulating several charge transport problems in terms of specific unitary operations (rotations) of a spinor on the Bloch sphere.
Liquid-vapor coexistence and the PVT surface of a lattice fluid
Authors: Cervera Javier , Gilabert M. Amparo , Manzanares José A.
Published: January 2011

The lattice fluid model in the grand canonical ensemble is presented as a useful system for teaching liquid-vapor coexistence and the PVT surface of a fluid. The state of the fluid in the grand canonical ensemble is specified by the temperature T, the volume V, and the chemical potential μ. The p̂(T,V,μ) and v(T,V,μ) equations of state of the lattice fluid, where v is the volume per particle, are derived from the grand canonical partition function in the mean-field approximation. We distinguish between the integral pressure p̂≡−Ω/V and the differential pressure p≡−(∂Ω/∂V)T,μ, where Ω is the Landau potential so that we can discuss finite size effects near first-order phase transitions. The nonequivalence of the canonical and grand canonical ensembles for describing the liquid-vapor phase transition is also discussed.
Resource Letter MP-2: The Manhattan project and related nuclear research
Authors: Reed B. Cameron
Published: January 2011

This Resource Letter is a supplement to my earlier Resource Letter MP-1 and provides further sources on the Manhattan Project and related nuclear research. Books and journal articles are cited for the following topics: General works, technical works, biographical and autobiographical works, foreign wartime programs and allied intelligence, technical papers of historical interest, and postwar policy and technical developments. I also give a list of videos and websites dealing with the Manhattan Project, nuclear weapons, and nuclear issues.
Understanding Bernoulli’s principle through simulations
Authors: Faulkner Brian E. , Ytreberg F. Marty
Published: January 2011

Computer simulations are used to develop a deeper understanding of Bernoulli’s principle. Hard disks undergoing elastic collisions are injected into a Venturi nozzle and the pressure in the narrow throat of the nozzle is compared to the pressure in the wider section of the pipe. This model system is an ideal student project because the theory and programming are straightforward, and the computational cost is low.
V
2
Receptor–Mediated Autocrine Role of Somatodendritic Release of AVP in Rat Vasopressin Neurons Under Hypo-Osmotic Conditions
Authors: Sato Kaori , Numata Tomohiro , Saito Takeshi , Ueta Yoichi , Okada Yasunobu
Published: January 2011

The antidiuretic hormone arginine vasopressin (AVP) is also an autocrine signal, allowing the hypothalamic neurons that produce it to maintain their volume during hypotonic stress.
Dependence Receptors: From Basic Research to Drug Development
Authors: Mehlen Patrick , Bredesen Dale E.
Published: January 2011

Discussion at a meeting in France focused on new insights into the biology of dependence receptors.
Science Signaling
Podcast: 25 January 2011
Authors: Wakino Shu , Okada Yasunobu , VanHook Annalisa M.
Published: January 2011

Researchers discuss recent findings on how mechanical stretch regulates signaling pathways in adipocytes and in hypothalamic neurons.
Lost Without a Raft
Authors: Adler Elizabeth M.
Published: January 2011

Cholesterol depletion enhances the proteolytic cleavage and release of the adhesion molecule CD44 and can inhibit glioma cell migration.
A Roundabout Way to Vascularization
Authors: Wong Wei
Published: January 2011

Robo4 acts as an in trans ligand for UNC5B in vascular endothelium to restrict angiogenesis.
Immune Evasion Tactic
Authors: Mueller Kristen L.
Published: January 2011

A viral homolog of a host microbial sensor inhibits viral detection by the host and subsequent antiviral immunity.
Clostridium
to the Rescue
Authors: Mueller Kristen L.
Published: January 2011

Bacteria of the genus
Clostridium
promote the induction of suppressor T cells in the colons of mice.
Resistance and Tolerance to Tropodithietic Acid, an Antimicrobial in Aquaculture, Is Hard To Select
Authors: Porsby Cisse Hedegaard , Webber Mark A. , Nielsen Kristian Fog , Piddock Laura J. V. , Gram Lone
Published: January 2011

The antibacterial compound tropodithietic acid (TDA) is produced by bacteria of the marine
Roseobacter
clade and is thought to explain the fish probiotic properties of some roseobacters. The aim of the present study was to determine the antibacterial spectrum of TDA and the likelihood of development of TDA resistance. A bacterial extract containing 95% TDA was effective against a range of human-pathogenic bacteria, including both Gram-negative and Gram-positive bacteria. TDA was bactericidal against
Salmonella enterica
serovar Typhimurium SL1344 and
Staphylococcus aureus
NCTC 12493 and killed both growing and nongrowing cells. Several experimental approaches were used to select mutants resistant to TDA or subpopulations of strains with enhanced tolerance to TDA. No approach (single exposures to TDA extract administered via different methods, screening of a transposon library for resistant mutants, or prolonged exposure to incremental concentrations of TDA) resulted in resistant or tolerant strains. After more than 300 generations exposed to sub-MIC and MIC concentrations of a TDA-containing extract, strains tolerant to 2× the MIC of TDA for wild-type strains were selected, but the tolerance disappeared after one passage in medium without TDA extract.
S.
Typhimurium mutants with nonfunctional efflux pump and porin genes had the same TDA susceptibility as wild-type strains, suggesting that efflux pumps and porins are not involved in innate tolerance to TDA. TDA is a promising broad-spectrum antimicrobial in part due to the fact that enhanced tolerance is difficult to gain and that the TDA-tolerant phenotype appears to confer only low-level resistance and is very unstable.
Antimicrobial Susceptibilities and Molecular Epidemiology of Clinical Isolates of
Clostridium difficile
in Taiwan
Authors: Lin Yi-Chun , Huang Yu-Tsung , Tsai Pei-Jane , Lee Tai-Fen , Lee Nan-Yao , Liao Chun-Hsing , Lin Shyr-Yi , Ko Wen-Chien , Hsueh Po-Ren
Published: January 2011

The antimicrobial susceptibility and virulence factors of
Clostridium difficile
clinical isolates in Taiwan have not previously been reported. One hundred and thirteen isolates were collected from two major teaching hospitals in Taiwan from 2001 to 2009. Molecular typing was performed by an automated repetitive extragenic palindromic sequence-based PCR (rep-PCR) method (DiversiLab; Bacterial Barcodes, Inc., Athens, GA) and PCR ribotyping. Detection of
tcdA
,
tcdB
,
cdtA
, and
cdtB
genes was performed using a multiplex PCR assay, and
gyrA
and
gyrB
genes of moxifloxacin-nonsusceptible isolates were sequenced. All isolates were susceptible to vancomycin and metronidazole. Ninety-five (84%) isolates were susceptible to moxifloxacin, and the MIC
90
for nemonoxacin was 4 μg/ml. Tigecycline showed favorable antibacterial activity (MIC
90
of 0.06 μg/ml). Thirteen rep-PCR types were identified as a predominant rep-PCR type (type A; non-North American pulsed-field gel electrophoresis type 1 [NAP1], -NAP7, or -NAP8) accounting for 52.2% (59 isolates). Nine of 18 moxifloxacin-nonsusceptible isolates belonged to the rep-PCR type A. The rep-PCR type A and C isolates were distinct from NAP1 (ribotype 027) and NAP8 (ribotype 078) as determined by PCR ribotyping. Seventy-four (65%) isolates harbored
tcdA
and
tcdB
, and 15 (13%) harbored
cdtAB
encoding binary toxin. Eleven isolates had a gene deletion in
tcdC
, including a 39-bp deletion (9 isolates) and an 18-bp deletion (2). In conclusion, dissemination of a predominant
C. difficile
clone in southern and northern Taiwan was noted. However, no NAP1 (ribotype 027) isolate could be discovered in this study.
Experimental Infection withSchistosoma mansoniin CCR5-Deficient Mice Is Associated with Increased Disease Severity, as CCR5 Plays a Role in Controlling Granulomatous Inflammation
Authors: Souza Adriano L. S. , Souza Patrícia R. S. , Pereira Cíntia A. , Fernandes Adriana , Guabiraba Rodrigo , Russo Remo C. , Vieira Leda Q. , Corrêa Ary , Teixeira Mauro M. , Negrão-Corrêa Deborah
Published: January 2011

The plasma level of the chemokine CCL3 is elevated in patients with chronic severe schistosomiasis mansoni. We have previously shown that CCL3−/−mice with experimental infection showed diminished pathology and worm burden compared to those of wild-type (WT) mice. To elucidate further the role of CC chemokines during schistosomiasis mansoni infection, we evaluated the course of infection in C57BL/6J mice deficient in CCR5, one of the receptors for CCL3. The CCR5 deficiency proved to be remarkably deleterious to the host, since mortality rates reached 70% at 14 weeks postinfection in CCR5−/−mice and 19% in WT mice. The increased lethality was not associated with an increased parasite burden, since similar numbers of eggs and adult worms were found in mice from both groups. Liver granulomas of chronically infected CCR5−/−mice were larger and showed greater numbers of cells and collagen deposition than liver granulomas from WT mice. This was associated with higher levels of production of intereleukin-5 (IL-5), IL-13, CCL3, and CCL5 in infected CCR5−/−mice than in infected WT mice. Moreover, at 8 weeks after infection, just before changes in pathology and mortality, the numbers of FoxP3-positive cells were lower in liver granulomas of CCR5−/−mice than in WT mice. In conclusion, the CCR5 deletion is deleterious to mice infected withSchistosoma mansoni, and this is associated with enhanced fibrosis and granulomatous inflammation.